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Sample records for ostiomeatal unit ct

  1. Anatomical relationship between the optic nerve and posterior paranasal sinuses on ostiomeatal unit CT

    International Nuclear Information System (INIS)

    Cho, June Il; Kim, Hong In; Seol, Hae Young; Lee, Nam Joon; Kim, Jung Hyuk; Cha, In Ho

    1997-01-01

    To determine the anatomic variations that can lead to optic nerve damage during the sugical treatment of posterior paranasal sinus lesions two hundred optic nerves of 100 persons were examined using ostiomeatal unit CT(OMU CT). The anatomical features of this nerve and posterior paranasal sinuses were classified into four types:the optic nerve adjacent to the sphenoid sinus without indentation of the sinus wall (type 1);the optic nerve adjacent to the sphenoid sinus, causing indentation of the sinus wall (type 2);the optic nerve passing through the sphenoid sinus (type 3);and the optic nerve adjacent to the sphenoid sinus and posterior ethmoid sinus (type 4). Bony dehiscence around the optic nerve and pneumatization of the anterior clinoid process were also evaluated. The anatomical classification of the optic nerve and posterior paranasal sinuses was as follows:type 1, 1326(66%); type 2, 60(30%); type 3, 6(3%), and type 4, 2(1%). Bony dehiscence around the optic nerve had developed in 58 cases (29%) and pneumatization of the anterior clinoid process in 13(6.5%). These conditions were most common in type 3 optic nerve, and second most common in type 2. The 2 and 3 optic nerves, bony dehiscence around the optic nerve and pneumatization of the anterior clinoid process are the anatomic variations that can lead to optic nerve damage during the surgical treatment of posterior paranasal sinus lesions. To prevent optic nerve damage, these factors should be carefully evaluated by OMU CT

  2. Numerical optimization of targeted delivery of charged nanoparticles to the ostiomeatal complex for treatment of rhinosinusitis

    Directory of Open Access Journals (Sweden)

    Xi J

    2015-07-01

    Full Text Available Jinxiang Xi,1 Jiayao Eddie Yuan,1 Xiuhua April Si,2 James Hasbany1 1School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI, 2Department of Mechanical Engineering, California Baptist University, Riverside, CA, USA Background: Despite the prevalence of rhinosinusitis that affects 10%–15% of the population, current inhalation therapy shows limited efficacy. Standard devices deliver <5% of the drugs to the sinuses due to the complexity of nose structure, secluded location of the sinus, poor ventilation, and lack of control of particle motions inside the nasal cavity. Methods: An electric-guided delivery system was developed to guide charged particles to the ostiomeatal complex (OMC. Its performance was numerically assessed in an MRI-based nose–sinus model. Key design variables related to the delivery device, drug particles, and patient breathing were determined using sensitivity analysis. A two-stage optimization of design variables was conducted to obtain the best performance of the delivery system using the Nelder-Mead algorithm. Results and discussion: The OMC delivery system exhibited high sensitivity to the applied electric field and electrostatic charges carried by the particles. Through the synthesis of electric guidance and point drug release, the new delivery system eliminated particle deposition in the nasal valve and turbinate regions and significantly enhanced the OMC doses. An OMC delivery efficiency of 72.4% was obtained with the optimized design, which is one order of magnitude higher than the standard nasal devices. Moreover, optimization is imperative to achieve a sound delivery protocol because of the large number of design variables. The OMC dose increased from 45.0% in the baseline model to 72.4% in the optimized system. The optimization framework developed in this study can be easily adapted for the delivery of drugs to other sites in the nose such as the ethmoid sinus and olfactory region

  3. Radiation doses in head CT examinations in Serbia: comparison among different CT units

    International Nuclear Information System (INIS)

    Arandjic, D.; Ciraj-Bjelac, O.; Bozovic, P.; Stankovic, J.; Hadnadjev, D.; Stojanovic, S.

    2012-01-01

    A rapid increase in number of Computed Tomography (CT) examinations has been observed world wide. As haed CT is the most frequent CT examination, the purpose of this study was to collect and analyse patient doses in children and adults in different CT units for this procedure. The study included 8 CT units from three manufacturers (Siemens, Toshiba and General Electric). Data for adults and pediatric patients were collected in terms of CTDIvol and DLP values. The doses were estimated as a mean value of 10 patients on each CT unit. For pediatrics, doses were collected for four age groups (0-1year, >1-5years, >5-10years and >10-15years). Comparing different manufacturers and the same number of detector rows it was observed that, in case of 16 slices units, doses were very similar on Siemens and General Electric scanner. CTDIvol and DLP on Siemens scanner were 60 mGy and 1066 mGy·cm, respectively, while on General Electric those values were 66 mGy and 1050 mGy·cm. However, this trend was not observed in case of 64 slices units. CTDIvol and DLP values collected on Toshiba were much higher (177 mGy and 2109 mGy·cm) than in case of Siemens scanner (59 mGy and 1060 mGy·cm). Doses on 16 and 64 slices Siemens scanners were very similar, while on 4 slices were higher. Except in two units, doses were were in line with DRLs. In case of pediatrics, doses increase with patient age and again Siemens scanner showed the lowest values while the highest were observed on Toshiba. (authors)

  4. Patient doses from CT examinations in the United Arab Emirates

    International Nuclear Information System (INIS)

    Janeczek, J.

    2006-01-01

    Full text of publication follows: The main goal of the study was to estimate effective patient doses from the 6 most common CT examinations for different types of CT scanners within the United Arab Emirates. The results were used to assess future trends in patient CT doses following rapid replacement of axial and single-slice spiral scanners by multi-slice scanners. At present all three types of scanner technology exist: axial, spiral and multi-slice with axial scanners being gradually replaced by multi-slice scanners as the medical infrastructure of the country is modernized. Altogether there are more than 30 CT scanners in the country with a population of 4 million. Out of these 11 scanners are 16-slice models with tube-current modulation system. The majority of larger United Arab Emirates hospitals have at least two CT scanners: a single slice and 4 or 16-slice scanner. The survey was carried out with data collection forms distributed to the majority of CT scanner users in the United Arab Emirates hospitals, both private and government. Effective doses for different examinations were calculated from T.L.D. measurements using an Alderson Rando phantom simulating an average size patient. Our results show that effective doses to patients initially increased with the introduction of 4-slice scanners. Multi-slice scanners with 16 and more slices have tube-current modulation system as a standard. It is routinely used by radiographers in almost all examinations resulting in patient dose reduction up to 40 % in certain examinations. Another factor affecting population dose is the increased number of patients examined using multi-slice scanners. In the United Arab Emirates there was an increase of more than 30 % in the annual number of patients examined using multi-slice scanners in comparison to single-slice scanners. This fact is attributed to the ease and speed of operation of multi-slice scanners. Rapid increase in number of CT examinations is of concern. Medical

  5. Dual purpose QA tool developed for teletherapy unit and CT scan in SNDH

    International Nuclear Information System (INIS)

    Shilvant, D.V.; Tamane, C.J.; Pangam, S.B.; Raees, M.D.; Aynoor, S.K.; Pol, P.S.; Verghese, Aju; Ghorpade, C.J.

    2007-01-01

    To make a simple device used in Teletherapy unit and CT scan for depth data measurement. The accurate depth data is essential and very important factor for precise treatment in SAD isocentric setup calculation. In CT scan based treatment planning, the calculation obtained is from the depth given by the CT scan. The success of treatment depends on the same parameters in treatment unit matched with diagnostic CT scan data. To check the depth parameters in both CT scan and Teletherapy unit we have developed a single QA tool in our hospital. As this tool is precise, handy and easily accessible the results obtained from it assures the quality of Teletherapy unit as well as CT scan depth data. This small device resulted data helps a lot in calculations of complicated SAD setup in Telecobalt and also useful in recent new treatment modalities such as IMRT, micro MLC, etc

  6. Our experience in using the whole body computed tomography unit (GE CT/T)

    International Nuclear Information System (INIS)

    Murakawa, Yasuhiro; Morimoto, Mitsuo; Ishigaki, Naoya; Zaitsu, Hiroaki; Kawabata, Kohji

    1983-01-01

    Since our hospital installed the CT unit of the head and neck (SCT-100N) in April, 1979, we reported our experience in using this equipment in 1980 and 1982. After that, since the whole body CT unit (GE CT/T) was installed in our hospital in April, 1982, the total number of CT examination have reached approximately three thousand five handred till this August. Consequently, this CT image seemed to be superior in image quality to that obtained by other CT equipment. The most important characteristic of this equipment is that the retrospective and prospective reviews of the target image and the coronal and sagittal recontruction from contiguous transverse axial scans are possible. We show in this report two experimental CT photograms obtained by the reviews of the target image in using of microchart phantom and CT photograms of uterus myoma, metastatic thyroid and liver cancers and further, of contiguous transverse axial scans of cerebral embolism and the coronal recontruction. The important problems for the future of this equipment are those of absorbed X-ray dose of the patients and the scan time. (author)

  7. SU-E-P-46: Clinical Acceptance Testing and Implementation of a Portable CT Unit

    International Nuclear Information System (INIS)

    LaFrance, M; Marsh, S; Hicks, R; O’Donnell-Moran, G

    2015-01-01

    Purpose: Planning for the first installation in New England of a new portable CT unit to be used in the Operating Room required the integration of many departments including Surgery, Neurosurgery, Information Services, Clinical Engineering, Radiology and Medical Physics/Radiation Safety. Acceptance testing and the quality assurance procedures were designed to optimize image quality and patient and personnel radiation exposure. Methods: The vendor’s protocols were tested using the CT Dosimetry phantoms. The system displayed the CTDIw instead of the CTDIvol while testing the unit. Radiation exposure was compared to existing CT scanners from installed CT units throughout the facility. Brainlab measures all 4 periphery slots on the CT Dosimetry phantom. The ACR measures only the superior slot for the periphery measurement. A comprehensive radiation survey was also performed for several locations. Results: The CTDIvol measurements were comparable for the following studies: brain, C-Spine, and sinuses. However, the mobile CT measurements were slightly higher than other CT units but within acceptable tolerance if measured using the ACR method.Based on scatter measurements, it was determined if any personnel were to stay in the OR Suite during image acquisition that the appropriate lead apron and thyroid shields had to be worn.In addition, to reduce unnecessary scatter, there were two mobile 6 foot wide shields (1/16″ lead equivalent) available to protect personnel in the room and adjacent areas. Conclusion: Intraoperative CT provides the physician new opportunities for evaluation of the progression of surgical resections and device placement at the cost of increasing the amount of trained personnel required to perform this procedure. It also brings with it challenges to keep the radiation exposure to the patients and staff within reasonable limits

  8. SU-E-P-46: Clinical Acceptance Testing and Implementation of a Portable CT Unit

    Energy Technology Data Exchange (ETDEWEB)

    LaFrance, M; Marsh, S; Hicks, R; O’Donnell-Moran, G [Baystate Health Systems, Inc., Springfield, MA (United States)

    2015-06-15

    Purpose: Planning for the first installation in New England of a new portable CT unit to be used in the Operating Room required the integration of many departments including Surgery, Neurosurgery, Information Services, Clinical Engineering, Radiology and Medical Physics/Radiation Safety. Acceptance testing and the quality assurance procedures were designed to optimize image quality and patient and personnel radiation exposure. Methods: The vendor’s protocols were tested using the CT Dosimetry phantoms. The system displayed the CTDIw instead of the CTDIvol while testing the unit. Radiation exposure was compared to existing CT scanners from installed CT units throughout the facility. Brainlab measures all 4 periphery slots on the CT Dosimetry phantom. The ACR measures only the superior slot for the periphery measurement. A comprehensive radiation survey was also performed for several locations. Results: The CTDIvol measurements were comparable for the following studies: brain, C-Spine, and sinuses. However, the mobile CT measurements were slightly higher than other CT units but within acceptable tolerance if measured using the ACR method.Based on scatter measurements, it was determined if any personnel were to stay in the OR Suite during image acquisition that the appropriate lead apron and thyroid shields had to be worn.In addition, to reduce unnecessary scatter, there were two mobile 6 foot wide shields (1/16″ lead equivalent) available to protect personnel in the room and adjacent areas. Conclusion: Intraoperative CT provides the physician new opportunities for evaluation of the progression of surgical resections and device placement at the cost of increasing the amount of trained personnel required to perform this procedure. It also brings with it challenges to keep the radiation exposure to the patients and staff within reasonable limits.

  9. Quality control of CT units - methodology of performance I

    International Nuclear Information System (INIS)

    Prlic, I.; Radalj, Z.

    1996-01-01

    Increasing use of x-ray computed tomography systems (CT scanners) in the diagnostic requires an efficient means of evaluating the performance of them. Therefore, this paper presents the way to measure (Quality Control procedure-Q/C) and define the CT scanner performance through a special phantom which is based on the recommendation of the American association of Physicists in Medicine (AAPM). The performance parameters measurable with the phantom represent the capability, so periodical evaluation of the parameters enable the users to recognize the stability of the CT scanner no matter on the manufacturer, model or software option of the scanner. There are five important performance parameters which are to be measured: Noise, Contrast scale, Nominal tomographic section thickness, High and Low contrast resolution (MTF). The sixth parameter is, of course the dose per scan and slice which gives the patient dose for the certain diagnostic procedure. The last but not the least parameter is the final image quality which is given through the image processing device connected to the scanner. This is the final medical information needed for the good medical practice according to the Quality Assurance (Q/A) procedures in diagnostic radiology. We have to assure the results of the performance evaluation without environmental influences (the measurements are to be made under the certain conditions according Q/A). This paper will give no detailed methodology recipe but will show on the one example; the system noise measurements and linearity; the need and relevant results of the measurements.1 The rest of the methodology is to be published. (author)

  10. Relationship between Hounsfield Unit in CT Scan and Gray Scale in CBCT

    Directory of Open Access Journals (Sweden)

    Tahmineh Razi

    2014-06-01

    Full Text Available Background and aims. Cone-beam computed tomography (CBCT is an imaging system which has many advantages over computed tomography (CT. In CT scan, Hounsfield Unit (HU is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value. The aim of the present study was to investigate the relationship between gray scale in CBCT and Hounsfield Unit (HU in CT scan. Materials and methods. In this descriptive study, the head of a sheep was scanned with 3 CBCT and one medical CT scanner. Gray scales and HUs were detected on images. Reconstructed data were analyzed to investigate relationship between CBCT gray scales and HUs. Results. A strong correlation between gray scales of CBCT and HUs of CT scan was determined. Conclusion. Considering the fact that gray scale in CBCT is the criteria in measurement of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.

  11. Utilization of head CT during injury visits to United States emergency departments: 2012-2015.

    Science.gov (United States)

    Yun, Brian J; Borczuk, Pierre; Zachrison, Kori S; Goldstein, Joshua N; Berlyand, Yosef; Raja, Ali S

    2018-05-18

    Studies have shown increasing utilization of head computed tomography (CT) imaging of emergency department (ED) patients presenting with an injury-related visit. Multiple initiatives, including the Choosing Wisely™ campaign and evidence-based clinical decision support based on validated decision rules, have targeted head CT use in patients with injuries. Therefore, we investigated national trends in the use of head CT during injury-related ED visits from 2012 to 2015. This was a secondary analysis of data from the annual United States (U.S.) National Hospital Ambulatory Medical Care Survey from 2012 to 2015. The study population was defined as injury-related ED visits, and we sought to determine the percentage in which a head CT was ordered and, secondarily, to determine both the diagnostic yield of clinically significant intracranial findings and hospital characteristics associated with increased head CT utilization. Between 2012 and 2015, 12.25% (95% confidence interval [CI] 11.48-13.02%) of injury-related visits received at least one head CT. Overall head CT utilization showed an increased trend during the study period (2012: 11.7%, 2015: 13.23%, p = 0.09), but the results were not statistically significant. The diagnostic yield of head CT for a significant intracranial injury over the period of four years was 7.4% (9.68% in 2012 vs. 7.67% in 2015, p = 0.23). Head CT use along with diagnostic yield has remained stable from 2012 to 2015 among patients presenting to the ED for an injury-related visit. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Coronal CT of the paranasal sinuses before and after functional endoscotic sinus surgery

    International Nuclear Information System (INIS)

    Mantoni, M.; Larsen, P.; Hansen, H.; Tos, M.; Berner, B.; Oerntoft, S.

    1996-01-01

    Coronal CT of the paranasal sinuses and the ostiomeatal complex (OMC) was performed before and 12 months after bilateral functional endoscopic sinus surgery (FESS) in 30 patients with sinusitis and 12 patients with nasal polyposis. The extent of sinus mucosal thickening was graded, and the patency of the OMC was evaluated. After FESS, the percentage of open OMCs had increased from 42% to 83% in the sinusitis group, and from 8% to 45% in the polyposis group. There was only a small improvement in mucosal score in sinuses with opened OMC, so that the overall extent of sinus opacification before and after FESS was almost the same. Despite this, 91% of the patients reported clinical relief of symptoms. Preoperative coronal CT of the paranasal sinuses serves as an anatomical map for the surgeon, but there is no benefit of routine postoperative CT. (orig.)

  13. Clinical feasibility of a Asahi Mark J MR-CT unit in routine practice, 3

    International Nuclear Information System (INIS)

    Fujii, Kyoichi; Araki, Akiteru; Mikami, Fumio

    1985-01-01

    Slice thickness for demonstrating tumors of the cerebellum and spinal cord using a 0.1 Tesla MR-CT unit was assessed. Slices 5 mm and 10 mm in thickness yielded clear images of the contour of masses and cysts in a patient with astrocytoma of the cerebellum. A 5-mm-thick slice gave a clear image of the structure inside the mass. In a patient with osteoarthritis of the spine, although a 5-mm-thick slice provided by spin-echo (SE) technique visualized compression and deviation of the cervical cord, a 10-mm-thick slice failed to show fine twisting of the cervical cord. In a patient with tumor of the thoracic cord, a SE image slice 5 mm in thickness visualized extending of lesions. Spinal nerve roots were shown on coronal scanning with a slice 5 mm in thickness in a patient with tumor of the lumbar cord. (Namekawa, K.)

  14. Unit Cost Analysis of PET-CT at an Apex Public Sector Health Care Institute in India.

    Science.gov (United States)

    Gajuryal, S H; Daga, A; Siddharth, V; Bal, C S; Satpathy, S

    2017-01-01

    PET/CT scan service is one of the capital intensive and revenue-generating centres of a tertiary care hospital. The cost associated with the provisioning of PET services is dependent upon the unit costs of the resources consumed. The study aims to determine the cost of providing PET/CT Scan services in a hospital. This descriptive and observational study was conducted in the Department of Nuclear Medicine at a tertiary apex teaching hospital in New Delhi, India in the year 2014-15. Traditional costing methodology was used for calculating the unit cost of PET/CT scan service. The cost was calculated under two heads that is capital and operating cost. Annualized cost of capital assets was calculated using methodology prescribed by WHO and operating costs was taken on an actual basis. Average number of PET/CT scan performed in a day is 30. The annual cost of providing PET/CT scan services was calculated to be 65,311,719 Indian Rupees (INR) (US$ 1,020,496), while the unit cost of PET scan was calculated to be 9625.92 INR (US$ 150). 3/4th cost was spent on machinery and equipment (75.3%) followed by healthcare personnel (11.37%), electricity (5%), consumables and supplies (4%) engineering maintenance (3.24%), building, furniture and HVAC capital cost (0.76%), and manifold cost (0.05%). Of the total cost, 76% was capital cost while the remaining was operating cost. Total cost for establishing PET/CT scan facility with cyclotron and chemistry module and PET/CT scan without cyclotron and chemistry module was calculated to be INR 610,873,517 (US$9944899) and 226,745,158 (US$3542893), respectively. (US$ 1=INR 64).

  15. Graphics Processing Unit-Accelerated Nonrigid Registration of MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations.

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    Tokuda, Junichi; Plishker, William; Torabi, Meysam; Olubiyi, Olutayo I; Zaki, George; Tatli, Servet; Silverman, Stuart G; Shekher, Raj; Hata, Nobuhiko

    2015-06-01

    Accuracy and speed are essential for the intraprocedural nonrigid magnetic resonance (MR) to computed tomography (CT) image registration in the assessment of tumor margins during CT-guided liver tumor ablations. Although both accuracy and speed can be improved by limiting the registration to a region of interest (ROI), manual contouring of the ROI prolongs the registration process substantially. To achieve accurate and fast registration without the use of an ROI, we combined a nonrigid registration technique on the basis of volume subdivision with hardware acceleration using a graphics processing unit (GPU). We compared the registration accuracy and processing time of GPU-accelerated volume subdivision-based nonrigid registration technique to the conventional nonrigid B-spline registration technique. Fourteen image data sets of preprocedural MR and intraprocedural CT images for percutaneous CT-guided liver tumor ablations were obtained. Each set of images was registered using the GPU-accelerated volume subdivision technique and the B-spline technique. Manual contouring of ROI was used only for the B-spline technique. Registration accuracies (Dice similarity coefficient [DSC] and 95% Hausdorff distance [HD]) and total processing time including contouring of ROIs and computation were compared using a paired Student t test. Accuracies of the GPU-accelerated registrations and B-spline registrations, respectively, were 88.3 ± 3.7% versus 89.3 ± 4.9% (P = .41) for DSC and 13.1 ± 5.2 versus 11.4 ± 6.3 mm (P = .15) for HD. Total processing time of the GPU-accelerated registration and B-spline registration techniques was 88 ± 14 versus 557 ± 116 seconds (P processing time. The GPU-accelerated volume subdivision technique may enable the implementation of nonrigid registration into routine clinical practice. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  16. A new irradiation unit constructed of self-moving gantry-CT and linac

    International Nuclear Information System (INIS)

    Kuriyama, Kengo; Onishi, Hiroshi; Sano, Naoki; Komiyama, Takafumi; Aikawa, Yoshihito; Tateda, Yoshihito; Araki, Tsutomu; Uematsu, Minoru

    2003-01-01

    Purpose: To improve reproducibility in stereotactic irradiation (STI) without using noninvasive immobilization devices or body frames, we have developed an integrated computed tomography (CT)-linac irradiation system connecting CT scanner and linac via a common treatment couch. Methods and Materials: This system consists of a linac, a CT scanner, and a common treatment couch. The linac and the CT gantry are positioned on opposite ends of the couch so that, by rotating the treatment couch, linac radiotherapy or CT scanning can be performed. The rotational axis of the linac gantry is coaxial with that of the CT gantry, and the position of the linac isocenter on the couch matches the origin of the coordinate system for CT scanning when the couch is rotated 180 degree sign toward the CT side. Instead of the couch moving into the gantry, as in conventional CT, in this case the table is fixed and scanning is accomplished by moving the gantry. We evaluated the rotational accuracy of the common couch and the scan-position accuracy of the self-moving gantry CT. Results: The positional accuracy of the common couch was 0.20, 0.18, and 0.39 mm in the lateral, longitudinal, and vertical directions, respectively. The scan-position accuracy of the CT gantry was less than 0.4 mm in the lateral, longitudinal, and vertical directions. Conclusion: This irradiation system has a high accuracy and is useful for noninvasive STI and for verification of the position of a target in three-dimensional conformal radiotherapy

  17. Size-appropriate radiation doses in pediatric body CT: a study of regional community adoption in the United States

    International Nuclear Information System (INIS)

    Hopkins, Katharine L.; Vajtai, Petra L.; Pettersson, David R.; Spinning, Kristopher; Beckett, Brooke R.; Koudelka, Caroline W.; Bardo, Dianna M.E.

    2013-01-01

    During the last decade, there has been a movement in the United States toward utilizing size-appropriate radiation doses for pediatric body CT, with smaller doses given to smaller patients. This study assesses community adoption of size-appropriate pediatric CT techniques. Size-specific dose estimates (SSDE) in pediatric body scans are compared between community facilities and a university children's hospital that tailors CT protocols to patient size as advocated by Image Gently. We compared 164 pediatric body scans done at community facilities (group X) with 466 children's hospital scans. Children's hospital scans were divided into two groups: A, 250 performed with established pediatric weight-based protocols and filtered back projection; B, 216 performed with addition of iterative reconstruction technique and a 60% reduction in volume CT dose index (CTDI vol ). SSDE was calculated and differences among groups were compared by regression analysis. Mean SSDE was 1.6 and 3.9 times higher in group X than in groups A and B and 2.5 times higher for group A than group B. A model adjusting for confounders confirmed significant differences between group pairs. Regional community hospitals and imaging centers have not universally adopted child-sized pediatric CT practices. More education and accountability may be necessary to achieve widespread implementation. Since even lower radiation doses are possible with iterative reconstruction technique than with filtered back projection alone, further exploration of the former is encouraged. (orig.)

  18. Size-appropriate radiation doses in pediatric body CT: a study of regional community adoption in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, Katharine L.; Vajtai, Petra L. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States); Pettersson, David R.; Spinning, Kristopher; Beckett, Brooke R. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Koudelka, Caroline W. [Oregon Health and Science University, Division of Biostatistics, Department of Public Health and Preventive Medicine, Portland, OR (United States); Bardo, Dianna M.E. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Oregon Health and Science University, Department of Cardiovascular Medicine, Portland, OR (United States)

    2013-09-15

    During the last decade, there has been a movement in the United States toward utilizing size-appropriate radiation doses for pediatric body CT, with smaller doses given to smaller patients. This study assesses community adoption of size-appropriate pediatric CT techniques. Size-specific dose estimates (SSDE) in pediatric body scans are compared between community facilities and a university children's hospital that tailors CT protocols to patient size as advocated by Image Gently. We compared 164 pediatric body scans done at community facilities (group X) with 466 children's hospital scans. Children's hospital scans were divided into two groups: A, 250 performed with established pediatric weight-based protocols and filtered back projection; B, 216 performed with addition of iterative reconstruction technique and a 60% reduction in volume CT dose index (CTDI{sub vol}). SSDE was calculated and differences among groups were compared by regression analysis. Mean SSDE was 1.6 and 3.9 times higher in group X than in groups A and B and 2.5 times higher for group A than group B. A model adjusting for confounders confirmed significant differences between group pairs. Regional community hospitals and imaging centers have not universally adopted child-sized pediatric CT practices. More education and accountability may be necessary to achieve widespread implementation. Since even lower radiation doses are possible with iterative reconstruction technique than with filtered back projection alone, further exploration of the former is encouraged. (orig.)

  19. Policy drivers and barriers for coal-to-liquids (CtL) technologies in the United States

    International Nuclear Information System (INIS)

    Vallentin, Daniel

    2008-01-01

    Because of a growing dependence on oil imports, powerful industrial, political and societal stakeholders in the United States are trying to enhance national energy security through the conversion of domestic coal into synthetic hydrocarbon liquid fuels-so-called coal-to-liquids (CtL) processes. However, because of the technology's high costs and carbon intensity, its market deployment is strongly affected by the US energy, technology and climate policy setting. This paper analyses and discusses policy drivers and barriers for CtL technologies in the United States and reaches the conclusion that an increasing awareness of global warming among US policy-makers raises the requirements for the technology's environmental performance and, thus, limits its potential to regional niche markets in coal-producing states or strategic markets, such as the military, with specific security and fuel requirements

  20. Hounsfield units variations: impact on CT-density based conversion tables and their effects on dose distribution.

    Science.gov (United States)

    Zurl, B; Tiefling, R; Winkler, P; Kindl, P; Kapp, K S

    2014-01-01

    Determination of dose error margins in radiation therapy planning due to variations in Hounsfield Units (HU) values dependent on the use of different CT scanning protocols. Based on a series of different CT scanning protocols used in clinical practice, conversion tables for radiation dose calculations were generated and subsequently tested on a phantom. These tables were then used to recalculate the radiation therapy plans of 28 real patients after an incorrect scanning protocol had inadvertently been used for these patients. Different CT parameter settings resulted in errors of HU values of up to 2.6% for densities of 1.1 g/cm(3). The largest errors were associated with changes in the tube voltage. Tests on a virtual water phantom with layers of variable thickness and density revealed a sawtooth-shaped curve for the increase of dose differences from 0.3 to 0.6% and 1.5% at layer thicknesses of 1, 3, and 7 cm, respectively. Use of a beam hardening filter resulted in a reference dose difference of 0.6% in response to a density change of 5%. The recalculation of data from 28 patients who received radiation therapy to the head revealed an overdose of 1.3 ± 0.4% to the bone and 0.7 ± 0.1% to brain tissue. On average, therefore, one monitor unit (range 0-3 MU) per 100 MU more than the correct dose had been given. Use of different CT scanning protocols leads to variations of up to 20% in the HU values. This can result in a mean systematic dose error of 1.5%. Specific conversion tables and automatic CT scanning protocol recognition could reduce dose errors of these types.

  1. Measurement of MV CT dose index for Hi-ART helical tomotherapy unit

    International Nuclear Information System (INIS)

    Wang Yunlai; Liao Xiongfei

    2010-01-01

    Objective: To evaluate the patient dose from Hi-ART MV helical CT imaging in image-guided radiotherapy. Methods: Weighted CT dose index (CTDI W ) was measured with PTW TM30009 CT ion chamber in head and body phantoms, respectively,for slice thicknesses of 2, 4, 6 mm with scanned range of 5 cm and 15 cm. Dose length products (DLP) were subsequently calculated. The CTDI W and DLP were compared with XVI kV CBCT and ACQSim simulator CT for routine clinical protocols. Results: An inverse relationship between CTDI and the slice thickness was found. The dose distribution was inhomogeneous owing to the attenuation of the couch. CTDI and DLP had close relationship with the slice thickness and the scanned range. Patient dose from MVCT was lower than XVI CBCT for head, but larger for body scan. Conclusions: CTDI W can be used to assess the patient dose in MV helical CT due to its simplicity for measurement and reproducibility. Regular measurement should be performed in QA and QC program. Appropriate slice thickness and scan range should be chosen to reduce the patient dose. (authors)

  2. Development and validation of a 3D-printed model of the ostiomeatal complex and frontal sinus for endoscopic sinus surgery training.

    Science.gov (United States)

    Alrasheed, Abdulaziz S; Nguyen, Lily H P; Mongeau, Luc; Funnell, W Robert J; Tewfik, Marc A

    2017-08-01

    Endoscopic sinus surgery poses unique training challenges due to complex and variable anatomy, and the risk of major complications. We sought to create and provide validity evidence for a novel 3D-printed simulator of the nose and paranasal sinuses. Sinonasal computed tomography (CT) images of a patient were imported into 3D visualization software. Segmentation of bony and soft tissue structures was then performed. The model was printed using simulated bone and soft tissue materials. Rhinologists and otolaryngology residents completed 6 prespecified tasks including maxillary antrostomy and frontal recess dissection on the simulator. Participants evaluated the model using survey ratings based on a 5-point Likert scale. The average time to complete each task was calculated. Descriptive analysis was used to evaluate ratings, and thematic analysis was done for qualitative questions. A total of 20 participants (10 rhinologists and 10 otolaryngology residents) tested the model and answered the survey. Overall the participants felt that the simulator would be useful as a training/educational tool (4.6/5), and that it should be integrated as part of the rhinology training curriculum (4.5/5). The following responses were obtained: visual appearance 4.25/5; realism of materials 3.8/5; and surgical experience 3.9/5. The average time to complete each task was lower for the rhinologist group than for the residents. We describe the development and validation of a novel 3D-printed model for the training of endoscopic sinus surgery skills. Although participants found the simulator to be a useful training and educational tool, further model development could improve the outcome. © 2017 ARS-AAOA, LLC.

  3. Evaluation of CT findings in patients with adult respiratory distress syndrome in intensive care unit

    International Nuclear Information System (INIS)

    Honda, Ryoichi; Yoshida, Kazuhiro; Sato, Morihito; Yoshida, Masashi; Ura, Nobuyuki; Kaneko, Masamitsu

    1996-01-01

    Computed tomographic (CT) findings of 19 critically ill patients with adult respiratory distress syndrome (ARDS) in ICU were analyzed retrospectively. ARDS was diagnosed according to Murray's criteria (Lung Injury Score> 2.5). The CT findings obtained were diffuse increased lung opacities [100%] (ground-glass opacity [100%] and air-space consolidation [74%]), lobular distributions of increased opacity [53%], loss of lung volume [53%], bronchiectasis and bronchioloectasis [42%] , fine reticular opacity [26%] and peribronchovascular distributions of increased density [11%]. Among those findings, diffuse increased lung opacities were seen in almost all patients. Especially ground-glass opacity was seen in all patients and distributed in the whole lung. Air-space consolidation was observed in 14 patients and involved mainly lower lung fields. Loss of lung volume and bronchiectasis and bronchioloectasis were likely to exist in the same area of air-space consolidation. Lobular distributions of increased opacity was seen in 10 patients without specific distribution. Those findings were thought to be relatively specific CT findings of ARDS. It is concluded that CT findings provide more information than bedside plain roentgenograms and was useful for clinical management of patients with ARDS. (author)

  4. Ultralow dose dentomaxillofacial CT imaging and iterative reconstruction techniques: variability of Hounsfield units and contrast-to-noise ratio

    Science.gov (United States)

    Bischel, Alexander; Stratis, Andreas; Kakar, Apoorv; Bosmans, Hilde; Jacobs, Reinhilde; Gassner, Eva-Maria; Puelacher, Wolfgang; Pauwels, Ruben

    2016-01-01

    Objective: The aim of this study was to evaluate whether application of ultralow dose protocols and iterative reconstruction technology (IRT) influence quantitative Hounsfield units (HUs) and contrast-to-noise ratio (CNR) in dentomaxillofacial CT imaging. Methods: A phantom with inserts of five types of materials was scanned using protocols for (a) a clinical reference for navigated surgery (CT dose index volume 36.58 mGy), (b) low-dose sinus imaging (18.28 mGy) and (c) four ultralow dose imaging (4.14, 2.63, 0.99 and 0.53 mGy). All images were reconstructed using: (i) filtered back projection (FBP); (ii) IRT: adaptive statistical iterative reconstruction-50 (ASIR-50), ASIR-100 and model-based iterative reconstruction (MBIR); and (iii) standard (std) and bone kernel. Mean HU, CNR and average HU error after recalibration were determined. Each combination of protocols was compared using Friedman analysis of variance, followed by Dunn's multiple comparison test. Results: Pearson's sample correlation coefficients were all >0.99. Ultralow dose protocols using FBP showed errors of up to 273 HU. Std kernels had less HU variability than bone kernels. MBIR reduced the error value for the lowest dose protocol to 138 HU and retained the highest relative CNR. ASIR could not demonstrate significant advantages over FBP. Conclusions: Considering a potential dose reduction as low as 1.5% of a std protocol, ultralow dose protocols and IRT should be further tested for clinical dentomaxillofacial CT imaging. Advances in knowledge: HU as a surrogate for bone density may vary significantly in CT ultralow dose imaging. However, use of std kernels and MBIR technology reduce HU error values and may retain the highest CNR. PMID:26859336

  5. CT characterization of inflammatory paranasal sinus disease in cystic fibrosis

    International Nuclear Information System (INIS)

    Eggesboe, H.B.

    2002-01-01

    Purpose: In patients with cystic fibrosis (CF) the prevalence of paranasal sinus affection approaches 100%. We hypothesized that the hyper viscous mucus reducing mucociliary clearance in CF patients could give sinonasal inflammatory patterns different from those in non-CF patients. We wanted to compare the extent and distribution of paranasal sinus disease and the inflammatory patterns in these two groups of patients. Material and Methods: One-hundred-and-eight CF patients (3-54 years old) and 79 controls (7-51 years old) with paranasal sinus disease confirmed at coronal CT were compared. The extent of disease was noted for each sinus and summed for all sinuses. Inflammatory patterns were identified and classified into: 1) routine surgery group (sporadic, infundibular and ostiomeatal complex (OMC) patterns) and 2) complex surgery group (sinonasal polyposis and sphenoethmoid recess (SER) patterns). Results: CF patients had more widespread sinonasal inflammatory changes and more advanced disease for each sinus. Most CF patients displayed sinonasal polyposis and SER patterns while most controls displayed sporadic, infundibular or OMC patterns. As a result, 67% of CF patients were classified to the complex surgery group, compared to only 19% of controls. Conclusion: The impaired mucociliary clearance in CF causes widespread inflammatory paranasal sinus disease, with inflammatory patterns more often requiring extensive surgery, with a higher risk of cerebrospinal fluid leak or bleeding, or involving areas that are more difficult to reach with the endoscope

  6. The CT (Hounsfield unit) number of brain tissue in healthy infants. A new reliable method for detection of possible degenerative disease.

    Science.gov (United States)

    Boris, P; Bundgaard, F; Olsen, A

    1987-01-01

    It is difficult to correlate CT Hounsfield unit (H. U.) numbers from one CT investigation to another and from one CT scanner to another, especially when dealing with small changes in the brain substance, as in degenerative brain diseases in children. By subtracting the mean value of cerebrospinal fluid (CSF) from the mean value of grey and white matter, it is possible to remove most of the errors due, for example, to maladjustments, short and long-term drift, X-ray fan, and detector asymmetry. Measurements of white and grey matter using these methods showed CT H. U. numbers changing from 15 H. U. to 22 H. U. in white matter and 23 H. U. to 30 H. U. in grey matter in 86 healthy infants aged 0-5 years. In all measurements, the difference between grey and white matter was exactly 8 H. U. The method has proven to be highly accurate and reproducible.

  7. Radiation Exposure to Staff in Intensive Care Unit with Portable CT Scanner

    Directory of Open Access Journals (Sweden)

    Zhichao Xie

    2016-01-01

    Full Text Available Background. Bedside radiological procedures pose a risk of radiation exposure to ICU staff. The perception of risk may increase the degree of caution among the health care staff and raise new barriers preventing patients from obtaining prompt care. Objective. The aim of this study was to estimate the annual cumulative radiation dose to individual ICU staff. Methods. In this prospective study, forty subjects were required to wear thermoluminescent dosimeter badges during their working hours. The badges were analyzed to determine the exposure after 3 months. Results. A total of 802 radiological procedures were completed at bedside during the study period. The estimated annual dosage to doctors and nurses on average was 0.99 mSv and 0.88 mSv (p<0.001, respectively. Residents were subjected to the highest radiation exposure (1.04 mSv per year, p=0.002. The radiation dose was correlated with day shift working hours (r=0.426; p=0.006 and length of service (r=-0.403; p<0.01. Conclusions. With standard precautions, bedside radiological procedures—including portable CT scans—do not expose ICU staff to high dose of ionizing radiation. The level of radiation exposure is related to the daytime working hours and length of service.

  8. TU-H-207A-03: CT Hounsfield Unit Accuracy: Effect of Beam Hardening On Phantom and Clinical Whole-Body CT Images

    Energy Technology Data Exchange (ETDEWEB)

    Ai, H; Wendt, R [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To assess the effect of beam hardening on measured CT HU values. Methods: An anthropomorphic knee phantom was scanned with the CT component of a GE Discovery 690 PET/CT scanner (120kVp, 300mAs, 40?0.625mm collimation, pitch=0.984, FOV=500mm, matrix=512?512) with four different scan setups, each of which induces different degrees of beam hardening by introducing additional attenuation media into the field of view. Homogeneous voxels representing “soft tissue” and “bone” were segmented by HU thresholding followed by a 3D morphological erosion operation which removes the non-homogenous voxels located on the interface of thresholded tissue mask. HU values of segmented “soft tissue” and “bone” were compared.Additionally, whole-body CT data with coverage from the skull apex to the end of toes were retrospectively retrieved from seven PET/CT exams to evaluate the effect of beam hardening in vivo. Homogeneous bone voxels were segmented with the same method previously described. Total In-Slice Attenuation (TISA) for each CT slice, defined as the summation of HU values over all voxels within a CT slice, was calculated for all slices of the seven whole-body CT datasets and evaluated against the mean HU values of homogeneous bone voxels within that slice. Results: HU values measured from the phantom showed that while “soft tissue” HU values were unaffected, added attenuation within the FOV caused noticeable decreases in the measured HU values of “bone” voxels. A linear relationship was observed between bone HU and TISA for slices of the torso and legs, but not of the skull. Conclusion: Beam hardening effect is not an issue of concern for voxels with HU in the soft tissue range, but should not be neglected for bone voxels. A linear relationship exists between bone HU and the associated TISA in non-skull CT slices, which can be exploited to develop a correction strategy.

  9. Combining Mean and Standard Deviation of Hounsfield Unit Measurements from Preoperative CT Allows More Accurate Prediction of Urinary Stone Composition Than Mean Hounsfield Units Alone.

    Science.gov (United States)

    Tailly, Thomas; Larish, Yaniv; Nadeau, Brandon; Violette, Philippe; Glickman, Leonard; Olvera-Posada, Daniel; Alenezi, Husain; Amann, Justin; Denstedt, John; Razvi, Hassan

    2016-04-01

    The mineral composition of a urinary stone may influence its surgical and medical treatment. Previous attempts at identifying stone composition based on mean Hounsfield Units (HUm) have had varied success. We aimed to evaluate the additional use of standard deviation of HU (HUsd) to more accurately predict stone composition. We identified patients from two centers who had undergone urinary stone treatment between 2006 and 2013 and had mineral stone analysis and a computed tomography (CT) available. HUm and HUsd of the stones were compared with ANOVA. Receiver operative characteristic analysis with area under the curve (AUC), Youden index, and likelihood ratio calculations were performed. Data were available for 466 patients. The major components were calcium oxalate monohydrate (COM), uric acid, hydroxyapatite, struvite, brushite, cystine, and CO dihydrate (COD) in 41.4%, 19.3%, 12.4%, 7.5%, 5.8%, 5.4%, and 4.7% of patients, respectively. The HUm of UA and Br was significantly lower and higher than the HUm of any other stone type, respectively. HUm and HUsd were most accurate in predicting uric acid with an AUC of 0.969 and 0.851, respectively. The combined use of HUm and HUsd resulted in increased positive predictive value and higher likelihood ratios for identifying a stone's mineral composition for all stone types but COM. To the best of our knowledge, this is the first report of CT data aiding in the prediction of brushite stone composition. Both HUm and HUsd can help predict stone composition and their combined use results in higher likelihood ratios influencing probability.

  10. Hounsfield Units ranges in CT-scans of bog bodies and mummies

    DEFF Research Database (Denmark)

    Villa, Chiara; Lynnerup, Niels

    2012-01-01

    Mummification processes, either artificial or natural, preserve the tissues from postmortem decay, but change them from their original state. In this study we provided the first comprehensive set of Hounsfield Unit (HU) ranges specific for tissues mummified under different environmental conditions...... (peat bog, cold-dry and hot-dry environment). We also analyzed the impact of different museal preservation techniques on the HU ranges, as e.g. in the Tollund Man and Grauballe Man, two bog bodies from Denmark. The HU results for mummies were compared with HU results from forensic cases, cremated...

  11. Coronary artery calcification detected by a mobile helical CT unit in a mass screening. The frequency and relationship to coronary risk factors and coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Itani, Yasutaka; Watanabe, Shigeru; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine; Hanamura, Kazuhisa; Asakura, Kazuhiro; Sone, Shusuke; Sunami, Yuko; Shimura, Akimitsu; Miyamoto, Tadaaki

    2001-06-01

    A strong relationship is known to exist between coronary artery disease (CAD) and coronary artery calcification (CAC) detected by CT. In this study, we investigated the frequency of CAC and the relationship between coronary risk factors, CAD and CAC in a mass screening using a mobile helical CT unit. The total number of participants was 10008 people undergoing a medical examination for lung cancer and tuberculosis using a mobile helical CT unit. We measured the CT density of the coronary artery to detect CAC. The CT density threshold for determining CAC was above +110HU. The frequency of CAC was 16.0% in the overall patient population and significantly higher in males than in females (20.6% vs 10.7%). Frequency increased with age in both genders. Hypertension and diabetes mellitus were significantly related to CAC. Smoking showed a correlation with CAC only in males. A significant relationship was observed between CAD and CAC in males. In particular, the relationship between them was strongest in males under 60 years of age. Furthermore, the odds ratio of CAC in predicting CAD increased with increasing risk factors in both genders. (author)

  12. Hounsfield unit recovery in clinical cone beam CT images of the thorax acquired for image guided radiation therapy

    DEFF Research Database (Denmark)

    Thing, Rune Slot; Bernchou, Uffe; Mainegra-Hing, Ernesto

    2016-01-01

    -correspondence with the planning CT images, and total volume HU error. Artefacts are reduced and CT-like HUs are recovered in the artefact corrected CBCT images. Visual inspection confirms that artefacts are indeed suppressed by the proposed method, and the HU root mean square difference between reconstructed CBCTs...

  13. Absorbed dose in CT. Comparison by CT dose index

    International Nuclear Information System (INIS)

    Yamamoto, Kenji; Akazawa, Hiroshi; Andou, Takashi

    2002-01-01

    Few reports have discussed the absorbed dose on CT units with increased scanning capacity even with the current widespread adoption of multi-slice CT units. To compare and investigate the dose indexes among CT units, we measured the absorbed dose on CT units operating in Nagano Prefecture Japan. The measurements showed proportionality between phantom absorbed dose and the exposured mAs values in conventional scanning operation. Further, the measurements showed that the absorbed dose in the center of the phantom differed by about 2.1-fold between the highest and lowest levels on individual CT units. Within a single company, multi-slice CT units of the same company gave absorbed doses of about 1.3 to 1.5 times those of conventional single-slice CT units under the same exposured conditions of conventional scanning. When the scanning pitch was reduced in helical scanning, the absorbed dose at the center of the phantom increased. (author)

  14. Identification of infusion strategy for achieving repeatable nanoparticle distribution and quantification of thermal dosage using micro-CT Hounsfield unit in magnetic nanoparticle hyperthermia.

    Science.gov (United States)

    LeBrun, Alexander; Joglekar, Tejashree; Bieberich, Charles; Ma, Ronghui; Zhu, Liang

    2016-01-01

    The objective of this study was to identify an injection strategy leading to repeatable nanoparticle deposition patterns in tumours and to quantify volumetric heat generation rate distribution based on micro-CT Hounsfield unit (HU) in magnetic nanoparticle hyperthermia. In vivo animal experiments were performed on graft prostatic cancer (PC3) tumours in immunodeficient mice to investigate whether lowering ferrofluid infusion rate improves control of the distribution of magnetic nanoparticles in tumour tissue. Nanoparticle distribution volume obtained from micro-CT scan was used to evaluate spreading of the nanoparticles from the injection site in tumours. Heating experiments were performed to quantify relationships among micro-CT HU values, local nanoparticle concentrations in the tumours, and the ferrofluid-induced volumetric heat generation rate (q(MNH)) when nanoparticles were subject to an alternating magnetic field. An infusion rate of 3 µL/min was identified to result in the most repeatable nanoparticle distribution in PC3 tumours. Linear relationships have been obtained to first convert micro-CT greyscale values to HU values, then to local nanoparticle concentrations, and finally to nanoparticle-induced q(MNH) values. The total energy deposition rate in tumours was calculated and the observed similarity in total energy deposition rates in all three infusion rate groups suggests improvement in minimising nanoparticle leakage from the tumours. The results of this study demonstrate that micro-CT generated q(MNH) distribution and tumour physical models improve predicting capability of heat transfer simulation for designing reliable treatment protocols using magnetic nanoparticle hyperthermia.

  15. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine ... CT scans should have no immediate side effects. Risks The risk of serious allergic reaction to contrast ...

  16. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  17. Why Caldwell-Luc and nasoantral window procedures fail in patients with chronic sinusitis

    International Nuclear Information System (INIS)

    Zinreich, S.J.; Kennedy, D.W.; Rosenbaum, A.E.; Kumar, A.J.; Stammberger, H.

    1986-01-01

    CT was performed on 80 patients with recurrent symptoms of chronic sinusitis after Caldwell-Luc and/or nasoantral window procedures. In each case there was anterior ethmoid sinus inflammatory disease with obstruction of the normal ipsilateral maxillary sinus drainage, the ostiomeatal unit. When the ipsilateral frontal sinus was also diseased, the anterior ethmoid sinus inflammatory process was found to block the frontal recess. These findings indicate that patients who have chronic sinusitis after Caldwell-Luc and/or nasoantral window procedures fail because of persistent disease. The disease is characteristically situated in the anterior ethmoid cells, with blockage of mucociliary clearance from the maxillary and frontal sinuses. Therefore, the cure is predicated on surgical procedures directed to restoring patency of the ostiomeatal unit and frontal recess

  18. Tuberculous peritonitis: CT appearance

    International Nuclear Information System (INIS)

    Hanson, R.D.; Hunter, T.B.

    1985-01-01

    Rare, sporadic cases of tuberculous peritonitis do occur in the United States and other advanced countries. Because there are few descriptions of the CT appearance of the peritoneal forms of tuberculous (TB), this report illustrates a case of tuberculous peritonitis with prominent CT findings and discusses the differentiation of this entity from other, more common diseases

  19. Clinical characteristics of patients with diabetes mellitus and fatty liver diagnosed by liver/spleen Hounsfield units on CT scan

    OpenAIRE

    Sakitani, Kosuke; Enooku, Kenichiro; Kubo, Hirokazu; Tanaka, Akifumi; Arai, Hisakatsu; Kawazu, Shoji; Koike, Kazuhiko

    2017-01-01

    Objective The leading cause of liver injuries in diabetes mellitus may be associated with fatty liver. We aimed to elucidate the relationship between fatty liver and diabetes characteristics. Methods Retrospectively, 970 patients with diabetes were analysed. Fatty liver was diagnosed when the liver/spleen Hounsfield unit ratio by computed tomography was below 0.9. Clinical diabetes characteristics were compared between patients with and without fatty liver. Results Of 970 patients (717 male a...

  20. SU-E-T-161: Characterization and Validation of CT Simulator Hounsfield Units to Relative Stopping Power Values for Proton Treatment Planning

    International Nuclear Information System (INIS)

    Schnell, E; Ahmad, S; De La Fuente Herman, T

    2015-01-01

    Purpose: To develop a calibration curve that includes and minimizes the variations of Hounsfield Unit (HU) from a CT scanner to Relative Stopping Power (RSP) of tissues along the proton beam path. The variations are due to scanner and proton energy, technique, phantom size and placement, and tissue arrangement. Methods: A CIRS 062 M phantom with 10 plugs of known relative electron density (RED) was scanned through a 16 slice GE Discovery CT Simulator scanner. Three setup combinations of plug distributions and techniques clinically implemented for five treatment regions were scanned with energies of 100, 120, and 140 kV. Volumetric HU values were measured for each plug and scan. The RSP values derived through the Bethe-Bloch formula are currently being verified with parallel-plate ionization chamber measurements in water using 80, 150, and 225 MeV proton beam. Typical treatment plans for treatment regions of brain, head-&-neck, chest, abdomen, and pelvis are being planned and dose delivered will be compared with film and Optically Stimulated Luminescence (OSL) measurements. Results: Percentage variations were determined for each variable. For tissues close to water, variations were <1% from any given parameter. Tissues far from water equivalence (lung and bone) showed the greatest sensitivity to change (7.4% maximum) with scanner energy and up to 5.3% with positioning of the phantom. No major variations were observed for proton energies within the treatment range. Conclusion: When deriving a calibration curve, attention should be placed to low and high HU values. A thorough verification process of calculated vs. water-phantom measured RSP values at different proton energies, followed by dose validation of planned vs. measured doses in phantom with film and OSL detectors are currently being undertaken

  1. Clinical characteristics of patients with diabetes mellitus and fatty liver diagnosed by liver/spleen Hounsfield units on CT scan.

    Science.gov (United States)

    Sakitani, Kosuke; Enooku, Kenichiro; Kubo, Hirokazu; Tanaka, Akifumi; Arai, Hisakatsu; Kawazu, Shoji; Koike, Kazuhiko

    2017-06-01

    Objective The leading cause of liver injuries in diabetes mellitus may be associated with fatty liver. We aimed to elucidate the relationship between fatty liver and diabetes characteristics. Methods Retrospectively, 970 patients with diabetes were analysed. Fatty liver was diagnosed when the liver/spleen Hounsfield unit ratio by computed tomography was below 0.9. Clinical diabetes characteristics were compared between patients with and without fatty liver. Results Of 970 patients (717 male and 253 female; mean age 64.4 years), 175 males (24.4%) and 60 females (23.7%) had fatty liver. None of the 28 patients with type 1 diabetes had fatty liver. In male patients with type 2 diabetes, age, visceral adipose tissue (VAT), albumin, alanine amino-transferase (ALT), and triglycerides were independently associated with fatty liver. In females, age and bilirubin were associated with fatty liver. Conclusions Fatty liver is associated with type 2 diabetes characteristics, including younger age and elevated VAT, albumin, ALT, and triglycerides in males and younger age and elevated bilirubin levels in females.

  2. Clinical characteristics of patients with diabetes mellitus and fatty liver diagnosed by liver/spleen Hounsfield units on CT scan

    Science.gov (United States)

    Sakitani, Kosuke; Enooku, Kenichiro; Kubo, Hirokazu; Tanaka, Akifumi; Arai, Hisakatsu; Kawazu, Shoji; Koike, Kazuhiko

    2017-01-01

    Objective The leading cause of liver injuries in diabetes mellitus may be associated with fatty liver. We aimed to elucidate the relationship between fatty liver and diabetes characteristics. Methods Retrospectively, 970 patients with diabetes were analysed. Fatty liver was diagnosed when the liver/spleen Hounsfield unit ratio by computed tomography was below 0.9. Clinical diabetes characteristics were compared between patients with and without fatty liver. Results Of 970 patients (717 male and 253 female; mean age 64.4 years), 175 males (24.4%) and 60 females (23.7%) had fatty liver. None of the 28 patients with type 1 diabetes had fatty liver. In male patients with type 2 diabetes, age, visceral adipose tissue (VAT), albumin, alanine amino-transferase (ALT), and triglycerides were independently associated with fatty liver. In females, age and bilirubin were associated with fatty liver. Conclusions Fatty liver is associated with type 2 diabetes characteristics, including younger age and elevated VAT, albumin, ALT, and triglycerides in males and younger age and elevated bilirubin levels in females. PMID:28553763

  3. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive ...

  4. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children is faster than the older CT scanners, reducing the need for sedation and general anesthesia. New technologies that will make even faster scanning possible ...

  5. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children is faster than the older CT scanners, reducing the need for sedation and general anesthesia. New technologies that will make even faster scanning possible are ...

  6. SU-F-T-215: An Investigation Of Multi-Scanner CT Hounsfield Unit Calibration for Pencil Beam Scanning Proton Therapy Using 3D Gamma Analysis

    International Nuclear Information System (INIS)

    Zhang, J; Li, X; Liu, G; Liu, Q; Liang, J; Ding, X

    2016-01-01

    Purpose: We compare and investigate the dosimetric impacts on pencil beam scanning (PBS) proton treatment plans generated with CT calibration curves from four different CT scanners and one averaged ‘global’ CT calibration curve. Methods: The four CT scanners are located at three different hospital locations within the same health system. CT density calibration curves were collected from these scanners using the same CT calibration phantom and acquisition parameters. Mass density to HU value tables were then commissioned in a commercial treatment planning system. Five disease sites were chosen for dosimetric comparisons at brain, lung, head and neck, adrenal, and prostate. Three types of PBS plans were generated at each treatment site using SFUD, IMPT, and robustness optimized IMPT techniques. 3D dose differences were investigated using 3D Gamma analysis. Results: The CT calibration curves for all four scanners display very similar shapes. Large HU differences were observed at both the high HU and low HU regions of the curves. Large dose differences were generally observed at the distal edges of the beams and they are beam angle dependent. Out of the five treatment sites, lung plans exhibits the most overall range uncertainties and prostate plans have the greatest dose discrepancy. There are no significant differences between the SFUD, IMPT, and the RO-IMPT methods. 3D gamma analysis with 3%, 3 mm criteria showed all plans with greater than 95% passing rate. Two of the scanners with close HU values have negligible dose difference except for lung. Conclusion: Our study shows that there are more than 5% dosimetric differences between different CT calibration curves. PBS treatment plans generated with SFUD, IMPT, and the robustness optimized IMPT has similar sensitivity to the CT density uncertainty. More patient data and tighter gamma criteria based on structure location and size will be used for further investigation.

  7. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... benefits vs. risks? Benefits Using a multidetector CT unit to examine children is faster than the older ... clearly needed. Another strategy is to consider other tests, such as MRI or ultrasound which might give ...

  8. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... that will provide the needed diagnostic information. The benefit of an accurate diagnosis far outweighs the risk. ...

  9. CT pelvimetry

    International Nuclear Information System (INIS)

    Vicens, J.L.; Charles, G.; Le Berre, J.; Flageat, J.

    1989-01-01

    Pelvimetry aims at providing the obstetrician with information on the size and morphology of the female pelvis, thus enabling him to assess the obstetrical prognosis as accurately as possible. Computed tomography (CT) has several advantages, in particular the lower mother and fetus radiation dose. After a brief description of obstetrical anatomy, the usual CT exploration method is presented and its results are considered in terms of measurements, indices and morphological findings. If performed with a very strict exploration procedure, CT pelvimetry is a very reliable, fact and comfortable method of examination. All these advantages, combined with the minimized patient dose, should lead to an increasingly widespread use of this technique [fr

  10. CT Scan

    Science.gov (United States)

    ... disease, lung nodules and liver masses Monitor the effectiveness of certain treatments, such as cancer treatment Detect ... scan done in a hospital or an outpatient facility. CT scans are painless and, with newer machines, ...

  11. Thoracic CT

    Science.gov (United States)

    ... through a vein (IV) in your hand or forearm. It may be given through the rectum using ... CT scan Vertebra, thoracic (mid back) Normal lung anatomy Thoracic organs References Gotway MB, Panse PM, Gruden ...

  12. CT Enterography

    Science.gov (United States)

    ... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... other medical conditions, and if you have a history of heart disease, asthma, diabetes, kidney disease or ...

  13. Helical CT defecography

    International Nuclear Information System (INIS)

    Ferrando, R.; Fiorini, G.; Beghello, A.; Cicio, G.R.; Derchi, L.E.; Consigliere, M.; Resasco, M.; Tornago, S.

    1999-01-01

    The purpose of this work is to investigate the possible role of Helical CT defecography in pelvic floor disorders by comparing the results of the investigations with those of conventional defecography. The series analyzed consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with Helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; it is used a remote-control unit. The parameters for Helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 m As and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images. Coronal Helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, Helical CT defecography performed well in study of pelvic floor disorders and can follow conventional defecography especially in questionable cases [it

  14. CT-docking patient stretcher

    International Nuclear Information System (INIS)

    Mirvis, S.E.; Owens, E.; Maslyn, J.; Rizutto, M.

    1990-01-01

    This paper assesses the use of a patient stretcher that directly docks to a CT scanner for acutely injured and/or critically ill patients. The stretcher permits performance of radiography and acts as a platform for critical care monitoring and patient support devices. During a 1-year period, the prototype CT-docking stretcher was used for 35 patients sustaining acute trauma and 25 patients from critical care units. Observations were elicited from physicians, nurses and technologists concerning the advantages or disadvantages of the docking stretcher. Advantages of the CT-docking stretcher included time saved in moving patients to the CT table from the admitting/emergency ward, transfer of critically ill patients onto the stretcher in the controlled environment of the intensive care unit rather than the CT suite, increasing CT throughput by direct docking of the patient stretcher to the CT scanner rather than manual transfer of complex support and monitoring devices with the patient, decreased risk associated with physical movement of patients with potentially unstable spinal injuries or unstable physiologic status, and decrease in potential for injury to medical personnel performing patient transfer

  15. Estimation of the exposure and a risk-benefit analysis for a CT system designed for a lung cancer mass screening unit

    International Nuclear Information System (INIS)

    Nishizawa, K.; Matsumoto, T.; Sakashita, K.; Tateno, Y.; Miyamoto, T.; Iwai, K.; Shimura, A.; Takagi, H.

    1996-01-01

    Organ or tissue doses from examination by a computed tomography system called LSCT were determined by in-phantom measurement. LSCT has been developed for lung cancer screening, with spiral scanning capability. Dose measurements were performed under the actual screening conditions of the chest CT examination. The effective dose recommended by ICRP 60 was evaluated using the organ or tissue doses. Risk-benefit analysis in the LSCT screening was also performed. The resultant effective dose per LSCT examination was 3.6 mSv and surface dose was 7.6 mGy. It was half to a third lower than the doses by traditional CT systems. The risk-benefit analysis of LSCT showed that the benefit will exceed the risk for Japanese over forty years for men and over forty-five for women. (Author)

  16. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  17. Concerted evolution of the tandemly repeated genes encoding primate U2 small nuclear RNA (the RNU2 locus) does not prevent rapid diversification of the (CT){sub n} {center_dot} (GA){sub n} microsatellite embedded within the U2 repeat unit

    Energy Technology Data Exchange (ETDEWEB)

    Liao, D.; Weiner, A.M. [Yale Univ., New Haven, CT (United States)

    1995-12-10

    The RNU2 locus encoding human U2 small nuclear RNA (snRNA) is organized as a nearly perfect tandem array containing 5 to 22 copies of a 5.8-kb repeat unit. Just downstream of the U2 snRNA gene in each 5.8-kb repeat unit lies a large (CT){sub n}{center_dot}(GA){sub n} dinucleotide repeat (n {approx} 70). This form of genomic organization, in which one repeat is embedded within another, provides an unusual opportunity to study the balance of forces maintaining the homogeneity of both kinds of repeats. Using a combination of field inversion gel electrophoresis and polymerase chain reaction, we have been able to study the CT microsatellites within individual U2 tandem arrays. We find that the CT microsatellites within an RNU2 allele exhibit significant length polymorphism, despite the remarkable homogeneity of the surrounding U2 repeat units. Length polymorphism is due primarily to loss or gain of CT dinucleotide repeats, but other types of deletions, insertions, and substitutions are also frequent. Polymorphism is greatly reduced in regions where pure (CT){sub n} tracts are interrupted by occasional G residues, suggesting that irregularities stabilize both the length and the sequence of the dinucleotide repeat. We further show that the RNU2 loci of other catarrhine primates (gorilla, chimpanzee, ogangutan, and baboon) contain orthologous CT microsatellites; these also exhibit length polymorphism, but are highly divergent from each other. Thus, although the CT microsatellite is evolving far more rapidly than the rest of the U2 repeat unit, it has persisted through multiple speciation events spanning >35 Myr. The persistence of the CT microsatellite, despite polymorphism and rapid evolution, suggests that it might play a functional role in concerted evolution of the RNU2 loci, perhaps as an initiation site for recombination and/or gene conversion. 70 refs., 5 figs.

  18. Optimum size of a calibration phantom for x-ray CT to convert the Hounsfield units to stopping power ratios in charged particle therapy treatment planning.

    Science.gov (United States)

    Inaniwa, T; Tashima, H; Kanematsu, N

    2018-03-01

    In charged-particle therapy treatment planning, the volumetric distribution of stopping power ratios (SPRs) of body tissues relative to water is used for patient dose calculation. The distribution is conventionally obtained from computed tomography (CT) images of a patient using predetermined conversion functions from the CT numbers to the SPRs. One of the biggest uncertainty sources of patient SPR estimation is insufficient correction of beam hardening arising from the mismatch between the size of the patient cross section and the calibration phantom for producing the conversion functions. The uncertainty would be minimized by selecting a suitable size for the cylindrical water calibration phantom, referred to as an 'effective size' of the patient cross section, Leffective. We investigated the Leffective for pelvis, abdomen, thorax, and head and neck regions by simulating an ideal CT system using volumetric models of the reference male and female phantoms. The Leffective values were 23.3, 20.3, 22.7 and 18.8 cm for the pelvis, abdomen, thorax, and head and neck regions, respectively, and the Leffective for whole body was 21.0 cm. Using the conversion function for a 21.0-cm-diameter cylindrical water phantom, we could reduce the root mean square deviation of the SPRs and their mean deviation to ≤0.011 and ≤0.001, respectively, in the whole body. Accordingly, for simplicity, the effective size of 21.0 cm can be used for the whole body, irrespective of body-part regions for treatment planning in clinical practice.

  19. CT cystography

    International Nuclear Information System (INIS)

    Tsili, A.

    2012-01-01

    Full text: Cancer of the urinary bladder is one of the commonest urothelial neoplasms. Conventional cystoscopy remains the mainstay in the diagnosis of urinary bladder carcinomas. But it is an invasive and uncomfortable procedure, associated with complications. Computed tomographic (CT) virtual cystoscopy has been proposed as an alternative imaging modality with potential advantages in the detection of urinary bladder neoplasms and good patient acceptance. It is a minimally invasive technique, allowing imaging of the urinary bladder in multiple planes and a 360 0 view. CT cystoscopy provides information about the location, size and morphologic features of urinary bladder lesions, indicating appropriate areas for biopsy. It can be performed in cases in which conventional cystoscopy is not feasible, such as in the presence of urethral strictures, marked prostatic hypertrophy or active bleeding, and in cases in which cystoscopic findings are inconclusive. The technique can be used to evaluate areas of the urinary bladder difficult to evaluate with cystoscopy, such as the anterior bladder neck and narrowmouthed diverticula. Finally, virtual cystoscopy provides both intraluminal and extraluminal pathologic changes, so intravesical disease and exrtavesical extension can be evaluated in the same study. One of the limitations of this technique is the difficulty to demonstrate small-sized lesions. The introduction of multi-detector row CT (MDCT) scanners was a major technological advancement because among other things it substantially improves z-axis resolution by reducing section collimation and allowing the detection of very small lesions. The near isotropic or isotropic pixels achieved with a multidetector CT scanner, enable the creation of multiplanar reformatted images with a resolution very close to that of the axial images and three-dimensional (3D) renderings of outstanding quality. Transverse, multiplanar reformations and virtual endoscopic images are complementary

  20. Cardiac CT

    International Nuclear Information System (INIS)

    Dewey, Marc

    2011-01-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  1. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  2. CT of the neonatal head

    International Nuclear Information System (INIS)

    Mohan, S.; Rogan, E.A.; Batty, R.; Raghavan, A.; Whitby, E.H.; Hart, A.R.; Connolly, D.J.A.

    2013-01-01

    Computed tomography (CT) is used less often than other techniques on neonatal units. However, in the acute setting, CT can be invaluable in diagnosing or excluding potentially life-threatening conditions and guiding initial management in neonates. Common indications for scanning include trauma, suspected non-accidental injury, infection, or an acute hypoxic or metabolic event. The aim of this review is to provide an overview of the normal neonatal head at CT and compare this to the common pathological abnormalities. Several key features of each condition will be highlighted. It is important to note that some pathological conditions can have overlapping features at CT and, therefore, the clinical history and additional investigations are also of key importance in determining the diagnosis

  3. CT-Urography; Urografia CT

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Palma, Ludovico; Grotto, Maurizio [Trieste Univ., Trieste (Italy). Dipartimento di scienze cliniche, morfologiche e tecnologiche, UCO di radiologia; Morra, Aldo [CRO, Aviano (Italy). Reparto di radiologia

    2005-09-15

    In this paper we present an overview of CT-Urography. With the advent of multislice CT scanners and the evolution of image processing methods this technique now affords optimal urographic images comparable to those obtained with conventional techniques. We describe the acquisition techniques and protocols used by the various authors. Effective radiation dose has conditioned the use of CT-Urography so that the tendency today is to reduce the number of scans by performing, after the non enhanced scan, a single contrast-enhanced scan comprising both the nephrographic and urographic phase. With the use of multislice CT the quality of the urogram improves with the number of slices. We illustrate a variety of processing techniques, multiplanar reconstruction (MPR), maximum (MIP) and average intensity projection (AIP) and volume rendering (VR) and present a series of upper urinary tract tumours testifying to the superiority of the AIP technique over MIP. We then review the results of comparative studies of CT-Urography with conventional urography in upper urinary tract diagnostics. Finally, we describe the advantages and limitations of CT-Urography. [Italian] Gli Autori presentano una panoramica sulla Urografia TC (Uro TC). L'avvento della TC multistrato e l'evoluzione delle tecniche di elaborazione consentono di ottenere dei quadri urografici ottimali comparativi con quelli convenzionali. Vengono ricordate le varie tecniche di acquisizione e i protocolli usati dai vari Autori. La dose effettiva di radiazioni ha rappresentato uno dei fattori condizionanti per cui oggi prevale l'orientamento di ridurre il numero di scansioni, considerando dopo la scansione senza mezzo di contrasto un'unica scansione contrasto grafica comprendente sia la fase nefrografica che quella urografica. Con l'uso della TC multistrato la qualita dell'urogramma migliora con l'aumento del numero degli strati. Vengono descritte le varie tecniche di elaborazione, la

  4. Functional CT of the kidney

    International Nuclear Information System (INIS)

    Tsushima, Yoshito.

    1999-01-01

    The iodinated contrast agents used for computed tomography (CT) are filtered at the glomerulus and not reabsorbed by the tubules and have pharmacokinetics comparable to inulin. They can thus measure physiological indices such as contrast clearance per unit volume, which is closely related to glomerular filtration rate per unit renal volume of kidney, after due allowance for the difference between blood and plasma clearance. In this review, we show how dynamic CT can be used to measure both regional and global blood clearance of contrast material. A single slice of kidney is scanned sequentially after bolus intravenous (i.v.) injection of contrast material. Next, time-attenuation curves are constructed and contrast clearance per unit volume is calculated using a Patlak graphical analysis. CT determination of renal volume is made and global contrast clearance can be then also calculated. In normal kidneys, clearance/volume averaged 0.49±0.11 ml min -1 ml -1 (mean ±S.D.), and these values agreed with literature data obtained using other techniques. A negative correlation between patient's age and clearance/volume was seen. A strong correlation was observed between creatinine whole blood clearance and the global contrast clearance (the product of renal volume determined by CT and contrast clearance/volume). Dynamic CT can provide quantitative renal physiological information on a regional basis non-invasively

  5. Functional CT of the kidney

    Energy Technology Data Exchange (ETDEWEB)

    Tsushima, Yoshito. E-mail: yoshito@xa2.so-net.ne.jp

    1999-06-01

    The iodinated contrast agents used for computed tomography (CT) are filtered at the glomerulus and not reabsorbed by the tubules and have pharmacokinetics comparable to inulin. They can thus measure physiological indices such as contrast clearance per unit volume, which is closely related to glomerular filtration rate per unit renal volume of kidney, after due allowance for the difference between blood and plasma clearance. In this review, we show how dynamic CT can be used to measure both regional and global blood clearance of contrast material. A single slice of kidney is scanned sequentially after bolus intravenous (i.v.) injection of contrast material. Next, time-attenuation curves are constructed and contrast clearance per unit volume is calculated using a Patlak graphical analysis. CT determination of renal volume is made and global contrast clearance can be then also calculated. In normal kidneys, clearance/volume averaged 0.49{+-}0.11 ml min{sup -1} ml{sup -1} (mean {+-}S.D.), and these values agreed with literature data obtained using other techniques. A negative correlation between patient's age and clearance/volume was seen. A strong correlation was observed between creatinine whole blood clearance and the global contrast clearance (the product of renal volume determined by CT and contrast clearance/volume). Dynamic CT can provide quantitative renal physiological information on a regional basis non-invasively.

  6. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  7. CT features of appendiceal mucocele

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Won Jong; Byun, Jae Young; Jung, Jung Im; Lee, Hae Gyu; Park, Young Ha; Shin, Kyung Sub [Catholic University Medical College, Seoul (Korea, Republic of)

    1995-10-15

    To evaluate the usefulness of CT features of appendiceal mucocele in the diagnosis and evaluation of complications. We retrospectively reviewed CT findings and compared with operative findings in 7 cases of pathologically proven appendiceal mucocele. CT findings such as location and extent of the lesion, tissue density, thickness or calcification of the wall, presence of adjacent inflammatory infiltration, and visualization of normal vermiform appendix were analyzed. Appendiceal mucocele was found as homogeneous low density cystic mass adjacent to the cecum, which has no surrounding inflammatory infiltration except in one case of perforation and one case of intussusception. Mean CT number measured in 4 cases was 21 Hounsfield unit. Thin curvilinear calcifications were noted along the cystic wall in 2 cases. Normal vermiform appendix couldn't be demonstrated in all cases. Appendiceal mucocele is characterized by homogeneously low density and thin walled cystic tumor adjacent to cecum without surrounding inflammatory infiltration, and absence of normal vermiform appendix on CT. Therefore, CT is valuable in preventing operative complications of appendiceal mucocele.

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... are the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed ... nasal cavity by small openings. top of page What are some common uses of the procedure? CT ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder ...

  11. Abdominal and Pelvic CT

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  14. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special ... the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen and pelvis is a ... is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a CT or CAT ...

  17. SU-G-IeP2-12: The Effect of Iterative Reconstruction and CT Tube Voltage On Hounsfield Unit Values of Iodinated Contrast

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, K; Greene-Donnelly, K; Vallabhaneni, D; Scalzetti, E [SUNY Upstate Medical University, Syracuse, New York (United States)

    2016-06-15

    Purpose: To investigate the effects of changing iterative reconstruction strength and tube voltage on Hounsfield Unit (HU) values of varying concentrations of Iodinated contrast medium in a phantom. Method: Iodinated contrast (Omnipaque 300, GE Healthcare, Princeton NJ) was diluted with distilled water to concentrations of 0.6, 0.9, 1.8, 3.6, 7.2, and 10.8 mg/mL of Iodine. The solutions were scanned in a patient equivalent water phantom on two MDCT scanners: VCT 64 slice (GE Medical Systems, Waukesha, WI) and an Aquilion One 320 slice scanner (Toshiba America Medical Systems, Tustin CA). The phantom was scanned at 80, 100, 120, 140 kV using 400, 255, 180, and 130 mAs, respectively, for the VCT scanner, and 80, 100, 120, and 135 kV using 400, 250, 200, and 150 mAs, respectively, on the Aquilion One. Images were reconstructed at 2.5 mm (VCT) and 0.5 mm (Aquilion One). The VCT images were reconstructed using Advanced Statistical Iterative Reconstruction (ASIR) at 6 different strengths: 0%, 20%, 40%, 60%, 80%, and 100%. Aquilion One images were reconstructed using Adaptive Iterative Dose Reduction (AIDR) at 4 strengths: no AIDR, Weak AIDR, Standard AIDR, and Strong AIDR. Regions of interest (ROIs) were drawn on the images to measure the HU values and standard deviations of the diluted contrast. Second order polynomials were used to fit the HU values as a function of Iodine concentration. Results: For both scanners, there was no significant effect of changing the iterative reconstruction strength. The polynomial fits yielded goodness-of-fit (R2) values averaging 0.997. Conclusion: Changing the strength of the iterative reconstruction has no significant effect on the HU values of Iodinated contrast in a tissue-equivalent phantom. Fit values of HU vs Iodine concentration are useful in quantitative imaging protocols such as the determination of cardiac output from time-density curves in the main pulmonary artery.

  18. SPECT/CT imaging in children with papillary thyroid carcinoma

    International Nuclear Information System (INIS)

    Kim, Hwa-Young; Gelfand, Michael J.; Sharp, Susan E.

    2011-01-01

    SPECT/CT improves localization of single photon-emitting radiopharmaceuticals. To determine the utility of SPECT/CT in children with papillary thyroid carcinoma. 20 SPECT/CT and planar studies were reviewed in 13 children with papillary thyroid carcinoma after total thyroidectomy. Seven studies used I-123 and 13 used I-131, after elevating TSH by T4 deprivation or intramuscular thyrotropin alfa. Eight children had one study and five children had two to four studies. Studies were performed at initial post-total thyroidectomy evaluation, follow-up and after I-131 treatment doses. SPECT/CT was performed with a diagnostic-quality CT unit in 13 studies and a localization-only CT unit in 7. Stimulated thyroglobulin was measured (except in 2 cases with anti-thyroglobulin antibodies). In 13 studies, neck activity was present but poorly localized on planar imaging; all foci of uptake were precisely localized by SPECT/CT. Two additional foci of neck uptake were found on SPECT/CT. SPECT/CT differentiated high neck uptake from facial activity. In six studies (four children), neck uptake was identified as benign by SPECT/CT (three thyroglossal duct remnants, one skin contamination, two by precise anatomical CT localization). In two children, SPECT/CT supported a decision not to treat with I-131. When SPECT/CT was unable to identify focal uptake as benign, stimulated thyroglobulin measurements were valuable. In three of 13 studies with neck uptake, SPECT/CT provided no useful additional information. SPECT/CT precisely localizes neck iodine uptake. In small numbers of patients, treatment is affected. SPECT/CT should be used when available in thyroid carcinoma patients. (orig.)

  19. Spinal CT scan, 1

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

  20. Cost-Effectiveness of 18f-Fdg Pet/Ct for Screening Distant Metastasis in Stage Ii/Iii Breast Cancer Patients of the UK, the United States and the Netherlands

    NARCIS (Netherlands)

    Miquel-Cases, A.; Da Silva Teixeira, Sandra; Retel, Valesca; Retel, V.P.; Steuten, Lotte Maria Gertruda; Valdes Olmos, R.; Rutgers, E.; van Harten, Willem H.

    2015-01-01

    Objectives: 18F-FDG-PET/CT is accurate in detecting distant metastases (DM) in breast cancer patients scheduled for neoadjuvant chemotherapy. If DMs are screen-detected in an early phase, morbidity and mortality may be reduced. Because 18F-FDG-PET/CT comes at a significant cost, we compared its

  1. CT appearance of splenosis

    Energy Technology Data Exchange (ETDEWEB)

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-12-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT.

  2. CT appearance of splenosis

    International Nuclear Information System (INIS)

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-01-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  5. Abdominal and Pelvic CT

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... cavities (ventricles) in patients with hydrocephalus . diseases or malformations of the skull. CT scanning is also performed ... biopsy ) from the brain. assess aneurysms or arteriovenous malformations through a technique called CT angiography. For more ...

  7. Abdominal and Pelvic CT

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    Full Text Available ... CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  9. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. ... Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise in several radiologic ...

  12. Abdominal and Pelvic CT

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    Full Text Available ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. CT ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ...

  13. Abdominal and Pelvic CT

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... CT scan, an experienced radiologist can diagnose many causes of abdominal pain or injury from trauma with ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  15. Abdominal and Pelvic CT

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    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... about tumors of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page ... for sinusitis. CT of the sinuses can help plan the safest and most effective surgery. CT of ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography (CT) - Head Sponsored by ...

  20. Abdominal and Pelvic CT

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... related to Computed Tomography (CT) - Abdomen and Pelvis Videos related to Computed Tomography (CT) - Abdomen and Pelvis ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  4. Abdominal and Pelvic CT

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    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  5. Abdominal and Pelvic CT

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    Full Text Available ... of CT Scanning of the Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed ... soft tissues and blood vessels. top of page What are some common uses of the procedure? This ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... head CT scanning. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  8. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Viewing a CT scan, an experienced radiologist can ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need ...

  11. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation ... Image Gallery Patient undergoing computed tomography (CT) scan View full size with caption Pediatric Content Some imaging ...

  12. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT) of the abdomen and pelvis is a diagnostic imaging test used to help detect diseases of ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ...

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... sometimes compared to looking into a loaf of bread by cutting the loaf into thin slices. When ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging ...

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  18. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Viewing a CT scan, an experienced radiologist ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits A CT scan is one of the ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... membranes covering the brain. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... for the moving table. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, ... and blood vessels. A CT scan of the face produces images that also show a patient's paranasal ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  6. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  8. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  10. CT of the knee

    International Nuclear Information System (INIS)

    Ghelman, B.

    1987-01-01

    CT can be combined with arthrography of the knee to study the following abnormalities: meniscal tears and cysts, synovial plicae, chondromalacia patellae, and osteochondritis dissecans. The CT-arthrogram images present abnormalities in a manner that resembles the ''in situ'' surgical findings, allowing management decisions to be made with greater confidence. The CT techniques for imaging the knee after arthrography are discussed, as is the use of plain CT

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  12. CT of laryngotracheal trauma

    International Nuclear Information System (INIS)

    Lupetin, A.R.; Daffner, R.H.

    1991-01-01

    This paper evaluates the usefulness of CT for the diagnosis of traumatic laryngotracheal abnormalities. The authors retrospectively evaluated the neck CT studies of 50 patients (36 males, 14 females; age range, 16-75 years) who presented to a level I trauma center after suffering a blunt or penetrating laryngotracheal injury. CT results were correlated with endoscopic or surgical findings in 43 cases. Three groups emerge. CT positive: hyloid bone or laryngotracheal cartilage injury; CT positive: soft-tissue injury only; and CT negative. In group 1, CT demonstrated all bony or cartilaginous injuries proved at surgery or suggested at endoscopy. CT failed to demonstrate laryngotracheal separation in 1 case. In group 2, CT demonstrated all soft-tissue injuries suggested at endoscopy. In group 3, CT findings agreed with those of endoscopy in 7 cases, but minor soft-tissue findings seen at endoscopy were missed in 3 cases. Seven patients were studied only with CT. Ct is an accurate technique for detecting bony or cartilaginous laryngotracheal traumatic abnormalities. However, laryngotracheal separation and minor soft-tissue injuries can be missed

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  14. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  17. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

  19. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  2. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  3. CT findings of peritoneal carcinomatosis

    International Nuclear Information System (INIS)

    Kim, Eun Sook; Park, Mi Sook; Cho, On Koo; Koh, Byung Hee; Kim, Soon Yong

    1989-01-01

    CT findings in 137 patients with peritoneal cacinomatosis were reviewed to determine the CT signs of peritoneal malignancy. CT of the 20 liver cirrhosis and 17 tuberculous peritonitis were also reviewed to define the differential point between benign and malignant peritoneal change. The results were as follows. 1. The most common primary malignancy encountered in peritoneal carcinomatosis was stomach Ca.(50.4%), followed by pancreas Ca, hepatoma, colon Ca. and ovarian Ca. 2. Ascites was the most common CT feature of peritoneal malignancy, present in 99 cases (72.3%). The amount of ascites was voluminous, grade III in 70% of cases and showed high density ascites with average 23 Hounsfield units. 3. Greater omentum involvement was noted in 88 patients, peritoneum in 71 patients and mesentery in 65% patients. There was no correlation of the primary malignancy type with the incidence or pattern of the above mentioned site. 4. Bowel wall thickenings were observed in 51 patients, among which transverse colon was most frequently involved. 5. Mean attenuation value of ascites in liver cirrhosis was 10.7 HU, which was much lower than that of peritoneal carcinomatosis. 6. Even though intraperitoneal findings in Tbc. Peritonitis showed tendency of relatively small amount of ascites with more predominant mesenteric change, but, the findings of high density ascites, change of peritoneum and omentum etc. were very similar to those of peritoneal carcinomatosis. Therefore, based on only intraperitoneal change, differential diagnosis between them was difficult. 7. False negatives in CT diagnosis of peritoneal carcinomatosis occurred in 7 cases. There were tiny nodular changes in intraperitoneal cavity without ascites on operative findings

  4. Cervical tuberculous adenitis: CT manifestations.

    Science.gov (United States)

    Reede, D L; Bergeron, R T

    1985-03-01

    Cervical tuberculous adenitis is being seen with increasing frequency in the United States; in the appropriate clinical setting it should be included in the differential diagnosis of an asymptomatic neck mass. Patients are typically young adults who are recent arrivals from Southeast Asia. A history of tuberculosis is not always elicited nor is the chest radiograph always abnormal. All of these patients have positive purified protein derivative tests unless they are anergic. The CT findings may lead to the diagnosis. Several CT patterns of nodal disease can be seen in tuberculous adenitis; some may mimic benign and neoplastic disease. The presence of a multiloculated or multichambered (conglomerate nodal) mass with central lucency and thick rims of enhancement and minimally effaced fascial planes is highly suggestive of tuberculous adenitis, especially if the patient has a strongly positive tuberculosis skin test.

  5. Cervical tuberculous adenitis: CT manifestations

    International Nuclear Information System (INIS)

    Reede, D.L.; Bergeron, R.T.

    1985-01-01

    Cervical tuberculous adenitis is being seen with increasing frequency in the United States; in the appropriate clinical setting it should be included in the differential diagnosis of an asymptomatic neck mass. Patients are typically young adults who are recent arrivals from Southeast Asia. A history of tuberculosis is not always elicited nor is the chest radiograph always abnormal. All of these patients have positive purified protein derivative tests unless they are anergic. The CT findings may lead to the diagnosis. Several CT patterns of nodal disease can be seen in tuberculous adenitis; some may mimic benign and neoplastic disease. The presence of a multiloculated or multichambered (conglomerate nodal) mass with central lucency and thick rims of enhancement and minimally effaced fascial planes is highly suggestive of tuberculous adenitis, especially if the patient has a strongly positive tuberculosis skin test

  6. Bone quality evaluation at dental implant site using multislice CT, micro-CT, and cone beam CT

    NARCIS (Netherlands)

    Parsa, A.; Ibrahim, N.; Hassan, B.; van der Stelt, P.; Wismeijer, D.

    2015-01-01

    Objectives The first purpose of this study was to analyze the correlation between bone volume fraction (BV/TV) and calibrated radiographic bone density Hounsfield units (HU) in human jaws, derived from micro-CT and multislice computed tomography (MSCT), respectively. The second aim was to assess the

  7. Spinal CT scan, 2

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Plain CT described fairly accurately the anatomy and lesions of the lumbar and sacral spines on their transverse sections. Since hernia of the intervertebral disc could be directly diagnosed by CT, indications of myelography could be restricted. Spinal-canal stenosis of the lumbar spine occurs because of various factors, and CT not only demonstrated the accurate size and morphology of bony canals, but also elucidated thickening of the joints and yellow ligament. CT was also useful for the diagnosis of tumors in the lumbar and sacral spines, visualizing the images of bone changes and soft tissues on the trasverse sections. But the diagnosis of intradural tumors required myelography and metrizamide CT. CT has become important for the diagnosis of spinal and spinal-cord diseases and for selection of the route of surgical arrival. (Chiba, N.)

  8. CT of Mirizzi syndrome

    International Nuclear Information System (INIS)

    Yamamoto, Shinichiro; Fukushima, Keisuke; Ishihara, Kenji; Hirano, Yutaka; Sano, Kaizo

    1983-01-01

    PTC or ERCP findings of four cases of Mirizzi syndrome were demonstrated. They consisted of a smooth stricture of the common hepatic duct, curved impressions of the duct and dilatation of proximal biliary radicles. CT could visualize the impacted stone in the neck of the gallbladder, dilatation of proximal common hepatic and intrahepatic duct. Absence of the dilatation of distal common bile duct could also be confirmed by CT, thus the diagnosis of Mirizzi syndrome might be possible by CT. (author)

  9. Coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2009-07-01

    Coronary CT angiography has attained increasing scientific attention at academic institutions and has become a highly accurate diagnostic modality. Extending this knowledge into a practice setting is the purpose of 'Coronary CT Angiography'. This book will assist you in integrating cardiac CT into your daily practice, while also giving an overview of the current technical status and applications. The specific features of scanners from all four main vendors are also presented providing an objective overview of noninvasive coronary angiography using CT. (orig.)

  10. Head CT scan

    Science.gov (United States)

    ... scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... head size in children Changes in thinking or behavior Fainting Headache, when you have certain other signs ...

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  12. MR-based attenuation correction for PET/MRI neurological studies with continuous-valued attenuation coefficients for bone through a conversion from R2* to CT-Hounsfield units.

    Science.gov (United States)

    Juttukonda, Meher R; Mersereau, Bryant G; Chen, Yasheng; Su, Yi; Rubin, Brian G; Benzinger, Tammie L S; Lalush, David S; An, Hongyu

    2015-05-15

    MR-based correction for photon attenuation in PET/MRI remains challenging, particularly for neurological applications requiring quantitation of data. Existing methods are either not sufficiently accurate or are limited by the computation time required. The goal of this study was to develop an MR-based attenuation correction method that accurately separates bone tissue from air and provides continuous-valued attenuation coefficients for bone. PET/MRI and CT datasets were obtained from 98 subjects (mean age [±SD]: 66yrs [±9.8], 57 females) using an IRB-approved protocol and with informed consent. Subjects were injected with 352±29MBq of (18)F-Florbetapir tracer, and PET acquisitions were begun either immediately or 50min after injection. CT images of the head were acquired separately using a PET/CT system. Dual echo ultrashort echo-time (UTE) images and two-point Dixon images were acquired. Regions of air were segmented via a threshold of the voxel-wise multiplicative inverse of the UTE echo 1 image. Regions of bone were segmented via a threshold of the R2* image computed from the UTE echo 1 and UTE echo 2 images. Regions of fat and soft tissue were segmented using fat and water images decomposed from the Dixon images. Air, fat, and soft tissue were assigned linear attenuation coefficients (LACs) of 0, 0.092, and 0.1cm(-1), respectively. LACs for bone were derived from a regression analysis between corresponding R2* and CT values. PET images were reconstructed using the gold standard CT method and the proposed CAR-RiDR method. The RiDR segmentation method produces mean Dice coefficient±SD across subjects of 0.75±0.05 for bone and 0.60±0.08 for air. The CAR model for bone LACs greatly improves accuracy in estimating CT values (28.2%±3.0 mean error) compared to the use of a constant CT value (46.9%±5.8, punits. From our analysis, we conclude that the proposed method closely approaches (<3% error) the gold standard CT-scaled method in PET reconstruction accuracy

  13. [Mobile CT at neurointensive sections--it is possible].

    Science.gov (United States)

    Frost, Majbritt; Stenkær, Susanne; Kellenberger, Simone; Ehlers, Lars

    2011-01-24

    Intrahospital transportation can be complicated and hazardous. Mobile computerized tomography (CT) of the head performed at the neurointensive care unit is a new technique that minimizes the need for transportation of unstable patients. Even small changes in physiological parameters can be detrimental for these patients and cause secondary injury and thus affect their prognoses. The portable CT scanner in the neurointensive care unit holds great potential, but the high price level may limit its use.

  14. CT scanning in Australia: a report by the National Health Technology Advisory Panel

    International Nuclear Information System (INIS)

    1988-06-01

    An overview of trends in the usage of CT scanning in Australia is given and the areas of benefit and uncertainty associated with this technology are outlined. Numbers and distribution of CT units, costs of CT services, clinical applications, safety aspects and the effects of new developments are discussed. 54 refs., 5 figs., 18 tabs

  15. Image mottle in abdominal CT.

    Science.gov (United States)

    Ende, J F; Huda, W; Ros, P R; Litwiller, A L

    1999-04-01

    To investigate image mottle in conventional CT images of the abdomen as a function of radiographic technique factors and patient size. Water-filled phantoms simulating the abdomens of adult (32 cm in diameter) and pediatric (16 cm in diameter) patients were used to investigate image mottle in CT as a function of x-ray tube potential and mAs. CT images from 39 consecutive patients with noncontrast liver scans and 49 patients with iodine contrast scans were analyzed retrospectively. Measurements were made of the mean liver parenchyma Hounsfield unit value and the corresponding image mottle. For a given water phantom and x-ray tube potential, image mottle was proportional to the mAs-0.5. Increasing the phantom diameter from 16 cm (pediatric) to 32 cm increased the mottle by a factor of 2.4, and increasing the x-ray tube potential from 80 kVp to 140 kVp reduced the mottle by a factor of 2.5. All patients were scanned at 120 kVp, with no correlation between patient size and the x-ray tube mAs. The mean mottle level was 7.8 +/- 2.2 and 10.0 +/- 2.5 for the noncontrast and contrast studies, respectively. An increase in patient diameter of 3 cm would require approximately 65% more mAs to maintain the same level of image mottle. The mottle in abdominal CT images may be controlled by adjusting radiographic technique factors, which should be adjusted to take into account the size of the patient undergoing the examination.

  16. 'Ready-access' CT imaging for an orthopaedic trauma clinic.

    LENUS (Irish Health Repository)

    Cawley, D

    2011-03-01

    \\'Ready-Access\\' to CT imaging facilities in Orthopaedic Trauma Clinics is not a standard facility. This facility has been available at the regional trauma unit, in Merlin Park Hospital, Galway for the past four years. We reviewed the use of this facility over a 2-year period when 100 patients had CT scans as part of their trauma clinic assessment. The rate of CT scan per clinic was 0.6. The mean waiting time for a CT scan was 30 minutes. 20 (20%) new fractures were confirmed, 33 (33%) fractures were out-ruled, 25 (25%) fractures demonstrated additional information and 8 (8%) had additional fractures. 20 (20%) patients were discharged and 12 (12%) patients were admitted as a result of the CT scan. It adds little time and cost to CT scanning lists.

  17. CT of pleural abnormalities

    International Nuclear Information System (INIS)

    Webb, W.R.

    1995-01-01

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.)

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. A ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  1. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  2. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  5. CT of pleural abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Webb, W R [California Univ., San Francisco, CA (United States). Dept. of Radiology

    1996-12-31

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.).

  6. CT urography and hematuria

    DEFF Research Database (Denmark)

    Bretlau, Thomas; Hansen, Rasmus H; Thomsen, Henrik S

    2015-01-01

    BACKGROUND: Computed tomography (CT) urography is now used in the work-up of patients with hematuria. The dose of contrast medium and radiation varies considerably between the different CT protocols. PURPOSE: To study the disease prevalence in a consecutive group of patients with hematuria...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... can help plan the safest and most effective surgery. CT of the sinuses is now widely available and is performed in a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... about tumors of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page How should ... for sinusitis. CT of the sinuses can help plan the safest and most effective surgery. CT of the sinuses is now widely available ...

  9. Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Zhihua; Gates, Erica L.; Trout, Andrew T. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); O' Brien, Maureen M. [Cincinnati Children' s Hospital Medical Center, Division of Oncology, Cancer and Blood Disease Institute, Cincinnati, OH (United States)

    2018-02-15

    Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (P<0.0001). Average dose savings with the combined approach was 24.8±17.8% (2.60±2.51 mSv [range: 0.32-4.72 mSv]) of total CT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations. (orig.)

  10. Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma

    International Nuclear Information System (INIS)

    Qi, Zhihua; Gates, Erica L.; Trout, Andrew T.; O'Brien, Maureen M.

    2018-01-01

    Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (P<0.0001). Average dose savings with the combined approach was 24.8±17.8% (2.60±2.51 mSv [range: 0.32-4.72 mSv]) of total CT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations. (orig.)

  11. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  12. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... or nurse at the time of the CT examination. If your child has a known contrast material ... be given to your child for the CT examination. top of page What does the CT equipment ...

  13. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ...

  14. CT of splenic trauma

    International Nuclear Information System (INIS)

    Griffiths, B.G.; Federle, M.P.; Minagi, H.; Jeffrey, R.B.

    1986-01-01

    Fifty-five consecutive cases of surgically proved splenic injuries were evaluated by CT. CT correctly identified 54 splenic injuries, with one false-negative and three false-positive studies. In the single false-negative study and in two of the three false-positive studies, CT correctly indicated the presence of a large hemoperitoneum and other abdominal visceral lacerations and so correctly indicated the need for surgery. Of the 55 proved cases of splenic injury, CT revealed hemoperitoneum in 54 (99%), perisplenic clot in 47 (85%), splenic laceration in 39 (71%), and subcapsular hematoma in 13 (24%). Perisplenic clot can be distinguished from lysed blood in the peritoneal cavity and is a sensitive and specific sign of splenic trauma, even in the absence of visible splenic laceration. The authors conclude that CT is highly reliable means of evaluating splenic trauma

  15. CT of abdominal abscesses

    International Nuclear Information System (INIS)

    Korobkin, M.T.

    1987-01-01

    The imaging search for a suspected abdominal abscess is common in hospitalized patients, especially after recent abdominal surgery. This paper examines the role of CT in the detection, localization, and treatment of abdominal abscess. The accuracy, limitations, and technical aspects of CT in this clinical setting are discussed. The diagnosis of an abscess is based on the demonstration of a circumscribed abnormal fluid collection. Although percutaneous aspiration with gram stain and culture is usually indicated to differentiate abscess from other fluid collections, the CT-based detection of extraluminal gas bubbles makes the diagnosis of an abscess highly likely. CT is compared with conventional radiographic studies, US, and radio-nuclide imaging. Specific CT and clinical features of abscesses in the following sites are emphasized: subphrenic space, liver, pancreas, kidneys, psoas muscle, appendix, and colonic diverticula. Most abdominal abscesses can be successfully treated with percutaneous drainage techniques. The techniques, results, and limitations of percutaneous abscess drainage are reviewed

  16. CT of tracheal agenesis

    International Nuclear Information System (INIS)

    Strouse, Peter J.; Hernandez, Ramiro J.; Newman, Beverley

    2006-01-01

    Tracheal agenesis is a rare and usually lethal anomaly. In the past, opaque contrast medium was injected via the esophagus to demonstrate the anatomy. To demonstrate the utility of helical and multidetector CT in delineating the aberrant anatomy in newborns with tracheal agenesis. Four newborns with tracheal agenesis were identified from three institutions. Imaging studies and medical records were reviewed. Each child was imaged with chest radiography. One child was imaged on a single-detector helical CT scanner and the other three on multidetector scanners. Helical and multidetector CT with 2D and 3D reconstructions clearly delineated the aberrant tracheobronchial and esophageal anatomy in each infant. Minimum intensity projection reformatted CT images were particularly helpful. One infant each had type I and type II tracheal agenesis. Two infants had type III tracheal agenesis. All four infants died. CT is a useful tool for delineating the aberrant anatomy of newborns with tracheal agenesis and thus helps in making rational clinical decisions. (orig.)

  17. Head trauma and CT

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    In our cases of acute and subacute subdural hematoma, the use of CT was evaluated. In our department of surgery, acute subdural hematoma was found in 46 of 388 patients of head trauma who underwent CT. Acute subdural hematoma, like epidural hematoma was usually visualized as a high-density area along the cranial inner table, and this was easily differenciated from epidural hematoma because of difference in shape from the other. The picture of acute subdural hematoma was occasionally confused with that of intracerebral hematoma or cerebral contusion. Single use of CT does not differenciate subacute subdural hematoma from chronic subdural hematoma. However, CT usually visualized acute hematoma as a high-density area, showing the extent of hematoma. Comparison of the thickness of hematoma with the axis deviation of the median part such as the 3rd cerebral ventricle suggested severity of cerebral edema. CT also revealed bilateral or multiple lesions of cerebral contusion or intracerebral hematoma. (Ueda, J.)

  18. CT of laryngeal trauma

    International Nuclear Information System (INIS)

    Jeffrey, R.B.

    1986-01-01

    Computed tomography has made a significant contribution to the radiologic assessment of the injured larynx. CT is an accurate, noninvasive modality that can rapidly diagnose both soft tissue and cartilaginous injuries. CT of the larynx involves a minimal degree of patient manipulation and discomfort and can be performed in conjunction with CT evaluation of intracranial or facial injuries. Conventional radiologic studies (anteroposterior and lateral soft tissue films of the neck, tomograms, or xerograms) are capable of demonstrating some cartilaginous fractures but are of limited value in defining the extent of soft tissue injury. In the acute trauma setting, laryngography is often technically difficult to perform because of patient discomfort and inability to cooperate. Although the overall experience is somewhat limited, CT appears to overcome many of the limitations of these conventional radiologic methods. The following is a discussion of the role of CT scanning in evaluating injuries to the larynx and cervical soft tissues

  19. CT after transsphenoidal surgery

    International Nuclear Information System (INIS)

    Tazawa, Satoru

    1991-01-01

    Two hundred and ten CT studies of 95 patients after transsphenoidal surgery were reviewed. Spheno-ethmoid opacificaiton, intrasellar hematoma and gas bubbles were noted within 2 weeks after surgery. Bone defect of the sellar floor and bone stent were seen on coronal scans in most cases. The packing material frequently disappeared on follow-up studies. Hormonal assessment of the functioning tumor, according to which the effect of treatment was evaluated, was correlated with CT findings. Because differentiation between postoperative changes and residual mass was difficult, there was no definite CT criteria to indicate residual functioning tumor except upward convexity of the diaphragma sellae on CT more than 3 months after surgery. Initial follow up CT study is recommended to be performed at about 3 months after surgery, at which time the immediate postoperative inflammatory changes have been disappeared. The incidence of recurrence was 3/47 (6%), which was shown on follow-up CT from 4 to 10 years after surgery. Therefore, subsequent CT study should be done in every year or two, taking the clinical symptoms and hormonal data into consideration. (author)

  20. CT of the heart

    International Nuclear Information System (INIS)

    Lipton, M.J.

    1986-01-01

    Advances based upon the detector elements instead of X-ray film have greatly increased the power of X-ray imaging. Computed tomography (CT) creates cross sectional rather than projected images. Recently, high speed CT devices have been developed for cardiovascular studies. The Cine-CT scanner employs a scanning electron beam deflected on an extended tungsten target ring. Fast scans of 50 millisecond exposures at multiple levels can provide information concerning blood flow in vessels and tissues, myocardial wall motion, valve integrity, coronary bypass graft patency and proximal coronary artery anatomy. Cine-CT dynamic scanning can also provide volume imaging with small quantities (0.05 - 1.5 ml/kg) of contrast medium administered via peripheral vein injections. Cine-CT provides simultaneous measurements of cardiac dimensions and function and is rapidly becoming a new tool for quantitating myocardial blood flow, cardiac chamber volumes and wall mechanics. The future outlook is very promising for this three-dimensional cine-CT technique with high spatial resolution. High speed CT should provide unique diagnostic information and as the technology continues to improve at a rapid speed, this new imaging modality could be a challenge for angiography. (Auth.)

  1. CT after transsphenoidal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Tazawa, Satoru [Tohoku Univ., Sendai (Japan). School of Medicine

    1991-03-01

    Two hundred and ten CT studies of 95 patients after transsphenoidal surgery were reviewed. Spheno-ethmoid opacificaiton, intrasellar hematoma and gas bubbles were noted within 2 weeks after surgery. Bone defect of the sellar floor and bone stent were seen on coronal scans in most cases. The packing material frequently disappeared on follow-up studies. Hormonal assessment of the functioning tumor, according to which the effect of treatment was evaluated, was correlated with CT findings. Because differentiation between postoperative changes and residual mass was difficult, there was no definite CT criteria to indicate residual functioning tumor except upward convexity of the diaphragma sellae on CT more than 3 months after surgery. Initial follow up CT study is recommended to be performed at about 3 months after surgery, at which time the immediate postoperative inflammatory changes have been disappeared. The incidence of recurrence was 3/47 (6%), which was shown on follow-up CT from 4 to 10 years after surgery. Therefore, subsequent CT study should be done in every year or two, taking the clinical symptoms and hormonal data into consideration. (author).

  2. Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma.

    Science.gov (United States)

    Qi, Zhihua; Gates, Erica L; O'Brien, Maureen M; Trout, Andrew T

    2018-02-01

    Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (PCT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations.

  3. CT pelvimetry. La scanopelvimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Vicens, J.L.; Charles, G.; Le Berre, J.; Flageat, J. (Hopital d' Instruction des Armees Begin, 94 - Saint-Mande (FR))

    1989-01-01

    Pelvimetry aims at providing the obstetrician with information on the size and morphology of the female pelvis, thus enabling him to assess the obstetrical prognosis as accurately as possible. Computed tomography (CT) has several advantages, in particular the lower mother and fetus radiation dose. After a brief description of obstetrical anatomy, the usual CT exploration method is presented and its results are considered in terms of measurements, indices and morphological findings. If performed with a very strict exploration procedure, CT pelvimetry is a very reliable, fact and comfortable method of examination. All these advantages, combined with the minimized patient dose, should lead to an increasingly widespread use of this technique.

  4. CT of chest trauma

    International Nuclear Information System (INIS)

    Goodman, P.C.

    1986-01-01

    There appears to be a limited role for computed tomography in the evaluation of chest trauma. The literature contains few papers specifically addressing the use of CT in the setting of chest trauma. Another series of articles relates anecdotal experiences in this regard. This paucity of reports attests to the remarkable amount of information present on conventional chest radiographs as well as the lack of clear indications for CT in the setting of chest trauma. In this chapter traumatic lesions of various areas of the thorax are discussed. The conventional radiographic findings are briefly described and the potential or proven application of CT is addressed

  5. NMR-CT scanner

    International Nuclear Information System (INIS)

    Kose, Katsumi; Sato, Kozo; Sugimoto, Hiroshi; Sato, Masataka.

    1983-01-01

    A brief explanation is made on the imaging methods for a practical diagnostic NMR-CT scanner : A whole-body NMR-CT scanner utilizing a resistive magnet has been developed by Toshiba in cooperation with the Institute for Solid State Physics, the University of Tokyo. Typical NMR-CT images of volunteers and patients obtained in the clinical experiments using this device are presented. Detailed specifications are also shown about the practical NMR-CTs which are to be put on the market after obtaining the government approval. (author)

  6. Dual energy cardiac CT.

    Science.gov (United States)

    Carrascosa, Patricia; Deviggiano, Alejandro; Rodriguez-Granillo, Gastón

    2017-06-01

    Conventional single energy CT suffers from technical limitations related to the polychromatic nature of X-rays. Dual energy cardiac CT (DECT) shows promise to attenuate and even overcome some of these limitations, and might broaden the scope of patients eligible for cardiac CT towards the inclusion of higher risk patients. This might be achieved as a result of both safety (contrast reduction) and physiopathological (myocardial perfusion and characterization) issues. In this article, we will review the main clinical cardiac applications of DECT, that can be summarized in two core aspects: coronary artery evaluation, and myocardial evaluation.

  7. Bone quality evaluation at dental implant site using multislice CT, micro-CT, and cone beam CT.

    Science.gov (United States)

    Parsa, Azin; Ibrahim, Norliza; Hassan, Bassam; van der Stelt, Paul; Wismeijer, Daniel

    2015-01-01

    The first purpose of this study was to analyze the correlation between bone volume fraction (BV/TV) and calibrated radiographic bone density Hounsfield units (HU) in human jaws, derived from micro-CT and multislice computed tomography (MSCT), respectively. The second aim was to assess the accuracy of cone beam computed tomography (CBCT) in evaluating trabecular bone density and microstructure using MSCT and micro-CT, respectively, as reference gold standards. Twenty partially edentulous human mandibular cadavers were scanned by three types of CT modalities: MSCT (Philips, Best, the Netherlands), CBCT (3D Accuitomo 170, J Morita, Kyoto, Japan), and micro-CT (SkyScan 1173, Kontich, Belgium). Image analysis was performed using Amira (v4.1, Visage Imaging Inc., Carlsbad, CA, USA), 3Diagnosis (v5.3.1, 3diemme, Cantu, Italy), Geomagic (studio(®) 2012, Morrisville, NC, USA), and CTAn (v1.11, SkyScan). MSCT, CBCT, and micro-CT scans of each mandible were matched to select the exact region of interest (ROI). MSCT HU, micro-CT BV/TV, and CBCT gray value and bone volume fraction of each ROI were derived. Statistical analysis was performed to assess the correlations between corresponding measurement parameters. Strong correlations were observed between CBCT and MSCT density (r = 0.89) and between CBCT and micro-CT BV/TV measurements (r = 0.82). Excellent correlation was observed between MSCT HU and micro-CT BV/TV (r = 0.91). However, significant differences were found between all comparisons pairs (P micro-CT BV/TV (P = 0.147). An excellent correlation exists between bone volume fraction and bone density as assessed on micro-CT and MSCT, respectively. This suggests that bone density measurements could be used to estimate bone microstructural parameters. A strong correlation also was found between CBCT gray values and BV/TV and their gold standards, suggesting the potential of this modality in bone quality assessment at implant site. © 2013 John Wiley & Sons A/S. Published by

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... of any kind, unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding ... information is needed to determine the extent of soft tissue of the tumor, magnetic resonance imaging (MRI) ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... often used to determine the cause of unexplained pain. CT scanning is fast, painless, noninvasive and accurate. ... help diagnose the cause of abdominal or pelvic pain and diseases of the internal organs, small bowel ...

  10. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic, or have chronic pain, you may find a CT exam to be ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be ...

  12. Abdominal and Pelvic CT

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    Full Text Available ... wear during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... wear during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... wear during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... hard time staying still, are claustrophobic, or have chronic pain, you may find a CT exam to ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to ...

  19. Abdominal and Pelvic CT

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... still, are very nervous or anxious or have chronic pain, you may find a CT exam to ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ... iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ... iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are ...

  2. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT of the sinuses is primarily used to: help diagnose sinusitis . evaluate sinuses that are filled with ... elevated. Straps and pillows may be used to help the patient maintain the correct position and to ...

  3. Abdominal and Pelvic CT

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    Full Text Available ... emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. Tell your ... emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has ...

  4. CT diagnosis of hepatoma

    Energy Technology Data Exchange (ETDEWEB)

    Itai, Yuji [Tokyo Univ. (Japan). Faculty of Medicine

    1982-04-01

    In hepatocellular carcinoma, present status of CT diagnosis was discussed. Hepatocellular carcinoma is sometimes imaged in same concentration as that of surrounding tissues, and the detection rate ranged from 79 to 94%. The rate of differential diagnosis between primary and metastatic carcinoma was only 83% (includes 22% of false diagnosis) using contrast enhancement. The rates of detection of hepatocellular carcinoma and metastatic one were also only 87% and 75%, respectively, even by the combined use of arterial infusion CT and dynamic CT. However, the CT images is reproducible, and is supplemented by the information of US. Thus, the combination of these methods is useful in diagnosing the presence, extension, and nature of liver carcinoma.

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page How should ... can help plan the safest and most effective surgery. CT of the sinuses is now widely available ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... treatments. plan for and assess the results of surgery, such as organ transplants. stage, plan and properly ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... as: infections such as appendicitis , pyelonephritis or infected fluid collections, also known as abscesses. inflammatory bowel disease ... caused by a burst appendix or an infected fluid collection and the subsequent spread of infection. CT ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  12. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  14. Abdominal and Pelvic CT

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    Full Text Available ... tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... is painless, noninvasive and accurate. It’s also the most reliable imaging technique for determining if the sinuses ... CT scan of the sinuses, the patient is most commonly positioned lying flat on the back. The ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed ... GI Tract X-ray (Radiography) - Upper GI Tract Colorectal Cancer Images related to Computed Tomography (CT) - Abdomen ...

  17. Heart CT scan

    Science.gov (United States)

    ... make to decrease the risk of heart disease. Risks Risks of CT scans include: Being exposed to ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  18. Abdominal and Pelvic CT

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    Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

  19. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

  1. Abdominal and Pelvic CT

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    Full Text Available ... Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed on ... GI Tract X-ray (Radiography) - Upper GI Tract Colorectal Cancer Images related to Computed Tomography (CT) - Abdomen and ...

  2. Abdominal and Pelvic CT

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    Full Text Available ... should always inform their physician and the CT technologist if there is any possibility that they may ... located in a separate control room, where the technologist operates the scanner and monitors your examination in ...

  3. Computed Tomography (CT) -- Head

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  5. Abdominal and Pelvic CT

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  6. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Magnetic Resonance Imaging (MRI) - Head Head and Neck Cancer Treatment Radiation Dose in X-Ray and CT Exams Contrast Materials Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... x-ray equipment to evaluate the paranasal sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, noninvasive and accurate. It’s ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. If ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... membranes covering the brain. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... for the moving table. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head ...

  14. Abdominal and Pelvic CT

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  17. Abdominal and Pelvic CT

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    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

  19. Computed Tomography (CT) -- Sinuses

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  19. Body CT (CAT Scan)

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    Full Text Available ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ... us improve RadiologyInfo.org by taking our brief survey: Survey Do you have a personal story about ...

  17. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... or liver cirrhosis. cancers of the liver, kidneys, pancreas, ovaries and bladder as well as lymphoma. kidney ... and organs such as the liver, kidneys and pancreas. When you enter the CT scanner, special light ...

  18. CT of abdominal tumor

    International Nuclear Information System (INIS)

    Endo, Satoshi; Yamada, Kenji; Ito, Masatoshi; Ito, Hisao; Yamaura, Harutsugu

    1981-01-01

    CT findings in 33 patients who had an abdominal tumor were evaluated. CT revealed a tumor in 31 cases. The organ from which the tumor originated was correctly diagnosed in 18 patients. Whether the tumor was solid or cystic was correctly predicted in 28 patients. The diagnosis malignant or benign nature of tumor was correct, incorrect and impossible, in 23, 3, and five patiens, respectively. (Kondo, M.)

  19. CT of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H; Tanaka, T; Sai, H; Kawamoto, S; Morimoto, K [Osaka Univ. (Japan). Faculty of Medicine

    1982-06-01

    CT was investigated in 125 cases of hepatocelluar carcinoma and 47 cases of metastatic hepatic neoplasm. The entire contour of each tumor was traced and the average CT value in the tumor was estimated. As a result, the CT value for hepatocellular carcinoma tended to be higher on plain CT and also after contrast enhancement. The CT findings seen frequently were as follows: capsule in 76 cases (60.8%) and septum in 67 cases (53.6%); tumor thrombus in portal vein in 39 cases (31.2%) and that in inferior vena cava in 3 cases (2.4%); localized enlargement of hepatic bile duct in 24 cases (19.2%). These findings were rarely seen in the cases of metastatic hepatic neoplasm. As a relatively outstanding feature of hepatic metastases, a double contour, like concentric circles or contour lines, with a relatively large inner circle or contour line, was found in 21 cases (44.7%). By paying attention to the change of CT value on contrast enhancement and the characteristic image of each case, hepatocellular carcinoma could be differentiated from metastatic hepatic neoplasm with high probability.

  20. Pediatric CT angiography

    International Nuclear Information System (INIS)

    Siegel, M.J.

    2005-01-01

    Advances in CT technology are having profound impact on imaging children and have made CT angiography possible even in neonates. Even with the tiny anatomy of neonates, small volumes of contrast material, and small venous access catheters, successful CT angiography can be performed with attention to detail. Meticulous attention to patient preparation, the proper selection of technical factors, and optimal delivery of contrast material are crucial. Data post-processing and the creation of 3-D reconstructions are also essential in establishing a correct diagnosis. The applications fo CT angiography are different in children than in adults and most applications in children involve assessment of congenital and postoperative vascular and cardiac diseases. The use of CT angiography offers the opportunity to eliminate the long periods of sedation associated with MR and reduce the radiation exposure associated with conventional angiography. Generally, the benefits of CT angiography in children outweigh the risk, namely that of radiation exposure. However, care must still be taken to minimize the radiation exposure. (orig.)

  1. CT-Urography

    International Nuclear Information System (INIS)

    Dalla Palma, Ludovico; Grotto, Maurizio; Morra, Aldo

    2005-01-01

    In this paper we present an overview of CT-Urography. With the advent of multislice CT scanners and the evolution of image processing methods this technique now affords optimal urographic images comparable to those obtained with conventional techniques. We describe the acquisition techniques and protocols used by the various authors. Effective radiation dose has conditioned the use of CT-Urography so that the tendency today is to reduce the number of scans by performing, after the non enhanced scan, a single contrast-enhanced scan comprising both the nephrographic and urographic phase. With the use of multislice CT the quality of the urogram improves with the number of slices. We illustrate a variety of processing techniques, multiplanar reconstruction (MPR), maximum (MIP) and average intensity projection (AIP) and volume rendering (VR) and present a series of upper urinary tract tumours testifying to the superiority of the AIP technique over MIP. We then review the results of comparative studies of CT-Urography with conventional urography in upper urinary tract diagnostics. Finally, we describe the advantages and limitations of CT-Urography [it

  2. Head trauma and CT

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    It has been said that chronic subdural hematoma cannot be diagnosed by CT. In our cases, CT was used, and the results were described. According to the density of the picture, CT findings of chronic subdural hematoma could be classified into 3 types, those of higher density than that of the cerebral paranchyma, those of isodensity, and those of lower density than that of the cerebral parenchyma. The difference among them appeared to be due to variation in the fluid in hematoma, especially that in hemoglobin concentration. Chronic subdural hematoma was found in 27 of 388 cases of head trauma in which CT was undertaken in our department of surgery for last 2 years. It is difficult to differenciate this disease from subdural edema or subarachnoideal retention of the cerebrospinal fluid. In many cases, use of contrast medium added no change to the CT picture. Cerebral angiography is necessary for definite diagnosis of the disease. Chronic subdural hematoma gives more varieties of findings than other intracranial hematomas. However, if the film is very carefully read, CT is still useful for diagnosing this disease in spite of initially remarked difficulties. (Ueda, J.)

  3. CT findings of orbital langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Yi, Gina; Yoon, Hye Kyung; Han, Bokyung Kim; Kim, Kyeong Ah; Choo, In Wook

    2000-01-01

    To evaluate the CT findings in patients with Langerhans cell histiocytosis (LCH) involving the orbit. Orbital CT scans of six children with pathologically proven LCH were retrospectively analyzed. Follow-up CT (n=3D5) and MR (n=3D1) imaging findings were also reviewed. Initial CT scans revealed varying degree of bone destruction with soft-tissue masses, and on nonenhanced images the mean attenuation value was 44 Hounsfield units (HU). All masses showed mild to moderate enhancement with a mean attenuation value of 74 HU. The bony margins abutting onto soft tissue masses were irregular but clearly demarcated. No evidence of calcification or periosteal reaction was noted. Suprasellar mass and rib involvement was noted in one patient and hepatosplenomegaly in two. Follow-up CT and MR images showed that the soft tissue masses were almost completely resolved, with bone remodeling and reossification. A soft tissue mass with irregular but clearly demarcated bone destruction is thought to be a characteristic finding of LCH involving the orbit. Follow-up images after treatment showed bone remodeling and reossification. (author)

  4. Numerical optimization of targeted delivery of charged nanoparticles to the ostiomeatal complex for treatment of rhinosinusitis

    OpenAIRE

    Xi, Jinxiang; Yuan,Jiayao; Si,Xiuhua; Hasbany,James

    2015-01-01

    Jinxiang Xi,1 Jiayao Eddie Yuan,1 Xiuhua April Si,2 James Hasbany1 1School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI, 2Department of Mechanical Engineering, California Baptist University, Riverside, CA, USA Background: Despite the prevalence of rhinosinusitis that affects 10%–15% of the population, current inhalation therapy shows limited efficacy. Standard devices deliver <5% of the drugs to the sinuses due to the complexity of nose stru...

  5. The Need for New Dosimetric Approach in CT Dosimetry

    International Nuclear Information System (INIS)

    Ben-Shlomo, A.; Iacobovici, E.

    2004-01-01

    Three decades after the invention of the first CT in 1972, it became a major tool in diagnostic radiology. The use of CT for various applications is getting wider every year. The quantity of CT procedures performed in Israel every year is estimated as 500,000. About 10% of those are pediatric procedures, for children under age 10. CT procedures increase is estimated at 5-10 % per annum. In spite the fact that CT contributes to about 1/8 of the total number of diagnostic X-ray procedures in Israel, the CT collective dosage is about 40% of the total collective dosage in the said procedures (about 3,500 Man*Sv per year). Medical radiation dosage is the first contributor to population dosage, resulting from artificial radiation sources. Diagnostic X-ray radiation dosage is the first contributor to medical radiation dose (including radiation dose from diagnostic X-ray, nuclear medicine and radiotherapy with exclusion of the target organ dose). Among medical X-ray different applications, CT procedure is the first cause to radiation dose of the population according to X-ray diagnostic procedures. The above facts emphasize the need to focus on CT in order to reduce the medical collective dose of the public. Several dosimetric units have appeared in recent years in order to comply with the need for CT Dosimetry. The CTDI Unit that served so well during the first CT years is no longer sufficient, as is, for modern instruments. This basic unit has become a complex concept that covers new units: CTDI W , CTDI VOL , CTDI 100 , MSAD and DLP. The search for a simple way to apply these units in order to calculate effective dosage during CT examinations is not straightforward. Modern equipment is simultaneously using 4 and 16 slices. Manufacturers are endeavoring to develop the next generation equipment with 256 slices used simultaneously (expected on the market in the next 1-2 years). This situation sets technology one step forward regarding the dosimetry methods used for organ

  6. CT urethrography. New imaging technique of the urethra

    International Nuclear Information System (INIS)

    Takeyama, Nobuyuki; Munechika, Hirotsugu

    2005-01-01

    The purpose of the study is to assess the usefulness of CT urethrography for evaluation of the posterior urethra and surrounding structures. The CT images were performed with 4 channel multidetector row CT unit. Twenty-six cases (12 cases of CT urethrography and 14 cases of conventional urethrography) were included in this study. 3D-volume rendering (VR) images and VR-multiplaner reconstruction (MPR) sagittal images were compared with conventional retrograde urethrography (RUG) images to evaluate the following anatomical structures; the inferior wall of bladder, the neck of bladder, the posterior urethra, and the prostate. Two radiologists undertook a task of evaluation of the images. There was no significant difference in image quality between RUG and 3D-VR. However, VR-MPR sagittal images were significantly better than RUG or 3D-VR images in any anatomical structures set up beforehand for evaluation. CT urerthrography was useful for evaluation of the posterior urethra and surrounding structures. (author)

  7. Correlation between CT grading and blood interleukin-6 in severe acute pancreatitis

    International Nuclear Information System (INIS)

    Yokohari, Kenji; Hirasawa, Hiroyuki; Oda, Shigeto; Shiga, Hidetoshi; Nakanishi, Kazuya; Nakamura, Masataka

    2003-01-01

    Computed tomography (CT) and an evaluating of the degree of severity in patients with severe acute pancreatitis (SAP) are required to decide the therapeutic strategy. We measured blood interleukin-6 (IL-6) in critically ill patients at our intensive care unit (ICU) in a daily clinical setting. To determine the significance of grading CT findings in SAP, we studied the correlation between CT grading and blood IL-6 in SAP patients on ICU admission. Among 31 SAP cases, 66 were CT grade III, 22 CT grade IV, and 3 cases CT grade V. Patients with a higher CT grade tended to have higher blood IL-6. Data also showed that mean blood IL-6 among SAP patients in stage 2 was significantly higher than that among those in stage 3 (p<0.05). From these results, we concluded that CT grading and IL-6 blood level have a different significance in the management of SAP patients. (author)

  8. CT of portal vein tumor thrombosis. Usefulness of dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Inoue, Yuichi; Tanaka, Masahiro; Nemoto, Yutaka; Nakamura, Kenji [Osaka City Univ. (Japan). Faculty of Medicine

    1983-08-01

    We evaluated CT findings of portal vein tumor thrombosis in 16 hepatomas by plain, contrast and dynamic CT. Plain and contrast CT findings were an enlargement of the portal vein (81%), intraluminal low density area (63%). Dynamic CT enhanced the diagnostic capability of the tumor thrombus as a relatively low density area because of the marked enhancement of the portal vein. In addition, dynamic CT newly demonstrated hyperdense peripheral ring (35%) and arterio portal shunt (35%). It is advisable to select the scan level to include the portal vein when dynamic CT is performed in the patient of hepatocellular carcinoma.

  9. CT images of gossypiboma

    International Nuclear Information System (INIS)

    Jeon, Hae Jeong; Lim, Jong Nam; Choi, Young Chil; Park, Jeong Hee

    1994-01-01

    Surgical sponges retained after laparotomy can cause serious problem if they were not be identified in early state. In these circumstances abdominal CT yields the accurate diagnostic images. The purpose of this report is to present highly indicative findings permitting correct preoperative diagnosis of the gossypiboma. We experienced three cases in which CT showed the images sufficiently characteristic to suggest the correct preoperative diagnosis. We evaluated retrospectively the radiological images of gossypiboma confirmed by operation. Three patients were admitted due to palpable masses. Two female patients had medical histories of cesarean sections and a male patient had been operated due to malignant fibrous histiocytoma, previously. Abdominal CT scan of one case revealed huge ovoid hypodense mass with enhanced peripheral rim. Calcific spots and whirl-like stripes were noted within the lesion. Towel was found in pathologic specimen. CT images of two patients showed well-encapsulated, mixed fluid and soft tissue density mass with several gas bubbles. Surgical sponges were found within abscesses. The authors conclude that these characteristic CT findings and careful histories of surgery are very useful for correct pre-operative diagnosis and permit the guideline for the optimal plan of the surgical treatment

  10. CT of thymoma

    International Nuclear Information System (INIS)

    Sone, Shusuke; Higashihara, Tokuro; Morimoto, Shizuo; Ikezoe, Junpei; Arisawa, Jun

    1982-01-01

    Based on 17 patients with thymoma (8 with myasthenia gravis and 9 free from it); 1. The effectiveness of CT, conventional radiography and pneumomediastinography in the detection of thymomas was determined and the results compared. 2. The CT findings of thymomas were discussed and the CT features which seemed to suggest malignant thymomas were evaluated. The results were as follows: 1. Of the 17 cases with thymomas, 13 were diagnosed from p-a films, 13 from lateral films, and 16 from CT. Of the 16 thymomas, 14 were diagnosed from lateral tomography. Mass densities were shown in all 15 cases in which pneumomediastinography were performed. 2. Benign thymomas showed round or oval smoothly marginated mass. The fatty plane between the mass and the mediastinal structures was nicely preserved. 3. Malignant thymoma frequently showed a plaque-like mass with more or less irregular or lobulated contoures with obliteration of the fatty planes of the cardiovascular structures. Tumor calcification was shown in 4 of 10 malignant thymomas. 4. Slight tumor invasion to the mediastinal pleura and lung was difficult to predict from the CT images. (author)

  11. CT of thymoma

    Energy Technology Data Exchange (ETDEWEB)

    Sone, S.; Higashihara, T.; Morimoto, S.; Ikezoe, J.; Arisawa, J. (Osaka Univ. (Japan). Faculty of Medicine)

    1982-08-01

    Based on 17 patients with thymoma (8 with myasthenia gravis and 9 free from it); 1. The effectiveness of CT, conventional radiography and pneumomediastinography in the detection of thymomas was determined and the results compared. 2. The CT findings of thymomas were discussed and the CT features which seemed to suggest malignant thymomas were evaluated. The results were as follows: 1. Of the 17 cass with thymomas, 13 were diagnosed from p-a films, 13 from lateral films, and 16 from CT. Of the 16 thymomas, 14 were diagnosed from lateral tomography. Mass densities were shown in all 15 cases in which pneumomediastinography were performed. 2. Benign thymomas showed round or oval smoothly marginated mass. The fatty plane between the mass and the mediastinal structures was nicely preserved. 3. Malignant thymoma frequently showed a plaque-like mass with more or less irregular or lobulated contours with obliteration of the fatty planes of the cardiovascular structures. Tumor calcification was shown in 4 of 10 malignant thymomas. 4. Slight tumor invasion to the mediastinal pleura and lung was difficult to predict from the CT images.

  12. CT and MR urography

    International Nuclear Information System (INIS)

    Hadjidekov, G.

    2012-01-01

    Full text: Learning objectives:1) To describe the techniques of CT Urography and of MR urography; 2) To illustrate the benefit of the methods in clinical practice; 3)To present typical cases from the daily practice CT has become the mainstay of uroradiology in adults. CT urography is an excellent technique for the evaluation of urinary tract calculi, trauma, infections, complicated cysts, renal masses, having high sensitivity and specificity for both conditions facilitated by the possibilities for multiplanar imaging of the urinary system. It resembles excretory urography and consists of unenhanced, nephrographic, and pyelographic phases and can be used even as routine investigation. MR urography is a new, modern modality for evaluation of various urological abnormalities providing both morphological and functional information by means of different sequences with or without injection of gadolinium. The method is clinically useful in the evaluation of the collecting system, various variants and congenital abnormalities of the kidney, different cases of obstruction of the excretory system, tumors and inflammatory processes, hematuria. Compared to CT urography, MR urography is particularly beneficial in pediatric group or pregnant patients. It can also be performed in patients with renal insufficiency, iodine allergy and other cases of contraindications to the use of ionizing radiation. CT and MR urography are promising diagnostic methods of the wide spectrum of pathological conditions affecting the urinary tract. They are highly informative and overcome a lot of limitations of the other imaging modalities with the potential to become leading modalities to diagnose kidney diseases and other urogenital disorders.

  13. CT images of gossypiboma

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hae Jeong; Lim, Jong Nam; Choi, Young Chil; Park, Jeong Hee [College of Medicine, Kon-Kuk University, Seoul (Korea, Republic of)

    1994-04-15

    Surgical sponges retained after laparotomy can cause serious problem if they were not be identified in early state. In these circumstances abdominal CT yields the accurate diagnostic images. The purpose of this report is to present highly indicative findings permitting correct preoperative diagnosis of the gossypiboma. We experienced three cases in which CT showed the images sufficiently characteristic to suggest the correct preoperative diagnosis. We evaluated retrospectively the radiological images of gossypiboma confirmed by operation. Three patients were admitted due to palpable masses. Two female patients had medical histories of cesarean sections and a male patient had been operated due to malignant fibrous histiocytoma, previously. Abdominal CT scan of one case revealed huge ovoid hypodense mass with enhanced peripheral rim. Calcific spots and whirl-like stripes were noted within the lesion. Towel was found in pathologic specimen. CT images of two patients showed well-encapsulated, mixed fluid and soft tissue density mass with several gas bubbles. Surgical sponges were found within abscesses. The authors conclude that these characteristic CT findings and careful histories of surgery are very useful for correct pre-operative diagnosis and permit the guideline for the optimal plan of the surgical treatment.

  14. Dual source CT imaging

    International Nuclear Information System (INIS)

    Seidensticker, Peter R.; Hofmann, Lars K.

    2008-01-01

    The introduction of Dual Source Computed Tomography (DSCT) in 2005 was an evolutionary leap in the field of CT imaging. Two x-ray sources operated simultaneously enable heart-rate independent temporal resolution and routine spiral dual energy imaging. The precise delivery of contrast media is a critical part of the contrast-enhanced CT procedure. This book provides an introduction to DSCT technology and to the basics of contrast media administration followed by 25 in-depth clinical scan and contrast media injection protocols. All were developed in consensus by selected physicians on the Dual Source CT Expert Panel. Each protocol is complemented by individual considerations, tricks and pitfalls, and by clinical examples from several of the world's best radiologists and cardiologists. This extensive CME-accredited manual is intended to help readers to achieve consistently high image quality, optimal patient care, and a solid starting point for the development of their own unique protocols. (orig.)

  15. CT in dental osseointegration

    International Nuclear Information System (INIS)

    Witte, D.

    1992-01-01

    Computerised tomography (CT) plays a key role in the pre-surgical evaluation of the alveolar process for titanium dental implants. The successful replacement of lost teeth by tissue integrated tooth root implants is a major advance in clinical dentistry. The paper will discuss briefly the history of osseointegration and how CT is now involved in helping the edentulous patient. CT is considered as a quick and convenient method of obtaining excellent anatomical information about the maxilla. Conventional tomography is difficult to obtain and does not provide valuable cross-sectional images. Exact height and width calculations can be made as well as screening out patients with advanced bone resorption. 3 refs. 6 figs

  16. CT in colon cancer

    International Nuclear Information System (INIS)

    Fujita, Nobuyuki; Hasegawa, Takashi; Kubo, Kozo; Ogawa, Hajime; Sato, Yukihiko; Tomita, Masayoshi; Hanawa, Makoto; Matsuzawa, Tohru; Nishioka, Ken

    1990-01-01

    CT pictures from 59 lesions of advanced colon cancer including rectal cancer were reviewed to evaluate a role of CT in preoperative staging diagnosis. CT findings were recorded following general rules for clinical and pathological studies on cancer of colon rectum and anus, proposed by Japanese society for cancer of colon and rectum. Tumors were detected in 90% of advanced colon cancers. Sensitivity in local extension (S factor) was 58.0%. Sensitivity in lymphonode involvement (N factor) was 50.0%. Sensitivity in final staging diagnosis, dividing colon cancer into two groups below st II and above st III, was 63.3%. Further study should be necessitated to provide useful information for preoperative staging diagnosis of colon cancer. (author)

  17. Axial skeletal CT densitometry

    International Nuclear Information System (INIS)

    Lampmann, L.E.H.

    1982-01-01

    Since the discovery of the Roentgen ray a precise and accurate assessment of bone mineral content has been a challenge to many investigators. A number of methods have been developed but no one satisfied. Considering its technical possibilities computed tomography is very promising in determination of bone mineral content (BMC). The new modality enables BMC estimations in the axial skeletal trabecular bone. CT densitometry can be performed on a normal commercially available third generation whole body CT scanner. No dedicated device in a special clinical set-up is necessary. In this study 106 patients, most of them clinically suspected of osteoporosis, were examined. The new method CT densitometry has been evaluated. The results have been correlated to alternative BMC determination methods. (Auth.)

  18. Cardiac MR imaging: Comparison with echocardiography and dynamic CT

    International Nuclear Information System (INIS)

    Colletti, P.M.; Norris, S.; Raval, J.; Boswell, W.; Lee, K.; Ralls, P.; Haywood, J.; Halls, J.

    1986-01-01

    The authors compared gated cardiac MR imaging with two-dimensional and Doppler echocardiography and dynamic CT. Gated cardiac MR imaging (VISTA unit, 0.5 T) was performed in 55 patients with a variety of conditions. Accuracy of diagnosis was compared. CT showed arterial, valvular, and pericardial calcifications not seen on MR imaging. Many lesions were seen as well on CT as on MR imaging. Two-dimensional echocardiography was superior in demonstrating wall motion and valvular disease. MR imaging was superior in demonstrating myocardial structures

  19. Clinical application of gated CT and dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T; Oyama, Y; Ashida, H; Uji, T [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1980-03-01

    Gated CT and dynamic CT were outlined. Experiences of portal hypertension accompanied by venous mass in posterior mediastinum and the usefulness of dynamic CT for this disease were described. Gated CT of the heart could visualize intracardiac structures and morphological abnormalities by improving technique of post-data-aquisition correlation. Changes with time in CT images of normal kidneys were discussed on patients whose unilateral or bilateral kidneys were thought to be normal and who had received dynamic scan. Dynamic scan could visualize well blood circulation and mechanism of urine excretion in the kidney, which suggests a possibility of CT to detect not only morphological abnormalities but also functional disturbance of the kidney. The effectiveness of conventional CT study might be promoted in dynamic CT of the head.

  20. CT findings of slilcosis

    International Nuclear Information System (INIS)

    Jung, Dong Hee; Kim, Kun Il; Son, Hyun Ju; Ro, Young Jin; Jung, Doo Young; Park, Jae Yeong; Lee, Jun Woo; Kim, Byung Soo

    1996-01-01

    To describe chest radiographic and CT findings of silicosis, and to compare their findings. Ten coal miners and six stonemasons were included in this study. All were male and their mean age was 53.1. The mean duration of dust exposure was 15.2 years(range, 5-30 years) in coal miners and 25.3 years(range, 15-35 years) in stonemasons. Chest radiographs(n=16), conventional CT scans(n=4), and high resolution CT(HRCT) scans(n=13) were evaluated. Parenchymal abnormalities were interpreted on the basis of ILO standard films(1980) in chest radiographs and on the basis of CAP(College of American Pathologists, 1979) in CT(HRCT) films. Chest radiographs revealed large opacities(n=8), small opacities(n=6), and normal findings(n=2). Type r(n=4) and category 1/1(n=2) were most common for small opacities, while for large opacities, category B(n=4) and category c(n=4) were most common. These small and large opacities were located predominantly in the area of the upper and middle lung. Associated findings were emphysema(n=7), eggshell nodal calcifications(n=3), pneumothorax(n=3), C-P angle blunting(n=4), and pleural thickening(n=1). CT scans revealed micronodules(n=16), nodules(n=3), and progressive massive fibrosis(PMF, n=8). All these lesions were located in the upper and middle lungs, especially in the central portion of the posterior lung. PMF showed diffuse and homogenous(n=3) and puntate(n=2) calcifications, cavitations(n=5), air bronchograms(n=3), and necrosis(n=1). Peripheral paracicatrical emphysema was associated with PMF(n=8). Other findings were pneumothorax(n=4), emphysema(n=10), hilar and mediastinal nodal enlargement(n=11) bronchial wall thick- enings(n=6), bronchiectasis(n=1), pleural thickening(n=7), parenchymal fibrosis(n=1), and pulmonary tuberculosis(n=2). Small and large opacities in chest radiographs and micronodules, nodules, and PMFs in CT (HRCT) films were located predominately in the upper and middle lungs, especially in the central portion of the

  1. Normal cranial CT anatomy

    International Nuclear Information System (INIS)

    Gado, M.H.; Rao, K.C.V.G.

    1987-01-01

    The human brain consists of well-known anatomical components. Some parts of these components have been shown to be concerned with certain functions. A complete cranial CT examination consists of a series of several slices obtained in a sequence usually from the base to the vertex of the cranial vault, in the axial mode. The ultimate goal of this chapter is to pinpoint those slices that depict a given anatomical structure or several structures that deal with a given function. To achieve this goal, the discussion of CT cranial anatomy is presented in three sections

  2. CT- and MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Bülow, Steffen; Rosenberg, J

    2002-01-01

    BACKGROUND: Colorectal cancer is the second most frequent cancer and adenomas are widely accepted as precursors to colorectal cancer. Diagnosis and removal of adenomas are recommended to reduce cancer incidence and mortality. The current diagnostic methods include sigmoidoscopy and colonoscopy....... CONCLUSIONS: With the exponential development in computer processing power, CT- and MR colonography holds the promise for future colon examination with the advantages of non-invasiveness, no need for sedation, and probably no bowel preparation. A major disadvantage, however, is the radiation dose during CT...

  3. CT findings of medulloblastoma

    International Nuclear Information System (INIS)

    Tsuchida, Tadashi; Fukuda, Mitsunori; Takeda, Norio; Tanaka, Ryuichi; Ito, Jusuke.

    1982-01-01

    Computed tomography (CT) of ten patients with medulloblastomas was evaluated. Six of them showed solid, nearly homogeneous lesions and a definite enhancement after the infusion of the contrast medium. However, 4 cases showed heterogenous mass lesions composed of areas of a low density and an iso- or slightly high density which was attenuated by contrast enhancement. Histological examinations revealed differentiated medulloblastomas in two of them, but the other two cases were typical medulloblastomas. It should be remembered that medulloblastomas can reveal heterogenous cerebellar midline mass lesions in CT scans. (author)

  4. SedCT: MATLAB™ tools for standardized and quantitative processing of sediment core computed tomography (CT) data collected using a medical CT scanner

    Science.gov (United States)

    Reilly, B. T.; Stoner, J. S.; Wiest, J.

    2017-08-01

    Computed tomography (CT) of sediment cores allows for high-resolution images, three-dimensional volumes, and down core profiles. These quantitative data are generated through the attenuation of X-rays, which are sensitive to sediment density and atomic number, and are stored in pixels as relative gray scale values or Hounsfield units (HU). We present a suite of MATLAB™ tools specifically designed for routine sediment core analysis as a means to standardize and better quantify the products of CT data collected on medical CT scanners. SedCT uses a graphical interface to process Digital Imaging and Communications in Medicine (DICOM) files, stitch overlapping scanned intervals, and create down core HU profiles in a manner robust to normal coring imperfections. Utilizing a random sampling technique, SedCT reduces data size and allows for quick processing on typical laptop computers. SedCTimage uses a graphical interface to create quality tiff files of CT slices that are scaled to a user-defined HU range, preserving the quantitative nature of CT images and easily allowing for comparison between sediment cores with different HU means and variance. These tools are presented along with examples from lacustrine and marine sediment cores to highlight the robustness and quantitative nature of this method.

  5. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... obtain CT images. It is known that high levels of radiation may cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is debatable ...

  6. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... trauma to blood vessels or lung CT is well-suited for visualizing diseases or injury of important ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ...

  7. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... CT is well-suited for visualizing diseases or injury of important organs in the abdomen including the liver, kidney and spleen. CT is sometimes used to: diagnose appendicitis detect ...

  8. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  9. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... medications and allergies. Inform your doctor and the technologist prior to the exam if your child has ... exam. This can be discussed with the CT technologist, the specialist who will be performing the CT ...

  10. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  11. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... vessels. CT scans may be performed on newborns, infants and older children. top of page What are ... heart and blood vessels in children, even newborn infants. Except for the chest x-ray, CT is ...

  12. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... outside of the CT scanner itself is very low. If you suspect you may be pregnant, however, ... cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is ...

  13. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... is Children's CT? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... is used to evaluate: complications from infections such as pneumonia a tumor that arises in the lung ...

  14. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... of imaging in these procedures in children. A diagnosis determined by CT scanning may eliminate the need ...

  15. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... with the CT technologist or nurse at the time of the CT examination. If your child has ... detectors rotate around the patient. At the same time, the examination table is moving through the scanner, ...

  16. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... be performed to evaluate blood vessels throughout the body. With CT, it is possible to obtain very ...

  17. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... such as inflammation of the bronchi (breathing passages) birth defects trauma to blood vessels or lung CT ... used to: diagnose appendicitis detect abdominal tumors or birth defects In the pelvic region, CT scans can ...

  18. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... a very detailed multidimensional view of the body's interior. Refinements in detector technology allow new CT scanners ... to read. top of page What will my child experience during and after the procedure? CT exams ...

  19. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... also be discussed with the CT technologist or nurse at the time of the CT examination. If ... difficulty breathing, you should notify the technologist or nurse, as it may indicate a more severe allergic ...

  20. CT manifestations of liver abscess

    International Nuclear Information System (INIS)

    Yan Jianfeng; Peng Yongjun

    2006-01-01

    Objective: To study CT findings of hepatic abscess. Methods: CT findings and clinical materials of 38 patients with liver abscess verified by aspiration were retrospectively viewed. All patients were examined by non-enhanced and contrast enhanced CT. Results: In 25 cases, inhomogeneous hypodense lesions with unclear demarcation were found on non-enhanced CT. On contrast enhanced CT scan, target or cluster enhancement was found Additionally, air was found within some lesions. In the rest 13 cases with early stage liver abscess, no typical sign was found on non-enhanced CT, while rosette sign and continued enhancement sign were demonstrated after the contrast agent was given. Conclusion: Various CT findings are found in different stages of liver abscess. The diagnosis and differential diagnosis should be based on CT manifestations and clinical history as well. (authors)

  1. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ... best for your child. top of page Additional Information and Resources The Alliance for Radiation Safety in ...

  2. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  3. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... or other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... or other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ...

  5. Abdominal and Pelvic CT

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    Full Text Available ... colitis or Crohn's disease , pancreatitis or liver cirrhosis. cancers of the liver, kidneys, pancreas, ovaries and bladder as well as lymphoma. kidney ... and organs such as the liver, kidneys and pancreas. When you enter the CT ... chance of cancer from excessive exposure to radiation. However, the benefit ...

  6. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... over time. Follow-up examinations are sometimes the best way to see if treatment is working or if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... works very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... area of the body being studied. top of page How is the ...

  8. Abdominal and Pelvic CT

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    Full Text Available ... works very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... area of the body being studied. top of page How is the ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... works very much like other x-ray examinations. Different body parts absorb the x-rays in varying degrees. ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... area of the body being studied. top of page How is the ...

  10. Abdominal and Pelvic CT

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Abdomen ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT ...

  14. Abdominal and Pelvic CT

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    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT ...

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... to help detect diseases of the small bowel, colon and other internal organs and is often used to determine the cause of unexplained pain. CT scanning is fast, painless, noninvasive and accurate. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  18. Abdominal and Pelvic CT

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    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  20. Abdominal and Pelvic CT

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    Full Text Available ... and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed on ... with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. ... Images related to Computed Tomography (CT) - Abdomen and ...

  1. Abdominal and Pelvic CT

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    Full Text Available ... in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much ...

  4. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. ... immediate side effects. Risks There is always a slight chance of ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... conditions may increase the risk of an unusual adverse effect. The radiologist also should know if you have ... CT scanning may eliminate the need for exploratory surgery and surgical ... immediate side effects. Risks There is always a slight chance of ...

  6. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. ... immediate side effects. Risks There is always a slight chance of ...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... lie still is reduced. Though the scanning itself causes no pain, there may be some discomfort from ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... for children who cannot hold still. Motion will cause blurring of the images and degrade the quality ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different body parts absorb the x-rays in varying ...

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different body parts absorb the x-rays in varying ...

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different body parts absorb the x-rays in varying ...

  17. CT-guided puncture

    International Nuclear Information System (INIS)

    Noeldge, G.; Richter, G.M.; Grenacher, L.; Brado, M.; Kauffmann, G.W.

    1996-01-01

    Sonographic and CT-guided punctures allow the evaluation of suspected lesions in the head, thorax, abdomen, retroperitoneum and skeletal system. The size of the lesion to be evaluated determines the size and the diameter of the puncture needle. The quantity of the material obtained will be defined by the diameter of the needle, i.e. fine-needle biopsy is more adequate for cytological than for histological evaluation. Strict adherence to the indications and contraindications for puncture and painstaking performance of the procedure go a long why towards minimizing the complications. The advantage of CT-guided puncture, in contrast to an ultrasound-guided procedure, is visualization during the puncture procedure free from overshadowing. This permits punctures of lesions located deep in the thorax or the abdomen which are overshadowed by the lungs, by air in the small or large bowel or by bone structures. Moreover, this technique yields much more information about the tissues and organs surrounding the suspected lesion. This information is much more investigator-related with ultrasoundguided puncture. Therefore, the CT-guided puncture has become mandatory in the evaluation of suspected lesions. Moreover, using the same technique, percutaneous drainage of fluids in the interpleural space, abscesses in organs, hematomas, lymphoceles and urinomas; ablation of metastases; and sympathicolysis can be carried out. CT-guided puncture thus changes from a minimally invasive diagnostic procedure to a minimally invasive therapy. (orig./MG) [de

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  20. CT image of thymoma

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, Nobuo; Shudo, Yuji; Jahana, Masanobu; Matsuki, Tsutomu; Kotani, Kazuhiko (Tottori Univ., Yonago (Japan). School of Medicine)

    1983-10-01

    Computor tomographic images of 11 patients who had had thymectomy for myasthenia gravis or thymoma were studied retrospectively. Of those 11 patients, malignant thymoma and benign condition including normal thymus were 6 and 5 respectively. On CT, calcification and lobulation with irregular margin seem to be reliable findings of malignancy. Defect or abscence of fatty plane and non-homogenous density are ancillary.

  1. CT image of thymoma

    International Nuclear Information System (INIS)

    Morioka, Nobuo; Shudo, Yuji; Jahana, Masanobu; Matsuki, Tsutomu; Kotani, Kazuhiko

    1983-01-01

    Computor tomographic images of 11 patients who had had thymectomy for myasthenia gravis or thymoma were studied retrospectively. Of those 11 patients, malignant thymoma and benign condition including normal thymus were 6 and 5 respectively. On CT, calcification and lobulation with irregular margin seem to be reliable findings of malignancy. Defect or abscence of fatty plane and non-homogenous density are ancillary. (author)

  2. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ...

  4. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... pancreatic, uterine or ovarian abnormalities, the evaluation and diagnosis with MRI may be preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... shield may stay in the room with their child. However, the technologist will always be able to ...

  6. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... shield may stay in the room with their child. However, the technologist will always be able to ...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... shield may stay in the room with their child. However, the technologist will always be able to ...

  8. Pulmonary hypertension CT imaging

    International Nuclear Information System (INIS)

    Nedevska, A.

    2013-01-01

    Full text: The right heart catheterization is the gold standard in the diagnosis and determines the severity of pulmonary hypertension. The significant technical progress of noninvasive diagnostic imaging methods significantly improves the pixel density and spatial resolution in the study of cardiovascular structures, thus changes their role and place in the overall diagnostic plan. Learning points: What is the etiology, clinical manifestation and general pathophysiological disorders in pulmonary hypertension. What are the established diagnostic methods in the diagnosis and follow-up of patients with pulmonary hypertension. What is the recommended protocol for CT scanning for patients with clinically suspected or documented pulmonary hypertension. What are the important diagnostic findings in CT scan of a patient with pulmonary hypertension. Discussion: The prospect of instantaneous complex - anatomical and functional cardiopulmonary and vascular diagnostics seems extremely attractive. The contrast enhanced multislice computed (CT ) and magnetic resonance imaging are very suitable methods for imaging the structures of the right heart, with the possibility of obtaining multiple projections and three-dimensional imaging reconstructions . There are specific morphological features that, if carefully analyzed, provide diagnostic information. Thus, it is possible to avoid or at least reduce the frequency of use of invasive diagnostic cardiac catheterization in patients with pulmonary hypertension. Conclusion: This review focuses on the use of contrast-enhanced CT for comprehensive evaluation of patients with pulmonary hypertension and presents the observed characteristic changes in the chest, lung parenchyma , the structures of the right half of the heart and pulmonary vessels

  9. Abdominal aspergillosis: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Suk Keu, E-mail: pagoda20@hanmail.net [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Hye Jin, E-mail: kimhyejin@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Byun, Jae Ho, E-mail: jhbyun@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Ah Young, E-mail: aykim@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Lee, Moon-Gyu, E-mail: mglee@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Ha, Hyun Kwon, E-mail: hkha@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of)

    2011-03-15

    Objective: In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients. Materials and methods: CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome. Results: All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum. Conclusion: Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... operates the scanner and monitors your examination in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much ...

  11. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... operates the scanner and monitors your examination in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much ...

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... operates the scanner and monitors your examination in direct visual contact and usually with the ability to hear and talk to you with the use of a speaker and microphone. top of page How does the procedure work? In many ways CT scanning works very much ...

  13. Pediatric CT scan usage in Japan. Results of a hospital survey

    Energy Technology Data Exchange (ETDEWEB)

    Ghotbi, N; Morishita, Mariko; Norimatsu, Nana; Namba, Hiroyuki; Yamashita, Shunichi [Nagasaki Univ., Graduate School of Biomedical Sciences, Nagasaki, Nagasaki (Japan); Ohtsuru, Akira [Nagasaki Univ., Hospital, Takashi Nagai Memorial International Hibakusha Medical Center, Nagasaki, Nagaski (Japan); Ogawa, Yoji; Uetani, Masataka; Moriuchi, Hiroyuki [Nagasaki Univ., Hospital, Nagasaki, Nagasaki (Japan)

    2006-10-15

    The aim of this study was to examine the usage parameters of diagnostic computed tomography (CT) in children because of concerns of possible overuse in Japanese hospitals, including the ''technical'' CT exposure settings and the ''clinical'' grounds for CT requests. We examined the methodology at the radiology department to reduce radiation exposure to children and performed a retrospective study on pediatric CT requests during a 1-year period at Nagasaki University Hospital. The parameters of diagnostic CT usage for minor head trauma and acute appendicitis were studied in detail. CT radiation dose settings are adjusted for children based on guidelines issued by the Japan Radiological Society, with few limitations. CT requests were made for 62% of minor head trauma cases and 76% of cases clinically suspected to be acute appendicitis. These figures are considerably higher than those reported by studies in the United Kingdom, Canada, or the United States. No specific guidelines are advocated regarding CT usage for minor head trauma. The diagnosis of acute appendicitis in children is almost routinely referred for confirmation'' by CT. CT radiation risks to children at Japanese hospitals need to be considered more seriously. Physicians should be encouraged to follow diagnostic algorithms that help avoid unnecessary CT usage in children. (author)

  14. Pediatric CT scan usage in Japan. Results of a hospital survey

    International Nuclear Information System (INIS)

    Ghotbi, N.; Morishita, Mariko; Norimatsu, Nana; Namba, Hiroyuki; Yamashita, Shunichi; Ohtsuru, Akira; Ogawa, Yoji; Uetani, Masataka; Moriuchi, Hiroyuki

    2006-01-01

    The aim of this study was to examine the usage parameters of diagnostic computed tomography (CT) in children because of concerns of possible overuse in Japanese hospitals, including the ''technical'' CT exposure settings and the ''clinical'' grounds for CT requests. We examined the methodology at the radiology department to reduce radiation exposure to children and performed a retrospective study on pediatric CT requests during a 1-year period at Nagasaki University Hospital. The parameters of diagnostic CT usage for minor head trauma and acute appendicitis were studied in detail. CT radiation dose settings are adjusted for children based on guidelines issued by the Japan Radiological Society, with few limitations. CT requests were made for 62% of minor head trauma cases and 76% of cases clinically suspected to be acute appendicitis. These figures are considerably higher than those reported by studies in the United Kingdom, Canada, or the United States. No specific guidelines are advocated regarding CT usage for minor head trauma. The diagnosis of acute appendicitis in children is almost routinely referred for confirmation'' by CT. CT radiation risks to children at Japanese hospitals need to be considered more seriously. Physicians should be encouraged to follow diagnostic algorithms that help avoid unnecessary CT usage in children. (author)

  15. CT Diagnosis of Appendicitis

    Directory of Open Access Journals (Sweden)

    Christopher Libby

    2017-01-01

    Full Text Available History of present illness: A 19-year-old male with no previous medical history presented with 7/10 non-radiating, constant, sharp, periumbilical pain associated with nausea, and four episodes of vomiting. He was seen at urgent care where his labs showed a WBC of 16,000/mcL. He was subsequently sent to the emergency department (ED for concern of appendicitis. Of note, his pain worsened with bumps during the drive to the ED. After arriving to the ED the pain migrated to the right lower quadrant. Computed tomography (CT revealed acute appendicitis and the patient was admitted to the surgery service and taken to the operating room (OR for an appendectomy. Significant findings: The CT abdomen/pelvis with IV contrast shows a dilated appendix (see red outline with thickened, hyperenhancing wall (see blue outline best visualized in the axial and coronal planes. Discussion: Appendicitis is a common diagnosis in the emergency department in patients presenting with abdominal pain, occurring most frequently in young adults with a peak incidence in those aged 10-19.1 Failure to quickly diagnose acute appendicitis can result in perforation rates as high as 80 percent.2 While the diagnosis of appendicitis can be made clinically, CT is a non-invasive modality that improves the detection of appendicitis with sensitivities of 88–100%, specificities of 91–99%, positive predictive values of 92–98%, negative predictive values of 95–100%, and accuracies of 94–98%.3-8 The major advantage of CT over both clinical exam and ultrasound is the ability of the radiologist to exclude acute appendicitis if the appendix appears normal. However, CT carries the risks associated with ionizing radiation. While previously there was some debate on the best choice for type of CT scan and use of IV and oral contrast, recent studies have shown that CT abdomen/pelvis with IV contrast alone is sufficient for diagnosis of appendicitis.9, 10

  16. PET/CT Facility at Radiation Medicine Centre, BARC

    International Nuclear Information System (INIS)

    Baghel, Nawab Singh; Banerjee, Sharmila

    2017-01-01

    Positron Emission Tomography (PET) integrated with Computed Tomography in a single unit (PET/CT) has become an established and valued imaging modality in the clinical arena. Integrated PET/CT has been shown to be more accurate for lesion localisation and characterisation than either PET or CT alone. Image fusion brings together two image datasets with the intention of registering them as closely as possible. Generally, the two image datasets would have been produced on different types of medical imaging devices. Various problems can evolve when using two geographically remote imaging devices. To overcome this, in recent times there has been a move towards the integration of the two medical imaging devices into one physical unit. The use of one imaging unit to produce two different image datasets is known as hybrid imaging

  17. Predictors of pneumothorax after CT-guided transthoracic needle lung biopsy: the role of quantitative CT

    International Nuclear Information System (INIS)

    Chami, H.A.; Faraj, W.; Yehia, Z.A.; Badour, S.A.; Sawan, P.; Rebeiz, K.; Safa, R.; Saade, C.; Ghandour, B.; Shamseddine, A.; Mukherji, D.; Haydar, A.A.

    2015-01-01

    Aim: To evaluate the association of quantitative computed tomography (CT) measures of emphysema with the occurrence of pneumothorax after CT-guided needle lung biopsy (NLB) accounting for other risk factors. Materials and methods: One hundred and sixty-three CT-guided NLBs performed between 2008 and 2013 with available complete chest CT within 30 days were reviewed for the occurrence of post-procedure pneumothorax. Percent emphysema was determined quantitatively as the percentage of lung voxels below −950 HU on chest CT images using automated software. Multivariable regression was used to assess the association of percent emphysema volume with the occurrence of post-procedure pneumothorax. The association of percent emphysema volume with the pneumothorax size and need for chest tube placement after NLB was also explored. Results: Percent emphysema was significantly associated with the incidence of post-NLB pneumothorax (OR=1.10 95% confidence interval: 1.01–1.15; p=0.03) adjusting for lower-lobe lesion location, needle path length, lesion size, number of passes, and pleural needle trajectory angle. Percent emphysema was not associated with the size of the pneumothorax, nor the need for chest tube placement after NLB. Conclusion: Percent emphysema determined quantitatively from chest CT is a significant predictor of post-NLB pneumothorax. - Highlights: • Examine the association between quantitative emphysema measures & post NLB pneumothorax. • The risk of post-NLB pneumothorax increases with every unit increase in percent emphysema. • Percent emphysema is a significant predictor of pneumothorax post transthoracic NLB. • Quantitative analysis of chest CT offers clinicians' objective measures to assess pneumothorax risk.

  18. Effective dose calculation in CT using high sensitivity TLDs

    International Nuclear Information System (INIS)

    Brady, Z.; Johnston, P.N.

    2010-01-01

    Full text: To determine the effective dose for common paediatric CT examinations using thermoluminescence dosimetry (TLD) mea surements. High sensitivity TLD chips (LiF:Mg,Cu,P, TLD-IOOH, Thermo Fisher Scientific, Waltham, MA) were calibrated on a linac at an energy of 6 MY. A calibration was also performed on a superricial X-ray unit at a kilovoltage energy to validate the megavoltage cali bration for the purpose of measuring doses in the diagnostic energy range. The dose variation across large organs was assessed and a methodology for TLD placement in a 10 year old anthropomorphic phantom developed. Effective dose was calculated from the TLD measured absorbed doses for typical CT examinations after correcting for the TLD energy response and taking into account differences in the mass energy absorption coefficients for different tissues and organs. Results Using new tissue weighting factors recommended in ICRP Publication 103, the effective dose for a CT brain examination on a 10 year old was 1.6 millisieverts (mSv), 4.9 mSv for a CT chest exa ination and 4.7 mSv for a CT abdomen/pelvis examination. These values are lower for the CT brain examination, higher for the CT chest examination and approximately the same for the CT abdomen/ pelvis examination when compared with effective doses calculated using ICRP Publication 60 tissue weighting factors. Conclusions High sensitivity TLDs calibrated with a radiotherapy linac are useful for measuring dose in the diagnostic energy range and overcome limitations of output reproducibility and uniformity asso ciated with traditional TLD calibration on CT scanners or beam quality matched diagnostic X-ray units.

  19. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... multislice CT" or "multidetector CT," allow thinner slices to be obtained, resulting in more detail of the body, in a shorter period of time. Modern CT scanners are so fast that they can scan through large sections of the body in just a few seconds. Such speed is beneficial for ...

  20. Postoperative CT in pancreas transplantation

    International Nuclear Information System (INIS)

    Powell, F.E.; Harper, S.J.F.; Callaghan, C.J.; Shaw, A.; Godfrey, E.M.; Bradley, J.A.; Watson, C.J.E.; Pettigrew, G.J.

    2015-01-01

    Aim: To examine the usage and value of computed tomography (CT) following simultaneous pancreas and kidney (SPK) transplantation. Materials and methods: Indications for postoperative CT, key findings, and their influence on management were determined by retrospective analysis. Results: Ninety-eight patients underwent 313 CT examinations. Common indications for the examinations included suspected intra-abdominal collection (31.1%) and elevated serum amylase/lipase (24.1%). CT findings most frequently showed non-specific mild inflammation (27.6%), a normal scan (17.1%) and fluid collections (16.3%). High capillary blood glucose (CBG) was associated with resultant CT demonstration of graft vascular abnormalities, but otherwise, particular clinical indications were not associated with specific CT findings. Conclusion: Clinical findings in patients with SPK transplants are non-specific. The pattern of abnormalities encountered is significantly different to those seen in native pancreatic disease and demands a tailored protocol. CT enables accurate depiction of vascular abnormalities and fluid collections, thus reducing the number of surgical interventions that might otherwise be required. Elevated CBG should prompt urgent CT to exclude potentially reversible vascular complications. - Highlights: • The value of CT following simultaneous pancreas and kidney transplantation was assessed. • 313 CT scans were performed on 98 patients between January 2005 and August 2010. • Elevated blood glucose was associated with CT findings of graft vascular anomalities. • CT was particularly useful in directing operative versus non-operative intervention.

  1. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  2. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... What is Children's CT? What are some common uses of the procedure? How should we prepare for the CT scan? What does the CT equipment look like? How does the procedure work? How is the procedure performed? What will my ...

  3. CT evaluation of acetabular fractures

    Energy Technology Data Exchange (ETDEWEB)

    Piazza, P; Girelli, G; Coran, F; Lutman, M

    1986-01-01

    The paper deals with sixteen cases of acetabular fractures studied with CT. After a short description of the normal CT findings, the different kind of fractures are reported. The usefulness of CT examination in evaluating acetabular fractures and their complications is confirmed both in conservative treatment and surgical approach.

  4. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  5. Do SNOMED CT Relationships Qualify?

    NARCIS (Netherlands)

    Cornet, Ronald

    2008-01-01

    An important feature of SNOMED CT is post-coordination, which is enabled as SNOMED CT specifies refinability of target concepts of relationships. In this paper the use of refinable relationships in SNOMED CT is analysed, and the interplay between refinable and defining relationships. Refinability is

  6. Perfusion CT in acute stroke

    International Nuclear Information System (INIS)

    Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

    2015-01-01

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  7. CT findings of infant epilepsy

    International Nuclear Information System (INIS)

    Hojoh, Hiroatsu; Kataoka, Kenkichi; Nakagawa, Yoshihiro; Nakano, Shozo; Tomita, Yutaka.

    1982-01-01

    CT diagnosis of infantile epilepsy was evaluated. High incidence of abnormal CT findings in infantile spasms and Lennox-Gastaut syndrome was same as in other reports. Comparison between CT findings and neurological complications and that between CT findings and electroencephalogram findings revealed a stronger relationship existing in the former. This suggested that CT is more useful as a measure to detect underlying diseases which are due to organic change of the brain to cause epilepsy, rather than as that to disclose epileptic primary lesions of functional change. (Ueda, J.)

  8. The clinical evaluation of CT and radionuclide examination in renal diseases

    International Nuclear Information System (INIS)

    Kutani, Wataru; Ishida, Hirofumi; Shirakawa, Shigetoshi; Shintaku, Takao; Funaki, Ryo

    1980-01-01

    One hundred and twelve cases of renal diseases were studied by computed tomography (CT) using EMI 5005/12. Of them, 60 were examined by both CT and renal scintigraphy, and comparatively evaluated. The CT units were checked before and after the contrast enhancement. Renal scintigrams were obtained by gamma cameras (PHO/GAMMA HP 6406, PHO/GAMMA LFOV) using 99 M Tc-DMSA. CT was especially useful in diagnosing the renal cysts and the hydronephrosis. Cysts in other organs (liver, spleen and pancreas) were simultaneously ascertained in polycystic diseases. CT was not helpful in diagnosing nephritis and diabetic nephropathy. Floating kidney and horse-shoe kidney were difficult to diagnose with CT. The renal scintigram was the reflection of the renal function, and was relatively more useful than CT in diagnosing horse-shoe kidney, floating kidney and nephritis, while it was not useful for non-functioning kidneys. (author)

  9. Brain tumor and CT, 1

    International Nuclear Information System (INIS)

    Suzuki, Nobuyuki; Katada, Kazuhiro; Shinomiya, Youichi; Sano, Hirotoshi; Kanno, Tetsuo

    1981-01-01

    It is very important for a neurosurgeon to know the consistency of a brain tumor preoperatively, since the information which is of much use in indicating the likely difficulty of the operation, which operative tools should be selected, the amount of bleeding to be expected from the tumor, and so on. The authors, therefore, tried to evaluate the consistency of brain tumors preoperatively 27 cases in which the margin of the tumor was made clear with a homogeneous stain were studied concerning the relationship between the tumor consistency and the CT findings. The results are as follows: 1) A higher CT number on a plain CT indicated a harder consistency of the tumor. 2) A lesser contrast index (CT number on enhancement CT/CT number on plain CT) showed a harder consistency of the tumor. (author)

  10. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  11. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  12. Evaluation of a dual-room sliding gantry CT concept for workflow optimisation in polytrauma and regular in- and outpatient management

    Energy Technology Data Exchange (ETDEWEB)

    Frellesen, Claudia; Boettcher, Marie; Wichmann, Julian L.; Drieske, Martina; Kerl, J. Matthias; Lehnert, Thomas [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Nau, Christoph; Geiger, Emmanuel; Wutzler, Sebastian [Department of Trauma, Reconstructive and Hand Surgery, Clinic of the Goethe University, Frankfurt (Germany); Ackermann, Hanns [Department of Biostatistics and Mathematical Modelling, Clinic of the Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Bauer, Ralf W., E-mail: ralfwbauer@aol.com [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany)

    2015-01-15

    Highlights: • A sliding gantry trauma room CT solution facilitates significantly faster polytrauma management. • Faster and more efficient resumption of regularly scheduled patients due to a two room solution is supported. • Sliding gantry CT achieves the same patient throughput as two separate conventional CT devices. - Abstract: Objectives: To reveal the impact on workflow from introducing a dual-room sliding gantry CT to the trauma room for polytrauma and regularly scheduled in- outpatients with regard to efficiency and degree of capacity utilisation. Materials and methods: Time analysis was performed for 30 polytrauma patients each in 2 different trauma room settings, the new trauma room comprising a sliding gantry CT, the old one a stationary single-room CT. Complete trauma room and diagnostic workup times were manually measured and compared for both groups. In a third scenario, the number of CT scans performed with one single sliding gantry CT and the two-room concept was compared to the number of CT scans performed on two separate regular CT units in a 5 days clinical routine sample. Results: Patients demographics and type of CT examinations were comparable for all patient groups. The median time from patient arrival in the trauma room until beginning of CT scanning was 6 min shorter for the sliding gantry CT group (21 vs.15 min). Sliding gantry CT embedded in a two-room solution achieved 252 CT scans in 5 working days, compared to 250 CT scans on two separate regular CT units with the same man power. Conclusions: Sliding gantry CT in the trauma room allows for significant time saving in the diagnostic workup of polytrauma patients and faster resumption of the regular in- outpatient's CT schedule is possible. With the same man power, the dual-room solution is able to generate the same throughput as two separate CT units.

  13. Evaluation of a dual-room sliding gantry CT concept for workflow optimisation in polytrauma and regular in- and outpatient management

    International Nuclear Information System (INIS)

    Frellesen, Claudia; Boettcher, Marie; Wichmann, Julian L.; Drieske, Martina; Kerl, J. Matthias; Lehnert, Thomas; Nau, Christoph; Geiger, Emmanuel; Wutzler, Sebastian; Ackermann, Hanns; Vogl, Thomas J.; Bauer, Ralf W.

    2015-01-01

    Highlights: • A sliding gantry trauma room CT solution facilitates significantly faster polytrauma management. • Faster and more efficient resumption of regularly scheduled patients due to a two room solution is supported. • Sliding gantry CT achieves the same patient throughput as two separate conventional CT devices. - Abstract: Objectives: To reveal the impact on workflow from introducing a dual-room sliding gantry CT to the trauma room for polytrauma and regularly scheduled in- outpatients with regard to efficiency and degree of capacity utilisation. Materials and methods: Time analysis was performed for 30 polytrauma patients each in 2 different trauma room settings, the new trauma room comprising a sliding gantry CT, the old one a stationary single-room CT. Complete trauma room and diagnostic workup times were manually measured and compared for both groups. In a third scenario, the number of CT scans performed with one single sliding gantry CT and the two-room concept was compared to the number of CT scans performed on two separate regular CT units in a 5 days clinical routine sample. Results: Patients demographics and type of CT examinations were comparable for all patient groups. The median time from patient arrival in the trauma room until beginning of CT scanning was 6 min shorter for the sliding gantry CT group (21 vs.15 min). Sliding gantry CT embedded in a two-room solution achieved 252 CT scans in 5 working days, compared to 250 CT scans on two separate regular CT units with the same man power. Conclusions: Sliding gantry CT in the trauma room allows for significant time saving in the diagnostic workup of polytrauma patients and faster resumption of the regular in- outpatient's CT schedule is possible. With the same man power, the dual-room solution is able to generate the same throughput as two separate CT units

  14. Estimating radiation risk induced by CT screening for Korean population

    Science.gov (United States)

    Yang, Won Seok; Yang, Hye Jeong; Min, Byung In

    2017-02-01

    The purposes of this study are to estimate the radiation risks induced by chest/abdomen computed tomography (CT) screening for healthcare and to determine the cancer risk level of the Korean population compared to other populations. We used an ImPACT CT Patient Dosimetry Calculator to compute the organ effective dose induced by CT screening (chest, low-dose chest, abdomen/pelvis, and chest/abdomen/pelvis CT). A risk model was applied using principles based on the BEIR VII Report in order to estimate the lifetime attributable risk (LAR) using the Korean Life Table 2010. In addition, several countries including Hong Kong, the United States (U.S.), and the United Kingdom, were selected for comparison. Herein, each population exposed radiation dose of 100 mSv was classified according to country, gender and age. For each CT screening the total organ effective dose calculated by ImPACT was 6.2, 1.5, 5.2 and 11.4 mSv, respectively. In the case of Korean female LAR, it was similar to Hong Kong female but lower than those of U.S. and U.K. females, except for those in their twenties. The LAR of Korean males was the highest for all types of CT screening. However, the difference of the risk level was negligible because of the quite low value.

  15. CT in meningitis purulenta

    International Nuclear Information System (INIS)

    Yoshida, Akira; Fujiwara, Katsuhiko; Iino, Shigeru; Ochi, Masaharu; Yoshioka, Hiroshi

    1982-01-01

    Twenty nine infants with meningitis purulenta were classified into 5 groups according to CT findings in the acute stage: cerebral infarction group, subdural hygroma group, ventricular enlargement group, and a group of other diseases. In each group, clinical findings, surgical procedures and prognosis were evaluated. In the cerebral infarction group, although 3 of 4 patients underwent V-P shunt or subdural drainage, remarkable sequelae were found in all the cases. Of 4 subdural hygroma patients, 2 had subdural drainage, and 4 of 8 patients with ventricular enlargement underwent V-P shunt. All the patients of the two groups had favorable prognosis without any sequela. A patient with cerebral herniation in the group of other diseases died in its acute stage. Eleven infants without abnormal CT findings showed normal psychomotor development. (Ueda, J.)

  16. CT of maxillofacial injury

    International Nuclear Information System (INIS)

    DeLaPaz, R.; Brant-Zawadzki, M.; Rowe, L.D.

    1986-01-01

    Computed tomography has the ability to evaluate maxillofacial trauma quickly. The well-known contrast resolution capabilities of CT play a role in the usefulness of this modality. However, it is the image manipulation capability which is of singular advantage in these cases. The spatial resolution of computed tomography has matched that of conventional pluridirectional tomography in current generation equipment. Since a set of axial CT sections can be obtained with automatic table incrementation within 12 minutes, the information content per time of study ratio is improved over that of conventional tomography, despite the fact that image reformation requires extra time on the part of the radiologist. Radiation savings are significantly in favor of computed tomography as well. In the authors' experience, computed tomography is the primary diagnostic imaging modality used in the evaluation of complex facial trauma, after routine screening films are obtained

  17. CT scans in encephalitis

    International Nuclear Information System (INIS)

    Imanishi, Masami; Morimoto, Tetsuya; Iida, Noriyuki; Hisanaga, Manabu; Kinugawa, Kazuhiko

    1980-01-01

    Generally, CT scans reveal a decrease in the volume of the ventricular system, sylvian fissures and cortical sulci in the acute stage of encephalitis, and softening of the cerebral lobes with dilatation of the lateral ventricles and subarachnoidian dilated spaces in the chronic stage. We encountered three cases of encephalitis: mumps (case 1), herpes simplex (case 2), and syphilis (case 3). In case 1, brain edema was seen in the acute stage and brain atrophy in the chronic stage. In case 2, necrosis of the temporal pole, which is pathognomonic in herpes simplex encephalitis, was recognized. And in case 3, multiple lesions whose CT appearance was enhanced by contrast materials were found scattered over the whole brain. These lesions were diagnosed as inflammatory granuloma by histological examination. (author)

  18. CT and MR angiography

    International Nuclear Information System (INIS)

    Bert, A.L.; Marshal, G.

    1995-01-01

    CT-angiography is a new vessel imaging technique based on the volumetric scanning of the region of interst during the first pass of IV bolus injection of contrast medium. MR-angiography is a titally noninvasive technique. The differentiation of flowing blood from the adjecent stationary tissues is based on the detection of blood motion. The flowing blood is highlighted with white light. CT- and MR-angiographic techniques are used to establish% stenoses and occlusions in intracranial arteries; aneurisms; trombosis of intracranial veins and venous angioma; diseases of neck vessels, thoracic vessels, abdominal vessels. Blood flow direction in cirrotic patients with portal hypertension can be determined in the portal vein, as well as the presence of thrombosis

  19. CT findings in mucopolysaccharidoses

    International Nuclear Information System (INIS)

    Tsuchida, Tomio; Nemoto, Shigeru; Fujiwara, Kazue; Hayakawa, Isao; Nihei, Kenji.

    1981-01-01

    The CT findings for four patients with mucopolysaccharidosis were analyzed using a Delta scan-25 (Ohio Nuclear). In three cases of Hunter's syndrome (MPS IIA 13-year-old male, MPS IIB 12-year-old male, and 25-year-old male), a dilatation of the cortical sulci was observed. Moderate dilatations were also seen in the basal cistern, the quadrigeminal cistern, and the ambient cistern. In one case of Hunter's syndrome, a low-density area was observed in the bilateral tharamic regions. An irregular low-density area was also seen in the white matter in some cases. PVL was not apparent in any case. Marked ventricular dilations were observed in cases with mental retardation, for example, in one case of Hurler's syndrome (8-year-old male) and one case of MPS IIA. The circulation and absorbtion of CSF in cortical snbarachnoid spaces were supposed to be moderately retarded by metrizamide CT cisternography. (author)

  20. 4D CT and lung cancer surgical resectability: a technical innovation

    International Nuclear Information System (INIS)

    Troupis, John M.; Pasricha, Sundeep S.; Narayanan, Harish; Rybicki, Frank J.

    2014-01-01

    A 74-year-old man presents with a left upper lobe lung adenocarcinoma, which demonstrated a wide base intimately with the aortic arch. We utilised 4D CT technique with a wide field of view CT unit to preoperatively determine likely surgical resectability. We propose that 4D CT may be of use in further investigating lung cancer with likely invasion of adjacent structures.

  1. Early experience with a picture archiving and communication system for X-ray CT

    International Nuclear Information System (INIS)

    Nakano, Y.; Komori, M.; Minato, K.

    1987-01-01

    A network using fiberoptic ring architecture has been implemented to connect an x-ray CT unit with an image work station and optical disk storage unit. The work station has three noninterlaced cathode-ray tube (CRT) monitors of 1,024 X 1,024 pixels. The optical disk system stores 32 optical disk cartridges (2.6 Gbytes per cartridge). A general-purpose interface bus is used for communication between the CT unit and the network interface unit. Transfer time from CT to interface unit is 40 kbyte/second, 5 seconds per image. On-line data acquisition, long-term archiving, and CT interpretation using CRTs have been tested and the system has been working for 3 months in a clinical environment

  2. CT of pancreatitis

    International Nuclear Information System (INIS)

    Fukuda, Toshio

    1990-01-01

    One hundred and two cases of acute and chronic pancreatitis were studied by computed tomography. Fluid collection was detected by CT in 45 cases, and the common extrapancreatic sites of involvement included the lesser sac (13 cases), anterior pararenal space (9 cases), transverse mesocolon (7 cases) and posterior pararenal space (5 cases). Ten cases of spontaneous resolution of pancreatic pseudocysts were encountered. Cystojejunostomy was done on 6 patients. A 4-to-6-weeks time interval has been currently accepted as necessary for pseudocyst wall maturation. However, the surgery was not possible in two patients in this series since the cyst wall was too thin. It is considered that the time over 3 months is required for surgical anastomosis of the cyst to the gastrointestinal tract. Pancreatic abscess has become the most common cause of death from pancreatitis. In this series pancreatic abscess occurred in 8 patients. Gas collection in the pancreas was observed in only one patient. In the other patients, pseudocysts had become infected and converted to abscesses. The CT number of 4 infected pseudocysts was less than 15 HU. Thus, it was not possible to distinguish infected from noninfected pseudocysts by CT. The author studied 9 patients with focal inflammatory mass of the pancreas with histologically proved severe fibrosis. All masses were small. Angiography showed occlusion or marked stenosis of the splenic vein in 3 cases. The postcontract CT (after intravenous bolus injection) in 7 cases of focal inflammatory mass demonstrated almost equal enhanced effect of the mass as compared with the adjacent normal pancreatic parenchyma. This finding is considered to be useful in distinguishing inflammatory mass from pancreatic carcinoma. (author)

  3. CT in hepatic abscess

    International Nuclear Information System (INIS)

    Fujita, Nobuyuki; Hiromura, Tadao; Saitoh, Hiroya; Choji, Kiyoshi; Takahashi, Hiromichi; Shinohara, Masahiro; Irie, Goroh; Nojima, Takayuki; Morita, Yuzuru.

    1987-01-01

    Fifteen CT pictures from 10 cases of hepatic abscess were reviewed. Rim enhancement was noted only in 2. On the other hand, ill defined low density surrounding central cystic structure was demonstrated in 11. Following contrast injection, this ill defined low density becomes isodense to the normal liver. Histologically, the ill defined low density was granulation tissue composed of neutrophils, lymphocytes and Macrophages. We emphasized the importance of the recognition of the granulation tissue surraounding a cyst of hepatic abscess. (author)

  4. CT in pontine hemorrhage

    International Nuclear Information System (INIS)

    Iwasaki, Yasuo; Kinoshita, Masao; Ikeda, Ken; Sasaki, Atsushi.

    1988-01-01

    The clinical and CT findings in 10 patients with primary pontine hemorrhage were reviewed. All patients were hypertensive. Pontine hemorrhage can be divided into 3 groups from the viewpoint of location of hematomas. These are the tegmentobasilar type, tegmental type and basilar type. The tegmentobasilar type produces characteristic clinical features for pontine hemorrhage and poor prognosis, otherwise, another two types produce atypical clinical features for pontine hemorrhage and good prognosis. (author)

  5. The Appendix on CT

    Energy Technology Data Exchange (ETDEWEB)

    Whitley, S. [Sunnybrook Health Sciences Center, Toronto, Ontario (Canada); Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)], E-mail: siobhanwhitley@yahoo.co.uk; Sookur, P.; McLean, A.; Power, N. [Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)

    2009-02-15

    Appendicitis can be a difficult clinical diagnosis to make. A negative appendicectomy rate of 20% has traditionally been accepted as the consequences of appendiceal perforation can be grave. Cross-sectional imaging is increasingly being employed in the investigation of adults with suspected appendicitis. This review will demonstrate the appearance of the normal appendix on computed tomography (CT) and its appearance in a range of inflammatory and neoplastic processes including appendicitis, Crohn's disease, infections, and benign and malignant tumour000.

  6. Correction of conebeam CT values using a planning CT for derivation of the 'dose of the day'

    International Nuclear Information System (INIS)

    Zijtveld, Mathilda van; Dirkx, Maarten; Heijmen, Ben

    2007-01-01

    Background and purpose: Verification of the actually delivered 3D dose distribution during each treatment fraction ('dose of the day') is the most complete and clinical relevant 'in-vivo' check of an IMRT treatment. To do this, during patient treatment portal dose images are routinely acquired with our electronic portal imaging device to derive the delivered fluence map for each treatment field. In addition, a conebeam CT scan is acquired just prior to treatment to derive the patient geometry at the time of treatment. However, the use of conebeam CT scans for dose calculation is hampered by inaccuracies in the conversion of CT values to electron densities due to an enlarged scatter contribution. Materials and methods: In this work, a method is described for mapping of Hounsfield Units of the planning CT to the conebeam CT scan, while accounting for non-rigidity in the anatomy, e.g. related to weight loss, in an approximate way. The method was validated for head and neck cancer patients by comparing dose distributions calculated using adjusted Hounsfield Units with a golden standard. Results and conclusions: The observed dose differences were less than 1% in the majority of points, and in at least 96% of the points a 3D γ analysis resulted in γ values of less than 1 when applying a 2%/2 mm criterion, showing that this straightforward approach allows for an accurate dose calculation based on conebeam CT scans

  7. Estimating cancer risks to adults undergoing body CT examinations

    International Nuclear Information System (INIS)

    Huda, W.; He, W.

    2012-01-01

    The purpose of the study is to estimate cancer risks from the amount of radiation used to perform body computed tomography (CT) examination. The ImPACT CT Patient Dosimetry Calculator was used to compute values of organ doses for adult body CT examinations. The radiation used to perform each examination was quantified by the dose-length product (DLP). Patient organ doses were converted into corresponding age and sex dependent cancer risks using data from BEIR VII. Results are presented for cancer risks per unit DLP and unit effective dose for 11 sensitive organs, as well as estimates of the contribution from 'other organs'. For patients who differ from a standard sized adult, correction factors based on the patient weight and antero-posterior dimension are provided to adjust organ doses and the corresponding risks. At constant incident radiation intensity, for CT examinations that include the chest, risks for females are markedly higher than those for males, whereas for examinations that include the pelvis, risks in males were slightly higher than those in females. In abdominal CT scans, risks for males and female patients are very similar. For abdominal CT scans, increasing the patient age from 20 to 80 resulted in a reduction in patient risks of nearly a factor of 5. The average cancer risk for chest/abdomen/pelvis CT examinations was ∼26 % higher than the cancer risk caused by 'sensitive organs'. Doses and radiation risks in 80 kg adults were ∼10 % lower than those in 70 kg patients. Cancer risks in body CT can be estimated from the examination DLP by accounting for sex, age, as well as patient physical characteristics. (authors)

  8. Role of Anatomic Variations of Paranasal Sinuses on the ...

    African Journals Online (AJOL)

    2017-05-09

    May 9, 2017 ... and optic nerve, the surgeon does not only see the critical points for ..... narrows ostiomeatal unit and causes sinusitis, we did not find any statistically ... penetration into the middle cranial fossa, and if it is together with a ...

  9. CT in neuromuscular disorders: A comparison of CT and histology

    International Nuclear Information System (INIS)

    Vliet, A.M. van der; Thijssen, H.O.M.; Merx, J.L.; Joosten, E.

    1988-01-01

    The value of CT-examination of the muscles compared to histology was studied in a retrospective analysis of 30 patients with clinical suspicion of neuromuscular disorder. In the evaluation of the CT-results descriptive criteria were used. The histologic diagnosis came from needle-biopsies taken from the quadriceps muscle. Considering the whole group of neuromuscular disorders, CT has an overall accuracy of 84.8%, a positive predictive value of 95.5% and a negative predictive value of 63.6%. This makes the use of CT as a diagnostic tool in neuromuscular disorders a reliable examination technique. In patients with a polymyositis there is even a 100% correlation between CT findings and biopsy results. Discrepancy between the biopsy results is remarkable of the quadriceps muscle and the CT findings: The number of abnormal histological findings is twice the number of abnormal CT findings. Using the more proximal gluteal region as a biopsy site would have decreased this discrepancy and would therefore have given a better correlation between CT and histology. The choice of protocol in determining the levels to be scanned is of great importance in achieving good reproducability in follow-up CT examinations. (orig.)

  10. Study on the testing standards of quality assurance for CT image

    International Nuclear Information System (INIS)

    Liu Jingxin; Yang Haishan; Liu Gang; Wang Liyun

    2000-01-01

    Objective: To establish national testing standards of quality assurance for CT image. Methods: 104 sets of CT system were tested using quality assurance test phantoms and devices including American RMI 461A, RMI 463, MDH 1015 C with ION Chamber, Sweden UNF 9004 kvp meter. These CT were made from different manufacturers including out of date of CT and state-of-art spiral CT system. Thirteen kinds of standards on CT from different countries and 87 sets of technical specifications of CT were collected. The results of the test were compared using phantoms of RMI, Victoreen, Catphan on the same CT system (Siemens HQS). Results: Based on the test results of this study, with reference to the foreign standards and some of regulations in China, CT test items should include high contrast resolution, low contrast resolution, noise, uniformity, mean CT unit, dose slice thickness, localization light, positioning of patient support and gantry tilt. Standards including acceptance test, status test, and constancy test were made in specification. Among them, constancy test equals to IEC 122-2-6; items and results in acceptance test are stricter than in the status test; and low contrast resolution, uniformity, localization light accuracy and positioning of patient support in the acceptance test are even stricter than that in foreign standards. Conclusion: The testing standards of quality assurance for CT developed in this study shows practical and useful in China, which supplemented to the existing international standards

  11. CT of diffuse pulmonary diseases

    International Nuclear Information System (INIS)

    Itoh, Harumi; Murata, Kiyoshi; Todo, Giro

    1987-01-01

    While the theory of chest radiographic interpretation in diagnosing diffuse pulmonary diseases has not yet been established, X-ray computed tomography (CT), having intrinsic high contrast resolution and improved spatial resolution, has proved to offer important imformation concerning the location and invasion of diffuse pulmonary lesions. This study related to CT-pathologic correlation, focusing on perivascular interstitial space and secondary pulmonary lobule at macroscopic levels. The perivascular interstitial space was thickened as a result of the infiltration of cancer, granulomas, and inflammatory cells. This finding appeared as irregular contour of the blood vessel on CT. Centrilobular nodules were distributed at the tip of the bronchus or pulmonary artery on CT. The distance from the terminal and respiratory bronchioles to the lobular border was 2 to 3 mm. Lobular lesions were delineated as clear margin on CT. Contribution of these CT features to chest radiographic interpretation must await further studies. (Namekawa, K.)

  12. CT of the normal and pathologic stapes

    International Nuclear Information System (INIS)

    Veillon, F.; Meriot, P.; Bintner, M.; Baur, P.; Bourjat, P.

    1991-01-01

    This paper reports on CT in the pathologic stapes. The radiologic aspect of the stapes was analyzed in 287 patients with noncholesteatomatous chronic otitis media (n = 46), cholesteatoma (n = 162), malformations (n = 52), and otosclerosis (n = 27) by using axial and, occasionally, coronal sections. Two CT scanners (M1 and M2) that differ in spatial resolution were used. The radiologic and surgical results are presented. In chronic cholesteatomous otitis, we analyzed two populations, P1 and P2. In the P1 population, (n = 92), studied on the M1 unit, there was stapes destruction in 39% (n = 36), versus 38% (n = 27) in the P2 population (n = 70), studied on the M2 unit. In P1, the diagnostic sensitivity was 97% and specificity was 78%. In P2, the sensitivity was 100% and specificity was 95%. The specificity of P2 was greater than that of P1 because of the smaller number of false-positive diagnoses with the M2 unit. Equivalent results are obtained in the malformation (n = 29) and trauma (n = 16) cases. In stapedo-vestibular otosclerosis, studied only with M2, the sensitivity was 92% and specificity was 100%

  13. Comparison of CT numbers between cone-beam CT and multi-detector CT

    International Nuclear Information System (INIS)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, ρ(g/cm 3 ), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were ρ=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, ρ=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, ρ=0.001 H+1.43 with R2 value of 0.980 for i-CAT and ρ=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  14. Comparison of CT numbers between cone-beam CT and multi-detector CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-06-15

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, {rho}(g/cm{sup 3}), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were {rho}=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, {rho}=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, {rho}=0.001 H+1.43 with R2 value of 0.980 for i-CAT and {rho}=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  15. CT finding of emphysematous gastritis

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang Won; Juhn, Jae Ryang; Cha, Seong Sook; Eun, Tchoong Kie; Chung, Duck Hwan [Inje Medical College Paik HospitalYonsei University College of Medicine, Seoul (Korea, Republic of)

    1988-12-15

    Emphysematous gastritis is a rare entity of infectious gastritis caused by gas-forming organisms and only 32 cases have been reported. CT is helpful in the diagnosis particularly in mild cases that there is only a small amount of gas. Typical CT findings of emphysematous gastritis are gas bubbles within the irregular thickened gastric wall and dilated stomach filled with secretions, debris and a large amount of gas. We report a case that was diagnosed by CT and operation.

  16. CT finding of emphysematous gastritis

    International Nuclear Information System (INIS)

    Ahn, Sang Won; Juhn, Jae Ryang; Cha, Seong Sook; Eun, Tchoong Kie; Chung, Duck Hwan

    1988-01-01

    Emphysematous gastritis is a rare entity of infectious gastritis caused by gas-forming organisms and only 32 cases have been reported. CT is helpful in the diagnosis particularly in mild cases that there is only a small amount of gas. Typical CT findings of emphysematous gastritis are gas bubbles within the irregular thickened gastric wall and dilated stomach filled with secretions, debris and a large amount of gas. We report a case that was diagnosed by CT and operation.

  17. CT features of peritonitis carcinomatosa

    International Nuclear Information System (INIS)

    Ishii, Chikako; Kaneko, Kenji; Kato, Hitonari; Tada, Shinpei

    1988-01-01

    Fifty patients with peritonitis carcinomatosa were evaluated with computed tomography (CT). CT findings included evidence of mesenteric thickening (60 %), solid mass (20 %), loculated ascites (16 %), ascites (14 %), partly dilated intestine (10 %). Mesenteric thickening showed both intraperitoneal and subperitoneal metastasis. Arrested flow of ascitic fluid (loculated ascites) was one of the most predicting findings of peritonitis carcinomatosa. The seven false negative cases related to small metastatic foci, long distance between autopsy and the last CT examination, or paucity of intraabdominal fat. (author)

  18. CT dose management

    International Nuclear Information System (INIS)

    Zasheva, Ts.; Georgiev, E.; Kirova, G.

    2013-01-01

    Full text: Introduction: In recent decades Computed Tomography established itself as one of the most common study with a very wide range of applications and techniques of scanning. Best diagnostic value of the method resist to the risks of ionizing radiation, as statistics show that CT is one of the main sources of continuously increasing dose to the population. What you will learn: The physical parameters of the X-ray tube and the principles of image reconstruction; The relationship between variables parameters and the received dose; The ratio between the force and voltage of the current to the image quality, Influence of the used contrast medium to the physical properties of the image, The ratio of patient BMI to image processing, Effective use of knowledge for the optimal CT protocol. Discussions: The goal to reduce the dose received by the patient during a CT scan while keeping the diagnostic quality of the image puts to the test as handset X-ray producers and technicians who need to master the technique of study protocol forming as well as to balance the harm - benefit ratio. Among the most popular techniques are these of dose modulation, low-dose computed tomography at the expense of a reduction of the current or voltage intensity, and control of the number of post-processing algorithms for the image reconstruction. Conclusion: The training of radiologists and X-ray technicians plays a major role in optimizing of technical parameters in view of the reduction of the dose for the patient, while maintaining the diagnostic quality of the image

  19. CtOS Enabler

    OpenAIRE

    Crespo Cepeda, Rodrigo; El Yamri El Khatibi, Meriem; Carrera García, Juan Manuel

    2015-01-01

    Las Smart Cities son, indudablemente, el futuro próximo de la tecnología al que nos acercamos cada día, lo que se puede observar en la abundancia de dispositivos móviles entre la población, que informatizan la vida cotidiana mediante el uso de la geolocalización y la información. Pretendemos unir estos dos ámbitos con CtOS Enabler para crear un estándar de uso que englobe todos los sistemas de Smart Cities y facilite a los desarrolladores de dicho software la creación de nuevas herramientas. ...

  20. High Dose MicroCT Does Not Contribute Toward Improved MicroPET/CT Image Quantitative Accuracy and Can Limit Longitudinal Scanning of Small Animals

    Directory of Open Access Journals (Sweden)

    Wendy A. McDougald

    2017-10-01

    Full Text Available Obtaining accurate quantitative measurements in preclinical Positron Emission Tomography/Computed Tomography (PET/CT imaging is of paramount importance in biomedical research and helps supporting efficient translation of preclinical results to the clinic. The purpose of this study was two-fold: (1 to investigate the effects of different CT acquisition protocols on PET/CT image quality and data quantification; and (2 to evaluate the absorbed dose associated with varying CT parameters.Methods: An air/water quality control CT phantom, tissue equivalent material phantom, an in-house 3D printed phantom and an image quality PET/CT phantom were imaged using a Mediso nanoPET/CT scanner. Collected data was analyzed using PMOD software, VivoQuant software and National Electric Manufactures Association (NEMA software implemented by Mediso. Measured Hounsfield Unit (HU in collected CT images were compared to the known HU values and image noise was quantified. PET recovery coefficients (RC, uniformity and quantitative bias were also measured.Results: Only less than 2 and 1% of CT acquisition protocols yielded water HU values < −80 and air HU values < −840, respectively. Four out of 11 CT protocols resulted in more than 100 mGy absorbed dose. Different CT protocols did not impact PET uniformity and RC, and resulted in <4% overall bias relative to expected radioactive concentration.Conclusion: Preclinical CT protocols with increased exposure times can result in high absorbed doses to the small animals. These should be avoided, as they do not contributed toward improved microPET/CT image quantitative accuracy and could limit longitudinal scanning of small animals.