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Sample records for ct screening studies

  1. Recruitment for 'A pilot study of randomized controlled trial to evaluate the efficacy of lung cancer screening by thoracic CT'

    International Nuclear Information System (INIS)

    Sagawa, Motoyasu; Tanaka, Makoto; Mizukami, Satoru

    2011-01-01

    The objective of this study was to evaluate the efficacy of lung cancer screening by thoracic computed tomography (CT), a randomized controlled trial was planned in Japan. The randomized trial was designed as follows: participants were randomly assigned into 2 groups, CT group and XP group; XP group would receive 10 times of lung cancer screening by chest x-ray annually for 10 years; smokers in CT group would receive 10 times of lung cancer screening by thoracic CT annually for 10 years; non-smokers in CT group would receive 3 times of lung cancer screening by thoracic CT and 7 times of chest x-ray during 10 years. A pilot study was performed to evaluate the feasibility of the trial. A letter for recruitment to participate in the above trial was mailed to the citizens in Hakui City, who were 50-64 years old and underwent regular lung cancer screening using chest x-ray this year. In the letter we explained that the efficacy of lung cancer screening by thoracic CT had not been proved yet; only half of the participants could undergo thoracic CT screening; thoracic CT screening might cause unfavorable consequences like radiation exposure, false positives or overdiagnosis. Of 329 persons who received the letter of recruitment, 117 replied. After meeting with us for detailed explanation, 111 persons participated in the above randomized trial. The compliance of recruitment is high (approximately one third) and the above trial may be feasible. (author)

  2. Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT

    International Nuclear Information System (INIS)

    Picozzi, Giulia; Paci, Enrico; Lopes Pegna, Andrea

    2005-01-01

    Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64±4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was [it

  3. Study of the usefulness of large intestine screening inspections using multi-slice CT (MSCT)

    International Nuclear Information System (INIS)

    Yamasaki, Michihiro; Nonogaki, Hidehiko; Hara, Koji; Naruse, Yutaka; Hara, Hiroto; Suematsu, Seiji; Yanase, Tadahiko; Otou, Taiji

    2005-01-01

    CT-colonography (CT-C), a new diagnostic imaging technique for cancer of the large intestine-which is increasing rapidly owing to westernized eating habits-has advanced from the developmental stage to the stage of practical application, thanks to progress in MSCT and workstation development. Therefore, based on the results of CT-C application using 16 lines of MSCT to a screening test, we reviewed the usefulness of CT-C in our clinic. We supplemented defective depiction, and found that change of position was effective for virtual image exclusion. We consider that CT-C can support diagnosis if the target of screening tests is a polypoid lesion of more than 6 mm. In addition, it is expected that the number of examinations performed during office visits will increase because of the decreased invasiveness of the procedure, its lack of pain, and its ability to provide early lesion detection. (author)

  4. Radiation dose reduction for CT lung cancer screening using ASIR and MBIR: a phantom study.

    Science.gov (United States)

    Mathieu, Kelsey B; Ai, Hua; Fox, Patricia S; Godoy, Myrna Cobos Barco; Munden, Reginald F; de Groot, Patricia M; Pan, Tinsu

    2014-03-06

    The purpose of this study was to reduce the radiation dosage associated with computed tomography (CT) lung cancer screening while maintaining overall diagnostic image quality and definition of ground-glass opacities (GGOs). A lung screening phantom and a multipurpose chest phantom were used to quantitatively assess the performance of two iterative image reconstruction algorithms (adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR)) used in conjunction with reduced tube currents relative to a standard clinical lung cancer screening protocol (51 effective mAs (3.9 mGy) and filtered back-projection (FBP) reconstruction). To further assess the algorithms' performances, qualitative image analysis was conducted (in the form of a reader study) using the multipurpose chest phantom, which was implanted with GGOs of two densities. Our quantitative image analysis indicated that tube current, and thus radiation dose, could be reduced by 40% or 80% from ASIR or MBIR, respectively, compared with conventional FBP, while maintaining similar image noise magnitude and contrast-to-noise ratio. The qualitative portion of our study, which assessed reader preference, yielded similar results, indicating that dose could be reduced by 60% (to 20 effective mAs (1.6 mGy)) with either ASIR or MBIR, while maintaining GGO definition. Additionally, the readers' preferences (as indicated by their ratings) regarding overall image quality were equal or better (for a given dose) when using ASIR or MBIR, compared with FBP. In conclusion, combining ASIR or MBIR with reduced tube current may allow for lower doses while maintaining overall diagnostic image quality, as well as GGO definition, during CT lung cancer screening.

  5. Longitudinal follow-up study of smoking-induced emphysema progression in low-dose CT screening of lung cancer

    Science.gov (United States)

    Suzuki, H.; Matsuhiro, M.; Kawata, Y.; Niki, N.; Nakano, Y.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, Masahiro; Moriyama, N.

    2014-03-01

    Chronic obstructive pulmonary disease is a major public health problem that is predicted to be third leading cause of death in 2030. Although spirometry is traditionally used to quantify emphysema progression, it is difficult to detect the loss of pulmonary function by emphysema in early stage, and to assess the susceptibility to smoking. This study presents quantification method of smoking-induced emphysema progression based on annual changes of low attenuation volume (LAV) by each lung lobe acquired from low-dose CT images in lung cancer screening. The method consists of three steps. First, lung lobes are segmented using extracted interlobar fissures by enhancement filter based on fourdimensional curvature. Second, LAV of each lung lobe is segmented. Finally, smoking-induced emphysema progression is assessed by statistical analysis of the annual changes represented by linear regression of LAV percentage in each lung lobe. This method was applied to 140 participants in lung cancer CT screening for six years. The results showed that LAV progressions of nonsmokers, past smokers, and current smokers are different in terms of pack-year and smoking cessation duration. This study demonstrates effectiveness in diagnosis and prognosis of early emphysema in lung cancer CT screening.

  6. Virtual Colonoscopy Screening With Ultra Low-Dose CT and Less-Stressful Bowel Preparation: A Computer Simulation Study

    Science.gov (United States)

    Wang, Jing; Wang, Su; Li, Lihong; Fan, Yi; Lu, Hongbing; Liang, Zhengrong

    2008-10-01

    Computed tomography colonography (CTC) or CT-based virtual colonoscopy (VC) is an emerging tool for detection of colonic polyps. Compared to the conventional fiber-optic colonoscopy, VC has demonstrated the potential to become a mass screening modality in terms of safety, cost, and patient compliance. However, current CTC delivers excessive X-ray radiation to the patient during data acquisition. The radiation is a major concern for screening application of CTC. In this work, we performed a simulation study to demonstrate a possible ultra low-dose CT technique for VC. The ultra low-dose abdominal CT images were simulated by adding noise to the sinograms of the patient CTC images acquired with normal dose scans at 100 mA s levels. The simulated noisy sinogram or projection data were first processed by a Karhunen-Loeve domain penalized weighted least-squares (KL-PWLS) restoration method and then reconstructed by a filtered backprojection algorithm for the ultra low-dose CT images. The patient-specific virtual colon lumen was constructed and navigated by a VC system after electronic colon cleansing of the orally-tagged residue stool and fluid. By the KL-PWLS noise reduction, the colon lumen can successfully be constructed and the colonic polyp can be detected in an ultra low-dose level below 50 mA s. Polyp detection can be found more easily by the KL-PWLS noise reduction compared to the results using the conventional noise filters, such as Hanning filter. These promising results indicate the feasibility of an ultra low-dose CTC pipeline for colon screening with less-stressful bowel preparation by fecal tagging with oral contrast.

  7. Radiation risk from CT: implications for cancer screening.

    Science.gov (United States)

    Albert, Jeffrey M

    2013-07-01

    The cancer risks associated with patient exposure to radiation from medical imaging have become a major topic of debate. The higher doses necessary for technologies such as CT and the increasing utilization of these technologies further increase medical radiation exposure to the population. Furthermore, the use of CT for population-based cancer screening continues to be explored for common malignancies such as lung cancer and colorectal cancer. Given the known carcinogenic effects of ionizing radiation, this warrants evaluation of the balance between the benefit of early cancer detection and the risk of screening-induced malignancy. This report provides a brief review of the process of radiation carcino-genesis and the literature evaluating the risk of malignancy from CT, with a focus on the risks and benefits of CT for cancer screening. The available data suggest a small but real risk of radiation-induced malignancy from CT that could become significant at the population level with widespread use of CT-based screening. However, a growing body of literature suggests that the benefits of CT screening for lung cancer in high-risk patients and CT colonography for colorectal cancer may significantly outweigh the radiation risk. Future studies evaluating the benefits of CT screening should continue to consider potential radiation risks.

  8. Interval lung cancer after a negative CT screening examination: CT findings and outcomes in National Lung Screening Trial participants

    International Nuclear Information System (INIS)

    Gierada, David S.; Pinsky, Paul F.; Duan, Fenghai; Garg, Kavita; Hart, Eric M.; Kazerooni, Ella A.; Nath, Hrudaya; Watts, Jubal R.; Aberle, Denise R.

    2017-01-01

    This study retrospectively analyses the screening CT examinations and outcomes of the National Lung Screening Trial (NLST) participants who had interval lung cancer diagnosed within 1 year after a negative CT screen and before the next annual screen. The screening CTs of all 44 participants diagnosed with interval lung cancer (cases) were matched with negative CT screens of participants who did not develop lung cancer (controls). A majority consensus process was used to classify each CT screen as positive or negative according to the NLST criteria and to estimate the likelihood that any abnormalities detected retrospectively were due to lung cancer. By retrospective review, 40/44 cases (91%) and 17/44 controls (39%) met the NLST criteria for a positive screen (P < 0.001). Cases had higher estimated likelihood of lung cancer (P < 0.001). Abnormalities included pulmonary nodules ≥4 mm (n = 16), mediastinal (n = 8) and hilar (n = 6) masses, and bronchial lesions (n = 6). Cancers were stage III or IV at diagnosis in 32/44 cases (73%); 37/44 patients (84%) died of lung cancer, compared to 225/649 (35%) for all screen-detected cancers (P < 0.0001). Most cases met the NLST criteria for a positive screen. Awareness of missed abnormalities and interpretation errors may aid lung cancer identification in CT screening. (orig.)

  9. Interval lung cancer after a negative CT screening examination: CT findings and outcomes in National Lung Screening Trial participants

    Energy Technology Data Exchange (ETDEWEB)

    Gierada, David S. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, Box 8131, St. Louis, MO (United States); Pinsky, Paul F. [National Cancer Institute, Bethesda, MD (United States); Duan, Fenghai [Brown University School of Public Health, Department of Biostatistics and Center for Statistical Sciences, Providence, RI (United States); Garg, Kavita [University of Colorado School of Medicine, Mail Stop F726, Box 6510, Aurora, CO (United States); Hart, Eric M. [Northwestern University, Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Kazerooni, Ella A. [University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Nath, Hrudaya; Watts, Jubal R. [University of Alabama at Birmingham School of Medicine, Department of Radiology-JTN370, Birmingham, AL (United States); Aberle, Denise R. [David Geffen School of Medicine at UCLA, Department of Radiological Sciences, Los Angeles, CA (United States)

    2017-08-15

    This study retrospectively analyses the screening CT examinations and outcomes of the National Lung Screening Trial (NLST) participants who had interval lung cancer diagnosed within 1 year after a negative CT screen and before the next annual screen. The screening CTs of all 44 participants diagnosed with interval lung cancer (cases) were matched with negative CT screens of participants who did not develop lung cancer (controls). A majority consensus process was used to classify each CT screen as positive or negative according to the NLST criteria and to estimate the likelihood that any abnormalities detected retrospectively were due to lung cancer. By retrospective review, 40/44 cases (91%) and 17/44 controls (39%) met the NLST criteria for a positive screen (P < 0.001). Cases had higher estimated likelihood of lung cancer (P < 0.001). Abnormalities included pulmonary nodules ≥4 mm (n = 16), mediastinal (n = 8) and hilar (n = 6) masses, and bronchial lesions (n = 6). Cancers were stage III or IV at diagnosis in 32/44 cases (73%); 37/44 patients (84%) died of lung cancer, compared to 225/649 (35%) for all screen-detected cancers (P < 0.0001). Most cases met the NLST criteria for a positive screen. Awareness of missed abnormalities and interpretation errors may aid lung cancer identification in CT screening. (orig.)

  10. Pulmonary function and CT biomarkers as risk factors for cardiovascular events in male lung cancer screening participants: the NELSON study

    International Nuclear Information System (INIS)

    Takx, Richard A.P.; Hoesein, Firdaus A.A.M.; Mali, Willem P.T.M.; Leiner, Tim; Jong, Pim A. de; Vliegenthart, Rozemarijn; Isgum, Ivana; Koning, Harry J. de; Aalst, Carlijn M. van der; Zanen, Pieter; Lammers, Jan-Willem J.; Groen, Harry J.M.; Rikxoort, Eva M. van; Ginneken, Bram van; Schmidt, Michael; Oudkerk, Matthijs

    2015-01-01

    The objective of this study was to investigate the association of spirometry and pulmonary CT biomarkers with cardiovascular events. In this lung cancer screening trial 3,080 male participants without a prior cardiovascular event were analysed. Fatal and non-fatal cardiovascular events were included. Spirometry included forced expiratory volume measured in units of one-second percent predicted (FEV 1 %predicted) and FEV 1 divided by forced vital capacity (FVC; FEV 1 /FVC). CT examinations were quantified for coronary artery calcium volume, pulmonary emphysema (perc15) and bronchial wall thickness (pi10). Data were analysed via a Cox proportional hazard analysis, net reclassification improvement (NRI) and C-indices. 184 participants experienced a cardiovascular event during a median follow-up of 2.9 years. Age, pack-years and smoking status adjusted hazard ratios were 0.992 (95 % confidence interval (CI) 0.985-0.999) for FEV 1 %predicted, 1.000 (95%CI 0.986-1.015) for FEV 1 /FVC, 1.014 (95%CI 1.005-1.023) for perc15 per 10 HU, and 1.269 (95%CI 1.024-1.573) for pi10 per 1 mm. The incremental C-index ( 3 , an increase in C-index of 0.076 and an NRI of 16.9 % (P < 0.0001). Pulmonary CT biomarkers and spirometry measurements were significantly associated with cardiovascular events, but did not contain clinically relevant independent prognostic information for cardiovascular events. (orig.)

  11. Implementation of lung cancer CT screening in the Nordic countries

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Sørensen, Jens Benn; Saghir, Zaigham

    2017-01-01

    INTRODUCTION: We review the current knowledge of CT screening for lung cancer and present an expert-based, joint protocol for the proper implementation of screening in the Nordic countries. MATERIALS AND METHODS: Experts representing all the Nordic countries performed literature review...... and concensus for a joint protocol for lung cancer screening. RESULTS AND DISCUSSION: Areas of concern and caution are presented and discussed. We suggest to perform CT screening pilot studies in the Nordic countries in order to gain experience and develop specific and safe protocols for the implementation...

  12. Evaluation of total workstation CT interpretation quality: a single-screen pilot study

    Science.gov (United States)

    Beard, David V.; Perry, John R.; Muller, Keith E.; Misra, Ram B.; Brown, P.; Hemminger, Bradley M.; Johnston, Richard E.; Mauro, J. Matthew; Jaques, P. F.; Schiebler, M.

    1991-07-01

    An interpretation report, generated with an electronic viewbox, is affected by two factors: image quality, which encompasses what can be seen on the display, and computer human interaction (CHI), which accounts for the cognitive load effect of locating, moving, and manipulating images with the workstation controls. While a number of subject experiments have considered image quality, only recently has the affect of CHI on total interpretation quality been measured. This paper presents the results of a pilot study conducted to evaluate the total interpretation quality of the FilmPlane2.2 radiology workstation for patient folders containing single forty-slice CT studies. First, radiologists interpreted cases and dictated reports using FilmPlane2.2. Requisition forms were provided. Film interpretation was provided by the original clinical report and interpretation forms generated from a previous experiment. Second, an evaluator developed a list of findings for each case based on those listed in all the reports for each case and then evaluated each report for its response on each finding. Third, the reports were compared to determine how well they agreed with one another. Interpretation speed and observation data was also gathered.

  13. Radiation exposure in whole body CT screening.

    Science.gov (United States)

    Suresh, Pamidighantam; Ratnam, S V; Rao, K V J

    2011-04-01

    Using a technology that "takes a look" at people's insides and promises early warnings of cancer, cardiac disease, and other abnormalities, clinics and medical imaging facilities nationwide are touting a new service for health conscious people: "Whole body CT screening" this typically involves scanning the body from the chin to below the hips with a form of x-ray imaging that produces cross-sectional images. In USA direct-to-consumer marketing of whole body CT is occurring today in many metropolitan areas. Free standing CT screening centres are being sited in shopping malls and other high density public areas, and these centres are being advertised in the electronic and print media. In this context the present article discussed the pros and cons of having such centres in India with the advent of multislice CT leading to fast scan times.

  14. Pulmonary function and CT biomarkers as risk factors for cardiovascular events in male lung cancer screening participants: the NELSON study

    Energy Technology Data Exchange (ETDEWEB)

    Takx, Richard A.P.; Hoesein, Firdaus A.A.M.; Mali, Willem P.T.M.; Leiner, Tim; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Isgum, Ivana [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Koning, Harry J. de; Aalst, Carlijn M. van der [Erasmus Medical Center Rotterdam, Department of Public Health, Rotterdam (Netherlands); Zanen, Pieter; Lammers, Jan-Willem J. [University Medical Center Utrecht, Department of Pulmonology, Utrecht (Netherlands); Groen, Harry J.M. [University Medical Center Groningen, Department of Pulmonology, Groningen (Netherlands); Rikxoort, Eva M. van; Ginneken, Bram van [Radboud University Nijmegen Medical Centre, Department of Radiology, Nijmegen (Netherlands); Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen (Germany); Schmidt, Michael [Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen (Germany); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands)

    2015-01-15

    The objective of this study was to investigate the association of spirometry and pulmonary CT biomarkers with cardiovascular events. In this lung cancer screening trial 3,080 male participants without a prior cardiovascular event were analysed. Fatal and non-fatal cardiovascular events were included. Spirometry included forced expiratory volume measured in units of one-second percent predicted (FEV{sub 1}%predicted) and FEV{sub 1} divided by forced vital capacity (FVC; FEV{sub 1}/FVC). CT examinations were quantified for coronary artery calcium volume, pulmonary emphysema (perc15) and bronchial wall thickness (pi10). Data were analysed via a Cox proportional hazard analysis, net reclassification improvement (NRI) and C-indices. 184 participants experienced a cardiovascular event during a median follow-up of 2.9 years. Age, pack-years and smoking status adjusted hazard ratios were 0.992 (95 % confidence interval (CI) 0.985-0.999) for FEV{sub 1}%predicted, 1.000 (95%CI 0.986-1.015) for FEV{sub 1}/FVC, 1.014 (95%CI 1.005-1.023) for perc15 per 10 HU, and 1.269 (95%CI 1.024-1.573) for pi10 per 1 mm. The incremental C-index (<0.015) and NRI (<2.8 %) were minimal. Coronary artery calcium volume had a hazard ratio of 1.046 (95%CI 1.034-1.058) per 100 mm{sup 3}, an increase in C-index of 0.076 and an NRI of 16.9 % (P < 0.0001). Pulmonary CT biomarkers and spirometry measurements were significantly associated with cardiovascular events, but did not contain clinically relevant independent prognostic information for cardiovascular events. (orig.)

  15. CT screening of vertebrarterial circulatory disorder

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeru; Toyoda, Keiko; Moriyama, Hiroshi [Jikei Univ., Tokyo (Japan). School of Medicine

    2001-09-01

    The frequency of MR angiography (MRA) used to diagnose vertebrobasiliar insufficiency appears high. Findings of abnormality by MRA show cases with maldescription of hemivertebral artery. In such cases, it is unclear whether these are due to anaplasia of the vertebral artery or to the existence of morbid constriction, thus requiring confirmation by a vertebral arteriography (VAG). We observe the vascular morphology of vertebral artery by Computed tomography (CT) scanning for screening circulatory disorders. In photography and CT scan reading, the region was severally photographed between foramen magnum and aortic arch by plain CT and contrast CT at a slice of 5 mm. The constrictive region of the vertebral artery was estimated by comparing plain and contrast CT. Subjects were 34 clinical cases of vascular maldescription in the vertebrobasilar artery, nearly no blood vessel description, or blood vessel winding or inclination. We determined the constrictive morbid state of the vertebral or subclavian artery and cervical vertebra deformity. In findings of maldescription by MRA, it was suggested that discrimination is feasible to a certain degree, whether the vertebral artery has a morbid constrictive region or due to anaplasia. Our results suggest that screening by CT scanning may be more efficient than that by MRA. (author)

  16. CT screening of vertebrarterial circulatory disorder

    International Nuclear Information System (INIS)

    Yoshida, Shigeru; Toyoda, Keiko; Moriyama, Hiroshi

    2001-01-01

    The frequency of MR angiography (MRA) used to diagnose vertebrobasiliar insufficiency appears high. Findings of abnormality by MRA show cases with maldescription of hemivertebral artery. In such cases, it is unclear whether these are due to anaplasia of the vertebral artery or to the existence of morbid constriction, thus requiring confirmation by a vertebral arteriography (VAG). We observe the vascular morphology of vertebral artery by Computed tomography (CT) scanning for screening circulatory disorders. In photography and CT scan reading, the region was severally photographed between foramen magnum and aortic arch by plain CT and contrast CT at a slice of 5 mm. The constrictive region of the vertebral artery was estimated by comparing plain and contrast CT. Subjects were 34 clinical cases of vascular maldescription in the vertebrobasilar artery, nearly no blood vessel description, or blood vessel winding or inclination. We determined the constrictive morbid state of the vertebral or subclavian artery and cervical vertebra deformity. In findings of maldescription by MRA, it was suggested that discrimination is feasible to a certain degree, whether the vertebral artery has a morbid constrictive region or due to anaplasia. Our results suggest that screening by CT scanning may be more efficient than that by MRA. (author)

  17. The Danish randomized lung cancer CT screening trial

    DEFF Research Database (Denmark)

    Pedersen, Jesper H; Ashraf, Haseem; Dirksen, Asger

    2009-01-01

    INTRODUCTION: Lung cancer screening with low dose computed tomography (CT) has not yet been evaluated in randomized clinical trials, although several are underway. METHODS: In The Danish Lung Cancer Screening Trial, 4104 smokers and previous smokers from 2004 to 2006 were randomized to either...... lung cancer. Ten of these had stage I disease. Eleven of 17 lung cancers at baseline were treated surgically, eight of these by video assisted thoracic surgery resection. CONCLUSIONS: Screening may facilitate minimal invasive treatment and can be performed with a relatively low rate of false......-positive screen results compared with previous studies on lung cancer screening....

  18. 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.

  19. Helical CT for lung-cancer screening. 3. Fundamental study for ultra-low-dose CT by application of small tube current and filter

    International Nuclear Information System (INIS)

    Itoh, Shigeki; Koyama, Shuji; Tusaka, Masatoshi; Maekoshi, Hisashi; Satake, Hiroko; Ishigaki, Takeo.

    1996-01-01

    In order to develop ultra-low-dose helical CT for lung cancer screening, the effect of reduction of the tube current to 20 mA and application of a 10 mm thick aluminium filter upon radiation dose and image quality was evaluated with a phantom. Exposure dose at the center of a gantry and absorbed dose at the center of an acrylic phantom at 20 mA with the filter were 15% and 29% of the dose at 50 mA without the filter, respectively. For reduction of absorbed dose, reduction of the tube current was more useful than application of the filter. Image noise at 20 mA with the filter was double that at 50 mA without the filter. Neither reduction of the tube current nor application of the filter changed full width at half maximum on section sensitivity of the Z-axis. Although reduction of the tube current did not affect the difference in CT values between an acrylic sphere and styroform, application of the filter caused a reduction of 4.5% in the difference in CT values. Neither reduction of the tube current nor application of the filter affected the contrast resolution of the high-contrast phantom; however, that of the low-contrast phantom deteriorated. Although improvement of the filter and evaluation of clinical images are necessary, reduction of the tube current to 20 mA and application of the aluminium filter appear to be a promising method for ultra-low-dose helical CT of the lung. (author)

  20. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

    International Nuclear Information System (INIS)

    Yi, Chin A.; Lee, Kyung Soo; Shin, Myung-Hee; Cho, Yun Yung; Choi, Yoon-Ho; Kwon, O. Jung; Shin, Kyung Eun

    2015-01-01

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  1. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Chin A. [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Myung-Hee; Cho, Yun Yung [Sungkyunkwan University School of Medicine, Department of Social and Preventive Medicine, Seoul (Korea, Republic of); Choi, Yoon-Ho [Sungkyunkwan University School of Medicine, Center for Health Promotion, Seoul (Korea, Republic of); Kwon, O. Jung [Sungkyunkwan University School of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Kyung Eun [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Kyung Hee University Hospital, Department of Diagnostic Radiology, Seoul (Korea, Republic of)

    2015-08-15

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  2. Deep convolutional neural networks for automatic coronary calcium scoring in a screening study with low-dose chest CT

    Science.gov (United States)

    Lessmann, Nikolas; Išgum, Ivana; Setio, Arnaud A. A.; de Vos, Bob D.; Ciompi, Francesco; de Jong, Pim A.; Oudkerk, Matthjis; Mali, Willem P. Th. M.; Viergever, Max A.; van Ginneken, Bram

    2016-03-01

    The amount of calcifications in the coronary arteries is a powerful and independent predictor of cardiovascular events and is used to identify subjects at high risk who might benefit from preventive treatment. Routine quantification of coronary calcium scores can complement screening programs using low-dose chest CT, such as lung cancer screening. We present a system for automatic coronary calcium scoring based on deep convolutional neural networks (CNNs). The system uses three independently trained CNNs to estimate a bounding box around the heart. In this region of interest, connected components above 130 HU are considered candidates for coronary artery calcifications. To separate them from other high intensity lesions, classification of all extracted voxels is performed by feeding two-dimensional 50 mm × 50 mm patches from three orthogonal planes into three concurrent CNNs. The networks consist of three convolutional layers and one fully-connected layer with 256 neurons. In the experiments, 1028 non-contrast-enhanced and non-ECG-triggered low-dose chest CT scans were used. The network was trained on 797 scans. In the remaining 231 test scans, the method detected on average 194.3 mm3 of 199.8 mm3 coronary calcifications per scan (sensitivity 97.2 %) with an average false-positive volume of 10.3 mm3 . Subjects were assigned to one of five standard cardiovascular risk categories based on the Agatston score. Accuracy of risk category assignment was 84.4 % with a linearly weighted κ of 0.89. The proposed system can perform automatic coronary artery calcium scoring to identify subjects undergoing low-dose chest CT screening who are at risk of cardiovascular events with high accuracy.

  3. The impact of radiologists' expertise on screen results decisions in a CT lung cancer screening trial

    International Nuclear Information System (INIS)

    Heuvelmans, Marjolein A.; Vliegenthart, Rozemarijn; Oudkerk, Matthijs; Jong, Pim A. de; Mali, Willem P.; Groen, Harry J.M.

    2015-01-01

    To evaluate the impact of radiological expertise on screen result decisions in a CT lung cancer screening trial. In the NELSON lung cancer screening trial, the baseline CT result was based on the largest lung nodule's volume. The protocol allowed radiologists to manually adjust screen results in cases of high suspicion of benign or malignant nodule nature. Participants whose baseline CT result was based on a solid or part-solid nodule were included in this study. Adjustments by radiologists at baseline were evaluated. Histology was the reference for diagnosis or to confirm benignity and stability on subsequent CT examinations. A total of 3,318 participants (2,796 male, median age 58.0 years) were included. In 195 participants (5.9 %) the initial baseline screen result was adjusted by the radiologist. Adjustment was downwards from positive or indeterminate to negative in two and 119 participants, respectively, and from positive to indeterminate in 65 participants. None of these nodules turned out to be malignant. In 9/195 participants (4.6 %) the screen result was adjusted upwards from negative to indeterminate or indeterminate to positive; two nodules were malignant. In one in 20 cases of baseline lung cancer screening, nodules were reclassified by the radiologist, leading to a reduction of false-positive screen results. (orig.)

  4. [CT-Screening for Lung Cancer - what is the Evidence?

    Science.gov (United States)

    Watermann, Iris; Reck, Martin

    2018-04-01

    In patients with lung cancer treatment opportunities and prognosis are correlated to the stage of disease with a chance for curative treatment in patients with early stage disease. Therefore, early detection of lung cancer is of paramount importance for improving the prognosis of lung cancer patients.The National Lung Screening Trial (NLST) has already shown that low-dose CT increases the number of identified early stage lung cancer patients and reduces lung cancer related mortality. Critically considered in terms of CT-screening are false-positive results, overdiagnosis and unessential invasive clarification. Preliminary results of relatively small European trials haven´t yet confirmed the results of the NLST-study.Until now Lung Cancer Screening by low dose CT-scan or other methods is neither approved nor available in Germany.To improve the efficacy of CT-Screening and to introduce early detection of lung cancer in standard practice, additional, complementing methods should be further evaluated. One option might be the supplementary analysis of biomarkers in liquid biopsies or exhaled breath condensates. In addition, defining the high-risk population is of great relevance to identify candidates who might benefit of early detection programs. © Georg Thieme Verlag KG Stuttgart · New York.

  5. [A temporal bone CT study of the infants with hearing loss referred from universal newborn hearing screening].

    Science.gov (United States)

    Tao, Zheng; Li, Yun; Hou, Zheng; Cheng, Lan

    2007-02-01

    To explore the high resolution CT image of temporal bone in infants with hearing loss, and its value in evaluating the cause of hearing loss. In 2005, 0.12 million newborns have been included in the hearing screening system in Shanghai, and 1077 infants have failed to pass the hearing screening. One hundred and eight four infants were diagnosed as congenital hearing loss from mild to profound. A temporal bone HRCT scanning was performed to these infants. Among the 184 patients with congenital hearing loss, HRCT showed that 26 cases (14.1%) were associated with external ear malformation, and 21 cases (11.4%) were associated with middle ear malformation, 31 cases (16.8%) associated with inner ear malformation. The patients with inner ear malformation included 12 cases with Mondini malformation, 1 case with common cavity malformation, 6 cases with large vestibule malformation, 5 cases with internal auditory canal abnormalities, and 10 cases with vestibule, semicircular canals abnormalities. In addition, there were 20 cases (10.8%) with fluid in middle ear. HRCT image play an important role in the differential diagnosis and treatment of infants with congenital hearing loss.

  6. Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT; Screening della neoplasia polmonare con TC spirale a bassa dose: risultati di uno studio pilota triennale e disegno dello studio clinico randomizzato Italung-CT

    Energy Technology Data Exchange (ETDEWEB)

    Picozzi, Giulia [Firenze Univ., Firenze (Italy). Radiodiagnostica I-Dipartimento di Fisiopatologia Clinica; Paci, Enrico [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). Unita' di Epidemiologia Clinica e Descrittiva Centro per lo Studio e la Prevenzione Oncologica; Lopes Pegna, Andrea [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). U.O. Pneumologia] [and others

    2005-02-01

    Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64{+-}4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5mm in diameter in 20 subjects. 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma. Conclusions: The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the Italung Ct trial which hast just began. [Italian] Scopo: Riportare i risultati di uno studio pilota osservazionale di screening della neoplasia polmonare con TC a bassa dose della durata di tre anni e presentare il disegno dello studio clinico randomizzato Italung-CT. Materiale e metodi: Sessanta (47 uomini e 13 donne, eta' media 64{+-}4,5 anni) forti fumatori (almeno 20 pacchetti/anno) sono stati sottoposti ad un esame basale e a due controlli annuali con TC single o

  7. CT screening for lung cancer. Update 2008

    International Nuclear Information System (INIS)

    Henschke, C.I.; Yip, R.; Yankelevitz, D.F.

    2009-01-01

    Screening for a cancer should be considered when the cancer is significant in terms of incidence and mortality, treatment of early stage disease is better than treatment of late stage disease, and there is a screening regimen that provides for earlier diagnosis rather than later, symptom-prompted diagnosis. Lung cancer qualifies as it kills more people than any other cancer worldwide. In the United States it kills more people than colon, breast, and prostate cancer combined and more women than breast cancer. The fundamental concepts of screening are presented. Screening for a cancer is a repetitive process, starting with the baseline round followed by repeat rounds of screening at set intervals. The regimen of screening defines the initial diagnostic test and the sequence of tests to be performed leading to a rule-in diagnosis of the cancer. The regimen should provide lead time of the diagnosis of the cancer. The regimen for the first, baseline round may be different from the regimen for the repeat rounds as the former is inherently different from the subsequent repeat rounds. Baseline screening identifies a greater proportion of cancers with a longer latent (asymptomatic) phase than repeat screening, called length bias. Length bias exists for any screening program, regardless of the design of the study or the cancer. Repeat rounds of screening identify the same proportion of cancer diagnoses found in absence of screening for people having the same risk of the cancer and these repeat rounds of screening can be pooled. It is also a consequence of length bias that cancers found in repeat rounds are earlier in their latent phase than those of the baseline round, a less frequently mentioned consequence. Overdiagnosis bias, another bias of screening, can occur in two ways: a cancer' detected by the screening, pathologically proven, that is not life-threatening even when not resected and a genuine life-threatening cancer that is diagnosed and treated but the person dies

  8. Lung cancer screening with low-dose CT

    International Nuclear Information System (INIS)

    Diederich, S.; Wormanns, D.; Heindel, W.

    2003-01-01

    Screening for lung cancer is hoped to reduce mortality from this common tumour, which is characterised by a dismal overall survival, relatively well defined risk groups (mainly heavy cigarette smokers and workers exposed to asbestos) and a lack of early symptoms. In the past studies using sputum cytology and chest radiography have failed to demonstrate any reduction in lung cancer mortality through screening. One of the reasons is probably the relatively poor sensitivity of both these tests in early tumours. Low radiation dose computed tomography (CT) has been shown to have a much higher sensitivity for small pulmonary nodules, which are believed to be the most common presentation of early lung cancer. As, however, small pulmonary nodules are common and most are not malignant, non-invasive diagnostic algorithms are required to correctly classify the detected lesions and avoid invasive procedures in benign nodules. Nodule density, size and the demonstration of growth at follow-up have been shown to be useful in this respect and may in the future be supplemented by contrast-enhanced CT and positron emission tomography. Based on these diagnostic algorithms preliminary studies of low-dose CT in heavy smokers have demonstrated a high proportion of asymptomatic, early, resectable cancers with good survival. As, however, several biases could explain these findings in the absence of the ultimate goal of cancer screening, i.e. mortality reduction, most researchers believe that randomised controlled trials including several 10000 subjects are required to demonstrate a possible mortality reduction. Only then general recommendations to screen individuals at risk of lung cancer with low-dose CT should be made. It can be hoped that international cooperation will succeed in providing results as early as possible

  9. PET or PET-CT with cancer screening

    International Nuclear Information System (INIS)

    Wang Taisong; Zhao Jinhua; Song Jianhua

    2007-01-01

    At present, cancer screening remains a lot of debate in contemporary medical practice. Many constitutes have done a lot of experiments in cancer screening. The same version is that recommendations and decisions regarding cancer screening should be based on reliable data, not self- approbation. Now, some institutes advocate 18 F-FDG PET or 18 F-FDG PET-CT for cancer screening, here, discussed status quo, potential financial, radiation safety and statistical data in 18 F-FDG PET or 18 F-FDG PET- CT cancer screening. (authors)

  10. Estimating cancer risks induced by CT screening for Korea population

    International Nuclear Information System (INIS)

    Yang, Hye Jeong; Yang, Won Seok

    2016-01-01

    Computed Tomography(CT) has been used to diagnose early stages of cancer and other diseases. Since the number of CT screening has been increasing, there is now a debate about the possible benefits and risks of CT screening on asymptomatic individuals. CT screening has definite benefits, however the radiation risk of screening an asymptomatic individual is a serious problem that cannot be overlooked. Despite its potential risks, CT screening for asymptomatic individual has been gradually increased in Korea and it is attributed to increase collective effective dose. Therefore, we reported the risk level of each organ which is included in scan field for CT screening and analyzed and then evaluated the risk level of Korean population comparison to others, Hong Kong, U.S. and U.K. populations. LARs are lower with older ages for all populations of both sexes. We recommend CT screening after the age of 40 because from that age, LAR decreases and the danger of top 5 cancer increases.

  11. Low-dose CT: new tool for screening lung cancer?

    International Nuclear Information System (INIS)

    Diederich, S.; Wormanns, D.; Heindel, W.

    2001-01-01

    Lung cancer is the leading cause of death from malignant tumours as it is very common and has a poor prognosis at advanced tumour stages. Prognosis could be improved by treatment at early stages. As these stages are usually asymptomatic, a diagnostic test that would allow detection of early tumour stages in a population at risk could potentially reduce mortality from lung cancer. Previous approaches using chest radiography and sputum cytology in smokers have been disappointing. Fluorescent bronchoscopy and molecular markers are not yet applicable in clinical routine. Because of its high sensitivity for small pulmonary nodules, which are the most common manifestation of early lung cancer, CT appears suitable as a screening test. Low-dose examination parameters can and should be used for this purpose. From clinical practice it is well known that chest CT often demonstrates small pulmonary nodules, which do not represent lung cancer. Therefore, non-invasive diagnostic algorithms are required to avoid unnecessary biopsies in benign lesions. In preliminary studies of low-dose CT using algorithms based on size and density of detected nodules a large proportion of asymptomatic lung cancers and a large proportion of early, resectable tumour stages were found with a small proportion of invasive procedures for benign nodules. Before this technology can be recommended for broad application, however, further information is required regarding appropriate inclusion criteria (smoking habits, age groups) and screening intervals. Most importantly, further data are required to clarify whether lung cancer screening using low-dose CT can actually reduce mortality from lung cancer. (orig.)

  12. Utility of multiple rule out CT screening of high-risk atraumatic patients in an emergency department-a feasibility study

    DEFF Research Database (Denmark)

    Pries-Heje, Mia M; Hasselbalch, Rasmus B; Raaschou, Henriette

    2018-01-01

    malignant tumors in 10 (10%) cases. The mean size specific radiation dose was 15.9 mSv (± 3.1 mSv). CONCLUSION: Screening with a multi-rule out CT scan of high-risk patients in an ED is feasible and result in discovery of clinically unrecognized diagnoses and malignant tumors, but at the cost of radiation......BACKGROUND: Several large trials have evaluated the effect of CT screening based on specific symptoms, with varying outcomes. Screening of patients with CT based on their prognosis alone has not been examined before. For moderate-to-high risk patients presenting in the emergency department (ED......), the potential gain from a CT scan might outweigh the risk of radiation exposure. We hypothesized that an accelerated "multiple rule out" CT screening of moderate-to-high risk patients will detect many clinically unrecognized diagnoses that affect change in treatment. METHOD: Patients ≥ 40 years, triaged as high...

  13. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT : The Measuring Athlete's Risk of Cardiovascular events (MARC) study

    NARCIS (Netherlands)

    Schurink, M. M.; Braber, T. L.; Prakken, N. H. J.; Doevendans, P. A. F. M.; Backx, F. J. G.; Grobbee, D. E.; Rienks, R.; Nathoe, H. M.; Bots, M. L.; Velthuis, B. K.; Mosterd, A.

    Background Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged >= 45 years. Methods Coronary

  14. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT : The Measuring Athlete’s Risk of Cardiovascular events (MARC) study

    NARCIS (Netherlands)

    Schurink, M. M.; Braber, T. L.; Prakken, N. H J; Doevendans, P. A F M; Backx, F. J G; Grobbee, D. E.; Rienks, R.; Nathoe, H. M.; Bots, M. L.; Velthuis, B. K.; Mosterd, A.

    2017-01-01

    Background Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged ≥45 years. Methods Coronary artery

  15. The impact of radiologists' expertise on screen results decisions in a CT lung cancer screening trial

    Energy Technology Data Exchange (ETDEWEB)

    Heuvelmans, Marjolein A.; Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); University of Groningen / University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); Jong, Pim A. de; Mali, Willem P. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Groen, Harry J.M. [University of Groningen, University Medical Center Groningen, Department of Pulmonology, Groningen (Netherlands)

    2014-11-04

    To evaluate the impact of radiological expertise on screen result decisions in a CT lung cancer screening trial. In the NELSON lung cancer screening trial, the baseline CT result was based on the largest lung nodule's volume. The protocol allowed radiologists to manually adjust screen results in cases of high suspicion of benign or malignant nodule nature. Participants whose baseline CT result was based on a solid or part-solid nodule were included in this study. Adjustments by radiologists at baseline were evaluated. Histology was the reference for diagnosis or to confirm benignity and stability on subsequent CT examinations. A total of 3,318 participants (2,796 male, median age 58.0 years) were included. In 195 participants (5.9 %) the initial baseline screen result was adjusted by the radiologist. Adjustment was downwards from positive or indeterminate to negative in two and 119 participants, respectively, and from positive to indeterminate in 65 participants. None of these nodules turned out to be malignant. In 9/195 participants (4.6 %) the screen result was adjusted upwards from negative to indeterminate or indeterminate to positive; two nodules were malignant. In one in 20 cases of baseline lung cancer screening, nodules were reclassified by the radiologist, leading to a reduction of false-positive screen results. (orig.)

  16. Multislice CT as a Primary Screening Tool for the Prediction of an Involved Mesorectal Fascia and Distant Metastases in Primary Rectal Cancer : A Multicenter Study

    NARCIS (Netherlands)

    Wolberink, Steven V. R. C.; Beets-Tan, Regina G. H.; de Haas-Kock, Danielle F. M.; van de Jagt, Eric J.; Span, Mark M.; Wiggers, Theo

    PURPOSE: The purposes of this study were to assess whether multislice CT can identify tumors having a free or involved circumferential margin, to investigate the additional role of multislice CT as a "one-stop shopping'' staging tool for staging nodal and distant metastases. METHODS: A total of 250

  17. Comparative reading support system for lung cancer CT screening

    International Nuclear Information System (INIS)

    Kubo, Mitsuru; Saita, Shinsuke; Kawata, Yoshiki; Niki, Noboru; Suzuki, Hidenobu; Ohmatsu, Hironobu; Eguchi, Kenji; Kaneko, Masahiro; Moriyama, Noriyuki

    2010-01-01

    The comparative reading is performed using current and past images of the same case obtained from lung cancer CT screening. The result of this is useful for the early detection of lung cancer. Our paper describes the efficiency improvement of comparative reading using 10 mm slice thickness CT images by developing the system consists of slice registration method, pulmonary nodule registration method, and quantitative evaluation method of pulmonary nodule's degree of change. The proposed system is applied to CT images scanned for 1107 times of 85 cases with 198 pulmonary nodules and is evaluated by comparing it with the reading result of the doctors. We show the effectiveness of the system. (author)

  18. Healthcare costs in the Danish randomised controlled lung cancer CT-screening trial

    DEFF Research Database (Denmark)

    Rasmussen, J.F.; Siersma, V.; Pedersen, Jesper H.

    2014-01-01

    : This registry study was nested in a randomised controlled trial (DLCST). 4104 participants, current or former heavy smokers, aged 50-70 years were randomised to five annual low dose CT scans or usual care during 2004-2010. Total healthcare costs and healthcare utilisation data for both the primary...... and the secondary healthcare sector were retrieved from public registries from randomisation - September 2011 and compared between (1) the CT-screening group and the control group and, (2) the control group and each of the true-positive, false-positive and true-negative groups. RESULTS: The median annual costs per...... participant were significantly higher in the CT-screening group (Euros [EUR] 1342, interquartile range [IQR] 750-2980) compared with the control group (EUR 1190, IQR 590-2692) (pcost of the CT-screening programme was excluded, there was no longer a statistically significant difference...

  19. Helical CT for secondary screening of lung cancer

    International Nuclear Information System (INIS)

    Mori, Kiyoshi; Onishi, Tsukasa; Tominaga, Keigo; Kishiro, Izumi; Yokoyama, Kohki.

    1995-01-01

    Helical CT was used on a trial basis for secondary screening of lung cancer, and its clinical usefulness is discussed in this report. The subjects of 157 patients with abnormal shadows on plain chest X-ray images were chosen between November 1993 and August 1994. Imaging parameters used for screening CT were as follows: 50 mA, 120 kV, a couch-top movement speed of 20 mm/s, and a beam width of 10 mm. The entire lung field was scanned during a single breath-hold. Reconstructed images were generated at 10-mm intervals by the 180deg interpolation method, and films were produced. Images of the entire lung field were made during a single breath-hold in all patients. Abnormal shadows were detected in 73 of 157 patients by screening CT. These 73 patients included 14 with lung cancer, 53 with benign lesions, one under observation, and five others. The average diameter of the tumors was 11.1 mm. The lung cancers detected all arose in the periphery, and were classified into stage I (10 patients), stage IIIA (3 patients), and stage IV with bone metastases (1 patient). Lung cancers in clinical stage I (3 patients) and stage IV (1 patient) were difficult to see on plain chest X-ray films. We conclude that screening CT is useful for early diagnosis of lung cancer because the entire lung field can be imaged during a single breath-hold. Therefore, helical CT can be expected to be useful in screening for lung cancer. (author)

  20. Whole-Body CT Screening--Should I or Shouldn't I Get One?

    Science.gov (United States)

    ... Procedures Medical Imaging Medical X-ray Imaging Whole-Body CT Screening--Should I or shouldn't I ... What are the risks and benefits of whole-body CT screening? Many people believe incorrectly that a ...

  1. Lung cancer screening with thoracic X-ray and CT. Current situation; Lungenkarzinomscreening mit Roentgenthorax oder CT. Aktuelle Datenlage

    Energy Technology Data Exchange (ETDEWEB)

    Stackelberg, O. von; Kauczor, H.U. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologe, Heidelberg (Germany); Translationales Lungen Forschungszentrum Heidelberg (TLRC), Mitglied des Deutschen Zentrums fuer Lungenforschung (DZL), Heidelberg (Germany)

    2016-09-15

    Attempts at the early detection of lung cancer using imaging methods began as far back as the 1950s. Several studies attempted to demonstrate a reduction of lung cancer mortality by chest radiography screening but all were unsuccessful. Even the first small screening studies using computed tomography (CT) could not demonstrate a reduction in lung cancer-specific mortality until in 2011 the results of the largest randomized controlled low-dose CT screening study in the USA (NLST) were published. The NLST results could show a significant 20 % reduction of lung cancer mortality in elderly and heavy smokers using CT. Confirmation of the NLST results are urgently needed so that the data of the largest European study (NELSON) are eagerly awaited. Pooled with the data from several smaller European studies these results will provide important information and evidence for the establishment of future CT screening programs in Europe. Randomized controlled trials are the basis of evidence-based medicine; therefore, the positive results of the methodologically very good NLST study cannot be ignored, even if it is the only such study completed so far with highly convincing conclusions. The NLST results clearly demonstrate that positive effects for the health of the population can only be expected if the processes are clearly defined and the quality is assured. (orig.) [German] Bestrebungen zur Frueherkennung von Lungenkrebs mit bildgebenden Methoden gibt es schon lange. Alle Studien, die eine Reduktion der Lungenkrebsmortalitaet mittels Roentgenthoraxscreening nachzuweisen versuchten, scheiterten. Auch die ersten kleineren Screeningstudien mit der CT konnten keine Reduktion der Lungenkrebssterblichkeit nachweisen, bis 2011 die Ergebnisse der bisher groessten randomisierten kontrollierten Niedrigdosis-CT-Screeningstudie (NLST) aus den USA veroeffentlicht wurden. Diese konnten eine signifikante 20 %ige Reduktion der Lungenkrebssterblichkeit bei Personen, die aelter und starke

  2. New approach to lung cancer screening with helical volume CT

    International Nuclear Information System (INIS)

    Midorikawa, S.; Hashimoto, N.; Katakura, T.; Suzuki, K.

    1990-01-01

    This paper evaluates the relationship between reducing radiation dose to the patient and maintaining the clinical quality of the chest image in lung cancer screening by helical-volume CT (HVCT). The authors evaluated the changing relationship between radiation dose and clinical quality after changing the HVCY scanning conditions (such as stroke of patient transport and section thickness) as well as adding copper filters of various thickness and using high-voltage x-ray examination to complement CT examinations. The authors were able to reduce radiation dose by changing the HVCT scanning conditions (eg, stroke of 20 mm/sec, with a section thickness of 10 mm)

  3. [Lung cancer screening with thoracic X‑ray and CT : Current situation].

    Science.gov (United States)

    von Stackelberg, O; Kauczor, H-U

    2016-09-01

    Attempts at the early detection of lung cancer using imaging methods began as far back as the 1950s. Several studies attempted to demonstrate a reduction of lung cancer mortality by chest radiography screening but all were unsuccessful. Even the first small screening studies using computed tomography (CT) could not demonstrate a reduction in lung cancer-specific mortality until in 2011 the results of the largest randomized controlled low-dose CT screening study in the USA (NLST) were published. The NLST results could show a significant 20 % reduction of lung cancer mortality in elderly and heavy smokers using CT. Confirmation of the NLST results are urgently needed so that the data of the largest European study (NELSON) are eagerly awaited. Pooled with the data from several smaller European studies these results will provide important information and evidence for the establishment of future CT screening programs in Europe. Randomized controlled trials are the basis of evidence-based medicine; therefore, the positive results of the methodologically very good NLST study cannot be ignored, even if it is the only such study completed so far with highly convincing conclusions. The NLST results clearly demonstrate that positive effects for the health of the population can only be expected if the processes are clearly defined and the quality is assured.

  4. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT: The Measuring Athlete's Risk of Cardiovascular events (MARC) study.

    Science.gov (United States)

    Schurink, M M; Braber, T L; Prakken, N H J; Doevendans, P A F M; Backx, F J G; Grobbee, D E; Rienks, R; Nathoe, H M; Bots, M L; Velthuis, B K; Mosterd, A

    2017-04-01

    Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged ≥45 years. Coronary artery disease (CAD) was defined as a coronary artery calcium score ≥100 Agatson units and/or ≥50% luminal stenosis on contrast-enhanced cardiac CT. Psychological impact was measured with the Impact of Event Scale (IES) (seven items) on a six-point scale (grade 0-5). A sum score ≥19 indicates clinically relevant psychological distress. A Likert scale was used to assess overall experiences and impact on sports and lifestyle. A total of 275 participants (86.5% response rate, 95% CI 83-90%) with a mean age of 54.5 ± 6.4 years completed the questionnaires, 48 (17.5%, 95% CI 13-22%) of whom had CAD. The median IES score was 1 (IQR 0-2, [0-23]). IES was slightly higher in those with CAD (mean rank 175 vs. 130, p psychological distress (IES = 23). Participants reported numerous benefits, including feeling safer exercising (58.6%, 95% CI 53-65%) and positive lifestyle changes, especially in those with CAD (17.2 vs. 52.1%, p psychological distress in older sportsmen. Psychological distress should not be a reason to forego screening in sportsmen.

  5. Effect of CT screening on smoking habits at 1-year follow-up in the Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Ashraf, H; Tønnesen, P; Holst Pedersen, J

    2008-01-01

    BACKGROUND: The effect of low-dose CT screening for lung cancer on smoking habits has not been reported in large randomised controlled trials. METHODS: This study evaluated the effect on smoking habits of screening with low-dose CT at 1-year follow up in the Danish Lung Cancer Screening Trial...... pack years. Smoking habits were determined at baseline and at annual screening. Smoking status was verified using exhaled carbon monoxide levels. Lung function tests, nicotine dependency and motivation to quit smoking were assessed. Quit rates and relapse rates were determined at 1-year follow...... (DLCST), a 5-year randomised controlled trial comprising 4104 subjects; 2052 subjects received annual low-dose CT scan (CT group) and 2052 received no intervention (control group). Participants were healthy current and former smokers (>4 weeks since smoking cessation) with a tobacco consumption of >20...

  6. Cancerogenesis Risks between 64 and 320 Row Detector CT for Coronary CTA Screening

    Directory of Open Access Journals (Sweden)

    Atif N Khan

    2014-01-01

    Full Text Available Objectives: This study compares cancerogenesis risks posed by the 64 row detector and the 320 row detector computed tomography scanners used during coronary computed tomography angiography (CCTA following decennial screening guidelines. Material and Methods: Data of the radiation absorbed after CCTA by lung, thyroid, and female breast in patients between 50 and 70 years of age obtained from prior published literature for the 64 row CT scanner were compared with data from our study using 320 row detector CT scanner. Data from the 64 row and the 320 row detector CT scanners was used to determine lifetime attributable risks (LAR of cancer based on the biological effects of ionizing radiation (BEIR VII report. Results: The relative reduction of LAR (% for 50-, 60-, and 70-year-old patients undergoing scanning with the 320 row detector CT scanner was 30% lower for lung, and more than 50% lower for female breast when compared with results from 64 row detector CT scanner. The use of 320 row detector CT would result in a combined cumulative cancer incidence of less than 1/500 for breast in women and less than 1/1000 for lung in men; By comparison, this is much lower than other more common risk factors: 16-fold for lung cancer in persistent smokers, 2-fold for breast cancer with a first degree family member history of breast cancer, and 10-fold for thyroid cancer with a family member with thyroid cancer. Decennial screening would benefit at least 355,000 patients from sudden cardiac death each year, 94% of whom have significant coronary artery disease, with at least one stenosis >75%. LAR for thyroid cancer was negligible for both scanners. Conclusion: Lung and female breast LAR reductions with 320 row detector compared with 64 row detector CT are substantial, and the benefits would outweigh increased cancer risks with decennial screening in the age group of 50-70 years.

  7. Adherence to Radiology Recommendations in a Clinical CT Lung Screening Program.

    Science.gov (United States)

    Alshora, Sama; McKee, Brady J; Regis, Shawn M; Borondy Kitts, Andrea K; Bolus, Christopher C; McKee, Andrea B; French, Robert J; Flacke, Sebastian; Wald, Christoph

    2018-02-01

    Assess patient adherence to radiologist recommendations in a clinical CT lung cancer screening program. Patients undergoing CT lung cancer screening between January 12, 2012, and June 12, 2013, were included in this institutional review board-approved retrospective review. Patients referred from outside our institution were excluded. All patients met National Comprehensive Cancer Network Guidelines Lung Cancer Screening high-risk criteria. Full-time program navigators used a CT lung screening program management system to schedule patient appointments, generate patient result notification letters detailing the radiologist follow-up recommendation, and track patient and referring physician notification of missed appointments at 30, 60, and 90 days. To be considered adherent, patients could be no more than 90 days past due for their next recommended examination as of September 12, 2014. Patients who died, were diagnosed with cancer, or otherwise became ineligible for screening were considered adherent. Adherence rates were assessed across multiple variables. During the study interval, 1,162 high-risk patients were screened, and 261 of 1,162 (22.5%) outside referrals were excluded. Of the remaining 901 patients, 503 (55.8%) were male, 414 (45.9%) were active smokers, 377 (41.8%) were aged 65 to 73, and >95% were white. Of the 901 patients, 772 (85.7%) were adherent. Most common reasons for nonadherence were patient refusal of follow-up exam (66.7%), inability to successfully contact the patient (20.9%), and inability to obtain the follow-up order from the referring provider (7.8%); 23 of 901 (2.6%) were discharged for other reasons. High rates of adherence to radiologist recommendations are achievable for in-network patients enrolled in a clinical CT lung screening program. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. Clinical study of CT colonography

    International Nuclear Information System (INIS)

    Nakazawa, Saburo; Hattori, Toshiyuki; Inui, Kazuo

    2011-01-01

    We studied the usefulness of CT colonography (CTC) for colon cancer diagnosis. CTC and optical colonoscopy were performed for 150 cases mainly including patients with a positive fecal occult blood test (FOBT). The results were compared and analyzed. The following are the final diagnoses given to the patients: advanced colon cancer: 41 cases; early cancer: 25 cases; adenoma: 74 cases; hyperplasia: 3 cases; submucosal tumor: 1 case; and no lesion: 6 cases. In terms of diagnostic performance of CTC, accuracy was found to be 96%, sensitivity was found to be 97.9%, and specificity was found to be 50%. Cancer stage-specific sensitivity was as follows: advanced colon cancer: 100%; early cancer: 96.3%; adenoma: 71.2%; and hyperplasia: 47.4%. Lesion site-specific sensitivity was as follows: caecum: 76.2%; ascending colon: 57.6%; transverse colon: 66.2%; descending colon: 83.3%; sigmoid colon: 85.1%; and rectum: 78.0%. Lesion size-specific sensitivity was as follows: 2 to 5 mm: 56.7%; 6 to 9 mm: 88.1%; 10 mm or more: 92.5%; and 6 mm or more: 90.9%. Therefore, the diagnostic sensitivity of CTC was confirmed to be high. The results suggest that CTC would be useful for colon cancer screening. (author)

  9. High affective risk perception is associated with more lung cancer-specific distress in CT screening for lung cancer

    NARCIS (Netherlands)

    Bunge, Eveline M.; van den Bergh, Karien A. M.; Essink-Bot, Marie-Louise; van Klaveren, Rob J.; de Koning, Harry J.

    2008-01-01

    Screening for cancer can cause distress. People who perceive their risk of cancer as high may be more vulnerable to distress. This study evaluated whether participants of a lung cancer Computed Tomography (CT) screening trial with a high affective risk perception of developing lung cancer had a

  10. Cancer screening using 18F-FDG PET/CT in Korean asymptomatic volunteers. A preliminary report

    International Nuclear Information System (INIS)

    Lee, Jeong-Won; Kang, Keon-Wook; Paeng, Jin-Chul; Lee, Sang-Mi; Jang, Su-Jin; Chung, June-Key; Lee, Myung-Chul; Lee, Dong-Soo

    2009-01-01

    This study was performed to evaluate the clinical value of 18 F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) for cancer screening in Korean asymptomatic people. Between February 2004 and December 2006, 1,587 asymptomatic individuals underwent FDG PET/CT as part of a cancer screening program with some other diagnostic tests at the healthcare center of our hospital. After excluding patients with a history of malignant tumor, 1,336 subjects were enrolled. All PET/CT images were visually analyzed. In subjects showing positive findings for PET/CT or other screening tests, further diagnostic tests and pathological confirmation were performed. Of the 1,336 subjects, malignant tumors were found in 16 participants (1.2%, thyroid cancer: 9, lung cancer: 2, stomach cancer: 2, and others: 4). There were 47 cases (3.6%) of positive PET/CT findings- 11 cases were true positive (thyroid cancer: 8, lung cancer: 1, renal cancer: 1, and invasive thymoma), and 36 false positive, and five cases were false negative. The overall detection rate of PET/CT was 0.8%, and the sensitivity, specificity, positive-predictive value, and negative-predictive value of PET/CT were 68.8, 97.2, 23.4, and 99.6%, respectively. Fluorodeoxyglucose positron-emission tomography has the potential to detect various kinds of malignant tumors in cancer screening test, and the overall detection rate of PET/CT was 0.8%. FDG PET/CT can be a useful cancer screening modality with the selection of high-risk group and appropriate combination with other screening modalities. (author)

  11. Screening cervical spine CT in the emergency department, phase 3: increasing effectiveness of imaging.

    Science.gov (United States)

    Griffith, Brent; Vallee, Phyllis; Krupp, Seth; Jung, Melissa; Slezak, Michelle; Nagarwala, Jumana; Loeckner, C Patrick; Schultz, Lonni R; Jain, Rajan

    2014-02-01

    The aim of this study was to determine the effect of a clinical education initiative on the appropriate utilization of screening cervical spine CT in the emergency department. The purpose was to assess if clinical education can produce stricter adherence to the ACR Appropriateness Criteria and improve the utilization of screening CT examinations in the emergency department. Institutional review board approval was obtained for this HIPAA-compliant study. All adult patients presenting to a level 1 trauma center with blunt trauma prompting screening cervical spine CT were eligible. For each study, the requesting clinician completed a survey selecting all clinical indications. CT examinations were evaluated by a board-certified radiologist blinded to survey data. Results were compared with retrospective and prospective studies performed before the institution of the education initiative. Of the 388 cervical spine CT examinations performed, 12 (3.1%) were positive for acute cervical spine injury, compared to only 1.0% before the clinical education program (phase 2). Of the 376 examinations without injury, 13% met all 5 National Emergency X-Radiography Utilization Study criteria for nonimaging (down from 16.1% in phase 2), and 15 (4%) required no imaging when both National Emergency X-Radiography Utilization Study and abbreviated Canadian cervical spine rule criteria were applied. Implementation of a clinical education initiative resulted in improved adherence to ACR Appropriateness Criteria and improved clinical effectiveness of the studies by increasing fracture detection rate. Initiatives such as these could potentially influence imaging overutilization without burdening emergency department clinicians with excessive roadblocks to image ordering. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  12. High prevalence of bronchiectasis in adults. Analysis of CT findings in a health screening program

    International Nuclear Information System (INIS)

    Kwak, Hyun-Jung; Moon, Ji-Yong; Choi, Vo-Won; Kim, Tae-Hyung; Sohn, Jang-Won; Yoon, Ho-Joo; Shin, Dong-Ho; Park, Sung-Soo; Kim, Sang-Heon

    2010-01-01

    Bronchiectasis is one of the common chronic respiratory diseases and associated with respiratory morbidity and mortality. However, neither its prevalence nor its etiology is well-defined. We aimed to estimate the prevalence and risk factors of bronchiectasis in adults. In a retrospective study, we analyzed radiologic findings on chest computed tomography (CT) images performed as part of a health-screening program. From January to December 2008, 1,409 (24.6%) of 5,727 participants in the screening program of a health promotion center at a university hospital underwent chest CT scans based on the subject's decision. Bronchiectasis was diagnosed, if there was abnormal bronchial dilatation in any area of both lungs on chest CT. Respiratory symptoms, smoking status, and past medical history were also analyzed to define clinical characteristics and risk factors of bronchiectasis. Of 1,409 patients (aged 23-86 years), who were screened for respiratory diseases using chest CT for one year in a health promotion center, 129 patients (9.1%) were diagnosed with bronchiectasis. The prevalence of bronchiectasis was higher in females than in males (11.5% vs. 7.9%, p=0.022) and increased with age. Respiratory symptoms were reported in 53.7% of subjects. Previous history of tuberculosis (TB) (odds ratio (OR) 4.61, 95% confidence interval (Cl) 2.39-8.88, p=0.001) and age (OR 2.49, 95% Cl 1.56-3.98, p=0.001) were significantly associated with bronchiectasis. This retrospective analysis of chest CT findings in health screening examinees revealed a very high prevalence of bronchiectasis in adults. Previous TB infection is one of the major causes of bronchiectasis. (author)

  13. Strategy for improving the detailed examination rate for colorectal cancer screening. New approach for detailed colorectal cancer examination. Study for optimal pre-treatment for CT colonography

    International Nuclear Information System (INIS)

    Mitsushima, Toru; Fujiwara, Masanori; Nagata, Koichi

    2012-01-01

    In order to drastically improve the detailed examination rate for strategic colorectal cancer examination in Japan, it is necessary to introduce CT colonography (CTC) as a detailed examination method for colorectal cancer examination, in addition to colonoscopy (CS) which is the conventional detailed examination method. In our study, a cleansing enema/contrast solution (3% Nif-C) was prepared by adding 60 ml of a water-soluble iodine-based contrast agent (Gastrografin) and water to an oral cleansing enema agent (Niflec) in solid (powder) form to a final amount of 2000 ml. The solution was compared with a Niflec solution. In terms of patient's acceptability, more than half of the examined patients answered ''easier to drink than the Niflec solution'' or ''as easy to drink as the Niflec solution. '' Also, the Nif-C solution was comparable or superior to the Niflec solution in terms of cleansing enema effects. Regarding imaging effects essential for CTC, the CT level was found to be 200 HU or greater for any large intestine region upon CTC using the Nif-C solution. Thus, practically sufficient imaging effects were achieved. In conclusion, CTC with pretreatment involving a cleansing enema with oral administration of 3% Nif-C is superior to CS in terms of patient's acceptability. In addition, at least in view of the overseas reports on CTC, there is no particular problem in terms of diagnostic accuracy. Thus, CTC is expected to resolve various problems related to colorectal cancer examination in Japan. (author)

  14. Application of PET and PET/CT imaging for cancer screening

    International Nuclear Information System (INIS)

    Chen Yenkung; Hu Fenglan; Shen Yehyou; Liao, A.C.; Hung, T.Z.; Su, Chentau; Chen Liangkuang

    2004-01-01

    The aim of this study was to evaluate the potential application of 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and PET/CT for cancer screening in asymptomatic individuals. Methods: The subjects consisted of 3631 physical check up examinees (1947 men, 1684 women; mean age ±SD, 52.1±8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain and bladder were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Results: Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were performed with the PET-CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 of 32 examinees. Conclusion: The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET in a resectable stage. CT of the PET/CT for localization and characteristics of the lesion shows an increased specificity of the PET scan. Using ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms. (authors)

  15. Detection of lung cancer through low-dose CT screening (NELSON): a prespecified analysis of screening test performance and interval cancers.

    Science.gov (United States)

    Horeweg, Nanda; Scholten, Ernst Th; de Jong, Pim A; van der Aalst, Carlijn M; Weenink, Carla; Lammers, Jan-Willem J; Nackaerts, Kristiaan; Vliegenthart, Rozemarijn; ten Haaf, Kevin; Yousaf-Khan, Uraujh A; Heuvelmans, Marjolein A; Thunnissen, Erik; Oudkerk, Matthijs; Mali, Willem; de Koning, Harry J

    2014-11-01

    Low-dose CT screening is recommended for individuals at high risk of developing lung cancer. However, CT screening does not detect all lung cancers: some might be missed at screening, and others can develop in the interval between screens. The NELSON trial is a randomised trial to assess the effect of screening with increasing screening intervals on lung cancer mortality. In this prespecified analysis, we aimed to assess screening test performance, and the epidemiological, radiological, and clinical characteristics of interval cancers in NELSON trial participants assigned to the screening group. Eligible participants in the NELSON trial were those aged 50-75 years, who had smoked 15 or more cigarettes per day for more than 25 years or ten or more cigarettes for more than 30 years, and were still smoking or had quit less than 10 years ago. We included all participants assigned to the screening group who had attended at least one round of screening. Screening test results were based on volumetry using a two-step approach. Initially, screening test results were classified as negative, indeterminate, or positive based on nodule presence and volume. Subsequently, participants with an initial indeterminate result underwent follow-up screening to classify their final screening test result as negative or positive, based on nodule volume doubling time. We obtained information about all lung cancer diagnoses made during the first three rounds of screening, plus an additional 2 years of follow-up from the national cancer registry. We determined epidemiological, radiological, participant, and tumour characteristics by reassessing medical files, screening CTs, and clinical CTs. The NELSON trial is registered at www.trialregister.nl, number ISRCTN63545820. 15,822 participants were enrolled in the NELSON trial, of whom 7915 were assigned to low-dose CT screening with increasing interval between screens, and 7907 to no screening. We included 7155 participants in our study, with

  16. Opportunistic screening for osteoporosis by routine CT in Southern Europe.

    Science.gov (United States)

    Alacreu, Elena; Moratal, David; Arana, Estanislao

    2017-03-01

    Feasibility evaluation of early detection of osteoporosis in oncologic patients by bone mineral density (BMD) on abdominal computed tomography (CT) scans performed for other clinical indications, by using dual-energy X-ray absorptiometry (DXA) as reference. Abdominal CT images can identify patients with osteoporosis BMD without additional radiation exposure or cost. The purpose of the study is to evaluate the feasibility of early detection of osteoporosis by bone mineral density (BMD) on abdominal computed tomography (CT) scans performed in oncologic patients, comparing calibrated and uncalibrated measurements by using dual-energy X-ray absorptiometry (DXA) as reference. We also performed an external validation of a threshold of 160 Hounsfield units (HU), proposed as highly sensitive. Cohort comprised CT-DXA pairs within a 6-month period performed for any indication on 326 consecutive adults, aged 62.4 ± 12.38 years (mean ± standard deviation). CT attenuation of trabecular bone in HU was measured at the axial cross sections of L1, L2, L3, and L4 vertebrae. Vertebral compression fractures were assessed by sagittal reconstruction view. Diagnostic performance measures and the area under the receiver operator characteristic curve (AUC) for diagnosing osteoporosis were calculated. BMD values were statistical significantly lower at any vertebral level from L1 to L4 for patients with osteoporosis defined by DXA (p < 0.001). Calibrated and uncalibrated BMD values were significantly correlated (R 2  = 0.833, p < 0.01). An uncalibrated L1 CT attenuation threshold of 160 HU was more than 90 % sensitive, and a threshold of 73 HU was more than 90 % specific for distinguishing osteoporosis BMD. Fifty-nine percent of patients with vertebral compression fracture had non-osteoporotic DXA T-scores. Abdominal CT images obtained for other reasons can identify patients with osteoporosis BMD without additional radiation exposure or cost. Uncalibrated values at L1 can

  17. Smoking habits in the randomised Danish Lung Cancer Screening Trial with low-dose CT

    DEFF Research Database (Denmark)

    Ashraf, Haseem; Saghir, Zaigham; Dirksen, Asger

    2014-01-01

    BACKGROUND: We present the final results of the effect of lung cancer screening with low-dose CT on the smoking habits of participants in a 5-year screening trial. METHODS: The Danish Lung Cancer Screening Trial (DLCST) was a 5-year screening trial that enrolled 4104 subjects; 2052 were randomised...... to annual low-dose CT (CT group) and 2052 received no intervention (control group). Participants were current and ex-smokers (≥4 weeks abstinence from smoking) with a tobacco consumption of ≥20 pack years. Smoking habits were determined annually. Missing values for smoking status at the final screening...... round were handled using two different models. RESULTS: There were no statistically significant differences in annual smoking status between the CT group and control group. Overall the ex-smoker rates (CT + control group) significantly increased from 24% (baseline) to 37% at year 5 of screening (p

  18. CT study in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Heii; Kobayashi, Kazunari; Ikeda, Kenji; Nagao, Yoshiko; Ogihara, Ryuji; Kosaka, Kenji [Tokyo Metropolitan Matsuzawa Hospital (Japan)

    1983-01-01

    Cerebral atrophy on CT was studied in 18 patients with clinically diagnosed Alzheimer's disease and in 14 healthy age-matched subjects as the control. The patients with Alzheimer's disease were divided into three groups of Stages I, II and III, according to their clinical symptoms. The study of the measurement method disclosed that the computerized measurement involving calculation of the number of pixels contained within the range of the designated CT numbers is liable to produce errors for the determination of the subarachnoid spaces and the ventricles with calcified colloid plexus. Therefore, for the present study was the method adopted, in which the subarachnoid spaces and the ventricles are measured based on the number of pixels contained in the region of interest by tracing them on the display monitor. Then, both Subarachnoid Space Volume Index (SVI) and Ventricle Volume Index (VVI) were calculated as the indices for cortical atrophy and ventricular dilatation in a slice through the level of the foramen interventriculare Monroi and other three successive ones through upper regions. Cerebral atrophy observed on CT in Alzheimer patients is attributable to Alzheimer's disease processes, rather than to physiological aging of the brain. The degree of the atrophy increases in proportion to the clinical stage, and cortical atrophy is apparent even at Stage I, whereas ventricular dilatation becomes pronounced at later stage. CT is one of effective clinical tests for the diagnosis of Alzheimer's disease.

  19. CT study in Alzheimer's disease

    International Nuclear Information System (INIS)

    Arai, Heii; Kobayashi, Kazunari; Ikeda, Kenji; Nagao, Yoshiko; Ogihara, Ryuji; Kosaka, Kenji

    1983-01-01

    Cerebral atrophy on CT was studied in 18 patients with clinically diagnosed Alzheimer's disease and in 14 healthy age-matched subjects as the control. The patients with Alzheimer's disease were divided into three groups of Stages I, Ii and III, according to their clinical symptoms. The study of the measurement method disclosed that the computerized measurement involving calculation of the number of pixels contained within the range of the designated CT numbers is liable to produce errors for the determination of the subarachnoid spaces and the ventricles with calcified colloid plexus. Therefor, for the present study was the method adopted, in which the subarachnoid spaces and the ventricles are measured based on the number of pixels contained in the region of interest by tracing them on the display monitor. Then, both Subarachnoid Space Volume Index (SVI) and Ventricle Volume Index (VVI) were calculated as the indices for cortical atrophy and ventricular dilatation in a slice through the level of the foramen interventriculare Monroi and other three successive ones through upper regions. Cerebral atrophy observed on CT in Alzheimer patients is attributable to Alzheimer's disease processes, rather than to physiological aging of the brain. The degree of the atrophy increases in proportion to the clinical stage, and cortical atrophy is apparent even at Stage I, whereas ventricular dilatation becomes pronounced at later stage. CT is one of effective clinical tests for the diagnosis of Alzheimer's disease. (J.P.N.)

  20. WE-D-207-03: CT Protocols for Screening and the ACR Designated Lung Screening Program

    International Nuclear Information System (INIS)

    McNitt-Gray, M.

    2015-01-01

    In the United States, Lung Cancer is responsible for more cancer deaths than the next four cancers combined. In addition, the 5 year survival rate for lung cancer patients has not improved over the past 40 to 50 years. To combat this deadly disease, in 2002 the National Cancer Institute launched a very large Randomized Control Trial called the National Lung Screening Trial (NLST). This trial would randomize subjects who had substantial risk of lung cancer (due to age and smoking history) into either a Chest X-ray arm or a low dose CT arm. In November 2010, the National Cancer Institute announced that the NLST had demonstrated 20% fewer lung cancer deaths among those who were screened with low-dose CT than with chest X-ray. In December 2013, the US Preventive Services Task Force recommended the use of Lung Cancer Screening using low dose CT and a little over a year later (Feb. 2015), CMS announced that Medicare would also cover Lung Cancer Screening using low dose CT. Thus private and public insurers are required to provide Lung Cancer Screening programs using CT to the appropriate population(s). The purpose of this Symposium is to inform medical physicists and prepare them to support the implementation of Lung Screening programs. This Symposium will focus on the clinical aspects of lung cancer screening, requirements of a screening registry for systematically capturing and tracking screening patients and results (such as required Medicare data elements) as well as the role of the medical physicist in screening programs, including the development of low dose CT screening protocols. Learning Objectives: To understand the clinical basis and clinical components of a lung cancer screening program, including eligibility criteria and other requirements. To understand the data collection requirements, workflow, and informatics infrastructure needed to support the tracking and reporting components of a screening program. To understand the role of the medical physicist in

  1. Lung cancer incidence and mortality in National Lung Screening Trial participants who underwent low-dose CT prevalence screening: a retrospective cohort analysis of a randomised, multicentre, diagnostic screening trial.

    Science.gov (United States)

    Patz, Edward F; Greco, Erin; Gatsonis, Constantine; Pinsky, Paul; Kramer, Barnett S; Aberle, Denise R

    2016-05-01

    Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55-74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov, number NCT00047385. Our cohort consisted of 26 231 participants assigned to the low-dose CT screening group who had undergone their T0 screen. The 19 066 participants with a negative T0 screen had a lower incidence of lung cancer than did all 26 231 T0-screened participants (371·88 [95% CI 337·97-408·26] per 100 000 person-years vs 661·23 [622·07-702·21]) and had lower lung cancer-related mortality (185·82 [95% CI 162·17

  2. CT-Screening for lung cancer does not increase the use of anxiolytic or antidepressant medication

    DEFF Research Database (Denmark)

    Kaerlev, Linda; Iachina, Maria; Pedersen, Jesper Holst

    2012-01-01

    CT screening for lung cancer has recently been shown to reduce lung cancer mortality, but screening may have adverse mental health effects. We calculated risk ratios for prescription of anti-depressive (AD) or anxiolytic (AX) medication redeemed at Danish pharmacies for participants in The Danish...... Lung Cancer Screening Trial (DLCST)....

  3. WE-B-207-02: CT Lung Cancer Screening and the Medical Physicist: A Dosimetry Summary of CT Participants in the National Lung Cancer Screening Trial (NLST)

    International Nuclear Information System (INIS)

    Lee, C.

    2015-01-01

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  4. WE-B-207-02: CT Lung Cancer Screening and the Medical Physicist: A Dosimetry Summary of CT Participants in the National Lung Cancer Screening Trial (NLST)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C. [National Cancer Institute (United States)

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  5. Quantitative assessment of smoking-induced emphysema progression in longitudinal CT screening for lung cancer

    Science.gov (United States)

    Suzuki, H.; Mizuguchi, R.; Matsuhiro, M.; Kawata, Y.; Niki, N.; Nakano, Y.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, M.; Moriyama, N.

    2015-03-01

    Computed tomography has been used for assessing structural abnormalities associated with emphysema. It is important to develop a robust CT based imaging biomarker that would allow quantification of emphysema progression in early stage. This paper presents effect of smoking on emphysema progression using annual changes of low attenuation volume (LAV) by each lung lobe acquired from low-dose CT images in longitudinal screening for lung cancer. The percentage of LAV (LAV%) was measured after applying CT value threshold method and small noise reduction. Progression of emphysema was assessed by statistical analysis of the annual changes represented by linear regression of LAV%. This method was applied to 215 participants in lung cancer CT screening for five years (18 nonsmokers, 85 past smokers, and 112 current smokers). The results showed that LAV% is useful to classify current smokers with rapid progression of emphysema (0.2%/year, pemphysema in CT screening for lung cancer.

  6. Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT

    Energy Technology Data Exchange (ETDEWEB)

    Hutt, Antoine; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [CHRU et Universite de Lille, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain; Deken, Valerie [CHRU et Universite de Lille, Department of Biostatistics (EA 2694), Lille (France); Molinari, Francesco [Centre Hospitalier General de Tourcoing, Department of Radiology, Tourcoing (France)

    2016-06-15

    To investigate the reliability of ungated, high-pitch dual-source CT for coronary artery calcium (CAC) screening. One hundred and eighty-five smokers underwent a dual-source CT examination with acquisition of two sets of images during the same session: (a) ungated, high-pitch and high-temporal resolution acquisition over the entire thorax (i.e., chest CT); (b) prospectively ECG-triggered acquisition over the cardiac cavities (i.e., cardiac CT). Sensitivity and specificity of chest CT for detecting positive CAC scores were 96.4 % and 100 %, respectively. There was excellent inter-technique agreement for determining the quantitative CAC score (ICC = 0.986). The mean difference between the two techniques was 11.27, representing 1.81 % of the average of the two techniques. The inter-technique agreement for categorizing patients into the four ranks of severity was excellent (weighted kappa = 0.95; 95 % CI 0.93-0.98). The inter-technique differences for quantitative CAC scores did not correlate with BMI (r = 0.05, p = 0.575) or heart rate (r = -0.06, p = 0.95); 87.2 % of them were explained by differences at the level of the right coronary artery (RCA: 0.8718; LAD: 0.1008; LCx: 0.0139; LM: 0.0136). Ungated, high-pitch dual-source CT is a reliable imaging mode for CAC screening in the conditions of routine chest CT examinations. (orig.)

  7. WE-D-207-00: CT Lung Cancer Screening and the Medical Physicist: Moving Forward

    International Nuclear Information System (INIS)

    2015-01-01

    In the United States, Lung Cancer is responsible for more cancer deaths than the next four cancers combined. In addition, the 5 year survival rate for lung cancer patients has not improved over the past 40 to 50 years. To combat this deadly disease, in 2002 the National Cancer Institute launched a very large Randomized Control Trial called the National Lung Screening Trial (NLST). This trial would randomize subjects who had substantial risk of lung cancer (due to age and smoking history) into either a Chest X-ray arm or a low dose CT arm. In November 2010, the National Cancer Institute announced that the NLST had demonstrated 20% fewer lung cancer deaths among those who were screened with low-dose CT than with chest X-ray. In December 2013, the US Preventive Services Task Force recommended the use of Lung Cancer Screening using low dose CT and a little over a year later (Feb. 2015), CMS announced that Medicare would also cover Lung Cancer Screening using low dose CT. Thus private and public insurers are required to provide Lung Cancer Screening programs using CT to the appropriate population(s). The purpose of this Symposium is to inform medical physicists and prepare them to support the implementation of Lung Screening programs. This Symposium will focus on the clinical aspects of lung cancer screening, requirements of a screening registry for systematically capturing and tracking screening patients and results (such as required Medicare data elements) as well as the role of the medical physicist in screening programs, including the development of low dose CT screening protocols. Learning Objectives: To understand the clinical basis and clinical components of a lung cancer screening program, including eligibility criteria and other requirements. To understand the data collection requirements, workflow, and informatics infrastructure needed to support the tracking and reporting components of a screening program. To understand the role of the medical physicist in

  8. Nutrient intake and nutrient patterns and risk of lung cancer among heavy smokers: results from the COSMOS screening study with annual low-dose CT

    International Nuclear Information System (INIS)

    Gnagnarella, Patrizia; Maisonneuve, Patrick; Bellomi, Massimo; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Palli, Domenico; Veronesi, Giulia

    2013-01-01

    The role of nutrients in lung cancer aetiology remains controversial and has never been evaluated in the context of screening. Our aim was to investigate the role of single nutrients and nutrient patterns in the aetiology of lung cancer in heavy smokers. Asymptomatic heavy smokers (≥20 pack-years) were invited to undergo annual low-dose computed tomography. We assessed diet using a self-administered food frequency questionnaire and collected information on multivitamin supplement use. We performed principal component analysis identifying four nutrient patterns and used Cox proportional Hazards regression to assess the association between nutrients and nutrients patterns and lung cancer risk. During a mean follow-up of 5.7 years, 178 of 4,336 participants were diagnosed with lung cancer by screening. We found a significant risk reduction of lung cancer with increasing vegetable fat consumption (HR for highest vs. lowest quartile = 0.50, 95 % CI = 0.31–0.80; P-trend = 0.02). Participants classified in the high “vitamins and fiber” pattern score had a significant risk reduction of lung cancer (HR = 0.57; 95 % CI = 0.36–0.90, P-trend = 0.01). Among heavy smokers enrolled in a screening trial, high vegetable fat intake and adherence to the “vitamin and fiber” nutrient pattern were associated with reduced lung cancer incidence.

  9. A practical approach to radiological evaluation of CT lung cancer screening examinations

    NARCIS (Netherlands)

    Xie, Xueqian; Heuvelmans, Marjolein A.; van Ooijen, Peter M. A.; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

    2013-01-01

    Lung cancer is the most common cause of cancer-related death in the world. The Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON) was launched to investigate whether screening for lung cancer by low-dose multidetector computed tomography (CT) in high-risk patients will lead

  10. Risk-benefit analysis and cost-effectiveness analysis of lung cancer screening by spiral CT

    International Nuclear Information System (INIS)

    Iinuma, Takeshi

    1999-01-01

    Mass screening of lung cancer has been widely performed using indirect chest X-ray method in Japan. However reduction of the mortality for lung cancer is questioned. We have proposed that recently developed spiral CT should be adopted for the screening of lung cancer, since CT has an excellent detectability for small nodule. Lung Cancer Screening CT (LSCT) has been developed by author's group using spiral CT with low dose and light weight in order to make a mobile unit. In this paper risk-benefit analysis and cost-effectiveness analysis are described for the LSCT screening of lung cancer. As a risk, radiation carcinogenesis due to exposure from LSCT are compared with gain of life-expectancy by screening and men of 40 years or more and women of 45 years or more are justified. The cost per person-year is estimated for LSCT screening which is better than that of present method, although total cost is higher. The LSCT screening could be recommended if total cost is affordable. (author)

  11. WE-B-207-00: CT Lung Cancer Screening Part 1

    International Nuclear Information System (INIS)

    2015-01-01

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  12. WE-B-207-00: CT Lung Cancer Screening Part 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  13. CT-colonography in population-based colorectal cancer screening

    NARCIS (Netherlands)

    de Haan, M.C.

    2012-01-01

    In een proefbevolkingsonderzoek naar dikkedarmkanker vergeleek Margriet de Haan coloscopie (onderzoek met een dunne flexibele slang met camera om de darm van binnenuit te bekijken) met CT-colografie (onderzoek waarbij de darmen worden onderzocht zonder slang) wat betreft opkomst, opbrengst,

  14. Elevated serum CA 19-9 at screening tests: underlying conditions and role of abdominopelvic CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Yang [University of Louisville, Department of Radiology and Molecular Imaging Research Center, Louisville, KY (United States); Seoul National University Hospital, Department of Radiology, Healthcare System Gangnam Center, Seoul (Korea, Republic of); Kim, Se Hyung [Seoul National University Hospital, Department of Radiology and the Institute of Radiation Medicine, Seoul (Korea, Republic of); Kim, Soo Young [Seoul National University Hospital, Department of Radiology, Healthcare System Gangnam Center, Seoul (Korea, Republic of); Bundang CHA Hospital, Department of Radiology, Bundang (Korea, Republic of)

    2014-10-15

    To investigate underlying conditions of patients with elevated CA 19-9 at screening tests and to evaluate diagnostic performance of abdominopelvic CT. One hundred and thirteen patients with elevated CA 19-9 (>37 U/ml) who underwent abdominopelvic CT in a screening program were selected. Underlying conditions were determined by reviewing all available data and follow-up records. Patients were categorized into malignancy, benign, and normal/non-related disease groups. Their mean CA 19-9 and percent of patients with CA 19-9 ≥ 100 U/ml were compared. Diagnostic sensitivity of CT for detecting underlying conditions of elevated CA 19-9 was analysed. Seventeen patients (17/113, 15 %) had 17 elevated CA 19-9-related malignancies, and 55 patients (55/113, 48.7 %) had 70 benign diseases. Mean CA 19-9 and percent of patients with CA 19-9 ≥ 100 U/ml in the malignancy group were significantly higher than in the two other groups. CT detected all except one malignant lesion with a detection sensitivity of 94.1 % (16/17). Of 70 CA 19-9-related benign diseases, CT detected 34 benign diseases (48.6 %) providing an alternative diagnosis for elevated CA 19-9. Abdominopelvic CT is not only useful in detecting malignancies, but can also diagnose alternative benign causes of elevated CA 19-9 in asymptomatic screening tests. (orig.)

  15. Low-dosage helical CT applications for chest medical checkup and lung cancer screening

    International Nuclear Information System (INIS)

    Wang Ping; Cui Fa; Liang Huanqing; Zheng Minfei

    2005-01-01

    Objective: A discussion on low-dosage helical CT applications on chest medical checkup and lung cancer screening. Methods: On the 100 chest medical check up with three different of protocols, including standard-dosage (the tube current was 230 mAs) were compared with low-dose (tube current was 50 mAs or 30 mAs). Results: Low-dosage helical CT scan provides excellent images. In 100 chest medical checkup, 39 nodules or masses were revealed, enlarged lymph node was noted in 1 case; emphysema or bullae was demonstrated in 3 segments; thickening of bronchial wall was shown in 2 cases; and localized pleural thickening was found in 1 case. Conclusion: In chest checkup or lung cancer screening low-dosage helical CT (tube current 30 mAs) will not only guarantee image quality but also reduce the radiation dose during the examination. (authors)

  16. Screening for distant metastases in head and neck cancer patients by chest CT or whole body FDG-PET: A prospective multicenter trial

    International Nuclear Information System (INIS)

    Senft, Asaf; Bree, Remco de; Hoekstra, Otto S.; Kuik, Dirk J.; Golding, Richard P.; Oyen, Wim J.G.; Pruim, Jan; Hoogen, Frank J. van den; Roodenburg, Jan L.N.; Leemans, C. Rene

    2008-01-01

    Background and purpose: The aim of the study was to define the added value of whole body FDG-PET in screening for distant metastases in patients with head and neck squamous cell carcinoma and risk factors. Materials and methods: In a multi-center prospective study between 1998 and 2003, 145 consecutive HNSCC patients with risk factors for distant metastases underwent chest CT and whole body FDG-PET for screening of distant metastases. The data of 92 evaluable patients who developed distant metastases or who had a follow-up of at least 12 months were analyzed. Besides their performance in clinical practice, the operational characteristics of PET and CT using ROC analyses were investigated. Results: Pretreatment screening identified distant metastases in 19 patients (21%). FDG-PET had a higher sensitivity (53% vs. 37%) and positive predictive value (80% vs. 75%) than CT. The combination of CT and FDG-PET had the highest sensitivity (63%). The ROC analyses of the five point ordinal scales revealed that the 'area under the curve' (AUC) of FDG-PET was significantly higher as compared to CT. Conclusion: In HNSCC patients with risk factors, pretreatment screening for distant metastases by chest CT is improved by FDG-PET

  17. Lung cancer screening with low-dose helical CT in Korea: experiences at the Samsung Medical Center.

    Science.gov (United States)

    Chong, Semin; Lee, Kyung Soo; Chung, Myung Jin; Kim, Tae Sung; Kim, Hojoong; Kwon, O Jung; Choi, Yoon-Ho; Rhee, Chong H

    2005-06-01

    To determine overall detection rates of lung cancer by low-dose CT (LDCT) screening and to compare histopathologic and imaging differences of detected cancers between high- and low-risk groups, this study included 6,406 asymptomatic Korean adults with >or=45 yr of age who underwent LDCT for lung cancer screening. All were classified into high- (>or=20 pack-year smoking; 3,353) and low-risk (3,053; <20 pack-yr smoking and non-smokers) groups. We compared CT findings of detected cancers and detection rates between high- and low-risk. At initial CT, 35% (2,255 of 6,406) had at least one or more non-calcified nodule. Lung cancer detection rates were 0.36% (23 of 6,406). Twenty-one non-small cell lung cancers appeared as solid (n=14) or ground-glass opacity (GGO) (n=7) nodules. Cancer likelihood was higher in GGO nodules than in solid nodules (p<0.01). Fifteen of 23 cancers occurred in high-risk group and 8 in low-risk group (p=0.215). Therefore, LDCT screening help detect early stage of lung cancer in asymptomatic Korean population with detection rate of 0.36% on a population basis and may be useful for discovering early lung cancer in low-risk group as well as in high-risk group.

  18. The efficacy of low-dose helical CT screening as an option for health examination

    International Nuclear Information System (INIS)

    Kishi, Kazuma; Hara, Shigeko; Kurosaki, Atsuko; Fujii, Takeshi; Yoshimura, Kunihiko

    2007-01-01

    We retrospectively evaluated the results of low-dose helical CT screening as an option for health examinations. From November 2002 to October 2005, CT screening was performed in 2,306 individuals (men 1,766, women 540, mean age 56.1 years). Among them, 71 individuals (3.1%) were diagnosed as having active thoracic diseases consisting of 14 neoplasms and 57 non-neoplastic diseases. Of 14 patients with neoplastic lesions, 13 had lung cancer, 1 of whom had double primary lung cancer, and 1 had atypical adenomatous hyperplasia. The mean diameter of the 14 lung cancers was 14.4 mm. The histology of these lesions was adenocarcinoma in 13 and squamous cell carcinoma in 1. The pathological stage was IA in 12 patients and IIA in 1. All patients underwent surgical resection. On the other hand, emphysema was diagnosed in 40 asymptomatic individuals based on CT and spirometry, and smoking cessation was strongly implemented for those who were current smokers. CT screening is useful for detecting not only early lung cancer but also non-neoplastic lung diseases. (author)

  19. Cost analysis of colorectal cancer screening with CT colonography in Italy.

    Science.gov (United States)

    Mantellini, Paola; Lippi, Giuseppe; Sali, Lapo; Grazzini, Grazia; Delsanto, Silvia; Mallardi, Beatrice; Falchini, Massimo; Castiglione, Guido; Carozzi, Francesca Maria; Mascalchi, Mario; Milani, Stefano; Ventura, Leonardo; Zappa, Marco

    2018-06-01

    Unit costs of screening CT colonography (CTC) can be useful for cost-effectiveness analyses and for health care decision-making. We evaluated the unit costs of CTC as a primary screening test for colorectal cancer in the setting of a randomized trial in Italy. Data were collected within the randomized SAVE trial. Subjects were invited to screening CTC by mail and requested to have a pre-examination consultation. CTCs were performed with 64- and 128-slice CT scanners after reduced or full bowel preparation. Activity-based costing was used to determine unit costs per-process, per-participant to screening CTC, and per-subject with advanced neoplasia. Among 5242 subjects invited to undergo screening CTC, 1312 had pre-examination consultation and 1286 ultimately underwent CTC. Among 129 subjects with a positive CTC, 126 underwent assessment colonoscopy and 67 were ultimately diagnosed with advanced neoplasia (i.e., cancer or advanced adenoma). Cost per-participant of the entire screening CTC pathway was €196.80. Average cost per-participant for the screening invitation process was €17.04 and €9.45 for the pre-examination consultation process. Average cost per-participant of the CTC execution and reading process was €146.08 and of the diagnostic assessment colonoscopy process was €24.23. Average cost per-subject with advanced neoplasia was €3777.30. Cost of screening CTC was €196.80 per-participant. Our data suggest that the more relevant cost of screening CTC, amenable of intervention, is related to CTC execution and reading process.

  20. SU-E-I-34: Evaluating Use of AEC to Lower Dose for Lung Cancer Screening CT Protocols

    International Nuclear Information System (INIS)

    Arbique, G; Anderson, J; Guild, J; Duan, X; Malguria, N; Omar, H; Brewington, C; Zhang, D

    2015-01-01

    Purpose: The National Lung Screening Trial mandated manual low dose CT technique factors, where up to a doubling of radiation output could be used over a regular to large patient size range. Recent guidance from the AAPM and ACR for lung cancer CT screening recommends radiation output adjustment for patient size either through AEC or a manual technique chart. This study evaluated the use of AEC for output control and dose reduction. Methods: The study was performed on a multidetector helical CT scanner (Aquillion ONE, Toshiba Medical) equipped with iterative reconstruction (ADIR-3D), AEC was adjusted with a standard deviation (SD) image quality noise index. The protocol SD parameter was incrementally increased to reduce patient population dose while image quality was evaluated by radiologist readers scoring the clinical utility of images on a Likert scale. Results: Plots of effective dose vs. body size (water cylinder diameter reported by the scanner) demonstrate monotonic increase in patient dose with increasing patient size. At the initial SD setting of 19 the average CTDIvol for a standard size patient was ∼ 2.0 mGy (1.2 mSv effective dose). This was reduced to ∼1.0 mGy (0.5 mSv) at an SD of 25 with no noticeable reduction in clinical utility of images as demonstrated by Likert scoring. Plots of effective patient diameter and BMI vs body size indicate that these metrics could also be used for manual technique charts. Conclusion: AEC offered consistent and reliable control of radiation output in this study. Dose for a standard size patient was reduced to one-third of the 3 mGy CTDIvol limit required for ACR accreditation of lung cancer CT screening. Gary Arbique: Research Grant, Toshiba America Medical Systems; Cecelia Brewington: Research Grant, Toshiba America Medical Systems; Di Zhang: Employee, Toshiba America Medical Systems

  1. Teleradiology based CT colonography to screen a population group of a remote island; at average risk for colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, Philippe, E-mail: radiologie@skynet.be [VCTC, Virtual Colonoscopy Teaching Centre, Akkerstraat 32c, B-8830 Hooglede (Belgium); Silva, Celso, E-mail: caras@uma.pt [Human Anatomy of Medical Course, University of Madeira, Praça do Município, 9000-082 Funchal (Portugal); Gryspeerdt, Stefaan, E-mail: stefaan@sgryspeerdt.be [VCTC, Virtual Colonoscopy Teaching Centre, Akkerstraat 32c, B-8830 Hooglede (Belgium); Rodrigues, António, E-mail: nucleo@nid.pt [Nucleo Imagem Diagnostica, Rua 5 De Outubro, 9000-216 Funchal (Portugal); Vasconcelos, Rita, E-mail: rita@uma.pt [Department of Engineering and Mathematics, University of Madeira, Praça do Município, 9000-082 Funchal (Portugal); Teixeira, Ricardo, E-mail: j.teixeira1947@gmail.com [Department of Gastroenterology, Central Hospital of Funchal, Avenida Luís de Camões, 9004513 Funchal (Portugal); Gouveia, Francisco Henriques de, E-mail: fhgouveia@netmadeira.com [LANA, Pathology Centre, Rua João Gago, 10, 9000-071 Funchal (Portugal)

    2013-06-15

    Purpose: To prospectively assess the performance of teleradiology-based CT colonography to screen a population group of an island, at average risk for colorectal cancer. Materials and methods: A cohort of 514 patients living in Madeira, Portugal, was enrolled in the study. Institutional review board approval was obtained and all patients signed an informed consent. All patients underwent both CT colonography and optical colonoscopy. CT colonography was interpreted by an experienced radiologist at a remote centre using tele-radiology. Per-patient sensitivity, specificity, positive (PPV) and negative (NPV) predictive values with 95% confidence intervals (95%CI) were calculated for colorectal adenomas and advanced neoplasia ≥6 mm. Results: 510 patients were included in the study. CT colonography obtained a per-patient sensitivity, specificity, PPV and, NPV for adenomas ≥6 mm of 98.11% (88.6–99.9% 95% CI), 90.97% (87.8–93.4% 95% CI), 56.52% (45.8–66.7% 95% CI), 99.75% (98.4–99.9% 95% CI). For advanced neoplasia ≥6 mm per-patient sensitivity, specificity, PPV and, NPV were 100% (86.7–100% 95% CI), 87.07% (83.6–89.9% 95% CI), 34.78% (25.3–45.5% 95% CI) and 100% (98.8–100% 95% CI), respectively. Conclusion: In this prospective trial, teleradiology-based CT colonography was accurate to screen a patient cohort of a remote island, at average risk for colorectal cancer.

  2. Teleradiology based CT colonography to screen a population group of a remote island; at average risk for colorectal cancer

    International Nuclear Information System (INIS)

    Lefere, Philippe; Silva, Celso; Gryspeerdt, Stefaan; Rodrigues, António; Vasconcelos, Rita; Teixeira, Ricardo; Gouveia, Francisco Henriques de

    2013-01-01

    Purpose: To prospectively assess the performance of teleradiology-based CT colonography to screen a population group of an island, at average risk for colorectal cancer. Materials and methods: A cohort of 514 patients living in Madeira, Portugal, was enrolled in the study. Institutional review board approval was obtained and all patients signed an informed consent. All patients underwent both CT colonography and optical colonoscopy. CT colonography was interpreted by an experienced radiologist at a remote centre using tele-radiology. Per-patient sensitivity, specificity, positive (PPV) and negative (NPV) predictive values with 95% confidence intervals (95%CI) were calculated for colorectal adenomas and advanced neoplasia ≥6 mm. Results: 510 patients were included in the study. CT colonography obtained a per-patient sensitivity, specificity, PPV and, NPV for adenomas ≥6 mm of 98.11% (88.6–99.9% 95% CI), 90.97% (87.8–93.4% 95% CI), 56.52% (45.8–66.7% 95% CI), 99.75% (98.4–99.9% 95% CI). For advanced neoplasia ≥6 mm per-patient sensitivity, specificity, PPV and, NPV were 100% (86.7–100% 95% CI), 87.07% (83.6–89.9% 95% CI), 34.78% (25.3–45.5% 95% CI) and 100% (98.8–100% 95% CI), respectively. Conclusion: In this prospective trial, teleradiology-based CT colonography was accurate to screen a patient cohort of a remote island, at average risk for colorectal cancer

  3. Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Takashi; Urata, Joji [Diagnostic Imaging Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Mitsuzaki, Katsuhiko; Matsuda, Katsuhiko; Kawakami, Megumi [Medical Examination Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Utsunomiya, Daisuke; Yamamura, Sadahiro; Yamashita, Yasuyuki [Diagnostic Radiology, Faculty of Life Sciences, Kumamoto Univ., Kumamoto (Japan)], e-mail: utsunomi@kumamoto-u.ac.jp

    2012-09-15

    Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Results: Detection sensitivity for flat polyps was 31.3 %, 44.4 %, and 87.5 % for lesions measuring 2-3 mm, 4-5 mm, and {>=}6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6 %, 79.0 %, and 91.7 %. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

  4. Interpolated sagittal and coronal reconstruction of CT images in the screening of neck abnormalities

    International Nuclear Information System (INIS)

    Koga, Issei

    1983-01-01

    Recontructed sagittal and coronal images were analyzed for their usefulness during clinical applications and to determine the correct use of recontruction techniques. Recontructed stereoscopic images can be formed by continuous or interrupted image reconstruction using interpolation. This study showed that lesions less than 10 mm in diameter should be made continuously and recontructed with uninterrupted technique. However, 5 mm interrupted distances are acceptable for interpolated reconstruction except in cases of lesions less than 10 mm in diameter. Clinically, interpolated reconstruction is not adequated for semicircular lesions less than 10 mm. Blood vessels and linear lesions are good condiated for the application of interpolated recontruction. Reconstruction of images using interrupted interpolation is therefore recommended for screening and for demonstrating correct stereoscopic information, except cases of small lesions less than 10 mm in diameter. Results of this study underscore the fact that obscure information in transverse CT images should be routinely utilized by interporating recontruction techniques, if transverse images are not made continuously. Interpolated recontruction may be helpful in obtaining stereoscopic information. (author)

  5. Diagnostic value of CT-colonography as compared to colonoscopy in an asymptomatic screening population: a meta-analysis

    International Nuclear Information System (INIS)

    Haan, Margriet C. de; Gelder, Rogier E. van; Bipat, Shandra; Stoker, Jaap; Graser, Anno

    2011-01-01

    Previous meta-analyses on CT-colonography included both average and high risk individuals, which may overestimate the diagnostic value in screening. A meta-analysis was performed to obtain the value of CT-colonography for screening. A search was performed using PubMed, Embase and Cochrane. Article selection and critical appraisal was done by two reviewers. Inclusion criteria: prospective, randomized trials or cohort studies comparing CT-colonography with colonoscopy (≥50 participants), ≥95% average risk participants ≥50 years. Study characteristics and 2 x 2 contingency Tables were recorded. Sensitivity and specificity estimates were calculated per patient and per polyp (≥6 mm, ≥10 mm), using univariate and bivariate analyses. Five of 1,021 studies identified were included, including 4,086 participants ( 2 -values showed substantial heterogeneity, especially for 6-9 mm polyps and adenomas: 68.1% vs. 78.6% (sensitivity per patient). Estimated sensitivities for patients with polyps or adenomas ≥ 6 mm were 75.9% and 82.9%, corresponding specificities 94.6% and 91.4%. Estimated sensitivities for patients with polyps or adenomas ≥ 10 mm were 83.3% and 87.9%, corresponding specificities 98.7% and 97.6%. Estimated sensitivities per polyp for advanced adenomas ≥ 6 mm and ≥ 10 mm were 83.9% and 83.8%. Compared to colonoscopy, CT-colonography has a high sensitivity for adenomas ≥ 10 mm. For (advanced) adenomas ≥ 6 mm sensitivity is somewhat lower. (orig.)

  6. The effect of inspiration on airway dimensions measured in CT images from the Danish Lung Cancer Screening Trial

    DEFF Research Database (Denmark)

    Petersen, Jens; Wille, Mathilde; Thomsen, Laura

    2013-01-01

    of the same subject using image registration. Mixed effect models were used to predict the relative change in lumen diameter (LD) and wall thickness (WT) in airways of generation 0 (trachea) to 6 based on relative changes in the segmented total lung volume (TLV). Results: On average, 1.0, 2.0, 3.9, 7.6, 15...... and Materials: We selected from the Danish Lung Cancer Screening Trial 978 subjects without COPD who were scanned annually for 5 years with low-dose multi-slice CT. Using in-house developed software, the lungs and airways were automatically segmented and corresponding airway branches were found in all scans......Purpose: Airway dimensions measured from CT are increasingly being used to investigate diseases such as chronic obstructive pulmonary disease (COPD). In this study, we investigate the effect of differences in inspiration level on such measurements in voluntary inspiration breathhold scans. Methods...

  7. The relationship of cancer characteristics and patient outcome with time to lung cancer diagnosis after an abnormal screening CT

    Energy Technology Data Exchange (ETDEWEB)

    Sonavane, Sushilkumar K.; Watts, Jubal; Singh, Satinder P.; Nath, Hrudaya [University of Alabama in Birmingham School of Medicine, Department of Radiology- Cardiopulmonary section, Birmingham, AL (United States); Pinsky, Paul [National Cancer Institute, Division of Cancer Prevention, Bethesda, MD (United States); Gierada, David S. [Washington University School of Medicine, Department of Radiology, St. Louis, MO (United States); Munden, Reginald [Wake Forest School of Medicine, Department of Radiology, Winston Salem, NC (United States)

    2017-12-15

    The National Lung Screening Trial (NLST) demonstrated a reduction in lung cancer and all-cause mortality with low-dose CT (LDCT) screening. The aim of our study was to examine the time to diagnosis (TTD) of lung cancer in the LDCT arm of the NLST and assess its relationship with cancer characteristics and survival. The subjects (N = 462) with a positive baseline screen and subsequent lung cancer diagnosis within 3 years were evaluated by data and image review to confirm the baseline abnormality. The cases were analysed for the relationship between TTD and imaging features, cancer type, stage and survival for 7 years from baseline screen. Cancer was judged to be present at baseline in 397/462 cases. The factors that showed significant association (p value trend less than 0.05) with longer TTD included smaller nodule size, pure ground glass nodules (GGNs), smooth/lobulated margins, stages I/II, adenocarcinoma, and decreasing lung cancer mortality. The logistic regression model for lung cancer death showed significant inverse relationships with size less than 20 mm (OR = 0.32), pure GGNs (OR = 0.24), adenocarcinoma (OR = 0.57) and direct relationship with age (OR = 1.4). TTD after a positive LDCT screen in the NLST showed a strong association with imaging features, stage and mortality. (orig.)

  8. The relationship of cancer characteristics and patient outcome with time to lung cancer diagnosis after an abnormal screening CT

    International Nuclear Information System (INIS)

    Sonavane, Sushilkumar K.; Watts, Jubal; Singh, Satinder P.; Nath, Hrudaya; Pinsky, Paul; Gierada, David S.; Munden, Reginald

    2017-01-01

    The National Lung Screening Trial (NLST) demonstrated a reduction in lung cancer and all-cause mortality with low-dose CT (LDCT) screening. The aim of our study was to examine the time to diagnosis (TTD) of lung cancer in the LDCT arm of the NLST and assess its relationship with cancer characteristics and survival. The subjects (N = 462) with a positive baseline screen and subsequent lung cancer diagnosis within 3 years were evaluated by data and image review to confirm the baseline abnormality. The cases were analysed for the relationship between TTD and imaging features, cancer type, stage and survival for 7 years from baseline screen. Cancer was judged to be present at baseline in 397/462 cases. The factors that showed significant association (p value trend less than 0.05) with longer TTD included smaller nodule size, pure ground glass nodules (GGNs), smooth/lobulated margins, stages I/II, adenocarcinoma, and decreasing lung cancer mortality. The logistic regression model for lung cancer death showed significant inverse relationships with size less than 20 mm (OR = 0.32), pure GGNs (OR = 0.24), adenocarcinoma (OR = 0.57) and direct relationship with age (OR = 1.4). TTD after a positive LDCT screen in the NLST showed a strong association with imaging features, stage and mortality. (orig.)

  9. Automated quantification of emphysema in CT studies of the lung

    International Nuclear Information System (INIS)

    Archer, D.C.; deKemp, R.A.; Coblentz, C.L.; Nahmias, C.

    1991-01-01

    Emphysema by definition is a pathologic diagnosis. Recently, in vivo quantification of emphysema from CT with point counting and with a GE 9800 CT scanner program called Density Mask has been described. These methods are laborious and time-consuming, making them unsuitable for screening. The propose of this paper is to create a screening test for emphysema. The authors developed a computer program that quantifies the amount of emphysema from standard CT-scans. The computer was programmed to recognize the lung edges on each section by identifying abrupt changes in CT numbers; grow regions within each lung to identify and separate the lungs from other structures; count regions of lung containing CT numbers measuring <-900 HU corresponding to areas of emphysema; and calculation the percentage of emphysema present from the volume of normal emphysematous lung. The programs were written in C and urn on a Sun 4/100 workstation

  10. Five year colorectal cancer outcomes in a large negative CT colonography screening cohort

    Energy Technology Data Exchange (ETDEWEB)

    Kim, David H.; Pooler, B.D.; Pickhardt, Perry J. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Weiss, Jennifer M. [University of Wisconsin School of Medicine and Public Health, Section of Gastroenterology, Department of Internal Medicine, Madison, WI (United States)

    2012-07-15

    To assess the 5-year incidence of clinically presenting colorectal cancers following a negative CT colonography (CTC) screening examination, as few patient outcome data regarding a negative CTC screening result exist. Negative CTC screening patients (n = 1,050) in the University of Wisconsin Health system over a 14-month period were included. An electronic medical record (EMR) review was undertaken, encompassing provider, colonoscopy, imaging and histopathology reports. Incident colorectal cancers and other important GI tumours were recorded. Of the 1,050 cohort (mean [{+-}SD] age 56.9 {+-} 7.4 years), 39 (3.7%) patients were excluded owing to lack of follow-up within our system beyond the initial screening CTC. The remaining 1,011 patients were followed for an average of 4.73 {+-} 1.15 years. One incident colorectal adenocarcinoma represented a crude cancer incidence of 0.2 cancers per 1,000 patient years. EMR revealed 14 additional patients with clinically important GI tumours including: advanced adenomas (n = 11), appendiceal goblet cell carcinoid (n = 1), appendiceal mucinous adenoma (n = 1) and metastatic ileocolonic carcinoid (n = 1). All positive patients including the incident carcinoma are alive at the time of review. Clinically presenting colorectal adenocarcinoma is rare in the 5 years following negative screening CTC, suggesting that current strategies, including non-reporting of diminutive lesions, are appropriate. (orig.)

  11. Five year colorectal cancer outcomes in a large negative CT colonography screening cohort

    International Nuclear Information System (INIS)

    Kim, David H.; Pooler, B.D.; Pickhardt, Perry J.; Weiss, Jennifer M.

    2012-01-01

    To assess the 5-year incidence of clinically presenting colorectal cancers following a negative CT colonography (CTC) screening examination, as few patient outcome data regarding a negative CTC screening result exist. Negative CTC screening patients (n = 1,050) in the University of Wisconsin Health system over a 14-month period were included. An electronic medical record (EMR) review was undertaken, encompassing provider, colonoscopy, imaging and histopathology reports. Incident colorectal cancers and other important GI tumours were recorded. Of the 1,050 cohort (mean [±SD] age 56.9 ± 7.4 years), 39 (3.7%) patients were excluded owing to lack of follow-up within our system beyond the initial screening CTC. The remaining 1,011 patients were followed for an average of 4.73 ± 1.15 years. One incident colorectal adenocarcinoma represented a crude cancer incidence of 0.2 cancers per 1,000 patient years. EMR revealed 14 additional patients with clinically important GI tumours including: advanced adenomas (n = 11), appendiceal goblet cell carcinoid (n = 1), appendiceal mucinous adenoma (n = 1) and metastatic ileocolonic carcinoid (n = 1). All positive patients including the incident carcinoma are alive at the time of review. Clinically presenting colorectal adenocarcinoma is rare in the 5 years following negative screening CTC, suggesting that current strategies, including non-reporting of diminutive lesions, are appropriate. (orig.)

  12. CT perfusion study of neck lymph nodes

    International Nuclear Information System (INIS)

    Zhong Jin; Liu Jun; Hua Rui; Qiao Hui; Gong Yi

    2011-01-01

    Objective: To study the CT perfusion features of various lymph nodes in the neck. Methods: Dynamic perfusion CT scanning was performed in 83 neck lymph nodes proved by pathology, including tuberculosis lymph nodes, lymphoma and metastatic lymph nodes. The shapes, blood flow modes, and perfusion parameters of these lymph nodes were compared among 3 groups. Statistical analysis of L/T and CT perfusion parameters was performed by one-way ANOVA and LSD test. Results: The values of MTT of tuberculosis lymph nodes, lymphoma and metastatic lymph nodes were (28.13±5.08), (31.08±5.82), and (11.24±5.31) s, respectively. The MTT of metastatic lymph nodes was statistically lower than that of tuberculosis lymph nodes and lymphoma (P -1 · 100 g -1 , respectively. The values of BV were (24.68±2.84), (25.30±3.16), and (25.15± 8.81) ml·100 g -1 respectively. The values of TTP were (40.90±8.85), (40.67±6.45), and (40.98±6.62) s, respectively. There were no significant differences in L/T, BF, BV and TTP among tuberculosis lymph nodes, lymphoma and metastatic lymph nodes (P>0.05). Conclusion: CT perfusion, especially combination functional imaging with perfusion images may be helpful in judging the nature of neck lymph nodes. (authors)

  13. WE-B-207-01: CT Lung Cancer Screening and the Medical Physicist: Background, Findings and Participant Dosimetry Summary of the National Lung Screening Trial (NLST)

    International Nuclear Information System (INIS)

    Kruger, R.

    2015-01-01

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  14. WE-B-207-01: CT Lung Cancer Screening and the Medical Physicist: Background, Findings and Participant Dosimetry Summary of the National Lung Screening Trial (NLST)

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, R. [Marshfield Clinic, Marshfield, WI (United States)

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  15. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study

    International Nuclear Information System (INIS)

    Feng Shiting; Law, Martin Wai-Ming; Huang Bingsheng; Ng, Sherry; Li Ziping; Meng Quanfei; Khong, Pek-Lan

    2010-01-01

    Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.

  16. Relationship between abdominal fat area measured by screening abdominal fat CT and metabolic syndrome in asymptomatic Korean individuals

    International Nuclear Information System (INIS)

    Park, Dae Woong; Park, Noh Hyuck; Park, Ji Yeon; Kim, Seon Jeong

    2017-01-01

    The purpose of this study was to investigate the relationship between abdominal fat as assessed by abdominal fat CT and metabolic syndrome (MS), especially in asymptomatic Korean individuals. Retrospectively, a medical record analysis was performed in a total of 111 patients with screening abdominal fat CT. The data such as visceral fat (VF), subcutaneous fat (SF) and VF/SF were elicited by abdominal fat CT, and we analyzed the relationship of VF, SF, and VF/SF with MS and cardiovascular risk factors. In males, VF and SF had a positive correlation with many cardiovascular risk factors and MS, but VF was superior to SF. In females, VF, but not SF, had a positive correlation with some cardiovascular risk factors and MS. The cut-off values of VF and SF to predict MS, which were calculated by drawing receiver operating characteristic curves, were as follows: the cut-off value of VF in men: 136.50 cm"2, the cut-off value of SF in men: 159.50 cm"2, and the cut-off value of VF in women: 134.50 cm"2. In conclusion, VF accumulation was the best predictor of MS and it had a positive correlation with cardiovascular risk factors in both sexes. SF also had a significant association with MS, especially in men, although it was not superior to VF

  17. Relationship between abdominal fat area measured by screening abdominal fat CT and metabolic syndrome in asymptomatic Korean individuals

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dae Woong; Park, Noh Hyuck; Park, Ji Yeon; Kim, Seon Jeong [Dept. of Radiology, MyoungJi Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of)

    2017-07-15

    The purpose of this study was to investigate the relationship between abdominal fat as assessed by abdominal fat CT and metabolic syndrome (MS), especially in asymptomatic Korean individuals. Retrospectively, a medical record analysis was performed in a total of 111 patients with screening abdominal fat CT. The data such as visceral fat (VF), subcutaneous fat (SF) and VF/SF were elicited by abdominal fat CT, and we analyzed the relationship of VF, SF, and VF/SF with MS and cardiovascular risk factors. In males, VF and SF had a positive correlation with many cardiovascular risk factors and MS, but VF was superior to SF. In females, VF, but not SF, had a positive correlation with some cardiovascular risk factors and MS. The cut-off values of VF and SF to predict MS, which were calculated by drawing receiver operating characteristic curves, were as follows: the cut-off value of VF in men: 136.50 cm{sup 2}, the cut-off value of SF in men: 159.50 cm{sup 2}, and the cut-off value of VF in women: 134.50 cm{sup 2}. In conclusion, VF accumulation was the best predictor of MS and it had a positive correlation with cardiovascular risk factors in both sexes. SF also had a significant association with MS, especially in men, although it was not superior to VF.

  18. CT studies of brain abscesses in cats

    International Nuclear Information System (INIS)

    Kretzschmar, K.; Wallenfang, T.; Bohl, J.

    1981-01-01

    Cerebral abscesses were produced in 56 cats by introducing staphylococcus aureus into the white matter of one cerebral hemisphere, using a stereotaxic apparatus. The cats were treated with antibiotics and/or steroids. The size and density of the inflammatory process and the abscess ring were measured on postcontrast CT scans. Differences were found depending on the stage of the abscess, but the deviation of values was too great for determining the age of the abscess from one measurement, to be able to apply proper treatment. The size and density of the abscesses were the same on CT whether the animals were treated or not. This was contrary to the clinical picture, the measurements of edema, and the histopathological studies. (orig.)

  19. Improved quantitation and reproducibility in multi-PET/CT lung studies by combining CT information.

    Science.gov (United States)

    Holman, Beverley F; Cuplov, Vesna; Millner, Lynn; Endozo, Raymond; Maher, Toby M; Groves, Ashley M; Hutton, Brian F; Thielemans, Kris

    2018-06-05

    Matched attenuation maps are vital for obtaining accurate and reproducible kinetic and static parameter estimates from PET data. With increased interest in PET/CT imaging of diffuse lung diseases for assessing disease progression and treatment effectiveness, understanding the extent of the effect of respiratory motion and establishing methods for correction are becoming more important. In a previous study, we have shown that using the wrong attenuation map leads to large errors due to density mismatches in the lung, especially in dynamic PET scans. Here, we extend this work to the case where the study is sub-divided into several scans, e.g. for patient comfort, each with its own CT (cine-CT and 'snap shot' CT). A method to combine multi-CT information into a combined-CT has then been developed, which averages the CT information from each study section to produce composite CT images with the lung density more representative of that in the PET data. This combined-CT was applied to nine patients with idiopathic pulmonary fibrosis, imaged with dynamic 18 F-FDG PET/CT to determine the improvement in the precision of the parameter estimates. Using XCAT simulations, errors in the influx rate constant were found to be as high as 60% in multi-PET/CT studies. Analysis of patient data identified displacements between study sections in the time activity curves, which led to an average standard error in the estimates of the influx rate constant of 53% with conventional methods. This reduced to within 5% after use of combined-CTs for attenuation correction of the study sections. Use of combined-CTs to reconstruct the sections of a multi-PET/CT study, as opposed to using the individually acquired CTs at each study stage, produces more precise parameter estimates and may improve discrimination between diseased and normal lung.

  20. The Value of Calcium-scoring CT for Ischemic Cardiovascular Disease Screening

    International Nuclear Information System (INIS)

    Oh, Jung Hoan; An, Sung Min

    2009-01-01

    The cardiovascular disease has been known as a common cause of death for a long time in the west. The eating habits of Asia, including Korea, have changed recently, so that this disease is also a problem in Asia now. Annual Report on the Cause of Death Statistics from 1996 to 2006 reported that the cardiovascular disease would become the number one cause of death in the next years. Therefore we realize that more accurate examination is required. The aim of this study was to investigate the accuracy of Calcium-scoring CT and the relationship between risk factor and quantitative scores of Calcium-scoring CT. Through this study we expect that the national public health will be improved. Seventy patients with chest pain were chosen at random. The patients were undergone both coronary CT antigraphy and Calcium - scoring CT at G hospital in Incheon from February 1 to June 30, 2008. The result of the Calcium-scoring CT showed its usefulness for Ischemic cardiovascular disease, with an accuracy similar to that of exercise/pharmacologic stress or ECG when it is difficult for a patient to exercise due to joint problems, aging or for other reasons.

  1. Experimental and clinical studies on CT lymphography

    International Nuclear Information System (INIS)

    Hirata, Yuzo; Kono, Michio

    1982-01-01

    Indirect lymphography using computed tomographic apparatus (CT Lymphography) was attempted in 15 dogs with newly devised contrast medium for the opacification of hilar and mediastinal lymphnodes. Clinical application was performed in 2 cases of lung cancer. Newly devised contrast material is an emulsion, which consists of oily contrast medium, non-ionic surfactant and glucose solution. The contrast medium was injected percutaneously into subdiaphragmatic space, or into bronchial walls by bronchofiberscopic technique. CT was able to demonstrate the opacified hilar and mediastinal nodes much more in number than demonstrated in conventional radiograms. It was true in 6 to 11 cases when injected into subdiaphragmatic spaces, and in 2 of 4 cases with an injection into bronchial walls. In clinical studies, CT revealed opacification of mediastinal nodes in one case of lung cancer. Although the procedure is still inferior to the demonstrability of routine indirect lymphography for the evaluation of the fine structure of each node, it showed no remarkable side effects. As the satisfactory method of opacifying hilar and mediastinal nodes has not yet been established, our method is thought to be of value in applying for detection of the metastatic lymphnodes. (author)

  2. Screens

    OpenAIRE

    2016-01-01

    This Sixth volume in the series The Key Debates. Mutations and Appropriations in European Film Studies investigates the question of screens in the context both of the dematerialization due to digitalization and the multiplication of media screens. Scholars offer various infomations and theories of topics such as the archeology of screen, film and media theories, contemporary art, pragmatics of new ways of screening (from home video to street screening).

  3. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 Report

    NARCIS (Netherlands)

    Field, John K.; Smith, Robert A.; Aberle, Denise R.; Oudkerk, Matthijs; Baldwin, David R.; Yankelevitz, David; Pedersen, Jesper Holst; Swanson, Scott James; Travis, William D.; Wisbuba, Ignacio I.; Noguchi, Masayuki; Mulshine, Jim L.

    The International Association for the Study of Lung Cancer (IASLC) Board of Directors convened a computed tomography (CT) Screening Task Force to develop an IASLC position statement, after the National Cancer Institute press statement from the National Lung Screening Trial showed that lung cancer

  4. Luminescence studies on phosphor screens

    International Nuclear Information System (INIS)

    Panayiotakis, G.; Nomikos, C.; Bakas, A.; Proimos, B.

    1994-01-01

    We report our results on x-ray phosphor screens prepared of some new materials focusing attention on their efficiency under fluoroscopy conditions, on optimization conditions and on comparisons among the various materials. All data are presented in absolute values. A theoretical model is presented, that takes into account the granular structure of the screens, permitting the explanation and prediction of the luminescence properties of the screens. (authors)

  5. Luminescence studies on phosphor screens

    Energy Technology Data Exchange (ETDEWEB)

    Panayiotakis, G; Nomikos, C; Bakas, A; Proimos, B [Medical Physics Department, University of Patras, 265 00 Patras, Greece (Greece)

    1994-12-31

    We report our results on x-ray phosphor screens prepared of some new materials focusing attention on their efficiency under fluoroscopy conditions, on optimization conditions and on comparisons among the various materials. All data are presented in absolute values. A theoretical model is presented, that takes into account the granular structure of the screens, permitting the explanation and prediction of the luminescence properties of the screens. (authors). 12 refs, 3 figs.

  6. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 report

    DEFF Research Database (Denmark)

    Field, John K; Smith, Robert A; Aberle, Denise R

    2011-01-01

    national screening programs; (iii) develop guidelines for the clinical work-up of "indeterminate nodules" resulting from CT screening programmers; (iv) guidelines for pathology reporting of nodules from lung cancer CT screening programs; (v) recommendations for surgical and therapeutic interventions...... of suspicious nodules identified through lung cancer CT screening programs; and (vi) integration of smoking cessation practices into future national lung cancer CT screening programs....

  7. Serial volumetric registration of pulmonary CT studies

    Science.gov (United States)

    Silva, José Silvestre; Silva, Augusto; Sousa Santos, Beatriz

    2008-03-01

    Detailed morphological analysis of pulmonary structures and tissue, provided by modern CT scanners, is of utmost importance as in the case of oncological applications both for diagnosis, treatment, and follow-up. In this case, a patient may go through several tomographic studies throughout a period of time originating volumetric sets of image data that must be appropriately registered in order to track suspicious radiological findings. The structures or regions of interest may change their position or shape in CT exams acquired at different moments, due to postural, physiologic or pathologic changes, so, the exams should be registered before any follow-up information can be extracted. Postural mismatching throughout time is practically impossible to avoid being particularly evident when imaging is performed at the limiting spatial resolution. In this paper, we propose a method for intra-patient registration of pulmonary CT studies, to assist in the management of the oncological pathology. Our method takes advantage of prior segmentation work. In the first step, the pulmonary segmentation is performed where trachea and main bronchi are identified. Then, the registration method proceeds with a longitudinal alignment based on morphological features of the lungs, such as the position of the carina, the pulmonary areas, the centers of mass and the pulmonary trans-axial principal axis. The final step corresponds to the trans-axial registration of the corresponding pulmonary masked regions. This is accomplished by a pairwise sectional registration process driven by an iterative search of the affine transformation parameters leading to optimal similarity metrics. Results with several cases of intra-patient, intra-modality registration, up to 7 time points, show that this method provides accurate registration which is needed for quantitative tracking of lesions and the development of image fusion strategies that may effectively assist the follow-up process.

  8. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    OpenAIRE

    Plumb, Andrew A.; Ghanouni, Alex; Rees, Colin J.; Hewitson, Paul; Nickerson, Claire; Wright, Suzanne; Taylor, Stuart A.; Halligan, Steve; von Wagner, Christian

    2016-01-01

    Objective To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Methods Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as compl...

  9. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    OpenAIRE

    Plumb, A. A.; Ghanouni, A.; Rees, C. J.; Hewitson, P.; Nickerson, C.; Wright, S.; Taylor, S. A.; Halligan, S.; von Wagner, C.

    2017-01-01

    OBJECTIVE: To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. METHODS: Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as com...

  10. Image processing algorithm of computer-aided diagnosis in lung cancer screening by CT

    International Nuclear Information System (INIS)

    Yamamoto, Shinji

    2004-01-01

    In this paper, an image processing algorithm for computer-aided diagnosis of lung cancer by X-ray CT is described, which has been developed by my research group for these 10 years or so. CT lung images gathered at the mass screening stage are almost all normal, and lung cancer nodules will be found as the rate of less than 10%. To pick up such a very rare nodules with the high accuracy, a very sensitive detection algorithm is requested which is detectable local and very slight variation of the image. On the contrary, such a sensitive detection algorithm introduces a bad effect that a lot of normal shadows will be detected as abnormal shadows. In this paper I describe how to compromise this complicated subject and realize a practical computer-aided diagnosis tool by the image processing algorithm developed by my research group. Especially, I will mainly focus my description to the principle and characteristics of the Quoit filter which is newly developed as a high sensitive filter by my group. (author)

  11. Simple pulmonary eosinophilia detected at low-dose CT for lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kyung Nyeo; Bae, Kyung Soo; Kim, Ho Cheol [Gyeongsang National University Hospital, Jinju (Korea, Republic of)] (and others)

    2006-05-15

    The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration ({rho} < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn ({rho} < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules

  12. Simple pulmonary eosinophilia detected at low-dose CT for lung cancer screening

    International Nuclear Information System (INIS)

    Jeon, Kyung Nyeo; Bae, Kyung Soo; Kim, Ho Cheol

    2006-01-01

    The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration (ρ < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn (ρ < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules or

  13. CT screening before treatment of latent tuberculous infection for the diagnosis of clinical TB among contacts

    International Nuclear Information System (INIS)

    Yoshiyama, Takashi; Ogata, Hideo

    2008-01-01

    The objective of this study was to evaluate the value of CT scan for the detection of tuberculous diseases among persons who are suspected to be infected at the contact examination. The settings of this study was to Fukujuji Hospital, Japan. Retrospective review of the medical records of 22 persons who were normal with plain chest X-ray at an outbreak at a private school, with which total 46 tuberculosis (TB) cases and 93 infected persons were detected by either symptomatic visits or contact examinations done mainly at public health centers. Among the 44 persons who visited Fukujuji Hospital, 4 persons were symptomatic visits, 3 persons were detected as TB cases by the contact examination at public health centers and 3 persons visited Fukujuji Hospital for the purpose of contact examination before examinations at the public health centers. Eight of these 10 persons were with abnormal chest plain X-ray findings and the remaining two persons were normal with plain chest X-ray findings (group A). Among the 34 persons who were referred to Fukujuji Hospital from public health centers as the infected person without diseases, one person showed abnormal chest plain X-ray and 33 persons showed normal chest plain X-ray (group B). Group A persons were examined in June and Group B persons were examined in July. The 2 persons in the group A were with abnormal CT findings. They were not diagnosed as TB by the CT findings but followed up after sputum examinations. Both of them were diagnosed as TB by the positive TB culture. Among the 33 persons in the group B, 20 persons were tested with CT scan at the examination done before starting treatment of latent tuberuclous infection and six of these 20 persons were with abnormal findings and were judged as TB diseases. In the case of outbreak with many TB cases and infected persons, CT should be considered for the detection of TB cases among contacts. (author)

  14. Use of newly developed standardized form for interpretation of high-resolution CT in screening for pneumoconiosis

    International Nuclear Information System (INIS)

    Julien, P.J.; Sider, L.; Silverman, J.M.; Dahlgren, J.; Harber, P.; Bunn, W.

    1991-01-01

    This paper reports that although the International Labour Office (ILO) standard for interpretation of the posteroanterior chest radiograph has been available for 10 years, there has been no attempt to standardize the high-resolution CT (HRTC) readings for screening of pneumoconiosis. An integrated respirator surveillance program for 87 workers exposed to inorganic dust was conducted. This program consisted of a detailed occupational exposure history, physical symptoms and signs, spirometry, chest radiography, and HRCT. Two groups of workers with known exposure were studied with HRCT. Group 1 had normal spirometry results and chest radiographs, and group 2 had abnormalities at spirometry or on chest radiographs. The HRCT scans were read independently of the clinical findings and chest radiographs. The HRCT scans were interpreted by using an ILO-based standard form developed by the authors for this project. With the newly developed HRCT form, individual descriptive abnormality localized severity, and overall rating systems have been developed and compared for inter- and intraobserver consistency

  15. Empirical study of supervised gene screening

    Directory of Open Access Journals (Sweden)

    Ma Shuangge

    2006-12-01

    Full Text Available Abstract Background Microarray studies provide a way of linking variations of phenotypes with their genetic causations. Constructing predictive models using high dimensional microarray measurements usually consists of three steps: (1 unsupervised gene screening; (2 supervised gene screening; and (3 statistical model building. Supervised gene screening based on marginal gene ranking is commonly used to reduce the number of genes in the model building. Various simple statistics, such as t-statistic or signal to noise ratio, have been used to rank genes in the supervised screening. Despite of its extensive usage, statistical study of supervised gene screening remains scarce. Our study is partly motivated by the differences in gene discovery results caused by using different supervised gene screening methods. Results We investigate concordance and reproducibility of supervised gene screening based on eight commonly used marginal statistics. Concordance is assessed by the relative fractions of overlaps between top ranked genes screened using different marginal statistics. We propose a Bootstrap Reproducibility Index, which measures reproducibility of individual genes under the supervised screening. Empirical studies are based on four public microarray data. We consider the cases where the top 20%, 40% and 60% genes are screened. Conclusion From a gene discovery point of view, the effect of supervised gene screening based on different marginal statistics cannot be ignored. Empirical studies show that (1 genes passed different supervised screenings may be considerably different; (2 concordance may vary, depending on the underlying data structure and percentage of selected genes; (3 evaluated with the Bootstrap Reproducibility Index, genes passed supervised screenings are only moderately reproducible; and (4 concordance cannot be improved by supervised screening based on reproducibility.

  16. Cost-effectiveness analysis on the results of screening of lung cancer using helical CT conducted by the anti-lung cancer association (ALCA)

    International Nuclear Information System (INIS)

    Iinuma, Takeshi; Kaneko, Masahiro; Moriyama, Noriyuki; Misawa, Jun

    1999-01-01

    To compare Yen/person saved in lung cancer screening using helical CT with Yen/person in the screening using conventional direct chest X-rays conducted under the Anti-lung cancer association program of the Tokyo Health Service Association. A mathematical model for cancer screening was used to estimate net number of person relieved from lung cancer by the screening and net cost required for the screening. Finally cost-effectiveness ratios in terms of Yen/person saved were calculated and compared between the two programs. Several important variables employed in the model were as follows: 5 year survival rate in chest X-ray group was 50%, and the rate in helical CT group was 75%. Cost of screening in the chest X-ray group was 15,000 Yen, and that in the helical CT group was 25,000 Yen. Cost/person screened was 14,470 Yen for chest X-ray and 21,890 Yen for helical CT. Cost/person saved was 267 x 10 5 Yen in X-ray group and 112 x 10 5 Yen in CT group. Thus the cost was higher, but cost-effectiveness ratio was better in the CT screening group. Helical CT can be adopted for lung cancer screening in stead of chest X-ray if total cost is affordable. (author)

  17. Prevalence of emphysematous changes as shown by low-dose spiral CT screening images in 6144 healthy subjects

    International Nuclear Information System (INIS)

    Nawa, Takeshi

    2002-01-01

    We assessed the prevalence of emphysematous changes among healthy workers and retired persons, using subjective evaluations of low-dose spiral CT images obtained during thoracic CT screenings for lung cancer. Among 6144 male participants (50-69 years old; mean age, 57), we detected 686 cases (11.2%) with emphysematous changes. The majority (95.3%) of CT-detected emphysema cases were in current or former smokers, and 169 cases (24.6%) showed significant obstructive impairment. Of 236 cases with emphysematous changes in the internal region (more than 20 mm from the costal margin), 98 (41.5%) had significant obstructive impairment. Smoking was found to be the major risk factor for CT-detected emphysema. Longitudinal observation of the emphysema cases, as well as health care support for cessation of smoking, is very important. (author)

  18. TH-AB-207A-12: CT Lung Cancer Screening and the Effects of Further Dose Reduction On CAD Performance

    International Nuclear Information System (INIS)

    Young, S; Lo, P; Hoffman, J; Kim, H; Hsu, W; Flores, C; Lee, G; Brown, M; McNitt-Gray, M

    2016-01-01

    Purpose: CT lung screening is already performed at low doses. In this study, we investigated the effects of further dose reduction on a lung-nodule CAD detection algorithm. Methods: The original raw CT data and images from 348 patients were obtained from our local database of National Lung Screening Trial (NLST) cases. 61 patients (17.5%) had at least one nodule reported on the NLST reader forms. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, a CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST forms. Sensitivities and false-positive rates (FPR) were calculated for each dose level, with a sub-analysis by nodule LungRADS category. Results: For larger category 4 nodules, median sensitivities were 100% at all three dose levels, and mean sensitivity decreased with dose. For the more challenging category 2 and 3 nodules, the dose dependence was less obvious. Overall, mean subject-level sensitivity varied from 38.5% at 100% dose to 40.4% at 50% dose, a difference of only 1.9%. However, median FPR quadrupled from 1 per case at 100% dose to 4 per case at 25% dose. Conclusions: Dose reduction affected nodule detectability differently depending on the LungRADS category, and FPR was very sensitive at sub-screening levels. Care should be taken to adapt CAD for the very challenging noise characteristics of screening. Funding support: NIH U01 CA181156; Disclosures (McNitt-Gray): Institutional research agreement, Siemens

  19. TH-AB-207A-12: CT Lung Cancer Screening and the Effects of Further Dose Reduction On CAD Performance

    Energy Technology Data Exchange (ETDEWEB)

    Young, S; Lo, P; Hoffman, J; Kim, H; Hsu, W; Flores, C; Lee, G; Brown, M; McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2016-06-15

    Purpose: CT lung screening is already performed at low doses. In this study, we investigated the effects of further dose reduction on a lung-nodule CAD detection algorithm. Methods: The original raw CT data and images from 348 patients were obtained from our local database of National Lung Screening Trial (NLST) cases. 61 patients (17.5%) had at least one nodule reported on the NLST reader forms. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, a CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST forms. Sensitivities and false-positive rates (FPR) were calculated for each dose level, with a sub-analysis by nodule LungRADS category. Results: For larger category 4 nodules, median sensitivities were 100% at all three dose levels, and mean sensitivity decreased with dose. For the more challenging category 2 and 3 nodules, the dose dependence was less obvious. Overall, mean subject-level sensitivity varied from 38.5% at 100% dose to 40.4% at 50% dose, a difference of only 1.9%. However, median FPR quadrupled from 1 per case at 100% dose to 4 per case at 25% dose. Conclusions: Dose reduction affected nodule detectability differently depending on the LungRADS category, and FPR was very sensitive at sub-screening levels. Care should be taken to adapt CAD for the very challenging noise characteristics of screening. Funding support: NIH U01 CA181156; Disclosures (McNitt-Gray): Institutional research agreement, Siemens

  20. Benefits and harms of CT screening for lung cancer: a systematic review.

    Science.gov (United States)

    Bach, Peter B; Mirkin, Joshua N; Oliver, Thomas K; Azzoli, Christopher G; Berry, Donald A; Brawley, Otis W; Byers, Tim; Colditz, Graham A; Gould, Michael K; Jett, James R; Sabichi, Anita L; Smith-Bindman, Rebecca; Wood, Douglas E; Qaseem, Amir; Detterbeck, Frank C

    2012-06-13

    Lung cancer is the leading cause of cancer death. Most patients are diagnosed with advanced disease, resulting in a very low 5-year survival. Screening may reduce the risk of death from lung cancer. To conduct a systematic review of the evidence regarding the benefits and harms of lung cancer screening using low-dose computed tomography (LDCT). A multisociety collaborative initiative (involving the American Cancer Society, American College of Chest Physicians, American Society of Clinical Oncology, and National Comprehensive Cancer Network) was undertaken to create the foundation for development of an evidence-based clinical guideline. MEDLINE (Ovid: January 1996 to April 2012), EMBASE (Ovid: January 1996 to April 2012), and the Cochrane Library (April 2012). Of 591 citations identified and reviewed, 8 randomized trials and 13 cohort studies of LDCT screening met criteria for inclusion. Primary outcomes were lung cancer mortality and all-cause mortality, and secondary outcomes included nodule detection, invasive procedures, follow-up tests, and smoking cessation. Critical appraisal using predefined criteria was conducted on individual studies and the overall body of evidence. Differences in data extracted by reviewers were adjudicated by consensus. Three randomized studies provided evidence on the effect of LDCT screening on lung cancer mortality, of which the National Lung Screening Trial was the most informative, demonstrating that among 53,454 participants enrolled, screening resulted in significantly fewer lung cancer deaths (356 vs 443 deaths; lung cancer−specific mortality, 274 vs 309 events per 100,000 person-years for LDCT and control groups, respectively; relative risk, 0.80; 95% CI, 0.73-0.93; absolute risk reduction, 0.33%; P = .004). The other 2 smaller studies showed no such benefit. In terms of potential harms of LDCT screening, across all trials and cohorts, approximately 20% of individuals in each round of screening had positive results requiring

  1. Incidental renal tumours on low-dose CT lung cancer screening exams.

    Science.gov (United States)

    Pinsky, Paul F; Dunn, Barbara; Gierada, David; Nath, P Hrudaya; Munden, Reginald; Berland, Lincoln; Kramer, Barnett S

    2017-06-01

    Introduction Renal cancer incidence has increased markedly in the United States in recent decades, largely due to incidentally detected tumours from computed tomography imaging. Here, we analyze the potential for low-dose computed tomography lung cancer screening to detect renal cancer. Methods The National Lung Screening Trial randomized subjects to three annual screens with either low-dose computed tomography or chest X-ray. Eligibility criteria included 30 + pack-years, current smoking or quit within 15 years, and age 55-74. Subjects were followed for seven years. Low-dose computed tomography screening forms collected information on lung cancer and non-lung cancer abnormalities, including abnormalities below the diaphragm. A reader study was performed on a sample of National Lung Screening Trial low-dose computed tomography images assessing presence of abnormalities below the diaphragms and abnormalities suspicious for renal cancer. Results There were 26,722 and 26,732 subjects enrolled in the low-dose computed tomography and chest X-ray arms, respectively, and there were 104 and 85 renal cancer cases diagnosed, respectively (relative risk = 1.22, 95% CI: 0.9-1.5). From 75,126 low-dose computed tomography screens, there were 46 renal cancer diagnoses within one year. Abnormalities below the diaphragm rates were 39.1% in screens with renal cancer versus 4.1% in screens without (P cancer cases versus 13% of non-cases had abnormalities below the diaphragms; 55% of cases and 0.8% of non-cases had a finding suspicious for renal cancer (P cancers. The benefits to harms tradeoff of incidental detection of renal tumours on low-dose computed tomography is unknown.

  2. Accuracy and efficiency of radiologists reporting CT studies from a multiscreen electronic workstation

    International Nuclear Information System (INIS)

    Foley, W.D.; Lawson, T.L.; Erickson, S.J.

    1988-01-01

    This paper describes a limited picture archiving communication system linking, a via fiber optic cable, two computed tomographic (CT) scanners, and a double-screen (1,000-line monitors) display station with a 600-megabyte image memory evaluated for accuracy and efficiency in the generation of a radiology report. Twenty preselected CT studies (an average of 30 images per study, ten with prior examination for comparison) in cases with pathologically or clinically proved diagnoses were read by five radiologists, in random order, from both the electronic display console and conventional multiformat images. All cases were reread after 1-month interval in a different random order viewing sequence and the opposite viewing modality

  3. Localized thin-section CT with radiomics feature extraction and machine learning to classify early-detected pulmonary nodules from lung cancer screening

    Science.gov (United States)

    Tu, Shu-Ju; Wang, Chih-Wei; Pan, Kuang-Tse; Wu, Yi-Cheng; Wu, Chen-Te

    2018-03-01

    Lung cancer screening aims to detect small pulmonary nodules and decrease the mortality rate of those affected. However, studies from large-scale clinical trials of lung cancer screening have shown that the false-positive rate is high and positive predictive value is low. To address these problems, a technical approach is greatly needed for accurate malignancy differentiation among these early-detected nodules. We studied the clinical feasibility of an additional protocol of localized thin-section CT for further assessment on recalled patients from lung cancer screening tests. Our approach of localized thin-section CT was integrated with radiomics features extraction and machine learning classification which was supervised by pathological diagnosis. Localized thin-section CT images of 122 nodules were retrospectively reviewed and 374 radiomics features were extracted. In this study, 48 nodules were benign and 74 malignant. There were nine patients with multiple nodules and four with synchronous multiple malignant nodules. Different machine learning classifiers with a stratified ten-fold cross-validation were used and repeated 100 times to evaluate classification accuracy. Of the image features extracted from the thin-section CT images, 238 (64%) were useful in differentiating between benign and malignant nodules. These useful features include CT density (p  =  0.002 518), sigma (p  =  0.002 781), uniformity (p  =  0.032 41), and entropy (p  =  0.006 685). The highest classification accuracy was 79% by the logistic classifier. The performance metrics of this logistic classification model was 0.80 for the positive predictive value, 0.36 for the false-positive rate, and 0.80 for the area under the receiver operating characteristic curve. Our approach of direct risk classification supervised by the pathological diagnosis with localized thin-section CT and radiomics feature extraction may support clinical physicians in determining

  4. Evaluation of low-dose CT implementation for lung cancer screening in a general practice hospital

    Science.gov (United States)

    Karostik, D. V.; Kamyshanskaya, I. G.; Cheremisin, V. M.; Drozdov, A. A.; Vodovatov, A. V.

    2018-02-01

    The aim of the current study was to evaluate the possibility of the implementation of LDCT for the screening for lung cancer and tuberculosis in a typical general hospital practice. Diagnostic and economic effectiveness, patient doses and the corresponding radiation risks for LDCT were compared with the existing digital chest screening radiography. The results of the study indicate that the implementation of LDCT allowed verifying false-positive cases or providing additional excessive diagnostic information, but did not significantly improve the sensitivity of screening. Per capita costs for LDCT were higher compared to digital radiography up to a factor of 12; corresponding radiation risk - by a factor of 4. Hence, it was considered unjustified to implement LDCT in a general practice hospital.

  5. 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)

  6. FDG-PET/CT detection of very early breast cancer in women with breast microcalcification lesions found in mammography screening

    International Nuclear Information System (INIS)

    Peng, Nang-Jing; Chou, Chen-Pin; Pan, Huay-Ben; Chang, Tsung-Hsien; Hu, Chin; Chiu, Yu-Li; Fu, Ting-Ying; Chang, Hong-Tai

    2015-01-01

    To assess the efficacy of positron emission tomography/computed tomography with the glucose analogue 2-[ 18 F]fluoro-2-deoxy-D-glucose (FDG-PET/CT) in Taiwanese women with early breast cancer detected by mammography screening. Dual-time-point imaging of whole-body supine and breast prone scans using FDG-PET/CT were performed sequentially in the pre-operative stage. A total of 11,849 patients underwent screening mammography, of whom 1,209 (10.2%) displayed positive results. After further investigation, 54 patients underwent FDG-PET/CT. Post-operative pathology examinations revealed malignancies in 26 lesions, including invasive breast cancer in 11 cases and non-invasive breast cancer in 15 cases, as well as benign disease in 30 lesions. The FDG-PET/CT findings from the whole-body scans were positive for 9 of 11 invasive breast cancers (81.8%) and 3 of 15 non-invasive cancers (20%), and they were negative for all benign lesions. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FDG-PET/CT with whole-body supine imaging were 46.2%, 100%, 100% and 68.2%, respectively. Breast prone imaging revealed another patient with ductal carcinoma in situ, increasing the sensitivity to 50%. Importantly, positive PET findings were significantly correlated with tumour histology (P = 0.006), tumour size (P = 0.039) and Ki-67 expression (P = 0.011). FDG-PET/CT with whole-body scanning demonstrated high sensitivity to invasive breast cancer, limited sensitivity to non-invasive breast cancer, and high specificity for breast cancer. FDG-PET/CT might be useful for differentiating tumour invasiveness. However, the good PPV but poor NPV do not allow the physician to discard the biopsy.

  7. Small median tumor diameter at cure threshold (lung cancers in male smokers predicts both chest X-ray and CT screening outcomes in a novel simulation framework.

    Science.gov (United States)

    Goldwasser, Deborah L; Kimmel, Marek

    2013-01-01

    The effectiveness of population-wide lung cancer screening strategies depends on the underlying natural course of lung cancer. We evaluate the expected stage distribution in the Mayo CT screening study under an existing simulation model of non-small cell lung cancer (NSCLC) progression calibrated to the Mayo lung project (MLP). Within a likelihood framework, we evaluate whether the probability of 5-year NSCLC survival conditional on tumor diameter at detection depends significantly on screening detection modality, namely chest X-ray and computed tomography. We describe a novel simulation framework in which tumor progression depends on cellular proliferation and mutation within a stem cell compartment of the tumor. We fit this model to randomized trial data from the MLP and produce estimates of the median radiologic size at the cure threshold. We examine the goodness of model fit with respect to radiologic tumor size and 5-year NSCLC survival among incident cancers in both the MLP and Mayo CT studies. An existing model of NSCLC progression under-predicts the number of advanced-stage incident NSCLCs among males in the Mayo CT study (p-value = 0.004). The probability of 5-year NSCLC survival conditional on tumor diameter depends significantly on detection modality (p-value = 0.0312). In our new model, selected solution sets having a median tumor diameter of 16.2-22.1 mm at cure threshold among aggressive NSCLCs predict both MLP and Mayo CT outcomes. We conclude that the median lung tumor diameter at cure threshold among aggressive NSCLCs in male smokers may be small (<20 mm). Copyright © 2012 UICC.

  8. Computer Vision Tool and Technician as First Reader of Lung Cancer Screening CT Scans

    NARCIS (Netherlands)

    Ritchie, A.J.; Sanghera, C.; Jacobs, C.; Zhang, W.; Mayo, J.; Schmidt, H.; Gingras, M.; Pasian, S.; Stewart, L.; Tsai, S.; Manos, D.; Seely, J.M.; Burrowes, P.; Bhatia, R.; Atkar-Khattra, S.; Ginneken, B. van; Tammemagi, M.; Tsao, M.S.; Lam, S.; et al.,

    2016-01-01

    To implement a cost-effective low-dose computed tomography (LDCT) lung cancer screening program at the population level, accurate and efficient interpretation of a large volume of LDCT scans is needed. The objective of this study was to evaluate a workflow strategy to identify abnormal LDCT scans in

  9. Appearances of screen-detected versus symptomatic colorectal cancers at CT colonography

    International Nuclear Information System (INIS)

    Plumb, Andrew A.; Pathiraja, Fiona; Taylor, Stuart A.; Halligan, Steve; Nickerson, Claire; Wooldrage, Katherine; Atkin, Wendy S.; Burling, David

    2016-01-01

    The aim of this study was to compare the morphology, radiological stage, conspicuity, and computer-assisted detection (CAD) characteristics of colorectal cancers (CRC) detected by computed tomographic colonography (CTC) in screening and symptomatic populations. Two radiologists independently analyzed CTC images from 133 patients diagnosed with CRC in (a) two randomized trials of symptomatic patients (35 patients with 36 tumours) and (b) a screening program using fecal occult blood testing (FOBt; 98 patients with 100 tumours), measuring tumour length, volume, morphology, radiological stage, and subjective conspicuity. A commercial CAD package was applied to both datasets. We compared CTC characteristics between screening and symptomatic populations with multivariable regression. Screen-detected CRC were significantly smaller (mean 3.0 vs 4.3 cm, p < 0.001), of lower volume (median 9.1 vs 23.2 cm 3 , p < 0.001) and more frequently polypoid (34/100, 34 % vs. 5/36, 13.9 %, p = 0.02) than symptomatic CRC. They were of earlier stage than symptomatic tumours (OR = 0.17, 95 %CI 0.07-0.41, p < 0.001), and were judged as significantly less conspicuous (mean conspicuity 54.1/100 vs. 72.8/100, p < 0.001). CAD detection was significantly lower for screen-detected (77.4 %; 95 %CI 67.9-84.7 %) than symptomatic CRC (96.9 %; 95 %CI 83.8-99.4 %, p = 0.02). Screen-detected CRC are significantly smaller, more frequently polypoid, subjectively less conspicuous, and less likely to be identified by CAD than those in symptomatic patients. (orig.)

  10. Appearances of screen-detected versus symptomatic colorectal cancers at CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Pathiraja, Fiona; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); Nickerson, Claire [Fulwood House, Public Health England, Sheffield (United Kingdom); Wooldrage, Katherine; Atkin, Wendy S. [Imperial College London, Department of Surgery and Cancer, London (United Kingdom); Burling, David [St Mark' s Hospital, Intestinal Imaging Centre, Harrow (United Kingdom)

    2016-12-15

    The aim of this study was to compare the morphology, radiological stage, conspicuity, and computer-assisted detection (CAD) characteristics of colorectal cancers (CRC) detected by computed tomographic colonography (CTC) in screening and symptomatic populations. Two radiologists independently analyzed CTC images from 133 patients diagnosed with CRC in (a) two randomized trials of symptomatic patients (35 patients with 36 tumours) and (b) a screening program using fecal occult blood testing (FOBt; 98 patients with 100 tumours), measuring tumour length, volume, morphology, radiological stage, and subjective conspicuity. A commercial CAD package was applied to both datasets. We compared CTC characteristics between screening and symptomatic populations with multivariable regression. Screen-detected CRC were significantly smaller (mean 3.0 vs 4.3 cm, p < 0.001), of lower volume (median 9.1 vs 23.2 cm{sup 3}, p < 0.001) and more frequently polypoid (34/100, 34 % vs. 5/36, 13.9 %, p = 0.02) than symptomatic CRC. They were of earlier stage than symptomatic tumours (OR = 0.17, 95 %CI 0.07-0.41, p < 0.001), and were judged as significantly less conspicuous (mean conspicuity 54.1/100 vs. 72.8/100, p < 0.001). CAD detection was significantly lower for screen-detected (77.4 %; 95 %CI 67.9-84.7 %) than symptomatic CRC (96.9 %; 95 %CI 83.8-99.4 %, p = 0.02). Screen-detected CRC are significantly smaller, more frequently polypoid, subjectively less conspicuous, and less likely to be identified by CAD than those in symptomatic patients. (orig.)

  11. Air trapping on chest CT is associated with worse ventilation distribution in infants with cystic fibrosis diagnosed following newborn screening.

    Directory of Open Access Journals (Sweden)

    Graham L Hall

    Full Text Available BACKGROUND: In school-aged children with cystic fibrosis (CF structural lung damage assessed using chest CT is associated with abnormal ventilation distribution. The primary objective of this analysis was to determine the relationships between ventilation distribution outcomes and the presence and extent of structural damage as assessed by chest CT in infants and young children with CF. METHODS: Data of infants and young children with CF diagnosed following newborn screening consecutively reviewed between August 2005 and December 2009 were analysed. Ventilation distribution (lung clearance index and the first and second moment ratios [LCI, M(1/M(0 and M(2/M(0, respectively], chest CT and airway pathology from bronchoalveolar lavage were determined at diagnosis and then annually. The chest CT scans were evaluated for the presence or absence of bronchiectasis and air trapping. RESULTS: Matched lung function, chest CT and pathology outcomes were available in 49 infants (31 male with bronchiectasis and air trapping present in 13 (27% and 24 (49% infants, respectively. The presence of bronchiectasis or air trapping was associated with increased M(2/M(0 but not LCI or M(1/M(0. There was a weak, but statistically significant association between the extent of air trapping and all ventilation distribution outcomes. CONCLUSION: These findings suggest that in early CF lung disease there are weak associations between ventilation distribution and lung damage from chest CT. These finding are in contrast to those reported in older children. These findings suggest that assessments of LCI could not be used to replace a chest CT scan for the assessment of structural lung disease in the first two years of life. Further research in which both MBW and chest CT outcomes are obtained is required to assess the role of ventilation distribution in tracking the progression of lung damage in infants with CF.

  12. CT screened arterial calcification as a risk factor for mortality after trauma.

    Science.gov (United States)

    De'Ath, Henry D; Oakland, Kathryn; Brohi, Karim

    2016-10-10

    Arterial calcification on Computerised Tomography (CT) is a marker of cardiovascular disease. It is predictive of future adverse cardiac events and mortality in many disease states. The incidence of arterial disease and its impact on outcomes of the injured is not known. The objectives of this study were to describe the incidence of arterial calcification in trauma patients, and establish its impact on mortality. A retrospective cohort study of all injured patients aged over 45 years presenting to a major trauma centre over a 34-month period. The presence and quantity of coronary, aortic and abdominal arterial calcification on admission CT scans of the chest, abdomen and pelvis was established, and the association between cardiovascular disease and in-hospital mortality following trauma was determined. Five hundred ninety-one patients were included in the study. Cardiac calcium was visible on 432 (73 %) scans, and abdominal arterial calcification on 472 (79.9 %). Fifty (8.5 %) patients died. Patients with Superior Mesenteric (SMA) and Common Iliac Artery calcification had a significantly higher mortality than those without (p < 0.01). In multivariarate analysis, only SMA calcification was independently associated with mortality (OR 2.462, 95 % CI 1.08-5.60, p = 0.032). Coronary calcium demonstrated no independent statistical relationship with death (Left Anterior Descending Artery OR 1.189, 95 % CI 0.51-2.78, Circumflex OR 1.290, 95 % CI 0.56-2.98, Right Coronary Artery OR 0.483, 95 % CI 0.21-1.10). This study has demonstrated that the identification of arterial calcification on admission CT scans of trauma patients is possible. Calcification was common, and present in around three-quarters of injured individuals over the age of 45 years. SMA calcium was an independent predictor of mortality. However, whilst the presence of arterial calcium demonstrated a tendency towards lower survival, this association was not significant in other territories

  13. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening

    International Nuclear Information System (INIS)

    Zhang, Li; YangDai, Tianyi

    2016-01-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile. - Highlights: • EDXRD combined with dual-energy CT has been utilized for deriving the molecular interference function of an unknown liquid. • The liquid's equivalent molecular formula is estimated based on the effective atomic number reconstructed from dual-energy CT. • The proposed method provides two ways to estimate the molecular interference function: the simplified way and accurate way. • A new effective atomic number of the liquid could be obtained.

  14. Reliability analysis of visual ranking of coronary artery calcification on low-dose CT of the thorax for lung cancer screening: comparison with ECG-gated calcium scoring CT.

    Science.gov (United States)

    Kim, Yoon Kyung; Sung, Yon Mi; Cho, So Hyun; Park, Young Nam; Choi, Hye-Young

    2014-12-01

    Coronary artery calcification (CAC) is frequently detected on low-dose CT (LDCT) of the thorax. Concurrent assessment of CAC and lung cancer screening using LDCT is beneficial in terms of cost and radiation dose reduction. The aim of our study was to evaluate the reliability of visual ranking of positive CAC on LDCT compared to Agatston score (AS) on electrocardiogram (ECG)-gated calcium scoring CT. We studied 576 patients who were consecutively registered for health screening and undergoing both LDCT and ECG-gated calcium scoring CT. We excluded subjects with an AS of zero. The final study cohort included 117 patients with CAC (97 men; mean age, 53.4 ± 8.5). AS was used as the gold standard (mean score 166.0; range 0.4-3,719.3). Two board-certified radiologists and two radiology residents participated in an observer performance study. Visual ranking of CAC was performed according to four categories (1-10, 11-100, 101-400, and 401 or higher) for coronary artery disease risk stratification. Weighted kappa statistics were used to measure the degree of reliability on visual ranking of CAC on LDCT. The degree of reliability on visual ranking of CAC on LDCT compared to ECG-gated calcium scoring CT was excellent for board-certified radiologists and good for radiology residents. A high degree of association was observed with 71.6% of visual rankings in the same category as the Agatston category and 98.9% varying by no more than one category. Visual ranking of positive CAC on LDCT is reliable for predicting AS rank categorization.

  15. A roentgenographical study of the morphology of ventricles of the brain using computed tomography (CT)

    International Nuclear Information System (INIS)

    Inugami, Atsushi

    1981-01-01

    A basic experiment using an experimental model for the ventricles of the brain was made of the reproductivity of CT images using a whole body CT scanner, and the dimensions of the ventricles of 450 children on CT images were measured, to study changes in dimensions of the ventricles with the method for providing the sectional planes, or with the type of the CT scanner used, and the children with ventricular abnormalities were further studied. The sectional plane at OM-0 0 clinically gave a better reproductivity of the ventricles than at OM-15 0 . The measurements of the ventricles proved to vary with the mean value and also with the window width. In measuring the dimensions of the ventricles on the CT image, the ratio of widths of the anterior horn, third ventricle, corpus and posterior horn to that of the cerebral parenchyma was found to be correlated to the dimensions of the ventricles. No particular changes with the age structure of each cerebroventricular index (CVI) were noted. Apparent differences in the measurement were noted between each CVI of the abnormal group and the normal. CT scanning is a safe, easy non-invasive method for screening and observing the couse of ventricular diseases, accompanied by less risk. (author)

  16. Neck after total laryngectomy: CT study

    International Nuclear Information System (INIS)

    DiSantis, D.J.; Balfe, D.M.; Hayden, R.E.; Sagel, S.S.; Sessions, D.; Lee, J.K.T.

    1984-01-01

    Computed tomographic scans in 23 patients who had undergone total laryngectomy were analyzed retrospectively to determine normal postoperative appearance and to evaluate the role of CT in assessing recurrent neoplasm. Nine patients without clinical evidence of recurrence illustrated the normal postoperative changes: a round or ovoid neopharynx connecting the base of the tongue with the cervical esophagus and intact fat planes surrounding the neopharynx, neurovascular bundles, and sternocleidomastoid muscles. In the 12 patients with recurrent neoplasm, the CT manifestations included masses involving the internal jugular lymph node chain, tracheostomy site, or paratracheal region. CT supplemented physical examination and indirect mirror examination, providing data regarding presence and extent of recurrent tumor and aiding in planning the mode and scope of therapy

  17. The experimental study of sinal wall thickening on CT

    International Nuclear Information System (INIS)

    Kase, Yasuhiro; Iinuma, Tositaka; Oyama, Kazuyuki.

    1988-01-01

    In our previous report, we investigated several factors which cause apparent thickening of the walls of maxillary sinus. We confirmed, however, that the major factor for the sinal wall thickening is the artifact of CT. In present study, we report the results obtained by phantom models of isolated maxillary bone and egg shell. As the substance corresponding to the soft tissue density, solutions of CaCl 2 in various concentrations were used. In the maxillary bone studies, the thickness of the anterior sinus wall by CT was larger than the actual value even though only the air was contained. When solutions of CaCl 2 were contained and in touch with the anterior wall, the thickness by CT was larger than that of containing air. In the egg shell studies, the increase in thickness by CT correlated to the increase in percentage of solutions. The above results indicate that the apparent increased thickness of the sinal walls by CT is largely the artifact by CT and is dependent upon the soft tissue density or CT value (X-ray attenuation coefficient) of substances in touch with the sinal walls. In CT images obtained by clinical cases, the increased thickness of the sinal walls, in sinuses filled with soft tissue density, is more apparent than real. (author)

  18. CT colonography versus double-contrast barium enema for screening of colorectal cancer: comparison of radiation burden.

    Science.gov (United States)

    Neri, Emanuele; Faggioni, Lorenzo; Cerri, Francesca; Turini, Francesca; Angeli, Simone; Cini, Lorenzo; Perrone, Franco; Paolicchi, Fabio; Bartolozzi, Carlo

    2010-10-01

    Our aim is to compare the radiation dose associated with a low-dose CT colonography (CTC) protocol for colorectal cancer screening with that delivered by double-contrast barium enema (DCBE). CTC of twenty asymptomatic individuals (M:F = 10:10) participating to a colorectal cancer screening program and DCBE of fifteen patients (M:F = 6:9) were evaluated. For CTC, absorbed dose was determined by calculating the dose-length product for each CTC examination from measurements on a CT dose phantom equipped with a CT ion chamber. For DCBE, the free-in-air Kerma at the patient's X-ray entry surface and the Kerma-area product during fluoroscopy and fluorography were measured with a Barracuda system, with fluoroscopy times being recorded blinded to the performing operator. Effective dose at CTC was 2.17 ± 0.12 mSv, with good and excellent image quality in 14/20 (70%) and 6/20 cases (30%), respectively. With DCBE, effective patient dose was 4.12 ± 0.17 mSv, 1.9 times greater than CTC (P < 0.0001). Our results show that effective dose from screening CTC is substantially lower than that from DCBE, suggesting that CTC is the radiological imaging technique of the large bowel with the lowest risk of stochastic radiation effects.

  19. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the

  20. 18F-FDG uptake in the stomach on screening PET/CT: value for predicting Helicobacter pylori infection and chronic atrophic gastritis

    International Nuclear Information System (INIS)

    Kobayashi, Shigeki; Ogura, Mayumi; Suzawa, Naohisa; Horiki, Noriyuki; Katsurahara, Masaki; Ogura, Toru; Sakuma, Hajime

    2016-01-01

    The aim of this study was to determine the value of 18 F-FDG uptake on screening PET/CT images for the prediction of Helicobacter pylori (H. pylori) infection and chronic atrophic gastritis. Among subjects who underwent 18 F-FDG PET/CT for cancer screening from April 2005 to November 2015, PET/CT images were analyzed in 88 subjects who had gastrointestinal fiberscopy within 6 months. The volumes of interest (VOIs) were placed in the fornix, corpus and antrum of the stomach to determine maximal standardized uptake value (SUVmax) and mean SUV (SUVmean). Receiver operating characteristic curve (ROC) analysis was performed to determine the diagnostic performance of SUV indicators in predicting H. pylori infection and chronic atrophic gastritis. SUV indicators of the stomach were significantly higher in subjects with H. pylori infection than those without (from P < 0.001 to P < 0.05). ROC analysis revealed that SUVmean had the highest performance in predicting H. pylori infection (AUC 0.807) and chronic atrophic gastritis (AUC 0.784). SUVmean exhibited the sensitivity of 86.5 % and the specificity of 70.6 % in predicting H. pylori infection, and the sensitivity of 75.0 % and 78.6 % in predicting chronic atrophic gastritis. Assessment of 18 F-FDG uptake in the stomach reflecting active inflammation is useful in predicting patients with H. pylori infection and subsequent chronic atrophic gastritis which is closely associated with the risk of gastric neoplasms

  1. Colon distension, perceived burden and side-effects of CT-colonography for screening using hyoscine butylbromide or glucagon hydrochloride as bowel relaxant

    NARCIS (Netherlands)

    de Haan, Margriet C.; Boellaard, Thierry N.; Bossuyt, Patrick M.; Stoker, Jaap

    2012-01-01

    Objective: Compare colonic distension and perceived burden of CT-colonography between participants receiving hyoscine butylbromide (buscopan) and glucagon hydrochloride as bowel relaxant. Materials and methods: Data were collected within a screening trial. Participants received 20 mg buscopan

  2. Study of dosimetry CT in Skull for pediatric patients

    International Nuclear Information System (INIS)

    Ramos Amores, D.; Serna Berna, A.; Mata Colodro, F.; Puchades Puchades, V.

    2013-01-01

    The dose that receiving the patients in CT studies is the highest that can be received in a study of Radiology. If patients are children and we do studies with the same parameters as adults, they will receive a higher dose of radiation. This work seeks to expose the result of a dosimetric study on CT for children aged 0-15, carried out at the Hospital General Universitario de Santa Lucia in Cartagena during the year 2012. (Author)

  3. Screening for coronary artery disease in respiratory patients: comparison of single- and dual-source CT in patients with a heart rate above 70 bpm

    International Nuclear Information System (INIS)

    Pansini, Vittorio; Remy-Jardin, Martine; Tacelli, Nunzia; Faivre, Jean-Baptiste; Remy, Jacques; Flohr, Thomas; Deken, Valerie; Duhamel, Alain

    2008-01-01

    To evaluate the assessibility of coronary arteries in respiratory patients with high heart rates. This study was based on the comparative analysis of two paired populations of 54 patients with a heart rate >70 bpm evaluated with dual-source (group 1) and single-source (group 2) CT. The mean heart rate was 89.1 bpm in group 1 and 86.7 bpm in group 2 (P=0.26). The mean number of assessable segments per patient was significantly higher in group 1 compared to group 2 (P≤0.0001). The proportions of patients in whom proximal and mid-coronary segments were assessable (i.e., the anatomical level enabling screening for asymptomatic coronary artery disease) were 35.3% for heart rates <110 bpm, 35.6% for heart rates <100 bpm, 40% for heart rates <90 bpm, and 60% for heart rates <80 bpm in group 1 and 11.3, 12.2, 8.8, and 10% for the corresponding thresholds in group 2 (P<0.05). In both groups of patients, coronary artery imaging was obtained from standard CT angiograms of the chest. The improvement in coronary imaging with dual-source CT suggests that high heart rates should no longer be considered as contraindications for ECG-gated CT angiograms of the chest whenever clinically relevant. (orig.)

  4. CT quantitative diagnosis in fatty liver: a clinical study

    International Nuclear Information System (INIS)

    He Wen; Qian Linxue; Zhao Jixue; Ma Daqing; Feng Jie; Hu Zhihai

    2001-01-01

    Objective: To establish the CT criteria of quantitative diagnosis for liver steatosis by means of studying the CT features of fatty liver cases proven histologically. Methods: Twenty-eight cases of fatty liver were underwent non-enhanced CT scan, and the attenuation of liver parenchyma was measured. To differentiate the degree of fatty liver, the mean CT value and the relative density of hepatic vessels were observed. The quantitative diagnosis was made according to the CT number threshold and the criteria of relative density of hepatic vessels, respectively. Results: Among the 28 cases, there were 17 cases of mild steatosis with mean CT number of 46 HU (32-65 HU), 7 cases of middle degree fatty liver with mean CT number of 28 HU (15-38 HU), and 4 cases of sever fatty liver with mean CT number of 0.2 HU (-7-11 HU). For the relative density of hepatic vessels, 16 of the 17 cases of mild fatty liver had a appearance of hepatic vessels immersion and 1 mild case had reverse hepatic vessels display, 6 of 7 middle degree cases had reverse hepatic vessels display with 1 case having the appearance of hepatic vessels immersion, and all the 4 case of sever steatosis had the appearance of reverse hepatic vessels display with sharp contrast between vessels and the liver parenchyma. The accuracy of quantitative diagnosis was 65.9% and 93.1% by means of criteria of CT number threshold and relative density of hepatic vessels, respectively (x 2 = 7.153, P < 0.01). Conclusion: The criteria of relative density of hepatic vessels is more reliable than that of CT number threshold in quantitative diagnosis of fatty liver

  5. Study on broad beam heavy ion CT

    International Nuclear Information System (INIS)

    Ohno, Yumiko; Kohno, Toshiyuki; Sasaki, Hitomi; Nanbu, S.; Kanai, Tatsuaki

    2003-01-01

    To achieve the heavy ion radiotherapy more precisely, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. From a heavy ion CT image, we can directly obtain the 2-D distribution of the electron density in a sample. For this purpose, we have developed a broad beam heavy ion CT system. The electron density was obtained using some kinds of solutions targets. Also the dependence of the spatial resolution on the target size and the kinds of beams was estimated in this work using cylinders targets of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. (author)

  6. CT study of intracionial Wegener's Granulomatosis

    International Nuclear Information System (INIS)

    Yago, M.D.; Torres, T.; Martinez, G.; Lopez, A.; Barrena, R.

    1995-01-01

    Wegener granulamatosis is a multi systemic necrotizing granulomatous vasculitis distinguished from others by its predilection to affect the respiratory tract and the kidneys. Nervous system involvement occurs in 25% of cases, and the most common neurological manifestation is mono neuritis multiplex. However, primary affectation of CNS in an unusual manifestation. We report a case of Wegener Granulomatosis with almost unique neurological manifestation. CT imaging findings of meningeal involvement and retro-orbital pseudotumor are presented. 12 refs

  7. Computer Vision Tool and Technician as First Reader of Lung Cancer Screening CT Scans.

    Science.gov (United States)

    Ritchie, Alexander J; Sanghera, Calvin; Jacobs, Colin; Zhang, Wei; Mayo, John; Schmidt, Heidi; Gingras, Michel; Pasian, Sergio; Stewart, Lori; Tsai, Scott; Manos, Daria; Seely, Jean M; Burrowes, Paul; Bhatia, Rick; Atkar-Khattra, Sukhinder; van Ginneken, Bram; Tammemagi, Martin; Tsao, Ming Sound; Lam, Stephen

    2016-05-01

    To implement a cost-effective low-dose computed tomography (LDCT) lung cancer screening program at the population level, accurate and efficient interpretation of a large volume of LDCT scans is needed. The objective of this study was to evaluate a workflow strategy to identify abnormal LDCT scans in which a technician assisted by computer vision (CV) software acts as a first reader with the aim to improve speed, consistency, and quality of scan interpretation. Without knowledge of the diagnosis, a technician reviewed 828 randomly batched scans (136 with lung cancers, 556 with benign nodules, and 136 without nodules) from the baseline Pan-Canadian Early Detection of Lung Cancer Study that had been annotated by the CV software CIRRUS Lung Screening (Diagnostic Image Analysis Group, Nijmegen, The Netherlands). The scans were classified as either normal (no nodules ≥1 mm or benign nodules) or abnormal (nodules or other abnormality). The results were compared with the diagnostic interpretation by Pan-Canadian Early Detection of Lung Cancer Study radiologists. The overall sensitivity and specificity of the technician in identifying an abnormal scan were 97.8% (95% confidence interval: 96.4-98.8) and 98.0% (95% confidence interval: 89.5-99.7), respectively. Of the 112 prevalent nodules that were found to be malignant in follow-up, 92.9% were correctly identified by the technician plus CV compared with 84.8% by the study radiologists. The average time taken by the technician to review a scan after CV processing was 208 ± 120 seconds. Prescreening CV software and a technician as first reader is a promising strategy for improving the consistency and quality of screening interpretation of LDCT scans. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  8. Correlative CT and anatomic study of the sciatic nerve

    International Nuclear Information System (INIS)

    Pech, P.; Haughton, V.

    1985-01-01

    Sciatica can be caused by numerous processes affecting the sciatic nerve or its components within the pelvis including tumors, infectious diseases, aneurysms, fractures, and endometriosis. The CT diagnosis of these causes of sciatica has not been emphasized. This study identified the course and appearance of the normal sciatic nerve in the pelvis by correlating CT and anatomic slices in cadavers. For purposes of discussion, the sciatic nerve complex is conveniently divided into three parts: presacral, muscular, and ischial. Each part is illustrated here by two cryosections with corresponding CT images

  9. A national survey of lung cancer specialists' views on low-dose CT screening for lung cancer in Korea.

    Directory of Open Access Journals (Sweden)

    Dong Wook Shin

    Full Text Available Lung cancer specialists play an important role in designing and implementing lung cancer screening. We aimed to describe their 1 attitudes toward low-dose lung computed tomography (LDCT screening, 2 current practices and experiences of LDCT screening and 3 attitudes and opinions towards national lung cancer screening program (NLCSP. We conducted a national web-based survey of pulmonologists, thoracic surgeons, medical oncologists, and radiological oncologists who are members of Korean Association for Lung Cancer (N = 183. Almost all respondents agreed that LDCT screening increases early detection (100%, improves survival (95.1%, and gives a good smoking cessation counseling opportunity (88.6%. Most were concerned about its high false positive results (79.8% and the subsequent negative effects. Less than half were concerned about radiation hazard (37.2%. Overall, most (89.1% believed that the benefits outweigh the risks and harms. Most (79.2% stated that they proactively recommend LDCT screening to those who are eligible for the current guidelines, but the screening propensity varied considerably. The majority (77.6% agreed with the idea of NLCSP and its beneficial effect, but had concerns about the quality control of CT devices (74.9%, quality assurance of radiologic interpretation (63.3%, poor access to LDCT (56.3%, and difficulties in selecting eligible population using self-report history (66.7%. Most (79.2% thought that program need to be funded by a specialized fund rather than by the National Health Insurance. The opinions on the level of copayment for screening varied. Our findings would be an important source for health policy decision when considering for NLCSP in Korea.

  10. Osteoblastic lesion screening with an advanced post-processing package enabling in-plane rib reading in CT-images.

    Science.gov (United States)

    Seuss, Hannes; Dankerl, Peter; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

    2016-05-20

    To evaluate screening and diagnostic accuracy for the detection of osteoblastic rib lesions using an advanced post-processing package enabling in-plane rib reading in CT-images. We retrospectively assessed the CT-data of 60 consecutive prostate cancer patients by applying dedicated software enabling in-plane rib reading. Reading the conventional multiplanar reconstructions was considered to be the reference standard. To simulate clinical practice, the reader was given 10 s to screen for sclerotic rib lesions in each patient applying both approaches. Afterwards, every rib was evaluated individually with both approaches without a time limit. Sensitivities, specificities, positive/negative predictive values and the time needed for detection were calculated depending on the lesion's size (largest diameter  10 mm). In 53 of 60 patients, all ribs were properly displayed in plane, in five patients ribs were partially displayed correctly, and in two patients none of the ribs were displayed correctly. During the 10-s screening approach all patients with sclerotic rib lesions were correctly identified reading the in-plane images (including the patients without a correct rib segmentation), whereas 14 of 23 patients were correctly identified reading conventional multiplanar images. Overall screening sensitivity, specificity, and positive/negative predictive values were 100/27.0/46.0/100 %, respectively, for in-plane reading and 60.9/100/100/80.4 %, respectively, for multiplanar reading. Overall diagnostic (no time limit) sensitivity, specificity, and positive/negative predictive values of in-plane reading were 97.8/92.8/74.6/99.5 %, respectively. False positive results predominantly occurred for lesions <5 mm in size. In-plane reading of the ribs allows reliable detection of osteoblastic lesions for screening purposes. The limited specificity results from false positives predominantly occurring for small lesions.

  11. Lung studies with spiral CT. pitch 1 versus pitch 2

    International Nuclear Information System (INIS)

    Sartoni Galloni, S.; Miceli, M.; Lipparino, M.; Burzi, M.; Gigli, F.; Rossi, M.S.; Santoli, G.; Guidarelli, G.

    1999-01-01

    In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality [it

  12. Clinical application of low-dose CT combined with computer-aided detection in lung cancer screening

    International Nuclear Information System (INIS)

    Xu Zushan; Hou Hongjun; Xu Yan; Ma Daqing

    2010-01-01

    Objective: To investigate the clinical value of chest low-dose CT (LDCT) combined with computer-aided detection (CAD) system for lung cancer screening in high risk population. Methods: Two hundred and nineteen healthy candidates underwent 64-slice LDCT scan. All images were reviewed in consensus by two radiologists with 15 years of thoracic CT diagnosis experience. Then the image data were analyzed with CAD alone. Finally images were reviewed by two radiologists with 5 years of CT diagnosis experience with and without CT Viewer software. The sensitivity, false positive rate of CAD for pulmonary nodule detection were calculated. SPSS 11.5 software and Chi-square test were used for the statistics. Results: Of 219 candidates ,104(47.5% ) were detected with lung nodules. There were 366 true nodules confirmed by the senior radiologists. The CAD system detected 271 (74.0%) true nodules and 424 false-positive nodules. The false-positive rate was 1.94/per case. The two junior radiologists indentifid 292 (79.8%), 286(78.1%) nodules without CAD and 336 (91.8%), 333 (91.0%) nodules with CAD respectively. There were significant differences for radiologists in indentifying nodules with or without CAD system (P<0.01). Conclusions: CAD is more sensitive than radiologists for indentifying the nodules in the central area or in the hilar region of the lung. While radiologists are more sensitive for the peripheral and sub-pleural nodules,or ground glass opacity nodules, or nodules smaller than 4 mm. CAD can not be used alone. The detection rate can be improved with the combination of radiologist and CAD in LDCT screen. (authors)

  13. Study on CT changes in autistic children

    International Nuclear Information System (INIS)

    Yaguchi, Katsumi

    1993-01-01

    Since 1979 we have performed CT examinations on 132 autistic children. Neurological diagnosis of the lesion was established by Dr. Segawa's group. On the CT of many autistic children, we found a small low density change located in the anterior wall of the temporal horn, or localized dilatation of the inferior horn near the damaged brain. We reviewed 96 of these patients who all had the obvious low density changes, or localized irregular dilatations in the anterior wall of the temporal horn. By measuring the distance of damage from the midline, we divided the 96 cases into two groups. Group 1 consisted of those with damage located laterally more than 30 mm line from the midline. Group 2 consisted of those with damage medially to the 30 mm line from the midline. Those cases with a large lesion both laterally and medially of the 30 mm line were categorized into group 1. In the adult brain the lateral border of the amygdaloid nucleus was never located laterally more than 30 mm from the midline. Laterally over the 30 mm line there were two marked fiber systems running near the anterior wall of the temporal horn: the fiber of the anterior commissure and the uncinate fascicle. Group 1 consisted of 62 patients and group 2 of 34 patients. The majority of the two group patients were pure autism children. This suggested that the main lesion in autism was in the amygdala. (author)

  14. Potential role of 68Ga-DOTATOC PET/CT in screening for pancreatic neuroendocrine tumour in patients with von Hippel-Lindau disease

    International Nuclear Information System (INIS)

    Prasad, Vikas; Brenner, Winfried; Tiling, Nikolaus; Ploeckinger, Ursula; Denecke, Timm

    2016-01-01

    Neuroendocrine tumours of the pancreas (pNET) are observed in 8 - 17 % of patients with von Hippel-Lindau disease (vHLD), and 11 - 20 % of these patients develop metastatic disease. MRI and CT have a very high resolution; however, their sensitivity and specificity for the detection of pNET amongst cystic lesions in the pancreas of vHLD patients are generally considered insufficient. In contrast, 68 Ga-DOTATOC PET/CT demonstrates a high sensitivity for the diagnosis and staging of neuroendocrine tumours. In this study we investigated the potential role of 68 Ga-DOTATOC PET/CT in screening of patients with vHLD. 68 Ga-DOTATOC PET/three-phase contrast-enhanced CT was performed according to guidelines in all consecutive vHLD patients between January 2012 and November 2015. All patients underwent additional MRI imaging of the abdomen, spine, and head. Chromogranin A (CgA) was determined at the time of the PET/CT examination. A lesion seen on 68 Ga-DOTATOC PET in the pancreas was defined as positive if the uptake was visually higher than in the surrounding tissues. Lesions were quantified using maximum SUV. Overall, 20 patients (8 men, 12 women; mean age 44.7 ± 11.1 years) were prospectively examined. Genetically, 12 patients had type 1 vHLD and 8 had type 2 vHLD. 68 Ga-DOTATOC PET/CT detected more pNET than morphological imaging (CT or MRI): 11 patients (55 %; 8 type 1, 3 type 2) vs. 9 patients (45 %; 6 type 1, 3 type 2). The concentration of CgA was mildly elevated in 2 of 11 patients with pNET. The mean SUVmax of the pancreatic lesions was 18.9 ± 21.9 (range 5.0 - 65.6). Four patients (36.4 %) had multiple pNETs. The mean size of the lesions on CT and/or MRI was 10.4 ± 8.3 mm (range 4 - 38 mm), and 41.1 % were larger than 10 mm. In addition, somatostatin receptor-positive cerebellar and spinal haemangioblastomas were detected in three patients (SUVmax 2.1 - 10.1). One patient presented with a solitary somatostatin receptor-positive lymph node metastasis. pNETs were

  15. Potential role of {sup 68}Ga-DOTATOC PET/CT in screening for pancreatic neuroendocrine tumour in patients with von Hippel-Lindau disease

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Vikas; Brenner, Winfried [Charite Universitaetsmedizin Berlin, Department of Nuclear Medicine, Campus Virchow-Klinikum, Berlin (Germany); Tiling, Nikolaus; Ploeckinger, Ursula [Charite Universitaetsmedizin Berlin, Interdisziplinaeren Stoffwechsel-Centrum, Campus Virchow Klinikum, Berlin (Germany); Denecke, Timm [Charite Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany)

    2016-10-15

    Neuroendocrine tumours of the pancreas (pNET) are observed in 8 - 17 % of patients with von Hippel-Lindau disease (vHLD), and 11 - 20 % of these patients develop metastatic disease. MRI and CT have a very high resolution; however, their sensitivity and specificity for the detection of pNET amongst cystic lesions in the pancreas of vHLD patients are generally considered insufficient. In contrast, {sup 68}Ga-DOTATOC PET/CT demonstrates a high sensitivity for the diagnosis and staging of neuroendocrine tumours. In this study we investigated the potential role of {sup 68}Ga-DOTATOC PET/CT in screening of patients with vHLD. {sup 68}Ga-DOTATOC PET/three-phase contrast-enhanced CT was performed according to guidelines in all consecutive vHLD patients between January 2012 and November 2015. All patients underwent additional MRI imaging of the abdomen, spine, and head. Chromogranin A (CgA) was determined at the time of the PET/CT examination. A lesion seen on {sup 68}Ga-DOTATOC PET in the pancreas was defined as positive if the uptake was visually higher than in the surrounding tissues. Lesions were quantified using maximum SUV. Overall, 20 patients (8 men, 12 women; mean age 44.7 ± 11.1 years) were prospectively examined. Genetically, 12 patients had type 1 vHLD and 8 had type 2 vHLD. {sup 68}Ga-DOTATOC PET/CT detected more pNET than morphological imaging (CT or MRI): 11 patients (55 %; 8 type 1, 3 type 2) vs. 9 patients (45 %; 6 type 1, 3 type 2). The concentration of CgA was mildly elevated in 2 of 11 patients with pNET. The mean SUVmax of the pancreatic lesions was 18.9 ± 21.9 (range 5.0 - 65.6). Four patients (36.4 %) had multiple pNETs. The mean size of the lesions on CT and/or MRI was 10.4 ± 8.3 mm (range 4 - 38 mm), and 41.1 % were larger than 10 mm. In addition, somatostatin receptor-positive cerebellar and spinal haemangioblastomas were detected in three patients (SUVmax 2.1 - 10.1). One patient presented with a solitary somatostatin receptor-positive lymph

  16. A study on CT features of intrahepatic bile duct abscess

    International Nuclear Information System (INIS)

    Min Pengqiu; Li Peng; He Zhiyan; Chen Weixia; Liu Yan

    2001-01-01

    Objective: To evaluate CT features of intrahepatic bile duct abscess (IBDA) and its pathologic basis. Methods: The CT imaging data of 31 consecutive cases of intrahepatic bile duct abscess proved by surgery or clinical treatments from October 1989 to February 1999 were retrospectively studied. The causes included acute obstructive suppurative cholangitis and retrograde infection due to different etiologies. For all the cases, the CT manifestations of liver abscess, bile duct abnormalities, and their relationship were observed respectively. Results: Manifestations of liver abscess were revealed in all cases (31/31, 100%). The CT manifestations of bile duct abnormalities included signs of etiologies caused bile duct obstruction and other signs including cholangiectasis (29/31, 93.5%), the dilated bile ducts communicated with (5/31, 16.1%) or abut on (8/31, 25.8%) the abscesses, and gas collection in bile ducts (10/31, 32.2%). The signs showing the relationship between liver abscess and bile duct abnormalities were that the abscesses complied with the obstructive site and the dilated bile ducts (15/31, 48.4%), and the liver abscesses located in different (7/31, 22.6%) or same (4/31, 12.9%) liver lobes or segments with gas collection in the dilated bile ducts. Conclusion: The CT manifestations of IBDA included signs of liver abscess, abnormalities of bile ducts, and signs showing their relationship. CT scanning was helpful in making comprehensive and accurate diagnosis of IBDA

  17. Studies of extracerebral space on brain CT of infants

    International Nuclear Information System (INIS)

    Shibakiri, Ippei; Furukawa, Takashi; Fukakusa, Shunichi; Nemoto, Yutaka; Takashima, Sumio.

    1983-01-01

    Frontal extracerebral space (ECS) is frequently noticed on brain CT of infants. Based on 70 infants whose initial CTs were available under 1 year of age and who were observed serially by brain CT, we studied the relation between degrees of ECS enlargement and mental and physical development of infants. Development was assessed by clinical observation and the mental test according to Tsumori and Inage at about 1 year of age. 1) Under 1 year of age, ECS was observed both in the normally developed infants and the infants with retarded development. At 1 year of age, CT of the former showed no or only mild widening, but most CT of the latter showed marked dilatation of ECS. 2) Serial observation of brain CT revealed that ECS of normally developed infants tended to reduce at 1 year of age, but that of infants with retarded development did not. 3) Regarding prediction of infantile development, it is important to observe presence of ECS and of the tendency to reduce on brain CT at 1 year of age. 4) Appearance of ECS of normally developed infants is considered to be a physiological phenomenon. (author)

  18. CT in the study of thoracic-pulmonary complications after liver transplantation

    International Nuclear Information System (INIS)

    Robiati, S.; Veltri, A.; Martina, M. C.; Gariazzo, G.; Gandini, G.; Cerutti, E.; Ottobrelli, A.

    2000-01-01

    In this article is reviewed the role of Computed Tomography (CT) in thoracic complications following ortho topic liver transplantation (OLT). In a post-OLT population of 567 patients transplanted in the Italian institutions, 100 patients (17.6%) were examined with chest CT. It was reviewed data relative to the total number of examinations, clinical and/or radiographic indications, the CT technique-i.e., conventional (with (out) intravenous, i.v., contrast material) or high-resolution (HRCT). It also reviewed the radiologic patterns and their correlation with the other clinical, bronchoscopic and/or laboratory results. Of 152 chest CT examinations, 45 (29.6%) were performed because of clinical indications, 31 (20.4%) because of a radiographic abnormality, 64 (42.1%) because of clinical and radiographic abnormality, 64 (42.1%) because of clinical and radiographic indications, while in 12 cases (7.9%) the reasons were unknown; 133/152 (87.5%) examinations had been performed with conventional CT scanning (100 with i.v. contrast agent and 33 without) and 19/152 (12.5%) with HRCT. Twenty of 152 (13.2%) examinations, in 16 patients were normal; in the other 84 patients, 132/152 (86.8%) CT/HRCT studies showed 247 pathological findings (99 pleural effusions, 3 pericardial effusions, 62 cases of atelectasis, 1 pulmonary calcification, 70 suspected inflammatory parenchymal consolidations, 64 of them alveolar and 6 interstitial, 4 cases of interstitial edema and finally 8 neoplastic infiltrates). Correlated with clinical data, CT findings are very useful in detailing clinical-radiographic screening findings, despite the limitations in typifying pleural effusions, in differentiating atelectasis from inflammatory parenchymal consolidations and in assessing pneumonia etiology. Also, despite its high sensitivity (94.1%) and specificity (92.8%), CT was not accurate enough in the differential diagnosis of pneumonia. History data were necessary to characterize the histology of

  19. Screening in asymptomatic SDHx mutation carriers: added value of {sup 18}F-FDG PET/CT at initial diagnosis and 1-year follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Lepoutre-Lussey, C.; Deandreis, D.; Berdelou, A.; Nascimento, C.; Lumbroso, J.; Schlumberger, M.; Baudin, E.; Leboulleux, S. [Gustave Roussy Institut, Universite Paris-Sud, Department of Nuclear Medicine and Endocrine Oncology, Villejuif (France); Caramella, C.; Bidault, F.; Deschamps, F. [Gustave Roussy Institut, Department of Radiology, Villejuif (France); Al Ghuzlan, A. [Gustave Roussy Institut, Department of Medical Biology and Pathology, Villejuif (France); Hartl, D.; Dumont, F. [Gustave Roussy Institut, Department of Surgery, Villejuif (France); Borget, I. [Gustave Roussy Institut, Department of Biostatistic and Epidemiology, Villejuif (France); Paris-Sud University, Villejuif (France); Gimenez-Roqueplo, A.P. [Assistance Publique-Hopitaux de Paris, Hopital Europeen Georges Pompidou, Department of Genetics, Paris (France); Paris Descartes University, Faculty of Medicine, Paris (France); Guillaud Bataille, M. [Gustave Roussy Institut, Department of Genetics, Villejuif (France)

    2015-05-01

    Specific recommendations on screening modalities for paraganglioma (PGL) and phaeochromocytoma (PCC) in asymptomatic SDHx mutation carriers (relatives) are still lacking. We evaluated the added value of {sup 18}F-FDG PET/CT in comparison with morphological imaging at initial diagnosis and 1 year of follow-up in this population. The study included 30 consecutive relatives with a proven SDHx mutation who were investigated by {sup 18}F-FDG PET/CT, gadolinium-enhanced magnetic resonance angiography of the head and neck, thoracic/abdominal/pelvic (TAP) contrast-enhanced CT and/or TAP MRI. {sup 123}I-MIBG scintigraphy was performed in 20 subjects and somatostatin receptor scintigraphy (SRS) in 20 subjects. The gold standard was based on pathology or a composite endpoint as defined by any other positive imaging method and persistent tumour on follow-up. Images were considered as false-positive when the lesions were not detected by another imaging method or not confirmed at 1 year. At initial work-up, an imaging abnormality was found in eight subjects (27 %). The final diagnosis was true-positive in five subjects (two with abdominal PGL, one with PCC and two with neck PGL) and false-positives in the other three subjects (detected with {sup 18}F-FDG PET/CT in two and TAP MRI in one). At 1 year, an imaging abnormality was found in three subjects of which one was an 8-mm carotid body PGL in a patient with SDHD mutation and two were considered false-positive. The tumour detection rate was 100 % for {sup 18}F-FDG PET/CT and conventional imaging, 80 % for SRS and 60 % for {sup 123}I-MIBG scintigraphy. Overall, disease was detected in 4 % of the subjects at the 1-year follow-up. {sup 18}F-FDG PET/CT demonstrated excellent sensitivity but intermediate specificity justifying combined modality imaging in these patients. Given the slow progression of the disease, if {sup 18}F-FDG PET/CT and MRI are normal at baseline, the second imaging work-up should be delayed and an examination

  20. Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Suzuki, Kayo [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Nakamoto, Yuji [Kyoto University Hospital, Department of Diagnostic Radiology, Kyoto (Japan); Onishi, Yumiko; Sakamoto, Setsu; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Senda, Michio [Institute of Biomedical Research and Innovation, Department of Molecular Imaging, Kobe (Japan); Kita, Masato [Kobe City Medical Center General Hospital, Department of Obstetrics and Gynecology, Kobe (Japan)

    2010-08-15

    To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated {sup 18}F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer. A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months. Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT. PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations. (orig.)

  1. Aortic non communicating dissections. A study with helical CT

    International Nuclear Information System (INIS)

    Midiri, M.; Strada, A.; Stabile Ianora, A.A.; Rotondo, A.; Angelelli, G.; D'Agostino, D.; De Luca Tupputi Schinosa, L.

    2000-01-01

    The evaluate the signs of aortic intramural hematoma with helical CT and the diagnostic role of this technique in patients with this condition. It was reviewed the CT findings of 396 patients submitted to emergency examinations for suspected aortic dissection from 1995 to 1999. Only 18 patients (6 women and 12 men) had CT signs of aortic intramural hematoma. Helical CT studies were carried out with the following parameters: slice thickness 10 mm, reconstruction index 10, feed 1.5 mm, conventional algorithm with minimum values of 130 kV and 125mA. All patients were examined with dynamic contrast-enhanced CT, before and after a power injection of 130 mL ionic contrast material. It was studied: hematoma localization and longitudinal extension; thickness and density of aortic wall; presence and location of intimal calcifications; integrity of intimal wall; hemo mediastinum and/or hemo thorax. Aortic wall thickening appeared as a high density crescent-shaped area at baseline CT and had low density on enhanced images in all patients. Thickening was eccentric in 14/18 patients and concentric in 4/18 only; it always exceeded 4 mm. It was found some intimal calcifications in 8 patients and hemo thorax and/or hemo mediastinum in 9 patients. A patient with type A hematoma died of cardiac tamponade a few hours after CT diagnosis. Six patients (5 type B and 1 type A) underwent anti-hypertensive treatment and radiological follow-up. Eleven patients (6 type A and 5 type B) underwent prosthesis replacement and 5 of them (3 type A and 2 type B) died of postoperative complications. In the 5 type B patients surgery was performed because of treatment-resistant pain and of the onset of ischemic complications to abdominal organs caused by involvement of the main collateral branches of the aorta. One patient with type A hematoma was submitted to drug treatment because it was judged unresectable. Intramural hematoma of the aorta is a distinct pathological entity, which should not be

  2. Quantification of Aortic Valve Calcifications Detected During Lung Cancer-Screening CT Helps Stratify Subjects Necessitating Echocardiography for Aortic Stenosis Diagnosis.

    Science.gov (United States)

    Lee, Hee Young; Kim, Sung Mok; Lee, Kyung Soo; Park, Seung Woo; Chung, Myung Jin; Cho, Hyoun; Jung, Jung Im; Jang, Hye Won; Jung, Sin-Ho; Goo, Juna

    2016-05-01

    No study has been published on aortic valve calcification (AVC) extent at lung cancer screening low-dose CT (LDCT) and its relationship with aortic stenosis (AS). The purpose of this study was to estimate the cutoff value of AVC on LDCT for detecting AS in asymptomatic Asian subjects. Six thousand three hundred thirty-eight subjects (mean age, 55.9 years ± 8.6) self-referred to health-promotion center underwent LDCT, coronary calcium scoring CT (CSCT), and echocardiography. AVC was quantified using Agatston methods on CT. AVC extent on LDCT was compared with that on CSCT, and AVC threshold for diagnosing AS was calculated. Clinical factors associated with AS and AVC were sought.AVC was observed in 403 subjects (64.9 years ± 8.7) on LDCT (6.4%), and AVC score measured from LDCT showed strong positive correlation with that from CSCT (r = 0.83, P AVC score for detecting AS was 138.37 with sensitivity of 90.0% and specificity 83.2%. On multivariate analysis, age (odds ratio [OR] = 1.10, 95% CI: 1.09-1.12) and hypertension (OR = 1.39, 95% CI: 1.10-1.76) were associated with the presence of AVC, whereas AVC extent at LDCT (OR = 104.32, 95% CI: 16.16-673.70) was the only significant clinical factor associated with AS; AVC extent on LDCT (OR = 104.32, 95% CI: 16.16-673.70) was the significant clinical factor associated with AS.The AVC extent on LDCT is significantly related to the presence of AS, and we recommend echocardiography for screening AS based on quantified AVC values on LDCT.

  3. Does CT colonography have a role for population-based colorectal cancer screening?

    NARCIS (Netherlands)

    de Haan, Margriet C.; Halligan, Steve; Stoker, Jaap

    2012-01-01

    Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool

  4. More than lung cancer: Automated analysis of low-dose screening CT scans

    NARCIS (Netherlands)

    Mets, O.M.

    2012-01-01

    Smoking is a major health care problem and is projected to cause over 8 million deaths per year worldwide in the coming decades. To reduce lung cancer mortality in heavy smokers, several randomized screening trials were initiated in the past years using screening with low-dose Computed Tomography

  5. CT colonography with rectal iodine tagging: Feasibility and comparison with oral tagging in a colorectal cancer screening population.

    Science.gov (United States)

    Neri, Emanuele; Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca; D'Ippolito, Giuseppe; Bartolozzi, Carlo

    2015-09-01

    To evaluate feasibility, diagnostic performance, patient acceptance, and overall examination time of CT colonography (CTC) performed through rectal administration of iodinated contrast material. Six-hundred asymptomatic subjects (male:female=270:330; mean 63 years) undergoing CTC for colorectal cancer screening on an individual basis were consecutively enrolled in the study. Out of them, 503 patients (group 1) underwent CTC with rectal tagging, of which 55 had a total of 77 colonic lesions. The remaining 97 patients (group 2) were randomly selected to receive CTC with oral tagging of which 15 had a total of 20 colonic lesions. CTC findings were compared with optical colonoscopy, and per-segment image quality was visually assessed using a semi-quantitative score (1=poor, 2=adequate, 3=excellent). In 70/600 patients (11.7%), CTC was performed twice with both types of tagging over a 5-year follow-up cancer screening program. In this subgroup, patient acceptance was rated via phone interview two weeks after CTC using a semi-quantitative scale (1=poor, 2=fair, 3=average, 4=good, 5=excellent). Mean per-polyp sensitivity, specificity, positive and negative predictive values of CTC with rectal vs oral tagging were 96.1% (CI95% 85.4÷99.3%) vs 89.4% (CI95% 65.4÷98.1%), 95.3% (CI95% 90.7÷97.8%) vs 95.8% (CI95% 87.6÷98.9%), 86.0% (CI95% 73.6÷93.3) vs 85.0% (CI95% 61.1÷96.0%), and 98.8% (CI95% 95.3÷99.8%) vs 97.2% (CI95% 89.4÷99.5%), respectively (p>0.05). Polyp detection rates were not statistically different between groups 1 and 2 (p>0.05). Overall examination time was significantly shorter with rectal than with oral tagging (18.3±3.5 vs 215.6±10.3 minutes, respectively; pRectal iodine tagging can be an effective alternative to oral tagging for CTC with the advantages of greater patient acceptance and lower overall examination time. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Brain atrophy during aging. Quantitative studies with X-CT and NMR-CT

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzawa, Taiju; Yamada, Kenji; Yamada, Susumu; Ono, Shuichi; Takeda, Shunpei; Hatazawa, Jun; Ito, Masatoshi; Kubota, Kazuo

    1985-12-01

    Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT. Brain atrophy was minimal in 34-35 years old in both sexes, increased exponentially to the increasing age after 34-35 years, and probably resulted in dementia, such as vascular or multi-infarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34-35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extent of brain atrophy (20 - 30 %) existed among aged subjects. Progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was the decrease in the cerebral blood flow. We have classified brain atrophy into sulcal and cisternal enlargement type (type I), ventricular enlargement type (type II) and mixed type (type III) according to the clinical study using NMR-CT. Brain atrophy of type I progresses significantly in almost all of the geriatric disorders. This type of brain atrophy progresses significantly in heavy smokers and drinkers. Therefore this type of brain atrophy might be caused by the decline in the blood flow in anterior and middle cerebral arteries. Brain atrophy of type II was caused by the disturbance of cerebrospinal fluid circulation after cerebral bleeding and subarachnoid bleeding. Brain atrophy of type III was seen in vascular dementia or multi-infarct dementia which was caused by loss of brain matter after multiple infarction, and was seen also in dementia of Alzheimer type in which degeneration of nerve cells results in brain atrophy. NMR-CT can easily detect small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy. (J.P.N.).

  7. Prevalance rate of low-dose CT lung cancer screening. Results of a questionnaire survey of member facilities of Japan society of ningen dock with special concerns regarding the actual status and disincentives for implementing such screening

    International Nuclear Information System (INIS)

    Takizawa, Hirotaka

    2012-01-01

    We conducted a survey of member facilities of the Japan Society of Ningen Dock to elucidate the actual status of chest computed tomography (CT) screening and the reasons for not being able to change to low-dose CT. We sent a questionnaire consisting of 9 items to 531 member facilities in July 2010, response by facsimile to obtain an analysis. The prevalence rate of low-dose CT lung cancer screening slightly increased to 35% in comparison with the former survey done in November 2008. Some facilities indicated some shift in tube current to a lower range even though this was insufficient to meet the definition of low-dose CT. This reflects their thinking of ''Even with knowledge, there is strong hesitation to change to low-dose CT''. Among the reasons why they did not change to low-dose CT, a priority for high quality images was the top reason among problems of devices and performance. Informed consent was not yet adequate. It is necessary for manufactures to develop better technology to improve the image quality of low-dose CT and to report enough information to clinicians. On the medical side, perception of the necessity for appropriate reduction of radiation dose and the decision to move to low-dose CT would be of crucial significance for facility heads as well as radiologists and technicians. (author)

  8. Diagnostic work-up of pulmonary nodules. Management of pulmonary nodules detected with low-dose CT screening; Abklaerung von Lungenrundherden. Management durch Frueherkennungsuntersuchungen detektierter pulmonaler Rundherde

    Energy Technology Data Exchange (ETDEWEB)

    Wormanns, D. [Evangelische Lungenklinik Berlin, Berlin (Germany)

    2016-09-15

    Pulmonary nodules are the most frequent pathological finding in low-dose computed tomography (CT) scanning for early detection of lung cancer. Early stages of lung cancer are often manifested as pulmonary nodules; however, the very commonly occurring small nodules are predominantly benign. These benign nodules are responsible for the high percentage of false positive test results in screening studies. Appropriate diagnostic algorithms are necessary to reduce false positive screening results and to improve the specificity of lung cancer screening. Such algorithms are based on some of the basic principles comprehensively described in this article. Firstly, the diameter of nodules allows a differentiation between large (>8 mm) probably malignant and small (<8 mm) probably benign nodules. Secondly, some morphological features of pulmonary nodules in CT can prove their benign nature. Thirdly, growth of small nodules is the best non-invasive predictor of malignancy and is utilized as a trigger for further diagnostic work-up. Non-invasive testing using positron emission tomography (PET) and contrast enhancement as well as invasive diagnostic tests (e.g. various procedures for cytological and histological diagnostics) are briefly described in this article. Different nodule morphology using CT (e.g. solid and semisolid nodules) is associated with different biological behavior and different algorithms for follow-up are required. Currently, no obligatory algorithm is available in German-speaking countries for the management of pulmonary nodules, which reflects the current state of knowledge. The main features of some international and American recommendations are briefly presented in this article from which conclusions for the daily clinical use are derived. (orig.) [German] Lungenrundherde sind die haeufigsten pathologischen Befunde bei Untersuchungen mit der Niedrigdosis-CT zur Lungenkrebsfrueherkennung. Fruehstadien des Lungenkarzinoms manifestieren sich meist als Rundherd

  9. The Oncogenic Risks of Diagnostic CT Scam Studies in Children

    International Nuclear Information System (INIS)

    Brent, R.

    2004-01-01

    Brenner et al (2001) reported that estimates of the exposure to children from CT scans indicates that the exposures are both higher than from conventional radiographic studies and higher than is necessary to obtain quality examinations. utilizing the oncogenic risk data from the RERF study in Japan, Brenner et al estimated that the oncogenic risk in this population of CT exposed children exposed each year would result in an additional 500 cases of cancer. This risk estimate is supported by the RERF epidemiological data obtained from the populations exposed in Hiroshima and Nagasaki. the increased risks associated with the increased exposure from CT scans have raised concern and stimulated discussion. Although there is little doubt about the benefits of CT scans in improving the health care of children, there is concern about the estimated oncogenic risk, especially since the frequency of CT studies has been increasing. Applying the oncogenic risks of ionizing radiation from the RERF data may not be appropriate for all types of radiation exposure for accurately predicting the incidence of cancer in exposed children because of the impact of 1) partial versus whole-body irradiation, and 2) the protraction of the exposure. Other population of children who have been exposed to radiation and whose incidence of cancer has been studied will be presented and those studies indicate that the risk of cancer is much lower or not increased at all with exposures in the diagnostic range. finally, the dramatic impact of the use of CT scans in clinical pediatric practice saves lives and improves diagnostic accuracy. Therefore, it is crucial that a scholarly evaluation of the risks and benefits should be initiated. The radiology community and the manufacturers have already initiated programs to decrease the exposure significantly. But it is essential that well-planned, retrospective and prospective epidemiology studies should be initiated to study the oncogenic risks. If you want to

  10. Fundamental studies for CT in the oral region

    International Nuclear Information System (INIS)

    Suzuki, Shinichiro

    1984-01-01

    Fundamental studies were attempted regarding the clinical application of CT (TCT-60A) in the oral region. The investigation assessed the following: 1) calculation of CT-No for oral hard tissues, 2) test for linearity CT-No vs. the linear attenuation coefficient in high X-ray attenuation materials, 3) observation of artifacts caused by dental materials and 4) measurement of patient doses of CT used at the maxillary sinus. The results obtained were as follows. 1) Calculated CT-No (E=70 KeV) values for oral hard tissues were enamel 3.51 x 10 3 , dentine 2.40 x 10 3 , cementum 1.88 x 10 3 , cortical bone 1.48 x 10 3 and mandible 1.01 x 10 3 . 2) Linearity for CT-No vs. the linear attenuation coefficient gave a good relative coefficient between lucite and teflon, but linearity between lucite and aluminum was not good enough. 3) Three different artifacts from the copper rod were observed: (1) connection line artifact, (2) star-burst artifact and (3) figure-eight artifact. 4) Under shot caused by composite resin was observed, and artifact from both the radiopaque composite resin and amalgam were the same kinds as those from the copper rod. 5) Calculated CT-No (E=66 KeV) values for dental materials were copper 5.48 x 10 4 , composite resin 1.24 x 10 3 , radiopaque composite resin 4.65 x 10 3 and amalgam 2.27 x 10 5 . 6) Absorbed doses of lenses and thyroid gland using CT at the mixillary sinus region were 59 mrad (59 x 10 -2 mGy) and 17 mrad (17 x 10 -2 mGy) for a single scanning. 7) The volume dose of the head under a single CT scanning was estimated as 820 g.rad (820 x 10 -5 Kg.Gy) by the TLD method, and 900 g.rad (900 x 10 -5 Kg.Gy) by the film dosimetry method. The difference in these values was considered to be the effect arising from ununiformity of the X-ray beam. (author)

  11. Optimal dose levels in screening chest CT for unimpaired detection and volumetry of lung nodules, with and without computer assisted detection at minimal patient radiation.

    Directory of Open Access Journals (Sweden)

    Andreas Christe

    Full Text Available OBJECTIVES: The aim of this phantom study was to minimize the radiation dose by finding the best combination of low tube current and low voltage that would result in accurate volume measurements when compared to standard CT imaging without significantly decreasing the sensitivity of detecting lung nodules both with and without the assistance of CAD. METHODS: An anthropomorphic chest phantom containing artificial solid and ground glass nodules (GGNs, 5-12 mm was examined with a 64-row multi-detector CT scanner with three tube currents of 100, 50 and 25 mAs in combination with three tube voltages of 120, 100 and 80 kVp. This resulted in eight different protocols that were then compared to standard CT sensitivity (100 mAs/120 kVp. For each protocol, at least 127 different nodules were scanned in 21-25 phantoms. The nodules were analyzed in two separate sessions by three independent, blinded radiologists and computer-aided detection (CAD software. RESULTS: The mean sensitivity of the radiologists for identifying solid lung nodules on a standard CT was 89.7% ± 4.9%. The sensitivity was not significantly impaired when the tube and current voltage were lowered at the same time, except at the lowest exposure level of 25 mAs/80 kVp [80.6% ± 4.3% (p = 0.031]. Compared to the standard CT, the sensitivity for detecting GGNs was significantly lower at all dose levels when the voltage was 80 kVp; this result was independent of the tube current. The CAD significantly increased the radiologists' sensitivity for detecting solid nodules at all dose levels (5-11%. No significant volume measurement errors (VMEs were documented for the radiologists or the CAD software at any dose level. CONCLUSIONS: Our results suggest a CT protocol with 25 mAs and 100 kVp is optimal for detecting solid and ground glass nodules in lung cancer screening. The use of CAD software is highly recommended at all dose levels.

  12. Reliable categorisation of visual scoring of coronary artery calcification on low-dose CT for lung cancer screening: validation with the standard Agatston score

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yi-Luan; Wu, Fu-Zong; Wang, Yen-Chi [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); Ju, Yu-Jeng [National Taiwan University, Department of Psychology, Taipei (China); Mar, Guang-Yuan [Kaohsiung Veterans General Hospital, Division of Cardiology, Department of Medicine, Kaohsiung 813 (China); Chuo, Chiung-Chen [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); Lin, Huey-Shyan [Fooyin University, School of Nursing, Kaohsiung (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); National Yang Ming University, Institute of Clinical Medicine, Taipei (China)

    2013-05-15

    To validate the reliability of the visual coronary artery calcification score (VCACS) on low-dose CT (LDCT) for concurrent screening of CAC and lung cancer. We enrolled 401 subjects receiving LDCT for lung cancer screening and ECG-gated CT for the Agatston score (AS). LDCT was reconstructed with 3- and 5-mm slice thickness (LDCT-3mm and LDCT-5mm respectively) for VCACS to obtain VCACS-3mm and VCACS-5mm respectively. After a training session comprising 32 cases, two observers performed four-scale VCACS (absent, mild, moderate, severe) of 369 data sets independently, the results were compared with four-scale AS (0, 1-100, 101-400, >400). CACs were present in 39.6 % (146/369) of subjects. The sensitivity of VCACS-3mm was higher than for VCACS-5mm (83.6 % versus 74.0 %). The median of AS of the 24 false-negative cases in VCACS-3mm was 2.3 (range 1.1-21.1). The false-negative rate for detecting AS {>=} 10 on LDCT-3mm was 1.9 %. VCACS-3mm had higher concordance with AS than VCACS-5mm (k = 0.813 versus k = 0.685). An extended test of VCACS-3mm for four junior observers showed high inter-observer reliability (intra-class correlation = 0.90) and good concordance with AS (k = 0.662-0.747). This study validated the reliability of VCACS on LDCT for lung cancer screening and showed that LDCT-3mm was more feasible than LDCT-5mm for CAD risk stratification. (orig.)

  13. TU-H-207A-08: Estimating Radiation Dose From Low-Dose Lung Cancer Screening CT Exams Using Tube Current Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, A; Bostani, M [University of California, Los Angeles, Los Angeles, CA (United States); McMillan, K [Mayo Clinic, Rochester, MN (United States); Zankl, M [Helmholtz Zentrum Munchen, Neuherberg (Germany); Cagnon, C [UCLA Medical Center, Los Angeles, CA (United States); McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2016-06-15

    Purpose: The purpose of this work is to estimate effective and lung doses from a low-dose lung cancer screening CT protocol using Tube Current Modulation (TCM) across patient models of different sizes. Methods: Monte Carlo simulation methods were used to estimate effective and lung doses from a low-dose lung cancer screening protocol for a 64-slice CT (Sensation 64, Siemens Healthcare) that used TCM. Scanning parameters were from the AAPM protocols. Ten GSF voxelized patient models were used and had all radiosensitive organs identified to facilitate estimating both organ and effective doses. Predicted TCM schemes for each patient model were generated using a validated method wherein tissue attenuation characteristics and scanner limitations were used to determine the TCM output as a function of table position and source angle. The water equivalent diameter (WED) was determined by estimating the attenuation at the center of the scan volume for each patient model. Monte Carlo simulations were performed using the unique TCM scheme for each patient model. Lung doses were tallied and effective doses were estimated using ICRP 103 tissue weighting factors. Effective and lung dose values were normalized by scanspecific 32 cm CTDIvol values based upon the average tube current across the entire simulated scan. Absolute and normalized doses were reported as a function of WED for each patient. Results: For all ten patients modeled, the effective dose using TCM protocols was below 1.5 mSv. Smaller sized patient models experienced lower absolute doses compared to larger sized patients. Normalized effective and lung doses showed some dependence on patient size (R2 = 0.77 and 0.78, respectively). Conclusion: Effective doses for a low-dose lung screening protocol using TCM were below 1.5 mSv for all patient models used in this study. Institutional research agreement, Siemens Healthcare; Past recipient, research grant support, Siemens Healthcare; Consultant, Toshiba America Medical

  14. TU-H-207A-08: Estimating Radiation Dose From Low-Dose Lung Cancer Screening CT Exams Using Tube Current Modulation

    International Nuclear Information System (INIS)

    Hardy, A; Bostani, M; McMillan, K; Zankl, M; Cagnon, C; McNitt-Gray, M

    2016-01-01

    Purpose: The purpose of this work is to estimate effective and lung doses from a low-dose lung cancer screening CT protocol using Tube Current Modulation (TCM) across patient models of different sizes. Methods: Monte Carlo simulation methods were used to estimate effective and lung doses from a low-dose lung cancer screening protocol for a 64-slice CT (Sensation 64, Siemens Healthcare) that used TCM. Scanning parameters were from the AAPM protocols. Ten GSF voxelized patient models were used and had all radiosensitive organs identified to facilitate estimating both organ and effective doses. Predicted TCM schemes for each patient model were generated using a validated method wherein tissue attenuation characteristics and scanner limitations were used to determine the TCM output as a function of table position and source angle. The water equivalent diameter (WED) was determined by estimating the attenuation at the center of the scan volume for each patient model. Monte Carlo simulations were performed using the unique TCM scheme for each patient model. Lung doses were tallied and effective doses were estimated using ICRP 103 tissue weighting factors. Effective and lung dose values were normalized by scanspecific 32 cm CTDIvol values based upon the average tube current across the entire simulated scan. Absolute and normalized doses were reported as a function of WED for each patient. Results: For all ten patients modeled, the effective dose using TCM protocols was below 1.5 mSv. Smaller sized patient models experienced lower absolute doses compared to larger sized patients. Normalized effective and lung doses showed some dependence on patient size (R2 = 0.77 and 0.78, respectively). Conclusion: Effective doses for a low-dose lung screening protocol using TCM were below 1.5 mSv for all patient models used in this study. Institutional research agreement, Siemens Healthcare; Past recipient, research grant support, Siemens Healthcare; Consultant, Toshiba America Medical

  15. Hepatic alveolar echinococcosis: correlative US and CT study

    Energy Technology Data Exchange (ETDEWEB)

    Didier, D.; Weiler, S.; Rohmer, P.; Lasseque, A.; Deschamps, J.P.; Vuitton, D.; Miguet, J.P.; Weill, F.

    1985-01-01

    A total of 24 cases of hepatic alveolar echinococcosis (HAE) due to Echinococcus multilocularis was assessed by US and CT. The diagnosis was confirmed in all cases by immunologic and histologic study. Both US and CT patterns of HAE showed changes of liver morphology in both contour and size. Abnormal areas of parenchyma were nodular or in fields, irregular, heterogeneous, and basically echogenic. Clustered microcalcifications were encountered within the abnormal parenchymal fields in 50% of cases, and necrotized zones occurred in 40% of cases. Dilatation of intrahepatic bile ducts was commonly seen, especially on US; hilar involvement was frequent. Follow-up by both techniques can display increases of primary lesions, occurrence of new foci, and local or regional extensions. Precise evaluations of the lesions arising from correlative use of US and CT permits adequate therapeutic management.

  16. CT study in primary low spinal fluid pressure syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Moritoshi; Okayama, Kenji; Kubo, Hiromasa; Watanabe, Hiromi; Endou, Riuko (Ohmiya Red Cross Hospital, Yono, Saitama (Japan))

    1991-02-01

    CT findings in primary low spinal fluid pressure syndrome were studied on the basis of 3 cases. Case 1 was a 43-year-old male with a complicated bilateral isodense subdural hematoma (SDH). Case 2 was a 45-year-old female with a complicated bilateral high dense SDH. Case 3 was a 36-year-old female discharged without any complications after spinal fluid pressure normalized. Slight downward displacement of the brain under low spinal fluid pressure was shown as the narrowing of a Sylvian fissures and infratentorial cisterns on CT. On the other hand, in this syndrome with a complicated bilateral isodense SDH, in addition to this finding, CT revealed distortion and narrowing of body lateral ventricles, which might be differential findings from this syndrome without complicated SDH. Under low spinal fluid pressure, bridging veins are more stretched by a downward displacement of the brain. And consequently they were easily injured and SDH was developed. (author).

  17. Hepatic alveolar echinococcosis: correlative US and CT study

    International Nuclear Information System (INIS)

    Didier, D.; Weiler, S.; Rohmer, P.; Lasseque, A.; Deschamps, J.P.; Vuitton, D.; Miguet, J.P.; Weill, F.

    1985-01-01

    A total of 24 cases of hepatic alveolar echinococcosis (HAE) due to Echinococcus multilocularis was assessed by US and CT. The diagnosis was confirmed in all cases by immunologic and histologic study. Both US and CT patterns of HAE showed changes of liver morphology in both contour and size. Abnormal areas of parenchyma were nodular or in fields, irregular, heterogeneous, and basically echogenic. Clustered microcalcifications were encountered within the abnormal parenchymal fields in 50% of cases, and necrotized zones occurred in 40% of cases. Dilatation of intrahepatic bile ducts was commonly seen, especially on US; hilar involvement was frequent. Follow-up by both techniques can display increases of primary lesions, occurrence of new foci, and local or regional extensions. Precise evaluations of the lesions arising from correlative use of US and CT permits adequate therapeutic management

  18. Normal sacroiliac joint: a CT study of asymptomatic patients

    International Nuclear Information System (INIS)

    Vogler, J.B. III; Brown, W.H.; Helms, C.A.; Genant, H.K.

    1984-01-01

    The sacroiliac (SI) joints of 45 asymptomatic subjects were prospectively studied to define better the normal appearance of SI joints on CT scans and therby attach appropriate significance to CT signs of sacroiliitis. Joint space narrowing, subchondral sclerosis, erosions, ankylosis, osteophytes, subchondral cysts, and symmetry were evaluted. The results indicate that the SI joints demonstrate symmetry in patients under the age of 30 (100% of subjects in this age group). Those CT findings of sacroiliitis that occurred infrequently in the asymptomatic population, and hence may represent good indicators of sacroiliac disease, include increased sacral subchondral sclerosis in subjects under the age of 40 (11%), bilateral or unilateral uniform joint space of less than 2 mm (2% or 0%, respectively), erosions (2%), and intraarticular ankylosis (0%)

  19. Burden of waiting for surveillance CT colonography in patients with screen-detected 6-9 mm polyps

    Energy Technology Data Exchange (ETDEWEB)

    Tutein Nolthenius, Charlotte J. [University of Amsterdam, Department of Radiology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Boellaard, Thierry N.; Nio, C.Y.; Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Haan, Margriet C. de [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Thomeer, Maarten G.J. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Montauban van Swijndregt, Alexander D. [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Essink-Bot, Marie-Louise [University of Amsterdam, Public Health, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Kuipers, Ernst J. [Erasmus University Medical Center, Gastroenterology and Hepatology, Rotterdam (Netherlands); Erasmus University Medical Center, Internal medicine, Rotterdam (Netherlands); Dekker, Evelien [University of Amsterdam, Gastroenterology and Hepatology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands)

    2016-11-15

    We assessed the burden of waiting for surveillance CT colonography (CTC) performed in patients having 6-9 mm colorectal polyps on primary screening CTC. Additionally, we compared the burden of primary and surveillance CTC. In an invitational population-based CTC screening trial, 101 persons were diagnosed with <3 polyps 6-9 mm, for which surveillance CTC after 3 years was advised. Validated questionnaires regarding expected and perceived burden (5-point Likert scales) were completed before and after index and surveillance CTC, also including items on burden of waiting for surveillance CTC. McNemar's test was used for comparison after dichotomization. Seventy-eight (77 %) of 101 invitees underwent surveillance CTC, of which 66 (85 %) completed the expected and 62 (79 %) the perceived burden questionnaire. The majority of participants (73 %) reported the experience of waiting for surveillance CTC as 'never' or 'only sometimes' burdensome. There was almost no difference in expected and perceived burden between surveillance and index CTC. Waiting for the results after the procedure was significantly more burdensome for surveillance CTC than for index CTC (23 vs. 8 %; p = 0.012). Waiting for surveillance CTC after primary CTC screening caused little or no burden for surveillance participants. In general, the burden of surveillance and index CTC were comparable. (orig.)

  20. CT screening for lung cancer: Frequency of enlarged adrenal glands identified in baseline and annual repeat rounds

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Minxia [Icahn School of Medicine at Mount Sinai, Department of Radiology, New York, NY (United States); Capital Medical University, Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Beijing (China); Yip, Rowena; Yankelevitz, David Y.; Henschke, Claudia I. [Icahn School of Medicine at Mount Sinai, Department of Radiology, New York, NY (United States)

    2016-12-15

    To determine the frequency of adrenal enlargement of participants in a CT-screening program for lung cancer and demonstrate the progression during follow-up, separately for baseline and annual repeat rounds. HIPAA-compliant informed consent was obtained in 4,776 participants. The adrenal gland was defined as enlarged if it measured ≥6 mm at its largest diameter. Logistic regression analyses were performed. At baseline, 202 (4 %) of 4,776 participants had adrenal enlargement. Significant factors were age (OR = 1.4, 95 % CI: 1.2-1.7) and current smoker (OR = 1.8, 95 % CI: 1.3-2.4). Follow-up 7-18 months after baseline for 133 cases with adrenal enlargement <40 mm showed it decreased or was stable in 85 (64 %), and increased by <10 mm in 48 (36 %). Five (0.04 %) cases of adrenal enlargement were newly identified, none increased beyond 40 mm on follow-up. Adrenal enlargement was a significant predictor of a subsequent diagnosis of lung cancer (OR = 2.0, 95 % CI: 1.2-3.4). Participants with adrenal enlargement <40 mm identified at baseline and on repeat screening could be reasonably assessed on subsequent annual screening. Adrenal enlargement increased with increasing pack-years of smoking. Adrenal enlargement was an independent predictor of a subsequent diagnosis of lung cancer. (orig.)

  1. Screening for lung cancer with digital chest radiography: sensitivity and number of secondary work-up CT examinations

    NARCIS (Netherlands)

    de Hoop, Bartjan; Schaefer-Prokop, Cornelia; Gietema, Hester A.; de Jong, Pim A.; van Ginneken, Bram; van Klaveren, Rob J.; Prokop, Mathias

    2010-01-01

    To estimate the performance of digital chest radiography for detection of lung cancer. The study had ethics committee approval, and a nested case-control design was used and included 55 patients with lung cancer detected at computed tomography (CT) and confirmed with histologic examination and a

  2. Study of CT image texture using deep learning techniques

    Science.gov (United States)

    Dutta, Sandeep; Fan, Jiahua; Chevalier, David

    2018-03-01

    For CT imaging, reduction of radiation dose while improving or maintaining image quality (IQ) is currently a very active research and development topic. Iterative Reconstruction (IR) approaches have been suggested to be able to offer better IQ to dose ratio compared to the conventional Filtered Back Projection (FBP) reconstruction. However, it has been widely reported that often CT image texture from IR is different compared to that from FBP. Researchers have proposed different figure of metrics to quantitate the texture from different reconstruction methods. But there is still a lack of practical and robust method in the field for texture description. This work applied deep learning method for CT image texture study. Multiple dose scans of a 20cm diameter cylindrical water phantom was performed on Revolution CT scanner (GE Healthcare, Waukesha) and the images were reconstructed with FBP and four different IR reconstruction settings. The training images generated were randomly allotted (80:20) to a training and validation set. An independent test set of 256-512 images/class were collected with the same scan and reconstruction settings. Multiple deep learning (DL) networks with Convolution, RELU activation, max-pooling, fully-connected, global average pooling and softmax activation layers were investigated. Impact of different image patch size for training was investigated. Original pixel data as well as normalized image data were evaluated. DL models were reliably able to classify CT image texture with accuracy up to 99%. Results show that the deep learning techniques suggest that CT IR techniques may help lower the radiation dose compared to FBP.

  3. Anatomic study of celiac ganglia using CT in cadavers

    International Nuclear Information System (INIS)

    Zhao Qionghui; Zhang Xiaoming; Zeng Nanlin; Cai Changping; Xie Xingguo; Li Chengjun

    2005-01-01

    Objective: To identify the celiac ganglia in cadavers by using current CT techniques, and to facilitate its identification in vivo by CT. Methods: Fifty cadavers were dissected, moving peritoneal organs such as liver and stomach to expose the celiac ganglia. The location, morphology, and dimensions of celiac ganglia, and their relationship to abutting structures, were noted. The celiac ganglia in 6 of the 50 cadavers without peripancreatic diseases and with clear anatomy were isolated and marked with yellow dye and Iohexol injection. In these 6 cadavers, the moved organs were relocated, the abdomen was closed, and CT was performed. CT derived measurements of celiac ganglia were compared with those from cadavers study. Results: The celiac ganglia of 47 of 50 cadavers (94%) were located between T12-L1, and those of 3 cadavers (6%) were located between T11-12. The superior-inferior diameter of the right ganglia was (25.01 ±6.09) mm, long (left-right) diameter was (13.18 ± 3.62) mm, and short (thickness) diameter was (1.40 ± 0.55) mm. In the left ganglia, these three diameters were (22.74 ± 5.70) mm, (15.07 ± 4.35) mm, and (2.00 ± 0.71 ) mm, respectively. On the CT images of 6 cadavers, the right and left ganglia were all identified and were hyperdense relative to viscus, such as liver and spleen. The long and short diameters on CT images were (15.20 ± 1.64) mm and (1.53 ± 0.52) mm for the right ganglia and (16.25 ± 1.73 ) mm and (2.20 ± 0.73) mm for the left ganglia. There was no significant difference between the diameters of the ganglia measured on CT images and by dissection (P>0.05). Conclusion: Current CT techniques can demonstrate accurately the celiac ganglia in cadavers. This can be a reference for identifying the celiac plexus in vivo. (authors)

  4. The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

    International Nuclear Information System (INIS)

    Gao Sijia; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui; Zang Peizhuo; Shi Qiang; Wang Qiang; Liang Chuansheng; Xu Ke

    2009-01-01

    type differentiations of all the other 16 patients were consistent with DSA results. For 13 cases with positive CT spinal angiography results, DSA displayed 20 feeding vessels, among which 16 vessels were displayed correctly by CT spinal angiography, four could not be visualized, and two turned out to be false-positive. Fistulas were not displayed in six cases by CT spinal angiography. Draining veins were displayed clearly in all cases, which agreed with DSA results. Four cases who took CE-MRA obtained the same type diagnosis as that from CT spinal angiography. Feeding arteries were not displayed in CE-MRA of one case, but could be clearly visualized in other three cases, and the results agreed with CTA and DSA results. Fistulas could be seen in two cases. Draining veins and the disease range could be displayed distinctly by 3D CE-MRA. Conclusion: CT spinal angiography is quite valuable for diagnosing vascular malformation of spinal cord. It can be a screening exam before DSA, and has a guiding effect on DSA, reducing the amount of time required for DSA.

  5. The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

    Energy Technology Data Exchange (ETDEWEB)

    Gao Sijia [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)], E-mail: scarlettgao@126.com; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Zang Peizhuo [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Shi Qiang; Wang Qiang [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Liang Chuansheng [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Xu Ke [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)

    2009-07-15

    AVM not AVF. The type differentiations of all the other 16 patients were consistent with DSA results. For 13 cases with positive CT spinal angiography results, DSA displayed 20 feeding vessels, among which 16 vessels were displayed correctly by CT spinal angiography, four could not be visualized, and two turned out to be false-positive. Fistulas were not displayed in six cases by CT spinal angiography. Draining veins were displayed clearly in all cases, which agreed with DSA results. Four cases who took CE-MRA obtained the same type diagnosis as that from CT spinal angiography. Feeding arteries were not displayed in CE-MRA of one case, but could be clearly visualized in other three cases, and the results agreed with CTA and DSA results. Fistulas could be seen in two cases. Draining veins and the disease range could be displayed distinctly by 3D CE-MRA. Conclusion: CT spinal angiography is quite valuable for diagnosing vascular malformation of spinal cord. It can be a screening exam before DSA, and has a guiding effect on DSA, reducing the amount of time required for DSA.

  6. Visualizing Typical Features of Breast Fibroadenomas Using Phase-Contrast CT: An Ex-Vivo Study

    Science.gov (United States)

    Grandl, Susanne; Willner, Marian; Herzen, Julia; Sztrókay-Gaul, Anikó; Mayr, Doris; Auweter, Sigrid D.; Hipp, Alexander; Birnbacher, Lorenz; Marschner, Mathias; Chabior, Michael; Reiser, Maximilian; Pfeiffer, Franz; Bamberg, Fabian; Hellerhoff, Karin

    2014-01-01

    Background Fibroadenoma is the most common benign solid breast lesion type and a very common cause for histologic assessment. To justify a conservative therapy, a highly specific discrimination between fibroadenomas and other breast lesions is crucial. Phase-contrast imaging offers improved soft-tissue contrast and differentiability of fine structures combined with the potential of 3-dimensional imaging. In this study we assessed the potential of grating-based phase-contrast CT imaging for visualizing diagnostically relevant features of fibroadenomas. Materials and Methods Grating-based phase-contrast CT was performed on six ex-vivo formalin-fixed breast specimens containing a fibroadenoma and three samples containing benign changes that resemble fibroadenomas using Talbot Lau interferometry and a polychromatic X-ray source. Phase-contrast and simultaneously acquired absorption-based 3D-datasets were manually matched with corresponding histological slices. The visibility of diagnostically valuable features was assessed in comparison with histology as the gold-standard. Results In all cases, matching of grating-based phase-contrast CT images and histology was successfully completed. Grating-based phase-contrast CT showed greatly improved differentiation of fine structures and provided accurate depiction of strands of fibrous tissue within the fibroadenomas as well as of the diagnostically valuable dilated, branched ductuli of the fibroadenomas. A clear demarcation of tumor boundaries in all cases was provided by phase- but not absorption-contrast CT. Conclusions Pending successful translation of the technology to a clinical setting and considerable reduction of the required dose, the data presented here suggest that grating-based phase-contrast CT may be used as a supplementary non-invasive diagnostic tool in breast diagnostics. Phase-contrast CT may thus contribute to the reduction of false positive findings and reduce the recall and core biopsy rate in population

  7. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    DEFF Research Database (Denmark)

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules.......In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

  8. CT screening for lung cancer: Importance of emphysema for never smokers and smokers.

    Science.gov (United States)

    Henschke, Claudia I; Yip, Rowena; Boffetta, Paolo; Markowitz, Steven; Miller, Albert; Hanaoka, Takaomi; Wu, Ning; Zulueta, Javier J; Yankelevitz, David F

    2015-04-01

    To address the prevalence of lung cancer in high and low-risk people according to their smoking history, age, and CT findings of emphysema. We reviewed the baseline low-dose CT scans of 62,124 current, former and never smokers, aged 40-90 to determine the prevalence of lung cancer. We performed logistic regression analysis of the prevalence of lung cancer to determine the odds ratio (OR) for emphysema, conditionally on age, female gender, and ethnicity. The prevalence of lung cancer was 1.4% (95% CI: 1.3-1.6) for current smokers, 1.1% (95% CI: 1.0-1.2) for former smokers, and 0.4% (95% CI: 0.3-0.6) for never smokers. Emphysema was identified in 28.5% (6,684), 20.6% (5,422), and 1.6% (194) of current, former, and never smokers, respectively. The prevalence of lung cancer among current smokers was 1.1% for those without emphysema vs. 2.3% for those with emphysema (odds ratio [OR] 1.8; 95% confidence interval [CI]: 1.4-2.2) and the corresponding difference for former smokers was 0.9% vs. 1.8% (OR: 1.7; 95% CI: 1.3-2.2), and for never smokers, it was 0.4% vs. 2.6% (OR: 6.3; 95% CI: 2.4-16.9). Identification of emphysema in low-dose CT scans increases the risk of lung cancer and is important in determining follow-up of current, former, and never smokers. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Combining automatic tube current modulation with adaptive statistical iterative reconstruction for low-dose chest CT screening.

    Directory of Open Access Journals (Sweden)

    Jiang-Hong Chen

    Full Text Available To reduce radiation dose while maintaining image quality in low-dose chest computed tomography (CT by combining adaptive statistical iterative reconstruction (ASIR and automatic tube current modulation (ATCM.Patients undergoing cancer screening (n = 200 were subjected to 64-slice multidetector chest CT scanning with ASIR and ATCM. Patients were divided into groups 1, 2, 3, and 4 (n = 50 each, with a noise index (NI of 15, 20, 30, and 40, respectively. Each image set was reconstructed with 4 ASIR levels (0% ASIR, 30% ASIR, 50% ASIR, and 80% ASIR in each group. Two radiologists assessed subjective image noise, image artifacts, and visibility of the anatomical structures. Objective image noise and signal-to-noise ratio (SNR were measured, and effective dose (ED was recorded.Increased NI was associated with increased subjective and objective image noise results (P<0.001, and SNR decreased with increasing NI (P<0.001. These values improved with increased ASIR levels (P<0.001. Images from all 4 groups were clinically diagnosable. Images with NI = 30 and 50% ASIR had average subjective image noise scores and nearly average anatomical structure visibility scores, with a mean objective image noise of 23.42 HU. The EDs for groups 1, 2, 3 and 4 were 2.79 ± 1.17, 1.69 ± 0.59, 0.74 ± 0.29, and 0.37 ± 0.22 mSv, respectively. Compared to group 1 (NI = 15, the ED reductions were 39.43%, 73.48%, and 86.74% for groups 2, 3, and 4, respectively.Using NI = 30 with 50% ASIR in the chest CT protocol, we obtained average or above-average image quality but a reduced ED.

  10. Combining automatic tube current modulation with adaptive statistical iterative reconstruction for low-dose chest CT screening.

    Science.gov (United States)

    Chen, Jiang-Hong; Jin, Er-Hu; He, Wen; Zhao, Li-Qin

    2014-01-01

    To reduce radiation dose while maintaining image quality in low-dose chest computed tomography (CT) by combining adaptive statistical iterative reconstruction (ASIR) and automatic tube current modulation (ATCM). Patients undergoing cancer screening (n = 200) were subjected to 64-slice multidetector chest CT scanning with ASIR and ATCM. Patients were divided into groups 1, 2, 3, and 4 (n = 50 each), with a noise index (NI) of 15, 20, 30, and 40, respectively. Each image set was reconstructed with 4 ASIR levels (0% ASIR, 30% ASIR, 50% ASIR, and 80% ASIR) in each group. Two radiologists assessed subjective image noise, image artifacts, and visibility of the anatomical structures. Objective image noise and signal-to-noise ratio (SNR) were measured, and effective dose (ED) was recorded. Increased NI was associated with increased subjective and objective image noise results (PASIR levels (PASIR had average subjective image noise scores and nearly average anatomical structure visibility scores, with a mean objective image noise of 23.42 HU. The EDs for groups 1, 2, 3 and 4 were 2.79 ± 1.17, 1.69 ± 0.59, 0.74 ± 0.29, and 0.37 ± 0.22 mSv, respectively. Compared to group 1 (NI = 15), the ED reductions were 39.43%, 73.48%, and 86.74% for groups 2, 3, and 4, respectively. Using NI = 30 with 50% ASIR in the chest CT protocol, we obtained average or above-average image quality but a reduced ED.

  11. Non-enhanced CT versus contrast-enhanced CT in integrated PET/CT studies for nodal staging of rectal cancer

    International Nuclear Information System (INIS)

    Tateishi, Ukihide; Maeda, Tetsuo; Morimoto, Tsuyoshi; Miyake, Mototaka; Arai, Yasuaki; Kim, E.E.

    2007-01-01

    The purpose of the present study was to determine the diagnostic accuracy of non-enhanced CT and contrast-enhanced CT in integrated PET/CT studies for preoperative nodal staging of rectal cancer. Retrospective analysis was performed in 53 patients with pathologically proven rectal cancer who had been referred for preoperative staging. All patients underwent integrated PET/CT consisting of non-enhanced and contrast-enhanced CT followed by whole-body fluorine-18-fluorodeoxyglucose ([ 18 F]FDG) PET. Both non-enhanced and contrast-enhanced PET/CT images were evaluated separately by two observers in consensus. The reference standard was histopathologic results. For nodal staging of rectal cancer, we compared diagnostic accuracy on a per-patient basis between the two modalities. Nodal staging was correctly determined with non-enhanced studies in 37 patients (70%) and with contrast-enhanced studies in 42 patients (79%). On a per-patient basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging were 85%, 68%, 83%, 72%, and 79%, respectively, with contrast-enhanced studies, and 85%, 42%, 73%, 62%, and 70%, respectively, with non-enhanced studies. The difference in the accuracy of nodal staging between the two modalities was not significant (p = 0.063). Compared with non-enhanced studies, contrast-enhanced studies determined more correctly the status of pararectal lymph nodes (p 0.002), internal iliac lymph nodes (p = 0.004), and obturator lymph nodes (p < 0.0001). Contrast-enhanced PET/CT is superior to non-enhanced PET/CT for precise definition of regional nodal status in rectal cancer. (orig.)

  12. Patient dosimetry study of a paediatric CT examination

    International Nuclear Information System (INIS)

    Hranitzky, C.; Stadtmann, H.

    2011-01-01

    Dosimetry studies are of increasing interest in diagnostic high-dose applications such as computed tomography especially for examinations of children. A routine CT scan protocol for paediatric head and neck imaging was investigated at a new multi-detector CT scanner using LiF:Mg,Cu,P thermoluminescence dosemeters (TLDs) and a 0.125 cm 3 thimble ionization chamber. Calibrations of the detectors in terms of absorbed dose to water were carried out at the Dosimetry Laboratory Seibersdorf in standard radiation fields. The dosimetry method was validated in the spiral CT X-ray field by comparing TLD and ionization chamber measurement results in cylindrical PMMA phantoms. Absorbed dose results were within stated uncertainties. An anthropomorphic phantom representing a child of about 5 years was loaded with TLD chips at various organ and tissue positions in the head and neck region as well as at some critical organ locations. Organ dose values were calculated from TLD based average absorbed dose with about 5% total uncertainty, e.g. 22 mGy (eyes), 21 mGy (thyroid), 19 mGy (brain), 3.4 mGy (thymus), and 0.03 mGy (testes). For comparison purposes an effective dose of 1.9 mSv was estimated for the investigated paediatric CT examination based on ICRP-103 age-independent tissue-weighting factors.

  13. Normal development of paranasal sinuses in children: A CT study

    International Nuclear Information System (INIS)

    Kim, Hyung Jin; Park, Eui Dong; Choi, Pil Youb; Kim, Jae Hyoung; Chung, Sung Hoon; Chung, Hae Gyeong

    1993-01-01

    To evaluate the normal development of the paranasal sinuses in children with CT, authors prospectively studied with brain CT scans of 260 children without known sinus disease, ranging image from 7 days to 16 years. Maximal anteroposterior and transverse diameters(mm) and maximal cross- sectional area(mm 2 ) of both sides of the maxillary sinus were measured with the aid of computer device. As to the ethmoidal and spheroidal sinuses, we simply documented the presence of the aplastic ethmoidal sinus and calculated the age-incidence of the spheroidal sinus pneumatization, respectively.There noted three phases in the development of the maxillary sinus. The anteroposterior and transverse diameters of the maxillary sinus increased nearly in parallel. The former was always greater than the latter. In no cases was the edathamil sinus aplastic and almost all sinuses were pneumatized even in infants as early as 7 old days. CT identified the conchal pattern of sphenoidal sinus pneumatization infants as early as 11 days old. Sphenoidal sinus pneumatization was seen in 38% of the children under the age of 1 year, 82% of the children between the age of 1 and 2 years, and almost all children older than 2 years. The anteroposterior and transverse diameters of the maxillary sinus seem to reach the adult size by 8 years of age, and the conchal pattern of sphemoidal sinus pneumatization can be recognized earlier with CT than on the plain radiographs

  14. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Wille, Mathilde Marie Winkler

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure...... that will yield improvements in both diagnosis and treatment. The standard-of-care surgical treatment of early lung cancer is still minimally invasive lobectomy with systematic lymph node dissection. However, recent research has shown that some GGO lesions may be treated with sublobar resections; these findings......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...

  15. CT colonography with rectal iodine tagging: Feasibility and comparison with oral tagging in a colorectal cancer screening population

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele, E-mail: emanuele.neri@med.unipi.it [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy); Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy); D’Ippolito, Giuseppe [Federal University of São Paulo – Sena Madureira 1500 – Vila Mariana, UNIFESP, São Paulo, SP (Brazil); Bartolozzi, Carlo [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy)

    2015-09-15

    Highlights: • In the group receiving rectal tagging, mean per-polyp sensitivity, specificity were 96.1% and 95.3%; while in the group receiving oral tagging, mean per-polyp sensitivity, specificity were 89.4% and 95.8%. The difference between the two groups was not statistically significant (p = 0.549). • Rectal tagging can be an effective alternative to oral tagging. • Rectal tagging allowed greater patient acceptance and lower overall examination time. - Abstract: Purpose: To evaluate feasibility, diagnostic performance, patient acceptance, and overall examination time of CT colonography (CTC) performed through rectal administration of iodinated contrast material. Materials and methods: Six-hundred asymptomatic subjects (male:female = 270:330; mean 63 years) undergoing CTC for colorectal cancer screening on an individual basis were consecutively enrolled in the study. Out of them, 503 patients (group 1) underwent CTC with rectal tagging, of which 55 had a total of 77 colonic lesions. The remaining 97 patients (group 2) were randomly selected to receive CTC with oral tagging of which 15 had a total of 20 colonic lesions. CTC findings were compared with optical colonoscopy, and per-segment image quality was visually assessed using a semi-quantitative score (1 = poor, 2 = adequate, 3 = excellent). In 70/600 patients (11.7%), CTC was performed twice with both types of tagging over a 5-year follow-up cancer screening program. In this subgroup, patient acceptance was rated via phone interview two weeks after CTC using a semi-quantitative scale (1 = poor, 2 = fair, 3 = average, 4 = good, 5 = excellent). Results: Mean per-polyp sensitivity, specificity, positive and negative predictive values of CTC with rectal vs oral tagging were 96.1% (CI{sub 95%} 85.4 ÷ 99.3%) vs 89.4% (CI{sub 95%} 65.4 ÷ 98.1%), 95.3% (CI{sub 95%} 90.7 ÷ 97.8%) vs 95.8% (CI{sub 95%} 87.6 ÷ 98.9%), 86.0% (CI{sub 95%} 73.6 ÷ 93.3) vs 85.0% (CI{sub 95%} 61.1 ÷ 96.0%), and 98.8% (CI{sub 95

  16. CT colonography with rectal iodine tagging: Feasibility and comparison with oral tagging in a colorectal cancer screening population

    International Nuclear Information System (INIS)

    Neri, Emanuele; Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca; D’Ippolito, Giuseppe; Bartolozzi, Carlo

    2015-01-01

    Highlights: • In the group receiving rectal tagging, mean per-polyp sensitivity, specificity were 96.1% and 95.3%; while in the group receiving oral tagging, mean per-polyp sensitivity, specificity were 89.4% and 95.8%. The difference between the two groups was not statistically significant (p = 0.549). • Rectal tagging can be an effective alternative to oral tagging. • Rectal tagging allowed greater patient acceptance and lower overall examination time. - Abstract: Purpose: To evaluate feasibility, diagnostic performance, patient acceptance, and overall examination time of CT colonography (CTC) performed through rectal administration of iodinated contrast material. Materials and methods: Six-hundred asymptomatic subjects (male:female = 270:330; mean 63 years) undergoing CTC for colorectal cancer screening on an individual basis were consecutively enrolled in the study. Out of them, 503 patients (group 1) underwent CTC with rectal tagging, of which 55 had a total of 77 colonic lesions. The remaining 97 patients (group 2) were randomly selected to receive CTC with oral tagging of which 15 had a total of 20 colonic lesions. CTC findings were compared with optical colonoscopy, and per-segment image quality was visually assessed using a semi-quantitative score (1 = poor, 2 = adequate, 3 = excellent). In 70/600 patients (11.7%), CTC was performed twice with both types of tagging over a 5-year follow-up cancer screening program. In this subgroup, patient acceptance was rated via phone interview two weeks after CTC using a semi-quantitative scale (1 = poor, 2 = fair, 3 = average, 4 = good, 5 = excellent). Results: Mean per-polyp sensitivity, specificity, positive and negative predictive values of CTC with rectal vs oral tagging were 96.1% (CI 95% 85.4 ÷ 99.3%) vs 89.4% (CI 95% 65.4 ÷ 98.1%), 95.3% (CI 95% 90.7 ÷ 97.8%) vs 95.8% (CI 95% 87.6 ÷ 98.9%), 86.0% (CI 95% 73.6 ÷ 93.3) vs 85.0% (CI 95% 61.1 ÷ 96.0%), and 98.8% (CI 95% 95.3 ÷ 99.8%) vs 97.2% (CI 95% 89

  17. Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Adrian [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); University Hospital Pitie-Salpetriere, Department of Polyvalent and Oncological Radiology, Paris (France); Landau, Julia; Buetikofer, Yanik; Leidolt, Lars; Brela, Barbara; May, Michelle; Heverhagen, Johannes; Christe, Andreas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Ebner, Lukas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2016-10-15

    To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions. In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs. The detection rate was 95.5 % with standard dose (DLP 126 mGy*cm) and 93.3 % with ultralow-dose (DLP: 9 mGy*cm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose. Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible. (orig.)

  18. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, Division of Medicine, London (United Kingdom); Ghanouni, Alex; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Rees, Colin J. [Durham University School of Medicine, Pharmacy and Health, Durham (United Kingdom); Hewitson, Paul [University of Oxford, Health Services Research Unit, Nuffield Department of Population Health, Oxford (United Kingdom); Nickerson, Claire; Wright, Suzanne [Fulwood House, NHS Cancer Screening Programmes, Sheffield (United Kingdom)

    2017-03-15

    To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as complications. CTC and colonoscopy responses were compared using multilevel logistic regression. Of 67,114 subjects identified, 52,805 (79 %) responded. Understanding of test risks was lower for CTC (1712/1970 = 86.9 %) than colonoscopy (48783/50975 = 95.7 %, p < 0.0001). Overall, a slightly greater proportion of screenees found CTC unexpectedly uncomfortable (506/1970 = 25.7 %) than colonoscopy (10,705/50,975 = 21.0 %, p < 0.0001). CTC was tolerated well as a completion procedure for failed colonoscopy (unexpected discomfort; CTC = 26.3 %: colonoscopy = 57.0 %, p < 0.001). Post-procedural pain was equally common (CTC: 288/1970,14.6 %, colonoscopy: 7544/50,975,14.8 %; p = 0.55). Adverse event rates were similar in both groups (CTC: 20/2947 = 1.2 %; colonoscopy: 683/64,312 = 1.1 %), but generally less serious with CTC. Even though CTC was reserved for individuals either unsuitable for or unable to complete colonoscopy, we found only small differences in test-related discomfort. CTC was well tolerated as a completion procedure and was extremely safe. CTC can be delivered across a national screening programme with high patient satisfaction. (orig.)

  19. Inquiry about the uses of special equipment (CT equipment, angiography systems, mammography devices, screens)

    International Nuclear Information System (INIS)

    Schwager, P.; Stieve, F.E.

    1986-01-01

    There are at least 1100 special devices in medical establishment in Bavaria which require special inspection and surveillance with regard to quality of equipment and radiation protection. In addition, there are at least 53 tomographs available for operation, and at least 120 installed X-ray screens. These devices need special approval testing and quality control services as they contribute a very significant amount of the medically indicated radiation exposure of the population. Appropriate measures are explained that can be applied in order to reduce the medical radiation exposure to an optimum. (orig.) [de

  20. 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)

  1. Automated docking screens: a feasibility study.

    Science.gov (United States)

    Irwin, John J; Shoichet, Brian K; Mysinger, Michael M; Huang, Niu; Colizzi, Francesco; Wassam, Pascal; Cao, Yiqun

    2009-09-24

    Molecular docking is the most practical approach to leverage protein structure for ligand discovery, but the technique retains important liabilities that make it challenging to deploy on a large scale. We have therefore created an expert system, DOCK Blaster, to investigate the feasibility of full automation. The method requires a PDB code, sometimes with a ligand structure, and from that alone can launch a full screen of large libraries. A critical feature is self-assessment, which estimates the anticipated reliability of the automated screening results using pose fidelity and enrichment. Against common benchmarks, DOCK Blaster recapitulates the crystal ligand pose within 2 A rmsd 50-60% of the time; inferior to an expert, but respectrable. Half the time the ligand also ranked among the top 5% of 100 physically matched decoys chosen on the fly. Further tests were undertaken culminating in a study of 7755 eligible PDB structures. In 1398 cases, the redocked ligand ranked in the top 5% of 100 property-matched decoys while also posing within 2 A rmsd, suggesting that unsupervised prospective docking is viable. DOCK Blaster is available at http://blaster.docking.org .

  2. Non- or full-laxative CT colonography vs. endoscopic tests for colorectal cancer screening: A randomised survey comparing public perceptions and intentions to undergo testing

    Energy Technology Data Exchange (ETDEWEB)

    Ghanouni, Alex; Wardle, Jane; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Halligan, Steve; Plumb, Andrew; Boone, Darren [University College London, Centre for Medical Imaging, London (United Kingdom)

    2014-07-15

    Compare public perceptions and intentions to undergo colorectal cancer screening tests following detailed information regarding CT colonography (CTC; after non-laxative preparation or full-laxative preparation), optical colonoscopy (OC) or flexible sigmoidoscopy (FS). A total of 3,100 invitees approaching screening age (45-54 years) were randomly allocated to receive detailed information on a single test and asked to return a questionnaire. Outcomes included perceptions of preparation and test tolerability, health benefits, sensitivity and specificity, and intention to undergo the test. Six hundred three invitees responded with valid questionnaire data. Non-laxative preparation was rated more positively than enema or full-laxative preparations [effect size (r) = 0.13 to 0.54; p < 0.0005 to 0.036]; both forms of CTC and FS were rated more positively than OC in terms of test experience (r = 0.26 to 0.28; all p-values < 0.0005). Perceptions of health benefits, sensitivity and specificity (p = 0.250 to 0.901), and intention to undergo the test (p = 0.213) did not differ between tests (n = 144-155 for each test). Despite non-laxative CTC being rated more favourably, this study did not find evidence that offering it would lead to substantially higher uptake than full-laxative CTC or other methods. However, this study was limited by a lower than anticipated response rate. (orig.)

  3. Preliminary study of the scan-delay-time during the combined examation of CT perfusion and CT angiography after contrast media administration in cerebral and cervical CT angiography

    International Nuclear Information System (INIS)

    Cai Wu; Gong Jianping; Zhu Jiangtao; Qiao Fang; Chen Guangqiang; Zhang Bo; Yi Bixing; Qian Minghui

    2010-01-01

    Objective: To discuss the feasibility of the time to peak of cerebral CT perfusion (CTP) in predicting the scan-delay-time after contrast media administration in cerebral and cervical CT angiography (CTA). Methods: Retrospective Analysis was performed in eighty patients who had been examined with cerebral and cervical CTA, they were divided randomly into two groups. Group A:40 patients were performed by the method of experience of 20 seconds as scan-delay-time. Group B:the other 40 patients were examined with the combination scanning technology of CTP-CTA. They were all measured with enhancement value of CT in the M1 segment of left middle cerebral artery, superior sagittal sinus , left common carotid artery adjacent to the fourth cervical vertebrace and internal jugular vein, and then calculate the difference between the arterys and the veins in the same layer. Statistical significance was determined with t test. Results: (1)The enhancement value of CT in the cerebral and cervical artery vessels and the resolving power between the arterys and the veins in the same layer of group B were higher than that in group A. (2) Group B whose cerebral and cervical artery vessels rescontructed from the raw CT data set showed clearly; There were an advance in 3 cases (7.5%), a delay in 5 cases (12.5%) in group A whose cerebral and cervical artery vessels rescontructed from the raw CT data set didn't show clearly.Conclusion It's a satisfactory method based on successful cerebral and cervical CTA study to take the time to peak in CT perfusion as the scan-delay-time during the combined examination of CTP and CTA with 64-detector spiral CT. (authors)

  4. Indications for chest CT. Retrospective study of cases with normal chest CT

    International Nuclear Information System (INIS)

    Obata, Shiro

    1995-01-01

    The usefulness of computed tomography (CT) in thoracic radiology is now well appreciated, and the number of chest CTs has greatly increased. There are, however, many chest CT cases that are completely or almost completely normal. Indications for chest CT should be re-evaluated considering the cost and radiation exposure associated with the examination. Reviewing the reports of 4930 chest CT examinations performed in three hospitals during the period of two years, the author found 620 (12.6%) negative CT examinations. In 312 of the 620, the CT was requested because of 'abnormal shadow' on chest radiograph. When the same chest radiographs were re-evaluated by two radiologists, no abnormality was noted in 257 cases (82.4%). CT examinations were considered justified in only 55 cases (17.6%). There was a significant difference in the frequency of normal chest CT examinations between the university hospital and two other hospitals. The causes of false positive interpretation of chest radiographs were analyzed, and it was felt that fundamental knowledge necessary to interpret chest radiographs was lacking. The importance of close cooperation between clinicians and radiologists should be emphasized. (author)

  5. CT study in senile dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Ryoichi; Otomo, Eiichi [Yokufukai Geriatric Hospital, Tokyo (Japan)

    1989-10-01

    In order to evaluate the utility of cranial CT in diagnosis of senile dementia of Alzheimer type (SDAT), various CT findings were studied. CT scans of 62 cases of SDAT (83{plus minus}6 years old) were compared with those of 357 aged cases (means 78{plus minus}8 years old) without psychiatric and/or neurological illness (NC). To evaluate CT findings linear measurements of the ventricle, observation of sulci, brain atrophy ranking of microscopic observation were compared along with presence of periventricular lucency. When SDAT were compared with NC, the cases were divided into two groups by the age (the eighth decade, 80 years old or over) to avoid the influence of physiological brain atrophy. In SDAT there was a positive correlation between the volume of the lateral ventricle in autopsy brain and each index which demonstrates the size of the lateral ventricle on CT. In SDAT the incidence of cases with degree III or more was significantly higher than that in NC. It was 82.6% in SDAT, 15.7% in NC in the eighth decade and 92.3% in SDAT, 32.1% in NC in 80 years or over. The mean values of indexes of lateral ventricle enlargement in SDAT increased more than those in NC. In the eighth decade the mean lateral body ratio was 33.8% in SDAT, and 27.0% in NC and in 80 years or over, it was 33.1% in SDAT, 28.1% in NC. The differences between SDAT and NC were statistically significant. In SDAT the incidence of PVL was significantly higher than in NC. The mean maximum width of Sylvian fissure in SDAT was significantly larger than those in NC. However, the width of cingulate sulcus and central sulcus in SDAT were similar to those of NC. Brain atrophy ranking tended to increase with aging in SDAT, but this tendency was less clear than that in NC. In SDAT temporal atrophy was more significant than the other areas. Overall, CT revealed that brain atrophy in stage III patients was more remarkable than that in stage II patients.

  6. CT study in senile dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Yoshida, Ryoichi; Otomo, Eiichi

    1989-01-01

    In order to evaluate the utility of cranial CT in diagnosis of senile dementia of Alzheimer type (SDAT), various CT findings were studied. CT scans of 62 cases of SDAT (83±6 years old) were compared with those of 357 aged cases (means 78±8 years old) without psychiatric and/or neurological illness (normal control NC). The methods of evaluating CT findings were linear measurements of the ventricle, observation of sulci, brain atrophy ranking of microscopic observation, and presence of periventricular lucency. When SDAT were compared with NC, the cases were divided into two groups by the age (the eighth decade, 80 years old or over) to avoid the influence of physiological brain atrophy. In SDAT there was a positive correlation between the volume of the lateral ventricle in autopsy brain and each index which demonstrates the size of the lateral ventricle on CT. In SDAT the incidence of cases with degree III or more was significantly higher than that in NC. It was 82.6% in SDAT, 15.7% in NC in the eighth decade and 92.3% in SDAT, 32.1% in NC in 80 years or over. The mean values of indexes of lateral ventricle enlargement in SDAT increased more than those in NC significantly. In the eighth decade the mean lateral body ratio was 33.8% in SDAT, and 27.0% in NC and in 80 years or over, it was 33.1% in SDAT, 28.1% in NC. The differences between SDAT and NC were statistically significant. In SDAT the incidence of PVL was significantly higher than in NC. The mean maximum width of Sylvian fissure in SDAT was significantly larger than those in NC. However, the width of cingulate sulcus and central sulcus in SDAT were similar to those of NC. Brain atrophy ranking tended to increase with aging in SDAT, but this tendency was less clear than that in NC. In SDAT temporal atrophy was significantly remarkable than the other areas. Overall, CT revealed that brain atrophy in stage III patients was more remarkable than that in stage II patients. (J.P.N.)

  7. CT study of avascular necrosis of femoral head in adults

    International Nuclear Information System (INIS)

    Liu Jihua; Du Yuqing; Xu Aide

    2000-01-01

    Objective: To study the early and new CT signs of avascular necrosis of femoral head in adults. Methods: The CT scans of 127 cases with this condition were analyzed. Results: There were 90 hip joints with femoral head normal in shape, including 67 femoral heads with only high-density sclerosis and 23 ones with high-density and low-density areas. In 111 hip joints, the femoral head was depressed and manifested purely high-density sclerosis in 25 and mixed-density areas in 86. Air-filled cysts appeared in 43 femoral heads. In follow-up cases, the changes in shape and density of femoral head followed some rules. Conclusion: Purely high-density sclerosis is an early sign and is of great diagnostic value combined with its special shape. Air in femoral heads is also a sign of the disease

  8. Incidental physiological sliding hiatal hernia: a single center comparison study between CT with water enema and CT colonography.

    Science.gov (United States)

    Revelli, Matteo; Furnari, Manuele; Bacigalupo, Lorenzo; Paparo, Francesco; Astengo, Davide; Savarino, Edoardo; Rollandi, Gian Andrea

    2015-08-01

    Hiatal hernia is a well-known factor impacting on most mechanisms underlying gastroesophageal reflux, related with the risk of developing complications such as erosive esophagitis, Barrett's esophagus and ultimately, esophageal adenocarcinoma. It is our firm opinion that an erroneous reporting of hiatal hernia in CT exams performed with colonic distention may trigger a consecutive diagnostic process that is not only unnecessary, inducing a unmotivated anxiety in the patient, but also expensive and time-consuming for both the patient and the healthcare system. The purposes of our study were to determine whether colonic distention at CT with water enema and CT colonography can induce small sliding hiatal hernias and to detect whether hiatal hernias size modifications could be considered significant for both water and gas distention techniques. We retrospectively evaluated 400 consecutive patients, 200 undergoing CT-WE and 200 undergoing CTC, including 59 subjects who also underwent a routine abdominal CT evaluation on a different time, used as internal control, while a separate group of 200 consecutive patients who underwent abdominal CT evaluation was used as external control. Two abdominal radiologists assessed the CT exams for the presence of a sliding hiatal hernia, grading the size as small, moderate, or large; the internal control groups were directly compared with the corresponding CT-WE or CTC study looking for a change in hernia size. We used the Student's t test applying a size-specific correction factor, in order to account for the effect of colonic distention: these "corrected" values were then individually compared with the external control group. A sliding hiatal hernia was present in 51 % (102/200) of the CT-WE patients and in 48.5 % (97/200) of the CTC patients. Internal control CT of the 31 patients with a hernia at CT-WE showed resolution of the hernia in 58.1 % (18/31) of patients, including 76.5 % (13/17) and 45.5 % (5/11) of small and moderate

  9. Sheep head frame validation for CT and MRI studies

    Directory of Open Access Journals (Sweden)

    marco trovatelli

    2017-05-01

    Full Text Available Abstract   Introductions Aim of EDEN 2020 project’s Milestone 5 is the development of a steerable catheter for CED system in glioblastoma therapy. The VET group is involved in realization and validation of the proper animal model. Materials and methods In this part of the study two fresh sheep’s head from the local slaughter were used. The heads were located into an ad hoc Frame system based on anatomical measures and CT images, producted by Renishaw plc partner in this project. The frame was adapted and every components were checked for the ex vivo validation tests. CT imaging was taken in Lodi at Università degli studi di Milano, Facoltà di Medicina Veterinaria, with CT scanner and MRI imaging was taken in La Cittadina, Cremona Results System validation was approved by the ex vivo trial. The frame system doesn’t compromise the imaging acquisition in MRI and CT systems. Every system components are functional to their aims. Discussion The Frame system is adapted to the sheep head. It is composed by elements able to lock the head during the imaging acquisition. Frame system is characterized by a support base helpings the animals to keep the head straight forward during imaging time, under general anesthesia. The design of these device support the airways anatomy, avoiding damaging or obstruction of airflows during anesthesia period. The role of elements like mouth bar and ovine head pins is to lock the head in a stable position during imaging acquisition; fixing is guaranteed by V shape head pins, that are arranged against the zygomatic arches. Lateral compression forces to the cranium, and the V shape pins avoid the vertical shifting of the head and any kind of rotations. (fig. 1

  10. An experimental study on the noise properties of x-ray CT sinogram data in Radon space

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jing; Liang Zhengrong; Eremina, Daria; Wang Su; Manzione, James [Department of Radiology, State University of New York, Stony Brook, NY 11794 (United States); Lu Hongbing [Department of Biomedical Engineering, Fourth Military Medical University, Xi' An, Shaanxi 710032 (China); Zhang Guangxiang; Chen, John [Department of Preventive Medicine, State University of New York, Stony Brook, NY 11794 (United States)], E-mail: jerome.liang@sunysb.edu

    2008-06-21

    Computed tomography (CT) has been well established as a diagnostic tool through hardware optimization and sophisticated data calibration. For screening purposes, the associated x-ray exposure risk must be minimized. An effective way to minimize the risk is to deliver fewer x-rays to the subject or lower the mAs parameter in data acquisition. This will increase the data noise. This work aims to study the noise property of the calibrated or preprocessed sinogram data in Radon space as the mAs level decreases. An anthropomorphic torso phantom was scanned repeatedly by a commercial CT imager at five different mAs levels from 100 down to 17 (the lowest value provided by the scanner). The preprocessed sinogram datasets were extracted from the CT scanner to a laboratory computer for noise analysis. The repeated measurements at each mAs level were used to test the normality of the repeatedly measured samples for each data channel using the Shapiro-Wilk statistical test merit. We further studied the probability distribution of the repeated measures. Most importantly, we validated a theoretical relationship between the sample mean and variance at each channel. It is our intention that the statistical test and particularly the relationship between the first and second statistical moments will improve low-dose CT image reconstruction for screening applications.

  11. Cone-beam volume CT mammographic imaging: feasibility study

    Science.gov (United States)

    Chen, Biao; Ning, Ruola

    2001-06-01

    X-ray projection mammography, using a film/screen combination or digital techniques, has proven to be the most effective imaging modality for early detection of breast cancer currently available. However, the inherent superimposition of structures makes small carcinoma (a few millimeters in size) difficult to detect in the occultation case or in dense breasts, resulting in a high false positive biopsy rate. The cone-beam x-ray projection based volume imaging using flat panel detectors (FPDs) makes it possible to obtain three-dimensional breast images. This may benefit diagnosis of the structure and pattern of the lesion while eliminating hard compression of the breast. This paper presents a novel cone-beam volume CT mammographic imaging protocol based on the above techniques. Through computer simulation, the key issues of the system and imaging techniques, including the x-ray imaging geometry and corresponding reconstruction algorithms, x-ray characteristics of breast tissues, x-ray setting techniques, the absorbed dose estimation and the quantitative effect of x-ray scattering on image quality, are addressed. The preliminary simulation results support the proposed cone-beam volume CT mammographic imaging modality in respect to feasibility and practicability for mammography. The absorbed dose level is comparable to that of current two-view mammography and would not be a prominent problem for this imaging protocol. Compared to traditional mammography, the proposed imaging protocol with isotropic spatial resolution will potentially provide significantly better low contrast detectability of breast tumors and more accurate location of breast lesions.

  12. Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Ridley Kate

    2010-12-01

    Full Text Available Abstract Background Much attention has been paid to adolescents' screen time, however very few studies have examined non-screen sedentary time (NSST. This study aimed to (1 describe the magnitude and composition of screen sedentary time (SST and NSST in Australian adolescents, (2 describe the socio-demographic correlates of SST and NSST, and (3 determine whether screen time is an adequate surrogate for total sedentary behaviour in this population. Methods 2200 9-16 year old Australians provided detailed use of time data for four days. Non-screen sedentary time (NSST included time spent participating in activities expected to elicit Results Adolescents spent a mean (SD of 345 (105 minutes/day in NSST, which constituted 60% of total sedentary time. School activities contributed 42% of NSST, socialising 19%, self-care (mainly eating 16%, and passive transport 15%. Screen time and NSST showed opposite patterns in relation to key socio-demographic characteristics, including sex, age, weight status, household income, parental education and day type. Because screen time was negatively correlated with NSST (r = -0.58, and exhibited a moderate correlation (r = 0.53 with total sedentary time, screen time was only a moderately effective surrogate for total sedentary time. Conclusions To capture a complete picture of young people's sedentary time, studies should endeavour to measure both screen time and NSST.

  13. Ultra-low-dose lung screening CT with model-based iterative reconstruction: an assessment of image quality and lesion conspicuity.

    Science.gov (United States)

    Ju, Yun Hye; Lee, Geewon; Lee, Ji Won; Hong, Seung Baek; Suh, Young Ju; Jeong, Yeon Joo

    2018-05-01

    Background Reducing radiation dose inevitably increases image noise, and thus, it is important in low-dose computed tomography (CT) to maintain image quality and lesion detection performance. Purpose To assess image quality and lesion conspicuity of ultra-low-dose CT with model-based iterative reconstruction (MBIR) and to determine a suitable protocol for lung screening CT. Material and Methods A total of 120 heavy smokers underwent lung screening CT and were randomly and equally assigned to one of five groups: group 1 = 120 kVp, 25 mAs, with FBP reconstruction; group 2 = 120 kVp, 10 mAs, with MBIR; group 3 = 100 kVp, 15 mAs, with MBIR; group 4 = 100 kVp, 10 mAs, with MBIR; and group 5 = 100 kVp, 5 mAs, with MBIR. Two radiologists evaluated intergroup differences with respect to radiation dose, image noise, image quality, and lesion conspicuity using the Kruskal-Wallis test and the Chi-square test. Results Effective doses were 61-87% lower in groups 2-5 than in group 1. Image noises in groups 1 and 5 were significantly higher than in the other groups ( P image quality was best in group 1, but diagnostic acceptability of overall image qualities in groups 1-3 was not significantly different (all P values > 0.05). Lesion conspicuities were similar in groups 1-4, but were significantly poorer in group 5. Conclusion Lung screening CT with MBIR obtained at 100 kVp and 15 mAs enables a ∼60% reduction in radiation dose versus low-dose CT, while maintaining image quality and lesion conspicuity.

  14. CT-guided suprascapular nerve blocks: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Schneider-Kolsky, M.E.; Pike, J.; Connell, D.A. [Department of Medical Imaging, Victoria House Private Hospital, 316 Malvern Road, Prahran 3181, Melbourne, Victoria (Australia)

    2004-05-01

    The objective of this study was to describe the suprascapular nerve block using CT guidance and to evaluate the short- and medium-term efficacy in a range of shoulder pathologies. CT-guided infiltration around the suprascapular nerve was performed with bupivacaine and Celestone Chronodose on 40 consecutive patients presenting with chronic shoulder pathologies unresponsive to conventional treatment. Patients were interviewed using the Shoulder Pain and Disability Index (SPADI) before the procedure, 30 min after the procedure and at 3 days, 3 weeks and 6 weeks afterwards. Within 30 min of the block overall pain scores decreased from a mean ({+-}SEM) pain score of 7.0 ({+-}0.4) to 3.5 ({+-}0.5) (n=39, P<0.001). At 3 days after the procedure, the mean overall improvement of the pain and disability scores were 20.4% ({+-}4.9, P<0.001) and 16.8% ({+-}4.8, P=0.004) respectively. Sustained pain relief and reduced disability were achieved in 10 of 35 (29%) patients at 3 weeks and longer. Patients suffering from soft tissue pathologies were the most likely patients to benefit from the injection. No serious side effects were noted. In some patients with chronic soft tissue pathologies who do not respond to conventional treatment, a CT-guided suprascapular nerve block can provide safe short- and medium-term relief from pain and disability. (orig.)

  15. CT-guided suprascapular nerve blocks: a pilot study

    International Nuclear Information System (INIS)

    Schneider-Kolsky, M.E.; Pike, J.; Connell, D.A.

    2004-01-01

    The objective of this study was to describe the suprascapular nerve block using CT guidance and to evaluate the short- and medium-term efficacy in a range of shoulder pathologies. CT-guided infiltration around the suprascapular nerve was performed with bupivacaine and Celestone Chronodose on 40 consecutive patients presenting with chronic shoulder pathologies unresponsive to conventional treatment. Patients were interviewed using the Shoulder Pain and Disability Index (SPADI) before the procedure, 30 min after the procedure and at 3 days, 3 weeks and 6 weeks afterwards. Within 30 min of the block overall pain scores decreased from a mean (±SEM) pain score of 7.0 (±0.4) to 3.5 (±0.5) (n=39, P<0.001). At 3 days after the procedure, the mean overall improvement of the pain and disability scores were 20.4% (±4.9, P<0.001) and 16.8% (±4.8, P=0.004) respectively. Sustained pain relief and reduced disability were achieved in 10 of 35 (29%) patients at 3 weeks and longer. Patients suffering from soft tissue pathologies were the most likely patients to benefit from the injection. No serious side effects were noted. In some patients with chronic soft tissue pathologies who do not respond to conventional treatment, a CT-guided suprascapular nerve block can provide safe short- and medium-term relief from pain and disability. (orig.)

  16. PET/CT and contrast enhanced CT in single vs. two separate sessions: a cost analysis study.

    Science.gov (United States)

    Picchio, M; Mansueto, M; Crivellaro, C; Guerra, L; Marcelli, S; Arosio, M; Sironi, S; Gianolli, L; Grimaldi, A; Messa, C

    2012-06-01

    Aim of the study was to quantify the economic impact of PET/CT and contrast enhanced (c.e.) CT performed in a single session examination vs. stand-alone modalities in oncological patients. One-hundred-forty-five cancer patients referred to both PET/CT and c.e. CT, to either stage (N.=46) or re-stage (N.=99) the disease, were included. Seventy-two/145 performed both studies in a single session (innovative method) and 73/145 in two different sessions (traditional method). The cost-minimization analysis was performed by evaluating: 1) institutional costs, data obtained by hospital accountability (staff, medical materials, equipment maintenance and depreciation, departments utilities); 2) patients costs, data obtained by a specific survey provided to patients (travel, food, accommodation costs, productivity loss). Economic data analysis showed that the costs for innovative method was lower than those of traditional method, both for Institution (106 € less per test) and for patient (21 € less per patient). The loss of productivity for patient and caregivers resulted lower for the innovative method than the traditional method (3 work-hour less per person). PET/CT and c.e. CT performed in a single session is more cost-effective than stand-alone modalities, by reducing both Institutional and patients costs. These advantages are mainly due to lower Institutional cost (single procedure) and to lower cost related to travel and housing.

  17. Breast cancer screening: An outpatient clinic study

    Directory of Open Access Journals (Sweden)

    Mustafa Girgin

    2017-03-01

    Conclusion: A multidisciplinary cancer screening program should be maintained. With such a process, the aim is to reduce the morbidity and mortality of the disease without adversely affecting the health conditions of asymptomatic individuals based on the screening. Success is brought about by the combination of individual features. [Arch Clin Exp Surg 2017; 6(1.000: 23-27

  18. Spent-fuel-stabilizer screening studies

    International Nuclear Information System (INIS)

    Wynhoff, N.; Girault, S.E.; Fish, R.L.

    1980-11-01

    A broad range of potential stabilizer materials was identified and screened for packaging spent fuel assemblies for underground storage. The screening took into consideration the thermal gradient, stress, differential thermal expansion, nuclear criticality, radiation shielding, cost, and availability. Recommended stabilizer materials for further testing include silica, quartz, mullite, zircon, bentonite, graphite, gases, lead, Zn alloys, Cu alloys, etc

  19. HERCA WG Medical Applications / WP justification. Survey about the situation in Europe regarding the use of CT on asymptomatic individuals outside screening programs

    International Nuclear Information System (INIS)

    2013-06-01

    In recent years, commercial services offering CT scans to individuals for the detection of lung, cardiac and colorectal disease has been reported in the USA and in some parts of Europe (e.g. Germany and the UK). Some of these private services are associated with aggressive advertisement and are in conflict with the general principle of justification. Faced with this situation, in July 2012, HERCA WG Medical Applications launched a survey about the situation in Europe regarding the use of CT on asymptomatic individuals outside screening programs for group 2.c. This document presents the results of the survey

  20. [Economic impact of lung cancer screening in France: A modeling study].

    Science.gov (United States)

    Gendarme, S; Perrot, É; Reskot, F; Bhoowabul, V; Fourre, G; Souquet, P-J; Milleron, B; Couraud, S

    2017-09-01

    The National Lung Screening Trial found that, in a selected population with a high risk of lung cancer, an annual low-dose CT-scan decreased lung cancer mortality by 20% and overall mortality by 7% compared to annual chest X-Ray. In France, a work group stated that individual screening should be considered in this setting. However, the economic impact of an organized and generalized (to all eligible individuals) screening in France was never reported. This is a modeling study using French population demographic data and published data from randomized screening trials. We used the same selection criteria as NLST: 55-74-year-old smokers for at least 30 pack-years, current smoker or quit less than 15 years. We computed a second model including also 50-54-year-old individuals. Then, we used different participation rates: 65%, 45%, and 32%. According to the considered model, there would be 1,650,588 to 2,283,993 subjects eligible to screening in France. According to the model and participation rate, lung cancer screening would diagnose 3600 to 10,118 stages 1/2 lung cancer each year. There would be 5991 to 16,839 false-positives, of whom 1416 to 3981 would undergo unnecessary surgery. Screening policy would cost 105 to 215 € million per year. However, increasing the price of a cigarette pack by 0.05 to 0.10 € would fully cover the screening costs. Participation rate is a key point for screening impact. Screening could be easily funded by a small increase in cigarette prices. Copyright © 2015 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  1. Optimization of SPECT-CT Hybrid Imaging Using Iterative Image Reconstruction for Low-Dose CT: A Phantom Study.

    Directory of Open Access Journals (Sweden)

    Oliver S Grosser

    Full Text Available Hybrid imaging combines nuclear medicine imaging such as single photon emission computed tomography (SPECT or positron emission tomography (PET with computed tomography (CT. Through this hybrid design, scanned patients accumulate radiation exposure from both applications. Imaging modalities have been the subject of long-term optimization efforts, focusing on diagnostic applications. It was the aim of this study to investigate the influence of an iterative CT image reconstruction algorithm (ASIR on the image quality of the low-dose CT images.Examinations were performed with a SPECT-CT scanner with standardized CT and SPECT-phantom geometries and CT protocols with systematically reduced X-ray tube currents. Analyses included image quality with respect to photon flux. Results were compared to the standard FBP reconstructed images. The general impact of the CT-based attenuation maps used during SPECT reconstruction was examined for two SPECT phantoms. Using ASIR for image reconstructions, image noise was reduced compared to FBP reconstructions for the same X-ray tube current. The Hounsfield unit (HU values reconstructed by ASIR were correlated to the FBP HU values(R2 ≥ 0.88 and the contrast-to-noise ratio (CNR was improved by ASIR. However, for a phantom with increased attenuation, the HU values shifted for low X-ray tube currents I ≤ 60 mA (p ≤ 0.04. In addition, the shift of the HU values was observed within the attenuation corrected SPECT images for very low X-ray tube currents (I ≤ 20 mA, p ≤ 0.001.In general, the decrease in X-ray tube current up to 30 mA in combination with ASIR led to a reduction of CT-related radiation exposure without a significant decrease in image quality.

  2. WE-FG-207A-01: Introduction to Dedicated Breast CT - Early Studies

    International Nuclear Information System (INIS)

    Vedantham, S.

    2016-01-01

    . In diagnostic studies, the median MGD from BCT and mammography were 12.6 and 11.1 mGy, respectively [Vedantham et al., Phys Med Biol. 58: 7921–36, 2013]. Moreover, in diagnostic imaging of the breast the location of the lesion is known and therefore characterization and not detection is by far the primary consideration. The role of bCT is particularly compelling for diagnostic imaging of the breast because it may replace in part the multiple mammographic views of the breast under vigorous compression. Other non-screening potential applications of bCT include the assessment of response to neoadjuvant therapy [Vedantham et al., J Clin Imaging Sci 4, 64, 2014] and pre-surgical evaluation. Learning Objectives: To understand the metrics used to evaluate screening and diagnostic imaging To understand the benefits and limitations of current clinical modalities To understand how breast CT can improve over current clinical modalities To note the early attempts to translate breast CT to the clinic in 1970s-1990s To understand the recent developments in low-dose cone-beam breast CT To understand the recent developments in photon-counting breast CT To understand the radiation dose, clinical translation, and recent developments in diagnostic imaging with breast CT Supported in part by NIH grants R21 CA134128, R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or the NCI.; S. Vedantham, Funding sources: Supported in part by NIH/NCI grants R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH/NCI. Disclosures: Research collaboration with Koning Corporation, West Henrietta, NY. Conflicts of Interest: J. Boone, This research was supported in part by NIH grant R01CA181081; W. Kalender, WK is founder and CEO of CT Imaging GmbH Erlangen, Germany.; A. Karellas, NIH R21 CA134128, R01 CA128906, and R01 CA195512 and

  3. WE-FG-207A-01: Introduction to Dedicated Breast CT - Early Studies

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, S. [University of Massachusetts Medical School (United States)

    2016-06-15

    . In diagnostic studies, the median MGD from BCT and mammography were 12.6 and 11.1 mGy, respectively [Vedantham et al., Phys Med Biol. 58: 7921–36, 2013]. Moreover, in diagnostic imaging of the breast the location of the lesion is known and therefore characterization and not detection is by far the primary consideration. The role of bCT is particularly compelling for diagnostic imaging of the breast because it may replace in part the multiple mammographic views of the breast under vigorous compression. Other non-screening potential applications of bCT include the assessment of response to neoadjuvant therapy [Vedantham et al., J Clin Imaging Sci 4, 64, 2014] and pre-surgical evaluation. Learning Objectives: To understand the metrics used to evaluate screening and diagnostic imaging To understand the benefits and limitations of current clinical modalities To understand how breast CT can improve over current clinical modalities To note the early attempts to translate breast CT to the clinic in 1970s-1990s To understand the recent developments in low-dose cone-beam breast CT To understand the recent developments in photon-counting breast CT To understand the radiation dose, clinical translation, and recent developments in diagnostic imaging with breast CT Supported in part by NIH grants R21 CA134128, R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or the NCI.; S. Vedantham, Funding sources: Supported in part by NIH/NCI grants R01 CA128906 and R01 CA195512. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH/NCI. Disclosures: Research collaboration with Koning Corporation, West Henrietta, NY. Conflicts of Interest: J. Boone, This research was supported in part by NIH grant R01CA181081; W. Kalender, WK is founder and CEO of CT Imaging GmbH Erlangen, Germany.; A. Karellas, NIH R21 CA134128, R01 CA128906, and R01 CA195512 and

  4. Patient and Clinician Perspectives on Shared Decision-making in Early Adopting Lung Cancer Screening Programs: a Qualitative Study.

    Science.gov (United States)

    Wiener, Renda Soylemez; Koppelman, Elisa; Bolton, Rendelle; Lasser, Karen E; Borrelli, Belinda; Au, David H; Slatore, Christopher G; Clark, Jack A; Kathuria, Hasmeena

    2018-02-21

    Guidelines recommend, and Medicare requires, shared decision-making between patients and clinicians before referring individuals at high risk of lung cancer for chest CT screening. However, little is known about the extent to which shared decision-making about lung cancer screening is achieved in real-world settings. To characterize patient and clinician impressions of early experiences with communication and decision-making about lung cancer screening and perceived barriers to achieving shared decision-making. Qualitative study entailing semi-structured interviews and focus groups. We enrolled 36 clinicians who refer patients for lung cancer screening and 49 patients who had undergone lung cancer screening in the prior year. Participants were recruited from lung cancer screening programs at four hospitals (three Veterans Health Administration, one urban safety net). Using content analysis, we analyzed transcripts to characterize communication and decision-making about lung cancer screening. Our analysis focused on the recommended components of shared decision-making (information sharing, deliberation, and decision aid use) and barriers to achieving shared decision-making. Clinicians varied in the information shared with patients, and did not consistently incorporate decision aids. Clinicians believed they explained the rationale and gave some (often purposely limited) information about the trade-offs of lung cancer screening. By contrast, some patients reported receiving little information about screening or its trade-offs and did not realize the CT was intended as a screening test for lung cancer. Clinicians and patients alike did not perceive that significant deliberation typically occurred. Clinicians perceived insufficient time, competing priorities, difficulty accessing decision aids, limited patient comprehension, and anticipated patient emotions as barriers to realizing shared decision-making. Due to multiple perceived barriers, patient

  5. Evaluation of recovery in hydronephrosis using renal functional CT studies

    International Nuclear Information System (INIS)

    Watanabe, Kiyotaka

    1985-01-01

    Using renal functional CT studies, we studied 22 patients who underwent surgical treatment for unilateral hydronephrosis. The tissue-plasma ratio of contrast enhancement (TPR), which is an indicator of renal function per unit of parenchymal volume, improved after the operation. On the other hand, the renal parenchymal volume (PV) decreased in proportion to the shrinkage of the kidney. The pre and postoperative values of renal functional index (RFI), the product of the TPR and PV, showed a good correlation (r=0.928, p<0.01). Therefore, RFI values were found to be useful for assessing the recovery of hydronephrosis. (author)

  6. Usefulness of CT based SPECT Fusion Image in the lung Disease : Preliminary Study

    International Nuclear Information System (INIS)

    Park, Hoon Hee; Lyu, Kwang Yeul; Kim, Tae Hyung; Shin, Ji Yun

    2012-01-01

    Recently, SPECT/CT system has been applied to many diseases, however, the application is not extensively applied at pulmonary disease. Especially, in case that, the pulmonary embolisms suspect at the CT images, SPECT is performed. For the accurate diagnosis, SPECT/CT tests are subsequently undergoing. However, without SPECT/CT, there are some limitations to apply these procedures. With SPECT/CT, although, most of the examination performed after CT. Moreover, such a test procedures generate unnecessary dual irradiation problem to the patient. In this study, we evaluated the amount of unnecessary irradiation, and the usefulness of fusion images of pulmonary disease, which independently acquired from SPECT and CT. Using NEMA PhantomTM (NU2-2001), SPECT and CT scan were performed for fusion images. From June 2011 to September 2010, 10 patients who didn't have other personal history, except lung disease were selected (male: 7, female: 3, mean age: 65.3±12.7). In both clinical patient and phantom data, the fusion images scored higher than SPECT and CT images. The fusion images, which is combined with pulmonary vessel images from CT and functional images from SPECT, can increase the detection possibility in detecting pulmonary embolism in the resin of lung parenchyma. It is sure that performing SPECT and CT in integral SPECT/CT system were better. However, we believe this protocol can give more informative data to have more accurate diagnosis in the hospital without integral SPECT/CT system.

  7. A study of whole brain perfusion CT and CT angiography in hyperacute and acute cerebral infarction

    International Nuclear Information System (INIS)

    Zhang Yonghai; Bai Junhu; Zhang Ming; Yang Guocai; Tang Guibo; Fang Jun; Shi Wei; Li Xinghua; Liu Suping; Lu Qing; Tang Jun

    2005-01-01

    Objective: To evaluate the diagnostic value of whole-brain perfusion blood volume-weighted CT imaging (PWCT) and simultaneous CT angiography (CTA) on early stage of cerebral ischemic infarction. Methods: Non-contrast CT (NCCT), CT perfusion-weighted imaging (PWCT) and delayed CT (DCT) were conducted on 20 cases of early ischemic infarction of whose onset time ranged from 2 to 24 hours. All cases were reexamined with CT or MRI one week to one month later. CT values and perfusion blood volume (PBV) of central and peripheral low perfusion areas as well as those of collateral side were measured. CTA was reconstructed with PWCT as source images to evaluate occlusion or stenosis of blood vessel, and DCT was used to detect the collateral circulation. Results: Of the 20 cases, NCCT, PWCT and CTA were negative in 10 cases in which 6 were confirmed as Transient Ischemic Attack (TIA) on reexamined CT and clinical features, and the other 4 were confirmed as lacunar infarction. For the remaining 10 cases, a comparison was made with ANOVA between low perfusion area (central, peripheral inside and outside) and collateral side. The difference was significant (P<0.01). However, no significant difference was revealed in the central, peripheral inside and outside areas. PBV values were significant in low perfusion area and collateral side (P<0.05). The area of the final infarction was larger than that of the low perfusion area, and the percentage of enlargement exhibited medium negative correlation to the time of ischemia. CTA indicated that 2 cases suffered from left middle cerebral artery occlusion, meanwhile anterior and middle branches of MCA in the other 3 cases were not identified. The sensitivity of NCCT, PWCT and CTA were 28.5%, 71.4% and 35.7% respectively. DCT indicated that 5 cases had asymmetrical blood vessels. Conclusion: The whole-brain perfusion-weighted CT imaging and simultaneous CT angiography (CTA) is p roved to be a simple, timesaving and effective method for the

  8. Adaptive statistical iterative reconstruction reduces patient radiation dose in neuroradiology CT studies

    Energy Technology Data Exchange (ETDEWEB)

    Komlosi, Peter; Zhang, Yanrong; Leiva-Salinas, Carlos; Ornan, David; Grady, Deborah [University of Virginia, Department of Radiology and Medical Imaging, Division of Neuroradiology, PO Box 800170, Charlottesville, VA (United States); Patrie, James T.; Xin, Wenjun [University of Virginia, Department of Public Health Sciences, Charlottesville, VA (United States); Wintermark, Max [University of Virginia, Department of Radiology and Medical Imaging, Division of Neuroradiology, PO Box 800170, Charlottesville, VA (United States); Centre Hospitalier Universitaire Vaudois, Department of Radiology, Lausanne (Switzerland)

    2014-03-15

    Adaptive statistical iterative reconstruction (ASIR) can decrease image noise, thereby generating CT images of comparable diagnostic quality with less radiation. The purpose of this study is to quantify the effect of systematic use of ASIR versus filtered back projection (FBP) for neuroradiology CT protocols on patients' radiation dose and image quality. We evaluated the effect of ASIR on six types of neuroradiologic CT studies: adult and pediatric unenhanced head CT, adult cervical spine CT, adult cervical and intracranial CT angiography, adult soft tissue neck CT with contrast, and adult lumbar spine CT. For each type of CT study, two groups of 100 consecutive studies were retrospectively reviewed: 100 studies performed with FBP and 100 studies performed with ASIR/FBP blending factor of 40 %/60 % with appropriate noise indices. The weighted volume CT dose index (CTDI{sub vol}), dose-length product (DLP) and noise were recorded. Each study was also reviewed for image quality by two reviewers. Continuous and categorical variables were compared by t test and free permutation test, respectively. For adult unenhanced brain CT, CT cervical myelography, cervical and intracranial CT angiography and lumbar spine CT both CTDI{sub vol} and DLP were lowered by up to 10.9 % (p < 0.001), 17.9 % (p = 0.005), 20.9 % (p < 0.001), and 21.7 % (p = 0.001), respectively, by using ASIR compared with FBP alone. Image quality and noise were similar for both FBP and ASIR. We recommend routine use of iterative reconstruction for neuroradiology CT examinations because this approach affords a significant dose reduction while preserving image quality. (orig.)

  9. Adaptive statistical iterative reconstruction reduces patient radiation dose in neuroradiology CT studies

    International Nuclear Information System (INIS)

    Komlosi, Peter; Zhang, Yanrong; Leiva-Salinas, Carlos; Ornan, David; Grady, Deborah; Patrie, James T.; Xin, Wenjun; Wintermark, Max

    2014-01-01

    Adaptive statistical iterative reconstruction (ASIR) can decrease image noise, thereby generating CT images of comparable diagnostic quality with less radiation. The purpose of this study is to quantify the effect of systematic use of ASIR versus filtered back projection (FBP) for neuroradiology CT protocols on patients' radiation dose and image quality. We evaluated the effect of ASIR on six types of neuroradiologic CT studies: adult and pediatric unenhanced head CT, adult cervical spine CT, adult cervical and intracranial CT angiography, adult soft tissue neck CT with contrast, and adult lumbar spine CT. For each type of CT study, two groups of 100 consecutive studies were retrospectively reviewed: 100 studies performed with FBP and 100 studies performed with ASIR/FBP blending factor of 40 %/60 % with appropriate noise indices. The weighted volume CT dose index (CTDI vol ), dose-length product (DLP) and noise were recorded. Each study was also reviewed for image quality by two reviewers. Continuous and categorical variables were compared by t test and free permutation test, respectively. For adult unenhanced brain CT, CT cervical myelography, cervical and intracranial CT angiography and lumbar spine CT both CTDI vol and DLP were lowered by up to 10.9 % (p < 0.001), 17.9 % (p = 0.005), 20.9 % (p < 0.001), and 21.7 % (p = 0.001), respectively, by using ASIR compared with FBP alone. Image quality and noise were similar for both FBP and ASIR. We recommend routine use of iterative reconstruction for neuroradiology CT examinations because this approach affords a significant dose reduction while preserving image quality. (orig.)

  10. CT studies in hyperprolactinemia; Badania KT w hiperprolaktynemii

    Energy Technology Data Exchange (ETDEWEB)

    Gradzki, J.; Paprzycki, W.; Krzyzagorska, E.; Wasko, R.; Warenik-Szymankiewicz, A. [Akademia Medyczna, Poznan (Poland)

    1993-12-31

    Computerized tomography studies in 62 patients (55 females and 7 males) with hyperprolactinemia are presented. The female patients had secondary amenorrhea and galactorrhea, whereas the male patients suffered from impotency, gynaecomastia and very rarely galactorrhea. In 39 cases CT revealed a pituitary adenoma (prolactinoma), in 14 cases of them microadenoma, as the cause of hormonal and clinical disturbances. In 21 cases an empty sella with rudimentary pituitary surrounded by cerebrospinal fluid or lack of pituitary mass were found. In one case suprasellar and intrasellar calcifications were present. (author). 17 refs, 4 figs.

  11. CT studies in hyperprolactinemia; Badania KT w hiperprolaktynemii

    Energy Technology Data Exchange (ETDEWEB)

    Gradzki, J; Paprzycki, W; Krzyzagorska, E; Wasko, R; Warenik-Szymankiewicz, A [Akademia Medyczna, Poznan (Poland)

    1994-12-31

    Computerized tomography studies in 62 patients (55 females and 7 males) with hyperprolactinemia are presented. The female patients had secondary amenorrhea and galactorrhea, whereas the male patients suffered from impotency, gynaecomastia and very rarely galactorrhea. In 39 cases CT revealed a pituitary adenoma (prolactinoma), in 14 cases of them microadenoma, as the cause of hormonal and clinical disturbances. In 21 cases an empty sella with rudimentary pituitary surrounded by cerebrospinal fluid or lack of pituitary mass were found. In one case suprasellar and intrasellar calcifications were present. (author). 17 refs, 4 figs.

  12. Renal functional CT studies of patients with nephrolithotomy

    International Nuclear Information System (INIS)

    Yokoyama, Masayoshi; Fujita, Kiyoshi; Watanabe, Kiyotaka; Ochi, Kenji; Takeuchi, Masafumi

    1985-01-01

    Renal functions of 13 patients, who underwent nephrolithotomy, were examined by the functional CT study. The warm ischemic time was 41+/-10 (mean+/-SD). After the operation, the tissueplasma ratio of contrast enhancement values failed to improve satisfactorily compared to that of the nonischemic hydronephrosis patients. Parenchymal volume decreased as much as that in the non-ischemic patients. As a result, Renal Functional Index (RFI) decreased significantly after nephrolithotomy. As RFI does not usually change in non-ischemic hydronephrosis after release of obstruction, the postischemic decrease of RFI may be caused mainly by ischemic damage and the effects of parechymal incision may not be dominant. (author)

  13. Evidence-based investigation of the influence of computer-aided detection of polyps on screening of colon cancer with CT colonography

    International Nuclear Information System (INIS)

    Yoshida, Hiroyuki

    2008-01-01

    Computed tomographic colonography (CTC), also known as virtual colonoscopy, is a CT examination of the colon for colorectal neoplasms. Recent large-scale clinical trials have demonstrated that CTC yields sensitivity comparable to optical colonoscopy in the detection of clinically significant polyps in a screening population, making CTC a promising technique for screening of colon cancer. For CTC to be a clinically practical means of screening, it must reliably and consistently detect polyps with high accuracy. However, high-level expertise is required to interpret the resulting CT images to find polyps, resulting in variable diagnostic accuracy among radiologists in the detection of polyps. A key technology to overcome this problem and to bring CTC to prime time for screening of colorectal cancer is computer-aided detection (CAD) of polyps. CAD automatically detects the locations of suspicious polyps in CTC images and presents them to radiologists. CAD has the potential to increase diagnostic performance in the detection of polyps as well as to reduce variability of the diagnostic accuracy among radiologists. This paper presents an evidence-based investigation of the influence of CAD on screening of colon cancer with CTC by describing the benefits of using CAD in the diagnosis of CTC, the fundamental CAD scheme for the detection of polyps in CTC, its detection performance, the effect on the improvement of detection performance, as well as the current and future challenges in CAD. (author)

  14. Study on the brain CT scan of SLE patients

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, S; Narita, M; Katoh, K; Matsunaga, K; Ishigatsubo, Y [Yokohama City Univ. (Japan). Faculty of Medicine

    1982-03-01

    Cranial CT scanning revealed abnormality in 12 of 25 patients with SLE (48%). Ventricular sulcal enlargement was found mostly in younger patients between 16 and 36 years, an average of 25 years. Abnormality in electroencephalogram, principally paroxysmal abnormality, was found in 8 of 13 cases (62%) of normal CT findings. Non-paroxysmal slow-wave abnormality was observed in 9 of 12 abnormal CT cases. Of 13 patients with CNS symptoms, 8 had abnormal CT findings, and 5 had only mental disorder with normal CT findings. In 12 patients without neuropsychiatric involvement, 4 (33%) had abnormal CT findings. The rate of abnormal CT findings was increased in the patients receiving a high dosage of a steroid agent. Five of 6 patients who showed ventricular sulcal enlargement had been given prednisolone in a dosage of 35 mg or more per day.

  15. Comparison the diagnostic value of serological and molecular methods for screening and detecting Chlamydia trachomatis in semen of infertile men: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Amin Khoshakhlagh

    2017-12-01

    Full Text Available Background: Chlamydia trachomatis (CT with damaging effects on sperm quality parameters can often cause infertility in men. Objective: The main objective of this study was to determine the diagnostic value of polymerase chain reaction (PCR and enzyme linked immuno sorbent assay (ELISA for screening and detecting CT in semen samples of infertile men. Materials and Methods: In this cross-sectional study, 465 men referring to the clinical laboratory of Royan Institute were chosen for primary screening and detection of the presence of CT. 93 samples were normozoospermia with normal sperm parameters i.e. sperm number, motility and morphology (Asymptomatic and 372 had abnormal sperm parameters (Symptomatic in semen analysis. ELISA test was performed as the screening test. Samples with optical density (OD >0.200 were selected as the case and asymptomatic samples with OD 0.400 as the ELISA positive, the diagnostic value of CT-ELISA positive in symptomatic and asymptomatic infertile patients were 0.019 (7 of 372 and 0.021 (2 of 93, respectively. There was no relationship between the presence of CT infection and different sperm abnormalities. Conclusion: The anti-CT IgA ELISA test may be introduced as an appropriate tool for screening purpose in the seminal plasma to select suspicious samples for PCR confirmatory tests.

  16. Dose profile study in head CT scans using radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Ladino G, A. M.; Prata M, A., E-mail: amlgphys@gmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  17. Dose profile study in head CT scans using radiochromic films

    International Nuclear Information System (INIS)

    Ladino G, A. M.; Prata M, A.

    2016-10-01

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  18. Automated assessment of aortic and main pulmonary arterial diameters using model-based blood vessel segmentation for predicting chronic thromboembolic pulmonary hypertension in low-dose CT lung screening

    Science.gov (United States)

    Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Sugiura, Toshihiko; Tanabe, Nobuhiro; Kusumoto, Masahiko; Eguchi, Kenji; Kaneko, Masahiro

    2018-02-01

    Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by obstruction of the pulmonary vasculature by residual organized thrombi. A morphological abnormality inside mediastinum of CTEPH patient is enlargement of pulmonary artery. This paper presents an automated assessment of aortic and main pulmonary arterial diameters for predicting CTEPH in low-dose CT lung screening. The distinctive feature of our method is to segment aorta and main pulmonary artery using both of prior probability and vascular direction which were estimated from mediastinal vascular region using principal curvatures of four-dimensional hyper surface. The method was applied to two datasets, 64 lowdose CT scans of lung cancer screening and 19 normal-dose CT scans of CTEPH patients through the training phase with 121 low-dose CT scans. This paper demonstrates effectiveness of our method for predicting CTEPH in low-dose CT screening.

  19. Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT.

    Science.gov (United States)

    Gay, F; Pavia, Y; Pierrat, N; Lasalle, S; Neuenschwander, S; Brisse, H J

    2014-01-01

    To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. • Iterative reconstruction helps lower radiation exposure levels in children undergoing CT. • Adaptive statistical iterative reconstruction (ASIR) significantly increases SNR without impairing spatial resolution. • For abdomen and chest CT, ASIR allows at least a 30 % dose reduction.

  20. Postoperative follow-up study of craniosynostosis using three-dimensional surface reconstruction CT (3D-CT)

    Energy Technology Data Exchange (ETDEWEB)

    Nishimoto, Hiroshi; Tsukiyama, Takashi; Nishimura, Jiro; Fujioka, Mutsuhisa; Tsubokawa, Takashi.

    1988-12-01

    In 1983, Michael W. Vannier and Jeffrey L. Marsh developed a computer method that reconstructs three-dimensional images from high-resolution CT-scan series of the facial skeleton. This method has been applied to craniofacial anomalies, basal encephalocele, and other skeletal pathologies. In this study, the postoperative assessment of craniofacial surgical results has been accomplished using 3D-CT techniques in craniosynostosis. The results are as follows: (1) Postoperative 3D-CTs reveal the bony anatomical details corrected by the craniofacial surgery more precisely and more stereographically than do conventional radiological techniques. (2) Secondary changes in the cranium after the surgery, such as reossification at the area of osteotomies or postoperative asymmetric skull deformities, are more early detected by the 3D-CT imaging technique than by a craniogram. (3) In 3D-CT images, internal views of the skull, such mid-sagittal, rear internal, or top axial views of the intracranial skull base, are most useful in postoperative assessments of the surgical results and of postoperative secondary changes in the cranium. Based on our experience, we expect that 3D-CT imaging techniques will become more important in the management of craniosynostosis.

  1. Postoperative follow-up study of craniosynostosis using three-dimensional surface reconstruction CT (3D-CT)

    International Nuclear Information System (INIS)

    Nishimoto, Hiroshi; Tsukiyama, Takashi; Nishimura, Jiro; Fujioka, Mutsuhisa; Tsubokawa, Takashi.

    1988-01-01

    In 1983, Michael W. Vannier and Jeffrey L. Marsh developed a computer method that reconstructs three-dimensional images from high-resolution CT-scan series of the facial skeleton. This method has been applied to craniofacial anomalies, basal encephalocele, and other skeletal pathologies. In this study, the postoperative assessment of craniofacial surgical results has been accomplished using 3D-CT techniques in craniosynostosis. The results are as follows: 1) Postoperative 3D-CTs reveal the bony anatomical details corrected by the craniofacial surgery more precisely and more stereographically than do conventional radiological techniques. 2) Secondary changes in the cranium after the surgery, such as reossification at the area of osteotomies or postoperative asymmetric skull deformities, are more early detected by the 3D-CT imaging technique than by a craniogram. 3) In 3D-CT images, internal views of the skull, such mid-sagittal, rear internal, or top axial views of the intracranial skull base, are most useful in postoperative assessments of the surgical results and of postoperative secondary changes in the cranium. Based on our experience, we expect that 3D-CT imaging techniques will become more important in the management of craniosynostosis. (author)

  2. Eighteen cases of small breast cancer: a comparative study of mammography, CT scan and pathology

    International Nuclear Information System (INIS)

    Wu Yaopan; Lin Haogao; Cai Peiqiang; Ouyang Yi; Zhang Weizhang; Lu Bingui

    2003-01-01

    Objective: To improve the early diagnosis of breast cancer through a study of the mammography and CT findings of small breast cancer. Methods: The mammography and CT findings of 18 cases of small breast cancer (φ≤2.0 cm in diameter) were studied and compared with pathological results. Results: The diagnostic accuracy of CT and mammography was 83% and 61%, respectively. There was a statistical difference between both modalities (P<0.05), CT scan was superior to mammography. However, there was no difference between them when assessing the lesion arising in F-type breast. In detecting breast fine cluster of calcification, the sensitivity of mammography was better than CT scan. Conclusion: The patient suspected of small breast cancer should take mammography as the first evaluation. CT scan is reserved for the further investigation. The mammography combined with CT scan can improve the early diagnostic rate of breast cancer

  3. Using micropower impulse radar technology to screen for pneumothorax: an international bi-institutional study.

    Science.gov (United States)

    van der Wilden, Gwendolyn M; Van der Wilden, Gwen; Albers, Christoph E; Albers, Christof; Haefeli, Pascal C; Haefeli, Peter; Zimmermann, Heinz; Zimmerman, Heinz; Exadaktylos, Aristomenis; Exadaktylos, Aris; Levy, Phillip; Birkhan, Oscar; Birkham, Oscar; Michaildou, Maria; Michailidou, Maria; Sideris, Antonios; Velmahos, George C; Velmahos, George; Alam, Hasan B; Alam, Hasan; King, David R; King, David; Fagenholz, Peter J; Fagenholz, Peter; Yeh, D Dante; Yeh, Dante; de Moya, Marc A

    2012-12-01

    Pneumothoraces (PTXs) are a common entity in thoracic trauma. Micropower impulse radar (MIR) has been able to detect PTXs in surgical patients. However, this technology has not been tested previously on trauma patients. The purpose of this study was to determine the sensitivity and specificity of MIR to detect clinically significant PTXs. We hypothesized that MIR technology can effectively screen trauma patients for clinically significant PTXs. This was a prospective observational study in Level I trauma centers in Boston, Massachusetts, and Bern, Switzerland. All trauma patients undergoing a chest computed tomographic (CT) scan were eligible for the study. Consent was obtained, and readings were performed within 30 minutes before or after the CT scan. The patients had eight lung fields tested (four on each side). The qualitative and quantitative MIR results were blinded and stored on the device. We then compared the results of the MIR to the CT scan and the need for chest tube drainage. We defined PTXs as clinically significant if they required a chest tube. Seventy-five patients were enrolled, with a mean age of 46 ± 16 years. Eighty-four percent were male. The screening test took approximately 1 minute. All but two patients had blunt chest trauma. Six true-positives, 6 false-positives, 63 true-negatives, and 0 false-negatives resulted in an overall sensitivity of 100%. MIR is an easy to use handheld technology that effectively screened patients for clinically significant PTXs, with a sensitivity and negative predictive value of 100%. MIR may be used for rapid, repeatable, and ongoing surveillance of trauma patients. Diagnostic study, level III.

  4. Virtual colonoscopy (CT colonography) in the identification of colorectal cancer. A prospective study in symptomatic patients

    International Nuclear Information System (INIS)

    Regge, D.; Martincich, L.; Gallo, T.; Pollone, M.; Galatola, G.; Secreto, P.; Pera, A.; Rivolta, A.

    2000-01-01

    Aim of this study was to evaluate the sensitivity of virtual colonoscopy (CT colonography) in the identification of colorectal cancer and to define the limitations and the advantages of this imaging modality, as well as indications to the examination. It was examined prospectively 62 symptomatic patients aged 36 to 82 years (28 women and 34 men). All patients underwent both conventional and virtual colonoscopy on the same day; the conventional examination allowed exploration of the entire colon. Conventional colonoscopy identified 89 lesions 3-50 mm in diameter, namely 84 benign and 5 malignant lesions. No lesions were identified in 12 patients. CT colonography identified 52 of the 89 lesions, with 57.1% diagnostic accuracy. They were 11 false positives (82.5% positive predictive value and 52.2% specificity) and 37 false negatives (24.5% negative predictive value and 58.4% sensitivity). Sensitivity was significantly higher (85.7%) for polyps ≥ 1 cm. Virtual colonoscopy is an imaging modality with good diagnostic yield, well tolerated by patients and with great potentials for further development. It was suggested that the examination be performed in symptomatic patients who cannot undergo total colonoscopy or refuse the other imaging modalities. Further studies are waranted in larger series of patients, possibly introducing it in screening programs [it

  5. TU-G-204-09: The Effects of Reduced- Dose Lung Cancer Screening CT On Lung Nodule Detection Using a CAD Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Young, S; Lo, P; Kim, G; Hsu, W; Hoffman, J; Brown, M; McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2015-06-15

    Purpose: While Lung Cancer Screening CT is being performed at low doses, the purpose of this study was to investigate the effects of further reducing dose on the performance of a CAD nodule-detection algorithm. Methods: We selected 50 cases from our local database of National Lung Screening Trial (NLST) patients for which we had both the image series and the raw CT data from the original scans. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. 10 of the cases had at least one nodule reported on the NLST reader forms. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, the CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST reports. Subject-level mean sensitivities and false-positive rates were calculated for each dose level. Results: The mean sensitivities of the CAD algorithm were 35% at the original dose, 20% at 50% dose, and 42.5% at 25% dose. The false-positive rates, in decreasing-dose order, were 3.7, 2.9, and 10 per case. In certain cases, particularly in larger patients, there were severe photon-starvation artifacts, especially in the apical region due to the high-attenuating shoulders. Conclusion: The detection task was challenging for the CAD algorithm at all dose levels, including the original NLST dose. However, the false-positive rate at 25% dose approximately tripled, suggesting a loss of CAD robustness somewhere between 0.5 and 1.0 mGy. NCI grant U01 CA181156 (Quantitative Imaging Network); Tobacco Related Disease Research Project grant 22RT-0131.

  6. TU-G-204-09: The Effects of Reduced- Dose Lung Cancer Screening CT On Lung Nodule Detection Using a CAD Algorithm

    International Nuclear Information System (INIS)

    Young, S; Lo, P; Kim, G; Hsu, W; Hoffman, J; Brown, M; McNitt-Gray, M

    2015-01-01

    Purpose: While Lung Cancer Screening CT is being performed at low doses, the purpose of this study was to investigate the effects of further reducing dose on the performance of a CAD nodule-detection algorithm. Methods: We selected 50 cases from our local database of National Lung Screening Trial (NLST) patients for which we had both the image series and the raw CT data from the original scans. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. 10 of the cases had at least one nodule reported on the NLST reader forms. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, the CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST reports. Subject-level mean sensitivities and false-positive rates were calculated for each dose level. Results: The mean sensitivities of the CAD algorithm were 35% at the original dose, 20% at 50% dose, and 42.5% at 25% dose. The false-positive rates, in decreasing-dose order, were 3.7, 2.9, and 10 per case. In certain cases, particularly in larger patients, there were severe photon-starvation artifacts, especially in the apical region due to the high-attenuating shoulders. Conclusion: The detection task was challenging for the CAD algorithm at all dose levels, including the original NLST dose. However, the false-positive rate at 25% dose approximately tripled, suggesting a loss of CAD robustness somewhere between 0.5 and 1.0 mGy. NCI grant U01 CA181156 (Quantitative Imaging Network); Tobacco Related Disease Research Project grant 22RT-0131

  7. 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

  8. Studies on diagnosis of lung emphysema by CT image using experimental models and clinical cases

    International Nuclear Information System (INIS)

    Nakatani, Seiki

    1998-01-01

    Since the detailed report between the degree of functional disorder in lung emphysema and the analysis of CT image is quite unknown, the present study was attempted to produce the experimental model of lung emphysema with various stages by the administration of papain to the focal lobe in canine lung. Using this model or clinical lung emphysema, the relationship between the degree of destruction of alveolar walls, clinical pulmonary functions and CT images was investigated. CT scan was performed at the level of 50% vital capacity in both experimental models and clinical subjects by using spirometric gating CT. CT density histogram was obtained from CT image which was produced by using the developed software for this purpose. Densitometric parameters, such as mean CT value, %LAA, the peak in the histogram and 5% tile were selected from CT image. Papain solution of 5 mg/kg body weight was cumulatively administered to the left lower lobe in canine lung, resulting in the destruction of lung alveolar walls in parallel to the increasing dosage of papain. There was a significant correlation between not only the increasing dosage of papain, but also %FEV 1.0 and CT densitometric parameters, indicating that the histological changes of alveolar walls and the lung function in lung emphysema could be estimated by analysis of CT image. These experimental and clinical studies suggest that the analysis of CT image can reflect the pathophysiological changes in the lung and be useful for precise clinical diagnosis of lung emphysema. (author)

  9. Postmortem CT Angiography Compared with Autopsy: A Forensic Multicenter Study.

    Science.gov (United States)

    Grabherr, Silke; Heinemann, Axel; Vogel, Hermann; Rutty, Guy; Morgan, Bruno; Woźniak, Krzysztof; Dedouit, Fabrice; Fischer, Florian; Lochner, Stefanie; Wittig, Holger; Guglielmi, Giuseppe; Eplinius, Franziska; Michaud, Katarzyna; Palmiere, Cristian; Chevallier, Christine; Mangin, Patrice; Grimm, Jochen M

    2018-05-01

    Purpose To determine if postmortem computed tomography (CT) and postmortem CT angiography help to detect more lesions than autopsy in postmortem examinations, to evaluate the strengths and weaknesses of each method, and to define their indications. Materials and Methods Postmortem CT angiography was performed on 500 human corpses and followed by conventional autopsy. Nine centers were involved. All CT images were read by an experienced team including one forensic pathologist and one radiologist, blinded to the autopsy results. All findings were recorded for each method and categorized by anatomic structure (bone, organ parenchyma, soft tissue, and vascular) and relative importance in the forensic case (essential, useful, and unimportant). Results Among 18 654 findings, autopsies helped to identify 61.3% (11 433 of 18 654), postmortem CT helped to identify 76.0% (14 179 of 18 654), and postmortem CT angiography helped to identify 89.9% (16 780 of 18 654; P < .001). Postmortem CT angiography was superior to autopsy, especially at helping to identify essential skeletal lesions (96.1% [625 of 650] vs 65.4% [425 of 650], respectively; P < .001) and vascular lesions (93.5% [938 of 1003] vs 65.3% [655 of 1003], respectively; P < .001). Among the forensically essential findings, 23.4% (1029 of 4393) were not detected at autopsy, while only 9.7% (428 of 4393) were missed at postmortem CT angiography (P < .001). The best results were obtained when postmortem CT angiography was combined with autopsy. Conclusion Postmortem CT and postmortem CT angiography and autopsy each detect important lesions not detected by the other method. More lesions were identified by combining postmortem CT angiography and autopsy, which may increase the quality of postmortem diagnosis. Online supplemental material is available for this article.

  10. Basic studies of CT in the maxillofacial areas, 1

    International Nuclear Information System (INIS)

    Suzuki, Shinichiro; Kaneko, Hiroshi; Higashi, Tomomitsu; Takenaka, Eiichi.

    1982-01-01

    As CT values of hard tissues would pose problems in the application of CT to the maxillofacial area, attenuation coefficients of each oral hard tissue were examined based on the existing data, and the linearity in the area of high x-ray attenuation was examined. We thought that a new contrast scale suitable for each area should be established for measurements of CT values of tissues of high x-ray attenuation such as teeth. (Chiba, N.)

  11. 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

  12. Study of metastatic foci by CT in autopsied lung cancer

    International Nuclear Information System (INIS)

    Koga, Mitsuru; Nobe, Yoshifumi; Fujii, Kyoichi.

    1983-01-01

    The authors reexamined all of the image diagnoses made during whole hospitalization in 11 lung cancer cases with autopsy. Of 39 metastatic foci observed at autopsy in the liver, kidney, pancreas, adrenal and brain, 12 had been diagnosed on transverse CT images before death. Three foci were missed at initial readings. The period from CT to autopsy was less than 3 months for 9 of 12 correctly diagnosed foci. For 13 of 27 foci undetected by CT, CT was conducted more than 3 months before death. (Chiba, N)

  13. Non-small cell lung cancer brain metastasis screening in the era of positron emission tomography-CT staging: Current practice and outcomes.

    Science.gov (United States)

    Diaz, Mauricio E; Debowski, Maciej; Hukins, Craig; Fielding, David; Fong, Kwun M; Bettington, Catherine S

    2018-05-10

    Several clinical guidelines indicate that brain metastasis screening (BMS) should be guided by disease stage in non-small cell lung cancer (NSCLC). We estimate that screening is performed more broadly in practice, and patients undergo brain imaging at considerable cost with questionable benefit. Our aim was to quantify the use and detection rate of BMS in a contemporary cohort staged with 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT). We conducted a retrospective review of prospectively collected data from three major lung cancer referral centres in Brisbane between January 2011 and December 2015. Patients included had a new diagnosis of NSCLC and had undergone a PET-CT to stage extra-cranial disease. BMS was defined as dedicated brain imaging with contrast-enhanced computed tomography (CE-CT) or magnetic resonance (MR), in the absence of clinically apparent neurological deficits. A total of 1751 eligible cases were identified and of these 718 (41%) underwent BMS. The majority had CE-CT imaging (n = 703). Asymptomatic brain metastases (BM) were detected in 18 patients (2.5%). Of these patients, 12 had concurrent non-brain metastases. Only six patients (0.8%) had BM alone. The rate of detection increased with N-stage (P = 0.02) and overall stage (P < 0.001). It was 0.5%, 1%, 1.6% and 7.3% for stage I, II, III and IV respectively. The overall screening rate increased with T-stage (P = 0.001), N-Stage (P < 0.001) and overall stage (P < 0.001). Non-small cell lung cancer BMS practices remain at odds with published guidelines. The low number of occult BMs detected supports the existing international recommendations. Rationalising BMS would minimise the burden on patients and the health care system. © 2018 The Royal Australian and New Zealand College of Radiologists.

  14. Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Gay, F.; Lasalle, S.; Neuenschwander, S.; Brisse, H.J. [Institut Curie, Imaging Department, Paris (France); Pavia, Y.; Pierrat, N. [Institut Curie, Medical Physics Department, Paris (France)

    2014-01-15

    To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. (orig.)

  15. Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT

    International Nuclear Information System (INIS)

    Gay, F.; Lasalle, S.; Neuenschwander, S.; Brisse, H.J.; Pavia, Y.; Pierrat, N.

    2014-01-01

    To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. (orig.)

  16. Hepatic manifestations of tuberous sclerosis studied by US and CT

    International Nuclear Information System (INIS)

    Galant, J.; Marti-Bonmati, L.; Ripolles, T.; Martinez-Rodrigo, J.; Ferrer, M.D.

    1995-01-01

    Liver hamartomas in tuberous sclerosis (TS) have been uncommonly documented compared with hamartomatous lesions in other organs. We prospectively studied by US 21 patients that fulfilled the established criteria of TS, looking for hepatic and renal lesions. Nine patients (43%) showed multiple, rounded hyperechoic liver lesions. Of these patients, 8 were also studied with CT showing several round low-density fatty lesions. Multiple hyperechoic renal lesions similar to those described in the liver were present in 17 patients (81%). Fat-containing tumors in the liver in TS have been described as liver hamartomas. We believe, considering the high prevalence of liver hamartomas in patients with TS and the scarcity of fat-containing lesions in the general population, that their presence should be considered as a criterion of TS, even in the absence of histological confirmation. (orig.)

  17. Studies of IR-screening smoke clouds

    Energy Technology Data Exchange (ETDEWEB)

    Cudzilo, S. [Military Univ. of Technology, Warsaw (Poland)

    2001-02-01

    This paper contains some results of research on the IR-screening capability of smoke clouds generated during the combustion process of varied pyrotechnic formulations. The smoke compositions were made from some oxygen or oxygen-free mixtures containing metal and chloroorganic compounds or mixtures based on red phosphorus. The camouflage effectiveness of clouds generated by these formulations was investigated under laboratory conditions with an infrared camera. The technique employed enables determination of radiant temperature distributions in a smoke cloud treated as an energy equivalent of a grey body emission. The results of the analysis of thermographs from the camera were the basis on which the mixtures producing screens of the highest countermeasure for thermal imaging systems have been chosen. (orig.)

  18. Prevalence of incidental or unexpected findings on low-dose CT performed during routine SPECT/CT nuclear medicine studies

    International Nuclear Information System (INIS)

    Yap, Kelvin Kwok-Ho; Sutherland, Tom; Shafik-Eid, Raymond; Taubman, Kim; Schlicht, Stephen; Ramaseshan, Ganeshan

    2015-01-01

    In nuclear medicine, single-photon-emission computed tomography (SPECT) is often combined with ‘simultaneous’ low-dose CT (LDCT) to provide complementary anatomical and functional correlation. As a consequence, numerous incidental and unexpected findings may be detected on LDCT. Recognition of these findings and appropriate determination of their relevance can add to the utility of SPECT/CT. We aimed to evaluate the prevalence and categorise the relevance of incidental and unexpected findings on LDCT scans performed as part of routine SPECT/CT studies. All available LDCT scans performed as part of SPECT/CT studies at St. Vincent's Hospital Melbourne in the year 2013 were retrospectively reviewed. Two qualified radiologists independently reviewed the studies and any previous available imaging and categorised any detected incidental findings. A total of 2447 LDCT studies were reviewed. The relevance of the findings was classified according to a modified version of a scale used in the Colonography Reporting and Data System: E1 = normal or normal variant (28.0%); E2 = clinically unimportant (63.5%); E3 = likely unimportant or incompletely characterised (6.2%); E4 = potentially important (2.5%). Imaging specialists need to be cognisant of incidental and unexpected findings present on LDCT studies performed as part of SPECT/CT. Appropriate categorisation of findings and communication of potentially important findings to referring clinicians should form part of routine practice. The overall prevalence of potentially significant incidental and unexpected findings in our series was 8.7% (E3, 6.2%; E4, 2.5%) and was comparable to rates in other published imaging series.

  19. CT study of pancreatic diseases with modified dynamic scanning

    International Nuclear Information System (INIS)

    Qian Minghui; Zhu Guangying

    1990-01-01

    Experience of 20 cases modified dynamic CT scanning is presented. With a slight increased X-ray tube burden, it is possible to investigate tumor blood supply and find small pancreatic insulinoma with this method. The capsular sign typical for chronic traumatic pancreatic hematoma on CT is presented

  20. Evaluation of a PACS workstation for interpreting body CT studies

    International Nuclear Information System (INIS)

    Franken, E.A.; Berbaum, K.S.; Honda, H.; McGuire, C.; Weis, R.R.; Barloon, T.

    1989-01-01

    This paper reports conventional hard-copy images from 266 body CT studies compared with those provided by a picture archiving and communication system (PACS) workstation. PACS images were evaluated before and after use of various image processing features. Most cases were depicted equally well, but in about one-fourth of the cases, diagnostic features were shown more clearly on PACS images. When PACS images were viewed first, a change in diagnosis after subsequent hardcopy inspection was infrequent, but when hard-copy images were viewed first, the results were converse. The image processing features of PACS were critical for its superior performance. The ability of a PACS to provide both image display and manipulation results in the superiority of that system

  1. Nano-CT study on nanostructure of porous ceramics

    International Nuclear Information System (INIS)

    Wu Wenquan; Li Wenjie; Guan Yong; Yang Yunhao; Chen Jie; Zhou Jie; Yu Xiyue; Song Xiangxia; Tian Yangchao; Li Wei; Chen Chusheng

    2010-01-01

    The porous structure of ceramic materials has a great impact on their performance. However, the existing characterization techniques fail to give 3D structure of the ceramics. In this work, nano-CT imaging technique was used to study 3D structure of a ceramic fiber tube prepared by a phase inversion technology. The results showed the shape, direction, size distribution, and 3D map of the pores inside the ceramic wall. The pore size is 0.4-1.5 μm, with a porosity of 38.31%. The data can be used to improve their preparation processes and optimize the structure parameters, for applications in chemical, energy, environmental protection and other fields. (authors)

  2. Emergency department CT screening of patients with nontraumatic neurological symptoms referred to the posterior fossa: comparison of thin versus thick slice images.

    Science.gov (United States)

    Kamalian, Shervin; Atkinson, Wendy L; Florin, Lauren A; Pomerantz, Stuart R; Lev, Michael H; Romero, Javier M

    2014-06-01

    Evaluation of the posterior fossa (PF) on 5-mm-thick helical CT images (current default) has improved diagnostic accuracy compared to 5-mm sequential CT images; however, 5-mm-thick images may not be ideal for PF pathology due to volume averaging of rapid changes in anatomy in the Z-direction. Therefore, we sought to determine if routine review of 1.25-mm-thin helical CT images has superior accuracy in screening for nontraumatic PF pathology. MRI proof of diagnosis was obtained within 6 h of helical CT acquisition for 90 consecutive ED patients with, and 88 without, posterior fossa lesions. Helical CT images were post-processed at 1.25 and 5-mm-axial slice thickness. Two neuroradiologists blinded to the clinical/MRI findings reviewed both image sets. Interobserver agreement and accuracy were rated using Kappa statistics and ROC analysis, respectively. Of the 90/178 (51 %) who were MR positive, 60/90 (66 %) had stroke and 30/90 (33 %) had other etiologies. There was excellent interobserver agreement (κ > 0.97) for both thick and thin slice assessments. The accuracy, sensitivity, and specificity for 1.25-mm images were 65, 44, and 84 %, respectively, and for 5-mm images were 67, 45, and 85 %, respectively. The diagnostic accuracy was not significantly different (p > 0.5). In this cohort of patients with nontraumatic neurological symptoms referred to the posterior fossa, 1.25-mm-thin slice CT reformatted images do not have superior accuracy compared to 5-mm-thick images. This information has implications on optimizing resource utilizations and efficiency in a busy emergency room. Review of 1.25-mm-thin images may help diagnostic accuracy only when review of 5-mm-thick images as current default is inconclusive.

  3. Study of CT and etiology In 11B cases of eoute headache without hemlplegla

    Institute of Scientific and Technical Information of China (English)

    Daoming Tong

    2000-01-01

    objectal To study the relation between CT and etiology of acute headache without hemiplegia. Methods 118 cases of acute headache without hemiplegia were studied with CT scan. The patients with normal CT were diagnosed with lumbar punc -tura or diagnostic standard for establishing disease. Results The first three etiologies were cerebrovescular disease (65 cases, 55%), migraine (25 cases, 21%), meningitis and encephalitis (19 cases, 155. 9%). 53% of patients with subarachnoid hemorrhage(SAH) was diagnosed in CT unnormal group, and 12.4% of patients with Sall was showed by lumbar puncture in CT normal group(P<0. 001). CT was normal in 18% of patients with a definite SAH(7/39). The positive rates of intracranial infection in CT normal group(by lumbar puncture) was reearkably higher than in CT unnormal group (18/58 versus 2/60, p<0.005), Conolusion CT is more sensitive to intracranial hemorrhage, tumor and infarction. SAH of a negative Ctscan is not rare. CT is far inferior to lumbar puncture in meningitis or encephalitis.

  4. Reducing dose in paediatric CT: a preliminary study of radiographers' knowledge

    International Nuclear Information System (INIS)

    Heagney, J.; Lewis, S.; Chaffey, C.; Howlett, G.; Moran, A.; McLean, D.

    2003-01-01

    The objective of this study is to evaluate the responses of Australian radiographers in comparison with current literature on paediatric protocols and scanning recommendations in order to determine how and if paediatric Computed Tomography (CT) exposure reductions are taking place within Medical Imaging Departments. Subjects and Methods: The method involved a dual format; consisting of surveying 30 CT radiographers, and additionally, interviewing 5 senior CT radiographers. Of the 30 surveys completed, one was completed by a PDY radiographer, 7 by CT Senior radiographers and 22 by CT radiographers. The survey contained a range of questions about appropriate paediatric CT scanning parameters and protocols. Five CT Seniors were interviewed to ascertain the current level and opinion of training in paediatric protocols, in-house educational programs and the implementation of radiation dose saving parameters. Radiographers demonstrated reasonable ability to identify suitable paediatric protocols and believed the in-house CT protocols resident to their medical imaging department to be adequate, despite many utilising exposures higher than those from recommended literature. The interviews revealed that no further training in CT paediatric dose reduction was currently available, however survey responses indicated that further training would be beneficial. This study demonstrates that radiographers are aware of the need to reduce exposure parameters for paediatric CT and tend to follow protocols in place within their workplace, regardless of suitability and patient needs. Copyright (2003) Australian Institute of Radiography

  5. Reducing dose in paediatric CT: a preliminary study of radiographers' Knowledge

    International Nuclear Information System (INIS)

    Heagney, Jillian; Lewis, Sarah; Chaffey, Clare; Howlett, Genevieve; Moran, Alexander; McLean, Donald

    2003-01-01

    The objective of this study is to evaluate the responses of Australian radiographers in comparison with current literature on paediatric protocols and scanning recommendations in order to determine how and if paediatric Computed Tomography (CT) exposure reductions are taking place within Medical Imaging Departments. Subjects and Methods: The method involved a dual format; consisting of surveying 30 CT radiographers, and additionally, interviewing 5 senior CT radiographers. Of the 30 surveys completed, one was completed by a PDY radiographer, 7 by CT Senior radiographers and 22 by CT radiographers. The survey contained a range of questions about appropriate paediatric CT scanning parameters and protocols. Five CT Seniors were interviewed to ascertain the current level and opinion of training in paediatric protocols, in-house educational programs and the implementation of radiation dose saving parameters. Radiographers demonstrated reasonable ability to identify suitable paediatric protocols and believed the in-house CT protocols resident to their medical imaging department to be adequate, despite many utilising exposures higher than those from recommended literature. The interviews revealed that no further training in CT paediatric dose reduction was currently available, however survey responses indicated that further training would be beneficial. This study demonstrates that radiographers are aware of the need to reduce exposure parameters for paediatric CT and tend to follow protocols in place within their workplace, regardless of suitability and patient needs Copyright (2003) Australian Institute of Radiography

  6. Dual resolution cone beam breast CT: A feasibility study

    International Nuclear Information System (INIS)

    Chen Lingyun; Shen Youtao; Lai, Chao-Jen; Han Tao; Zhong Yuncheng; Ge Shuaiping; Liu Xinming; Wang Tianpeng; Yang, Wei T.; Whitman, Gary J.; Shaw, Chris C.

    2009-01-01

    Purpose: In this study, the authors investigated the feasibility of a dual resolution volume-of-interest (VOI) cone beam breast CT technique and compared two implementation approaches in terms of dose saving and scatter reduction. Methods: With this technique, a lead VOI mask with an opening is inserted between the x-ray source and the breast to deliver x-ray exposure to the VOI while blocking x rays outside the VOI. A CCD detector is used to collect the high resolution projection data of the VOI. Low resolution cone beam CT (CBCT) images of the entire breast, acquired with a flat panel (FP) detector, were used to calculate the projection data outside the VOI with the ray-tracing reprojection method. The Feldkamp-Davis-Kress filtered backprojection algorithm was used to reconstruct the dual resolution 3D images. Breast phantoms with 180 μm and smaller microcalcifications (MCs) were imaged with both FP and FP-CCD dual resolution CBCT systems, respectively. Two approaches of implementing the dual resolution technique, breast-centered approach and VOI-centered approach, were investigated and evaluated for dose saving and scatter reduction with Monte Carlo simulation using a GEANT4 package. Results: The results showed that the breast-centered approach saved more breast absorbed dose than did VOI-centered approach with similar scatter reduction. The MCs in fatty breast phantom, which were invisible with FP CBCT scan, became visible with the FP-CCD dual resolution CBCT scan. Conclusions: These results indicate potential improvement of the image quality inside the VOI with reduced breast dose both inside and outside the VOI.

  7. Does gender discrimination impact regular mammography screening? Findings from the race differences in screening mammography study.

    Science.gov (United States)

    Dailey, Amy B; Kasl, Stanislav V; Jones, Beth A

    2008-03-01

    ABSTRACT Objective: To determine if gender discrimination, conceptualized as a negative life stressor, is a deterrent to adherence to mammography screening guidelines. African American and white women (1451) aged 40-79 years who obtained an index screening mammogram at one of five urban hospitals in Connecticut between October 1996 and January 1998 were enrolled in this study. This logistic regression analysis includes the 1229 women who completed telephone interviews at baseline and follow-up (average 29.4 months later) and for whom the study outcome, nonadherence to age-specific mammography screening guidelines, was determined. Gender discrimination was measured as lifetime experience in seven possible situations. Gender discrimination, reported by nearly 38% of the study population, was significantly associated with nonadherence to mammography guidelines in women with annual family incomes of > or =$50,000 (OR 1.99, 95% CI 1.33, 2.98) and did not differ across racial/ethnic group. Our findings suggest that gender discrimination can adversely influence regular mammography screening in some women. With nearly half of women nonadherent to screening mammography guidelines in this study and with decreasing mammography rates nationwide, it is important to address the complexity of nonadherence across subgroups of women. Life stressors, such as experiences of gender discrimination, may have considerable consequences, potentially influencing health prevention prioritization in women.

  8. Breast Cancer Challenges and Screening in China: Lessons From Current Registry Data and Population Screening Studies.

    Science.gov (United States)

    Song, Qing-Kun; Wang, Xiao-Li; Zhou, Xin-Na; Yang, Hua-Bing; Li, Yu-Chen; Wu, Jiang-Ping; Ren, Jun; Lyerly, Herbert Kim

    2015-07-01

    screening program targeting women aged 35-59 years had a low detection rate that resulted in a second-generation screening program that extended the cohort size and ages screened to 35-64 years. Cancer registration has been active in China for decades; however, a national survey of registries has not been routinely reported. This study used MapInfo to describe the reported data and found asymmetric registration activities, geographic variations in breast cancer (BC) burdens, and an increasing incidence with a peak at age 50. The initial Chinese BC screening programs focused on a relatively young population of women aged 35-59 years and had a low detection rate, but 69.7% of patients had early stage BC. Older women were included in the second-generation screening programs, and an additional 6 million women were screened. Consideration of regional variations and age is necessary to optimize the efficiency and utility of BC screening in China, with the ultimate goal to reduce BC mortality. ©AlphaMed Press.

  9. Low-dose CT pulmonary angiography on a 15-year-old CT scanner: a feasibility study

    Directory of Open Access Journals (Sweden)

    Moritz Kaup

    2016-12-01

    Full Text Available Background Computed tomography (CT low-dose (LD imaging is used to lower radiation exposure, especially in vascular imaging; in current literature, this is mostly on latest generation high-end CT systems. Purpose To evaluate the effects of reduced tube current on objective and subjective image quality of a 15-year-old 16-slice CT system for pulmonary angiography (CTPA. Material and Methods CTPA scans from 60 prospectively randomized patients (28 men, 32 women were examined in this study on a 15-year-old 16-slice CT scanner system. Standard CT (SD settings were 100 kV and 150 mAs, LD settings were 100 kV and 50 mAs. Attenuation of the pulmonary trunk, various anatomic landmarks, and image noise were quantitatively measured; contrast-to-noise ratios (CNR and signal-to-noise ratios (SNR were calculated. Three independent blinded radiologists subjectively rated each image series using a 5-point grading scale. Results CT dose index (CTDI in the LD series was 66.46% lower compared to the SD settings (2.49 ± 0.55 mGy versus 7.42 ± 1.17 mGy. Attenuation of the pulmonary trunk showed similar results for both series (SD 409.55 ± 91.04 HU; LD 380.43 HU ± 93.11 HU; P = 0.768. Subjective image analysis showed no significant differences between SD and LD settings regarding the suitability for detection of central and peripheral PE (central SD/LD, 4.88; intra-class correlation coefficients [ICC], 0.894/4.83; ICC, 0.745; peripheral SD/LD, 4.70; ICC, 0.943/4.57; ICC, 0.919; all P > 0.4. Conclusion The LD protocol, on a 15-year-old CT scanner system without current high-end hardware or post-processing tools, led to a dose reduction of approximately 67% with similar subjective image quality and delineation of central and peripheral pulmonary arteries.

  10. Pilot study: relative dose of the TLD, OSL and Radiochromic film applied in CT exams dosimetry

    International Nuclear Information System (INIS)

    Kikuti, C.F.; Maia, R.S.I.; Romano, R.F.T.; Daros, K. A.C.

    2015-01-01

    At DDI/UNIFESP, the abdomen and chest CT exams correspond to 38% of the exams, becoming the focus of studies. The aim of this study is to assess the relative dose using TLDs, OSLs and RF for the evaluation of the dose distribution in the skin in abdomen CT exams. The simulation of the CT exam was performed in an anthropomorphic phantom, using a CT scanner Philips, Brilliance/64 and TLDs, OSLs and RF fixed along the sagittal axis of the phantom. The OSLs showed similar performance to the TLDs and RF shows low accuracy, resulting in an average value (0.927±0.022). (author)

  11. Pilot study: relative dose of the TLD, OSL and Radiochromic film applied in CT exams dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kikuti, C.F. [Universidade Federal do Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Hospital Universitario Maria Aparecida Pedrossian; Maia, R.S.I.; Romano, R.F.T.; Daros, K. A.C., E-mail: daros.kellen@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Departamento de Diagnostico por Imagem

    2015-07-01

    At DDI/UNIFESP, the abdomen and chest CT exams correspond to 38% of the exams, becoming the focus of studies. The aim of this study is to assess the relative dose using TLDs, OSLs and RF for the evaluation of the dose distribution in the skin in abdomen CT exams. The simulation of the CT exam was performed in an anthropomorphic phantom, using a CT scanner Philips, Brilliance/64 and TLDs, OSLs and RF fixed along the sagittal axis of the phantom. The OSLs showed similar performance to the TLDs and RF shows low accuracy, resulting in an average value (0.927±0.022). (author)

  12. A study on usefulness of CT arthrography for the temporomandibular joint

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Shumei [Osaka Univ. (Japan). School of Dentistry

    1992-06-01

    In the field of orthopedics, CT arthrography has been utilized for the shoulder and the knee joints diagnosis. In this study, CT arthrography was applied to the temporomandibular joint (TMJ) and the usefulness of this method was evaluated experimentally and clinically. In the experimental study, CT, CT arthrography and arthrotomogtaphy were compared each other with serial section from human autopsy specimen. It was confirmed that arthrography was indispensable for diagnosis of the location and configuration of the articular disk. In the sagittal section, CT arthrography was almost equal to arthrotomography. But in the coronal section, CT arthrography proved to be advantageous to arthrotomography, because there were various blur images on the arthrotomographic images from the complex bony structures of the skull. In the clinical study, coronal CT arthrography was applied for the patients with internal derangements of the TMJ. The mesio-lateral displacement of the disk (62%), perforation of the attachment (23%), and the intra-articular adhesion (70%) could be diagnosed. BY CT arthrography, the mesio-lateral displacement of the disk was more clearly diagnosed and the intra-articular adhesions were proved with higher rate than by the arthrotomography. From this study, it was concluded that CT arthrography has an important role in diagnosis of the TMJ soft tissue. (author) 51 refs.

  13. Fatty liver: prospective comparative study with sonography and CT

    International Nuclear Information System (INIS)

    Kim, Sung Jin; Kim, Y. M.; Kim, W. S.; Choi, B. I.; Lee, J. S.; Han, C. K.; Kim, C. W.

    1990-01-01

    To identify the reasonable criteria in detection of the degree of Fatty liver, we prospectively evaluated sonograms and CT scans in 33 Patients With bright liver on sonography. On sonograms, we analyzed the echogenicity of the liver, acoustic attenuation, and visualization of the portal vein and the diaphragm, Each criterion was scored from 0 to 2. CT criterion for fatty liver was assessed by the attenuation difference between the liver and the spleen on nonocontrast CT scans, The average sonographic grade for CT Grade I was 1.3, Grade II was 2.1,and Grade III was 2.8. The accurate detection rate of each sonographic grade was as follows, Grade

  14. Clinical study of retrocaval ureter diagnosed by CT scan

    International Nuclear Information System (INIS)

    Kiriyama, Isao; Hata, Ryosuke; Amemiya, Hiroshi

    1987-01-01

    Although retrocaval ureter is relatively uncommon congenital anomaly, surgical intervention is often necessary to alleviate the clinical signs and symptoms of the patients. Vena cavography has been indispensable imaging modality for the definitive diagnosis of this anomaly. Recently, however, CT scan in addition to excretory urography (IVP) and retrograde pyelography(RP) has been utilized in many reported cases in the diagnosis of retrocaval ureter. We have experienced 3 cases of retrocaval ureter consecutively. In this paper we report these 3 cases of retrocaval ureter, in which CT scan enabled us to confirm the definitive diagnosis. We also report another case of pelviureteric stenosis that was taken for retrocaval ureter by CT scan. Causes of the misdiagnosis is discussed. In conclusion CT scan is useful diagnostic modality in the diagnosis of retrocaval ureter and this lesser invasive technique might lessen the need for vena cavography. (author)

  15. Low-Dose Contrast-Enhanced Breast CT Using Spectral Shaping Filters: An Experimental Study.

    Science.gov (United States)

    Makeev, Andrey; Glick, Stephen J

    2017-12-01

    Iodinated contrast-enhanced X-ray imaging of the breast has been studied with various modalities, including full-field digital mammography (FFDM), digital breast tomosynthesis (DBT), and dedicated breast CT. Contrast imaging with breast CT has a number of advantages over FFDM and DBT, including the lack of breast compression, and generation of fully isotropic 3-D reconstructions. Nonetheless, for breast CT to be considered as a viable tool for routine clinical use, it would be desirable to reduce radiation dose. One approach for dose reduction in breast CT is spectral shaping using X-ray filters. In this paper, two high atomic number filter materials are studied, namely, gadolinium (Gd) and erbium (Er), and compared with Al and Cu filters currently used in breast CT systems. Task-based performance is assessed by imaging a cylindrical poly(methyl methacrylate) phantom with iodine inserts on a benchtop breast CT system that emulates clinical breast CT. To evaluate detectability, a channelized hoteling observer (CHO) is used with sums of Laguerre-Gauss channels. It was observed that spectral shaping using Er and Gd filters substantially increased the dose efficiency (defined as signal-to-noise ratio of the CHO divided by mean glandular dose) as compared with kilovolt peak and filter settings used in commercial and prototype breast CT systems. These experimental phantom study results are encouraging for reducing dose of breast CT, however, further evaluation involving patients is needed.

  16. How is adults' screen time behaviour influencing their views on screen time restrictions for children? A cross-sectional study.

    Science.gov (United States)

    Schoeppe, Stephanie; Rebar, Amanda L; Short, Camille E; Alley, Stephanie; Van Lippevelde, Wendy; Vandelanotte, Corneel

    2016-03-01

    High screen time in children and its detrimental health effects is a major public health problem. How much screen time adults think is appropriate for children remains little explored, as well as whether adults' screen time behaviour would determine their views on screen time restrictions for children. This study aimed to investigate how adults' screen time behaviour influences their views on screen time restrictions for children, including differences by gender and parental status. In 2013, 2034 Australian adults participated in an online survey conducted by the Population Research Laboratory at Central Queensland University, Rockhampton. Adult screen time behaviour was assessed using the Workforce Sitting Questionnaire. Adults reported the maximum time children aged between 5-12 years should be allowed to spend watching TV and using a computer. Ordinal logistic regression was used to compare adult screen time behaviour with views on screen time restrictions for children. Most adults (68%) held the view that children should be allowed no more than 2 h of TV viewing and computer use on school days, whilst fewer adults (44%) thought this screen time limit is needed on weekend days. Women would impose higher screen time restrictions for children than men (p 2 h on watching TV and using the computer at home on work days (66%) and non-work days (88%). Adults spending ≤ 2 h/day in leisure-related screen time were less likely to permit children > 2 h/day of screen time. These associations did not differ by adult gender and parental status. Most adults think it is appropriate to limit children's screen time to the recommended ≤ 2 h/day but few adults themselves adhere to this screen time limit. Adults with lower screen use may be more inclined to limit children's screen time. Strategies to reduce screen time in children may also need to target adult screen use.

  17. Feasibility study of CT perfusion imaging for prostate carcinoma

    International Nuclear Information System (INIS)

    Cullu, Nesat; Kantarci, Mecit; Ogul, Hayri; Pirimoglu, Berhan; Karaca, Leyla; Kizrak, Yesim; Adanur, Senol; Koc, Erdem; Polat, Ozkan; Okur, Aylin

    2014-01-01

    The aim of this feasibility study was to obtain initial data with which to assess the efficiency of perfusion CT imaging (CTpI) and to compare this with magnetic resonance imaging (MRI) in the diagnosis of prostate carcinoma. This prospective study involved 25 patients with prostate carcinoma undergoing MRI and CTpI. All analyses were performed on T2-weighted images (T2WI), apparent diffusion coefficient (ADC) maps, diffusion-weighted images (DWI) and CTp images. We compared the performance of T2WI combined with DWI and CTp alone. The study was approved by the local ethics committee, and written informed consent was obtained from all patients. Tumours were present in 87 areas according to the histopathological results. The diagnostic performance of the T2WI+DWI+CTpI combination was significantly better than that of T2WI alone for prostate carcinoma (P < 0.001). The diagnostic value of CTpI was similar to that of T2WI+DWI in combination. There were statistically significant differences in the blood flow and permeability surface values between prostate carcinoma and background prostate on CTp images. CTp may be a valuable tool for detecting prostate carcinoma and may be preferred in cases where MRI is contraindicated. If this technique is combined with T2WI and DWI, its diagnostic value is enhanced. (orig.)

  18. Morphological study of maxillary canine region based on CT

    International Nuclear Information System (INIS)

    Yamada, Maiko; Takamori, Hitoshi; Ide, Yoshiaki; Yosue, Takashi

    2010-01-01

    The maxilla is generally known as a site where anatomical limitations make it difficult to obtain sufficient bone volume. A large amount of bone exists in the canine region between the anterior margin of the maxillary sinus and the piriform aperture margin. Although this region is crucial for implant treatments, there have not been any reports on morphological studies of the region. In this study, we investigated the morphology of the canine region based on CT, and also the morphology and position of the maxillary sinus located posterior to the canine region. The results were as follows: In the area above the anterior nasal spine, the higher the level, the smaller the mesio-distal length and the bucco-lingual width tended to become. In the area above the anterior nasal spine, the mesio-distal length and the bucco-lingual width tended to be smaller in female patients than in male patients. In the area above the anterior nasal spine, no significant differences in mesio-distal length and bucco-lingual width were observed between dentulous and edentulous jaws. The morphology of the maxillary sinus was mainly of an inverse-trapezoidal, circular, or triangular form. The position of the anterior wall of the maxillary sinus was most frequently found at the site corresponding to the second premolar. Through this study, we have reconfirmed that the canine region is vital for implant treatments in the maxilla. (author)

  19. Colonoscopic screening for colorectal cancer improves quality of life measures: a population-based screening study

    Directory of Open Access Journals (Sweden)

    Shadbolt Bruce

    2006-10-01

    Full Text Available Abstract Background Screening asymptomatic individuals for neoplasia can have adverse consequences on quality of life. Colon cancer screening is widespread but the quality of life (QOL consequences are unknown. This study determined the impact of screening colonoscopy on QOL measures in asymptomatic average-risk participants. Methods Asymptomatic male and female participants aged 55–74 years were randomly selected from the Australian Electoral Roll or six primary care physicians' databases. Participants completed the Short-Form (SF-36 Quality of Life Assessment at baseline and at a mean of 39 days after colonoscopy. Outcome measures were (i significant changes in raw scores in any of the eight SF-36 domains assessed following colonoscopic screening and (ii improvements or declines in previously validated categories, representing clinically significant changes, within any of the eight SF-36 domains. Results Baseline QOL measures were similar to those of a matched general population sample. Role Limitations due to Emotions, Mental Health and Vitality raw scores significantly improved following colonoscopy (P Conclusion Average-risk persons benefit significantly from colon cancer screening with colonoscopy, improving in Mental Health and Vitality domains of Quality of Life. This improvement is not offset by declines in other domains.

  20. PET/CT-guided interventional procedures: rationale, justification, initial study, and research plan

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.; Rahill, J.; Cleary, K. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Petrillo, S.; Earl-Graef, D. [Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Banovac, F.; Levy, E. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Shekhar, R. [Dept. of Radiology, Univ. of Maryland Medical Center, Baltimore, MD (United States)

    2007-06-15

    Positron-emission tomography (PET) and PET/CT (computed tomography) are becoming increasingly important for diagnosis and treatment of cancer. Clinically relevant changes can sometimes be seen on PET that are not seen on other imaging modalities. However, PET is not suitable for guiding biopsy as the images are not obtained in real-time. Therefore, our research group has begun developing a concept for PET/CT-guided interventional procedures. This paper presents the rationale for this concept, outlines our research plan, and includes an initial study to evaluate the relative sensitivity of CT and PET/CT in detecting suspicious lesions. (orig.)

  1. A Study on Knowledge and Screening for Cervical Cancer among ...

    African Journals Online (AJOL)

    A Study on Knowledge and Screening for Cervical Cancer among Women in ... and source of information for awareness of women about cervical cancer in India. ... Results: Majority of the women have poor knowledge about cervical cancer ...

  2. Percutaneous CT-guided lung biopsy: sequential versus spiral scanning. A randomized prospective study

    International Nuclear Information System (INIS)

    Ghaye, B.; Dondelinger, R.F.; Dewe, W.

    1999-01-01

    The aim of this study was to evaluate in a prospective and randomized study spiral versus sequential scanning in the guidance of percutaneous lung biopsy. Fifty thoracic lesions occurring in 48 patients were biopsied by a senior and a junior operator. Six different time segments of the procedure were measured. Scanning mode versus length of procedure, pathological results, irradiation and complications were evaluated. Total duration of the procedure and of the first sampling was significantly longer with spiral CT for the senior operator (p < 0.004). No significant time difference was observed for the junior operator. Diameter of the lesion, depth of location, position of the patient and needle entry site did not influence the results. The sensitivity was 90.9, specificity 100, positive predictive value 100 and negative predictive value 60 % for spiral CT, and 94.7, 100, 100 and 85.7 % for sequential CT, respectively. Eleven pneumothoraces and ten perinodular hemorrhages were seen with spiral CT and six and ten, respectively, with sequential CT. The mean dose of irradiation was 4027 mAs for spiral CT and 2358 mAs for conventional CT. Spiral CT does neither reduce procedure time nor the rate of complications. Pathological results do not differ compared with sequential CT, and total dose of irradiation is higher with spiral scanning. (orig.)

  3. Improved attenuation correction for respiratory gated PET/CT with extended-duration cine CT: a simulation study

    Science.gov (United States)

    Zhang, Ruoqiao; Alessio, Adam M.; Pierce, Larry A.; Byrd, Darrin W.; Lee, Tzu-Cheng; De Man, Bruno; Kinahan, Paul E.

    2017-03-01

    Due to the wide variability of intra-patient respiratory motion patterns, traditional short-duration cine CT used in respiratory gated PET/CT may be insufficient to match the PET scan data, resulting in suboptimal attenuation correction that eventually compromises the PET quantitative accuracy. Thus, extending the duration of cine CT can be beneficial to address this data mismatch issue. In this work, we propose to use a long-duration cine CT for respiratory gated PET/CT, whose cine acquisition time is ten times longer than a traditional short-duration cine CT. We compare the proposed long-duration cine CT with the traditional short-duration cine CT through numerous phantom simulations with 11 respiratory traces measured during patient PET/CT scans. Experimental results show that, the long-duration cine CT reduces the motion mismatch between PET and CT by 41% and improves the overall reconstruction accuracy by 42% on average, as compared to the traditional short-duration cine CT. The long-duration cine CT also reduces artifacts in PET images caused by misalignment and mismatch between adjacent slices in phase-gated CT images. The improvement in motion matching between PET and CT by extending the cine duration depends on the patient, with potentially greater benefits for patients with irregular breathing patterns or larger diaphragm movements.

  4. Evaluation of radiation exposure with singleslice- and a multislice-spiral CT system (a phantom study)

    International Nuclear Information System (INIS)

    Giacomuzzi, S.M.; Rieger, M.; Lottersberger, C.; Peer, S.; Peer, R.; Buchberger, W.; Bale, R.; Mallouhi, A.; Jaschke, W.; Torbica, P.; Perkmann, R.

    2001-01-01

    The purpose of study was to compare patient dose applying singleslice- and multislice-spiral CT. Methods: The examinations were performed with a singleslice-spiral CT (Highspeed Advantage; GE Medical Systems; Milwaukee, USA) and with a multislice CT systems (LightSpeed QX/i GE Medical Systems; Milwaukee, USA). For the determination of the radiation exposure (absorbed dose) a selection of most executed protocols (thorax-helical, abdomen-helical, petrous bone-axial, head-axial) were simulated using an Alderson Rando Phantom. The dose was determined by means of lithiumfluorid-thermoluminescence dosimeters (TLD-GR 200). Results: For thorax and abdomen protocols higher energy dose values could be found using a multislice CT. On the average the energy dose values were increased by 2.6 on an average in relation to single slice spiral CT. The energy dose values of the multisclice CT using head protocols could be reduced by 30% in relation to single slice spiral CT due to suitable parameter selections. The energy dose applying a petrous bone protocol resulted in an average increase by a factor 1.5 using a multislice CT. Conclusion: Using the new multislice CT technique protocol strategies must be optimized regarding the patient doses. Users can operate critically in the sense of the radiation protection only if they are aware of the occurring dose amounts to the patient. (orig.) [de

  5. A CT study of the prevalence of carotid artery calcification in dental patients

    International Nuclear Information System (INIS)

    Yoon, Suk Ja; Lee, Jae Seo; Yoon, Woong

    2006-01-01

    Stroke is one of the leading causes of death in Korea. Atherosclerotic disease in the carotid artery bifurcation is the most common cause of stroke. The carotid artery calcification is easily appreciated by CT(Computed tomography). CT is often taken in a dental hospital for the diagnosis of inflammation. injury, cyst or tumor on maxillofacial region. However, there was no report of carotid artery calcification on CT in dental patients. The presence of carotid artery calcification was evaluated by an experienced radiologist on CT scans of 287 patients (166 males, 121 females, average age 42, range 6 to 86 years) and the medical history of the patient and the interpretation of CT were reviewed. Carotid artery calcification was detected on CT scans of 57 patients (19.8%; 35 males, 22 females). All the male patients with carotid artery calcification were older than 50, and all the female patients with carotid artery calcification were older than 60. Among the 57 patients, 10 had Diabetes mellitus, 20 had cardiovascular disease, 3 had history of stroke and 3 underwent radiation therapy for head and neck cancer. Carotid artery calcification was not included in the interpretation of CT of dental patients except one patient. The prevalence of carotid artery calcification on CT of dental patients was about 20% in this study. Carotid artery calcification should be included in the interpretation of CT of dental patients

  6. Stroke Pattern in Enugu. A Study of CT images in South East Nigeria ...

    African Journals Online (AJOL)

    Non-contrast cranial computed tomography (CT) scan reliably distinguishes between ischemic stroke (IS) and hemorrhagic strokes (HS) and will provide a reliable characterization of stroke types in the developing countries. Aims: To examine stroke types based on CT Imaging studies and the differences in stroke types ...

  7. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark

    DEFF Research Database (Denmark)

    Hansen, David Christoffer; Seco, Joao; Sørensen, Thomas Sangild

    2015-01-01

    Background. Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in...... development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. Material and methods. A CT calibration phantom and an abdomen cross section...... phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling...

  8. Micro-CT in situ study of carbonate rock microstructural evolution for geologic CO2 storage

    DEFF Research Database (Denmark)

    Zheng, Yi; Yang, Yan; Rogowska, M.

    2017-01-01

    to achieve this is to find a suitable condition to create a stable 3D space in carbonate rock by injecting liquid to prepare space for the later CO2 injection. Micro-CT imaging is a non-destructive 3D method that can be used to study the property changes of carbonate rocks during and after CO2 injection....... The advance in lab source based micro-CT has made it capable of in situ experiments. We used a commercial bench top micro-CT (Zeiss Versa XRM410) to study the microstructure changes of chalk during liquid injection. Flexible temporal CT resolution is essential in this study because that the time scales...... of coupled physical and chemical processes can be very different. The results validated the feasibility of using a bench top CT system with a pressure cell to monitor the mesoscale multiphase interactions in chalk....

  9. Cystic degeneration of liver malignancies. Study by US and CT

    Energy Technology Data Exchange (ETDEWEB)

    Kumada, Takashi; Nakano, Satoshi; Kitamura, Kimio; Watahiki, Hajime; Takeda, Isao

    1983-03-01

    CT and US were carried out on 81 patients with hepatocellular carcinoma, 20 patients with cholangiocellular carcinoma and 94 patients with metastatic liver cancer. 1) Cystic degeneration was observed in one with hepatocellular carcinoma (1.2%), one with cholangiocellular carcinoma (5.0%) and 12 with metastatic liver cancer (12.8%) by US, but this change was observed in only 5 by CT (1,0,4, respectively). Metastatic liver cancer showed the highest incidence among these tumors. 2) The characteristics of cystic degeneration of the liver tumors were thickened wall and irregularity of the inner surface of the wall. 3) Judging from macroscopic and histopathological findings, liquefactive necrosis in the tumors was shown as ''echoluent'' area. We concluded that cystic degeneration was one of the important findings in metastatic liver cancer and that careful observation by US and CT avoided the confusion with other hepatic cystic diseases.

  10. Multi-institutional collaborating study on CT scan of schizophrenia

    International Nuclear Information System (INIS)

    Takahashi, Ryo; Sato, Tokijiro; Okuma, Teruo

    1984-01-01

    More abnormal CT findings were observed in nuclear schizophrenic patients (55%) than in the matchable controls with a statistically significant difference. According to the site of the brain, these were marked in the whole ventricle (especially the third ventricle) and in the cortex including the longitudinal fissure, frontal lobe, temporal lobe, and sylvian fissure (especially of the left hemisphere). There was no correlation between the cerebral ventricular enlargement and the patient's age, the duration of illness or drug dosage, suggesting that the enlargement may exist from the onset of the disease. Aging or taking drug(s) were also not responsible for the cortical atrophy. CT findings were associated mainly with negative symptoms. In particular, the association between abnormalities of the left hemisphere and psychiatric symptoms was marked. Direct measurements of CT images revealed significantly higher incidences only in the third ventricular enlargement in schizophrenic patients. These results suggest the possibility that subtypes of schizophrenia can be classified. (Namekawa, K.)

  11. [Hearing screening at nursery schools: results of an evaluation study].

    Science.gov (United States)

    Weichbold, Viktor; Rohrer, Monika; Winkler, Cornelia; Welzl-Müller, Kunigunde

    2004-07-31

    This study aimed to evaluate the hearing screening of pre-school children at nursery schools in Tyrol, Austria. 47 nursery schools with a total of 2199 enrolled children participated in the study. At the screening, the children were presented a series of tones at frequencies 0.5 kHz (25dB), 1 kHz, 2 kHz, 3 kHz, and 4 kHz (20 dB each) from portable audiometers. The tones were presented over headphones for each ear separately and at irregular intervals. Failure to respond to any of the frequencies was considered failure of the screening. Parents were then advised in written form to have the child examined by an ENT-specialist. 1832 individuals were screened (coverage: 83% of nursery school children; corresponding to at least 63% of all Tyrolean children aged 3 to 5 years). Of these, 390 failed the test (referral rate: 21% of all screened). Examination through an ENT-specialist occurred with 217 children, and this confirmed the positive test in 139 children (hit rate: 64%). In most cases, a temporary conductive hearing loss due to external or middle ear problems (glue ear, tube dysfunction, cerumen, otitis media) was diagnosed. A sensorineural hearing loss was found in 4 children (in 3 of them bilateral). The need for therapy was recognized in 81 children (4% of all screened). Pre-school hearing screening identifies children with ear and hearing problems that need therapeutical intervention. Although the hearing problems are mostly of a temporary nature, some may require monitoring over some period. Also some children with permanent sensorineural hearing loss may be detected through this measure. Hearing screening is an efficient means of assessing ear and hearing problems in pre-school children. However, the follow-up rate needs to be improved for optimizing the efficacy.

  12. A comparative study of FDG PET/CT and enhanced multi-detector CT for detecting liver metastasis according to the size and location.

    Science.gov (United States)

    Park, Jung Mi; Kim, Il Young; Kim, Sang Won; Lee, Sang Mi; Kim, Hyun Gi; Kim, Shin Young; Shin, Hyung Chul

    2013-04-01

    The aim of this study was to compare the diagnosability between (18)F-fluorodeoxyglucose (FDG) PET/CT and enhanced multi-detector CT (MDCT) for the detection of liver metastasis (LM) according to the size and location in liver and to evaluate standard maximum standardized uptake values (SUVmax) of all liver metastatic lesions. One hundred two consecutive patients with malignancy who underwent both FDG PET/CT and MDCT for LM evaluation were retrospectively reviewed. Among them, 56 patients with LM were enrolled in this study. LM was confirmed by follow-up imaging studies after at least 6 months or by histopathology. FDG PET/CT and MDCT images were visually analyzed using three-point scale by the consensus of two radiologists and two nuclear medicine physicians. The size and location (central vs. sub-capsular) of the all liver lesions were evaluated using MDCT images. Furthermore, SUVmax of all liver lesions on FDG PET/CT images were calculated. A total of 146 liver lesions were detected by FDG PET/CT and MDCT and 142 of the lesions were diagnosed as LM. The detection rates of MDCT and FDG PET/CT for LM by visual analysis were 77 and 78%, respectively. There was no significant difference of detection rate according to the overall location and size of the lesions. However, FDG PET/CT was more sensitive than MDCT for detecting small and sub-capsular LM. The detection rate of FDG PET/CT for LM was 68% by the cutoff SUVmax of 2.7. Although the diagnosabilities of MDCT and FDG PET/CT for detecting LM were comparable, FDG PET/CT is superior to MDCT for detecting small LM located in the sub-capsular portion of liver.

  13. CT quantitative diagnosis in fatty liver. An experimental study

    International Nuclear Information System (INIS)

    Zhao Hong; Li Binxiang; Zhang Lizhong; Liang Jianfang

    1997-01-01

    Purpose: To evaluate the relation between liver fat content and CT value in animal experiment for the diagnosis and treatment of fatty liver in clinical practice. Materials and methods: Fatty liver model was established in 30 Wistar rats (experimental group), 5 rats was used as the control group. The 5 rats of the control group and 5 rats randomly chosen from experimental group at the first, second, third, and the fourth weekends, were measured for the CT number of total liver. Three pieces of liver specimen from each rats were removed from left, central and right lobes for histologic examination. The ratio of liver fat content to liver volume (Vv value) was measured by microscopic image pattern analyzer. Results: Significant linear negative correlation (r = -0.950, t = 12.90, P<0.001) was found between CT and Vv values. Conclusion: Using CT monitoring, the degree and amount of liver fat could be assessed and liver biopsy obviated in the diagnosis and follow up during treatment of fatty liver

  14. Reducing dose in head CT: A phantom study

    International Nuclear Information System (INIS)

    Perez Diaz, M.; Carvalho, A. E.; Andrade, M. E.; Khoury, H. J.

    2013-01-01

    Thirty two head CT scans were acquired employing an anthropomorphic phantom which contains small lesions in posterior fosse, using 2 scanners, one with 64 slices 'Siemens Sensation' and other with 6 slices P hilip Brilliance . Parameters as Tube current (I [mA]), Collimation (C [mm]), spectrum energy (kVp) and dynamic range were changed during studies, looking for the optimal acquisition/processing conditions which permit both, good lesion detectability and the lowest dose. Air kerma (mGy) was measured with a ionization chamber and the air kerma index (Ca,100 [mGy]) was calculated as dose index. Image quality was analyzed by 5 expert criteria using a 5 points-scale (1=poor, 2=fair, 3=good, 4=very good, 5=excellent) and also using 5 Figure of merit in the spatial and frequency domains: Contrast C(%), Contrast to Noise Ratio CNR, Signal to Noise Ratio SNR, Normalized Mean Square Error (NMSE) and the Spectral Distance (SD). Objective and subjective results were correlated. We observed that doses can be diminished until a 25% respect to the usual practice with both technologies, diminishing mainly the mAs, without affecting lesion detection. As a result, we propose an optimized protocol for each scanner as follow: The use of 250 mAs, 120 kVp and the collimation of 6 slices x 1.50 mm per rotation to detect the lesions in posterior fosse with good image quality for the Philips Brilliance 6 tested, while 150 mAs, 100 kVp and slice thickness of 3 mm were needed with the Siemens Sensation 64. (Author)

  15. IronMaking Process Alternatives Screening Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2000-10-01

    This study by Lockwood Greene evaluates a number ironmaking processes. The appendices provide greater detail and further exploration of the ironmaking processes, including components, relative costs, and comparisons.

  16. [Comparing audiological evaluation and screening: a study on presbycusis].

    Science.gov (United States)

    Samelli, Alessandra Giannella; Negretti, Camila Aparecida; Ueda, Kerli Saori; Moreira, Renata Rodrigues; Schochat, Eliane

    2011-01-01

    Given the high prevalence of presbycusis and the damage it brings about, a screening test can be useful in the identification of hearing loss in primary care. To estimate the prevalence of hearing loss in a representative sample of elderly people living at Butantan using an audiological screening method (questionnaire) and a basic audiological evaluation; to compare the results of the two kinds of evaluations, checking the validity of this tool for hearing loss screening. Cross sectional descriptive study. 200 individuals (above 60 years old, both genders) were randomly selected to undergo audiological screening (questionnaire). Another randomly selected group encompassed 100 individuals who were submitted to a set of audiological tests. Then, we compared the results from the two methods. There were no statistically significant associations between the questionnaire and the degree of hearing loss of the patients. The prevalence of hearing loss in our sample was of 56% in the screening and of 95% when checked by the audiological evaluation. Therefore, screening was not proven valid to assess hearing when compared to audiological evaluation.

  17. Diabetic Retinopathy Screening Using Telemedicine Tools: Pilot Study in Hungary

    Directory of Open Access Journals (Sweden)

    Dóra J. Eszes

    2016-01-01

    Full Text Available Introduction. Diabetic retinopathy (DR is a sight-threatening complication of diabetes. Telemedicine tools can prevent blindness. We aimed to investigate the patients’ satisfaction when using such tools (fundus camera examination and the effect of demographic and socioeconomic factors on participation in screening. Methods. Pilot study involving fundus camera screening and self-administered questionnaire on participants’ experience during fundus examination (comfort, reliability, and future interest in participation, as well as demographic and socioeconomic factors was performed on 89 patients with known diabetes in Csongrád County, a southeastern region of Hungary. Results. Thirty percent of the patients had never participated in any ophthalmological screening, while 25.7% had DR of some grade based upon a standard fundus camera examination and UK-based DR grading protocol (Spectra™ software. Large majority of the patients were satisfied with the screening and found it reliable and acceptable to undertake examination under pupil dilation; 67.3% were willing to undergo nonmydriatic fundus camera examination again. There was a statistically significant relationship between economic activity, education and marital status, and future interest in participation. Discussion. Participants found digital retinal screening to be reliable and satisfactory. Telemedicine can be a strong tool, supporting eye care professionals and allowing for faster and more comfortable DR screening.

  18. Chest CT study of patients with asbestos exposure, 1

    International Nuclear Information System (INIS)

    Hatakeyama, Masayuki

    1988-01-01

    Thin-slice high-resolution computed tomographic (CT) findings of 36 patients (34 men, 2 women) with histories of long-term (11 to 43 years) occupational asbestos exposure (AS) were analyzed for pulmonary abnormalities, which were classified by the subpleural curvilinear shadow (SCLS) and/or the extent of honeycomb shadow (HS) into five types (O to IV). SCLS was detected in 22 patients (62 %), and HS in 14 patients (39 %). SCLS was distributed mainly in the lower lobe in patients with mild pulmonary fibrosis (Types I and II) and in segments where fibrosis was mild in patients with HS (Types III and IV). This may reflect the initiation of pulmonary fibrosis leading to the formation of a HS. Most (63.7 %) SCLS measured > 5 cm but < 10 cm in length and occurred < 1 cm from the inner chest wall in all cases. Radiologic-pathologic correlation of SCLS and HS in CT imagings, achieved in two post mortem specimens, seemed to indicate that SCLS was associated with the initial change of fibrosing bronchiolo-alveolitis, which is characteristic of pulmonary asbestosis. Thin-slice high-resolution CT findings of 36 patients with AS and 33 patients with idiopathic interstitial pneumonia (IIP) were compared. Though the incidence of SCLS was low (21 %) in this series of IIP, its presence suggests that SCLS is not specific to pulmonary asbestosis but occurs also in chronic interstitial pneumonia. In order to explore the mechanism of the appearance of SCLS, further analysis of CT and histopathologic findings not only of pulmonary asbestosis and IIP but also of many other pulmonary interstitial diseases is necessary. It could be considered that thin-slice high-resolution CT which first detected SCLS is very useful in the visualization of fine structures of the lungs. (author)

  19. A study of long boone measurement by CT scanogram - Comparison with spot scanogram -

    International Nuclear Information System (INIS)

    Suh, Chang Hae; Kang, Heung Sik; Jung, Jin Wook; Yeon, Kyung Mo

    1987-01-01

    CT scanogram is a new technique for measuring leg length discrepancy and has many advantage as compared with conventional spot scanogram. 30 dried bones were measured by direct measurement, spot scanogram and CT scanogram. Accuracy of CT scanogram was compared with spot scanogram. For evaluation of systemic error of CT, steel rulers and dried bones were measured at two different window settings. Decentering error in spot scanogram was measured by using dried bones, and 180 spots of 30 clinical cases of Beli-thompson studies were reviewed for evaluation of incidence and degree of decentering. The results of measurements of CT and spot scanogram in ideal position and technique were equivalent to those of direct measurements. But in spot scanogram, significant errors were noted in flexion status and decentered film. 54 spot (42.9%) of 30 clinical cases were decentered more than 1 cm. In CT scanogram, decentering error was completely excluded and shortening due to flexion deformity was overcomed by lateral scanogram. CT scanogram is a simple and accurate method for leg length measurement. Thus we recommend CT scanogram as a routine use for evaluation of leg length discrepancy.

  20. Clinical investigation of flat panel CT following middle ear reconstruction: a study of 107 patients

    Energy Technology Data Exchange (ETDEWEB)

    Zaoui, K. [University Hospital Heidelberg, Ruprecht Karls University, Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg (Germany); Kromeier, J. [St. Josefs Hospital, RkK, Department of Radiology, Freiburg (Germany); Neudert, M.; Beleites, T.; Zahnert, T. [University Hospital Dresden, Technical University, Department of Otorhinolaryngology, Head and Neck Surgery, Dresden (Germany); Laszig, R.; Offergeld, C. [University Hospital Freiburg, Albert Ludwigs University, Department of Otorhinolaryngology, Head and Neck Surgery, Freiburg (Germany)

    2014-03-15

    After middle ear reconstruction using partial or total ossicular replacement prostheses (PORP/TORP), an air-bone gap (ABG) may persist because of prosthesis displacement or malposition. So far, CT of the temporal bone has played the main role in the diagnosis of reasons for postoperative insufficient ABG improvement. Recent experimental and clinical studies have evaluated flat panel CT (fpCT) as an alternative imaging technique that provides images with high isovolumetric resolution, fewer metal-induced artefacts and lower irradiation doses. One hundred and seven consecutive patients with chronic otitis media with or without cholesteatoma underwent reconstruction by PORP (n = 52) or TORP (n = 55). All subjects underwent preoperative and postoperative audiometric testing and postoperative fpCT. Statistical evaluation of all 107 patients as well as the sole sub-assembly groups (PORP or TORP) showed a highly significant correlation between hearing improvement and fpCT-determined prosthesis position. FpCT enables detailed postoperative information on patients with middle ear reconstruction. FpCT is a new imaging technique that provides immediate feedback on surgical results after reconstructive middle ear surgery. Specific parameters evaluated by fpCT may serve as a predictive tool for estimated postoperative hearing improvement. Therefore this imaging technique is suitable for postoperative quality control in reconstructive middle ear surgery. (orig.)

  1. A clinical study of mucin producing tumor of pancreas with US and CT

    International Nuclear Information System (INIS)

    Suzuki, Tadashi; Imaizumi, Toshihide; Nakasako, Toshiaki; Hatori, Takashi; Takasaki, Ken

    1999-01-01

    We conclude that multilocular cysts are 3 cm and over, or elevated types as in mucin producing pancreatic tumors must be neoplasm in the pathological study. But, we question whether or not we can diagnose the elevated type before the operation. So, for the purpose of making a clear guideline of diagnosis for elevated types, we examined 46 operating cases of mucin producing tumors (Kuroda type I) documented from 1985 to 1994. We examined existence, height and properties of elevated lesions, 25 cases of elevated type and 21 cases of flat type. There is a significant difference of height with US and CT, and existence of enhancement with CT. As a result, we have obtained the following guidelines. The height of an elevated lesion with US is 4 mm and over, and the height of that with CT is 3 mm and over. It is enhanced with CT. Therefore, we find it possible to diagnose elevated types with US and CT. (author)

  2. Phytochemical screening and study of comparative antibacterial ...

    African Journals Online (AJOL)

    SARAH

    2013-06-30

    Jun 30, 2013 ... Objectives: In this study, methanol, ethanol and aqueous extracts of ... of resistance in bacteria previously susceptible to ... increase in antibiotic resistance in hospitals and ..... extraction process (Masoko et al., 2008). Use of ...

  3. Clinical utility of FDG PET/CT in acute complicated pyelonephritis - results from an observational study

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Chih-Hsing [Mackay Memorial Hospital at Taipei, Department of Nuclear Medicine, Taipei (China); Tseng, Jing-Ren; Yen, Tzu-Chen [Chang Gung Memorial Hospital at Linkou, Department of Nuclear Medicine and Center for Advanced Molecular Imaging and Translation, Taoyuan (China); Chang Gung University, Department of Medical Imaging and Radiological Science, College of Medicine, Taoyuan (China); Lee, Ming-Hsun [Chang Gung Memorial Hospital at Linkou, Division of Infectious Diseases, Department of Internal Medicine, Taoyuan (China); Yang, Lan-Yan [Chang Gung Memorial Hospital at Linkou, Biostatistics Unit, Clinical Trial Center, Taoyuan (China)

    2018-03-15

    Acute complicated pyelonephritis (ACP) is an upper urinary tract infection associated with coexisting urinary tract abnormalities or medical conditions that could predispose to serious outcomes or treatment failures. Although CT and magnetic resonance imaging (MRI) are frequently used in patients with ACP, the clinical value of {sup 18}F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) has not been systematically investigated. This single-center retrospective study was designed to evaluate the potential usefulness of FDG PET/CT in patients with ACP. Thirty-one adult patients with ACP who underwent FDG PET/CT were examined. FDG PET/CT imaging characteristics, including tracer uptake patterns, kidney volumes, and extrarenal imaging findings, were reviewed in combination with clinical data and conventional imaging results. Of the 31 patients, 19 (61%) showed focal FDG uptake. The remaining 12 study participants showed a diffuse FDG uptake pattern. After volumetric approximation, the affected kidneys were found to be significantly enlarged. Patients who showed a focal uptake pattern had a higher frequency of abscess formation requiring drainage. ACP patients showing diffuse tracer uptake patterns had a more benign clinical course. Seven patients had suspected extrarenal coinfections, and FDG PET/CT successfully confirmed the clinical suspicion in five cases. FDG PET/CT was as sensitive as CT in identifying the six patients (19%) who developed abscesses. Notably, FDG PET/CT findings caused a modification to the initial antibiotic regimen in nine patients (29%). FDG PET/CT may be clinically useful in the assessment of patients with ACP who have a progressive disease course. (orig.)

  4. Clinical studies on thyroid CT number in Graves' disease and destructive thyrotoxicosis

    International Nuclear Information System (INIS)

    Kamijo, Keiichi

    1994-01-01

    The purpose of the present study was to investigate CT Hounsfield unit (H.U.) of the thyroid in hyperthyroid and euthyroid Graves' disease and destructive thyrotoxicosis. The mean thyroid CT number in 95 controls was 122±18 H.U.(±SD) and did not change significatly with advancing age. The mean thyroid CT number (±SD) of 85±22 H.U. in 60 patients with hyperthyroid Graves' disease was significantly lower than either in normal controls or 116±22 H.U. in 11 patients with euthyroid Graves' disease. Comparison of thyroid hormones and TSH receptor Ab values of untreated patients with a normal and an abnormally low thyroid CT number showed that serum total and free T 3 were significantly higher in the latter group than the former group. With respect to the effect of methimazol (MMI) on the thyroid CT number, in the untreated 10 patients with a low thyroid CT number, the initial mean CT number was 65±11 H.U. and increased significantly to 76±14 H.U. after treatment with MMI. In contrast, in 6 patients with a normal thyroid CT number prior to therapy, the initial mean thyroid CT number was 102±11 H.U. and fell significantly to 84±16 H.U. after treatment with MMI. The thyroid CT number in destructive thyrotoxicosis is markedly decreased to less than 70 H.U. and the mean values of 57±7 H.U. in 6 patients with silent thyroiditis and of 61±5 H.U. in 7 with subacute thyroiditis differ significantly from Graves' disease. In conclusion, the thyroid CT number is significantly reduced in hyperthyroid Graves' disease, normal in euthyroid Graves' disease and markedly decreased in destructive thyrotoxicosis. The high T-3 value seemed to play an important role in the pathogenesis of a decline in the thyroid CT number in Graves' disease. An antithyroid drug therapy caused two different changes in the thyroid CT number, depending on whether the thyroid CT number prior to therapy was normal or low. (author)

  5. Clinical studies on thyroid CT number in Graves' disease and destructive thyrotoxicosis

    Energy Technology Data Exchange (ETDEWEB)

    Kamijo, Keiichi (Kamijo Thyroid and Pituitary Clinic, Sapporo (Japan))

    1994-02-01

    The purpose of the present study was to investigate CT Hounsfield unit (H.U.) of the thyroid in hyperthyroid and euthyroid Graves' disease and destructive thyrotoxicosis. The mean thyroid CT number in 95 controls was 122[+-]18 H.U.([+-]SD) and did not change significatly with advancing age. The mean thyroid CT number ([+-]SD) of 85[+-]22 H.U. in 60 patients with hyperthyroid Graves' disease was significantly lower than either in normal controls or 116[+-]22 H.U. in 11 patients with euthyroid Graves' disease. Comparison of thyroid hormones and TSH receptor Ab values of untreated patients with a normal and an abnormally low thyroid CT number showed that serum total and free T[sub 3] were significantly higher in the latter group than the former group. With respect to the effect of methimazol (MMI) on the thyroid CT number, in the untreated 10 patients with a low thyroid CT number, the initial mean CT number was 65[+-]11 H.U. and increased significantly to 76[+-]14 H.U. after treatment with MMI. In contrast, in 6 patients with a normal thyroid CT number prior to therapy, the initial mean thyroid CT number was 102[+-]11 H.U. and fell significantly to 84[+-]16 H.U. after treatment with MMI. The thyroid CT number in destructive thyrotoxicosis is markedly decreased to less than 70 H.U. and the mean values of 57[+-]7 H.U. in 6 patients with silent thyroiditis and of 61[+-]5 H.U. in 7 with subacute thyroiditis differ significantly from Graves' disease. In conclusion, the thyroid CT number is significantly reduced in hyperthyroid Graves' disease, normal in euthyroid Graves' disease and markedly decreased in destructive thyrotoxicosis. The high T-3 value seemed to play an important role in the pathogenesis of a decline in the thyroid CT number in Graves' disease. An antithyroid drug therapy caused two different changes in the thyroid CT number, depending on whether the thyroid CT number prior to therapy was normal or low. (author).

  6. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    Science.gov (United States)

    Osman, N. D.; Shamsuri, S. B. M.; Tan, Y. W.; Razali, M. A. S. M.; Isa, S. M.

    2017-05-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDIvol and CTDIw) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDIw ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients.

  7. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    International Nuclear Information System (INIS)

    Osman, N D; Shamsuri, S B M; Razali, M A S M; Isa, S M; Tan, Y W

    2017-01-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDI vol and CTDI w ) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDI w ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients. (paper)

  8. Quality control within the multicentre perfusion CT study of primary colorectal cancer (PROSPeCT): results of an iodine density phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Maria; Honey, Ian [Trust, Medical Physics Department, Guy' s and St. Thomas' NHS Foundation, London (United Kingdom); Goh, Vicky [King' s College London, St Thomas' Hospital, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Beggs, Shaun [Bradford Teaching Hospitals NHS Foundation Trust, Radiation Physics Services, Bradford (United Kingdom); Bridges, Andrew; Wayte, Sarah [Radiology Physics University Hospitals Coventry and Warwickshire NHS Trust, Coventry (United Kingdom); Clewer, Philip [Medical Physics Department, University Hospital Southampton NHS Foundation Trust, Southampton (United Kingdom); Davis, Anne [Portsmouth Hospitals NHS Trust, Medical Physics Department, Portsmouth (United Kingdom); Foy, Trevelyan [Royal Cornwall Hospital NHS Trust, Medical Physics Department, Truro (United Kingdom); Fuller, Karen [Sheffield Teaching Hospitals NHS Foundation Trust, Medical Physics Department, Sheffield (United Kingdom); George, Jennifer [University Hospital of North Staffordshire NHS Trust, Medical Physics Department, Stoke-on-Trent (United Kingdom); Higginson, Antony [Portsmouth Hospitals NHS Trust, Department of Radiology, Portsmouth (United Kingdom); Iball, Gareth [Leeds Teaching Hospitals NHS Trust, Department of Medical Physics and Engineering, Leeds (United Kingdom); Mutch, Steve [Oxford University Hospitals NHS Trust, Radiation Physics and Protection Department, Oxford (United Kingdom); Neil, Shellagh; Sutton, David [NHS Tayside, Medical Physics Department, Dundee, Scotland (United Kingdom); Rivett, Cat [Plymouth Hospitals NHS Trust, Clinical and Radiation Physics, Plymouth (United Kingdom); Slater, Andrew [Oxford University Hospitals NHS Trust, Department of Radiology, Oxford (United Kingdom); Weir, Nick [Queen' s Medical Research Institute, Clinical Research Imaging Centre, Edinburgh, Scotland (United Kingdom); Collaboration: on behalf of the PROSPeCT Investigators

    2014-09-15

    To assess the cross-centre consistency of iodine enhancement, contrast-to-noise ratio and radiation dose in a multicentre perfusion CT trial of colorectal cancer. A cylindrical water phantom containing different iodine inserts was examined on seven CT models in 13 hospitals. The relationship between CT number (Hounsfield units, HU) and iodine concentration (milligrams per millilitre) was established and contrast-to-noise ratios (CNRs) calculated. Radiation doses (CTDI{sub vol}, DLP) were compared across all sites. There was a linear relationship between CT number and iodine density. Iodine enhancement varied by a factor of at most 1.10, and image noise by at most 1.5 across the study sites. At an iodine concentration of 1 mg ml{sup -1} and 100 kV, CNRs ranged from 3.6 to 4.8 in the 220-mm phantom and from 1.4 to 1.9 in the 300-mm phantom. Doses varied by a factor of at most 2.4, but remained within study dose constraints. Iterative reconstruction algorithms did not alter iodine enhancement but resulted in reduced image noise by a factor of at most 2.2, allowing a potential dose decrease of at most 80 % compared to filtered back projection (FBP). Quality control of CT performance across centres indicates that CNR values remain relatively consistent across all sites, giving acceptable image quality within the agreed dose constraints. (orig.)

  9. Quality control within the multicentre perfusion CT study of primary colorectal cancer (PROSPeCT): results of an iodine density phantom study

    International Nuclear Information System (INIS)

    Lewis, Maria; Honey, Ian; Goh, Vicky; Beggs, Shaun; Bridges, Andrew; Wayte, Sarah; Clewer, Philip; Davis, Anne; Foy, Trevelyan; Fuller, Karen; George, Jennifer; Higginson, Antony; Iball, Gareth; Mutch, Steve; Neil, Shellagh; Sutton, David; Rivett, Cat; Slater, Andrew; Weir, Nick

    2014-01-01

    To assess the cross-centre consistency of iodine enhancement, contrast-to-noise ratio and radiation dose in a multicentre perfusion CT trial of colorectal cancer. A cylindrical water phantom containing different iodine inserts was examined on seven CT models in 13 hospitals. The relationship between CT number (Hounsfield units, HU) and iodine concentration (milligrams per millilitre) was established and contrast-to-noise ratios (CNRs) calculated. Radiation doses (CTDI vol , DLP) were compared across all sites. There was a linear relationship between CT number and iodine density. Iodine enhancement varied by a factor of at most 1.10, and image noise by at most 1.5 across the study sites. At an iodine concentration of 1 mg ml -1 and 100 kV, CNRs ranged from 3.6 to 4.8 in the 220-mm phantom and from 1.4 to 1.9 in the 300-mm phantom. Doses varied by a factor of at most 2.4, but remained within study dose constraints. Iterative reconstruction algorithms did not alter iodine enhancement but resulted in reduced image noise by a factor of at most 2.2, allowing a potential dose decrease of at most 80 % compared to filtered back projection (FBP). Quality control of CT performance across centres indicates that CNR values remain relatively consistent across all sites, giving acceptable image quality within the agreed dose constraints. (orig.)

  10. Preliminary study on the differentiation between parapelvic cyst and hydronephrosis with non-calculous using only pre-contrast dual-energy spectral CT scans

    Science.gov (United States)

    Han, Dong; Ma, Guangming; Wei, Lequn; Ren, Chenglong; Zhou, Jieli; Shen, Chen

    2017-01-01

    Objective: To investigate the value of using the quantitative parameters from only the pre-contrast dual-energy spectral CT imaging for distinguishing between parapelvic cyst and hydronephrosis with non-calculous (HNC). Methods: This retrospective study was approved by the institutional review board. 28 patients with parapelvic cyst and 24 patients with HNC who underwent standard pre-contrast and multiphase contrast-enhanced dual-energy spectral CT imaging were retrospectively identified. The parapelvic cyst and HNC were identified using the contrast-enhanced scans, and their CT number in the 70-keV monochromatic images, effective atomic number (Zeff), iodine concentration (IC) and water concentration in the pre-contrast images were measured. The slope of the spectral curve (λ) was calculated. The difference in the measurements between parapelvic cyst and HNC was statistically analyzed using SPSS® v. 19.0 (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) statistical software. Receiver-operating characteristic analysis was performed to assess the diagnostic performance. Results: The CT numbers in the 70-keV images, Zeff and IC values were statistically different between parapelvic cyst and HNC (all p  0.05). Conclusion: The quantitative parameters obtained in the pre-contrast dual-energy spectral CT imaging may be used to differentiate between parapelvic cyst and HNC. Advances in knowledge: The pre-contrast dual-energy spectral CT scans may be used to screen parapelvic cysts for patients who are asymptomatic, thereby avoiding contrast-enhanced CT or CT urography examination for these patients to reduce ionizing radiation dose and contrast dose. PMID:28281789

  11. Rapid screening assay for calcium bioavailability studies

    International Nuclear Information System (INIS)

    Luhrsen, K.R.; Hudepohl, G.R.; Smith, K.T.

    1986-01-01

    Calcium bioavailability has been studied by numerous techniques. The authors report here the use of the gamma emitting isotope of calcium ( 47 Ca) in a whole body retention assay system. In this system, calcium sources are administered by oral gavage and subsequent counts are determined and corrected for isotopic decay. Unlike iron and zinc retention curves, which exhibit a 2-3 day equilibration period, calcium reaches equilibration after 24 hours. Autoradiographic analysis of the femurs indicate that the newly absorbed calcium is rapidly distributed to the skeletal system. Moreover, the isotope is distributed along the entire bone. Comparisons of calcium bioavailability were made using intrinsic/extrinsic labeled milk from two species i.e. rat and goat as well as CaCO 3 . In addition, extrinsic labeled cow milk was examined. In the rat, the extrinsic labeled calcium from milk was better absorbed than the intrinsic calcium. This was not the case in goat milk or the calcium carbonate which exhibited no significant differences. Chromatographic analysis of the labeled milk indicates a difference in distribution of the 47 Ca. From these data, the authors recommend the use of this assay system in calcium bioavailability studies. The labeling studies and comparisons indicate caution should be used, however, in labeling techniques and species milk comparison

  12. Blind CT image quality assessment via deep learning strategy: initial study

    Science.gov (United States)

    Li, Sui; He, Ji; Wang, Yongbo; Liao, Yuting; Zeng, Dong; Bian, Zhaoying; Ma, Jianhua

    2018-03-01

    Computed Tomography (CT) is one of the most important medical imaging modality. CT images can be used to assist in the detection and diagnosis of lesions and to facilitate follow-up treatment. However, CT images are vulnerable to noise. Actually, there are two major source intrinsically causing the CT data noise, i.e., the X-ray photo statistics and the electronic noise background. Therefore, it is necessary to doing image quality assessment (IQA) in CT imaging before diagnosis and treatment. Most of existing CT images IQA methods are based on human observer study. However, these methods are impractical in clinical for their complex and time-consuming. In this paper, we presented a blind CT image quality assessment via deep learning strategy. A database of 1500 CT images is constructed, containing 300 high-quality images and 1200 corresponding noisy images. Specifically, the high-quality images were used to simulate the corresponding noisy images at four different doses. Then, the images are scored by the experienced radiologists by the following attributes: image noise, artifacts, edge and structure, overall image quality, and tumor size and boundary estimation with five-point scale. We trained a network for learning the non-liner map from CT images to subjective evaluation scores. Then, we load the pre-trained model to yield predicted score from the test image. To demonstrate the performance of the deep learning network in IQA, correlation coefficients: Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are utilized. And the experimental result demonstrate that the presented deep learning based IQA strategy can be used in the CT image quality assessment.

  13. Screening for congenital hypothyroidism (CH) among Filipino newborn infants. Philippine Newborn Screening Study Group.

    Science.gov (United States)

    Fagela-Domingo, C; Padilla, C D; Cutiongco, E M

    1999-01-01

    From June 1996 to June 1998 a total of 62.841 newborn infants were screened for congenital hypothyroidism with thyroid stimulating hormone assay as a primary test. The method used was an immunofluorescent assay using the DELFIA TSH Kit on dried blood specimens collected by heelprick on filter paper. All infants with TSH values greater than 20 microU/ml were retested. If the results remained abnormally high, confirmatory testing was done by radioimmunoassay. All infants who were confirmed to be hypothyroid were referred to pediatric endocrinologists for initial management. The overall weighted incidence of congenital hypothyroidism obtained in this study was 0.000277 (95% CI; 0.000122 - 0.000432) or 1:3,610 which may be higher than that reported by most screening programs worldwide. The recall rate was 0.16%. The higher recall rate may be explained by early testing in a number of cases and by the possibility of iodine deficiency in some of the mothers. On the basis of the results of this study, we would recommend (1) screening on a greater number of infants to verify the incidence of CH and (2) establishing normal TSH values at different hours of life to improve our recall rate.

  14. Study of residual stresses in CT test specimens welded by electron beam

    Science.gov (United States)

    Papushkin, I. V.; Kaisheva, D.; Bokuchava, G. D.; Angelov, V.; Petrov, P.

    2018-03-01

    The paper reports result of residual stress distribution studies in CT specimens reconstituted by electron beam welding (EBW). The main aim of the study is evaluation of the applicability of the welding technique for CT specimens’ reconstitution. Thus, the temperature distribution during electron beam welding of a CT specimen was calculated using Green’s functions and the residual stress distribution was determined experimentally using neutron diffraction. Time-of-flight neutron diffraction experiments were performed on a Fourier stress diffractometer at the IBR-2 fast pulsed reactor in FLNP JINR (Dubna, Russia). The neutron diffraction data estimates yielded a maximal stress level of ±180 MPa in the welded joint.

  15. Comparative study on developmental stages of the clavicle by postmortem MRI and CT imaging

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Lynnerup, Niels; Jensen, K.E.

    2013-01-01

    Objectives: The developmental stages of the clavicles are important for forensic age estimation purposes in adolescents. This study compares the 4-stage system to evaluate the ossification of the medial end of the clavicle as visualized by magnetic resonance imaging (MRI) and computed tomography...... (CT). As several forensic institutes routinely perform CT scans, the large amount of available data may serve as reference sample for MRI in specific cases. Material and methods: This prospective study included an MRI and CT scan of 47 autopsy cases performed prior to medico-legal autopsy (age range...

  16. A STUDY OF CORRELATION BETWEEN NASAL ENDOSCOPY AND CT SCAN IN CASES OF CHRONIC RHINOSINUSITIS

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-07-01

    Full Text Available BACKGROUND: The accurate diagnosis of Chronic Rhinosinusitis (CRS is still a challenge therefore, the American Academy of Otorhinolaryngology - Head and Neck Surgery (AAO - HNS 1 has met in a multidisciplinary encounter and formulated a consensus based on only clinical symptoms. The computed tomography (CT scan and the nasal endoscopy (NE were introduced to make an accurate diagnosis of CRS and verify the disease severity. AIM: The aim of this study is to make a correlation between nasal endoscopy and CT scan in cases of clinically diagnosed Chronic Rhinosinusitis patients. METHOD: A study was carried out on 90 patients at Jhalawar Medical College, Jhalawar (Raj. during Sept. 20 12 to Dec. 2014. Diagnostic Nasal Endoscopy and CT Scan PNS done in patients, suffering from Chronic Rhinosinusitis. As a classification instruments, Metson / Gliklich's classification was used to evaluate the tomographic diagnosis and the Stankiewicz / Chow' s classification to evaluate the endoscopic diagnosis of Chronic Rhinosinusitis. RESULTS: Our study showed high specificity of endoscopy in comparison to CT scan though CT scan results are more sensitive. CONCLUSION: Endoscopy can confirm a Chronic Rhinosi nusitis diagnosis, but cannot rule it out, and that CT should be performed in cases of suspected CRS even if mucopurulence is not noted on endoscopy. The CT scan and the nasal endoscopy making easier the treatment planning and the disease resolution.

  17. Clinical study on primary epilepsy by computerized analysis of CT

    International Nuclear Information System (INIS)

    Tominaga, Hidefumi; Ueyama, Kenichi; Mizutani, Hiroshi; Imamura, Keisuke; Yoshidome, Kazushi; Matsumoto, Kei

    1985-01-01

    CT scans were examined by conventional linear measurement method and computerized analysis in 17 patients with primary epilepsy (Group A). Results were compared with those in healthy volunteers (Group B). Relationship between CT and EEG findings was also examined. The maximum width of the third cerebral ventricle (TCV) was narrowed in Group A than in Group B, with statistically significant difference. Low density rates (LDR) in Group A tended to be lower than those in Group B. There was significant difference in narrowed maximum width of TCV between Group A presenting with sudden dysrhythmia and Group B. For this type of Group A, LDR was significantly lower than that for Group B. These results suggest some changes in the brain in young epilepsy patients, especially those presenting with sudden dysrhythemia. (Namekawa, K.)

  18. Brain atrophy in Huntington's disease: A CT-scan study

    International Nuclear Information System (INIS)

    Starkstein, S.E.; Folstein, S.E.; Brandt, J.; McDonnell, A.; Folstein, M.

    1989-01-01

    CT-scan measurements of cortical and subcortical atrophy were carried out in 34 patients with Huntington's disease (HD). While a significant correlation was observed between parameters of subcortical atrophy (bicaudate ratio, bifrontal ratio and third ventricular ratio) and duration of the disease, there was no significant correlation between these parameters and age. On the other hand, measurements of cortical atrophy (frontal fissure ratio and cortical sulci ratio) correlated significantly with age but not with duration of the disease. When a group of 24 HD patients were compared on CT-scan measurements with a group of 24 age-matched normal controls, significant differences were obtained for all the variables examined, but the bicaudate ratio showed the highest sensitivity and specificity. Even mildly affected patients, with duration of motor symptoms less than 3 years had higher bicaudate ratios than age-matched controls. (orig.)

  19. Study of three-dimensional image display by systemic CT

    International Nuclear Information System (INIS)

    Fujioka, Tadao; Ebihara, Yoshiyuki; Unei, Hiroshi; Hayashi, Masao; Shinohe, Tooru; Wada, Yuji; Sakai, Takatsugu; Kashima, Kenji; Fujita, Yoshihiro

    1989-01-01

    A head phantom for CT was scanned at 2 mm intervals from the cervix to the vertex in an attempt to obtain a three-dimensional image display of bones and facial epidermis from an ordinary axial image. Clinically, three-dimensional images were formed at eye sockets and hip joints. With the three-dimensional image using the head phantom, the entire head could be displayed at any angle. Clinically, images were obtained that could not be attained by ordinary CT scanning, such as broken bones in eye sockets and stereoscopic structure at the bottom of a cranium. The three-dimensional image display is considered to be useful in clinical diagnosis. (author)

  20. Improving the false-negative rate of CT in acute appendicitis-Reassessment of CT images by body imaging radiologists: A blinded prospective study

    International Nuclear Information System (INIS)

    Poortman, Pieter; Lohle, Paul N.M.; Schoemaker, Cees M.; Cuesta, Miguel A.; Oostvogel, Henk J.M.; Lange-de Klerk, Elly S.M. de; Hamming, Jaap F.

    2010-01-01

    Purpose: To compare the accuracy of computed tomography (CT) analyzed by individual radiology staff members and body imaging radiologists in a non-academic teaching hospital for the diagnosis of acute appendicitis. Patients and methods: In a prospective study 199 patients with suspected acute appendicitis were examined with unenhanced CT. CT images were pre-operatively analyzed by one of the 12 members of the radiology staff. In a later stage two body imaging radiologist reassessed all CT images without knowledge of the surgical findings and without knowledge of the primary CT diagnosis. The results, independently reported, were correlated with surgical and histopathologic findings. Results: In 132 patients (66%) acute appendicitis was found at surgery, in 67 patients (34%) a normal appendix was found. The sensitivity of the primary CT analysis and of the reassessment was 76% and 88%, respectively; the specificity was 84% and 87%; the positive predictive value was 90% and 93%; the negative predictive value was 64% and 78%; and the accuracy was 78% and 87%. Conclusion: Reassessment of CT images for acute appendicitis by body imaging radiologists results in a significant improvement of sensitivity, negative predictive value and accuracy. To prevent false-negative interpretation of CT images in acute appendicitis the expertise of the attending radiologist should be considered.

  1. Improving the false-negative rate of CT in acute appendicitis-Reassessment of CT images by body imaging radiologists: A blinded prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Poortman, Pieter [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: ppoortman@wlz.nl; Lohle, Paul N.M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: plohle@elisabeth.nl; Schoemaker, Cees M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: mcschoemaker@elisabeth.nl; Cuesta, Miguel A. [Department of Surgery, VU Medical Centre, Amsterdam (Netherlands)], E-mail: ma.cuesta@vumc.nl; Oostvogel, Henk J.M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: h.oostvogel@elisabeth.nl; Lange-de Klerk, Elly S.M. de [Department of Epidemiology and Biostatistics, VU Medical Centre, Amsterdam (Netherlands)], E-mail: esm.delange@vumc.nl; Hamming, Jaap F. [Department of Surgery, Leiden University Medical Centre (Netherlands)], E-mail: j.f.hamming@lumc.nl

    2010-04-15

    Purpose: To compare the accuracy of computed tomography (CT) analyzed by individual radiology staff members and body imaging radiologists in a non-academic teaching hospital for the diagnosis of acute appendicitis. Patients and methods: In a prospective study 199 patients with suspected acute appendicitis were examined with unenhanced CT. CT images were pre-operatively analyzed by one of the 12 members of the radiology staff. In a later stage two body imaging radiologist reassessed all CT images without knowledge of the surgical findings and without knowledge of the primary CT diagnosis. The results, independently reported, were correlated with surgical and histopathologic findings. Results: In 132 patients (66%) acute appendicitis was found at surgery, in 67 patients (34%) a normal appendix was found. The sensitivity of the primary CT analysis and of the reassessment was 76% and 88%, respectively; the specificity was 84% and 87%; the positive predictive value was 90% and 93%; the negative predictive value was 64% and 78%; and the accuracy was 78% and 87%. Conclusion: Reassessment of CT images for acute appendicitis by body imaging radiologists results in a significant improvement of sensitivity, negative predictive value and accuracy. To prevent false-negative interpretation of CT images in acute appendicitis the expertise of the attending radiologist should be considered.

  2. Pathophysiological study of experimental hydrocephalus with computed tomography (CT) scan

    International Nuclear Information System (INIS)

    Murata, Takaho

    1980-01-01

    In order to investigate the pathophysiological changes during a development of hydrocephalus, the observations employing computed tomography (CT) scans and monitorings of intracranial epidural pressure (EDP) were performed in a series of kaolin-induced canine hydrocephalus. According to ''volume index'' of ventricles which was calculated from printed-out CT numbers, great individual variations were recognized in the degree of a ventricular enlargement as well as the rate of EDP. They are thought to be due to the difference in types of hydrocephalus, which have been induced by a discrepancy in the site and degree of an obstruction caused by kaolin. Periventricular lucency (PVL) of various degrees were also detected on CT scans of experimental hydrocephalus. It was always marked in the superolateral angle of frontal horn of the lateral ventricles, and differed in degree from severe to mild. PVLs were distinct in the acute stage with high EDP, and gradually became indistinct and had a tendency to disappear thereafter along with decreased EDP. They immediately disappeared after shunting operation. The pathogenesis of PVL was investigated with histological examinations, as well as by using contrast enhancement, Metrizamide ventriculography, the analysis of linear density profiles, and the measurement of regional cerebral blood flow (rCBF). Consequently, PVLs in hydrocephalus are considered to represent an acute edema or a chronic CSF retention in the periventricular white matter caused by increase of water content. In other words, they are regarded as a sign of present or preceding intraventricular hypertension on CT scan, and may become a clinical indication for shunting operation. (author)

  3. Postnatal development of the atlas and axis: CT study

    International Nuclear Information System (INIS)

    Byun, Sung Su; Kim, Hyung Jin; Lim, Myung Kwan; Kim, Won Hong; Jeon, Yong Sun; Kim, Jeong Ho; Kim, Sung Tae

    2003-01-01

    To evaluate normal postnatal development of the atlas and axis by means of CT scanning. We prospectively analyzed CT scans of the developing atlas and axis of 200 normal children aged less than 14, investigating the CT appearance of these regions with particular attenuation to two synchondroses related to the atlas and four synchondroses and one ossification center related to the axis. Fusion varying was categorized as either low (grade1-5) or high (grade4-5), according to the varying degrees of fusion at each synchondrosis of ossification center. Neurocentral synchondrosis of the atlas was low grade in all children less than five, and high grade in all aged nine or more, while posterior synchondrosis of the atlas was low grade in 97% of children less than three and high grade in 99% aged three or more. As for the axis, neurocentral synchondrosis was low grade in all children less than three, and high grade in 97% of children aged five or more. PS of the axis was low grade in both children less than 6 months, and high grade in all aged two years or more. Dentocentral synchondrosis of the axis was low grade in 93% of children less than three and high grade in 96% of those aged at least five. Intradental axial synchondrosis was high grade in all children. Fusion of the terminal ossicle with the remainder of the dens was low in all children less than five and high in 97% of those aged nine of more. CT can help determine the parameters of normal postnatal development of the atlas and axis. A knowledge of normal ossification patterns of these regions may help provide an understanding of developmental anomalies and also help prevent confusion with fractures

  4. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark.

    Science.gov (United States)

    Hansen, David C; Seco, Joao; Sørensen, Thomas Sangild; Petersen, Jørgen Breede Baltzer; Wildberger, Joachim E; Verhaegen, Frank; Landry, Guillaume

    2015-01-01

    Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. A CT calibration phantom and an abdomen cross section phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling of detectors and the corresponding noise characteristics. Stopping power maps were calculated for all three scans, and compared with the ground truth stopping power from the phantoms. Proton CT gave slightly better stopping power estimates than the dual energy CT method, with root mean square errors of 0.2% and 0.5% (for each phantom) compared to 0.5% and 0.9%. Single energy CT root mean square errors were 2.7% and 1.6%. Maximal errors for proton, dual energy and single energy CT were 0.51%, 1.7% and 7.4%, respectively. Better stopping power estimates could significantly reduce the range errors in proton therapy, but requires a large improvement in current methods which may be achievable with proton CT.

  5. Clinical study on left atrial thrombi. Comparative study between echocardiography and CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, E; Asano, H; Kurasawa, T; Mitsumoto, K; Yamane, Y [Tokyo Kosei-Nenkin Hospital (Japan)

    1981-09-01

    We studied left atrial thrombi (LAT) by both echocardiography and computed tomography (CT) and compared the features of the 2 methods. A total of 15 patients with mitral stenosis complicated by atrial fibrillation were selected as the subjects. LAT were noted on the M-mode echocardiograms in 2 patients including a questionably positive one, on the two-dimensional echocardiograms in 5, and on the CT scans in 6 of 15. The history of thromboembolism was rather frequent and was found in 7 of 15 patients. However, LAT was found in only 3 of these on the CT scans. A shaggy or fuzzy pattern on the M-mode echocardiogram cannot be regarded as representing thrombi, while a laminar pattern undoubtedly represented thrombi. Two-dimensional echocardiography has considerably contributed to the improved detection rate of LAT. For the characteristic properties of ultrasound beams, however, it was impossible to investigate the entire left atrium. The detection of the thrombi in the appendage was especially difficult. However, computed tomography, permitting transverse cross-sectional tomography, was capable of sectioning the heart even in the presence of air and bones. The measurement of CT values was suggestive of the properties of the substance or substances involved, and also allowed the presumption as to whether the thrombus has been fibrosed. Furthermore, it was possible to estimate more accurately as well as 3-dimensionally the location, shape and dimensions of the thrombi by the reconstruction of the heart according to the CT values. It was concluded that echocardiography and computed tomography are the mutual aid to further improvement in the detection rate of left atrial thrombi.

  6. Variation in the quality of CT images of the upper abdomen when CT automatic exposure control is employed

    International Nuclear Information System (INIS)

    Aizawa, Isao; Muramatsu, Yoshihisa; Nomura, Keiichi; Shimizu, Fuminori

    2010-01-01

    The aim of this study was to analyze the reason for variation of image quality in the upper abdomen CT with the use of CT-automatic exposure control (AEC). The CT investigated was 3D modulation in the 16 multi detector row CT (MDCT) and lung cancer screening CT (LSCT) phantom was used to simulate the patient. When there was a phase difference, an image noise increase of around 15% at the maximum was accepted. It is concluded that the major reason for variation in image quality is respiratory motion and the importance of respiration control must be recognized. (author)

  7. Thermodynamic Studies for Drug Design and Screening

    Science.gov (United States)

    Garbett, Nichola C.; Chaires, Jonathan B.

    2012-01-01

    Introduction A key part of drug design and development is the optimization of molecular interactions between an engineered drug candidate and its binding target. Thermodynamic characterization provides information about the balance of energetic forces driving binding interactions and is essential for understanding and optimizing molecular interactions. Areas covered This review discusses the information that can be obtained from thermodynamic measurements and how this can be applied to the drug development process. Current approaches for the measurement and optimization of thermodynamic parameters are presented, specifically higher throughput and calorimetric methods. Relevant literature for this review was identified in part by bibliographic searches for the period 2004 – 2011 using the Science Citation Index and PUBMED and the keywords listed below. Expert opinion The most effective drug design and development platform comes from an integrated process utilizing all available information from structural, thermodynamic and biological studies. Continuing evolution in our understanding of the energetic basis of molecular interactions and advances in thermodynamic methods for widespread application are essential to realize the goal of thermodynamically-driven drug design. Comprehensive thermodynamic evaluation is vital early in the drug development process to speed drug development towards an optimal energetic interaction profile while retaining good pharmacological properties. Practical thermodynamic approaches, such as enthalpic optimization, thermodynamic optimization plots and the enthalpic efficiency index, have now matured to provide proven utility in design process. Improved throughput in calorimetric methods remains essential for even greater integration of thermodynamics into drug design. PMID:22458502

  8. Thermodynamic studies for drug design and screening.

    Science.gov (United States)

    Garbett, Nichola C; Chaires, Jonathan B

    2012-04-01

    A key part of drug design and development is the optimization of molecular interactions between an engineered drug candidate and its binding target. Thermodynamic characterization provides information about the balance of energetic forces driving binding interactions and is essential for understanding and optimizing molecular interactions. This review discusses the information that can be obtained from thermodynamic measurements and how this can be applied to the drug development process. Current approaches for the measurement and optimization of thermodynamic parameters are presented, specifically higher throughput and calorimetric methods. Relevant literature for this review was identified in part by bibliographic searches for the period 2004 - 2011 using the Science Citation Index and PUBMED and the keywords listed below. The most effective drug design and development platform comes from an integrated process utilizing all available information from structural, thermodynamic and biological studies. Continuing evolution in our understanding of the energetic basis of molecular interactions and advances in thermodynamic methods for widespread application are essential to realize the goal of thermodynamically driven drug design. Comprehensive thermodynamic evaluation is vital early in the drug development process to speed drug development toward an optimal energetic interaction profile while retaining good pharmacological properties. Practical thermodynamic approaches, such as enthalpic optimization, thermodynamic optimization plots and the enthalpic efficiency index, have now matured to provide proven utility in the design process. Improved throughput in calorimetric methods remains essential for even greater integration of thermodynamics into drug design. © 2012 Informa UK, Ltd.

  9. Adverse events during CT colonography for screening, diagnosis and preoperative staging of colorectal cancer: a Japanese national survey

    International Nuclear Information System (INIS)

    Nagata, Koichi; Takabayashi, Ken; Yasuda, Takaaki; Hirayama, Michiaki; Endo, Shungo; Nozaki, Ryoichi; Shimada, Takenobu; Kanazawa, Hidenori; Fujiwara, Masanori; Shimizu, Norihito; Iwatsuki, Tatema; Iwano, Teruaki; Saito, Hiroshi

    2017-01-01

    To retrospectively evaluate the frequencies and magnitudes of adverse events associated with computed tomographic colonography (CTC) for screening, diagnosis and preoperative staging of colorectal cancer. A Japanese national survey on CTC was administered by use of an online survey tool in the form of a questionnaire. The questions covered mortality, colorectal perforation, vasovagal reaction, total number of examinations, and examination procedures. The survey data was collated and raw frequencies were determined. Fisher's exact test was used to determine differences in event rates between groups. At 431 institutions, 147,439 CTC examinations were performed. No deaths were reported. Colorectal perforations occurred in 0.014% (21/147,439): 0.003% (1/29,823) in screening, 0.014% (13/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The perforation risk was significantly lower in screening than in preoperative staging CTC procedures (p = 0.028). Eighty-one per cent of perforation cases (17/21) did not require emergency surgery. Vasovagal reaction occurred in 0.081% (120/147,439): 0.111% (33/29,823) in screening, 0.088% (80/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The risk of colorectal perforation and vasovagal reaction in CTC is low. The frequency of colorectal perforation associated with CTC is least in the screening group and greatest in the preoperative-staging group. (orig.)

  10. Adverse events during CT colonography for screening, diagnosis and preoperative staging of colorectal cancer: a Japanese national survey

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Koichi [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Takabayashi, Ken [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Hokkaido Gastroenterology Hospital, Department of Radiology, Sapporo (Japan); Yasuda, Takaaki [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Nagasaki Kamigoto Hospital, Department of Radiology, Nagasaki (Japan); Hirayama, Michiaki [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Tonan Hospital, Department of Gastroenterology, Sapporo (Japan); Endo, Shungo [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Fukushima Medical University, Department of Coloproctology, Aizu Medical Centre, Aizu-Wakamatsu, Fukushima (Japan); Nozaki, Ryoichi [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Takano Hospital, Coloproctology Centre, Kumamoto (Japan); Shimada, Takenobu [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); Cancer Detection Centre of the Miyagi Cancer Society, Sendai, Miyagi (Japan); Kanazawa, Hidenori [National Cancer Centre, Division of Screening Technology, Centre for Public Health Sciences, Tokyo (Japan); Jichi Medical University, Department of Radiology, Shimotsuke, Tochigi (Japan); Fujiwara, Masanori [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Kameda Medical Centre Makuhari, Radiology Section, Mihama-ku, Chiba (Japan); Shimizu, Norihito [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Matsuoka Clinic, Radiology Section, Nara (Japan); Iwatsuki, Tatema [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Matsuda Hospital, Radiology Section, Hamamatsu, Shizuoka (Japan); Iwano, Teruaki [Gastrointestinal Advanced Imaging Academy, Tochigi (Japan); Tokushima Kensei Hospital, Radiology Section, Tokushima (Japan); Saito, Hiroshi [Japanese Society of Gastrointestinal Cancer Screening, Committee for Quality Assessment of Colorectal Cancer Screening, Tokyo (Japan); National Cancer Centre, Division of Screening Assessment and Management, Centre for Public Health Sciences, Tokyo (Japan)

    2017-12-15

    To retrospectively evaluate the frequencies and magnitudes of adverse events associated with computed tomographic colonography (CTC) for screening, diagnosis and preoperative staging of colorectal cancer. A Japanese national survey on CTC was administered by use of an online survey tool in the form of a questionnaire. The questions covered mortality, colorectal perforation, vasovagal reaction, total number of examinations, and examination procedures. The survey data was collated and raw frequencies were determined. Fisher's exact test was used to determine differences in event rates between groups. At 431 institutions, 147,439 CTC examinations were performed. No deaths were reported. Colorectal perforations occurred in 0.014% (21/147,439): 0.003% (1/29,823) in screening, 0.014% (13/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The perforation risk was significantly lower in screening than in preoperative staging CTC procedures (p = 0.028). Eighty-one per cent of perforation cases (17/21) did not require emergency surgery. Vasovagal reaction occurred in 0.081% (120/147,439): 0.111% (33/29,823) in screening, 0.088% (80/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The risk of colorectal perforation and vasovagal reaction in CTC is low. The frequency of colorectal perforation associated with CTC is least in the screening group and greatest in the preoperative-staging group. (orig.)

  11. Smoking cessation and lung cancer screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Johannes Holst; Tønnesen, Philip; Ashraf, Haseem

    2016-01-01

    Smoking behavior may have a substantial influence on the overall effect of lung cancer screening. Non-randomized studies of smoking behavior during screening have indicated that computer tomography (CT) screening induces smoking cessation. Randomized studies have further elaborated that this effect...... and decrease smoking relapse rate. Also low smoking dependency and high motivation to quit smoking at baseline predicted smoking abstinence in screening trials. Lung cancer screening therefore seems to be a teachable moment for smoking cessation. Targeted smoking cessation counselling should be an integrated...... part of future lung cancer screening trials....

  12. Intracranial ring enhancing lesions in dogs: a correlative CT scanning and neuropathologic study

    International Nuclear Information System (INIS)

    Wolf, Michael; Pedroia, Vince; Higgins, Robert J.; Koblik, Philip D.; Turrel, Jane M.; Owens, Jerry M.

    1995-01-01

    This retrospective analysis of 15 dogs with postcontrast ring enhancing brain lesions, each detected by a single Computed Tomography (CT) examination, searched for any association between their CT appearance and the pathologic diagnosis. In a subgroup of these dogs (n = 71) necropsied within 2 days of the last CT scan, we evaluated whether there was any anatomic correlation between the ring zone and the histopathologic features of the lesions. Our study consisted of eight dogs with primary brain tumors (3 meningiomas, 3 astrocytomas, 1 mixed glioma, 1 oligodendroglioma), 4 with metastatic brain tumors (2 fibrosarcomas, 1 mammary carcinoma, 1 melanoma) and 3 with non-neoplastic brain lesions (2 intraparenchymal hemorrhages, 1 pyogranulomatous meningoencephalitis). The overall size and shape of the contrast enhancing CT lesions, as well as the thickness, surface texture and degree of enhancement of the ring were subjectively evaluated. No association was found between the CT lesion characteristics and the pathologic diagnosis. In the sub-group of dogs euthanatized within 2 days of the CT examination, distinct histologic features which anatomically correlated with the zone of ring enhancement were found in 3 of 7 lesions. The findings of this study are consistent with those of ring-enhancing lesions in people, and indicates that CT ring enhancement is a nonspecific phenomenon which can occur in a variety of neoplastic and non-neoplastic lesions in the dog

  13. Xenon-enhanced CT using subtraction CT: Basic and preliminary clinical studies for comparison of its efficacy with that of dual-energy CT and ventilation SPECT/CT to assess regional ventilation and pulmonary functional loss in smokers

    International Nuclear Information System (INIS)

    Ohno, Yoshiharu; Yoshikawa, Takeshi; Takenaka, Daisuke; Fujisawa, Yasuko; Sugihara, Naoki; Kishida, Yuji; Seki, Shinichiro; Koyama, Hisanobu; Sugimura, Kazuro

    2017-01-01

    Purpose: To prospectively and directly compare the capability for assessments of regional ventilation and pulmonary functional loss in smokers of xenon-ventilation CT obtained with the dual-energy CT (DE-CT) and subtraction CT (Sub-CT) Materials and methods: Twenty-three consecutive smokers (15 men and 8 women, mean age: 69.7 ± 8.7 years) underwent prospective unenhanced and xenon-enhanced CTs, the latter by Sub-CT and DE-CT methods, ventilation SPECT and pulmonary function tests. Sub-CT was generated from unenhanced and xenon-enhanced CT, and all co-registered SPECT/CT data were produced from SPECT and unenhanced CT data. For each method, regional ventilation was assessed by using a 11-point scoring system on a per-lobe basis. To determine the functional lung volume by each method, it was also calculated for individual sublets with a previously reported method. To determine inter-observer agreement for each method, ventilation defect assessment was evaluated by using the χ2 test with weighted kappa statistics. For evaluation of the efficacy of each method for pulmonary functional loss assessment, functional lung volume was correlated with%FEV 1 . Results: Each inter-observer agreement was rated as substantial (Sub-CT: κ = 0.69, p < 0.0001; DE-CT: κ = 0.64, p < 0.0001; SPECT/CT: κ = 0.64, p < 0.0001). Functional lung volume for each method showed significant to good correlation with%FEV 1 (Sub-CT: r = 0.72, p = 0.0001; DE-CT: r = 0.74, p < 0.0001; SPECT/CT: r = 0.66, p = 0.0006). Conclusion: Xenon-enhanced CT obtained by Sub-CT can be considered at least as efficacious as that obtained by DE-CT and SPECT/CT for assessment of ventilation abnormality and pulmonary functional loss in smokers.

  14. Early screening for Chlamydia trachomatis in young women for primary prevention of pelvic inflammatory disease (i-Predict): study protocol for a randomised controlled trial.

    Science.gov (United States)

    Tamarelle, Jeanne; Thiébaut, Anne C M; Sabin, Bénédicte; Bébéar, Cécile; Judlin, Philippe; Fauconnier, Arnaud; Rahib, Delphine; Méaude-Roufai, Layidé; Ravel, Jacques; Morré, Servaas A; de Barbeyrac, Bertille; Delarocque-Astagneau, Elisabeth

    2017-11-13

    Genital infection with Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection, especially among young women. Mostly asymptomatic, it can lead, if untreated, to pelvic inflammatory disease (PID), tubal factor infertility and ectopic pregnancy. Recent data suggest that Ct infections are not controlled in France and in Europe. The effectiveness of a systematic strategy for Ct screening in under-25 women remains controversial. The main objective of the i-Predict trial (Prevention of Diseases Induced by Chlamydia trachomatis) is to determine whether early screening and treatment of 18- to-24-year-old women for genital Ct infection reduces the incidence of PID over 24 months. This is a randomised prevention trial including 4000 eighteen- to twenty-four-year-old sexually active female students enrolled at five universities. The participants will provide a self-collected vaginal swab sample and fill in an electronic questionnaire at baseline and at 6, 12 and 18 months after recruitment. Vaginal swabs in the intervention arm will be analysed immediately for Ct positivity, and participants will be referred for treatment if they have a positive test result. Vaginal swabs from the control arm will be analysed at the end of the study. All visits to general practitioners, gynaecologists or gynaecology emergency departments for pelvic pain or other gynaecological symptoms will be recorded to evaluate the incidence of PID, and all participants will attend a final visit in a hospital gynaecology department. The primary endpoint measure will be the incidence of PID over 24 months. The outcome status (confirmed, probable or no PID) will be assessed by two independent experts blinded to group assignment and Ct status. This trial is expected to largely contribute to the development of recommendations for Ct screening in young women in France to prevent PID and related complications. It is part of a comprehensive approach to gathering data to

  15. Accurate localization of intracavitary brachytherapy applicators from 3D CT imaging studies

    International Nuclear Information System (INIS)

    Lerma, F.A.; Williamson, J.F.

    2002-01-01

    Purpose: To present an accurate method to identify the positions and orientations of intracavitary (ICT) brachytherapy applicators imaged in 3D CT scans, in support of Monte Carlo photon-transport simulations, enabling accurate dose modeling in the presence of applicator shielding and interapplicator attenuation. Materials and methods: The method consists of finding the transformation that maximizes the coincidence between the known 3D shapes of each applicator component (colpostats and tandem) with the volume defined by contours of the corresponding surface on each CT slice. We use this technique to localize Fletcher-Suit CT-compatible applicators for three cervix cancer patients using post-implant CT examinations (3 mm slice thickness and separation). Dose distributions in 1-to-1 registration with the underlying CT anatomy are derived from 3D Monte Carlo photon-transport simulations incorporating each applicator's internal geometry (source encapsulation, high-density shields, and applicator body) oriented in relation to the dose matrix according to the measured localization transformations. The precision and accuracy of our localization method are assessed using CT scans, in which the positions and orientations of dense rods and spheres (in a precision-machined phantom) were measured at various orientations relative to the gantry. Results: Using this method, we register 3D Monte Carlo dose calculations directly onto post insertion patient CT studies. Using CT studies of a precisely machined phantom, the absolute accuracy of the method was found to be ±0.2 mm in plane, and ±0.3 mm in the axial direction while its precision was ±0.2 mm in plane, and ±0.2 mm axially. Conclusion: We have developed a novel, and accurate technique to localize intracavitary brachytherapy applicators in 3D CT imaging studies, which supports 3D dose planning involving detailed 3D Monte Carlo dose calculations, modeling source positions, shielding and interapplicator shielding

  16. Ironmaking Process Alternative Screening Study, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood Greene, . .

    2005-01-06

    Iron in the United States is largely produced from iron ore mined in the United States or imported from Canada or South America. The iron ore is typically smelted in Blast Furnaces that use primarily iron ore, iron concentrate pellets metallurgical coke, limestone and lime as the raw materials. Under current operating scenarios, the iron produced from these Blast Furnaces is relatively inexpensive as compared to current alternative iron sources, e.g. direct iron reduction, imported pig iron, etc. The primary problem the Blast Furnace Ironmaking approach is that many of these Blast furnaces are relatively small, as compared to the newer, larger Blast Furnaces; thus are relatively costly and inefficient to operate. An additional problem is also that supplies of high-grade metallurgical grade coke are becoming increasingly in short supply and costs are also increasing. In part this is due to the short supply and costs of high-grade metallurgical coals, but also this is due to the increasing necessity for environmental controls for coke production. After year 2003 new regulations for coke product environmental requirement will likely be promulgated. It is likely that this also will either increase the cost of high-quality coke production or will reduce the available domestic U.S. supply. Therefore, iron production in the United States utilizing the current, predominant Blast Furnace process will be more costly and would likely be curtailed due to a coke shortage. Therefore, there is a significant need to develop or extend the economic viability of Alternate Ironmaking Processes to at least partially replace current and declining blast furnace iron sources and to provide incentives for new capacity expansion. The primary conclusions of this comparative Study of Alternative Ironmaking Process scenarios are: (1) The processes with the best combined economics (CAPEX and OPEX impacts in the I.R.R. calculation) can be grouped into those Fine Ore based processes with no scrap

  17. [18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer: A Prospective Comparative Study of Dual-Time-Point FDG-PET/CT, Contrast-Enhanced CT, and Bone Scintigraphy.

    Science.gov (United States)

    Hildebrandt, Malene Grubbe; Gerke, Oke; Baun, Christina; Falch, Kirsten; Hansen, Jeanette Ansholm; Farahani, Ziba Ahangarani; Petersen, Henrik; Larsen, Lisbet Brønsro; Duvnjak, Sandra; Buskevica, Inguna; Bektas, Selma; Søe, Katrine; Jylling, Anne Marie Bak; Ewertz, Marianne; Alavi, Abass; Høilund-Carlsen, Poul Flemming

    2016-06-01

    To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence. One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four-point assessment scale, and readers were blinded to other test results. The reference standard was biopsy along with treatment decisions and clinical follow-up (median, 17 months). FDG-PET/CT resulted in no false negatives and fewer false positives than the other imaging techniques. Accuracy of results were similar for 1-hour and 3-hour FDG-PET/CT. For distant recurrence, the area under the receiver operating curve was 0.99 (95% CI, 0.97 to 1) for FDG-PET/CT, 0.84 (95% CI, 0.73 to 0.94) for ceCT, and 0.86 (95% CI, 0.77 to 0.94) for the combined ceCT+BS. Of 100 patients, 22 (22%) were verified with distant recurrence, and 18 of these had bone involvement. Nineteen patients (19%) had local recurrence only. In exploratory analyses, diagnostic accuracy of FDG-PET/CT was better than ceCT alone or ceCT combined with BS in diagnosing distant, bone, and local recurrence, shown by a greater area under the receiver operating curve and higher sensitivity, specificity, and superior likelihood ratios. FDG-PET/CT was accurate in diagnosing recurrence in breast cancer patients. It allowed for distant recurrence to be correctly ruled out and resulted in only a small number of false-positive cases. Exploratory findings suggest that FDG-PET/CT has greater accuracy than conventional imaging technologies in this patient group. © 2016 by American Society of Clinical Oncology.

  18. Study of mammography in mass screening for breast cancer

    International Nuclear Information System (INIS)

    Kitada, Masahiro; Sakai, Hiroko; Kubo, Yoshihiko; Samejima, Natsuki; Kurowarabi, Kunio; Iwabuchi, Shuji.

    1995-01-01

    In order to examine the rate of correct diagnosis by mammography at initial mass screening for breast cancer, we carried out a retrospective study of mammography findings in 267 cases of breast cancer detected at Asahikawa Cancer Screening Center. The screening was performed by physical examination, and in cases where disease was suspected, mammography, ultrasonography, and needle biopsy were done. Mammographically, 172 cases (64.4%) were cancer-positive, 58 cases (21.7%) were suspicious for cancer, and 37 cases (13.9%) were cancer-negative. Patients below 50 years of age and those with tumors of small diameter (<20 mm) showed a significantly lower rate of cancer positivity than patients aged 50 years or more and those with tumors 20 mm or more in diameter. Mammographic abnormalities were not specific, since these changes were also found in normal subjects and patients with benign diseases. Therefore, we concluded that mammography without physical examination at initial mass screening has a high risk of missing breast cancer. Mass screening for breast cancer should be performed by physical examination involving inspection and palpation at the first instance. If any suspicious findings are obtained, mammography, ultrasonography, and needle biopsy should be done. (author)

  19. Comparison of cerebrospinal fluid dynamics studied by computed tomography (CT) and radioisotope (RI) cisternography

    International Nuclear Information System (INIS)

    Tamaki, N.; Kanazawa, Y.; Asada, M.; Kusunoki, T.; Matsumoto, S.

    1978-01-01

    CT and RI cisternography were done on 55 cases with normal and abnormal CSF circulation. Of 19 cases in which both studies were done, 14 cases disclosed a good correspondence. The remaining five cases showed no correspondence because of technical failure. Analyzing the results, CT cisternography demonstrates pathology of the CSF dynamics in a more precise and quantitative manner than RI cisternography does. Metrizamide CT cisternography will soon be the most reliable method of investigation for the evaluation of the CSF kinetics. (orig.) [de

  20. SPECT/CT co-registration of nuclear medicine studies and technologists: challenges and victories

    International Nuclear Information System (INIS)

    Cameron, P.J.

    2002-01-01

    Full text: A dual modality SPECT/CT gamma camera was installed in the Department of Nuclear Medicine at Fremantle Hospital, WA in 2000. The challenges were satisfying the requirements of the Radiological Advisory Council of WA with respect to room modifications and presence of a radiographer during CT acquisitions and once installation was complete, learning to operate the camera in dual modality mode. The victories are making CT/SPECT acquisitions a simple and routine procedure and the impact of the co-registered studies in both diagnostic and therapeutic applications in our practice. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  1. How is adults’ screen time behaviour influencing their views on screen time restrictions for children? A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Stephanie Schoeppe

    2016-03-01

    Full Text Available Abstract Background High screen time in children and its detrimental health effects is a major public health problem. How much screen time adults think is appropriate for children remains little explored, as well as whether adults’ screen time behaviour would determine their views on screen time restrictions for children. This study aimed to investigate how adults’ screen time behaviour influences their views on screen time restrictions for children, including differences by gender and parental status. Methods In 2013, 2034 Australian adults participated in an online survey conducted by the Population Research Laboratory at Central Queensland University, Rockhampton. Adult screen time behaviour was assessed using the Workforce Sitting Questionnaire. Adults reported the maximum time children aged between 5–12 years should be allowed to spend watching TV and using a computer. Ordinal logistic regression was used to compare adult screen time behaviour with views on screen time restrictions for children. Results Most adults (68 % held the view that children should be allowed no more than 2 h of TV viewing and computer use on school days, whilst fewer adults (44 % thought this screen time limit is needed on weekend days. Women would impose higher screen time restrictions for children than men (p  2 h on watching TV and using the computer at home on work days (66 % and non-work days (88 %. Adults spending ≤ 2 h/day in leisure-related screen time were less likely to permit children > 2 h/day of screen time. These associations did not differ by adult gender and parental status. Conclusions Most adults think it is appropriate to limit children’s screen time to the recommended ≤ 2 h/day but few adults themselves adhere to this screen time limit. Adults with lower screen use may be more inclined to limit children’s screen time. Strategies to reduce screen time in children may also need to target adult screen use.

  2. A study on CT-guided stereotactic technique for functional neurosurgery

    International Nuclear Information System (INIS)

    Uetsuhara, Koichi; Asakura, Tetsuhiko; Hirahara, Kazuho; Gondo, Masazumi; Oda, Hiroshige

    1987-01-01

    Recently, CT-guided stereotactic surgery has become of major interest, and some authors have discussed its potential in functional neurosurgery. The following is a comparative study of the CT-guided stereotactic technique and the conventional roentogenographic stereotactic technique. The Brown-Roberts-Wells apparatus was used for both types of procedures. 37 stereotactic procedures were performed on 35 patients under local anesthesia; 16 for stereotactic biopsy and 21 for stereotactic functional neurosurgery. Target points for stereotactic biopsy were determined by the CT-guided technique and target points for functional neurosurgery were determined by the conventional roentogenographic technique. The correlation with the position of target point determined by both techniques was investigated in the 21 functional neurosurgical procedures. On these occasions the authors used the reformatted horizontal and sagittal CT through the anterior and posterior commissure to determine the position of target point by the CT-guided technique. Results: It was found that the AC-PC line crossed with Reid's base line at angle of 11 ± 1 deg, and therefore it is important to obtain a CT images including AC-PC line at this angle. When applying the CT guided stereotactic procedure for functional surgery, it should be known that there could be a discrepancy within 2 mm from the conventional target determination. (author)

  3. Application of artificial neural networks in the CT study of solitary pulmonary nodule

    International Nuclear Information System (INIS)

    Wang Xiaohua; Ma Daqing; Chen Hui; Gao Peiyi; Zhou Xinhua

    2006-01-01

    Objective: To establish a new-type discriminative method in differentiating benign from malignant solitary pulmonary nodule (SPN) on high-resolution CT/thin-section CT by using artificial neural networks theory in the CT diagnostic study of SPN. Methods: Two hundred SPNs pathologically proved by operation or biopsy (primary pulmonary carcinoma 135 eases, benign nodules 65 cases) were collected, 3 clinical characteristics (age, sex, with or without bloody sputum) and 9 high-resolution CT/thin-section CT characteristics (location, long and short diameter, contour, spiculation, halo sign, air-space, relation with the adjacent blood vessels and pleura) were analyzed. 140 cases were randomly selected to form the training samples, on which artificial neural networks model (BP networks) was built and compared with Logistic model from Statistical Package for the Social Science (SPSS) software. Results: The total consistent rate of BP neural networks (98.0%, 196/200) was higher than that of Logistic model (86.0%, 172/200) (P<0.001). Areas under ROC curve were 0.996±0.004 and 0.936±0.017, respectively, and the difference between the two was significant (P<0.001). Conclusion: Using high-resolution CT and thin-section CT in combination with artificial neural networks theory is feasible, and it is expected to become a useful and reliable clinical tool in differentiating benign from malignant SPN. (authors)

  4. Feasibility of perfusion CT technique integrated into conventional {sup 18}FDG/PET-CT studies in lung cancer patients: clinical staging and functional information in a single study

    Energy Technology Data Exchange (ETDEWEB)

    Ippolito, Davide; Capraro, Cristina; Sironi, Sandro [University of Milano-Bicocca, School of Medicine, Milan (Italy); University of Milano-Bicocca, Department of Diagnostic Radiology, H.S. Gerardo Monza, Via Pergolesi 11, Monza, Milan (Italy); Guerra, Luca [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); De Ponti, Elena [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Medical Physics, Monza (Italy); Messa, Cristina [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); Tecnomed Foundation, University of Milano-Bicocca, Institute for Bioimaging and Molecular Physiology, National Research Council, Milan (Italy)

    2013-02-15

    To assess the additional functional vascular information and the relationship between perfusion measurements and glucose metabolism (SUVmax) obtained by including a perfusion CT study in a whole-body contrast-enhanced PET/CT protocol in primary lung cancer lesions. Enrolled in this prospective study were 34 consecutive patients with a biopsy-proven diagnosis of lung cancer who were referred for contrast-enhanced PET/CT staging. This prospective study was approved by our institutional review board, and informed consent was obtained from all patients. Perfusion CT was performed with the following parameters: 80 kV, 200 mAs, 30 scans during intravenous injection of 50 ml contrast agent, flow rate 5 ml/s. Another bolus of contrast medium (3.5 ml/s, 80 ml, 60-s delay) was administered to ensure a full diagnostic contrast-enhanced CT scan for clinical staging. The perfusion CT data were used to calculate a range of tumour vascularity parameters (blood flow, blood volume and mean transit time), and tumour FDG uptake (SUVmax) was used as a metabolic indicator. Quantitative and functional parameters were compared and in relation to location, histology and tumour size. The nonparametric Kruskal-Wallis rank sum test was used for statistical analysis. A cut-off value of 3 cm was used according to the TNM classification to discriminate between T1 and T2 tumours (i.e. T1b vs. T2a). There were significant perfusion differences (lower blood volumes and higher mean transit time) between tumours with diameter >30 mm and tumours with diameter <30 mm (p < 0.05; blood volume 5.6 vs. 7.1 ml/100 g, mean transit time 8.6 vs. 3.9 s, respectively). Also there was a trend for blood flow to be lower in larger lesions (p < 0.053; blood flow 153.1 vs. 98.3 ml/100 g tissue/min). Significant inverse correlations (linear regression) were found between blood volume and SUVmax in tumours with diameter >30 mm in diameter. Perfusion CT combined with PET/CT is feasible technique that may provide

  5. Image quality of conventional images of dual-layer SPECTRAL CT: a phantom study.

    Science.gov (United States)

    van Ommen, F; Bennink, E; Vlassenbroek, A; Dankbaar, J W; Schilham, A M R; Viergever, M A; de Jong, H W A M

    2018-05-10

    Spectral CT using a dual layer detector offers the possibility of retrospectively introducing spectral information to conventional CT images. In theory, the dual-layer technology should not come with a dose or image quality penalty for conventional images. In this study, we evaluate the influence of a dual-layer detector (IQon Spectral CT, Philips) on the image quality of conventional CT images, by comparing these images with those of a conventional but otherwise technically comparable single-layer CT scanner (Brilliance iCT, Philips), by means of phantom experiments. For both CT scanners conventional CT images were acquired using four adult scanning protocols: i) body helical, ii) body axial, iii) head helical and iv) head axial. A CATPHAN 600 phantom was scanned to conduct an assessment of image quality metrics at equivalent (CTDI) dose levels. Noise was characterized by means of noise power spectra (NPS) and standard deviation (SD) of a uniform region, and spatial resolution was evaluated with modulation transfer functions (MTF) of a tungsten wire. In addition, contrast-to-noise ratio (CNR), image uniformity, CT number linearity, slice thickness, slice spacing, and spatial linearity were measured and evaluated. Additional measurements of CNR, resolution and noise were performed in two larger phantoms. The resolution levels at 50%, 10% and 5% MTF of the iCT and IQon showed small but significant differences up to 0.25 lp/cm for body scans, and up to 0.2 lp/cm for head scans in favor of the IQon. The iCT and IQon showed perfect CT linearity for body scans, but for head scans both scanners showed an underestimation of the CT numbers of materials with a high opacity. Slice thickness was slightly overestimated for both scanners. Slice spacing was comparable and reconstructed correctly. In addition, spatial linearity was excellent for both scanners, with a maximum error of 0.11 mm. CNR was higher on the IQon compared to the iCT for both normal and larger phantoms with

  6. Reporting of coronary artery calcification on chest CT studies in breast cancer patients at high risk of cancer therapy related cardiac events

    Directory of Open Access Journals (Sweden)

    William J. Phillips

    2018-03-01

    Full Text Available Background: The identification of coronary artery calcification (CAC detected coincidentally on chest CT exams could assist in cardiovascular risk assessment but may not be reported consistently on clinical studies. Cardiovascular risk factor stratification is important to predict short term cardiac events during cancer therapy and long term cardiac event free survival in cancer patients. We sought to determine the prevalence of CAC and clinical reporting rates in a cohort of cancer patients at high risk of cancer therapy related cardiac events. Methods: 408 Breast cancer patients who were referred to a cardiac oncology clinic were screened. Inclusion criteria included having had a CT chest and the absence of known coronary disease. Among those screened 263 patients were included in the study. Results: CAC was identified in 70 patients (26%. CAC was reported in 18% of studies. The reporting rates of CAC increased with the extent of coronary calcification (p < 0.01 and increased during the period of the study (p < 0.05. Conclusions: CAC was commonly detected on chest CT studies in this observational study of breast cancer patients at high risk of cardiac oncology events. The presence of CAC was often not reported clinically but reporting rates have increased over time. Recent SCCT/STR guidelines recommend reporting the presence of CAC on routine chest CT scans in recognition of the importance of CAC as a predictor of cardiovascular events. Reporting of CAC on chest CTs may help to further risk stratify breast cancer patients and improve cardiovascular outcomes in this vulnerable population. Keywords: Cardiac oncology, Coronary calcification and chest CT

  7. Colon distension, perceived burden and side-effects of CT-colonography for screening using hyoscine butylbromide or glucagon hydrochloride as bowel relaxant

    International Nuclear Information System (INIS)

    Haan, Margriet C. de; Boellaard, Thierry N.; Bossuyt, Patrick M.; Stoker, Jaap

    2012-01-01

    Objective: Compare colonic distension and perceived burden of CT-colonography between participants receiving hyoscine butylbromide (buscopan) and glucagon hydrochloride as bowel relaxant. Materials and methods: Data were collected within a screening trial. Participants received 20 mg buscopan intravenously or 1 mg of glucagon intravenously (if buscopan contra-indicated). Colon distension per segment was assessed using a 4-point scale (prone and supine). Data on perceived burden of CT-colonography were collected using a questionnaire two weeks after the examination. Outcome measures between groups were compared using propensity score matching. We used a stratified Wilcoxon–Mann–Whitney test statistic for quantitative and Cochran–Mantel–Haenszel statistics for categorical variables. Results: 541 participants were included: 336 (62%) received buscopan and 205 received glucagon. All buscopan recipients had an adequately distended colon, compared to 96% in the glucagon group (RR 7.31, 95% CI: 1.61–33.28). More glucagon recipients scored the insufflation as rather or extremely burdensome (25% vs. 16%; overall mean score 2.7 vs. 2.4; p < 0.001) and more found the entire CT-colonography rather or extremely burdensome (14% vs. 7%; 2.2 vs. 1.9; p = 0.001). Most frequently reported side effects were a dry mouth in the buscopan group (15%) and nausea in the glucagon group (13%). Conclusion: Compared to glucagon, premedication with buscopan results in significantly more adequately distended colons and a less burdensome procedure. When buscopan can be used, it is the preferred bowel relaxant.

  8. Colon distension, perceived burden and side-effects of CT-colonography for screening using hyoscine butylbromide or glucagon hydrochloride as bowel relaxant

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de, E-mail: margrietcdehaan@gmail.com [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Boellaard, Thierry N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Bossuyt, Patrick M., E-mail: p.m.bossuyt@amc.uva.nl [Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Stoker, Jaap, E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands)

    2012-08-15

    Objective: Compare colonic distension and perceived burden of CT-colonography between participants receiving hyoscine butylbromide (buscopan) and glucagon hydrochloride as bowel relaxant. Materials and methods: Data were collected within a screening trial. Participants received 20 mg buscopan intravenously or 1 mg of glucagon intravenously (if buscopan contra-indicated). Colon distension per segment was assessed using a 4-point scale (prone and supine). Data on perceived burden of CT-colonography were collected using a questionnaire two weeks after the examination. Outcome measures between groups were compared using propensity score matching. We used a stratified Wilcoxon-Mann-Whitney test statistic for quantitative and Cochran-Mantel-Haenszel statistics for categorical variables. Results: 541 participants were included: 336 (62%) received buscopan and 205 received glucagon. All buscopan recipients had an adequately distended colon, compared to 96% in the glucagon group (RR 7.31, 95% CI: 1.61-33.28). More glucagon recipients scored the insufflation as rather or extremely burdensome (25% vs. 16%; overall mean score 2.7 vs. 2.4; p < 0.001) and more found the entire CT-colonography rather or extremely burdensome (14% vs. 7%; 2.2 vs. 1.9; p = 0.001). Most frequently reported side effects were a dry mouth in the buscopan group (15%) and nausea in the glucagon group (13%). Conclusion: Compared to glucagon, premedication with buscopan results in significantly more adequately distended colons and a less burdensome procedure. When buscopan can be used, it is the preferred bowel relaxant.

  9. Register-based studies of cancer screening effects

    DEFF Research Database (Denmark)

    Von Euler-Chelpin, My; Lynge, Elsebeth; Rebolj, Matejka

    2011-01-01

    INTRODUCTION: There are two organised cancer screening programmes in Denmark, against cervical and breast cancers. The aim with this study was to give an overview of the available register-based research regarding these two programmes, to demonstrate the usefulness of data from the national regis...

  10. Temporal bone trauma: correlative study between CT findings and clinical manifestations

    International Nuclear Information System (INIS)

    Kim, Jung Hee; Kim, Hyung Jin; Kim, Jae Hyoung

    1994-01-01

    To assess how accurately computed tomography (CT) can demonstrate the abnormal findings which are believed to cause the clinical signs and symptoms of hearing loss (HL), vertigo and facial paralysis (FP) in patients with temporal bone trauma. The authors studied CT scans of 39 ears in 35 patients with temporal bone trauma. CT scans were performed with 1-1.5 mm slice thickness and table incrementation. Both axial and coronal scans were obtained in 32 patients and in three patients only axial scans were obtained. We analyzed CT with special reference to the structural abnormalities of the external auditory canal, middle ear cavity, bony labyrinth, and facial nerve canal, and correlated these findings with the actual clinical signs and symptoms. As to hearing loss, we evaluated 32 ears in which pure tone audiometry or brainstem evoked response audiometry had been performed. With respect to the specific types of HL, CT accurately showed the abnormalities in 84% (16/19) in conductive HL, 100% (2/2) in sensorineural HL, and 25% (2/8) for mixed HL. When we categorized HL simply as conductive and sensorineural, assuming that mixed be the result of combined conductive and sensorineural HL, CT demonstrated the abnormalities in 89% (24/27) for conductive HL and 50% (5/10) for sensorineural HL. Concerning vertigo and FP, CT demonstrated abnormalities in 67%(4/6), and 29% (4/14), respectively. Except for conductive HL, CT seems to have a variable degree of limitation for the demonstration of the structural abnormalities resulting sensorineural HL, vertigo or facial paralysis. It is imperative to correlate the CT findings with the signs and symptoms in those clinical settings

  11. Temporal bone trauma: correlative study between CT findings and clinical manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hee; Kim, Hyung Jin; Kim, Jae Hyoung [College of Medicine, Gyeongsang National University, Jinju (Korea, Republic of)

    1994-11-15

    To assess how accurately computed tomography (CT) can demonstrate the abnormal findings which are believed to cause the clinical signs and symptoms of hearing loss (HL), vertigo and facial paralysis (FP) in patients with temporal bone trauma. The authors studied CT scans of 39 ears in 35 patients with temporal bone trauma. CT scans were performed with 1-1.5 mm slice thickness and table incrementation. Both axial and coronal scans were obtained in 32 patients and in three patients only axial scans were obtained. We analyzed CT with special reference to the structural abnormalities of the external auditory canal, middle ear cavity, bony labyrinth, and facial nerve canal, and correlated these findings with the actual clinical signs and symptoms. As to hearing loss, we evaluated 32 ears in which pure tone audiometry or brainstem evoked response audiometry had been performed. With respect to the specific types of HL, CT accurately showed the abnormalities in 84% (16/19) in conductive HL, 100% (2/2) in sensorineural HL, and 25% (2/8) for mixed HL. When we categorized HL simply as conductive and sensorineural, assuming that mixed be the result of combined conductive and sensorineural HL, CT demonstrated the abnormalities in 89% (24/27) for conductive HL and 50% (5/10) for sensorineural HL. Concerning vertigo and FP, CT demonstrated abnormalities in 67%(4/6), and 29% (4/14), respectively. Except for conductive HL, CT seems to have a variable degree of limitation for the demonstration of the structural abnormalities resulting sensorineural HL, vertigo or facial paralysis. It is imperative to correlate the CT findings with the signs and symptoms in those clinical settings.

  12. Quantifying the impact of respiratory-gated 4D CT acquisition on thoracic image quality : a digital phantom study

    NARCIS (Netherlands)

    Bernatowicz, K; Keall, P; Mishra, P; Knopf, A; Lomax, A; Kipritidis, J

    PURPOSE: Prospective respiratory-gated 4D CT has been shown to reduce tumor image artifacts by up to 50% compared to conventional 4D CT. However, to date no studies have quantified the impact of gated 4D CT on normal lung tissue imaging, which is important in performing dose calculations based on

  13. Comparison of Ct and MRI in the study of the pituitary gland

    International Nuclear Information System (INIS)

    Juliani, G.; Avataneo, T.; Potenzoni, F.; Sorrentino, T

    1989-01-01

    Normal CT and MR anatomy was studied in two series (53 and 25 cases respectively) of young volunteers of both sexes, asymptomatic and certainly without lesions of the pituitary gland. 115 other pathological cases (73 hyperprolactinemias, 8 acromegalies, 15 Cushing syndromes, 2 hyperthyroidisms, 17 non-secreting adenomas) were examined using both CT and MRI. Both an accurate review of the relative literature and the results of our own series prove that MR is superior to CT in diagnosing pituitary microadenomas (3.2% not diagnosed with MRI and 25.8% not diagnosed with CT), in the follow-up of prolactinomas subjected to medical therapy and in the study of extrasellar involvement of pituitery adenomas, particularly with regard to the demonstration of compression of the optic chiasma

  14. Pulmonary actinomycosis: CT studies of diagnostic and post-treatment findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jung; Song, Sun Wha; Bo, Seal Hwang; Park, Hyun Jin; Kim, Hyeon Sook; Kim, Ki Jun; Kim, Horrim; Park, Seog Hee [College of Medicine, the Catholic University of Korea, Uijeongbu (Korea, Republic of)

    2008-05-15

    To investigate the value of the computed tomography (CT) in the study of diagnostic and post-treatment findings of pulmonary actinomycosis. Clinical data and CT findings were retrospectively analyzed in 10 patients with histopathologically confirmed pulmonary actinomycosis. We analyzed the initial CT findings in search of patterns and distributions which suggest possible lung abnormalities and found the pleura, chest wall, and lymphadenopathy to be involved as part of the indicators of lung abnormalities. We analyzed follow-up CT findings for changes in the lungs after antibiotic therapy and recurrence after surgery. Of the 10 patients analyzed by CT for lung lesions, seven had been diagnosed with alcoholism and nine were male. The initial CTs (n = 10) indicated that all the pulmonary lesions were solitary without chest wall involvement. However, a transfissural extension was observed in 20% of the study population (n = 2). Furthermore, peripheral lung distribution and adjacent pleural thickening was observed in 70% of the study population (n = 7). Within the consolidation (n = 6) or mass (n = 4), a central low density with peripheral enhancement was seen in 70% of the study population (n = 7). A follow-up CT of the seven cases following antiobiotic therapy revealed that four cases showed minimal improvement or aggravation of their lung lesions, whereas three cases showed resolution or improvement. The improvement of the central low density was related to the improvement of consolidation or mass. Furthermore the presence of fibrosis was observed after the resolution of pulmonary lesions (n = 2). No relationship was found between the duration and response of antibiotic therapy. A follow-up CT (n = 4) subsequent to a lung resection revealed the onset of chest wall actinomycosis and a thickened pleura in one case. The results of this study highlight the value of the CT in pulmonary actinomycosis in order to diagnose and evaluate antibiotic responses, complications, or

  15. Study of CT Scan Flooding System at High Temperature and Pressure

    Science.gov (United States)

    Chen, X. Y.

    2017-12-01

    CT scan flooding experiment can scan micro-pore in different flooding stages by the use of CT scan technology, without changing the external morphology and internal structure of the core, and observe the distribution characterization in pore medium of different flooding fluid under different pressure.thus,it can rebuilt the distribution images of oil-water distribution in different flooding stages. However,under extreme high pressure and temperature conditions,the CT scan system can not meet the requirements. Container of low density materials or thin shell can not resist high pressure,while high density materials or thick shell will cause attenuation and scattering of X-ray. The experiment uses a simple Ct scanning systems.X ray from a point light source passing trough a micro beryllium shell on High pressure stainless steal container,continuously irradiates the core holder that can continuously 360° rotate along the core axis. A rare earth intensifying screen behind the core holder emitting light when irradiated with X ray can show the core X ray section image. An optical camera record the core X ray images through a transparency high pressure glazing that placed on the High pressure stainless steal container.Thus,multiple core X ray section images can reconstruct the 3D core reconstruction after a series of data processing.The experiment shows that both the micro beryllium shell and rare earth intensifying screen can work in high temperature and high pressure environment in the stainless steal container. This way that X-ray passes through a thin layer of micro beryllium shell , not high pressure stainless steal shell,avoid the attenuation and scattering of X-ray from the container shell,while improving the high-pressure experiment requirements.

  16. CT study of infantile cerebral vitamin B1 deficiency (analysis of 22 cases)

    International Nuclear Information System (INIS)

    Liu Bin; Xi Meifang; Wang Mengding; Wang Chaoxiu

    1998-01-01

    Purpose: To study the CT features of infantile cerebral vitamin B 1 deficiency. Methods: The authors retrospectively reviewed the clinical manifestations and CT findings of 22 cases of infantile vitamin B 1 deficiency. Results: The main clinical signs were seizure malaise dullness and vomiting. CT scans showed bilateral symmetrical hypodense foci in lenticular nucleus (20/22), head of caudate nucleus (15/22), thalamus (3/22), anterior limb of internal capsule (4/22), external capsule (1/22) and para-ventricle white matter (2/22), and in many cases, signs of cerebral atrophy. 22 cases received thiamine treatment and were fully recovered. Conclusion: The authors concluded that bilateral symmetric hypodense foci in lenticular nucleus thalamus, head of caudate nucleus, anterior limb of internal capsule, external capsule and para-ventricle white matter were important CT signs suggestive of infantile cerebral vitamin B 1 deficiency

  17. Lesion concordance, image quality and artefacts in PET/CT. Results of a multicenter study

    International Nuclear Information System (INIS)

    Stergar, H.; Bockisch, A.; Krause, B.J.; Eschmann, S.M.; Juergens, K.U.; Kuehl, H.; Pfannenberg, A.C.; Stollfuss, J.; Weckesser, M.

    2010-01-01

    This study had three major objectives: (1.) to record the number of concordant (both in PET and CT) pathological lesions in different body regions/organs, (2.) to evaluate the image quality and (3.) to determine both, the quantity and the quality of artefacts in whole body FDG PET/CT scans. Routine whole body scans of 353 patients referred to FDG-PET/CT exams at 4 university hospitals were employed. All potentially malignant lesions in 13 different body regions/organs were classified as either concordant or suspicious in FDG-PET or CT only. In the latter case the diagnostic relevance of this disparity was judged. The image quality in PET and CT was rated as a whole and separately in 5 different body regions. Furthermore we investigated the frequency and site of artefacts caused by metal implants and oral or intravenous contrast media as well as the subjective co-registration quality (in 4 body regions) and the diagnostic impact of such artefacts or misalignment. In addition, the readers rated the diagnostic gain of adding the information from the other tomographic method. In total 1941 lesions (5.5 per patient) were identified, 1094 (56%) out of which were concordant. 602 (71%) out of the 847 remaining lesions were detected only with CT, 245 (29%) were only PET-positive. As expected, CT particularly depicted the majority of lesions in the lungs and abdominal organs. However, the diagnostic relevance was greater with PET-only positive lesions. Most of the PET/CT scans were performed with full diagnostic CT including administration of oral and intravenous contast media (> 80%). The image quality in PET and CT was rated excellent. Artefacts occurred in more than 60% of the scans and were mainly due to (dental) metal implants and contrast agent. Nevertheless there was almost no impact on diagnostic confidence if reading of the non attenuation corrected PET was included. The co-registration quality in general was also rated as excellent. Misalignment mostly occurred due

  18. A study comparing the use of dynamic CT and Xe-CT CBF for ischemic cerebro-vascular disease

    International Nuclear Information System (INIS)

    Terada, Tomoaki; Kikuchi, Haruhiko; Kuriyama, Yoshihiro; Nagata, Izumi; Yamagata, Sen; Naruo, Yoshito; Minamikawa, Jun; Kaneko, Takaji; Sakashita, Yoshiharu

    1987-01-01

    The simultaneous measurement of dynamic computerized tomography scanning (DCT) with an iodine-contrast enhancement material bolus injection and a simultaneous xenon CT-CBF-study was done on 15 patients (8 cases of unilateral internal carotid occlusion; 3, of unilateral middle cerebral arterial occlusion, and 4, without any major cerebral arterial occlusion or significant arterial stenosis) with ischemic cerebro-vascular diseases at the subacute and/or chronic stage. The value of the width and corrected first moment (cMT1) as well as their functional images, as acquired from DCT data, were compared to the 1-CBF value and the 1-CBF map of the xenon CT-CBF-study. A comparison of the functional images of DCT and 1-CBF showed that there was a good correlation between them in the cases without leptomeningeal anastomosis as a collateral circulation. However, a poor correlation between them was found in the cases with leptomeningeal anastomosis as a collateral circulation. The correlation of 1-CBF and 1/width with 1/cMT1 was significant (r = 0.78, p < 0.01) in the former cases, but it was not significant in the latter cases. The results of our data were thought to be due to the difference in the tracer inflow pattern between the cases without leptomeningeal anastomosis and those with it as a collateral circulation. The factor of cerebral blood volume should be considered in a more detailed study, although our cases did not include any patients with acute cerebral infarction or recanalized cases, which are thought to show various changes in the cerebral blood volume. The 1/width and 1/cMT1 values acquired from DCT well reflected the CBF in the cases without leptomeningeal anastomosis as a collateral circulation. (author)

  19. Impact of a CAD system in a screen-film mammography screening program: A prospective study

    International Nuclear Information System (INIS)

    Sanchez Gómez, S.; Torres Tabanera, M.; Vega Bolivar, A.; Sainz Miranda, M.; Baroja Mazo, A.; Ruiz Diaz, M.; Martinez Miravete, P.; Lag Asturiano, E.; Muñoz Cacho, P.; Delgado Macias, T.

    2011-01-01

    Objective: The purpose of our study was to perform a prospective assessment of the impact of a CAD system in a screen-film mammography screening program during a period of 3 years. Materials and methods: Our study was carried out on a population of 21,855 asymptomatic women (45–65 years). Mammograms were processed in a CAD system and independently interpreted by one of six radiologists. We analyzed the following parameters: sensitivity of radiologist's interpretation (without and with CAD), detection increase, recall rate and positive predictive value of biopsy, CAD's marks, radiologist's false negatives and comparative analysis of carcinomas detected and non-detected by CAD. Results: Detection rate was 4.3‰. CAD supposed an increase of 0.1‰ in detection rate and 1% in the total number of cases (p < 0.005). The impact on recall rate was not significant (0.4%) and PPV of percutaneous biopsy was unchanged by CAD (20.23%). CAD's marks were 2.7 per case and 0.7 per view. Radiologist's false negatives were 13 lesions which were initially considered as CAD's false positives. Conclusions: CAD supposed a significant increase in detection, without modifications in recall rates and PPV of biopsy. However, better results could have been achieved if radiologists had considered actionable those cases marked by CAD but initially misinterpreted.

  20. Radiological findings of dissecting aneurysm -a correlative study of CT with angiography-

    International Nuclear Information System (INIS)

    Bae, Tae Yeong; Park, Jae Hyung; Kim, Seung Hyup; Han, Man Chung

    1987-01-01

    This study comprised 16 patients with aortic dissecting aneurysm who were admitted to Seoul National University Hospital from May 1984 to January 1987. CT findings in 16 cases of aortic dissecting aneurysm were correlated with angiographic findings retrospectively. The results were analysed. 1. Number of male was 11 and that of female was 5. Male patients in fifties were most common and 4 in number. 13 patients had hypertension or history of hypertension among 14 patients. There were one case of Marfan's syndrome, preeclampsia and Takayasu's arteritis respectively. 2. There were 5 cases of DeBakey type I, 1 case of type II and 9 cases of types III dissecting aneurysm. Type III was most common. 3. CT confirmed as superior vena cava which was not identified whether it was superior vena cava or unopacified false lumen by angiography in one case. Regarding distal extent, authors defined A whose extent was proximal to diaphragm and B beyond it for convenience sake. There was one false negative case in CT among 16 cases which was diagnosed as dissecting aneurysm type IIIB by angiography and confirmed as type III surgically. One case was diagnosed as type IB by CT and as type IIIB by angiography and confirmed as type I surgically. Extent was more accurate in CT than angiography. One case was diagnosed as type II by CT but misdiagnosed as right atrial tumor by angiography. 4. Diagnostic sensitivities of CT and angiography in this study were 94% (15/16) respectively. CT was more advantageous in hemothorax, hemopericardium, hemomediastinum, unopacified false lumen, aortic wall calcification and getting information about mediastinum. In angiography aortic regurgitation and tear site and involvement of abdominal vessels could be observed

  1. Radiological findings of dissecting aneurysm -a correlative study of CT with angiography-

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Tae Yeong; Park, Jae Hyung; Kim, Seung Hyup; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1987-06-15

    This study comprised 16 patients with aortic dissecting aneurysm who were admitted to Seoul National University Hospital from May 1984 to January 1987. CT findings in 16 cases of aortic dissecting aneurysm were correlated with angiographic findings retrospectively. The results were analysed. 1. Number of male was 11 and that of female was 5. Male patients in fifties were most common and 4 in number. 13 patients had hypertension or history of hypertension among 14 patients. There were one case of Marfan's syndrome, preeclampsia and Takayasu's arteritis respectively. 2. There were 5 cases of DeBakey type I, 1 case of type II and 9 cases of types III dissecting aneurysm. Type III was most common. 3. CT confirmed as superior vena cava which was not identified whether it was superior vena cava or unopacified false lumen by angiography in one case. Regarding distal extent, authors defined A whose extent was proximal to diaphragm and B beyond it for convenience sake. There was one false negative case in CT among 16 cases which was diagnosed as dissecting aneurysm type IIIB by angiography and confirmed as type III surgically. One case was diagnosed as type IB by CT and as type IIIB by angiography and confirmed as type I surgically. Extent was more accurate in CT than angiography. One case was diagnosed as type II by CT but misdiagnosed as right atrial tumor by angiography. 4. Diagnostic sensitivities of CT and angiography in this study were 94% (15/16) respectively. CT was more advantageous in hemothorax, hemopericardium, hemomediastinum, unopacified false lumen, aortic wall calcification and getting information about mediastinum. In angiography aortic regurgitation and tear site and involvement of abdominal vessels could be observed.

  2. An experimental study for qualitatively diagnosing stapes lesions by helical 3-dimensional CT

    International Nuclear Information System (INIS)

    Kawaue, Akifumi; Kuki, Kiyonori; Yamanaka, Noboru; Nishimura, Michihiko

    2001-01-01

    To evaluate qualitative diagnosis of stapes lesions by 3-dimensional computed tomography (3D-CT) combined with superselective image processing (3D-SS) of stapes, we studied helical 3D-CT on a phantom model of the temporal bone. Two stapes models were used-1 made from the bone filler, Celatite, consistent in bone density but changing in cross sectional area, and the other made from an apacerum rod used in quantitative computed tomography (QCT), consistent in cross sectional area but changing in bone density. These stapes models were put into a skull phantom and analyzed by helical 3D-CT. The influence of the tympanic cavity conditions on CT images of stapes was evaluated by filling the phantom model with Vaseline following 3D selective reconstruction. In all stapes models, lowering the lower CT window width threshold resulted in an enlarged cross-sectional area of the model. The higher the bone density, the lower the increase in cross-sectional area in the image. The stapes model with lower density had greater influence on the imaging by tympanic cavity conditions and was likely to be misdiagnosed as showing higher bone density. Based on the experimental study, 3D-SS by helical 3D-CT appears to be a useful measure for qualitatively diagnosing stapes lesions. (author)

  3. A comparative study for spatial resolution and subjective image characteristics of a multi-slice CT and a cone-beam CT for dental use

    International Nuclear Information System (INIS)

    Watanabe, Hiroshi; Honda, Eiichi; Tetsumura, Akemi; Kurabayashi, Tohru

    2011-01-01

    Purpose: Multi-slice CT (MSCT) and cone-beam CT (CBCT) are widely used in dental practice. This study compared the spatial resolution of these CT systems to elucidate which CT modalities should be selected for various clinical cases. Materials and methods: As MSCT and CBCT apparatuses, Somatom Sensation 64 and 3D Accuitomo instruments, respectively, were used. As an objective evaluation of spatial resolution of these CT systems, modulation transfer function (MTF) analysis was performed employing an over-sampling method. The results of MTF analysis were confirmed with a line-pair test using CATPHAN. As a subjective evaluation, a microstructure visualization ability study was performed using a Jcl:SD rat and a head CT phantom. Results: MTF analysis showed that for the in-plane direction, the z-axis ultrahigh resolution mode (zUHR) of the Sensation 64 and 3D Accuitomo instruments had higher spatial resolutions than the conventional mode (64x) of the Sensation 64, but for the longitudinal direction, the 3D Accuitomo had clearly higher spatial resolution than either mode of the Sensation 64. A line-pair test study and microstructure visualization ability studies confirmed the results for MTF analysis. However, images of the rat and the CT phantom revealed that the 3D Accuitomo demonstrated the failure to visualize the soft tissues along with aliasing and beam-hardening artifacts, which were not observed in the Sensation 64. Conclusions: This study successfully applied spatial resolution analysis using MSCT and CBCT systems in a comparative manner. These findings could help in deciding which CT modality should be selected for various clinical cases.

  4. Scintillating screens study for LEIR/LHC heavy ion beams

    CERN Document Server

    Bal, C; Lefèvre, T; Scrivens, R; Taborelli, M

    2005-01-01

    It has been observed on different machines that scintillating ceramic screens (like chromium doped alumina) are quickly damaged by low energy ion beams. These particles are completely stopped on the surface of the screens, inducing both a high local temperature increase and the electrical charging of the material. A study has been initiated to understand the limiting factors and the damage mechanisms. Several materials, ZrO2, BN and Al2O3, have been tested at CERN on LINAC3 with 4.2MeV/u lead ions. Alumina (Al2O3) is used as the reference material as it is extensively used in beam imaging systems. Boron nitride (BN) has better thermal properties than Alumina and Zirconium oxide (ZrO2). BN has in fact the advantage of increasing its electrical conductivity when heated. This contribution presents the results of the beam tests, including the post-mortem analysis of the screens and the outlook for further measurements. The strategy for the choice of the screens for the Low Energy Ion Ring (LEIR), currently under ...

  5. Timing-Invariant CT Angiography Derived from CT Perfusion Imaging in Acute Stroke : A Diagnostic Performance Study

    NARCIS (Netherlands)

    Smith, E. J.; Vonken, E. -J.; Meijer, F. J. A.; Dankbaar, J. W.; Horsch, A. D.; van Ginneken, B.; Velthuis, B.; van der Schaaf, I.; Prokop, M.

    2015-01-01

    BACKGROUND AND PURPOSE: Timing-invariant (or delay-insensitive) CT angiography derived from CT perfusion data may obviate a separate cranial CTA in acute stroke, thus enhancing patient safety by reducing total examination time, radiation dose, and volume of contrast material. We assessed the

  6. Three dimensional CT imaging of ossicular chain: a preliminary study

    International Nuclear Information System (INIS)

    Hu Chunhong; Zhong Shenbin; Fu Yindi; Zhu Wei; Wang Xueyuan; Chen Jianhua; Ding Yi

    2001-01-01

    Objective: To analysis the features of normal and abnormal ossicular chain in three dimensional images and asses the best parameters and its usefulness in diagnosis and treatment of chronic otitis media (COM). Methods: All patients, including 43 patients with normal ears and 24 ears with COM, were examined using spiral CT with inner ear software, 1-mm slice width and 1 pitch. SSD method was used in three dimensional reconstruction and the threshold was 100-300 Hu. Results: In normal cases, Malleus, incus, stapes crura, incudomalleal joints and incudostapedial joints were displayed well, but stapes footplate unsatisfactorily. The disruption of the ossicular chain showed in three-dimensional images in cases of chronic otitis media was in accord with that seen in the operation. Conclusion: It is very important for imaging with high quality through selecting proper parameters, and three-dimensional image can provide valuable information for surgery

  7. An ergonomics study of thumb movements on smartphone touch screen.

    Science.gov (United States)

    Xiong, Jinghong; Muraki, Satoshi

    2014-01-01

    This study investigated the relationships between thumb muscle activity and thumb operating tasks on a smartphone touch screen with one-hand posture. Six muscles in the right thumb and forearm were targeted in this study, namely adductor pollicis, flexor pollicis brevis, abductor pollicis brevis (APB), abductor pollicis longus, first dorsal interosseous (FDI) and extensor digitorum. The performance measures showed that the thumb developed fatigue rapidly when tapping on smaller buttons (diameter: 9 mm compared with 3 mm), and moved more slowly in flexion-extension than in adduction-abduction orientation. Meanwhile, the electromyography and perceived exertion values of FDI significantly increased in small button and flexion-extension tasks, while those of APB were greater in the adduction-abduction task. This study reveals that muscle effort among thumb muscles on a touch screen smartphone varies according to the task, and suggests that the use of small touch buttons should be minimised for better thumb performance.

  8. Comparative Study of the CT Findings and Clinical Features in Pediatric and Adult Sialadenitis

    International Nuclear Information System (INIS)

    Han, Jong Kyu; Jo, Seong Shik; Kim, Sang Won; Kim, Young Tong; Shin, Hyeong Cheol; Kim, Il Young; Lee, Yong Man

    2010-01-01

    We wanted to compare the CT findings and clinical features of parotitis and submandibular sialadenitis in children and adults and to evaluate the statistical significance of these in different age groups and the usefulness of a CT scan. Ninety-seven adults and 36 pediatric patients with sialadenitis were included in this retrospective study. Regardless of the site of involvement, we evaluated the CT findings and clinical manifestations between the pediatric and adult groups, and between the pediatric and adult parotitis and submandibular sialadenitis groups. At last, all the patients were classified into seven age groups. Abscess formations were more prominent in the parotitis groups, and sialiths were more common in the submandibular sialadenitis group with the lowest incidence in the young children group (≤ 10 years). Cellulitis seen on a CT scan showed a higher incidence in the adult parotitis group, and this finding was closely connected with pain. A number of patients showed cervical lymphadenitis on a CT scan and this coincided with lymph node palpation. Tonsillitis associated sialadenitis was common in the pediatric group. The therapeutic durations were longer in the pediatric parotitis patient group and the adult submandibular sialadenitis group. CT scans were very helpful to evaluate for abscess, stone, lymphadenitis and estimating the associated clinical manifestations such as swelling, palpable lymph nodes, pain with operation and the therapeutic plan

  9. The comparative study of CT and MRI on femoral head necrosis

    International Nuclear Information System (INIS)

    Lin Yunliang; Liu Xianghua; Wu Shiqiang; Zeng Kangnian

    2008-01-01

    Objective: To compare the imaging features of CT and MRI in the femoral head necrosis as well as their pathological basis. Methods: 18 cases (30 hips) with femoral head necrosis proved by follow-up studies or pathology were analyzed, including 3 cases of pathological data. Results: The blurred high-density sclerotic line on CT in 28 hips were corresponded to 'line-like signs' on MRI, whereas, the other two hips without blurred high-density sclerosis line appeared 'line-like signs' on MRI. The normal area surrounded by the high-density line on CT in 26 hips were corresponded to fat-like signal area in 12 hips and mixed signal area in 14 hips on MRI. The other 4 hips with blurred bony trabeculum surrounded by the high-density line on CT showed mixed signal intensity on MRI. Conclusion: The high-density sclerotic line on CT corresponds to 'line-like sign' on MRI, which was considered as reactive interface between necrotic and viable region, was a specific signs to diagnose FHN. Compared with CT, MRI can accurately reflect pathological process during different repaired stages. (authors)

  10. A primitive study on unsupervised anomaly detection with an autoencoder in emergency head CT volumes

    Science.gov (United States)

    Sato, Daisuke; Hanaoka, Shouhei; Nomura, Yukihiro; Takenaga, Tomomi; Miki, Soichiro; Yoshikawa, Takeharu; Hayashi, Naoto; Abe, Osamu

    2018-02-01

    Purpose: The target disorders of emergency head CT are wide-ranging. Therefore, people working in an emergency department desire a computer-aided detection system for general disorders. In this study, we proposed an unsupervised anomaly detection method in emergency head CT using an autoencoder and evaluated the anomaly detection performance of our method in emergency head CT. Methods: We used a 3D convolutional autoencoder (3D-CAE), which contains 11 layers in the convolution block and 6 layers in the deconvolution block. In the training phase, we trained the 3D-CAE using 10,000 3D patches extracted from 50 normal cases. In the test phase, we calculated abnormalities of each voxel in 38 emergency head CT volumes (22 abnormal cases and 16 normal cases) for evaluation and evaluated the likelihood of lesion existence. Results: Our method achieved a sensitivity of 68% and a specificity of 88%, with an area under the curve of the receiver operating characteristic curve of 0.87. It shows that this method has a moderate accuracy to distinguish normal CT cases to abnormal ones. Conclusion: Our method has potentialities for anomaly detection in emergency head CT.

  11. An experimental comparative study of radiography, ultrasonography and CT imaging in the IV catheter fragment

    International Nuclear Information System (INIS)

    Kweon, Dae Cheol

    2016-01-01

    The objective of this study was to detect the fragments generated during IV (intravenous) catheter injection of contrast medium and drug administration in a clinical setting and removal was performed by experimentally producing a phantom, and to compare the radiography, ultrasonography, and multi-detector computed tomography (MDCT) imaging and radiation dose. A 1 cm fragment of an 18 gage Teflon® IV catheter with saline was inserted into the IV control line. Radiography, CT, and ultrasonography were performed and radiography and CT dose were calculated. CT and ultrasonography showed an IV catheter fragment clinically and radiography showed no visible difference in the ability to provide a useful image of an IV catheter fragment modality (p >.05). Radiography of effective dose (0.2139 mSv·Gy-1·cm-2) form DAP DAP (0.93 μGy·m2 ), and dose length product (DLP) (201 mGy·cm) to effective dose was calculated as 0.483 mSv. IV catheter fragment were detected of radiography, ultrasonography and CT. These results can be obtained by menas of an excellent IV catheter fragment of detection capability CT. However, CT is followed by radiation exposure. IV catheter fragment confirming the position and information recommend an ultrasonography

  12. Inter- and intrascanner variability of pulmonary nodule volumetry on low-dose 64-row CT: an anthropomorphic phantom study

    Science.gov (United States)

    Xie, X; Willemink, M J; Zhao, Y; de Jong, P A; van Ooijen, P M A; Oudkerk, M; Greuter, M J W

    2013-01-01

    Objective: To assess inter- and intrascanner variability in volumetry of solid pulmonary nodules in an anthropomorphic thoracic phantom using low-dose CT. Methods: Five spherical solid artificial nodules [diameters 3, 5, 8, 10 and 12 mm; CT density +100 Hounsfield units (HU)] were randomly placed inside an anthropomorphic thoracic phantom in different combinations. The phantom was examined on two 64-row multidetector CT (64-MDCT) systems (CT-A and CT-B) from different vendors with a low-dose protocol. Each CT examination was performed three times. The CT examinations were evaluated twice by independent blinded observers. Nodule volume was semi-automatically measured by dedicated software. Interscanner variability was evaluated by Bland–Altman analysis and expressed as 95% confidence interval (CI) of relative differences. Intrascanner variability was expressed as 95% CI of relative variation from the mean. Results: No significant difference in CT-derived volume was found between CT-A and CT-B, except for the 3-mm nodules (pvolumetry of artificial pulmonary nodules between 5 mm and 12 mm in diameter. Inter- and intrascanner variability decreases at a larger nodule size to a maximum of 4.9% for ≥8 mm nodules. Advances in knowledge: The commonly accepted cut-off of 25% to determine nodule growth has the potential to be reduced for ≥8 mm nodules. This offers the possibility of reducing the interval for repeated CT scans in lung cancer screenings. PMID:23884758

  13. Xenon-enhanced CT using subtraction CT: Basic and preliminary clinical studies for comparison of its efficacy with that of dual-energy CT and ventilation SPECT/CT to assess regional ventilation and pulmonary functional loss in smokers

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe (Japan); Yoshikawa, Takeshi [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe (Japan); Takenaka, Daisuke [Department of Radiology, Hyogo Cancer Center, Akashi (Japan); Fujisawa, Yasuko; Sugihara, Naoki [Toshiba Medical Systems Corporation, Otawara (Japan); Kishida, Yuji; Seki, Shinichiro; Koyama, Hisanobu; Sugimura, Kazuro [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine (Japan)

    2017-01-15

    Purpose: To prospectively and directly compare the capability for assessments of regional ventilation and pulmonary functional loss in smokers of xenon-ventilation CT obtained with the dual-energy CT (DE-CT) and subtraction CT (Sub-CT) Materials and methods: Twenty-three consecutive smokers (15 men and 8 women, mean age: 69.7 ± 8.7 years) underwent prospective unenhanced and xenon-enhanced CTs, the latter by Sub-CT and DE-CT methods, ventilation SPECT and pulmonary function tests. Sub-CT was generated from unenhanced and xenon-enhanced CT, and all co-registered SPECT/CT data were produced from SPECT and unenhanced CT data. For each method, regional ventilation was assessed by using a 11-point scoring system on a per-lobe basis. To determine the functional lung volume by each method, it was also calculated for individual sublets with a previously reported method. To determine inter-observer agreement for each method, ventilation defect assessment was evaluated by using the χ2 test with weighted kappa statistics. For evaluation of the efficacy of each method for pulmonary functional loss assessment, functional lung volume was correlated with%FEV{sub 1}. Results: Each inter-observer agreement was rated as substantial (Sub-CT: κ = 0.69, p < 0.0001; DE-CT: κ = 0.64, p < 0.0001; SPECT/CT: κ = 0.64, p < 0.0001). Functional lung volume for each method showed significant to good correlation with%FEV{sub 1} (Sub-CT: r = 0.72, p = 0.0001; DE-CT: r = 0.74, p < 0.0001; SPECT/CT: r = 0.66, p = 0.0006). Conclusion: Xenon-enhanced CT obtained by Sub-CT can be considered at least as efficacious as that obtained by DE-CT and SPECT/CT for assessment of ventilation abnormality and pulmonary functional loss in smokers.

  14. Giant-cell arteritis. Concordance study between aortic CT angiography and FDG-PET/CT in detection of large-vessel involvement

    International Nuclear Information System (INIS)

    Boysson, Hubert de; Dumont, Anael; Boutemy, Jonathan; Maigne, Gwenola; Martin Silva, Nicolas; Sultan, Audrey; Bienvenu, Boris; Aouba, Achille; Liozon, Eric; Ly, Kim Heang; Lambert, Marc; Aide, Nicolas; Manrique, Alain

    2017-01-01

    The purpose of our study was to assess the concordance of aortic CT angiography (CTA) and FDG-PET/CT in the detection of large-vessel involvement at diagnosis in patients with giant-cell arteritis (GCA). We created a multicenter cohort of patients with GCA diagnosed between 2010 and 2015, and who underwent both FDG-PET/CT and aortic CTA before or in the first ten days following treatment introduction. Eight vascular segments were studied on each procedure. We calculated concordance between both imaging techniques in a per-patient and a per-segment analysis, using Cohen's kappa concordance index. We included 28 patients (21/7 women/men, median age 67 [56-82]). Nineteen patients had large-vessel involvement on PET/CT and 18 of these patients also presented positive findings on CTA. In a per-segment analysis, a median of 5 [1-7] and 3 [1-6] vascular territories were involved on positive PET/CT and CTA, respectively (p = 0.03). In qualitative analysis, i.e., positivity of the procedure suggesting a large-vessel involvement, the concordance rate between both procedures was 0.85 [0.64-1]. In quantitative analysis, i.e., per-segment analysis in both procedures, the global concordance rate was 0.64 [0.54-0.75]. Using FDG-PET/CT as a reference, CTA showed excellent sensitivity (95%) and specificity (100%) in a per-patient analysis. In a per-segment analysis, sensitivity and specificity were 61% and 97.9%, respectively. CTA and FDG-PET/CT were both able to detect large-vessel involvement in GCA with comparable results in a per-patient analysis. However, PET/CT showed higher performance in a per-segment analysis, especially in the detection of inflammation of the aorta's branches. (orig.)

  15. Giant-cell arteritis. Concordance study between aortic CT angiography and FDG-PET/CT in detection of large-vessel involvement

    Energy Technology Data Exchange (ETDEWEB)

    Boysson, Hubert de; Dumont, Anael; Boutemy, Jonathan; Maigne, Gwenola; Martin Silva, Nicolas; Sultan, Audrey; Bienvenu, Boris; Aouba, Achille [Caen University Hospital, Department of Internal Medicine, Caen (France); Liozon, Eric; Ly, Kim Heang [Limoges University Hospital, Department of Internal Medicine, Limoges (France); Lambert, Marc [Lille University Hospital, Department of Internal Medicine, Lille (France); Aide, Nicolas [Caen University Hospital, Department of Nuclear Medicine, Caen (France); INSERM U1086 ' ' ANTICIPE' ' , Francois Baclesse Cancer Centre, Caen (France); Manrique, Alain [Caen University Hospital, Department of Nuclear Medicine, Caen (France); Normandy University, Caen (France)

    2017-12-15

    The purpose of our study was to assess the concordance of aortic CT angiography (CTA) and FDG-PET/CT in the detection of large-vessel involvement at diagnosis in patients with giant-cell arteritis (GCA). We created a multicenter cohort of patients with GCA diagnosed between 2010 and 2015, and who underwent both FDG-PET/CT and aortic CTA before or in the first ten days following treatment introduction. Eight vascular segments were studied on each procedure. We calculated concordance between both imaging techniques in a per-patient and a per-segment analysis, using Cohen's kappa concordance index. We included 28 patients (21/7 women/men, median age 67 [56-82]). Nineteen patients had large-vessel involvement on PET/CT and 18 of these patients also presented positive findings on CTA. In a per-segment analysis, a median of 5 [1-7] and 3 [1-6] vascular territories were involved on positive PET/CT and CTA, respectively (p = 0.03). In qualitative analysis, i.e., positivity of the procedure suggesting a large-vessel involvement, the concordance rate between both procedures was 0.85 [0.64-1]. In quantitative analysis, i.e., per-segment analysis in both procedures, the global concordance rate was 0.64 [0.54-0.75]. Using FDG-PET/CT as a reference, CTA showed excellent sensitivity (95%) and specificity (100%) in a per-patient analysis. In a per-segment analysis, sensitivity and specificity were 61% and 97.9%, respectively. CTA and FDG-PET/CT were both able to detect large-vessel involvement in GCA with comparable results in a per-patient analysis. However, PET/CT showed higher performance in a per-segment analysis, especially in the detection of inflammation of the aorta's branches. (orig.)

  16. Differentiation of adrenal adenomas from nonadenomas using CT histogram analysis method: A prospective study

    International Nuclear Information System (INIS)

    Halefoglu, Ahmet Mesrur; Bas, Nagihan; Yasar, Ahmet; Basak, Muzaffer

    2010-01-01

    Objective: The objective of our study was to prospectively evaluate the effectiveness of computed tomography (CT) histogram analysis method in the differentiation of benign and malignant adrenal masses. Materials and Methods: Between March 2007 and June 2008, 94 patients (46 males, 48 females, age range: 30-79 years, mean age: 57.7 years) with 113 adrenal masses (mean diameter: 3.03 cm, range: 1.07-8.02 cm) were prospectively evaluated. These included 66 adenomas, 45 metastases and 2 pheochromocytomas. Histogram analysis method was performed using a circular region of interest (ROI) and mean attenuation, total number of pixels, number of negative pixels and subsequent percentage of negative pixels were detected on both unenhanced and delayed contrast-enhanced CT images for each adrenal mass. A mean attenuation threshold of 10 Hounsfield unit (HU) for unenhanced CT and 5% and 10% negative pixel thresholds for both unenhanced and delayed contrast-enhanced CT were calculated by a consensus of at least two reviewers and the correlation between mean attenuation and percentage of negative pixels was determined. Final diagnoses were based on imaging follow-up of minimum 6 months, biopsy, surgery and adrenal washout study. Results: 51 of 66 adenomas (77.3%) showed attenuation values of ≤10 HU and 15 (22.7%) adenomas showed more than 10 HU on unenhanced CT. All of these adenomas contained negative pixels on unenhanced CT. Eight of 66 (12.1%) adenomas showed a mean attenuation value of ≤10 HU on delayed contrast-enhanced scans and 45 adenomas (68.2%) persisted on containing negative pixels. All metastases had an attenuation value of greater than 10 HU on unenhanced CT images. 21 of 45 (46.6%) metastases contained negative pixels on unenhanced images but only seven metastases (15.5%) had negative pixels on delayed contrast-enhanced images. Two pheochromocytomas had negative pixels on both unenhanced and delayed contrast-enhanced CT images. Increase in the percentage of

  17. Detectability index of differential phase contrast CT compared with conventional CT: a preliminary channelized Hotelling observer study

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi; Tang, Shaojie

    2013-03-01

    Under the framework of model observer with signal and background exactly known (SKE/BKE), we investigate the detectability of differential phase contrast CT compared with that of the conventional attenuation-based CT. Using the channelized Hotelling observer and the radially symmetric difference-of-Gaussians channel template , we investigate the detectability index and its variation over the dimension of object and detector cells. The preliminary data show that the differential phase contrast CT outperforms the conventional attenuation-based CT significantly in the detectability index while both the object to be detected and the cell of detector used for data acquisition are relatively small. However, the differential phase contrast CT's dominance in the detectability index diminishes with increasing dimension of either object or detector cell, and virtually disappears while the dimension of object or detector cell approaches a threshold, respectively. It is hoped that the preliminary data reported in this paper may provide insightful understanding of the differential phase contrast CT's characteristic in the detectability index and its comparison with that of the conventional attenuation-based CT.

  18. Evaluating patients' preferences for type of bowel preparation prior to screening CT colonography: Convenience and comfort versus sensitivity and specificity

    International Nuclear Information System (INIS)

    Ghanouni, A.; Halligan, S.; Taylor, S.A.; Boone, D.; Plumb, A.; Wardle, J.; Wagner, C. von

    2013-01-01

    Aims: To explore the relative value patients place on comfort and convenience versus test sensitivity and specificity in the context of computed tomographic colonography (CTC) screening. Materials and methods: Twenty semi-structured interviews were carried out with patients attending hospital for radiological tests unrelated to CTC. Preferences for CTC with different types of bowel preparation for CTC screening were examined and interviews were analysed thematically. The discussion guide included separate sections on CTC, bowel preparation methods (non-, reduced- and full-laxative), and sensitivity and specificity. Patients were given information on each topic in turn and asked about their views and preferences during each section. Results: Following information about the test, patients' attitudes towards CTC were positive. Following information on bowel preparation, full-laxative purgation was anticipated to cause more adverse physical and lifestyle effects than using reduced- or non-laxative preparation. However, stated preferences were approximately equally divided, largely due to patients anticipating that non-laxative preparations would reduce test accuracy (because the bowel was not thoroughly cleansed). Following information on sensitivity and specificity (which supported patients' expectations), the predominant stated preference was for full-laxative preparation. Conclusions: Patients are likely to value test sensitivity and specificity over a more comfortable and convenient preparation. Future research should test this hypothesis on a larger sample

  19. [Study of patients with prolonged fever with (18)F-FDG PET/CT].

    Science.gov (United States)

    Moragas, M; Cozar, M Puig; Buxeda, M; Soler, M; Riera, E; García, J R

    2015-01-01

    To review the findings on (18)F-FDG PET-CT in patients with fever of unknown origin lasting more than 7 days. This retrospective descriptive observational study included 93 (18)F-FDG PET-CT studies to detect a fever-causing focus done at three nuclear medicine centers from October 2006 through February 2014. A nuclear medicine specialist and a radiologist reviewed the images for foci of pathological uptake; another specialist's opinion resolved discrepancies. The findings on (18)F-FDG PET-CT studies were checked against clinical and/or histological findings. Abnormal (18)F-FDG uptake on PET-CT that could explain the cause of the fever was found in 52 (56%) of the 93 studies, and the cause of the fever was confirmed in 50 of these 52 studies. In the 50 cases in which the cause of the fever was confirmed, infection was the most common cause (54%), followed by noninfectious inflammatory disease (28%) and tumors (18%). (18)F-FDG PET-CT is useful in diagnosing the cause of prolonged febrile illness, so it might be practical to use it earlier in the diagnostic process. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  20. A study of effective sequences on micro-CT in the dent-maxillo-facial region

    International Nuclear Information System (INIS)

    Kato, Masataka; Mori, Shintaro; Sakayanagi, Masashi; Fujita, Yuzo; Kaneda, Takashi

    2005-01-01

    Microfocus computed tomography (micro-CT) using cone-beam scan is becoming widely used for various studies of oral structures. However, this machine has not been used to evaluate the effective parameters for two-dimensional (2D) or three-dimensional (3D) images. This study evaluated the effective parameters of micro-CT for 2D or 3D images of oral hard tissue structures. We evaluated the CT value of 5 human teeth (upper first molars) to determine suitable CT value examined according to several X-ray parameters using conformal radiotherapy (CRT) on a work station. CT information from the specimens was obtained using a micro-CT (Toscaner-31300 μ, Toshiba ITC), under the conditions of tube voltage of 75 kV, tube current of 120 μA, 100∼1600 views, the number of times of addition, 512 x 512 pixel matrix, and 0.2 slice thickness. We made 3D-reconstruction images from the micro-CT data. Three-dimensional reconstruction was performed using 2D images processed by the volume-rendering method using 3D-reconstruction software (TRI/3D BON, RATOC system engineering). Then, we evaluate the 3D tooth images. In the assessment of images, three dental radiologists evaluated several 3D tooth images using 3D-reconstruction images. Each image was scored on a five-level scale by Scheffe one-pair comparison method as follows: 5: much easier to evaluate, 4: easier to evaluate, 3: equivalent, 2: harder to evaluate, 1: much harder to evaluate. In scoring, each of the three dental radiologists made an individual assessment, and when differences among individual scores occurred, the score was ultimately assigned by consensus among the three individuals. Statistical analysis of the scores assigned by the three dental radiologists as described above was carried out using Stat View-J 5.0 (Abacus Concepts, Inc, USA) statistical software and Tukey-Kramer multiple-comparison testing. The optimal CT value for evaluating the human tooth by micro-CT is 600 on 2D images. On 3D images, the optimal

  1. Periventricular hypodensity in communicating hydrocephalus studied by metrizamide CT cisternography

    International Nuclear Information System (INIS)

    Hiratsuka, Hideo; Okada, Kodai; Takasato, Yoshio; Inaba, Yutaka; Tsuyumu, Matsutaira.

    1979-01-01

    Modification of periventricular hypodensity in suspected communicating hydrocephalus was investigated by metrizamide CT cisternography. Six to eight ml of metrizamide isotonic solution with a concentration of 170 mgI/ml was given through lumbar puncture and scanning was conducted 1, 3, 6, 24 and 48 hrs after injection. In addition to visual analysis of images, mean value and standard deviation were calculated for Hounsfield units of the regions of interest at the anterolateral angle of frontal horn and the time courses of the attenuation values were statistically compared to each other at each scanning time. The results were classified into four groups: 1) periventricular low density zone with gradual penetration of metrizamide therein; 2) periventricular low density zone without penetration of metrizamide therein; 3) minimal periventricular low density zone with minimal metrizamide penetration; and 4) no periventricular low density zone and no penetration of metrizamide. The presence of a periventricular low density zone with increase of the density after ventricular reflux of metrizamide would be an important criterion for CSF shunting operation in normal pressure hydrocephalus or communicating hydrocephalus. (author)

  2. Labyrinthine otosclerosis studied by high-resolution CT

    International Nuclear Information System (INIS)

    Funai, Hiroaki; Horiuchi, Yasuharu; Yano, Jun; Ushijima, Tatujiro; Iinuma, Toshitaka; Oyama, Kazuyuki

    1986-01-01

    Labyrinthine lesions of 10 patients (20 ears) with surgically confirmed otosclerosis were investigated by means of high-resolution CT (HRCT). All ears were scaned in horizontal plane and a slice thickness of 2.0 mm was used to avoid the excessive loss of sharpness by partial volume averaging. HRCTs of 14 normal ears and 18 ears with otitis media were analyzed as controls. (1) Three patients (6 ears) demonstrated lucent zones around the cochleae. In one of 3 cases the zone extended to involve the vestibule and the semicircular canals. (2) The definitive lucent zone was not observed in the control scans. (3) The clinical data of the 3 patients whose HRCTs demonstrated the lucent zones were compared with the other 7 patients with clinical otosclerosis. Three patients showed no distinctive features regarding to age, sex, Schwartze sign and the operative findings. (4) Average bone conduction loss was significantly greater in ears with lucent zones than those without the lucent zones. Serial audiograms revealed progressive hearing impairment in 3 ears of 2 patients with the definitive lucent zone. The present report confirmed that foci of demineralization (otospongiotic lesion) in the labyrinthine capsule were imaged by the HRCT as lucent areas. HRCT provides a reproducible and reliable mean of diagnosis for the labyrinthine otosclerosis. (author)

  3. Epidemiology Study on P53 (Rs1614984 C>T Mutation in Cigarette Smokers

    Directory of Open Access Journals (Sweden)

    Dilshad Ahmad

    2017-05-01

    Full Text Available ABSTRACT Epidemiology data have established that smoking is a prime threat for the cancers, largely lung cancer. Single-nucleotide polymorphisms (SNPs,P53 SNPs have been found to be associated with the predisposition of different cancers. Their decreased expression is reported in breast and lung cancer patients. p53 (rs1614984 had been reported to be linked with the SNPs found associated with breast cancer. The primary aim of this study to determine the association of p53 variant rs1614984 with the cigarette smokers and smoking related cancers in smokers. Among the smokers, 38% were found with CC genotype, 55% were heterozygous CT and 7% were TT, respectively. The homozygous TT genotype was seen in lower percentage of smokers (7% when compared to non-smokers (8% whereas; Significant difference was not observed when encompassed by CC, CT and TT genotypes (χ2 = 4.892, p=0.087. However, CC vs CT genotype showed a significant difference between smokers and non-smokers (p=0.031, OR 1.447 (1.035-2.025 and the dominant model CC vs CT+TT was also significantly different among smoker and non-smokers (p=0.047, OR 1.39 (1.004-1.924. Furthermore, smokers are at the risk of developing variety of diseases including lung cancer. Our finding suggests a higher percentage of heterozygous CT genotype in smokers when compared to non-smokers. Therefore, this finding gives a clue that the transition mutation of C>T (rs1614984 may leads to the lung diseases including cancer in smokers. However, there will be a need of more extensive and elaborated study to set down the aspect of p53(rs1614984 C>T in lung cancer among smokers.

  4. Relationship between the thickness of the renal cortex and age: study with CT measurement

    International Nuclear Information System (INIS)

    Xu Yufeng; Tang Guangjian

    2004-01-01

    Objective: To study the relationship between the renal cortical thickness and age, and to establish the range of the normal renal cortex thickness by using CT measurement in different age groups so as to obtain a best age-related and practicable method for clinical measurement. Methods: (1) the accuracy of measuring renal cortical thickness by CT was evaluated: 18 kidney resected due to renal neoplasm were studied and the cortical thickness of the normal part of these specimens was assessed. The difference between the renal cortical thickness of specimens and preoperative measurements of renal cortex of the same patient by contrast enhanced CT was analyzed statistically. (2) 120 patients without history of renal disease or long term usage of potentially renal toxic drugs or history of hypertension were examined by CT with indication (s) other than renal disease. All the patients were divided into 20-40, 41-60, and 61-80 year-old groups. The renal cortical and parenchymal thickness and renal size were measured in three CT sections. The difference of the measurements among the three groups and their relationship to age was analyzed statistically. Results: There was no significant difference between the renal cortical thickness measured by enhanced spiral CT and measured in renal specimens (t=0.80, P=0.43). The renal cortical thickness in three groups was 0.73 cm, 0.65 cm, and 0.53 cm, respectively, and the differences among the three groups were significant (F=93.430, P 0.05). Conclusion: The measurement of the renal cortical thickness with enhanced spiral CT was reliable and was a sensitive method in investigating the morphologic changes of the kidney. The renal cortical thickness of normal kidney diminishes with age, but the change of the ratio of thickness of renal cortex to renal parenchyma with age was not significant

  5. A study of requested CT head examinations and their positive yield rate

    International Nuclear Information System (INIS)

    Coakley, K.S.

    2004-01-01

    Full text: Requests for CT examinations are ever increasing, partly due to the excellent clinical information they can provide for patient management and partly due to a perceived need for 'evidence' that everything has been done to diagnose a patient correctly. This has led to many CT examinations being done on patients where many of the radiology community does not necessarily feel CT will yield a positive finding, i.e. in their eyes - a possible unjustified use of radiation. To determine whether this was in fact true, or merely a perception, a study was performed by medical imaging and physics staff at the Royal Brisbane Hospital to determine statistics of positive yield for CT head exams. 600 CT head examinations from the Emergency Department at the Royal Brisbane Hospital were retrospectively examined and their findings were tabulated under various clinical categories to determine positive yield statistics. These categories were also tabulated with the radiologists advice as to whether they would have expected a positive finding. For several categories the positive yield for CT head exams was so low as to be considered negligible. Other categories, although low were still considered significant. These will be presented to the emergency department along with a suggested protocol for requesting CT head exams. It was unfortunate that this study had to be performed to prove to clinical staff that medical imaging staff members do in general have an excellent idea of what will show up in an x-ray and what will not! However, it was useful to be able to categorise 'positive yield' statistics into such specific classes. The next step is to try and communicate these findings to staff to create more trust and better communication between departments. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  6. Child gluteal aggressive fibromatosis: a correlative study of CT findings and pathology

    International Nuclear Information System (INIS)

    Fan Miao; Li Ziping; Meng Quanfei; Guo Yan; Ye Bingbing; Xiao Gang

    2005-01-01

    Objective: To evaluate CT imaging in the diagnosis of child gluteal aggressive fibromatosis. Methods: CT manifestations of child gluteal aggressive fibromatosis were retrospectively analyzed. In total 7 males and 1 female, 2 to 11 years old, were enrolled in study. All cases had been confirmed by surgery and pathology. CT findings were correlatively studied with pathology. Results: Lesions located on the left side were noted in 7 cases, and a lesion located on right side was seen in the rest 1 cam The lesions were elliptical or lobulated on CT images. Three tumors originated from solitary muscle and multiple muscles were involved in other 5 cases. Tumors were well demarcated. Invasion to the adjacent structure was shown in 7 cases. All tumors were homogeneous in density in non-enhanced scan. Compared to the muscles in the same section, 5 tumors were iso -density and 3 tumors were hypo-density. Inside the lesions no hemorrhage, necrosis, cystic degeneration and calcification was revealed. After contrast medium was administrated, iso-dense and homogeneous enhancement as the adjacent muscles was seen in 1 tumor and apparent enhancement were demonstrated in 7 tumors. Seven tumors tended to grow along the longitudinal axis of muscles and infiltrated into fascial space. Atrophy resulting from compression was shown in the adjacent muscles in 6 cases. The major clinical manifestation was limp. Gluteal aggressive fibromatosis was confirmed by pathology in all cases. Conclusion: There are characteristics of child gluteal aggressive fibromatosis in age of onset, gender of the patients, site of the lesion and CT findings as well. CT manifestations were consistent with pathology. CT imaging is helpful in initial diagnosis and differential diagnosis, as well as in assessing the expansion of the tumor and involvement of the adjacent structures. (authors)

  7. Accuracy of bone mineral density quantification using dual-layer spectral detector CT: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Hamersvelt, Robbert W. van; Schilham, Arnold M.R.; Harder, Annemarie M. den; Leiner, Tim; Jong, Pim A. de; Willemink, Martin J. [University Medical Centre Utrecht, Department of Radiology, P.O. Box 85500, Utrecht (Netherlands); Engelke, Klaus [University of Erlangen-Nuernberg, Institute of Medical Physics, Erlangen (Germany); Keizer, Bart de [University Medical Centre Utrecht, Department of Nuclear Medicine, Utrecht (Netherlands); Verhaar, Harald J. [University Medical Centre Utrecht, Department of Geriatric Medicine, Utrecht (Netherlands)

    2017-10-15

    To investigate the accuracy of bone mineral density (BMD) quantification using dual-layer spectral detector CT (SDCT) at various scan protocols. Two validated anthropomorphic phantoms containing inserts of 50-200 mg/cm{sup 3} calcium hydroxyapatite (HA) were scanned using a 64-slice SDCT scanner at various acquisition protocols (120 and 140 kVp, and 50, 100 and 200 mAs). Regions of interest (ROIs) were placed in each insert and mean attenuation profiles at monochromatic energy levels (90-200 keV) were constructed. These profiles were fitted to attenuation profiles of pure HA and water to calculate HA concentrations. For comparison, one phantom was scanned using dual energy X-ray absorptiometry (DXA). At both 120 and 140 kVp, excellent correlations (R = 0.97, P < 0.001) were found between true and measured HA concentrations. Mean error for all measurements at 120 kVp was -5.6 ± 5.7 mg/cm{sup 3} (-3.6 ± 3.2%) and at 140 kVp -2.4 ± 3.7 mg/cm{sup 3} (-0.8 ± 2.8%). Mean measurement errors were smaller than 6% for all acquisition protocols. Strong linear correlations (R{sup 2} ≥ 0.970, P < 0.001) with DXA were found. SDCT allows for accurate BMD quantification and potentially opens up the possibility for osteoporosis evaluation and opportunistic screening in patients undergoing SDCT for other clinical indications. However, patient studies are needed to extend and translate our findings. (orig.)

  8. MR imaging of hepatic metastasis in patients with malignant melanoma: Evaluation of suspected lesions screened at contrast-enhanced CT

    International Nuclear Information System (INIS)

    Sofue, Keitaro; Tateishi, Ukihide; Tsurusaki, Masakatsu; Arai, Yasuaki; Yamazaki, Naoya; Sugimura, Kazuro

    2012-01-01

    Purpose: To evaluate the magnetic resonance (MR) imaging feature of suspected hepatic metastasis in patients with malignant melanoma which showed intermediate findings on screened contrast-enhanced computed tomography (CECT). Materials and methods: MR imaging was performed in 38 patients (22 men, 16 women; mean age, 58 years) whose CECT findings were intermediate. Hepatic metastases had been diagnosed on MR imaging in 23 of the 38 patients. Verification of hepatic metastasis was made by histological examination: ultrasonographic-guided needle biopsy (n = 3), autopsy (n = 3), and surgical resection (n = 1), or by an obvious progression in number and/or size of the lesions on follow-up MR imaging (n = 24). Two diagnostic radiologists reviewed MR images by consensus. The median follow-up duration was 14.2 months. Results: Abnormal findings were detected in 31 patients on MR images, and undetected in the remaining seven patients resulting in false-positive on CECT. The mean size of the lesion was 11.0 mm. False-positive results were obtained in two lesions which disappeared on follow-up MR imaging. In six patients, lesions were considered as hepatic cysts on MR images. As a result, a total of 35 hepatic metastases were detected on MR images. Of these, 18 patients demonstrated typical melanotic appearance on MR images which showed shortened T1 and T2 relaxation times, and five patients demonstrated atypical melanotic appearance. In 16 patients, extra-hepatic metastases were also developed. Conclusion: MR imaging could rule out hepatic metastasis in patients with malignant melanoma which showed intermediate findings on screened CECT, and could detect additional extra-hepatic metastases.

  9. Head holder using negative pressure bag packed with plastic beads in xenon CT CBF study

    International Nuclear Information System (INIS)

    Araki, Yuzo; Sakai, Noboru

    2003-01-01

    Employing analysis of cerebral blood flow (CBF) confidence maps, we investigated the usefulness of a head holder using a negative pressure bag packed with plastic beads in a xenon CT CBF study. A total of 272 consecutive patients for the CBF study were enrolled and classified into 3 groups: 88 patients with a negative pressure bag (M group), 87 patients with an air pillow (A group), and 97 patients with a sponge pillow (S group). The degree of effect of head movements on the CBF measurement in each patient was expressed as a confidence value (mean of the confidence values at one CT slice). The mean of confidence value in the M group (0.461) was statistically lower than that in the A group (0.866) and that in the S group (1.043). These findings showed that the head holder described here was useful for obtaining CBF maps of high quality in a xenon CT CBF study. (author)

  10. Comparison of image quality in head CT studies with different dose-reduction strategies

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke

    The number of multi-detector CT examinations is increasing rapidly. They allow high quality reformatted images providing accurate and precise diagnosis at maximum speed. Brain examinations are the most commonly requested studies, and although they come at a lower effective dose than body CT, can...... account to a considerable radiation dose as many patients undergo repeated studies. Therefore, various dose-reduction strategies are applied such as automated tube current and voltage modulation and recently different iterative reconstruction algorithms. However, the trade-off of all dose......-reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

  11. 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

  12. Repeated CT studies of a patient with herpes simplex encephalitis during his entire clinical course

    International Nuclear Information System (INIS)

    Shiraishi, Masahiro; Fukui, Keiji; Takeda, Sadanori; Sadamoto, Kazuhiko; Kimura, Hideki; Sakaki, Saburo.

    1985-01-01

    We encountered a patient with herpes simplex encephalitis whose cerebral lesions were studied by repeated CT scannings during his entire clinical course. The purpose of this paper is to report the earliest lesions of the brain as revealed by CT scans. A 63-year-old man was admitted to our clinic complaining of headache, nausea, fever, and disorientation. On admission, a physical examination showed a high fever, while a neurological examination revealed a stiff neck, a positive Kernig's sign, and disorientation. Laboratory examinations revealed a pleocytosis of the cerebrospinal fluid. Electroencephalograms showed the so-called ''periodic sharp-and-slow-waves complex''. The complement fixation titer for herpes simplex virus was x32 in the serum and x128 in the cerebrospinal fluid, suggesting the diagnosis of herpes simplex encephalitis. We treated him with adenine arabinoside and gamma-globulin, but the patient did not recover; rather, he died of pneumonia and gastrointestinal bleeding three months later. Plain CT scans taken on the 12th day after the onset revealed a low-density area with signs of a slight mass in the region from the right island of Reil to the right uncus. Contrast-enhanced CT scans revealed an irregular enhancement in the low-density area. CT scans taken on the 19th day after the onset showed an extensive low-density area with a streak-like enhancement in the right temporal lobe, which is in aggreement with the findings reported by others as characteristic CT findings for herpes simplex encephalitis. In order to make an early diagnosis of a patient, we should pay attention to a low-density area with an irregular contrast enhancement in the region from the island of Reil to the uncus on a CT scan. (author)

  13. Variations in screening outcome among pairs of screening radiologists at non-blinded double reading of screening mammograms: a population-based study

    NARCIS (Netherlands)

    Klompenhouwer, E. G.; Duijm, L. E. M.; Voogd, A. C.; den Heeten, G. J.; Nederend, J.; Jansen, F. H.; Broeders, M. J. M.

    2014-01-01

    Substantial inter-observer variability in screening mammography interpretation has been reported at single reading. However, screening results of pairs of screening radiologists have not yet been published. We determined variations in screening performances among pairs of screening radiologists at

  14. Effect of clinical information in brain CT scan interpretation : a blinded double crossover study

    International Nuclear Information System (INIS)

    Zhianpour, M.; Janghorbani, M.

    2004-01-01

    Errors and variations in interpretation can happen in clinical imaging. Few studies have examined the biased effect of clinical information on reporting of brain CT scans. In a blinded double crossover design, we studied whether three radiologists were biased by clinical information when making CT scan diagnosis of the brain. Three consultant radiologists in three rounds with at least a one month interval assessed 100 consecutive cases of brain CT scan. In the first round, clinical information was not available and 100 films without clinical information were given to radiologists. In the second round, the same 100 films were given and true clinical information was available. In the third round, the same 100 films were given and false clinical information was allocated. In 180 cases (60%) the evaluation resulted in the same diagnosis on all three occasions (95% confidence interval (CI): 54.5, 65.5), whereas 120(40%; 95% CI:34.5, 45.5) sets were evaluated differently. 48 cases (16%; 95% CI:11.9,20.1) had discordant evaluation with true and 33 (11%; 95% CI:7.5, 14.5) with false clinical information. Discordance without and with true and false clinical information was 39 (13%; 95% CI:9.2, 16.8). Correct clinical information improves the brain CT report, while the report became less accurate false clinical information was allocated. These results indicate that radiologists are biased by clinical information when reporting brian CT scans

  15. Evaluation of radiation dose in pediatric head CT examination: a phantom study

    Science.gov (United States)

    Norhasrina Nik Din, Nik; Zainon, Rafidah; Rahman, Ahmad Taufek Abdul

    2018-01-01

    The aim of this study was to evaluate the radiation dose in pediatric head Computed Tomography examination. It was reported that decreasing tube voltage in CT examination can reduce the dose to patients significantly. A head phantom was scanned with dual-energy CT at 80 kV and 120 kV. The tube current was set using automatic exposure control mode and manual setting. The pitch was adjusted to 1.4, 1.45 and 1.5 while the slice thickness was set at 5 mm. The dose was measured based on CT Dose Index (CTDI). Results from this study have shown that the image noise increases substantially with low tube voltage. The average dose was 2.60 mGy at CT imaging parameters of 80 kV and 10 - 30 mAs. The dose increases up to 17.19 mGy when the CT tube voltage increases to 120 kV. With the reduction of tube voltage from 120 kV to 80 kV, the radiation dose can be reduced by 12.1% to 15.1% without degradation of contrast-to-noise ratio.

  16. Imaging benign pathology and variants with uptake in 68ga-Dotatate PET/CT studies

    International Nuclear Information System (INIS)

    Servente, L.; Bianco, C.; Gigirey, V.; Alonso, O.

    2017-01-01

    Purpose: To evaluate the physiological, anatomical variants and benign lesions in positron emission computed tomography (PET/CT) studies with 68Ga-DOTATATE.Materials and methods: We retrospectively reviewed PET/CT reports scanned with 68Ga-DOTATATE and selected those that contained words in the report related to anatomical, physiological variants and benign tumors. The degree of 68Ga-DOTATATE uptake was evaluated qualitatively and quantitatively by measuring the standarized uptake max value (SUVmax value). The anatomical location, SUVmax value and morphological CT image findings were recorded. All cases had clinical and imaging follow-up. Results: From a total of 772 PET/CT reports, 28 patients were obtained with 33 benign variants or tumors, 14 females and 14 males with a median age of 63 years. Uptake patterns were classified into four groups: anatomic and physiological variants (15), dependent on osteoblastic activity (4), dependent on inflammatory activity (10) and non-neuro-endocrine benign tumors (4).Discussion: Somatostatin receptors are overexpressed not only in the neuroendocrine system but also in other tissues. Physiological, anatomical variants and benign tumors expressing these receptors may be misleading. In the present work the frequency of this finding is 5.1%.Conclusion: Physiological variants and benign lesions (tumor and inflammatory) can accumulate 68Ga-DOTATATE since their tissues can express somatostatin receptors. The semiologic analysis of the tomographic component of this hybrid method enhances the diagnostic efficacy, optimizing PET/CT study performance. (authors) [es

  17. Experimental study on image quality when using screens in mammography

    International Nuclear Information System (INIS)

    Maurer, H.J.; Goos, F.

    1979-01-01

    1) Different types of screens and X-ray films have been investigated using a Kodak mamma-phantom I.T.O. 745 and compared with conventional non screen industrial film radiography. 2) Dosisreduction by using screens depends on the used film/screen system. It is possible to reach a relation of 1:10. 3) The information depends on type of screen and of type of film. Therefore, it is possible to reach the information of non screen industrial film radiographs. 4) A suitable film/screen system allows without loss of any diagnostic information to replace non screen industrial films needing a high exposure dosis by a film/screen system needing decreased dosis. (orig.) [de

  18. Overdiagnosis in organised mammography screening in Denmark. A comparative study

    DEFF Research Database (Denmark)

    Jørgensen, Karsten J; Zahl, Per-Henrik; Gøtzsche, Peter C

    2009-01-01

    % of the Danish population has been offered organised mammography screening over a long time-period. METHODS: We collected incidence rates of carcinoma in situ and invasive breast cancer in areas with and without screening over 13 years with screening (1991-2003), and 20 years before its introduction (1971...... an overdiagnosis of 35% when we compared unadjusted incidence rates for the screened and non-screened areas, but after compensating for a small decline in incidence in older, previously screened women. Our adjusted Poisson regression analysis indicated a relative risk of 1.40 (95% CI: 1.35-1.45) for the whole...... screening period, and a potential compensatory drop in older women of 0.90 (95% CI: 0.88-0.96), yielding an overdiagnosis of 33%, which we consider the most reliable estimate. The drop in previously screened women was only present in one of the two screened regions and was small in absolute numbers...

  19. CT study of the ethmoid labyrinth: technique of examination and normal anatomy

    International Nuclear Information System (INIS)

    Duvoisin, B.; Schnyder, P.; Chapuis, L.; Agrifoglio, A.; Krayenbuehl, M.

    1990-01-01

    These recent years, conservative endoscopic surgical treatments for inflammatory ethmoid disease have gained popularity and prompted a need for an optimal preoperative radiologic study. For this purpose, the routinely used axial and coronal CT slices are not sufficient. In our Center, the ethmoid labyrinth is studied with planes determined by the axis of drainage of all ethmoid cells. This axis corresponds to the axis of the nasofrontal duct, which is approximately angulated 50 sup(0) cephalad relative to the canto-meatal line (CML). We perform routinely CT sections in the planes CML sup(+) and CML -40 (which are respectively parallel and perpendicular to the nasofrontal duct axis). The normal anatomy of the ethmoid labyrinth is illustrated by sequential CT slices in these two planes. (author)

  20. Comparative study of patellar subluxation syndrome and normal group using axial radiography and CT

    Energy Technology Data Exchange (ETDEWEB)

    Kitagawa, Mamoru; Tomonaga, Kunio; Egawa, Tadashi; Nakamura, Yasushi; Gotoh, Shoji; Mihara, Shigeru (Nagasaki Municipal Hospital (Japan))

    1989-10-01

    A comparative study was conducted on the 20 knees of 10 females with normal knee joints (age, 22-35 years) and on 7 knees of 7 patients with subluxation syndrome (age, 15-24 years), using axial radiography and CT. In axial radiography where the angle of knee flexion was 30 deg or 60 deg, no significant difference was recognized between the two groups with respect to tilting angle, patellofemoral angle, congruence angle and lateral shift. However, a significant difference was found using CT. Thus, CT was considered useful for diagnosis. Because of these results, all 7 cases underwent surgery for detachment of the lateral side and tightening of the medial side. Three cases underwent shifting of the tibial tuberosity to the anteromedial side, resulting in a favourable outcome. Here, we report the study. (author).

  1. Comparative study of patellar subluxation syndrome and normal group using axial radiography and CT

    International Nuclear Information System (INIS)

    Kitagawa, Mamoru; Tomonaga, Kunio; Egawa, Tadashi; Nakamura, Yasushi; Gotoh, Shoji; Mihara, Shigeru

    1989-01-01

    A comparative study was conducted on the 20 knees of 10 females with normal knee joints (age, 22-35 years) and on 7 knees of 7 patients with subluxation syndrome (age, 15-24 years), using axial radiography and CT. In axial radiography where the angle of knee flexion was 30 deg or 60 deg, no significant difference was recognized between the two groups with respect to tilting angle, patellofemoral angle, congruence angle and lateral shift. However, a significant difference was found using CT. Thus, CT was considered useful for diagnosis. Because of these results, all 7 cases underwent surgery for detachment of the lateral side and tightening of the medial side. Three cases underwent shifting of the tibial tuberosity to the anteromedial side, resulting in a favourable outcome. Here, we report the study. (author)

  2. The oblique occipital sinus: anatomical study using bone subtraction 3D CT venography.

    Science.gov (United States)

    Shin, Hwa Seon; Choi, Dae Seob; Baek, Hye Jin; Choi, Ho Cheol; Choi, Hye Young; Park, Mi Jung; Kim, Ji Eun; Han, Jeong Yeol; Park, SungEun

    2017-06-01

    An occipital sinus draining into the sigmoid sinus has been termed the oblique occipital sinus (OOS). The frequency, anatomical features, patterns, and relationship with the transverse sinus of the oblique occipital sinus were analyzed in this study. The study included 1805 patients who underwent brain CT angiography during a 3-year period from 2013 to 2015. CT examinations were performed using a 64-slice MDCT system. The OOS was identified in 41 patients (2.3%). There were many anatomical variations in the oblique occipital sinuses. A hypoplastic or aplastic TS was seen in 31 (75.6%) of the 41 patients with OOS. Many anatomical variations in the oblique occipital sinus can be seen on CT venography. Some OOSs function as the main drainage route of the intracranial veins instead of the TS. Thus, careful examination is essential for preoperative evaluation in posterior fossa lesions.

  3. Screening for periodontal disease in research dogs - a methodology study.

    Science.gov (United States)

    Kortegaard, Hanne E; Eriksen, Thomas; Baelum, Vibeke

    2014-11-19

    It has been shown that the prevalence of both clinical attachment loss (CAL) ≥1 mm and pocket probing depth (PPD) ≥4 mm is relatively high even in younger dogs, but also that only a minority of the dogs have such clinical signs of periodontal disease (PD) in more than a few teeth. Hence, a minority of dogs carry the major PD burden. These epidemiological features suggest that screening for PD in larger groups of dogs, allowing for rapid assessment of treatment planning, or for the selection of dogs with or without PD prior to be included in experimental trials, should be possible. CAL is the central variable in assessing PD extent and severity while PPD is the central variable used in treatment planning which make these two variables obvious in a screening protocol with the dual aim of disease identification and treatment planning. The main purpose of the present study in 98 laboratory Beagle dogs was to construct a fast, simple and accurate screening tool, which is highly sensitive for the identification of dogs with PD. Examination of the maxillary P4, P3, P2, I1 and C would, in this population, result in the identification of 85.5% of all dogs and 96% of all teeth positive for CAL ≥1 mm, and 58.9% of all dogs and 82.1% of all teeth positive for PD ≥4 mm. Examination of tooth pairs, all C's, maxillary I2, M2 and the mandibular P4 would, in this population result in identification of 92.9% of all dogs and 97.3% of all teeth positive for PD ≥4 mm, and 65.5% of all dogs and 83.2% of all teeth positive for CAL ≥1 mm. The results presented here only pertain to the present study population. This screening protocol is suitable for examination of larger groups of laboratory Beagle dogs for PD and our findings indicate that diseased dogs are identified with a high degree of sensitivity. Before this screening can be used in clinical practice, it has to be validated in breeds other than Beagle dogs and in populations with larger age variation.

  4. Malignancy risk estimation of screen-detected nodules at baseline CT: comparison of the PanCan model, Lung-RADS and NCCN guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Riel, Sarah J. van; Ciompi, Francesco; Jacobs, Colin; Scholten, Ernst T.; Prokop, Mathias; Ginneken, Bram van [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Winkler Wille, Mathilde M.; Naqibullah, Matiullah [University of Copenhagen, Department of Pulmonology Gentofte Hospital, Hellerup (Denmark); Lam, Stephen [British Columbia Cancer Agency, Department of Integrative Oncology, Vancouver, British Columbia (Canada); Schaefer-Prokop, Cornelia [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Meander Medical Center, Department of Radiology, Amersfoort (Netherlands)

    2017-10-15

    To compare the PanCan model, Lung-RADS and the 1.2016 National Comprehensive Cancer Network (NCCN) guidelines for discriminating malignant from benign pulmonary nodules on baseline screening CT scans and the impact diameter measurement methods have on performances. From the Danish Lung Cancer Screening Trial database, 64 CTs with malignant nodules and 549 baseline CTs with benign nodules were included. Performance of the systems was evaluated applying the system's original diameter definitions: D{sup longest-C} (PanCan), D{sup meanAxial} (NCCN), both obtained from axial sections, and D{sup mean3D} (Lung-RADS). Subsequently all diameter definitions were applied uniformly to all systems. Areas under the ROC curves (AUC) were used to evaluate risk discrimination. PanCan performed superiorly to Lung-RADS and NCCN (AUC 0.874 vs. 0.813, p = 0.003; 0.874 vs. 0.836, p = 0.010), using the original diameter specifications. When uniformly applying D{sup longest-C}, D{sup mean3D} and D{sup meanAxial}, PanCan remained superior to Lung-RADS (p < 0.001 - p = 0.001) and NCCN (p < 0.001 - p = 0.016). Diameter definition significantly influenced NCCN's performance with D{sup longest-C} being the worst (D{sup longest-C} vs. D{sup mean3D}, p = 0.005; D{sup longest-C} vs. D{sup meanAxial}, p = 0.016). Without follow-up information, the PanCan model performs significantly superiorly to Lung-RADS and the 1.2016 NCCN guidelines for discriminating benign from malignant nodules. The NCCN guidelines are most sensitive to nodule size definition. (orig.)

  5. F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive: the APACH1 study.

    Science.gov (United States)

    Quak, Elske; Blanchard, David; Houdu, Benjamin; Le Roux, Yannick; Ciappuccini, Renaud; Lireux, Barbara; de Raucourt, Dominique; Grellard, Jean-Michel; Licaj, Idlir; Bardet, Stéphane; Reznik, Yves; Clarisse, Bénédicte; Aide, Nicolas

    2018-04-01

    To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT. We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up. Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0-98.9) and 90.5% (95%CI: 69.6-98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6-97.3) and 86.4% (95%CI: 65.1-97.1), respectively. Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l. Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients

  6. F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive. The APACH1 study

    Energy Technology Data Exchange (ETDEWEB)

    Quak, Elske; Lireux, Barbara; Bardet, Stephane [Francois Baclesse Cancer Centre, Department of Nuclear Medicine and Thyroid Unit, Caen (France); Blanchard, David; Raucourt, Dominique de [Francois Baclesse Cancer Centre, Department of Head and Neck Surgery, Caen (France); Houdu, Benjamin [University Hospital, Department of Nuclear Medicine, Caen (France); Le Roux, Yannick [University Hospital, Department of General and Endocrine Surgery, Caen (France); Ciappuccini, Renaud [Francois Baclesse Cancer Centre, Department of Nuclear Medicine and Thyroid Unit, Caen (France); Caen University, INSERM 1086 ANTICIPE, Caen (France); Grellard, Jean-Michel; Licaj, Idlir; Clarisse, Benedicte [Francois Baclesse Cancer Centre, Department of Clinical Research, Caen (France); Reznik, Yves [University Hospital, Department of Endocrinology, Caen (France); Aide, Nicolas [Francois Baclesse Cancer Centre, Department of Nuclear Medicine and Thyroid Unit, Caen (France); University Hospital, Department of Nuclear Medicine, Caen (France); Caen University, INSERM 1086 ANTICIPE, Caen (France)

    2018-04-15

    To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT. We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up. Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0-98.9) and 90.5% (95%CI: 69.6-98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6-97.3) and 86.4% (95%CI: 65.1-97.1), respectively. Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l. Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients with primary

  7. F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive. The APACH1 study

    International Nuclear Information System (INIS)

    Quak, Elske; Lireux, Barbara; Bardet, Stephane; Blanchard, David; Raucourt, Dominique de; Houdu, Benjamin; Le Roux, Yannick; Ciappuccini, Renaud; Grellard, Jean-Michel; Licaj, Idlir; Clarisse, Benedicte; Reznik, Yves; Aide, Nicolas

    2018-01-01

    To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT. We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up. Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0-98.9) and 90.5% (95%CI: 69.6-98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6-97.3) and 86.4% (95%CI: 65.1-97.1), respectively. Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l. Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients with primary

  8. Comparative study of CT scan findings and intellectual function between Parkinson's disease and vascular Parkinsonism

    International Nuclear Information System (INIS)

    Indo, Toshikatsu

    1986-01-01

    Comparative study of CT scan findings and intellectual function between 64 cases with Parkinson's disease and 25 cases with vascular Parkinsonism was carried out. The rate of abnormality of CT scan findings, either ventricular dilatation or widening of sulci, in vascular Parkinsonism was strikingly high compared with Parkinson's disease. Patients could be divided into three groups according to the degree of overall abnormalities of CT scan findings (group A: markedly abnormal, group B: mildly abnormal, group C: normal). Incidences of group A were 9.4 % in Parkinson's disease and 52 % in vascular Parkinsonism, whereas those of group C were 56 % in the former and 28 % in the latter. All patients of group A were over 65 years of age in Parkinson's disease, but one-third of patients in group A were under 59 years of age in vascular Parkinsonism. Moreover, in vascular Parkinsonism, the level of disability was directly proportional to the abnormality of CT scan findings. The rate of predementia and dementia classified by Hasegawa's intelligence scale was 12.5 % in Parkinson's disease and 48 % in vascular Parkinsonism. No difference was found between the mean values of intelligence scale and background factors in Parkinson's disease. On the other hand, the mean value was significantly low in proportion to the poverty of L-dopa effect in vascular Parkinsonism. From these results, the abnormality of CT scan findings and intellectual impairment were probably related to the cerebral pathological process in vascular Parkinsonism, but these relationship was absent in Parkinson's disease. (author)

  9. The evaluation study of helical CT for hepatocellular carcinoma with microwave coagulation treatment

    International Nuclear Information System (INIS)

    Zheng Keguo; Xu Dasheng; Xie Xiaoyan; Peng Zhenpeng

    2002-01-01

    Objective: To study the helical CT signs of the hepatocellular carcinoma (HCC) after percutaneous microwave coagulation therapy (PMCT) and to evaluate the correlation between the helical CT signs and the therapeutic effect of HCC. Methods: The helical CT signs were analyzed in 22 cases with 26 lesions of the hepatocellular carcinoma that were treated with PMCT under ultrasonic guidance. Results: In 21 lesions, no enhancement was detected in the lesion border or inside the lesion at hepatic arterial phase (HAP) and portal venous phase (PVP). In 7 lesions, the slight or marked patchy enhancement was revealed in the surrounding liver of the lesions in HAP. In 5 lesions, nodular enhancement was found in the lesion border or inside the lesion in HAP. Conclusion: The dual-phase helical CT might be accurate in judging the therapeutic effect of HCC after PMCT. If no enhancement was showed in the lesions in the dual-phase helical CT, it indicated that no tumor survived. If slight or marked patchy pattern enhancement was revealed in the surrounding liver of the lesions in HAP, it was a normal reaction after PMCT. If nodular enhancement was found in the lesion border or inside the lesion in HAP, it indicated that the tumor partially survived

  10. Studies on evaluation of staging of cancer of the uterine cervix by means of CT

    Energy Technology Data Exchange (ETDEWEB)

    Kakizaki, D

    1987-03-01

    The present study was undertaken to evaluate the stage classification (FIGO) by using CT in 50 cases with cancer of the uterine cervix in which the final stage had been diagnosed. An accurate diagnosis was obtained in 6 of 14 Ib cases, 14 of 21 IIa cases, 5 of 6 IIb cases, 2 of 3 IIIa cases, 3 of 3 IIIb cases and 3 of 3 IVa cases, for a total of 33 of 50 (66 %). The diagnostic rate for Ib and IIa staging was 57 %, while that for IIb or more was 87 %, but the accuracy rate in IIIb and IVa was 100 %. As the equipment, a high resolutional GE 9800 CT using a special technique was employed. Employing special pretreatment for the patient, it became possible to accurately grasp the pelvic condition of the patients. CT evaluation was related to the extent of the cervical cancer and the presence of infiltration into the vaginal wall. According to a 4-stage classification of the CT image, the extent of infiltration to surrounding parametrium and the bladder was determined. As a result, the sensitivity for evaluating invasion into surrounding tissue raised 92 %, and it showed 100 % for cases with adhesion or invasion of the bladder. Therefore, CT can an extremely effective method to determine the clinical staging of cancer of the uterine cervix.

  11. Study of CT head scans using different voltages: image quality evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco de Freitas C, I.; Prata M, A. [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil); Alonso, T. C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P., E-mail: iarapfcorrea@gmail.com [Universidade Federal de Minas Gerais, Departamento de Anatomia e Imagem, Av. Prof. Alfredo Balena 190, 30130-100 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  12. Dose reduction in multidetector CT of the urinary tract. Studies in a phantom model

    International Nuclear Information System (INIS)

    Coppenrath, E.; Meindl, T.; Herzog, P.; Khalil, R.; Mueller-Lisse, U.; Krenn, L.; Reiser, M.; Mueller-Lisse, U.G.

    2006-01-01

    A novel ureter phantom was developed for investigations of image quality and dose in CT urography. The ureter phantom consisted of a water box (14 cm x 32 cm x 42 cm) with five parallel plastic tubes (diameter 2.7 mm) filled with different concentrations of contrast media (1.88-30 mg iodine/ml). CT density of the tubes and noise of the surrounding water were determined using two multidetector scanners (Philips MX8000 with four rows, Siemens Sensation 16 with 16 rows) with varying tube current-time product (15-100 mAs per slice), voltage (90 kV, 100 kV, 120 kV), pitch (0.875-1.75), and slice thickness (1 mm, 2 mm, 3.2 mm). Contrast-to-noise ratio as a parameter of image quality was correlated with dose (CTDI) and was compared with image evaluation by two radiologists. The CT densities of different concentrations of contrast media and contrast-to-noise ratio were significantly higher when low voltages (90 kV versus 120 kV, 100 kV versus 120 kV) were applied. Smaller slice thickness (1 mm versus 2 mm) did not change CT density but decreased contrast-to-noise ratio due to increased noise. Contrast phantom studies showed favourable effects of low tube voltage on image quality in the low dose range. This may facilitate substantial dose reduction in CT urography. (orig.)

  13. A related study of the CT imaging of the chronic low back pain

    International Nuclear Information System (INIS)

    Zhan Zhigang

    2006-01-01

    Objective: To study the clinical application of the CT imaging in patients with chronic low back pain. Methods: CT images were retrospectively analyzed in 164 cases of chronic low back pain. All the cases were diagnosed with CT imaging, or confirmed by operation, or proved in follow-up. Results: Intervertebral disc bulging in different level as a result from the degeneration of the disc was found in 148 cases (90.24%) out of 164. Disc protrusion was presented in 129 cases(78.66%). Bony narrowing of the spinal canal was revealed in 33 cases(20.12%). Degenerative lumbar spinal instability yielded in 14 cases (8.5%). Ossification or calcification of posterior longitudinal ligament was seen in 26 cases (15.85%). Thickening of ligamenta flava was shown in the 22 eases (13.41%). Conclusion: Chronic low back pain is mainly caused by the disorders of the intervertebral disc, which has typical CT findings: narrowed spinal canal or lateral recess. Ossification or calcification of posterior longitudinal ligament also plays a role in low back pain. An accurate interpretation of the CT images is essential for the clinical management. (authors)

  14. Detection of pulmonary fat embolism with dual-energy CT: an experimental study in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chun Xiang; Zhou, Chang Sheng; Zhao, Yan E.; Han, Zong Hong; Qi, Li; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Mangold, Stefanie; Ball, B.D. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2017-04-15

    To evaluate the use of dual-energy CT imaging of the lung perfused blood volume (PBV) for the detection of pulmonary fat embolism (PFE). Dual-energy CT was performed in 24 rabbits before and 1 hour, 1 day, 4 days and 7 days after artificial induction of PFE via the right ear vein. CT pulmonary angiography (CTPA) and lung PBV images were evaluated by two radiologists, who recorded the presence, number, and location of PFE on a per-lobe basis. Sensitivity, specificity, and accuracy of CTPA and lung PBV for detecting PFE were calculated using histopathological evaluation as the reference standard. A total of 144 lung lobes in 24 rabbits were evaluated and 70 fat emboli were detected on histopathological analysis. The overall sensitivity, specificity and accuracy were 25.4 %, 98.6 %, and 62.5 % for CTPA, and 82.6 %, 76.0 %, and 79.2 % for lung PBV. Higher sensitivity (p < 0.001) and accuracy (p < 0.01), but lower specificity (p < 0.001), were found for lung PBV compared with CTPA. Dual-energy CT can detect PFE earlier than CTPA (all p < 0.01). Dual-energy CT provided higher sensitivity and accuracy in the detection of PFE as well as earlier detection compared with conventional CTPA in this animal model study. (orig.)

  15. Comparative study of CT scan findings and intellectual function between Parkinson's disease and vascular Parkinsonism

    Energy Technology Data Exchange (ETDEWEB)

    Indo, Toshikatsu

    1986-01-01

    Comparative study of CT scan findings and intellectual function between 64 cases with Parkinson's disease and 25 cases with vascular Parkinsonism was carried out. The rate of abnormality of CT scan findings, either ventricular dilatation or widening of sulci, in vascular Parkinsonism was strikingly high compared with Parkinson's disease. Patients could be divided into three groups according to the degree of overall abnormalities of CT scan findings (group A: markedly abnormal, group B: mildly abnormal, group C: normal). Incidences of group A were 9.4 % in Parkinson's disease and 52 % in vascular Parkinsonism, whereas those of group C were 56 % in the former and 28 % in the latter. All patients of group A were over 65 years of age in Parkinson's disease, but one-third of patients in group A were under 59 years of age in vascular Parkinsonism. Moreover, in vascular Parkinsonism, the level of disability was directly proportional to the abnormality of CT scan findings. The rate of predementia and dementia classified by Hasegawa's intelligence scale was 12.5 % in Parkinson's disease and 48 % in vascular Parkinsonism. No difference was found between the mean values of intelligence scale and background factors in Parkinson's disease. On the other hand, the mean value was significantly low in proportion to the poverty of L-dopa effect in vascular Parkinsonism. From these results, the abnormality of CT scan findings and intellectual impairment were probably related to the cerebral pathological process in vascular Parkinsonism, but these relationship was absent in Parkinson's disease.

  16. Study of CT head scans using different voltages: image quality evaluation

    International Nuclear Information System (INIS)

    Pacheco de Freitas C, I.; Prata M, A.; Alonso, T. C.; Santana, P.

    2016-10-01

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  17. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kaasalainen, Touko; Lampinen, Anniina [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); University of Helsinki, Department of Physics, Helsinki (Finland); Palmu, Kirsi [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); School of Science, Aalto University, Department of Biomedical Engineering and Computational Science, Helsinki (Finland); Reijonen, Vappu; Kortesniemi, Mika [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); Leikola, Junnu [University of Helsinki and Helsinki University Hospital, Department of Plastic Surgery, Helsinki (Finland); Kivisaari, Riku [University of Helsinki and Helsinki University Hospital, Department of Neurosurgery, Helsinki (Finland)

    2015-09-15

    Medical professionals need to exercise particular caution when developing CT scanning protocols for children who require multiple CT studies, such as those with craniosynostosis. To evaluate the utility of ultra-low-dose CT protocols with model-based iterative reconstruction techniques for craniosynostosis imaging. We scanned two pediatric anthropomorphic phantoms with a 64-slice CT scanner using different low-dose protocols for craniosynostosis. We measured organ doses in the head region with metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters. Numerical simulations served to estimate organ and effective doses. We objectively and subjectively evaluated the quality of images produced by adaptive statistical iterative reconstruction (ASiR) 30%, ASiR 50% and Veo (all by GE Healthcare, Waukesha, WI). Image noise and contrast were determined for different tissues. Mean organ dose with the newborn phantom was decreased up to 83% compared to the routine protocol when using ultra-low-dose scanning settings. Similarly, for the 5-year phantom the greatest radiation dose reduction was 88%. The numerical simulations supported the findings with MOSFET measurements. The image quality remained adequate with Veo reconstruction, even at the lowest dose level. Craniosynostosis CT with model-based iterative reconstruction could be performed with a 20-μSv effective dose, corresponding to the radiation exposure of plain skull radiography, without compromising required image quality. (orig.)

  18. Indications for computed tomography (CT-) diagnostics in proximal humeral fractures: a comparative study of plain radiography and computed tomography

    OpenAIRE

    Weise Kuno; Pereira Philippe L; Dietz Klaus; Eingartner Christoph; Schmal Hagen; Südkamp Norbert P; Rolauffs Bernd; Bahrs Christian; Lingenfelter Erich; Helwig Peter

    2009-01-01

    Abstract Background Precise indications for computed tomography (CT) in proximal humeral fractures are not established. The purpose of this study was a comparison of conventional radiographic views with different CT reconstructions with 2 D and 3 D imaging to establish indications for additional CT diagnostics depending on the fractured parts. Methods In a prospective diagnostic study in two level 1 trauma centers, 44 patients with proximal humeral fractures were diagnosed with conventional X...

  19. Anterior mediastinal masses in the Framingham Heart Study: Prevalence and CT image characteristics

    International Nuclear Information System (INIS)

    Araki, Tetsuro; Nishino, Mizuki; Gao, Wei; Dupuis, Josée; Washko, George R.; Hunninghake, Gary M.; Murakami, Takamichi; O’Connor, George T.; Hatabu, Hiroto

    2015-01-01

    To investigate the prevalence and CT image characteristics of anterior mediastinal masses in a population-based cohort and their association with the demographics of the participants. Chest CT scans of 2571 Framingham Heart Study participants (mean age 58.9 years, 51% female) were evaluated by two board-certified radiologists with expertise in thoracic imaging for the presence of anterior mediastinal masses, their shape, contour, location, invasion of adjacent structures, fat content, and calcification. For participants with anterior mediastinal masses, a previous cardiac CT scan was reviewed for interval size change of the masses, when available. The demographics of the participants were studied for any association with the presence of anterior mediastinal masses. Of 2571, 23 participants (0.9%, 95% CI: 0.6–1.3) had anterior mediastinal masses on CT. The most common CT characteristics were oval shape, lobular contour, and midline location, showing soft tissue density (median 32.1 HU). Fat content was detected in a few cases (9%, 2/23). Six out of eight masses with available prior cardiac CT scans demonstrated an interval growth over a median period of 6.5 years. No risk factors for anterior mediastinal masses were detected among participants’ demographics, including age, sex, BMI, and cigarette smoking. The prevalence of anterior mediastinal masses is 0.9% in the Framingham Heart Study. Those masses may increase in size when observed over 5–7 years. Investigation of clinical significance in incidentally found anterior mediastinal masses with a longer period of follow-up would be necessary

  20. A clinical study of acute cerebral infarction with a midline shift on the CT scan

    International Nuclear Information System (INIS)

    Takemae, Toshiki; Mizukami, Masahiro; Kin, Hiroshi; Kawase, Takeshi; Araki, Goro

    1978-01-01

    Twenty-one cases of acute cerebral infarction with a midline shift on the CT scan were studied with respect to the development of the midline shift, the angiographic findings, the clinical pictures and the outcome of these patients. The CT findings of hemorrhagic infarction were also studied. No cases showed a midline shift on a CT scan taken within 6 hours after the onset. A midline shift was, however, noted as early as 9 hours after the onset, and it reached its peak between the 2nd and 7th day of the onset. It gradually disappeared by the end of the third week. Hemorrhagic infarction was diagnosed in 6 patients by either spinal tap or autopsy. The CT findings of these hemorrhagic infarction were divided into two types, solid hemorrhages with an unequivocal high density within the low-density area, and small, scattered hemorrhagic of almost the same density as normal brain tissue within the low-density area. In 19 of 21 patients, an round-edged occlusion and/or embolus were observed on the initial angiograms. The recanalization of the occluded vessels was proved in 10 of 14 patients by subsequent angiographic studies. Twenty of 21 patients showed a sudden development of neurological symptoms, and 15 patients had a history of various kinds of heart disease, such as atrial fibrillation, valvular heart disease and myocardial infarction. The patients had atrial fibrillation on EKG on admission. These angiographic findings and clinical pictures strongly suggest that the infarction with a midline shift on the CT scan may be caused by a cerebral embolism of cardiac origin. Eight patients died of cerebral herniation between the 2nd and 6th day of the onset. Taking these poor outcomes into consideration, surgical as well as medical decompression of the brain would seem to be most important when the CT scan shows a midline shift. (author)

  1. Clinical study of acute cerebral infarction with a midline shift on the CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Takemae, T; Mizukami, M; Kin, H; Kawase, T; Araki, G [Mihara Memorial Hospital, Isezaki, Gunma (Japan)

    1978-12-01

    Twenty-one cases of acute cerebral infarction with a midline shift on the CT scan were studied with respect to the development of the midline shift, the angiographic findings, the clinical pictures and the outcome of these patients. The CT findings of hemorrhagic infarction were also studied. No cases showed a midline shift on a CT scan taken within 6 hours after the onset. A midline shift was, however, noted as early as 9 hours after the onset, and it reached its peak between the 2nd and 7th day of the onset. It gradually disappeared by the end of the third week. Hemorrhagic infarction was diagnosed in 6 patients by either spinal tap or autopsy. The CT findings of these hemorrhagic infarction were divided into two types, solid hemorrhages with an unequivocal high density within the low-density area, and small, scattered hemorrhagic of almost the same density as normal brain tissue within the low-density area. In 19 of 21 patients, an round-edged occlusion and/or embolus were observed on the initial angiograms. The recanalization of the occluded vessels was proved in 10 of 14 patients by subsequent angiographic studies. Twenty of 21 patients showed a sudden development of neurological symptoms, and 15 patients had a history of various kinds of heart disease, such as atrial fibrillation, valvular heart disease and myocardial infarction. The patients had atrial fibrillation on EKG on admission. These angiographic findings and clinical pictures strongly suggest that the infarction with a midline shift on the CT scan may be caused by a cerebral embolism of cardiac origin. Eight patients died of cerebral herniation between the 2nd and 6th day of the onset. Taking these poor outcomes into consideration, surgical as well as medical decompression of the brain would seem to be most important when the CT scan shows a midline shift.

  2. Generalisability of the results of the Dutch-Belgian randomised controlled lung cancer CT screening trial (NELSON) : Does self-selection play a role?

    NARCIS (Netherlands)

    van der Aalst, C. M.; van Iersel, C. A.; van Klaveren, R. J.; Frenken, F. J. M.; Fracheboud, J.; Otto, S. J.; de Jong, P. A.; Oudkerk, M.; de Koning, H. J.

    The degree of self-selection in the Dutch-Belgian randomised controlled lung cancer screening trial (NELSON) was determined to assess the generalisability of the study results. 335,441 (mainly) men born in 1928-1953 received a questionnaire. Of the respondents (32%), eligible subjects were invited

  3. Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

    NARCIS (Netherlands)

    Wille, M.M.W.; Riel, S.J. van; Saghir, Z.; Dirksen, A.; Pedersen, J.H.; Jacobs, C.; Thomsen, L.H.u.; Scholten, E.T.; Skovgaard, L.T.; Ginneken, B. van

    2015-01-01

    Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models.From the DLCST database, 1,152

  4. CT urography in the diagnosis of renal masses in patients with hematuria

    International Nuclear Information System (INIS)

    Warshauer, D.M.; Street, L.; McCarthy, S.M.; Glickman, M.G.; Ritcher, J.; Rosenfield, A.T.

    1987-01-01

    The optimal method for the diagnosis of renal masses in patients with hematuria has been in question since the introduction of axial imaging techniques. A prospective study comparing excretory urography and nephrotomography (EU) with limited renal CT was undertaken. Results showed EU able to detect approximately 75% of CT-confirmed masses greater than 2 cm, but less than 10% of CT masses smaller than 2 cm. These results suggest that a combination study of CT/EU utilizing a single contrast injection with EU for imaging the collecting system and CT for renal parenchymal evaluation would be the best screening study in patients with hematuria

  5. Comparative study of myelography with postmyelographic CT in cervical spondylosis and herniated disk

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyoon Soon; Park, Yong Tae; Choi, Woo Suk; Lee, Sun Wha; Lim, Jae Hoon [Kyung Hee University College of Medicine, Seoul (Korea, Republic of)

    1988-10-15

    Eight patients, who had symptoms and signs of cervical spondylosis and/or disk were studied with myelography (using Omnipaque) followed by postmyelographic computed tomography to evaluate the relative efficacy of these two methods in the determination of cervical herniation and spondylosis. Thirty nine levels in 26 patients were confirmed by surgery. Of these, 20 levels proved to have operative evidence of herniated disk. Postmyelographic CT adds useful information to the myelographic findings. Cord and root compression are better evaluated and osteopathy can be differentiated from disk herniation. In osteopathy, myelography was as diagnostic as postmyelographic CT. But, disk herniation was identified in 70% (14/20 levels) with postmyelographic CT and only in 15% (3/20 levels) with myelography.

  6. Comparative study of myelography with postmyelographic CT in cervical spondylosis and herniated disk

    International Nuclear Information System (INIS)

    Jung, Kyoon Soon; Park, Yong Tae; Choi, Woo Suk; Lee, Sun Wha; Lim, Jae Hoon

    1988-01-01

    Eight patients, who had symptoms and signs of cervical spondylosis and/or disk were studied with myelography (using Omnipaque) followed by postmyelographic computed tomography to evaluate the relative efficacy of these two methods in the determination of cervical herniation and spondylosis. Thirty nine levels in 26 patients were confirmed by surgery. Of these, 20 levels proved to have operative evidence of herniated disk. Postmyelographic CT adds useful information to the myelographic findings. Cord and root compression are better evaluated and osteopathy can be differentiated from disk herniation. In osteopathy, myelography was as diagnostic as postmyelographic CT. But, disk herniation was identified in 70% (14/20 levels) with postmyelographic CT and only in 15% (3/20 levels) with myelography.