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Sample records for fluoroscopy

  1. Cancer following multiple fluoroscopies

    International Nuclear Information System (INIS)

    Newcombe, H.B.

    1975-08-01

    An epidemiological investigation of persons exposed repeatedly to diagnostic x-rays is proposed. Tuberculosis patients treated in the late 1930's to early 1950's, when artificial pneumothorax was a standard procedure, constitute a suitable large study group; and records of the fluoroscopies of many of these persons still exist. The study is expected to yield needed data on the risks of cancer in irradiated versus unirradiated persons. Computer methods are described by which the fluoroscopy records may be ''linked'' rapidly by machine with the corresponding death registrations, where the patients have died. The proposed computer techniques will make possible the collection of a much larger body of data than could otherwise have been obtained by any of the conventional methods for individual follow-up. (Author)

  2. Fluoroscopy without image intensifier

    International Nuclear Information System (INIS)

    Canevaro, L.; Drexler, G.

    2001-01-01

    The objective of the present work was to evaluate the doses received by patients during fluoroscopy procedures carried out with an equipment without image intensifier. This evaluation is providing dose levels that our patients are presently exposed, and gives the data for epidemiological studies on risk estimate of cancer induction in patients exposed earlier when no image intensifiers existed. Diamentor M4 and E meters were used to measure the product dose-area (DAP). The data were acquired during barium enema, barium meal, barium swallow and histerosalpingographies. The measured values of DAP are considered high. This work intends to call the attention toward the optimization of the radiological protection in facilities that still use equipment without image intensifiers. While this equipment cannot be disabled, the patient exposure monitoring should be an incentive, and the application of radiological protection practices and programs of quality assurance should be of priority. (author)

  3. Fluoroscopy

    Science.gov (United States)

    ... Society/Society for Cardiac Angiography and Interventions: Clinical Competence Statement on Physician Knowledge to Optimize Patient Safety ... English FDA Accessibility Careers FDA Basics FOIA No FEAR Act Site Map Nondiscrimination Website Policies U.S. Food ...

  4. CT and fluoroscopy guided celiac ganglion block

    International Nuclear Information System (INIS)

    Lim, Sun Kyung; Kwon, Dae Ik; Ahn, Hyup; Kim, Jong Il; Kim, Byung Young; Lee, Jong Gil

    1994-01-01

    To evaluate the effects and usefulness of fluoroscopy guided celiac ganglion block after marking of needle path with CT scan. Celiac ganglion block with 100% ethyl alcohol was performed in 50 cancer patients who were inoperable and had intractable abdominal pain. Duration and degree of pain relief after the procedure and its complication were analyzed. Early pain relief was observed in 98% and long term relief in 68% without serious complication. Fluoroscopy guided celiac ganglion block after marking of needle path with CT scan was a safe and valuable procedure in relieving intractable pain in terminal cancer patients and reduced the time in the CT room

  5. Cold neutron fluoroscopy of operating automotive engines

    International Nuclear Information System (INIS)

    Stewart, P.A.E.; Heritage, J.

    1983-01-01

    The application of neutron fluoroscopy in the automotive industry is a natural extension of previous studies with aircraft engines. This paper describes investigations with two sub-compact car engines. The extent and manner in which lubricants reached the various parts of the engines are compared and contrasted. The paper goes on to describe a study of the deposits inside turbochargers and postulates future topics worthy of investigation. The authors confirm that there is a place for neutron fluoroscopy both as a design tool and for investigations of ''in-service'' phenomena. (Auth.)

  6. Reference Dose Rates for Fluoroscopy Guided Interventions

    International Nuclear Information System (INIS)

    Geleijns, J.; Broerse, J.J.; Hummel, W.A.; Schalij, M.J.; Schultze Kool, L.J.; Teeuwisse, W.; Zoetelief, J.

    1998-01-01

    The wide diversity of fluoroscopy guided interventions which have become available in recent years has improved patient care. They are being performed in increasing numbers, particularly at departments of cardiology and radiology. Some procedures are very complex and require extended fluoroscopy times, i.e. longer than 30 min, and radiation exposure of patient and medical staff is in some cases rather high. The occurrence of radiation-induced skin injuries on patients has shown that radiation protection for fluoroscopy guided interventions should not only be focused on stochastic effects, i.e. tumour induction and hereditary risks, but also on potential deterministic effects. Reference dose levels are introduced by the Council of the European Communities as an instrument to achieve optimisation of radiation protection in radiology. Reference levels in conventional diagnostic radiology are usually expressed as entrance skin dose or dose-area product. It is not possible to define a standard procedure for complex interventions due to the large inter-patient variations with regard to the complexity of specific interventional procedures. Consequently, it is not realistic to establish a reference skin dose or dose-area product for complex fluoroscopy guided interventions. As an alternative, reference values for fluoroscopy guided interventions can be expressed as the entrance dose rates on a homogeneous phantom and on the image intensifier. A protocol has been developed and applied during a nationwide survey of fluoroscopic dose rate during catheter ablations. From this survey reference entrance dose rates of respectively 30 mGy.min -1 on a polymethylmethacrylate (PMMA) phantom with a thickness of 21 cm, and of 0.8 μGy.s -1 on the image intensifier have been derived. (author)

  7. Pharyngeal video fluoroscopy: Selected unusual cases

    International Nuclear Information System (INIS)

    Conoley, P.M.; Fox, D.R.

    1987-01-01

    The videotape in this exhibit presents cases illustrative of the use of pharyngeal video fluoroscopy in diagnostic evaluations and therapeutic decision-making in a variety of speech and swallowing disorders of adults and children. Clinical problems addressed include an interesting compensatory speech mechanism in a cleft-palate patient, a preoperative candidate for a Lefort procedure, uncontrolled nasality in a singer, and dysphagia in an antimony worker

  8. Radiation protection at urological fluoroscopy working stations

    International Nuclear Information System (INIS)

    Forster, D.; Mohr, H.

    1979-01-01

    Two newly developed radiation protection devices for urological working stations are presented. The local dose to which doctor and assisting personnel are exposed during fluoroscopy and radiography was measured and the radiation burden with and without radiation protection determined. The studies show that without these devices organs such as the eyes are exposed, at a normal working distance from the table, to such an amount of scattered radiation as to reduce the permitted number of examinations per week. (Auth.)

  9. Canadian study of cancer following multiple fluoroscopies

    International Nuclear Information System (INIS)

    Howe, G.R.

    1985-01-01

    Records of patients treated in Canadian Sanatoria during the period 1930-1952 have been linked with the National Death Index maintained by Statistics Canada to provide fact and cause of death information for the years 1950-1980. Of 31,710 women known to be under observation on January 1, 1950, 13,795 were exposed to fluoroscopy for control of collapse therapy, while the remaining 17,915 were unexposed. The unexposed had the similar mortality from breast cancer to that expected from general population rates. Those exposed to fluoroscopy had increasing mortality with increasing radiation dose to the breast, the best fit to the dose-response curve being a quadratic function. Estimates of risk at doses above 300 rads were largely derived from patients treated in Nova Scotia, where fluoroscopy was administered antero-posterior, as distinct from the more usual postero-antero practiced elsewhere. There is evidence of age-related susceptibility to radiation-induced breast cancer. The risk was maximal for those who first received fluoroscopy in their teens or twenties, but it was similar to expectation for those first exposed at age 30 or more. The latent period from onset of exposure to first increase in the death rate from breast cancer was 15 years for those first exposed at ages 10-24 and 10 years for those first exposed at ages 25 or more. However, these periods coincide with years when mortality from breast cancer normally rises and may therefore not be a true latent period effect. Estimates of predicted excess deaths from breast cancer per million women first exposed at ages 10-29 vary depending on the model used to represent the effect and whether or not data from the Nova Scotia Series are included in the computations

  10. Swiss National Reference Levels in Fluoroscopy

    International Nuclear Information System (INIS)

    Aroua, A.; Baechler, S.; Verdun, F.R.; Rickli, H.; Trueb, Ph.R.; Vock, P.

    2006-01-01

    A nationwide survey was launched in Switzerland in order to investigate the use of fluoroscopy and to establish national reference levels (R.L.) for dose-intensive procedures particularly in interventional radiology. The 2-year investigation covered 5 radiology and 9 cardiology departments in public hospitals and private clinics, and focused on twelve types of examinations: six diagnostic and six interventional. The performance of the fluoroscopy units used in these health-care centres (image quality and dose) was assessed extensively and 1000 examinations were registered. Information on the fluoroscopy time (T), the number of frames (N), the dose-area product (D.A.P.), the difficulty of the case, the age, gender, height and weight of the patient, as well as the experience of the practitioner was provided. The whole set of data was used in relative values (to the mean values for each type of examination) to establish the distributions of T, N and the D.A.P.. From these distributions a set of R.L. values was deduced for the types of examinations investigated using the 3.-quartile method. The R.L. values found are compared to the data published in the literature. (authors)

  11. Digital fluoroscopy: a new development in medical imaging

    International Nuclear Information System (INIS)

    Maher, K.P.; Malone, J.F.; Dublin Inst. of Technology

    1986-01-01

    Medical fluoroscopy is briefly reviewed and video-image digitization is described. Image processing requirements and image processors available for digital fluoroscopy are discussed in detail. Specific reference is made to an application of digital fluoroscopy in the imaging of blood-vessels. This application involves an image substraction technique which is referred to as digital subtraction angiography (DSA). A number of DSA images of relevance to the discussion are included. (author)

  12. Dose reduction in fluoroscopy with modern DSA equipment

    International Nuclear Information System (INIS)

    Waggershauser, T.; Herrmann, K.; Schaetzl, M.; Reiser, M.

    1995-01-01

    The new Multistar T.O.P. (Siemens) is equipped with various features for dose reduction. In this study pulsed fluoroscopy was tested versus standard continuous fluoroscopy and supervisions. Fluoroscope with 3, 7.5, and 15 pulses/s in the Multistar T.O.P. were compared to standard fluoroscopy and to reduced-dose supervision in a human pelvic phantom. The skin entry dose and pelvic dose were continuously registered. The supervision mode used 58% of the dose used in continuous fluoroscopy. Pulsed fluoroscopy with 15 pulses/s required 54%, 7.5 pulses/s 27% and 3 pulses/s. These provide adequate image quality with only 10% of the standard dose. (orig./MG) [de

  13. Thermoluminescent dosimetry in fluoroscopy of pediatric patients

    International Nuclear Information System (INIS)

    Garcia V, E.; Azorin N, J.; Hidalgo T, S.; Dies S, P.

    2016-10-01

    The use of thermoluminescent dosimeters in the area of medical physics and especially in radiology is of paramount importance to guarantee the quality of a particular study, which for this reason the need to verify by means of measurements of peripheral dose in studies of esophagogastroduodenal series by fluoroscopy using TLD of LiF:Mg, Ti. For this the necessary measurements were carried out directly in patients of the Children s Hospital of Mexico Federico Gomez. Previously characterized the dosimeters were used the graphs of the linear equation to obtain the absorbed dose of each dosimeter and was found that the values of the absorbed dose in each patient changes for various reasons like the anatomy, thickness of the tissues, age and exposure time during the study and was verify that none of the studies performed on patients exceeded dose levels that could affect healthy organs. (Author)

  14. A systematic review of the uses of fluoroscopy in dentistry.

    Science.gov (United States)

    Uzbelger Feldman, Daniel; Yang, Jie; Susin, Cristiano

    2010-01-01

    To determine the quality of the evidence for the uses of fluoroscopy in dentistry. A systematic review using Ovid and MEDLINE was conducted to identify papers showing the uses of fluoroscopy in dentistry published between 1953 and September 2009. Human, animal and phantom/skull/mannequin studies on fluoroscopy with regard to its diagnostic value, research performance, and clinical and safety applications in dentistry were included in this analysis. Studies that were not in English, as well as those that employed fluoroscopy in dentistry without the use of image intensification, were excluded. Articles were evaluated, classified and graded by levels of evidence. Fifty-five out of 139 papers fulfilled the inclusion criteria. Amongst them, 19 were related to diagnosis, 15 to research, 12 to clinical and nine to safety applications. Fluoroscopy has contributed to nine different areas of dentistry. Also, it was used on 895 dental patients, 37 animals and 17 phantoms/skulls/mannequins. Two randomised controlled trials, two cohort studies, two case controls, 48 case reports and one expert opinion were found. Fluoroscopy with image intensification has been a useful, but not consistently used tool in dentistry for over 50 years. Several lines of evidence have shown fluoroscopy's diagnostic potential, research use, and clinical and safety applications in dentistry.

  15. Does fluoroscopy improve outcomes in paediatric forearm fracture reduction?

    International Nuclear Information System (INIS)

    Menachem, S.; Sharfman, Z.T.; Perets, I.; Arami, A.; Eyal, G.; Drexler, M.; Chechik, O.

    2016-01-01

    Aim: To compare the radiographic results of paediatric forearm fracture reduced with and without fluoroscopic enhancement to investigate whether fractures reduced under fluoroscopic guidance would have smaller residual deformities and lower rates of re-reduction and surgery. Materials and methods: A retrospective cohort analysis was conducted comparing paediatric patients with acute forearm fracture in two trauma centres. Demographics and radiographic data from paediatric forearm fractures treated in Trauma Centre A with the aid of a C-arm fluoroscopy were compared to those treated without fluoroscopy in Trauma Centre B. Re-reduction, late displacement, post-reduction deformity, and need for surgical intervention were compared between the two groups. Results: The cohort included 229 children (175 boys and 54 girls, mean age 9.41±3.2 years, range 1–16 years) with unilateral forearm fractures (83 manipulated with fluoroscopy and 146 without). Thirty-four (15%) children underwent re-reduction procedures in the emergency department. Fifty-three (23%) children had secondary displacement in the cast, of which 18 were operated on, 20 were re-manipulated, and the remaining 15 were kept in the cast with an acceptable deformity. Twenty-nine additional children underwent operation for reasons other than secondary displacement. There were no significant differences in re-reduction and surgery rates or in post-reduction deformities between the two groups. Conclusion: The use of fluoroscopy during reduction of forearm fractures in the paediatric population apparently does not have a significant effect on patient outcomes. Reductions performed without fluoroscopy were comparably accurate in correcting deformities in both coronal and sagittal planes. - Highlights: • Compared outcomes of pediatric forearm fracture reduction with and without fluoroscopy. • The use of fluoroscopy during reduction of forearm fractures in the pediatric population apparently does not have a

  16. Occurrence of aspiration pneumonia in dysphagic children post video fluoroscopy

    Directory of Open Access Journals (Sweden)

    Lagos, Hellen Nataly Correia

    2011-10-01

    Full Text Available Introduction: The literature reports that when it comes of instrumental assessment of swallowing in children, undoubtedly, video fluoroscopy of swallow offers great advantages over the endoscopic study. Objective: Check the risk of aspiration pneumonia after the study of swallowing by video fluoroscopy, in children with dysphagia. Method: In a study of prospective cutting, participated 16 children aged between 6 months and 10 years, with an average of 5,2 years, referred for study of swallowing by video fluoroscopy. Were tested 4 consistencies, pudding, nectar, honey and liquid. The presences of signs and/or respiratory symptoms were evaluated pre and post study of deglutition by video fluoroscopy, through history and clinical exam. When necessary was asked chest x-ray. Results: Of 16 children, 5 didn't presented dysphagia. In 11 children the exam showed 4 with mild dysphagia, 2 moderate and 5 severe, as classification of OTT (1996 - Classification of severity of dysphagia to the video fluoroscopy. Of the 7 children who aspirated during the exam, only 1 presented respiratory symptoms after the deglutition study, but without signal of pneumonia to the physical examination. Conclusion: In the studied population there were no occurrences of aspiration pneumonia after the study of deglutition was performed by video fluoroscopy, despite the occurrence of aspiration during the exam in about 50% of cases.

  17. Patient dose in CT fluoroscopy examinations

    International Nuclear Information System (INIS)

    Ito, Yusuke; Kobayashi, Masanao; Kataoka, Yumi; Ida, Yoshihiro; Kato, Ryoichi; Katada, Kazuhiro; Asada, Yasuki; Suzuki, Shoichi

    2008-01-01

    CT fluoroscopy(CTF) results in a high dose for the area under investigation in comparison with other types of examination. On the basis of data from April 2005 to March 2008, we measured the X-ray doses at the target site in CTF of the lungs, lumbar vertebrae, and pelvis as well as the X-ray dose to the female reproductive organs, and calculated the effective dose. The CT equipment used was an Aquilion 16. TLDs were inserted into an anthropomorphic phantom in positions corresponding to the target sites and the reproductive organs. Standard tube voltage and tube current were used as measurement conditions, and the scanning time used was the average value for each type of examination during the two years. Dose measurements were taken in the following order: scanography, helical scan, CTF, helical scan. X-ray element calibration was carried out through reciprocal comparison made between an ionization chamber dosimeter corrected according to government standards and the TLD for each tube voltage used for measurement. Dose estimation software was used to calculate the effective doses. During the two years there were 136 CTF examinations. These included 43 scans of the lungs, 13 of lumbar vertebrae, and 18 of the pelvis. The X-ray doses were 0.1 mGy at both the ovaries and the uterus for lung scans, 2 mGy at the ovaries and 1 mGy at the uterus for lumbar vertebrae scans, and 40 mGy at the ovaries and 20 mGy at the uterus for pelvic scans. The effective dose was highest for the lumbar vertebrae, followed by the lungs and finally the pelvis. (author)

  18. Initial experience with magnetic resonance fluoroscopy in the evaluation of oesophageal motility disorders. Comparison with manometry and barium fluoroscopy

    International Nuclear Information System (INIS)

    Panebianco, Valeria; Anzidei, Michele; Catalano, Carlo; Passariello, Roberto; Habib, Fortunee I.; Tomei, Ernesto; Paolantonio, Pasquale; Laghi, Andrea

    2006-01-01

    The aim of this paper was to assess the diagnostic value of magnetic resonance (MR) fluoroscopy in the study of oesophageal motility disorders and to compare MR fluoroscopy results with those of manometry and barium contrast radiography. Twenty-five subjects referred for dysphagia and three patients in follow-up after pneumatic dilatation of the lower oesophageal sphincter to treat severe achalasia underwent esophageal manometry, barium contrast radiography and MR fluoroscopy. Examinations were performed on a 1.5 T scanner. Dynamic turbo- fast low angle shot (turbo-FLASH) sequences acquired during oral contrast agent administration were used to perform MR fluoroscopy. MR fluoroscopy correctly diagnosed achalasia in nine patients, uncoordination of esophageal body motility in ten and scleroderma oesophagus in one. Diagnostic performance was satisfactory, with a sensitivity of 87.5% and a specificity of 100% in the general depiction of motility alterations. Our work demonstrates that MR fluoroscopic examination in subject affected by oesophageal motility disorders is feasible and can properly depict motility and morphology alterations, achieving correct diagnosis in the majority of cases. Studies on larger populations are necessary to obtain statistically significant results. (orig.)

  19. Initial experience with magnetic resonance fluoroscopy in the evaluation of oesophageal motility disorders. Comparison with manometry and barium fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Panebianco, Valeria; Anzidei, Michele; Catalano, Carlo; Passariello, Roberto [University of Rome ' ' La Sapienza' ' , Department of Radiological Sciences, Rome (Italy); Habib, Fortunee I.; Tomei, Ernesto [University of Rome ' ' La Sapienza' ' , Division of Gastroenterology, Rome (Italy); Paolantonio, Pasquale; Laghi, Andrea [University of Rome ' ' La Sapienza' ' , Department of Radiological Sciences - Polo Didattico Pontino I.C.O.T, Rome (Italy)

    2006-09-15

    The aim of this paper was to assess the diagnostic value of magnetic resonance (MR) fluoroscopy in the study of oesophageal motility disorders and to compare MR fluoroscopy results with those of manometry and barium contrast radiography. Twenty-five subjects referred for dysphagia and three patients in follow-up after pneumatic dilatation of the lower oesophageal sphincter to treat severe achalasia underwent esophageal manometry, barium contrast radiography and MR fluoroscopy. Examinations were performed on a 1.5 T scanner. Dynamic turbo- fast low angle shot (turbo-FLASH) sequences acquired during oral contrast agent administration were used to perform MR fluoroscopy. MR fluoroscopy correctly diagnosed achalasia in nine patients, uncoordination of esophageal body motility in ten and scleroderma oesophagus in one. Diagnostic performance was satisfactory, with a sensitivity of 87.5% and a specificity of 100% in the general depiction of motility alterations. Our work demonstrates that MR fluoroscopic examination in subject affected by oesophageal motility disorders is feasible and can properly depict motility and morphology alterations, achieving correct diagnosis in the majority of cases. Studies on larger populations are necessary to obtain statistically significant results. (orig.)

  20. Percutaneous vertebroplasty with the rotational fluoroscopy imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Cannavale, Alessandro; Salvatori, Filippo Maria; Wlderk, Andrea; Cirelli, Carlo; D' Adamo, Alessandro; Fanelli, Fabrizio [University of Rome, Vascular and Interventional Unit, Department of Radiological Sciences, Rome (Italy)

    2014-11-15

    To evaluate the feasibility of the rotational angiography unit (RAU) as a single technique to guide percutaneous vertebroplasty (PVP). Twenty-five consecutive patients (35 vertebral bodies, 20 lumbar and 15 thoracic) were treated using RA fluoroscopy. Using a state-of-the-art flat-panel angiographer (Artis zee, Siemens, Erlangen, Germany), rotational acquisitions were obtained in all patients for immediate post-procedure 2D/3D reconstructions. Pre- and postoperative back pain was assessed with the visual analog scale (VAS). Fluoroscopy time, patient radiation dose exposure, technical success, mean procedure time, mean number of rotational acquisitions and procedural complications were recorded. All features were compared with a historical cohort of patients (N = 25) who underwent PVP under CT and mobile C-arm fluoroscopy guidance. In all cases, safe and accurate control of the needle insertion and bone-cement injection was successfully obtained with high-quality fluoroscopy images. One cement leakage was detected in the RAU group, and two leakages were detected in the CT and C-arm fluoroscopy group. Technical features were significantly different between the two groups (RAU vs. CT): mean procedure time: 38.2 min vs. 60.2 min (p = 0.02); median fluoroscopy time: 14.58 and 4.58 min (p = 0.02); median number of rotational acquisitions: 5 vs. 10 (p = 0.02); mean patient dose: 6 ± 1.3 mSv vs. 23 ± 1.3 mSv (p = 0.02). There were minor complications (pain, small hematoma) in two patients (8%) in the study group and three cases (12%) in the control group. RAU guidance is an effective and safe technique for performing PVP because it reduces the procedural time and radiation exposure. (orig.)

  1. Detection of electrophysiology catheters in noisy fluoroscopy images.

    Science.gov (United States)

    Franken, Erik; Rongen, Peter; van Almsick, Markus; ter Haar Romeny, Bart

    2006-01-01

    Cardiac catheter ablation is a minimally invasive medical procedure to treat patients with heart rhythm disorders. It is useful to know the positions of the catheters and electrodes during the intervention, e.g. for the automatization of cardiac mapping. Our goal is therefore to develop a robust image analysis method that can detect the catheters in X-ray fluoroscopy images. Our method uses steerable tensor voting in combination with a catheter-specific multi-step extraction algorithm. The evaluation on clinical fluoroscopy images shows that especially the extraction of the catheter tip is successful and that the use of tensor voting accounts for a large increase in performance.

  2. The study on clinical conditions and skin dose of upper-gastrointestinal x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Kim, Sung Chul; Ahn, Sung Min; Jang, Sang Sup

    2007-01-01

    This study examined present conditions of upper-gastrointestinal X-ray fluoroscopy and patient skin dose. The authors elected 21 equipment to check the X-ray equipment and exposure factor of fluoroscopy and spot exposure in university hospitals, hospitals, and clinics where perform upper-gastrointestinal X-ray fluoroscopy more than five times every day in Incheon areas. The amount of patient's skin dose during upper-gastrointestinal X-ray fluoroscopy was measured by ionization chamber

  3. Dosimetric study in fluoroscopy procedures realized on Recife, PE, Brazil

    International Nuclear Information System (INIS)

    Maia, Ana Figueiredo

    2001-08-01

    Fluoroscopy is a special radiological examination that uses radiation to visualize the image directly in a TV monitor. Due to of the large exposure times, these procedures often give high doses to the patient, usually higher than those from conventional radiology. Since there are not international diagnostic references levels for fluoroscopy procedures, this research had the objective of making the first study of the fluoroscopy procedures in the Northeast Region of Brazil, providing, therefore, data for the implementation of diagnostic reference levels. Three institutions were evaluated in Recife, two of them teaching hospitals. The quantities measured were the air kerma-area-product, the screening time and the number of radiographs taken in each exam. The results show that the value of the air kerma-area-product varied among the institutions and the results in the institution which uses the last generation equipment were better than those obtained in the other institutions. A relevant fact, and also alarming, is that the population in the institutions that showed the worse results are children. The results obtained in these institutions are higher than those observed in other countries. The results of this research show that there is a need for optimization in those procedures, specially the ones that involve older equipment. It is also points to the continuity of this study to gather more information to define the fluoroscopy reference levels in the country. (author)

  4. Patient radiation dose during fluoroscopy testes with contrast medium

    International Nuclear Information System (INIS)

    Darsalih, Abir Abdelrady El noor

    2016-09-01

    The purpose of this study was to assess the patient radiation dose received in fluoroscopy examinations during contrast medium. The cumulative air kerma (Ck), kerma area product (KAP) and fluoroscopy time were measured for sixty ( male and female ) patients undergoing five fluoroscopy examinations KAP metre which was installed for the purpose of this study. The mean kerma area product were found to be 2.681, 5.1561, 9.85529. 5.7974 and 13.09 Gy.cm"2 for HSG, A.S and D.S, GI Track and sonogram tests, respectively. The obtained mean cumulative dose was were 6.31, 13.88, 24.61, 22.56 and 32.14 mGy for HSG, A.S, A.S and D.S , GI Track, respectively, the mean fluoroscopy time were. 0.18, 0.51,0.89,1.57 and 1.75 min, for HSG, A.S, A.S, and D.S, G1 Track and sonogram test respectively. Patient dose is mainly dependent on the patient size, procedure, equipment used exposure factor and user experience. As KV and mA were controlled by the AEC and it was found to be well calibrated, possible optimization could be achieved by radiologist by decreasing the exposure time if possible. (Author)

  5. Quality control for some digital fluoroscopy equipment used in Sudan

    International Nuclear Information System (INIS)

    Nayledam, A. I.

    2009-07-01

    The aim of this work was to perform quality control (QC) for six digital fluoroscopy units used for cardiovascular and interventional radiology procedures. Measurement were based on the QC protocol developed in the framework of European Commission (EU) DIMOND111 project. Measurement made included: beam quality (half-value layer, HVL), peak tube voltage (kVp) accuracy, automatic exposure control (Aec) and patient dose in terms of entrance surface air kerma rate plus image intensifier input air kerma rate. Dose measurements were made using Calibrated dose rate meter. Field limitation and source to skin distant measurement in addition to evaluation radiation protection tools for occupation exposure were performed. Image quality was evaluated in terms of spatial resolution and Contrast detail detectability. Patient dose measurements was performed using polymethylmethacrylate (PMMA) patient equivalent phantom whereas image quality was assessed using Haunter Type 53 spatial frequency grating and TO10 contrast detail phantom. The results show that the measured HVL and peak tube voltage were within the recommended limits of 10% in four fluoroscopy units. Entrance surface air kerma rate measured ranged from 6.1 to 250 mGy/min for fluoroscopy units operated in pulsed, continuous and cine mode of operation. These results were obtained using varying thicknesses of PMMA phantom. Most values are in reasonable agreement with internationally established reference levels with exception to one fluoroscopy unit where doses were remarkably high. Field limitation and minimum source to skin distance were well within the recommended limits of 30 cm for all fluoroscopy units. The limiting resolution was ranged from 1.0 to 2.2 Lp /mm for image intensifier field diameters between 7 ad 23 cm. The results of present study can be used as baseline for future quality assurance measurements. (Author)

  6. Operation logic and functionality of automatic dose rate and image quality control of conventional fluoroscopy

    International Nuclear Information System (INIS)

    Lin, Pei-Jan Paul

    2009-01-01

    New generation of fluoroscopic imaging systems is equipped with spectral shaping filters complemented with sophisticated automatic dose rate and image quality control logic called ''fluoroscopy curve'' or ''trajectory''. Such fluoroscopy curves were implemented first on cardiovascular angiographic imaging systems and are now available on conventional fluoroscopy equipment. This study aims to investigate the control logic operations under the fluoroscopy mode and acquisition mode (equivalent to the legacy spot filming) of a conventional fluoroscopy system typically installed for upper-lower gastrointestinal examinations, interventional endoscopy laboratories, gastrointestinal laboratory, and pain clinics.

  7. Operation logic and functionality of automatic dose rate and image quality control of conventional fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Pei-Jan Paul [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2009-05-15

    New generation of fluoroscopic imaging systems is equipped with spectral shaping filters complemented with sophisticated automatic dose rate and image quality control logic called ''fluoroscopy curve'' or ''trajectory''. Such fluoroscopy curves were implemented first on cardiovascular angiographic imaging systems and are now available on conventional fluoroscopy equipment. This study aims to investigate the control logic operations under the fluoroscopy mode and acquisition mode (equivalent to the legacy spot filming) of a conventional fluoroscopy system typically installed for upper-lower gastrointestinal examinations, interventional endoscopy laboratories, gastrointestinal laboratory, and pain clinics.

  8. Comparative study about doses and radiological protection in gastrointestinal fluoroscopy

    International Nuclear Information System (INIS)

    Caneravo, L.V.; Borges, J.C.; Carlos, M.T.; Koch, H.A.

    1996-01-01

    The Radiation Protection and Dosimetry Institute of the National Nuclear Energy Commission (IRD/CNEN) and the Radiodiagnostic Service of the Rio de Janeiro Federal University Hospital, have been engaged in the development of quality control programs applied to radiodiagnostics, one of them concerning gastrointestinal fluoroscopy. Since fluoroscopy examinations normally deal with high doses, they represent an important fraction of public exposure. They deserve special attention and the risks to patients should be considered individually, not only as a population statistics. Another target should be the search for procedures that reduce doses to patients and, therefore, reduce dose to medical staff involved. This work describes steps followed and results obtained in the estimation of doses for patients and physicians. Investigated examinations were esophagography, gastroduodenal seriographic and colon with double contrast media, using conventional equipment with fluorescent screens, carried on by physicians engaged in the first year of medical residence. (authors). 9 refs., 1 fig., 2 tabs

  9. Biplanar x-ray fluoroscopy for sacroiliac joint fusion.

    Science.gov (United States)

    Vanaclocha-Vanaclocha, Vicente; Verdú-López, Francisco; Sáiz-Sapena, Nieves; Herrera, Juan Manuel; Rivera-Paz, Marlon

    2016-07-01

    Chronic pain originating from the sacroiliac joint (SI) can cause severe dysfunction. Although many patients respond to conservative management with NSAIDs, some do need further treatment in the form of SI joint fusion (SIJF). To achieve safe and successful SIJF, intraoperative x-ray fluoroscopy is mandatory to avoid serious damages to nearby vascular and neural structures. Each step of the procedure has to be confirmed by anteroposterior (AP) and lateral projections. With a single-arm x-ray, the arch has to be moved back and forth for the AP and lateral projections, and this lengthens the procedure. To achieve the same results in less time, the authors introduced simultaneous biplanar fluoroscopy with 2 x-ray arches. After the patient is positioned prone with the legs spread apart in the so-called Da Vinci position, one x-ray arch for the lateral projection is placed at a right angle to the patient, and a second x-ray machine is placed with its arch between the legs of the patient. This allows simultaneous AP and lateral x-ray projections and, in the authors' hands, markedly speeds up the procedure. Biplanar fluoroscopy allows excellent AP and lateral projections to be made quickly at any time during the surgical procedure. This is particularly useful in cases of bilateral SI joint fusion if both sides are done at the same time. The video can be found here: https://youtu.be/TX5gz8c765M .

  10. Guideline for fluoroscopy of low gastrointestinal tract in pediatrics

    International Nuclear Information System (INIS)

    Chang, Yun Woo; Jeon, Tae Yeon; Kim, Ji Hye; Lee, Mi Jung; Lim, Yun Jung; Yoon, Hye Kyung; Lim, Gye Yeon; Lee, Hee Jung

    2015-01-01

    Although the availability of CT, MRI and endoscopy has resulted in a marked decline in fluoroscopic procedures in adult patients, fluoroscopy remains an important and frequently used procedure in pediatric patients because there is no appropriate choice of diagnostic imaging or treatment modality for certain diseases. The Korean Society of Pediatric Radiology has formulated evidence-based guidelines for fluoroscopy of the lower intestinal tract in the pediatric population (under age 18 including neonates) in order to assist physicians in clinical practice. The guidelines offer standards of examination practice including radiation doses that are as low as reasonably achievable for children under 18 years old, including neonates, for fluoroscopy of the lower intestinal tract, which has typically used relatively high doses. The recommendations of these guidelines should not be used as an absolute standard, and physicians should always refer to methods that do not adhere to the guidelines when those methods are considered more reasonable and beneficial to an individual patient's medical situation

  11. Radiation-Induced Alopecia after Endovascular Embolization under Fluoroscopy

    Directory of Open Access Journals (Sweden)

    Vipawee Ounsakul

    2016-01-01

    Full Text Available Radiation-induced alopecia after fluoroscopically guided procedures is becoming more common due to an increasing use of endovascular procedures. It is characterized by geometric shapes of nonscarring alopecia related to the area of radiation. We report a case of a 46-year-old man presenting with asymptomatic, sharply demarcated rectangular, nonscarring alopecic patch on the occipital scalp following cerebral angiography with fistula embolization under fluoroscopy. His presentations were compatible with radiation-induced alopecia. Herein, we also report a novel scalp dermoscopic finding of blue-grey dots in a target pattern around yellow dots and follicles, which we detected in the lesion of radiation-induced alopecia.

  12. Radiofrequency ablation of lung and liver lesions using CT fluoroscopy

    International Nuclear Information System (INIS)

    Chai, A.; Glenn, D.

    2002-01-01

    Full text: Tumour ablation with radiofrequency (RF) energy is a relatively new procedure for the treatment of focal malignant disease. At our institution this is currently being used in the treatment of certain liver and lung lesions with the patients involved being enrolled in clinical trials. The poster describes the technique used at our institution for the placement of the radiofrequency ablation electrode using CT fluoroscopy. Criteria for patient selection are included. Complications from the procedure are described, as well as follow up appearances and results. Our results from the treatment of primary and secondary lesions in the liver correlate well with published literature. Treatment is still not as successful as surgical resection but there is significantly less morbidity. Where this method may be appropriate is when the patient is not a candidate for surgical resection. The treatment of colorectal metastases in the lung shows early promise as a possible second line treatment (as for liver) where the patient is not a candidate for surgery. Preliminary results are soon to be published in conjunction with the Department of Surgery at our institution. RF Electrode placement using CT Fluoroscopy is performed at our institution. While still at its early stages, RF Ablation shows promise as a possible second line treatment (with other adjuvant therapy) for the management of focal malignant disease in the lung and liver. Copyright (2002) Blackwell Science Pty Ltd

  13. An interactive Web-based radiation protection course in fluoroscopy

    International Nuclear Information System (INIS)

    Aldrich, J.

    2001-01-01

    The teaching of radiation protection to a large group of physicians, who are separated geographically and have complicated schedules, is a formidable problem. Therefore a Web-based solution is attractive, allowing access to the material at any time and place. In this implementation the didactic material is presented in a Web-based format. Subsequently, students attend a practical demonstration in one of the departments' fluoroscopy rooms. Because of local experience with distance education, WebCT was chosen to present the material. WebCT (Web Course Tools) was developed by the University of British Columbia (UBC) to allow educators, with or without technical expertise, to create a sophisticated Web-base. Authors use a standard Web browser to create courses, and students use their browsers to access course material. WebCT provides a wide variety of tools and features that can be added to a course. Among the most useful tools used in this fluoroscopy course are the glossary, multiple-choice questions for each section, and a final test which is scored by the computer. As with all Web-based material the courses can be viewed in the traditional linear fashion or in any random way through the use of linkages. (author)

  14. A kinematic assessment of knee prosthesis from fluoroscopy images

    International Nuclear Information System (INIS)

    Hossain, Mohammad Abrar; Fukunaga, Michihiko; Hirokawa, Shunji

    2008-01-01

    We have developed a technique for estimation 3D motion of knee prosthesis from its 2D perspective projections. Our estimation algorithm includes some innovations such as a two-step estimation algorithm, incorporative use of a geometric articulation model and a new method to solve two silhouettes' overlapping problem. Computer model simulations and experiments results demonstrated that our algorithms give sufficient accuracy. Next, with the cooperation of medical surgeons, we assessed the algorithm's clinical performance by applying it to moving fluoroscopy images of patients who had just undergone total knee arthroplasty (TKA) recently. Our experiments were done in four steps; first we have taken the moving X-ray pictures called fluoroscopy images of the knee prosthesis at different knee motions; second, introduced the absolute positions/orientations for both components, third, introduced the relative positions/orientations between the femoral and the tibial components and finally, introduced the contact points trajectories between the femur and the tibial insert. We drew the estimation results graphically and made the computer-aided detection (CAD) model pictures of the prosthesis, thereby helping us to assess how the relative motions between the femoral and the tibial components were generated. Estimation results of the clinical applications demonstrated that our algorithm worked well as like as theoretical. (author)

  15. Gated Treatment Delivery Verification With On-Line Megavoltage Fluoroscopy

    International Nuclear Information System (INIS)

    Tai An; Christensen, James D.; Gore, Elizabeth; Khamene, Ali; Boettger, Thomas; Li, X. Allen

    2010-01-01

    Purpose: To develop and clinically demonstrate the use of on-line real-time megavoltage (MV) fluoroscopy for gated treatment delivery verification. Methods and Materials: Megavoltage fluoroscopy (MVF) image sequences were acquired using a flat panel equipped for MV cone-beam CT in synchrony with the respiratory signal obtained from the Anzai gating device. The MVF images can be obtained immediately before or during gated treatment delivery. A prototype software tool (named RTReg4D) was developed to register MVF images with phase-sequenced digitally reconstructed radiograph images generated from the treatment planning system based on four-dimensional CT. The image registration can be used to reposition the patient before or during treatment delivery. To demonstrate the reliability and clinical usefulness, the system was first tested using a thoracic phantom and then prospectively in actual patient treatments under an institutional review board-approved protocol. Results: The quality of the MVF images for lung tumors is adequate for image registration with phase-sequenced digitally reconstructed radiographs. The MVF was found to be useful for monitoring inter- and intrafractional variations of tumor positions. With the planning target volume contour displayed on the MVF images, the system can verify whether the moving target stays within the planning target volume margin during gated delivery. Conclusions: The use of MVF images was found to be clinically effective in detecting discrepancies in tumor location before and during respiration-gated treatment delivery. The tools and process developed can be useful for gated treatment delivery verification.

  16. Iso-uncertainty control in an experimental fluoroscopy system

    International Nuclear Information System (INIS)

    Siddique, S.; Fiume, E.; Jaffray, D. A.

    2014-01-01

    Purpose: X-ray fluoroscopy remains an important imaging modality in a number of image-guided procedures due to its real-time nature and excellent spatial detail. However, the radiation dose delivered raises concerns about its use particularly in lengthy treatment procedures (>0.5 h). The authors have previously presented an algorithm that employs feedback of geometric uncertainty to control dose while maintaining a desired targeting uncertainty during fluoroscopic tracking of fiducials. The method was tested using simulations of motion against controlled noise fields. In this paper, the authors embody the previously reported method in a physical prototype and present changes to the controller required to function in a practical setting. Methods: The metric for feedback used in this study is based on the trace of the covariance of the state of the system, tr(C). The state is defined here as the 2D location of a fiducial on a plane parallel to the detector. A relationship between this metric and the tube current is first developed empirically. This relationship is extended to create a manifold that incorporates a latent variable representing the estimated background attenuation. The manifold is then used within the controller to dynamically adjust the tube current and maintain a specified targeting uncertainty. To evaluate the performance of the proposed method, an acrylic sphere (1.6 mm in diameter) was tracked at tube currents ranging from 0.5 to 0.9 mA (0.033 s) at a fixed energy of 80 kVp. The images were acquired on a Varian Paxscan 4030A (2048 × 1536 pixels, ∼100 cm source-to-axis distance, ∼160 cm source-to-detector distance). The sphere was tracked using a particle filter under two background conditions: (1) uniform sheets of acrylic and (2) an acrylic wedge. The measured tr(C) was used in conjunction with a learned manifold to modulate the tube current in order to maintain a specified uncertainty as the sphere traversed regions of varying thickness

  17. Breast cancer incidence and mortality in the Canadian fluoroscopy study

    International Nuclear Information System (INIS)

    Howe, G.R.

    1993-03-01

    This report describes the formation of the National Cancer Incidence Reporting System in a data base format suitable for computerized record linkage, and the linkage of the data from the Canadian study of cancer following multiple fluoroscopies to that database and to the Canadian National Mortality Data Base between 1940 and 1987. A comprehensive statistical analysis of the breast cancer mortality data occurring among female members of the cohort between 1950 and 1987 with respect to exposure to low-LET radiation is reported, together with a parallel analysis of the breast cancer incidence data between 1975 and 1983. The Canadian fluoroscopy study is a cohort study of tuberculosis patients first treated in Canadian institutions between 1930 and 1952. The present mortality analysis relates to the breast cancer mortality experience between 1950 and 1987. A total of 677 deaths from breast cancer was observed in this period. The most appropriate dose-response relationship appears to be a simple linear one. There is a strong modifying influence of age at first exposure; women first exposed past the age of 30 have little excess risk due to radiation exposure. The breast cancer incidence analysis is based upon 628 cases observed between 1975 and 1983. Again a simple linear model appears to provide an adequate fit to the data. There is a suggestion of time dependency under the additive model, but this is not statistically significant. The results from this latest analysis continue to be reassuring in terms of radiation risk from mammography. (L.L.) 15 refs., figs., tabs

  18. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography

    International Nuclear Information System (INIS)

    Lopes, Cintya Carolina Barbosa

    2006-04-01

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  19. Radiation-protective effect with screens of fluoroscopy

    International Nuclear Information System (INIS)

    Kitagawa, H.; Sasaki, Y.; Chaya, K.; Furui, Y.

    1991-01-01

    In a fluoroscopic situation supposing heartworm removal using flexible alligator forceps, the radiationprotective effect of lead-containing screens was examined. Regarding measurements using a gamma-survey meter, X-ray exposure to the operator was reduced from 24.6±7.5 micro-Sievert (μSv)/hr to 0.47±0.08μSv/hr by using protective screens at position A, which corresponds to the operator's face level. At position B, which corresponds to the position of operator's left-hand fingers, the exposure level decreased from 33.1±1.37μSv/hr to 3.01±1.23μSv/hr when screens were used, and decreased more to 0.44±0.16μSv/ hr with the use of protective gloves. At position C, which was at the operator's foot, the exposure level decreased from 0.65±0.27μSv/hr to 0.24±0.10μSv/hr. Regarding measurements using a film badge for 20 experimental dogs, in which each dog was fluoroscopied for 20 sec×15 times, the operator would be totally exposed to 0.1 mSv in H 3mm , dose equivalent value against the eye lens and H 70μm , dose equivalent value against the skin at position B, but below the minimal limit for detection of X-ray (0.1 mSv) in H 1cm , effective dose-equivalent value. Exposure levels were below the minimal limit at positions A and C and at all positions which were protected with screens. Also, dogs were exposed to X-ray 2.20±0.96 mSv on fluoroscopy for 20 sec x 15 times. (author)

  20. Comparison of pulsed fluoroscopy by direct control using a grid-controlled x-ray tube with pulsed fluoroscopy by primary control

    International Nuclear Information System (INIS)

    Chida, Koichi; Zuguchi, Masayuki; Ito, Daisuke; Sato, Kunihiko; Shimura, Hirotaka; Sasaki, Masatoshi

    2001-01-01

    Interventional radiology (IVR) procedures may involve high radiation doses that are potentially harmful to the patient. In IVR procedures, pulsed fluoroscopy can greatly decrease the radiation that the physician and patient receive. There are two types of pulsed fluoroscopy: direct control and primary (indirect) control. The purpose of this study was to compare pulsed fluoroscopy by direct control, using a grid-controlled x-ray tube, with pulsed fluoroscopy using primary control. For both types of pulsed fluoroscopy, we measured the waveforms (x-ray tube voltage, x-ray tube current, and x-ray output) and the relative radiation dose. In addition, we compared the decrease in radiation during pulsed fluoroscopy using a care filter. The studies were performed using a Siemens Bicor Plus x-ray System (direct control) and a Siemens Multistar Plus x-ray System (primary control). Using primary pulse control, a 50% decrease in the x-ray output waveform took approximately 0.5-1.0 msec, or longer with a lower x-ray tube current. Using direct pulse control, a 50% decrease in the x-ray output waveform took approximately 0.1 msec, and was independent of x-ray tube current. The rate of radiation reduction with primary pulse control using the care filter with a lower x-ray tube current had a slope exceeding 10%. Pulsed fluoroscopy by direct control using a grid-controlled x-ray tube permits an optimal radiation dose. To decrease the radiation in primary pulse control, a care filter must be used, particularly with a lower x-ray tube current. (author)

  1. Depth-resolved registration of transesophageal echo to x-ray fluoroscopy using an inverse geometry fluoroscopy system

    Energy Technology Data Exchange (ETDEWEB)

    Hatt, Charles R. [Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Tomkowiak, Michael T.; Dunkerley, David A. P.; Slagowski, Jordan M. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Funk, Tobias [Triple Ring Technologies, Inc., Newark, California 94560 (United States); Raval, Amish N. [Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Speidel, Michael A., E-mail: speidel@wisc.edu [Departments of Medical Physics and Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2015-12-15

    Purpose: Image registration between standard x-ray fluoroscopy and transesophageal echocardiography (TEE) has recently been proposed. Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system designed for cardiac procedures. This study presents a method for 3D registration of SBDX and TEE images based on the tomosynthesis and 3D tracking capabilities of SBDX. Methods: The registration algorithm utilizes the stack of tomosynthetic planes produced by the SBDX system to estimate the physical 3D coordinates of salient key-points on the TEE probe. The key-points are used to arrive at an initial estimate of the probe pose, which is then refined using a 2D/3D registration method adapted for inverse geometry fluoroscopy. A phantom study was conducted to evaluate probe pose estimation accuracy relative to the ground truth, as defined by a set of coregistered fiducial markers. This experiment was conducted with varying probe poses and levels of signal difference-to-noise ratio (SDNR). Additional phantom and in vivo studies were performed to evaluate the correspondence of catheter tip positions in TEE and x-ray images following registration of the two modalities. Results: Target registration error (TRE) was used to characterize both pose estimation and registration accuracy. In the study of pose estimation accuracy, successful pose estimates (3D TRE < 5.0 mm) were obtained in 97% of cases when the SDNR was 5.9 or higher in seven out of eight poses. Under these conditions, 3D TRE was 2.32 ± 1.88 mm, and 2D (projection) TRE was 1.61 ± 1.36 mm. Probe localization error along the source-detector axis was 0.87 ± 1.31 mm. For the in vivo experiments, mean 3D TRE ranged from 2.6 to 4.6 mm and mean 2D TRE ranged from 1.1 to 1.6 mm. Anatomy extracted from the echo images appeared well aligned when projected onto the SBDX images. Conclusions: Full 6 DOF image registration between SBDX and TEE is feasible and accurate to within 5 mm. Future studies will focus on

  2. Depth-resolved registration of transesophageal echo to x-ray fluoroscopy using an inverse geometry fluoroscopy system

    International Nuclear Information System (INIS)

    Hatt, Charles R.; Tomkowiak, Michael T.; Dunkerley, David A. P.; Slagowski, Jordan M.; Funk, Tobias; Raval, Amish N.; Speidel, Michael A.

    2015-01-01

    Purpose: Image registration between standard x-ray fluoroscopy and transesophageal echocardiography (TEE) has recently been proposed. Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system designed for cardiac procedures. This study presents a method for 3D registration of SBDX and TEE images based on the tomosynthesis and 3D tracking capabilities of SBDX. Methods: The registration algorithm utilizes the stack of tomosynthetic planes produced by the SBDX system to estimate the physical 3D coordinates of salient key-points on the TEE probe. The key-points are used to arrive at an initial estimate of the probe pose, which is then refined using a 2D/3D registration method adapted for inverse geometry fluoroscopy. A phantom study was conducted to evaluate probe pose estimation accuracy relative to the ground truth, as defined by a set of coregistered fiducial markers. This experiment was conducted with varying probe poses and levels of signal difference-to-noise ratio (SDNR). Additional phantom and in vivo studies were performed to evaluate the correspondence of catheter tip positions in TEE and x-ray images following registration of the two modalities. Results: Target registration error (TRE) was used to characterize both pose estimation and registration accuracy. In the study of pose estimation accuracy, successful pose estimates (3D TRE < 5.0 mm) were obtained in 97% of cases when the SDNR was 5.9 or higher in seven out of eight poses. Under these conditions, 3D TRE was 2.32 ± 1.88 mm, and 2D (projection) TRE was 1.61 ± 1.36 mm. Probe localization error along the source-detector axis was 0.87 ± 1.31 mm. For the in vivo experiments, mean 3D TRE ranged from 2.6 to 4.6 mm and mean 2D TRE ranged from 1.1 to 1.6 mm. Anatomy extracted from the echo images appeared well aligned when projected onto the SBDX images. Conclusions: Full 6 DOF image registration between SBDX and TEE is feasible and accurate to within 5 mm. Future studies will focus on

  3. A search for improved technique factors in paediatric fluoroscopy

    International Nuclear Information System (INIS)

    Tapiovaara, M.J.; Sandborg, M.; Dance, D.R.

    1999-01-01

    A Monte Carlo computational model of a fluoroscopic imaging chain was used for deriving optimal technique factors for paediatric fluoroscopy. The optimal technique was defined as the one that minimizes the absorbed dose (or dose rate) in the patient with a constraint of constant image quality. Image quality was assessed for the task of detecting a detail in the image of a patient-simulating phantom, and was expressed in terms of the ideal observer's signal-to-noise ratio (SNR) for static images and in terms of the accumulating rate of the square of SNR for dynamic imaging. The entrance air kerma (or air kerma rate) and the mean absorbed dose (or dose rate) in the phantom quantified radiation detriment. The calculations were made for homogeneous phantoms simulating newborn, 3-, 10- and 15-year-old patients, barium and iodine contrast material details, several x-ray spectra, and for imaging with or without an antiscatter grid. The image receptor was modelled as a CsI x-ray image intensifier (XRII). For the task of detecting low- or moderate-contrast iodine details, the optimal spectrum can be obtained by using an x-ray tube potential near 50 kV and filtering the x-ray beam heavily. The optimal tube potential is near 60 kV for low- or moderate-contrast barium details, and 80-100 kV for high-contrast details. The low-potential spectra above require a high tube load, but this should be acceptable in paediatric fluoroscopy. A reasonable choice of filtration is the use of an additional 0.25 mm Cu, or a suitable K-edge filter. No increase in the optimal tube potential was found as phantom thickness increased. With the constraint of constant low-contrast detail detectability, the mean absorbed doses obtained with the above spectra are approximately 50% lower than those obtained with the reference conditions of 70 kV and 2.7 mm Al filter. For the smallest patient and x-ray field size, not using a grid was slightly more dose-efficient than using a grid, but when the patient

  4. Classical fluoroscopy criteria poorly predict right ventricular lead septal positioning by comparison with echocardiography.

    Science.gov (United States)

    Squara, Fabien; Scarlatti, Didier; Riccini, Philippe; Garret, Gauthier; Moceri, Pamela; Ferrari, Emile

    2018-03-13

    Fluoroscopic criteria have been described for the documentation of septal right ventricular (RV) lead positioning, but their accuracy remains questioned. Consecutive patients undergoing pacemaker or defibrillator implantation were prospectively included. RV lead was positioned using postero-anterior and left anterior oblique 40° incidences, and right anterior oblique 30° to rule out coronary sinus positioning when suspected. RV lead positioning using fluoroscopy was compared to true RV lead positioning as assessed by transthoracic echocardiography (TTE). Precise anatomical localizations were determined with both modalities; then, RV lead positioning was ultimately dichotomized into two simple clinically relevant categories: RV septal or RV free wall. Accuracy of fluoroscopy for RV lead positioning was then assessed by comparison with TTE. We included 100 patients. On TTE, 66/100 had a septal RV lead and 34/100 had a free wall RV lead. Fluoroscopy had moderate agreement with TTE for precise anatomical localization of RV lead (k = 0.53), and poor agreement for septal/free wall localization (k = 0.36). For predicting septal RV lead positioning, classical fluoroscopy criteria had a high sensitivity (95.5%; 63/66 patients having a septal RV lead on TTE were correctly identified by fluoroscopy) but a very low specificity (35.3%; only 12/34 patients having a free wall RV lead on TTE were correctly identified by fluoroscopy). Classical fluoroscopy criteria have a poor accuracy for identifying RV free wall leads, which are most of the time misclassified as septal. This raises important concerns about the efficacy and safety of RV lead positioning using classical fluoroscopy criteria.

  5. Comparison of Ultrasound-Guided and Fluoroscopy-Assisted Antegrade Common Femoral Artery Puncture Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, Michael M.; Goh, Gerard S.; Power, Sarah; Given, Mark F.; McGrath, Frank P.; Lee, Michael J., E-mail: mlee@rcsi.ie [Beaumont Hospital, Department of Radiology (Ireland)

    2015-06-15

    PurposeTo prospectively compare the procedural time and complication rates of ultrasound-guided and fluoroscopy-assisted antegrade common femoral artery (CFA) puncture techniques.Materials and MethodsHundred consecutive patients, undergoing a vascular procedure for which an antegrade approach was deemed necessary/desirable, were randomly assigned to undergo either ultrasound-guided or fluoroscopy-assisted CFA puncture. Time taken from administration of local anaesthetic to vascular sheath insertion in the superficial femoral artery (SFA), patients’ age, body mass index (BMI), fluoroscopy radiation dose, haemostasis method and immediate complications were recorded. Mean and median values were calculated and statistically analysed with unpaired t tests.ResultsSixty-nine male and 31 female patients underwent antegrade puncture (mean age 66.7 years). The mean BMI was 25.7 for the ultrasound-guided (n = 53) and 25.3 for the fluoroscopy-assisted (n = 47) groups. The mean time taken for the ultrasound-guided puncture was 7 min 46 s and for the fluoroscopy-assisted technique was 9 min 41 s (p = 0.021). Mean fluoroscopy dose area product in the fluoroscopy group was 199 cGy cm{sup 2}. Complications included two groin haematomas in the ultrasound-guided group and two retroperitoneal haematomas and one direct SFA puncture in the fluoroscopy-assisted group.ConclusionUltrasound-guided technique is faster and safer for antegrade CFA puncture when compared to the fluoroscopic-assisted technique alone.

  6. Computed tomographic fluoroscopy-guided transthoracic needle biopsy for diagnosis of pulmonary nodules

    International Nuclear Information System (INIS)

    Hirose, Takashi; Mori, Kiyoshi; Machida, Suguru; Tominaga, Keigo; Yokoi, Kohei; Adachi, Mitsuru

    2000-01-01

    The purpose of this study was to evaluate the usefulness of computed tomographic (CT) fluoroscopy-guided transthoracic needle biopsy (TTNB) with an 18-gauge automatic biopsy gun for the diagnosis of pulmonary nodules. Between March 1996 and January 1998, 50 patients in whom pulmonary lesions could not be diagnosed cytopathologically with fiberoptic bronchoscopy or were not clearly visualized with fluoroscopy underwent CT fluoroscopy-guided TTNB. Final pathological diagnoses were 23 lung carcinomas, five pulmonary metastases and 22 benign lesions. Sufficient tissue for analysis was obtained from 48 of the 50 lesions (96%). The overall diagnostic yield of CT fluoroscopy-guided TTNB was 90%. The sensitivity, specificity and accuracy for malignancy were 89%, 100% and 94%, respectively. In 20 of the 22 cases (91%) of benign lesions, histological analysis yielded correct and specific diagnoses. Complications occurred in 22 of the 50 cases (44%). The most common complication was pneumothorax, which occurred in 21 of the 50 cases (42%). Chest tube insertion was required in 6 (12%). Although CT fluoroscopy could not decrease the complication rate, CT fluoroscopy-guided TTNB with an automatic biopsy gun appears to be a promising technique for diagnosing pulmonary lesions, particularly benign lesions. (author)

  7. Real time CT-fluoroscopy: diagnostic and therapeutic applications

    International Nuclear Information System (INIS)

    Mey, J. de; Op de Beeck, B.; Meysman, M.; Noppen, M.; Maeseneer, M. de; Vanhoey, M.; Vincken, W.; Osteaux, M.

    2000-01-01

    The synergetic progression of CT technology and computer hardware has made ultrafast acquisition and image reconstruction possible. This has lead to the availability of CT interactive diagnosis and therapeutic procedures. Making use of our own material (337 intervention procedures during the last 17 months), we have compared our techniques and results to the recent literature data. One of the advantages of the biopsy technique is an improved sensitivity for neoplastic lesions, most certainly in cases of intrapulmonary lesions, surrounded by aerated tissue (now 94% compared to 87% in our previous study). A second advantage is the safety of the technique (only one major complication in our series). Fluid collection drainages, and more complex interventions like local injection of drugs, radio-frequency ablation, wire hook placement and ethanol injection were performed without complication. Yet another interesting feature is the shortening of the procedure time (reduced in average to an 'in-room' time of less than 30 min), which has definite economical implications. Furthermore it increases the patient's comfort and safety, and extends the scope of outpatient procedures (80% outpatient procedures in our material). On the other side the radiation exposure can be raised as an issue, especially when we consider the operator's hands. However, the described technique and the use of dedicated tools can alleviate the problem. As a conclusion, real time CT fluoroscopy has given a new input and broadens the scope of clinical indications of CT-guided diagnostic and therapeutic procedures

  8. Changing Default Fluoroscopy Equipment Settings Decreases Entrance Skin Dose in Patients.

    Science.gov (United States)

    Canales, Benjamin K; Sinclair, Lindsay; Kang, Diana; Mench, Anna M; Arreola, Manuel; Bird, Vincent G

    2016-04-01

    Proper fluoroscopic education and protocols may reduce the patient radiation dose but few prospective studies in urology have been performed. Using optically stimulated luminescent dosimeters we tested whether fluoroscopy time and/or entrance skin dose would decrease after educational and radiation reduction protocols. At default manufacturer settings fluoroscopy time and entrance skin dose were prospectively measured using optically stimulated luminescent dosimeters in patients undergoing ureteroscopy, retrograde pyelogram/stent or percutaneous nephrolithotomy with access for stone disease. A validated radiation safety competency test was administered to urology faculty and residents before and after web based, hands-on fluoroscopy training. Default fluoroscopy settings were changed from continuous to intermittent pulse rate and from standard to half-dose output. Fluoroscopy time and entrance skin dose were then measured again. The cohorts of 44 pre-protocol and 50 post-protocol patients with stones were similarly matched. The change in mean fluoroscopy time and entrance skin dose from pre-protocol to post-protocol was -0.6 minutes and -11.6 mGy (33%) for percutaneous nephrolithotomy (p = 0.62 and default settings to intermittent pulse rate (12 frames per second) and half-dose lowered the entrance skin dose by 30% across all endourology patients but most significantly during percutaneous nephrolithotomy. To limit patient radiation exposure fluoroscopy default settings should be decreased before all endourology procedures and image equipment manufacturers should consider lowering standard default renal settings. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  9. Noise aliasing in interline-video-based fluoroscopy systems

    International Nuclear Information System (INIS)

    Lai, H.; Cunningham, I.A.

    2002-01-01

    Video-based imaging systems for continuous (nonpulsed) x-ray fluoroscopy use a variety of video formats. Conventional video-camera systems may operate in either interlaced or progressive-scan modes, and CCD systems may operate in interline- or frame-transfer modes. A theoretical model of the image noise power spectrum corresponding to these formats is described. It is shown that with respect to frame-transfer or progressive-readout modes, interline or interlaced cameras operating in a frame-integration mode will result in a spectral shift of 25% of the total image noise power from low spatial frequencies to high. In a field-integration mode, noise power is doubled with most of the increase occurring at high spatial frequencies. The differences are due primarily to the effect of noise aliasing. In interline or interlaced formats, alternate lines are obtained with each video field resulting in a vertical sampling frequency for noise that is one half of the physical sampling frequency. The extent of noise aliasing is modified by differences in the statistical correlations between video fields in the different modes. The theoretical model is validated with experiments using an x-ray image intensifier and CCD-camera system. It is shown that different video modes affect the shape of the noise-power spectrum and therefore the detective quantum efficiency. While the effect on observer performance is not addressed, it is concluded that in order to minimize image noise at the critical mid-to-high spatial frequencies for a specified x-ray exposure, fluoroscopic systems should use only frame-transfer (CCD camera) or progressive-scan (conventional video) formats

  10. Pediatric and staff dose evaluation in fluoroscopy upper gastrointestinal series

    Energy Technology Data Exchange (ETDEWEB)

    Filipov, Danielle; Nascimento, Eduarda X. do; Lacerda, Camila M., E-mail: diilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UFTPR), Curitiba, PR (Brazil); Schelin, Hugo R.; Ledesma, Jorge A.; Denyak, Valeriy; Legnani, Adriano, E-mail: ledesmajorgealberto@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil)

    2014-07-01

    Fluoroscopy upper GI series are widely used for the diagnosis of gastroesophageal reflux disease in children. Pediatric radiological procedures bring concern due to the high life expectancy and radiosensitivity on children, as well as the risks to the exposed staff Important studies present the mean KAP values on patients and the European Commission (EC) recommends specific techniques for these procedures. For the occupational expositions, staffs doses must be within the annual limit, according to the CNEN 3.01. Based on those data, the aims of the current study are: analyzing the upper GI procedure; determining the KAP on the patient and estimating the annual equivalent dose on the staff's crystalline. LiF :Mg,Ti TLDs were positioned on the patient upper chest center, so that the entrance surface air kerma could be determined. The field size on the patient s surface and the kerma were multiplied so that the KAP was obtained. LiF:Mg,Cu,P dosimeters were used to estimate the equivalent dose on the staff s crystalline. The results showed discrepancy in the kVp range and in the exposure time when compared to the EC data. The mean KAP values for the 0-1,1-3 and 3-10 years old patients were, respectively: 102 ± 19 cGy.cm2, 142 ± 25 cGy.cm2 and 323 ± 39 cGy.cm2; which are higher than the KAPs presented in the studies used for comparison. The estimated annual equivalent dose in the staff s crystalline would be approximately 85% higher than the limit set by the CNEN. Analyzing the data, it becomes clear that an optimization implementation is necessary in order to reduce the radiation levels. (author)

  11. Pediatric and staff dose evaluation in fluoroscopy upper gastrointestinal series

    International Nuclear Information System (INIS)

    Filipov, Danielle; Nascimento, Eduarda X. do; Lacerda, Camila M.; Schelin, Hugo R.; Ledesma, Jorge A.; Denyak, Valeriy; Legnani, Adriano

    2014-01-01

    Fluoroscopy upper GI series are widely used for the diagnosis of gastroesophageal reflux disease in children. Pediatric radiological procedures bring concern due to the high life expectancy and radiosensitivity on children, as well as the risks to the exposed staff Important studies present the mean KAP values on patients and the European Commission (EC) recommends specific techniques for these procedures. For the occupational expositions, staffs doses must be within the annual limit, according to the CNEN 3.01. Based on those data, the aims of the current study are: analyzing the upper GI procedure; determining the KAP on the patient and estimating the annual equivalent dose on the staff's crystalline. LiF :Mg,Ti TLDs were positioned on the patient upper chest center, so that the entrance surface air kerma could be determined. The field size on the patient s surface and the kerma were multiplied so that the KAP was obtained. LiF:Mg,Cu,P dosimeters were used to estimate the equivalent dose on the staff s crystalline. The results showed discrepancy in the kVp range and in the exposure time when compared to the EC data. The mean KAP values for the 0-1,1-3 and 3-10 years old patients were, respectively: 102 ± 19 cGy.cm2, 142 ± 25 cGy.cm2 and 323 ± 39 cGy.cm2; which are higher than the KAPs presented in the studies used for comparison. The estimated annual equivalent dose in the staff s crystalline would be approximately 85% higher than the limit set by the CNEN. Analyzing the data, it becomes clear that an optimization implementation is necessary in order to reduce the radiation levels. (author)

  12. Fluoroscopy-guided transnasal biopsy of nasopharyngeal carcinoma using a flexible bronchoscopic biopsy forcep

    International Nuclear Information System (INIS)

    Kim, Jai Keun; Chung, Tae Sub; Kim, Dong Ik; Suh, Jung Ho

    1996-01-01

    Otolaryngoscopic biopsy of nasopharyngeal carcinoma is a generalized method which may be associated with inadequate sampling of tissue and patient discomfort. So, we tried fluoroscopy-guided transnasal biopsy using bronchoscopic biopsy forcep and evaluated its safety and efficacy. Prospectively we performed fluoroscopy-guided transnasal biopsy in 11 patients who were radiographically suspected of nasopharyngeal carcinoma. The posterior wall of the nasopharynx was coated with barium sulfate under fluoroscopy. A flexible bronchoscopic biopsy forcep with a steerable guiding catheter which was used in removal of intrahepatic duct stones was inserted through the nare. After localization of the tip of the biopsy forcep at tumor site with fluoroscopy, a tissue specimen was obtained. We also tried CT guided biopsy in initial 2cases. Each patient had otolaryngoscopic biopsy to compare the biopsy result and patient discomfort. We could have sufficient amount of tissue for pathological evaluation in 10 of 11 patients by the first pass with the fluoroscopic technique. Contrarily, otolaryngoscopic biopsy was successful in 7 of 11 patients on single passage. Additionally, 2 patients had complaint in our method comparing with 9 patients in otolaryngoscopic biopsy. Fluoroscopy-guided transnasal biopsy of nasopharyngeal carcinoma using the bronchoscopic biopsy forcep is safe and accurate. It can be a appropriate method competing otolaryngoscopic biopsy

  13. Evaluation of sleep apnea syndrome (SAS) with low field MR fluoroscopy

    International Nuclear Information System (INIS)

    Fukatsu, Hiroshi; Ando, Yoko; Ishigaki, Takeo; Okada, Tamotsu.

    1995-01-01

    Eight cases of clinically diagnosed sleep apnea syndrome (SAS) and two normal volunteers were studied with low field MR fluoroscopy in order to monitor the waking and sleeping status of the upper airway. MR fluoroscopy revealed that only the sleeping patients showed occlusions of the upper airway. This technique provided us with useful information about the level, frequency and duration of occlusion in each case. Four of the eight patients demonstrated simple retropalatal occlusion, whereas the other four demonstrated mixed retropalatal and retropalato-retroglossal occlusion. Thus long-time monitoring, which is only possible with MR fluoroscopy, is needed to appreciate the complex nature of the disease. In addition, the comfortable surroundings and low noise level provided by the low field enabled physiological study to be performed without any tranquilizers in most of the patients, which is again only possible with MR fluoroscopy. MR fluoroscopy may become a tool of great clinical value, providing much important information for disease evaluation and treatment selection. (author)

  14. Navigation for fluoroscopy-guided cryo-balloon ablation procedures of atrial fibrillation

    Science.gov (United States)

    Bourier, Felix; Brost, Alexander; Kleinoeder, Andreas; Kurzendorfer, Tanja; Koch, Martin; Kiraly, Attila; Schneider, Hans-Juergen; Hornegger, Joachim; Strobel, Norbert; Kurzidim, Klaus

    2012-02-01

    Atrial fibrillation (AFib), the most common arrhythmia, has been identified as a major cause of stroke. The current standard in interventional treatment of AFib is the pulmonary vein isolation (PVI). PVI is guided by fluoroscopy or non-fluoroscopic electro-anatomic mapping systems (EAMS). Either classic point-to-point radio-frequency (RF)- catheter ablation or so-called single-shot-devices like cryo-balloons are used to achieve electrically isolation of the pulmonary veins and the left atrium (LA). Fluoroscopy-based systems render overlay images from pre-operative 3-D data sets which are then merged with fluoroscopic imaging, thereby adding detailed 3-D information to conventional fluoroscopy. EAMS provide tracking and visualization of RF catheters by means of electro-magnetic tracking. Unfortunately, current navigation systems, fluoroscopy-based or EAMS, do not provide tools to localize and visualize single shot devices like cryo-balloon catheters in 3-D. We present a prototype software for fluoroscopy-guided ablation procedures that is capable of superimposing 3-D datasets as well as reconstructing cyro-balloon catheters in 3-D. The 3-D cyro-balloon reconstruction was evaluated on 9 clinical data sets, yielded a reprojected 2-D error of 1.72 mm +/- 1.02 mm.

  15. Safety and outcome using endoscopic dilation for benign esophageal stricture without fluoroscopy

    Directory of Open Access Journals (Sweden)

    E R Siddeshi

    2015-01-01

    Full Text Available Aim : The aim was to investigate the use of Savary-Gilliard marked dilators in tight esophageal strictures without fluoroscopy. Materials and Methods: Four hundred and six patients with significant dysphagia from benign strictures due to a variety of causes were dilated endoscopically. Patients with achalasia, malignant lesions, and external compression were excluded. The procedure consisted of two parts. First, Savary-Gilliard or zebra guide wire was placed through video endoscopy and then dilatation was performed without fluoroscopy. In general, "the rule of three" was followed. Effective treatment was defined as the ability of patients, with or without repeated dilatations, to maintain a solid or semisolid diet for more than 12 months. Results: One thousand and twenty-four dilatations sessions in a total of 408 patients were carried out. The success rate for placement of a guide wire was 100% and for dilatation 97% without the use of fluoroscopy, after 6 months-24 years of follow-up. The number of sessions per patient was between one and seven, with an average of three sessions. The ability of patients, after one or more sessions of dilatations to maintain a solid or semisolid diet for more than 12 months was obtained in 386 patients (95.8%. All patients improved clinically without complications after the endoscopic procedure without fluoroscopy, but we noted 22 failures. Conclusions: Dilatation (dilation using Savary-Gilliard dilators without fluoroscopy are safe and effective in the treatment of very tight esophageal strictures if performed with care.

  16. Monitoring radiation use in cardiac fluoroscopy imaging procedures

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Nathaniel T.; Steiner, Stefan H.; Smith, Ian R.; MacKay, R. Jock [Department of Statistics and Actuarial Sciences, Business and Industrial Statistics Research Group, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); St. Andrew' s Medical Institute, St. Andrew' s War Memorial Hospital, Brisbane, Queensland 4000 (Australia); Department of Statistics and Actuarial Sciences, Business and Industrial Statistics Research Group, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2011-01-15

    Purpose: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue, the authors propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms. Methods: Data used in this study were obtained from records routinely collected during procedures performed in the cardiac catheterization imaging facility at St. Andrew's War Memorial Hospital, Brisbane, Australia, over the period January 2008-March 2010. A two stage monitoring process employing individual and exponentially weighted moving average (EWMA) control charts was developed and used to identify unexpectedly high or low radiation exposure levels for individual patients, as well as detect persistent changes in the radiation output delivered by the imaging systems. To increase sensitivity of the charts, we account for variation in dose area product (DAP) values due to other measured factors (patient weight, fluoroscopy time, and digital acquisition frame count) using multiple linear regression. Control charts are then constructed using the residual values from this linear regression. The proposed monitoring process was evaluated using simulation to model the performance of the process under known conditions. Results: Retrospective application of this technique to actual clinical data identified a number of cases in which the DAP result could be considered unexpected. Most of these, upon review, were attributed to data entry errors. The charts monitoring the overall system radiation output trends demonstrated changes in equipment

  17. Monitoring radiation use in cardiac fluoroscopy imaging procedures

    International Nuclear Information System (INIS)

    Stevens, Nathaniel T.; Steiner, Stefan H.; Smith, Ian R.; MacKay, R. Jock

    2011-01-01

    Purpose: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue, the authors propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms. Methods: Data used in this study were obtained from records routinely collected during procedures performed in the cardiac catheterization imaging facility at St. Andrew's War Memorial Hospital, Brisbane, Australia, over the period January 2008-March 2010. A two stage monitoring process employing individual and exponentially weighted moving average (EWMA) control charts was developed and used to identify unexpectedly high or low radiation exposure levels for individual patients, as well as detect persistent changes in the radiation output delivered by the imaging systems. To increase sensitivity of the charts, we account for variation in dose area product (DAP) values due to other measured factors (patient weight, fluoroscopy time, and digital acquisition frame count) using multiple linear regression. Control charts are then constructed using the residual values from this linear regression. The proposed monitoring process was evaluated using simulation to model the performance of the process under known conditions. Results: Retrospective application of this technique to actual clinical data identified a number of cases in which the DAP result could be considered unexpected. Most of these, upon review, were attributed to data entry errors. The charts monitoring the overall system radiation output trends demonstrated changes in equipment performance

  18. Circulatory disease mortality in the Massachusetts tuberculosis fluoroscopy cohort study

    International Nuclear Information System (INIS)

    Little, Mark P.; Zablotska, Lydia B.; Brenner, Alina V.; Lipshultz, Steven E.

    2016-01-01

    High-dose ionizing radiation is associated with circulatory disease. Risks from lower-dose fractionated exposures, such as from diagnostic radiation procedures, remain unclear. In this study we aimed to ascertain the relationship between fractionated low-to-medium dose radiation exposure and circulatory disease mortality in a cohort of 13,568 tuberculosis patients in Massachusetts, some with fluoroscopy screenings, between 1916 and 1961 and follow-up until the end of 2002. Analysis of mortality was in relation to cumulative thyroid (cerebrovascular) or lung (all other circulatory disease) radiation dose via Poisson regression. Over the full dose range, there was no overall radiation-related excess risk of death from circulatory disease (n = 3221; excess relative risk/Gy −0.023; 95 % CI −0.067, 0.028; p = 0.3574). Risk was somewhat elevated in hypertensive heart disease (n = 89; excess relative risk/Gy 0.357; 95 % CI −0.043, 1.030, p = 0.0907) and slightly decreased in ischemic heart disease (n = 1950; excess relative risk/Gy −0.077; 95 % CI −0.130, −0.012; p = 0.0211). However, under 0.5 Gy, there was a borderline significant increasing trend for all circulatory disease (excess relative risk/Gy 0.345; 95 % CI −0.032, 0.764; p = 0.0743) and for ischemic heart disease (excess relative risk/Gy 0.465; 95 % CI, −0.032, 1.034, p = 0.0682). Pneumolobectomy increased radiation–associated risk (excess relative risk/Gy 0.252; 95 % CI 0.024, 0.579). Fractionation of dose did not modify excess risk. In summary, we found no evidence of radiation-associated excess circulatory death risk overall, but there are indications of excess circulatory death risk at lower doses (<0.5 Gy). Although consistent with other radiation-exposed groups, the indications of higher risk at lower doses are unusual and should be confirmed against other data.

  19. Survey of gonad and bone marrow doses from IUCD fluoroscopy in women of Guangdong province

    International Nuclear Information System (INIS)

    Zeng Xishen; Fan Jincai

    1984-01-01

    The local exposure doses in fluoroscopy for intrauterine contraceptive device (IUCD) were surveyed with TLD in 150 women. The gonad and bone marrow doses were calculated by adopting both the results of radiation experiment on MIXD phantom and related data. The mean gonad and bone marrow doses are 13.6 and 18.7 mrad, respectively. The collective bone marrow dose equivalent was estimated from the numbers of women fitted with IUCD and of women undergoing fluoroscopy, and the census of women of child-bearing age in Guangdong Province. The significance of collective bone marrow dose equivalent by IUCD fluoroscopy is discussed on the basis of the risk estimate of leukemia in ICRP publication No 26. (author)

  20. Endoscopic retrograde JJ-stenting of the ureter without fluoroscopy guidance--an appraisal of outcome.

    Science.gov (United States)

    Shuaibu, S I; Gidado, S; Oseni-Momodu, E

    2013-01-01

    JJ- ureteral stenting is a means of relieving ureteric obstruction. It is done as a retrograde or antegrade procedure, usually under fluoroscopy guidance. We reviewed our results in 2 independent tertiary health centers in Nigeria which lack fluoroscopy units. A 2 year retrospective review of data of patients who had retrograde JJ- ureteric stenting was done. Data relating to age, indication and outcome of procedure were retrieved and analysed. 22 (71%) patients had successful retrograde JJ- ureteric stenting out of 31 patients who were taken for the procedure. These 22 patients had stenting of 27 ureteric units. Mean age was 48.5 years. Commonest indication was carcinoma of the cervix (31.8%). Commonest complication was irritative lower urinary tract symptoms (43.5%). In spite of inherent complications, JJ-stenting is a simple and safe technique. Therefore, the decision to attempt JJ -stenting in carefully selected patients in the absence of fluoroscopy is acceptable.

  1. A survey in Portuguese X-ray fluoroscopy equipment: dose rates and image quality

    International Nuclear Information System (INIS)

    Teixeira, Nuno G.; Cunha, Gilda R.; Coutinho, Guilherme M.; Trindade, Hugo R.; Carvoeiras, Pedro P.

    2015-01-01

    X-ray fluoroscopy is essential in both diagnosis and medical intervention, although it may contribute to significant radiation doses to patients that have to be optimised and justified. Therefore, it is crucial to the patient to be exposed to the lowest achievable dose without compromising the image quality. The purpose of this study was to perform an analysis of the quality control measurements, particularly dose rates, contrast and spatial resolution of Portuguese fluoroscopy equipment and also to provide a contribution to the establishment of reference levels for the equipment performance parameters. Measurements carried out between 2007 and 2013 on 143 fluoroscopy equipment distributed by 34 nationwide health units were analysed. The measurements suggest that image quality and dose rates of Portuguese equipment are congruent with other studies, and in general, they are as per the Portuguese law. However, there is still a possibility of improvements intending optimisation at a national level. (authors)

  2. Dose reduction in pulsed fluoroscopy by modifying the high-voltage pulse shape

    International Nuclear Information System (INIS)

    Sabau, M.N.; Phelps, G.

    1988-01-01

    This paper presents the dose reduction results in pulsed fluoroscopy by modifying the high-voltage pulse shape (HVPS). Since the HVPS in regular pulsed fluoroscopy has a long tail, the radiation pulse shape (RPS) is similar. Using specially designed circuitry in the high-voltage generator to produce a rectangular HVPS, and consequently a rectangular RPS, it was possible to obtain a reduction of up to 25% of patient exposure. This dose reduction obtained by cutting the long tail of RPS does not damage the image quality

  3. Diaphragmatic paralysis evaluated by phrenic nerve stimulation during fluoroscopy or real-time ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    McCauley, R.G.K.; Labib, K.B.

    1984-10-01

    Stimulation of the phrenic nerve by supplying an electrical impulse to the neck during fluoroscopy or real-time ultrasound (sonoscopy) of the diaphragm allows more precise functional evaluation than fluoroscopy and/or sonoscopy alone. This is especially true of patients who are unable to cooperate because the are on a ventilator, unconscious, or very young. The authors cite cases in which diaphragmatic paralysis was diagnosed by conventional methods but stimulation of the phrenic nerve demonstrated good diaphragmatic motion, leading to a change in prognosis in some cases and a change in therapy in others.

  4. Diaphragmatic paralysis evaluated by phrenic nerve stimulation during fluoroscopy or real-time ultrasound

    International Nuclear Information System (INIS)

    McCauley, R.G.K.; Labib, K.B.

    1984-01-01

    Stimulation of the phrenic nerve by supplying an electrical impulse to the neck during fluoroscopy or real-time ultrasound (sonoscopy) of the diaphragm allows more precise functional evaluation than fluoroscopy and/or sonoscopy alone. This is especially true of patients who are unable to cooperate because the are on a ventilator, unconscious, or very young. The authors cite cases in which diaphragmatic paralysis was diagnosed by conventional methods but stimulation of the phrenic nerve demonstrated good diaphragmatic motion, leading to a change in prognosis in some cases and a change in therapy in others

  5. Accuracy and consequences of 3D-fluoroscopy in upper and lower extremity fracture treatment: A systematic review

    NARCIS (Netherlands)

    Beerekamp, M. S. H. Suzan; Sulkers, George S. I.; Ubbink, Dirk T.; Maas, Mario; Schep, Niels W. L.; Goslings, J. Carel

    2012-01-01

    Objectives: The aim of this systematic review was to compare the diagnostic accuracy, subjective image quality and clinical consequences of 3D-fluoroscopy with standard imaging modalities (2D-fluoroscopy, X-ray or CT) during reduction and fixation of intra-articular upper and lower extremity

  6. CT-guided percutaneous lung biopsy: Comparison of conventional CT fluoroscopy to CT fluoroscopy with electromagnetic navigation system in 60 consecutive patients

    Energy Technology Data Exchange (ETDEWEB)

    Grand, David Justin, E-mail: dgrand@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Atalay, Michael A., E-mail: matalay@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Cronan, John J., E-mail: cronan@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Mayo-Smith, William W., E-mail: wmayo-smith@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States); Dupuy, Damian E., E-mail: ddupuy@lifespan.org [Department of Diagnostic Imaging, Warren Alpert School of Medicine, Brown University, Providence, RI 02903 (United States)

    2011-08-15

    Purpose: To determine if use of an electromagnetic navigation system (EMN) decreases radiation dose and procedure time of CT fluoroscopy guided lung biopsy in lesions smaller than 2.5 cm. Materials/methods: 86 consecutive patients with small lung masses (<2.5 cm) were approached. 60 consented and were randomized to undergo biopsy with CT fluoroscopy (CTF) (34 patients) or EMN (26 patients). Technical failure required conversion to CTF in 8/26 EMN patients; 18 patients completed biopsy with EMN. Numerous biopsy parameters were compared as described below. Results: Average fluoroscopy time using CTF was 28.2 s compared to 35.0 s for EMN (p = 0.1). Average radiation dose was 117 mGy using CTF and 123 mGy for EMN (p = 0.7). Average number of needle repositions was 3.7 for CTF and 4.4 for EMN (p = 0.4). Average procedure time was 15 min for CTF and 20 min for EMN (p = 0.01). There were 7 pneumothoracesin the CTF group and 6 pneumothoraces in the EMN group (p = 0.7). One pneumothorax in the CTF group and 3 pneumothoraces in the EMN group required chest tube placement (p = 0.1). One pneumothorax patient in each group required hospital admission. Diagnostic specimens were obtained in 31/34 patients in the CTF group and 22/26 patients in the EMN group (p = 0.4). Conclusions: EMN was not statistically different than CTF for fluoroscopy time, radiation dose, number of needle repositions, incidence of pneumothorax, need for chest tube, or diagnostic yield. Procedure time was increased with EMN.

  7. Zero-fluoroscopy permanent pacemaker implantation using Ensite NavX system: Clinical viability or fanciful technique?

    Science.gov (United States)

    Guo, Ping; Qiu, Jie; Wang, Yan; Chen, Guangzhi; Proietti, Riccardo; Fadhle, Al-Selmi; Zhao, Chunxia; Wen Wang, Dao

    2018-02-01

    Fluoroscopy is the imaging modality routinely used for cardiac device implantation and electrophysiological procedures. Due to the rising concern regarding the harmful effects of radiation exposure to both the patients and operation staffs, novel 3D mapping systems have been developed and implemented in electrophysiological procedure for the navigation of catheters inside the heart chambers. Their applicability in cardiac device implantation has been rarely reported. Our aim is to evaluate the feasibility and safety of permanent pacemaker implantation without fluoroscopy. From January 2012 to June 2016, six patients (50 ± 15 years, four of six were female, one of who was at the 25th week of gestation) who underwent permanent pacemaker implantation were included (zero-fluoroscopy group). Data from 20 consecutive cases of implantation performed under fluoroscopy guidance were chosen as a control group (fluoroscopy group). Total implantation procedure time for single-chamber pacemaker was 51.3 ± 13.1 minutes in the zero-fluoroscopy group and 42.6 ± 7.4 minutes in the fluoroscopy group (P  =  0.155). The implantation procedural time for a dual-chamber pacemaker was 88.3 ± 19.6 minutes and 67.3 ± 7.6 minutes in the zero-fluoroscopy and fluoroscopy groups (P  =  0.013), respectively. No complications were observed during the procedure and the follow-up in the two groups, and all pacemakers worked with satisfactory parameters. Ensite NavX system can be used as a reliable and safe zero-fluoroscopy approach for the implantation of single- or dual-chamber permanent pacemakers in specific patients, such as pregnant women or in extreme situations when the x-ray machine is not available. © 2017 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.

  8. Feasibility Study of Needle Placement in Percutaneous Vertebroplasty: Cone-Beam Computed Tomography Guidance Versus Conventional Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Braak, Sicco J., E-mail: sjbraak@gmail.com [St. Antonius Hospital, Department of Radiology (Netherlands); Zuurmond, Kirsten, E-mail: kirsten.zuurmond@philips.com; Aerts, Hans C. J., E-mail: hans.cj.aerts@philips.com [Philips Medical, Department of Clinical Development (Netherlands); Leersum, Marc van, E-mail: m.van.leersum@antoniusziekenhuis.nl; Overtoom, Timotheus T. Th., E-mail: overtm@knoware.nl; Heesewijk, Johannes P. M. van, E-mail: j.heesewijk@antoniusziekenhuis.nl; Strijen, Marco J. L. van, E-mail: m.van.strijen@antoniusziekenhuis.nl [St. Antonius Hospital, Department of Radiology (Netherlands)

    2013-08-01

    ObjectiveTo investigate the accuracy, procedure time, fluoroscopy time, and dose area product (DAP) of needle placement during percutaneous vertebroplasty (PVP) using cone-beam computed tomography (CBCT) guidance versus fluoroscopy.Materials and MethodsOn 4 spine phantoms with 11 vertebrae (Th7-L5), 4 interventional radiologists (2 experienced with CBCT guidance and two inexperienced) punctured all vertebrae in a bipedicular fashion. Each side was randomization to either CBCT guidance or fluoroscopy. CBCT guidance is a sophisticated needle guidance technique using CBCT, navigation software, and real-time fluoroscopy. The placement of the needle had to be to a specific target point. After the procedure, CBCT was performed to determine the accuracy, procedure time, fluoroscopy time, and DAP. Analysis of the difference between methods and experience level was performed.ResultsMean accuracy using CBCT guidance (2.61 mm) was significantly better compared with fluoroscopy (5.86 mm) (p < 0.0001). Procedure time was in favor of fluoroscopy (7.39 vs. 10.13 min; p = 0.001). Fluoroscopy time during CBCT guidance was lower, but this difference is not significant (71.3 vs. 95.8 s; p = 0.056). DAP values for CBCT guidance and fluoroscopy were 514 and 174 mGy cm{sup 2}, respectively (p < 0.0001). There was a significant difference in favor of experienced CBCT guidance users regarding accuracy for both methods, procedure time of CBCT guidance, and added DAP values for fluoroscopy.ConclusionCBCT guidance allows users to perform PVP more accurately at the cost of higher patient dose and longer procedure time. Because procedural complications (e.g., cement leakage) are related to the accuracy of the needle placement, improvements in accuracy are clinically relevant. Training in CBCT guidance is essential to achieve greater accuracy and decrease procedure time/dose values.

  9. Computed tomography fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures

    International Nuclear Information System (INIS)

    Iguchi, Toshihiro; Ogawa, Ken-Ichi; Doi, Takeshi; Munetomo, Kazuo; Miyasho, Koji; Hiraki, Takao; Kanazawa, Susumu; Ozaki, Toshifumi

    2010-01-01

    The purpose of this study was to evaluate retrospectively the safety and effectiveness of the computed tomography (CT) fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures. Six patients (four women and two men; mean age 55.8 years; range 35-77 years) with unstable posterior pelvic fractures underwent iliosacral screw placement under CT fluoroscopy guidance between November 2007 and August 2008. Unstable pelvic ring injury (AO types B and C) was the indication for this procedure. In all the six patients except one, CT fluoroscopy-guided placement had been technically successful. In one patient, a second screw had been inserted, with a tilt to the caudal site, and slightly advanced into the extrasacral body; afterward, it could be exchanged safely for a shorter screw. Five patients and one patient underwent placement of two screws and one screw, respectively. The mean duration of the procedure was 15.0 min (range 9-30 min) per screw; the duration was 12.3 min and 18.2 min for the first and second screws, respectively. No complications requiring treatment occurred during or after the procedure. The mean clinical and radiologic follow-up period was 14 months (range 6-21 months). All pelvic injuries had healed satisfactorily, without complication, and all patients are now doing well clinically and can walk. CT fluoroscopy-guided placement of iliosacral screws is a safe and effective treatment in patients with unstable posterior pelvic fractures. (orig.)

  10. A simple ergonomic measure reduces fluoroscopy time during ERCP: A multivariate analysis.

    Science.gov (United States)

    Jowhari, Fahd; Hopman, Wilma M; Hookey, Lawrence

    2017-03-01

    Background and study aims  Endoscopic retrograde cholangiopancreatgraphy (ERCP) carries a radiation risk to patients undergoing the procedure and the team performing it. Fluoroscopy time (FT) has been shown to have a linear relationship with radiation exposure during ERCP. Recent modifications to our ERCP suite design were felt to impact fluoroscopy time and ergonomics. This multivariate analysis was therefore undertaken to investigate these effects, and to identify and validate various clinical, procedural and ergonomic factors influencing the total fluoroscopy time during ERCP. This would better assist clinicians with predicting prolonged fluoroscopic durations and to undertake relevant precautions accordingly. Patients and methods  A retrospective analysis of 299 ERCPs performed by 4 endoscopists over an 18-month period, at a single tertiary care center was conducted. All inpatients/outpatients (121 males, 178 females) undergoing ERCP for any clinical indication from January 2012 to June 2013 in the chosen ERCP suite were included in the study. Various predetermined clinical, procedural and ergonomic factors were obtained via chart review. Univariate analyses identified factors to be included in the multivariate regression model with FT as the dependent variable. Results  Bringing the endoscopy and fluoroscopy screens next to each other was associated with a significantly lesser FT than when the screens were separated further (-1.4 min, P  = 0.026). Other significant factors associated with a prolonged FT included having a prior ERCP (+ 1.4 min, P  = 0.031), and more difficult procedures (+ 4.2 min for each level of difficulty, P  < 0.001). ERCPs performed by high-volume endoscopists used lesser FT vs. low-volume endoscopists (-1.82, P = 0.015). Conclusions  Our study has identified and validated various factors that affect the total fluoroscopy time during ERCP. This is the first study to show that decreasing the distance

  11. Analysis of diaphragmatic movement before and after pulmonary rehabilitation using fluoroscopy imaging in patients with COPD

    Directory of Open Access Journals (Sweden)

    Chun EM

    2015-01-01

    Full Text Available Eun Mi Chun,1 Soo Jeong Han,2 Hitesh N Modi3 1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul, Republic of Korea; 2Rehabilitation Medicine, Ewha Womans University School of Medicine, Seoul, Republic of Korea; 3Scoliosis Research Institute, Department of Orthopedics, Korea University Guro Hospital, Seoul, Republic of Korea Background: The diaphragm is the principal inspiratory muscle. The purpose of this study was to assess improvements in diaphragmatic movement before and after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD, using a fluoroscopy-guided chest X-ray.Patients and methods: Among 117 patients with COPD receiving pulmonary rehabilitation who underwent the initial fluoroscopy-guided chest X-ray and pulmonary function test, 37 of those patients who underwent both initial and follow-up fluoroscopy and pulmonary function tests were enrolled in this study. After hospital education, participants received pulmonary rehabilitation through regular home-based training for at least 3 months by the same physiatrist. We assessed the changes in diaphragm area with fluoroscopy-guided posteroanterior chest X-rays between pre- and postpulmonary rehabilitation. To minimize radiation hazards for subjects, the exposure time for fluoroscopy to take chest X-rays was limited to less than 5 seconds.Results: There were significant improvements (2,022.8±1,548.3 mm² to 3,010.7±1,495.6 mm² and 2,382.4±1,475.9 mm² to 3,315.9±1,883.5 mm²; right side P=0.001 and left side P=0.019, respectively in diaphragmatic motion area during full inspiration and expiration in both lungs after pulmonary rehabilitation. Pulmonary function tests showed no statistically significant difference between pre- and postpulmonary rehabilitation.Conclusion: The study suggests that the strategy to assess diaphragm movement using fluoroscopy is a relatively effective tool for the evaluation of pulmonary

  12. Radiation exposure to the patient during X-ray fluoroscopy and radiography

    International Nuclear Information System (INIS)

    Dimov, A.; Vassileva, J.

    2006-01-01

    Full text: The aim of this study is to assess the patient doses received during conventional and digital X-ray radiography, conventional fluoroscopy of the lungs, and one of the highest dose X-ray procedures - contrast examination of the large intestine (Barium enema examination). The measured quantity is Kerma area product (KAP), registered with a clinical dosimeter DRK-1 (Doza, Russia). A total number of 89 patients are included in the study. The Organ doses and Effective doses were assessed using Monte Carlo calculation code (PCXMC 1.4 (Finland). The measurements took place at the following X-ray units: a CGR (Koch and Sterzel) with two working posts - for radiography and fluoroscopy, a Philips Telediagnost (for barium enema) and an Oldelft N800HF Digidelca (for digital radiography of the chest). The typical KAP per procedure at digital radiography, conventional X-ray radiography and fluoroscopy and Barium enema examination are: 17; 95; 928 and 3630 cGy.cm 2 respectively; the average effective doses are: 0.022; 0.053; 0.728 and 8.0 mSv respectively. Doses to the lungs at digital radiography, conventional radiography and fluoroscopy are: 0.066; 0.136 and 2.412 mSv respectively and the dose to the upper and lower large intestine are: 11.7 and 8.6 mSv respectively. Conclusion: The approach used is applicable for assessment of radiation exposure to the patient during X-ray radiography and fluoroscopy. It needs registration of KAP meter readings when this device is installed on the stationary X-ray units

  13. 3D reconstruction from X-ray fluoroscopy for clinical veterinary medicine using differential volume rendering

    International Nuclear Information System (INIS)

    Khongsomboon, K.; Hamamoto, Kazuhiko; Kondo, Shozo

    2007-01-01

    3D reconstruction from ordinary X-ray equipment which is not CT or MRI is required in clinical veterinary medicine. Authors have already proposed a 3D reconstruction technique from X-ray photograph to present bone structure. Although the reconstruction is useful for veterinary medicine, the technique has two problems. One is about exposure of X-ray and the other is about data acquisition process. An x-ray equipment which is not special one but can solve the problems is X-ray fluoroscopy. Therefore, in this paper, we propose a method for 3D-reconstruction from X-ray fluoroscopy for clinical veterinary medicine. Fluoroscopy is usually used to observe a movement of organ or to identify a position of organ for surgery by weak X-ray intensity. Since fluoroscopy can output a observed result as movie, the previous two problems which are caused by use of X-ray photograph can be solved. However, a new problem arises due to weak X-ray intensity. Although fluoroscopy can present information of not only bone structure but soft tissues, the contrast is very low and it is very difficult to recognize some soft tissues. It is very useful to be able to observe not only bone structure but soft tissues clearly by ordinary X-ray equipment in the field of clinical veterinary medicine. To solve this problem, this paper proposes a new method to determine opacity in volume rendering process. The opacity is determined according to 3D differential coefficient of 3D reconstruction. This differential volume rendering can present a 3D structure image of multiple organs volumetrically and clearly for clinical veterinary medicine. This paper shows results of simulation and experimental investigation of small dog and evaluation by veterinarians. (author)

  14. Accuracy and consequences of 3D-fluoroscopy in upper and lower extremity fracture treatment: A systematic review

    International Nuclear Information System (INIS)

    Beerekamp, M.S.H.; Sulkers, George S.I.; Ubbink, Dirk T.; Maas, Mario; Schep, Niels W.L.; Goslings, J. Carel

    2012-01-01

    Objectives: The aim of this systematic review was to compare the diagnostic accuracy, subjective image quality and clinical consequences of 3D-fluoroscopy with standard imaging modalities (2D-fluoroscopy, X-ray or CT) during reduction and fixation of intra-articular upper and lower extremity fractures. Methods: A systematic literature search was performed in MEDLINE, EMBASE and the Cochrane library. In total 673 articles were identified (up to March 2012). The 19 included studies described patients/cadavers with intra-articular upper/lower extremity fractures and compared 3D-fluoroscopy to standard imaging. The study was performed in accordance with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) guidelines. Diagnostic accuracy was defined by the quality of fracture reduction or implant position and, if possible, expressed as sensitivity and specificity; subjective image quality was determined by the quality of depiction of bone or implants; clinical consequences were defined as corrections in reduction or implant position following 3D-fluoroscopy. Results: Ten cadaver- and nine clinical studies were included. A meta-analysis was not possible, because studies used different scoring protocols to express diagnostic accuracy and reported incomplete data. Based on the individual studies, diagnostic accuracy of 3D-fluoroscopy was better than 2D-fluoroscopy and X-ray, but similar to CT-scanning. Subjective image quality of 3D-fluoroscopy was inferior compared to all other imaging modalities. In 11–40% of the operations additional corrections were performed after 3D-fluoroscopy, while the necessity for these corrections were not recognized based on 2D-fluoroscopic images. Conclusions: Although subjective image quality is rated inferior compared to other imaging modalities, intra-operative use of 3D-fluoroscopy is a helpful diagnostic tool for improving the quality of reduction and implant position in intra-articular fractures.

  15. Combined Fluoroscopy- and CT-Guided Transthoracic Needle Biopsy Using a C-Arm Cone-Beam CT System: Comparison with Fluoroscopy-Guided Biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Joo Yeon; Kim, Yoo Kyung; Shim, Sung Shine; Lim, Soo Mee [School of Medicine, Ewha Womans University, Seoul (Korea, Republic of)

    2011-02-15

    The aim of this study was to evaluate the usefulness of combined fluoroscopy- and CT-guided transthoracic needle biopsy (FC-TNB) using a cone beam CT system in comparison to fluoroscopy-guided TNB (F-TNB). We retrospectively evaluated 74 FC-TNB cases (group A) and 97 F-TNB cases (group B) to compare their respective diagnostic accuracies according to the size and depth of the lesion, as well as complications, procedure time, and radiation dose. The sensitivity for malignancy and diagnostic accuracy for small (< 30 mm in size) and deep ({>=} 50 mm in depth) lesions were higher in group A (91% and 94%, 92% and 94%) than in group B (73% and 81%, 84% and 88%), however not statistically significant (p > 0.05). Concerning lesions {>=} 30 mm in size and < 50 mm in depth, both groups displayed similar results (group A, 91% and 92%, 80% and 87%: group B, 90% and 92%, 86% and 90%). Pneumothorax occurred 26% of the time in group A and 14% for group B. The mean procedure time and patient skin dose were significantly higher in group A (13.6 {+-} 4.0 minutes, 157.1 {+-} 76.5 mGy) than in group B (9.0 {+-} 3.5 minutes, 21.9 {+-} 15.2 mGy) (p < 0.05). Combined fluoroscopy- and CT-guided TNB allows the biopsy of small (< 30 mm) and deep lesions ({>=} 50 mm) with high diagnostic accuracy and short procedure times, whereas F-TNB is still a useful method for large and superficial lesions with a low radiation dose

  16. Comparative study between NCRP-49 and NCRP-147 methodologies for shielding calculus to fluoroscopy rooms

    International Nuclear Information System (INIS)

    Ferreira, Christiano Eduardo Martins

    2011-01-01

    The walls of a fluoroscopy room must be shielded to prevent unnecessary exposures to technicians and public individuals. Thus this dissertation aims to describe the methodologies contained in two documents which are references for the calculation of shielding those rooms. They are the National Council on Radiation Protection and Measurements Report No. 49 (NCRP Report No. 49) and No. 147 (NCRP Report No. 147), the latter being more recent publication. And based on such description was made a comparative study between the two methodologies, using for this, as a benchmark, spreadsheets computer program developed by Wolfram Mathematica 6. With that we could reach the final thickness of the barriers to a Standard Plan for a fluoroscopy room (provided by Siemens) and noted that the NCRP-49 presents a methodology with results more conservative. (author)

  17. Evaluation of Kerma rate in the skin entrance in interventional procedures guided by fluoroscopy

    International Nuclear Information System (INIS)

    Medeiros, Regina Bitelli; Alves, Fatima Faloppa Rodrigues; Ruberti Filha, Eny M.

    2005-01-01

    Interventional therapeutic procedures guided by fluoroscopy are responsible for delayed exposure to radiation of professionals and patients. The technology employed on generation of the pulsed fluoroscopy can be an important tool of protection used for reducing the exposure time. It generates constant width and varied frequency pulse or width pulse or varied frequency for a constant frequency. The typical doses into the skin and its relationship with the quality of the images in the various technical and operational conditions should be known by the professionals so that they can optimize them. Generated radiation doses were evaluated using the Toshiba Infinitix equipment used in invasive cardiology procedures and electrophysiological studies through the Kerma rate at the entrance of the patient's skin measured throughout the year of 2004. With these information shall be set out the criteria for the decision of the technical-operational conditions that allow minimizing of dose

  18. Oral versus intravenous premedication for small bowel biopsy in children: effect on procedure and fluoroscopy times.

    Science.gov (United States)

    Stenhammar, L; Wärngård, O; Lewander, P; Nordvall, M

    1993-01-01

    Oral alimemazine and cisapride, or diazepam and cisapride, or iv midazolam and metoclopramide were given as premedication for small bowel biopsy to three groups of children from a total population of 185 individuals. The biopsy procedures were performed under intermittent fluoroscopy and times for both were recorded. The median biopsy procedure time was significantly shorter in children given iv midazolam and metoclopramide (6 min) compared to those given oral premedication (10 min) (p < 0.001). The median fluoroscopy time was very short in all groups, ranging between 3 and 6 s. It is concluded that iv premedication is superior to oral premedication for small bowel biopsy in children because more effective sedation is obtained.

  19. Use of intraoperative fluoroscopy during laparotomy to identify fragments of retained Essure microinserts: case report.

    Science.gov (United States)

    Howard, David L; Christenson, Paul J; Strickland, Julie L

    2012-01-01

    In previous case-reports of Essure microinsert perforation, the microinsert was successfully removed at laparoscopy. Herein is discussed the scenario of persistent pelvic pain over several years after an apparently successful laparoscopic retrieval of a perforating right-sided microinsert. In the interim, the patient underwent 2 unsuccessful exploratory laparotomy procedures in an attempt to retrieve additional microinsert fragments that had perforated the uterus. Successful management of Essure microinsert perforation in this patient ultimately required use of intraoperative fluoroscopy. Surgeons performing laparoscopy or laparotomy to retrieve Essure microinserts that have perforated should be aware that these are not always visible to the naked eye, and there should be a low threshold to use intraoperative fluoroscopy to ensure that all perforating fragments have been removed. Copyright © 2012 AAGL. Published by Elsevier Inc. All rights reserved.

  20. Effectiveness of fluoroscopy-guided intra-articular steroid injection for hip osteoarthritis

    International Nuclear Information System (INIS)

    Subedi, N.; Chew, N.S.; Chandramohan, M.; Scally, A.J.; Groves, C.

    2015-01-01

    Aim: To demonstrate the benefits of fluoroscopy-guided intra-articular steroid injection in the hip with varying degrees of disease severity, and to investigate the financial aspects of the procedure and impact on waiting time. Materials and methods: A prospective study was undertaken of patients who underwent fluoroscopic intra-articular steroid injection over the 9-month study period. Comparative analysis of the Oxford hip pain score pre- and 6–8 weeks post-intra-articular injection was performed. Hip radiographs of all patients were categorised as normal, mild, moderate, or severe disease (four categories) based on the modified Kellgren–Lawrence severity scale, and improvement on the Oxford hip pain score on each of these four severity categories were assessed. Results: Within the study cohort of 100 patients, the mean increase in post-procedure hip score of 7.32 points confirms statistically significant benefits of the therapy (p<0.001, 95% confidence interval: 5.55–9.09). There was no significant difference in pre-injection hip score or change in score between the four severity categories (p=0.51). Significant improvement in hip score (p<0.05) was demonstrated in each of the four severity categories 6–8 weeks post-injection. No associated complications were observed. Conclusion: The present study confirms that fluoroscopy-guided intra-articular steroid injection is a highly effective therapeutic measure for hip osteoarthritis across all grades of disease severity with significant cost savings and the potential to reduce waiting times. - Highlights: • Comparable clinical effectiveness of fluoroscopy guided and theatre based therapeutic intra-articular hip injections. • Significant cost savings on fluoroscopy guided hip injection performed in a radiology department. • A potential reduction in patients' waiting time for the procedure.

  1. Usefulness of fluoroscopy-guided intra-articular injection of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Myung, Jae Sung; Lee, Joon Woo [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Lee, Ji Yeon [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)] (and others)

    2007-06-15

    To determine the accuracy of the intra-articular location of hyaluronic acid injection using a blind approach and to establish the usefulness of fluoroscopy-guided intra-articular injection. A fluoroscopy unit was used for 368 intra-articular injections of hyaluronic acid to 93 knees in 65 patients. Initially, blind needle positioning was conducted on the fluoroscopy table. The failure rate of the blind approach among the 368 injections was evaluated, and a relationship between the Kellgren-Lawrence grade (K-L grade) and the incidence of repeated failures using the blind approach was determined for injections to 52 knees in 37 patients who received a complete cycle of injections (five consecutive injections with a one-week interval between injections). Using a blind approach, 298 of 368 trials (81.2%) resulted in a needle tip being placed in an intra-articular location, while 70 of 368 trials resulted in an extra-articular placement of the needle tip. Among 52 knees to which a complete cycle of injection (five consecutive injections with a one-week interval between injections) was administered, repeated failure of intra-articular placement using the blind approach was seen for 18 knees (34.6%); a more severe K-L grade assigned was associated with a higher rate of repeated failure. However, the trend was not statistically significant based on the Chi-squared test ({rho} value = 0.14). Fluoroscopy-guided needle placement may be helpful to ensure therapeutic intra-articular injection of the knee.

  2. Usefulness of fluoroscopy-guided intra-articular injection of the knee

    International Nuclear Information System (INIS)

    Myung, Jae Sung; Lee, Joon Woo; Lee, Ji Yeon

    2007-01-01

    To determine the accuracy of the intra-articular location of hyaluronic acid injection using a blind approach and to establish the usefulness of fluoroscopy-guided intra-articular injection. A fluoroscopy unit was used for 368 intra-articular injections of hyaluronic acid to 93 knees in 65 patients. Initially, blind needle positioning was conducted on the fluoroscopy table. The failure rate of the blind approach among the 368 injections was evaluated, and a relationship between the Kellgren-Lawrence grade (K-L grade) and the incidence of repeated failures using the blind approach was determined for injections to 52 knees in 37 patients who received a complete cycle of injections (five consecutive injections with a one-week interval between injections). Using a blind approach, 298 of 368 trials (81.2%) resulted in a needle tip being placed in an intra-articular location, while 70 of 368 trials resulted in an extra-articular placement of the needle tip. Among 52 knees to which a complete cycle of injection (five consecutive injections with a one-week interval between injections) was administered, repeated failure of intra-articular placement using the blind approach was seen for 18 knees (34.6%); a more severe K-L grade assigned was associated with a higher rate of repeated failure. However, the trend was not statistically significant based on the Chi-squared test (ρ value = 0.14). Fluoroscopy-guided needle placement may be helpful to ensure therapeutic intra-articular injection of the knee

  3. New ultrasound stone locking system in extracorporeal lithotripsy: Decreased duration of fluoroscopy and radiation doses

    International Nuclear Information System (INIS)

    Abid, N.; Ravier, E.; Codas, R.; Crouzet, S.; Martin, X.

    2013-01-01

    Extracorporeal shock wave lithotripsy is the most common method of treatment for kidney stones. Both fluoroscopy and ultrasound imaging can be used to locate stones, but fluoroscopy is more frequently employed. Evaluation of a new stereotaxic navigational system: the stone was located using an ultrasound probe, and its 3D location was saved. The table automatically moved to position the stone at the focal point. A real-time follow-up was possible during treatment. Our objective was to demonstrate a decrease in the use of fluoroscopy to locate kidney stones for extracorporeal shock wave lithotripsy through the use of a 3D ultrasound stone locking system. Prospective analysis of the case records of the 20 patients preceding and the 20 patients succeeding the arrival of the ultrasound stone locking system Visio-Track (EDAP-TMS). We used a Student test to compare age, BMI, kidney stone size, number of shock waves and administered energy. Patient characteristics were comparable. The average age was 55 years old and the average kidney stone size was 10.7 mm. Radiation duration was 174.8 seconds in the group without Visio-Track versus 57.1 seconds in the group with it (P < 0.0001). A similar result was observed for radiation doses: 5197.25 mGy.cm 2 for the group without versus 1987.6 mGy.cm 2 for the group with Visio-Track (P ≡ 0.0033). The stone locking system Visio-Track reduced fluoroscopy in our first group of patients, which decreased the patient's individual absorbed irradiation dose. (authors)

  4. Fluoroscopy-guided insertion of nasojejunal tubes in children - setting local diagnostic reference levels

    International Nuclear Information System (INIS)

    Vitta, Lavanya; Raghavan, Ashok; Sprigg, Alan; Morrell, Rachel

    2009-01-01

    Little is known about the radiation burden from fluoroscopy-guided insertions of nasojejunal tubes (NJTs) in children. There are no recommended or published standards of diagnostic reference levels (DRLs) available. To establish reference dose area product (DAP) levels for the fluoroscopy-guided insertion of nasojejunal tubes as a basis for setting DRLs for children. In addition, we wanted to assess our local practice and determine the success and complication rates associated with this procedure. Children who had NJT insertion procedures were identified retrospectively from the fluoroscopy database. The age of the child at the time of the procedure, DAP, screening time, outcome of the procedure, and any complications were recorded for each procedure. As the radiation dose depends on the size of the child, the children were assigned to three different age groups. The sample size, mean, median and third-quartile DAPs were calculated for each group. The third-quartile values were used to establish the DRLs. Of 186 procedures performed, 172 were successful on the first attempt. These were performed in a total of 43 children with 60% having multiple insertions over time. The third-quartile DAPs were as follows for each age group: 0-12 months, 2.6 cGy cm 2 ; 1-7 years, 2.45 cGy cm 2 ; >8 years, 14.6 cGy cm 2 . High DAP readings were obtained in the 0-12 months (n = 4) and >8 years (n = 2) age groups. No immediate complications were recorded. Fluoroscopy-guided insertion of NJTs is a highly successful procedure in a selected population of children and is associated with a low complication rate. The radiation dose per procedure is relatively low. (orig.)

  5. Usefulness of CT fluoroscopy-guided percutaneous needle biopsy in the presence of pneumothorax during biopsy

    International Nuclear Information System (INIS)

    O, Dong Hyun; Cho, Young Jun; Park, Yong Sung; Hwang, Cheol Mok; Kim, Keum Won; Kim, Ji Hyung

    2006-01-01

    When pneumothorax occurs during a percutaneous needle biopsy, the radiologist usually stops the biopsy. We evaluated the usefulness of computed tomographic (CT) fluoroscopy-guided percutaneous needle biopsy in the presence of pneumothorax during biopsy. We performed 288 CT fluoroscopy guided percutaneous needle biopsies to diagnose the pulmonary nodules. Twenty two of these patients had pneumothorax that occurred during the biopsy without obtaining an adequate specimen. After pneumothorax occurred, we performed immediate CT fluoroscopy guided percutaneous needle biopsies using an 18-gauge cutting needle. We evaluated the success rate of the biopsies and also whether or not the pneumothorax progressed. We classified these patients into two groups according to whether the pneumothorax progressed (Group 2) or not (Group 1) by measuring the longest distance between the parietal pleura and the visceral pleura both in the early and late pneumothorax. Additionally, we analyzed the relationship between the progression of pneumothorax after biopsy and 1) the depth of the pulmonary nodule; 2) the number of biopsies; 3) the presence or absence of emphysema at the biopsy site; and 4) the size of the pulmonary nodule. Biopsy was successful in 19 of 22 nodules (86.3%). Of the 19 nodules, 12 (63.2%) were malignant and 7 (36.8%) were benign. Twelve patients (54.5%) were classified as group 1 and 10 patients (45.4%) as group 2. The distance between the lung lesion and pleura showed a statistically significant difference between these two groups: ≤ 1 cm in distance for group 1 (81.8%) and group 2 (18.2%), and > 1 cm in distance for group 1 (30%) and group 2 (70%), ρ 0.05). When early pneumothorax occurs during a biopsy, CT fluoroscopy guided percutaneous needle biopsy is an effective and safe procedure. Aggravation of pneumothorax after biopsy is affected by the depth of the pulmonary nodule

  6. Radiological protection in studies of interventionist fluoroscopy; Proteccion radiologica en estudios de fluoroscopia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Juarez R, K.M

    2004-07-01

    The main objective of this study is to determine, if it is necessary or not, to establish appropriate additional procedures of radiological protection for the personal occupationally exposed. The particular objectives are: To evaluate the dose received in different parts of the body, for the personnel occupationally exposed (doctors, technicians and/or nurses) during studies with fluoroscopy. To compare the annual effective dose received by each OEP with the values of the limits settled down by the norms. To recommend protection measures in the event of being necessary. In the chapter 1 an introduction it is presented on the fluoroscopy, the types of studies that are carried out in interventionist fluoroscopy, as well as some characteristics of the equipment, and antecedents of studies carried out so much to patient as to the personnel. The chapter 2 contains the basic concepts of the interaction of the ionizing radiation with the matter, of the dosimetry and of the radiological protection. The characteristics and treatments of the dosemeters, the experimental techniques, devices and used calibration methods, as well as the studies with fluoroscopy and the regions of the body of the OEP for those that the measures of the dose were made are presented in the chapter 3. The chapter 4 contains the such experimental results as the values of the dose, for study in the different parts of the body, for the main doctors, auxiliary and anesthesiologist; the dose, for study, as function of the one time of duration of the study and of the patient's weight, as well as the annual effective dose to whole body, equivalent dose to crystalline, to hands, to feet and to skin, for each doctor and their comparison with the limits. The chapter 5 it contains the conclusions. Finally in the appendix the charts are included of the dose received by the principal doctor, the auxiliary doctor and the anesthesiologist during the carried out studies. (Author)

  7. Percutaneous Transhepatic Catheterization of the Portal Vein: A Combined CT- and Fluoroscopy-Guided Technique

    International Nuclear Information System (INIS)

    Weimar, Bernd; Rauber, Klaus; Brendel, Mathias D.; Bretzel, Reinhard G.; Rau, Wigbert S.

    1999-01-01

    Combined CT- and fluoroscopy-guided transhepatic portal vein catheterization was performed in 44 patients selected for pancreatic islet cell transplantation. The method allowed catheterization with a single puncture attempt in 39 patients. In four patients two attempts and in one patient four attempts were necessary. One minor hematoma of the liver capsule occurred that required no further treatment. Compared with other methods the average number of puncture attempts was reduced

  8. Measurements of surgeons' exposure to ionizing radiation dose during intraoperative use of C-arm fluoroscopy.

    Science.gov (United States)

    Lee, Kisung; Lee, Kyoung Min; Park, Moon Seok; Lee, Boram; Kwon, Dae Gyu; Chung, Chin Youb

    2012-06-15

    Measurement of radiation dose from C-arm fluoroscopy during a simulated intraoperative use in spine surgery. OBJECTIVE.: To investigate scatter radiation doses to specific organs of surgeons during intraoperative use of C-arm fluoroscopy in spine surgery and to provide practical intraoperative guidelines. There have been studies that reported the radiation dose of C-arm fluoroscopy in various procedures. However, radiation doses to surgeons' specific organs during spine surgery have not been sufficiently examined, and the practical intraoperative radioprotective guidelines have not been suggested. Scatter radiation dose (air kerma rate) was measured during the use of a C-arm on an anthropomorphic chest phantom on an operating table. Then, a whole body anthropomorphic phantom was located besides the chest phantom to simulate a surgeon, and scatter radiation doses to specific organs (eye, thyroid, breast, and gonads) and direct radiation dose to the surgeon's hand were measured using 4 C-arm configurations (standard, inverted, translateral, and tube translateral). The effects of rotating the surgeon's head away from the patient and of a thyroid shield were also evaluated. Scatter radiation doses decreased as distance from the patient increased during C-arm fluoroscopy use. The standard and translateral C-arm configurations caused lower scatter doses to sensitive organs than inverted and tube translateral configurations. Scatter doses were highest for breast and lowest for gonads. The use of a thyroid shield and rotating the surgeon's head away from the patient reduced scatter radiation dose to the surgeon's thyroid and eyes. The direct radiation dose was at least 20 times greater than scatter doses to sensitive organs. The following factors could reduce radiation exposure during intraoperative use of C-arm; (1) distance from the patient, (2) C-arm configuration, (3) radioprotective equipments, (4) rotating the surgeons' eyes away from the patient, and (5) avoiding

  9. CT Fluoroscopy-Guided Transsacral Intervertebral Drainage for Pyogenic Spondylodiscitis at the Lumbosacral Junction

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Tomohiro, E-mail: t-matsu@tokai-u.jp; Mine, Takahiko, E-mail: mine@tsc.u-tokai.ac.jp; Hayashi, Toshihiko, E-mail: t.hayashi@tokai.ac.jp [Tokai University School of Medicine, Department of Radiology, Tokai University Hachioji Hospital (Japan); Kamono, Masahiro, E-mail: kamono@tsc.u-tokai.ac.jp; Taoda, Akiko, E-mail: acco@is.icc.u-tokai.ac.jp; Higaki, Megumu, E-mail: higaki@hachioji-hosp.tokai.ac.jp [Tokai University School of Medicine, Department of General Internal Medicine, Tokai University Hachioji Hospital (Japan); Hasebe, Terumitsu, E-mail: hasebe@tokai-u.jp [Tokai University School of Medicine, Department of Radiology, Tokai University Hachioji Hospital (Japan)

    2017-01-15

    PurposeTo retrospectively describe the feasibility and efficacy of CT fluoroscopy-guided transsacral intervertebral drainage for pyogenic spondylodiscitis at the lumbosacral junction with a combination of two interventional radiological techniques—CT-guided bone biopsy and abscess drainage.Materials and methodsThree patients with pyogenic spondylodiscitis at the lumbosacral junction were enrolled in this study between July 2013 and December 2015. The procedure of CT fluoroscopy-guided transsacral intervertebral drainage for pyogenic spondylodiscitis at the lumbosacral junction was as follows: the sacrum at S1 pedicle was penetrated with an 11-gauge (G) bone biopsy needle to create a path for an 8-French (F) pigtail drainage catheter. The bone biopsy needle was withdrawn, and an 18-G needle was inserted into the intervertebral space of the lumbosacral junction. Then, a 0.038-inch guidewire was inserted into the intervertebral space. Finally, the 8-F pigtail drainage catheter was inserted over the guidewire until its tip reached the intervertebral space. All patients received six-week antibiotics treatment.ResultsSuccessful placement of the drainage catheter was achieved for each patient without procedural complications. The duration of drainage was 17–33 days. For two patients, specific organisms were isolated; thus, definitive medical therapy was possible. All patients responded well to the treatment.ConclusionsCT fluoroscopy-guided transsacral intervertebral drainage for pyogenic spondylodiscitis at the lumbosacral junction is feasible and can be effective with a combination of two interventional techniques—CT fluoroscopy-guided bone biopsy and abscess drainage.

  10. Sensitivity of the diagnostic radiological index of protection to procedural factors in fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. Kyle, E-mail: kyle.jones@mdanderson.org [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Pasciak, Alexander S. [Department of Radiology, The University of Tennessee Medical Center at Knoxville, Knoxville, Tennessee 37922 (United States); Wagner, Louis K. [Department of Diagnostic and Interventional Imaging, The John P. and Katharine G. McGovern Medical School, Houston, Texas 77030 (United States)

    2016-07-15

    Purpose: To evaluate the sensitivity of the diagnostic radiological index of protection (DRIP), used to quantify the protective value of radioprotective garments, to procedural factors in fluoroscopy in an effort to determine an appropriate set of scatter-mimicking primary beams to be used in measuring the DRIP. Methods: Monte Carlo simulations were performed to determine the shape of the scattered x-ray spectra incident on the operator in different clinical fluoroscopy scenarios, including interventional radiology and interventional cardiology (IC). Two clinical simulations studied the sensitivity of the scattered spectrum to gantry angle and patient size, while technical factors were varied according to measured automatic dose rate control (ADRC) data. Factorial simulations studied the sensitivity of the scattered spectrum to gantry angle, field of view, patient size, and beam quality for constant technical factors. Average energy (E{sub avg}) was the figure of merit used to condense fluence in each energy bin to a single numerical index. Results: Beam quality had the strongest influence on the scattered spectrum in fluoroscopy. Many procedural factors affect the scattered spectrum indirectly through their effect on primary beam quality through ADRC, e.g., gantry angle and patient size. Lateral C-arm rotation, common in IC, increased the energy of the scattered spectrum, regardless of the direction of rotation. The effect of patient size on scattered radiation depended on ADRC characteristics, patient size, and procedure type. Conclusions: The scattered spectrum striking the operator in fluoroscopy is most strongly influenced by primary beam quality, particularly kV. Use cases for protective garments should be classified by typical procedural primary beam qualities, which are governed by the ADRC according to the impacts of patient size, anatomical location, and gantry angle.

  11. Fluoroscopy-Guided Percutaneous Lung Biopsy: A Valuable Alternative to Computed Tomography

    International Nuclear Information System (INIS)

    Kurban, L.A.; Gomersall, L.; Weir, J.; Wade, P.

    2008-01-01

    Background: Computed tomography (CT) fluoroscopy nowadays is the most preferred method of guidance to perform percutaneous lung biopsy of pulmonary masses. Conventional fluoroscopy is an increasingly forgotten technique that still can be used to perform lung biopsies, with many advantages. Purpose: To compare the accuracy, safety, and effective dose (ED) of conventional fluoroscopy-guided needle lung biopsy (FNLB) with CT-guided needle lung biopsy procedures (CTNLB) reported in the literature. Material and Methods: 100 consecutive patients who underwent FNLB were reviewed retrospectively. Using the final histological diagnoses and the clinical and radiological course of the disease as references, the accuracy and sensitivity of FNLB were calculated. The complication rates of FNLB were assessed. Using computer software (XDOSE), the ED was calculated. The accuracy, complication rates, and the ED of FNLB were compared with CTNLB reported in the literature. Results: The overall accuracy rate and sensitivity of FNLB were both 87%, which are comparable to the range of accuracies reported in the literature for CTNLB (74-97%). The complication rates of FNLB were also comparable to the complication rates reported for CTNLB. The commonest complication was pneumothorax, at a rate of 25%. The ED of FNLB was small, significantly lower than reported in the literature for CT-guided procedures. The mean ED of FNLB was 0.029 mSv, which is approximately equivalent to one chest X-ray. Conclusion: Conventional fluoroscopy is an accurate, safe, and low-dose alternative modality to CT to obtain an image-guided histological diagnosis of pulmonary lesions

  12. [Fluoroscopy dose reduction of computed tomography guided chest interventional radiology using real-time iterative reconstruction].

    Science.gov (United States)

    Hasegawa, Hiroaki; Mihara, Yoshiyuki; Ino, Kenji; Sato, Jiro

    2014-11-01

    The purpose of this study was to evaluate the radiation dose reduction to patients and radiologists in computed tomography (CT) guided examinations for the thoracic region using CT fluoroscopy. Image quality evaluation of the real-time filtered back-projection (RT-FBP) images and the real-time adaptive iterative dose reduction (RT-AIDR) images was carried out on noise and artifacts that were considered to affect the CT fluoroscopy. The image standard deviation was improved in the fluoroscopy setting with less than 30 mA on 120 kV. With regard to the evaluation of artifact visibility and the amount generated by the needle attached to the chest phantom, there was no significant difference between the RT-FBP images with 120 kV, 20 mA and the RT-AIDR images with low-dose conditions (greater than 80 kV, 30 mA and less than 120 kV, 20 mA). The results suggest that it is possible to reduce the radiation dose by approximately 34% at the maximum using RT-AIDR while maintaining image quality equivalent to the RT-FBP images with 120 V, 20 mA.

  13. Equipment performance and radiation protection status in X-ray fluoroscopy units in Sudan

    International Nuclear Information System (INIS)

    Ahmed, N. A.; Nayl, A. I.; Suliman, I. I.

    2012-01-01

    The number of fluoroscopy and fluoroscopically guided procedures has been substantially growing in developing countries at the same time advanced and sophisticated equipment are used in some hospitals. However, radiation protection requirements are not necessarily well adopted. In this study nine fluoroscopy X-ray units in Sudan were examined for compliance with international standards. The tests included: beam quality, entrance surface air kerma, image quality and radiation field measurements. Staff radiation protection tools such as lead aprons and eye glasses were also visually examined to find out whether international recommendations were fulfilled and to determine the level of staff awareness. The measured peak tube voltage deviation exceeded the recommended tolerance level in 30 % of the measurements. The results of patient doses measurements exceeded the recommended reference dose levels in 43 % of the measurements; however image quality and radiation field generally fulfilled the requirements for most units. The study revealed that a considerable number of fluoroscopy units were not performing according to the international standards and highlights the need of optimisation of radiation protection. (authors)

  14. Diagnostic impact of thallium scintigraphy and cardiac fluoroscopy when the exercise ECG is strongly positive

    International Nuclear Information System (INIS)

    Chaitman, B.R.; Brevers, G.; Dupras, G.; Lesperance, J.; Bourassa, M.G.

    1984-01-01

    We studied 83 men, who had a chest pain syndrome, no prior history of myocardial infarction, and exercise-induced horizontal or downsloping ST segment depression greater than or equal to 0.2 mV. The 38 patients unable to complete Bruce stage II had a significant increased risk of coronary (0.97 vs 0.71) and multivessel (0.88 vs 0.61) disease (p less than 0.01) compared to the pretest risk; data obtained from exercise-reperfusion thallium scintigraphy and cardiac fluoroscopy did not alter the risk of coronary or multivessel disease. The 45 patients who had ST depression greater than or equal to 0.2 mV and a peak work capacity greater than or equal to Bruce stage III did not have a significant increased risk of coronary (0.76) or multivessel disease (0.44). When both exercise-reperfusion thallium scintigraphy and cardiac fluoroscopy were abnormal in this latter patient subgroup, the post-test risk of multivessel disease was increased from 0.44 to 0.82 (p less than 0.03); when both tests were normal, none of the patients had multivessel disease (p less than 0.03) and only 0.18 had coronary artery disease. Thus, cardiac fluoroscopy and exercise thallium scintigraphy increase the diagnostic content of the strongly positive exercise ECG, particularly in men who have a peak work capacity greater than or equal to Bruce stage III

  15. A new technique for localization of hepatic tumors that are poorly visible with CT fluoroscopy

    International Nuclear Information System (INIS)

    Arrive, Lionel; Azizi, Louisa; Monnier-Cholley, Laurence; Lewin, Maite; Tubiana, Jean-Michel; Rosmorduc, Olivier; Beaussier, Marc

    2006-01-01

    The purpose of this study was to report a new technique for localization of hepatic tumors that are poorly visible with CT fluoroscopy. Forty-three hepatocellular carcinomas were not visible with CT fluoroscopy. A 22-gauge Chiba end-hole needle was inserted in the approximate location of a lesion estimated on the basis of anatomical landmarks demonstrated on both previous MR and CT images. We injected 3 ml of a mixture of nonionic contrast material and saline solution. Following the first injection, contrast solution filled the hepatic lesion in 29 of 43 cases. In 8 of 43 cases, contrast solution was distributed in the normal surrounding liver. In 7 of these 8 cases, repositioning allowed us to adjust the needle in the tumor. In the other 6 of 43 cases, contrast solution spread within capsule or pseudocapsule (pattern 3). In all 6 cases, repositioning allowed to adjust the needle in the tumor. This new technique allows an accurate localization of hepatic tumors that are poorly visible with CT fluoroscopy. (orig.)

  16. Patient radiation dose during fluoroscopy examinations in a selected hospital in Sudan

    International Nuclear Information System (INIS)

    Darsalih, Abir Abdelrady Elnoor

    2016-04-01

    The purpose of this study was to assess patient radiation dose during fluoroscopy examinations using contrast media in Sudan. Data was collected from the Department of Radiology of the Military Hospital in Omdurman. The quality control tests on the Fluoroscopy machine indicated that it is performing self-consistently. The patient doses were obtained from measurements made using Kerma Area Product (KAP) meter. Measurements were made on sixty patients. The special examinations considered were hysterosalpinogram (HSG), A sanding (A.S), D.Standing (D.S) , Gastrointestinal (G.I) tract and Sinogram. The KAP meter readings obtained were 2.68 ±1.80 mGy.m 2 ; 5.16 ±3.53 mGy.m 2 ; 9.15 ± 3.53 mGy.m 2 ; 5.80 ±6.22 mGy.m 2 and 10.33 ±10.69 mGy.m 2 respectively. Improved patient protection can be achieved by the adoption of standardized and optimized institutional protocols using equipment with an integrated dose management system. The cumulative reference point air-kerma data, along with KAP, should be routinely recorded in the patient records for trend analysis to provide the means to enhance optimization of patient protection in fluoroscopy practice. (au)

  17. CT Fluoroscopy-Guided Core Biopsy for Diagnosis of Small ({<=} 20 mm) Pulmonary Nodules

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hye Larn; Kim, Yoon Kyung; Woo, Ok Hee; Yong, Hwan Seok; Kang, Eun Young [Dept. of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Kim, Hyun Koo [Dept. of Thoracic Surgery, Korea University Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Shin, Bong Kyung [Dept. of Pathology, Korea University Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of)

    2011-10-15

    To evaluate the efficacy of CT fluoroscopy-guided core biopsy of small pulmonary nodules. This study included 62 patients (35 men, 27 women; age range, 36-85 years) that had a small ({<=} 20 mm) pulmonary nodule and underwent CT fluoroscopy-guided core biopsy. The overall diagnostic accuracy and complication rate were calculated. The diagnostic accuracy was compared between two groups according to the nodule size ({<=} 10 mm vs. > 10 mm), and nodule density (solid vs. subsolid). Malignant or premalignant lesions were finally diagnosed in 39 patients; 36 true-positive and three false-negative findings (sensitivity, 92%). A benign lesion was finally diagnosed in 23 patients, with no false-positive results (specificity, 100%). The overall diagnostic accuracy was 95%. The sensitivity and diagnostic accuracy were 85% and 91% for nodules {<=} 10 mm, and 96% and 97% for nodules > 10 mm (p > 0.05). The sensitivity and diagnostic accuracy were 93% and 96% in the solid group and 90% and 92% in the subsolid group (p > 0.05). Seventeen (27%) patients had a pneumothorax and two (3%) required a closed thoracostomy. CT fluoroscopy-guided core biopsy of small pulmonary nodules yields high diagnostic accuracy with acceptable complication rates.

  18. Radiofrequency ablation of hepatocellular carcinoma located in the liver dome under intermittent CT fluoroscopy guidance

    Energy Technology Data Exchange (ETDEWEB)

    Park, Darlene; Cho, Yun Ku; Cho, Hyun Je; KIm, Mi Young [Dept. of Radiology, VHS Medical Center, Seoul (Korea, Republic of)

    2014-02-15

    To evaluate the clinical effectiveness of an intermittent computed tomography (CT) fluoroscopy-guided radiofrequency (RF) ablation of hepatocellular carcinoma located in the liver dome. Between 2005 and 2010 23 patients with hepatocellular carcinoma (HCC) nodules located in the liver dome underwent an intermittent CT fluoroscopy-guided RF ablation. The primary endpoint was the local tumor progression. Procedure-related complications occurred in 3 of 23 patients. To evaluate the prognostic factors for the local tumor progression, univariate and multivariate analyses were performed using the Cox proportional hazards model. The chi-squared test was performed to evaluate the association of access route and procedure-related complication. The study was approved by the Institutional Review Board of our hospital. The Tumor sizes ranged between 1.0 and 2.9 cm. An initial complete ablation was achieved in all patients. The median follow-up period was 31 months and the major complication rate was 4.3%. The cumulative rate of local tumor progression at 3 years was 20%. The univariate analysis revealed that only serum total bilirubin level (p = 0.048) and prior chemoembolization were statistically significant (p = 0.044), but there was no independently significant prognostic factor on multivariate analysis. Procedure-related complications occurred in 3 of 23 patients. For HCC located in the liver dome an intermittent CT fluoroscopy-guided RF ablation could be performed safely and effectively.

  19. Fluoroscopy Learning Curve in Hip Arthroscopy-A Single Surgeon's Experience.

    Science.gov (United States)

    Smith, Kevin M; Duplantier, Neil L; Crump, Kimbelyn H; Delgado, Domenica A; Sullivan, Stephanie L; McCulloch, Patrick C; Harris, Joshua D

    2017-10-01

    To determine if (1) absorbed radiation dose and (2) fluoroscopy time decreased with experience over the first 100 cases of a single surgeon's hip arthroscopy practice. Subjects who underwent hip arthroscopy for symptomatic femoroacetabular impingement and labral injury were eligible for analysis. Inclusion criteria included the first 100 subjects who underwent hip arthroscopy by a single surgeon (December 2013 to December 2014). Subject demographics, procedure details, fluoroscopy absorbed dose (milligray [mGy]), and time were recorded. Subjects were categorized by date of surgery to one of 4 possible groups (25 per group). One-way analysis of variance was used to determine if a significant difference in dose (mGy) or time was present between groups. Simple linear regression analysis was performed to determine the relation between case number and both radiation dose and fluoroscopy time. Subjects underwent labral repair (n = 93), cam osteoplasty (n = 90), and pincer acetabuloplasty (n = 65). There was a significant (P arthroscopy practice learning curve. Level IV, therapeutic, retrospective, noncomparative case series. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  20. Critical analysis of dose reduction trends with special reference to procedures involved in fluoroscopy

    International Nuclear Information System (INIS)

    Anderson, K.; Mattsson, O.

    1985-01-01

    Experiences of a half-year's use of dose-checking instrumentation in fluoroscopy are presented. Radiologists under training succeeded in lowering the patient dose surprisingly well - the diagnostic results remaining unchanged or even improving, because of higher image quality as a result of better diaphragming. Other factors involved in fluoroscopy are discussed. Present systems with heavy bulky intensifiers create problems for close patient contact and for the necessary manipulation, patient adjustment and application of compression. The examination will be simplified and facilitated by the use of a flat image system: proper adjustments need fewer fluoroscopic observations, and patient dose as well as examination time can be saved. Flat display principles will take over the function of the present old-fashioned intensifiers and monitors, either as single units or equipped with TV, video or digital processing accessories. A flat image system, the 'PET-scope', was tested and found to be very convenient for fluoroscopic procedures. The physical properties were studied thoroughly - the high intensification particularly gives these systems an advantage in dose reduction. New applications are possible with these light-weight low-dose units. Fluoroscopy represents a field where considerable contributions to the 'Quality Assurance' trend can be obtained. (author)

  1. A Randomized Comparison Between Ultrasound- and Fluoroscopy-Guided Sacral Lateral Branch Blocks.

    Science.gov (United States)

    Finlayson, Roderick J; Etheridge, John-Paul B; Elgueta, Maria Francisca; Thonnagith, Atikun; De Villiers, Frederick; Nelems, Bill; Tran, De Q

    This randomized trial compared ultrasound (US)- and fluoroscopy-guided sacral lateral branch (SLB) blocks. We hypothesized that US would require a shorter performance time. Forty patients who required unilateral sacral lateral branch blocks for chronic low back pain were randomized to US or fluoroscopy guidance. Before the performance of the assigned block, an investigator who was not involved in patient care carried out baseline analgesic testing. With US, the dorsal sacroiliac ligament, the sacroiliac joint, and the interosseous ligament were probed with a 22-gauge block needle. The patient was asked to rate the level of discomfort using an 11-point numerical rating scale.After the analgesic test, attending anesthesiologists or supervised trainees carried out the SLB blocks. The local anesthetic agent (lidocaine 2%) was identical in all subjects. In the US group, local anesthetic (1.5 mL) was first injected on the lateral crest at the mid-point between S2 and S3. Subsequently, 2 more injections of 0.5 mL were carried out on the lateral crest, immediately cephalad to S2 and at the S1 level. In the fluoroscopy group, SLB blocks were performed according to a previously described 17-injection technique, which involves 9 skin entry sites and the targeting of the L5 posterior root and S1-S3 sacral lateral branches. A 0.4-mL volume of local anesthetic was deposited at each target point. The performance time, number of needle passes, and the incidence of vascular breach were recorded during the performance of the block.Twenty minutes after the end of local anesthetic injection, the same investigator who performed preblock analgesic testing carried out postblock testing in an identical manner. Compared with fluoroscopy, the US technique was associated with a shorter performance time (267.5 ± 99.3 vs 628.7 ± 120.3 seconds; P < 0.001), fewer needle passes and a lower incidence of vascular breach (0 vs 10 occurrences; P = 0.001). However, the block effect (ie, the

  2. Fluoroscopically guided transforaminal epidural steroid injections at a quaternary-care teaching institution: effect of trainee involvement and patient body mass index on fluoroscopy time and patient dose

    International Nuclear Information System (INIS)

    Tiegs-Heiden, C.A.; Murthy, N.S.; Geske, J.R.; Diehn, F.E.; Schueler, B.A.; Wald, J.T.; Kaufmann, T.J.; Lehman, V.T.; Carr, C.M.; Amrami, K.K.; Morris, J.M.; Thielen, K.R.; Maus, T.P.

    2016-01-01

    Aim: To investigate whether there are differences in fluoroscopy time and patient dose for fluoroscopically guided lumbar transforaminal epidural steroid injections (TFESIs) performed by staff radiologists versus with trainees and to evaluate the effect of patient body mass index (BMI) on fluoroscopy time and patient dose, including their interactions with other variables. Materials and methods: Single-level lumbar TFESIs (n=1844) between 1 January 2011 and 31 December 2013 were reviewed. Fluoroscopy time, reference point air kerma (K_a_,_r), and kerma area product (KAP) were recorded. BMI and trainee involvement were examined as predictors of fluoroscopy time, K_a_,_r, and KAP in models adjusted for age and gender in multivariable linear models. Stratified models of BMI groups by trainee presence were performed. Results: Increased age was the only significant predictor of increased fluoroscopy time (p<0.0001). K_a_,_r and KAP were significantly higher in patients with a higher BMI (p<0.0001 and p=0.0009). When stratified by BMI, longer fluoroscopy time predicted increased K_a_,_r and KAP in all groups (p<0.0001). Trainee involvement was not a statistically significant predictor of fluoroscopy time or K_a_,_r in any BMI category. KAP was lower with trainees in the overweight group (p=0.0009) and higher in male patients for all BMI categories (p<0.02). Conclusion: Trainee involvement did not result in increased fluoroscopy time or patient dose. BMI did not affect fluoroscopy time; however, overweight and obese patients received significantly higher K_a_,_r and KAP. Male patients received a higher KAP in all BMI categories. Limiting fluoroscopy time and good collimation practices should be reinforced in these patients. - Highlights: • Trainee involvement did not contribute to increased fluoroscopy time or dose. • BMI did not affect fluoroscopy time. • Overweight and obese patients received significantly higher Ka,r and KAP.

  3. Is There a Relationship Between Body Mass Index and Fluoroscopy Time During Sacroiliac Joint Injection? A Multicenter Cohort Study.

    Science.gov (United States)

    McCormick, Zachary L; Cushman, Daniel; Lee, David T; Scholten, Paul; Chu, Samuel K; Babu, Ashwin N; Caldwell, Mary; Ziegler, Craig; Ashraf, Humaira; Sundar, Bindu; Clark, Ryan; Gross, Claire; Cara, Jeffrey; McCormick, Kristen; Ross, Brendon; Smith, Clark C; Press, Joel; Smuck, Matthew; Walega, David R

    2016-07-01

    To determine the relationship between BMI and fluoroscopy time during intra-articular sacroiliac joint (SIJ) injections performed for a pain indication. Multicenter retrospective cohort study. Three academic, outpatient pain treatment centers. Patients who underwent fluoroscopy guided SIJ injection with encounter data regarding fluoroscopy time during the procedure and body mass index (BMI). Median and 25-75% Interquartile Range (IQR) fluoroscopy time. 459 SIJ injections (350 patients) were included in this study. Patients had a median age of 57 (IQR 44, 70) years, and 72% were female. The median BMI in the normal weight, overweight, and obese groups were 23 (IQR 21, 24), 27 (IQR 26, 29), and 35 (IQR 32, 40), respectively. There was no significant difference in the median fluoroscopy time recorded between these BMI classes (p = 0.45). First-time SIJ injection (p = 0.53), bilateral injection (p = 0.30), trainee involvement (p = 0.47), and new trainee involvement (trainee participation during the first 2 months of the academic year) (p = 0.85) were not associated with increased fluoroscopy time for any of the three BMI categories. Fluoroscopy time during sacroiliac joint injection is not increased in patients who are overweight or obese, regardless of whether a first-time sacroiliac joint injection was performed, bilateral injections were performed, a trainee was involved, or a new trainee was involved. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. PA/Lateral chest X-ray is equivalent to cine-fluoroscopy for the detection of conductor externalization in defibrillation leads.

    Science.gov (United States)

    Steinberg, Christian; Sarrazin, Jean-François; Philippon, François; Champagne, Jean; Molin, Franck; Nault, Isabelle; Blier, Louis; Bouchard, Marc-André; Arsenault, Jean; O'Hara, Gilles

    2015-01-01

    Riata™ and Riata ST defibrillation leads (St. Jude Medical, Sylmar, CA, USA) are susceptible to insulation defects with conductor externalization. Cine-fluoroscopy is considered to be the gold standard for the documentation of insulation defects, but similar detection rates have been reported for posterior-anterior (PA)/lateral chest x-ray (CXR) with zooming. Prospective single-center study to assess the diagnostic equivalence of a PA/lateral CXR with zooming for the detection of Riata insulation defects in a direct comparison to cine-fluoroscopy. Seventy-eight consecutive patients underwent 3-view cine-fluoroscopy and a PA/lateral CXR. All CXRs and cine-fluoroscopy images were reviewed by blinded electrophysiologists and staff radiologists. Forty-four of 78 patients had an abnormal cine-fluoroscopy (56%). The diagnostic correlation between PA/lateral CXR and cine-fluoroscopy was excellent (κ = 0.90; 95% confidence interval 0.80-1.00). PA/lateral CXR was equivalent to cine-fluoroscopy for the detection of conductor externalization showing a sensitivity of 97.7% and a specificity of 91.2%. The mean radiation effective dose of CXR was significantly lower compared to cine-fluoroscopy (0.09 millisievert [mSV] vs 0.85 ± 0.47 mSv; P cine-fluoroscopy for the detection of Riata insulation defects and should be considered as the preferred screening method. ©2014 Wiley Periodicals, Inc.

  5. MO-DE-BRA-04: Hands-On Fluoroscopy Safety Training with Real-Time Patient and Staff Dosimetry

    International Nuclear Information System (INIS)

    Vanderhoek, M; Bevins, N

    2016-01-01

    Purpose: Fluoroscopically guided interventions (FGI) are routinely performed across many different hospital departments. However, many involved staff members have minimal training regarding safe and optimal use of fluoroscopy systems. We developed and taught a hands-on fluoroscopy safety class incorporating real-time patient and staff dosimetry in order to promote safer and more optimal use of fluoroscopy during FGI. Methods: The hands-on fluoroscopy safety class is taught in an FGI suite, unique to each department. A patient equivalent phantom is set on the patient table with an ion chamber positioned at the x-ray beam entrance to the phantom. This provides a surrogate measure of patient entrance dose. Multiple solid state dosimeters (RaySafe i2 dosimetry systemTM) are deployed at different distances from the phantom (0.1, 1, 3 meters), which provide surrogate measures of staff dose. Instructors direct participating clinical staff to operate the fluoroscopy system as they view live fluoroscopic images, patient entrance dose, and staff doses in real-time. During class, instructors work with clinical staff to investigate how patient entrance dose, staff doses, and image quality are affected by different parameters, including pulse rate, magnification, collimation, beam angulation, imaging mode, system geometry, distance, and shielding. Results: Real-time dose visualization enables clinical staff to directly see and learn how to optimize their use of their own fluoroscopy system to minimize patient and staff dose, yet maintain sufficient image quality for FGI. As a direct result of the class, multiple hospital departments have implemented changes to their imaging protocols, including reduction of the default fluoroscopy pulse rate and increased use of collimation and lower dose fluoroscopy modes. Conclusion: Hands-on fluoroscopy safety training substantially benefits from real-time patient and staff dosimetry incorporated into the class. Real-time dose display helps

  6. MO-DE-BRA-04: Hands-On Fluoroscopy Safety Training with Real-Time Patient and Staff Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Vanderhoek, M; Bevins, N [Henry Ford Health System, Detroit, MI (United States)

    2016-06-15

    Purpose: Fluoroscopically guided interventions (FGI) are routinely performed across many different hospital departments. However, many involved staff members have minimal training regarding safe and optimal use of fluoroscopy systems. We developed and taught a hands-on fluoroscopy safety class incorporating real-time patient and staff dosimetry in order to promote safer and more optimal use of fluoroscopy during FGI. Methods: The hands-on fluoroscopy safety class is taught in an FGI suite, unique to each department. A patient equivalent phantom is set on the patient table with an ion chamber positioned at the x-ray beam entrance to the phantom. This provides a surrogate measure of patient entrance dose. Multiple solid state dosimeters (RaySafe i2 dosimetry systemTM) are deployed at different distances from the phantom (0.1, 1, 3 meters), which provide surrogate measures of staff dose. Instructors direct participating clinical staff to operate the fluoroscopy system as they view live fluoroscopic images, patient entrance dose, and staff doses in real-time. During class, instructors work with clinical staff to investigate how patient entrance dose, staff doses, and image quality are affected by different parameters, including pulse rate, magnification, collimation, beam angulation, imaging mode, system geometry, distance, and shielding. Results: Real-time dose visualization enables clinical staff to directly see and learn how to optimize their use of their own fluoroscopy system to minimize patient and staff dose, yet maintain sufficient image quality for FGI. As a direct result of the class, multiple hospital departments have implemented changes to their imaging protocols, including reduction of the default fluoroscopy pulse rate and increased use of collimation and lower dose fluoroscopy modes. Conclusion: Hands-on fluoroscopy safety training substantially benefits from real-time patient and staff dosimetry incorporated into the class. Real-time dose display helps

  7. Fluoroscopy-guided lumbar drainage of cerebrospinal fluid for patients in whom a blind beside approach is difficult

    Energy Technology Data Exchange (ETDEWEB)

    Chee, Choong Guen; Lee, Guen Young; Lee, Joon Woo; Lee, Eu Gene; Kang, Heung Sik [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-08-15

    To evaluate the rates of technical success, clinical success, and complications of fluoroscopy-guided lumbar cerebrospinal fluid drainage. This retrospective study was approved by the Institutional Review Board of our hospital, and informed consent was waived. Ninety-six procedures on 60 consecutive patients performed July 2008 to December 2013 were evaluated. The patients were referred for the fluoroscopy-guided procedure due to failed attempts at a bedside approach, a history of lumbar surgery, difficulty cooperating, or obesity. Fluoroscopy-guided lumbar drainage procedures were performed in the lateral decubitus position with a midline puncture of L3/4 in the interspinous space. The catheter tip was positioned at the T12/L1 level, and the catheter was visualized on contrast agent-aided fluoroscopy. A standard angiography system with a rotatable C-arm was used. The definitions of technical success, clinical success, and complications were defined prior to the study. The technical and clinical success rates were 99.0% (95/96) and 89.6% (86/96), respectively. The mean hospital stay for an external lumbar drain was 4.84 days. Nine cases of minor complications and eight major complications were observed, including seven cases of meningitis, and one retained catheter requiring surgical removal. Fluoroscopy-guided external lumbar drainage is a technically reliable procedure in difficult patients with failed attempts at a bedside procedure, history of lumbar surgery, difficulties in cooperation, or obesity.

  8. Comparison of radiation exposure during fluoroscopy-guided transforaminal epidural steroid injections at different vertebral levels

    International Nuclear Information System (INIS)

    Hwang, Yun Mi; Lee, Min Hee; Kim, Seon Jeong; Shin, Myung Jin; Lee, Sang Hoon; Chung, Hye Won; Lee, Sheen Woo

    2015-01-01

    To estimate and compare radiation exposure during transforaminal fluoroscopy-guided epidural steroid injection (TFESI) at different vertebral levels. Fluoroscopy-guided TFESI was performed in 181 patients. The patients were categorized into three groups according to the injected lumbosacral nerve level of L2-4, L5, or S1. Fluoroscopy time (FT) and dose area product (DAP) were recorded for all patients; correlations between FT and DAP were determined at each level, and both FT and DAP were compared between the different vertebral levels. The numbers of patients who received ESI at L2-4, L5, and S1 were 29, 123, and 29. Mean FT was 44 seconds at L2-4, 33.5 seconds at L5, and 37.7 seconds at S1. Mean DAP was 138.6 microGy.m2 at L2-4, 100.6 microGy.m2 at L5, and 72.1 microGy.m2 at S1. FT and DAP were positively correlated in each group (p values < 0.001). FT was significantly shorter at L5 than that at L2-4 (p = 0.004) but was not significantly different between S1 and L2-4 or L5 (p values = 0.286 and 0.532, respectively). DAP was significantly smaller at L5 and S1 than that at L2-4, but L5 and S1 were not significantly different. After correcting for FT, DAP was significantly smaller at S1 than that at either L2-4 or L5 (p values = 0.001 and 0.010). The radiation dose was small during a single procedure of ESI and showed differences between different lumbosacral spine levels.

  9. Comparison of radiation exposure during fluoroscopy-guided transforaminal epidural steroid injections at different vertebral levels

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yun Mi; Lee, Min Hee; Kim, Seon Jeong; Shin, Myung Jin; Lee, Sang Hoon; Chung, Hye Won [Dept. of Radiology, and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Sheen Woo [Dept. of Radiology, Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2015-04-15

    To estimate and compare radiation exposure during transforaminal fluoroscopy-guided epidural steroid injection (TFESI) at different vertebral levels. Fluoroscopy-guided TFESI was performed in 181 patients. The patients were categorized into three groups according to the injected lumbosacral nerve level of L2-4, L5, or S1. Fluoroscopy time (FT) and dose area product (DAP) were recorded for all patients; correlations between FT and DAP were determined at each level, and both FT and DAP were compared between the different vertebral levels. The numbers of patients who received ESI at L2-4, L5, and S1 were 29, 123, and 29. Mean FT was 44 seconds at L2-4, 33.5 seconds at L5, and 37.7 seconds at S1. Mean DAP was 138.6 microGy.m2 at L2-4, 100.6 microGy.m2 at L5, and 72.1 microGy.m2 at S1. FT and DAP were positively correlated in each group (p values < 0.001). FT was significantly shorter at L5 than that at L2-4 (p = 0.004) but was not significantly different between S1 and L2-4 or L5 (p values = 0.286 and 0.532, respectively). DAP was significantly smaller at L5 and S1 than that at L2-4, but L5 and S1 were not significantly different. After correcting for FT, DAP was significantly smaller at S1 than that at either L2-4 or L5 (p values = 0.001 and 0.010). The radiation dose was small during a single procedure of ESI and showed differences between different lumbosacral spine levels.

  10. A cost effective and high fidelity fluoroscopy simulator using the Image-Guided Surgery Toolkit (IGSTK)

    Science.gov (United States)

    Gong, Ren Hui; Jenkins, Brad; Sze, Raymond W.; Yaniv, Ziv

    2014-03-01

    The skills required for obtaining informative x-ray fluoroscopy images are currently acquired while trainees provide clinical care. As a consequence, trainees and patients are exposed to higher doses of radiation. Use of simulation has the potential to reduce this radiation exposure by enabling trainees to improve their skills in a safe environment prior to treating patients. We describe a low cost, high fidelity, fluoroscopy simulation system. Our system enables operators to practice their skills using the clinical device and simulated x-rays of a virtual patient. The patient is represented using a set of temporal Computed Tomography (CT) images, corresponding to the underlying dynamic processes. Simulated x-ray images, digitally reconstructed radiographs (DRRs), are generated from the CTs using ray-casting with customizable machine specific imaging parameters. To establish the spatial relationship between the CT and the fluoroscopy device, the CT is virtually attached to a patient phantom and a web camera is used to track the phantom's pose. The camera is mounted on the fluoroscope's intensifier and the relationship between it and the x-ray source is obtained via calibration. To control image acquisition the operator moves the fluoroscope as in normal operation mode. Control of zoom, collimation and image save is done using a keypad mounted alongside the device's control panel. Implementation is based on the Image-Guided Surgery Toolkit (IGSTK), and the use of the graphics processing unit (GPU) for accelerated image generation. Our system was evaluated by 11 clinicians and was found to be sufficiently realistic for training purposes.

  11. CT fluoroscopy guided transpleural cutting needle biopsy of small ({<=}2.5 cm) subpleural pulmonary nodules

    Energy Technology Data Exchange (ETDEWEB)

    Prosch, Helmut; Oschatz, Elisabeth; Eisenhuber, Edith; Wohlschlager, Helmut [Otto Wagner Hospital, Department of Radiology, Sanatoriumsstrasse 2, 1140 Vienna (Austria); Mostbeck, Gerhard H., E-mail: gerhard.mostbeck@wienkav.at [Otto Wagner Hospital, Department of Radiology, Sanatoriumsstrasse 2, 1140 Vienna (Austria)

    2011-01-15

    Purpose: Small subpleural pulmonary lesions are difficult to biopsy. While the direct, short needle path has been reported to have a lower rate of pneumothorax, the indirect path provides a higher diagnostic yield. Therefore, we tried to optimize the needle pathway and minimize the iatrogenic pneumothorax risk by evaluating a CT fluoroscopy guided direct approach to biopsy subpleural lesions. Material and methods: Between 01/2005 and 01/2007, CT fluoroscopy guided core biopsies were performed in 24 patients. Using our technique, the tip of the guide needle remains outside the visceral pleura (17 G coaxial guide needle, 18 G Biopsy-gun, 15 or 22 mm needle path). The position of the lesion relative to the needle tip can be optimized using CT fluoroscopy by adjusting the breathing position of the patient. The Biopty gun is fired with the needle tip still outside the pleural space. Cytological smears are analyzed by a cytopathologist on-site, and biopsies are repeated as indicated with the coaxial needle still outside the pleura. Results: Median nodule size was 1.6 cm (0.7-2.3 cm). A definitive diagnosis was obtained in 22 patients by histology and/or cytology. In one patient, only necrotic material could be obtained. In another patient, the intervention had to be aborted as the dyspnoic patient could not follow breathing instructions. An asymptomatic pneumothorax was present in seven patients; chest tube placement was not required. Conclusion: The presented biopsy approach has a high diagnostic yield and is especially advantageous for biopsies of small subpleural lesions in the lower lobes.

  12. Reduction of radiation exposure and image quality using dose reduction tool on computed tomography fluoroscopy

    International Nuclear Information System (INIS)

    Sakabe, Daisuke; Tochihara, Syuichi; Ono, Michiaki; Tokuda, Masaki; Kai, Noriyuki; Nakato, Kengo; Hashida, Masahiro; Funama, Yoshinori; Murazaki, Hiroo

    2012-01-01

    The purpose of our study was to measure the reduction rate of radiation dose and variability of image noise using the angular beam modulation (ABM) on computed tomography (CT) fluoroscopy. The Alderson-Rando phantom and the homemade phantom were used in our study. These phantoms were scanned at on-center and off-center positions at -12 cm along y-axis with and without ABM technique. Regarding the technique, the x-ray tube is turned off in a 100-degree angle sector at the center of 12 o'clock, 10 o'clock, and 2 o'clock positions during CT fluoroscopy. CT fluoroscopic images were obtained with tube voltages, 120 kV; tube current-time product per reconstructed image, 30 mAs; rotation time, 0.5 s/rot; slice thickness, 4.8 mm; and reconstruction kernel B30s in each scanning. After CT scanning, radiation exposure and image noise were measured and the image artifacts were evaluated with and without the technique. The reduction rate for radiation exposure was 75-80% with and without the technique at on-center position regardless of each angle position. In the case of the off-center position at -12 cm, the reduction rate was 50% with and without the technique. In contrast, image noise remained constant with and without the technique. Visual inspection for image artifacts almost have the same scores with and without the technique and no statistical significance was found in both techniques (p>0.05). ABM is an appropriate tool for reducing radiation exposure and maintaining image-noise and artifacts during CT fluoroscopy. (author)

  13. Effectiveness of imaging-guided intra-articular injection: a comparison study between fluoroscopy and ultrasound.

    Science.gov (United States)

    Furtado, Rita Nely Vilar; Pereira, Daniele Freitas; da Luz, Karine Rodrigues; dos Santos, Marla Francisca; Konai, Monique Sayuri; Mitraud, Sonia de Aguiar Vilela; Rosenfeld, Andre; Fernandes, Artur da Rocha Correa; Natour, Jamil

    2013-01-01

    Compare the effectiveness of ultrasound and fluoroscopy to guide intra-articular injections (IAI) in selected cases. A prospective study in our outpatient clinics at the Rheumatology Division at Universidade Federal de São Paulo (UNIFESP), Brazil, was conducted to compare the short-term (4 weeks) effectiveness of ultrasound and fluoroscopy-guided IAI in patients with rheumatic diseases. Inclusion criteria were: adults with refractory synovitis undergoing IAI with glucocorticoid. All patients had IAI performed with triamcinolone hexacetonide (20mg/ml) with varying doses according to the joint injected. A total of 71 rheumatic patients were evaluated (52 women, 44 whites). Mean age was 51.9 ± 13 years and 47 of them (66.2%) were on regular DMARD use. Analysis of the whole sample (71 patients) and hip sub-analysis (23 patients) showed that significant improvement was observed for both groups in terms of pain (P < 0.001). Global analysis also demonstrated better outcomes for patients in the FCG in terms of joint flexion (P < 0.001) and percentage change in joint flexion as compared to the USG. Likert scale score analyses demonstrated better results for the patients in the USG as compared to the FCG at the end of the study (P < 0.05). No statistically significant difference between groups was observed for any other study variable. Imaging-guided IAI improves regional pain in patients with various types of synovitis in the short term. For the vast majority of variables, no significant difference in terms of effectiveness was observed between fluoroscopy and ultrasound guided IAI.

  14. Reduction of Radiation Exposure Using Dynamic Trace Digital Angiography and Spot Fluoroscopy During Adrenal Venous Sampling

    International Nuclear Information System (INIS)

    Morita, Satoru; Endo, Kenji; Suzaki, Shingo; Ishizaki, Umiko; Yamazaki, Hiroshi; Nishina, Yu; Sakai, Shuji

    2017-01-01

    PurposeTo compare radiation exposure of adrenal venous sampling (AVS) using dynamic trace digital angiography (DTDA) and spot fluoroscopy with that using conventional methods.Materials and MethodsAVS was performed in 11 patients using DTDA and spot fluoroscopy (Group A) and 11 patients using conventional digital subtraction angiography (DSA) with collimation (Group B). Radiation exposure and image quality of adrenal venography using a five-point scale were compared between the groups.ResultsThe acquisition dose–area product (DAP) using DTDA and fluoro-DAP using spot fluoroscopy in Group A were lower than those using conventional DSA (5.3 ± 3.7 vs. 29.1 ± 20.1 Gy cm"2, p < 0.001) and collimation (33.3 ± 22.9 vs. 59.1 ± 35.7 Gy cm"2, p = 0.088) in Group B. The total DAP in Group A was significantly lower than that in Group B (38.6 ± 25.9 vs. 88.2 ± 53.6 Gy cm"2, p = 0.006). The peak skin dose for patients and operator radiation exposure in Group A were significantly lower than those in Group B (403 ± 340 vs. 771 ± 416 mGy, p = 0.030, and 17.1 ± 14.8 vs. 36.6 ± 21.7 μSv, p = 0.013). The image quality of DTDA (4.4 ± 0.6) was significantly higher than that of digital angiography (3.8 ± 0.9, p = 0.011) and equivalent to that of DSA (4.3 ± 0.8, p = 0.651).ConclusionsRadiation exposure during AVS can be reduced by approximately half for both patients and operators by using DTDA and spot fluoroscopy without sacrificing image quality.

  15. Ablation of an atriofascicular accessory pathway with a zero-fluoroscopy procedure

    Directory of Open Access Journals (Sweden)

    Riccardo Proietti, MD, PhD

    2015-10-01

    Full Text Available A 16-year-old patient with recurrent palpitations and documented left bundle branch block superior axis wide complex tachycardia underwent an electrophysiological study and ablation with a zero-fluoroscopy procedure. The electrophysiological study showed a decremental antegrade conducting atriofascicular pathway. Three-dimensional CARTO-guided mapping of the tricuspid annulus in sinus rhythm was performed, and a distinct signal corresponding to the accessory pathway potential of the atriofascicular pathway was found in the posterolateral region. By using an SR0 sheath and a 4-mm-tip catheter, radiofrequency application was delivered at this point on the annulus and successfully eliminated conduction through the accessory pathway.

  16. C-arm fluoroscopy: a reliable modality for retrieval of foreign bodies in the maxillofacial region.

    Science.gov (United States)

    Pandyan, Deepak; Nandakumar, N; Qayyumi, Burhanuddin N; Kumar, Santosh

    2013-11-01

    The anatomic complexity of the maxillofacial region makes the retrieval of foreign bodies a daunting task for the maxillofacial Surgeon. Moreover the inability of 2-dimensional imaging to precisely locate foreign bodies makes it challenging. The anatomic proximity of critical structures and esthetic considerations limits the access and thus poses a greater challenge for the surgeon in cases of foreign body retrieval. Hereby we propose a simple technique and a case report to support, the retrieval of small (mobile C arm Fluoroscopy and a needle triangulation method to precisely locate a loosened miniplate screw in the mandibular angle region.

  17. Reduction of Radiation Exposure Using Dynamic Trace Digital Angiography and Spot Fluoroscopy During Adrenal Venous Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Satoru, E-mail: i@imodey.com; Endo, Kenji; Suzaki, Shingo; Ishizaki, Umiko; Yamazaki, Hiroshi; Nishina, Yu; Sakai, Shuji [Tokyo Women’s Medical University Hospital, Department of Diagnostic Imaging and Nuclear Medicine (Radiology) (Japan)

    2017-05-15

    PurposeTo compare radiation exposure of adrenal venous sampling (AVS) using dynamic trace digital angiography (DTDA) and spot fluoroscopy with that using conventional methods.Materials and MethodsAVS was performed in 11 patients using DTDA and spot fluoroscopy (Group A) and 11 patients using conventional digital subtraction angiography (DSA) with collimation (Group B). Radiation exposure and image quality of adrenal venography using a five-point scale were compared between the groups.ResultsThe acquisition dose–area product (DAP) using DTDA and fluoro-DAP using spot fluoroscopy in Group A were lower than those using conventional DSA (5.3 ± 3.7 vs. 29.1 ± 20.1 Gy cm{sup 2}, p < 0.001) and collimation (33.3 ± 22.9 vs. 59.1 ± 35.7 Gy cm{sup 2}, p = 0.088) in Group B. The total DAP in Group A was significantly lower than that in Group B (38.6 ± 25.9 vs. 88.2 ± 53.6 Gy cm{sup 2}, p = 0.006). The peak skin dose for patients and operator radiation exposure in Group A were significantly lower than those in Group B (403 ± 340 vs. 771 ± 416 mGy, p = 0.030, and 17.1 ± 14.8 vs. 36.6 ± 21.7 μSv, p = 0.013). The image quality of DTDA (4.4 ± 0.6) was significantly higher than that of digital angiography (3.8 ± 0.9, p = 0.011) and equivalent to that of DSA (4.3 ± 0.8, p = 0.651).ConclusionsRadiation exposure during AVS can be reduced by approximately half for both patients and operators by using DTDA and spot fluoroscopy without sacrificing image quality.

  18. Value of Examination Under Fluoroscopy for the Assessment of Sacroiliac Joint Dysfunction.

    Science.gov (United States)

    Eskander, Jonathan P; Ripoll, Juan G; Calixto, Frank; Beakley, Burton D; Baker, Jeffrey T; Healy, Patrick J; Gunduz, O H; Shi, Lizheng; Clodfelter, Jamie A; Liu, Jinan; Kaye, Alan D; Sharma, Sanjay

    2015-01-01

    Pain emanating from the sacroiliac (SI) joint can have variable radiation patterns. Single physical examination tests for SI joint pain are inconsistent with multiple tests increasing both sensitivity and specificity. To evaluate the use of fluoroscopy in the diagnosis of SI joint pain. Prospective double blind comparison study. Pain clinic and radiology setting in urban Veterans Administration (VA) in New Orleans, Louisiana. Twenty-two adult men, patients at a southeastern United States VA interventional pain clinic, presented with unilateral low back pain of more than 2 months' duration. Patients with previous back surgery were excluded from the study. Each patient was given a Gapping test, Patrick (FABERE) test, and Gaenslen test. A second blinded physician placed each patient prone under fluoroscopic guidance, asking each patient to point to the most painful area. Pain was provoked by applying pressure with the heel of the palm in that area to determine the point of maximum tenderness. The area was marked with a radio-opaque object and was placed on the mark with a fluoroscopic imgage. A site within 1 cm of the SI joint was considered as a positive test. This was followed by a diagnostic injection under fluoroscopy with 1 mL 2% lidocaine. A positive result was considered as more than 2 hours of greater than 75% reduction in pain. Then, in 2-3 days this was followed by a therapeutic injection under fluoroscopy with 1 mL 0.5% bupivacaine and 40 mg methylprednisolone. Each patient was reassessed after 6 weeks. The sensitivity and specificity in addition to the positive and negative predictive values were determined for both the conventional examinations, as well as the examination under fluoroscopy. Finally, a receiver operating characteristic (ROC) curve was constructed to evaluate test performance. The sensitivity and specificity of the fluoroscopic examination were 0.82 and 0.80 respectively; Positive predictive value and negative predictive value were 0.93 and

  19. Fluoroscopy time - an overestimated factor for patient radiation exposure in invasive cardiology

    International Nuclear Information System (INIS)

    Kuon, E.; Robinson, D.M.; Empen, K.; Dahm, J.B.

    2005-01-01

    Purpose: to analyze the effects of an optimized fluoroscopy time on patient radiation exposure in the course of coronary angiography (CA) and percutaneous coronary interventions (PTCA), in comparison to those with consistent collimation to the region of interest (ROI). Furthermore, to analyze efforts concerning reduction of radiographic frames as well as concerning adequate instead of best possible image quality. Material and methods: for 3,115 elective CAs and 1,713 PTCA performed by one interventionist since 1997, we documented the radiographic dose-area products (DAP R ) and fluoroscopic dose-area products (DAP F ), the number of radiographic frames and the fluoroscopy times during selected 2-month intervals. Under conditions of constant image intensifier entrance dose, levels of DAP R /frame and DAP F /s represent valid parameters for consistent collimation. Results: in 1997, the mean baseline values of DAP for elective CA and PTCA amounted to 37.1 and 31.6 Gy x cm 2 , respectively. A reduction of mean fluoroscopy times from 264 to 126 seconds for CA and from 630 to 449 seconds for PCI, both resulted in an overall DAP-reduction of merely 20%. Optimization of mean radiographic frames from 543 to 98 for CA and from 245 to 142 for PTCA enabled reductions of 53 and 13%, respectively. By restriction to adequate instead of best-possible image quality for coronary angiography in clinical routine, we achieved an optimized radiographic DAP/frame of 30.3 to 13.3 mGy x cm 2 , which enabled a 45% reduction of overall DAP. Most efficient however was a consistent collimation to the ROI, which resulted in a remarkable radiation reduction by 46% for CA and by 65% for PTCA. Conclusions: radiation-reducing educational efforts in the clinical routine of invasive cardiology should - against widely held opinion - focus less exclusively toward a reduction of fluoroscopy time but more efficiently toward consistent collimation to the region of interest, reduction of radiographic

  20. Tuberculosis Fluoroscopy

    Science.gov (United States)

    Follow-up though Dec 31, 2002 has been completed for a study of site-specific cancer mortality among tuberculosis patients treated with artificial lung collapse therapy in Massachusetts tuberculosis sanatoria (1930-1950).

  1. Radiologic evaluation of adenoids and tonsils in children with obstructive sleep apnea: Plain films and fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kreplick Fernbach, S.; Brouillette, T.; Riggs, T.W.; Hunt, C.E.

    1983-07-01

    Twenty-six children with obstructive sleep apnea were evaluated by lateral neck radiographs during wakefulness, and by polygraphic monitoring and upper airway fluoreoscopy during natural sleep. Children with craniofacial abnormalities, palatal surgery, and central nervous system disease were excluded from the study. Moderate or marked enlargement of tonsils and adenoids was noted on lateral neck radiographs of 18 of 26 patients. An objective measure of adenoidal enlargement, the adenoidal-nasopharyngeal ratio, correlated well with subjective judgment of adenoidal size but was not generally more useful than subjective estimation. Upper airway fluroescopy demonstrated the site and mechanism of obstruction in all patients. Because all children with moderate to marked adenotonsillar enlargement demonstrated obstruction at the adenoidal or tonsillar level on fluoroscopy, we now screen children with suspected sleep apnea with lateral airway radiographs and polysomnography. Fluoroscopy is reserved for children with mild adenotosillar enlargement, craniofacial dysplasia, prior cleft palate repair, or neuromuscular disorders. These results suggest that the pathogenesis of obstuctive sleep apnea in children involve anatomic factors which narrow the upper airway, sleep-related hypotonia of pharyngeal dilator musculature, and compensatory mechanisms to prevent or alleviate asphyxia.

  2. Radiologic evaluation of adenoids and tonsils in children with obstructive sleep apnea: Plain films and fluoroscopy

    International Nuclear Information System (INIS)

    Kreplick Fernbach, S.; Brouillette, T.; Riggs, T.W.; Hunt, C.E.

    1983-01-01

    Twenty-six children with obstructive sleep apnea were evaluated by lateral neck radiographs during wakefulness, and by polygraphic monitoring and upper airway fluoreoscopy during natural sleep. Children with craniofacial abnormalities, palatal surgery, and central nervous system disease were excluded from the study. Moderate or marked enlargement of tonsils and adenoids was noted on lateral neck radiographs of 18 of 26 patients. An objective measure of adenoidal enlargement, the adenoidal-nasopharyngeal ratio, correlated well with subjective judgment of adenoidal size but was not generally more useful than subjective estimation. Upper airway fluroescopy demonstrated the site and mechanism of obstruction in all patients. Because all children with moderate to marked adenotonsillar enlargement demonstrated obstruction at the adenoidal or tonsillar level on fluoroscopy, we now screen children with suspected sleep apnea with lateral airway radiographs and polysomnography. Fluoroscopy is reserved for children with mild adenotosillar enlargement, craniofacial dysplasia, prior cleft palate repair, or neuromuscular disorders. These results suggest that the pathogenesis of obstuctive sleep apnea in children involve anatomic factors which narrow the upper airway, sleep-related hypotonia of pharyngeal dilator musculature, and compensatory mechanisms to prevent or alleviate asphyxia. (orig.)

  3. Evaluation of the dosimetric performance characteristic of fluoroscopy system used in medicine

    International Nuclear Information System (INIS)

    Qi Xuesong; Wei Kedao; Cheng Yuxi; Zhou Qifu; Ge Lijuan; Hou Changsong

    2001-01-01

    Objective: To discuss establishment of diagnostic reference dose value in fluoroscopic examinations for survey of 16 different types of fluoroscopy systems. Methods: Choosing dosimetric characteristic parameters including: IIESDR, ESDR (typical value) and ESDR max (ESDR maximum), and DAP, which was calibrated in situ on the X-ray unit. Results: Results of dose survey are summarized in three tables, from these we could get wide changes in accordance with those in many other countries resulting from maximum and minimum of IIESDR, ESDR and ESDRmax when measurements were performed at same entrance field size on I.I. Image Intensifier of the 15 fluoroscopy systems and under conditions of ABC. And also we could get less changes of DAP mean values, though differences for patient weight, technological parameters of fluoroscopic exam setting, fluoroscopic time and number of film were more remarkable. Conclusions: Measurements on IIESDR, ESDR (typical value) and ESDRmax (ESDR maximum) are not satisfied as diagnostic reference level. But it is suggested that DAP values, in fluoroscopic exam, are used as a tool to achieve this. (author)

  4. Management of pediatric radiation dose using Philips fluoroscopy systems DoseWise: perfect image, perfect sense

    International Nuclear Information System (INIS)

    Stueve, Dick

    2006-01-01

    Although image quality (IQ) is the ultimate goal for accurate diagnosis and treatment, minimizing radiation dose is equally important. This is especially true when pediatric patients are examined, because their sensitivity to radiation-induced cancer is two to three times greater than that of adults. DoseWise is an ALARA-based philosophy within Philips Medical Systems that is active at every level of product design. It encompasses a set of techniques, programs and practices that ensures optimal IQ while protecting people in the X-ray environments. DoseWise methods include management of the X-ray beam, less radiation-on time and more dose information for the operator. Smart beam management provides automatic customization of the X-ray beam spectrum, shape, and pulse frequency. The Philips-patented grid-controlled fluoroscopy (GCF) provides grid switching of the X-ray beam in the X-ray tube instead of the traditional generator switching method. In the examination of pediatric patients, DoseWise technology has been scientifically documented to reduce radiation dose to <10% of the dose of traditional continuous fluoroscopy systems. The result is improved IQ at a significantly lower effective dose, which contributes to the safety of patients and staff. (orig.)

  5. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, R.; McCarty, M. [Div. of Radiology, South Cleveland Hospital, South Tees Acute Hospitals NHS Trust, Marton Road, Middlesbrough, Cleveland (United Kingdom); McCallum, H.M. [Regional Medical Physics Dept., South Cleveland Hospital, Middlesbrough (United Kingdom); Montgomery, R. [Dept. of Orthopaedics, South Tees Hospitals NITS Trust, Middlesbrough (United Kingdom); Aszkenasy, M. [Tees and North East Yorkshire NHS Trust, West Lane Hospital, Middlesbrough (United Kingdom)

    2001-05-01

    Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

  6. Radiation protection for an intraoperative X-ray source compared to C-arm fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Frank; Clausen, Sven; Jahnke, Anika; Steil, Volker; Wenz, Frederik [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Radiation Oncology; Bludau, Frederic; Obertacke, Udo [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Trauma Surgery; Suetterlin, Marc [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Obstetrics and Gynaecology

    2014-10-01

    Background: Intraoperative radiotherapy (IORT) using the INTRABEAM {sup registered} system promises a flexible use regarding radiation protection compared to other approaches such as electron treatment or HDR brachytherapy with {sup 192}Ir or {sup 60}Co. In this study we compared dose rate measurements of breast- and Kypho-IORT with C-arm fluoroscopy which is needed to estimate radiation protection areas. Materials and Methods: C-arm fluoroscopy, breast- and Kypho-IORTs were performed using phantoms (silicon breast or bucket of water). Dose rates were measured at the phantom's surface, at 30 cm, 100 cm and 200 cm distance. Those measurements were confirmed during 10 Kypho-IORT and 10 breast-IORT patient treatments. Results: The measured dose rates were in the same magnitude for all three paradigms and ranges from 20 μSv/h during a simulated breast-IORT at two meter distance up to 64 mSv/h directly at the surface of a simulated Kypho-IORT. Those measurements result in a circle of controlled area (yearly doses > 6 mSv) for each paradigm of about 4 m ± 2 m. Discussion/Conclusions: All three paradigms show comparable dose rates which implies that the radiation protection is straight forward and confirms the flexible use of the INTRABEAM {sup registered} system. (orig.)

  7. Results and complications of CT-guided biopsy with CT fluoroscopy

    International Nuclear Information System (INIS)

    Saika, Yoshinori; Ogura, Yasuharu; Doi, Kenji; Misaki, Toshimasa; Shimizu, Masashi; Narabayashi, Isamu

    2002-01-01

    We studied the results and complications of CT-guided biopsy with CT fluoroscopy performed 66 lesions in 64 patients from March 1999 to February 2001. In addition to the conventional procedure of CT-guided biopsy, we use CT fluoroscopy for confirmation of the location of the tip of the biopsy needle and the accurate contact, in some cases, at the time of puncturing. Examination results showed malignancy in 36 lesions and benign findings in 30 lesions. The sensitivity was 85.7%, specificity was 100.0%, and accuracy was 90.9%. Pneumothorax occurred in 20 out of 64 patients (31.3%). In a study on 26 small lesions (≤2 cm) in 25 patients, the sensitivity was 81.8%, specificity was 100.0%, accuracy was 92.3%. Pneumothorax occurred in 12 out of 25 patients (48.0%), more frequently than in patients with large lesions. In a study on 6 false negative cases, they tended to be intrapulmonary on location, small in diameter, and far from the skin puncture point. Examination results were satisfactory, especially in terms of accuracy in small lesions (≤2 cm). However, when the lesions were small, pneumothorax occurred frequently (48.0%). (author)

  8. Using biplanar fluoroscopy to guide radiopaque vascular injections: a new method for vascular imaging.

    Directory of Open Access Journals (Sweden)

    Haley D O'Brien

    Full Text Available Studying vascular anatomy, especially in the context of relationships with hard tissues, is of great interest to biologists. Vascular studies have provided significant insight into physiology, function, phylogenetic relationships, and evolutionary patterns. Injection of resin or latex into the vascular system has been a standard technique for decades. There has been a recent surge in popularity of more modern methods, especially radiopaque latex vascular injection followed by CT scanning and digital "dissection." This technique best displays both blood vessels and bone, and allows injections to be performed on cadaveric specimens. Vascular injection is risky, however, because it is not a standardizable technique, as each specimen is variable with regard to injection pressure and timing. Moreover, it is not possible to view the perfusion of injection medium throughout the vascular system of interest. Both data and rare specimens can therefore be lost due to poor or excessive perfusion. Here, we use biplanar video fluoroscopy as a technique to guide craniovascular radiopaque latex injection. Cadaveric domestic pigs (Sus scrofa domestica and white-tailed deer (Odocoileus virginianus were injected with radiopaque latex under guidance of fluoroscopy. This method was found to enable adjustments, in real-time, to the rate, location, and pressure at which latex is injected in order to avoid data and specimen loss. In addition to visualizing the injection process, this technique can be used to determine flow patterns, and has facilitated the development of consistent markers for complete perfusion.

  9. Percutaneous Extraction of Cement Leakage After Vertebroplasty Under CT and Fluoroscopy Guidance: A New Technique

    International Nuclear Information System (INIS)

    Amoretti, Nicolas; Huwart, Laurent

    2012-01-01

    Purpose: We report a new minimally invasive technique of extraction of cement leakage following percutaneous vertebroplasty in adults. Methods: Seven adult patients (five women, two men; mean age: 81 years) treated for vertebral compression fractures by percutaneous vertebroplasty had cement leakage into perivertebral soft tissues along the needle route. Immediately after vertebroplasty, the procedure of extraction was performed under computed tomography (CT) and fluoroscopy guidance: a Chiba needle was first inserted using the same route as the vertebroplasty until contact was obtained with the cement fragment. This needle was then used as a guide for an 11-gauge Trocar t’am (Thiebaud, France). After needle withdrawal, a 13-gauge endoscopy clamp was inserted through the cannula to extract the cement fragments. The whole procedure was performed under local anesthesia. Results: In each patient, all cement fragments were withdrawn within 10 min, without complication. Conclusions: This report suggests that this CT- and fluoroscopy-guided percutaneous technique of extraction could reduce the rate of cement leakage-related complications.

  10. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy.

    Science.gov (United States)

    Waugh, R; McCallum, H M; McCarty, M; Montgomery, R; Aszkenasy, M

    2001-05-01

    An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83%, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving.

  11. Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

    International Nuclear Information System (INIS)

    Waugh, R.; McCarty, M.; McCallum, H.M.; Montgomery, R.; Aszkenasy, M.

    2001-01-01

    Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

  12. Medical imaging using ionizing radiation: Optimization of dose and image quality in fluoroscopy

    International Nuclear Information System (INIS)

    Jones, A. Kyle; Balter, Stephen; Rauch, Phillip; Wagner, Louis K.

    2014-01-01

    The 2012 Summer School of the American Association of Physicists in Medicine (AAPM) focused on optimization of the use of ionizing radiation in medical imaging. Day 2 of the Summer School was devoted to fluoroscopy and interventional radiology and featured seven lectures. These lectures have been distilled into a single review paper covering equipment specification and siting, equipment acceptance testing and quality control, fluoroscope configuration, radiation effects, dose estimation and measurement, and principles of flat panel computed tomography. This review focuses on modern fluoroscopic equipment and is comprised in large part of information not found in textbooks on the subject. While this review does discuss technical aspects of modern fluoroscopic equipment, it focuses mainly on the clinical use and support of such equipment, from initial installation through estimation of patient dose and management of radiation effects. This review will be of interest to those learning about fluoroscopy, to those wishing to update their knowledge of modern fluoroscopic equipment, to those wishing to deepen their knowledge of particular topics, such as flat panel computed tomography, and to those who support fluoroscopic equipment in the clinic

  13. 2D-3D Registration of CT Vertebra Volume to Fluoroscopy Projection: A Calibration Model Assessment

    Directory of Open Access Journals (Sweden)

    P. Bifulco

    2010-01-01

    Full Text Available This study extends a previous research concerning intervertebral motion registration by means of 2D dynamic fluoroscopy to obtain a more comprehensive 3D description of vertebral kinematics. The problem of estimating the 3D rigid pose of a CT volume of a vertebra from its 2D X-ray fluoroscopy projection is addressed. 2D-3D registration is obtained maximising a measure of similarity between Digitally Reconstructed Radiographs (obtained from the CT volume and real fluoroscopic projection. X-ray energy correction was performed. To assess the method a calibration model was realised a sheep dry vertebra was rigidly fixed to a frame of reference including metallic markers. Accurate measurement of 3D orientation was obtained via single-camera calibration of the markers and held as true 3D vertebra position; then, vertebra 3D pose was estimated and results compared. Error analysis revealed accuracy of the order of 0.1 degree for the rotation angles of about 1 mm for displacements parallel to the fluoroscopic plane, and of order of 10 mm for the orthogonal displacement.

  14. An evaluation of the fluoroscopy-guided percutaneous gastrostomy with the pull technique

    International Nuclear Information System (INIS)

    Uhm, Chang Wook; Won, Jong Yun; Yu, Jeong Sik; Ko, Heung Kyu; Lee, Kwang Hun; Lee, Do Yun; Lee, Jong Tae

    2008-01-01

    To evaluate the safety and usefulness of the fluoroscopy-guided percutaneous gastrostomy (FPG) using a large profile gastrostomy tube accompanied with the pull technique, and without the use of an endoscopy or a gastropexy. From March 2005 to February 2007, 25 patients underwent an FPG using a large profile gastrostomy tube accompanied by the pull technique, in which a 24F pull-type tube was inserted into a patient's mouth and was pulled to the upper abdominal puncture site using a snare, under fluoroscopy. The 18 patients with difficulty swallowing due to muscular atrophic lateral sclerosis or transitional myodystrophy included 5 cases of quadriplegia, 1 case of Parkinson's disease, and 1 metastatic mediastinal tumor. The technical success rate, occurrence of complications, and clinical outcomes were examined. The technical success rate was found to be 100%. In addition, the retention periods for the indwelling tube ranged from 1 to 24 months (mean: 6.5 months), with all tubes retained at a normal position with normal function. No procedure-related mortality occurred. One patient (4%) did however develop a complication in the form of ascites and ascitic fluid leakage around the tube, which was of hepatic origin and was ultimately resolved after the drainage of ascites. As a result of this study the FPG, accompanied with the pull technique using a 24F tube, should be considered as a safe and effective method for examining patients. It was found to have a high success rate and a low complication rate

  15. Fluoroscopy-guided balloon dilation in patients with Eustachian tube dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun Yung; Tsauo, Jiaywei; Song, Ho-Young [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Park, Hong Ju; Kang, Woo Seok [University of Ulsan College of Medicine, Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, Seoul (Korea, Republic of); Park, Jung-Hoon [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); University of Ulsan College of Medicine, Department of Biomedical Engineering Research Center, Asan Medical Center, Seoul (Korea, Republic of); Wang, Zhe [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Tianjin Medical University General Hospital, Department of Radiology (China)

    2018-03-15

    To prospectively evaluate the technical feasibility and safety of fluoroscopy-guided balloon dilation in patients with Eustachian tube (ET) dysfunction. Patients who could not do a Valsalva manoeuvre for more than 6 months and diagnosed with chronic otitis media or ET dysfunction were prospectively enrolled. A 0.035-in. guide wire and 6-mm long balloon catheter with a diameter of 2 mm were used to dilate the cartilaginous portion of the ET under fluoroscopic guidance. The balloon was inflated by manual injection twice for 1 min each time. Clinical outcomes were assessed by the patient's ability to perform a Valsalva manoeuvre, and symptoms were assessed using the 7-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7) score. Balloon dilation was attempted in a total of ten adult patients from October 2016 to March 2017. Technical success was achieved in all procedures (10/10). Ninety percent (9/10) of the balloons were fully dilated without waist deformity. There were no major complications. All patients were able to perform a Valsalva manoeuvre at the time of their last visit and/or improvement of at least one ETDQ-7 score. Fluoroscopy-guided balloon dilation seems to be technically feasible and safe in the treatment of ET dysfunction. (orig.)

  16. X-ray fluoroscopy spatio-temporal filtering with object detection

    International Nuclear Information System (INIS)

    Aufrichtig, R.; Wilson, D.L.; University Hospitals of Cleveland, OH

    1995-01-01

    One potential way to reduce patient and staff x-ray fluoroscopy dose is to reduce the quantum exposure to the detector and compensate the additional noise with digital filtering. A new filtering method, spatio-temporal filtering with object detection, is described that reduces noise while minimizing motion and spatial blur. As compared to some conventional motion-detection filtering schemes, this object-detection method incorporates additional a priori knowledge of image content; i.e. much of the motion occurs in isolated long thin objects (catheters, guide wires, etc.). The authors create object-likelihood images and use these to control spatial and recursive temporal filtering such as to reduce blurring the objects of interest. They use automatically computed receiver operating characteristic (ROC) curves to optimize the object-likelihood enhancement method and determine that oriented matched filter kernels with 4 orientations are appropriate. The matched filter kernels are simple projected cylinders. The authors demonstrate the method on several representative x-ray fluoroscopy sequences to which noise is added to simulate very low dose acquisitions. With processing, they find that noise variance is significantly reduced with slightly less noise reduction near moving objects. They estimate an effective exposure reduction greater than 80%

  17. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    Energy Technology Data Exchange (ETDEWEB)

    Salleh, H.; Matori, M. K.; Isa, M. J. M. [Agensi Nuklear Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Samat, S. B. [Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

  18. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    International Nuclear Information System (INIS)

    Salleh, H.; Matori, M. K.; Isa, M. J. M.; Samat, S. B.

    2015-01-01

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube

  19. Evaluation of percutaneous vertebroplasty in osteoporotic vertebral fractures using a combination of CT fluoroscopy and conventional lateral fluoroscopy; Perkutane Vertebroplastie osteoporosebedingter Wirbelkoerperfrakturen: Erfahrungen mit der CT-Fluoroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Pitton, M.B.; Schneider, J.; Brecher, B.; Herber, S.; Mohr, W.; Thelen, M. [Klinik fuer Radiologie, Universitaetskliniken Mainz (Germany); Drees, P.; Eckardt, A.; Heine, J. [Klinik fuer Orthopaedie, Universitaetskliniken Mainz (Germany)

    2004-07-01

    Purpose: Evaluation of vertebroplasty using a combination of CT-fluoroscopy and conventional lateral fluoroscopy in patients with osteoporotic vertebral fractures. Materials and Methods: Fifty-eight patients (23male, 35 women, age 69.7 {+-} 10.2 years) with painful osteoporotic vertebral fractures were treated with vertebroplasty in conscious sedation and local anesthesia. Spiral-CT with sagittal reconstructions of the respective vertebral bodies was used for classification of the fracture. The cannula was placed under CT-guidance in the ventral third of the respective vertebral bodies and cement instilled under CT fluoroscopy and lateral fluoroscopy. When cement migrated towards the vertebral canal, the injection was immediately stopped for 30-60 seconds. After polymerization in this location, the injection was continued until sufficient filling of the vertebra. Results were documented by spiral CT with sagittal reconstructions. Results: A total of 123 vertebral bodies were treated, comprising 39 thoracic and 84 lumbar vertebral bodies, with a mean of 2.1 {+-} 1.3 (range 1 to 6) vertebral bodies in each patient and a maximum of 3 vertebral bodies per session. All interventions were successfully completed in conscious sedation and local anesthesia. A mean volume of 5.9 {+-} 0.6 ml (range 2 to 14 ml) cement was applied for each vertebra, with 79.7% of procedures performed using a unilateral access. To achieve a sufficient cement deposit, a bilateral access was used in 20.3%. The dorsal wall of the vertebra was included in 23.6% of the fractures. In one case, cement migration into the spinal canal was detected, reducing the diameter of the canal by 30%. In two other cases, cement leakage was seen at the puncture site of the vertebra (one intercostotransversally in the 10{sup th} thoracic vertebra and one dorsolaterally in the 1{sup st} lumbar vertebra) with retrograde cement migration through the neuroforamen into the epidural space. In one of these cases, the

  20. Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

    Energy Technology Data Exchange (ETDEWEB)

    Zanca, F., E-mail: Federica.Zanca@med.kuleuven.be [Department of Radiology, Leuven University Center of Medical Physics in Radiology, UZ Leuven, Herestraat 49, 3000 Leuven, Belgium and Imaging and Pathology Department, UZ Leuven, Herestraat 49, Box 7003 3000 Leuven (Belgium); Jacobs, A. [Department of Radiology, Leuven University Center of Medical Physics in Radiology, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium); Crijns, W. [Department of Radiotherapy, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium); De Wever, W. [Imaging and Pathology Department, UZ Leuven, Herestraat 49, Box 7003 3000 Leuven, Belgium and Department of Radiology, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium)

    2014-07-15

    Purpose: To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations. Methods: Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure. Results: The median measured MSD was 141 mGy (range 38–410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24–262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12–4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size. Conclusions: On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure.

  1. Deformable 3D–2D registration for CT and its application to low dose tomographic fluoroscopy

    International Nuclear Information System (INIS)

    Flach, Barbara; Brehm, Marcus; Sawall, Stefan; Kachelrieß, Marc

    2014-01-01

    Many applications in medical imaging include image registration for matching of images from the same or different modalities. In the case of full data sampling, the respective reconstructed images are usually of such a good image quality that standard deformable volume-to-volume (3D–3D) registration approaches can be applied. But research in temporal-correlated image reconstruction and dose reductions increases the number of cases where rawdata are available from only few projection angles. Here, deteriorated image quality leads to non-acceptable deformable volume-to-volume registration results. Therefore a registration approach is required that is robust against a decreasing number of projections defining the target position. We propose a deformable volume-to-rawdata (3D–2D) registration method that aims at finding a displacement vector field maximizing the alignment of a CT volume and the acquired rawdata based on the sum of squared differences in rawdata domain. The registration is constrained by a regularization term in accordance with a fluid-based diffusion. Both cost function components, the rawdata fidelity and the regularization term, are optimized in an alternating manner. The matching criterion is optimized by a conjugate gradient descent for nonlinear functions, while the regularization is realized by convolution of the vector fields with Gaussian kernels. We validate the proposed method and compare it to the demons algorithm, a well-known 3D–3D registration method. The comparison is done for a range of 4–60 target projections using datasets from low dose tomographic fluoroscopy as an application example. The results show a high correlation to the ground truth target position without introducing artifacts even in the case of very few projections. In particular the matching in the rawdata domain is improved compared to the 3D–3D registration for the investigated range. The proposed volume-to-rawdata registration increases the robustness

  2. Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

    International Nuclear Information System (INIS)

    Zanca, F.; Jacobs, A.; Crijns, W.; De Wever, W.

    2014-01-01

    Purpose: To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations. Methods: Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure. Results: The median measured MSD was 141 mGy (range 38–410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24–262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12–4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size. Conclusions: On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure

  3. Novel real-time tumor-contouring method using deep learning to prevent mistracking in X-ray fluoroscopy.

    Science.gov (United States)

    Terunuma, Toshiyuki; Tokui, Aoi; Sakae, Takeji

    2018-03-01

    Robustness to obstacles is the most important factor necessary to achieve accurate tumor tracking without fiducial markers. Some high-density structures, such as bone, are enhanced on X-ray fluoroscopic images, which cause tumor mistracking. Tumor tracking should be performed by controlling "importance recognition": the understanding that soft-tissue is an important tracking feature and bone structure is unimportant. We propose a new real-time tumor-contouring method that uses deep learning with importance recognition control. The novelty of the proposed method is the combination of the devised random overlay method and supervised deep learning to induce the recognition of structures in tumor contouring as important or unimportant. This method can be used for tumor contouring because it uses deep learning to perform image segmentation. Our results from a simulated fluoroscopy model showed accurate tracking of a low-visibility tumor with an error of approximately 1 mm, even if enhanced bone structure acted as an obstacle. A high similarity of approximately 0.95 on the Jaccard index was observed between the segmented and ground truth tumor regions. A short processing time of 25 ms was achieved. The results of this simulated fluoroscopy model support the feasibility of robust real-time tumor contouring with fluoroscopy. Further studies using clinical fluoroscopy are highly anticipated.

  4. Fluoroscopy-guided Sacroiliac Joint Steroid Injection for Low Back Pain in a Patient with Osteogenesis Imperfecta.

    Science.gov (United States)

    Dawson, P U; Rose, R E; Wade, N A

    2015-09-01

    Osteogenesis imperfecta, also known as 'brittle bone disease', is a genetic connective tissue disease. It is characterized by bone fragility and osteopenia (low bone density). In this case, a 57-year old female presented to the University Hospital of the West Indies (UHWI), Physical Medicine and Rehabilitation Clinic with left low back pain rated 6/10 on the numeric rating scale (NRS). Clinically, the patient had sacroiliac joint mediated pain although X-rays did not show the sacroiliac joint changes. Fluoroscopy-guided left sacroiliac joint steroid injection was done. Numeric rating scale and Oswestry Disability Index (ODI) questionnaire were used to evaluate outcome. This was completed at baseline, one week follow-up and at eight weeks post fluoroscopy-guided sacroiliac joint steroid injection. Numeric rating scale improved from 6/10 before the procedure to 0/10 post procedure, and ODI questionnaire score improved from a moderate disability score of 40% to a minimal disability score of 13%. Up to eight weeks, the NRS was 0/10 and ODI remained at minimal disability of 15%. Fluoroscopy-guided sacroiliac joint injection is a known diagnostic and treatment method for sacroiliac joint mediated pain. To our knowledge, this is the first case published on the use of fluoroscopy-guided sacroiliac joint steroid injection in the treatment of sacroiliac joint mediated low back pain in a patient with osteogenesis imperfecta.

  5. Dosimetric study in fluoroscopy procedures realized on Recife, PE, Brazil; Estudo dosimetrico em procedimentos de fluoroscopia realizados no Recife

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Ana Figueiredo

    2001-08-01

    Fluoroscopy is a special radiological examination that uses radiation to visualize the image directly in a TV monitor. Due to of the large exposure times, these procedures often give high doses to the patient, usually higher than those from conventional radiology. Since there are not international diagnostic references levels for fluoroscopy procedures, this research had the objective of making the first study of the fluoroscopy procedures in the Northeast Region of Brazil, providing, therefore, data for the implementation of diagnostic reference levels. Three institutions were evaluated in Recife, two of them teaching hospitals. The quantities measured were the air kerma-area-product, the screening time and the number of radiographs taken in each exam. The results show that the value of the air kerma-area-product varied among the institutions and the results in the institution which uses the last generation equipment were better than those obtained in the other institutions. A relevant fact, and also alarming, is that the population in the institutions that showed the worse results are children. The results obtained in these institutions are higher than those observed in other countries. The results of this research show that there is a need for optimization in those procedures, specially the ones that involve older equipment. It is also points to the continuity of this study to gather more information to define the fluoroscopy reference levels in the country. (author)

  6. Dose level investigation in tests with gastrointestinal fluoroscopy as a part of a quality control program

    International Nuclear Information System (INIS)

    Canevaro, L.V.; Borges, J.C.; Kocj, H.A.

    1995-01-01

    The Radiation Protection and Dosimetry Institute of the National Nuclear Energy Commission (IRD/CNEN) Brazilian and the Radiodiagnostic Service of the Rio de Janeiro Federal University Hospital, (Brazil), have been engaged in the development of quality control programs applied to radiodiagnostics, one of them concerning gastrointestinal fluoroscopy. Since fluoroscopic examinations normally deals with high doses, they represent an important fraction of public exposure. They deserve special attention and risks to patients should be considered individually, not only as a population statistics. This work describes steps followed and results obtained in the estimation of doses for patients and physicians. Examinations investigated were esofagography, gastroduodenal seriography and colon with double contrast media, using conventional equipment with fluorescent screens, carried on by physicians engaged in the first year of medical residence. (author). 14 refs., 2 tabs

  7. Removal of a Wire Brush Bristle from the Hypopharynx Using Suspension, Microscope, and Fluoroscopy

    Directory of Open Access Journals (Sweden)

    Matthew R. Naunheim

    2015-01-01

    Full Text Available Wire brush bristles are an increasingly recognized hazard that can present as a foreign body in the aerodigestive tract. Due to their small size and tendency to become embedded in surrounding tissue, these small metallic bristles present a unique operative challenge to otolaryngologists. Here we present a case of a 40-year-old woman who underwent endoscopic extraction of a wire bristle from the posterior pharyngeal wall using suspension, microscopy, and C-arm fluoroscopy. We believe this is the first published case of an endoscopic removal of a buried foreign body in the hypopharynx using these methods of localization concurrently. By leveraging multiple techniques for visualization, surgeons can avoid open exploration while ensuring complete removal of the object. Additionally, this case highlights the importance of regulatory oversight and consumer awareness of the hazards of grill brushes.

  8. Thermoluminescent dosimetry in fluoroscopy of pediatric patients; Dosimetria termoluminiscente en fluoroscopia de pacientes pediatricos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia V, E.; Azorin N, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Fisica, San Rafael Atlixco 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico); Hidalgo T, S.; Dies S, P., E-mail: azorin@xanum.uam.mx [Hospital Infantil de Mexico Federico Gomez, Dr. Marquez 162, Col. Doctores, 06720 Ciudad de Mexico (Mexico)

    2016-10-15

    The use of thermoluminescent dosimeters in the area of medical physics and especially in radiology is of paramount importance to guarantee the quality of a particular study, which for this reason the need to verify by means of measurements of peripheral dose in studies of esophagogastroduodenal series by fluoroscopy using TLD of LiF:Mg, Ti. For this the necessary measurements were carried out directly in patients of the Children s Hospital of Mexico Federico Gomez. Previously characterized the dosimeters were used the graphs of the linear equation to obtain the absorbed dose of each dosimeter and was found that the values of the absorbed dose in each patient changes for various reasons like the anatomy, thickness of the tissues, age and exposure time during the study and was verify that none of the studies performed on patients exceeded dose levels that could affect healthy organs. (Author)

  9. A filtering method for signal equalization in region-of-interest fluoroscopy

    International Nuclear Information System (INIS)

    Robert, Normand; Komljenovic, Philip T; Rowlands, J. A.

    2002-01-01

    A method to significantly reduce the exposure area product in fluoroscopy using a pre-patient region-of-interest (ROI) attenuator is presented. The attenuator has a thin central region and a gradually increasing thickness away from the center. It is shown that the unwanted brightening artifact caused by the attenuator can be eliminated by attenuating the low spatial frequencies in the detected image using digital image processing techniques. An investigation of the best image processing method to correct for the presence of the attenuator is undertaken. The correction procedure selected is suitable for use with real-time image processors and the ROI attenuator can be permitted to move during image acquisition. Images of an anthropomorphic chest phantom acquired in the presence of the ROI attenuator using an x-ray image intensifier/video chain are corrected to illustrate the clinical feasibility of our approach

  10. A set of X-ray test objects for quality control in television fluoroscopy

    International Nuclear Information System (INIS)

    Hay, G.A.; Clarke, O.F.; Coleman, N.J.; Cowen, A.R.

    1985-01-01

    The history of performance testing in Leeds of television fluoroscopic systems is briefly outlined. Using the visual, physical and technological requirements as a basis, a set of nine test objects for quality control in television fluoroscopy is described. The factors measured by the test objects are listed in the introduction; the test objects and their function are fully described in the remainder of the paper. The test objects, in conjunction with a television oscilloscope, give both subjective and objective information about the X-ray system. Three of the test objects enable the physicist or engineer to adjust certain aspects of the performance of the X-ray system. The set of nine test objects is available commercially. (author)

  11. CT Fluoroscopy-Guided Lung Biopsy with Novel Steerable Biopsy Canula: Ex-Vivo Evaluation in Ventilated Porcine Lung Explants

    International Nuclear Information System (INIS)

    Schaefer, Philipp J.; Fabel, Michael; Bolte, Hendrik; Schaefer, Fritz K. W.; Jahnke, Thomas; Heller, Martin; Lammer, Johannes; Biederer, Juergen

    2010-01-01

    The purpose was to evaluate ex-vivo a prototype of a novel biopsy canula under CT fluoroscopy-guidance in ventilated porcine lung explants in respiratory motion simulations. Using an established chest phantom for porcine lung explants, n = 24 artificial lesions consisting of a fat-wax-Lipiodol mixture (approx. 70HU) were placed adjacent to sensible structures such as aorta, pericardium, diaphragm, bronchus and pulmonary artery. A piston pump connected to a reservoir beneath a flexible silicone reconstruction of a diaphragm simulated respiratory motion by rhythmic inflation and deflation of 1.5 L water. As biopsy device an 18-gauge prototype biopsy canula with a lancet-like, helically bended cutting edge was used. The artificial lesions were punctured under CT fluoroscopy-guidance (SOMATOM Sensation 64, Siemens, Erlangen, Germany; 30mAs/120 kV/5 mm slice thickness) implementing a dedicated protocol for CT fluoroscopy-guided lung biopsy. The mean-diameter of the artificial lesions was 8.3 ± 2.6 mm, and the mean-distance of the phantom wall to the lesions was 54.1 ± 13.5 mm. The mean-displacement of the lesions by respiratory motion was 14.1 ± 4.0 mm. The mean-duration of CT fluoroscopy was 9.6 ± 5.1 s. On a 4-point scale (1 = central; 2 = peripheral; 3 = marginal; 4 = off target), the mean-targeted precision was 1.9 ± 0.9. No misplacement of the biopsy canula affecting adjacent structures could be detected. The novel steerable biopsy canula proved to be efficient in the ex-vivo set-up. The chest phantom enabling respiratory motion and the steerable biopsy canula offer a feasible ex-vivo system for evaluating and training CT fluoroscopy-guided lung biopsy adapted to respiratory motion.

  12. Validation of single-plane fluoroscopy and 2D/3D shape-matching for quantifying shoulder complex kinematics.

    Science.gov (United States)

    Lawrence, Rebekah L; Ellingson, Arin M; Ludewig, Paula M

    2018-02-01

    Fluoroscopy and 2D/3D shape-matching has emerged as the standard for non-invasively quantifying kinematics. However, its accuracy has not been well established for the shoulder complex when using single-plane fluoroscopy. The purpose of this study was to determine the accuracy of single-plane fluoroscopy and 2D/3D shape-matching for quantifying full shoulder complex kinematics. Tantalum markers were implanted into the clavicle, humerus, and scapula of four cadaveric shoulders. Biplane radiographs were obtained with the shoulder in five humerothoracic elevation positions (arm at the side, 30°, 60°, 90°, maximum). Images from both systems were used to perform marker tracking, while only those images acquired with the primary fluoroscopy system were used to perform 2D/3D shape-matching. Kinematics errors due to shape-matching were calculated as the difference between marker tracking and 2D/3D shape-matching and expressed as root mean square (RMS) error, bias, and precision. Overall RMS errors for the glenohumeral joint ranged from 0.7 to 3.3° and 1.2 to 4.2 mm, while errors for the acromioclavicular joint ranged from 1.7 to 3.4°. Errors associated with shape-matching individual bones ranged from 1.2 to 3.2° for the humerus, 0.5 to 1.6° for the scapula, and 0.4 to 3.7° for the clavicle. The results of the study demonstrate that single-plane fluoroscopy and 2D/3D shape-matching can accurately quantify full shoulder complex kinematics in static positions. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  13. Reduced medical and occupational exposures by optimizing working procedures in fluoroscopy equipment in the University Hospital of Santa Maria (RS)

    International Nuclear Information System (INIS)

    Weis, Guilherme L.; Claus, Thiago V.; Baumhardt, Tadeu; Shuch, Luiz A.

    2013-01-01

    This work seeks to reduce medical (patient) and occupational (workers) exposure by standardizing resources available in fluoroscopy equipment used in interventional procedures. Such procedures use transportable surgical arch type fluoroscopy equipment, with applications in orthopedics, angiography and pacemaker implantation. Improper use of these devices generates excessive radiation doses in both patients and the medical staff. It is observed that the equipment after being connected to the grid, is pre-selected to work in continuous fluoroscopy and no additional filtration, producing higher doses of radiation. For specific applications, changes in protocols should be undertaken according to medical indication. This work used a fluoroscopy equipment Shimadzu Active Opescope two radiation monitoring equipment, brand Radcal, models 9010 and 9015, two ionization chambers, of 60 cc and 180 cc and a low contrast phantom and a catheter, information that simulate the human body. Incidences were performed by changing the conditions of exposure as frame rates (fps - frames per second) and additional filtration. For each composition parameters was generated and filed an image, with the extent of their respective doses. These images were evaluated by radiologists. In more extreme cases we obtained a reduction of a factor 25 in occupational exposure (medical personnel) using the pulsed with the greatest 2 fps additional filter (0.3 mm Cu) compared to continuous system without any additional filtration. In medical exposure (of patients), decreased by a factor 39, the same conditions described above. With these arguments it is justified the optimization and standardization of the equipment used in fluoroscopy, which besides providing a dose reduction the patient and the medical personnel, increases the life of the X-ray tube while maintaining the quality of medical diagnosis. (author)

  14. Determination of Gastrointestinal Transit Times in Barred Owls ( Strix varia ) by Contrast Fluoroscopy.

    Science.gov (United States)

    Doss, Grayson A; Williams, Jackie M; Mans, Christoph

    2017-06-01

    Contrast imaging studies are routinely performed in avian patients when an underlying abnormality of the gastrointestinal (GI) tract is suspected. Fluoroscopy offers several advantages over traditional radiography and can be performed in conscious animals with minimal stress and restraint. Although birds of prey are commonly encountered as patients, little is known about GI transit times and contrast imaging studies in these species, especially owls. Owls are commonly encountered in zoological, educational, and wildlife settings. In this study, 12 adult barred owls ( Strix varia ) were gavage fed a 30% weight-by-volume barium suspension (25 mL/kg body weight). Fluoroscopic exposures were recorded at 5, 15, 30, 60, 120, 180, 240, and 300 minutes after administration. Overall GI transit time and transit times of various GI organs were recorded. Median (interquartile range [IQR]) overall GI transit time was 60 minutes (IQR: 19-60 minutes) and ranged from 5-120 minutes. Ventricular and small intestinal contrast filling was rapid. Ventricular emptying was complete by a median of 60 minutes (IQR: 30-120 minutes; range: 30-240 minutes), whereas small intestinal emptying was not complete in 9/12 birds by 300 minutes. Median small intestinal contraction rate was 15 per minute (IQR: 13-16 minutes; range: 10-19 minutes). Median overall GI transit time in barred owls is more rapid than mean transit times reported for psittacine birds and red-tailed hawks ( Buteo jamaicensis ). Fluoroscopy is a safe, suitable method for investigating GI motility and transit in this species.

  15. Direct percutaneous endoscopic jejunostomy using single-balloon enteroscopy without fluoroscopy: a case series

    Directory of Open Access Journals (Sweden)

    Carlos Bernardes

    Full Text Available Background: Direct percutaneous endoscopic jejunostomy (DPEJ is a useful method to provide enteral nutrition to individuals when gastric feeding is not possible or contraindicated. The aim of this study was to analyze the efficacy and safety of DPEJ tube placement with the Gauderer-Ponsky technique by the pull method, using single-balloon enteroscopy (SBE without fluoroscopy. Methods: This is a retrospective analysis of patients undergoing SBE for DPEJ placement in a referral hospital between January 2010 and March 2016. Technical success, clinical success and procedure related complications were recorded. Results: Twenty-three patients were included (17 males, median age 71 years, range 37-93 years. The most frequent indications for DPEJ were gastroesophageal cancer (n = 10 and neurological disease (n = 8. Eighty-seven percent of the patients had a contraindication to percutaneous endoscopic gastrostomy (PEG and PEG was unsuccessful in the remaining patients. The technical success rate was 83% (19/23, transillumination was not possible in three patients and an accidental exteriorization of the bumper resulting in a jejunal perforation occurred in one patient. The clinical success was 100% (19/19. The median follow-up was five months (range 1-35 months. Apart from the case of jejunal perforation and the two cases of accidental exteriorization, there were no other complications during follow-up. The 6-month survival was 65.8% and the 1-year survival was 49.3%. Conclusion: DPEJ can be carried out successfully via SBE without fluoroscopy with a low rate of significant adverse events. Although, leaving the overtube in place during the bumper pulling can be useful for distal jejunal loops, it can be safely removed in proximal loops to minimize complications.

  16. Breast cancer after multiple chest fluoroscopies: second follow-up of Massachusetts women with tuberculosis

    International Nuclear Information System (INIS)

    Hrubec, Z.; Boice, J.D. Jr.; Monson, R.R.; Rosenstein, M.

    1989-01-01

    A second follow-up was conducted of 1742 women with tuberculosis who were treated in one of two sanatoria in Massachusetts between 1930 and 1956. One hospital treated only children under the age of 17. Patient follow-up was extended from 1975 through 1980, and an additional 18 breast cancers were identified from hospital records, death certificates, and responses to a mailed questionnaire. Vital status was established for 97% of the subjects. Among 1044 women who were examined an average of 101 times with X-ray fluoroscopies during lung collapse therapy, 55 breast cancers were observed in contrast to 35.8 expected, based on incidence rates from the general population. No excess was found for 698 women treated by other means (19 observed versus 22.8 expected). Excess breast cancer risk did not appear until 15 years after initial exposure and was present at the end of 50 years of observation. Risk appeared to decrease with increasing age at exposure. Estimates of radiation dose to the breast for individuals (mean = 96 rad) were based on the most current information for the numbers of fluoroscopies, reconstruction of exposure conditions, and absorbed dose calculations. The relation between dose and breast cancer risk was consistent with linearity up to 400 rads (4 Gy). For 10-year survivors, the absolute excess risk was 5.5/1 million woman-year-rad, the excess relative risk per rad was 0.73%, and the relative risk at 100 rad was 1.7. These data indicate that a woman's lifetime risk of breast cancer is influenced by events occurring in early reproductive life, that low-dose fractionated exposures are as effective as single exposures of the same total dose in inducing breast cancer, and that risk of radiogenic breast cancer persists for many years, and perhaps for life

  17. Combined ultrasound and fluoroscopy guided port catheter implantation-High success and low complication rate

    International Nuclear Information System (INIS)

    Gebauer, Bernhard; El-Sheik, Michael; Vogt, Michael; Wagner, Hans-Joachim

    2009-01-01

    Purpose: To evaluate peri-procedural, early and late complications as well as patients' acceptance of combined ultrasound and fluoroscopy guided radiological port catheter implantation. Materials and methods: In a retrospective analysis, all consecutive radiological port catheter implantations (n = 299) between August 2002 and December 2004 were analyzed. All implantations were performed in an angio suite under analgosedation and antibiotic prophylaxis. Port insertion was guided by ultrasonographic puncture of the jugular (n = 298) or subclavian (n = 1) vein and fluoroscopic guidance of catheter placement. All data of the port implantation had been prospectively entered into a database for interventional radiological procedures. To assess long-term results, patients, relatives or primary physicians were interviewed by telephone; additional data were generated from the hospital information system. Patients and/or the relatives were asked about their satisfaction with the port implantion procedure and long-term results. Results: The technical success rate was 99% (298/299). There were no major complications according to the grading system of SIR. A total of 23 (0.33 per 1000 catheter days) complications (early (n = 4), late (n = 19)) were recorded in the follow-period of a total of 72,727 indwelling catheter days. Infectious complications accounted for 0.15, thrombotic for 0.07 and migration for 0.04 complications per 1000 catheter days. Most complications were successfully treated by interventional measures. Twelve port catheters had to be explanted due to complications, mainly because of infection (n = 9). Patients' and relatives' satisfaction with the port catheter system was very high, even if complications occurred. Conclusion: Combined ultrasound and fluoroscopy guided port catheter implantation is a very safe and reliable procedure with low peri-procedural, early and late complication rate. The intervention achieves very high acceptance by the patients and

  18. A method for measuring three-dimensional mandibular kinematics in vivo using single-plane fluoroscopy

    Science.gov (United States)

    Chen, C-C; Lin, C-C; Chen, Y-J; Hong, S-W; Lu, T-W

    2013-01-01

    Objectives Accurate measurement of the three-dimensional (3D) motion of the mandible in vivo is essential for relevant clinical applications. Existing techniques are either of limited accuracy or require the use of transoral devices that interfere with jaw movements. This study aimed to develop further an existing method for measuring 3D, in vivo mandibular kinematics using single-plane fluoroscopy; to determine the accuracy of the method; and to demonstrate its clinical applicability via measurements on a healthy subject during opening/closing and chewing movements. Methods The proposed method was based on the registration of single-plane fluoroscopy images and 3D low-radiation cone beam CT data. It was validated using roentgen single-plane photogrammetric analysis at static positions and during opening/closing and chewing movements. Results The method was found to have measurement errors of 0.1 ± 0.9 mm for all translations and 0.2° ± 0.6° for all rotations in static conditions, and of 1.0 ± 1.4 mm for all translations and 0.2° ± 0.7° for all rotations in dynamic conditions. Conclusions The proposed method is considered an accurate method for quantifying the 3D mandibular motion in vivo. Without relying on transoral devices, the method has advantages over existing methods, especially in the assessment of patients with missing or unstable teeth, making it useful for the research and clinical assessment of the temporomandibular joint and chewing function. PMID:22842637

  19. CT fluoroscopy-guided core needle biopsy of anterior mediastinal masses.

    Science.gov (United States)

    Iguchi, T; Hiraki, T; Matsui, Y; Fujiwara, H; Sakurai, J; Masaoka, Y; Uka, M; Tanaka, T; Gobara, H; Kanazawa, S

    2018-02-01

    To retrospectively evaluate the safety, diagnostic yield, and risk factors of diagnostic failure of computed tomography (CT) fluoroscopy-guided biopsies of anterior mediastinal masses. Biopsy procedures and results of anterior mediastinal masses in 71 patients (32 women/39 men; mean [±standard deviation] age, 53.8±20.0years; range, 14-88years) were analyzed. Final diagnoses were based on surgical outcomes, imaging findings, or clinical follow-up findings. The biopsy results were compared with the final diagnosis, and the biopsy procedures grouped by pathologic findings into diagnostic success and failure groups. Multiple putative risk factors for diagnostic failure were then assessed. Seventy-one biopsies (71 masses; mean size, 67.5±27.3mm; range 8.6-128.2mm) were analyzed. We identified 17 grade 1 and one grade 2 adverse events (25.4% overall) according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Sixty-nine biopsies (97.2%) provided samples fit for pathologic analysis. Diagnostic failure was found for eight (11.3%) masses; the 63 masses diagnosed successfully included thymic carcinoma (n=17), lung cancer (n=14), thymoma (n=12), malignant lymphoma (n=11), germ cell tumor (n=3), and others (n=6). Using a thinner needle (i.e., a 20-gauge needle) was the sole significant risk factor for diagnostic failure (P=0.039). CT fluoroscopy-guided biopsy of anterior mediastinal masses was safe and had a high diagnostic yield; however, using a thinner biopsy needle significantly increased the risk of a failed diagnosis. Copyright © 2017 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  20. An evaluation of the fluoroscopy-guided percutaneous gastrostomy with the pull technique

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    Uhm, Chang Wook; Won, Jong Yun; Yu, Jeong Sik; Ko, Heung Kyu; Lee, Kwang Hun; Lee, Do Yun; Lee, Jong Tae [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2008-04-15

    To evaluate the safety and usefulness of the fluoroscopy-guided percutaneous gastrostomy (FPG) using a large profile gastrostomy tube accompanied with the pull technique, and without the use of an endoscopy or a gastropexy. From March 2005 to February 2007, 25 patients underwent an FPG using a large profile gastrostomy tube accompanied by the pull technique, in which a 24F pull-type tube was inserted into a patient's mouth and was pulled to the upper abdominal puncture site using a snare, under fluoroscopy. The 18 patients with difficulty swallowing due to muscular atrophic lateral sclerosis or transitional myodystrophy included 5 cases of quadriplegia, 1 case of Parkinson's disease, and 1 metastatic mediastinal tumor. The technical success rate, occurrence of complications, and clinical outcomes were examined. The technical success rate was found to be 100%. In addition, the retention periods for the indwelling tube ranged from 1 to 24 months (mean: 6.5 months), with all tubes retained at a normal position with normal function. No procedure-related mortality occurred. One patient (4%) did however develop a complication in the form of ascites and ascitic fluid leakage around the tube, which was of hepatic origin and was ultimately resolved after the drainage of ascites. As a result of this study the FPG, accompanied with the pull technique using a 24F tube, should be considered as a safe and effective method for examining patients. It was found to have a high success rate and a low complication rate.

  1. A standardized and safe method of sterile field maintenance during intra-operative horizontal plane fluoroscopy

    Directory of Open Access Journals (Sweden)

    Kaska Serge C

    2010-12-01

    Full Text Available Abstract Background Intra-operative fluoroscopy for orthopaedic procedures frequently involves imaging in the horizontal plane, which requires the lower portion of the C-arm (x-ray tube to be rotated from an unsterile zone (beneath the table into the sterile field. To protect the integrity of the sterile field the C-arm must be draped repeatedly throughout the surgical case. The current, un-standardized, practice employs draping procedures which violate the Association of peri-Operative Registered Nurses (AORN Standards and Recommended Practices, waste time and material, and pose an increased risk for surgical site infection. Presentation of the hypothesis Use of a novel sterile C-arm drape (C-armor that maintains the integrity of the sterile field, will improve operating room efficiency and reduce surgical site infection risk factors. This reduction in risk factors may potentially reduce surgical site infections in orthopaedic surgical cases requiring repeated horizontal x-ray imaging. Testing the Hypothesis Savings in time and material and the reduction in surgical site infection risk factors afforded by using C-armor are intuitive to those skilled in the practice of orthopaedic surgery. Testing for a reduction in the number of microorganisms introduced to the surgical site by improved C-arm draping would be challenging due to the multiple confounding factors during a surgical operation. Determination of an absolute reduction in surgical site infections may be possible, but will require accounting for many confounding variables and a large study sample in order to achieve statistical significance. Implications of the Hypothesis Improved intraoperative workflow, healthcare savings and a reduction in surgical site infection risk factors will be achieved by utilizing a standardized and safe method of sterile field maintenance during intra-operative horizontal plane fluoroscopy.

  2. Fluoroscopy-guided barium marking for localizing small pulmonary lesions before video-assisted thoracoscopic surgery

    International Nuclear Information System (INIS)

    Yamada, Takahiro; Koyama, Yasunori; Masui, Asami

    2009-01-01

    Small pulmonary lesions not previously seen on chest radiographs will likely be detected with increasing frequency because of the spread of CT screening. For the diagnosis and treatment of such lesions, we frequently perform resection by video-assisted thoracoscopic surgery (VATS). We performed fluoroscopy-guided barium marking for localization of small peripheral pulmonary lesions before VATS resection, and examined its reliability, safety, and usefulness. We studied 46 patients with peripheral pulmonary lesions 20 mm or less in diameter who were scheduled to undergo VATS resection. The average diameter of the lesions was 10.2±0.5 mm (mean±standard error), and the average distance from the pleural surface was 10.1±0.8 mm. The optimal site for the catheter tip was decided on chest radiographs using CT scans for reference beforehand, and a catheter was inserted bronchoscopically into the target segment and guided to the presumed lesion. A 50% (weight/volume) barium sulfate suspension was instilled into the bronchus through the catheter, and the site of barium marking was checked by CT scanning. The average instilled volume of barium was 0.36±0.03 ml. On CT scans, barium spots were superimposed on the target lesions in 35 of the 46 patients and were only 15 mm from the lesions in the other patients. Barium was well recognized in all patients at the time of VATS resection, and we could confirm the diagnosis in all patients. A mild cough persisted for about 1 week in 1 patient, but the other patients had no specific complications. Fluoroscopy-guided barium marking is a safe, convenient, and reliable method for localization of small pulmonary lesions before VATS resection. (author)

  3. Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions

    International Nuclear Information System (INIS)

    Mahnken, Andreas H.; Sedlmair, Martin; Ritter, Christine; Banckwitz, Rosemarie; Flohr, Thomas

    2012-01-01

    Purpose: Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient. Material and Methods: All examinations were performed with a 128-slice dual source CT scanner (12 × 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement. Results: On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner’s isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at ≥150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r 2 = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product. Conclusion: Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.

  4. Simulation-based education leads to decreased use of fluoroscopy in diagnostic coronary angiography.

    Science.gov (United States)

    Prenner, Stuart B; Wayne, Diane B; Sweis, Ranya N; Cohen, Elaine R; Feinglass, Joe M; Schimmel, Daniel R

    2017-08-02

    The aim of this study is to determine whether simulation-based education (SBE) translates into reduced procedure time, radiation, and contrast use in actual clinical care. As a high volume procedure often performed by novice cardiology fellows, diagnostic coronary angiography represents an excellent target for SBE. Reports of SBE in interventional cardiology are limited and there is little understanding of the potential downstream clinical impact of these interventions. All diagnostic coronary angiograms performed at a single center between January 1, 2011 and June 30, 2015 were analyzed. Random effects linear regression models were used to compare outcomes between procedures performed by 12 cardiology fellows who underwent simulation-based training and those performed by 20 traditionally trained fellows. Thirty-two cardiology fellows performed 2,783 diagnostic coronary angiograms. Procedures performed by fellows trained with SBE were shorter (mean of 23.98 min vs. 24.94 min, P = 0.034) and were performed with decreased radiation (mean of 56,348 mGycm 2 vs. 66,120 mGycm 2 , P < 0.001). After controlling for year in training, procedure year, access site, and supervising attending physician, training on the simulator was independently associated with 117 fewer seconds of fluoroscopy time per procedure (P = 0.04). Diagnostic coronary angiography SBE is associated with decreased use of fluoroscopy in downstream clinical care. SBE may be a useful tool to reduce radiation exposure in the cardiac catheterization laboratory. © 2017 Wiley Periodicals, Inc.

  5. Moving back: The radiation dose received from lumbar spine quantitative fluoroscopy compared to lumbar spine radiographs with suggestions for dose reduction.

    Science.gov (United States)

    Mellor, F E; Thomas, P; Breen, A

    2014-08-01

    Quantitative fluoroscopy is an emerging technology for assessing continuous inter-vertebral motion in the lumbar spine, but information on radiation dose is not yet available. The purposes of this study were to compare the radiation dose from quantitative fluoroscopy of the lumbar spine with lumbar spine radiographs, and identify opportunities for dose reduction in quantitative fluoroscopy. Internationally reported dose area product (DAP) and effective dose data for lumbar spine radiographs were compared with the same for quantitative fluoroscopy and with data from a local hospital for functional radiographs (weight bearing AP, lateral, and/or flexion and extension) ( n  = 27). The effects of procedure time, age, weight, height and body mass index on the fluoroscopy dose were determined by multiple linear regression using SPSS v19 software (IBM Corp., Armonck, NY, USA). The effective dose (and therefore the estimated risk) for quantitative fluoroscopy is 0.561 mSv which is lower than in most published data for lumbar spine radiography. The dose area product (DAP) for sagittal (flexion + extension) quantitative fluoroscopy is 3.94 Gy cm 2 which is lower than local data for two view (flexion and extension) functional radiographs (4.25 Gy cm 2 ), and combined coronal and sagittal dose from quantitative fluoroscopy (6.13 Gy cm 2 ) is lower than for four view functional radiography (7.34 Gy cm 2 ). Conversely DAP for coronal and sagittal quantitative fluoroscopy combined (6.13 Gy cm 2 ) is higher than that published for both lumbar AP or lateral radiographs, with the exception of Nordic countries combined data. Weight, procedure time and age were independently positively associated with total dose, and height (after adjusting for weight) was negatively associated, thus as height increased, the DAP decreased.

  6. Moving back: The radiation dose received from lumbar spine quantitative fluoroscopy compared to lumbar spine radiographs with suggestions for dose reduction

    International Nuclear Information System (INIS)

    Mellor, F.E.; Thomas, P.; Breen, A.

    2014-01-01

    Purpose: Quantitative fluoroscopy is an emerging technology for assessing continuous inter-vertebral motion in the lumbar spine, but information on radiation dose is not yet available. The purposes of this study were to compare the radiation dose from quantitative fluoroscopy of the lumbar spine with lumbar spine radiographs, and identify opportunities for dose reduction in quantitative fluoroscopy. Methods: Internationally reported dose area product (DAP) and effective dose data for lumbar spine radiographs were compared with the same for quantitative fluoroscopy and with data from a local hospital for functional radiographs (weight bearing AP, lateral, and/or flexion and extension) (n = 27). The effects of procedure time, age, weight, height and body mass index on the fluoroscopy dose were determined by multiple linear regression using SPSS v19 software (IBM Corp., Armonck, NY, USA). Results and conclusion: The effective dose (and therefore the estimated risk) for quantitative fluoroscopy is 0.561 mSv which is lower than in most published data for lumbar spine radiography. The dose area product (DAP) for sagittal (flexion + extension) quantitative fluoroscopy is 3.94 Gy cm 2 which is lower than local data for two view (flexion and extension) functional radiographs (4.25 Gy cm 2 ), and combined coronal and sagittal dose from quantitative fluoroscopy (6.13 Gy cm 2 ) is lower than for four view functional radiography (7.34 Gy cm 2 ). Conversely DAP for coronal and sagittal quantitative fluoroscopy combined (6.13 Gy cm 2 ) is higher than that published for both lumbar AP or lateral radiographs, with the exception of Nordic countries combined data. Weight, procedure time and age were independently positively associated with total dose, and height (after adjusting for weight) was negatively associated, thus as height increased, the DAP decreased

  7. Time of fluoroscopy and number of gastrointestinal tract by doctors in the ten years. On the annual transition of patients, age groups and risks

    International Nuclear Information System (INIS)

    Iba, Shozo; Hirose, Kouichi; Hirano, Masato; Kawarada, Akira; Futami, Tsutomu.

    1997-01-01

    On the period ranging from May, 1986 to March, 1996. We investigated the actual conditions by doctors on the time while examining by X-ray fluoroscopy and the number of radiograph for the gastrointestinal tract examination using barium contrast medium. The time of fluoroscopy and the number of radiograph per X-ray examination of the stomach were about 8.5 minutes, 25 radiographs. On the patients of examination of barium enema were about 11 minutes, 19 radiographs. The time of fluoroscopy and the number of radiograph for diagnosis, there are observed the difference in the average value of several years. The time of fluoroscopy and the number of radiograph for X-ray examination of stomach by doctors have not always seen decreasing in proportion to their experience. We were estimated somatic individual risks from X-ray examination of gastrointestinal tract using a human body phantom. (author)

  8. Performance evaluation of flat panel detector in x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Grewal, R.K.; Mclean, I.D.

    2004-01-01

    Full text: Flat panel detectors are currently replacing the conventional image intensifiers in R-F imaging. We evaluated the performance of a biplane cardiac imaging system (Siemens Axiom Artis dBC), the image acquisition was based on a 25 cm diagonal digital fiat panel detector. Performance characteristics included image quality, typical patient entrance dose and measurement of input to the surface of flat detector. The results were compared with conventional image intensifier systems (Siemens Hicor Unit and Toshiba DPF 2000 A Biplane Unit) used in cardiac imaging at Westmead. Image quality and dose measurements were performed following standard protocols using Westmead test object and 20 cm solid water as absorber in the beam. For measurement of input to the surface of flat detector, 2 mm copper was placed on the collimator. Radcal 3cc and 180 cc ion chambers were used for dose measurements. Image quality: Our measurements on flat panel system indicate that high contrast resolution and threshold contrast is not affected by changing field size. This is expected due to minimum loss of signal in the imaging chain of digital systems and the independence of detector pixel size with change in field of view. While low contrast resolution was found to be similar to conventional systems, high contrast resolution was significantly superior using flat detector system for large and intermediate field of view (25-28 1p/cm against 18-20). Typical patient dose as measured using flat detector system was similar to the conventional Toshiba pulsed fluoroscopy system( ∼ 3 - 8 mGy/min depending on the field size). This was 40-50 % lower than our old Siemens hicore unit. Input to the surface of flat detector was found to vary with field size as is the case with a conventional II system. As described elsewhere, although there is no necessity to increase exposure or video gain in a digital magnification, digital data interpolation process introduces noise. As a result system

  9. Evaluation of the Quality Control Program for Diagnostic Radiography and Fluoroscopy Devices in Syria during 2005-2013

    Directory of Open Access Journals (Sweden)

    M. H. Kharita

    2017-06-01

    Full Text Available Introduction: Extensive use of diagnostic radiology is the largest contributor to total population radiation doses. Thus, appropriate equipment and safe practice are necessary for good-quality images with optimal doses. This study aimed to perform quality control (QC audit for radiography and fluoroscopy devices owned by private sector in Syria (2005-2013 to verify compliance of performance of X-ray machines with the regulatory requirements stipulated by the national regulatory body. Materials and Methods: In this study, QC audit included 487 X-ray diagnostic machines, (363 radiography and 124 fluoroscopy devices, installed in 306 medical diagnostic radiology centers in 14 provinces in Syria. We employed an X-ray beam analyzer device (NERO model 8000, Victoreen, USA, which was tested and calibrated at the National Secondary Standard Dosimetry Laboratory traceable to the IAEA Network of Secondary Standard Dosimetry Laboratories. Standard QC tool kits were used to evaluate tube and generator of the X-ray machines, which constituted potential (kVp, timer accuracy, radiation output consistency, tube filtration, small and large focal spot sizes, X-ray beam collimation and alignment, as well as high- and low-resolution and entrance surface dose in fluoroscopy. Results: According to our results, most of the assessed operating parameters were in compliance with the standards stipulated by the National Regulatory Authority. In cases of noncompliance for the assessed parameters, maximum value (28.77% pertained to accuracy of kVp calibration for radiography units, while the lowest value (2.42% belonged to entrance surface dose in fluoroscopy systems. Conclusion: Effective QC program in diagnostic radiology leads to obtaining information regarding quality of radiology devices used for medical diagnosis and minimizing the doses received by patients and medical personnel. The findings of this QC program, as the main part of QA program, illustrated that most

  10. Personalized Feedback on Staff Dose in Fluoroscopy-Guided Interventions: A New Era in Radiation Dose Monitoring.

    Science.gov (United States)

    Sailer, Anna M; Vergoossen, Laura; Paulis, Leonie; van Zwam, Willem H; Das, Marco; Wildberger, Joachim E; Jeukens, Cécile R L P N

    2017-11-01

    Radiation safety and protection are a key component of fluoroscopy-guided interventions. We hypothesize that providing weekly personal dose feedback will increase radiation awareness and ultimately will lead to optimized behavior. Therefore, we designed and implemented a personalized feedback of procedure and personal doses for medical staff involved in fluoroscopy-guided interventions. Medical staff (physicians and technicians, n = 27) involved in fluoroscopy-guided interventions were equipped with electronic personal dose meters (PDMs). Procedure dose data including the dose area product and effective doses from PDMs were prospectively monitored for each consecutive procedure over an 8-month period (n = 1082). A personalized feedback form was designed displaying for each staff individually the personal dose per procedure, as well as relative and cumulative doses. This study consisted of two phases: (1) 1-5th months: Staff did not receive feedback (n = 701) and (2) 6-8th months: Staff received weekly individual dose feedback (n = 381). An anonymous evaluation was performed on the feedback and occupational dose. Personalized feedback was scored valuable by 76% of the staff and increased radiation dose awareness for 71%. 57 and 52% reported an increased feeling of occupational safety and changing their behavior because of personalized feedback, respectively. For technicians, the normalized dose was significantly lower in the feedback phase compared to the prefeedback phase: [median (IQR) normalized dose (phase 1) 0.12 (0.04-0.50) µSv/Gy cm 2 versus (phase 2) 0.08 (0.02-0.24) µSv/Gy cm 2 , p = 0.002]. Personalized dose feedback increases radiation awareness and safety and can be provided to staff involved in fluoroscopy-guided interventions.

  11. SU-D-209-05: Sensitivity of the Diagnostic Radiological Index of Protection (DRIP) to Procedural Factors in Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A [UT MD Anderson Cancer Center, Houston, TX (United States); Pasciak, A [University of Tennessee Medical Center, Knoxville, TN (United States); Wagner, L [UT Medical School, Houston, TX (United States)

    2016-06-15

    Purpose: To evaluate the sensitivity of the Diagnostic Radiological Index of Protection (DRIP) to procedural factors in fluoroscopy in an effort to determine an appropriate set of scatter-mimicking primary beams (SMPB) to be used in measuring the DRIP. Methods: A series of clinical and factorial Monte Carlo simulations were conducted to determine the shape of the scattered X-ray spectra incident on the operator in different clinical fluoroscopy scenarios. Two clinical evaluations studied the sensitivity of the scattered spectrum to gantry angle and patient size while technical factors were varied according to measured automatic dose rate control (ADRC) data. Factorial evaluations studied the sensitivity of the scattered spectrum to gantry angle, field of view, patient size and beam quality for constant technical factors. Average energy was the figure of merit used to condense fluence in each energy bin to a single numerical index. Results: Beam quality had the strongest influence on the scattered spectrum in fluoroscopy. Many procedural factors affected the scattered spectrum indirectly through their effects on primary beam quality through ADRC, e.g., gantry angle and patient size. Lateral C-arm rotation, common in interventional cardiology, increased the energy of the scattered spectrum, regardless of the direction of rotation. The effect of patient size on scattered radiation depended on ADRC characteristics, patient size, and procedure type. Conclusion: The scattered spectrum striking the operator in fluoroscopy, and therefore the DRIP, is most strongly influenced by primary beam quality, particularly kV. Use cases for protective garments should be classified by typical procedural primary beam qualities, which are governed by the ADRC according to the impacts of patient size, anatomical location, and gantry angle. These results will help determine an appropriate set of SMPB to be used for measuring the DRIP.

  12. Rapid fusion of 2D X-ray fluoroscopy with 3D multislice CT for image-guided electrophysiology procedures

    Science.gov (United States)

    Zagorchev, Lyubomir; Manzke, Robert; Cury, Ricardo; Reddy, Vivek Y.; Chan, Raymond C.

    2007-03-01

    Interventional cardiac electrophysiology (EP) procedures are typically performed under X-ray fluoroscopy for visualizing catheters and EP devices relative to other highly-attenuating structures such as the thoracic spine and ribs. These projections do not however contain information about soft-tissue anatomy and there is a recognized need for fusion of conventional fluoroscopy with pre-operatively acquired cardiac multislice computed tomography (MSCT) volumes. Rapid 2D-3D integration in this application would allow for real-time visualization of all catheters present within the thorax in relation to the cardiovascular anatomy visible in MSCT. We present a method for rapid fusion of 2D X-ray fluoroscopy with 3DMSCT that can facilitate EP mapping and interventional procedures by reducing the need for intra-operative contrast injections to visualize heart chambers and specialized systems to track catheters within the cardiovascular anatomy. We use hardware-accelerated ray-casting to compute digitally reconstructed radiographs (DRRs) from the MSCT volume and iteratively optimize the rigid-body pose of the volumetric data to maximize the similarity between the MSCT-derived DRR and the intra-operative X-ray projection data.

  13. Fluoroscopy- vs ultrasound-guided aspiration techniques in the management of periprosthetic joint infection: which is the best?

    Science.gov (United States)

    Randelli, Filippo; Brioschi, Marco; Randelli, Pietro; Ambrogi, Federico; Sdao, Silvana; Aliprandi, Alberto

    2018-01-01

    Fluid samples obtained from an affected joint still play a central role in the diagnosis of periprosthetic joint infection (PJI). It is the only preoperative test able to discover the causative microbiological agent. In the hip, fluid aspiration can be performed through fluoroscopy, ultrasound, or, less commonly, computed tomography. However, there is still a lack of consensus on which method is preferable in terms of efficacy and costbenefit. We, therefore, asked whether (1) the benefits in terms of sensitivity and specificity and (2) the costs were comparable between fluoroscopy- and ultrasound-guided joint aspirations in a suspicious of hip PJI. Between 2013 and 2016, 52 hip aspirations were performed on 49 patients with clinical, radiological, or serological suspicion of PJI, waiting for a revision surgery. The patients were divided in two groups: fluoroscopy- (n = 26) vs ultrasound-guided hip aspiration group (n = 26). These groups were also divided in control and infected patients. The criteria of MusculoSkeletal Infection Society (MSIS) were used, as gold standard, to define PJI. (1) Ultrasound-guided aspiration revealed valid sensitivity (89% vs 60%) and specificity (94% vs 81%) in comparison with fluoroscopic-guided aspiration. (2) The cost analysis was also in favor of ultrasound-guided aspiration (125.30€) than fluoroscopic-guided aspiration (343.58€). We concluded that ultrasound-guided hip aspiration could represent a valid, safe, and less expensive diagnostic alternative to fluoroscopic-guided aspiration in hip PJI.

  14. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Radiology, Nice (France); Hauger, Olivier [Hopital Pellegrin, Centre Hospitalo-Universitaire de Bordeaux, Department of Radiology, Bordeaux (France); Marcy, Pierre-Yves [Antoine Lacassagne Cancer Research Institute, Department of Radiology, Nice (France); Boileau, Pascal [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Orthopedic Surgery, Nice (France)

    2012-12-15

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements {+-} SD decreased from 7.8 {+-} 0.9 preoperatively to 1.5 {+-} 1.1 at the last 2-year follow-up, and from 62.3 {+-} 17.2 to 15.1 {+-} 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  15. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    International Nuclear Information System (INIS)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline; Hauger, Olivier; Marcy, Pierre-Yves; Boileau, Pascal

    2012-01-01

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements ± SD decreased from 7.8 ± 0.9 preoperatively to 1.5 ± 1.1 at the last 2-year follow-up, and from 62.3 ± 17.2 to 15.1 ± 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  16. Real-time fusion of coronary CT angiography with x-ray fluoroscopy during chronic total occlusion PCI.

    Science.gov (United States)

    Ghoshhajra, Brian B; Takx, Richard A P; Stone, Luke L; Girard, Erin E; Brilakis, Emmanouil S; Lombardi, William L; Yeh, Robert W; Jaffer, Farouc A

    2017-06-01

    The purpose of this study was to demonstrate the feasibility of real-time fusion of coronary computed tomography angiography (CTA) centreline and arterial wall calcification with x-ray fluoroscopy during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Patients undergoing CTO PCI were prospectively enrolled. Pre-procedural CT scans were integrated with conventional coronary fluoroscopy using prototype software. We enrolled 24 patients who underwent CTO PCI using the prototype CT fusion software, and 24 consecutive CTO PCI patients without CT guidance served as a control group. Mean age was 66 ± 11 years, and 43/48 patients were men. Real-time CTA fusion during CTO PCI provided additional information regarding coronary arterial calcification and tortuosity that generated new insights into antegrade wiring, antegrade dissection/reentry, and retrograde wiring during CTO PCI. Overall CTO success rates and procedural outcomes remained similar between the two groups, despite a trend toward higher complexity in the fusion CTA group. This study demonstrates that real-time automated co-registration of coronary CTA centreline and calcification onto live fluoroscopic images is feasible and provides new insights into CTO PCI, and in particular, antegrade dissection reentry-based CTO PCI. • Real-time semi-automated fusion of CTA/fluoroscopy is feasible during CTO PCI. • CTA fusion data can be toggled on/off as desired during CTO PCI • Real-time CT calcium and centreline overlay could benefit antegrade dissection/reentry-based CTO PCI.

  17. Fluoroscopy-controlled voiding cystourethrography in infants and children: Are the radiation risks trivial?

    International Nuclear Information System (INIS)

    Perisinakis, Kostas; Damilakis, John; Stratakis, John; Raissaki, Maria; Neratzoulakis, John; Gourtsoyiannis, Nicholas

    2006-01-01

    The purpose of this study was to determine the gonadal dose, effective dose and relevant radiogenic risks associated with pediatric patients undergoing voiding cystourethrography (VCUG). Exposure parameters were monitored in 118 consecutive children undergoing VCUG. The entrance surface dose (ESD) was determined by thermoluminescent dosimeters (TLDs). For male patients, the gonadal dose was determined by TLDs attached on the anterior scrotum. For female patients, the gonadal dose was estimated by converting ESD to the ovarian dose. ESD-to-ovarian dose conversion factors were determined by thermoluminescence dosimetry and physical anthropomorphic phantoms representing newborn and 1-, 5- and 10-year-old individuals. The effective dose was estimated by using ESD and data obtained from the literature. The mean fluoroscopy time and number of radiographs during VCUG were 0.73 min and 2.3 for female and 0.91 min and 3.0 for male pediatric patients, respectively. The gonadal dose range was 0.34-5.17 mGy in boys and 0.36-2.57 mGy in girls. The corresponding ranges of effective dosage were 0.12-1.67 mSv and 0.15-1.45 mSv. Mean radiation risks for genetic anomalies and carcinogenesis following VCUG during childhood were estimated to be up to 15 per million and 125 per million, respectively. Radiation risks associated with pediatric patients undergoing VCUG should not be disregarded if such a procedure is to be justified adequately. (orig.)

  18. Doses in pediatric urinary studies guided by fluoroscopy: methodology oriented to the education

    International Nuclear Information System (INIS)

    Cotelo, E.; Castillo, C.; Padilla, M.; Rabin, C.

    2006-01-01

    The challenge of the Radiological Protection (RP) it is to implement Programs of Quality Guarantee without limiting them to the quality control. Radiologists and technicians should to familiarize with the dosimetry of patient, and the specialists in RP need to have clinical practice. The children (more radiosensitive that the adults) they present difficulties own to establish clinical approaches of quality due to their variations anthropomorphic (wide age range) and to specific illnesses. Also, those studies guided by fluoroscopy are of difficult standardization by the numerous ones pathologies (with anatomic-physiologic variations). It was determined the Kerma Area Product (P K,A ) in 25 subjected patients to cystourethrographies carried out by the same radiologist doctor. Its were registered anthropometric data, technical parameters, irradiated area, number radiographs, P K,A , pathologies. The complications (collaboration, delays in urinating), the radiological protocols and the learning curve of the radiologist were analyzed. When knowing the 'in situ' dose, the radiologist could relate it with those variables that determine it, optimizing immediately it practice. The hope wide range of obtained P K,A (0.17 - 1.85) Gy.cm 2 deepened the analysis. The measurement of P K,A (non mandatory in all Latin America) it constitutes an incomparable educational tool in RP, should be used, at least, in reference hospitals. (Author)

  19. Improvement of image quality and dose management in CT fluoroscopy by iterative 3D image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Grosser, Oliver S.; Kupitz, Dennis; Powerski, Maciej; Mohnike, Konrad; Ricke, Jens [University Hospital Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Wybranski, Christian [University Hospital Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); University Hospital Cologne, Institute for Diagnostic and Interventional Radiology, Cologne (Germany); Pech, Maciej [University Hospital Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Medical University of Gdansk, Second Department of Radiology, Gdansk (Poland); Amthauer, Holger [University Hospital Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Charite, Department of Nuclear Medicine, Berlin (Germany)

    2017-09-15

    The objective of this study was to assess the influence of an iterative CT reconstruction algorithm (IA), newly available for CT-fluoroscopy (CTF), on image noise, readers' confidence and effective dose compared to filtered back projection (FBP). Data from 165 patients (FBP/IA = 82/74) with CTF in the thorax, abdomen and pelvis were included. Noise was analysed in a large-diameter vessel. The impact of reconstruction and variables (e.g. X-ray tube current I) influencing noise and effective dose were analysed by ANOVA and a pairwise t-test with Bonferroni-Holm correction. Noise and readers' confidence were evaluated by three readers. Noise was significantly influenced by reconstruction, I, body region and circumference (all p ≤ 0.0002). IA reduced the noise significantly compared to FBP (p = 0.02). The effect varied for body regions and circumferences (p ≤ 0.001). The effective dose was influenced by the reconstruction, body region, interventional procedure and I (all p ≤ 0.02). The inter-rater reliability for noise and readers' confidence was good (W ≥ 0.75, p < 0.0001). Noise and readers' confidence were significantly better in AIDR-3D compared to FBP (p ≤ 0.03). Generally, IA yielded a significant reduction of the median effective dose. The CTF reconstruction by IA showed a significant reduction in noise and effective dose while readers' confidence increased. (orig.)

  20. Visualization of femorotibial contact in total knee arthroplasty using X-ray fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Takaharu E-mail: yamazaki@image.med.osaka-u.ac.jp; Watanabe, Tetsu; Nakajima, Yoshikazu; Sugamoto, Kazuomi; Tomita, Tetsuya; Maeda, Daisuke; Sahara, Wataru; Yoshikawa, Hideki; Tamura, Shinichi

    2005-01-01

    The purpose of this study was to build a visualization technique of the femorotibial contact in fixed-bearing total knee arthroplasty (TKA) using X-ray fluoroscopy, and to apply this technique to a TKA patient during dynamic motion. In vivo kinametcis of the metallic knee implant was determined using a 2D/3D registration technique, which uses computer assisted design (CAD) model of the implant to estimate the 3D pose of radiopaque metallic femoral and tibial components from a single-plane fluoroscopic image. In fixed-bearing TKA, a 3D pose of radiolucent tibial polyethylene insert can be determined from the estimated pose of the tibial component. To visualize femorotibial contact, the proximity between surfaces of femoral component and tibial insert was calculated, and mapped onto the insert surface model. For the clinical application, dynamic states of contact on the tibial insert were observed including axial rotation and unilateral loading during knee flexion, and post-cam contact of posterior stabilized TKA. The present technique provided us new information and enabled us to better understand the relationship between in vivo knee kinematics and articular shape of the implant.

  1. CT fluoroscopy-assisted puncture of thoracic and abdominal masses: a randomized trial.

    Science.gov (United States)

    Kirchner, Johannes; Kickuth, Ralph; Laufer, Ulf; Schilling, Esther Maria; Adams, Stephan; Liermann, Dieter

    2002-03-01

    We investigated the benefit of real-time guidance of interventional punctures by means of computed tomography fluoroscopy (CTF) compared with the conventional sequential acquisition guidance. In a prospective randomized trial, 75 patients underwent either CTF-guided (group A, n = 50) or sequential CT-guided (group B, n = 25) punctures of thoracic (n = 29) or abdominal (n = 46) masses. CTF was performed on the CT machine (Somatom Plus 4 Power, Siemens Corp., Forchheim, Germany) equipped with the C.A.R.E. Vision application (tube voltage 120 kV, tube current 50 mA, rotational time 0.75 s, slice thickness 10 mm, 8 frames/s). The average procedure time showed a statistically significant difference between the two study groups (group A: 564 s, group B 795 s, P = 0.0032). The mean total mAs was 7089 mAs for the CTF and 4856 mAs for the sequential image-guided intervention, respectively. The sensitivity was 71% specificity 100% positive predictive value 100% and negative predictive value 60% for the CTF-guided puncture, and 68, 100, 100 and 50% for sequential CT, respectively. CTF guidance realizes a time-saving but increases the radiation exposure dosage.

  2. MO-G-18A-01: Radiation Dose Reducing Strategies in CT, Fluoroscopy and Radiography

    International Nuclear Information System (INIS)

    Mahesh, M; Gingold, E; Jones, A

    2014-01-01

    Advances in medical x-ray imaging have provided significant benefits to patient care. According to NCRP 160, there are more than 400 million x-ray procedures performed annually in the United States alone that contributes to nearly half of all the radiation exposure to the US population. Similar growth trends in medical x-ray imaging are observed worldwide. Apparent increase in number of medical x-ray imaging procedures, new protocols and the associated radiation dose and risk has drawn considerable attention. This has led to a number of technological innovations such as tube current modulation, iterative reconstruction algorithms, dose alerts, dose displays, flat panel digital detectors, high efficient digital detectors, storage phosphor radiography, variable filters, etc. that are enabling users to acquire medical x-ray images at a much lower radiation dose. Along with these, there are number of radiation dose optimization strategies that users can adapt to effectively lower radiation dose in medical x-ray procedures. The main objectives of this SAM course are to provide information and how to implement the various radiation dose optimization strategies in CT, Fluoroscopy and Radiography. Learning Objectives: To update impact of technological advances on dose optimization in medical imaging. To identify radiation optimization strategies in computed tomography. To describe strategies for configuring fluoroscopic equipment that yields optimal images at reasonable radiation dose. To assess ways to configure digital radiography systems and recommend ways to improve image quality at optimal dose

  3. Fluoroscopy-guided hydrostatic reduction of intussusception in infancy: role of pharmacological premedication.

    Science.gov (United States)

    Esposito, Francesco; Ambrosio, Concetta; De Fronzo, Simona; Panico, Maria Rita; D'Aprano, Marilena; Giugliano, Anna Marcella; Noviello, Domenico; Oresta, Patrizia

    2015-06-01

    Intussusception is one of the most common causes of paediatric emergency. Fluoroscopy-guided hydrostatic reduction is a common nonoperative management strategy for the treatment of intussusception. The role of pharmacological premedication in increasing the success rate of hydrostatic reduction is still controversial. The purpose of this study was to verify the presence of a possible correlation between pharmacological premedication and the percentage of hydrostatic reduction of intussusception in paediatric patients. This study considered children with a diagnosis of idiopathic intussusception treated at our hospital between January 2007 and June 2013. One group of patients underwent hydrostatic reduction by barium enema without any preliminary therapy. A second group of patients received pharmacological premedication with both a sedative and an anti-oedematous agent before the procedure. A total of 398 patients were treated with barium enema for therapeutic purposes. In the group of patients who received no premedication (n = 254), 165 (65 %) children achieved hydrostatic reduction of the intussusception. Among the patients who received pharmacological premedication prior to barium enema (n = 144), 122 (85 %) children achieved resolution of the intussusception. Our study shows that the use of pharmacological premedication is effective for the reduction of the intussusception, as its limit patient stress, fluoroscopic time and radiation dose.

  4. Fluoroscopy without the grid: a method of reducing the radiation dose

    International Nuclear Information System (INIS)

    Drury, P.; Robinson, A.

    1980-01-01

    The anti-scatter grid has been removed from the fluoroscopic set during the course of over 80 contrast examinations performed routinely during the ordinary workload of a busy paediatric radiology department. This manoeuvre approximatley halves the radiation dose to the patient during both fluoroscopy and radiography. Experience suggests that the degree of loss of contrast consequent on the abandonment of the grid is diagnostically acceptable during many examinations performed on children (of all ages), when balanced against the lower radiation dose received. In addition, an assessment has been made of the contrast improvement factor of the grids in two fluoroscopic sets in common use, using tissue-equivalent phantoms of various thicknesses. Although the contrast was significantly improved by the use of the grid, to a degree dependent on various factors, the relevance of this improvement in clinical radiology depends on exactly what information is being sought. It is recommended that radiologists should use the grid with discretion when performing fluoroscopic examinations on children and that the apparatus for such examinations should have the capability for easy removal and reintroduction of the grid. (author)

  5. Assessing patient dose in interventional fluoroscopy using patient-dependent hybrid phantoms

    Science.gov (United States)

    Johnson, Perry Barnett

    Interventional fluoroscopy uses ionizing radiation to guide small instruments through blood vessels or other body pathways to sites of clinical interest. The technique represents a tremendous advantage over invasive surgical procedures, as it requires only a small incision, thus reducing the risk of infection and providing for shorter recovery times. The growing use and increasing complexity of interventional procedures, however, has resulted in public health concerns regarding radiation exposures, particularly with respect to localized skin dose. Tracking and documenting patient-specific skin and internal organ dose has been specifically identified for interventional fluoroscopy where extended irradiation times, multiple projections, and repeat procedures can lead to some of the largest doses encountered in radiology. Furthermore, inprocedure knowledge of localized skin doses can be of significant clinical importance to managing patient risk and in training radiology residents. In this dissertation, a framework is presented for monitoring the radiation dose delivered to patients undergoing interventional procedures. The framework is built around two key points, developing better anthropomorphic models, and designing clinically relevant software systems for dose estimation. To begin, a library of 50 hybrid patient-dependent computational phantoms was developed based on the UF hybrid male and female reference phantoms. These phantoms represent a different type of anthropomorphic model whereby anthropometric parameters from an individual patient are used during phantom selection. The patient-dependent library was first validated and then used in two patient-phantom matching studies focused on cumulative organ and local skin dose. In terms of organ dose, patient-phantom matching was shown most beneficial for estimating the dose to large patients where error associated with soft tissue attenuation differences could be minimized. For small patients, inherent difference

  6. SU-F-P-44: A Direct Estimate of Peak Skin Dose for Interventional Fluoroscopy Procedures

    International Nuclear Information System (INIS)

    Weir, V; Zhang, J

    2016-01-01

    Purpose: There is an increasing demand for medical physicist to calculate peak skin dose (PSD) for interventional fluoroscopy procedures. The dose information (Dose-Area-Product and Air Kerma) displayed in the console cannot directly be used for this purpose. Our clinical experience shows that the use of the existing methods may overestimate or underestimate PSD. This study attempts to develop a direct estimate of PSD from the displayed dose metrics. Methods: An anthropomorphic torso phantom was used for dose measurements for a common fluoroscopic procedure. Entrance skin doses were measured with a Piranha solid state point detector placed on the table surface below the torso phantom. An initial “reference dose rate” (RE) measurement was conducted by comparing the displayed dose rate (mGy/min) to the dose rate measured. The distance from table top to focal spot was taken as the reference distance (RD at the RE. Table height was then adjusted. The displayed air kerma and DAP were recorded and sent to three physicists to estimate PSD. An inverse square correction was applied to correct displayed air kerma at various table heights. The PSD estimated by physicists and the PSD by the proposed method were then compared with the measurements. The estimated DAPs were compared to displayed DAP readings (mGycm2). Results: The difference between estimated PSD by the proposed method and direct measurements was less than 5%. For the same set of data, the estimated PSD by each of three physicists is different from measurements by ±52%. The DAP calculated by the proposed method and displayed DAP readings in the console is less than 20% at various table heights. Conclusion: PSD may be simply estimated from displayed air kerma or DAP if the distance between table top and tube focal spot or if x-ray beam area on table top is available.

  7. Fluoroscopy-Guided Sacroiliac Intraarticular Injection via the Middle Portion of the Joint.

    Science.gov (United States)

    Kurosawa, Daisuke; Murakami, Eiichi; Aizawa, Toshimi

    2017-09-01

    Sacroiliac intraarticular injection is necessary to confirm sacroiliac joint (SIJ) pain and is usually performed via the caudal one-third portion of the joint. However, this is occasionally impossible for anatomical reasons, and the success rate is low in clinical settings. We describe a technique via the middle portion of the joint. Observational study. Enrolled were 69 consecutive patients (27 men and 42 women, with an average age of 53 years) in whom the middle portion of 100 joints was targeted. With the patient lying prone-oblique with the painful side down, a spinal needle was inserted into the middle portion of the joint. Subsequently, the fluoroscopy tube was angled at a caudal tilt of 25-30° to clearly detect the recess between the ilium and sacrum and the needle depth and direction. When the needle reached the posterior joint line, 2% lidocaine was injected after the contrast medium outlined the joint. The success rate of the injection method was 80% (80/100). Among 80 successful cases, four were previously unsuccessful when the conventional method was used. Intraarticular injection using the new technique was unsuccessful in 20 joints; in three of these cases, the conventional method proved successful, and no techniques were successful in the other 17 cases. The injection technique via the middle portion of the joint can overcome some of the difficulties of the conventional injection method and can improve the chances of successful intraarticular injection. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  8. Optimization of detector pixel size for stent visualization in x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Jiang Yuhao; Wilson, David L.

    2006-01-01

    Pixel size is of great interest in the flat-panel detector design because of its potential impact on image quality. In the particular case of angiographic x-ray fluoroscopy, small pixels are required in order to adequately visualize interventional devices such as guidewires and stents which have wire diameters as small as 200 and 50 μm, respectively. We used quantitative experimental and modeling techniques to investigate the optimal pixel size for imaging stents. Image quality was evaluated by the ability of subjects to perform two tasks: detect the presence of a stent and discriminate a partially deployed stent from a fully deployed one in synthetic images. With measurements at 50, 100, 200, and 300 μm, the 100 μm pixel size gave the maximum contrast sensitivity for the detection experiment with the idealized direct detector. For an idealized indirect detector with a scintillating layer, an optimal pixel size was obtained at 200 μm pixel size. A channelized human observer model predicted a peak at 150 and 170 μm, for the idealized direct and indirect detectors, respectively. With regard to the stent deployment task for both detector types, smaller pixel sizes are favored and there is a steep drop in performance with larger pixels. In general, with the increasing exposures, the model and measurements give the enhanced contrast sensitivities and a smaller optimal pixel size. The effects of electronic noise and fill factor were investigated using the model. We believe that the experimental results and human observer model predications can help guide the flat-panel detector design. In addition, the human observer model should work on the similar images and be applicable to the future model and actual flat-panel implementations

  9. SU-F-I-71: Fetal Protection During Fluoroscopy: To Shield Or Not to Shield?

    International Nuclear Information System (INIS)

    Joshi, S; Vanderhoek, M

    2016-01-01

    Purpose: Lead aprons are routinely used to shield the fetus from radiation during fluoroscopically guided interventions (FGI) involving pregnant patients. When placed in the primary beam, lead aprons often reduce image quality and increase fluoroscopic radiation output, which can adversely affect fetal dose. The purpose of this work is to identify an effective and practical method to reduce fetal dose without affecting image quality. Methods: A pregnant patient equivalent abdominal phantom is set on the table along with an image quality test object (CIRS model 903) representing patient anatomy of interest. An ion chamber is positioned at the x-ray beam entrance to the phantom, which is used to estimate the relative fetal dose. For three protective methods, image quality and fetal dose measurements are compared to baseline (no protection):1. Lead apron shielding the entire abdomen; 2. Lead apron shielding part of the abdomen, including the fetus; 3. Narrow collimation such that fetus is excluded from the primary beam. Results: With lead shielding the entire abdomen, the dose is reduced by 80% relative to baseline along with a drastic deterioration of image quality. With lead shielding only the fetus, the dose is reduced by 65% along with complete preservation of image quality, since the image quality test object is not shielded. However, narrow collimation results in 90% dose reduction and a slight improvement of image quality relative to baseline. Conclusion: The use of narrow collimation to protect the fetus during FGI is a simple and highly effective method that simultaneously reduces fetal dose and maintains sufficient image quality. Lead aprons are not as effective at fetal dose reduction, and if placed improperly, they can severely degrade image quality. Future work aims to investigate a wider variety of fluoroscopy systems to confirm these results across many different system geometries.

  10. Rigorous accuracy assessment for 3D reconstruction using time-series Dual Fluoroscopy (DF) image pairs

    Science.gov (United States)

    Al-Durgham, Kaleel; Lichti, Derek D.; Kuntze, Gregor; Ronsky, Janet

    2017-06-01

    High-speed biplanar videoradiography, or clinically referred to as dual fluoroscopy (DF), imaging systems are being used increasingly for skeletal kinematics analysis. Typically, a DF system comprises two X-ray sources, two image intensifiers and two high-speed video cameras. The combination of these elements provides time-series image pairs of articulating bones of a joint, which permits the measurement of bony rotation and translation in 3D at high temporal resolution (e.g., 120-250 Hz). Assessment of the accuracy of 3D measurements derived from DF imaging has been the subject of recent research efforts by several groups, however with methodological limitations. This paper presents a novel and simple accuracy assessment procedure based on using precise photogrammetric tools. We address the fundamental photogrammetry principles for the accuracy evaluation of an imaging system. Bundle adjustment with selfcalibration is used for the estimation of the system parameters. The bundle adjustment calibration uses an appropriate sensor model and applies free-network constraints and relative orientation stability constraints for a precise estimation of the system parameters. A photogrammetric intersection of time-series image pairs is used for the 3D reconstruction of a rotating planar object. A point-based registration method is used to combine the 3D coordinates from the intersection and independently surveyed coordinates. The final DF accuracy measure is reported as the distance between 3D coordinates from image intersection and the independently surveyed coordinates. The accuracy assessment procedure is designed to evaluate the accuracy over the full DF image format and a wide range of object rotation. Experiment of reconstruction of a rotating planar object reported an average positional error of 0.44 +/- 0.2 mm in the derived 3D coordinates (minimum 0.05 and maximum 1.2 mm).

  11. Anatomic landmarks of fluoroscopy guided puncture of the pulseless femoral artery

    International Nuclear Information System (INIS)

    Jeon, Min Hee; Han, Gi Seok; Kim, Sung Jin; Park, Kil Sun; Cha, Sang Hoon; Bae, Il Hun; Lee, Seung Young

    2006-01-01

    We wanted to improve puncturing the pulseless femoral artery by evaluating the anatomic landmarks that suggest the course of the femoral artery on fluoroscopy. We analyzed 37 hemipelvis spot images that were centered on the arterial sheath after puncture of the femoral artery. The inguinal angles were measured between the inguinal line connecting the anterior superior iliac spine and the symphysis pubis, and the line of the arterial sheath. Inguinal ligament ratios were measured as the distance from the symphysis pubis to the arterial sheath to the length of the inguinal ligament on the inguinal line. The femoral head ratios were measured as the distance from the medial margin of the femur head to the arterial sheath to the transverse length of the femur head. The mean inguinal angle was 66.5 and the mean inguinal ligament ratio was 0.42 (± 0.03). The mean femoral head ratio was 0.08 (± 0.18). In comparing the men and women, there was no significant difference in the inguinal angle and the femoral head ratio, but the inguinal distance ratio was larger in women (men: 0.41 ± 0.033, women: 0.44 ± 0.031, ρ < 0.05). The femoral artery generally courses just lateral to the medial margin of the femur head (femoral head ratio: 0.08) and the medial 40% of the inguinal ligament (inguinal ligament ratio: 0.42). So, consideration of these relations may be helpful for puncturing the pulseless femoral artery

  12. SU-F-P-44: A Direct Estimate of Peak Skin Dose for Interventional Fluoroscopy Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Weir, V [Baylor Scott and White Healthcare System, Dallas, TX (United States); Zhang, J [University of Kentucky, Lexington, KY (United States)

    2016-06-15

    Purpose: There is an increasing demand for medical physicist to calculate peak skin dose (PSD) for interventional fluoroscopy procedures. The dose information (Dose-Area-Product and Air Kerma) displayed in the console cannot directly be used for this purpose. Our clinical experience shows that the use of the existing methods may overestimate or underestimate PSD. This study attempts to develop a direct estimate of PSD from the displayed dose metrics. Methods: An anthropomorphic torso phantom was used for dose measurements for a common fluoroscopic procedure. Entrance skin doses were measured with a Piranha solid state point detector placed on the table surface below the torso phantom. An initial “reference dose rate” (RE) measurement was conducted by comparing the displayed dose rate (mGy/min) to the dose rate measured. The distance from table top to focal spot was taken as the reference distance (RD at the RE. Table height was then adjusted. The displayed air kerma and DAP were recorded and sent to three physicists to estimate PSD. An inverse square correction was applied to correct displayed air kerma at various table heights. The PSD estimated by physicists and the PSD by the proposed method were then compared with the measurements. The estimated DAPs were compared to displayed DAP readings (mGycm2). Results: The difference between estimated PSD by the proposed method and direct measurements was less than 5%. For the same set of data, the estimated PSD by each of three physicists is different from measurements by ±52%. The DAP calculated by the proposed method and displayed DAP readings in the console is less than 20% at various table heights. Conclusion: PSD may be simply estimated from displayed air kerma or DAP if the distance between table top and tube focal spot or if x-ray beam area on table top is available.

  13. A novel radiation protection drape reduces radiation exposure during fluoroscopy guided electrophysiology procedures.

    Science.gov (United States)

    Germano, Joseph J; Day, Gina; Gregorious, David; Natarajan, Venkataraman; Cohen, Todd

    2005-09-01

    The purpose of this study was to evaluate a novel disposable lead-free radiation protection drape for decreasing radiation scatter during electrophysiology procedures. In recent years, there has been an exponential increase in the number of electrophysiology (EP) procedures exposing patients, operators and laboratory staff to higher radiation doses. The RADPAD was positioned slightly lateral to the incision site for pectoral device implants and superior to the femoral vein during electrophysiology studies. Each patient served as their own control and dosimetric measurements were obtained at the examiner's elbow and hand. Radiation badge readings for the operator were obtained three months prior to RADPAD use and three months after introduction. Radiation dosimetry was obtained in twenty patients: 7 electrophysiology studies, 6 pacemakers, 5 catheter ablations, and 2 implantable cardioverter-defibrillators. Eleven women and nine men with a mean age of 63 +/- 4 years had an average fluoroscopy time of 2.5 +/- 0.42 minutes per case. Mean dosimetric measurements at the hand were reduced from 141.38 +/- 24.67 to 48.63 +/- 9.02 milliroentgen (mR) per hour using the protective drape (63% reduction; p < 0.0001). Measurements at the elbow were reduced from 78.78 +/- 7.95 mR per hour to 34.50 +/- 4.18 mR per hour using the drape (55% reduction; p < 0.0001). Badge readings for three months prior to drape introduction averaged 2.45 mR per procedure versus 1.54 mR per procedure for 3 months post-initiation (37% reduction). The use of a novel radiation protection surgical drape can significantly reduce scatter radiation exposure to staff and operators during a variety of EP procedures.

  14. SU-F-I-71: Fetal Protection During Fluoroscopy: To Shield Or Not to Shield?

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, S; Vanderhoek, M [Henry Ford Health System, Detroit, MI (United States)

    2016-06-15

    Purpose: Lead aprons are routinely used to shield the fetus from radiation during fluoroscopically guided interventions (FGI) involving pregnant patients. When placed in the primary beam, lead aprons often reduce image quality and increase fluoroscopic radiation output, which can adversely affect fetal dose. The purpose of this work is to identify an effective and practical method to reduce fetal dose without affecting image quality. Methods: A pregnant patient equivalent abdominal phantom is set on the table along with an image quality test object (CIRS model 903) representing patient anatomy of interest. An ion chamber is positioned at the x-ray beam entrance to the phantom, which is used to estimate the relative fetal dose. For three protective methods, image quality and fetal dose measurements are compared to baseline (no protection):1. Lead apron shielding the entire abdomen; 2. Lead apron shielding part of the abdomen, including the fetus; 3. Narrow collimation such that fetus is excluded from the primary beam. Results: With lead shielding the entire abdomen, the dose is reduced by 80% relative to baseline along with a drastic deterioration of image quality. With lead shielding only the fetus, the dose is reduced by 65% along with complete preservation of image quality, since the image quality test object is not shielded. However, narrow collimation results in 90% dose reduction and a slight improvement of image quality relative to baseline. Conclusion: The use of narrow collimation to protect the fetus during FGI is a simple and highly effective method that simultaneously reduces fetal dose and maintains sufficient image quality. Lead aprons are not as effective at fetal dose reduction, and if placed improperly, they can severely degrade image quality. Future work aims to investigate a wider variety of fluoroscopy systems to confirm these results across many different system geometries.

  15. Skeletal imaging following reconstruction of the posterior cruciate ligament: in vivo comparison of fluoroscopy, radiography, and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Osti, Michael; Benedetto, Karl Peter [Academic Hospital Feldkirch, Department for Trauma Surgery and Sports Traumatology, Feldkirch (Austria); Krawinkel, Alessa [Academic Hospital Feldkirch, Department for Radiology, Feldkirch (Austria)

    2014-12-15

    Intra- and postoperative validation of anatomic footprint replication in posterior cruciate ligament (PCL) reconstruction can be conducted using fluoroscopy, radiography, or computed tomography (CT) scans. However, effectiveness and exposure to radiation of these imaging modalities are unknown. The objective of this study was to evaluate the comparative effectiveness of fluoroscopy, radiography, and CT in detecting femoral and tibial tunnel positions following an all-inside reconstruction of the PCL ligament in vivo. The study design was a retrospective case series. Intraoperative fluoroscopic images, postoperative radiographs, and CT scans were obtained in 50 consecutive patients following single-bundle PCL reconstruction. The centers of the tibial and femoral tunnel apertures were identified and correlated to measurement grid systems. The results of fluoroscopic, radiographic, and CT measurements were compared to each other and accumulated radiation dosages were calculated. Comparing the imaging groups, no statistically significant difference could be detected for the reference of the femoral tunnel to the intercondylar depth and height, for the reference of the tibial tunnel to the mediolateral diameter of the tibial plateau and for the superoinferior distance of the tibial tunnel entry to the tibial plateau and to the former physis line. Effective doses resulting from fluoroscopic, radiographic, and CT exposure averaged 2.9 mSv, standard deviation (±SD) 4.1 mSv, to 1.3 ± 0.8 mSv and to 3.6 ± 1.0 mSv, respectively. Fluoroscopy, radiography, and CT yield approximately equal effectiveness in detecting parameters used for quality validation intra- and postoperatively. An accumulating exposure to radiation must be considered. (orig.)

  16. Evaluation of RSA set-up from a clinical biplane fluoroscopy system for 3D joint kinematic analysis.

    Science.gov (United States)

    Bonanzinga, Tommaso; Signorelli, Cecilia; Bontempi, Marco; Russo, Alessandro; Zaffagnini, Stefano; Marcacci, Maurilio; Bragonzoni, Laura

    2016-01-01

    dinamic roentgen stereophotogrammetric analysis (RSA), a technique currently based only on customized radiographic equipment, has been shown to be a very accurate method for detecting three-dimensional (3D) joint motion. The aim of the present work was to evaluate the applicability of an innovative RSA set-up for in vivo knee kinematic analysis, using a biplane fluoroscopic image system. To this end, the Authors describe the set-up as well as a possible protocol for clinical knee joint evaluation. The accuracy of the kinematic measurements is assessed. the Authors evaluated the accuracy of 3D kinematic analysis of the knee in a new RSA set-up, based on a commercial biplane fluoroscopy system integrated into the clinical environment. The study was organized in three main phases: an in vitro test under static conditions, an in vitro test under dynamic conditions reproducing a flexion-extension range of motion (ROM), and an in vivo analysis of the flexion-extension ROM. For each test, the following were calculated, as an indication of the tracking accuracy: mean, minimum, maximum values and standard deviation of the error of rigid body fitting. in terms of rigid body fitting, in vivo test errors were found to be 0.10±0.05 mm. Phantom tests in static and kinematic conditions showed precision levels, for translations and rotations, of below 0.1 mm/0.2° and below 0.5 mm/0.3° respectively for all directions. the results of this study suggest that kinematic RSA can be successfully performed using a standard clinical biplane fluoroscopy system for the acquisition of slow movements of the lower limb. a kinematic RSA set-up using a clinical biplane fluoroscopy system is potentially applicable and provides a useful method for obtaining better characterization of joint biomechanics.

  17. [Assessment of the surgeon radiation exposure during a minimally invasive TLIF: Comparison between fluoroscopy and O-arm system].

    Science.gov (United States)

    Grelat, M; Zairi, F; Quidet, M; Marinho, P; Allaoui, M; Assaker, R

    2015-08-01

    Transforaminal lumbar interbody fusion with a minimally invasive approach (MIS TLIF) has become a very popular technique in the treatment of degenerative diseases of the lumbar spine, as it allows a decrease in muscle iatrogenic. However, iterative radiological controls inherent to this technique are responsible for a significant increase in exposure to ionizing radiation for the surgeon. New techniques for radiological guidance (O-arm navigation-assisted) would overcome this drawback, but this remains unproven. To analyze the exposure of the surgeon to intraoperative X-ray during a MIS TLIF under fluoroscopy and under O-arm navigation-assisted. This prospective study was conducted at the University Hospital of Lille from February to May 2013. Twelve patients underwent a MIS TLIF for the treatment of low-grade spondylolisthesis; six under standard fluoroscopy (group 1) and six under O-arm system (group 2). Passive dosimeters (rings and glasses) and active dosimeters for thorax were used to measure the radiation exposure of the surgeon. For group 1, the average time of fluoroscopy was 3.718 minutes (3.13-4.56) while no radioscopy was perform on group 2. For the first group, the average exposure dose was 12 μSv (5-20 μSv) on the thorax, 1168 μSv (510-2790 μSv) on the main hand and 179 μSv (103-486 μSv) on the lens. The exposure dose was measured zero on the second group. The maximum recommended doses can be reached, mainly for the lens. In addition to the radioprotection measures, O-arm navigation systems are safe alternatives to significantly reduce surgeon exposure. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. Survey of effective doses to patients undergoing contrast-based X-ray fluoroscopy procedures in Tanzania

    International Nuclear Information System (INIS)

    Ngaile, J.E.; Msaki, P.K.; Kazema, R.R.

    2017-01-01

    The aim of this study was to assess the radiation burden imparted to patients from contrast-based X-ray fluoroscopy procedures in Tanzania. The effective doses (EDs) to patients from five contrast-based fluoroscopy procedures were obtained from four hospitals. The ED was estimated using the knowledge of the patient characteristics, patient-related exposure parameters, measurements of air kerma area product and PCXCM software. The median EDs for the barium swallow (BS), barium meal (BM), barium enema (BE), hysterosalpingography (HSG) and retrograde urethrography (RUG) were 0.50, 1.43, 2.83, 0.65 and 0.59 mSv, respectively. The median ED per hospital for the BS and BM procedures varied by factors of up to 9.9 and 4.2, respectively, while for the BE, HSG and RUG varied by factors of up to 2.3, 2.4 and 4.3, respectively. The overall differences between individual EDs across the four hospitals varied by factors of up to 53, 58.9 and 11.4 for the BS, BM and BE, respectively, while for the HSG and RUG differed by factors of up to 22 and 46.7, respectively. The mean EDs in this study were mostly lower than reported values from Spain, the UK, Ghana and Greece, while slightly higher than those reported from India. The observed wide variations of procedural protocols and patient doses within and across the hospitals; and the observed high patient doses in this study relative to those from the literature call for the need to standardize procedural protocols and optimize contrast-based fluoroscopy procedures. (authors)

  19. Digital tumor fluoroscopy (DTF)--a new direct imaging system in the therapy planning for brain tumors.

    Science.gov (United States)

    Herbst, M; Fröder, M

    1990-01-01

    Digital Tumor Fluoroscopy is an expanded x-ray video chain optimized to iodine contrast with an extended Gy scale up to 64000 Gy values. Series of pictures are taken before and after injection of contrast medium. With the most recent unit, up to ten images can be taken and stored. The microprogrammable processor allows the subtraction of images recorded at any moment of the examination. Dynamic views of the distribution of contrast medium in the intravasal and extravasal spaces of brain and tumor tissue are gained by the subtraction of stored images. Tumors can be differentiated by studying the storage and drainage behavior of the contrast medium during the period of examination. Meningiomas store contrast medium very intensively during the whole time of investigation, whereas astrocytomas grade 2-3 pick it up less strongly at the beginning and release it within 2 min. Glioblastomas show a massive but delayed accumulation of contrast medium and a decreased flow-off-rate. In comparison with radiography and MR-imaging the most important advantage of Digital Tumor Fluoroscopy is that direct information on tumor localization is gained in relation to the skull-cap. This enables the radiotherapist to mark the treatment field directly on the skull. Therefore it is no longer necessary to calculate the tumor volume from several CT scans for localization. In radiotherapy Digital Tumor Fluoroscopy a unit combined with a simulator can replace CT planning. This would help overcome the disadvantages arising from the lack of a collimating system, and the inaccuracies which result from completely different geometric relationships between a CT unit and a therapy machine.

  20. Fluoroscopy-assisted vs fluoroless endoscopic ultrasound-guided transmural drainage of pancreatic fluid collections: A comparative study.

    Science.gov (United States)

    Consiglieri, Claudia F; Gornals, Joan B; Busquets, Juli; Peláez, Nuria; Secanella, Lluis; De-La-Hera, Meritxell; Sanzol, Resurrección; Fabregat, Joan; Castellote, José

    2018-01-01

    The need for fluoroscopy guidance in patients undergoing endoscopic ultrasound-guided transmural drainage (EUS-TMD) of peripancreatic fluid collections (PFCs) remains unclear. The aim of this study was to compare general outcomes of EUS-TMD of PFCs under fluoroscopy (F) vs fluoroless (FL). This is a comparative study with a retrospective analysis of a prospective and consecutive inclusion database at a tertiary centre, from 2009 to 2015. All patients were symptomatic pseudocyst (PSC) and walled-off pancreatic necrosis (WON). Two groups were assigned depending on availability of fluoroscopy. The groups were heterogeneous in terms of their demographic characteristics, PFCs and procedure. The main outcome measures included technical and clinical success, incidences, adverse events (AEs), and follow-up. Fifty EUS-TMD of PFCs from 86 EUS-guided drainages were included during the study period. Group F included 26 procedures, PSC 69.2%, WON 30.8%, metal stents 61.5% (46.1% lumen-apposing stent) and plastic stents 38.5%. Group FL included 24 procedures, PSC 37.5%, WON 62.5%, and metal stents 95.8% (lumen-apposing stents). Technical success was 100% in both groups, and clinical success was similar (F 88.5%, FL 87.5%). Technical incidences and intra-procedure AEs were only described in group F (7.6% and 11.5%, respectively) and none in group FL. Procedure time was less in group FL (8min, p=0.0341). Fluoroless in the EUS-TMD of PFCs does not involve more technical incidences or intra-procedure AEs. Technical and clinical success was similar in the two groups. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  1. Heel Effect: Dose Mapping And Profiling For Mobile C-Arm Fluoroscopy Unit Toshiba SXT-1000A

    International Nuclear Information System (INIS)

    Husaini Salleh; Mohd Khalid Matori; Muhammad Jamal Md Isa; Mohd Ramli Arshad; Shahrul Azlan Azizan; Mohd Firdaus Abdul Rahman; Md Khairusalih Md Zin

    2014-01-01

    Heel Effect is the well known phenomena in x-ray production. It contributes the effect to image formation and as well as scattered radiation. But there is paucity in the study related to heel effect. This study is for mapping and profiling the dose on the surface of water phantom by using mobile C-arm unit Toshiba SXT-1000A. Based on the result the dose profile is increasing up to about 57 % from anode to cathode bound of the irradiated area. This result and information can be used as a guide to manipulate these phenomena for better image quality and radiation safety for this specific and dedicated fluoroscopy unit. (author)

  2. Monte Carlo based estimation of organ and effective doses to patients undergoing hysterosalpingography and retrograde urethrography fluoroscopy procedures

    Science.gov (United States)

    Ngaile, J. E.; Msaki, P. K.; Kazema, R. R.

    2018-04-01

    Contrast investigations of hysterosalpingography (HSG) and retrograde urethrography (RUG) fluoroscopy procedures remain the dominant diagnostic tools for the investigation of infertility in females and urethral strictures in males, respectively, owing to the scarcity and high cost of services of alternative diagnostic technologies. In light of the radiological risks associated with contrast based investigations of the genitourinary tract systems, there is a need to assess the magnitude of radiation burden imparted to patients undergoing HSG and RUG fluoroscopy procedures in Tanzania. The air kerma area product (KAP), fluoroscopy time, number of images, organ dose and effective dose to patients undergoing HSG and RUG procedures were obtained from four hospitals. The KAP was measured using a flat transmission ionization chamber, while the organ and effective doses were estimated using the knowledge of the patient characteristics, patient related exposure parameters, geometry of examination, KAP and Monte Carlo calculations (PCXMC). The median values of KAP for the HSG and RUG were 2.2 Gy cm2 and 3.3 Gy cm2, respectively. The median organ doses in the present study for the ovaries, urinary bladder and uterus for the HSG procedures, were 1.0 mGy, 4.0 mGy and 1.6 mGy, respectively, while for urinary bladder and testes of the RUG were 3.4 mGy and 5.9 mGy, respectively. The median values of effective doses for the HSG and RUG procedures were 0.65 mSv and 0.59 mSv, respectively. The median values of effective dose per hospital for the HSG and RUG procedures had a range of 1.6-2.8 mSv and 1.9-5.6 mSv, respectively, while the overall differences between individual effective doses across the four hospitals varied by factors of up to 22.0 and 46.7, respectively for the HSG and RUG procedures. The proposed diagnostic reference levels (DRLs) for the HSG and RUG were for KAP 2.8 Gy cm2 and 3.9 Gy cm2, for fluoroscopy time 0.8 min and 0.9 min, and for number of images 5 and 4

  3. Three-dimensional tracking of cardiac catheters using an inverse geometry x-ray fluoroscopy system

    International Nuclear Information System (INIS)

    Speidel, Michael A.; Tomkowiak, Michael T.; Raval, Amish N.; Van Lysel, Michael S.

    2010-01-01

    tracking precision of ablation and diagnostic catheter tips ranged from ±0.2 mm at the highest image fluence to ±0.9 mm at the lowest fluence. Tracking precision depended on image fluence, the size of the tracked catheter electrode, and the contrast of the electrode. Conclusions: High speed multiplanar tomosynthesis with an inverse geometry x-ray fluoroscopy system enables 3D tracking of multiple high-contrast objects at the rate of fluoroscopic imaging. The SBDX system is capable of tracking electrodes in standard cardiac catheters with approximately 1 mm accuracy and precision.

  4. Principal component reconstruction (PCR) for cine CBCT with motion learning from 2D fluoroscopy.

    Science.gov (United States)

    Gao, Hao; Zhang, Yawei; Ren, Lei; Yin, Fang-Fang

    2018-01-01

    This work aims to generate cine CT images (i.e., 4D images with high-temporal resolution) based on a novel principal component reconstruction (PCR) technique with motion learning from 2D fluoroscopic training images. In the proposed PCR method, the matrix factorization is utilized as an explicit low-rank regularization of 4D images that are represented as a product of spatial principal components and temporal motion coefficients. The key hypothesis of PCR is that temporal coefficients from 4D images can be reasonably approximated by temporal coefficients learned from 2D fluoroscopic training projections. For this purpose, we can acquire fluoroscopic training projections for a few breathing periods at fixed gantry angles that are free from geometric distortion due to gantry rotation, that is, fluoroscopy-based motion learning. Such training projections can provide an effective characterization of the breathing motion. The temporal coefficients can be extracted from these training projections and used as priors for PCR, even though principal components from training projections are certainly not the same for these 4D images to be reconstructed. For this purpose, training data are synchronized with reconstruction data using identical real-time breathing position intervals for projection binning. In terms of image reconstruction, with a priori temporal coefficients, the data fidelity for PCR changes from nonlinear to linear, and consequently, the PCR method is robust and can be solved efficiently. PCR is formulated as a convex optimization problem with the sum of linear data fidelity with respect to spatial principal components and spatiotemporal total variation regularization imposed on 4D image phases. The solution algorithm of PCR is developed based on alternating direction method of multipliers. The implementation is fully parallelized on GPU with NVIDIA CUDA toolbox and each reconstruction takes about a few minutes. The proposed PCR method is validated and

  5. Radiofrequency Ablation Combined with Chemoembolization for Intermediate-Sized (3-5 cm) Hepatocellular Carcinomas Under Dual Guidance of Biplane Fluoroscopy and Ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Min, Ji Hye; Lee, Min Woo; Cha, Dong Ik [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Jeon, Yong Hwan [Department of Radiology, Kangwon National University College of Medicine, Chuncheon 200-722 (Korea, Republic of); Shin, Sung Wook; Cho, Sung Ki; Rhim, Hyunchul; Lim, Hyo K. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)

    2013-07-01

    To assess the technical feasibility and local efficacy of percutaneous radiofrequency ablation (RFA) combined with transcatheter arterial chemoembolization (TACE) for an intermediate-sized (3-5 cm in diameter) hepatocellular carcinoma (HCC) under the dual guidance of biplane fluoroscopy and ultrasonography (US). Patients with intermediate-sized HCCs were treated with percutaneous RFA combined with TACE. RFA was performed under the dual guidance of biplane fluoroscopy and US within 14 days after TACE. We evaluated the rate of major complications on immediate post-RFA CT images. Primary technique effectiveness rate was determined on one month follow-up CT images. The cumulative rate of local tumor progression was estimated with the use of Kaplan-Meier method. Twenty-one consecutive patients with 21 HCCs (mean size: 3.6 cm; range: 3-4.5 cm) were included. After TACE (mean: 6.7 d; range: 1-14 d), 20 (95.2%) of 21 HCCs were visible on fluoroscopy and were ablated under dual guidance of biplane fluoroscopy and US. The other HCC that was poorly visible by fluoroscopy was ablated under US guidance alone. Major complications were observed in only one patient (pneumothorax). Primary technique effectiveness was achieved for all 21 HCCs in a single RFA session. Cumulative rates of local tumor progression were estimated as 9.5% and 19.0% at one and three years, respectively. RFA combined with TACE under dual guidance of biplane fluoroscopy and US is technically feasible and effective for intermediate-sized HCC treatment.

  6. Influence of phantom and tube voltage in fluoroscopy on image intensifier (I.I.) incident dose rate

    International Nuclear Information System (INIS)

    Seguchi, Shigenobu; Ishikawa, Yoshinobu; Kuwahara, Kazuyoshi; Morita, Miki; Mizuno, Shouta; Nakamura, Akio

    1999-01-01

    We examined the influence of phantoms and tube voltage in fluoroscopy on the image intensifier (I.I.) conversion factor. We used 20-cm-thick acrylic resin, 20 mm aluminum, and 1.5 mm copper, which are generally used as phantoms in the measurement of I.I. incident dose rate. We measured I.I. incident dose rate and conversion factor under conditions in which the range of tube voltage was from 60 kV to 120 kV. The result showed that the conversion factor is influenced by the type of phantom, with copper showing the highest value, aluminum second, and acrylic the smallest under the same condition of aluminum at half value layer. It was determined that conversion factor depends on tube voltage and has peaks from 80-100 kV. The location and height of the peak are influenced by the type of phantom. Therefore, I.I. incident dose rate is influenced by both the type of phantom and tube voltage under automatic brightness control fluoroscopy. Unification of phantoms and tube voltage is necessary for long-term evaluation of I.I. incident dose rate. (author)

  7. Real-time fusion of coronary CT angiography with X-ray fluoroscopy during chronic total occlusion PCI

    Energy Technology Data Exchange (ETDEWEB)

    Ghoshhajra, Brian B.; Takx, Richard A.P. [Harvard Medical School, Cardiac MR PET CT Program, Massachusetts General Hospital, Department of Radiology and Division of Cardiology, Boston, MA (United States); Stone, Luke L.; Yeh, Robert W.; Jaffer, Farouc A. [Harvard Medical School, Cardiac Cathetrization Laboratory, Cardiology Division, Massachusetts General Hospital, Boston, MA (United States); Girard, Erin E. [Siemens Healthcare, Princeton, NJ (United States); Brilakis, Emmanouil S. [Cardiology Division, Dallas VA Medical Center and UT Southwestern Medical Center, Dallas, TX (United States); Lombardi, William L. [University of Washington, Cardiology Division, Seattle, WA (United States)

    2017-06-15

    The purpose of this study was to demonstrate the feasibility of real-time fusion of coronary computed tomography angiography (CTA) centreline and arterial wall calcification with X-ray fluoroscopy during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Patients undergoing CTO PCI were prospectively enrolled. Pre-procedural CT scans were integrated with conventional coronary fluoroscopy using prototype software. We enrolled 24 patients who underwent CTO PCI using the prototype CT fusion software, and 24 consecutive CTO PCI patients without CT guidance served as a control group. Mean age was 66 ± 11 years, and 43/48 patients were men. Real-time CTA fusion during CTO PCI provided additional information regarding coronary arterial calcification and tortuosity that generated new insights into antegrade wiring, antegrade dissection/reentry, and retrograde wiring during CTO PCI. Overall CTO success rates and procedural outcomes remained similar between the two groups, despite a trend toward higher complexity in the fusion CTA group. This study demonstrates that real-time automated co-registration of coronary CTA centreline and calcification onto live fluoroscopic images is feasible and provides new insights into CTO PCI, and in particular, antegrade dissection reentry-based CTO PCI. (orig.)

  8. The role of the MR-fluoroscopy in the diagnosis and staging of the pelvic organ prolapse

    International Nuclear Information System (INIS)

    Etlik, Oemer; Arslan, Halil; Odabasi, Oner; Odabasi, Hulya; Harman, Mustafa; Celebi, Hacer; Sakarya, M. Emin

    2005-01-01

    Introduction: The aim of the study is to investigate the efficacy of the magnetic resonance fluoroscopy in the diagnosis and staging of the pelvic prolapse. Materials and methods: The study consisted of 46 patients who were known to have pelvic prolapses from their vaginal examination. Thirty women who underwent vaginal exam and shown not have pelvic prolapse were selected as a control group. Firstly, pelvic sagittal FSE T2 weighted images of all the women were acquired in 0.3 T open MR equipment than sagittal MR-fluoroscopic images using spoiled gradient echo sequences were obtained during pelvic strain. Physical examination and MR-fluoroscopic findings were compared. The relationship between the stages of prolapse established by both of the methods was evaluated statistically with Pearson's correlation analysis. Results: Physical examination and MR findings were very concordant in the diagnosis of pelvic prolapse and statistical correlations in the stages of prolapse were established between both of the methods (P<0.01 for anterior and middle comportment, P<0.05 for posterior comportment). Conclusion: We conclude that MR-fluoroscopy is a non-invasive, easily applied, dynamic useful method without contrast agent in the diagnosis and staging of pelvic organ prolapse

  9. Clinical background and its relation to results of percutaneous needle biopsy of suspected bone metastasis under guidance with CT fluoroscopy

    International Nuclear Information System (INIS)

    Aoki, Jun; Koyama, Yoshinori; Morita, Hideo; Takahashi, Ayako; Nakajima, Takahito; Yagi, Akiko; Arai, Kiyokazu; Shinozaki, Tetsuya; Watanabe, Hideomi

    2005-01-01

    The purpose of this study was to investigate the clinical background of needle biopsy of suspected bone metastasis under guidance with CT fluoroscopy. During a 3-year period (from April 2000 to March 2003), 103 needle biopsies on 101 lesions of 90 patients were performed for pathological evaluation of suspected bone metastasis. The clinical course of these patients prior to biopsy and its relation to the biopsy results were retrospectively reviewed. Sixty-two patients (69% of total cases) were referred for biopsy from orthopedic surgeons, and 51 of these patients consulted orthopedic surgeons on the initial presentation. Malignancy was pathologically proved in 47 (76%) of the 62 orthopedic patients, and in 19 (68%) of the 28 patients referred from other clinicians. Thirteen (21%) of the orthopedic patients had a history of malignancy, while 22 (78%) of the non-orthopedic patients were cancer patients. Metastasis was pathologically proved in 23 (66%) of the 35 patients with a history of malignancy, while malignancy was pathologically proved in 43 (78%) of the 55 patients without known malignancy. Diagnostic accuracy of the needle bone biopsy was 96%, and its complication rate was 0.7%. In the era of CT fluoroscopy, needle biopsy for suspected bone metastasis was most frequently requested for the patients who consulted orthopedic surgeons for the occurrence of local bone pain as the initial symptom of unknown malignancy. Frequency of malignancy proved by the biopsy in those patients was as high as that in the cancer patients referred from other clinicians. (author)

  10. Quantitative image quality evaluation of pixel-binning in a flat-panel detector for x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Srinivas, Yogesh; Wilson, David L.

    2004-01-01

    X-ray fluoroscopy places stringent design requirements on new flat-panel (FP) detectors, requiring both low-noise electronics and high data transfer rates. Pixel-binning, wherein data from more that one detector pixel are collected simultaneously, not only lowers the data transfer rate but also increases x-ray counts and pixel signal-to-noise ratio (SNR). In this study, we quantitatively assessed image quality of image sequences from four acquisition methods; no-binning and three types of binning; in synthetic images using a clinically relevant task of detecting an extended guidewire in a four-alternative forced-choice paradigm. Binning methods were conventional data-line (D) and gate-line (G) binning, and a novel method in which alternate frames in an image sequence used D and G binning. Two detector orientations placed the data lines either parallel or perpendicular to the guide wire. At a low exposure of 0.6 μR (1.548x10 -10 C/kg) per frame, irrespective of detector orientation, D binning with its reduced electronic noise was significantly (p -10 C/kg) per frame, with data lines parallel to the guidewire, detection with D binning was significantly (p<0.1) better than G binning. However, with data lines perpendicular to the guidewire, G binning was significantly (p<0.1) better than D binning because the partial area effect was reduced. Alternate binning was the best binning method when results were averaged over both orientations, and it was as good as the best binning method at either orientation. In addition, at low and high exposures, alternate binning gave a temporally fused image with a smooth guidewire, an important image quality feature not assessed in a detection experiment. While at high exposure, detection with no binning was as good, or better, than the best binning method, it might be impractical at fluoroscopy imaging rates. A computational observer model based on signal detection theory successfully fit data and was used to predict effects of

  11. Ultrasound guidance to perform intra-articular injection of gadolinium-based contrast material for magnetic resonance arthrography as an alternative to fluoroscopy: the time is now

    Energy Technology Data Exchange (ETDEWEB)

    Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Banfi, Giuseppe [IRCCS Istituto Ortopedico Galeazzi, Milano (Italy); Universita Vita-Salute San Raffaele, Milano (Italy); Aliprandi, Alberto [Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milano (Italy); Mauri, Giovanni [Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milano (Italy); Istituto Europeo di Oncologia, Unita di Radiologia Interventistica, Milano (Italy); Secchi, Francesco; Sardanelli, Francesco; Sconfienza, Luca Maria [Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milano (Italy); IRCCS Policlinico San Donato, Servizio di Radiologia, San Donato, Milanese (Italy)

    2016-05-15

    Magnetic resonance (MR) imaging has been definitively established as the reference standard in the evaluation of joints in the body. Similarly, magnetic resonance arthrography has emerged as a technique that has been proven to increase significantly the diagnostic performance if compared with conventional MR imaging, especially when dealing with fibrocartilage and articular cartilage abnormalities. Diluted gadolinium can be injected in the joint space using different approaches: under palpation using anatomic landmarks or using an imaging guidance, such as fluoroscopy, computed tomography, or ultrasound. Fluoroscopy has been traditionally used, but the involvement of ionizing radiation should represent a remarkable limitation of this modality. Conversely, ultrasound has emerged as a feasible, cheap, quick, and radiation-free modality that can be used to inject joints, with comparable accuracy of fluoroscopy. In the present paper, we discuss the advantages and disadvantages of using fluoroscopy or ultrasound in injecting gadolinium-based contrast agents in joints to perform magnetic resonance arthrography, also in view of the new EuroSAFE Imaging initiative promoted by the European Society of Radiology and the recent updates to the European Atomic Energy Community 2013/59 directive on the medical use of ionizing radiation. (orig.)

  12. Prospective randomized comparison between fluoroscopy-guided ureteroscopy versus ureteroscopy with real-time ultrasonography for the management of ureteral stones

    Directory of Open Access Journals (Sweden)

    Vishwajeet Singh

    2016-01-01

    Conclusions: Ultrasound-guided ureteroscopy is safe and effectively for ureteric stone. Fluoroscopy can be avoided during ureteroscopy for uncomplicated stone. No radiation ureteroscopy is feasible with good success and minimal complication. Larger sample size with multicentric trial needed for its greater applicability.

  13. A prospective survey on the incidence of chest malignancies after repeated fluoroscopy during artificial pneumothorax therapy for pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Kitabatake, Takashi; Kurokawa, Shigeki; Yamasaki, Michio; Sato, Toshiro; Kurokawa, Hisae

    1975-01-01

    Patients with pulmonary tuberculosis treated in 4 sanatoria in Niigata Prefecture between 1941 and 1961 were followed up by a mail questionnaire. Of 2756 patients, 1193 responded and sent back effective information, letters to 1224 were returned because of uncertain or unknown new address, 326 did not respond, and 13 were excluded because of incomplete answers. Out of the 1193 effective responders, 568 had been treated by artificial pneumothorax (the pneumothorax group), and 552 had not been treated by pneumothorax (the control group). There were 65 deaths in the pneumothorax group, but none of them were from chest malignancies; and 40 deaths in the control group with 4 from chest malignancies. In this survey, there was no evidence of an increased number of chest malignancies (including leukemia) after pneumothorax fluoroscopy. (auth.)

  14. Intraoperative intermittent blocking of the common iliac arteries in cases of placenta percreta without the use of fluoroscopy

    International Nuclear Information System (INIS)

    Heinze, S.; Klinikum Oldenburg; Filsinger, B.; Kastenholz, G.; Schroeder, R.J.

    2016-01-01

    The number of patients with placenta accreta, percreta and increta is increasing. The morbidity and mortality are higher mostly due to hemorrhage. Therefore, new methods to reduce the risk of severe bleeding are necessary. Three patients were treated in collaboration by obstetricians, urologists, anesthesiologists, and radiologists. An MRI of the pelvis was performed and the diameters and lengths of the iliac arteries were measured to avoid fluoroscopy during the preoperative placement of catheter balloons into the iliac arteries. During the operational procedure the balloons were inflated and deflated depending on the operative site and the occurrence of bleeding. In comparison to the literature, severe bleeding was clearly reduced. No complications of the intervention were observed. The presented method to reduce severe bleeding might represent significant progress in the management of abnormal placenta implantation. Nevertheless, further controlled studies are needed in order to establish evidence-based recommendations.

  15. Successful Localization and Surgical Removal of Ingested Sewing Needles Under Mini C-Arm Fluoroscopy: A Case Report

    Directory of Open Access Journals (Sweden)

    Cheng-Jen Ma

    2006-09-01

    Full Text Available Foreign body ingestion is common, but ingestion of multiple sewing needles is rare. Most ingested sharp metallic bodies pass through the digestive tract spontaneously and patients can be managed conservatively. Sometimes, however, perforation develops and surgical treatment is necessary. It is hard to localize ingested sewing needles because they tend to scatter widely in the digestive tract and are impalpable manually. We report a psychiatric patient who ingested six sewing needles: one intact needle was found at the larynx, one had penetrated into the stomach, one was in the duodenum, one was in the cecum, one was broken into two pieces, and the final needle was broken into three pieces. All of the broken fragments were in the colon. The needle at the larynx was removed by a laryngoscope. Subsequently, we used mini C-arm fluoroscopy to localize the remaining needles and successfully removed all of them intraoperatively.

  16. Prospective survey on the incidence of chest malignancies after repeated fluoroscopy during artificial pneumothorax therapy for pulmonary tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Kitabatake, T; Kurokawa, S; Yamasaki, M; Sato, T; Kurokawa, H [Niigata Univ. (Japan). School of Medicine

    1975-10-01

    Patients with pulmonary tuberculosis treated in 4 sanatoria in Niigata Prefecture between 1941 and 1961 were followed up by a mail questionnaire. Of 2756 patients, 1193 responded and sent back effective information, letters to 1224 were returned because of uncertain or unknown new address, 326 did not respond, and 13 were excluded because of incomplete answers. Out of the 1193 effective responders, 568 had been treated by artificial pneumothorax (the pneumothorax group), and 552 had not been treated by pneumothorax (the control group). There were 65 deaths in the pneumothorax group, but none of them were from chest malignancies; and 40 deaths in the control group with 4 from chest malignancies. In this survey, there was no evidence of an increased number of chest malignancies (including leukemia) after pneumothorax fluoroscopy.

  17. Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Sweta [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Desouches, Stephane L. [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); St. Luke' s Hospital, Department of Radiology, Kansas City, MO (United States); Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton [University of Missouri-Kansas City SOM, Department of Radiology, Kansas City, MO (United States); Children' s Mercy Hospitals and Clinics, Department of Radiology, Kansas City, MO (United States)

    2014-07-24

    Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

  18. How Slow Can We Go? 4 Frames Per Second (fps) Versus 7.5 fps Fluoroscopy for Atrial Septal Defects (ASDs) Device Closure.

    Science.gov (United States)

    Hiremath, Gurumurthy; Meadows, Jeffery; Moore, Phillip

    2015-06-01

    Radiation exposure remains a significant concern for ASD device closure. In an effort to reduce radiation exposure, the default fluoroscopy frame rate in our Siemens biplane pediatric catheterization laboratory was reduced to 4 fps in November 2013 from an earlier 7.5 fps fluoro rate. This study aims to evaluate the components contributing to total radiation exposure and compare the procedural success and radiation exposure during ASD device closure using 4 versus 7.5 fps fluoroscopy rates. Twenty ASD device closures performed using 4 fps fluoro rate were weight-matched to 20 ASD closure procedures using 7.5 fps fluoro rate. Baseline characteristics, procedure times and case times were similar in the two groups. Device closure was successful in all but one case in the 4 fps group. The dose area product (DAP), normalized DAP to body weight, total radiation time and fluoro time were lower in the 4 fps group but not statistically different than the 7.5 fps. The number of cine images and cine times were identical in both groups. Fluoroscopy and cineangiography contributed equally to radiation exposure. Fluoroscopy at 4 fps can be safe and effective for ASD device closure in children and adults. There was no increase in procedure time, cine time, fluoro time or complications at this slow fluoro rate. There was a trend toward decreased radiation exposure as measured by indexed DAP although not statistically significant in this small study. Further study with multiple operators using 4 fps fluoroscopy for simple interventional procedures is recommended.

  19. SU-G-JeP4-12: Real-Time Organ Motion Monitoring Using Ultrasound and KV Fluoroscopy During Lung SBRT Delivery

    International Nuclear Information System (INIS)

    Omari, E; Tai, A; Li, X; Cooper, D; Lachaine, M

    2016-01-01

    Purpose: Real-time ultrasound monitoring during SBRT is advantageous in understanding and identifying motion irregularities which may cause geometric misses. In this work, we propose to utilize real-time ultrasound to track the diaphragm in conjunction with periodical kV fluoroscopy to monitor motion of tumor or landmarks during SBRT delivery. Methods: Transabdominal Ultrasound (TAUS) b-mode images were collected from 10 healthy volunteers using the Clarity Autoscan System (Elekta). The autoscan transducer, which has a center frequency of 5 MHz, was utilized for the scans. The acquired images were contoured using the Clarity Automatic Fusion and Contouring workstation software. Monitoring sessions of 5 minute length were observed and recorded. The position correlation between tumor and diaphragm could be established with periodic kV fluoroscopy periodically acquired during treatment with Elekta XVI. We acquired data using a tissue mimicking ultrasound phantom with embedded spheres placed on a motion stand using ultrasound and kV Fluoroscopy. MIM software was utilized for image fusion. Correlation of diaphragm and target motion was also validated using 4D-MRI and 4D-CBCT. Results: The diaphragm was visualized as a hyperechoic region on the TAUS b-mode images. Volunteer set-up can be adjusted such that TAUS probe will not interfere with treatment beams. A segment of the diaphragm was contoured and selected as our tracking structure. Successful monitoring sessions of the diaphragm were recorded. For some volunteers, diaphragm motion over 2 times larger than the initial motion has been observed during tracking. For the phantom study, we were able to register the 2D kV Fluoroscopy with the US images for position comparison. Conclusion: We demonstrated the feasibility of tracking the diaphragm using real-time ultrasound. Real-time tracking can help in identifying such irregularities in the respiratory motion which is correlated to tumor motion. We also showed the

  20. Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children

    International Nuclear Information System (INIS)

    Shah, Sweta; Desouches, Stephane L.; Lowe, Lisa H.; Kasraie, Nima; Reading, Brenton

    2015-01-01

    Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. Implementation of a competency check-off for radiology resident trainees can reduce average radiation

  1. Placement of iliosacral screws using 3D image-guided (O-Arm) technology and Stealth Navigation: comparison with traditional fluoroscopy.

    Science.gov (United States)

    Theologis, A A; Burch, S; Pekmezci, M

    2016-05-01

    We compared the accuracy, operating time and radiation exposure of the introduction of iliosacral screws using O-arm/Stealth Navigation and standard fluoroscopy. Iliosacral screws were introduced percutaneously into the first sacral body (S1) of ten human cadavers, four men and six women. The mean age was 77 years (58 to 85). Screws were introduced using a standard technique into the left side of S1 using C-Arm fluoroscopy and then into the right side using O-Arm/Stealth Navigation. The radiation was measured on the surgeon by dosimeters placed under a lead thyroid shield and apron, on a finger, a hat and on the cadavers. There were no neuroforaminal breaches in either group. The set-up time for the O-Arm was significantly longer than for the C-Arm, while total time for placement of the screws was significantly shorter for the O-Arm than for the C-Arm (p = 0.001). The mean absorbed radiation dose during fluoroscopy was 1063 mRad (432.5 mRad to 4150 mRad). No radiation was detected on the surgeon during fluoroscopy, or when he left the room during the use of the O-Arm. The mean radiation detected on the cadavers was significantly higher in the O-Arm group (2710 mRem standard deviation (sd) 1922) than during fluoroscopy (11.9 mRem sd 14.8) (p Cite this article: Bone Joint J 2016;98-B:696-702. ©2016 The British Editorial Society of Bone & Joint Surgery.

  2. Fluoroscopy-Guided Percutaneous Vertebral Body Biopsy Using a Novel Drill-Powered Device: Technical Case Series

    International Nuclear Information System (INIS)

    Wallace, Adam N.; Pacheco, Rafael A.; Tomasian, Anderanik; Hsi, Andy C.; Long, Jeremiah; Chang, Randy O.; Jennings, Jack W.

    2016-01-01

    BackgroundA novel coaxial biopsy system powered by a handheld drill has recently been introduced for percutaneous bone biopsy. This technical note describes our initial experience performing fluoroscopy-guided vertebral body biopsies with this system, compares the yield of drill-assisted biopsy specimens with those obtained using a manual technique, and assesses the histologic adequacy of specimens obtained with drill assistance.MethodsMedical records of all single-level, fluoroscopy-guided vertebral body biopsies were reviewed. Procedural complications were documented according to the Society of Interventional Radiology classification. The total length of bone core obtained from drill-assisted biopsies was compared with that of matched manual biopsies. Pathology reports were reviewed to determine the histologic adequacy of specimens obtained with drill assistance.ResultsTwenty eight drill-assisted percutaneous vertebral body biopsies met study inclusion criteria. No acute complications were reported. Of the 86 % (24/28) of patients with clinical follow-up, no delayed complications were reported (median follow-up, 28 weeks; range 5–115 weeks). The median total length of bone core obtained from drill-assisted biopsies was 28 mm (range 8–120 mm). This was longer than that obtained from manual biopsies (median, 20 mm; range 5–45 mm; P = 0.03). Crush artifact was present in 11 % (3/28) of drill-assisted biopsy specimens, which in one case (3.6 %; 1/28) precluded definitive diagnosis.ConclusionsA drill-assisted, coaxial biopsy system can be used to safely obtain vertebral body core specimens under fluoroscopic guidance. The higher bone core yield obtained with drill assistance may be offset by the presence of crush artifact

  3. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography; Avaliacao de dose em procedimentos especiais de fluoroscopia: histerossalpingografia e dacriocistografia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Cintya Carolina Barbosa

    2006-04-15

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  4. CT fluoroscopy-guided vs. multislice CT biopsy mode-guided lung biopsies: Accuracy, complications and radiation dose

    International Nuclear Information System (INIS)

    Prosch, Helmut; Stadler, Alfred; Schilling, Matthias; Bürklin, Sandra; Eisenhuber, Edith; Schober, Ewald; Mostbeck, Gerhard

    2012-01-01

    Background: The aim of this retrospective study was to compare the diagnostic accuracy, the frequency of complications, the duration of the interventions and the radiation doses of CT fluoroscopy (CTF) guided biopsies of lung lesions with those of multislice CT (MS-CT) biopsy mode-guided biopsies. Methods: Data and images from 124 consecutive patients undergoing CTF-guided lung biopsy (group A) and 132 MS-CT-biopsy mode-guided lung biopsy (group B) were reviewed. CTF-guided biopsies were performed on a Siemens Emotion 6 CT scanner with intermittent or continuous CT-fluoroscopy, MS-CT biopsy mode-guided biopsies were performed on a Siemens Emotion 16 CT scanner. All biopsies were performed with a coaxial needle technique. Results: The two groups (A vs. B) did not differ significantly regarding sensitivity (95.5% vs. 95.9%), specificity (96.7% vs. 95.5%), negative predictive value (87.9% vs. 84%) or positive predictive value (98.8% vs. 98.9%). Pneumothorax was observed in 30.0% and 32.5% of the patients, respectively. Chest tube placement was necessary in 4% (group A) and 13% (group B) of the patients. The duration of the intervention was significantly longer in group A (median 37 min vs. 32 min, p = 0.04). The mean CT dose index (CTDI) was 422 in group A and 36.3 in group B (p < 0.001). Conclusion: Compared to CTF-guided biopsies, chest biopsies using the MS-CT biopsy mode show dramatically lower CTDI levels. Although the diagnostic yield of the procedures do not differ significantly, biopsies using the MS-CT-biopsy mode have a three-fold higher rate of chest tube placement.

  5. SU-E-I-58: Experiences in Setting Up An Online Fluoroscopy Tracking System in a Large Healthcare System

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, R; Wunderle, K; Lingenfelter, M [The Cleveland Clinic, Cleveland, OH (United States)

    2015-06-15

    Purpose: Transitioning from a paper based to an online system for tracking fluoroscopic case information required by state regulation and to conform to NCRP patient dose tracking suggestions. Methods: State regulations require documentation of operator, equipment, and some metric of tube output for fluoroscopy exams. This information was previously collected in paper logs, which was cumbersome and inefficient for the large number of fluoroscopic units across multiple locations within the system. The “tech notes” feature within Siemens’ Syngo workflow RIS was utilized to create an entry form for technologists to input case information, which was sent to a third party vendor for archiving and display though an online web based portal. Results: Over 55k cases were logged in the first year of implementation, with approximately 6,500 cases per month once fully online. A system was built for area managers to oversee and correct data, which has increased the accuracy of inputted values. A high-dose report was built to automatically send notifications when patients exceed trigger levels. In addition to meeting regulatory requirements, the new system allows for larger scale QC in fluoroscopic cases by allowing comparison of data from specific procedures, locations, equipment, and operators so that instances that fall outside of reference levels can be identified for further evaluation. The system has also drastically improved identification of operators without documented equipment specific training. Conclusion: The transition to online fluoroscopy logs has improved efficiency in meeting state regulatory requirements as well as allowed for identification of particular procedures, equipment, and operators in need of additional attention in order to optimize patient and personnel doses, while high dose alerts improve patient care and follow up. Future efforts are focused on incorporating case information from outside of radiology, as well as on automating processes for

  6. Surface ECG and Fluoroscopy are Not Predictive of Right Ventricular Septal Lead Position Compared to Cardiac CT.

    Science.gov (United States)

    Rowe, Matthew K; Moore, Peter; Pratap, Jit; Coucher, John; Gould, Paul A; Kaye, Gerald C

    2017-05-01

    Controversy exists regarding the optimal lead position for chronic right ventricular (RV) pacing. Placing a lead at the RV septum relies upon fluoroscopy assisted by a surface 12-lead electrocardiogram (ECG). We compared the postimplant lead position determined by ECG-gated multidetector contrast-enhanced computed tomography (MDCT) with the position derived from the surface 12-lead ECG. Eighteen patients with permanent RV leads were prospectively enrolled. Leads were placed in the RV septum (RVS) in 10 and the RV apex (RVA) in eight using fluoroscopy with anteroposterior and left anterior oblique 30° views. All patients underwent MDCT imaging and paced ECG analysis. ECG criteria were: QRS duration; QRS axis; positive or negative net QRS amplitude in leads I, aVL, V1, and V6; presence of notching in the inferior leads; and transition point in precordial leads at or after V4. Of the 10 leads implanted in the RVS, computed tomography (CT) imaging revealed seven to be at the anterior RV wall, two at the anteroseptal junction, and one in the true septum. For the eight RVA leads, four were anterior, two septal, and two anteroseptal. All leads implanted in the RVS met at least one ECG criteria (median 3, range 1-6). However, no criteria were specific for septal position as judged by MDCT. Mean QRS duration was 160 ± 24 ms in the RVS group compared with 168 ± 14 ms for RVA pacing (P = 0.38). We conclude that the surface ECG is not sufficiently accurate to determine RV septal lead tip position compared to cardiac CT. © 2017 Wiley Periodicals, Inc.

  7. Fluoroscopy-Guided Percutaneous Vertebral Body Biopsy Using a Novel Drill-Powered Device: Technical Case Series

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Adam N., E-mail: wallacea@mir.wustl.edu; Pacheco, Rafael A., E-mail: pachecor@mir.wustl.edu; Tomasian, Anderanik, E-mail: tomasiana@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States); Hsi, Andy C., E-mail: hsia@path.wustl.edu [Washington University School of Medicine, Division of Anatomic Pathology, Department of Pathology & Immunology (United States); Long, Jeremiah, E-mail: longj@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States); Chang, Randy O., E-mail: changr@wusm.wustl.edu [Washington University School of Medicine (United States); Jennings, Jack W., E-mail: jenningsj@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States)

    2016-02-15

    BackgroundA novel coaxial biopsy system powered by a handheld drill has recently been introduced for percutaneous bone biopsy. This technical note describes our initial experience performing fluoroscopy-guided vertebral body biopsies with this system, compares the yield of drill-assisted biopsy specimens with those obtained using a manual technique, and assesses the histologic adequacy of specimens obtained with drill assistance.MethodsMedical records of all single-level, fluoroscopy-guided vertebral body biopsies were reviewed. Procedural complications were documented according to the Society of Interventional Radiology classification. The total length of bone core obtained from drill-assisted biopsies was compared with that of matched manual biopsies. Pathology reports were reviewed to determine the histologic adequacy of specimens obtained with drill assistance.ResultsTwenty eight drill-assisted percutaneous vertebral body biopsies met study inclusion criteria. No acute complications were reported. Of the 86 % (24/28) of patients with clinical follow-up, no delayed complications were reported (median follow-up, 28 weeks; range 5–115 weeks). The median total length of bone core obtained from drill-assisted biopsies was 28 mm (range 8–120 mm). This was longer than that obtained from manual biopsies (median, 20 mm; range 5–45 mm; P = 0.03). Crush artifact was present in 11 % (3/28) of drill-assisted biopsy specimens, which in one case (3.6 %; 1/28) precluded definitive diagnosis.ConclusionsA drill-assisted, coaxial biopsy system can be used to safely obtain vertebral body core specimens under fluoroscopic guidance. The higher bone core yield obtained with drill assistance may be offset by the presence of crush artifact.

  8. Clinical Feasibility and Usefulness of CT Fluoroscopy-Guided Percutaneous Transhepatic Biliary Drainage in Emergency Patients with Acute Obstructive Cholangitis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hyung [Sam Anyang Hospital, Anyang (Korea, Republic of)

    2009-04-15

    To evaluate the feasibility of CT fluoroscopy (CTF)-guided percutaneous transhepatic biliary drainage (PTBD) in emergency patients with acute obstructive cholangitis. The study included 28 patients admitted to the emergency center due to obstructive jaundice and found to require urgent biliary drainage, as well as judged to have a suitable peripheral bile duct for a CTF-guided puncture (at least 4 mm in width). Prior to the CTF-guided puncture, a CT scan was performed to evaluate bile duct dilatation and the underlying causes of biliary obstruction. If the patient was judged to be a suitable candidate, a CTF-guided PTBD was performed in the same CT unit without additional fluoroscopic guidance. Technical feasibility of the procedure was investigated with the evaluation of overall success rate and causes of failure. A hepatic puncture was attempted at the left lobe in 23 patients and right lobe in five patients. The procedure was successful in 24 of 28 patients (86%) Successful biliary puncture was achieved on the first attempt in 16 patients, the second attempt in five patients, and the third attempt in three patients. The causes of failure included guide wire twisting in one patient, biliary puncture failure in two patients, and poor visualization of the guide wire in one patient. There were no significant procedure-related complication. The CTF-guided PTBD is technically feasible and highly successful in patients judged to have a suitable indication. Moreover, although the procedure is unfamiliar and inconvenient to interventionalists, it has economical advantages in that it saves time and manpower. We believe this method can be used in the emergency patients requiring urgent biliary drainage as an alternative for the fluoroscopy-guided PTBD.

  9. SU-E-I-58: Experiences in Setting Up An Online Fluoroscopy Tracking System in a Large Healthcare System

    International Nuclear Information System (INIS)

    Fisher, R; Wunderle, K; Lingenfelter, M

    2015-01-01

    Purpose: Transitioning from a paper based to an online system for tracking fluoroscopic case information required by state regulation and to conform to NCRP patient dose tracking suggestions. Methods: State regulations require documentation of operator, equipment, and some metric of tube output for fluoroscopy exams. This information was previously collected in paper logs, which was cumbersome and inefficient for the large number of fluoroscopic units across multiple locations within the system. The “tech notes” feature within Siemens’ Syngo workflow RIS was utilized to create an entry form for technologists to input case information, which was sent to a third party vendor for archiving and display though an online web based portal. Results: Over 55k cases were logged in the first year of implementation, with approximately 6,500 cases per month once fully online. A system was built for area managers to oversee and correct data, which has increased the accuracy of inputted values. A high-dose report was built to automatically send notifications when patients exceed trigger levels. In addition to meeting regulatory requirements, the new system allows for larger scale QC in fluoroscopic cases by allowing comparison of data from specific procedures, locations, equipment, and operators so that instances that fall outside of reference levels can be identified for further evaluation. The system has also drastically improved identification of operators without documented equipment specific training. Conclusion: The transition to online fluoroscopy logs has improved efficiency in meeting state regulatory requirements as well as allowed for identification of particular procedures, equipment, and operators in need of additional attention in order to optimize patient and personnel doses, while high dose alerts improve patient care and follow up. Future efforts are focused on incorporating case information from outside of radiology, as well as on automating processes for

  10. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography; Avaliacao de dose em procedimentos especiais de fluoroscopia: histerossalpingografia e dacriocistografia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Cintya Carolina Barbosa

    2006-04-15

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  11. Radiation exposure from fluoroscopy during fixation of hip fracture and fracture of ankle: Effect of surgical experience

    Directory of Open Access Journals (Sweden)

    Botchu Rajesh

    2008-01-01

    Full Text Available Background: Over the years, there has been a tremendous increase in the use of fluoroscopy in orthopaedics. The risk of contracting cancer is significantly higher for an orthopedic surgeon. Hip and spine surgeries account for 99% of the total radiation dose. The amount of radiation to patients and operating surgeon depends on the position of the patient and the type of protection used during the surgery. A retrospective study to assess the influence of the radiation exposure of the operating surgeon during fluoroscopically assisted fixation of fractures of neck of femur (dynamic hip screw and ankle (Weber B was performed at a district general hospital in the United Kingdom. Materials and Methods: Sixty patients with undisplaced intertrochanteric fracture were included in the hip group, and 60 patients with isolated fracture of lateral malleolus without communition were included in the ankle group. The hip and ankle groups were further divided into subgroups of 20 patients each depending on the operative experience of the operating surgeon. All patients had fluoroscopically assisted fixation of fracture by the same approach and technique. The radiation dose and screening time of each group were recorded and analyzed. Results: The radiation dose and screening time during fluoroscopically assisted fixation of fracture neck of femur were significantly high with surgeons and trainees with less than 3 years of surgical experience in comparison with surgeons with more than 10 years of experience. The radiation dose and screening time during fluoroscopically assisted fixation of Weber B fracture of ankle were relatively independent of operating surgeon′s surgical experience. Conclusion: The experience of operating surgeon is one of the important factors affecting screening time and radiation dose during fluoroscopically assisted fixation of fracture neck of femur. The use of snapshot pulsed fluoroscopy and involvement of senior surgeons could

  12. Radiation dose reduction in CT-guided sacroiliac joint injections to levels of pulsed fluoroscopy: a comparative study with technical considerations

    Directory of Open Access Journals (Sweden)

    Artner J

    2012-08-01

    Full Text Available Juraj Artner, Balkan Cakir, Heiko Reichel, Friederike LattigDepartment of Orthopaedic Surgery, University of Ulm, RKU, GermanyBackground: The sacroiliac (SI joint is frequently the primary source of low back pain. Over the past decades, a number of different SI injection techniques have been used in its diagnosis and therapy. Despite the concerns regarding exposure to radiation, image-guided injection techniques are the preferred method to achieve safe and precise intra-articular needle placement. The following study presents a comparison of radiation doses, calculated for fluoroscopy and CT-guided SI joint injections in standard and low-dose protocol and presents the technical possibility of CT-guidance with maximum radiation dose reduction to levels of fluoroscopic-guidance for a precise intra-articular injection technique.Objective: To evaluate the possibility of dose reduction in CT-guided sacroiliac joint injections to pulsed-fluoroscopy-guidance levels and to compare the doses of pulsed-fluoroscopy-, CT-guidance, and low-dose CT-guidance for intra-articular SI joint injections.Study design: Comparative study with technical considerations.Methods: A total of 30 CT-guided intra-articular SI joint injections were performed in January 2012 in a developed low-dose mode and the radiation doses were calculated. They were compared to 30 pulsed-fluoroscopy-guided SI joint injections, which were performed in the month before, and to five injections, performed in standard CT-guided biopsy mode for spinal interventions. The statistical significance was calculated with the SPSS software using the Mann–Whitney U-Test. Technical details and anatomical considerations were provided.Results: A significant dose reduction of average 94.01% was achieved using the low-dose protocol for CT-guided SI joint injections. The radiation dose could be approximated to pulsed-fluoroscopy-guidance levels.Conclusion: Radiation dose of CT-guided SI joint injections can be

  13. Measurements of surgeons' exposure to ionizing radiation dose: comparison of conventional and mini C-arm fluoroscopy.

    Science.gov (United States)

    Sung, K H; Min, E; Chung, C Y; Jo, B C; Park, M S; Lee, K

    2016-03-01

    This study was performed to measure the equivalent scattered radiation dose delivered to susceptible organs while simulating orthopaedic surgery using conventional and mini C-arm fluoroscopy. In addition, shielding effects on the thyroid, thymus, and gonad, and the direct exposure delivered to the patient's hands were also compared. A conventional and mini C-arms were installed in an operating room, and a hand and an operator phantom were used to simulate a patient's hand and a surgeon. Photoluminescence dosimeters were used to measure the equivalent dose by scattered radiation arriving at the thyroid, thymus, and gonad on a whole-body phantom in the position of the surgeon. Equivalent scattered radiation doses were measured in four groups: (1) unshielded conventional C-arm group; (2) unshielded mini C-arm group; (3) lead-shielded conventional C-arm group; and (4) lead-shielded mini C-arm group. Equivalent scattered radiation doses to the unshielded group were significantly lower in the mini C-arm group than those in the conventional C-arm group for all organs. The gonad in the lead-shielded conventional C-arm group showed the highest equivalent dose among operator-susceptible organs, and radiation dose was reduced by approximately 96% compared with that in the unshielded group. Scattered radiation was not detected in any susceptible organ in the lead-shielded mini C-arm group. The direct radiation dose to the hand phantom measured from the mini C-arm was significantly lower than that measured from the conventional C-arm. The results show that the equivalent scattered radiation dose to the surgeon's susceptible organs and the direct radiation dose to a patient's hand can be decreased significantly by using a mini C-arm rather than a conventional C-arm. However, protective lead garments, such as a thyroid shield and apron, should be applied to minimize radiation exposure to susceptible organs, even during use of mini C-arm fluoroscopy. © The Author(s) 2015.

  14. SU-G-IeP3-13: Real-Time Patient and Staff Dose Monitoring in Fluoroscopy Guided Interventions

    International Nuclear Information System (INIS)

    Vergoossen, L; Sailer, A; Paulis, L; Wildberger, J; Jeukens, C

    2016-01-01

    Purpose: Interventional radiology procedures involve the use of X-rays, which can pose a large radiation burden on both patients and staff. Although some reports on radiation dose are available, most studies focus on limited types of procedures and only report patient dose. In our cathlabs a dedicated real-time patient and staff monitoring system was installed in November 2015. The aim of this study was to investigate the patient and staff dose exposure for different types of interventions. Methods: Radiologists involved in fluoroscopy guided interventional radiology procedures wore personal dose meters (PDM, DoseAware, Philips) on their lead-apron that measured the personal dose equivalent Hp(10), a measure for the effective dose (E). Furthermore, reference PDMs were installed in the C-arms of the fluoroscopy system (Allura XPer, Philips). Patient dose-area-product (DAP) and PDM doses were retrieved from the monitoring system (DoseWise, Philips) for each procedure. A total of 399 procedures performed between November 2015 and February 2016 were analyzed with respect to the type of intervention. Interventions were grouped by anatomy and radiologist position. Results: The mean DAP for the different types of interventions ranged from 2.86±2.96 Gycm"2 (percutaneous gastrostomy) to 147±178 Gycm"2 (aortic repair procedures). The radiologist dose (E) ranged from 5.39±7.38 µSv (cerebral interventions) to 84.7±106 µSv (abdominal interventions) and strongly correlated with DAP (R"2=0.83). The E normalized to DAP showed that the relative radiologist dose was higher for interventions in larger body parts (e.g. abdomen) compared to smaller body parts (e.g. head). Conclusion: Using a real-time dose monitoring system we were able to assess the staff and patient dose revealing that the relative staff dose strongly depended on the type of procedure and patient anatomy. This could be explained by the position of the radiologist with respect to the patient and X-ray tube. To

  15. The clinical efficacy observation of fluoroscopy-guided foam sclerotherapy with lauromacrogol for varicose veins of the lower extremities

    International Nuclear Information System (INIS)

    Zhu Yongqiang; Xu Jingxuan; Chen Junying; Wu Yan; Zhang Chuanhong; Li Liang

    2012-01-01

    Objective: To assess the clinical efficacy of foam sclerotherapy with lauromacrogol for varicose veins of the lower extremities. Methods: During the period from February to July 2011, we retrospectively analyzed 20 patients with varicose veins of the lower extremities, who were treated with lauromacrogol foam sclerosing agent injected directly at varicose veins, and in 5 extremities injected at the great saphenous vein (GSV) through a catheter at the same time. Elastic bandages were applied at the site of the injected varicosities after the therapy. The clogging of the varicose veins, the improvement of the clinical symptoms and the adverse reaction were observed. Results: Lauromacrogol foam sclerosing agent was successfully injected under the guidance of fluoroscopy in 20 patients with 28 affected extremities. The average volume of foam sclerosing agent in each affected extremity was 7.8 ml. All patients presented self limiting minor complications, including swelling and pain, which was obviously alleviated by the externally applied Mucopolysaccharide Polysulfate Cream. Two patients presented cough that was relieved after inhaling oxygen. Most of treated varicosities demonstrated pigmentation after the first week, which gradually disappeared after the four-month use of vitamin E capsule. A second foam sclerotherapy was carried out for 3 affected extremities of 3 patients two months after the first therapy. Two cases of leg venous ulcer were healed within a few weeks. All patients could walk immediately with no deep vein thrombosis, pulmonary embolism, anaphylaxis, or transient visual disturbance. Obvious abnormal varicose veins as well as the soreness and fatigue of the lower extremities disappeared in all patients at the 10th-month follow-up. The grading of the disease was significantly improved by the treatment (Z=5.103, P<0.01). Conclusions: The efficacy of lauromacrogol foam sclerosing agent in the treatment of varicose veins of the lower extremities is

  16. Combined hysteroscopy-laparoscopy approach for excision of pelvic nitinol fragment from Essure contraceptive device: Role of intraoperative fluoroscopy for uterine conservation.

    Science.gov (United States)

    Sills, E Scott; Palermo, Gianpiero D

    2016-07-01

    We describe the successful removal of a pelvic contraceptive coil in a symptomatic 46-year-old patient who had Essure devices for four years, using a combined hysteroscopy-laparoscopy-fluoroscopy approach. Following normal hysteroscopy, at laparoscopy the right Essure implant was disrupted and its outer nitinol coil had perforated the fallopian tube. However, the inner rod (containing polyethylene terephthalate) had migrated to an extrapelvic location, near the proximal colon. In contrast, the left implant was situated within the corresponding tube. Intraoperative fluoroscopy was used to confirm complete removal of the device, which was further verified by postoperative computed tomography. The patient's condition improved after surgery and she continues to do well. This is the first report to describe this technique in managing Essure complications remote from time of insertion. Our case highlights the value and limitations of preoperative and intraoperative imaging to map Essure fragment location before surgery.

  17. Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures

    International Nuclear Information System (INIS)

    Sommer, C.M.; Huber, J.; Radeleff, B.A.; Hosch, W.; Stampfl, U.; Loenard, B.M.; Hallscheidt, P.; Haferkamp, A.; Kauczor, H.U.; Richter, G.M.

    2011-01-01

    Aim: To report our experience of combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures. Patients and methods: Eighteen patients (23 kidneys) with non-obstructive uropathy due to urine leaks underwent combined CT- and fluoroscopy-guided nephrostomy. All procedures were indicated as second-line interventions after failed ultrasound-guided nephrostomy. Thirteen males and five females with an age of 62.3 ± 8.7 (40–84) years were treated. Urine leaks developed in majority after open surgery, e.g. postoperative insufficiency of ureteroneocystostomy (5 kidneys). The main reasons for failed ultrasound-guided nephrostomy included anatomic obstacles in the puncture tract (7 kidneys), and inability to identify pelvic structures (7 kidneys). CT-guided guidewire placement into the collecting system was followed by fluoroscopy-guided nephrostomy tube positioning. Procedural success rate, major and minor complication rates, CT-views and needle passes, duration of the procedure and radiation dose were analyzed. Results: Procedural success was 91%. Major and minor complication rates were 9% (one septic shock and one perirenal abscess) and 9% (one perirenal haematoma and one urinoma), respectively. 30-day mortality rate was 6%. Number of CT-views and needle passes were 9.3 ± 6.1 and 3.6 ± 2.6, respectively. Duration of the complete procedure was 87 ± 32 min. Dose-length product and dose-area product were 1.8 ± 1.4 Gy cm and 3.9 ± 4.3 Gy cm 2 , respectively. Conclusions: Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures was feasible with high technical success and a tolerable complication rate.

  18. Ultrasound versus fluoroscopy-guided caudal epidural steroid injection for the treatment of chronic low back pain with radiculopathy: A randomised, controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Arindam Kumar Hazra

    2016-01-01

    Full Text Available Background and Aims: Caudal epidural steroid administration is an effective treatment for chronic low back pain (LBP. Fluoroscopy guidance is the gold standard for pain procedures. Ultrasound guidance is recently being used in pain clinic procedures. We compared the fluoroscopy guidance and ultrasound guidance for caudal epidural steroid injection with respect to the time needed for correct placement of the needle and clinical effectiveness in patients with chronic LBP. Methods: Fifty patients with chronic LBP with radiculopathy, not responding to conventional medical management, were randomly allocated to receive injection depot methyl prednisolone (40 mg through caudal route either using ultrasound guidance (Group U, n = 25 or fluoroscopy guidance (Group F, n = 25. Pre-procedural visual analogue scale (VAS score and Oswestry Disability Index (ODI were noted. During the procedure, the time needed for correct placement of needle was observed. Adverse events, if any, were also noted. All patients were followed up for next 2 months to evaluate Visual Analogue Scale (VAS score and ODI at the 2nd week and again at the end of 1st and 2nd month. Results: The needle-placement time was less using ultrasound guidance as compared to fluoroscopy guidance (119 ± 7.66 vs. 222.28 ± 29.65 s, respectively,P< 0.001. Significant reduction in VAS score and ODI (clinical improvement was noted in the follow-up time points and comparable between the groups at all time points. Conclusion: Ultrasound guidance can be a safe alternative tool for achieving faster needle placement in caudal epidural space. Clinical effectiveness (reduction of VAS and ODI scores remains comparable between both the techniques.

  19. Laser Guidance in C-Arm Cone-Beam CT-Guided Radiofrequency Ablation of Osteoid Osteoma Reduces Fluoroscopy Time

    Energy Technology Data Exchange (ETDEWEB)

    Kroes, Maarten W., E-mail: Maarten.Kroes@radboudumc.nl; Busser, Wendy M. H.; Hoogeveen, Yvonne L.; Lange, Frank de; Schultze Kool, Leo J. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine (Netherlands)

    2017-05-15

    PurposeTo assess whether laser guidance can reduce fluoroscopy and procedure time of cone-beam computed tomography (CBCT)-guided radiofrequency (RF) ablations of osteoid osteoma compared to freehand CBCT guidance.Materials and Methods32 RF ablations were retrospectively analyzed, 17 laser-guided and 15 procedures using the freehand technique. Subgroup selection of 18 ablations in the hip–pelvic region with a similar degree of difficulty was used for a direct comparison. Data are presented as median (ranges).ResultsComparison of all 32 ablations resulted in fluoroscopy times of 365 s (193–878 s) for freehand and 186 s (75–587 s) for laser-guided procedures (p = 0.004). Corresponding procedure times were 56 min (35–97 min) and 52 min (30–85 min) (p = 0.355). The subgroup showed comparable target sizes, needle path lengths, and number of scans between groups. Fluoroscopy times were lower for laser-guided procedures, 215 s (75–413 s), compared to 384 s (193–878 s) for freehand (p = 0.012). Procedure times were comparable between groups, 51 min (30–72 min) for laser guidance and 58 min (35–79 min) for freehand (p = 0.172).ConclusionAdding laser guidance to CBCT-guided osteoid osteoma RF ablations significantly reduced fluoroscopy time without increasing procedure time.Level of EvidenceLevel 4, case series.

  20. CT fluoroscopy-guided renal tumour cutting needle biopsy: retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure.

    Science.gov (United States)

    Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

    2018-01-01

    To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. • CT fluoroscopy-guided renal tumour biopsy has a high diagnostic yield. • CT fluoroscopy-guided renal tumour biopsy is safe. • Small tumour size (≤1.5 cm) is a risk factor for diagnostic failure.

  1. Lightweight bilayer barium sulfate-bismuth oxide composite thyroid collars for superior radiation protection in fluoroscopy-guided interventions: a prospective randomized controlled trial.

    Science.gov (United States)

    Uthoff, Heiko; Benenati, Matthew J; Katzen, Barry T; Peña, Constantino; Gandhi, Ripal; Staub, Daniel; Schernthaner, Melanie

    2014-02-01

    To test whether newer bilayer barium sulfate-bismuth oxide composite (XPF) thyroid collars (TCs) provide superior radiation protection and comfort during fluoroscopy-guided interventions compared with standard 0.5-mm lead-equivalent TCs. Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study, and 144 fluoroscopy-guided vascular interventions were included at one center between October 2011 and July 2012, with up to two operators randomly assigned to wear XPF (n = 135) or standard 0.5-mm lead-equivalent (n = 121) TCs. Radiation doses were measured by using dosimeters placed outside and underneath the TCs. Wearing comfort was assessed at the end of each procedure on a visual analog scale (0-100, with 100 indicating optimal comfort). Adjusted differences in comfort and radiation dose reductions were calculated by using a mixed logistic regression model and the common method of inverse variance weighting, respectively. Patient (height, weight, and body mass index) and procedure (type and duration of intervention, operator, fluoroscopy time, dose-area product, and air kerma) data did not differ between the XPF and standard groups. Comfort was assessed in all 256 measurements. On average, the XPF TCs were 47.6% lighter than the standard TCs (mean weight ± standard deviation, 133 g ± 14 vs 254 g ± 44; P 90; odds ratio, 7.6; 95% confidence interval: 3.0, 19.2; P standard group). The mean radiation dose reductions (ie, radiation protection) provided by XPF and standard TCs were 90.7% and 72.4%, with an adjusted mean difference of 17.9% (95% confidence interval: 7.7%, 28.1%; P standard 0.5-mm lead-equivalent TCs and provide superior radiation protection during fluoroscopy-guided interventions. © RSNA, 2013.

  2. Noninvasive diagnostic test choices for the evaluation of coronary artery disease in women: a multivariate comparison of cardiac fluoroscopy, exercise electrocardiography and exercise thallium myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Hung, J.; Chaitman, B.R.; Lam, J.; Lesperance, J.; Dupras, G.; Fines, P.; Bourassa, M.G.

    1984-01-01

    Several diagnostic noninvasive tests to detect coronary and multivessel coronary disease are available for women. However, all are imperfect and it is not yet clear whether one particular test provides substantially more information than others. The aim of this study was to evaluate clinical findings, exercise electrocardiography, exercise thallium myocardial scintigraphy and cardiac fluoroscopy in 92 symptomatic women without previous infarction and determine which tests were most useful in determining the presence of coronary disease and its severity. Univariate analysis revealed two clinical, eight exercise electrocardiographic, seven myocardial scintigraphic and seven fluoroscopic variables predictive of coronary or multivessel disease with 70% or greater stenosis. The multivariate discriminant function analysis selected a reversible thallium defect, coronary calcification and character of chest pain syndrome as the variables most predictive of presence or absence of coronary disease. The ranked order of variables most predictive of multivessel disease were cardiac fluoroscopy score, thallium score and extent of ST segment depression in 14 electrocardiographic leads. Each provided statistically significant information to the model. The estimate of predictive accuracy was 89% for coronary disease and 97% for multivessel coronary disease. The results suggest that cardiac fluoroscopy or thallium scintigraphy provide significantly more diagnostic information than exercise electrocardiography in women over a wide range of clinical patient subsets

  3. Clinical accuracy of three-dimensional fluoroscopy (IsoC-3D)-assisted upper thoracic pedicle screw insertion

    International Nuclear Information System (INIS)

    Sugimoto, Yoshihisa; Ito, Yasuo; Shimokawa, Tetsuya; Shiozaki, Yasuyuki; Mazaki, Tetsuro; Tomioka, Masao; Tanaka, Masato

    2010-01-01

    Correct screw placement is especially difficult in the upper thoracic vertebrae. At the cervicothoracic junction (C7-T2), problems can arise because of the narrowness of the pedicle and the difficulty of using a lateral image intensifier there. Other upper thoracic vertebrae (T3-6) pose a problem for screw insertion also because of the narrower pedicle. We inserted 154 pedicle screws into 78 vertebrae (C7 to T6) in 38 patients. Screws were placed using intraoperative data acquisition by an isocentric C-arm fluoroscope (Siremobile Iso-C3D) and computer navigation. Out of 90 pedicle screws inserted into 45 vertebrae between C7 and T2, 87 of the 90 (96.7%) screws were classified as grade 1 (no perforation). Of 64 pedicle screws inserted into 33 vertebrae between T3 and T6, 61 of 64 (95.3%) screws were classified as grade 1. In this study, we reduced pedicle screw misplacement at the level of the C7 and upper thoracic (T1-6) vertebrae using the three-dimensional fluoroscopy navigation system. (author)

  4. A simple method to accurately position Port-A-Cath without the aid of intraoperative fluoroscopy or other localizing devices.

    Science.gov (United States)

    Horng, Huann-Cheng; Yuan, Chiou-Chung; Chao, Kuan-Chong; Cheng, Ming-Huei; Wang, Peng-Hui

    2007-06-01

    To evaluate the efficacy and acceptability of the Port-A-Cath (PAC) insertion method with (conventional group as II) and without (modified group as I) the aid of intraoperative fluoroscopy or other localizing devices. A total of 158 women with various kinds of gynecological cancers warranting PAC insertion (n = 86 in group I and n = 72 in group II, respectively) were evaluated. Data for analyses included patient age, main disease, dislocation site, surgical time, complications, and catheter outcome. There was no statistical difference between the two groups in terms of age, main disease, complications, and the experiencing of patent catheters. However, appropriate positioning (100% in group I, and 82% in group II) in the superior vena cava (SVC) showed statistical differences between the two groups (P = 0.001). In addition, the surgical time in group I was statistically shorter than that in group II (P < 0.001). The modified method for inserting the PAC offered the following benefits: including avoiding X-ray exposure for both the operator and the patient, defining the appropriate position in the SVC, and less surgical time. (c) 2007 Wiley-Liss, Inc.

  5. Theoretical and experimental studies of the influence of air kerma rate on threshold contrast in diagnostic fluoroscopy systems

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, R M; Day, M J [Newcastle upon Tyne Univ. (UK). Newcastle General Hospital

    1983-11-01

    Experimental measurements of threshold contrast (Csub(T)) as a function of air kerma rate at the input plane of the image intensifier have been made for several diagnostic fluoroscopy units in clinical use. Threshold contrasts are determined by viewing a test object containing holes of fixed diameter and various depths under defined irradiation conditions. Kerma rate variations are effected by introducing aluminum sheets into the x-ray beam at fixed values of tube potential and current. At low kerma rates where quantum noise dominates, low tube potentials (60 kVsub(p)) usually yield lower values of Csub(T) than do higher potentials (100 kVsub(p)). At higher kerma rates the opposite is often true. A simple theoretical model for noise propagation in fluoroscopic imaging systems using models of diagnostic x-ray spectra lends qualitative support to the experimental findings. The often-quoted suggested upper limit of 100 ..mu..R s/sup -1/ (0.87 ..mu..Gy s/sup -1/) at the input phosphor would seem to be justified under the test conditions since little improvement in Csub(T) is usually observed at higher kerma rates. However, application to clinical practice would ideally require the use of more realistic phantom studies.

  6. Fluoroscopy-Guided Percutaneous Gallstone Removal Using a 12-Fr Sheath in High-Risk Surgical Patients with Acute Cholecystitis

    International Nuclear Information System (INIS)

    Kim, Young Hwan; Kim, Yong Joo; Shin, Tae Beom

    2011-01-01

    To evaluate the technical feasibility and clinical efficacy of percutaneous transhepatic cholecystolithotomy under fluoroscopic guidance in high-risk surgical patients with acute cholecystitis. Sixty-three consecutive patients of high surgical risk with acute calculous cholecystitis underwent percutaneous transhepatic gallstone removal under conscious sedation. The stones were extracted through the 12-Fr sheath using a Wittich nitinol stone basket under fluoroscopic guidance on three days after performing a percutaneous cholecystostomy. Large or hard stones were fragmented using either the snare guide wire technique or the metallic cannula technique. Gallstones were successfully removed from 59 of the 63 patients (94%). Reasons for stone removal failure included the inability to grasp a large stone in two patients, and the loss of tract during the procedure in two patients with a contracted gallbladder. The mean hospitalization duration was 7.3 days for acute cholecystitis patients and 9.4 days for gallbladder empyema patients. Bile peritonitis requiring percutaneous drainage developed in two patients. No symptomatic recurrence occurred during follow-up (mean, 608.3 days). Fluoroscopy-guided percutaneous gallstone removal using a 12-Fr sheath is technically feasible and clinically effective in high-risk surgical patients with acute cholecystitis

  7. A new model with an anatomically accurate human renal collecting system for training in fluoroscopy-guided percutaneous nephrolithotomy access.

    Science.gov (United States)

    Turney, Benjamin W

    2014-03-01

    Obtaining renal access is one of the most important and complex steps in learning percutaneous nephrolithotomy (PCNL). Ideally, this skill should be practiced outside the operating room. There is a need for anatomically accurate and cheap models for simulated training. The objective was to develop a cost-effective, anatomically accurate, nonbiologic training model for simulated PCNL access under fluoroscopic guidance. Collecting systems from routine computed tomography urograms were extracted and reformatted using specialized software. These images were printed in a water-soluble plastic on a three-dimensional (3D) printer to create biomodels. These models were embedded in silicone and then the models were dissolved in water to leave a hollow collecting system within a silicone model. These PCNL models were filled with contrast medium and sealed. A layer of dense foam acted as a spacer to replicate the tissues between skin and kidney. 3D printed models of human collecting systems are a useful adjunct in planning PCNL access. The PCNL access training model is relatively low cost and reproduces the anatomy of the renal collecting system faithfully. A range of models reflecting the variety and complexity of human collecting systems can be reproduced. The fluoroscopic triangulation process needed to target the calix of choice can be practiced successfully in this model. This silicone PCNL training model accurately replicates the anatomic architecture and orientation of the human renal collecting system. It provides a safe, clean, and effective model for training in accurate fluoroscopy-guided PCNL access.

  8. A dental implant-based registration method for measuring mandibular kinematics using cone beam computed tomography-based fluoroscopy.

    Science.gov (United States)

    Lin, Cheng-Chung; Chen, Chien-Chih; Chen, Yunn-Jy; Lu, Tung-Wu; Hong, Shih-Wun

    2014-01-01

    This study aimed to develop and evaluate experimentally an implant-based registration method for measuring three-dimensional (3D) kinematics of the mandible and dental implants in the mandible based on dental cone beam computed tomography (CBCT), modified to include fluoroscopic function. The proposed implant-based registration method was based on the registration of CBCT data of implants/bones with single-plane fluoroscopy images. Seven registration conditions that included one to three implants were evaluated experimentally for their performance in a cadaveric porcine headmodel. The implant-based registration method was shown to have measurement errors (SD) of less than -0.2 (0.3) mm, 1.1 (2.2) mm, and 0.7 degrees (1.3 degrees) for the in-plane translation, out-of-plane translation, and all angular components, respectively, regardless of the number of implants used. The corresponding errors were reduced to less than -0.1 (0.1) mm, -0.3 (1.7) mm, and 0.5 degree (0.4 degree) when three implants were used. An implant-based registration method was developed to measure the 3D kinematics of the mandible/implants. With its high accuracy and reliability, the new method will be useful for measuring the 3D motion of the bones/implants for relevant applications.

  9. Bundle Adjustment-Based Stability Analysis Method with a Case Study of a Dual Fluoroscopy Imaging System

    Science.gov (United States)

    Al-Durgham, K.; Lichti, D. D.; Detchev, I.; Kuntze, G.; Ronsky, J. L.

    2018-05-01

    A fundamental task in photogrammetry is the temporal stability analysis of a camera/imaging-system's calibration parameters. This is essential to validate the repeatability of the parameters' estimation, to detect any behavioural changes in the camera/imaging system and to ensure precise photogrammetric products. Many stability analysis methods exist in the photogrammetric literature; each one has different methodological bases, and advantages and disadvantages. This paper presents a simple and rigorous stability analysis method that can be straightforwardly implemented for a single camera or an imaging system with multiple cameras. The basic collinearity model is used to capture differences between two calibration datasets, and to establish the stability analysis methodology. Geometric simulation is used as a tool to derive image and object space scenarios. Experiments were performed on real calibration datasets from a dual fluoroscopy (DF; X-ray-based) imaging system. The calibration data consisted of hundreds of images and thousands of image observations from six temporal points over a two-day period for a precise evaluation of the DF system stability. The stability of the DF system - for a single camera analysis - was found to be within a range of 0.01 to 0.66 mm in terms of 3D coordinates root-mean-square-error (RMSE), and 0.07 to 0.19 mm for dual cameras analysis. It is to the authors' best knowledge that this work is the first to address the topic of DF stability analysis.

  10. Fluoroscopy-Guided Percutaneous Gallstone Removal Using a 12-Fr Sheath in High-Risk Surgical Patients with Acute Cholecystitis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Hwan [Keimyung University, College of Medicine, Daegu (Korea, Republic of); Kim, Yong Joo [Andong General Hospital, Andong (Korea, Republic of); Shin, Tae Beom [Gyeonsang National University, College of Medicine, Jinju (Korea, Republic of)

    2011-04-15

    To evaluate the technical feasibility and clinical efficacy of percutaneous transhepatic cholecystolithotomy under fluoroscopic guidance in high-risk surgical patients with acute cholecystitis. Sixty-three consecutive patients of high surgical risk with acute calculous cholecystitis underwent percutaneous transhepatic gallstone removal under conscious sedation. The stones were extracted through the 12-Fr sheath using a Wittich nitinol stone basket under fluoroscopic guidance on three days after performing a percutaneous cholecystostomy. Large or hard stones were fragmented using either the snare guide wire technique or the metallic cannula technique. Gallstones were successfully removed from 59 of the 63 patients (94%). Reasons for stone removal failure included the inability to grasp a large stone in two patients, and the loss of tract during the procedure in two patients with a contracted gallbladder. The mean hospitalization duration was 7.3 days for acute cholecystitis patients and 9.4 days for gallbladder empyema patients. Bile peritonitis requiring percutaneous drainage developed in two patients. No symptomatic recurrence occurred during follow-up (mean, 608.3 days). Fluoroscopy-guided percutaneous gallstone removal using a 12-Fr sheath is technically feasible and clinically effective in high-risk surgical patients with acute cholecystitis

  11. Predicting factors for conversion from fluoroscopy guided Percutaneous transthoracic needle biopsy to cone-beam CT guided Percutaneous transthoracic needle biopsy

    International Nuclear Information System (INIS)

    Lee, Kang Ji; Han, Young Min; Jin, Gong Yong; Song, Ji Soo

    2015-01-01

    To evaluate the predicting factors for conversion from fluoroscopy guided percutaneous transthoracic needle biopsy (PTNB) to cone-beam CT guided PTNB. From January 2011 to December 2012, we retrospectively identified 38 patients who underwent cone-beam CT guided PTNB with solid pulmonary lesions, and 76 patients who underwent fluoroscopy guided PTNB were matched to the patients who underwent cone-beam CT guided PTNB for age, sex, and lesion location. We evaluated predicting factors such as, long-axis diameter, short-axis diameter, anterior-posterior diameter, and CT attenuation value of the solid pulmonary lesion affecting conversion from fluoroscopy guided PTNB to cone-beam CT guided PTNB. Pearson χ 2 test, Fisher exact test, and independent t test were used in statistical analyses; in addition, we also used receiver operating characteristics curve to find the proper cut-off values affecting the conversion to cone-beam CT guided PTNB. Short-axis, long-axis, anterior-posterior diameter and CT attenuation value of the solid pulmonary lesion in patients who underwent fluoroscopy guided PTNB were 2.70 ± 1.57 cm, 3.40 ± 1.92 cm, 3.06 ± 1.81 cm, and 35.67 ± 15.70 Hounsfield unit (HU), respectively. Short-axis, long-axis, anterior-posterior diameter and CT attenuation value of the solid pulmonary lesion in patients who underwent cone-beam CT guided PTNB were 1.60 ± 1.30 cm, 2.20 ± 1.45 cm, 1.91 ± 1.99 cm, and 18.32 ± 23.11 HU, respectively. Short-axis, long-axis, anterior-posterior diameter, and CT attenuation value showed a significantly different mean value between the 2 groups (p = 0.001, p < 0.001, p = 0.003, p < 0.001, respectively). Odd ratios of CT attenuation value and short-axis diameter of the solid pulmonary lesion were 0.952 and 0.618, respectively. Proper cut-off values affecting the conversion to cone-beam CT guided PTNB were 1.65 cm (sensitivity 68.4%, specificity 71.1%) in short-axis diameter and 29.50 HU (sensitivity 65.8%, specificity 65.8%) in

  12. SU-F-I-77: Radiation Dose in Cardiac Catheterization Procedures: Impact of a Systematic Reduction in Pulsed Fluoroscopy Frame Rate

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, C; Dixon, S [Beaumont Hospital, Royal Oak, MI (United States)

    2016-06-15

    Purpose: To evaluate whether one small systematic reduction in fluoroscopy frame rate has a significant effect on the total air kerma and/or dose area product for diagnostic and interventional cardiac catheterization procedures. Methods: The default fluoroscopy frame rate (FFR) was lowered from 15 to 10 fps in 5 Siemens™ Axiom Artis cardiac catheterization labs (CCL) on July 1, 2013. A total of 7212 consecutive diagnostic and interventional CCL procedures were divided into two study groups: 3602 procedures from 10/1/12 –6/30/13 with FFR of 15 fps; and 3610 procedures 7/1/13 – 3/31/14 at 10 fps. For each procedure, total air kerma (TAK), fluoroscopy skin dose (FSD), total/fluoroscopy dose area products (TAD, FAD), and total fluoroscopy time (FT) were recorded. Patient specific data collected for each procedure included: BSA, sex, height, weight, interventional versus diagnostic; and elective versus emergent. Results: For pre to post change in FFR, each categorical variable was compared using Pearson’s Chi-square test, Odds ratios and 95% confidence intervals. No statistically significant difference in BSA, height, weight, number of interventional versus diagnostic, elective versus emergent procedures was found between the two study groups. Decreasing the default FFR from 15 fps to 10 fps in the two study groups significantly reduced TAK from 1305 to 1061 mGy (p<0.0001), FSD from 627 to 454 mGy (p<0.0001), TAD from 8681 to 6991 uGy × m{sup 2}(p<0.0001), and FAD from 4493 to 3297 uGy × m{sup 2}(p<0.0001). No statistically significant difference in FT was noted. Clinical image quality was not analyzed, and reports of noticeable effects were minimal. From July 1, 2013 to date, the default FFR has remained 10 fps. Conclusion: Reducing the FFR from 15 to 10 fps significantly reduced total air kerma and dose area product which may decrease risk for potential radiation-induced skin injuries and improve patient outcomes.

  13. Percutaneous CT and Fluoroscopy-Guided Screw Fixation of Pathological Fractures in the Shoulder Girdle: Technical Report of 3 Cases

    Energy Technology Data Exchange (ETDEWEB)

    Garnon, Julien, E-mail: juliengarnon@gmail.com; Koch, Guillaume, E-mail: Guillaume.koch@gmail.com [University Hospital of Strasbourg, Department of Interventional Radiology (France); Ramamurthy, Nitin, E-mail: Nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Caudrelier, Jean, E-mail: caudjean@yahoo.fr [University Hospital of Strasbourg, Department of Interventional Radiology (France); Rao, Pramod, E-mail: pramodrao@me.com [University of Strasbourg, ICube (France); Tsoumakidou, Georgia, E-mail: Georgia.tsoumakidou@chru-strasbourg.fr; Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Gangi, Afshin, E-mail: Afshin.gangi@chru-strasbourg.fr [University Hospital of Strasbourg, Department of Interventional Radiology (France)

    2016-09-15

    ObjectiveTo review our initial experience with percutaneous CT and fluoroscopy-guided screw fixation of pathological shoulder-girdle fractures.Materials and MethodsBetween May 2014 and June 2015, three consecutive oncologic patients (mean age 65 years; range 57–75 years) with symptomatic pathological shoulder-girdle fractures unsuitable for surgery and radiotherapy underwent percutaneous image-guided screw fixation. Fractures occurred through metastases (n = 2) or a post-ablation cavity (n = 1). Mechanical properties of osteosynthesis were adjudged superior to stand-alone cementoplasty in each case. Cannulated screws were placed under combined CT and fluoroscopic guidance with complementary radiofrequency ablation or cementoplasty to optimise local palliation and secure screw fixation, respectively, in two cases. Follow-up was undertaken every few weeks until mortality or most recent appointment.ResultsFour pathological fractures were treated in three patients (2 acromion, 1 clavicular, 1 coracoid). Mean size of associated lesion was 2.6 cm (range 1–4.5 cm). Technical success was achieved in all cases (100 %), without complications. Good palliation and restoration of mobility were observed in two cases at 2–3 months; one case could not be followed due to early post-procedural oncologic mortality.ConclusionPercutaneous image-guided shoulder-girdle osteosynthesis appears technically feasible with good short-term efficacy in this complex patient subset. Further studies are warranted to confirm these promising initial results.

  14. Percutaneous CT and Fluoroscopy-Guided Screw Fixation of Pathological Fractures in the Shoulder Girdle: Technical Report of 3 Cases

    International Nuclear Information System (INIS)

    Garnon, Julien; Koch, Guillaume; Ramamurthy, Nitin; Caudrelier, Jean; Rao, Pramod; Tsoumakidou, Georgia; Cazzato, Roberto Luigi; Gangi, Afshin

    2016-01-01

    ObjectiveTo review our initial experience with percutaneous CT and fluoroscopy-guided screw fixation of pathological shoulder-girdle fractures.Materials and MethodsBetween May 2014 and June 2015, three consecutive oncologic patients (mean age 65 years; range 57–75 years) with symptomatic pathological shoulder-girdle fractures unsuitable for surgery and radiotherapy underwent percutaneous image-guided screw fixation. Fractures occurred through metastases (n = 2) or a post-ablation cavity (n = 1). Mechanical properties of osteosynthesis were adjudged superior to stand-alone cementoplasty in each case. Cannulated screws were placed under combined CT and fluoroscopic guidance with complementary radiofrequency ablation or cementoplasty to optimise local palliation and secure screw fixation, respectively, in two cases. Follow-up was undertaken every few weeks until mortality or most recent appointment.ResultsFour pathological fractures were treated in three patients (2 acromion, 1 clavicular, 1 coracoid). Mean size of associated lesion was 2.6 cm (range 1–4.5 cm). Technical success was achieved in all cases (100 %), without complications. Good palliation and restoration of mobility were observed in two cases at 2–3 months; one case could not be followed due to early post-procedural oncologic mortality.ConclusionPercutaneous image-guided shoulder-girdle osteosynthesis appears technically feasible with good short-term efficacy in this complex patient subset. Further studies are warranted to confirm these promising initial results.

  15. SU-F-P-19: Fetal Dose Estimate for a High-Dose Fluoroscopy Guided Intervention Using Modern Data Tools

    Energy Technology Data Exchange (ETDEWEB)

    Moirano, J [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: An accurate dose estimate is necessary for effective patient management after a fetal exposure. In the case of a high-dose exposure, it is critical to use all resources available in order to make the most accurate assessment of the fetal dose. This work will demonstrate a methodology for accurate fetal dose estimation using tools that have recently become available in many clinics, and show examples of best practices for collecting data and performing the fetal dose calculation. Methods: A fetal dose estimate calculation was performed using modern data collection tools to determine parameters for the calculation. The reference point air kerma as displayed by the fluoroscopic system was checked for accuracy. A cumulative dose incidence map and DICOM header mining were used to determine the displayed reference point air kerma. Corrections for attenuation caused by the patient table and pad were measured and applied in order to determine the peak skin dose. The position and depth of the fetus was determined by ultrasound imaging and consultation with a radiologist. The data collected was used to determine a normalized uterus dose from Monte Carlo simulation data. Fetal dose values from this process were compared to other accepted calculation methods. Results: An accurate high-dose fetal dose estimate was made. Comparison to accepted legacy methods were were within 35% of estimated values. Conclusion: Modern data collection and reporting methods ease the process for estimation of fetal dose from interventional fluoroscopy exposures. Many aspects of the calculation can now be quantified rather than estimated, which should allow for a more accurate estimation of fetal dose.

  16. Radiation Dose Reduction in CT Fluoroscopy-Guided Cervical Transforaminal Epidural Steroid Injection by Modifying Scout and Planning Steps

    Energy Technology Data Exchange (ETDEWEB)

    Paik, Nam Chull, E-mail: pncspine@gmail.com [Arumdaun Wooldul Spine Hospital, Department of Radiology (Korea, Republic of)

    2016-04-15

    Background and PurposeIn CT fluoroscopy (CTF)-guided cervical transforaminal epidural steroid injection (TFESI), the majority of radiation dose is contributed by the planning CT scan rather than the CTF procedure itself. We replaced the planning helical CT with a spot CTF and accordingly changed the patient posture during scout and planning scans. The aim of this study was to test whether radiation dose reduction would be achieved by this protocol modification while still maintaining technical performance.MethodsOverall, 338 consecutive procedures before (control group: n = 163) and after (study group: n = 175) instituting the above-mentioned protocol modification were analyzed retrospectively, comparing patient characteristics (age, sex, neck diameter, and level injected) and technical performance [technical success rate, dose-length product (DLP), inadvertent contrast flow incidence, number of CTF acquisitions, and procedural time] between the two groups.ResultsAll injections were technically successful at every level from C3–C4 to C7–T1 without serious complications in both groups. The median DLP of the study group (7.92 mGy·cm) was significantly reduced compared to that of the control group (39.05 mGy·cm, P < 0.001). There were no significant differences between the two groups regarding the incidence of inadvertent contrast flow (20.6 vs. 17.2 %, P = 0.426), number of CTF acquisitions (median 5 vs. 4, P = 0.123), and the procedural time (median 6.62 vs. 6.90 min, P = 0.100).ConclusionsWhen conducting CTF-guided cervical TFESIs, a significant radiation dose reduction (median 79.7 % in DLP) can be achieved by modifying scout and planning steps, without compromising the technical performance.

  17. Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation

    International Nuclear Information System (INIS)

    Chono, Taiki; Shimoshige, Shinya; Yoshikawa, Kenta; Mizonobe, Kazuhusa; Ogura, Keishi

    2013-01-01

    In CARTOMERGE for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time. (author)

  18. The design and imaging characteristics of dynamic, solid-state, flat-panel x-ray image detectors for digital fluoroscopy and fluorography

    International Nuclear Information System (INIS)

    Cowen, A.R.; Davies, A.G.; Sivananthan, M.U.

    2008-01-01

    Dynamic, flat-panel, solid-state, x-ray image detectors for use in digital fluoroscopy and fluorography emerged at the turn of the millennium. This new generation of dynamic detectors utilize a thin layer of x-ray absorptive material superimposed upon an electronic active matrix array fabricated in a film of hydrogenated amorphous silicon (a-Si:H). Dynamic solid-state detectors come in two basic designs, the indirect-conversion (x-ray scintillator based) and the direct-conversion (x-ray photoconductor based). This review explains the underlying principles and enabling technologies associated with these detector designs, and evaluates their physical imaging characteristics, comparing their performance against the long established x-ray image intensifier television (TV) system. Solid-state detectors afford a number of physical imaging benefits compared with the latter. These include zero geometrical distortion and vignetting, immunity from blooming at exposure highlights and negligible contrast loss (due to internal scatter). They also exhibit a wider dynamic range and maintain higher spatial resolution when imaging over larger fields of view. The detective quantum efficiency of indirect-conversion, dynamic, solid-state detectors is superior to that of both x-ray image intensifier TV systems and direct-conversion detectors. Dynamic solid-state detectors are playing a burgeoning role in fluoroscopy-guided diagnosis and intervention, leading to the displacement of x-ray image intensifier TV-based systems. Future trends in dynamic, solid-state, digital fluoroscopy detectors are also briefly considered. These include the growth in associated three-dimensional (3D) visualization techniques and potential improvements in dynamic detector design

  19. Extremely low-frame-rate digital fluoroscopy in catheter ablation of atrial fibrillation: A comparison of 2 versus 4 frame rate.

    Science.gov (United States)

    Lee, Ji Hyun; Kim, Jun; Kim, Minsu; Hwang, Jongmin; Hwang, You Mi; Kang, Joon-Won; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

    2017-06-01

    Despite the technological advance in 3-dimensional (3D) mapping, radiation exposure during catheter ablation of atrial fibrillation (AF) continues to be a major concern in both patients and physicians. Previous studies reported substantial radiation exposure (7369-8690 cGy cm) during AF catheter ablation with fluoroscopic settings of 7.5 frames per second (FPS) under 3D mapping system guidance. We evaluated the efficacy and safety of a low-frame-rate fluoroscopy protocol for catheter ablation for AF.Retrospective analysis of data on 133 patients who underwent AF catheter ablation with 3-D electro-anatomic mapping at our institute from January 2014 to May 2015 was performed. Since January 2014, fluoroscopy frame rate of 4-FPS was implemented at our institute, which was further decreased to 2-FPS in September 2014. We compared the radiation exposure quantified as dose area product (DAP) and effective dose (ED) between the 4-FPS (n = 57) and 2-FPS (n = 76) groups.The 4-FPS group showed higher median DAP (599.9 cGy cm; interquartile range [IR], 371.4-1337.5 cGy cm vs. 392.0 cGy cm; IR, 289.7-591.4 cGy cm; P FPS group. No major procedure-related complications such as cardiac tamponade were observed in either group. Over follow-up durations of 331 ± 197 days, atrial tachyarrhythmia recurred in 20 patients (35.1%) in the 4-FPS group and in 27 patients (35.5%) in the 2-FPS group (P = .96). Kaplan-Meier survival analysis revealed no significant different between the 2 groups (log rank, P = .25).In conclusion, both the 4-FPS and 2-FPS settings were feasible and emitted a relatively low level of radiation compared with that historically reported for DAP in a conventional fluoroscopy setting.

  20. CT fluoroscopy-guided preoperative short hook wire placement for small pulmonary lesions: evaluation of safety and identification of risk factors for pneumothorax.

    Science.gov (United States)

    Iguchi, Toshihiro; Hiraki, Takao; Gobara, Hideo; Fujiwara, Hiroyasu; Matsui, Yusuke; Miyoshi, Shinichiro; Kanazawa, Susumu

    2016-01-01

    To retrospectively evaluate the safety of computed tomography (CT) fluoroscopy-guided short hook wire placement for video-assisted thoracoscopic surgery and the risk factors for pneumothorax associated with this procedure. We analyzed 267 short hook wire placements for 267 pulmonary lesions (mean diameter, 9.9 mm). Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for pneumothorax. Complications (219 grade 1 and 4 grade 2 adverse events) occurred in 196 procedures. No grade 3 or above adverse events were observed. Univariate analysis revealed increased vital capacity (odds ratio [OR], 1.518; P = 0.021), lower lobe lesion (OR, 2.343; P =0.001), solid lesion (OR, 1.845; P = 0.014), prone positioning (OR, 1.793; P = 0.021), transfissural approach (OR, 11.941; P = 0.017), and longer procedure time (OR, 1.036; P = 0.038) were significant predictors of pneumothorax. Multivariate analysis revealed only the transfissural approach (OR, 12.171; P = 0.018) and a longer procedure time (OR, 1.048; P = 0.012) as significant independent predictors. Complications related to CT fluoroscopy-guided preoperative short hook wire placement often occurred, but all complications were minor. A transfissural approach and longer procedure time were significant independent predictors of pneumothorax. Complications related to CT fluoroscopy-guided preoperative short hook wire placement often occur. Complications are usually minor and asymptomatic. A transfissural approach and longer procedure time are significant independent predictors of pneumothorax.

  1. CT fluoroscopy-guided percutaneous gastrostomy with loop gastropexy and peel-away sheath trocar technique in 31 amyotrophic lateral sclerosis patients

    Energy Technology Data Exchange (ETDEWEB)

    De Bucourt, Maximilian; Collettini, Federico; Althoff, Christian; Streitparth, Florian; Greupner, Johannes; Hamm, Bernd (Dept. of Radiology, Charite - Univ. Medicine, Berlin (Germany)), Email: mdb@charite.de; Teichgraeber, U.K. (Dept. of Radiology, Jena Univ. (Germany))

    2012-04-15

    Background: In amyotrophic lateral sclerosis (ALS) patients with respiratory impairment and/or advanced disease, performing even mild sedation - as is usually necessary for percutaneous endoscopic gastrostomy (PEG) placements - is fraught with risk. These patients are often referred to Interventional Radiology for alternative percutaneous gastrostomy tube placement options. Purpose: To report our experience with CT fluoroscopy-guided percutaneous gastrostomy with a novel loop gastropexy and peel-away sheath trocar technique in ALS patients as an alternative to endoscopic techniques. Material and Methods: A consecutive series of 31 amyotrophic lateral sclerosis patients in whom endoscopic gastrostomy was considered too dangerous or impossible to perform underwent CT-guided percutaneous gastropexy and gastrostomy and prospective follow-up. All procedures were performed with a 15 FR Freka Pexact gastrostomy kit, a 16-row CT scanner (Aquilion 16) and single shot CT fluoroscopy mode. Results: The procedure was performed successfully in 30 of 31 patients (20 men, 11 women; median age 60 years, range 38-80 years). In the remaining case the stomach was punctured under CT fluoroscopy and CO2 insufflation was initiated thereafter, leading to successful gastrostomy without prior gastropexy and without further adverse events during follow-up. Two patients reported unproblematic exchange of a balloon tube due to skin irritations with no further adverse events. One patient reported accidental displacement of an exchanged new balloon tube in domestic environment due to balloon leakage: A new balloon tube was easily re-inserted in a hospital the same day. No serious adverse events such as peritonitis, persistent local bleeding, systemic blood loss, or any local infection requiring surgical intervention were observed. Until August 11, 2011 follow-up resulted in 7473 cumulative gastrostomy-days from the date of first placement. Conclusion: Initial results suggest that the described

  2. Fluoroscopy of spontaneous breathing is more sensitive than phrenic nerve stimulation for detection of right phrenic nerve injury during cryoballoon ablation of atrial fibrillation.

    Science.gov (United States)

    Linhart, Markus; Nielson, Annika; Andrié, René P; Mittmann-Braun, Erica L; Stöckigt, Florian; Kreuz, Jens; Nickenig, Georg; Schrickel, Jan W; Lickfett, Lars M

    2014-08-01

    Right phrenic nerve palsy (PNP) is a typical complication of cryoballoon ablation of the right-sided pulmonary veins (PVs). Phrenic nerve function can be monitored by palpating the abdomen during phrenic nerve pacing from the superior vena cava (SVC pacing) or by fluoroscopy of spontaneous breathing. We sought to compare the sensitivity of these 2 techniques during cryoballoon ablation for detection of PNP. A total of 133 patients undergoing cryoballoon ablation were monitored with both SVC pacing and fluoroscopy of spontaneous breathing during ablation of the right superior PV. PNP occurred in 27/133 patients (20.0%). Most patients (89%) had spontaneous recovery of phrenic nerve function at the end of the procedure or on the following day. Three patients were discharged with persistent PNP. All PNP were detected first by fluoroscopic observation of diaphragm movement during spontaneous breathing, while diaphragm could still be stimulated by SVC pacing. In patients with no recovery until discharge, PNP occurred at a significantly earlier time (86 ± 34 seconds vs. 296 ± 159 seconds, P < 0.001). No recovery occurred in 2/4 patients who were ablated with a 23 mm cryoballoon as opposed to 1/23 patients with a 28 mm cryoballoon (P = 0.049). Fluoroscopic assessment of diaphragm movement during spontaneous breathing is more sensitive for detection PNP as compared to SVC pacing. PNP as assessed by fluoroscopy is frequent (20.0%) and carries a high rate of recovery (89%) until discharge. Early onset of PNP and use of 23 mm cryoballoon are associated with PNP persisting beyond hospital discharge. © 2014 Wiley Periodicals, Inc.

  3. CT fluoroscopy-guided percutaneous gastrostomy with loop gastropexy and peel-away sheath trocar technique in 31 amyotrophic lateral sclerosis patients

    International Nuclear Information System (INIS)

    De Bucourt, Maximilian; Collettini, Federico; Althoff, Christian; Streitparth, Florian; Greupner, Johannes; Hamm, Bernd; Teichgraeber, U.K.

    2012-01-01

    Background: In amyotrophic lateral sclerosis (ALS) patients with respiratory impairment and/or advanced disease, performing even mild sedation - as is usually necessary for percutaneous endoscopic gastrostomy (PEG) placements - is fraught with risk. These patients are often referred to Interventional Radiology for alternative percutaneous gastrostomy tube placement options. Purpose: To report our experience with CT fluoroscopy-guided percutaneous gastrostomy with a novel loop gastropexy and peel-away sheath trocar technique in ALS patients as an alternative to endoscopic techniques. Material and Methods: A consecutive series of 31 amyotrophic lateral sclerosis patients in whom endoscopic gastrostomy was considered too dangerous or impossible to perform underwent CT-guided percutaneous gastropexy and gastrostomy and prospective follow-up. All procedures were performed with a 15 FR Freka Pexact gastrostomy kit, a 16-row CT scanner (Aquilion 16) and single shot CT fluoroscopy mode. Results: The procedure was performed successfully in 30 of 31 patients (20 men, 11 women; median age 60 years, range 38-80 years). In the remaining case the stomach was punctured under CT fluoroscopy and CO2 insufflation was initiated thereafter, leading to successful gastrostomy without prior gastropexy and without further adverse events during follow-up. Two patients reported unproblematic exchange of a balloon tube due to skin irritations with no further adverse events. One patient reported accidental displacement of an exchanged new balloon tube in domestic environment due to balloon leakage: A new balloon tube was easily re-inserted in a hospital the same day. No serious adverse events such as peritonitis, persistent local bleeding, systemic blood loss, or any local infection requiring surgical intervention were observed. Until August 11, 2011 follow-up resulted in 7473 cumulative gastrostomy-days from the date of first placement. Conclusion: Initial results suggest that the described

  4. Zero-fluoroscopy cryothermal ablation of atrioventricular nodal re-entry tachycardia guided by endovascular and endocardial catheter visualization using intracardiac echocardiography (Ice&ICE Trial).

    Science.gov (United States)

    Luani, Blerim; Zrenner, Bernhard; Basho, Maksim; Genz, Conrad; Rauwolf, Thomas; Tanev, Ivan; Schmeisser, Alexander; Braun-Dullaeus, Rüdiger C

    2018-01-01

    Stochastic damage of the ionizing radiation to both patients and medical staff is a drawback of fluoroscopic guidance during catheter ablation of cardiac arrhythmias. Therefore, emerging zero-fluoroscopy catheter-guidance techniques are of great interest. We investigated, in a prospective pilot study, the feasibility and safety of the cryothermal (CA) slow-pathway ablation in patients with symptomatic atrioventricular-nodal-re-entry-tachycardia (AVNRT) using solely intracardiac echocardiography (ICE) for endovascular and endocardial catheter visualization. Twenty-five consecutive patients (mean age 55.6 ± 12.0 years, 17 female) with ECG-documentation or symptoms suggesting AVNRT underwent an electrophysiology study (EPS) in our laboratory utilizing ICE for catheter navigation. Supraventricular tachycardia was inducible in 23 (92%) patients; AVNRT was confirmed by appropriate stimulation maneuvers in 20 (80%) patients. All EPS in the AVNRT subgroup could be accomplished without need for fluoroscopy, relying solely on ICE-guidance. CA guided by anatomical location and slow-pathway potentials was successful in all patients, median cryo-mappings = 6 (IQR:3-10), median cryo-ablations = 2 (IQR:1-3). Fluoroscopy was used to facilitate the trans-septal puncture and localization of the ablation substrate in the remaining 3 patients (one focal atrial tachycardia and two atrioventricular-re-entry-tachycardias). Mean EPS duration in the AVNRT subgroup was 99.8 ± 39.6 minutes, ICE guided catheter placement 11.9 ± 5.8 minutes, time needed for diagnostic evaluation 27.1 ± 10.8 minutes, and cryo-application duration 26.3 ± 30.8 minutes. ICE-guided zero-fluoroscopy CA in AVNRT patients is feasible and safe. Real-time visualization of the true endovascular borders and cardiac structures allow for safe catheter navigation during the ICE-guided EPS and might be an alternative to visualization technologies using geometry reconstructions. © 2017 Wiley Periodicals, Inc.

  5. Intervertebral anticollision constraints improve out-of-plane translation accuracy of a single-plane fluoroscopy-to-CT registration method for measuring spinal motion

    International Nuclear Information System (INIS)

    Lin, Cheng-Chung; Tsai, Tsung-Yuan; Hsu, Shih-Jung; Lu, Tung-Wu; Shih, Ting-Fang; Wang, Ting-Ming

    2013-01-01

    Purpose: The study aimed to propose a new single-plane fluoroscopy-to-CT registration method integrated with intervertebral anticollision constraints for measuring three-dimensional (3D) intervertebral kinematics of the spine; and to evaluate the performance of the method without anticollision and with three variations of the anticollision constraints via an in vitro experiment. Methods: The proposed fluoroscopy-to-CT registration approach, called the weighted edge-matching with anticollision (WEMAC) method, was based on the integration of geometrical anticollision constraints for adjacent vertebrae and the weighted edge-matching score (WEMS) method that matched the digitally reconstructed radiographs of the CT models of the vertebrae and the measured single-plane fluoroscopy images. Three variations of the anticollision constraints, namely, T-DOF, R-DOF, and A-DOF methods, were proposed. An in vitro experiment using four porcine cervical spines in different postures was performed to evaluate the performance of the WEMS and the WEMAC methods. Results: The WEMS method gave high precision and small bias in all components for both vertebral pose and intervertebral pose measurements, except for relatively large errors for the out-of-plane translation component. The WEMAC method successfully reduced the out-of-plane translation errors for intervertebral kinematic measurements while keeping the measurement accuracies for the other five degrees of freedom (DOF) more or less unaltered. The means (standard deviations) of the out-of-plane translational errors were less than −0.5 (0.6) and −0.3 (0.8) mm for the T-DOF method and the R-DOF method, respectively. Conclusions: The proposed single-plane fluoroscopy-to-CT registration method reduced the out-of-plane translation errors for intervertebral kinematic measurements while keeping the measurement accuracies for the other five DOF more or less unaltered. With the submillimeter and subdegree accuracy, the WEMAC method was

  6. Augmented reality fluoroscopy simulation of the guide-wire insertion in DHS surgery: A proof of concept study.

    Science.gov (United States)

    van Duren, B H; Sugand, K; Wescott, R; Carrington, R; Hart, A

    2018-05-01

    Hip fractures contribute to a significant clinical burden globally with over 1.6 million cases per annum and up to 30% mortality rate within the first year. Insertion of a dynamic hip screw (DHS) is a frequently performed procedure to treat extracapsular neck of femur fractures. Poorly performed DHS fixation of extracapsular neck of femur fractures can result in poor mobilisation, chronic pain, and increased cut-out rate requiring revision surgery. A realistic, affordable, and portable fluoroscopic simulation system can improve performance metrics in trainees, including the tip-apex distance (the only clinically validated outcome), and improve outcomes. We developed a digital fluoroscopic imaging simulator using orthogonal cameras to track coloured markers attached to the guide-wire which created a virtual overlay on fluoroscopic images of the hip. To test the accuracy with which the augmented reality system could track a guide-wire, a standard workshop femur was used to calibrate the system with a positional marker fixed to indicate the apex; this allowed for comparison between guide-wire tip-apex distance (TAD) calculated by the system to be compared to that physically measured. Tests were undertaken to determine: (1) how well the apex could be targeted; (2) the accuracy of the calculated TAD. (3) The number of iterations through the algorithm giving the optimal accuracy-time relationship. The calculated TAD was found to have an average root mean square error of 4.2 mm. The accuracy of the algorithm was shown to increase with the number of iterations up to 20 beyond which the error asymptotically converged to an error of 2 mm. This work demonstrates a novel augmented reality simulation of guide-wire insertion in DHS surgery. To our knowledge this has not been previously achieved. In contrast to virtual reality, augmented reality is able to simulate fluoroscopy while allowing the trainee to interact with real instrumentation and performing the procedure on

  7. Real-time x-ray fluoroscopy-based catheter detection and tracking for cardiac electrophysiology interventions

    International Nuclear Information System (INIS)

    Ma Yingliang; Housden, R. James; Razavi, Reza; Rhode, Kawal S.; Gogin, Nicolas; Cathier, Pascal; Gijsbers, Geert; Cooklin, Michael; O'Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo

    2013-01-01

    Purpose: X-ray fluoroscopically guided cardiac electrophysiology (EP) procedures are commonly carried out to treat patients with arrhythmias. X-ray images have poor soft tissue contrast and, for this reason, overlay of a three-dimensional (3D) roadmap derived from preprocedural volumetric images can be used to add anatomical information. It is useful to know the position of the catheter electrodes relative to the cardiac anatomy, for example, to record ablation therapy locations during atrial fibrillation therapy. Also, the electrode positions of the coronary sinus (CS) catheter or lasso catheter can be used for road map motion correction.Methods: In this paper, the authors present a novel unified computational framework for image-based catheter detection and tracking without any user interaction. The proposed framework includes fast blob detection, shape-constrained searching and model-based detection. In addition, catheter tracking methods were designed based on the customized catheter models input from the detection method. Three real-time detection and tracking methods are derived from the computational framework to detect or track the three most common types of catheters in EP procedures: the ablation catheter, the CS catheter, and the lasso catheter. Since the proposed methods use the same blob detection method to extract key information from x-ray images, the ablation, CS, and lasso catheters can be detected and tracked simultaneously in real-time.Results: The catheter detection methods were tested on 105 different clinical fluoroscopy sequences taken from 31 clinical procedures. Two-dimensional (2D) detection errors of 0.50 ± 0.29, 0.92 ± 0.61, and 0.63 ± 0.45 mm as well as success rates of 99.4%, 97.2%, and 88.9% were achieved for the CS catheter, ablation catheter, and lasso catheter, respectively. With the tracking method, accuracies were increased to 0.45 ± 0.28, 0.64 ± 0.37, and 0.53 ± 0.38 mm and success rates increased to 100%, 99.2%, and 96

  8. Real-time x-ray fluoroscopy-based catheter detection and tracking for cardiac electrophysiology interventions

    Energy Technology Data Exchange (ETDEWEB)

    Ma Yingliang; Housden, R. James; Razavi, Reza; Rhode, Kawal S. [Division of Imaging Sciences and Biomedical Engineering, King' s College London, London SE1 7EH (United Kingdom); Gogin, Nicolas; Cathier, Pascal [Medisys Research Group, Philips Healthcare, Paris 92156 (France); Gijsbers, Geert [Interventional X-ray, Philips Healthcare, Best 5680 DA (Netherlands); Cooklin, Michael; O' Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo [Department of Cardiology, Guys and St. Thomas' Hospitals NHS Foundation Trust, London SE1 7EH (United Kingdom)

    2013-07-15

    Purpose: X-ray fluoroscopically guided cardiac electrophysiology (EP) procedures are commonly carried out to treat patients with arrhythmias. X-ray images have poor soft tissue contrast and, for this reason, overlay of a three-dimensional (3D) roadmap derived from preprocedural volumetric images can be used to add anatomical information. It is useful to know the position of the catheter electrodes relative to the cardiac anatomy, for example, to record ablation therapy locations during atrial fibrillation therapy. Also, the electrode positions of the coronary sinus (CS) catheter or lasso catheter can be used for road map motion correction.Methods: In this paper, the authors present a novel unified computational framework for image-based catheter detection and tracking without any user interaction. The proposed framework includes fast blob detection, shape-constrained searching and model-based detection. In addition, catheter tracking methods were designed based on the customized catheter models input from the detection method. Three real-time detection and tracking methods are derived from the computational framework to detect or track the three most common types of catheters in EP procedures: the ablation catheter, the CS catheter, and the lasso catheter. Since the proposed methods use the same blob detection method to extract key information from x-ray images, the ablation, CS, and lasso catheters can be detected and tracked simultaneously in real-time.Results: The catheter detection methods were tested on 105 different clinical fluoroscopy sequences taken from 31 clinical procedures. Two-dimensional (2D) detection errors of 0.50 {+-} 0.29, 0.92 {+-} 0.61, and 0.63 {+-} 0.45 mm as well as success rates of 99.4%, 97.2%, and 88.9% were achieved for the CS catheter, ablation catheter, and lasso catheter, respectively. With the tracking method, accuracies were increased to 0.45 {+-} 0.28, 0.64 {+-} 0.37, and 0.53 {+-} 0.38 mm and success rates increased to 100%, 99

  9. A real-time regional adaptive exposure method for saving dose-area product in x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Burion, Steve; Funk, Tobias; Speidel, Michael A.

    2013-01-01

    Purpose: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. Methods: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm 2 , calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. Results: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). Conclusions: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising

  10. The impact of anthropometric patient-phantom matching on organ dose: A hybrid phantom study for fluoroscopy guided interventions

    International Nuclear Information System (INIS)

    Johnson, Perry B.; Geyer, Amy; Borrego, David; Ficarrotta, Kayla; Johnson, Kevin; Bolch, Wesley E.

    2011-01-01

    Purpose: To investigate the benefits and limitations of patient-phantom matching for determining organ dose during fluoroscopy guided interventions. Methods: In this study, 27 CT datasets representing patients of different sizes and genders were contoured and converted into patient-specific computational models. Each model was matched, based on height and weight, to computational phantoms selected from the UF hybrid patient-dependent series. In order to investigate the influence of phantom type on patient organ dose, Monte Carlo methods were used to simulate two cardiac projections (PA/left lateral) and two abdominal projections (RAO/LPO). Organ dose conversion coefficients were then calculated for each patient-specific and patient-dependent phantom and also for a reference stylized and reference hybrid phantom. The coefficients were subsequently analyzed for any correlation between patient-specificity and the accuracy of the dose estimate. Accuracy was quantified by calculating an absolute percent difference using the patient-specific dose conversion coefficients as the reference. Results: Patient-phantom matching was shown most beneficial for estimating the dose to heavy patients. In these cases, the improvement over using a reference stylized phantom ranged from approximately 50% to 120% for abdominal projections and for a reference hybrid phantom from 20% to 60% for all projections. For lighter individuals, patient-phantom matching was clearly superior to using a reference stylized phantom, but not significantly better than using a reference hybrid phantom for certain fields and projections. Conclusions: The results indicate two sources of error when patients are matched with phantoms: Anatomical error, which is inherent due to differences in organ size and location, and error attributed to differences in the total soft tissue attenuation. For small patients, differences in soft tissue attenuation are minimal and are exceeded by inherent anatomical differences

  11. Prospective evaluation of MR overlay on real-time fluoroscopy for percutaneous extremity biopsies of bone lesions visible on MRI but not on CT in children in the interventional radiology suite

    Energy Technology Data Exchange (ETDEWEB)

    Shellikeri, Sphoorti; Vatsky, Seth; Srinivasan, Abhay; Krishnamurthy, Ganesh; Zhu, Xiaowei; Keller, Marc S.; Cahill, Anne Marie [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Setser, Randolph M. [Siemens Medical Solutions USA, Inc., Hoffman Estates, IL (United States)

    2018-02-15

    Magnetic resonance imaging (MRI) often provides better visualization of bone marrow abnormalities than computed tomography (CT) or fluoroscopy, but bone biopsies are usually performed using conventional CT or, more recently, C-arm CT guidance. Biopsies of bone lesions solely visible on MRI are often challenging to localize and require the operator to review the MRI on a separate console to correlate with MRI anatomical landmarks during the biopsy. The MR overlay technique facilitates such biopsies in the angiographic suite by allowing the pre-procedural 3-D MRI to be overlaid on intraprocedural 2-D fluoroscopy. This study describes our initial experience with the MR overlay technique in the angiography suite during pediatric percutaneous extremity bone biopsies of lesions visible on MRI but not on CT or fluoroscopy and demonstrates its utility in relevant clinical cases. (orig.)

  12. Prospective evaluation of MR overlay on real-time fluoroscopy for percutaneous extremity biopsies of bone lesions visible on MRI but not on CT in children in the interventional radiology suite

    International Nuclear Information System (INIS)

    Shellikeri, Sphoorti; Vatsky, Seth; Srinivasan, Abhay; Krishnamurthy, Ganesh; Zhu, Xiaowei; Keller, Marc S.; Cahill, Anne Marie; Setser, Randolph M.

    2018-01-01

    Magnetic resonance imaging (MRI) often provides better visualization of bone marrow abnormalities than computed tomography (CT) or fluoroscopy, but bone biopsies are usually performed using conventional CT or, more recently, C-arm CT guidance. Biopsies of bone lesions solely visible on MRI are often challenging to localize and require the operator to review the MRI on a separate console to correlate with MRI anatomical landmarks during the biopsy. The MR overlay technique facilitates such biopsies in the angiographic suite by allowing the pre-procedural 3-D MRI to be overlaid on intraprocedural 2-D fluoroscopy. This study describes our initial experience with the MR overlay technique in the angiography suite during pediatric percutaneous extremity bone biopsies of lesions visible on MRI but not on CT or fluoroscopy and demonstrates its utility in relevant clinical cases. (orig.)

  13. Personnel dosimetry in fluoroscopy

    International Nuclear Information System (INIS)

    Baechler, S.; Gardon, M.; Bochud, F.; Sans-Merce, M.; Verdun, F.R.; Trueb, Ph.

    2006-01-01

    Physicians who frequently perform fluoroscopic examinations are exposed to high intensity radiation fields and should use protective equipment such as lead aprons, thyroid shields and lead glasses. Standard individual dosimeters are worn under the lead apron in order to measure a dose that is representative of effective dose. However, large parts of the body are not protected by the apron (e.g. arms, head). Given a protection factor for the apron of about 100, an important irradiation of a body part not under the apron could go undetected. A study was conducted to analyse this situation by measuring dose using two dosimeters, one over-apron and one under-apron, for radiologists performing frequent fluoroscopic examinations. Measurements made over six-month period show that, indeed, the use of a single under-apron dosimeter is inadequate for personnel monitoring. Large doses to the head and arms are going undetected by this technique. A method for weighting the doses measured by under- and over-apron dosimeters to obtain a value better representative of the effective dose will be proposed. (authors)

  14. Three-dimensional navigation is more accurate than two-dimensional navigation or conventional fluoroscopy for percutaneous sacroiliac screw fixation in the dysmorphic sacrum: a randomized multicenter study.

    Science.gov (United States)

    Matityahu, Amir; Kahler, David; Krettek, Christian; Stöckle, Ulrich; Grutzner, Paul Alfred; Messmer, Peter; Ljungqvist, Jan; Gebhard, Florian

    2014-12-01

    To evaluate the accuracy of computer-assisted sacral screw fixation compared with conventional techniques in the dysmorphic versus normal sacrum. Review of a previous study database. Database of a multinational study with 9 participating trauma centers. The reviewed group included 130 patients, 72 from the navigated group and 58 from the conventional group. Of these, 109 were in the nondysmorphic group and 21 in the dysmorphic group. Placement of sacroiliac (SI) screws was performed using standard fluoroscopy for the conventional group and BrainLAB navigation software with either 2-dimensional or 3-dimensional (3D) navigation for the navigated group. Accuracy of SI screw placement by 2-dimensional and 3D navigation versus conventional fluoroscopy in dysmorphic and nondysmorphic patients, as evaluated by 6 observers using postoperative computerized tomography imaging at least 1 year after initial surgery. Intraobserver agreement was also evaluated. There were 11.9% (13/109) of patients with misplaced screws in the nondysmorphic group and 28.6% (6/21) of patients with misplaced screws in the dysmorphic group, none of which were in the 3D navigation group. Raw agreement between the 6 observers regarding misplaced screws was 32%. However, the percent overall agreement was 69.0% (kappa = 0.38, P dysmorphic proximal sacral segment. We recommend the use of 3D navigation, where available, for insertion of SI screws in patients with normal and dysmorphic proximal sacral segments. Therapeutic level I.

  15. A motion-compensated image filter for low-dose fluoroscopy in a real-time tumor-tracking radiotherapy system

    International Nuclear Information System (INIS)

    Miyamoto, Naoki; Ishikawa, Masayori; Sutherland, Kenneth

    2015-01-01

    In the real-time tumor-tracking radiotherapy system, a surrogate fiducial marker inserted in or near the tumor is detected by fluoroscopy to realize respiratory-gated radiotherapy. The imaging dose caused by fluoroscopy should be minimized. In this work, an image processing technique is proposed for tracing a moving marker in low-dose imaging. The proposed tracking technique is a combination of a motion-compensated recursive filter and template pattern matching. The proposed image filter can reduce motion artifacts resulting from the recursive process based on the determination of the region of interest for the next frame according to the current marker position in the fluoroscopic images. The effectiveness of the proposed technique and the expected clinical benefit were examined by phantom experimental studies with actual tumor trajectories generated from clinical patient data. It was demonstrated that the marker motion could be traced in low-dose imaging by applying the proposed algorithm with acceptable registration error and high pattern recognition score in all trajectories, although some trajectories were not able to be tracked with the conventional spatial filters or without image filters. The positional accuracy is expected to be kept within ±2 mm. The total computation time required to determine the marker position is a few milliseconds. The proposed image processing technique is applicable for imaging dose reduction. (author)

  16. Fluoroscopy-guided intrA-articular facet joint steroid injection for the management of low back pain: Therapeutic effectiveness and arthrographic pattern

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jin; Lee, Jun Woo; Lee, Guen Young; You, Ja Yeon; Kang, Heung Sik [Dept. of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Chai, Jae Won [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Ahn, Joong Mo [Dept. of Radiology, University of Pittsburgh Medical Center, Pittsburgh (United States)

    2015-09-15

    To evaluate the effectiveness of fluoroscopy-guided intra-articular facet joint steroid injection for the management of low back pain, and to document the incidence of epidural leakage. In total, 320 facet joint injections of 244 consecutive patients were included in this study. All patients had undergone an intra-articular facet joint steroid injection in 2007 and had follow-up post-treatment medical records. The response to treatment was analyzed on the basis of chart documentation (aggravated, no change, slightly improved, much improved, no pain). Fluoroscopic arthrograms of the injections were retrospectively analyzed by two radiologists. Of the 244 patients, 85.2% (n = 208) showed improvement after an initial intra-articular facet joint steroid injection. A total of 77.9% (n = 162) of the patients showed symptom recurrence, with a median of a 69 day symptom-free interval, while 30.3% (n = 74) of the patients showed symptom-free intervals of more than six months. Overall, 74 (33.3%) of the 222 cases of intra-articular facet joint steroid injections without concomitant epidural steroid injection showed epidural leakage in fluoroscopic arthrograms. Fluoroscopy-guided intra-articular facet joint injection is a reliable technique for the management of low back pain, with excellent immediate effectiveness and good prolonged (> 2 months) pain relief. Epidural leakage during injection was detected in one-third of the cases.

  17. Fluoroscopy-guided intrA-articular facet joint steroid injection for the management of low back pain: Therapeutic effectiveness and arthrographic pattern

    International Nuclear Information System (INIS)

    Kim, Su Jin; Lee, Jun Woo; Lee, Guen Young; You, Ja Yeon; Kang, Heung Sik; Chai, Jae Won; Ahn, Joong Mo

    2015-01-01

    To evaluate the effectiveness of fluoroscopy-guided intra-articular facet joint steroid injection for the management of low back pain, and to document the incidence of epidural leakage. In total, 320 facet joint injections of 244 consecutive patients were included in this study. All patients had undergone an intra-articular facet joint steroid injection in 2007 and had follow-up post-treatment medical records. The response to treatment was analyzed on the basis of chart documentation (aggravated, no change, slightly improved, much improved, no pain). Fluoroscopic arthrograms of the injections were retrospectively analyzed by two radiologists. Of the 244 patients, 85.2% (n = 208) showed improvement after an initial intra-articular facet joint steroid injection. A total of 77.9% (n = 162) of the patients showed symptom recurrence, with a median of a 69 day symptom-free interval, while 30.3% (n = 74) of the patients showed symptom-free intervals of more than six months. Overall, 74 (33.3%) of the 222 cases of intra-articular facet joint steroid injections without concomitant epidural steroid injection showed epidural leakage in fluoroscopic arthrograms. Fluoroscopy-guided intra-articular facet joint injection is a reliable technique for the management of low back pain, with excellent immediate effectiveness and good prolonged (> 2 months) pain relief. Epidural leakage during injection was detected in one-third of the cases

  18. CT fluoroscopy-guided preoperative short hook wire placement for small pulmonary lesions: evaluation of safety and identification of risk factors for pneumothorax

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Toshihiro; Hiraki, Takao; Gobara, Hideo; Fujiwara, Hiroyasu; Matsui, Yusuke; Kanazawa, Susumu [Okayama University Medical School, Departments of Radiology, Okayama (Japan); Miyoshi, Shinichiro [Okayama University Medical School, General Thoracic Surgery, Okayama (Japan)

    2016-01-15

    To retrospectively evaluate the safety of computed tomography (CT) fluoroscopy-guided short hook wire placement for video-assisted thoracoscopic surgery and the risk factors for pneumothorax associated with this procedure. We analyzed 267 short hook wire placements for 267 pulmonary lesions (mean diameter, 9.9 mm). Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for pneumothorax. Complications (219 grade 1 and 4 grade 2 adverse events) occurred in 196 procedures. No grade 3 or above adverse events were observed. Univariate analysis revealed increased vital capacity (odds ratio [OR], 1.518; P = 0.021), lower lobe lesion (OR, 2.343; P = 0.001), solid lesion (OR, 1.845; P = 0.014), prone positioning (OR, 1.793; P = 0.021), transfissural approach (OR, 11.941; P = 0.017), and longer procedure time (OR, 1.036; P = 0.038) were significant predictors of pneumothorax. Multivariate analysis revealed only the transfissural approach (OR, 12.171; P = 0.018) and a longer procedure time (OR, 1.048; P = 0.012) as significant independent predictors. Complications related to CT fluoroscopy-guided preoperative short hook wire placement often occurred, but all complications were minor. A transfissural approach and longer procedure time were significant independent predictors of pneumothorax. (orig.)

  19. CT fluoroscopy-guided preoperative short hook wire placement for small pulmonary lesions: evaluation of safety and identification of risk factors for pneumothorax

    International Nuclear Information System (INIS)

    Iguchi, Toshihiro; Hiraki, Takao; Gobara, Hideo; Fujiwara, Hiroyasu; Matsui, Yusuke; Kanazawa, Susumu; Miyoshi, Shinichiro

    2016-01-01

    To retrospectively evaluate the safety of computed tomography (CT) fluoroscopy-guided short hook wire placement for video-assisted thoracoscopic surgery and the risk factors for pneumothorax associated with this procedure. We analyzed 267 short hook wire placements for 267 pulmonary lesions (mean diameter, 9.9 mm). Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for pneumothorax. Complications (219 grade 1 and 4 grade 2 adverse events) occurred in 196 procedures. No grade 3 or above adverse events were observed. Univariate analysis revealed increased vital capacity (odds ratio [OR], 1.518; P = 0.021), lower lobe lesion (OR, 2.343; P = 0.001), solid lesion (OR, 1.845; P = 0.014), prone positioning (OR, 1.793; P = 0.021), transfissural approach (OR, 11.941; P = 0.017), and longer procedure time (OR, 1.036; P = 0.038) were significant predictors of pneumothorax. Multivariate analysis revealed only the transfissural approach (OR, 12.171; P = 0.018) and a longer procedure time (OR, 1.048; P = 0.012) as significant independent predictors. Complications related to CT fluoroscopy-guided preoperative short hook wire placement often occurred, but all complications were minor. A transfissural approach and longer procedure time were significant independent predictors of pneumothorax. (orig.)

  20. CT fluoroscopy-guided renal tumour cutting needle biopsy. Retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure

    International Nuclear Information System (INIS)

    Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

    2018-01-01

    To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. (orig.)

  1. Gonad doses for male patients from stomach examination and oral cholegraphy using the X-ray image intensifying technique and television fluoroscopy

    International Nuclear Information System (INIS)

    Steinbach, W.; Richter, K.; Koenig, W.; Menzel, B.; Reisinger, W.; Uhlich, F.

    1979-01-01

    The gonad dose was measured for male patients undergoing stomach examinations and oral cholegraphy by means of a diagnostic twelve pulse generator (TuR D 1500) and an X-ray apparatus 'Diagnost 100' (Philips-Mueller). In a small group of patients the gonad dose was ascertained per exposure to a 70 mm single spot film, to a 24 cm x 30 cm full size radiograph, and per minute of exposure to image intensifier fluoroscopy. The total gonad dose in both the diagnostic techniques was determined seperately in larger groups of patients. In stomach examination large size radiography led to a gonad dose 20 times higher than that obtained with the spot film technique, while exposure from cholegraphy was 10 times higher. The gonad dose per exposure of a single spot film was about 0.5 mrad. In examinations of the stomach the gonad dose from one minute fluroscopy was 18 times higher than the doses determined for a single spot film, and in cholegraphy it was 10 times higher. Supposing mean values of the number of radiographs and of the fluoroscopy time according to the conditions applied, the gonad dose in stomach examination from the film-screen technique is about twice that from the television image-intensifying technique. By comparison, oral cholegraphy exclusively performed by large-size radiography yielded about the same gonad dose as the spot film television technique. Total dose values determined separately confirmed these evaluations. (author)

  2. Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp; Iguchi, Toshihiro, E-mail: i10476@yahoo.co.jp; Fujiwara, Hiroyasu, E-mail: hirofujiwar@gmail.com; Kawabata, Takahiro, E-mail: tkhr-kwbt@yahoo.co.jp [Okayama University Medical School, Department of Radiology (Japan); Yamauchi, Takatsugu, E-mail: me9248@hp.okayama-u.ac.jp; Yamaguchi, Takuya, E-mail: me8738@hp.okayama-u.ac.jp [Okayama University Hospital, Central Division of Radiology (Japan); Kanazawa, Susumu, E-mail: susumu@cc.okayama-u.ac.jp [Okayama University Medical School, Department of Radiology (Japan)

    2016-06-15

    IntroductionComputed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking.Materials and MethodsRadiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator’s finger skin was measured using thermoluminescent dosimeter rings.ResultsThe mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator’s finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA.ConclusionRadiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

  3. Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting.

    Science.gov (United States)

    Matsui, Yusuke; Hiraki, Takao; Gobara, Hideo; Iguchi, Toshihiro; Fujiwara, Hiroyasu; Kawabata, Takahiro; Yamauchi, Takatsugu; Yamaguchi, Takuya; Kanazawa, Susumu

    2016-06-01

    Computed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking. Radiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator's finger skin was measured using thermoluminescent dosimeter rings. The mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator's finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA. Radiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

  4. CT fluoroscopy-guided renal tumour cutting needle biopsy. Retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu [Okayama University Medical School, Department of Radiology, Okayama (Japan)

    2018-01-15

    To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. (orig.)

  5. Experimental determination of blurring in x-ray fluoroscopy last image hold due to patient movement and its repercussion to patient doses

    International Nuclear Information System (INIS)

    Guibelalde, E.; Gonzalez, L.; Vano, E.; Fernandez, J.M.; Alberdi, J.; Molinero, A.

    2001-01-01

    Significant dose reduction can be achieved in fluoroscopy and interventional radiology by using the last image hold (LIH). This feature in modern digital fluoroscopy x-ray units usually works with frame or temporal averaging techniques to reduce noise. This image quality works quite well for objects without motion but it could be a serious limitation in presence of motion blur. With an in-house developed robotic device, the authors have experimentally determined the image quality degradation introduced by normal physiological movements (i.e., respiratory and cardiac pulse movements). FAXIL test objects TO.10 and 18FG from Leeds University have been used for spatial resolution limit and threshold contrast detail detectability. Seven X-ray equipment with last image hold features from three different manufacturers were analysed. Although results show that motion blur affects LIH to different extends depending on equipment, magnification, entrance dose and detail size, it can be estimated that, on average for all equipment and analysed conditions, it represents 30% degradation in image quality parameters in comparison with static images. (author)

  6. Unique migration of a dental needle into the parapharyngeal space: successful removal by an intraoral approach and simulation for tracking visibility in X-ray fluoroscopy.

    Science.gov (United States)

    Okumura, Yuri; Hidaka, Hiroshi; Seiji, Kazumasa; Nomura, Kazuhiro; Takata, Yusuke; Suzuki, Takahiro; Katori, Yukio

    2015-02-01

    The first objective was to describe a novel case of migration of a broken dental needle into the parapharyngeal space. The second was to address the importance of simulation elucidating visualization of such a thin needle under X-ray fluoroscopy. Clinical case records (including computed tomography [CT] and surgical approaches) were reviewed, and a simulation experiment using a head phantom was conducted using the same settings applied intraoperatively. A 36-year-old man was referred after failure to locate a broken 31-G dental needle. Computed tomography revealed migration of the needle into the parapharyngeal space. Intraoperative X-ray fluoroscopy failed to identify the needle, so a steel wire was applied as a reference during X-ray to locate the foreign body. The needle was successfully removed using an intraoral approach with tonsillectomy under surgical microscopy. The simulation showed that the dental needle was able to be identified only after applying an appropriate compensating filter, contrasting with the steel wire. Meticulous preoperative simulation regarding visual identification of dental needle foreign bodies is mandatory. Intraoperative radiography and an intraoral approach with tonsillectomy under surgical microscopy offer benefits for accessing the parapharyngeal space, specifically for cases medial to the great vessels. © The Author(s) 2014.

  7. Significant Improvement of Puncture Accuracy and Fluoroscopy Reduction in Percutaneous Transforaminal Endoscopic Discectomy With Novel Lumbar Location System: Preliminary Report of Prospective Hello Study.

    Science.gov (United States)

    Fan, Guoxin; Guan, Xiaofei; Zhang, Hailong; Wu, Xinbo; Gu, Xin; Gu, Guangfei; Fan, Yunshan; He, Shisheng

    2015-12-01

    Prospective nonrandomized control study.The study aimed to investigate the implication of the HE's Lumbar LOcation (HELLO) system in improving the puncture accuracy and reducing fluoroscopy in percutaneous transforaminal endoscopic discectomy (PTED).Percutaneous transforaminal endoscopic discectomy is one of the most popular minimally invasive spine surgeries that heavily depend on repeated fluoroscopy. Increased fluoroscopy will induce higher radiation exposure to surgeons and patients. Accurate puncture in PTED can be achieved by accurate preoperative location and definite trajectory.The HELLO system mainly consists of self-made surface locator and puncture-assisted device. The surface locator was used to identify the exact puncture target and the puncture-assisted device was used to optimize the puncture trajectory. Patients who had single L4/5 or L5/S1 lumbar intervertebral disc herniation and underwent PTED were included the study. Patients receiving the HELLO system were assigned in Group A, and those taking conventional method were assigned in Group B. Study primary endpoint was puncture times and fluoroscopic times, and the secondary endpoint was location time and operation time.A total of 62 patients who received PTED were included in this study. The average age was 45.35 ± 8.70 years in Group A and 46.61 ± 7.84 years in Group B (P = 0.552). There were no significant differences in gender, body mass index, conservative time, and surgical segment between the 2 groups (P > 0.05). The puncture times were 1.19 ± 0.48 in Group A and 6.03 ± 1.87 in Group B (P HELLO system is accurate preoperative location and definite trajectory. This preliminary report indicated that the HELLO system significantly improves the puncture accuracy of PTED and reduces the fluoroscopic times, preoperative location time, as well as operation time. (ChiCTR-ICR-15006730).

  8. SU-E-J-59: Feasibility of Markerless Tumor Tracking by Sequential Dual-Energy Fluoroscopy On a Clinical Tumor Tracking System

    Energy Technology Data Exchange (ETDEWEB)

    Dhont, J; Poels, K; Verellen, D; Tournel, K; Gevaert, T; Steenbeke, F; Burghelea, M; De Ridder, M [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Brussels (Belgium)

    2015-06-15

    Purpose: To evaluate the feasibility of markerless tumor tracking through the implementation of a novel dual-energy imaging approach into the clinical dynamic tracking (DT) workflow of the Vero SBRT system. Methods: Two sequential 20 s (11 Hz) fluoroscopy sequences were acquired at the start of one fraction for 7 patients treated for primary and metastatic lung cancer with DT on the Vero system. Sequences were acquired using 2 on-board kV imaging systems located at ±45° from the MV beam axis, at respectively 60 kVp (3.2 mAs) and 120 kVp (2.0 mAs). Offline, a normalized cross-correlation algorithm was applied to match the high (HE) and low energy (LE) images. Per breathing phase (inhale, exhale, maximum inhale and maximum exhale), the 5 best-matching HE and LE couples were extracted for DE subtraction. A contrast analysis according to gross tumor volume was conducted based on contrast-to-noise ratio (CNR). Improved tumor visibility was quantified using an improvement ratio. Results: Using the implanted fiducial as a benchmark, HE-LE sequence matching was effective for 13 out of 14 imaging angles. Overlying bony anatomy was removed on all DE images. With the exception of two imaging angles, the DE images showed no significantly improved tumor visibility compared to HE images, with an improvement ratio averaged over all patients of 1.46 ± 1.64. Qualitatively, it was observed that for those imaging angles that showed no significantly improved CNR, the tumor tissue could not be reliably visualized on neither HE nor DE images due to a total or partial overlap with other soft tissue. Conclusion: Dual-energy subtraction imaging by sequential orthogonal fluoroscopy was shown feasible by implementing an additional LE fluoroscopy sequence. However, for most imaging angles, DE images did not provide improved tumor visibility over single-energy images. Optimizing imaging angles is likely to improve tumor visibility and the efficacy of dual-energy imaging. This work was in

  9. Balloon-Occluded Antegrade Transvenous Sclerotherapy to Treat Rectal Varices: A Direct Puncture Approach to the Superior Rectal Vein Through the Greater Sciatic Foramen Under CT Fluoroscopy Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Yasuyuki, E-mail: onoyasy@hirakata.kmu.ac.jp; Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp; Kono, Yumiko, E-mail: kohnoy@hirakata.kmu.ac.jp; Kan, Naoki, E-mail: kanna@takii.kmu.ac.jp; Ueno, Yutaka, E-mail: uenoyut@hirakata.kmu.ac.jp; Komemushi, Atsushi, E-mail: komemush@takii.kmu.ac.jp; Tanigawa, Noboru, E-mail: tanigano@hirakata.kmu.ac.jp [Kansai Medical University, Department of Radiology (Japan)

    2015-10-15

    Rectal varices occur in 44.5 % of patients with ectopic varices caused by portal hypertension, and 48.6 % of these patients are untreated and followed by observation. However, bleeding occurs in 38 % and shock leading to death in 5 % of such patients. Two patients, an 80-year-old woman undergoing treatment for primary biliary cirrhosis (Child-Pugh class A) and a 63-year-old man with class C hepatic cirrhosis (Child-Pugh class A), in whom balloon-occluded antegrade transvenous sclerotherapy was performed to treat rectal varices are reported. A catheter was inserted by directly puncturing the rectal vein percutaneously through the greater sciatic foramen under computed tomographic fluoroscopy guidance. In both cases, the rectal varices were successfully treated without any significant complications, with no bleeding from rectal varices after embolization.

  10. SU-E-I-55: The Contribution to Skin Dose Due to Scatter From the Patient Table and the Head Holder During Fluoroscopy

    International Nuclear Information System (INIS)

    Islam, N; Xiong, Z; Vijayan, S; Rudin, S; Bednarek, D

    2015-01-01

    Purpose: To determine contributions to skin dose due to scatter from the table and head holder used during fluoroscopy, and also to explore alternative design material to reduce the scatter dose. Methods: Measurements were made of the primary and scatter components of the xray beam exiting the patient table and a cylindrical head holder used on a Toshiba Infinix c-arm unit as a function of kVp for the various beam filters on the machine and for various field sizes. The primary component of the beam was measured in air with the object placed close to the x-ray tube with an air gap between it and a 6 cc parallel-plate ionization chamber and with the beam collimated to a size just larger than the chamber. The primary plus scatter radiation components were measured with the object moved to a position in the beam next to the chamber for larger field sizes. Both sets of measurements were preformed while keeping the source-to-chamber distance fixed. The scatter fraction was estimated by taking the ratio of the difference between the two measurements and the reading that included both primary and scatter. Similar measurements were also made for a 2.3 cm thick Styrofoam block which could substitute for the patient support. Results: The measured scatter fractions indicate that the patient table as well as the head holder contributes an additional 10–16% to the patient entrance dose depending on field size. Forward scatter was reduced with the Styrofoam block so that the scatter fraction was about 4–5%. Conclusion: The results of this investigation demonstrated that scatter from the table and head holder used in clinical fluoroscopy contribute substantially to the skin dose. The lower contribution of scatter from Styrofoam suggests that there is an opportunity to redesign patient support accessories to reduce the skin dose. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corporation Equipment Grant

  11. Ultrasound-guided versus fluoroscopy-guided sacroiliac joint intra-articular injections in the noninflammatory sacroiliac joint dysfunction: a prospective, randomized, single-blinded study.

    Science.gov (United States)

    Jee, Haemi; Lee, Ji-Hae; Park, Ki Deok; Ahn, Jaeki; Park, Yongbum

    2014-02-01

    To compare the short-term effects and safety of ultrasound (US)-guided sacroiliac joint (SIJ) injections with fluoroscopy (FL)-guided SIJ injections in patients with noninflammatory SIJ dysfunction. Prospective, randomized controlled trial. University hospital. Patients (N=120) with noninflammatory sacroiliac arthritis were enrolled. All procedures were performed using an FL or US apparatus. Subjects were randomly assigned to either the FL or US group. Immediately after the SIJ injections, fluoroscopy was applied to verify the correct placement of the injected medication and intravascular injections. Treatment effects and functional improvement were compared at 2 and 12 weeks after the procedures. The verbal numeric pain scale and Oswestry Disability Index improved at 2 and 12 weeks after the injections without statistical significances between groups. Of 55 US-guided injections, 48 (87.3%) were successful and 7 (12.7%) were missed. The FL-guided SIJ approach exhibited a greater accuracy (98.2%) than the US-guided approach. Vascularization around the SIJ was seen in 34 of 55 patients. Among the 34 patients, 7 had vascularization inside the joint, 23 had vascularization around the joint, and 4 had vascularization both inside and around the joint. Three cases of intravascular injections occurred in the FL group. The US-guided approach may facilitate the identification and avoidance of the critical vessels around or within the SIJ. Function and pain relief significantly improved in both groups without significant differences between groups. The US-guided approach was shown to be as effective as the FL-guided approach in treatment effects. However, diagnostic application in the SIJ may be limited because of the significantly lower accuracy rate (87.3%). Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  12. SU-E-I-55: The Contribution to Skin Dose Due to Scatter From the Patient Table and the Head Holder During Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Islam, N; Xiong, Z; Vijayan, S; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)

    2015-06-15

    Purpose: To determine contributions to skin dose due to scatter from the table and head holder used during fluoroscopy, and also to explore alternative design material to reduce the scatter dose. Methods: Measurements were made of the primary and scatter components of the xray beam exiting the patient table and a cylindrical head holder used on a Toshiba Infinix c-arm unit as a function of kVp for the various beam filters on the machine and for various field sizes. The primary component of the beam was measured in air with the object placed close to the x-ray tube with an air gap between it and a 6 cc parallel-plate ionization chamber and with the beam collimated to a size just larger than the chamber. The primary plus scatter radiation components were measured with the object moved to a position in the beam next to the chamber for larger field sizes. Both sets of measurements were preformed while keeping the source-to-chamber distance fixed. The scatter fraction was estimated by taking the ratio of the difference between the two measurements and the reading that included both primary and scatter. Similar measurements were also made for a 2.3 cm thick Styrofoam block which could substitute for the patient support. Results: The measured scatter fractions indicate that the patient table as well as the head holder contributes an additional 10–16% to the patient entrance dose depending on field size. Forward scatter was reduced with the Styrofoam block so that the scatter fraction was about 4–5%. Conclusion: The results of this investigation demonstrated that scatter from the table and head holder used in clinical fluoroscopy contribute substantially to the skin dose. The lower contribution of scatter from Styrofoam suggests that there is an opportunity to redesign patient support accessories to reduce the skin dose. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corporation Equipment Grant.

  13. Endovascular aneurysm repair simulation can lead to decreased fluoroscopy time and accurately delineate the proximal seal zone.

    Science.gov (United States)

    Kim, Ann H; Kendrick, Daniel E; Moorehead, Pamela A; Nagavalli, Anil; Miller, Claire P; Liu, Nathaniel T; Wang, John C; Kashyap, Vikram S

    2016-07-01

    The use of simulators for endovascular aneurysm repair (EVAR) is not widespread. We examined whether simulation could improve procedural variables, including operative time and optimizing proximal seal. For the latter, we compared suprarenal vs infrarenal fixation endografts, right femoral vs left femoral main body access, and increasing angulation of the proximal aortic neck. Computed tomography angiography was obtained from 18 patients who underwent EVAR at a single institution. Patient cases were uploaded to the ANGIO Mentor endovascular simulator (Simbionix, Cleveland, Ohio) allowing for three-dimensional reconstruction and adapted for simulation with suprarenal fixation (Endurant II; Medtronic Inc, Minneapolis, Minn) and infrarenal fixation (C3; W. L. Gore & Associates Inc, Newark, Del) deployment systems. Three EVAR novices and three experienced surgeons performed 18 cases from each side with each device in randomized order (n = 72 simulations/participant). The cases were stratified into three groups according to the degree of infrarenal angulation: 0° to 20°, 21° to 40°, and 41° to 66°. Statistical analysis used paired t-test and one-way analysis of variance. Mean fluoroscopy time for participants decreased by 48.6% (P time decreased by 33.8% (P zone coverage in highly angulated aortic necks was significantly decreased. The infrarenal device resulted in mean aortic neck zone coverage of 91.9%, 89.4%, and 75.4% (P zone coverage. The side of femoral access for the main body did not influence proximal seal zone coverage regardless of infrarenal angulation. Simulation of EVAR leads to decreased fluoroscopy times for novice and experienced operators. Side of femoral access did not affect precision of proximal endograft landing. The angulated aortic neck leads to decreased proximal seal zone coverage regardless of infrarenal or suprarenal fixation devices. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  14. Novel System for Real-Time Integration of 3-D Echocardiography and Fluoroscopy for Image-Guided Cardiac Interventions: Preclinical Validation and Clinical Feasibility Evaluation

    Science.gov (United States)

    Housden, R. James; Ma, Yingliang; Rajani, Ronak; Gao, Gang; Nijhof, Niels; Cathier, Pascal; Bullens, Roland; Gijsbers, Geert; Parish, Victoria; Kapetanakis, Stamatis; Hancock, Jane; Rinaldi, C. Aldo; Cooklin, Michael; Gill, Jaswinder; Thomas, Martyn; O'neill, Mark D.; Razavi, Reza; Rhode, Kawal S.

    2014-01-01

    Real-time imaging is required to guide minimally invasive catheter-based cardiac interventions. While transesophageal echocardiography allows for high-quality visualization of cardiac anatomy, X-ray fluoroscopy provides excellent visualization of devices. We have developed a novel image fusion system that allows real-time integration of 3-D echocardiography and the X-ray fluoroscopy. The system was validated in the following two stages: 1) preclinical to determine function and validate accuracy; and 2) in the clinical setting to assess clinical workflow feasibility and determine overall system accuracy. In the preclinical phase, the system was assessed using both phantom and porcine experimental studies. Median 2-D projection errors of 4.5 and 3.3 mm were found for the phantom and porcine studies, respectively. The clinical phase focused on extending the use of the system to interventions in patients undergoing either atrial fibrillation catheter ablation (CA) or transcatheter aortic valve implantation (TAVI). Eleven patients were studied with nine in the CA group and two in the TAVI group. Successful real-time view synchronization was achieved in all cases with a calculated median distance error of 2.2 mm in the CA group and 3.4 mm in the TAVI group. A standard clinical workflow was established using the image fusion system. These pilot data confirm the technical feasibility of accurate real-time echo-fluoroscopic image overlay in clinical practice, which may be a useful adjunct for real-time guidance during interventional cardiac procedures. PMID:27170872

  15. Fluoroscopy-guided reduction and fibular nail fixation to manage unstable ankle fractures in patients with diabetes: a retrospective cohort study.

    Science.gov (United States)

    Ashman, B D; Kong, C; Wing, K J; Penner, M J; Bugler, K E; White, T O; Younger, A S E

    2016-09-01

    Patients with diabetes are at increased risk of wound complications after open reduction and internal fixation of unstable ankle fractures. A fibular nail avoids large surgical incisions and allows anatomical reduction of the mortise. We retrospectively reviewed the results of fluoroscopy-guided reduction and percutaneous fibular nail fixation for unstable Weber type B or C fractures in 24 adult patients with type 1 or type 2 diabetes. The re-operation rate for wound dehiscence or other indications such as amputation, mortality and functional outcomes was determined. Two patients developed lateral side wound infection, one of whom underwent wound debridement. Three other patients required re-operation for removal of symptomatic hardware. No patient required a below-knee amputation. Six patients died during the study period for unrelated reasons. At a median follow-up of 12 months (7 to 38) the mean Short Form-36 Mental Component Score and Physical Component Score were 53.2 (95% confidence intervals (CI) 48.1 to 58.4) and 39.3 (95% CI 32.1 to 46.4), respectively. The mean Visual Analogue Score for pain was 3.1 (95% 1.4 to 4.9). The mean Ankle Osteoarthritis Scale total score was 32.9 (95% CI 16.0 to 49.7). Fluoroscopy-guided reduction and fibular nail fixation of unstable ankle fractures in patients with diabetes was associated with a low incidence of wound and overall complications, while providing effective surgical fixation. Cite this article: Bone Joint J 2016;98-B:1197-1201. ©2016 The British Editorial Society of Bone & Joint Surgery.

  16. WE-A-12A-01: Medical Physics 1.0 to 2.0, Session 2: Radiography, Mammography and Fluoroscopy

    International Nuclear Information System (INIS)

    Gingold, E; Karellas, A; Strauss, K

    2014-01-01

    . Fluoroscopy 2.0: Physics support of fluoroscopy should be operationally as opposed to compliance focused. Testing protocols must address new hardware, acquisition methods, and image processing. Future available tools are discussed. Proper configuration of acquisition parameters (focal spot size, voltage and added filter, tube current, pulse width, pulse rate, scatter removal) as a function of patient size from the neonate to bariatric patient is key to providing diagnostic image quality at properly managed radiation doses. Learning Objectives: Appreciate the limitations of the currently available tools and techniques in clinical medical physics in radiography, mammography, and fluoroscopy, and ways to improve upon current deficiencies. Appreciate the changing environment of imaging practice and the need for the medical physicist to be an expert consultant and educator in a capacity that extends beyond the annual survey of equipment. Understand the status of the rapidly changing environment in breast imaging from planar imaging to tomosynthesis and possibly to breast CT. Identify appropriate configuration of acquisition parameters as a function of patient size to manage radiation dose and ensure diagnostic image quality

  17. WE-A-12A-01: Medical Physics 1.0 to 2.0, Session 2: Radiography, Mammography and Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gingold, E [Thomas Jefferson University, Philadelphia, PA (United States); Karellas, A [University of Massachusetts Medical School, Worcester, MA (United States); Strauss, K [Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States)

    2014-06-15

    . Fluoroscopy 2.0: Physics support of fluoroscopy should be operationally as opposed to compliance focused. Testing protocols must address new hardware, acquisition methods, and image processing. Future available tools are discussed. Proper configuration of acquisition parameters (focal spot size, voltage and added filter, tube current, pulse width, pulse rate, scatter removal) as a function of patient size from the neonate to bariatric patient is key to providing diagnostic image quality at properly managed radiation doses. Learning Objectives: Appreciate the limitations of the currently available tools and techniques in clinical medical physics in radiography, mammography, and fluoroscopy, and ways to improve upon current deficiencies. Appreciate the changing environment of imaging practice and the need for the medical physicist to be an expert consultant and educator in a capacity that extends beyond the annual survey of equipment. Understand the status of the rapidly changing environment in breast imaging from planar imaging to tomosynthesis and possibly to breast CT. Identify appropriate configuration of acquisition parameters as a function of patient size to manage radiation dose and ensure diagnostic image quality.

  18. SU-G-JeP3-01: A Method to Quantify Lung SBRT Target Localization Accuracy Based On Digitally Reconstructed Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lafata, K; Ren, L; Cai, J; Yin, F [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: To develop a methodology based on digitally-reconstructed-fluoroscopy (DRF) to quantitatively assess target localization accuracy of lung SBRT, and to evaluate using both a dynamic digital phantom and a patient dataset. Methods: For each treatment field, a 10-phase DRF is generated based on the planning 4DCT. Each frame is pre-processed with a morphological top-hat filter, and corresponding beam apertures are projected to each detector plane. A template-matching algorithm based on cross-correlation is used to detect the tumor location in each frame. Tumor motion relative beam aperture is extracted in the superior-inferior direction based on each frame’s impulse response to the template, and the mean tumor position (MTP) is calculated as the average tumor displacement. The DRF template coordinates are then transferred to the corresponding MV-cine dataset, which is retrospectively filtered as above. The treatment MTP is calculated within each field’s projection space, relative to the DRF-defined template. The field’s localization error is defined as the difference between the DRF-derived-MTP (planning) and the MV-cine-derived-MTP (delivery). A dynamic digital phantom was used to assess the algorithm’s ability to detect intra-fractional changes in patient alignment, by simulating different spatial variations in the MV-cine and calculating the corresponding change in MTP. Inter-and-intra-fractional variation, IGRT accuracy, and filtering effects were investigated on a patient dataset. Results: Phantom results demonstrated a high accuracy in detecting both translational and rotational variation. The lowest localization error of the patient dataset was achieved at each fraction’s first field (mean=0.38mm), with Fx3 demonstrating a particularly strong correlation between intra-fractional motion-caused localization error and treatment progress. Filtering significantly improved tracking visibility in both the DRF and MV-cine images. Conclusion: We have

  19. Optimization of the radiological protection of patients undergoing radiography, fluoroscopy and computed tomography. Final report of a coordinated research project in Africa, Asia and eastern Europe

    International Nuclear Information System (INIS)

    2004-12-01

    Although radiography has been an established imaging modality for over a century, continuous developments have led to improvements in technique resulting in improved image quality at reduced patient dose. If one compares the technique used by Roentgen with the methods used today, one finds that a radiograph can now be obtained at a dose which is smaller by a factor of 100 or more. Nonetheless, some national surveys, particularly in the United Kingdom and in the United States of America in the 1980s and 1990s, have indicated large variations in patient doses for the same diagnostic examination, in some cases by a factor of 20 or more. This arises not only owing to the various types of equipment and accessories used by the different health care providers, but also because of operational factors. The IAEA has a statutory responsibility to establish standards for the protection of people against exposure to ionising radiation and to provide for the worldwide application of those standards. A fundamental requirement of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), issued by the IAEA in cooperation with the FAO, ILO, WHO, PAHO and NEA, is the optimization of radiological protection of patients undergoing medical exposure. Towards its responsibility of implementation of standards and under the subprogramme of radiation safety, in 1995, the IAEA launched a coordinated research project (CRP) on radiological protection in diagnostic radiology in some countries in the Eastern European, African and Asian region. Initially, the CRP addressed radiography only and it covered wide aspects of optimisation of radiological protection. Subsequently, the scope of the CRP was extended to fluoroscopy and computed tomography (CT), but it covered primarily situation analysis of patient doses and equipment quality control. It did not cover patient dose reduction aspects in fluoroscopy and CT. The project

  20. Fusion of CT Angiography or MR Angiography with Unenhanced CBCT and Fluoroscopy Guidance in Endovascular Treatments of Aorto-Iliac Steno-Occlusion: Technical Note on a Preliminary Experience

    Energy Technology Data Exchange (ETDEWEB)

    Ierardi, Anna Maria; Duka, Ejona [University of Insubria, Interventional Radiology, Department of Radiology (Italy); Radaelli, Alessandro [Philips Healthcare (Netherlands); Rivolta, Nicola; Piffaretti, Gabriele [University of Insubria, Vascular Surgery Department (Italy); Carrafiello, Gianpaolo, E-mail: gcarraf@gmail.com [University of Insubria, Interventional Radiology, Department of Radiology (Italy)

    2016-01-15

    AimTo evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease.Materials and MethodsBetween September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated.ResultsImage co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02–63.75 Gycm2). The mean total procedure time was 32.2 min (range 27–38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20–40 mL).ConclusionsIF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration.

  1. Fusion of CT Angiography or MR Angiography with Unenhanced CBCT and Fluoroscopy Guidance in Endovascular Treatments of Aorto-Iliac Steno-Occlusion: Technical Note on a Preliminary Experience

    International Nuclear Information System (INIS)

    Ierardi, Anna Maria; Duka, Ejona; Radaelli, Alessandro; Rivolta, Nicola; Piffaretti, Gabriele; Carrafiello, Gianpaolo

    2016-01-01

    AimTo evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease.Materials and MethodsBetween September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated.ResultsImage co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02–63.75 Gycm2). The mean total procedure time was 32.2 min (range 27–38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20–40 mL).ConclusionsIF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration

  2. Estimation of lung tissue doses following exposure to low-LET radiation in the Canadian study of cancer following multiple fluoroscopies

    International Nuclear Information System (INIS)

    Howe, G.R.; Yaffe, M.

    1992-02-01

    Lung tissue doses from exposure to external low-LET radiation have been estimated for each year between 1930 and 1960 for 92,707 tuberculosis patients first treated in Canadian institutions between 1930 and 1952. Many of these patients received multiple chest fluoroscopies together with treatment by artificial pneumothorax, and thus accumulated doses up to 15.7 grays. The estimated doses have been used in a statistical analysis of lung cancer mortality between 1950 and 1987 occurring among 64,698 patients known to be alive at the start of 1950, and followed by linkage to the Canadian national mortality data base. There were substantial variations in the total cumulative lung tissue dose received by the cohort, with 2,490 individuals having doses in excess of 1.7 grays. A total of 1,156 lung cancer deaths was observed in the cohort, and these have been used to estimate relative risks. The most appropriate risk model appears to be a simple linear relative risk function, with an excess relative risk coefficient of 0.089 for an absorbed dose of 1 gray. This contrasts with estimates of relative risk based on the atomic bomb survivors study, for which the excess relative risk coefficient for males 20 years after the first exposure is estimated to be 0.64. The difference is statistically significant. It is postulated that fractionation and dose rate effectiveness factors may account for some of the discrepancy. (Modified author abstract) (14 refs., 20 tabs.)

  3. Doses in pediatric urinary studies guided by fluoroscopy: methodology oriented to the education; Dosis en estudios urinarios pediatricos guiados por fluoroscopia: metodologia orientada a la educacion

    Energy Technology Data Exchange (ETDEWEB)

    Cotelo, E; Castillo, C; Padilla, M [Escuela Universitaria de Tecnologia Medica, Facultad de Medicina, Universidad de la Republica (UdelaR) Av. Italia s/n 3er. piso CP 11600, Montevideo (Uruguay); Rabin, C [Instituto de Fisica, Facultad de Ciencias, UdelaR, Montevideo (Uruguay)

    2006-07-01

    The challenge of the Radiological Protection (RP) it is to implement Programs of Quality Guarantee without limiting them to the quality control. Radiologists and technicians should to familiarize with the dosimetry of patient, and the specialists in RP need to have clinical practice. The children (more radiosensitive that the adults) they present difficulties own to establish clinical approaches of quality due to their variations anthropomorphic (wide age range) and to specific illnesses. Also, those studies guided by fluoroscopy are of difficult standardization by the numerous ones pathologies (with anatomic-physiologic variations). It was determined the Kerma Area Product (P{sub K,A} ) in 25 subjected patients to cystourethrographies carried out by the same radiologist doctor. Its were registered anthropometric data, technical parameters, irradiated area, number radiographs, P{sub K,A} , pathologies. The complications (collaboration, delays in urinating), the radiological protocols and the learning curve of the radiologist were analyzed. When knowing the 'in situ' dose, the radiologist could relate it with those variables that determine it, optimizing immediately it practice. The hope wide range of obtained P{sub K,A} (0.17 - 1.85) Gy.cm{sup 2} deepened the analysis. The measurement of P{sub K,A} (non mandatory in all Latin America) it constitutes an incomparable educational tool in RP, should be used, at least, in reference hospitals. (Author)

  4. Factors affecting results of fluoroscopy-guided facet joint injection: Probable differences in the outcome of treatment between pure facet joint hypertrophy and concomitant diseases

    Directory of Open Access Journals (Sweden)

    Akif Albayrak

    2016-01-01

    Full Text Available Study Design: Retrospective cohort study. Purpose: Facet joints are considered a common source of chronic low-back pain. To determine whether pathogens related to the facet joint arthritis have any effect on treatment failure. Materials and Methods: Facet joint injection was applied to 94 patients treated at our hospital between 2011 and 2012 (mean age 59.5 years; 80 women and 14 men. For the purpose of analysis, the patients were divided into two groups. Patients who only had facet hypertrophy were placed in group A (47 patients, 41 women and 6 men, mean age 55.3 years and patients who had any additional major pathology to facet hypertrophy were placed in group B (47 patients, 39 women and 8 men, mean age 58.9 years. Injections were applied around the facet joint under surgical conditions utilizing fluoroscopy device guidance. A mixture of methylprednisolone and lidocaine was used as the injection ingredient. Results: In terms of Oswestry Disability Index (ODI and visual analog scale (VAS scores, no significant difference was found between preinjection and immediate postinjection values in both groups, and the scores of group A patients were significantly lower (P < 0.005 compared with that of group B patients at the end of the third, sixth, and twelfth month. Conclusion: For low-back pain caused by facet hypertrophy, steroid injection around the facet joint is an effective treatment, but if there is an existing major pathology, it is not as effective.

  5. Measurement of Intervertebral Motion Using Quantitative Fluoroscopy: Report of an International Forum and Proposal for Use in the Assessment of Degenerative Disc Disease in the Lumbar Spine

    Directory of Open Access Journals (Sweden)

    Alan C. Breen

    2012-01-01

    Full Text Available Quantitative fluoroscopy (QF is an emerging technology for measuring intervertebral motion patterns to investigate problem back pain and degenerative disc disease. This International Forum was a networking event of three research groups (UK, US, Hong Kong, over three days in San Francisco in August 2009. Its aim was to reach a consensus on how best to record, analyse, and communicate QF information for research and clinical purposes. The Forum recommended that images should be acquired during regular trunk motion that is controlled for velocity and range, in order to minimise externally imposed variability as well as to correlate intervertebral motion with trunk motion. This should be done in both the recumbent passive and weight bearing active patient configurations. The main recommended outputs from QF were the true ranges of intervertebral rotation and translation, neutral zone laxity and the consistency of shape of the motion patterns. The main clinical research priority should initially be to investigate the possibility of mechanical subgroups of patients with chronic, nonspecific low back pain by comparing their intervertebral motion patterns with those of matched healthy controls.

  6. Doses in pediatric urinary studies guided by fluoroscopy: methodology oriented to the education; Dosis en estudios urinarios pediatricos guiados por fluoroscopia: metodologia orientada a la educacion

    Energy Technology Data Exchange (ETDEWEB)

    Cotelo, E.; Castillo, C.; Padilla, M. [Escuela Universitaria de Tecnologia Medica, Facultad de Medicina, Universidad de la Republica (UdelaR) Av. Italia s/n 3er. piso CP 11600, Montevideo (Uruguay); Rabin, C. [Instituto de Fisica, Facultad de Ciencias, UdelaR, Montevideo (Uruguay)]. e-mail: elecote@adinet.com.uy

    2006-07-01

    The challenge of the Radiological Protection (RP) it is to implement Programs of Quality Guarantee without limiting them to the quality control. Radiologists and technicians should to familiarize with the dosimetry of patient, and the specialists in RP need to have clinical practice. The children (more radiosensitive that the adults) they present difficulties own to establish clinical approaches of quality due to their variations anthropomorphic (wide age range) and to specific illnesses. Also, those studies guided by fluoroscopy are of difficult standardization by the numerous ones pathologies (with anatomic-physiologic variations). It was determined the Kerma Area Product (P{sub K,A} ) in 25 subjected patients to cystourethrographies carried out by the same radiologist doctor. Its were registered anthropometric data, technical parameters, irradiated area, number radiographs, P{sub K,A} , pathologies. The complications (collaboration, delays in urinating), the radiological protocols and the learning curve of the radiologist were analyzed. When knowing the 'in situ' dose, the radiologist could relate it with those variables that determine it, optimizing immediately it practice. The hope wide range of obtained P{sub K,A} (0.17 - 1.85) Gy.cm{sup 2} deepened the analysis. The measurement of P{sub K,A} (non mandatory in all Latin America) it constitutes an incomparable educational tool in RP, should be used, at least, in reference hospitals. (Author)

  7. In vitro quantification of the performance of model-based mono-planar and bi-planar fluoroscopy for 3D joint kinematics estimation.

    Science.gov (United States)

    Tersi, Luca; Barré, Arnaud; Fantozzi, Silvia; Stagni, Rita

    2013-03-01

    Model-based mono-planar and bi-planar 3D fluoroscopy methods can quantify intact joints kinematics with performance/cost trade-off. The aim of this study was to compare the performances of mono- and bi-planar setups to a marker-based gold-standard, during dynamic phantom knee acquisitions. Absolute pose errors for in-plane parameters were lower than 0.6 mm or 0.6° for both mono- and bi-planar setups. Mono-planar setups resulted critical in quantifying the out-of-plane translation (error bi-planar in quantifying the rotation along bone longitudinal axis (error bi-planar (error comparable to bi-planar, but with halved computational costs, halved segmentation time and halved ionizing radiation dose. Bi-planar analysis better compensated for the out-of-plane uncertainty that is differently propagated to relative kinematics depending on the setup. To take its full benefits, the motion task to be investigated should be designed to maintain the joint inside the visible volume introducing constraints with respect to mono-planar analysis.

  8. Accuracy and repeatability of quantitative fluoroscopy for the measurement of sagittal plane translation and finite centre of rotation in the lumbar spine.

    Science.gov (United States)

    Breen, Alexander; Breen, Alan

    2016-07-01

    Quantitative fluoroscopy (QF) was developed to measure intervertebral mechanics in vivo and has been found to have high repeatability and accuracy for the measurement of intervertebral rotations. However, sagittal plane translation and finite centre of rotation (FCR) are potential measures of stability but have not yet been fully validated for current QF. This study investigated the repeatability and accuracy of QF for measuring these variables. Repeatability was assessed from L2-S1 in 20 human volunteers. Accuracy was investigated using 10 consecutive measurements from each of two pairs of linked and instrumented dry human vertebrae as reference; one which tilted without translation and one which translated without tilt. The results found intra- and inter-observer repeatability for translation to be 1.1mm or less (SEM) with fair to substantial reliability (ICC 0.533-0.998). Intra-observer repeatability of FCR location for inter-vertebral rotations of 5° and above ranged from 1.5mm to 1.8mm (SEM) with moderate to substantial reliability (ICC 0.626-0.988). Inter-observer repeatability for FCR ranged from 1.2mm to 5.7mm, also with moderate to substantial reliability (ICC 0.621-0.878). Reliability was substantial (ICC>0.81) for 10/16 measures for translation and 5/8 for FCR location. Accuracy for translation was 0.1mm (fixed centre) and 2.2mm (moveable centre), with an FCR error of 0.3mm(x) and 0.4mm(y) (fixed centre). This technology was found to have a high level of accuracy and with a few exceptions, moderate to substantial repeatability for the measurement of translation and FCR from fluoroscopic motion sequences. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  9. Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy.

    Science.gov (United States)

    Zeller, Ian M; Sharma, Adrija; Kurtz, William B; Anderle, Mathew R; Komistek, Richard D

    2017-04-01

    Historically, knee arthroplasties have been designed using average patient anatomy. Recent advances in imaging and manufacturing have facilitated the development of customized prostheses designed to fit the unique shape of individual patients. The purpose of this study is to determine if improving implant design through customized total knee arthroplasty (TKA) improves kinematic function. Using state-of-the-art mobile fluoroscopy, tibiofemoral kinematics were analyzed for 24 subjects with a customized individually made (CIM), cruciate-retaining TKA, and 14 subjects having an asymmetric condylar cruciate-retaining TKA. Subjects performed a weight-bearing deep knee bend and a rise from a seated position. Each patient was evaluated for weight-bearing range of motion, femorotibial translation, femorotibial axial rotation, and condylar liftoff occurrence. Subjects having a CIM TKA experienced greater weight-bearing knee flexion compared with the traditional posterior cruciate-retaining (PCR) TKA design. During flexion, the CIM TKA subjects consistently exhibited more posterior femoral rollback than the traditional PCR TKA subjects. The CIM TKA was found to have statistically greater axial rotation compared with the traditional PCR TKA (P = .05). Of note, only the CIM TKA patients experienced femoral internal rotation at full extension, as exhibited in a normal knee. Compared with the traditional PCR TKA, the CIM TKAs demonstrated minimal occurrences of paradoxical sliding and reverse rotation during flexion and extension. The CIM TKA subjects showed minimal liftoff and hence better stability in earlyflexion to midflexion compared with the traditional PCR subjects. The CIM TKA demonstrated kinematics more similar to a normal knee. Therefore, using customized implant technology through CIM TKA designs affords benefits including more normal motion compared with a traditional PCR TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Intraoperative three-dimensional fluoroscopy after transpedicular positioning of Kirschner-wire versus conventional intraoperative biplanar fluoroscopic control: A retrospective study of 345 patients and 1880 pedicle screws

    Directory of Open Access Journals (Sweden)

    Ghassan Kerry

    2014-01-01

    Full Text Available Study Design: Retrospective study. Objective: The aim was to find out whether intraoperative three-dimensional imaging after transpedicular positioning of Kirschner wire (K-wire in lumbar and thoracic posterior instrumentation procedures is of benefit to the patients and if this technique is accurately enough to make a postoperative screw position control through computer tomography (CT dispensable. Patients and Methods: Lumbar and thoracic posterior instrumentation procedures conducted at our department between 2002 and 2012 were retrospectively reviewed. The patients were divided into two groups: group A, including patients who underwent intraoperative three-dimensional scan after transpedicular positioning of the K-wire and group B, including patients who underwent only intraoperative biplanar fluoroscopy. An early postoperative CT of the instrumented section was done in all cases to assess the screw position. The rate of immediate intraoperative correction of the K-wires in cases of mal-positioning, as well as the rate of postoperative screw revisions, was measured. Results: In general, 345 patients (1880 screws were reviewed and divided into two groups; group A with 225 patients (1218 screws and group B with 120 patients (662 screws. One patient (0.44% (one screw [0.082%] of group A underwent postoperative screw correction while screw revisions were necessary in 14 patients (11.7% (28 screws [4.2%] of group B. Twenty-three patients (10.2% (28 K-wires [2.3%] of group A underwent intraoperative correction due to primary intraoperative detected K-wire mal-position. None of the corrected K-wires resulted in a corresponding neurological deficit. Conclusion: Three-dimensional imaging after transpedicular K-wire positioning leads to solid intraoperative identification of misplaced K-wires prior to screw placement and reduces screw revision rates compared with conventional fluoroscopic control. When no clinical deterioration emerges, a

  11. Treatment of recurrent patellar dislocation via knee arthroscopy combined with C-arm fluoroscopy and reconstruction of the medial patellofemoral ligament.

    Science.gov (United States)

    Li, Li; Wang, Hongbo; He, Yun; Si, Yu; Zhou, Hongyu; Wang, Xin

    2018-06-01

    Recurrent patellar dislocations were treated via knee arthroscopy combined with C-arm fluoroscopy, and reconstruction of the medial patellofemoral ligaments. Between October 2013 and March 2017, 52 cases of recurrent patellar dislocation [27 males and 25 females; age, 16-47 years (mean, 21.90 years)] were treated. Arthroscopic exploration was performed and patellofemoral joint cartilage injuries were repaired. It was subsequently determined whether it was necessary to release the lateral patellofemoral support belt. Pre-operative measurements were used to decide whether tibial tubercle osteotomy was required. Medial patellofemoral ligaments were reconstructed using autologous semitendinosus tendons. Smith and Nephew model 3.5 line anchors were used to double-anchor the medial patellofemoral margin. On the femoral side, the medial patellofemoral ligament was fixed using 7-cm, absorbable, interfacial compression screws. All cases were followed for 1-40 months (average, 21 months). The Q angle, tibial tuberosity trochlear groove distance, Insall-Salvati index, patellofemoral angle, lateral patellofemoral angle and lateral shift were evaluated on X-Ray images using the picture archiving and communication system. Subjective International Knee Documentation Committee (IKDC) knee joint functional scores and Lysholm scores were recorded. Post-operative fear was absent, and no patellar re-dislocation or re-fracture was noted during follow-up. At the end of follow-up, the patellofemoral angle (0.22±4.23°), lateral patellofemoral angle (3.44±1.30°), and lateral shift (0.36+0.14°) differed significantly from the pre-operative values (all, Ppatellofemoral ligament was effective.

  12. Radiation dose and image quality of X-ray volume imaging systems: cone-beam computed tomography, digital subtraction angiography and digital fluoroscopy.

    Science.gov (United States)

    Paul, Jijo; Jacobi, Volkmar; Farhang, Mohammad; Bazrafshan, Babak; Vogl, Thomas J; Mbalisike, Emmanuel C

    2013-06-01

    Radiation dose and image quality estimation of three X-ray volume imaging (XVI) systems. A total of 126 patients were examined using three XVI systems (groups 1-3) and their data were retrospectively analysed from 2007 to 2012. Each group consisted of 42 patients and each patient was examined using cone-beam computed tomography (CBCT), digital subtraction angiography (DSA) and digital fluoroscopy (DF). Dose parameters such as dose-area product (DAP), skin entry dose (SED) and image quality parameters such as Hounsfield unit (HU), noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were estimated and compared using appropriate statistical tests. Mean DAP and SED were lower in recent XVI than its previous counterparts in CBCT, DSA and DF. HU of all measured locations was non-significant between the groups except the hepatic artery. Noise showed significant difference among groups (P < 0.05). Regarding CNR and SNR, the recent XVI showed a higher and significant difference compared to its previous versions. Qualitatively, CBCT showed significance between versions unlike the DSA and DF which showed non-significance. A reduction of radiation dose was obtained for the recent-generation XVI system in CBCT, DSA and DF. Image noise was significantly lower; SNR and CNR were higher than in previous versions. The technological advancements and the reduction in the number of frames led to a significant dose reduction and improved image quality with the recent-generation XVI system. • X-ray volume imaging (XVI) systems are increasingly used for interventional radiological procedures. • More modern XVI systems use lower radiation doses compared with earlier counterparts. • Furthermore more modern XVI systems provide higher image quality. • Technological advances reduce radiation dose and improve image quality.

  13. TH-CD-207A-02: Implementation of Live EPID-Based Inspiration Level Assessment (LEILA) for Deepinspiration Breath-Hold (DIBH) Monitoring Using MV Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, J [Calvary Mater Newcastle, Newcastle (Australia); The University of Sydney, Sydney (Australia); The University of Newcastle, Newcastle (Australia); Sun, J; Fuangrod, T; Bhatia, S [Calvary Mater Newcastle, Newcastle (Australia); Doebrich, M; Greer, P [Calvary Mater Newcastle, Newcastle (Australia); The University of Newcastle, Newcastle (Australia); Zwan, B [The University of Newcastle, Newcastle (Australia); Central Coast Cancer Centre, Gosford (Australia)

    2016-06-15

    Purpose: As prior work has shown that current DIBH monitoring approaches using surrogate measures (marker block on chest) do not always correspond with the clinical quantity of interest (lung depth, LD), a software tool and workflow are introduced to use MV fluoroscopy during treatment for real-time / Live EPID-based Inspiration Level Assessment (LEILA). Methods: A prototype software tool calculates and displays the LD during the treatment of left sided breast cancer. Calculations are based on MV cine images which are acquired with the treatment beam thereby not incurring any additional imaging dose. Image capture and processing are implemented using a dedicated frame grabber computer. The calculation engine automatically detects image orientation and includes provisions for large treatment fields that exceed the size of the EPID panel. LD is measured along a line profile in the middle of the field. LEILA’s interface displays the current MV image, a reference image (DRR), the current LD, as well as a trace of LD over treatment time. The display includes patient specific LD tolerances. Tolerances are specified for each field and loaded before the treatment. A visual warning is generated when the tolerance is exceeded. LEILA is initially run in parallel with current DIBH techniques. When later run by itself DIBH setup will be done using skin marks and room laser. Results: Offline tests of LEILA confirmed accurate automatic LD measurement for a variety of patient geometries. Deployment of the EPID during all left sided breast treatments was well tolerated by patients and staff during a multi-month pilot. The frame grabber provides 11 frames-per-second; the MATLAB based LEILA prototype software can analyze five frames-per-second standalone on standard desktop hardware. Conclusion: LEILA provides an automated approach to quantitatively monitor LD on MV images during DIBH treatment. Future improvements include a database and further speed optimization.

  14. Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver

    Energy Technology Data Exchange (ETDEWEB)

    Cornelis, F.; Takaki, H. [Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States); Laskhmanan, M. [Perfint Healthcare Inc (India); Durack, J. C.; Erinjeri, J. P.; Getrajdman, G. I.; Maybody, M.; Sofocleous, C. T.; Solomon, S. B.; Srimathveeravalli, G., E-mail: srimaths@mskcc.org [Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States)

    2015-10-15

    PurposeTo compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver.Materials and MethodsManual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5 mm fiducial seeds placed in swine liver (n = 6). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal–Wallis test.ResultsPaired comparison of manual and RPS-assisted placements to a target by the same physician indicated accuracy outcomes was not statistically different (manual: 4.53 mm; RPS: 4.66 mm; p = 0.41), but manual placement resulted in higher total radiation dose (manual: 1075.77 mGy/cm; RPS: 636.4 mGy/cm; p = 0.03), required more confirmation scans (manual: 6.6; RPS: 1.6; p < 0.0001) and needle manipulations (manual: 4.6; RPS: 0.4; p < 0.0001). Procedure time for RPS was longer than manual placement (manual: 6.12 min; RPS: 9.7 min; p = 0.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (p = 0.008) and number of repositions (p = 0.04) but not in other study measures (p > 0.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (p = 0.02) and not in other study measures (p > 0.05).ConclusionsCT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy.

  15. Quantitative Real-Time Fluoroscopy Analysis on Measurement of the Hepatic Arterial Flow During Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Comparison with Quantitative Digital Subtraction Angiography Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Yang; Lee, Rheun-Chuan, E-mail: rclee@vghtpe.gov.tw; Guo, Wan-Yuo, E-mail: wyguo@vghtpe.gov.tw; Chu, Wei-Fa [Taipei Veterans General Hospital, Department of Radiology (China); Wu, Frank Chun-Hsien [Siemens Healthcare Ltd. (China); Gehrisch, Sonja [Siemens Healthcare GmbH (Germany)

    2016-11-15

    PurposeTo quantify the arterial flow change during transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) using digital subtraction angiography, quantitative color-coding analysis (d-QCA), and real-time subtraction fluoroscopy QCA (f-QCA).Materials and MethodsThis prospective study enrolled 20 consecutive patients with HCC who had undergone TACE via a subsegmental approach between February 2014 and April 2015. The TACE endpoint was a sluggish antegrade tumor-feeding arterial flow. d-QCA and f-QCA were used for determining the relative maximal density time (rT{sub max}) of the selected arteries. The rT{sub max} of the selected arteries was analyzed in d-QCA and f-QCA before and after TACE, and its correlation in both analyses was evaluated.ResultsThe pre- and post-TACE rT{sub max} of the embolized segmental artery in d-QCA and f-QCA were 1.59 ± 0.81 and 2.97 ± 1.80 s (P < 0.001) and 1.44 ± 0.52 and 2.28 ± 1.02 s (P < 0.01), respectively. The rT{sub max} of the proximal hepatic artery did not significantly change during TACE in d-QCA and f-QCA. The Spearman correlation coefficients of the pre- and post-TACE rT{sub max} of the embolized segmental artery between d-QCA and f-QCA were 0.46 (P < 0.05) and 0.80 (P < 0.001). Radiation doses in one series of d-QCA and f-QCA were 140.7 ± 51.5 milligray (mGy) and 2.5 ± 0.7 mGy, respectively.Conclusionsf-QCA can quantify arterial flow changes with a higher temporal resolution and lower radiation dose. Flow quantification of the embolized segmental artery using f-QCA and d-QCA is highly correlated.

  16. Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver

    International Nuclear Information System (INIS)

    Cornelis, F.; Takaki, H.; Laskhmanan, M.; Durack, J. C.; Erinjeri, J. P.; Getrajdman, G. I.; Maybody, M.; Sofocleous, C. T.; Solomon, S. B.; Srimathveeravalli, G.

    2015-01-01

    PurposeTo compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver.Materials and MethodsManual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5 mm fiducial seeds placed in swine liver (n = 6). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal–Wallis test.ResultsPaired comparison of manual and RPS-assisted placements to a target by the same physician indicated accuracy outcomes was not statistically different (manual: 4.53 mm; RPS: 4.66 mm; p = 0.41), but manual placement resulted in higher total radiation dose (manual: 1075.77 mGy/cm; RPS: 636.4 mGy/cm; p = 0.03), required more confirmation scans (manual: 6.6; RPS: 1.6; p < 0.0001) and needle manipulations (manual: 4.6; RPS: 0.4; p < 0.0001). Procedure time for RPS was longer than manual placement (manual: 6.12 min; RPS: 9.7 min; p = 0.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (p = 0.008) and number of repositions (p = 0.04) but not in other study measures (p > 0.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (p = 0.02) and not in other study measures (p > 0.05).ConclusionsCT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy

  17. In Vivo Measurements of the Ischiofemoral Space in Recreationally Active Participants During Dynamic Activities: A High-Speed Dual Fluoroscopy Study.

    Science.gov (United States)

    Atkins, Penny R; Fiorentino, Niccolo M; Aoki, Stephen K; Peters, Christopher L; Maak, Travis G; Anderson, Andrew E

    2017-10-01

    Ischiofemoral impingement (IFI) is a dynamic process, but its diagnosis is often based on static, supine images. To couple 3-dimensional (3D) computed tomography (CT) models with dual fluoroscopy (DF) images to quantify in vivo hip motion and the ischiofemoral space (IFS) in asymptomatic participants during weightbearing activities and evaluate the relationship of dynamic measurements with sex, hip kinematics, and the IFS measured from axial magnetic resonance imaging (MRI). Cross-sectional study; Level of evidence, 3. Eleven young, asymptomatic adults (5 female) were recruited. 3D reconstructions of the femur and pelvis were generated from MRI and CT. The axial and 3D IFS were measured from supine MRI. In vivo hip motion during weightbearing activities was quantified using DF. The bone-to-bone distance between the lesser trochanter and ischium was measured dynamically. The minimum and maximum IFS were determined and evaluated against hip joint angles using a linear mixed-effects model. The minimum IFS occurred during external rotation for 10 of 11 participants. The IFS measured from axial MRI (mean, 23.7 mm [95% CI, 19.9-27.9]) was significantly greater than the minimum IFS observed during external rotation (mean, 10.8 mm [95% CI, 8.3-13.7]; P dynamic activities observed. The IFS was smaller in female than male participants for standing (mean, 20.9 mm [95% CI, 19.3-22.3] vs 30.4 mm [95% CI, 27.2-33.8], respectively; P = .034), level walking (mean, 8.8 mm [95% CI, 7.5-9.9] vs 21.1 mm [95% CI, 18.7-23.6], respectively; P = .001), and incline walking (mean, 9.1 mm [95% CI, 7.4-10.8] vs 21.3 mm [95% CI, 18.8-24.1], respectively; P = .003). Joint angles between the sexes were not significantly different for any of the dynamic positions of interest. The minimum IFS during dynamic activities was smaller than axial MRI measurements. Compared with male participants, the IFS in female participants was reduced during standing and walking, despite a lack of kinematic

  18. WE-AB-303-06: Combining DAO with MV + KV Optimization to Improve Skin Dose Sparing with Real-Time Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Grelewicz, Z; Wiersma, R [The University of Chicago, Chicago, IL (United States)

    2015-06-15

    Purpose: Real-time fluoroscopy may allow for improved patient positioning and tumor tracking, particularly in the treatment of lung tumors. In order to mitigate the effects of the imaging dose, previous studies have demonstrated the effect of including both imaging dose and imaging constraints into the inverse treatment planning object function. That method of combined MV+kV optimization may Result in plans with treatment beams chosen to allow for more gentle imaging beam-on times. Direct-aperture optimization (DAO) is also known to produce treatment plans with fluence maps more conducive to lower beam-on times. Therefore, in this work we demonstrate the feasibility of a combination of DAO and MV+kV optimization for further optimized real-time kV imaging. Methods: Therapeutic and imaging beams were modeled in the EGSnrc Monte Carlo environment, and applied to a patient model for a previously treated lung patient to provide dose influence matrices from DOSXYZnrc. An MV + kV IMRT DAO treatment planning system was developed to compare DAO treatment plans with and without MV+kV optimization. The objective function was optimized using simulated annealing. In order to allow for comparisons between different cases of the stochastically optimized plans, the optimization was repeated twenty times. Results: Across twenty optimizations, combined MV+kV IMRT resulted in an average of 12.8% reduction in peak skin dose. Both non-optimized and MV+kV optimized imaging beams delivered, on average, mean dose of approximately 1 cGy per fraction to the target, with peak doses to target of approximately 6 cGy per fraction. Conclusion: When using DAO, MV+kV optimization is shown to Result in improvements to plan quality in terms of skin dose, when compared to the case of MV optimization with non-optimized kV imaging. The combination of DAO and MV+kV optimization may allow for real-time imaging without excessive imaging dose. Financial support for the work has been provided in part by NIH

  19. Quantitative Real-Time Fluoroscopy Analysis on Measurement of the Hepatic Arterial Flow During Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Comparison with Quantitative Digital Subtraction Angiography Analysis

    International Nuclear Information System (INIS)

    Lin, Yi-Yang; Lee, Rheun-Chuan; Guo, Wan-Yuo; Chu, Wei-Fa; Wu, Frank Chun-Hsien; Gehrisch, Sonja

    2016-01-01

    PurposeTo quantify the arterial flow change during transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) using digital subtraction angiography, quantitative color-coding analysis (d-QCA), and real-time subtraction fluoroscopy QCA (f-QCA).Materials and MethodsThis prospective study enrolled 20 consecutive patients with HCC who had undergone TACE via a subsegmental approach between February 2014 and April 2015. The TACE endpoint was a sluggish antegrade tumor-feeding arterial flow. d-QCA and f-QCA were used for determining the relative maximal density time (rT_m_a_x) of the selected arteries. The rT_m_a_x of the selected arteries was analyzed in d-QCA and f-QCA before and after TACE, and its correlation in both analyses was evaluated.ResultsThe pre- and post-TACE rT_m_a_x of the embolized segmental artery in d-QCA and f-QCA were 1.59 ± 0.81 and 2.97 ± 1.80 s (P < 0.001) and 1.44 ± 0.52 and 2.28 ± 1.02 s (P < 0.01), respectively. The rT_m_a_x of the proximal hepatic artery did not significantly change during TACE in d-QCA and f-QCA. The Spearman correlation coefficients of the pre- and post-TACE rT_m_a_x of the embolized segmental artery between d-QCA and f-QCA were 0.46 (P < 0.05) and 0.80 (P < 0.001). Radiation doses in one series of d-QCA and f-QCA were 140.7 ± 51.5 milligray (mGy) and 2.5 ± 0.7 mGy, respectively.Conclusionsf-QCA can quantify arterial flow changes with a higher temporal resolution and lower radiation dose. Flow quantification of the embolized segmental artery using f-QCA and d-QCA is highly correlated.

  20. Evaluation Of Medical Fluoroscopy Imaging

    International Nuclear Information System (INIS)

    Hartana, Budi; Santoso

    2000-01-01

    It has been done to evaluate image system of medical fluoroscopic machine by Leeds Test Object (LTO). Two x-ray potentials of 70 kV and 40-60 kV were used to evaluate image by LTO on monitor and oscilloscope. Performance of imaging system decreased for some parameters of video signal, linearity of television scan, contras threshold of 4.5%, distortion integral of 65.1%, and focus uniformity decrease to edge image. Comparison of field diameter of television image to intensifier field vertically and horizontally were respectively 221:230 and 205:230, symmetrically vignetting, spatial resolution limit is 1.26 lp/mm

  1. The ALARA (as low as reasonably achievable) concept in pediatric interventional and fluoroscopic imaging: striving to keep radiation doses as low as possible during fluoroscopy of pediatric patients - a white paper executive summary

    International Nuclear Information System (INIS)

    Strauss, Keith J.; Kaste, Sue C.

    2006-01-01

    ALARA represents a practice mandate adhering to the principle of keeping radiation doses to patients and personnel As Low As Reasonably Achievable. This concept is strongly endorsed by the Society for Pediatric Radiology, particularly in the use of procedures and modalities involving higher radiation doses such as CT and fluoroscopic examinations of pediatric patients. There is no doubt that medical imaging, which has undergone tremendous technological advances in recent decades, is integral to patient care. However, these technological advances generally precede the knowledge of end-users concerning the optimal use and correct operation of the resulting imaging equipment, and such knowledge is essential to minimizing potential risks to the patients. Current imaging methods must be optimized for radiation dose reduction in pediatric patients who might be as much as ten times more radiosensitive than adults. Unlike straightforward radiographic examinations, radiation dose to the patient during fluoroscopy is dependent on the operator's training, experience with the fluoroscope, and efficiency in completing a diagnostic study. The range of pediatric radiation doses from fluoroscopy is wide because this examination is performed not only by pediatric radiologists but also by general radiologists who occasionally care for children, interventional cardiologists, gastroenterologists, urologists and others. Thus, a venue where multidisciplinary interaction by this variety of operators can occur serves to improve pediatric patient care

  2. Intraoperative intermittent blocking of the common iliac arteries in cases of placenta percreta without the use of fluoroscopy; Intraoperative intermittierende Blockung der Arteriae iliacae communes bei Placenta percreta unter Vermeidung von Roentgenstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Heinze, S. [Frankfurt Univ. (Germany). Inst. of Forensic Medicine; Klinikum Oldenburg (Germany). Inst. of Diagnostic and Interventional Radiology; Filsinger, B. [St. Marienkrankenhaus, Ludwigshafen (Germany). Maternity Clinic; Kastenholz, G.; Schroeder, R.J. [St. Marienkrankenhaus, Ludwigshafen (Germany). Dept. of Radiology

    2016-12-15

    The number of patients with placenta accreta, percreta and increta is increasing. The morbidity and mortality are higher mostly due to hemorrhage. Therefore, new methods to reduce the risk of severe bleeding are necessary. Three patients were treated in collaboration by obstetricians, urologists, anesthesiologists, and radiologists. An MRI of the pelvis was performed and the diameters and lengths of the iliac arteries were measured to avoid fluoroscopy during the preoperative placement of catheter balloons into the iliac arteries. During the operational procedure the balloons were inflated and deflated depending on the operative site and the occurrence of bleeding. In comparison to the literature, severe bleeding was clearly reduced. No complications of the intervention were observed. The presented method to reduce severe bleeding might represent significant progress in the management of abnormal placenta implantation. Nevertheless, further controlled studies are needed in order to establish evidence-based recommendations.

  3. MO-DE-201-03: This course presents a review of radiologic anatomy and physiology as it applies to projection radiography, fluoroscopy, CT, MRI, U/S, and nuclear medicine

    International Nuclear Information System (INIS)

    Fahey, F.

    2015-01-01

    Fundamental knowledge of radiologic anatomy and physiology is critical for medical physicists. Many physicists are exposed to this topic only in graduate school, and knowledge is seldom formally evaluated or assessed after Part I of the ABR exam. Successful interactions with clinicians, including surgeons, radiologists, and oncologists requires that the medical physicist possess this knowledge. This course presents a review of radiologic anatomy and physiology as it applies to projection radiography, fluoroscopy, CT, MRI, U/S, and nuclear medicine. We will review structural anatomy, manipulation of tissue contrast, the marriage between anatomy and physiology, and explore how medical imaging exploits normal and pathological processes in the body to generate contrast. Learning Objectives: Review radiologic anatomy. Examine techniques to manipulate tissue contrast in radiology. Integrate anatomy and physiology in molecular imaging

  4. MO-DE-201-03: This course presents a review of radiologic anatomy and physiology as it applies to projection radiography, fluoroscopy, CT, MRI, U/S, and nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Fahey, F.

    2015-06-15

    Fundamental knowledge of radiologic anatomy and physiology is critical for medical physicists. Many physicists are exposed to this topic only in graduate school, and knowledge is seldom formally evaluated or assessed after Part I of the ABR exam. Successful interactions with clinicians, including surgeons, radiologists, and oncologists requires that the medical physicist possess this knowledge. This course presents a review of radiologic anatomy and physiology as it applies to projection radiography, fluoroscopy, CT, MRI, U/S, and nuclear medicine. We will review structural anatomy, manipulation of tissue contrast, the marriage between anatomy and physiology, and explore how medical imaging exploits normal and pathological processes in the body to generate contrast. Learning Objectives: Review radiologic anatomy. Examine techniques to manipulate tissue contrast in radiology. Integrate anatomy and physiology in molecular imaging.

  5. Reduced medical and occupational exposures by optimizing working procedures in fluoroscopy equipment in the University Hospital of Santa Maria (RS); Reducao de exposicao medicas e ocupacionais pela otimizacao de procedimentos de trabalho em equipamento de fluoroscopia no Hospital Universitario de Santa Maria (RS)

    Energy Technology Data Exchange (ETDEWEB)

    Weis, Guilherme L.; Claus, Thiago V.; Baumhardt, Tadeu, E-mail: glweis@gmail.com [Hospital Universitario de Santa Maria, RS (Brazil); Shuch, Luiz A. [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Fisica

    2013-08-15

    This work seeks to reduce medical (patient) and occupational (workers) exposure by standardizing resources available in fluoroscopy equipment used in interventional procedures. Such procedures use transportable surgical arch type fluoroscopy equipment, with applications in orthopedics, angiography and pacemaker implantation. Improper use of these devices generates excessive radiation doses in both patients and the medical staff. It is observed that the equipment after being connected to the grid, is pre-selected to work in continuous fluoroscopy and no additional filtration, producing higher doses of radiation. For specific applications, changes in protocols should be undertaken according to medical indication. This work used a fluoroscopy equipment Shimadzu Active Opescope two radiation monitoring equipment, brand Radcal, models 9010 and 9015, two ionization chambers, of 60 cc and 180 cc and a low contrast phantom and a catheter, information that simulate the human body. Incidences were performed by changing the conditions of exposure as frame rates (fps - frames per second) and additional filtration. For each composition parameters was generated and filed an image, with the extent of their respective doses. These images were evaluated by radiologists. In more extreme cases we obtained a reduction of a factor 25 in occupational exposure (medical personnel) using the pulsed with the greatest 2 fps additional filter (0.3 mm Cu) compared to continuous system without any additional filtration. In medical exposure (of patients), decreased by a factor 39, the same conditions described above. With these arguments it is justified the optimization and standardization of the equipment used in fluoroscopy, which besides providing a dose reduction the patient and the medical personnel, increases the life of the X-ray tube while maintaining the quality of medical diagnosis. (author)

  6. Lung cancer mortality between 1950 and 1987 after exposure to fractionated moderate-dose-rate ionizing radiation in the Canadian fluoroscopy cohort study and a comparison with lung cancer mortality in the atomic bomb survivors study

    International Nuclear Information System (INIS)

    Howe, G.R.

    1995-01-01

    Current lung cancer risk estimates after exposure to low-linear energy transfer radiation such as X rays are based on studies of people exposed to such radiation at high dose rates, for example the atomic bomb survivors. Radiobiology and animal experiments suggest that risks from exposure at low to moderate dose rates, for example medical diagnostic procedures, may be overestimated by such risk models, but data for humans to examine this issue are limited. In this paper we report on lung cancer mortality between 1950 and 1987 in a cohort of 64,172 Canadian tuberculosis patients, of whom 39% were exposed to highly fractionated multiple chest fluoroscopies leading to a mean lung radiation dose of 1.02 Sv received at moderate dose rates. These data have been used to estimate the excess relative risk per sievert of lung cancer mortality, and this is compared directly to estimates derived from 75,991 atomic bomb survivors. Based on 1,178 lung cancer deaths in the fluoroscopy study, there was no evidence of any positive association between risk and dose, with the relative risk at 1 Sv being 1.00 (95% confidence interval 0.94, 1.07), which contrasts with that based on the atomic bomb survivors, 1.60 (1.27, 1.99). The difference in effect between the two studies almost certainly did not arise by chance (P = 0.0001). This study provides strong support from data for humans for a substantial fractionation/dose-rate effect for low-linear energy transfer radiation and lung cancer risk. This implies that lung cancer risk from exposures to such radiation at present-day dose rates is likely to be lower than would be predicted by current radiation risk models based on studies of high-dose-rate exposures. 25 refs., 8 tabs

  7. Comparison of fluoroscopy-guided pull-type percutaneous radiological gastrostomy (pull-type-PRG) with conventional percutaneous radiological gastrostomy (push-type-PRG): clinical results in 253 patients

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Schneider, J.; Dueber, C.; Pitton, M.B. [University Medical Center of the Johannes Gutenberg University Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany)

    2011-11-15

    To analyze the clinical results and complications of fluoroscopy guided internal-external pull-type percutaneous radiological gastrostomy (pull-type-PRG) and conventional external-internal percutaneous radiological gastrostomy (push-type-PRG). A total of 253 patients underwent radiological gastrostomy between January 2002 and January 2010. Data were collected retrospectively from radiology reports, Chart review of clinical notes, procedure reports, discharge summaries and subsequent hospital visits. Statistical analysis was performed to compare the two methods for gastrostomy with respect to peri-interventional aspects and clinical results. 128 patients received the Pull-type-PRG whereas the other 125 patients were served with the Push-type-PRG. Indications for gastrostomy were similar in these two groups. The most frequent indications for the both methods were stenotic oesophageal tumors or head/neck tumors (54.7% in pull-type-PRG, 68% in push-type-PRG). Gastrostomy procedures were successful in 98.3% in pull-type-PRG compared to 92% in push-type-PRG. There was no procedure-related mortality. Compared to Push-type-PRG, the peri-interventional complication rate was significantly reduced in pull-type-PRG (14.8% versus 34.4%, P = 0.002). Compared to the external-internal push-type-PRG, the internal-external Pull-type-PRG showed a high primary success rate and a decreased incidence of peri-interventional complications. (orig.)

  8. Comparison of fluoroscopy-guided pull-type percutaneous radiological gastrostomy (pull-type-PRG) with conventional percutaneous radiological gastrostomy (push-type-PRG): clinical results in 253 patients

    International Nuclear Information System (INIS)

    Yang, Yang; Schneider, J.; Dueber, C.; Pitton, M.B.

    2011-01-01

    To analyze the clinical results and complications of fluoroscopy guided internal-external pull-type percutaneous radiological gastrostomy (pull-type-PRG) and conventional external-internal percutaneous radiological gastrostomy (push-type-PRG). A total of 253 patients underwent radiological gastrostomy between January 2002 and January 2010. Data were collected retrospectively from radiology reports, Chart review of clinical notes, procedure reports, discharge summaries and subsequent hospital visits. Statistical analysis was performed to compare the two methods for gastrostomy with respect to peri-interventional aspects and clinical results. 128 patients received the Pull-type-PRG whereas the other 125 patients were served with the Push-type-PRG. Indications for gastrostomy were similar in these two groups. The most frequent indications for the both methods were stenotic oesophageal tumors or head/neck tumors (54.7% in pull-type-PRG, 68% in push-type-PRG). Gastrostomy procedures were successful in 98.3% in pull-type-PRG compared to 92% in push-type-PRG. There was no procedure-related mortality. Compared to Push-type-PRG, the peri-interventional complication rate was significantly reduced in pull-type-PRG (14.8% versus 34.4%, P = 0.002). Compared to the external-internal push-type-PRG, the internal-external Pull-type-PRG showed a high primary success rate and a decreased incidence of peri-interventional complications. (orig.)

  9. Narrow Lead Aprons under Medical Fluoroscopy Procedures

    International Nuclear Information System (INIS)

    Ben-Shlomo, A.

    2014-01-01

    Lead aprons are the major protective item of the medical staff whose work involves x-ray exposure. Heart catheterization and angiography procedures represent the most common exposures of the medical staff. The lead equivalent thickness of lead aprons worn by the medical staff is defined by many national standards. The frontal side of the aprons should be 0.25 mm lead equivalent at working conditions under 100 kV, 0.35 mm for working conditions above 100 kV, and 0.5 mm for heart catheterization and angiography. The back side of the body needs less protection and usually is covered by 0.25 mm of lead equivalent. The lead equivalent thickness is defined at the 80 kV level

  10. Exposure parameters in fluoroscopy equipment. Quality control

    International Nuclear Information System (INIS)

    Alonso, M.; Castaneda, M.J.; Matorras, P.; Diaz-Caneja, N.; Gutierrez, I.

    1992-01-01

    Within the quality control program in Diagnostic Radiology currently being undertaken at the 'Marques de Valdecilla' University Hospital, the corresponding specification and procedure prototypes for the control of conventional radioscopy equipment have been elaborated and applied. This paper presents the values proposed in the specifications and those obtained for the following radioscopy equipment parameters: reference kerma, and its reproducibility, kerma linearity, maximum kerma at the skin, and total filtration. The results obtained indicate that the equipment studied could comply with specified requirements if a Maintenance Program were to be implemented in coordination with the Quality Control Program. (author)

  11. Evaluation of doses in gastrointestinal fluoroscopy

    International Nuclear Information System (INIS)

    Canevaro, Lucia Viviana

    1995-04-01

    This work aims at the development of a methodology to measure radiation doses to patients and professionals (radiologists) in fluoroscopic gastrointestinal tract examinations. Also, it aims at the assessment of the performance of this type of medical x-ray equipment, from the radiation protection point of view at the Department of Radiology of the Hospital Universitario Clementino Fraga Filho (Universidade Federal de Rio de Janeiro). This work was developed in order to identify the actual status and to set base lines as a reference for a quality control program. The calibration procedures of thermoluminescent dosimeters for radiodiagnosis quality beams are discussed and described here as well as its application in dose measurements, for patients and radiologists. The performance of two types of x-ray equipment (fluorescent screen and image intensifier) usually used to perform this examinations was evaluated through appropriate tests. Radiation protection features are also considered. Dose to radiologists at unprotected regions and to patients at several sample points were measured. A comparison of the measured doses given by both types of equipment was made. After further analysis, the necessity to look for methods that reduce unnecessary doses became evident. The high values obtained in some procedures using fluorescent screen make the use of this type of equipment unacceptable. With these results, we consider that Health Care authorities have the responsibility of replacing all fluorescent screen equipment and of establishing standards, and raising awareness the responsible staff. (author)

  12. Computer-assisted optimization of chest fluoroscopy

    International Nuclear Information System (INIS)

    Korolyuk, I.P.; Filippova, N.V.; Kirillov, L.P.; Momsenko, S.F.

    1987-01-01

    The main trends in the use of computer for the optimization of chest fluorography among employees and workers of a large industrial enterprise are considered. The following directions were determined: automatted sorting of fluorograms, formalization of X-ray signs in describing fluorograms, organization of a special system of fluorographic data management. Four levels of algorithms to solve the problems of fluorography were considered: 1) shops, personnel department, etc.; 2) an automated center for mass screening and a medical unit; 3) a computer center and 4) planning and management service. The results of computer use over a 3-year period were analyzed. The efficacy of computer was shown

  13. Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis.

    Science.gov (United States)

    Dea, Nicolas; Fisher, Charles G; Batke, Juliet; Strelzow, Jason; Mendelsohn, Daniel; Paquette, Scott J; Kwon, Brian K; Boyd, Michael D; Dvorak, Marcel F S; Street, John T

    2016-01-01

    Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported. Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns. The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group). The patient sample consisted of consecutive patients treated surgically at a quaternary academic center. The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination. A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period

  14. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: a report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council.

    Science.gov (United States)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

    2012-05-01

    included in this report, was manufactured within the three year period from 2006 to 2008. Using polymethylmethacrylate (PMMA) plastic to simulate patient attenuation, each angiographic imaging system was evaluated by recording the following parameters: tube potential in units of kilovolts peak (kVp), tube current in units of milliamperes (mA), pulse width (PW) in units of milliseconds (ms), spectral filtration setting, and patient air kerma rate (PAKR) as a function of the attenuator thickness. Data were graphically plotted to reveal the manner in which the ADRIQ control logic responded to changes in object attenuation. There were similarities in the manner in which the ADRIQ control logic operated that allowed the four chosen devices to be divided into two groups, with two of the systems in each group. There were also unique approaches to the ADRIQ control logic that were associated with some of the systems, and these are described in the report. The evaluation revealed relevant information about the testing procedure and also about the manner in which different manufacturers approach the utilization of spectral filtration, pulsed fluoroscopy, and maximum PAKR limitation. This information should be particularly valuable to the clinical medical physicist charged with acceptance testing and performance evaluation of modern angiographic systems.

  15. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith [Henry Ford Health System, Detroit, Michigan 48202 (United States); Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115 (United States); Columbia University Medical Center, New York, New York 10032 (United States); Shiga Medical Center for Children, Moriyama City, Shiga-Ken, Japan 524-0022 (Japan); University of Virginia Health Science Center, Charlottesville, Virginia 22908 (United States); Baystate Health Systems, Inc., Springfield, Massachusetts 01199 (United States); Columbia University Medical Center, New York, New York 10032 (United States); University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Cincinnati Children' s Hospital Medical Center, Cincinnati, Ohio 45229 (United States)

    2012-05-15

    measurement data were included in this report, was manufactured within the three year period from 2006 to 2008. Using polymethylmethacrylate (PMMA) plastic to simulate patient attenuation, each angiographic imaging system was evaluated by recording the following parameters: tube potential in units of kilovolts peak (kVp), tube current in units of milliamperes (mA), pulse width (PW) in units of milliseconds (ms), spectral filtration setting, and patient air kerma rate (PAKR) as a function of the attenuator thickness. Data were graphically plotted to reveal the manner in which the ADRIQ control logic responded to changes in object attenuation. There were similarities in the manner in which the ADRIQ control logic operated that allowed the four chosen devices to be divided into two groups, with two of the systems in each group. There were also unique approaches to the ADRIQ control logic that were associated with some of the systems, and these are described in the report. The evaluation revealed relevant information about the testing procedure and also about the manner in which different manufacturers approach the utilization of spectral filtration, pulsed fluoroscopy, and maximum PAKR limitation. This information should be particularly valuable to the clinical medical physicist charged with acceptance testing and performance evaluation of modern angiographic systems.

  16. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

    International Nuclear Information System (INIS)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

    2012-01-01

    included in this report, was manufactured within the three year period from 2006 to 2008. Using polymethylmethacrylate (PMMA) plastic to simulate patient attenuation, each angiographic imaging system was evaluated by recording the following parameters: tube potential in units of kilovolts peak (kVp), tube current in units of milliamperes (mA), pulse width (PW) in units of milliseconds (ms), spectral filtration setting, and patient air kerma rate (PAKR) as a function of the attenuator thickness. Data were graphically plotted to reveal the manner in which the ADRIQ control logic responded to changes in object attenuation. There were similarities in the manner in which the ADRIQ control logic operated that allowed the four chosen devices to be divided into two groups, with two of the systems in each group. There were also unique approaches to the ADRIQ control logic that were associated with some of the systems, and these are described in the report. The evaluation revealed relevant information about the testing procedure and also about the manner in which different manufacturers approach the utilization of spectral filtration, pulsed fluoroscopy, and maximum PAKR limitation. This information should be particularly valuable to the clinical medical physicist charged with acceptance testing and performance evaluation of modern angiographic systems.

  17. Electrical modeling of X-Ray tubes used in fluoroscopy systems with the objective of minimizing radiation transmitted to patients; Modelagem eletrica dos tubos de raios-X utilizados em sistemas de fluoroscopia com o objetivo de minimizar a radiacao transmitida ao paciente

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Raghunatha Faria; Oliveira, Bruno Andrade de; Souza, Euzebio de, E-mail: raghunathafaria@gmail.com, E-mail: brunodoliver90@hotmail.com, E-mail: euzebio.souza@prof.unibh.br [Centro Universitario de Belo Horizonte (UniBH), Belo Horizonte, MG (Brazil)

    2017-09-01

    The purpose of this article was to demonstrate the processes and parameters that are necessary for the operation of all X-rays in the use in fluoroscopy technique, the constructive part of the High Voltage Generator and the X-ray tube and how the X-ray release occurs to the patient during the examination, the condition of how the current and potential difference generates the X-rays incident to the patient during the procedure and what unnecessary exposure to such rays may be detrimental in amounts that do not add an image to the examination. In this way, a proposal was made for the electric modeling of an X-ray tube, in which it addressed an alternative to minimize the radiation that passes through the patient without generating useful images. (author)

  18. Patient dose optimisation in cardiology during fluoroscopy examinations

    International Nuclear Information System (INIS)

    Verdun, F.R.; Valley, J.F.; Wicky, S.; Narbel, M.; Schnyder, P.

    2001-01-01

    Data from 1200 cardiac examinations recorded during the past ten months have been analysed. The DAP's obtained for most of the examinations are comparable to the published data. Moreover, an excellent correlation has been found between the high DAP value and the experience of the operator. DAP measurements for 'high dose examinations' are becoming mandatory in several countries, and medical physicists should help the physicians to interpret these measurements in order to improve the safety of the ionising radiation use. In our Centre it appeared that for their first examinations physicians should be more closely guided by seniors. (author)

  19. Fluoroscopy in paediatric fractures - Setting a local diagnostic reference level

    International Nuclear Information System (INIS)

    Pillai, A.; McAuley, A.; McMurray, K.; Jain, M.

    2006-01-01

    Background: The ionizing radiations (Medical Exposure) Regulation 2000 has made it mandatory to establish diagnostic reference levels (DRLs) for all typical radiological examinations. Objectives: We attempt to provide dose data for some common fluoroscopic procedures used in orthopaedic trauma that may be used as the basis for setting DRLs for paediatric patients. Materials and methods: The dose area product (DAP) in 865 paediatric trauma examinations was analysed. Median DAP values and screening times for each procedure type along with quartile values for each range are presented. Results: In the upper limb, elbow examinations had maximum exposure with a median DAP value of 1.21 cGy cm 2 . Median DAP values for forearm and wrist examinations were 0.708 and 0.538 cGy cm 2 , respectively. In lower limb, tibia and fibula examinations had a median DAP value of 3.23 cGy cm 2 followed by ankle examinations with a median DAP of 3.10 cGy cm 2 . The rounded third quartile DAP value for each distribution can be used as a provisional DRL for the specific procedure type. (authors)

  20. Detection of electrophysiology catheters in noisy fluoroscopy images

    NARCIS (Netherlands)

    Franken, E.M.; Rongen, P.M.J.; Almsick, van M.A.; Haar Romenij, ter B.M.

    2006-01-01

    Cardiac catheter ablation is a minimally invasive medical procedure to treat patients with heart rhythm disorders. It is useful to know the positions of the catheters and electrodes during the intervention, e.g. for the automatization of cardiac mapping. Our goal is therefore to develop a robust

  1. Outcomes of outpatient ureteral stenting without fluoroscopy at ...

    African Journals Online (AJOL)

    for several years, resource limitations in the form of hospital bed ... ureteric stone complicated by non-resolving pain, failure of medical ... The overall success rate for the procedures was 85.4%, independent of gender (p=0.87), age (p=0.13), ...

  2. Organ doses to examinees during photofluorography, fluoroscopy and computed tomography

    International Nuclear Information System (INIS)

    Kato, Kazuo; Antoku, Shigetoshi; Sawada, Shozo; Russell, W.J.; Wada, Takuro.

    1990-07-01

    Doses to the salivary glands, thyroid gland, breast, lung, stomach and colon during mass radiologic gastric screening, mass radiographic chest screening, upper gastrointestinal series, and computed tomography were determined by exposing a phantom female human to simulated radiological X-ray examinations in community hospitals. The doses were measured using thermoluminescent dosimeters, and the results will be used to document organ doses received by participants in the ABCC/RERF Adult Health Study. (author)

  3. Digital fluoroscopy: Technique and applications for evaluating left ventricular function

    International Nuclear Information System (INIS)

    Higgins, C.B.; Norris, S.L.; Gerber, K.H.; Ashburn, W.L.; Slutsky, R.A.

    1985-01-01

    Central cardiovascular dynamics can be studied without cardiac catheterization by digital processing of fluoroscopic images of the heart obtained after central intravenous injection of contrast media. While digital subtraction angiography has been used for studying peripheral vasculature for several years, it is only recently that this technique has been applied for assessing cardiac morphology and physiology. The conversion of fluoroscopic x-ray data into a digital form has an added advantage for the study of the central cardiovascular system since it not only permits contrast enhancement of the images but also facilitates quantitative and functional analysis of the x-ray data. The several applications described in this chapter suggest that digital subtraction cardiovascular angiography will prove to be a powerful tool for studying cardiovascular physiology in animals and for evaluating heart disease in patients

  4. Eye dose to staff involved in interventional and procedural fluoroscopy

    International Nuclear Information System (INIS)

    McLean, D; Hadaya, D; Tse, J

    2016-01-01

    In 2011 the International Commission on Radiological Protection (ICRP) lowered the occupational eye dose limit from 150 to 20 mSv/yr [1]. While international jurisdictions are in a process of adopting these substantial changes, medical physicists at the clinical level have been advising medical colleagues on specific situations based on dose measurements. Commissioned and calibrated TLDs mounted in commercially available holders designed to simulate the measurement of Hp(3), were applied to staff involved in x-ray procedures for a one month period. During this period clinical procedure data was concurrently collected and subject to audit. The use or not of eye personal protective equipment (PPE) was noted for all staff. Audits were conducted in the cardiac catheterisation laboratory, the interventional angiography rooms and the procedural room where endoscopic retrograde cholangiopancreatography (ERCP) procedures are performed. Significant levels of occupational dose were recorded in the cardiac and interventional procedures, with maximum reading exceeding the new limit for some interventional radiologists. No significant eye doses were measured for staff performing ERCP procedures. One outcome of the studies was increased use of eye PPE for operators of interventional equipment with increased availability also to nursing staff, when standing in close proximity to the patient during procedures. (paper)

  5. Distance factor on reducing scattered radiation risk during interventional fluoroscopy

    International Nuclear Information System (INIS)

    Husaini Salleh; Mohd Khalid Matori; Muhammad Jamal Mat Isa; Zainal Jamaluddin; Mohd Firdaus Abdul Rahman; Mohd Khairusalih Mohd Zin

    2012-01-01

    Interventional Radiology (IR) is subspecialty of diagnostic radiology where minimally invasive procedures are performed using an x-ray as a guidance. This procedure can deliver high radiation doses to patient and medical staff compared with other radiological method due to long screening time. The use of proper shielding, shorten the exposure time and keep the distance are the practices to reduce scattered radiation risks to staff involve in this procedure. This project is to study the distance factor on reducing the scattered radiation effect to the medical staff. It also may provide the useful information which can be use to establish the scattered radiation profile during the IR for the sake of radiation protection and safety to the medical staff involved. (author)

  6. Fluoroscopy-Guided Removal of Pull-Type Gastrostomy Tubes

    International Nuclear Information System (INIS)

    Ahlers, Christopher M.; Schneider, Jens; Lachmann, Ricarda; Herber, Sascha; Dueber, Christoph; Pitton, Michael B.

    2008-01-01

    These case reports demonstrate a radiologic interventional technique for removal of pull-type gastrostomy tubes. This approach proved to be a safe and efficient procedure in two patients. The procedure may be applicable in situations where endoscopic attempts fail.

  7. Time Demand and Radiation Dose in 3D-Fluoroscopy-based Navigation-assisted 3D-Fluoroscopy-controlled Pedicle Screw Instrumentations.

    Science.gov (United States)

    Balling, Horst

    2018-05-01

    Prospective single-center cohort study to record additional time requirements and radiation dose in navigation-assisted O-arm-controlled pedicle screw (PS) instrumentations. The aim of this study was to evaluate amount of extra-time and radiation dose for navigation-assisted PS instrumentations of the thoracolumbosacral spine using O-arm 3D-real-time-navigation (O3DN) compared to non-navigated spinal procedures (NNSPs) with a single C-arm and postoperative computed tomography (CT) scan for controlling PS positions. 3D-navigation is reported to enhance PS insertion accuracy. But time-consuming navigational steps and considerable additional radiation doses seem to limit this modern technique's attraction. A detailed analysis of additional time demand and extra-radiation dose in 3D-navigated spine surgery is not provided in literature, yet. From February 2011 through July 2015, 306 consecutive posterior instrumentations were performed in vertebral levels T10-S1 using O3DN for PS insertion. The duration of procedure-specific navigational steps of the overall collective (I) and the last cohort of 50 consecutive O3DN-surgeries (II) was compared to the average duration of analogous surgical steps in 100 consecutive NNSP using a single C-arm. 3D-radiation dose (dose-length-product, DLP) of navigational and postinstrumentation O-arm scans in group I and II was compared to the average DLP of 100 diagnostic lumbar CT scans. The average presurgical time from patient positioning on the operating table to skin incision was 46.2 ± 10.1 minutes (O3DN, I) and 40.6 ± 9.8 minutes (O3DN, II) versus 30.6 ± 8.3 minutes (NNSP) (P demand of 13.0 minutes compared to NNSP, and with a total DLP below that of a diagnostic lumbar CT scan (P ≈ 0.81). 4.

  8. Evaluation of occupational dose from the special procedures guided by fluoroscopy: cardiac catheterism

    International Nuclear Information System (INIS)

    Silva, Amanda Juliene da

    2011-01-01

    The purpose of this study was to evaluate the dose received by health professionals in the hemodynamic sector of a university hospital in Sao Paulo city. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account sociodemographic variables and variables related to the work with ionizing radiation. The assessment of occupational doses was performed by consulting of the individual dose records of the institution database from 2000 to 2009. A total of 240 records was evaluated, corresponding to 38 active professionals (2009), divided in different professional category: physician, nurses, radiologic technologists and nursing assistants. The annual doses were compared with the limits established by national regulatory authorities. Based on the effective doses received and recorded during the studied period, experimental measures were performed with TL dosimeters in five physicians to evaluate the equivalent dose, in the left hand, during hemodynamic procedures. In addition, the radioprotection measures adopted by health professionals were verified. This study allowed delineating the profile of medical staff that integrates the hemodynamic service as well as knowing the distribution of their doses in relation to limits over the years. (author)

  9. How accurately can the peak skin dose in fluoroscopy be determined using indirect dose metrics?

    International Nuclear Information System (INIS)

    Jones, A. Kyle; Ensor, Joe E.; Pasciak, Alexander S.

    2014-01-01

    Purpose: Skin dosimetry is important for fluoroscopically-guided interventions, as peak skin doses (PSD) that result in skin reactions can be reached during these procedures. There is no consensus as to whether or not indirect skin dosimetry is sufficiently accurate for fluoroscopically-guided interventions. However, measuring PSD with film is difficult and the decision to do so must be madea priori. The purpose of this study was to assess the accuracy of different types of indirect dose estimates and to determine if PSD can be calculated within ±50% using indirect dose metrics for embolization procedures. Methods: PSD were measured directly using radiochromic film for 41 consecutive embolization procedures at two sites. Indirect dose metrics from the procedures were collected, including reference air kerma. Four different estimates of PSD were calculated from the indirect dose metrics and compared along with reference air kerma to the measured PSD for each case. The four indirect estimates included a standard calculation method, the use of detailed information from the radiation dose structured report, and two simplified calculation methods based on the standard method. Indirect dosimetry results were compared with direct measurements, including an analysis of uncertainty associated with film dosimetry. Factors affecting the accuracy of the different indirect estimates were examined. Results: When using the standard calculation method, calculated PSD were within ±35% for all 41 procedures studied. Calculated PSD were within ±50% for a simplified method using a single source-to-patient distance for all calculations. Reference air kerma was within ±50% for all but one procedure. Cases for which reference air kerma or calculated PSD exhibited large (±35%) differences from the measured PSD were analyzed, and two main causative factors were identified: unusually small or large source-to-patient distances and large contributions to reference air kerma from cone beam computed tomography or acquisition runs acquired at large primary gantry angles. When calculated uncertainty limits [−12.8%, 10%] were applied to directly measured PSD, most indirect PSD estimates remained within ±50% of the measured PSD. Conclusions: Using indirect dose metrics, PSD can be determined within ±35% for embolization procedures. Reference air kerma can be used without modification to set notification limits and substantial radiation dose levels, provided the displayed reference air kerma is accurate. These results can reasonably be extended to similar procedures, including vascular and interventional oncology. Considering these results, film dosimetry is likely an unnecessary effort for these types of procedures when indirect dose metrics are available

  10. How should low-contrast detail detectability be measured in fluoroscopy?

    International Nuclear Information System (INIS)

    Tapiovaara, Markku J.; Sandborg, Michael

    2004-01-01

    The relationship and precision of four methods for measuring the low-contrast detail detectability in fluoroscopic imaging were studied. These included the physical measurement of the accumulation rate of the square of the signal-to-noise ratio (SNR rate 2 ), two-alternative forced-choice (2-AFC) experiments, sixteen-alternative forced-choice (16-AFC) experiments and subjective determination of the threshold contrast. The precision and sensitivity of the threshold contrast measurement were seen to be modest in the constancy testing of fluoroscopic equipment: only large changes in system performance could be reliably detected by that method. The measurement of the SNR rate 2 is suggested instead. The relationship between the results of the various methods were studied, and it was found that human performance can be related to SNR rate 2 by introducing the concept of the effective image information integration time (t eff ). When measured for an unlimited observation time, it depicts the saturation of human performance in detecting a static low-contrast detail in dynamic image noise. Here, t eff was found to be about 0.6 s in 2-AFC tests and 0.3 s in 16-AFC tests

  11. Measurement of signal-to-noise ratio performance of TV fluoroscopy systems

    International Nuclear Information System (INIS)

    Geluk, R.J.

    1985-01-01

    A method has been developed for direct measurement of Signal-to-Noise ratio performance on X-ray TV systems. To this end the TV signal resulting from a calibrated test object, is compared with the noise level in the image. The method is objective and produces instantaneous readout, which makes it very suitable for system evaluation under dynamic conditions. (author)

  12. Visualization of swallowing using real-time TrueFISP MR fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barkhausen, Joerg; Goyen, Mathias; Lauenstein, Thomas; Debatin, Joerg F. [Department of Diagnostic Radiology, University Hospital Essen (Germany); Winterfeld, F. von; Arweiler-Harbeck, Diana [Department of Otorhinolaryngology, University Hospital Essen (Germany)

    2002-01-01

    The aim of this study was to evaluate the ability of different real-time true fast imaging with steady precession (TrueFISP) sequences regarding their ability to depict the swallowing process and delineate oropharyngeal pathologies in patients with dysphagia. Real-time TrueFISP visualization of swallowing was performed in 8 volunteers and 6 patients with dysphagia using a 1.5 T scanner (Magnetom Sonata, Siemens, Erlangen Germany) equipped with high-performance gradients (amplitude 40 mT/m). Image quality of four different real-time TrueFISP sequences (TR 2.2-3.0 ms, TE 1.1-1.5 ms, matrix 63 x 128-135 x 256, field of view 250 mm{sup 2}, acquisition time per image 139-405 ms) was evaluated. Water, yoghurt, and semolina pudding were assessed as oral contrast agents. Functional exploration of the oropharyngeal apparatus was best possible using the fastest real-time TrueFISP sequence (TR 2.2 ms, TE 1.1 ms, matrix 63 x 128). Increased acquisition time resulted in blurring of anatomical structures. As the image contrast of TrueFISP sequences depends on T2/T1 properties, all tested foodstuff were well suited as oral contrast agents, but image quality was best using semolina pudding. Real-time visualization of swallowing is possible using real-time TrueFISP sequences in conjunction with oral contrast agents. For the functional exploration of swallowing high temporal resolution is more crucial than spatial resolution. (orig.)

  13. About the diagnostic accuracy rate of fluoroscopy-guided fine needle puncture

    International Nuclear Information System (INIS)

    Wernecke, K.; Teske, H.J.

    1983-01-01

    Percutaneous fine-needle biopsies guided by X-ray were performed in 100 patients utilizing the Nordenstroem canule. All cases have now been clinically controlled for at least 14 and up to 30 months. The follow up allowed further conclusions due to the dignity of histologically negative biopsies. Positive results on malignant lesions were obtained in 74% of cases. Our experience revealed that negative aspiration biopsies should be considered false negative until they could be confirmed by further investigations. (orig.) [de

  14. Use of X-ray essay and fluoroscopy in the armament industry

    International Nuclear Information System (INIS)

    Bohnsack, G.

    1989-01-01

    Of the nondestructive testing the process of test by radiography has a special place. With view to great variety of problems of essays in the armament industry, the X-Ray radiography has excellent possibilities of testing, that not possible, for example, with ultrasonography. Different possibilities that the X-ray radiography offer to essays of grenade and blasting cap, through practice examples described case to case are presented. (V.R.B.)

  15. RSA calibration accuracy of a fluoroscopy-based system using nonorthogonal images for measuring functional kinematics

    International Nuclear Information System (INIS)

    Kedgley, Angela E.; Jenkyn, Thomas R.

    2009-01-01

    When performing radiostereometric analysis (RSA) in a clinical setting it may be desirable to orient the two imaging devices nonorthogonally to obtain the best views of an anatomical structure. In this study, a calibration frame was constructed that allowed the relative angles of fiducial and control planes to be adjusted. Precision and accuracy were quantified across multiple trials and orientations. The 90 deg. frame was always of equivalent or greater accuracy than a calibration frame with the fiducial and control planes aligned parallel to the image intensifiers. This study also showed that RSA may be performed with imaging devices at relative angles other than 90 deg. without compromising accuracy. This allows researchers greater freedom in positioning equipment.

  16. Prosthetic component segmentation with blur compensation: a fast method for 3D fluoroscopy.

    Science.gov (United States)

    Tarroni, Giacomo; Tersi, Luca; Corsi, Cristiana; Stagni, Rita

    2012-06-01

    A new method for prosthetic component segmentation from fluoroscopic images is presented. The hybrid approach we propose combines diffusion filtering, region growing and level-set techniques without exploiting any a priori knowledge of the analyzed geometry. The method was evaluated on a synthetic dataset including 270 images of knee and hip prosthesis merged to real fluoroscopic data simulating different conditions of blurring and illumination gradient. The performance of the method was assessed by comparing estimated contours to references using different metrics. Results showed that the segmentation procedure is fast, accurate, independent on the operator as well as on the specific geometrical characteristics of the prosthetic component, and able to compensate for amount of blurring and illumination gradient. Importantly, the method allows a strong reduction of required user interaction time when compared to traditional segmentation techniques. Its effectiveness and robustness in different image conditions, together with simplicity and fast implementation, make this prosthetic component segmentation procedure promising and suitable for multiple clinical applications including assessment of in vivo joint kinematics in a variety of cases.

  17. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    International Nuclear Information System (INIS)

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook

    1995-01-01

    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy

  18. Quality considerations on cine-imaging and PTCA-fluoroscopy anticipating a digital future

    International Nuclear Information System (INIS)

    Leeuw, P. de

    1986-01-01

    In a modern catheterization laboratory coronary cineangiography, PTCA procedures and digital radiography are performed with one and the same X-ray system. On the basis of an optimization analysis of the image quality using the concepts of window signal-to-noise ratio and equivalent blur, overall performance can roughly be estimated. Some important aspects of a realistic X-ray system design resulting from this analysis have been identified. Specifically, the X-ray loadability and its loading strategy play a crucial role with respect to signal detection sensitivity and the safe, efficient use of X-ray radiation. The analysis shows also that some basic limitations exist to the use of digital subtraction techniques for moving objects. Last but not least, it shows that the video camera performance is critical with respect to the imaging tasks during PTCA and digital procedures. (Auth.)

  19. Gastrointestinal digital fluoroscopy: Comparison of digital pulsed progressive readout images with 100-mm spot films

    International Nuclear Information System (INIS)

    Steiner, E.; Ferrucci, J.T.; Mueller, P.R.; Hahn, P.F.

    1987-01-01

    New developments in pulsed progressive readout (PPR) techniques allow short, extremely intense pulses of radiation to be used to produce a latent image which is then progressively read off the video camera and placed in 1,024 x 1,024-pixel digital storage. The resulting image is produced by a 10-20-msec pulse, reducing motion artifact to below that achievable with conventional spot film techniques, with a potential for 50%-95% dose reduction. This technique of reducing motion artifact is ideal for digital applications in gastrointestinal radiology. The authors compared 10-mm spot films and PPR digital radiographs of 86 anatomic regions in 43 patients undergoing routine barium enema and cholangiographic examinations. Parameters evaluated included display of normal and pathologic features, image contrast, and resolution. The benefits of the PPR technique include postprocessing to evaluate low contrast region and the potential for significant dose reduction

  20. Documenting the prevalence of hiatal hernia and oesophageal abnormalities in brachycephalic dogs using fluoroscopy.

    Science.gov (United States)

    Reeve, E J; Sutton, D; Friend, E J; Warren-Smith, C M R

    2017-12-01

    To report the prevalence of abnormal fluoroscopic findings in brachycephalic dogs that were presented to a referral hospital for obstructive airway syndrome. Hospital records between May 2013 and November 2015 identified 36 brachycephalic dogs investigated for obstructive airway disease: 21 French bulldogs, six bulldogs, four Boston terriers, two pugs, two boxers and one shih-tzu. The presence or absence of hiatal hernia, delayed oesophageal transit, gastro-oesophageal reflux and redundant oesophagus were recorded. Of the 36 dogs, 16 had hiatal hernia, all of which were French bulldogs; 31 dogs had delayed oesophageal transit time, 27 had gastro-oesophageal reflux, and four had redundant oesophagus. Clinical Significance: The prevalence of hiatal hernia is higher than expected in the French bulldog, and there was a high prevalence of oesophageal disease in this group in general. These results suggest a need to investigate similar cases for evidence of gastrointestinal disease that may also require attention. © 2017 British Small Animal Veterinary Association.

  1. Comparative analysis of dose levels to patients in radiological procedures guided by fluoroscopy

    International Nuclear Information System (INIS)

    Gomez, Pablo Luis; Fernandez, Manuel; Ramos, Julio A.; Delgado, Jose Miguel; Cons, Nestor

    2013-01-01

    This work presents the comparative data of the dose indicators for patient in radiological processes with respect to the values published in the ICRP document. It is analyzed the need for different strategies to communicate to different specialists mechanisms to optimize the radiation beginning with practice by training of second degree level in radiological protection and then, working with them the basics of equipment management to reduce doses without detriment to the welfare purpose

  2. Precise X-ray and video overlay for augmented reality fluoroscopy.

    Science.gov (United States)

    Chen, Xin; Wang, Lejing; Fallavollita, Pascal; Navab, Nassir

    2013-01-01

    The camera-augmented mobile C-arm (CamC) augments any mobile C-arm by a video camera and mirror construction and provides a co-registration of X-ray with video images. The accurate overlay between these images is crucial to high-quality surgical outcomes. In this work, we propose a practical solution that improves the overlay accuracy for any C-arm orientation by: (i) improving the existing CamC calibration, (ii) removing distortion effects, and (iii) accounting for the mechanical sagging of the C-arm gantry due to gravity. A planar phantom is constructed and placed at different distances to the image intensifier in order to obtain the optimal homography that co-registers X-ray and video with a minimum error. To alleviate distortion, both X-ray calibration based on equidistant grid model and Zhang's camera calibration method are implemented for distortion correction. Lastly, the virtual detector plane (VDP) method is adapted and integrated to reduce errors due to the mechanical sagging of the C-arm gantry. The overlay errors are 0.38±0.06 mm when not correcting for distortion, 0.27±0.06 mm when applying Zhang's camera calibration, and 0.27±0.05 mm when applying X-ray calibration. Lastly, when taking into account all angular and orbital rotations of the C-arm, as well as correcting for distortion, the overlay errors are 0.53±0.24 mm using VDP and 1.67±1.25 mm excluding VDP. The augmented reality fluoroscope achieves an accurate video and X-ray overlay when applying the optimal homography calculated from distortion correction using X-ray calibration together with the VDP.

  3. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1995-10-15

    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

  4. Improvement of observer performance during fluoroscopy by local adaptive contrast enhancement

    International Nuclear Information System (INIS)

    Gould, R.G.; Demas, B.E.; Maroney, T.P.

    1988-01-01

    The ability of a video processor (FluoroVision FV-1), which performs two-dimensional locally adaptive contrast enhancement, to improve the detection of a low-contrast object was evaluated by means of receiver operating characteristic (ROC) curves. Three independent observers viewed a videotape of 50 fluoroscopic images of a varied background, in which a test object was present in 25. Each observer viewed the tape under four conditions: (1) no processing, (2) temporal noise reduction (gaussian weighted time averaging, (3) contrast enhancement, and (4) both noise reduction and contrast enhancement. The results were that detection was significantly improved by the locally adaptive contrast enhancement. Noise reduction did not significantly improve performance, probably because washer detection was limited by background contrast variations as well as noise and because only a small amount of noise reduction was used. The authors conclude that the processing device is potentially valuable in improving the quality of clinical fluoroscopic images

  5. Holmium-lipiodol-alginate microspheres for fluoroscopy-guided embolotherapy and multimodality imaging

    NARCIS (Netherlands)

    Oerlemans, Chris; Seevinck, Peter R.; Smits, Maarten L.; Hennink, Wim E.; Bakker, Chris J G; Van Den Bosch, Maurice A A J; Nijsen, J. Frank W

    2015-01-01

    Embolotherapy is a minimally invasive transcatheter technique aiming at reduction or complete obstruction of the blood flow by infusion of micro-sized particles in order to induce tumor regression. A major drawback of the current commercially available and clinically used microspheres is that they

  6. Dose distributions of patients from chest fluoroscopy, upper GI-tract radiography and cinematography in Japan

    International Nuclear Information System (INIS)

    Kusama, T.; Kai, M.; Ohta, K.

    1996-01-01

    The per caput dose from medical exposure in Japan is several times higher than in other developed countries. There are no dose limitations for medical exposure. Then, the appropriate applications of radiation diagnosis/treatments (justification of practices) and the quality control of diagnosis/treatments (optimization of protection) are needed to reduce the doses from medical exposure. It is well documented that patient doses from a X-ray diagnosis are distributed in the broad range. Recently, the IAEA introduced guidance levels for some typical X-ray diagnosis and in vivo nuclear medicines. We carried out the investigation of dose distribution of patients from the X-ray examinations of chest, cardiovascular cinematography and upper GI-tract X-ray examination in order to give the basic information on the quality control of each X-ray diagnosis. These X-ray diagnoses are performed frequently in Japan, and especially chest X-ray examinations are carried out periodically to all population more than 18 years old as legal health check and GI-tract X-ray examinations to the persons more than 35 years old. The cardiovascular cinematography and the upper GI-tract X-ray examination bring higher effective dose for patients. More information is therefore, needed for the reduction and quality control of medical exposure in Japan. (author)

  7. Informatics in radiology: use of a C-arm fluoroscopy simulator to support training in intraoperative radiography.

    Science.gov (United States)

    Bott, Oliver Johannes; Dresing, Klaus; Wagner, Markus; Raab, Björn-Werner; Teistler, Michael

    2011-01-01

    Mobile image intensifier systems (C-arms) are used frequently in orthopedic and reconstructive surgery, especially in trauma and emergency settings, but image quality and radiation exposure levels may vary widely, depending on the extent of the C-arm operator's knowledge and experience. Current training programs consist mainly of theoretical instruction in C-arm operation, the physical foundations of radiography, and radiation avoidance, and are largely lacking in hands-on application. A computer-based simulation program such as that tested by the authors may be one way to improve the effectiveness of C-arm training. In computer simulations of various scenarios commonly encountered in the operating room, trainees using the virtX program interact with three-dimensional models to test their knowledge base and improve their skill levels. Radiographs showing the simulated patient anatomy and surgical implants are "reconstructed" from data computed on the basis of the trainee's positioning of models of a C-arm, patient, and table, and are displayed in real time on the desktop monitor. Trainee performance is signaled in real time by color graphics in several control panels and, on completion of the exercise, is compared in detail with the performance of an expert operator. Testing of this computer-based training program in continuing medical education courses for operating room personnel showed an improvement in the overall understanding of underlying principles of intraoperative radiography performed with a C-arm, with resultant higher image quality, lower overall radiation exposure, and greater time efficiency. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.313105125/-/DC1. Copyright © RSNA, 2011.

  8. X-ray quality increasing system controlled by single-chip microcomputer in single phase fluoroscopy unit

    International Nuclear Information System (INIS)

    Wang Qiaolin; Gu Hongmei

    2004-01-01

    Objective: To decrease the amount of radiation that doctor and patient receives by increasing X-ray quality. Methods: Using Single-chip Microcomputer technology, test and modulate AC(Alternating Current) from high voltage generator by IGBT. X-ray tube generates X-rays only at high energy area. Thus the amount of radiation decreases. Results: The tube current decreases remarkably and the amount of radiation that doctor and patient receives decreases effectively. Conclusion: the system can effectively decrease the amount of radiation and is widely applicable to the upgrade of all kinds of single phase X-ray units. (authors)

  9. Rigiflex Balloon dilation without fluoroscopy for treatment of Achalasia: A long-term follow-up of 99 patients

    Directory of Open Access Journals (Sweden)

    "Mikaeli J

    2002-06-01

    Full Text Available Achalasia is a well- defined esophageal motor disorder. Graded pneumatic dilation using Rigiflex ballon is one of the therapeutic modalities that had not been evaluated in a large long-term study. We aimed at evaluating long-term efficacy of graded Rigiflex pneumatic dilation in the treatment of achalasia. Symptomatic patients with achalasia who had been referred to our center were consecutively enrolled. The diagnosis was established by clinical, radiographic and endoscopic criteria. Exclusion criteria included pregnancy, coagulopathy, serious medical illness or malignancy. Initially all patients were clinically scored based on the severity of five main symptoms and then underwent pneumatic dilation wit at 3 cm ballon. Symptom scores were evaluated at 1, 6, 12 .. months. Clinical recurrence was defined as an increase of symptom with 3.5 cm balloon dilation. If recurrence occurred again, third dilation was done with a 4 cm ballon. Over a five-year period, 99 patients [mean age: 35.6 (3.0-72 years.] were followed to an average length of 47.4 (18-20 months. 35 patients needed- retreatment, only 6 of them required third dilation. After third dilation two patients did not reveal improvement and underwent cardiomyotomy. Over this time period, cumulative remission rate was 65% without redilation and 94% with redilation. The mean remission period was 44.7 months (95% CI, 43.52-51.27 for single pneumatic dilation by use of Kaplan- Meier survival analysis. There was no significant predictive value for age, gender, previous treatment and severity of initial score to outcome (P>0.4 by use of Cox regression analysis. Pneumatic dilation by a Rigiflex balloon using a graded approach is effective long-term therapy for achalasia in majority of patients.

  10. The current status of fluoroscopy and echocardiography in the diagnosis of prosthetic valve thrombosis-a review article.

    Science.gov (United States)

    Gürsoy, Mustafa Ozan; Kalçik, Macit; Karakoyun, Süleyman; Özkan, Mehmet

    2015-01-01

    Prosthetic valve thrombosis (PVT) is a potentially life-threatening complication of heart valve replacement. Early diagnosis is crucial for the prevention of significantly morbid and lethal complications. Cinefluoroscopy (CF) and echocardiography have been widely used for diagnosing PVT. In recent years, the role of CF has declined since the introduction of transesophageal echocardiography and the great improvements in ultrasound technology including real time three-dimensional imaging. Nevertheless, both echocardiography and CF provide different kinds of information on prosthesis function, and therefore they are considered as complementary and not alternative. In this review, we aimed to summarize the current status of CF and echocardiography in the diagnosis of PVT. © 2014, Wiley Periodicals, Inc.

  11. Comparison of image quality and radiation exposure from digital and 105-mm film images in pediatric fluoroscopy

    International Nuclear Information System (INIS)

    Drake, D.G.; Day, D.L.; Alford, B.A.; Geise, R.; Thompson, W.M.

    1987-01-01

    This study was designed to compare image quality of digitally acquired films compared with conventional 105-mm films in pediatric gastrointestinal and genitourinary fluoroscopic studies. Films were acquired digitally in 1,024 x 1,024 matrix, 512 x 512 matrix, and 105-mm film. Based on the observers' median scoring, the 1,024 x 1,024 reduced to 512 x 512 matrix provided similar overall image quality to the 105-mm films. The digital images produced a patient radiation exposure of 25% to 30% that of the 105-mm images on their equipment. The authors conclude that digital images provide similar image quality to 105-mm images with a significant reduction in patient radiation exposure

  12. SU-D-209-04: Raise Your Table: An Effective Way to Reduce Radiation Dose for Fluoroscopy

    International Nuclear Information System (INIS)

    Huo, D; Hoerner, M; Toskich, B; Rill, L

    2016-01-01

    Purpose: Patient table height plays an important role in estimating patient skin dose for interventional radiology (IR) procedures, because the patient’s skin location is dependent on the height of table. Variation in table height can lead to as much as 150% difference in skin dose for patient exams with similar air kerma meter readings. In our facility, IR procedural workflow was recently changed to require the IR physicians to confirm the patient table height before the procedure. The patient table height data was collected before and after this workflow change to validate the implementation of this practice. Methods: Table height information was analyzed for all procedures performed in three IR rooms, which were impacted by the workflow change, covering three months before and after the change (Aug 2015 to Jan 2016). In total, 442, 425, and 390 procedures were performed in these three rooms over this time period. There were no personnel or procedure assignment changes during the six-month period of time. Statistical analysis was performed for the average table height changes before and after the workflow change. Results: For the three IR rooms investigated, after the workflow change, the average table heights were increased by 1.43 cm (p=0.004084), 0.66 cm (p=0.187089), and 1.59 cm (p=0.002193), providing a corresponding estimated skin dose savings of 6.76%, 2.94% and 7.62%, respectively. After the workflow change, the average table height was increased by 0.95 cm, 0.63 cm, 0.55 cm, 1.07 cm, 1.12 cm, and 3.36 cm for the six physicians who routinely work in these three rooms. Conclusion: Consistent improvement in table height settings has been observed for all IR rooms and all physicians following a simple workflow change. This change has led to significant patient dose savings by making physicians aware of the pre-procedure table position.

  13. Fluoroscopy-Guided Resolution of Ingested Thrombus Leading to Functional Disturbance of a Continuous-Flow Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Jens Garbade

    2012-01-01

    Full Text Available The third generation of left ventricular assist devices (LVADs has been shown to improve outcome and quality of life in patients suffering from acute and chronic heart failure. However, VAD-associated complications are still a challenge in the clinical practice. Here we report the resolution of a mobile thrombus formation in the proximity of the inflow cannula of a third generation of LVADs (HVAD Pump, HeartWare, Inc. in a patient with chronic heart failure 4 months after implantation.

  14. Technical Note: Thoracic duct embolization for treatment of chylothorax: A novel guidance technique for puncture using combined MRI and fluoroscopy

    International Nuclear Information System (INIS)

    Praveen, Alampath; Sreekumar, Karumathil Pullara; Nazar, Puthukudiyil Kader; Moorthy, Srikanth

    2012-01-01

    Thoracic duct embolization (TDE) is an established radiological interventional procedure for thoracic duct injuries. Traditionally, it is done under fluoroscopic guidance after opacifying the thoracic duct with bipedal lymphangiography. We describe our experience in usinga heavily T2W sequence for guiding thoracic duct puncture and direct injection of glue through the puncture needle without cannulating the duct

  15. Technical Note: Thoracic duct embolization for treatment of chylothorax: A novel guidance technique for puncture using combined MRI and fluoroscopy.

    Science.gov (United States)

    Praveen, Alampath; Sreekumar, Karumathil Pullara; Nazar, Puthukudiyil Kader; Moorthy, Srikanth

    2012-04-01

    Thoracic duct embolization (TDE) is an established radiological interventional procedure for thoracic duct injuries. Traditionally, it is done under fluoroscopic guidance after opacifying the thoracic duct with bipedal lymphangiography. We describe our experience in usinga heavily T2W sequence for guiding thoracic duct puncture and direct injection of glue through the puncture needle without cannulating the duct.

  16. Optimal volume of injectate for fluoroscopy-guided cervical interlaminar epidural injection in patients with neck and upper extremity pain.

    Science.gov (United States)

    Park, Jun Young; Kim, Doo Hwan; Lee, Kunhee; Choi, Seong-Soo; Leem, Jeong-Gil

    2016-10-01

    There is no study of optimal volume of contrast medium to use in cervical interlaminar epidural injections (CIEIs) for appropriate spread to target lesions. To determine optimal volume of contrast medium to use in CIEIs. We analyzed the records of 80 patients who had undergone CIEIs. Patients were divided into 3 groups according to the amount of contrast: 3, 4.5, and 6 mL. The spread of medium to the target level was analyzed. Numerical rating scale data were also analyzed. The dye had spread to a point above the target level in 15 (78.9%), 22 (84.6%), and 32 (91.4%) patients in groups 1 to 3, respectively. The dye reached both sides in 14 (73.7%), 18 (69.2%), and 23 (65.7%) patients, and reached the ventral epidural space in 15 (78.9%), 22 (84.6%), and 30 (85.7%) patients, respectively. There were no significant differences of contrast spread among the groups. There were no significant differences in the numerical rating scale scores among the groups during the 3 months. When performing CIEIs, 3 mL medication is sufficient volume for the treatment of neck and upper-extremity pain induced by lower cervical degenerative disease.

  17. Fluoroscopy-guided endovenous sclerotherapy using a microcatheter prior to endovenous laser ablation: Comparison between liquid and foam sclerotherapy for varicose tributaries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Woo; Yun, Ik Jin; Hwang, Jae Joon; Lee, Song Am; Kim, Jun Seok; Chee, Hyun Keun; Chang, Il Soo [Konkuk University Hospital, Konkuk University School of Medicine, Seoul (Korea, Republic of)

    2014-08-15

    To compare the efficacy and adverse effects of endovenous foam sclerotherapy (EFS) and liquid sclerotherapy (ELS) using a microcatheter for the treatment of varicose tributaries. From December 2007 to January 2009, patients with venous reflux in the saphenous vein were enrolled. The foam or liquid sclerosant was injected through a microcatheter just before endovenous laser ablation (EVLA). Patients were evaluated for the technical success, clinical success, and procedure-related complications during the procedure and follow-up visits. A total of 94 limbs were included: 48 limbs (great saphenous vein [GSV], 35; small saphenous vein [SSV], 13) were managed using EFS and EVLA (foam group; FG), and 46 limbs (GSV, 37; SSV, 9) were treated by ELS and EVLA (liquid group; LG). Varicose tributaries demonstrated complete sclerosis in 92.7% with FG and in 71.8% with LG (p = 0.014). Bruising (78.7% in FG vs. 73.2% in LG, p > 0.05), pain or tenderness (75.6% in FG vs. 51.2% in LG, p = 0.0237) were noted. Hyperpigmentation (51.2% in FG vs. 46.2% in LG, p > 0.05) was found. Endovenous foam sclerotherapy using a microcatheter is more effective than ELS for eliminating remnant varicose tributaries prior to EVLA. However, EFS is more commonly associated with local complications such as pain or tenderness than ELS. Furthermore, both techniques seem to prolong the duration of hyperpigmentation along with higher costs.

  18. CT- and fluoroscopy-guided percutaneous discectomy for lumbar radiculopathy related to disc herniation: a comparative prospective study comparing lateral to medial herniated discs

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Huwart, Laurent; Marcy, Pierre-Yves [Centre Hospital-Universitaire de Nice, Department of Radiology, Hopital archet 2, Nice (France); Foti, Pauline [Centre Hospital-Universitaire de Nice, Department of Medical Statistics, Hopital archet 2, Nice (France); Hauger, Olivier [Centre Hospitalo-Universitaire de Bordeaux, Department of Radiology, Hopital Pellegrin, Bordeaux (France); Boileau, Pascal [Centre Hospital-Universitaire de Nice, Department of Orthopedic Surgery, Hopital archet 2, Nice (France)

    2013-01-15

    To evaluate and compare two groups of patients with sciatica due to intervertebral disc herniation with no neurologic deficit. The groups consisted of patients with intervertebral disc herniation in a medial location (group 1) and those in a lateral location (group 2). A total of 200 patients were included in the study and were followed for a minimum of 6 months. In our series, we treated 80 postero-lateral herniated discs (40% of cases), 46 postero-medial herniated discs (23%), and 74 foraminal herniated discs (37%). Level L3-L4 was treated in 30 cases (15%), L4-L5 in 98 cases (49%), and L5-S1 in 72 cases (36%). The procedure was performed under dual guidance: fluoroscopic and CT. A helical probe was activated. It penetrates the herniated disc and causes the pulpous material to be mechanically evacuated through the probe. All 200 patients were followed for a minimum of 6 months. In group 1, the patients had a mean pain score of 7.9 {+-} 2.5 VAS units (range 6-10 units) prior to intervention. This was reduced to 3.2 {+-} 2.1 VAS units (range 0-10 units) at 48 h follow-up and increased to 3.9 {+-} 1.2 VAS units (range 0-10 VAS units) at 1 month follow-up and further reduced to 2.7 {+-} 1.2 units (range 0-10 VAS units) at 6 month follow-up. In group 2, the patients had a mean pain score of 8.2 {+-} 3.2 VAS units (range 6-10 units) prior to intervention. This was reduced to 2.8 {+-} 1.5 VAS units (range 0-10 units) at 48 h follow-up and decreased to 1.5 {+-} 0.9 VAS units (range 0-10 units) at 1 month and further reduced to 1.1 {+-} 0.5 VAS units (range 0-10 units) at 6 months. Our study showed that results were more satisfactory for the hernia located laterally (postero-lateral, foraminal, and extra-foraminal) as compared to the hernia located posteromedially. (orig.)

  19. CT- and fluoroscopy-guided percutaneous discectomy for lumbar radiculopathy related to disc herniation: a comparative prospective study comparing lateral to medial herniated discs

    International Nuclear Information System (INIS)

    Amoretti, Nicolas; Huwart, Laurent; Marcy, Pierre-Yves; Foti, Pauline; Hauger, Olivier; Boileau, Pascal

    2013-01-01

    To evaluate and compare two groups of patients with sciatica due to intervertebral disc herniation with no neurologic deficit. The groups consisted of patients with intervertebral disc herniation in a medial location (group 1) and those in a lateral location (group 2). A total of 200 patients were included in the study and were followed for a minimum of 6 months. In our series, we treated 80 postero-lateral herniated discs (40% of cases), 46 postero-medial herniated discs (23%), and 74 foraminal herniated discs (37%). Level L3-L4 was treated in 30 cases (15%), L4-L5 in 98 cases (49%), and L5-S1 in 72 cases (36%). The procedure was performed under dual guidance: fluoroscopic and CT. A helical probe was activated. It penetrates the herniated disc and causes the pulpous material to be mechanically evacuated through the probe. All 200 patients were followed for a minimum of 6 months. In group 1, the patients had a mean pain score of 7.9 ± 2.5 VAS units (range 6-10 units) prior to intervention. This was reduced to 3.2 ± 2.1 VAS units (range 0-10 units) at 48 h follow-up and increased to 3.9 ± 1.2 VAS units (range 0-10 VAS units) at 1 month follow-up and further reduced to 2.7 ± 1.2 units (range 0-10 VAS units) at 6 month follow-up. In group 2, the patients had a mean pain score of 8.2 ± 3.2 VAS units (range 6-10 units) prior to intervention. This was reduced to 2.8 ± 1.5 VAS units (range 0-10 units) at 48 h follow-up and decreased to 1.5 ± 0.9 VAS units (range 0-10 units) at 1 month and further reduced to 1.1 ± 0.5 VAS units (range 0-10 units) at 6 months. Our study showed that results were more satisfactory for the hernia located laterally (postero-lateral, foraminal, and extra-foraminal) as compared to the hernia located posteromedially. (orig.)

  20. Comparative analysis of dose levels to patients in radiological procedures guided by fluoroscopy; Analisis comparativo de los niveles de dosis a paciente en procedimientos radiologicos guiados por fluoroscopia

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Pablo Luis; Fernandez, Manuel; Ramos, Julio A.; Delgado, Jose Miguel; Cons, Nestor, E-mail: pablogll@eresmas.com [Hospital Universitario de Salamanca (Spain). Servicio de Radio fisica y Proteccion Radiologica

    2013-07-01

    This work presents the comparative data of the dose indicators for patient in radiological processes with respect to the values published in the ICRP document. It is analyzed the need for different strategies to communicate to different specialists mechanisms to optimize the radiation beginning with practice by training of second degree level in radiological protection and then, working with them the basics of equipment management to reduce doses without detriment to the welfare purpose.

  1. WE-E-18A-03: How Accurately Can the Peak Skin Dose in Fluoroscopy Be Determined Using Indirect Dose Metrics?

    International Nuclear Information System (INIS)

    Jones, A; Pasciak, A

    2014-01-01

    Purpose: Skin dosimetry is important for fluoroscopically-guided interventions, as peak skin doses (PSD) that Result in skin reactions can be reached during these procedures. The purpose of this study was to assess the accuracy of different indirect dose estimates and to determine if PSD can be calculated within ±50% for embolization procedures. Methods: PSD were measured directly using radiochromic film for 41 consecutive embolization procedures. Indirect dose metrics from procedures were collected, including reference air kerma (RAK). Four different estimates of PSD were calculated and compared along with RAK to the measured PSD. The indirect estimates included a standard method, use of detailed information from the RDSR, and two simplified calculation methods. Indirect dosimetry was compared with direct measurements, including an analysis of uncertainty associated with film dosimetry. Factors affecting the accuracy of the indirect estimates were examined. Results: PSD calculated with the standard calculation method were within ±50% for all 41 procedures. This was also true for a simplified method using a single source-to-patient distance (SPD) for all calculations. RAK was within ±50% for all but one procedure. Cases for which RAK or calculated PSD exhibited large differences from the measured PSD were analyzed, and two causative factors were identified: ‘extreme’ SPD and large contributions to RAK from rotational angiography or runs acquired at large gantry angles. When calculated uncertainty limits [−12.8%, 10%] were applied to directly measured PSD, most indirect PSD estimates remained within ±50% of the measured PSD. Conclusions: Using indirect dose metrics, PSD can be determined within ±50% for embolization procedures, and usually to within ±35%. RAK can be used without modification to set notification limits and substantial radiation dose levels. These results can be extended to similar procedures, including vascular and interventional oncology. Film dosimetry is likely an unnecessary effort for these types of procedures

  2. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: a truly hybrid x-ray/MR imaging system.

    Science.gov (United States)

    Fahrig, R; Wen, Z; Ganguly, A; DeCrescenzo, G; Rowlands, J A; Stevens, G M; Saunders, R F; Pelc, N J

    2005-06-01

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation.

  3. Preliminary results of an attempt to predict over apron occupational exposure of cardiologists from cardiac fluoroscopy procedures based on DAP (dose area product) values.

    Science.gov (United States)

    Toossi, Mohammad Taghi Bahreyni; Mehrpouyan, Mohammad; Nademi, Hossein; Fardid, Reza

    2015-03-01

    This study is an effort to propose a mathematical relation between the occupational exposure measured by a dosimeter worn on a lead apron in the chest region of a cardiologist and the dose area product (DAP) recorded by a meter attached to the X-ray tube. We aimed to determine factors by which DAP values attributed to patient exposure could be converted to the over-apron entrance surface air kerma incurred by cardiologists during an angiographic procedure. A Rando phantom representing a patient was exposed by an X-ray tube from 77 pre-defined directions. DAP value for each exposure angle was recorded. Cardiologist exposure was measured by a Radcal ionization chamber 10X5-180 positioned on a second phantom representing the physician. The exposure conversion factor was determined as the quotient of over apron exposure by DAP value. To verify the validity of this method, the over-apron exposure of a cardiologist was measured using the ionization chamber while performing coronary angiography procedures on 45 patients weighing on average 75 ± 5 kg. DAP values for the corresponding procedures were also obtained. Conversion factors obtained from phantom exposure were applied to the patient DAP values to calculate physician exposure. Mathematical analysis of our results leads us to conclude that a linear relationship exists between two sets of data: (a) cardiologist exposure measured directly by Radcal & DAP values recorded by the X-ray machine system (R (2) = 0.88), (b) specialist measured and estimated exposure derived from DAP values (R (2) = 0.91). The results demonstrate that cardiologist occupational exposure can be derived from patient data accurately.

  4. Practical measurement of radiation dose in pediatric radiology: use of the dose-area product on digital fluoroscopy and neonatal chest radiographs

    International Nuclear Information System (INIS)

    Chateil, J.F.; Rouby, C.; Brun, M.; Labessan, C.; Diard, F.

    2004-01-01

    Purpose. Control of radiation dose in pediatric radiology requires knowledge of the reference levels for all examinations. These data are useful for daily quality assessment, but are not perfectly known for some radiographic examinations. The purpose of our study was to evaluate the dose related to voiding cysto-urethrograms (VCUG), upper GI (UGI) and intravenous urography (IVU). Neonatal chest radiographs in the intensive care unit were also evaluated. Material and methods. For examinations with contrast material (478VCUG, 220UGI, 80IVU), the children were divided in groups based on their weight, from 5 to 30 Kg. Measurements were performed using an ionization chamber and expressed with the-dose-area product (DAP). For chest radiographs, a direct measurement of the entrance-skin dose was performed, with secondary calculation of the DAP. Results. For-VCUGs, the DAP ranged between 42.89 cGy.cm 2 and 125.41 cGy.cm 2 . The range was between 76.43, and 150.62 cGy.cm 2 for UGIs and between 49.06 and 83.33 cGy.cm 2 for IVUs. For neonate chest radiographs, DAP calculations were between 0.29 and 0.99 cGy.cm 2 . Conclusion. These values represent our reference doses. They allow continuous monitoring of our radiographic technical parameters and radiographic equipment and help to correct and improve them if necessary. (author)

  5. Quantifying skin motion artifact error of the hindfoot and forefoot marker clusters with the optical tracking of a multi-segment foot model using single-plane fluoroscopy.

    Science.gov (United States)

    Shultz, R; Kedgley, A E; Jenkyn, T R

    2011-05-01

    The trajectories of skin-mounted markers tracked with optical motion capture are assumed to be an adequate representation of the underlying bone motions. However, it is well known that soft tissue artifact (STA) exists between marker and bone. This study quantifies the STA associated with the hindfoot and midfoot marker clusters of a multi-segment foot model. To quantify STA of the hindfoot and midfoot marker clusters with respect to the calcaneus and navicular respectively, fluoroscopic images were collected on 27 subjects during four quasi-static positions, (1) quiet standing (non-weight bearing), (2) at heel strike (weight-bearing), (3) at midstance (weight-bearing) and (4) at toe-off (weight-bearing). The translation and rotation components of STA were calculated in the sagittal plane. Translational STA at the calcaneus varied from 5.9±7.3mm at heel-strike to 12.1±0.3mm at toe-off. For the navicular the translational STA ranged from 7.6±7.6mm at heel strike to 16.4±16.7mm at toe-off. Rotational STA was relatively smaller for both bones at all foot positions. For the calcaneus they varied between 0.1±2.2° at heel-strike to 0.2±0.6° at toe-off. For the navicular, the rotational STA ranged from 0.6±0.9° at heel-strike to 0.7±0.7° at toe-off. The largest translational STA found in this study (16mm for the navicular) was smaller than those reported in the literature for the thigh and the lower leg, but was larger than the STA of individual spherical markers affixed to the foot. The largest errors occurred at toe-off position for all subjects for both the hindfoot and midfoot clusters. Future studies are recommended to quantify true three-dimensional STA of the entire foot during gait. Copyright © 2011. Published by Elsevier B.V.

  6. Radiation protection during fluoroscopy of trucks with a mobile linear accelerator by Swiss Customs; Strahlenschutz bei der Durchleuchtung von Lastwagen mit einem mobilen Linearbeschleuniger durch den Schweizer Zoll

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, Stefan [Suva, Luzern (Switzerland)

    2016-08-01

    In 2015 the Swiss Customs Administration has taken into operation a vehicle inspection system of the newest generation. Higher radiation power yields better image quality. Image quality and the ALARA-principle are in competition with each other. In the drive-by mode the driver's cabin can also be inspected. Instead of limiting the maximum dose rate at the border of the controlled area, the maximum allowable dose per scan was calculated from the utilization frequency, in order to observe the regulations in radiation protection. In the vicinity of hills or tall buildings the limited height of the beam-stop must be taken into consideration. If pulsed X-rays are measured, saturation effects must be considered, which may cause too low measurement values - in particular if measurements of the direct beam are performed.

  7. Validation of 2 noninvasive, markerless reconstruction techniques in biplane high-speed fluoroscopy for 3-dimensional research of bovine distal limb kinematics.

    Science.gov (United States)

    Weiss, M; Reich, E; Grund, S; Mülling, C K W; Geiger, S M

    2017-10-01

    Lameness severely impairs cattle's locomotion, and it is among the most important threats to animal welfare, performance, and productivity in the modern dairy industry. However, insight into the pathological alterations of claw biomechanics leading to lameness and an understanding of the biomechanics behind development of claw lesions causing lameness are limited. Biplane high-speed fluoroscopic kinematography is a new approach for the analysis of skeletal motion. Biplane high-speed videos in combination with bone scans can be used for 3-dimensional (3D) animations of bones moving in 3D space. The gold standard, marker-based animation, requires implantation of radio-opaque markers into bones, which impairs the practicability for lameness research in live animals. Therefore, the purpose of this study was to evaluate the comparative accuracy of 2 noninvasive, markerless animation techniques (semi-automatic and manual) in 3D animation of the bovine distal limb. Tantalum markers were implanted into each of the distal, middle, and proximal phalanges of 5 isolated bovine distal forelimbs, and biplane high-speed x-ray videos of each limb were recorded to capture the simulation of one step. The limbs were scanned by computed tomography to create bone models of the 6 digital bones, and 3D animation of the bones' movements were subsequently reconstructed using the marker-based, the semi-automatic, and the manual animation techniques. Manual animation translational bias and precision varied from 0.63 ± 0.26 mm to 0.80 ± 0.49 mm, and rotational bias and precision ranged from 2.41 ± 1.43° to 6.75 ± 4.67°. Semi-automatic translational values for bias and precision ranged from 1.26 ± 1.28 mm to 2.75 ± 2.17 mm, and rotational values varied from 3.81 ± 2.78° to 11.7 ± 8.11°. In our study, we demonstrated the successful application of biplane high-speed fluoroscopic kinematography to gait analysis of bovine distal limb. Using the manual animation technique, kinematics can be measured with sub-millimeter accuracy without the need for invasive marker implantation. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: A truly hybrid x-ray/MR imaging system

    International Nuclear Information System (INIS)

    Fahrig, R.; Wen, Z.; Ganguly, A.; DeCrescenzo, G.; Rowlands, J.A.; Stevens, G.M.; Saunders, R.F.; Pelc, N.J.

    2005-01-01

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo TM flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP TM ) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation

  9. Plantar-flexion of the ankle joint complex in terminal stance is initiated by subtalar plantar-flexion: A bi-planar fluoroscopy study.

    Science.gov (United States)

    Koo, Seungbum; Lee, Kyoung Min; Cha, Young Joo

    2015-10-01

    Gross motion of the ankle joint complex (AJC) is a summation of the ankle and subtalar joints. Although AJC kinematics have been widely used to evaluate the function of the AJC, the coordinated movements of the ankle and subtalar joints are not well understood. The purpose of this study was to accurately quantify the individual kinematics of the ankle and subtalar joints in the intact foot during ground walking by using a bi-planar fluoroscopic system. Bi-planar fluoroscopic images of the foot and ankle during walking and standing were acquired from 10 healthy subjects. The three-dimensional movements of the tibia, talus, and calcaneus were calculated with a three-dimensional/two-dimensional registration method. The skeletal kinematics were quantified from 9% to 86% of the full stance phase because of the limited camera speed of the X-ray system. At the beginning of terminal stance, plantar-flexion of the AJC was initiated in the subtalar joint on average at 75% ranging from 62% to 76% of the stance phase, and plantar-flexion of the ankle joint did not start until 86% of the stance phase. The earlier change to plantar-flexion in the AJC than the ankle joint due to the early plantar-flexion in the subtalar joint was observed in 8 of the 10 subjects. This phenomenon could be explained by the absence of direct muscle insertion on the talus. Preceding subtalar plantar-flexion could contribute to efficient and stable ankle plantar-flexion by locking the midtarsal joint, but this explanation needs further investigation. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Fluoroscopic and arthrographic evaluation of carpal instability

    Energy Technology Data Exchange (ETDEWEB)

    Braunstein, E.M.; Louis, D.S.; Greene, T.L.; Hankin, F.M.

    1985-06-01

    The efficacy of a diagnostic protocol involving videotape fluoroscopy of carpal motion and radiocarpal arthrography was evaluated in patients with wrist pain unexplained by physical examination and conventional radiographs. Videotape fluoroscopy was performed as the first study in 68 consecutive cases and was positive in 44 (66%). Radiocarpal arthrography was performed after videotape fluoroscopy in 39 of the cases (57%), including the 24 in which videotape fluoroscopy was normal and 15 others in which further information was desired in spite of positive videotape fluoroscopy. The addition of radiocarpal arthrography to videotape fluoroscopy increased the diagnostic yield to 52 (76%) of the 68 cases and excluded significant anatomic or dynamic abnormality in the others. The diagnosis was proven surgically in 25 cases. This protocol was efficacious for ligament tears of the proximal carpal row, triangular fibrocartilage tears, and proximal and midcarpal instability.

  11. Characterization of a team biplane digital x-ray in the pediatric cardiology department; Caracterizacion de un equipo biplano de rayos x digital en el servicio de cardiologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez Marquez, J.; Huertas Martinez, C.; Corredora Silva, E.; Vano Carruana, E.; Luquero LLopis, N.; Huerga Cabrerizo, C.; Plaza Aparicio, R.; Tellez-Cepeda Ruiz, M.

    2011-07-01

    In cardiology, new digital technologies, are replacing fluoroscopy with image intensifier and television systems. There has been a characterization of the equipment prior to commissioning for clinical use.

  12. Orthopedic surgeons’ knowledge regarding risk of radiation exposition: a survey analysis

    Directory of Open Access Journals (Sweden)

    Tunçer Nejat

    2017-01-01

    Full Text Available Introduction: The purpose of this study is to evaluate the knowledge levels of orthopedic surgeons working in Turkey about the uses and possible risks of fluoroscopy and assess methods for preventing radiation damage. Methods: A questionnaire with a total of 12 questions was sent to 1121 orthopedic surgeons working in Turkey. The questionnaire evaluated participants’ knowledge about the uses and risks of fluoroscopy and methods for preventing damage. One thousand and twenty-four orthopedic surgeons were found to be suitable for inclusion in the study. The effects of fluoroscopy on patients were not assessed in our study. Results: The data obtained were statistically evaluated. Of the surveyed surgeons, 313 (30% had used fluoroscopy in over 50% of their operations. The average number of fluoroscopy shots per case was 54.5. A lead apron was the most commonly used (88% protection from the harmful effects of radiation. Fluoroscopy shots were performed with the help of operating room personnel (86%. A dosimeter was used 5% of the time. Conclusion: According to the survey results, the need for fluoroscopy was very high in orthopedic surgery. However, orthopedic surgeons have inadequate knowledge about the uses and risks of fluoroscopy and methods for preventing damage. Therefore, we believe that training on this topic should be provided to all orthopedic surgeons.

  13. Orthopedic surgeons' knowledge regarding risk of radiation exposition: a survey analysis.

    Science.gov (United States)

    Tunçer, Nejat; Kuyucu, Ersin; Sayar, Şafak; Polat, Gökhan; Erdil, İrem; Tuncay, İbrahim

    2017-01-01

    The purpose of this study is to evaluate the knowledge levels of orthopedic surgeons working in Turkey about the uses and possible risks of fluoroscopy and assess methods for preventing radiation damage. A questionnaire with a total of 12 questions was sent to 1121 orthopedic surgeons working in Turkey. The questionnaire evaluated participants' knowledge about the uses and risks of fluoroscopy and methods for preventing damage. One thousand and twenty-four orthopedic surgeons were found to be suitable for inclusion in the study. The effects of fluoroscopy on patients were not assessed in our study. The data obtained were statistically evaluated. Of the surveyed surgeons, 313 (30%) had used fluoroscopy in over 50% of their operations. The average number of fluoroscopy shots per case was 54.5. A lead apron was the most commonly used (88%) protection from the harmful effects of radiation. Fluoroscopy shots were performed with the help of operating room personnel (86%). A dosimeter was used 5% of the time. According to the survey results, the need for fluoroscopy was very high in orthopedic surgery. However, orthopedic surgeons have inadequate knowledge about the uses and risks of fluoroscopy and methods for preventing damage. Therefore, we believe that training on this topic should be provided to all orthopedic surgeons. © The Authors, published by EDP Sciences, 2017.

  14. The effect of introduction of axial cineangiography and echocardiography on contrast and radiation doses during cardiac catheterisation

    International Nuclear Information System (INIS)

    Sweet, E.M.; McLardy, J.L.

    1984-01-01

    The effects of routine preliminary echocardiography and adoption of axial cine angiography in a Paediatric Cardiac Investigation Centre were assessed in relation to contrast volume, fluoroscopy time and radiation dose. The results showed a significant increase in radiation dose with some reduction in fluoroscopy time in neonates and some increase in contrast volume used in infants [fr

  15. Occupational exposure of diagnostic radiology staff in Israel during 1994-1996

    International Nuclear Information System (INIS)

    Biran, T.; Malchi, S.; Shamai, Y.

    1997-01-01

    Personnel who perform interventional radiological procedures which involve long fluoroscopy times and with a high workload, may receive radiation doses comparable to one of the dose limits suggested by the International Commission on Radiological protection. It is therefore important to monitor accurately the radiation dose to every staff member. who is involved in fluoroscopy procedures. (authors)

  16. Arthrography

    Medline Plus

    Full Text Available ... MRI) or fluoroscopy – a form of real-time x-ray. Your preparation may vary depending on which imaging ... a joint often uses a special form of x-ray called fluoroscopy to guide and evaluate the injection ...

  17. Analyize manifestations of DR and CT of 20 cases of bronchioloalveolar carcinoma

    International Nuclear Information System (INIS)

    Yang Zhongcheng

    2006-01-01

    Objective: Exploring the characters and changing rules between DR chest fluoroscopy and CT of bronchioloalveolar carcinoma. Methods: Collecting 20 cases DR chest fluoroscopies and CT scanning results of bron-chioloalveolar carcinoma, proved by biopsy, to reviewing analysis. Results: Bronchioloalveolar carcinoma divided into 3 types, nodular type, diffused type, infiltrated type. Nodular type focuses congregate and fused into node, density of the nodular shadow bad-distributed, vesical low-density shadow showed; Diffused type focus, multiple diffused nodish shadow gradually fused into patech consolidated shadow;Infiltrated focus distributed to pulmonary segment or lobes,like common pneumonia feature, existed airobronchogram, CT contrast scan shows typical 'CT angiogram'. Conclusion: No matter which type: nodular, diffused or infiltrated type, whose DR chest fluoroscopy and CT exists some features: Nodular type, DR chest fluoroscopy shows focuses mostly in periphery of pulmonary, margin with burr and plueral sunken sign, and whose HRCT manifestationshows typical small vesical sign in mediastinal window; Diffused type, DR chest fluoroscopy shows multiple diffused granular nodish shadow, however, CT manifestation can find more multiple focus than DR chest fluoroscopy, typical manifestation of HRCT is extensive small nodular shadow, with the thicken lobular interal; Infiltrated focus: DR chest fluoroscopy shows pulmonary consolidation and airobronchogram, And CT manifestations are CT angiogram and low-density consolidation shadow, wth specific property. Master all types of manifestation of DR and CT of bronchioloalveolar carcinoma, can help you improve the diagnosis of bronchioloalveolar carcinoma. (authors)

  18. TH-B-12A-01: TG124 “A Guide for Establishing a Credentialing and Privileging Program for Users of Fluoroscopic Equipment in Healthcare Organizations”

    Energy Technology Data Exchange (ETDEWEB)

    Moore, M [Philadelphia VA Medical Ctr., Philadelphia, PA (United States)

    2014-06-15

    Fluoroscopy credentialing and privileging programs are being instituted because of recorded patient injuries and the widespread growth in fluoroscopy use by operators whose medical education did not include formal fluoroscopy training. This lack of training is recognized as a patient safety deficiency, and medical physicists and health physicists are finding themselves responsible for helping to establish fluoroscopy credentialing programs. While physicians are very knowledgeable about clinical credentials review and the privileging process, medical physicists and health physicists are not as familiar with the process and associated requirements. To assist the qualified medical physicist (QMP) and the radiation safety officer (RSO) with these new responsibilities, TG 124 provides an overview of the credentialing process, guidance for policy development and incorporating trained fluoroscopy users into a facility's established process, as well as recommendations for developing and maintaining a risk-based fluoroscopy safety training program. This lecture will review the major topics addressed in TG124 and relate them to practical situations. Learning Objectives: Understand the difference between credentialing and privileging. Understand the responsibilities, interaction and coordination among key individuals and committees. Understand options for integrating the QMP and/or RSO and Radiation Safety Committee into the credentialing and privileging process. Understand issues related to implementing the fluoroscopy safety training recommendations and with verifying and documenting successful completion.

  19. TH-B-12A-01: TG124 “A Guide for Establishing a Credentialing and Privileging Program for Users of Fluoroscopic Equipment in Healthcare Organizations”

    International Nuclear Information System (INIS)

    Moore, M

    2014-01-01

    Fluoroscopy credentialing and privileging programs are being instituted because of recorded patient injuries and the widespread growth in fluoroscopy use by operators whose medical education did not include formal fluoroscopy training. This lack of training is recognized as a patient safety deficiency, and medical physicists and health physicists are finding themselves responsible for helping to establish fluoroscopy credentialing programs. While physicians are very knowledgeable about clinical credentials review and the privileging process, medical physicists and health physicists are not as familiar with the process and associated requirements. To assist the qualified medical physicist (QMP) and the radiation safety officer (RSO) with these new responsibilities, TG 124 provides an overview of the credentialing process, guidance for policy development and incorporating trained fluoroscopy users into a facility's established process, as well as recommendations for developing and maintaining a risk-based fluoroscopy safety training program. This lecture will review the major topics addressed in TG124 and relate them to practical situations. Learning Objectives: Understand the difference between credentialing and privileging. Understand the responsibilities, interaction and coordination among key individuals and committees. Understand options for integrating the QMP and/or RSO and Radiation Safety Committee into the credentialing and privileging process. Understand issues related to implementing the fluoroscopy safety training recommendations and with verifying and documenting successful completion

  20. Radiation dose to the operator during fluoroscopically guided spine procedures

    Energy Technology Data Exchange (ETDEWEB)

    Roccatagliata, Luca; Pravata, Emanuele; Cianfoni, Alessandro [Department of Neuroradiology, Neurocenter of Southern Switzerland, Ospedale Regionale di Lugano, Lugano (Switzerland); Presilla, Stefano [Unita di Fisica Medica, Ente Ospedaliero Cantonale (EOC), Bellinzona (Switzerland)

    2017-09-15

    Fluoroscopy is widely used to guide diagnostic and therapeutic spine procedures. The purpose of this study was to quantify radiation incident on the operator (operator Air Kerma) during a wide range of fluoroscopy-guided spine procedures and its correlation with the amount of radiation incident on the patient (Kerma Area Product - KAP). We retrospectively included 57 consecutive fluoroscopically guided spine procedures. KAP [Gy cm{sup 2}] and total fluoroscopy time were recorded for each procedure. An electronic dosimeter recorded the operator Air Kerma [μGy] for each procedure. Operator Air Kerma for each procedure, correlation between KAP and operator Air Kerma, and between KAP and fluoroscopy time was obtained. Operator Air Kerma was widely variable across procedures, with median value of 6.4 μGy per procedure. Median fluoroscopy time and median KAP per procedure were 2.6 min and 4.7 Gy cm{sup 2}, respectively. There was correlation between operator Air Kerma and KAP (r{sup 2} = 0.60), with a slope of 1.6 μGy Air Kerma per unit Gy cm{sup 2} KAP incident on the patient and between fluoroscopy time and KAP (r{sup 2} = 0.63). Operator Air Kerma during individual fluoroscopy-guided spine procedures can be approximated from the commonly and readily available information of the total amount of radiation incident on the patient, measured as KAP. (orig.)

  1. Small Bowel Follow-Through

    Science.gov (United States)

    ... Small bowel follow-through uses a form of real-time x-ray called fluoroscopy and a barium-based ... Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow ...

  2. Hip joint injection

    Science.gov (United States)

    ... medicine into the joint. The provider uses a real-time x-ray (fluoroscopy) to see where to place ... Wakefield RJ. Arthrocentesis and injection of joints and soft tissue. In: Firestein GS, Budd RC, Gabriel SE, ...

  3. Discography (Discogram)

    Science.gov (United States)

    ... the area with a local anesthetic. Guided by real-time x-ray images ( fluoroscopy ), the physician will insert ... of CT is its ability to image bone, soft tissue and blood vessels all at the same ...

  4. Idiopathic pericardial effusion in 2 year old labrador managed with ...

    African Journals Online (AJOL)

    HP USER

    2College of Veterinary Medicine, Michigan State University East Lansing, Mi, 48824-1314. 3Faculty of ... Other known causes include cardiac neoplasia ... oedema of extremities and ascites. .... alternative technique is fluoroscopy, but this has.

  5. Pediatric Voiding Cystourethrogram

    Science.gov (United States)

    Scan for mobile link. Children's (Pediatric) Voiding Cystourethrogram A children’s (pediatric) voiding cystourethrogram uses fluoroscopy – a form of real-time x-ray – to examine a child’s bladder ...

  6. Hysterosalpingography

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. Fluoroscopy is ... light or radio waves. X-rays pass through most objects, including the body. Once it is carefully ...

  7. Arthrography

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. Fluoroscopy makes ... involves taking radiographs for documentation. These images are most often stored and viewed electronically. Similarly, direct MR ...

  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... complex and lengthy procedures requiring extended fluoroscopy use) death (rare) top of page What are the limitations ... filtered out by the liver. The TIPS may cause too much of these substances to bypass the ...

  9. Hysterosalpingography

    Medline Plus

    Full Text Available ... Index A-Z Hysterosalpingography Hysterosalpingography uses a real-time form of x-ray called fluoroscopy to examine ... or an untreated sexually transmitted disease at the time of the procedure. On the night before the ...

  10. Computer-assisted surgery in orthopedic oncology : Technique, indications, and a descriptive study of 130 cases

    NARCIS (Netherlands)

    Gerbers, Jasper G.; Stevens, Martin; Ploegmakers, Joris J. W.; Bulstra, Sjoerd K.; Jutte, Paul C.

    2014-01-01

    Background and purpose - In orthopedic oncology, computerassisted surgery (CAS) can be considered an alternative to fluoroscopy and direct measurement for orientation, planning, and margin control. However, only small case series reporting specific applications have been published. We therefore

  11. Outcome of complex tibial plateau fractures treated with external fixator

    Directory of Open Access Journals (Sweden)

    Sushil H Mankar

    2012-01-01

    Conclusion: We believe that minimally invasive treatment by percutaneous techniques and external fixation is a fairly reasonable treatment alternative, if near anatomical reduction of joint surface can be confirmed on fluoroscopy.

  12. Catheter Angiography

    Medline Plus

    Full Text Available ... two x-ray tubes and a television-like monitor that is located in the examining room. Fluoroscopy, ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  13. Hysterosalpingography

    Medline Plus

    Full Text Available ... called fluoroscopy to examine the uterus and fallopian tubes of a woman who is having difficulty becoming ... uterine fibroids. Hysterosalpingography can occasionally open blocked fallopian tubes to allow the patient to become pregnant afterwards. ...

  14. Arthrography

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or pulsed x-ray ... picture of the tissues scanned based on this information. The magnetic field is produced by passing an ...

  15. Arthrography

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    Full Text Available ... ray called fluoroscopy to guide and evaluate the injection of iodine contrast material directly into the joint. ... MRI) or computed tomography (CT) following contrast material injection into the joint. An x-ray (radiograph) is ...

  16. Arthrography

    Medline Plus

    Full Text Available ... medical imaging. Fluoroscopy makes it possible to see bones, joints and internal organs in real time. When ... within the joint, such as cartilage, ligaments and bones, and allows them to be evaluated by the ...

  17. Percutaneous nephrolithotripsy under assisted local anaesthesia for ...

    African Journals Online (AJOL)

    T.KH. Fathelbab

    fluoroscopy using high pressure balloon catheter in 35 and Alken's metal dilators in 12 cases. Stones ... 30 min prior to the procedure, and midazolam 5 mg intravenously ... Heart rate, blood pressure and peripheral oxygen saturation were.

  18. Hysterosalpingography

    Medline Plus

    Full Text Available ... through the body, recording an image on photographic film or a special detector. Fluoroscopy uses a continuous ... recently, x-ray images were maintained on large film sheets (much like a large photographic negative). Today, ...

  19. Arthrography

    Medline Plus

    Full Text Available ... guide the procedure. Alternate methods of direct arthrography examinations may also use magnetic resonance imaging (MRI) or ... the injection is typically monitored by fluoroscopy, the examination also commonly involves taking radiographs for documentation. These ...

  20. Arthrography

    Medline Plus

    Full Text Available ... CT arthrography and have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your ... and sometimes air are injected into the joint space while the radiologist observes with fluoroscopy or ultrasound. ...

  1. Arthrography

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or pulsed x-ray ... few seconds to a few minutes at a time. You will know when images are being recorded ...

  2. Differentiation of thrombus from pannus as the cause of acquired mechanical prosthetic heart valve obstruction by non-invasive imaging: a review of the literature

    NARCIS (Netherlands)

    Tanis, Wilco; Habets, Jesse; van den Brink, Renee B. A.; Symersky, Petr; Budde, Ricardo P. J.; Chamuleau, Steven A. J.

    2014-01-01

    For acquired mechanical prosthetic heart valve (PHV) obstruction and suspicion on thrombosis, recently updated European Society of Cardiology guidelines advocate the confirmation of thrombus by transthoracic echocardiography, transesophageal echocardiography (TEE), and fluoroscopy. However, no

  3. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... two snares. The catheter is guided into place just beyond the foreign object using x-ray fluoroscopy. ... perform surgery using ultrasound guidance. Ultrasound provides real-time imaging, making it a good tool for guiding ...

  4. Arthrography

    Medline Plus

    Full Text Available ... frequently compared to current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or ... usually have no side effects in the typical diagnostic range for this exam. Exams involving MR imaging: ...

  5. Radiation dose to surgeons in theatre | van der Merwe | South ...

    African Journals Online (AJOL)

    Thermoluminescent dosimeter measurements of accumulated dose to specific anatomical regions of a neurosurgeon, gastroenterologist and orthopaedic surgeon performing fluoroscopy on 39 patients undergoing treatment for back pain, 7 for endoscopic retrograde cholangiopancreatography procedures, and 48 for ...

  6. Arthrography

    Medline Plus

    Full Text Available ... injected into the joint. Arthrography may use computed tomography (CT) scanning, magnetic resonance imaging (MRI) or fluoroscopy – ... also use magnetic resonance imaging (MRI) or computed tomography (CT) following contrast material injection into the joint. ...

  7. Arthrography

    Medline Plus

    Full Text Available ... injected into the joint. Arthrography may use computed tomography (CT) scanning, magnetic resonance imaging (MRI) or fluoroscopy – a ... also use magnetic resonance imaging (MRI) or computed tomography (CT) following contrast material injection into the joint. An ...

  8. Arthrography

    Medline Plus

    Full Text Available ... imaging (MRI) or fluoroscopy – a form of real-time x-ray. Your preparation may vary depending on ... see bones, joints and internal organs in real time. When iodine contrast is injected into the joint, ...

  9. Hysterosalpingography

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Fluoroscopy ... Share your patient story here Related Articles and Media ... Sponsored by Please note RadiologyInfo. ...

  10. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... recording an image on photographic film or a special detector. Many foreign bodies, like coins and batteries, ... or white on x-ray. Fluoroscopy is a special x-ray technique that makes it possible to ...

  11. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... complex and lengthy procedures requiring extended fluoroscopy use) death (rare) top of page What are the limitations ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  12. Arthrography

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or pulsed x-ray ... joint area. You may feel pressure or even pain when the needle is advanced into the joint. ...

  13. Arthrography

    Medline Plus

    Full Text Available ... Examples include but are not limited to: artificial heart valves implanted drug infusion ports artificial limbs or ... to current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or pulsed x- ...

  14. Contribution of radiodiagnosis to genetically significant dose

    International Nuclear Information System (INIS)

    Pele, J.M.; Ouvrard, R.

    Surveys were carried out in France on 33,000 X-ray medical examinations. The genetically significant dose to the whole population from roentgenography and fluoroscopy, for typical examinations, should be about 65mrads [fr

  15. Arthrography

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or pulsed x-ray ... are in the scanner without causing any chemical changes in the tissues. As the hydrogen atoms return ...

  16. Radiation safety knowledge and practices among Irish orthopaedic trainees.

    LENUS (Irish Health Repository)

    Nugent, M

    2014-04-23

    Fluoroscopy is frequently used in orthopaedic surgery, particularly in a trauma setting. Exposure of patients and staff to ionising radiation has been studied extensively; however, little work has been done to evaluate current knowledge and practices among orthopaedic trainees.

  17. Foreign Body Retrieval

    Medline Plus

    Full Text Available ... that could damage tissue, nerves and blood vessels, block blood flow or cause a blood clot. Ultrasound ... dislodged during the Foley catheter technique may temporarily block your airway. By observing the procedures under fluoroscopy, ...

  18. Hysterosalpingography

    Medline Plus

    Full Text Available ... fluoroscopy to view and assess their anatomy and function. top of page What are some common uses ... a form of radiation like light or radio waves. X-rays pass through most objects, including the ...

  19. Arthrography

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. Fluoroscopy uses a continuous or pulsed x-ray ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  20. Hysterosalpingography

    Medline Plus

    Full Text Available ... the oldest and most frequently used form of medical imaging. Fluoroscopy is a special x-ray technique that ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  1. Arthrography

    Medline Plus

    Full Text Available ... joint. Arthrography may use computed tomography (CT) scanning, magnetic resonance imaging (MRI) or fluoroscopy – a form of real- ... methods of direct arthrography examinations may also use magnetic resonance imaging (MRI) or computed tomography (CT) following contrast ...

  2. Digital Subtraction Angiography (DSA) "Road Map": An Angiographic Tool

    Science.gov (United States)

    Turski, P. A.; Stieghorst, M. F.; Strother, C. M.; Crummy, A. B.; Lieberman, R. P.; Mistretta, C. A.

    1982-12-01

    Continuous Digital subtraction combined with intraarterial injections of contrast medium permits the display of arterial structures during real time fluoroscopy. This DSA "road map" facilitates selective catheterization and has proved useful in interventional procedures.

  3. Arthrography

    Medline Plus

    Full Text Available ... fluoroscopy to guide and evaluate the injection of iodine contrast material directly into the joint. In some ... joints and internal organs in real time. When iodine contrast is injected into the joint, it fills ...

  4. The exposure of radiologists and patients to radiation during coronary angiography and percutaneous transluminal coronary angioplasty (PTCA)

    International Nuclear Information System (INIS)

    Karppinen, J.; Parviainen, T.

    1993-03-01

    The exposure of radiologists and patients to radiation during coronary angiography and percutaneous transluminal coronary angioplasty (PTCA) in Finland was studied using phantom measurements. Additional tests were made concerning the performance of TV fluoroscopy systems, cine fluorographic units and film processing. These tests include sensitometric quality control of film processing, automatic exposure control in fluoroscopy and cinefluorography, and contrast and resolution in a cine frame and TV image

  5. Reduction of radiation exposure while maintaining high-quality fluoroscopic images during interventional cardiology using novel x-ray tube technology with extra beam filtering.

    Science.gov (United States)

    den Boer, A; de Feyter, P J; Hummel, W A; Keane, D; Roelandt, J R

    1994-06-01

    Radiographic technology plays an integral role in interventional cardiology. The number of interventions continues to increase, and the associated radiation exposure to patients and personnel is of major concern. This study was undertaken to determine whether a newly developed x-ray tube deploying grid-switched pulsed fluoroscopy and extra beam filtering can achieve a reduction in radiation exposure while maintaining fluoroscopic images of high quality. Three fluoroscopic techniques were compared: continuous fluoroscopy, pulsed fluoroscopy, and a newly developed high-output pulsed fluoroscopy with extra filtering. To ascertain differences in the quality of images and to determine differences in patient entrance and investigator radiation exposure, the radiated volume curve was measured to determine the required high voltage levels (kVpeak) for different object sizes for each fluoroscopic mode. The fluoroscopic data of 124 patient procedures were combined. The data were analyzed for radiographic projections, image intensifier field size, and x-ray tube kilovoltage levels (kVpeak). On the basis of this analysis, a reference procedure was constructed. The reference procedure was tested on a phantom or dummy patient by all three fluoroscopic modes. The phantom was so designed that the kilovoltage requirements for each projection were comparable to those needed for the average patient. Radiation exposure of the operator and patient was measured during each mode. The patient entrance dose was measured in air, and the operator dose was measured by 18 dosimeters on a dummy operator. Pulsed compared with continuous fluoroscopy could be performed with improved image quality at lower kilovoltages. The patient entrance dose was reduced by 21% and the operator dose by 54%. High-output pulsed fluoroscopy with extra beam filtering compared with continuous fluoroscopy improved the image quality, lowered the kilovoltage requirements, and reduced the patient entrance dose by 55% and

  6. Impact of attributed audit on procedural performance in cardiac electrophysiology catheter laboratory.

    Science.gov (United States)

    Sawhney, V; Volkova, E; Shaukat, M; Khan, F; Segal, O; Ahsan, S; Chow, A; Ezzat, V; Finlay, M; Lambiase, P; Lowe, M; Dhinoja, M; Sporton, S; Earley, M J; Hunter, R J; Schilling, R J

    2018-06-01

    Audit has played a key role in monitoring and improving clinical practice. However, audit often fails to drive change as summative institutional data alone may be insufficient to do so. We hypothesised that the practice of attributed audit, wherein each individual's procedural performance is presented will have a greater impact on clinical practice. This hypothesis was tested in an observational study evaluating improvement in fluoroscopy times for AF ablation. Retrospective analyses of fluoroscopy times in AF ablations at the Barts Heart Centre (BHC) from 2012-2017. Fluoroscopy times were compared pre- and post- the introduction of attributed audit in 2012 at St Bartholomew's Hospital (SBH). In order to test the hypothesis, this concept was introduced to a second group of experienced operators from the Heart Hospital (HH) as part of a merger of the two institutions in 2015 and change in fluoroscopy times recorded. A significant drop in fluoroscopy times (33.3 ± 9.14 to 8.95 ± 2.50, p audit. At the time of merger, a significant difference in fluoroscopy times between operators from the two centres was seen in 2015. Each operator's procedural performance was shared openly at the audit meeting. Subsequent audits showed a steady decrease in fluoroscopy times for each operator with the fluoroscopy time (min, mean±SD) decreasing from 13.29 ± 7.3 in 2015 to 8.84 ± 4.8 (p audit can promptsignificant improvement and hence should be adopted in clinical practice.

  7. Fluoroscopic radiation exposure: are we protecting ourselves adequately?

    Science.gov (United States)

    Hoffler, C Edward; Ilyas, Asif M

    2015-05-06

    While traditional intraoperative fluoroscopy protection relies on thyroid shields and aprons, recent data suggest that the surgeon's eyes and hands receive more exposure than previously appreciated. Using a distal radial fracture surgery model, we examined (1) radiation exposure to the eyes, thyroid, chest, groin, and hands of a surgeon mannequin; (2) the degree to which shielding equipment can decrease exposure; and (3) how exposure varies with fluoroscopy unit size. An anthropomorphic model was fit with radiation-attenuating glasses, a thyroid shield, an apron, and gloves. "Exposed" thermoluminescent dosimeters overlaid the protective equipment at the eyes, thyroid, chest, groin, and index finger while "shielded" dosimeters were placed beneath the protective equipment. Fluoroscopy position and settings were standardized. The mini-c-arm milliampere-seconds were fixed based on the selection of the kilovolt peak (kVp). Three mini and three standard c-arms scanned a model of the patient's wrist continuously for fifteen minutes each. Ten dosimeter exposures were recorded for each c-arm. Hand exposure averaged 31 μSv/min (range, 22 to 48 μSv/min), which was 13.0 times higher than the other recorded exposures. Eye exposure averaged 4 μSv/min, 2.2 times higher than the mean thyroid, chest, and groin exposure. Gloves reduced hand exposure by 69.4%. Glasses decreased eye exposure by 65.6%. There was no significant difference in exposure between mini and standard fluoroscopy. Surgeons' hands receive the most radiation exposure during distal radial plate fixation under fluoroscopy. There was a small but insignificant difference in mean exposure between standard fluoroscopy and mini-fluoroscopy, but some standard units resulted in lower exposure than some mini-units. On the basis of these findings, we recommend routine protective equipment to mitigate exposure to surgeons' hands and eyes, in addition to the thyroid, chest, and groin, during fluoroscopy procedures

  8. Trial of finger contamination reduction of the operator in nerve block treatment. Comparison of over- and under-table systems

    International Nuclear Information System (INIS)

    Saito, Hajime; Okabe, Keigo; Nakazawa, Yasuo

    2004-01-01

    Fluoroscopy-guided intervention of the lumbar spine, such as nerve block, plays an important role in the management of disc hernia patients. However, irradiation of operators' fingers remains a problem even with careful collimation and operation, especially when performed by non-radiologists. We compared the irradiation doses of under-table and over-table fluoroscopy systems, and we discuss the most advantageous method of reducing irradiation. The effectiveness and conditions of use of lead protection gloves were also evaluated. Skin dose was monitored using polymethyl methacrylate (PMMA) and an electronic dose meter. The skin doses of over- and under-table fluoroscopy were compared using C-arm fluoroscopy. Finger irradiation dose with 0.03 mmPb protection gloves was also measured. The under-table method reduced skin dose by 95% compared with the over-table method. Thicker PMMA resulted in a higher rate of irradiation reduction. Protection gloves reduced radiation dose by half, although this reduction was cancelled when automatic brightness control (ABC) was utilized. Under-tube fluoroscopy was superior to over-tube fluoroscopy in reducing irradiation to the fingers. (author)

  9. Objected constrained registration and manifold learning: A new patient setup approach in image guided radiation therapy of thoracic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ting; Jabbour, Salma K.; Haffty, Bruce G.; Yue, Ning [Radiation Oncology Department, Cancer Institute of New Jersey, University of Medicine and Dentistry of New Jersey, 195 Little Albany Street, New Brunswick, New Jersey 08901 (United States); Qin Songbing [Department of Radiation Oncology, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China)

    2013-04-15

    Purpose: The management of thoracic malignancies with radiation therapy is complicated by continuous target motion. In this study, a real time motion analysis approach is proposed to improve the accuracy of patient setup. Methods: For 11 lung cancer patients a long training fluoroscopy was acquired before the first treatment, and multiple short testing fluoroscopies were acquired weekly at the pretreatment patient setup of image guided radiotherapy (IGRT). The data analysis consisted of three steps: first a 4D target motion model was constructed from 4DCT and projected to the training fluoroscopy through deformable registration. Then the manifold learning method was used to construct a 2D subspace based on the target motion (kinetic) and location (static) information in the training fluoroscopy. Thereafter the respiratory phase in the testing fluoroscopy was determined by finding its location in the subspace. Finally, the phase determined testing fluoroscopy was registered to the corresponding 4DCT to derive the pretreatment patient position adjustment for the IGRT. The method was tested on clinical image sets and numerical phantoms. Results: The registration successfully reconstructed the 4D motion model with over 98% volume similarity in 4DCT, and over 95% area similarity in the training fluoroscopy. The machine learning method derived the phase values in over 98% and 93% test images of the phantom and patient images, respectively, with less than 3% phase error. The setup approach achieved an average accumulated setup error less than 1.7 mm in the cranial-caudal direction and less than 1 mm in the transverse plane. All results were validated against the ground truth of manual delineations by an experienced radiation oncologist. The expected total time for the pretreatment setup analysis was less than 10 s. Conclusions: By combining the registration and machine learning, the proposed approach has the potential to improve the accuracy of pretreatment setup for

  10. Objected constrained registration and manifold learning: A new patient setup approach in image guided radiation therapy of thoracic cancer

    International Nuclear Information System (INIS)

    Chen Ting; Jabbour, Salma K.; Haffty, Bruce G.; Yue, Ning; Qin Songbing

    2013-01-01

    Purpose: The management of thoracic malignancies with radiation therapy is complicated by continuous target motion. In this study, a real time motion analysis approach is proposed to improve the accuracy of patient setup. Methods: For 11 lung cancer patients a long training fluoroscopy was acquired before the first treatment, and multiple short testing fluoroscopies were acquired weekly at the pretreatment patient setup of image guided radiotherapy (IGRT). The data analysis consisted of three steps: first a 4D target motion model was constructed from 4DCT and projected to the training fluoroscopy through deformable registration. Then the manifold learning method was used to construct a 2D subspace based on the target motion (kinetic) and location (static) information in the training fluoroscopy. Thereafter the respiratory phase in the testing fluoroscopy was determined by finding its location in the subspace. Finally, the phase determined testing fluoroscopy was registered to the corresponding 4DCT to derive the pretreatment patient position adjustment for the IGRT. The method was tested on clinical image sets and numerical phantoms. Results: The registration successfully reconstructed the 4D motion model with over 98% volume similarity in 4DCT, and over 95% area similarity in the training fluoroscopy. The machine learning method derived the phase values in over 98% and 93% test images of the phantom and patient images, respectively, with less than 3% phase error. The setup approach achieved an average accumulated setup error less than 1.7 mm in the cranial-caudal direction and less than 1 mm in the transverse plane. All results were validated against the ground truth of manual delineations by an experienced radiation oncologist. The expected total time for the pretreatment setup analysis was less than 10 s. Conclusions: By combining the registration and machine learning, the proposed approach has the potential to improve the accuracy of pretreatment setup for

  11. The evaluation of radiologic methods for access guidance in percutaneous nephrolithotomy: a systematic review of the literature.

    Science.gov (United States)

    Breda, Alberto; Territo, Angelo; Scoffone, Cesare; Seitz, Christian; Knoll, Thomas; Herrmann, Thomas; Brehmer, Mariannhe; Osther, Palle J S; Liatsikos, Evangelos

    2017-11-12

    Percutaneous nephrolithotomy (PNL) is the treatment of choice for larger and complex renal calculi. First step in performing PNL is to obtain access to the renal cavity using either fluoroscopy or ultrasound (US) guidance or a combination of both. Which guiding method to choose is controversial? A systematic review of the literature was performed comparing image guidance modalities for obtaining access in PNL. Evidence acquisition and synthesis: A PubMed, Scopus and Cochrane search for peer-reviewed studies was performed using the keywords "ultrasound" AND "fluoroscopy" AND "Percutaneous nephrolithotomy". Eligible articles were reviewed according to PRISMA criteria. Two hundred and forty records were identified using the keywords. Of these twelve studies were considered relevant. US guidance seems to be associated with a slightly lower complication rate, which may be related to fewer puncture attempts needed for obtaining access and to better peri-renal organ visualization. On the other hand, US-guidance alone needs the adjunct of fluoroscopy in a significant number of cases for achieving access. Stone free rate (SFR) was comparable between groups. Using US for renal access unequivocally reduces radiation exposure. Current evidence indicates that both fluoroscopy and US guidance may be successfully used for obtaining percutaneous renal access. Combining the image-guiding modalities - US and fluoroscopy - seems to increase outcome in PNL both with regard to success in achieving access and reducing complications. Furthermore, including US in the access strategy of PNL reduces radiation exposure to surgeon and staff as well as patients.

  12. Capture and analysis of radiation dose reports for radiology

    International Nuclear Information System (INIS)

    Midgley, S.M.

    2014-01-01

    Radiographic imaging systems can produce records of exposure and dose parameters for each patient. A variety of file formats are in use including plain text, bit map images showing pictures of written text and radiation dose structured reports as text or extended markup language files. Whilst some of this information is available with image data on the hospital picture archive and communication system, access is restricted to individual patient records, thereby making it difficult to locate multiple records for the same scan protocol. This study considers the exposure records and dose reports from four modalities. Exposure records for mammography and general radiography are utilized for repeat analysis. Dose reports for fluoroscopy and computed tomography (CT) are utilized to study the distribution of patient doses for each protocol. Results for dosimetric quantities measured by General Radiography, Fluoroscopy and CT equipment are summarised and presented in the Appendix. Projection imaging uses the dose (in air) area product and derived quantities including the dose to the reference point as a measure of the air kerma reaching the skin, ignoring movement of the beam for fluoroscopy. CT uses the dose indices CTDIvol and dose length product as a measure of the dose per axial slice, and to the scanned volume. Suitable conversion factors are identified and used to estimate the effective dose to an average size patient (for CT and fluoroscopy) and the entrance skin dose for fluoroscopy.

  13. Estimating effective dose to pediatric patients undergoing interventional radiology procedures using anthropomorphic phantoms and MOSFET dosimeters.

    Science.gov (United States)

    Miksys, Nelson; Gordon, Christopher L; Thomas, Karen; Connolly, Bairbre L

    2010-05-01

    The purpose of this study was to estimate the effective doses received by pediatric patients during interventional radiology procedures and to present those doses in "look-up tables" standardized according to minute of fluoroscopy and frame of digital subtraction angiography (DSA). Organ doses were measured with metal oxide semiconductor field effect transistor (MOSFET) dosimeters inserted within three anthropomorphic phantoms, representing children at ages 1, 5, and 10 years, at locations corresponding to radiosensitive organs. The phantoms were exposed to mock interventional radiology procedures of the head, chest, and abdomen using posteroanterior and lateral geometries, varying magnification, and fluoroscopy or DSA exposures. Effective doses were calculated from organ doses recorded by the MOSFET dosimeters and are presented in look-up tables according to the different age groups. The largest effective dose burden for fluoroscopy was recorded for posteroanterior and lateral abdominal procedures (0.2-1.1 mSv/min of fluoroscopy), whereas procedures of the head resulted in the lowest effective doses (0.02-0.08 mSv/min of fluoroscopy). DSA exposures of the abdomen imparted higher doses (0.02-0.07 mSv/DSA frame) than did those involving the head and chest. Patient doses during interventional procedures vary significantly depending on the type of procedure. User-friendly look-up tables may provide a helpful tool for health care providers in estimating effective doses for an individual procedure.

  14. Physician-received scatter radiation with angiography systems used for interventional radiology: Comparison among many x-ray systems

    International Nuclear Information System (INIS)

    Chida, K.; Morishima, Y.; Inaba, Y.; Taura, M.; Ebata, A.; Takeda, K.; Shimura, H.; Zuguchi, M.

    2012-01-01

    Radiation protection for interventional radiology (IR) physicians is very important. Current IR X-ray systems tend to use flat-panel detectors (FPDs) rather than image intensifiers (IIs). The purpose of this study is to test the hypothesis that there is no difference in physician-received scatter radiation (PRSR) between FPD systems and II systems. This study examined 20 X-ray systems in 15 cardiac catheterisation laboratories (11 used a FPD and 9 used an II). The PRSR with digital cine-angiography and fluoroscopy were compared among the 20 X-ray systems using a phantom and a solid-state-detector electronic pocket dosemeter. The maximum PRSR exceeded the minimum PRSR by ∼12-fold for cine-angiography and ∼9-fold for fluoroscopy. For both fluoroscopy and digital cine-angiography, the PRSR had a statistically significant positive correlation with the entrance surface dose (fluoroscopy, r = 0.87; cine-angiography, r = 0.86). There was no statistically significant difference between the average PRSR of FPDs and IIs during either digital cine-angiography or fluoroscopy. There is a wide range of PRSR among the radiography systems evaluated. The PRSR correlated well with the entrance surface dose of the phantom in 20 X-ray units used for IR. Hence, decreasing the dose to the patient will also decrease the dose to staff. (authors)

  15. Radiation risk to the patient: a case study involving multiple diagnostic X ray exposures given over a period of 25 years

    International Nuclear Information System (INIS)

    Rainbow, A.J.; McMaster Univ., Hamilton, ON; Roginski, P.; McGeen, W.

    1992-01-01

    The cumulative somatic dose index (SDI) for a number of diagnostic X ray examinations was made for a 60 year old male. The history of diagnostic X ray exposure for this patient from 1957 to 1983 showed 29 diagnostic X ray examinations including more than 100 films and 15 minutes of fluoroscopy. The total cumulative SDI to this patient was 214 mGy (about 21 rad). More than half this dose, 142 mGy, was contributed from upper GI and barium enema examinations which used fluoroscopy, with 88 mGy from the fluoroscopy alone. Using the recently revised risk coefficient for fatal cancer following whole-body irradiation of adult workers recommended by the International Commission on Radiological Protection in 1990, the authors estimate a 0.9% cancer morality risk to this patient resulting from the 29 diagnostic X ray examinations. (author)

  16. Radiation exposure during ureteroscopy

    International Nuclear Information System (INIS)

    Bagley, D.H.; Cubler-Goodman, A.

    1990-01-01

    Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room

  17. Ultrasound-guided supra-acetabular pin placement in pelvic external fixation: description of a surgical technique and results.

    Science.gov (United States)

    Chana-Rodríguez, Francisco; Cuervas-Mons, Manuel; Rojo-Manaute, José; Mora, Félix; Arnal, Juan; Vaquero-Martín, Javier

    2017-11-01

    Pelvic fracture in trauma patients can lead to hemodynamic instability. External fixation is a treatment capable of stabilizing these injuries in the context of damage control surgery. Supra-acetabular pin offers the greater biomechanical stability but requires the use of intraoperative fluoroscopy. The aim of this study was to analyze our results for an ultrasound-guided supra-acetabular pinning. Cross-sectional study with cadaveric specimens. Ultrasound-guided pin placement assessed by fluoroscopy and dissection. Fourteen ultrasound-guided supra-acetabular pins were placed in seven cadaveric specimens. Excellent placement in all cases, evaluated with radiological control. Good qualitative bone fixation after dissection. One femoral cutaneous nerve was not found during anatomic dissection and was assumed injured. Ultrasound-guided supra-acetabular pin placement is a feasible and effective technique. Our study indicates that pin placement without intraoperative fluoroscopy is feasible without compromising the reliability of its placement. © 2017 Elsevier Ltd. All rights reserved.

  18. Survival Analysis of Occipital Nerve Stimulator Leads Placed under Fluoroscopic Guidance with and without Ultrasonography.

    Science.gov (United States)

    Jones, James H; Brown, Alison; Moyse, Daniel; Qi, Wenjing; Roy, Lance

    2017-11-01

    Electrical stimulation of the greater occipital nerves is performed to treat pain secondary to chronic daily headaches and occipital neuralgia. The use of fluoroscopy alone to guide the surgical placement of electrodes near the greater occipital nerves disregards the impact of tissue planes on lead stability and stimulation efficacy. We hypothesized that occipital neurostimulator (ONS) leads placed with ultrasonography combined with fluoroscopy would demonstrate increased survival rates and times when compared to ONS leads placed with fluoroscopy alone. A 2-arm retrospective chart review. A single academic medical center. This retrospective chart review analyzed the procedure notes and demographic data of patients who underwent the permanent implant of an ONS lead between July 2012 and August 2015. Patient data included the diagnosis (reason for implant), smoking tobacco use, disability, and age. ONS lead data included the date of permanent implant, the imaging modality used during permanent implant (fluoroscopy with or without ultrasonography), and, if applicable, the date and reason for lead removal. A total of 21 patients (53 leads) were included for the review. Chi-squared tests, Fishers exact tests, 2-sample t-tests, and Wilcoxon rank-sum tests were used to compare fluoroscopy against combined fluoroscopy and ultrasonography as implant methods with respect to patient demographics. These tests were also used to evaluate the primary aim of this study, which was to compare the survival rates and times of ONS leads placed with combined ultrasonography and fluoroscopy versus those placed with fluoroscopy alone. Survival analysis was used to assess the effect of implant method, adjusted for patient demographics (age, smoking tobacco use, and disability), on the risk of lead explant. Data from 21 patients were collected, including a total of 53 ONS leads. There was no statistically significant difference in the lead survival rate or time, disability, or patient age

  19. Point-of-Care Ultrasound-Guided Percutaneous Cannulation of Extracorporeal Membrane Oxygenation: Make it Simple.

    Science.gov (United States)

    Ahn, Hong Joon; Lee, Jun Wan; Joo, Ki Hyuk; You, Yeon Ho; Ryu, Seung; Lee, Jin Woong; Kim, Seung Whan

    2017-12-30

    Cannulation of the great vessels is required for extracorporeal membrane oxygenation (ECMO). Currently, there is no guideline for optimal imaging modalities during percutaneous cannulation of ECMO. The purpose of this study was to describe percutaneous cannulation guided by point-of-care ultrasound (POCUS) for ECMO and compare it with fluoroscopy and landmark guidance. Three groups (POCUS-, fluoroscopy-, and landmark-guided) of percutaneous cannulation for ECMO were analyzed retrospectively in a tertiary academic hospital. In the POCUS-guided group, visual confirmation of guidewire and cannula by ultrasound in both the access and return cannula were essential for successful cannulation. Fluoroscopy- and landmark-guided groups were cannulated with the conventional technique. A total of 128 patients were treated by ECMO during the study period, of which 94 (73.4%) cases were venoarterial ECMO. This included 56 cases of extracorporeal cardiopulmonary resuscitation. Also, there were 30 (23.4%) cases of venovenous ECMO and 4 (3.1%) cases of venoarteriovenous ECMO. A total of 71 (55.5%) patients were cannulated under POCUS guidance, and 43 (33.6%) patients were cannulated under fluoroscopy guidance and 14 (10.9%) patients were cannulated by landmark guidance. No surgical cut downs were required. Misplacement of cannula occurred in 3 (2.3%) cases. All three occurred in the landmark-guided group. POCUS-guided cannulation is comparable to fluoroscopy-guided cannulation in terms of avoiding cannula misplacement. In our experience, POCUS-guided cannulation is a useful strategy over fluoroscopy- and landmark-guided cannulation during peripheral ECMO. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Intussusception reduction: Effect of air vs. liquid enema on radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Summer L.; Edgar, J.C.; Anupindi, Sudha A.; Zhu, Xiaowei [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA (United States); Magill, Dennise; Felice, Marc A. [University of Pennsylvania, Environmental Health and Radiation Safety, Philadelphia, PA (United States)

    2017-10-15

    Both air and radiopaque liquid contrast are used to reduce ileocolic intussusception under fluoroscopy. Some suggest air lowers radiation dose due to shorter procedure times. However, air enema likely lowers radiation dose regardless of fluoroscopy time due to less density over the automatic exposure control cells. We test the hypothesis that air enema reduction of ileocolic intussusception results in lower radiation dose than liquid contrast enema independent of fluoroscopy time. We describe a role for automatic exposure control in this dose difference. We retrospectively evaluated air and liquid intussusception reductions performed on a single digital fluoroscopic unit during a 26-month period. We compared patient age, weight, gender, exam time of day and year, performing radiologist(s), radiographic image acquisitions, grid and magnification use, fluoroscopy time and dose area product. We compared categorical and continuous variables statistically using chi-square and Mann-Whitney U tests, respectively. The mean dose area product was 2.7-fold lower for air enema, 1.3 ± 0.9 dGy.cm{sup 2}, than for liquid, 3.5 ± 2.5 dGy.cm{sup 2} (P<0.005). The mean fluoroscopy time was similar between techniques. The mean dose area product/min was 2.3-fold lower for air, 0.6 ± 0.2 dGy.cm{sup 2}/min, than for liquid, 1.4 ± 0.5 dGy.cm{sup 2}/min (P<0.001). No group differences were identified in other measured dose parameters. Fluoroscopic intussusception reduction using air enema uses less than half the radiation dose of liquid contrast enema. Dose savings are independent of fluoroscopy time and are likely due to automatic exposure control interaction. (orig.)

  1. New labels for radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Susumu; Mukai, Minoru; Kato, Hirotoshi (National Inst. of Radiological Sciences, Chiba (Japan))

    1992-12-01

    In simulating radiotherapy, the bone and trachea identified by plain X-P and the other organs, such as the esophagus and bladder, outlined by contrast medium have so far been used as labels. However, irradiation with a high therapeutic ratio is required for an intracorporeal insertion of artificial labels that are identified by X-ray fluoroscopy. For this purpose, metal clips and seed dummies are available, although they cause artifacts in CT scans. Therefore, the authors are using an acupuncture needle and lipiodol for tracing as new artificial labels, since both are identified by X-ray fluoroscopy and CT scan and create few artifacts. (J.P.N.).

  2. Analysis of dose to crystalline in Interventional radiology: a purpose of one case

    International Nuclear Information System (INIS)

    Carrera M, F.; Moreno R, F.; Velazquez M, F.; Manzano M, F.J.; Moreno S, T.

    1998-01-01

    The present work shows the dose values to crystalline for the personnel which works in interventional radiology procedures. It was took data of 436 studies with a total of 2,133.4 minutes in fluoroscopy and 19,563 images. It was showed dose values to crystalline in three situations: without blinding, with blinding of 0.25 and 0.50 mm Pb and by type of study: fluoroscopy, graphie and total. The dose means and ranges to patient for each of these studies also are detailed. (Author)

  3. Reference levels in PTCA as a function of procedure complexity

    International Nuclear Information System (INIS)

    Peterzol, A.; Quai, E.; Padovani, R.; Bernardi, G.; Kotre, C. J.; Dowling, A.

    2005-01-01

    The multicentre assessment of a procedure complexity index (CI) for the introduction of reference levels (RLs) in percutaneous transluminal coronary angio-plasties (PTCA) is presented here. PTCAs were investigated based on methodology proposed by Bernardi et al. Multiple linear stepwise regression analysis, including clinical, anatomical and technical factors, was performed to obtain fluoroscopy time predictors. Based on these regression coefficients, a scoring system was defined and CI obtained. CI was used to classify dose values into three groups: low, medium and high complexity procedures, since there was good correlation (r = 0.41; P 2 , and 12, 20 and 27 min for fluoroscopy time, for the three CI groups. (authors)

  4. <