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Sample records for chest ct radiation

  1. CT of the chest in suspected child abuse using submillisievert radiation dose

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    Sanchez, Thomas R.; Seibert, J.A.; Stein-Wexler, Rebecca [Medical Center Children' s Hospital, Division of Pediatric Radiology, University of California-Davis, Sacramento, CA (United States); Lee, Justin S. [University of California-Davis, Department of Radiology, Sacramento, CA (United States); Coulter, Kevin P. [Medical Center Children' s Hospital, Department of Pediatrics, University of California-Davis, Sacramento, CA (United States)

    2015-07-15

    The cornerstone of child abuse imaging is the skeletal survey, but initial imaging with radiographs may not demonstrate acute and non-displaced fractures, especially those involving the ribs. Given the high mortality of undiagnosed non-accidental trauma, timely diagnosis is crucial. CT is more sensitive in assessing rib fractures; however the effective radiation dose of a standard chest CT is high. We retrospectively identified four children (three boys, one girl; age range 1-4 months) admitted between January 2013 and February 2014 with high suspicion for non-accidental trauma from unexplained fractures of the long bones; these children all had CT of the chest when no rib fractures were evident on the skeletal survey. The absorbed radiation dose estimates for organs and tissue from the four-view chest radiographs and subsequent CT were determined using Monte Carlo photon transport software, and the effective dose was calculated using published tissue-weighting factors. In two children, CT showed multiple fractures of the ribs, scapula and vertebral body that were not evident on the initial skeletal survey. The average effective dose for a four-view chest radiograph across the four children was 0.29 mSv and the average effective dose for the chest CT was 0.56 mSv. Therefore the effective dose of a chest CT is on average less than twice that of a four-view chest radiograph. Our protocol thus shows that a reduced-dose chest CT may be useful in the evaluation of high specificity fractures of non-accidental trauma when the four-view chest radiographs are negative. (orig.)

  2. Estimated risk of radiation-induced cancer from paediatric chest CT: two-year cohort study

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    Niemann, Tilo [Cantonal Hospital Baden, Department of Radiology, Baden (Switzerland); University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Colas, Lucie; Santangelo, Teresa; Faivre, Jean Baptiste; Remy, Jacques; Remy-Jardin, Martine [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Roser, Hans W.; Bremerich, Jens [University of Basel Hospital, Clinic of Radiology and Nuclear Medicine, Medical Physics, Basel (Switzerland)

    2015-03-01

    The increasing absolute number of paediatric CT scans raises concern about the safety and efficacy and the effects of consecutive diagnostic ionising radiation. To demonstrate a method to evaluate the lifetime attributable risk of cancer incidence/mortality due to a single low-dose helical chest CT in a two-year patient cohort. A two-year cohort of 522 paediatric helical chest CT scans acquired using a dedicated low-dose protocol were analysed retrospectively. Patient-specific estimations of radiation doses were modelled using three different mathematical phantoms. Per-organ attributable cancer risk was then estimated using epidemiological models. Additional comparison was provided for naturally occurring risks. Total lifetime attributable risk of cancer incidence remains low for all age and sex categories, being highest in female neonates (0.34%). Summation of all cancer sites analysed raised the relative lifetime attributable risk of organ cancer incidence up to 3.6% in female neonates and 2.1% in male neonates. Using dedicated scan protocols, total lifetime attributable risk of cancer incidence and mortality for chest CT is estimated low for paediatric chest CT, being highest for female neonates. (orig.)

  3. Chest CT using spectral filtration: radiation dose, image quality, and spectrum of clinical utility

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    Braun, Franziska M.; Johnson, Thorsten R.C.; Sommer, Wieland H.; Thierfelder, Kolja M.; Meinel, Felix G. [University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

    2015-06-01

    To determine the radiation dose, image quality, and clinical utility of non-enhanced chest CT with spectral filtration. We retrospectively analysed 25 non-contrast chest CT examinations acquired with spectral filtration (tin-filtered Sn100 kVp spectrum) compared to 25 examinations acquired without spectral filtration (120 kV). Radiation metrics were compared. Image noise was measured. Contrast-to-noise-ratio (CNR) and figure-of-merit (FOM) were calculated. Diagnostic confidence for the assessment of various thoracic pathologies was rated by two independent readers. Effective chest diameters were comparable between groups (P = 0.613). In spectral filtration CT, median CTDI{sub vol}, DLP, and size-specific dose estimate (SSDE) were reduced (0.46 vs. 4.3 mGy, 16 vs. 141 mGy*cm, and 0.65 vs. 5.9 mGy, all P < 0.001). Spectral filtration CT had higher image noise (21.3 vs. 13.2 HU, P < 0.001) and lower CNR (47.2 vs. 75.3, P < 0.001), but was more dose-efficient (FOM 10,659 vs. 2,231/mSv, P < 0.001). Diagnostic confidence for parenchymal lung disease and osseous pathologies was lower with spectral filtration CT, but no significant difference was found for pleural pathologies, pulmonary nodules, or pneumonia. Non-contrast chest CT using spectral filtration appears to be sufficient for the assessment of a considerable spectrum of thoracic pathologies, while providing superior dose efficiency, allowing for substantial radiation dose reduction. (orig.)

  4. Chest radiation - discharge

    Science.gov (United States)

    Radiation - chest - discharge; Cancer - chest radiation; Lymphoma - chest radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after your first treatment: It may be hard ...

  5. Coronary CT angiography for acute chest pain triage: Techniques for radiation exposure reduction; 128 vs. 64 multidetector CT

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    Goitein, Orly; Eshet, Yael; Konen, Eli (Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, and the Sackler Faculty of Medicine, Tel Aviv Univ., Tel Aviv (Israel)), email: orly.goitein@sheba.health.gov.il; Matetzky, Shlomi (Heart Inst., Sheba Medical Center, Tel Hashomer, and the Sackler Faculty of Medicine, Tel Aviv Univ., Tel Aviv (Israel)); Goitein, David (Surgery C, Sheba Medical Center, Tel Hashomer, and the Sackler Faculty of Medicine, Tel Aviv Univ., Tel Aviv (Israel)); Hamdan, Ashraf; Di Segni, Elio (Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, and the Sackler Faculty of Medicine, Tel Aviv Univ., Tel Aviv (Israel); Heart Inst., Sheba Medical Center, Tel Hashomer, and the Sackler Faculty of Medicine, Tel Aviv Univ., Tel Aviv (Israel))

    2011-10-15

    Background. Coronary CT angiography (CCTA) is used daily in acute chest pain triage, although exposing patients to significant radiation dosage. CCTA using prospective ECG gating (PG CCTA) enables significant radiation reduction Purpose. To determine whether the routine use of 128 vs. 64 multidetector CT (MDCT) can increase the proportion of patients scanned using PG CCTA technique, lowering radiation exposure, without decreasing image quality. Material and Methods. The study comprised 232 patients, 116 consecutive patients scanned using 128 MDCT (mean age 49 years, 79 men, BMI 28) and 116 consecutive patients (mean age 50 years, 75 men, BMI 28) which were scanned using 64 MDCT. PG CCTA was performed whenever technically permissible by each type of scanner: 64 MDCT = stable heart rate (HR) <60/min and weight <110 kg; 128 MDCT = stable HR < 70/min and weight <140 kg. All coronary segments were evaluated for image quality using a visual scale of 1-5. An estimated radiation dose was recorded. Results. PC CCTA was performed in 84% and 49% of the 128 and 64 MDCT groups, respectively (P < 0.0001). Average image quality score were 4.6 +- 0.3 and 4.7 +- 0.1 for the 128 and 64 MDCT, respectively (P = 0.08). The mean radiation dose exposure was 6.2 +- 4.8 mSv and 10.4 +- 7.5 mSv for the 128 and 64 MDCT, respectively (P = 0.008). Conclusion. The 128 MDCT scanner enables utilization of PG CCTA technique in a greater proportion of patients, thereby decreasing the related radiation significantly, without hampering image quality

  6. Radiation dose and image quality in pediatric chest CT: effects of iterative reconstruction in normal weight and overweight children

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    Yoon, Haesung; Kim, Myung-Joon; Shin, Hyun Joo; Kim, Hyun Gi; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Choi, Jiin [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

    2015-03-01

    New CT reconstruction techniques may help reduce the burden of ionizing radiation. To quantify radiation dose reduction when performing pediatric chest CT using a low-dose protocol and 50% adaptive statistical iterative reconstruction (ASIR) compared with age/gender-matched chest CT using a conventional dose protocol and reconstructed with filtered back projection (control group) and to determine its effect on image quality in normal weight and overweight children. We retrospectively reviewed 40 pediatric chest CT (M:F = 21:19; range: 0.1-17 years) in both groups. Radiation dose was compared between the two groups using paired Student's t-test. Image quality including noise, sharpness, artifacts and diagnostic acceptability was subjectively assessed by three pediatric radiologists using a four-point scale (superior, average, suboptimal, unacceptable). Eight children in the ASIR group and seven in the control group were overweight. All radiation dose parameters were significantly lower in the ASIR group (P < 0.01) with a greater than 57% dose reduction in overweight children. Image noise was higher in the ASIR group in both normal weight and overweight children. Only one scan in the ASIR group (1/40, 2.5%) was rated as diagnostically suboptimal and there was no unacceptable study. In both normal weight and overweight children, the ASIR technique is associated with a greater than 57% mean dose reduction, without significantly impacting diagnostic image quality in pediatric chest CT examinations. However, CT scans in overweight children may have a greater noise level, even when using the ASIR technique. (orig.)

  7. Evaluation of image quality and radiation dose by adaptive statistical iterative reconstruction technique level for chest CT examination.

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    Hong, Sun Suk; Lee, Jong-Woong; Seo, Jeong Beom; Jung, Jae-Eun; Choi, Jiwon; Kweon, Dae Cheol

    2013-12-01

    The purpose of this research is to determine the adaptive statistical iterative reconstruction (ASIR) level that enables optimal image quality and dose reduction in the chest computed tomography (CT) protocol with ASIR. A chest phantom with 0-50 % ASIR levels was scanned and then noise power spectrum (NPS), signal and noise and the degree of distortion of peak signal-to-noise ratio (PSNR) and the root-mean-square error (RMSE) were measured. In addition, the objectivity of the experiment was measured using the American College of Radiology (ACR) phantom. Moreover, on a qualitative basis, five lesions' resolution, latitude and distortion degree of chest phantom and their compiled statistics were evaluated. The NPS value decreased as the frequency increased. The lowest noise and deviation were at the 20 % ASIR level, mean 126.15 ± 22.21. As a result of the degree of distortion, signal-to-noise ratio and PSNR at 20 % ASIR level were at the highest value as 31.0 and 41.52. However, maximum absolute error and RMSE showed the lowest deviation value as 11.2 and 16. In the ACR phantom study, all ASIR levels were within acceptable allowance of guidelines. The 20 % ASIR level performed best in qualitative evaluation at five lesions of chest phantom as resolution score 4.3, latitude 3.47 and the degree of distortion 4.25. The 20 % ASIR level was proved to be the best in all experiments, noise, distortion evaluation using ImageJ and qualitative evaluation of five lesions of a chest phantom. Therefore, optimal images as well as reduce radiation dose would be acquired when 20 % ASIR level in thoracic CT is applied.

  8. Chest CT Scan

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    ... can combine these pictures to create three-dimensional (3D) models to help show the size, shape, and ... a medical imaging facility or hospital. The CT scanner is a large, tunnel-like machine that has ...

  9. Adaptive Iterative Dose Reduction Using Three Dimensional Processing (AIDR3D improves chest CT image quality and reduces radiation exposure.

    Directory of Open Access Journals (Sweden)

    Tsuneo Yamashiro

    Full Text Available To assess the advantages of Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D for image quality improvement and dose reduction for chest computed tomography (CT.Institutional Review Boards approved this study and informed consent was obtained. Eighty-eight subjects underwent chest CT at five institutions using identical scanners and protocols. During a single visit, each subject was scanned using different tube currents: 240, 120, and 60 mA. Scan data were converted to images using AIDR3D and a conventional reconstruction mode (without AIDR3D. Using a 5-point scale from 1 (non-diagnostic to 5 (excellent, three blinded observers independently evaluated image quality for three lung zones, four patterns of lung disease (nodule/mass, emphysema, bronchiolitis, and diffuse lung disease, and three mediastinal measurements (small structure visibility, streak artifacts, and shoulder artifacts. Differences in these scores were assessed by Scheffe's test.At each tube current, scans using AIDR3D had higher scores than those without AIDR3D, which were significant for lung zones (p<0.0001 and all mediastinal measurements (p<0.01. For lung diseases, significant improvements with AIDR3D were frequently observed at 120 and 60 mA. Scans with AIDR3D at 120 mA had significantly higher scores than those without AIDR3D at 240 mA for lung zones and mediastinal streak artifacts (p<0.0001, and slightly higher or equal scores for all other measurements. Scans with AIDR3D at 60 mA were also judged superior or equivalent to those without AIDR3D at 120 mA.For chest CT, AIDR3D provides better image quality and can reduce radiation exposure by 50%.

  10. Reducing the radiation dose with the adaptive statistical iterative reconstruction technique for chest CT in adults: a parameter study

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    Liu Wenyun; Ding Xiaobo; Kong Boyu; Fan Baoyan; Chen Liang

    2014-01-01

    Background Currently there is a trend towards reducing radiation dose while maintaining image quality during computer tomography (CT) examination.This results from the concerns about radiation exposure from CT and the potential increase in the incidence of radiation induced carcinogenesis.This study aimed to investigate the lowest radiation dose for maintaining good image quality in adult chest scanning using GE CT equipment.Methods Seventy-two adult patients were examined by Gemstone Spectral CT.They were randomly divided into six groups.We set up a different value of noise index (NI) when evaluating each group every other number from 13.0 to 23.0.The original images were acquired with a slice of 5 mm thickness.For each group,several image series were reconstructed using different levels of adaptive statistical iterative reconstruction (ASIR) (30%,50%,and 70%).We got a total of 18 image sequences of different combinations of NI and ASIR percentage.On one hand,quantitative indicators,such as CT value and standard deviation (SD),were assessed at the region of interest.The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.The volume CT dose index (CTDI) and dose length product (DLP) were recorded.On the other hand,two radiologists with >5 years of experience blindly reviewed the subjective image quality using the standards we had previously set.Results The different combinations of noise index and ASIR were assessed.There was no significant difference in CT values among the 18 image sequences.The SD value was reduced with the noise index's reduction or ASIR's increase.There was a trend towards gradually lower SNR and CNR with an NI increase.The CTDI and DLP were diminishing as the NI increased.The scores from subjective image quality evaluation were reduced in all groups as the ASIR increased.Conclusions Increasing NI can reduce radiation dose.With the premise of maintaining the same image quality,using a suitable percentage of

  11. Chest CT in children: anesthesia and atelectasis

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    Newman, Beverley; Gawande, Rakhee [Lucile Packard Children' s Hospital, Department of Radiology, Stanford, CA (United States); Krane, Elliot J. [Stanford University School of Medicine, Lucile Packard Children' s Hospital, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford, CA (United States); Holmes, Tyson H. [Stanford University School of Medicine, Lucile Packard Children' s Hospital, Department of Psychiatry and Behavioral Sciences, Stanford, CA (United States); Robinson, Terry E. [Stanford University School of Medicine, Lucile Packard Children' s Hospital, Department of Pulmonary Medicine and Cystic Fibrosis Center for Excellence in Pulmonary Biology, Stanford, CA (United States)

    2014-02-15

    There has been an increasing tendency for anesthesiologists to be responsible for providing sedation or anesthesia during chest CT imaging in young children. Anesthesia-related atelectasis noted on chest CT imaging has proven to be a common and troublesome problem, affecting image quality and diagnostic sensitivity. To evaluate the safety and effectiveness of a standardized anesthesia, lung recruitment, controlled-ventilation technique developed at our institution to prevent atelectasis for chest CT imaging in young children. Fifty-six chest CT scans were obtained in 42 children using a research-based intubation, lung recruitment and controlled-ventilation CT scanning protocol. These studies were compared with 70 non-protocolized chest CT scans under anesthesia taken from 18 of the same children, who were tested at different times, without the specific lung recruitment and controlled-ventilation technique. Two radiology readers scored all inspiratory chest CT scans for overall CT quality and atelectasis. Detailed cardiorespiratory parameters were evaluated at baseline, and during recruitment and inspiratory imaging on 21 controlled-ventilation cases and 8 control cases. Significant differences were noted between groups for both quality and atelectasis scores with optimal scoring demonstrated in the controlled-ventilation cases where 70% were rated very good to excellent quality scans compared with only 24% of non-protocol cases. There was no or minimal atelectasis in 48% of the controlled ventilation cases compared to 51% of non-protocol cases with segmental, multisegmental or lobar atelectasis present. No significant difference in cardiorespiratory parameters was found between controlled ventilation and other chest CT cases and no procedure-related adverse events occurred. Controlled-ventilation infant CT scanning under general anesthesia, utilizing intubation and recruitment maneuvers followed by chest CT scans, appears to be a safe and effective method to obtain

  12. Third-generation dual-source 70-kVp chest CT angiography with advanced iterative reconstruction in young children: image quality and radiation dose reduction

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    Rompel, Oliver; Janka, Rolf; Lell, Michael M.; Uder, Michael; Hammon, Matthias [University Hospital Erlangen, Department of Radiology, Erlangen (Germany); Gloeckler, Martin; Dittrich, Sven [University Hospital Erlangen, Department of Pediatric Cardiology, Erlangen (Germany); Cesnjevar, Robert [University Hospital Erlangen, Department of Pediatric Cardiac Surgery, Erlangen (Germany)

    2016-04-15

    Many technical updates have been made in multi-detector CT. To evaluate image quality and radiation dose of high-pitch second- and third-generation dual-source chest CT angiography and to assess the effects of different levels of advanced modeled iterative reconstruction (ADMIRE) in newborns and children. Chest CT angiography (70 kVp) was performed in 42 children (age 158 ± 267 days, range 1-1,194 days). We evaluated subjective and objective image quality, and radiation dose with filtered back projection (FBP) and different strength levels of ADMIRE. For comparison were 42 matched controls examined with a second-generation 128-slice dual-source CT-scanner (80 kVp). ADMIRE demonstrated improved objective and subjective image quality (P <.01). Mean signal/noise, contrast/noise and subjective image quality were 11.9, 10.0 and 1.9, respectively, for the 80 kVp mode and 11.2, 10.0 and 1.9 for the 70 kVp mode. With ADMIRE, the corresponding values for the 70 kVp mode were 13.7, 12.1 and 1.4 at strength level 2 and 17.6, 15.6 and 1.2 at strength level 4. Mean CTDI{sub vol}, DLP and effective dose were significantly lower with the 70-kVp mode (0.31 mGy, 5.33 mGy*cm, 0.36 mSv) compared to the 80-kVp mode (0.46 mGy, 9.17 mGy*cm, 0.62 mSv; P <.01). The third-generation dual-source CT at 70 kVp provided good objective and subjective image quality at lower radiation exposure. ADMIRE improved objective and subjective image quality. (orig.)

  13. Image quality in children with low-radiation chest CT using adaptive statistical iterative reconstruction and model-based iterative reconstruction.

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    Jihang Sun

    Full Text Available OBJECTIVE: To evaluate noise reduction and image quality improvement in low-radiation dose chest CT images in children using adaptive statistical iterative reconstruction (ASIR and a full model-based iterative reconstruction (MBIR algorithm. METHODS: Forty-five children (age ranging from 28 days to 6 years, median of 1.8 years who received low-dose chest CT scans were included. Age-dependent noise index (NI was used for acquisition. Images were retrospectively reconstructed using three methods: MBIR, 60% of ASIR and 40% of conventional filtered back-projection (FBP, and FBP. The subjective quality of the images was independently evaluated by two radiologists. Objective noises in the left ventricle (LV, muscle, fat, descending aorta and lung field at the layer with the largest cross-section area of LV were measured, with the region of interest about one fourth to half of the area of descending aorta. Optimized signal-to-noise ratio (SNR was calculated. RESULT: In terms of subjective quality, MBIR images were significantly better than ASIR and FBP in image noise and visibility of tiny structures, but blurred edges were observed. In terms of objective noise, MBIR and ASIR reconstruction decreased the image noise by 55.2% and 31.8%, respectively, for LV compared with FBP. Similarly, MBIR and ASIR reconstruction increased the SNR by 124.0% and 46.2%, respectively, compared with FBP. CONCLUSION: Compared with FBP and ASIR, overall image quality and noise reduction were significantly improved by MBIR. MBIR image could reconstruct eligible chest CT images in children with lower radiation dose.

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

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    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.)

  15. Automatic segmentation of pulmonary segments from volumetric chest CT scans.

    NARCIS (Netherlands)

    Rikxoort, E.M. van; Hoop, B. de; Vorst, S. van de; Prokop, M.; Ginneken, B. van

    2009-01-01

    Automated extraction of pulmonary anatomy provides a foundation for computerized analysis of computed tomography (CT) scans of the chest. A completely automatic method is presented to segment the lungs, lobes and pulmonary segments from volumetric CT chest scans. The method starts with lung segmenta

  16. Segmentation of anatomical structures in chest CT scans

    NARCIS (Netherlands)

    van Rikxoort, E.M.

    2009-01-01

    In this thesis, methods are described for the automatic segmentation of anatomical structures from chest CT scans. First, a method to segment the lungs from chest CT scans is presented. Standard lung segmentation algorithms rely on large attenuation differences between the lungs and the surrounding

  17. Pulmonary embolism findings on chest radiographs and multislice spiral CT

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    Coche, Emmanuel; Goncette, Louis [Department of Radiology, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Avenue Hippocrate 10, 1200, Brussels (Belgium); Verschuren, Franck [Department of Intensive Care and Emergency Medicine, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Avenue Hippocrate 10, 1200, Brussels (Belgium); Hainaut, Philippe [Department of Internal Medicine, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Avenue Hippocrate 10, 1200, Brussels (Belgium)

    2004-07-01

    Multislice spiral CT is becoming an increasingly important tool for diagnosing pulmonary embolism. However, in many instances, a chest radiograph is usually performed as a first-line examination. Many parenchymal, vascular, and other ancillary findings may be observed on both imaging modalities with a highly detailed depiction of abnormalities on multislice CT. A comprehensive review of chest radiograph findings is presented with side-by-side correlations of CT images reformatted mainly in the frontal plane. (orig.)

  18. Pulmonary embolism findings on chest radiographs and multislice spiral CT.

    Science.gov (United States)

    Coche, Emmanuel; Verschuren, Franck; Hainaut, Philippe; Goncette, Louis

    2004-07-01

    Multislice spiral CT is becoming an increasingly important tool for diagnosing pulmonary embolism. However, in many instances, a chest radiograph is usually performed as a first-line examination. Many parenchymal, vascular, and other ancillary findings may be observed on both imaging modalities with a highly detailed depiction of abnormalities on multislice CT. A comprehensive review of chest radiograph findings is presented with side-by-side correlations of CT images reformatted mainly in the frontal plane.

  19. Radiation dose for investigation of the chest and abdomen. Comparison of sequential, spiral and electron beam computed tomography; Strahlenexposition bei der CT-Untersuchung des Thorax und Abdomens. Vergleich von Einzelschicht-, Spiral- und Elektronenstrahlcomputertomographie

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    Becker, C.R.; Schaetzl, M.; Bruening, R.; Schoepf, U.J.; Reiser, M.F. [Klinikum Grosshadern, Muenchen (Germany). Inst. fuer Radiologische Diagnostik; Feist, H. [Muenchen Univ. (Germany). Radiologische Klinik und Poliklinik; Baeuml, A. [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Inst. fuer Strahlenhygiene

    1998-09-01

    Comparison of radiation exposure applied by different types of CT scanners for the investigation of the chest and abdomen. Determination of radiation exposure applied by multi-phase spiral CT. Estimation of the dose in air in the system axis of the scanner, the CT dose index (CTDI) and the effective dose for electron beam tomography (EBT) and two conventional CT scanners (sequence, SEQ; spiral, SCT). For EBT, dose in system axis for investigation of the abdomen was above 50 mGy. Effective dose for investigation of the chest and abdomen was higher with EBT (11 and 26 mSv, respectively), than with conventional CT (SEQ, 4 and 20 mSv; SCT, 2 and 7 mSv). The effective dose for a biphasic investigation (liver 5 mSv, kidney 4 mSv) was below, for a triphasic investigation of the abdomen (6 mSv). Investigation of the abdomen with the EBT should only be performed for certain indications. With spiral CT, effective dose is much lower than with EBT. (orig.) [Deutsch] Die Strahlenexposition bei der Untersuchung von Thorax und Abdomen mit verschiedenen CT-Scannertypen sollte verglichen werden. Zusaetzlich sollte die Exposition beim Mehrphasen-Spiral-CT ermittelt werden. Die Dosis in der Systemachse, gemessen in freier Luft, (Achsendosis), der Computertomographie-Dosis-Index (CTDI) und die effektive Dosis nach ICRP 60 wurden bei einem Elektronenstrahl-CT (EBT) und zwei konventionellen CT-Scannern (sequentiell=SEQ, spiral=SCT) bestimmt. Beim EBT liegt die Achsendosis bei der Untersuchung des Abdomens ueber 50 mGy. Die effektive Dosis fuer die Untersuchung von Thorax und Abdomen war bei der EBT (11 bzw. 26 mSv) hoeher als beim konventionellen CT (SEQ 4 bzw. 20 mSv; SCT 2 bzw. 7 Sv). Die effektive Dosis einer 2-Phasen-Untersuchung (Leber 5 mSv, Niere 4 mSv) liegt unter, die einer 3-Phasen-Untersuchung (Leber 7 mSv) ueber der effektiven Dosis einer Untersuchung des gesamten Abdomens (6 mSv). Die Untersuchung des Abdomens sollte mit dem EBT nur nach strenger Indikationsstellung

  20. Sedation versus general anaesthesia in paediatric patients undergoing chest CT

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    Lam, W.W.M.; So, N.M.C.; Metreweli, C. [Chinese Univ. of Hong Kong, Dept. of Diagnostic Radiology and Organ Imaging (China); Chen, P.P. [Chinese Univ. of Hong Kong, Anaesthesiology and Intensive Care (China)

    1998-05-01

    Objective: CT of the chest in paediatric patients often requires sedation or general anaesthesia to minimize motion artefacts. Both sedation and general anaesthesia are associated with atelectasis which obscures the underlying pulmonary pathology. We conducted a prospective study to compare these two methods with respect to degree of motion artefacts and extent of atelectasis. Material and Methods: Nineteen patients undergoing 22 chest CT examinations were randomly selected for either sedation or general anaesthesia. The total area of atelectasis and the degree of motion artefacts were measured. Results: The mean percentage of atelectasis was 6.67% for general anaesthesia and 0.01% for sedation (p=0.01). There was no significant difference in the quality of the images between the sedation patients and the general anaesthesia patients. Conclusion: Whenever the clinical condition permits it, sedation rather than general anaesthesia should be given to paediatric patients undergoing chest CT. (orig.).

  1. Radiation induced osteosarcoma of the chest wall

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    Sugimoto, Tsutomu; Yuki, Yoshihiro; Oizumi, Hiroyuki; Iijima, Yoshiyuki; Fujishima, Tsukasa; Shimazaki, Yasuhisa [Yamagata Univ. (Japan). School of Medicine

    1996-11-01

    We report a successful resection of an osteosarcoma in the chest wall developed 25 years after irradiation. A 74-year-old woman was admitted to our hospital for her swelling in the left chest wall at August 24, 1995. At 49-year-old, she had undergone an operation and postoperative irradiation for left breast cancer. A computed tomography demonstrated a mass in the left chest wall that destructed the first rib, extending into the pleural space and invaded into the left common carotid and subclavian arteries. We planned a radical resection of the mass after repeated CT scannings, since it was histopathologically diagnosed as a chondrosarcoma and showed a rapid growth. The tumor was completely removed with radical transmediastinal forequarter amputation of the partial chest wall and total left upper extremity. The left common carotid artery was partially replaced with 6 mm EPTFE vascular prosthesis. The chest wall was reconstructed with Marlex-mesh prosthesis and a myocutaneous flap. She was discharged uneventfully and has not shown any evidence of recurrence. (author)

  2. CT chest under general anesthesia: pulmonary, anesthetic and radiologic dilemmas

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    Mahmoud, Mohamed [Cincinnati Children' s Hospital Medical Center, Department of Anesthesiology, Cincinnati, OH (United States); Towe, Christopher [Cincinnati Children' s Hospital Medical Center, Department of Pulmonary Medicine, Cincinnati, OH (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2015-07-15

    Today's practice of medicine involves ever more complex patients whose care is coordinated with multidisciplinary teams. Caring for these patients can challenge all members of the health care team. Sedation/anesthesia in infants/toddlers as well as uncooperative or intellectually or emotionally impaired children who require imaging studies of the chest are ongoing challenges. High-quality computed tomography (CT) chest imaging studies in children under general anesthesia are extremely important for accurate interpretation and subsequent medical decision-making. Anesthesia-induced atelectasis may obscure or mimic true pathology creating a significant quality issue. Obtaining a high-quality, motion-free chest imaging study in infants and children under general anesthesia remains a difficult task in many institutions. Meticulous attention to anesthesia and imaging techniques and specialized knowledge are required to properly perform and interpret chest imaging studies. In this commentary, we discuss the continuous struggle to obtain high-quality CT chest imaging under general anesthesia. We will also discuss the major concerns of the anesthesiologist, radiologist and pulmonologist and why cooperation and coordination among these providers are critical for an optimal quality study.

  3. Dose reduction in computed tomography of the chest. Image quality of iterative reconstructions at a 50% radiation dose compared to filtered back projection at a 100% radiation dose; Dosisreduktion in der Thorax-CT. Vergleich der Bildqualitaet bei 50% Dosis und iterativer Bildrekonstruktion mit 100% Dosis und gefilterter Rueckprojektion

    Energy Technology Data Exchange (ETDEWEB)

    May, M.S.; Eller, A.; Stahl, C. [University Hospital Erlangen (Germany). Dept. of Radiology; and others

    2014-06-15

    Purpose: The aim of this study was to evaluate the potential of iterative reconstruction (IR) in chest computed tomography (CT) to reduce radiation exposure. The qualitative and quantitative image quality of standard reconstructions with filtered back projection (FBP) and half dose (HD) chest CT data reconstructed with FBP and IR was assessed. Materials and Methods: 52 consecutive patients underwent contrast-enhanced chest CT on a dual-source CT system at 120 kV and automatic exposure control. The tube current was equally split on both tube detector systems. For the HD datasets, only data from one tube detector system was utilized. Thus, FD and HD data was available for each patient with a single scan. Three datasets were reconstructed from the raw data: standard full dose (FD) images applying FBP which served as a reference, HD images applying FBP and IR. Objective image quality analysis was performed by measuring the image noise in tissue and air. The subjective image quality was evaluated by 2 radiologists according to European guidelines. Additional assessment of artifacts, lesion conspicuity and edge sharpness was performed. Results: Image noise did not differ significantly between HD-IR and FD-FBP (p = 0.254) but increased substantially in HD-FBP (p < 0.001). No statistically significant differences were found for the reproduction of anatomical and pathological structures between HD-IR and FD-FBP, subsegmental bronchi and bronchioli. The image quality of HD-FBP was rated inferior because of increased noise. Conclusion: A 50% dose reduction in contrast-enhanced chest CT is feasible without a loss of diagnostic confidence if IR is used for image data reconstruction. Iterative reconstruction is another powerful tool to reduce radiation exposure and can be combined with other dose-saving techniques. (orig.)

  4. Evaluation of the image quality of chest CT scans: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Martins N, P. I.; Prata M, A., E-mail: priscillainglid@gmail.com [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  5. Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yakun [Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Li, Xiang [Medical Physics Graduate Program, Department of Physics, Cleveland State University, Cleveland, Ohio 44115 (United States); Segars, W. Paul [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Samei, Ehsan, E-mail: samei@duke.edu [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Departments of Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States)

    2014-02-15

    Purpose: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for the three clinical chest x-ray imaging techniques (chest radiography, tomosynthesis, and CT) using 59 anatomically variable voxelized phantoms and Monte Carlo simulation methods. Methods: A total of 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms were used in this study. Organ doses and effective doses were estimated for a clinical radiography system with the capability of conducting chest radiography and tomosynthesis (Definium 8000, VolumeRAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). A Monte Carlo dose simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain) was used to mimic these two clinical systems. The Duke University (Durham, NC) technique charts were used to determine the clinical techniques for the radiographic modalities. An exponential relationship between CTDI{sub vol} and patient diameter was used to determine the absolute dose values for CT. The simulations of the two clinical systems compute organ and tissue doses, which were then used to calculate effective dose and risk index. The calculation of the two dose metrics used the tissue weighting factors from ICRP Publication 103 and BEIR VII report. Results: The average effective dose of the chest posteroanterior examination was found to be 0.04 mSv, which was 1.3% that of the chest CT examination. The average effective dose of the chest tomosynthesis examination was found to be about ten times that of the chest posteroanterior examination and about 12% that of the chest CT examination. With increasing patient average chest diameter, both the effective dose and risk index for CT increased considerably in an exponential fashion, while these two dose

  6. Radiation dose reduction in chest CT—Review of available options

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Takeshi, E-mail: tkubo@kuhpkyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan); Kauczor, Hans Ulrich, E-mail: hu.kauczor@med.uni-heidelberg.de [Diagnostic and Interventional Radiology, University Clinic Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg (Germany); Hatabu, Hiroto, E-mail: hhatabu@partners.org [Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)

    2014-10-15

    Highlights: • The present status of proliferating CT examinations was presented. • Technical improvements of CT scanners for radiation dose reduction were reviewed. • Advantage and disadvantage of methods for CT radiation dose reduction were discussed. • Evidences for safety of CT radiation dose reduction were reviewed. - Abstract: Computed tomography currently accounts for the majority of radiation exposure related to medical imaging. Although technological improvement of CT scanners has reduced the radiation dose of individual examinations, the benefit was overshadowed by the rapid increase in the number of CT examinations. Radiation exposure from CT examination should be kept as low as reasonably possible for patient safety. Measures to avoid inappropriate CT examinations are needed. Principles and information on radiation dose reduction in chest CT are reviewed in this article. The reduction of tube current and tube potential are the mainstays of dose reduction methods. Study results indicate that routine protocols with reduced tube current are feasible with diagnostic results comparable to conventional standard dose protocols. Tube current adjustment is facilitated by the advent of automatic tube current modulation systems by setting the appropriate image quality level for the purpose of the examination. Tube potential reduction is an effective method for CT pulmonary angiography. Tube potential reduction often requires higher tube current for satisfactory image quality, but may still contribute to significant radiation dose reduction. Use of lower tube potential also has considerable advantage for smaller patients. Improvement in image production, especially the introduction of iterative reconstruction methods, is expected to lower radiation dose significantly. Radiation dose reduction in CT is a multifaceted issue. Understanding these aspects leads to an optimal solution for various indications of chest CT.

  7. CT coronary angiography: new risks for low-risk chest pain.

    Science.gov (United States)

    Radecki, Ryan Patrick

    2013-10-01

    Widespread conservative management of low-risk chest pain has motivated the development of a rapid triage strategy based on CT coronary angiography (CTCA) in the Emergency Department (ED). Recently, three prominent trials using this technology in the ED setting have presented results in support of its routine use. However, these studies fail to show the incremental prognostic value of CTCA over clinical and biomarker-based risk-stratification strategies, demonstrate additional downstream costs and interventions, and result in multiple harms associated with radio-contrast and radiation exposure. Observing the widespread overdiagnosis of pulmonary embolism following availability of CT pulmonary angiogram as a practice pattern parallel, CTCA use for low-risk chest pain in the ED should be advanced only with caution.

  8. Spiral CT for evaluation of chest trauma; Spiral-CT beim Thoraxtrauma

    Energy Technology Data Exchange (ETDEWEB)

    Roehnert, W. [Universitaetsklinikum Dresden (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik; Weise, R. [Universitaetsklinikum Dresden (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik

    1997-07-01

    After implementation of spiral CT in our department, we carried out an analysis for determining anew the value of CT as a modality of chest trauma diagnosis in the emergency department. The retrospective study covers a period of 10 months and all emergency patients with chest trauma exmined by spiral CT. The major lesions of varying seriousness covered by this study are: pneumothorax, hematothorax, pulmonary contusion or laceration, mediastinal hematoma, rupture of a vessel, injury of the heart and pericardium. The various fractures are not included in this study. In many cases, spiral CT within relatively short time yields significant diagnostic findings, frequently saving additional angiography. A rigid diagnostic procedure cannot be formulated. Plain-film chest radiography still remains a diagnostic modality of high value. (Orig.) [Deutsch] Nach Einfuehrung der Spiral-CT in unserer Einrichtung versuchten wir, den Stellenwert der Computertomographie in der Notfalldiagnostik des Thoraxtraumas neu zu bestimmen. Dazu wurden retrospektiv ueber einen Zeitraum von 10 Monaten alle mittels Spiral-CT untersuchten Notfallpatienten mit Thoraxverletzungen ausgewertet. Im Vordergrund standen folgende Befunde unterschiedlichen Schweregrades: Pneumothorax, Haematothorax, Lungenkontusion/-lazeration, Mediastinalhaematom, Gefaessruptur, Herz- und Herzbeutelverletzung. Auf die unterschiedlichen Frakturen wird bewusst nicht naeher eingegangen. In vielen Faellen liefert die Spiral-CT mit relativ geringem Zeitaufwand wesentliche diagnostische Aussagen. Haeufig kann auf eine Angiographie verzichtet werden. Ein starres diagnostisches Stufenschema laesst sich nicht definieren. Die Thoraxuebersichtsaufnahme besitzt einen unveraendert hohen Stellenwert. (orig.)

  9. Study on Flash scan combined with iterative reconstruction in chest CT scan: image quality and radiation dose%Flash扫描联合迭代重建技术在胸部CT中的可行性研究

    Institute of Scientific and Technical Information of China (English)

    陈小芳; 沈莉

    2015-01-01

    Objective To assess radiation dose and image quality of chest CT examinations that acquired with Flash scan technique combined with iterative reconstruction.Methods Thirty continuous patients required no-contrast chest CT with Flash scan mode and contrast enhanced chest CT with conventional CT scan mode.For each examination,the images were reconstructed by filter back projection (FBP) and sinogram affirmed iterative reconstruction (SAFIRE).The volume CT dose index (CTDIvol),dose-length product (DLP),and effective dose (ED) were estimated.The image noise,signal to noise ratio (SNR),overall subjective image quality,and respiratory motion artifacts were evaluated blindly by two radiologists.Results For Flash scan and conventional scan,SAFIRE reduced the image noise 35% and 16%,respectively;and increased SNR 21.9% and 25% compared to FBP,respectively (P <0.05).There was significant lower subjective image scores acquired by SAFIRE than by FBP.Flash scan reduced the CTDIvol (mGy) 40.9%,DLP 32.1%,and ED 26.9% compared to conventional CT scan mode.The motion artifact scores were reduced significantly with Flash scan mode compared to conventional scan mode.Conclusions Flash scan technique of the chest can obtain image with minimum respiratory motion artifact due to dramatically increased scan speed,and when SAFIRE was combined with,it reduces significantly radiation dose and image noise.%目的 研究Flash扫描技术与迭代重建联合应用在胸部CT中对图像质量及辐射剂量的影响.方法 2014年12月至2015年4月本科进行胸部Flash扫描及常规螺旋扫描CT的连续30例患者,其中Flash扫描序列采用FLash螺旋扫描,常规螺旋扫描序列采用常规螺旋扫描,图像分别进行滤波反投影重建(FBP)及迭代重建(SAFIRE),两位放射科医师在未告知图像参数的情况下,对CT容积辐射指数(CTDIvol)、剂量长度乘积(DLP)、有效辐射剂量(ED)、图像噪声、信噪比及总体主观图像质量、

  10. Estimation of cartilaginous region in noncontrast CT of the chest

    Science.gov (United States)

    Zhao, Qian; Safdar, Nabile; Yu, Glenna; Myers, Emmarie; Sandler, Anthony; Linguraru, Marius George

    2014-03-01

    Pectus excavatum is a posterior depression of the sternum and adjacent costal cartilages and is the most common congenital deformity of the anterior chest wall. Its surgical repair can be performed via minimally invasive procedures that involve sternum and cartilage relocation and benefit from adequate surgical planning. In this study, we propose a method to estimate the cartilage regions in thoracic CT scans, which is the first step of statistical modeling of the osseous and cartilaginous structures for the rib cage. The ribs and sternum are first segmented by using interactive region growing and removing the vertebral column with morphological operations. The entire chest wall is also segmented to estimate the skin surface. After the segmentation, surface meshes are generated from the volumetric data and the skeleton of the ribs is extracted using surface contraction method. Then the cartilage surface is approximated via contracting the skin surface to the osseous structure. The ribs' skeleton is projected to the cartilage surface and the cartilages are estimated using cubic interpolation given the joints with the sternum. The final cartilage regions are formed by the cartilage surface inside the convex hull of the estimated cartilages. The method was validated with the CT scans of two pectus excavatum patients and three healthy subjects. The average distance between the estimated cartilage surface and the ground truth is 2.89 mm. The promising results indicate the effectiveness of cartilage surface estimation using the skin surface.

  11. Cardiac pathologies incidentally detected with non-gated chest CT; Inzidentelle Pathologien des Herzens im Thorax-CT

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Axel; Kroepil, P.; Lanzman, R.S.; Moedder, U. [Inst. fuer Radiologie, Universitaetsklinikum Duesseldorf, Heinrich-Heine-Univ. (Germany); Choy, G.; Abbara, S. [Cardiovascular Imaging Section, Massachusetts General Hospital, Harvard Medical School (United States)

    2009-12-15

    Cardiac imaging using electrocardiogram-gated multi-detector computed tomography (MDCT) permits noninvasive diagnosis of congenital and acquired cardiac pathologies and has thus become increasingly important in the last years. Several studies investigated the incidence and relevance of incidental extracardiac structures within the lungs, mediastinum, chest wall, and abdomen with gated coronary CT. This resulted in the general acceptance of the review of extracardiac structures as a routine component of coronary CT interpretation. On the other hand radiologists tend to neglect pericardial and cardiac pathologies in non-gated chest CT, which is primarily performed for the evaluation of the respiratory system or for tumor staging. Since the introduction of multi-detector spiral CT technology, the incidental detection of cardiac and pericardial findings has become possible using non-gated chest CT. This article reviews the imaging appearances and differential diagnostic considerations of incidental cardiac entities that may be encountered in non-gated chest CT. (orig.)

  12. [The chest CT findings and pathologic findings of pulmonary tuberculosis].

    Science.gov (United States)

    Ogata, Hideo

    2009-08-01

    The past research of the radiologic manifestations of pulmonary tuberculosis in Japan was based on morphological pathology of the untreated patient autopsy. I would like to show the chest CT scan of tuberculosis diseases with caseous granuloma at its exudative reaction, proliferative reaction, productive reaction, cirrhotic reaction until self cure. This progress reflects the normal cell mediated immunological responses. Also I would like to show the cavitation of granuloma, which results from liquefaction of caseous materials during the course and results in the formation of the source of infection. And finally I would like to show the morphological differences of acinous lesion, acino-nodular lesion and caseous lobular pneumonia. These differences reflect the amount of bacilli disseminated in the peripheral parts under the lobules. In this study, I do not show old age cases and HIV positive cases, who do not form typical granuloma due to the decreased cell mediated immnunity and whose X ray findings are atypical.

  13. Patient-centered clinical impact of incidentally detected abnormalities on chest CT scans

    Directory of Open Access Journals (Sweden)

    Sherine G. Moftah

    2014-09-01

    Conclusion: The clinically significant different incidental abnormalities on chest CT scans represented 10.4% of all incidental findings, 3.3% were due to malignancies. The clinical impact of incidental abnormalities on chest CT may be of utmost importance on patient care.

  14. Pediatric chest CT after trauma: impact on surgical and clinical management

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Rina P. [Vanderbilt University School of Medicine, Nashville, TN (United States); Hernanz-Schulman, Marta; Hilmes, Melissa A.; Kan, J.H. [Vanderbilt University, Department of Radiology and Radiological Sciences, Vanderbilt Children' s Hospital, Nashville, TN (United States); Yu, Chang [Vanderbilt University, Department of Biostatistics, Nashville, TN (United States); Ray, Jackie [Vanderbilt University, Department of Pediatric Surgery, Vanderbilt Children' s Hospital, Nashville, TN (United States)

    2010-07-15

    Chest CT after pediatric trauma is frequently performed but its clinical impact, particularly with respect to surgical intervention, has not been adequately evaluated. To assess the impact of chest CT compared with chest radiography on pediatric trauma management. Two hundred thirty-five consecutive pediatric trauma patients who had both chest CT and radiography were identified. Images were reviewed and findings were categorized and correlated with subsequent chest interventions, blinded to final outcome and management. Of the 235 children, 38.3% (90/235) had an abnormal chest radiograph and 63.8% (150/235) had an abnormal chest CT (P < 0.0001). Chest interventions followed in 4.7% (11/235); of these, the findings could be made 1 cm above the dome of the liver in 91% (10/11). Findings requiring chest intervention included pneumothorax (PTX) and vertebral fractures. PTX was found on 2.1% (5/235) of chest radiographs and 20.0% (47/235) of chest CTs (P < 0.0001); 1.7% (4/235) of the children received a chest tube for PTX, 0.85% (2/235) seen on chest CT only. Vertebral fractures were present in 3.8% of the children (9/235) and 66.7% (6/9) of those cases were treated with spinal fusion or brace. There were no instances of mediastinal vascular injury. Most intrathoracic findings requiring surgical management in our population were identified in the lower chest and would be included in routine abdominopelvic CT exams; this information needs to be taken into consideration in the diagnostic algorithm of pediatric trauma patients. (orig.)

  15. Patient doses in chest CT examinations: Comparison of various CT scanners

    Directory of Open Access Journals (Sweden)

    Božović Predrag

    2013-01-01

    Full Text Available This paper presents results from study on patient exposure level in chest CT examinations. CT scanners used in this study were various Siemens and General Electric (GE models. Data on patient doses were collected for adult and pediatric patients. Doses measured for adult patients were lower then those determined as Diagnostic Reference Levels (DRL for Europe, while doses for pediatric patients were similar to those found in published data. As for the manufactures, slightly higher doses were measured on GE devices, both for adult and pediatric patients.

  16. AP diameter shows the strongest correlation with CTDI and DLP in abdominal and chest CT.

    LENUS (Irish Health Repository)

    Zarb, Francis

    2010-01-01

    The purpose of this study is to investigate the relationships among cross-sectional diameters, weight and computed tomography (CT) dose descriptors (CTDI and DLP) to identify which is best used as a measure for the establishment of DRLs in CT. Data (gender, weight, cross-sectional diameters, dose descriptors) from 56 adult patients attending for either a CT examination of the abdomen or chest was obtained from two spiral CT units using automatic milliampere modulation. The AP diameter was demonstrated as the main contributing factor influencing the dose in CT (CTDI: r(2) = 0.269, p-value < or =0.001; DLP: r(2) = 0.260, p-value < or =0.001) since it has a greater correlation with radiation dose than body weight and can thus be its substitute in dose-reduction strategies and establishment of DRLs. The advantages of using the AP diameter are that it can easily be measured prior to scanning or retrospectively from previous CT images. However, further studies on the practicality of this approach are recommended.

  17. 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.

  18. Findings chest radiograph and CT in mediastinitis: effcacy of CT in patients with delayed diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Son, Eun Ju; Hong, Yong Kook; Choe, Kyu Ok [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-01-01

    To analyse the causes the radiologic findings in patients with mediastinitis and to evaluate the efficacy of chest CT scanning in patients with delayed diagnosis. Seventeen patients with histopathologically(n=15) or clinically diagnosed(n=2) mediastinitis were involved in this study. Eleven of the former group underwent surgery, and in four, tube drainage was performed. All underwent chest radiography and CT scanning, and in seven patients, the causes of delayed diagnosis were analysed. The most common cause of mediastinitis was esophageal rupture(n=11). Others were extension from neck abscess to the mediastinum(n=3), complications after a Benthall procedure(n=1), tuberculous lymphadenitis(n=1) and mycotic aneurysm(n=1). Patients with esophageal rupture suffered from underlying diseases such as esophageal cancer(n=2), iatrogenic esophageal rupture(n=2), Boerhaave's syndrome(n=2), and esophagitis(n=1). In patients with neck abscess (n=3), each was secondary to infected cystic hygroma, Ludwig angina, or deep neck infection, respectively. On chest CT, patients with esophageal rupture(n=11) had an abscess in the posterior mediastinum ; nine abscesses extended to the cervical area along the retropharyngeal space, and the patient with Ludwig angina had an abscess involving all compartments of the mediastinum. Among the total of 17 patients, diagnostic delays were found in seven, while five had spontaneous esophageal ruptures and two suffered complications after a Benthall procedure and Tbc lymphadenitis, respectively. The causes of diagnostic delay varied. Among seven patients, pnevmonia was initially diagnosed in two, who were treated ; one had multiorgan failure, and one was suffering from pericardial effusion and lung abscess. In three other patients, chest radiographs initially showed non-specific findings, leading to delayed CT examination. The most common cause of mediastinitis was esophageal rupture, and in these patients, chest radiographs and clinical

  19. Clinical evaluation of automatic tube voltage selection in chest CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Tilo; Henry, Simon; Faivre, Jean-Baptiste; Yasunaga, Kanna; Bendaoud, Sofiane; Simeone, Ariana; Remy, Jacques [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain [University Lille Nord de France, Department of Medical Statistics (EA 2694), Lille (France); Flohr, Thomas [Siemens Medical Systems, Department of Research and Development, Forchheim (Germany); Remy-Jardin, Martine [Hospital Calmette, Department of Thoracic Imaging, Lille cedex (France)

    2013-10-15

    To evaluate the clinical impact of automatic tube voltage selection on chest CT angiography (CTA). Ninety-three patients were prospectively evaluated with a CT protocol aimed at comparing two successive CTAs acquired under similar technical conditions except for the kV selection: (1) the initial CTA was systematically obtained at 120 kVp and 90 ref mAs; (2) the follow-up CTA was obtained with an automatic selection of the kilovoltage (Care KV; Siemens Healthcare) for optimised CTA. At follow-up, 90 patients (97 %) underwent CTA with reduced tube voltage, 100 kV (n = 26; 28 %) and 80 kV (n = 64; 69 %), resulting in a significant dose-length-product reduction (follow-up: 87.27; initial: 141.88 mGy.cm; P < 0.0001; mean dose reduction: 38.5 %) and a significant increase in the CNR at follow-up (follow-up: 11.5 {+-} 3.5 HU; initial: 10.9 {+-} 3.7 HU; P = 0.03). The increase in objective image noise at follow-up (follow-up: 23.2 {+-} 6.7 HU vs. 17.8 {+-} 5.1 HU; P < 0.0001) did not alter the diagnostic value of images. Automatic tube voltage selection reduced the radiation dose delivered during chest CT angiograms by 38.5 % while improving the contrast-to-noise ratio of the examinations. (orig.)

  20. A system for automatic aorta sections measurements on chest CT

    Science.gov (United States)

    Pfeffer, Yitzchak; Mayer, Arnaldo; Zholkover, Adi; Konen, Eli

    2016-03-01

    A new method is proposed for caliber measurement of the ascending aorta (AA) and descending aorta (DA). A key component of the method is the automatic detection of the carina, as an anatomical landmark around which an axial volume of interest (VOI) can be defined to observe the aortic caliber. For each slice in the VOI, a linear profile line connecting the AA with the DA is found by pattern matching on the underlying intensity profile. Next, the aortic center position is found using Hough transform on the best linear segment candidate. Finally, region growing around the center provides an accurate segmentation and caliber measurement. We evaluated the algorithm on 113 sequential chest CT scans, slice thickness of 0.75 - 3.75mm, 90 with contrast agent injected. The algorithm success rates were computed as the percentage of scans in which the center of the AA was found. Automated measurements of AA caliber were compared with independent measurements of two experienced chest radiologists, comparing the absolute difference between the two radiologists with the absolute difference between the algorithm and each of the radiologists. The measurement stability was demonstrated by computing the STD of the absolute difference between the radiologists, and between the algorithm and the radiologists. Results: Success rates of 93% and 74% were achieved, for contrast injected cases and non-contrast cases, respectively. These results indicate that the algorithm can be robust in large variability of image quality, such as the cases in a realworld clinical setting. The average absolute difference between the algorithm and the radiologists was 1.85mm, lower than the average absolute difference between the radiologists, which was 2.1mm. The STD of the absolute difference between the algorithm and the radiologists was 1.5mm vs 1.6mm between the two radiologists. These results demonstrate the clinical relevance of the algorithm measurements.

  1. Posterior diaphragmatic defect detected on chest CT: the incidence according to age and the lateral chest radiographic appearances

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Son Youl; Choi, Yo Won; Jeon, Seok Chol; Heo, Jeong Nam; Park, Choong Ki [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2007-03-15

    We wanted to investigate the incidence of posterior diaphragmatic defect on chest CT in various age groups and its lateral chest radiographic appearances. The chest CT scans of 78 patients of various ages with posterior diaphragmatic defect were selected among 1,991 patients, and they were analyzed for the incidence of defect in various age groups, the defect location and the herniated contents. Their lateral chest radiographs were analyzed for the shape of the posterior diaphragm and the posterior costophrenic sulcus. The patients' ages ranged from 34 to 87 with the tendency of a higher incidence in the older patients. The defect most frequently involved the medial two thirds (n = 49, 50.4%) and middle one third (n = 36, 37%) of the posterior diaphragm. The retroperitoneal fat was herniated into the thorax through the defect in all patients, and sometimes with the kidney (n = 8). Lateral chest radiography showed a normal diaphragmatic contour (n = 51, 49.5%), blunting of the posterior costophrenic sulcus (n = 41, 39.8%), focal humping of the posterior diaphragm (n = 7, 6.8%), or upward convexity (n = 4, 3.9%) of the posterior costophrenic sulcus on the affected side. The posterior diaphragmatic defect discovered in asymptomatic patients who are without a history of peridiaphragmatic disease is most likely acquired, and this malady increases in incidence according to age. An abnormal contour of the posterior diaphragm or the costophrenic sulcus on a lateral chest radiograph may be a finding of posterior diaphragmatic defect.

  2. Seamless insertion of real pulmonary nodules in chest CT exams

    Science.gov (United States)

    Pezeshk, Aria; Sahiner, Berkman; Zeng, Rongping; Wunderlich, Adam; Chen, Weijie; Petrick, Nicholas

    2014-03-01

    The availability of large medical image datasets is critical in many applications such as training and testing of computer aided diagnosis (CAD) systems, evaluation of segmentation algorithms, and conducting perceptual studies. However, collection of large repositories of clinical images is hindered by the high cost and difficulties associated with both the accumulation of data and establishment of the ground truth. To address this problem, we are developing an image blending tool that allows users to modify or supplement existing datasets by seamlessly inserting a real lesion extracted from a source image into a different location on a target image. In this study we focus on the application of this tool to pulmonary nodules in chest CT exams. We minimize the impact of user skill on the perceived quality of the blended image by limiting user involvement to two simple steps: the user first draws a casual boundary around the nodule of interest in the source, and then selects the center of desired insertion area in the target. We demonstrate examples of the performance of the proposed system on samples taken from the Lung Image Database Consortium (LIDC) dataset, and compare the noise power spectrum (NPS) of blended nodules versus that of native nodules in simulated phantoms.

  3. Diagnostic modalities x-ray and CT chest differ in the management of thoracic injury

    Directory of Open Access Journals (Sweden)

    D Chapagain

    2015-06-01

    Full Text Available Objective: To observe difference in the management of blunt trauma to the chest on the basis of conventional xray and computerised tomography of the chest. Methods: This prospective study was conducted between December 2011 to October 2012 in COMS in Bharatpur,a tertiary referral centre in central Nepal . Clinically stable thoracic injury patients were first evaluated with chest x-ray and the management on this basis was recorded. The findings of the CT chest were assessed and the type of management on the basis of CT was also recorded. Outcome was assessed in terms of mortality, morbidity, hospital and ICU stay with respect to the management on the basis of chest x-ray and CT scan. Results: Of the 129 patients, 74.4% were male and 25.6% were female with the patients ranging in age from 7 to 87 years (mean = 40.41 years. The most common mechanism of trauma to the chest was as a result of a motor vehicle accident (69.8%, followed by fall injury (20.2%. X-ray chest diagnosed rib fracture in 62%, haemothorax in 37%, pneumothorax in 27%, lung contusion in 10% and haemopneumothorax in 21% patients. Similarly CT chest diagnosed rib fracture in 86%, haemothorax in 54%, pneumothorax in 36%, lung contusion in 30% and haemopneumothorax in 30% patients. Mean hospital stay was 9.5 days in the group of patients having management on the basis of x-ray chest relative to mean stay of 10.2 days in the CT- chest group. In the management on the basis of xray group, there was a mean ICU stay of 2.8days compared to mean stays of 3.2 days in CT chest group. Conclusion: Though CT scan of the chest is more informative and differs the management of the blunt chest trauma, one should not forget to advise the cost effective, easily available and initial guiding agent, xray chest for early management of the chest injury patient. DOI: http://dx.doi.org/10.3126/jcmsn.v10i1.12764 Journal of College of Medical Sciences-Nepal, 2014, Vol.10(1; 22-31

  4. Triple Rule Out versus CT Angiogram Plus Stress Test for Evaluation of Chest Pain in the Emergency Department

    Directory of Open Access Journals (Sweden)

    Kelly N. Sawyer

    2015-10-01

    Full Text Available Introduction: Undifferentiated chest pain in the emergency department (ED is a diagnostic challenge. One approach includes a dedicated chest computed tomography (CT for pulmonary embolism or dissection followed by a cardiac stress test (TRAD. An alternative strategy is a coronary CT angiogram with concurrent chest CT (Triple Rule Out, TRO. The objective of this study was to describe the ED patient course and short-term safety for these evaluation methods. Methods: This was a retrospective observational study of adult patients presenting to a large, community ED for acute chest pain who had non-diagnostic electrocardiograms (ECGs and normal biomarkers. We collected demographics, ED length of stay, hospital costs, and estimated radiation exposures. We evaluated 30-day return visits for major adverse cardiac events. Results: A total of 829 patients underwent TRAD, and 642 patients had TRO. Patients undergoing TRO tended to be younger (mean 52.3 vs 56.5 years and were more likely to be male (42.4% vs. 30.4%. TRO patients tended to have a shorter ED length of stay (mean 14.45 vs. 21.86 hours, to incur less cost (median $449.83 vs. $1147.70, and to be exposed to less radiation (median 7.18 vs. 16.6mSv. No patient in either group had a related 30-day revisit. Conclusion: Use of TRO is feasible for assessment of chest pain in the ED. Both TRAD and TRO safely evaluated patients. Prospective studies investigating this diagnostic strategy are needed to further assess this approach to ED chest pain evaluation.

  5. 20 percent lower lung cancer mortality with low-dose CT vs chest X-ray

    Science.gov (United States)

    Scientists have found a 20 percent reduction in deaths from lung cancer among current or former heavy smokers who were screened with low-dose helical computed tomography (CT) versus those screened by chest X-ray.

  6. Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Hans-Christoph, E-mail: christoph.becker@med.uni-muenchen.de [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany); Johnson, Thorsten [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany)

    2012-12-15

    Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as “triple rule out” scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.

  7. Automated tube potential selection for standard chest and abdominal CT in follow-up patients with testicular cancer: comparison with fixed tube potential

    Energy Technology Data Exchange (ETDEWEB)

    Gnannt, Ralph; Winklehner, Anna; Frauenfelder, Thomas; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Eberli, Daniel [University Hospital Zurich, Clinic for Urology, Zurich (Switzerland); Knuth, Alexander [University Hospital Zurich, Clinic for Oncology, Zurich (Switzerland)

    2012-09-15

    To evaluate prospectively, in patients with testicular cancer, the radiation dose-saving potential and image quality of contrast-enhanced chest and abdominal CT with automated tube potential selection. Forty consecutive patients with testicular cancer underwent contrast-enhanced arterio-venous chest and portal-venous abdominal CT with automated tube potential selection (protocol B; tube potential 80-140 kVp), which is based on the attenuation of the CT topogram. All had a first CT at 120 kVp (protocol A) using the same 64-section CT machine and similar settings. Image quality was assessed; dose information (CTDI{sub vol}) was noted. Image noise and attenuation in the liver and spleen were significantly higher for protocol B (P < 0.05 each), whereas attenuation in the deltoid and erector spinae muscles was similar. In protocol B, tube potential was reduced to 100 kVp in 18 chest and 33 abdominal examinations, and to 80 kVp in 5 abdominal CT examinations; it increased to 140 kVp in one patient. Image quality of examinations using both CT protocols was rated as diagnostic. CTDI{sub vol} was significantly lower for protocol B compared to protocol A (reduction by 12%, P < 0.01). In patients with testicular cancer, radiation dose of chest and abdominal CT can be reduced with automated tube potential selection, while image quality is preserved. (orig.)

  8. Fat segmentation on chest CT images via fuzzy models

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Wu, Caiyun; Pednekar, Gargi; Subramanian, Janani Rajan; Lederer, David J.; Christie, Jason; Torigian, Drew A.

    2016-03-01

    Quantification of fat throughout the body is vital for the study of many diseases. In the thorax, it is important for lung transplant candidates since obesity and being underweight are contraindications to lung transplantation given their associations with increased mortality. Common approaches for thoracic fat segmentation are all interactive in nature, requiring significant manual effort to draw the interfaces between fat and muscle with low efficiency and questionable repeatability. The goal of this paper is to explore a practical way for the segmentation of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) components of chest fat based on a recently developed body-wide automatic anatomy recognition (AAR) methodology. The AAR approach involves 3 main steps: building a fuzzy anatomy model of the body region involving all its major representative objects, recognizing objects in any given test image, and delineating the objects. We made several modifications to these steps to develop an effective solution to delineate SAT/VAT components of fat. Two new objects representing interfaces of SAT and VAT regions with other tissues, SatIn and VatIn are defined, rather than using directly the SAT and VAT components as objects for constructing the models. A hierarchical arrangement of these new and other reference objects is built to facilitate their recognition in the hierarchical order. Subsequently, accurate delineations of the SAT/VAT components are derived from these objects. Unenhanced CT images from 40 lung transplant candidates were utilized in experimentally evaluating this new strategy. Mean object location error achieved was about 2 voxels and delineation error in terms of false positive and false negative volume fractions were, respectively, 0.07 and 0.1 for SAT and 0.04 and 0.2 for VAT.

  9. Novel Influenza A (H1N1) Virus Infection in Children: Chest Radiographic and CT Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Min Jeong; Lee, Young Seok; Lee, Jee Young; Lee, Kun Song [Dankook University College of Medicine, Dankook University Hospital, Cheonan (Korea, Republic of)

    2010-12-15

    The purpose of this study was to evaluate the chest radiographic and CT findings of novel influenza A (H1N1) virus infection in children, the population that is more vulnerable to respiratory infection than adults. The study population comprised 410 children who were diagnosed with an H1N1 infection from August 24, 2009 to November 11, 2009 and underwent chest radiography at Dankook University Hospital in Korea. Six of these patients also underwent chest CT. The initial chest radiographs were classified as normal or abnormal. The abnormal chest radiographs and high resolution CT scans were assessed for the pattern and distribution of parenchymal lesions, and the presence of complications such as atelectasis, pleural effusion, and pneumomediastinum. The initial chest radiograph was normal in 384 of 410 (94%) patients and abnormal in 26 of 410 (6%) patients. Parenchymal abnormalities seen on the initial chest radiographs included prominent peribronchial marking (25 of 26, 96%), consolidation (22 of 26, 85%), and ground-glass opacities without consolidation (2 of 26, 8%). The involvement was usually bilateral (19 of 26, 73%) with the lower lung zone predominance (22 of 26, 85%). Atelectasis was observed in 12 (46%) and pleural effusion in 11 (42%) patients. CT (n = 6) scans showed peribronchovascular interstitial thickening (n = 6), ground-glass opacities (n = 5), centrilobular nodules (n = 4), consolidation (n = 3), mediastinal lymph node enlargement (n = 5), pleural effusion (n = 3), and pneumomediastinum (n = 3). Abnormal chest radiographs were uncommon in children with a swine-origin influenza A (H1N1) virus (S-OIV) infection. In children, H1N1 virus infection can be included in the differential diagnosis, when chest radiographs and CT scans show prominent peribronchial markings and ill-defined patchy consolidation with mediastinal lymph node enlargement, pleural effusion and pneumomediastinum

  10. Chest Fat Quantification via CT Based on Standardized Anatomy Space in Adult Lung Transplant Candidates

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.; Odhner, Dewey; Wu, Caiyun; Pednekar, Gargi; Palmer, Scott; Rozenshtein, Anna; Shirk, Melissa A.; Newell, John D.; Porteous, Mary; Diamond, Joshua M.

    2017-01-01

    Purpose Overweight and underweight conditions are considered relative contraindications to lung transplantation due to their association with excess mortality. Yet, recent work suggests that body mass index (BMI) does not accurately reflect adipose tissue mass in adults with advanced lung diseases. Alternative and more accurate measures of adiposity are needed. Chest fat estimation by routine computed tomography (CT) imaging may therefore be important for identifying high-risk lung transplant candidates. In this paper, an approach to chest fat quantification and quality assessment based on a recently formulated concept of standardized anatomic space (SAS) is presented. The goal of the paper is to seek answers to several key questions related to chest fat quantity and quality assessment based on a single slice CT (whether in the chest, abdomen, or thigh) versus a volumetric CT, which have not been addressed in the literature. Methods Unenhanced chest CT image data sets from 40 adult lung transplant candidates (age 58 ± 12 yrs and BMI 26.4 ± 4.3 kg/m2), 16 with chronic obstructive pulmonary disease (COPD), 16 with idiopathic pulmonary fibrosis (IPF), and the remainder with other conditions were analyzed together with a single slice acquired for each patient at the L5 vertebral level and mid-thigh level. The thoracic body region and the interface between subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in the chest were consistently defined in all patients and delineated using Live Wire tools. The SAT and VAT components of chest were then segmented guided by this interface. The SAS approach was used to identify the corresponding anatomic slices in each chest CT study, and SAT and VAT areas in each slice as well as their whole volumes were quantified. Similarly, the SAT and VAT components were segmented in the abdomen and thigh slices. Key parameters of the attenuation (Hounsfield unit (HU) distributions) were determined from each chest slice and

  11. Comparison of image quality and radiation dose between high-pitch mode and low-pitch mode spiral chest CT in small uncooperative children: The effect of respiratory rate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Ho; Choi, Young Hun; Cho, Hyun-Hae; Lee, So Mi [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Shin, Su-Mi [SMG-SNU Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Cheon, Jung-Eun; Kim, Woo Sun; Kim, In-One [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of)

    2016-04-15

    To compare image quality and radiation dose between high-pitch mode (HPM) and low-pitch mode (LPM) CT in young children. Forty-seven children (mean age 35.6 months; range, 0-126 months) underwent 49 CT examinations in HPM or LPM and were divided into high or low respiratory rate (RR) groups. A qualitative image quality was compared between the two modes. The volume CT dose index (CTDI{sub vol}) and dose-length product (DLP) were evaluated from the dose reports, and effective doses were assessed using a paediatric phantom. Image quality was generally better for HPM than LPM (diagnostic acceptance score, 4.00 vs. 3.46, P = 0.004); the difference was more prominent in the high RR group (4.00 vs. 3.22, P = 0.001). However, there was no significant difference in the low RR group. The mean DLP value was higher in HPM than LPM (29.48 mGy . cm vs. 23.46 mGy . cm, P = 0.022), while CTDI{sub vol} was not significantly different. The total effective radiation dose was 26 % higher in HPM than LPM (1.82 mSv vs. 1.44 mSv). LPM can be considered for paediatric lung evaluation in young children with low RRs to reduce radiation dose while maintaining favourable image quality. (orig.)

  12. Study of the CT peripheral dose variation in a chest phantom

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, T. C.; Da Silva, T. A. [Development Center of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Mourao F, A. P., E-mail: alonso@cdtn.br [Federal University of Minas Gerais, Nuclear Energy Department, Program of Nuclear Science and Techniques, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRL) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The purpose of this study is to investigate, in a chest scan, the variation of dose in CT. To measure the dose profile are used lithium fluoride thermoluminescent dosimeters distributed in cylinders positioned in peripheral and central regions of a phantom of polymethylmethacrylate (PMMA). The data obtained allow to observe the variation of the dose profile inside the phantom. The peripheral region shows higher dose values than the central region. The longitudinal variation can be observed and the maximum dose was recorded at the edges of the phantom (15,99 ± 2,80) mGy at the midpoint of the longitudinal axis. The results will contribute to disseminate the proper procedure and optimize the dosimetry and the tests of quality control in CT, as well as make a critical analysis of the DRL. (Author)

  13. Unenhanced third-generation dual-source chest CT using a tin filter for spectral shaping at 100 kVp

    Energy Technology Data Exchange (ETDEWEB)

    Haubenreisser, Holger, E-mail: holger.haubenreisser@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Meyer, Mathias; Sudarski, Sonja [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Allmendinger, Thomas [Siemens Healthcare Sector, CT Division, Forchheim (Germany); Schoenberg, Stefan O.; Henzler, Thomas [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2015-08-15

    Highlights: • Spectral shaping can be done using an additional tin filter. • Spectral shaping can lead to a significantly lower dose for non-contrast CT. • The low dose protocol maintains sufficient image quality for diagnosis. • The protocol used should be used for non-contrast enhanced chest CT when possible. - Abstract: Objective: To prospectively investigate image quality and radiation dose of 100 kVp spectral shaping chest CT using a dedicated tin filter on a 3rd generation dual-source CT (DSCT) in comparison to standard 100 kVp chest CT. Methods: Sixty patients referred for a non-contrast chest on a 3rd generation DSCT were prospectively included and examined at 100 kVp with a dedicated tin filter. These patients were retrospectively matched with patients that were examined on a 2nd generation DSCT at 100 kVp without tin filter. Objective and subjective image quality was assessed in various anatomic regions and radiation dose was compared. Results: Radiation dose was decreased by 90% using the tin filter (3.0 vs 0.32 mSv). Soft tissue attenuation and image noise was not statistically different for both examination techniques (p > 0.05), however image noise was found to be significantly higher in the trachea when using the additional tin filter (p = 0.002). SNR was found to be statistically similar in pulmonary tissue, significantly lower when measured in air and significantly higher in the aorta for the scans on the 3rd generation DSCT. Subjective image quality with regard to overall quality and image noise and sharpness was not statistically significantly different (p > 0.05). Conclusion: 100 kVp spectral shaping chest CT by means of a tube-based tin-filter on a 3rd generation DSCT allows 90% dose reduction when compared to 100 kVp chest CT on a 2nd generation DSCT without spectral shaping.

  14. The Beatles, the Nobel Prize, and CT scanning of the chest.

    Science.gov (United States)

    Goodman, Lawrence R

    2010-01-01

    From its first test scan on a mouse, in 1967, to current medical practice, the CT scanner has become a core imaging tool in thoracic diagnosis. Initially financed by money from Beatles' record sales, the first patient scan was performed in 1971. Only 8 years later, a Nobel Prize in Physics and Medicine was awarded to Hounsfield and Cormack for their discovery. This article traces the history of CT scanner development and how each technical advance expanded chest diagnostic frontiers. Chest imaging now accounts for 30% of all CT scanning.

  15. Triple Rule Out versus CT Angiogram Plus Stress Test for Evaluation of Chest Pain in the Emergency Department

    OpenAIRE

    Sawyer, Kelly N.; Payal Shah; Lihua Qu; Kurz, Michael C.; Clark, Carol L.; Swor, Robert A.

    2015-01-01

    Introduction: Undifferentiated chest pain in the emergency department (ED) is a diagnostic challenge. One approach includes a dedicated chest computed tomography (CT) for pulmonary embolism or dissection followed by a cardiac stress test (TRAD). An alternative strategy is a coronary CT angiogram with concurrent chest CT (Triple Rule Out, TRO). The objective of this study was to describe the ED patient course and short-term safety for these evaluation methods. Methods: This was ...

  16. Acute chest pain in emergency room. Preliminary findings with 40-64-slice CT ECG-gated of the whole chest.

    Science.gov (United States)

    Coche, E

    2007-01-01

    ECG-gated MDCT of the entire chest represents the latest technical advance in the diagnostic work-up of atypical chest pain. The authors report their preliminary experience with the use of 40 and 64-slice CT in the emergency room and recommend to study only patients with moderate likelihood of coronary artery disease. ECG-gated MDCT of the entire chest will be preferentially performed on 64-slice MDCT rather than 40-slice MDCT because it enable to reduce the scan time (18 seconds versus 28 seconds acquisition time), the volume of contrast medium (82 mL + 15 mL versus 97 mL + 15 mL of highly concentrated contrast agent for a patient of 70 kgs) and radiation exposure (17 mSv versus 19 mSv). Approximately 1500 to 2000 of images are produced and need to be analysed on a dedicated workstation by a radiologist expert in cardiac and thoracic disorders. At the present time, only a few studies exist in the literature showing some promising results but further large clinical studies are needed before to implement such sophisticated protocol in emergency room.

  17. Radiographic, CT and MRI spectrum of hydatid disease of the chest: a pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Sinner, W.N. von [Dept. of Radiology MBC28, King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia)

    1993-01-01

    Thirty patients with thoracic hydatidosis (Echinococcus granulosus) were studied. The hydatid cysts were located in the lung parenchyma (70%), mediastinum (6.7%), inside the heart (10%), the pleurae (10%) and the chest wall (3.3%). Complications of thoracic hydatid cysts, such as rupture, infection, pleural involvement, spread and calcifications are presented. Computed tomography (CT) without and/or with contrast enhancement was performed in all patients (30). Findings from conventional chest radiographs were compared with CT and confirmed by pathology (30). In 10 cases (33.3%), magnetic resonance imaging was also performed. The diagnostic spectrum of hydatid cysts, including variations and developmental stages, is presented in this pictorial essay. (orig.)

  18. Possibilities for exposure reduction in computed tomography examination of acute chest pain; Moeglichkeiten der Dosisreduktion bei CT-Untersuchungen des akuten Thoraxschmerzes

    Energy Technology Data Exchange (ETDEWEB)

    Becker, H.C. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2012-10-15

    Electrocardiogram-gated (ECG) computed tomography (CT) investigations can be accompanied by high amounts of radiation exposure. This is particularly true for the investigation of patients with unclear and acute chest pain. The common approach in patients with acute chest pain is standard spiral CT of the chest. The chest pain or triple-rule-out CT protocol is a relatively new ECG-gated protocol of the entire chest. This article reviews and discusses different techniques for the CT investigation of patients with acute chest pain. By applying the appropriate scan technique, the radiation exposure for an ECG-gated protocol must not necessarily be higher than a standard chest CT scan Aortic pathologies are far better depicted by ECG-gated scan protocols and depending on the heart rate coronary artery disease can also be detected at the same time. The use of ECG-triggered scans will not support the diagnostics of the pulmonary arteries. However, in unspecific chest pain an ECG-triggered scan protocol can provide information on the differential diagnosis. (orig.) [German] EKG-getriggerte CT-Untersuchungen koennen mit einer relativ hohen Strahlenexposition einhergehen. Dies gilt im besonderen Masse fuer die Untersuchung des gesamten Thorax bei Patienten mit unklarem akutem Thoraxschmerz. Bisher wurden Untersuchungen bei Patienten mit akutem Thoraxschmerz in Spiraltechnik ohne EKG-Triggerung durchgefuehrt. Das ''Chest-pain-'' oder ''Triple-rule-out''-Protokoll ist ein neues EKG-getriggertes Untersuchungsprotokoll des gesamten Thorax. Im vorliegenden Artikel werden verschiedene Techniken zur CT-Untersuchung von Patienten mit akutem Thoraxschmerz vorgestellt und besprochen. Mit der richtigen Untersuchungstechnik muss die Strahlenexposition fuer ein EKG-getriggertes Untersuchungsprotokoll nicht hoeher sein als eine Standarduntersuchung ohne EKG. Mit einem EKG-getriggerten Untersuchungsprotokoll laesst sich die Aorta in Hinblick auf

  19. Volumetric measurement of pulmonary nodules at low-dose chest CT : effect of reconstruction setting on measurement variability

    NARCIS (Netherlands)

    Wang, Y.; de Bock, G.H.; van Klaveren, R.J.; van Ooyen, P.; Tukker, W.; Zhao, Y.; Dorrius, M.D.; Proenca, R.V.; Post, W.J.; Oudkerk, M.

    2010-01-01

    To assess volumetric measurement variability in pulmonary nodules detected at low-dose chest CT with three reconstruction settings. The volume of 200 solid pulmonary nodules was measured three times using commercially available semi-automated software of low-dose chest CT data-sets reconstructed wit

  20. Utility of CT scan for the diagnosis of chest wall tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, A.; Le Breton, C.; Tassart, M.; Korzec, J.; Bigot, J.M.; Carette, M.F. [Department of Radiology, Tenon Hospital, Paris (France)

    1999-10-01

    The objective of this study was to determine the utility of CT scan findings for the diagnosis of chest wall tuberculosis, excluding the spine. We reviewed 15 patients (13 Africans and 2 Indians) with chest wall tuberculosis, retrospectively. The radiologic examination consisted of a plain X-ray and a CT scan of the chest for each patient. The site of disease was the rib in 13 patients or the body of the sternum in 2 patients. One rib was involved in 11 patients, 2 contiguous ribs (one site) in 2 patients, and bilateral disease (two sites) was observed in the remaining patient. The 14 rib sites involved the posterior arc or costovertebral joint in 11 cases, the anterior arc in 2 cases, and the anterior and middle arc in 1 case. The CT scan findings were an abscess (n = 14) or a soft tissue mass (n = 2), osteolytic lesions (n = 13), periosteal reaction (n = 10), and sequestrum (n = 14). Bone sclerosis was observed only in 3 cases of rib involvement. The association of a soft tissue abscess, an osteolytic lesion, and sequestrum, especially in immigrants to France, suggests chest wall tuberculosis on CT scan. (orig.) With 5 figs., 2 tabs., 11 refs.

  1. Cross-sectional imaging with CT and/or MRI of pediatric chest tumors

    Energy Technology Data Exchange (ETDEWEB)

    Wyttenbach, R.; Vock, P.; Tschaeppeler, H. [Department of Diagnostic Radiology, Division of Children`s Radiology, University Hospital, Bern (Switzerland)

    1998-07-01

    The purpose of this study was to provide an overview of the spectrum of pediatric chest masses, to present the results of cross-sectional imaging with CT and/or MRI, and to define diagnostic criteria to limit differential diagnosis. Seventy-eight children with thoracic mass lesions were retrospectively evaluated using CT (72 patients) and/or MR imaging (12 patients). All masses were evaluated for tissue characteristics (attenuation values or signal intensity, enhancement, and calcification) and were differentiated according to age, gender, location, and etiology. Twenty-eight of 38 (74 %) mediastinal masses were malignant (neuroblastoma, malignant lymphoma). Thirty of 38 (79 %) pulmonary masses were metastatic in origin, all with an already known primary tumor (osteosarcoma, Wilms tumor). With one exception, all remaining pulmonary lesions were benign. Seventeen of 21 (81 %) chest wall lesions were malignant (Ewing sarcoma, primitive neuroectodermal tumor). The majority of mediastinal and chest wall tumors in children is malignant. Lung lesions are usually benign, unless a known extrapulmonary tumor suggests pulmonary metastases. Cross-sectional imaging with CT and/or MRI allows narrowing of the differential diagnosis of pediatric chest masses substantially by defining the origin and tissue characteristics. Magnetic resonance imaging is preferred for posterior mediastinal lesions, whereas CT should be used for pulmonary lesions. For the residual locations both modalities are complementary. (orig.) With 5 figs., 3 tabs., 20 refs.

  2. 比较不同体型特异性剂量评估算法在估算成人胸腹部CT扫描中辐射剂量的差异%Comparison of different SSDE methods in evaluating the radiation dose in chest and abdomen CT scan

    Institute of Scientific and Technical Information of China (English)

    袁子龙; 王国柱; 张照喜; 郑丽丽; 杜东屏; 陈迢; 彭伟; 邱建峰; 刘玉林

    2016-01-01

    目的 比较基于水等效直径(WED)的体型特异性剂量评估(SSDEwED)和基于有效直径(ED)的SSDEED在估算成人胸腹部CT辐射剂量中的差异.方法 采用德国西门子SOMATOMDefinition AS 64排128层CT机对240例成人患者行胸部(161例)、腹部(79例)平扫,按部位分别分为胸部A组左右径(LAT) <30 cm,B组30 cm≤LAT≤34 cm,C组LAT> 34 cm和腹部A组LAT<27cm,B组27 cm≤LAT≤32 cnm,C组LAT> 32cm.记录每例患者的CTDIvol值,并计算ED、WED和转换系数fsize,以及患者的SSDEED和SSDEWED.比较不同LAT组SSDEWED和SSDEED之间的差异.结果 胸部扫描患者ED与WEDfsize.ED与fsize.WED及SSDEED与SSDEWED之间差异均有统计学意义(t=-33.12、32.55、28.44,P <0.05),3组病例问LAT、ED、WED、SSDEED和SSDEWED差异均有统计学意义(F=273.67、140.97、77.05、19.87、32.21,P<0.05);腹部扫描患者ED与WED、fsize.ED与fsize.WED及SSDEED与SSDEWED之问差异均有统计学意义(t=-24.09、-22.96、22.46,P<0.05),3组病例间LAT、ED、WED、SSDEED和SSDEWED差异均有统计学意义(F=123.89、82.17、83.16、52.74、53.62,P<0.05).胸部WED较ED降低约12.0%,导致SSDEWED较SSDEED增加了约11.6%;腹部WED较ED增加了约5.2%,导致SSDEWED较SSDEED降低了约4.8%,且胸部及腹部3组病例SSDEWED较SSDEED均随着LAT的增加而增加.结论 WED能够更好地代表患者的体型大小及衰减特性,SSDEWED能够更准确地计算胸腹部CT患者的辐射剂量.%Objective To compare the difference between SSDEENand SSDEWED in evaluating the radiation dose of adult chest and abdomen CT scans.Methods A total of 240 adult patients were performed CT scan for chest or abdomen by Siemens 128 slice CT (161 cases in chest,79 cases in abdomen),and they were divided into three groups according to the different left-right (LAT) sizes of chest and abdomen (for chest,group A,LAT < 30 cm;group B,30 cm ≤ LAT ≤ 34 cm;group C,LAT > 34 cm;for abdomen,group A,LAT <27 cm

  3. CT staging of colorectal cancer: What do you find in the chest?

    Energy Technology Data Exchange (ETDEWEB)

    McQueen, A.S., E-mail: andrewmcqueen7@hotmail.com [Department of Radiology, Freeman Hospital, Newcastle upon Tyne (United Kingdom); Scott, J. [Department of Radiology, Freeman Hospital, Newcastle upon Tyne (United Kingdom)

    2012-04-15

    Aim: To clarify the chest computed tomography (CT) findings in patients with a new diagnosis of colorectal adenocarcinoma. Materials and methods: Patients diagnosed with colorectal cancer (CRC) over a 3-year period were retrospectively studied. All CT examinations were performed within a single NHS Trust using the same CT system and protocol. Two primary outcomes were assessed: the presence of pulmonary metastases and the identification of a significant, unexpected chest abnormality. Results: Five hundred and fourteen out of 568 (90.5%) CRC patients underwent complete CT staging. Thirty-one patients (6%) had lung metastases, of which four (0.8%) were isolated. Three hundred and fifty-three (68.7%) had no evidence of pulmonary metastases, but 130 (25.3%) had indeterminate lung nodules (ILNs). The ILNs of 12 patients were subsequently confirmed as metastases on follow-up. A major non-metastatic finding (pulmonary embolism or synchronous primary malignancy) was found in 15/514 patients (3%). Conclusions: Thoracic CT altered the initial TNM stage in fewer than 1% of CRC patients, but the detection of significant incidental chest disease and the establishment of an imaging baseline are useful outcomes of this imaging strategy. One-quarter of all staging examinations demonstrated ILNs.

  4. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, Sara A.; Svalkvist, Angelica; Maansson, Lars Gunnar; Baath, Magnus [University of Gothenburg, Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Medical Physics and Biomedical Engineering, Gothenburg (Sweden); Johnsson, Aase A.; Vikgren, Jenny; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A. [University of Gothenburg, Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Radiology, Gothenburg (Sweden)

    2014-07-15

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70 % of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100 % dose levels, respectively. The differences in FOM between the 12 % dose level and the 32, 70, and 100 % dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32 %. (orig.)

  5. Segmentation of the whole breast from low-dose chest CT images

    Science.gov (United States)

    Liu, Shuang; Salvatore, Mary; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

    2015-03-01

    The segmentation of whole breast serves as the first step towards automated breast lesion detection. It is also necessary for automatically assessing the breast density, which is considered to be an important risk factor for breast cancer. In this paper we present a fully automated algorithm to segment the whole breast in low-dose chest CT images (LDCT), which has been recommended as an annual lung cancer screening test. The automated whole breast segmentation and potential breast density readings as well as lesion detection in LDCT will provide useful information for women who have received LDCT screening, especially the ones who have not undergone mammographic screening, by providing them additional risk indicators for breast cancer with no additional radiation exposure. The two main challenges to be addressed are significant range of variations in terms of the shape and location of the breast in LDCT and the separation of pectoral muscles from the glandular tissues. The presented algorithm achieves robust whole breast segmentation using an anatomy directed rule-based method. The evaluation is performed on 20 LDCT scans by comparing the segmentation with ground truth manually annotated by a radiologist on one axial slice and two sagittal slices for each scan. The resulting average Dice coefficient is 0.880 with a standard deviation of 0.058, demonstrating that the automated segmentation algorithm achieves results consistent with manual annotations of a radiologist.

  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. A Survey of Pediatric CT Protocols and Radiation Doses in South Korean Hospitals to Optimize the Radiation Dose for Pediatric CT Scanning.

    Science.gov (United States)

    Hwang, Jae-Yeon; Do, Kyung-Hyun; Yang, Dong Hyun; Cho, Young Ah; Yoon, Hye-Kyung; Lee, Jin Seong; Koo, Hyun Jung

    2015-12-01

    Children are at greater risk of radiation exposure than adults because the rapidly dividing cells of children tend to be more radiosensitive and they have a longer expected life time in which to develop potential radiation injury. Some studies have surveyed computed tomography (CT) radiation doses and several studies have established diagnostic reference levels according to patient age or body size; however, no survey of CT radiation doses with a large number of patients has yet been carried out in South Korea. The aim of the present study was to investigate the radiation dose in pediatric CT examinations performed throughout South Korea. From 512 CT (222 brain CT, 105 chest CT, and 185 abdominopelvic CT) scans that were referred to our tertiary hospital, a dose report sheet was available for retrospective analysis of CT scan protocols and dose, including the volumetric CT dose index (CTDIvol), dose-length product (DLP), effective dose, and size-specific dose estimates (SSDE). At 55.2%, multiphase CT was the most frequently performed protocol for abdominopelvic CT. Tube current modulation was applied most often in abdominopelvic CT and chest CT, accounting for 70.1% and 62.7%, respectively. Regarding the CT dose, the interquartile ranges of the CTDIvol were 11.1 to 22.5 (newborns), 16.6 to 39.1 (≤1 year), 14.6 to 41.7 (2-5 years), 23.5 to 44.1 (6-10 years), and 31.4 to 55.3 (≤15 years) for brain CT; 1.3 to 5.7 (≤1 year), 3.9 to 6.8 (2-5 years), 3.9 to 9.3 (6-10 years), and 7.7 to 13.8 (≤15 years) for chest CT; and 4.0 to 7.5 (≤1 year), 4.2 to 8.9 (2-5 years), 5.7 to 12.4 (6-10 years), and 7.6 to 16.6 (≤15 years) for abdominopelvic CT. The SSDE and CTDIvol were well correlated for patients CT in South Korea. The CTDIvol, DLP, and effective dose were generally lower than in German and UK surveys, except in certain age groups.

  8. Thyroid nodules on chest CT of patients with tuberous sclerosis complex.

    Science.gov (United States)

    Auladell, Maria; Boronat, Susana; Barber, Ignasi; Thiele, Elizabeth A

    2015-12-01

    A few cases of thyroid disease have been reported in tuberous sclerosis complex (TSC); however, studies on prevalence and characterization of lesions have not been done. Patients with TSC are routinely screened using chest CT for assessment of lung disease. Incidental thyroid findings on chest CT have been reported in large studies of the general population. The purpose of this study is to evaluate the frequency and type of thyroid anomalies in a cohort of TSC patients. We performed a retrospective review of 93 patients with a definite diagnosis of TSC, who had a chest CT. Images of the thyroid gland and final radiological report were reviewed. Reports of additional thyroid studies performed in some patients were also reviewed. Thyroid abnormalities were present in 19 of 93 (20.4%) patients. They consisted mainly of hypodense lesions categorized as nodules. Multiple nodules were found in 10 patients (52.6%). There was one papillary carcinoma. Thyroid gland lesions may be part of the clinical spectrum of TSC. They are usually asymptomatic. As some cases of thyroid carcinoma have been described in TSC, ultrasound exams are recommended, given that CT is not the gold standard technique for thyroid evaluation.

  9. Comparison of Haller index values calculated with chest radiographs versus CT for pectus excavatum evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, Geetika; Jaju, Alok; Don, Steven; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Keys, Tim [Medical Physics Services Ltd., St Louis, MO (United States)

    2010-11-15

    Pectus excavatum is a common chest wall anomaly in children. Pre-operative imaging for pectus excavatum is performed with CT, which is used to calculate the Haller index to determine the severity of pectus excavatum. To determine the correlation between Haller index values calculated with two-view chest radiographs and those calculated with CT and to determine, with CT as the reference standard, the diagnostic performance of radiographic Haller index for identifying cases that meet imaging criteria for surgical correction of pectus excavatum. For the period 2001-2009, our radiology information system was searched to identify all children who had undergone CT for Haller index calculation. Children who had also undergone two-view chest radiography (CXR) within 6 months of the CT were included in this retrospective study. Two radiologists independently calculated CT Haller index and radiographic Haller index. Data distributions were tested for normality with the Shapiro-Wilk W test. The associations between CT Haller index and radiographic Haller index were determined with the Spearman coefficient of rank correlation. Differences between CT Haller index and radiographic Haller index were tested with the Wilcoxon signed rank test. Haller index values were dichotomized into positive (>3.2) and negative ({<=}3.2) cases. Using CT as the reference standard, the sensitivity, specificity, and accuracy of radiographic Haller index in identifying children who meet imaging criteria for surgery were calculated. CT and CXR for evaluation of pectus excavatum were available for 32 children (25 male; median age 14.5 years). With CT, the median Haller indices for observers 1 and 2 were 3.4 and 3.5 and with CXR 3.5 and 3.5. There were statistically significant correlations between the radiographic Haller index and CT Haller index estimated by the two observers [Spearman correlation coefficient (95% confidence interval) for observer 1 = 0.71 (0.48-0.85, P < 0.01) and for observer 2 = 0

  10. Pediatric chest CT at 70 kVp: a feasibility study in 129 children

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Tilo; Henry, Simon; Faivre, Jean-Baptiste; Colas, Lucie; Santangelo, Teresa; Remy, Jacques [Hospital Calmette, Department of Thoracic Imaging, Lille (France); Duhamel, Alain [Univ. Lille Nord de France, Department of Medical Statistics, Lille (France); Deschildre, Antoine [Hospital Jeanne de Flandre, Department of Pediatric Pulmonology, Lille (France); Remy-Jardin, Martine [Hospital Calmette, Department of Thoracic Imaging, Lille (France); Hospital Calmette, Department of Thoracic Imaging, Lille cedex (France)

    2014-11-15

    Before introducing 70-kVp settings in the low-kilovoltage strategies for pediatric examinations, it was mandatory to demonstrate, at similar dose levels, an equivalence of image quality at 70 kVp and 80 kVp. To assess image quality of chest CT examinations acquired at 70 kVp in comparison with standard scanning at 80 kVp. We prospectively evaluated 129 children with a 70-kVp scanning protocol (group 1). All scanning parameters were kept similar to those usually selected for pediatric standard 80-kVp protocols, except the milliamperage increased by a factor of 1.6 to maintain comparable radiation dose. Image quality of group 1 examinations was compared to that of a paired population scanned at 80 kVp (group 2). The noninferiority hypothesis was fixed at 10% of the mean level of image noise. There was no significant difference in the mean dose length product (DLP) and the volume computed tomography dose index (CTDI{sub vol}) between the groups (DLP: 20.5 ± 5.8 mGy.cm [group 1] vs. 19.7 ± 7.6 mGy.cm [group 2]; P = 0.06) (CTDI{sub vol}: 0.8 ± 0.1 mGy [group 1] vs. 0.8 ± 0.18 mGy [group 2]; P = 0.94). The mean of differences in image noise between group 1 and group 2 examinations was -1.38 (-2.59; -0.18), verifying the noninferiority hypothesis. Subjective image quality did not significantly differ between group 1 and group 2 examinations (P = 0.18). At equivalent radiation dose levels, 70-kVp protocols provide similar image quality to that achievable at 80 kVp. (orig.)

  11. Chest radiography versus chest CT in the evaluation for pulmonary metastases in patients with Wilms' tumor: a retrospective review

    Energy Technology Data Exchange (ETDEWEB)

    Wootton-Gorges, S.L.; Albano, E.A.; Riggs, J.M.; Ihrke, H.; Rumack, C.M.; Strain, J.D. [Colorado Univ., Denver, CO (United States). Dept. of Radiology

    2000-08-01

    Background. Determination of the presence of pulmonary metastases in children with Wilms' tumor is an important part of staging and treatment. We sought to compare the efficacy of chest radiography (CXR) and chest CT in the evaluation for pulmonary metastases in patients with Wilms' tumor. Materials and methods. This retrospective study included 83 children with Wilms' tumor diagnosed between 1980 and 1993. All patients with pulmonary nodules (n = 12) as well as 14 Wilms' tumor patients without pulmonary metastases (control group) had blinded review of the CXR and chest CTs by three pediatric radiologists. Presence, size, and certainty of metastatic diagnosis were recorded. Medical records were reviewed. The remaining 57 patients had review of their medical and imaging records to confirm the absence of pulmonary metastases. Results. Ten of the 12 with pulmonary masses had imaging available for review. Eight had both positive CXR and chest CT examinations. Two patients had pulmonary nodules seen by CT only: one had a right cardiophrenic angle mass and died as a result of liver metastases. The other had a solitary nodule, which proved to be a plasma-cell granuloma. Overall, the CXR and chest CT data concur in 79/81 (98 %). Conclusion. CXR alone appears adequate for the diagnosis or exclusion of pulmonary metastases in patients with Wilms' tumor. (orig.)

  12. Unrequested information from routine diagnostic chest CT predicts future cardiovascular events

    OpenAIRE

    Jacobs, Peter C.; Gondrie, Martijn J; Mali, Willem P.; Oen, Ayke L.; Prokop, Mathias; Grobbee, Diederick E.; van der Graaf, Yolanda

    2011-01-01

    Objectives An increase in the number of CT investigations will likely result in a an increase in unrequested information. Clinical relevance of these findings is unknown. This is the first follow-up study to investigate the prognostic relevance of subclinical coronary (CAC) and aortic calcification (TAC) as contained in routine diagnostic chest CT in a clinical care population. Methods The follow-up of 10,410 subjects (>40 years) from a multicentre, clinical care-based cohort of patients incl...

  13. Pitfalls and artifacts in the interpretation of oncologic PET/CT of the chest

    Science.gov (United States)

    Meirelles, Gustavo de Souza Portes; Capobianco, Julia; de Oliveira, Marco Antônio Condé

    2017-01-01

    PET/CT is widely used for the evaluation of patients with thoracic malignancies. Although the levels of 18F-fluorodeoxyglucose (FDG) uptake are usually high in neoplastic diseases, they can also be physiological, due to artifacts. In addition, FDG uptake can occur in benign conditions such as infectious, inflammatory, and iatrogenic lesions. Furthermore, some malignant tumors, such as adenocarcinoma in situ (formerly known as bronchoalveolar carcinoma) and carcinoid tumors, may not show FDG uptake. Here, we illustrate the main pitfalls and artifacts in the interpretation of the results of oncologic PET/CT of the chest, outlining strategies for avoiding misinterpretation. PMID:28298733

  14. X-ray tube current modulation and patient doses in chest CT.

    Science.gov (United States)

    He, Wenjun; Huda, Walter; Magill, Dennise; Tavrides, Emily; Yao, Hai

    2011-01-01

    The aim of the study was to investigate how patient effective doses vary as a function of X-ray tube projection angle, as well as the patient long axis, and quantify how X-ray tube current modulation affects patient doses in chest CT examinations. Chest examinations were simulated for a gantry CT scanner geometry with projections acquired for a beam width of 4 cm. PCXMC 2.0.1 was used to calculate patient effective doses at 15° intervals around the patient's isocentre, and at nine locations along the patient long axis. Idealised tube current modulation schemes were modelled as a function of the X-ray tube angle and the patient long axis. Tube current modulations were characterised by the modulation amplitude R, which was allowed to vary between 1.5 and 5. Effective dose maxima occur for anteroposterior projections at the location of the (radiosensitive) breasts. The maximum to minimum ratio of effective doses as a function of the patient long axis was 4.9, and as a function of the X-ray tube angle was 2.1. Doubling the value of R reduces effective doses from longitudinal modulation alone by ∼4% and from angular modulation alone by ∼2%. In chest CT, tube current modulation schemes currently have longitudinal R values of ∼2.2, and angular R values that range between 1.5 and 3.4. Current X-ray tube current modulation schemes are expected to reduce patient effective doses in chest CT examinations by ∼10%, with longitudinal modulation accounting for two-thirds and angular modulation for the remaining one-third.

  15. Fetal shielding combined with state of the art CT dose reduction strategies during maternal chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Chatterson, Leslie C., E-mail: lch088@mail.usask.ca [Department of Diagnostic Imaging, University of Saskatchewan (Canada); Leswick, David A.; Fladeland, Derek A. [Department of Diagnostic Imaging, University of Saskatchewan (Canada); Hunt, Megan M.; Webster, Stephen [Saskatchewan Ministry of Labour Relations and Workplace Safety (Canada); Lim, Hyun [Department of Community Health and Epidemiology, College of Medicine, University of Saskatchewan (Canada)

    2014-07-15

    Purpose: Custom bismuth-antimony shields were previously shown to reduce fetal dose by 53% on an 8DR (detector row) CT scanner without dynamic adaptive section collimation (DASC), automatic tube current modulation (ATCM) or adaptive statistical iterative reconstruction (ASiR). The purpose of this study is to compare the effective maternal and average fetal organ dose reduction both with and without bismuth-antimony shields on a 64DR CT scanner using DASC, ATCM and ASiR during maternal CTPA. Materials and methods: A phantom with gravid prosthesis and a bismuth-antimony shield were used. Thermoluminescent dosimeters (TLDs) measured fetal radiation dose. The average fetal organ dose and effective maternal dose were determined using 100 kVp, scanning from the lung apices to the diaphragm utilizing DASC, ATCM and ASiR on a 64DR CT scanner with and without shielding in the first and third trimester. Isolated assessment of DASC was done via comparing a new 8DR scan without DASC to a similar scan on the 64DR with DASC. Results: Average third trimester unshielded fetal dose was reduced from 0.22 mGy ± 0.02 on the 8DR to 0.13 mGy ± 0.03 with the conservative 64DR protocol that included 30% ASiR, DASC and ATCM (42% reduction, P < 0.01). Use of a shield further reduced average third trimester fetal dose to 0.04 mGy ± 0.01 (69% reduction, P < 0.01). The average fetal organ dose reduction attributable to DASC alone was modest (6% reduction from 0.17 mGy ± 0.02 to 0.16 mGy ± 0.02, P = 0.014). First trimester fetal organ dose on the 8DR protocol was 0.07 mGy ± 0.03. This was reduced to 0.05 mGy ± 0.03 on the 64DR protocol without shielding (30% reduction, P = 0.009). Shields further reduced this dose to below accurately detectable levels. Effective maternal dose was reduced from 4.0 mSv on the 8DR to 2.5 mSv on the 64DR scanner using the conservative protocol (38% dose reduction). Conclusion: ASiR, ATCM and DASC combined significantly reduce effective maternal and fetal

  16. Chest CT findings in patients with non-cardiovascular causes of chest pain: Focusing on pulmonary tuberculosis in a tuberculosis endemic country

    Energy Technology Data Exchange (ETDEWEB)

    Lee, So Won; Shim, Sung Shine; Kim, Yoo Kyung; Ryu, Yon Ju [Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

    2015-10-15

    To review the common causes of non-cardiovascular chest pain (NCCP) according to the location and lesion type as seen on chest CT, and to evaluate CT findings in tuberculosis (TB) as a cause of NCCP. In the period 2009 to 2012, patients having NCCP without definitive evidence of acute myocardial infarction, pulmonary thromboembolism, and aortic dissection, were included. In total, 162 patients (60.5% male; 39.5% female), with a mean age of 51 years, were enrolled. CT images were evaluated by location and lesion type, for causes of NCCP. Chest CT revealed that the most common location for the cause of NCCP was the pleura (45.1%), followed by the subpleural lung parenchyma (30.2%). The most common lesion causing NCCP was TB (33.3%), followed by pneumonia (19.1%). Of the 54 TB cases, 40 (74.1%) were stable TB and 14 (25.9%) were active TB; among these 54 patients, NCCP was most commonly the result of fibrotic pleural thickening (55.6%), followed by subpleural stable pulmonary TB (14.8%). Results of chest CT revealed that TB was a major cause of NCCP in a TB endemic area. Among the TB patients, fibrotic pleural thickening in patients with stable TB was the most common cause of NCCP.

  17. CT of the chest in the evaluation of idiopathic pulmonary arterial hypertension in children

    Energy Technology Data Exchange (ETDEWEB)

    Chaudry, Gulraiz [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); MacDonald, Cathy; Gundogan, Munire; Manson, David [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Adatia, Ian [UCSF Children' s Hospital, Department of Pediatric Cardiology, San Francisco, CA (United States)

    2007-04-15

    Idiopathic pulmonary arterial hypertension (IPAH) is a rare disease in children. By definition it is a diagnosis of exclusion, and CT of the chest is primarily performed to exclude other causes. Previous studies have defined CT features suggestive of the diagnosis of IPAH, but these have all been limited to the adult population. Contrast-enhanced chest CT and high-resolution CT findings in IPAH were evaluated in an attempt to define features consistently seen in children with this condition. The chest CT scans performed at initial presentation were reviewed in 17 children with echocardiographic or angiographic evidence of IPAH. There were nine boys and eight girls, ranging in age from 1 month to 17 years. The extrapulmonary findings included cardiomegaly with right-sided cardiac enlargement, which was seen in 13 children. The central pulmonary arteries were enlarged in 15 children, with peripheral enlargement in two. In six children this resulted in bronchial compression. In addition, mediastinal and hilar lymphadenopathy was noted in three children. Prominent intrapulmonary features included a peripheral vasculopathy, with enlarged tortuous vessels, seen in eight children. Ill-defined ground-glass centrilobular opacities were also noted in eight children, representing the most common parenchymal abnormality. Other findings included septal lines in five, diffuse ground-glass opacification in four and focal hyperlucent zones in three. Mosaic attenuation was seen in one child. A variety of imaging findings are identified in IPAH. Features particularly consistent with the diagnosis include peripheral vasculopathy and centrilobular opacities in the setting of cardiomegaly and central pulmonary arterial enlargement. (orig.)

  18. Evaluation of a Chest Circumference-Adapted Protocol for Low-Dose 128-Slice Coronary CT Angiography with Prospective Electrocardiogram Triggering

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chenying; Wang, Zufei; Ji, Jiansong; Wang, Hailin; Hu, Xianghua; Chen, Chunmiao [Department of Radiology, Lishui Central Hospital, The Fifth Affiliated Hospital of Wenzhou Medical College, Lishui, Zhejiang 323000 (China)

    2015-11-01

    To assess the effect of chest circumference-adapted scanning protocol on radiation exposure and image quality in patients undergoing prospective electrocardiogram (ECG)-triggered coronary CT angiography (CCTA). One hundred-eighty-five consecutive patients, who had undergone prospective ECG triggering CCTA with a 128-slice CT, were included in the present study. Nipple-level chest circumference, body weight and height were measured before CT examinations. Patients were divided into four groups based on kV/ref·mAs = 100/200, 100/250, 120/200, and 120/250, when patient's chest circumference was ≤ 85.0 (n = 56), 85.0-90.0 (n = 53), 90.0-95.0 (n = 44), and > 95.0 (n = 32), respectively. Image quality per-segment was independently assessed by two experienced observers. Image noise and attenuation were also measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The effective radiation dose was calculated using CT dose volume index and the dose-length product. A significant correlation was observed between patients' chest circumference and body mass index (r = 0.762, p < 0.001). Chest circumference ranged from 74 to 105 cm, and the mean effective radiation dose was 1.9-3.8 mSv. Diagnostic image quality was obtained in 98.5% (2440/2478) of all evaluated coronary segments without any significant differences among the four groups (p = 0.650). No significant difference in image noise was observed among the four groups (p = 0.439), thus supporting the validity of the chest circumference-adapted scanning protocol. However, vessel attenuation, SNR and CNR were significantly higher in the 100 kV groups than in the 120 kV groups (p < 0.05). A measure of chest circumference can be used to adapt tube voltage and current for individualized radiation dose control, with resultant similar image noise and sustained diagnostic image quality.

  19. A case of catastrophic antiphospholipid syndrome, which presented an acute interstitial pneumonia-like image on chest CT scan.

    Science.gov (United States)

    Kameda, Tomohiro; Dobashi, Hiroaki; Susaki, Kentaro; Danjo, Junichi; Nakashima, Shusaku; Shimada, Hiromi; Izumikawa, Miharu; Takeuchi, Yohei; Mitsunaka, Hiroki; Bandoh, Shuji; Imataki, Osamu; Nose, Masato; Matsunaga, Takuya

    2015-01-01

    We report the case of catastrophic antiphospholipid syndrome (CAPS) complicated with mixed connective tissue disease (MCTD). A female patient was diagnosed with acute interstitial pneumonia (AIP) with MCTD by chest CT scan. Corticosteroid therapy was refractory for lung involvement, and she died due to acute respiratory failure. The autopsy revealed that AIP was compatible with lung involvement of CAPS. We therefore suggest that chest CT might reveal AIP-like findings in CAPS patients whose condition is complicated with pulmonary manifestations.

  20. Blinded Validation of Breath Biomarkers of Lung Cancer, a Potential Ancillary to Chest CT Screening.

    Directory of Open Access Journals (Sweden)

    Michael Phillips

    Full Text Available Breath volatile organic compounds (VOCs have been reported as biomarkers of lung cancer, but it is not known if biomarkers identified in one group can identify disease in a separate independent cohort. Also, it is not known if combining breath biomarkers with chest CT has the potential to improve the sensitivity and specificity of lung cancer screening.Model-building phase (unblinded: Breath VOCs were analyzed with gas chromatography mass spectrometry in 82 asymptomatic smokers having screening chest CT, 84 symptomatic high-risk subjects with a tissue diagnosis, 100 without a tissue diagnosis, and 35 healthy subjects. Multiple Monte Carlo simulations identified breath VOC mass ions with greater than random diagnostic accuracy for lung cancer, and these were combined in a multivariate predictive algorithm. Model-testing phase (blinded validation: We analyzed breath VOCs in an independent cohort of similar subjects (n = 70, 51, 75 and 19 respectively. The algorithm predicted discriminant function (DF values in blinded replicate breath VOC samples analyzed independently at two laboratories (A and B. Outcome modeling: We modeled the expected effects of combining breath biomarkers with chest CT on the sensitivity and specificity of lung cancer screening.Unblinded model-building phase. The algorithm identified lung cancer with sensitivity 74.0%, specificity 70.7% and C-statistic 0.78. Blinded model-testing phase: The algorithm identified lung cancer at Laboratory A with sensitivity 68.0%, specificity 68.4%, C-statistic 0.71; and at Laboratory B with sensitivity 70.1%, specificity 68.0%, C-statistic 0.70, with linear correlation between replicates (r = 0.88. In a projected outcome model, breath biomarkers increased the sensitivity, specificity, and positive and negative predictive values of chest CT for lung cancer when the tests were combined in series or parallel.Breath VOC mass ion biomarkers identified lung cancer in a separate independent cohort

  1. Radiation exposure in CT-guided interventions

    Energy Technology Data Exchange (ETDEWEB)

    Kloeckner, Roman, E-mail: Roman.Kloeckner@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany); Santos, Daniel Pinto dos; Schneider, Jens [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany); Kara, Levent [Department of Radiology, Inselspital Bern, Freiburgstraße 18, 3010 Bern (Switzerland); Dueber, Christoph; Pitton, Michael B. [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany)

    2013-12-01

    Purpose: To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction. Materials and methods: We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series. Results: Eighy-five percent of the total radiation dose was applied during the pre- and post-interventional CT series, leaving only 15% applied by the CT-guided intervention itself. Single slice acquisition was associated with lower doses than continuous CT-fluoroscopy (37 mGy cm vs. 153 mGy cm, p < 0.001). The third quartile of radiation doses varied considerably for different interventions. The highest doses were observed in complex interventions like RFA/MWA of the liver, followed by vertebroplasty and RFA/MWA of the lung. Conclusions: This paper suggests preliminary reference levels for various intervention types and discusses strategies for dose reduction. A multicenter registry of radiation exposure including a broader spectrum of scanners and intervention types is needed to develop definitive reference levels.

  2. Computer-aided diagnosis workstation and database system for chest diagnosis based on multihelical CT images

    Science.gov (United States)

    Sato, Hitoshi; Niki, Noboru; Mori, Kiyoshi; Eguchi, Kenji; Kaneko, Masahiro; Moriyama, Noriyuki; Ohmatsu, Hironobu; Kakinuma, Ryutaro; Masuda, Hideo; Machida, Suguru; Sasagawa, Michizou

    2004-04-01

    Lung cancer is the most common cause, accounting for about 20% of all cancer deaths for males in Japan. Myocardial infarction is also known as a most fearful adult disease. Recently, multi-helical CT scanner advanced remarkably at the speed at which the chest CT images were acquired for screening examination. This screening examination requires a considerable number of images to be read. It is this time-consuming step that makes the use of multi-helical CT for mass screening. To overcome this problem, our group has developed a computer-aided diagnosis algorithm to automatically detect suspicious regions of lung cancer and coronary calcifications in chest CT images, so far. And in this time, our group has developed a newly computer-aided diagnosis workstation and database. These consist in three. First, it is an image processing system to automatically detect suspicious bronchial regions, pulmonary artery regions, plumonary vein regions and myocardial infarction regions at high speed. Second, they are two 1600 x 1200 matrix black and white liquid crystal monitor. Third, it is a terminal of image storage. These are connected mutually on the network. This makes it much easier to read images, since the 3D image of suspicious regions and shadow of suspicious regions can be displayed simultaneously on two 1600 x 1200 matrix liquid crystal monitor. The experimental results indicate that a newly computer-aided diagnosis workstation and database system can be effectively used in clinical practice to increase the speed and accuracy of routine diagnosis.

  3. Reducing radiation dose in CT enterography.

    Science.gov (United States)

    Del Gaizo, Andrew J; Fletcher, Joel G; Yu, Lifeng; Paden, Robert G; Spencer, Garrett Clay; Leng, Shuai; Silva, Annelise M; Fidler, Jeff L; Silva, Alvin C; Hara, Amy K

    2013-01-01

    Computed tomographic (CT) enterography is a diagnostic examination that is increasingly being used to evaluate disorders of the small bowel. An undesirable consequence of CT, however, is patient exposure to ionizing radiation. This is of particular concern with CT enterography because patients tend to be young and require numerous follow-up examinations. There are multiple strategies to reduce radiation dose at CT enterography, including adjusting acquisition parameters, reducing scan length, and reducing tube voltage or tube current. The drawback to dose reduction strategies is degradation of image quality due to increased image noise. However, image noise can be reduced with commercial iterative reconstruction and denoising techniques. With a combination of low-dose techniques and noise-control strategies, one can markedly reduce radiation dose at CT enterography while maintaining diagnostic accuracy.

  4. Cardiovascular disease prediction: do pulmonary disease-related chest CT features have added value?

    Energy Technology Data Exchange (ETDEWEB)

    Jairam, Pushpa M. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Jong, Pim A. de; Mali, Willem P.T.M. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Isgum, Ivana [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Graaf, Yolanda van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Collaboration: PROVIDI study-group

    2015-06-01

    Certain pulmonary diseases are associated with cardiovascular disease (CVD). Therefore we investigated the incremental predictive value of pulmonary, mediastinal and pleural features over cardiovascular imaging findings. A total of 10,410 patients underwent diagnostic chest CT for non-cardiovascular indications. Using a case-cohort approach, we visually graded CTs from the cases and from an approximately 10 % random sample of the baseline cohort (n = 1,203) for cardiovascular, pulmonary, mediastinal and pleural findings. The incremental value of pulmonary disease-related CT findings above cardiovascular imaging findings in cardiovascular event risk prediction was quantified by comparing discrimination and reclassification. During a mean follow-up of 3.7 years (max. 7.0 years), 1,148 CVD events (cases) were identified. Addition of pulmonary, mediastinal and pleural features to a cardiovascular imaging findings-based prediction model led to marginal improvement of discrimination (increase in c-index from 0.72 (95 % CI 0.71-0.74) to 0.74 (95 % CI 0.72-0.75)) and reclassification measures (net reclassification index 6.5 % (p < 0.01)). Pulmonary, mediastinal and pleural features have limited predictive value in the identification of subjects at high risk of CVD events beyond cardiovascular findings on diagnostic chest CT scans. (orig.)

  5. Which Iodine concentration in chest CT? - A prospective study in 300 patients

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenbruch, Georg [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Aachen (Germany); University Hospital, RWTH Aachen University, Aachen (Germany); Behrendt, Florian F.; Eddahabi, Mohammed A.; Das, Marco; Guenther, Rolf W.; Mahnken, Andreas H. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Aachen (Germany); Knackstedt, Christian [RWTH Aachen University Hospital, Department of Cardiology, Pulmonology and Angiology, Aachen (Germany); Stanzel, Sven [RWTH Aachen University Hospital, Institute of Medical Statistics, Aachen (Germany); Seidensticker, Peter [Bayer Schering Pharma AG, Berlin (Germany); Wildberger, Joachim E. [University Hospital Maastricht, Department of Radiology, Maastricht (Netherlands)

    2008-12-15

    In computed tomography(CT) several contrast media with different iodine concentrations are available. The aim of this study is to prospectively compare contrast media with iodine concentrations of 300, 370 and 400 mg iodine/ml for chest- CT. 300 consecutive patients were prospectively enrolled, under a waiver of the local ethics committee. The first (second, third) 100 patients, received contrast medium with 300(370, 400)mg iodine/ml. Injection protocols were adapted for an identical iodine delivery rate(1.3 mg/s) and total iodine load(33 g) for all three groups. Standardized MDCT of the chest (16 x 0.75 mm, 120 kVp, 100 mAseff.) was performed. Intravascular attenuation values were measured in the pulmonary trunk and the ascending aorta; subjective image quality was rated on a 3-point-scale. Discomfort during and after injection was evaluated. There were no statistically significant differences in contrast enhancement comparing the three contrast media at the pulmonary trunk(p = 0.3198) and at the ascending aorta(p = 0.0840). Image quality(p = 0.0176) and discomfort during injection(p = 0.7034) were comparable for all groups. General discomfort after injection of contrast media with 300 mg iodine/ml was statistically significant higher compared to 370 mg iodine/ml(p = 0.00019). Given identical iodine delivery rates of 1.3 g/s and iodine loads of 33 g, contrast media with concentrations of 300, 370 and 400 mg iodine/ml do not result in different intravascular enhancement in chest-CT. (orig.)

  6. Patient-specific dose calculations for pediatric CT of the chest, abdomen and pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Kost, Susan D.; Carver, Diana E.; Stabin, Michael G. [Vanderbilt University, Physics and Astronomy Department, Nashville, TN (United States); Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Fraser, Nicholas D.; Pickens, David R.; Price, Ronald R.; Hernanz-Schulman, Marta [Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States)

    2015-11-15

    Organ dose is essential for accurate estimates of patient dose from CT. To determine organ doses from a broad range of pediatric patients undergoing diagnostic chest-abdomen-pelvis CT and investigate how these relate to patient size. We used a previously validated Monte Carlo simulation model of a Philips Brilliance 64 multi-detector CT scanner (Philips Healthcare, Best, The Netherlands) to calculate organ doses for 40 pediatric patients (M:F = 21:19; range 0.6-17 years). Organ volumes and positions were determined from the images using standard segmentation techniques. Non-linear regression was performed to determine the relationship between volume CT dose index (CTDI{sub vol})-normalized organ doses and abdominopelvic diameter. We then compared results with values obtained from independent studies. We found that CTDI{sub vol}-normalized organ dose correlated strongly with exponentially decreasing abdominopelvic diameter (R{sup 2} > 0.8 for most organs). A similar relationship was determined for effective dose when normalized by dose-length product (R{sup 2} = 0.95). Our results agreed with previous studies within 12% using similar scan parameters (e.g., bowtie filter size, beam collimation); however results varied up to 25% when compared to studies using different bowtie filters. Our study determined that organ doses can be estimated from measurements of patient size, namely body diameter, and CTDI{sub vol} prior to CT examination. This information provides an improved method for patient dose estimation. (orig.)

  7. Chest computed tomography-based scoring of thoracic sarcoidosis: Inter-rater reliability of CT abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Heuvel, D.A.V. den; Es, H.W. van; Heesewijk, J.P. van; Spee, M. [St. Antonius Hospital Nieuwegein, Department of Radiology, Nieuwegein (Netherlands); Jong, P.A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Zanen, P.; Grutters, J.C. [University Medical Center Utrecht, Division Heart and Lungs, Utrecht (Netherlands); St. Antonius Hospital Nieuwegein, Center of Interstitial Lung Diseases, Department of Pulmonology, Nieuwegein (Netherlands)

    2015-09-15

    To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis. CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented. Median age of the 51 patients (36 men, 70 %) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities. In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings. (orig.)

  8. [What are the tools for post-occupational follow-up, how should they be performed and what are their performance, limits and benefit/risk ratio? Chest X-Ray and CT scan].

    Science.gov (United States)

    Ferretti, G

    2011-06-01

    Chest radiography and computed tomography (CT) are the two radiological techniques used for the follow-up of people exposed to asbestos. Since the last conference of consensus (1999), the scientific literature has primarily covered high-resolution CT and high-resolution volume CT (HR-VCT). We consider in turn the contribution of digital thoracic radiography, recommendations for the performance of HR-VCT to ensure the quality of examination while controlling the delivered radiation dose, and the need to refer to the "CT atlas of benign diseases related to asbestos exposure", published by a group of French experts in 2007, for interpretation. The results of the published studies concerning radiography or CT are then reviewed. We note the great interobserver variability in the recognition of pleural plaques and asbestosis, indicating the need for adequate training of radiologists, and the importance of defining standardized, quantified criteria for CT abnormalities. The very low agreement between thoracic and general radiologists must be taken into account. The reading of CT scans in cases of occupational exposure to asbestos should be entrusted to thoracic radiologists or to general radiologists having validated specific training. A double interpretation of CT could be considered in medicosocial requests. CT is more sensitive than chest radiography in the detection of bronchial carcinoma but generates a great number of false positive results (96 to 99%). No scientific data are available to assess the role of imaging by either CT or chest radiography in the early detection of mesothelioma.

  9. Interactive lung segmentation in abnormal human and animal chest CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Kockelkorn, Thessa T. J. P., E-mail: thessa@isi.uu.nl; Viergever, Max A. [Image Sciences Institute, University Medical Center Utrecht, 3584 CX Utrecht (Netherlands); Schaefer-Prokop, Cornelia M. [Department of Radiology, Meander Medical Centre, 3813 TZ Amersfoort, The Netherlands and Diagnostic Image Analysis Group, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen (Netherlands); Bozovic, Gracijela [Center for Diagnostic Imaging and Physiology, Skåne University Hospital, Lund University, SE-221 85 Lund (Sweden); Muñoz-Barrutia, Arrate [Cancer Imaging Laboratory, Center for Applied Medical Research, University of Navarra, ES-31008 Pamplona, Navarra (Spain); Rikxoort, Eva M. van [Diagnostic Image Analysis Group, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen (Netherlands); Brown, Matthew S. [Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, David Geffen School of Medicine at UCLA, University of California, Los Angeles, California 90024 (United States); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, 3584 CX Utrecht (Netherlands); Ginneken, Bram van [Diagnostic Image Analysis Group, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen (Netherlands); Image Sciences Institute, University Medical Center Utrecht, 3584 CX Utrecht (Netherlands)

    2014-08-15

    Purpose: Many medical image analysis systems require segmentation of the structures of interest as a first step. For scans with gross pathology, automatic segmentation methods may fail. The authors’ aim is to develop a versatile, fast, and reliable interactive system to segment anatomical structures. In this study, this system was used for segmenting lungs in challenging thoracic computed tomography (CT) scans. Methods: In volumetric thoracic CT scans, the chest is segmented and divided into 3D volumes of interest (VOIs), containing voxels with similar densities. These VOIs are automatically labeled as either lung tissue or nonlung tissue. The automatic labeling results can be corrected using an interactive or a supervised interactive approach. When using the supervised interactive system, the user is shown the classification results per slice, whereupon he/she can adjust incorrect labels. The system is retrained continuously, taking the corrections and approvals of the user into account. In this way, the system learns to make a better distinction between lung tissue and nonlung tissue. When using the interactive framework without supervised learning, the user corrects all incorrectly labeled VOIs manually. Both interactive segmentation tools were tested on 32 volumetric CT scans of pigs, mice and humans, containing pulmonary abnormalities. Results: On average, supervised interactive lung segmentation took under 9 min of user interaction. Algorithm computing time was 2 min on average, but can easily be reduced. On average, 2.0% of all VOIs in a scan had to be relabeled. Lung segmentation using the interactive segmentation method took on average 13 min and involved relabeling 3.0% of all VOIs on average. The resulting segmentations correspond well to manual delineations of eight axial slices per scan, with an average Dice similarity coefficient of 0.933. Conclusions: The authors have developed two fast and reliable methods for interactive lung segmentation in

  10. Automated segmentation of cardiac visceral fat in low-dose non-contrast chest CT images

    Science.gov (United States)

    Xie, Yiting; Liang, Mingzhu; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

    2015-03-01

    Cardiac visceral fat was segmented from low-dose non-contrast chest CT images using a fully automated method. Cardiac visceral fat is defined as the fatty tissues surrounding the heart region, enclosed by the lungs and posterior to the sternum. It is measured by constraining the heart region with an Anatomy Label Map that contains robust segmentations of the lungs and other major organs and estimating the fatty tissue within this region. The algorithm was evaluated on 124 low-dose and 223 standard-dose non-contrast chest CT scans from two public datasets. Based on visual inspection, 343 cases had good cardiac visceral fat segmentation. For quantitative evaluation, manual markings of cardiac visceral fat regions were made in 3 image slices for 45 low-dose scans and the Dice similarity coefficient (DSC) was computed. The automated algorithm achieved an average DSC of 0.93. Cardiac visceral fat volume (CVFV), heart region volume (HRV) and their ratio were computed for each case. The correlation between cardiac visceral fat measurement and coronary artery and aortic calcification was also evaluated. Results indicated the automated algorithm for measuring cardiac visceral fat volume may be an alternative method to the traditional manual assessment of thoracic region fat content in the assessment of cardiovascular disease risk.

  11. Alternative diagnoses based on CT angiography of the chest in patients with suspected pulmonary thromboembolism

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Eleci Vaz; Gazzana, Marcelo Basso; Seligman, Renato; Knorst, Marli Maria, E-mail: mknorst@gmail.com [Hospital de Clinicas de Porto Alegre, Porto Alegre, RS (Brazil); Guerra, Vinicius Andre [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil). Faculdade de Medicina. Programa de Pos-Graduacao em Ciencias Pneumologicas; Sarmento, Muriel Bossle; Guazzelli, Pedro Arends; Hoffmeister, Mariana Costa [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre (Brazil). Faculdade de Medicina

    2016-01-15

    Objective: To determine the prevalence of alternative diagnoses based on chest CT angiography (CTA) in patients with suspected pulmonary thromboembolism (PTE) who tested negative for PTE, as well as whether those alternative diagnoses had been considered prior to the CTA. Methods: This was a cross-sectional, retrospective study involving 191 adult patients undergoing CTA for suspected PTE between September of 2009 and May of 2012. Chest X-rays and CTAs were reviewed to determine whether the findings suggested an alternative diagnosis in the cases not diagnosed as PTE. Data on symptoms, risk factors, comorbidities, length of hospital stay, and mortality were collected. Results: On the basis of the CTA findings, PTE was diagnosed in 47 cases (24.6%). Among the 144 patients not diagnosed with PTE via CTA, the findings were abnormal in 120 (83.3%). Such findings were consistent with an alternative diagnosis that explained the symptoms in 75 patients (39.3%). Among those 75 cases, there were only 39 (20.4%) in which the same alterations had not been previously detected on chest X-rays. The most common alternative diagnosis, made solely on the basis of the CTA findings, was pneumonia (identified in 20 cases). Symptoms, risk factors, comorbidities, and the in-hospital mortality rate did not differ significantly between the patients with and without PTE. However, the median hospital stay was significantly longer in the patients with PTE than in those without (18.0 and 9.5 days, respectively; p = 0.001). Conclusions: Our results indicate that chest CTA is useful in cases of suspected PTE, because it can confirm the diagnosis and reveal findings consistent with an alternative diagnosis in a significant number of patients. (author)

  12. Alternative diagnoses based on CT angiography of the chest in patients with suspected pulmonary thromboembolism

    Science.gov (United States)

    Ferreira, Eleci Vaz; Gazzana, Marcelo Basso; Sarmento, Muriel Bossle; Guazzelli, Pedro Arends; Hoffmeister, Mariana Costa; Guerra, Vinicius André; Seligman, Renato; Knorst, Marli Maria

    2016-01-01

    Objective : To determine the prevalence of alternative diagnoses based on chest CT angiography (CTA) in patients with suspected pulmonary thromboembolism (PTE) who tested negative for PTE, as well as whether those alternative diagnoses had been considered prior to the CTA. Methods : This was a cross-sectional, retrospective study involving 191 adult patients undergoing CTA for suspected PTE between September of 2009 and May of 2012. Chest X-rays and CTAs were reviewed to determine whether the findings suggested an alternative diagnosis in the cases not diagnosed as PTE. Data on symptoms, risk factors, comorbidities, length of hospital stay, and mortality were collected. Results : On the basis of the CTA findings, PTE was diagnosed in 47 cases (24.6%). Among the 144 patients not diagnosed with PTE via CTA, the findings were abnormal in 120 (83.3%). Such findings were consistent with an alternative diagnosis that explained the symptoms in 75 patients (39.3%). Among those 75 cases, there were only 39 (20.4%) in which the same alterations had not been previously detected on chest X-rays. The most common alternative diagnosis, made solely on the basis of the CTA findings, was pneumonia (identified in 20 cases). Symptoms, risk factors, comorbidities, and the in-hospital mortality rate did not differ significantly between the patients with and without PTE. However, the median hospital stay was significantly longer in the patients with PTE than in those without (18.0 and 9.5 days, respectively; p = 0.001). Conclusions : Our results indicate that chest CTA is useful in cases of suspected PTE, because it can confirm the diagnosis and reveal findings consistent with an alternative diagnosis in a significant number of patients. PMID:26982039

  13. Alternative diagnoses based on CT angiography of the chest in patients with suspected pulmonary thromboembolism

    Directory of Open Access Journals (Sweden)

    Eleci Vaz Ferreira

    2016-02-01

    Full Text Available Objective : To determine the prevalence of alternative diagnoses based on chest CT angiography (CTA in patients with suspected pulmonary thromboembolism (PTE who tested negative for PTE, as well as whether those alternative diagnoses had been considered prior to the CTA. Methods : This was a cross-sectional, retrospective study involving 191 adult patients undergoing CTA for suspected PTE between September of 2009 and May of 2012. Chest X-rays and CTAs were reviewed to determine whether the findings suggested an alternative diagnosis in the cases not diagnosed as PTE. Data on symptoms, risk factors, comorbidities, length of hospital stay, and mortality were collected. Results : On the basis of the CTA findings, PTE was diagnosed in 47 cases (24.6%. Among the 144 patients not diagnosed with PTE via CTA, the findings were abnormal in 120 (83.3%. Such findings were consistent with an alternative diagnosis that explained the symptoms in 75 patients (39.3%. Among those 75 cases, there were only 39 (20.4% in which the same alterations had not been previously detected on chest X-rays. The most common alternative diagnosis, made solely on the basis of the CTA findings, was pneumonia (identified in 20 cases. Symptoms, risk factors, comorbidities, and the in-hospital mortality rate did not differ significantly between the patients with and without PTE. However, the median hospital stay was significantly longer in the patients with PTE than in those without (18.0 and 9.5 days, respectively; p = 0.001. Conclusions : Our results indicate that chest CTA is useful in cases of suspected PTE, because it can confirm the diagnosis and reveal findings consistent with an alternative diagnosis in a significant number of patients.

  14. THE DIAGNOSTIC ACCURACY OF CHEST CT IN THE DETECTION OF TUMOR AND NODAL STATUS IN NON SMALL CELL LUNG CARCINOMA

    Directory of Open Access Journals (Sweden)

    Aziza Icksan

    2003-12-01

    Full Text Available At this time there is an increasing demand for an accurate preoperative staging in non small cell lung cancer. Chest Computed Tomography (CT is one of the imaging modality of choice used for this purpose. This study evaluated the accuracy of the chest CT to determine the status of the tumor and nodules in non small cell lung cancer. During the years 1998 and 1999, a descriptive prospective study of 32 patients undergoing a contrast enhanced chest CT examination for non small cell lung cancer, stage I-IIIA, was conducted. Lobectomy, lymph nodes dissection and postoperative histo-pathological examination were done. CT findings were as follows: a sensitivity of 100%, a specificity of 25% and an accuracy of 60% in the detection of the nodule stage were found. In 17 patients with adeno-carcinoma, the sensitivity, the specificity and the accuracy were 86.6%, 100% and 88.2% respectively. The diagnosis of all patients was confirmed histo-pathologically. Six patients with T2 and 26 patients with T3 were detected by chest CT; the accuracy of the tumor status was 93.7%, confirmed by surgical and histo-pathological examinations. It was concluded that the CT played an important role in determining the clinical stage of non small cell lung cancer. The specificity and accuracy were higher in adeno-carcinoma as compared with squamous cell carcinoma in detecting the nodal status.

  15. Long-Term Clinical Impact of Coronary CT Angiography in Patients With Recent Acute-Onset Chest Pain

    DEFF Research Database (Denmark)

    Linde, Jesper J; Hove, Jens D; Sørgaard, Mathias

    2015-01-01

    was a composite of cardiac death, myocardial infarction (MI), hospitalization for unstable angina pectoris (UAP), late symptom-driven revascularizations, and readmission for chest pain. RESULTS: We randomized 299 patients to coronary CTA-guided strategy and 301 to standard care. After inclusion, 24 patients......OBJECTIVES: The aim of the CATCH (CArdiac cT in the treatment of acute CHest pain) trial was to investigate the long-term clinical impact of a coronary computed tomographic angiography (CTA)-guided treatment strategy in patients with recent acute-onset chest pain compared to standard care....... BACKGROUND: The prognostic implications of a coronary CTA-guided treatment strategy have not been compared in a randomized fashion to standard care in patients referred for acute-onset chest pain. METHODS: Patients with acute chest pain but normal electrocardiograms and troponin values were randomized...

  16. Measurement of radiation dose to ovaries from CT of the head and trunk

    Energy Technology Data Exchange (ETDEWEB)

    Al-Habdhan, M.A.M.; Kinsara, A.R. [King Abdul Aziz Univ., Nuclear Engineering Dept., Jeddah (Saudi Arabia)

    2001-07-01

    With the rise in concern about doses received by patients over recent years, there has been a growing requirement for information on typical doses and the range of dose received during Computerized Tomography (CT). This study was performed for the assessment of radiation dose to the ovaries from various CT protocols for head and trunk imaging. Thermo luminescent dosimeters (TLD) were used for the dosimetry measurement in an anthropomorphic Rando Alderson phantom. The wanted (obligatory) and unwanted (non-useful) radiation doses delivered to the ovaries during CT examinations of head, facial bone, orbits, abdomen, chest, pelvis, neck, nasopharynx, cervical spine, lumber spine and sacroiliac joint were assessed. The results are compared with the corresponding values published in the literature. A comparison of the received dose from CT examinations and general radiography examinations by the ovaries was made. It is found that relatively high doses of unwanted radiation are delivered with computerized tomography. (author)

  17. Unrequested information from routine diagnostic chest CT predicts future cardiovascular events

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Peter C. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Universiteitsweg 100, P.O. Box 85500, GA, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, CX, Utrecht (Netherlands); Gondrie, Martijn J.; Grobbee, Diederick E.; Graaf, Yolanda van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Universiteitsweg 100, P.O. Box 85500, GA, Utrecht (Netherlands); Mali, Willem P. [University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, CX, Utrecht (Netherlands); Oen, Ayke L. [Elkerliek Medical Center Helmond, Department of Radiology, Wesselmanlaan 25, HA, Helmond (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Center, Department of Radiology, Geert Grooteplein Zuid 10, GA, Nijmegen (Netherlands)

    2011-08-15

    An increase in the number of CT investigations will likely result in a an increase in unrequested information. Clinical relevance of these findings is unknown. This is the first follow-up study to investigate the prognostic relevance of subclinical coronary (CAC) and aortic calcification (TAC) as contained in routine diagnostic chest CT in a clinical care population. The follow-up of 10,410 subjects (>40 years) from a multicentre, clinical care-based cohort of patients included 240 fatal to 275 non-fatal cardiovascular disease (CVD) events (mean follow-up 17.8 months). Patients with a history of CVD were excluded. Coronary (0-12) and aortic calcification (0-8) were semi-quantitatively scored. We used Cox proportional-hazard models to compute hazard ratios to predict CVD events. CAC and TAC were significantly and independently predictive of CVD events. Compared with subjects with no calcium, the adjusted risk of a CVD event was 3.7 times higher (95% CI, 2.7-5.2) among patients with severe coronary calcification (CAC score {>=}6) and 2.7 times higher (95% CI, 2.0-3.7) among patients with severe aortic calcification (TAC score {>=}5). Subclinical vascular calcification on CT is a strong predictor of incident CVD events in a routine clinical care population. (orig.)

  18. Mosaic Pattern of Lung Attenuation on Chest CT in Patients with Pulmonary Hypertension

    Directory of Open Access Journals (Sweden)

    Kamonpun Ussavarungsi

    2015-09-01

    Full Text Available A mosaic pattern of lung attenuation on chest computed tomography (CT may be due to various etiologies. There is limited published data on CT results when used to evaluate pulmonary hypertension (PH. We retrospectively studied the frequency of mosaic pattern in patients with PH and the cause of the PH by diagnostic group, as well as the correlation between the mosaic pattern and the following: demographics, severity of the PH, main pulmonary artery (PA size, PA/aorta (PA/Ao ratio, pulmonary function tests (PFT, and ventilation perfusion scan results. Overall, 18% of the cohort had CT mosaic pattern (34/189. Mosaic pattern was present in 17/113 (15% in Group 1 pulmonary arterial hypertension, 5/13 (28% in Group 2 pulmonary venous hypertension and 8/50 (16% in Group 3 PH. Conversely, Group 4 chronic thromboembolic PH was more prevalent in 4/8 (50%. Main PA size, PA/Ao ratio, and segmental perfusion defect were positively associated with mosaic pattern. In contrast, factors such as age, gender, body mass index, functional class, hemodynamic data, and PFT values were not associated with mosaic pattern. Mosaic pattern is not specific as an isolated finding for distinguishing the subtype of PH.

  19. Automated Image Retrieval of Chest CT Images Based on Local Grey Scale Invariant Features.

    Science.gov (United States)

    Arrais Porto, Marcelo; Cordeiro d'Ornellas, Marcos

    2015-01-01

    Textual-based tools are regularly employed to retrieve medical images for reading and interpretation using current retrieval Picture Archiving and Communication Systems (PACS) but pose some drawbacks. All-purpose content-based image retrieval (CBIR) systems are limited when dealing with medical images and do not fit well into PACS workflow and clinical practice. This paper presents an automated image retrieval approach for chest CT images based local grey scale invariant features from a local database. Performance was measured in terms of precision and recall, average retrieval precision (ARP), and average retrieval rate (ARR). Preliminary results have shown the effectiveness of the proposed approach. The prototype is also a useful tool for radiology research and education, providing valuable information to the medical and broader healthcare community.

  20. Automated coronary artery calcification detection on low-dose chest CT images

    Science.gov (United States)

    Xie, Yiting; Cham, Matthew D.; Henschke, Claudia; Yankelevitz, David; Reeves, Anthony P.

    2014-03-01

    Coronary artery calcification (CAC) measurement from low-dose CT images can be used to assess the risk of coronary artery disease. A fully automatic algorithm to detect and measure CAC from low-dose non-contrast, non-ECG-gated chest CT scans is presented. Based on the automatically detected CAC, the Agatston score (AS), mass score and volume score were computed. These were compared with scores obtained manually from standard-dose ECG-gated scans and low-dose un-gated scans of the same patient. The automatic algorithm segments the heart region based on other pre-segmented organs to provide a coronary region mask. The mitral valve and aortic valve calcification is identified and excluded. All remaining voxels greater than 180HU within the mask region are considered as CAC candidates. The heart segmentation algorithm was evaluated on 400 non-contrast cases with both low-dose and regular dose CT scans. By visual inspection, 371 (92.8%) of the segmentations were acceptable. The automated CAC detection algorithm was evaluated on 41 low-dose non-contrast CT scans. Manual markings were performed on both low-dose and standard-dose scans for these cases. Using linear regression, the correlation of the automatic AS with the standard-dose manual scores was 0.86; with the low-dose manual scores the correlation was 0.91. Standard risk categories were also computed. The automated method risk category agreed with manual markings of gated scans for 24 cases while 15 cases were 1 category off. For low-dose scans, the automatic method agreed with 33 cases while 7 cases were 1 category off.

  1. Model-based iterative reconstruction in pediatric chest CT: assessment of image quality in a prospective study of children with cystic fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Mieville, Frederic A.; Bochud, Francois O.; Verdun, Francis R. [Lausanne University Hospital, Institute of Radiation Physics, Lausanne (Switzerland); Berteloot, Laureline; Brunelle, Francis [Necker Children' s Hospital of Paris and University of Paris Descartes, Department of Pediatric Radiology, Paris (France); Grandjean, Albane; Ayestaran, Paul [General Electric Medical Systems Europe, Paris (France); Gudinchet, Francois; Schmidt, Sabine [Lausanne University Hospital, Department of Radiology, Lausanne (Switzerland)

    2013-03-15

    The potential effects of ionizing radiation are of particular concern in children. The model-based iterative reconstruction VEO trademark is a technique commercialized to improve image quality and reduce noise compared with the filtered back-projection (FBP) method. To evaluate the potential of VEO trademark on diagnostic image quality and dose reduction in pediatric chest CT examinations. Twenty children (mean 11.4 years) with cystic fibrosis underwent either a standard CT or a moderately reduced-dose CT plus a minimum-dose CT performed at 100 kVp. Reduced-dose CT examinations consisted of two consecutive acquisitions: one moderately reduced-dose CT with increased noise index (NI = 70) and one minimum-dose CT at CTDI{sub vol} 0.14 mGy. Standard CTs were reconstructed using the FBP method while low-dose CTs were reconstructed using FBP and VEO. Two senior radiologists evaluated diagnostic image quality independently by scoring anatomical structures using a four-point scale (1 = excellent, 2 = clear, 3 = diminished, 4 = non-diagnostic). Standard deviation (SD) and signal-to-noise ratio (SNR) were also computed. At moderately reduced doses, VEO images had significantly lower SD (P < 0.001) and higher SNR (P < 0.05) in comparison to filtered back-projection images. Further improvements were obtained at minimum-dose CT. The best diagnostic image quality was obtained with VEO at minimum-dose CT for the small structures (subpleural vessels and lung fissures) (P < 0.001). The potential for dose reduction was dependent on the diagnostic task because of the modification of the image texture produced by this reconstruction. At minimum-dose CT, VEO enables important dose reduction depending on the clinical indication and makes visible certain small structures that were not perceptible with filtered back-projection. (orig.)

  2. Microstructure analysis of the pulmonary acinus using a synchrotron radiation CT

    Science.gov (United States)

    Tokumoto, Y.; Minami, K.; Kawata, Y.; Niki, N.; Umetani, K.; Nakano, Y.; Sakai, H.; Ohmatsu, H.; Itoh, H.

    2015-03-01

    Conversion of images at micro level of normal and with very early stage disease of the lung and quantitative analysis of morphology on CT image can contribute to the chest image diagnosis to the next generation. Previous, anatomy and pathology analysis of pulmonary lobule have been conducted to better understand the CT image of peripheral lung tissue disease. However, it is difficult to figure out three-dimensional (3D) conformation because of analyzing at the slice image. The purpose of this study is a 3D microstructual and quantitative analyses of pulmonary acinus with spatial resolution in the range of several micrometers by using a synchrotron radiation micro CT (SRμCT). In this paper, we present a semi-automatic method for segmenting the secondary pulmonary lobule into acinus or subacinus and extracting small vessel in human acinus imaged by the SRμCT.

  3. The impact of CT radiation dose reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring

    NARCIS (Netherlands)

    Willemink, M.J.; Takx, R.A.P.; Jong, P.A. de; Budde, R.P.; Bleys, R.L.; Das, M.; Wildberger, J.E.; Prokop, M.; Buls, N.; Mey, J. de; Schilham, A.M.; Leiner, T.

    2014-01-01

    o analyse the effects of radiation dose reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS).Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four dose levels us

  4. Diagnostic image quality of a comprehensive high-pitch dual-spiral cardiothoracic CT protocol in patients with undifferentiated acute chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Bamberg, Fabian, E-mail: fbamberg@med.lmu.de [Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich (Germany); Marcus, Roy; Sommer, Wieland; Schwarz, Florian; Nikolaou, Konstantin; Becker, Christoph R.; Reiser, Maximilian F.; Johnson, Thorsten R.C. [Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich (Germany)

    2012-12-15

    Objective: To evaluate diagnostic image quality of high-pitch dual source comprehensive cardiothoracic CT protocol in patients presenting with acute undifferentiated chest pain. Materials and methods: Consecutive symptomatic subjects (n = 51) with undifferentiated acute chest pain underwent ECG-synchronized high-pitch dual-spiral chest CT angiography (Definition Flash, Siemens Medical Solutions, 2 × 100 kVp or 2 × 120 kV if BMI > 30, collimation: 128 × 0.6 mm, pitch: 3.2). Independent investigators determined the image quality of each cardiac and pulmonary vessel segment, measured contrast-to-noise-ratio (CNR), and determined radiation exposure. In addition, the prevalence of CT findings (pulmonary embolism (PE), aortic dissection (AD) and significant coronary stenosis (≥50%)) was determined. Univariate and multivariate analysis were performed to determine the subpopulation with highest diagnostic quality. Results: Among 51 subjects (66% male, average age: 63 ± 15.8), the prevalence of positive CT findings was moderate (overall: 11.7%). Overall, image quality of the pulmonary, aortic and coronary vasculature was good (1.26 ± 0.43 and CNR: 2.52) with an average radiation dose of 3.82 mSv and 3.2% of segments rated non-evaluable. The image quality was lowest in the coronary arteries (p = 0.02), depending on the heart rate (r = 0.52, p < 0.001). In subjects with a heart rate of ≤65 bpm (n = 30) subjective image quality and CNR of the coronary arteries were higher (1.6 ± 0.5 vs. 2.1 ± 0.5, p = 0.03 and 1.21 ± 0.3 vs. 1.02 ± 0.3, p = 0.05) with only 1.5% segments classified as non-evaluable. Conclusion: High-pitch dual-spiral comprehensive cardiothoracic CT provides low radiation exposure with excellent image quality at heart rates ≤65 bpm. In subjects with higher heart rates, image quality of the aortic and pulmonary vasculature remains excellent, while the assessment of the coronary arteries degrades substantially.

  5. Segmentation of the sternum from low-dose chest CT images

    Science.gov (United States)

    Liu, Shuang; Xie, Yiting; Reeves, Anthony P.

    2015-03-01

    Segmentation of the sternum in medical images is of clinical significance as it frequently serves as a stable reference to image registration and segmentation of other organs in the chest region. In this paper we present a fully automated algorithm to segment the sternum in low-dose chest CT images (LDCT). The proposed algorithm first locates an axial seed slice and then segments the sternum cross section on the seed slice by matching a rectangle model. Furthermore, it tracks and segments the complete sternum in the cranial and caudal direction respectively through sequential axial slices starting from the seed slice. The cross section on each axial slice is segmented using score functions that are designed to have local maxima at the boundaries of the sternum. Finally, the sternal angle is localized. The algorithm is designed to be specifically robust with respect to cartilage calcifications and to accommodate the high noise levels encountered with LDCT images. Segmentation of 351 cases from public datasets was evaluated visually with only 1 failing to produce a usable segmentation. 87.2% of the 351 images have good segmentation and 12.5% have acceptable segmentation. The sternal body segmentation and the localization of the sternal angle and the vertical extents of the sternum were also evaluated quantitatively for 25 good cases and 25 acceptable cases. The overall weighted mean DC of 0.897 and weighted mean distance error of 2.88 mm demonstrate that the algorithm achieves encouraging performance in both segmenting the sternal body and localizing the sternal angle.

  6. A clinical evaluation of total variation-Stokes image reconstruction strategy for low-dose CT imaging of the chest

    Science.gov (United States)

    Liu, Yan; Zhang, Hao; Moore, William; Bhattacharji, Priya; Liang, Zhengrong

    2015-03-01

    One hundred "normal-dose" computed tomography (CT) studies of the chest (i.e., 1,160 projection views, 120kVp, 100mAs) data sets were acquired from the patients who were scheduled for lung biopsy at Stony Brook University Hospital under informed consent approved by our Institutional Review Board. To mimic low-dose CT imaging scenario (i.e., sparse-view scan), sparse projection views were evenly extracted from the total 1,160 projections of each patient and the total radiation dose was reduced according to how many sparse views were selected. A standard filtered backprojection (FBP) algorithm was applied to the 1160 projections to produce reference images for comparison purpose. In the low-dose scenario, both the FBP and total variation-stokes (TVS) algorithms were applied to reconstruct the corresponding low-dose images. The reconstructed images were evaluated by an experienced thoracic radiologist against the reference images. Both the low-dose reconstructions and the reference images were displayed on a 4- megapixel monitor in soft tissue and lung windows. The images were graded by a five-point scale from 0 to 4 (0, nondiagnostic; 1, severe artifact with low confidence; 2, moderate artifact or moderate diagnostic confidences; 3, mild artifact or high confidence; 4, well depicted without artifacts). Quantitative evaluation measurements such as standard deviations for different tissue types and universal quality index were also studied and reported for the results. The evaluation concluded that the TVS can reduce the view number from 1,160 to 580 with slightly lower scores as the reference, resulting in a dose reduction to close 50%.

  7. Fat quantification and analysis of lung transplant patients on unenhanced chest CT images based on standardized anatomic space

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.; Wu, Caiyun; Christie, Jason; Lederer, David J.

    2016-03-01

    Chest fat estimation is important for identifying high-risk lung transplant candidates. In this paper, an approach to chest fat quantification based on a recently formulated concept of standardized anatomic space (SAS) is presented. The goal of this paper is to seek answers to the following questions related to chest fat quantification on single slice versus whole volume CT, which have not been addressed in the literature. What level of correlation exists between total chest fat volume and fat areas measured on single abdominal and thigh slices? What is the anatomic location in the chest where maximal correlation of fat area with fat volume can be expected? Do the components of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) have the same area-to-volume correlative behavior or do they differ? The SAS approach includes two steps: calibration followed by transformation which will map the patient slice locations non-linearly to SAS. The optimal slice locations found for SAT and VAT based on SAS are different and at the mid-level of the T8 vertebral body for SAT and mid-level of the T7 vertebral body for VAT. Fat volume and area on optimal slices for SAT and VAT are correlated with Pearson correlation coefficients of 0.97 and 0.86, respectively. The correlation of chest fat volume with abdominal and thigh fat areas is weak to modest.

  8. Radiation Doses of Dual-Energy CT for Abdominopelvic CT: Comparison with Single-Energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Seo; Jeong, Woo Kyoung; Kim, Yong Soo; Heo, Jeong Nam [Dept. of Radiology, Hanyang University Guro Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-15

    To compare radiation doses of dual-energy CT (DECT) to single-energy CT (SECT) by a phantom experiment, with the application of mean tube currents for abdomino-pelvic CT. This study includes patients who were examined by contrast-enhanced CT for kidney evaluation. We divided the patients into six groups according to sex and body mass index. Each group consisted of five patients and a total of 30 patients were evaluated. We split the body parts (abdomen and pelvis), and calculated the mean tube current of each group as well as investigated the image noise. Applying the mean mAs from a CT scan, we measured the weighted CT dose index (CTDIw) of DECT and SECT. We compared the measured CTDIw to an estimated CTDI value displayed on the CT console. We also compared the radiation dose ratio of DECT to SECT (D/S ratio) for each subgroup. The radiation doses were compared by the student's t-test and analysis of variance. The difference of image noise between DECT and SECT was not statistically significant. Radiation dose of DECT was higher than SECT by about 21.6% (10.69 mGy, 8.79 mGy; p < 0.0001), and the measured CTDI of the DECT was significantly higher than the estimated CTDI by about 6% (p < 0.001). The D/S ratio was not significant between the six groups. The measured CTDIw of abdominopelvic DECT studies were significantly higher than those of SECT.

  9. Coronary artery visibility in free-breathing young children on non-gated chest CT: impact of temporal resolution

    Energy Technology Data Exchange (ETDEWEB)

    Bridoux, Alexandre; Hutt, Antoine; Faivre, Jean-Baptiste; Pagniez, Julien; Remy, Jacques; Remy-Jardin, Martine [CHRU et Universite de Lille, Department of Thoracic Imaging, Hospital Calmette (EA 2694), 59037 Lille Cedex (France); Flohr, Thomas [Siemens Healthcare, Department of Research and Development in CT, Forchheim (Germany); Duhamel, Alain [Universite de Lille, Department of Biostatistics, Lille (France)

    2015-11-15

    Dual-source CT allows scanning of the chest with high pitch and high temporal resolution, which can improve the detection of proximal coronary arteries in infants and young children when scanned without general anesthesia, sedation or beta-blockade. To compare coronary artery visibility between higher and standard temporal resolution. We analyzed CT images in 93 children who underwent a standard chest CT angiographic examination with reconstruction of images with a temporal resolution of 75 ms (group 1) and 140 ms (group 2). The percentage of detected coronary segments was higher in group 1 than in group 2 when considering all segments (group 1: 27%; group 2: 24%; P = 0.0004) and proximal segments (group 1: 37%; group 2: 32%; P = 0.0006). In both groups, the highest rates of detection were observed for the left main coronary artery (S1) (group 1: 65%; group 2: 58%) and proximal left anterior descending coronary artery (S2) (group 1: 43%; group 2: 42%). Higher rates of detection were seen in group 1 for the left main coronary artery (P = 0.03), proximal right coronary artery (P = 0.01), proximal segments of the left coronary artery (P = 0.02) and proximal segments of the left and right coronary arteries (P = 0.0006). Higher temporal resolution improved the visibility of proximal coronary arteries in pediatric chest CT. (orig.)

  10. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, David J., E-mail: david.murphy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); McEvoy, Sinead H., E-mail: s.mcevoy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); Iyengar, Sri, E-mail: sri.iyengar@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Feuchtner, Gudrun, E-mail: Gudrun.Feuchtner@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck (Austria); Cury, Ricardo C., E-mail: r.cury@baptisthealth.net [Department of Radiology, Baptist Cardiac and Vascular Institute, 8900 North Kendall Drive, Miami, FL 33176 (United States); Roobottom, Carl, E-mail: carl.roobottom@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Plymouth University Peninsula Schools of Medicine and Dentistry (United Kingdom); Baumueller, Stephan, E-mail: Hatem.Alkadhi@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Alkadhi, Hatem, E-mail: stephan.baumueller@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Dodd, Jonathan D., E-mail: jonniedodd@gmail.com [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland)

    2014-08-15

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm{sup 2}, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  11. Radiation Exposure in X-Ray and CT Examinations

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Radiation Dose in X-Ray and CT Exams What ... page for more information. top of page Measuring radiation dosage The scientific unit of measurement for radiation ...

  12. Effect of reference mAs in CARE kV technique on image quality and radiation dose in unenhanced chest CT%自动管电压调制技术参考毫安秒对胸部CT平扫图像质量和辐射剂量的影响

    Institute of Scientific and Technical Information of China (English)

    王晓华; 张艳; 袁慧书

    2015-01-01

    2.054、6.186和5.296,P值均>0.05).结论 与CARE Dose4D技术相比,在胸部CT平扫检查中使用合适参考毫安秒的CARE kV技术能在明显减低辐射剂量的同时获得诊断可接受的图像质量.%Objective To evaluate the effect of reference mAs on radiation dose and image quality characteristics of chest CT scanned with CARE kV technique compared with CARE Dose4D.Methods According to the date of examination,158 consecutive patients were selected in our department and randomly divided into 5 groups:CARE Dose4D group (30 cases,group 1); using CARE kV technology,reference mAs were 110 (32 cases),90 (31 cases),70 (33 cases),50 (32 cases),which were recorded asthe group from 2 to 5,respectively.Volume CT dose index (CTDIvol),dose length product (DLP) and the effective dose (ED) were analyzed.CT value and objective image noise were measured in the lungparenchyma and descending aorta.Two radiologists assessed the images for subjective noise,artefacts and diagnostic acceptability.The radiation dose,CT value and objective noise were compared with the analysis of variance,and the difference between two groups was compared with SNK test; the rank sum tests (Kruskal-Wallis) were used in subjective image quality score,and difference between two groups was compared with K-W test.Results The CTDIvol,DLP,ED values in five groups were (7.7±1.7),(7.7±2.0),(5.5±1.4),(4.2±1.5),(2.8±1.2)mGy,(290.7±67.4),(290.1±85.2),(194.2±52.1),(150.7±63.8),(96.5±38.9) mGy· cm,(4.1±0.9),(4.1±1.2),(2.7±0.7),(2.1 ± 0.9),(1.3±0.5) mSv,respectively.There were significant difference among the 5 groups(F=59.305,57.76,57.76,P<0.01).With the decrease of the reference mAs,the radiation dose decreased significantly.There were no significant difference among the 5 groups on the average CT values of lung parenchyma and descending aorta(F=0.353,0.102,P>0.05).The objective noise of 5 groups in pulmonary parenchyma and the descending aorta were (48.7 ± 9.1),(49.2 ± 10

  13. Computed tomography (CT)-guided interstitial permanent implantation of (125)I seeds for refractory chest wall metastasis or recurrence.

    Science.gov (United States)

    Jiang, Ping; Liu, Chen; Wang, Junjie; Yang, Ruijie; Jiang, Yuliang; Tian, Suqing

    2015-02-01

    To evaluate the efficacy and safety of 125I seeds implantation for refractory chest wall (CW) metastasis or recurrence under CT guidance. In addition we assessed initial data obtained on the therapeutic response for refractory CW metastasis or recurrence. Twenty consecutive patients underwent permanent implantation of 125I seeds (from Jul. 2004 to Jan. 2011) under computed tomography (CT) guidance. Postoperative dosimetry was routinely performed for all patients. The actuarial D90 of the implanted 125I seeds ranged from 100 Gy to 160 Gy (median: 130 Gy). The activity of 125I seeds ranged from 0.5 mCi to 0.78 mCi (median: 0.71 mCi). The total number of seeds implanted ranged from 8 to 269 (median: 53). The follow-up period ranged from 3 to 54 months (median: 11.5 months). The survival and local control probabilities were calculated by the Kaplan-Meier method. Among all the 20 patients, 3 patients had complete remission CR (15%), 12 patients had partial remission PR (60%), 5 patients had stable disease SD. The 1-, 2-, 3- and 4-year tumor control rates were all 88.7% respectively. The 1- and 2-, 3-, 4-year cancer specific survival rates were 56.5% and 47.1%, 47.1%, 47.1% respectively. The 1- and 2-, 3-, 4-year overall survival rates were 53.3% and 35.6%, 35.6%, 35.6% respectively, with a median survival of 15 months (95% CI, 7.0-22.9). Mild brachial plexus injury was seen in one patient; grade 1 or 2 skin reactions were seen in 6 patients (30%) who had received external beam radiation therapy (EBRT) before. No grade 3 and 4 skin side effects were found. Rib fracture, ulceration, pneumothorax or hemopneumothorax were not seen. Interstitial permanent implantation of 125I seeds under CT guidance is feasible, efficacious and safe for refractory CW metastasis or recurrence.

  14. The value of chest CT scan and tumor markers detection in sputum for early diagnosis of peripheral lung cancer

    Institute of Scientific and Technical Information of China (English)

    WANG Xu; CAO Aihong; PENG Mengqing; HU Chunfeng; LIU Delin; GU Tao; LIU Hui

    2004-01-01

    Objective To investigate the diagnostic value of chest CT scan combined with telomerase activity and p16 gene methylation from exfoliated cells of sputum in 55 cases of solitary pulmonary nodules (SPN; ≤30 mm)suspected early peripheral lung cancer. Methods The sputum specimens from 34 cases of cancer nodules and 21 cases of benign lesion were detected for telomerase activity by TRAP-PCR-ELISA and p16 gene methylation by PCR-based methylation analysis. Results The qualitative diagnostic accuracy of CT scan was 61.8%(34/55) for SPN provided by pathology. Cytology analysis of sputum was positive in 13 cases (38.2%). Telomerase activity was positive in 29 cases: sensitivity was 79.4%, specificity was 90.5%, accuracy was 83.6%; p16 gene methylation was found in 11 cases: sensitivity was 32.4%, specificity was 100.0%, and accuracy was 58.2%. The sensitivity was increased to 86.1% by combination of telomerase activity and p16 gene methylation. Compared with nodules without malignant CT signs, expression of telomerase activity and p16 methylation of SPN with malignant CT signs (lobulation or spiculate protuberance or spicule sign) had a significant difference (P<0.01). Conclusion The results suggest that chest CT scan combined with telomerase activity and p16 gene methylation detection in sputum for patients with peripheral lung cancer may enhance the diagnostic value of radiology and conventional cytology.

  15. Lung parenchymal change after the resolution of adenovirus pneumonia : chest radiographs and high-resolution CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung Hee; Kim, Joung Sook; Kim, Chang Kuen; Kang, Seung Pyung; Lee, Soo Hyun; Hur Gham [Inje Univ. Sanggye Paik Hospital, Seoul (Korea, Republic of)

    1998-07-01

    To evaluate lung parenchymal change as seen on chest radiographs and high-resolution CT (HRCT) after the resolution of adenovirus pneumonia (a common cause of lower respiratory infection in infants and children),and the usefulness of HRCT during follow-up. Material and Methods : Four to 13(mean, 8) months after recovery, ten patients infected with adenovirus pneumonia underwent HRCT and chest radiographs. Eight were boys and two were girls, and their mean age was 26(range, 14-45) months. Adenovirus pneumonia had been confirmed by viral isolation in culture or serologic test. CT scanning was performed during quiet breathing ; collimation was 2 mm and the interval from apex to diaphragm was 5-10 mm. Lung settings were 1600 HU (window width) and -700 HU(level). CT findings were assessed and compared with chest radiographs by two chest radiologists, who reached a consensus. The patients were clinically followed up for one year. Result : On chest radiographs, hyperlucent lung was seen in 8 of 10 patients (80%) ; in one other there was partial collapse, and in one, findings were normal. The most common HRCT finding was a mosaic pattern of lung attenuation with decreased pulmonary vascularity in the area of lower attenuation ; this was seen in 8 of 10 patients (80%). Other findings were partial collapse, bronchiectasis, and bronchial wall thickening, each seen in two patients, and reticulonodular density, seen in one. In two patients HRCT findings were normal ; in one of these, chest findings were normal but a mosaic pattern of lung attenuation was found in all lobes. During follow-up, three patients wheezed continuously. Conclusion : In cases of adenovirus pneumonia, HRCT demonstrated more specific parenchymal change than did chest radiographs ; a mosaic pattern of lung attenuation was seen, with decreased pulmonary vascularity in areas of lower attenuation ; bronchiectasis,bronchial wall thickening, and reticulo-odular density were also noted. These findings were

  16. Population exposure to ionising radiation from CT examinations in Aosta Valley between 2001 and 2008

    Science.gov (United States)

    Catuzzo, P; Aimonetto, S; Zenone, F; Fanelli, G; Marchisio, P; Meloni, T; Pasquino, M; Tofani, S

    2010-01-01

    Recent and continuous advances in CT, such as the development of multislice CT, have promoted a rapid increase in its clinical application. Today, CT accounts for approximately 10% of the total number of medical radiographic procedures worldwide. However, the growing performance of the new CT generations have increased not only the diagnostic opportunities, but also the radiation dose to the patient. The relative contribution to the collective radiation dose is now estimated to be approximately 50%. Several papers have been published concerning the intensive use of CT and its contribution to the collective dose. However, most of the literature concerns the years 1997–2003 and the dosimetric evaluations are generally limited to the main standard protocols (chest, head and abdomen), deriving the effective dose by the simple application of the diagnostic reference levels. Only specific dosimetric analyses of single and innovative procedures have been published recently. Moreover, few data comes from Italian radiology departments. This paper aims to bridge these gaps. Firstly, it characterises in terms of measured CT dose index (CTDI) two last-generation scanners of the Radiological Department of Aosta Hospital. Secondly, it evaluates the effective dose from most of the CT examinations performed from 2001 to 2008 to compare protocols and technologies in line with the suggestions of the 2007 Recommendations of the International Commission on Radiological Protection, Publication 103. Finally, it estimates the collective dose to the population. PMID:21088089

  17. Impact of image quality, radiologists, lung segments, and Gunnar eyewear on detectability of lung nodules in chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Christe, Andreas [Dept. of Radiology, Stanford Univ. Medical Center, Stanford (United States); Dept. of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Univ. Hospital, Univ. of Bern, Bern (Switzerland)], e-mail: andreas.christe@insel.ch; Ebner, Lukas; Steiger, Philipp; Vock, Peter [Dept. of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Univ. Hospital, Univ. of Bern, Bern (Switzerland); Parikh, Sachin R. [Dept. of Radiology, Emory Univ. School of Medicine, Atlanta (United States); Shah, Akash D. [Proscan Imaging, Cincinnati (United States); Roychoudhury, Kingshuk [Statistics Dept., Univ. Coll. Cork, Cork (Ireland); Roos, Justus E. [Dept. of Radiology, Stanford Univ. Medical Center, Stanford (United States)

    2013-07-15

    Background: Despite the increasingly higher spatial and contrast resolution of CT, nodular lesions are prone to be missed on chest CT. Tinted lenses increase visual acuity and contrast sensitivity by filtering short wavelength light of solar and artificial origin. Purpose: To test the impact of Gunnar eyewear, image quality (standard versus low dose CT) and nodule location on detectability of lung nodules in CT and to compare their individual influence. Material and Methods: A pre-existing database of CT images of patients with lung nodules >5 mm, scanned with standard does image quality (150 ref mAs/120 kVp) and lower dose/quality (40 ref mAs/120 kVp), was used. Five radiologists read 60 chest CTs twice: once with Gunnar glasses and once without glasses with a 1 month break between. At both read-outs the cases were shown at lower dose or standard dose level to quantify the influence of both variables (eyewear vs. image quality) on nodule sensitivity. Results: The sensitivity of CT for lung nodules increased significantly using Gunnar eyewear for two readers and insignificantly for two other readers. Over all, the mean sensitivity of all radiologist raised significantly from 50% to 53%, using the glasses (P value = 0.034). In contrast, sensitivity for lung nodules was not significantly affected by lowering the image quality from 150 to 40 ref mAs. The average sensitivity was 52% at low dose level, that was even 0.7 % higher than at standard dose level (P value = 0.40). The strongest impact on sensitivity had the factors readers and nodule location (lung segments). Conclusion: Sensitivity for lung nodules was significantly enhanced by Gunnar eyewear (+3 %), while lower image quality (40 ref mAs) had no impact on nodule sensitivity. Not using the glasses had a bigger impact on sensitivity than lowering the image quality.

  18. A decrease in lung cancer mortality following the introduction of low-dose chest CT screening in Hitachi, Japan.

    Science.gov (United States)

    Nawa, Takeshi; Nakagawa, Tohru; Mizoue, Tetsuya; Kusano, Suzushi; Chonan, Tatsuya; Hayashihara, Kenji; Suito, Tetsushi; Endo, Katsuyuki

    2012-12-01

    Recent US clinical trial demonstrated that CT screening prevents lung cancer death among high risk individuals. However, it remains unclear whether wide implementation of low-dose CT screening for lung cancer can decrease mortality in the community. Among residents in Hitachi City (Japan), where nearly 40% of inhabitants aged 50-69 years were estimated to have participated in the screening at least once from 1998 through 2009, the trend of lung cancer mortality was described in relation to the timing of implementation of the CT screening. Cancer mortality data were obtained from regional cancer registry and standardized mortality ratio (SMR) of lung cancer was calculated for each 5-year period during 1995-2009. In both men and women aged 60 years or older, age-specific lung cancer mortality rates were generally lower during 2005-2009 as compared with those during 1995-2004. For combined men and women aged 50-79 years, SMR was nearly unity prior to or during introductory phase of CT screening and during early period of implementation; however, it was significantly decreased during 2005-2009, well after the implementation of CT screening, with SMR (95% confidence interval) being 0.76 (0.67-0.86). Results suggest that wide implementation of low-dose chest CT screening may decrease lung cancer mortality in the community 4-8 years after introduction of the screening.

  19. Novel influenza A (H1N1) infection: chest CT findings from 21 cases in Seoul, Korea

    Energy Technology Data Exchange (ETDEWEB)

    Shim, S.S., E-mail: sinisim@ewha.ac.k [Department of Diagnostic Radiology and Center for Imaging Science, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of); Kim, Y. [Department of Diagnostic Radiology and Center for Imaging Science, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of); Ryu, Y.J. [Division of Pulmonary and Critical care medicine, Department of Internal Medicine, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

    2011-02-15

    Aim: To retrospectively evaluate the computed tomography (CT) appearances of novel influenza A (H1N1) infection. Materials and methods: Chest CT images obtained at clinical presentation in 21 patients (eight men, 13 women; mean age, 37 years; age range, 6-82 years) with confirmed novel influenza A (H1N1) infection were assessed. The radiological appearances of pulmonary parenchymal abnormalities, distribution, and extent of involvement on initial chest CT images were documented. The study group was divided on the basis of age [group 1, patients <18 years old (n = 8); group 2, patients {>=}18 years old (n = 13)]. Medical records were reviewed for underlying medical conditions and laboratory findings. The occurrence of recognizable CT patterns was compared for each group using the images from the initial CT examination. Results: The most common CT pattern observed in all patients was ground-glass attenuated (GGA) lesions (20/21, 95%). Bronchial wall thickening (9/21, 43%) was the second most common CT finding. Other common CT findings were consolidation (6/21, 29%), pleural effusion (6/21, 29%), pneumothorax or pneumomediastinum (5/21, 24%), and atelectasis (5/21, 24%). Among these, atelectasis and pneumomediastinum (pneumothorax) were only observed in group 1. The GGA lesions showed predilections for diffuse multifocal (10/20, 50%) or lower zone (8/20, 40%) distribution. Involvement of central lung parenchyma (12/20, 60%) was more common than a mixed peripheral and central pattern (6/20, 30%) or a subpleural pattern (2/20, 10%) at the time of presentation. Patchy GGA lesions were more frequent (18/20, 90%) than diffuse GGA lesions, and 75% (15/20) of these lesions had a bronchovascular distribution. Bilateral disease was present in all patients with GGA lesions. Bronchial wall thickening was predominantly centrally located and the distribution of the consolidation was non-specific. Conclusion: The predominantly centrally located GGA lesions, with common multifocal

  20. Primary Experiences in 320-Row-640-Slice Dynamic CT for Checking Acute Chest Pain%320排640层动态容积CT 在急性胸痛检查中的初步探讨

    Institute of Scientific and Technical Information of China (English)

    马国军; 于淑靖; 何翔; 郑婧; 魏书恒; 王燕

    2011-01-01

    Objective: To evaluate the image quality and clinic value of dynamic CT checking triple rule-out.Method:38 patients suffering acute chest pain were continuously selected and accepted 320-row-640-slice dynamic CT examination.The scan protocol was helical scanning the whole chest, under ECG-gate,intelligent and automatically trigger.80~90ml contrast media was needed.Two professional doctors measure the CT value of ascending main aorta,decline main aorta and pulmonary artery separately in pulmonary trunk level .The image quality of coronary artery was evaluated,which was graded in three levels:good,well,bad.The dose of radiation was also evaluated .Result: The average CT value of ascending main aorta, decline main aorta and pulmonary artery was (401 ±57)HU,(397±49) HU,(331 ±31)HU.84.7% of all image quality of coronary artery were good,13.2% were well,2.1% were bad.4 patients were diagnosed lung infection with pleurar effusion, 1 patient was lung cancer,2 patients pulmonary embolism,1 patient dissection of aorta,2 patients artrial myxoma.The degree of stenosis was more than 50% in 12 patients' coronary artery.Average radiation dose was (22 ±2.1)mSv. Conclusion:This scanning protocol can achieve high quality image of main aorta,pulmonary artery and coronary artery comparing with the reports of literature.lt is very valuable for finding pathogen of acute chest pain.The dose of contrast media and radiation were lower.%目的:探讨320 排640 层动态容积CT 胸痛三联检查的图像质量及临床价值.方法:连续选取38 例急性胸痛患者行320 排640 层动态容积CT 检查.扫描方案为心电门控下全胸部螺旋扫描(160 mm×0.5mm),采用智能自动触发技术.对比剂用量为80~90ml( 碘海醇350).分别由2位专业医生测定肺动脉干层面的升主动脉、降主动脉、肺动脉干CT 值并评价冠脉质量,冠脉质量分为优、良、差三级.同时评价辐射剂量.结果:升主动脉、降主动脉、肺动脉平均CT

  1. 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.

  2. AAPM/RSNA Physics Tutorial for Residents: Topics in CT. Radiation dose in CT.

    Science.gov (United States)

    McNitt-Gray, Michael F

    2002-01-01

    This article describes basic radiation dose concepts as well as those specifically developed to describe the radiation dose from computed tomography (CT). Basic concepts of radiation dose are reviewed, including exposure, absorbed dose, and effective dose. Radiation dose from CT demonstrates variations within the scan plane and along the z axis because of its unique geometry and usage. Several CT-specific dose descriptors have been developed: the Multiple Scan Average Dose descriptor, the Computed Tomography Dose Index (CTDI) and its variations (CTDI(100), CTDI(w), CTDI(vol)), and the dose-length product. Factors that affect radiation dose from CT include the beam energy, tube current-time product, pitch, collimation, patient size, and dose reduction options. Methods of reducing the radiation dose to a patient from CT include reducing the milliampere-seconds value, increasing the pitch, varying the milliampere-seconds value according to patient size, and reducing the beam energy. The effective dose from CT can be estimated by using Monte Carlo methods to simulate CT of a mathematical patient model, by estimating the energy imparted to the body region being scanned, or by using conversion factors for general anatomic regions. Issues related to radiation dose from CT are being addressed by the Society for Pediatric Radiology, the American Association of Physicists in Medicine, the American College of Radiology, and the Center for Devices and Radiological Health of the Food and Drug Administration.

  3. 登革热的胸部CT表现%CT appearance of dengue fever in the chest

    Institute of Scientific and Technical Information of China (English)

    周军; 周芳; 谢绍春; 黄勇; 雷斌

    2014-01-01

    Objective To describe and analyze the chest CT appearance in dengue fever. Methods Imaging data of chest CT in 75 patients with dengue fever was retrospectively analyzed. Results On chest CT of dengue fever,17 cases were negative, 58 cases were positive. The main performance was interstitial abnormalities, pleural ef-fusion, pleural thickening, bullae. And there were ground-glass opacity(n=17), dual markings increased disorder(n=14), interlobular septal thickening(n=15), parenchymal bands(n=9) , subpleural line(n=7), air-space nodules(n=6), pleural effusion (n=22),interlobar effusion (n=3), bullae (n=5), pleural thickening (n=4). Conclusion Dengue fever has some characteristic imaging features. And the main features were interstitial abnormalities. Combined the chest CT appear-ance with clinical manifestation and laboratory findings, the diagnostic accuracy can be improved.%目的:探讨登革热的CT表现。方法回顾性分析75例经临床确诊的登革热患者的胸部CT资料。结果胸部CT中,17例表现为阴性,58例有阳性表现,主要表现有肺间质病变、胸腔积液、胸膜增厚、肺大泡,其中肺间质实变的表现有磨玻璃样改变17例,双侧肺纹理增多14例,肺小叶间隔增厚15例,长索条9例,胸膜下线7例,气腔结节6例,另外,胸腔积液22例,叶间胸膜积液3例,肺大泡5例,胸膜增厚4例。结论登革热的胸部CT表现以肺间质病变等为主要特点,结合临床表现及实验室检查可提高对登革热的认识。

  4. Computer-aided diagnosis workstation and database system for chest diagnosis based on multi-helical CT images

    Science.gov (United States)

    Satoh, Hitoshi; Niki, Noboru; Mori, Kiyoshi; Eguchi, Kenji; Kaneko, Masahiro; Kakinuma, Ryutarou; Moriyama, Noriyuki; Ohmatsu, Hironobu; Masuda, Hideo; Machida, Suguru; Sasagawa, Michizou

    2006-03-01

    Multi-helical CT scanner advanced remarkably at the speed at which the chest CT images were acquired for mass screening. Mass screening based on multi-helical CT images requires a considerable number of images to be read. It is this time-consuming step that makes the use of helical CT for mass screening impractical at present. To overcome this problem, we have provided diagnostic assistance methods to medical screening specialists by developing a lung cancer screening algorithm that automatically detects suspected lung cancers in helical CT images and a coronary artery calcification screening algorithm that automatically detects suspected coronary artery calcification. We also have developed electronic medical recording system and prototype internet system for the community health in two or more regions by using the Virtual Private Network router and Biometric fingerprint authentication system and Biometric face authentication system for safety of medical information. Based on these diagnostic assistance methods, we have now developed a new computer-aided workstation and database that can display suspected lesions three-dimensionally in a short time. This paper describes basic studies that have been conducted to evaluate this new system. The results of this study indicate that our computer-aided diagnosis workstation and network system can increase diagnostic speed, diagnostic accuracy and safety of medical information.

  5. CT imaging of congenital lung lesions: effect of iterative reconstruction on diagnostic performance and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Haggerty, Jay E.; Smith, Ethan A.; Dillman, Jonathan R. [University of Michigan Health System, Section of Pediatric Radiology, Department of Radiology, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States); Kunisaki, Shaun M. [University of Michigan Health System, Section of Pediatric Surgery, Department of Surgery, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States)

    2015-07-15

    Different iterative reconstruction techniques are available for use in pediatric computed tomography (CT), but these techniques have not been systematically evaluated in infants. To determine the effect of iterative reconstruction on diagnostic performance, image quality and radiation dose in infants undergoing CT evaluation for congenital lung lesions. A retrospective review of contrast-enhanced chest CT in infants (<1 year) with congenital lung lesions was performed. CT examinations were reviewed to document the type of lung lesion, vascular anatomy, image noise measurements and image reconstruction method. CTDI{sub vol} was used to calculate size-specific dose estimates (SSDE). CT findings were correlated with intraoperative and histopathological findings. Analysis of variance and the Student's t-test were used to compare image noise measurements and radiation dose estimates between groups. Fifteen CT examinations used filtered back projection (FBP; mean age: 84 days), 15 used adaptive statistical iterative reconstruction (ASiR; mean age: 93 days), and 11 used model-based iterative reconstruction (MBIR; mean age: 98 days). Compared to operative findings, 13/15 (87%), 14/15 (93%) and 11/11 (100%) lesions were correctly characterized using FBP, ASiR and MBIR, respectively. Arterial anatomy was correctly identified in 12/15 (80%) using FBP, 13/15 (87%) using ASiR and 11/11 (100%) using MBIR. Image noise was less for MBIR vs. ASiR (P < 0.0001). Mean SSDE was different among groups (P = 0.003; FBP = 7.35 mGy, ASiR = 1.89 mGy, MBIR = 1.49 mGy). Congenital lung lesions can be adequately characterized in infants using iterative CT reconstruction techniques while maintaining image quality and lowering radiation dose. (orig.)

  6. Quantitative analysis of dynamic airway changes after methacholine and salbutamol inhalation on xenon-enhanced chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Joon; Goo, Jin Mo; Kim, Jong Hyo; Park, Eun-Ah [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Lee, Chang Hyun [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Jung, Jae-Woo; Park, Heung-Woo [Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of); Cho, Sang-Heon [Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of)

    2012-11-15

    To investigate the dynamic changes in airways in response to methacholine and salbutamol inhalation and to correlate the xenon ventilation index on xenon-enhanced chest CTs in asthmatics. Thirty-one non-smokers (6 normal, 25 asthmatics) underwent xenon-enhanced chest CT and pulmonary function tests. Images were obtained at three stages (basal state, after methacholine inhalation and after salbutamol inhalation), and the total xenon ventilation index (TXVI) as well as airway values were measured and calculated. The repeated measures ANOVA and Spearman's correlation coefficient were used for statistical analysis. TXVI in the normal group did not significantly change (P > 0.05) with methacholine and salbutamol. For asthmatics, however, the TXVI significantly decreased after methacholine inhalation and increased after salbutamol inhalation (P < 0.05). Of the airway parameters, the airway inner area (IA) significantly increased after salbutamol inhalation in all airways (P < 0.01) in asthmatics. Airway IA, wall thickness and wall area percentage did not significantly decrease after methacholine inhalation (P > 0.05). IA of the large airways was well correlated with basal TXVI, FEV{sub 1} and FVC (P < 0.05). Airway IA is the most reliable parameter for reflecting the dynamic changes after methacholine and salbutamol inhalation, and correlates well with TXVI in asthmatics on xenon-enhanced CT. (orig.)

  7. Evaluation of the efficiency of bismuth breast shield in CT chest paediatric examinations; Valoracion en el paciente pediatrico de la eficacia de los protectores de bien procedimientos de TC de torax con sistemas de control automatico de intensidad

    Energy Technology Data Exchange (ETDEWEB)

    Sevillano, D.; Espana, M. L.; Castro, P.; Minguez, C.; Albi, G.; Garcia, E.; Lopez Franco, P.

    2006-07-01

    The aim of this study is to evaluate the efficiency of bismuth breast shield in CT chest paediatric examinations when automatic exposure control techniques are used. The influence in the radiation dose and the image quality has been evaluated with and without the breast shield in the scoutview. In addition the radiation dose in shielded and non-shielded areas has been compared. Measurements were made in a 16 cm diameter cylindrical PMMA phantom simulating a newborn, and older children were simulated controlling the maximum intensities allowed by the automatic exposure control system AutomA. The highest dose reduction (59%) was obtained with AutomA system and when the breast shield is not used in the scoutview. This reduction in the radiation dose does not mean a significant increase of noise level. The use of the breast shield in the scoutview yielded an increase in the radiation dose in non-shielded areas. The use of bismuth breast shield is recommended only after the scoutview in order to optimise the radiation dose in CT chest paediatric examination when using automatic exposure control AutomA. (Author)

  8. Clinical indications and radiation doses to the conceptus associated with CT imaging in pregnancy: a retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Woussen, S.; Vanbeckevoort, D.; Bosmans, H.; Oyen, R. [University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Lopez-Rendon, X.; Zanca, F. [University Hospitals Leuven, Department of Imaging and Pathology, Leuven (Belgium)

    2016-04-15

    To perform an internal audit at a university hospital with the aim of evaluating the number, clinical indication and operating procedure of computed tomography (CT) performed on pregnant patients and of estimating the radiation doses to the conceptus. A retrospective review was conducted of all CT examinations performed in a single centre on pregnant patients between January 2008 and July 2013. The radiation doses to the conceptus were estimated. The results were compared with published data. The number of CT examinations during pregnancy increased from 3-4 per year in 2008-2011 to 11 per year in 2012. The mean estimated conceptus radiation dose was considered negligible for CT of the head and cervical spine, being less than 0.01 mGy, and for CT of the chest, less than 0.1 mGy. The estimated conceptus radiation dose from abdominopelvic CT was on average 28.7 mGy (range 6.7-60.5 mGy). The number of CT scans of pregnant patients increased threefold during the last few years. Most clinical indications and doses were in line with good clinical practice and literature; only in two cases the dose to the conceptus was higher than 50 mGy. (orig.)

  9. Thin-section chest CT findings of primary Sjoegren's syndrome: correlation with pulmonary function

    Energy Technology Data Exchange (ETDEWEB)

    Taouli, Bachir; Mourey, Isabelle [Department of Radiology, Universite Pierre et Marie Curie, Paris (France); Brauner, Michel W.; Lemouchi, Djamel [Department of Radiology, Universite Paris XIII, Bobigny (France); Grenier, Philippe A. [Department of Radiology, Universite Pierre et Marie Curie, Paris (France); Institut National de la Sante et de la Recherche Medicale, Universite Pierre et Marie Curie, Paris (France)

    2002-06-01

    The purpose of this study was to describe thin-section CT findings of lung involvement in patients with primary Sjoegren's syndrome (PSS), and to correlate them with pulmonary function tests (PFT). The chest thin-section CT examinations of 35 patients with proven diagnosis of PSS and respiratory symptoms were retrospectively assessed by two observers, in a first step independently with interobserver evaluation, and in a second step in consensus. The extent of the most frequent CT findings was scored. Correlation was made with PFT in 31 of these patients. Three main CT patterns were identified with good interobserver agreement (kappa coefficient 0.71): 19 of 35 (54%) large and/or small airways disease; 7 of 35 (20%) interstitial lung fibrosis (ILF); and 5 of 35 (14%) suggestive of lymphocytic interstitial pneumonia (LIP). The CT scans were normal in 2 patients (6%) and showed only dilatation of pulmonary vessels due to pulmonary arterial hypertension in two others (6%). Airway disease patients had predominantly obstructive profiles (mean FEV{sub 1}/FVC ratio 69.7{+-}12.7%, mean MEF{sub 25} 50.1{+-}22.9%), whereas patients with ILF and LIP had predominantly restrictive profiles and/or a decreased diffusing lung capacity (mean TLC 87.0{+-}26.0 and 64.6{+-}18.6%, mean DL{sub CO} 57.4{+-}21.2 and 52.0{+-}8.0%). Significant correlation (p<0.01) was found between the scores of ground-glass attenuation and TLC (r=-0.84) and DL{sub CO} (r=-0.70) and between the score of air trapping and FEV1 (r=-1.0). In patients with PSS and respiratory symptoms, thin-section CT may provide characterization of lung involvement which correlates with pulmonary function. (orig.)

  10. Low dose computed tomography of the chest : Applications and limitations

    NARCIS (Netherlands)

    Gietema, H.A.

    2007-01-01

    In areas with a high intrinsic contrast such as the chest, radiation dose can be reduced for specific indications. Low dose chest CT is feasible and cannot only be applied for lung cancer screening, but also in daily routine and for early detection of lung destruction. We showed in a small sample of

  11. Multicentre chest computed tomography standardisation in children and adolescents with cystic fibrosis

    DEFF Research Database (Denmark)

    Kuo, Wieying; Kemner-van de Corput, Mariette P. C.; Perez-Rovira, Adria

    2016-01-01

    was found in CT protocols, image quality and radiation dose usage among the centres. However, the performance of all CT scanners was found to be very similar, when taking spatial resolution and radiation dose into account. We conclude that multicentre standardisation of chest CT in children and adolescents...

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

    Energy Technology Data Exchange (ETDEWEB)

    Feng Shiting [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Law, Martin Wai-Ming [Department of Clinical Oncology, Queen Mary Hospital (Hong Kong); Huang Bingsheng [Department of Diagnostic Radiology, University of Hong Kong (Hong Kong); Ng, Sherry [Department of Clinical Oncology, Queen Mary Hospital (Hong Kong); Li Ziping; Meng Quanfei [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Khong, Pek-Lan, E-mail: plkhong@hkucc.hku.hk [Department of Diagnostic Radiology, University of Hong Kong (Hong Kong)

    2010-11-15

    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.

  13. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Bastarrika, Gorka [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Cardiac Imaging Unit, Clinica Univ. de Navarra, Pamplona (Spain)], e-mail: bastarrika@unav.es

    2012-06-15

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 {+-} 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 {+-} 58.3 mL) with respect to ECG-gated CT (142.7 {+-} 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 {+-} 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.

  14. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Weininger, Markus [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC (United States); Ramachandra, Ashok [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Rowe, Garrett W.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Henzler, Thomas [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  15. Aspects of radiation protection during chest X-radiography; Strahlenhygienische Aspekte bei der Roentgenuntersuchung des Thorax

    Energy Technology Data Exchange (ETDEWEB)

    Seidenbusch, M.C.; Schneider, K. [Dr. von Haunersches Kinderspital, Klinikum der Universitaet Muenchen, Institut fuer Klinische Radiologie - Kinderradiologie, Muenchen (Germany)

    2015-07-15

    Radiation safety in conventional X-ray diagnostics is based on the concepts of justification, optimization of an X-ray examination and limitation of the radiation exposure achieved during the examination. Optimization of an X-ray examination has to be considered as a multimodal process in which all technical components of the X-ray equipment have to be adapted to each other and also have to be adapted to the anthropometric characteristics of patients and the clinical indications. In this article the technical components of a conventional pediatric chest X-radiograph are presented, and recommendations for optimizing chest X-rays in children are provided. The following measures are of prime importance: correct x-ray beam limitation, using the posteroanterior projection when possible and not using anti-scatter grids in children under approximately 8 years old. In pediatric radiology chest x-rays that are taken not at the peak of inspiration can also be of some diagnostic significance. Optimization of an X-ray examination inevitably results in the limitation of radiation exposure. (orig.) [German] Die Strahlenhygiene in der konventionellen radiologischen Diagnostik basiert auf der Trias Rechtfertigung, Optimierung bzw. Limitierung der Roentgenuntersuchung bzw. Strahlenexposition. Die Optimierung einer Roentgenuntersuchung ist als multimodaler Prozess aufzufassen, in welchem saemtliche technische Komponenten der Roentgeneinrichtung sowohl miteinander als auch mit den anthropometrischen Eigenschaften des Patienten und der klinischen Fragestellung abzustimmen sind. Im vorliegenden Beitrag werden die technischen Komponenten bei der konventionellen Roentgenuntersuchung des paediatrischen Thorax in ihrer Beziehung zueinander dargestellt und Empfehlungen fuer eine Optimierung der konventionellen Thoraxaufnahme bei Kindern ausgesprochen. Die wichtigsten Massnahmen bestehen in einer korrekten Einblendung, in der Anfertigung der Aufnahmen im posteroanterioren Strahlengang und im

  16. CT equipment and performance issues: radiation protection 162.

    Science.gov (United States)

    Edyvean, S

    2013-02-01

    Since the development of the CT scanner in the early 1970s, CT scanner technology has continuously developed through technical advancement, faster computer processing, superior detectors and helical and multi-detector scanning modes. As a result, the scope of clinical examinations has broadened considerably, and in parallel, this has been achieved with improvement in image quality and radiation dose efficiency. Despite this, and perhaps because image quality can always be improved at the expense of increased radiation dose, CT examinations are among the highest-dose procedures encountered routinely in medical imaging. The qualitative criteria for acceptability in RP 162 address some functional and operational issues, and the quantitative criteria, in the form of suspension levels, focus primarily around hardware aspects of the CT scanner, though consideration is also given to software, operator aspects and selection of scan protocols. Some of the specific aspects and challenges in modern CT systems, in particular multi-slice and wide beams are also addressed.

  17. Strategies to reduce radiation dose in cardiac PET/CT

    Science.gov (United States)

    Wu, Tung Hsin; Wu, Nien-Yun; Wang, Shyh-Jen; Wu, Jay; S. P. Mok, Greta; Yang, Ching-Ching; Huang, Tzung-Chi

    2011-08-01

    Our aim was to investigate CT dose reduction strategies on a hybrid PET/CT scanner for cardiac applications.MaterialsImage quality and dose estimation of different CT scanning protocols for CT coronary angiography (CTCA), and CT-based attenuation correction for PET imaging were investigated. Fifteen patients underwent CTCA, perfusion PET imaging at rest and under stress, and FDG PET for myocardial viability. These patients were divided into three groups based on the CTCA technique performed: retrospectively gated helical (RGH), ECG tube current modulation (ETCM), and prospective gated axial (PGA) acquisitions. All emission images were corrected for photon attenuation using CT images obtained by default setting and an ultra-low dose CT (ULDCT) scan.ResultsRadiation dose in RGH technique was 22.2±4.0 mSv. It was reduced to 10.95±0.82 and 4.13±0.31 mSv using ETCM and PGA techniques, respectively. Radiation dose in CT transmission scan was reduced by 96.5% (from 4.53±0.5 to 0.16±0.01 mSv) when applying ULDCT as compared to the default CT. No significant difference in terms of image quality was found among various protocols.ConclusionThe proposed CT scanning strategies, i.e. ETCM or PGA for CTCA and ULDCT for PET attenuation correction, could reduce radiation dose up to 47% without degrading imaging quality in an integrated cardiac PET/CT coronary artery examination.

  18. 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.

  19. Gradual progression of intrapulmonary lymph nodes associated with usual interstitial pneumonia in progressive systemic sclerosis on chest radiographs and CT

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Joon Young; Chung, Myung Hee; Kim, Seon Mun [The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Yong Hyun [The Catholic Univ. of Korea, Bucheon (Korea, Republic of)

    2012-10-15

    A 40 year old female visited the clinic for evaluation of Raynaud's phenomenon for a period of four years. The initial chest radiograph showed a fine reticular density and ground glass opacity with lower lobe predominance. These findings are consistent interstitial fibrosis. Additionally, high resolution CT showed multiple, small, coexisting nodular opacities, ranging from 3 to 7 mm in size in both lungs. These nodules grew up to 1.5 cm and showed moderate enhancement. Because of the rareness of intrapulmonary lymph node in patient of progressive systemic sclerosis, we couldn't exclude the possibility of malignancy. These nodules are turned out to be intrapulmonary lymph nodes on video assisted thoracoscopic lung biopsy.

  20. Reduction of adult fingers visualized on pediatric intensive care unit (PICU) chest radiographs after radiation technologist and PICU staff radiation safety education

    Energy Technology Data Exchange (ETDEWEB)

    Tynan, J.R.; Duncan, M.D.; Burbridge, B.E., E-mail: jentynan@hotmail.com [Univ. of Saskatchewan, Royal Univ. Hospital, Dept. of Medical Imaging, Saskatoon, Saskatchewan (Canada)

    2009-10-15

    A recent publication from our centre revealed a disturbing finding of a significant incidence of adult fingers seen on the pediatric intensive care unit (PICU) chest radiographs. This is inappropriate occupational exposure to diagnostic radiation. We hypothesized that the incidence of adult fingers on PICU chest radiographs would decline after radiation safety educational seminars were given to the medical radiation technologists and PICU staff. The present study's objectives were addressed by using a pretest-posttest design. Two cross-sectional PICU chest radiograph samples, taken before and after the administration of radiation safety education for our medical radiation technologists and PICU staff, were compared by using a {chi}{sup 2} test. There was a 61.2% and 76.9% reduction in extraneous adult fingers, directly exposed to the x-ray beam and those seen in the coned regions of the film, respectively, on PICU chest radiographs (66.7% reduction overall). This reduction was statistically significant ({chi}2 = 20.613, P < .001). Limiting unnecessary occupational radiation exposure is a critical issue in radiology. There was a statistically and clinically significant association between radiation safety education and the decreased number of adult fingers seen on PICU chest radiographs. This study provides preliminary evidence in favour of the benefit of radiation safety seminars. (author)

  1. Radiation doses to paediatric patients and comforters undergoing chest X rays.

    Science.gov (United States)

    Sulieman, A; Vlychou, M; Tsougos, I; Theodorou, K

    2011-09-01

    Pneumonia is an important cause of hospital admission among children in the developed world and it is estimated to be responsible for 3-18 % of all paediatric admissions. Chest X ray is an important examination for pneumonia diagnosis and for evaluation of complications. This study aims to determine the entrance surface dose (ESD), organ, effective doses and propose a local diagnostic reference level. The study was carried out at the university hospital of Larissa, Greece. Patients were divided into three groups: organ and effective doses were estimated using National Radiological Protection Board software. The ESD was determined by thermoluminescent dosemeters for 132 children and 76 comforters. The average ESD value was 55 ± 8 µGy. The effective dose for patients was 11.2 ± 5 µSv. The mean radiation dose for comforter is 22 ± 3 µGy. The radiation dose to the patients is well within dose constraint, in the light of the current practice.

  2. Radiation dose from multidetector CT studies in children: results from the first Italian nationwide survey

    Energy Technology Data Exchange (ETDEWEB)

    Granata, Claudio [IRCCS Istituto Giannina Gaslini, Department of Radiology, Genoa (Italy); Origgi, Daniela; Palorini, Federica [Istituto Europeo di Oncologia, Department of Medical Physics, Milan (Italy); Matranga, Domenica [University of Palermo, Department of Sciences for Health Promotion and Mother and Child Care ' ' G. D' Alessandro' ' , Palermo (Italy); Salerno, Sergio [University of Palermo, Department of Medical and Forensic Biopathology and Biotechnologies, Section of Radiology, Palermo (Italy)

    2015-05-01

    Multidetector CT (MDCT) scanners have contributed to the widespread use of CT in paediatric imaging. However, concerns are raised for the associated radiation exposure. Very few surveys on radiation exposure from MDCT studies in children are available. The aim of this study was to outline the status of radiation exposure in children from MDCT practice in Italy. In this retrospective multicentre study we asked Italian radiology units with an MDCT scanner with at least 16 slices to provide dosimetric and acquisition parameters of CT examinations in three age groups (1-5, 6-10, 11-15 years) for studies of head, chest and abdomen. The dosimetric results were reported in terms of third-quartile volumetric CT dose index (CTDI{sub vol}) (mGy), size-specific dose estimate (SSDE) (mGy), dose length product (DLP) (mGy cm), and total DLP for multiphase studies. These results were compared with paediatric European and adult Italian published data. A multivariate analysis assessed the association of CTDI{sub vol} with patient characteristics and scanning modalities. We collected data from 993 MDCT examinations performed at 25 centres. For age groups 1-5 years, 6-10 years and 11-15 years, the CTDI{sub vol}, DLP and total DLP values were statistically significantly below the values observed in our analogous national survey in adults, although the difference decreased with increasing age. CTDI{sub vol} variability among centres was statistically significant (variance = 0.07; 95% confidence interval = 0.03-0.16; P < 0.001). This study reviewed practice in Italian centres performing paediatric imaging with MDCT scanners. The variability of doses among centres suggests that the use of standardised CT protocols should be encouraged. (orig.)

  3. Unrequested information from routine diagnostic chest CT predicts future cardiovascular events

    NARCIS (Netherlands)

    Jacobs, P.C.; Gondrie, M.J.; Mali, W.P.Th.; Oen, A.L.; Prokop, M.; Grobbee, D.E.; Graaf, Y. van der

    2011-01-01

    OBJECTIVES: An increase in the number of CT investigations will likely result in a an increase in unrequested information. Clinical relevance of these findings is unknown. This is the first follow-up study to investigate the prognostic relevance of subclinical coronary (CAC) and aortic calcification

  4. Computer-aided diagnosis workstation and network system for chest diagnosis based on multislice CT images

    Science.gov (United States)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Moriyama, Noriyuki; Ohmatsu, Hironobu; Masuda, Hideo; Machida, Suguru

    2008-03-01

    Mass screening based on multi-helical CT images requires a considerable number of images to be read. It is this time-consuming step that makes the use of helical CT for mass screening impractical at present. To overcome this problem, we have provided diagnostic assistance methods to medical screening specialists by developing a lung cancer screening algorithm that automatically detects suspected lung cancers in helical CT images, a coronary artery calcification screening algorithm that automatically detects suspected coronary artery calcification and a vertebra body analysis algorithm for quantitative evaluation of osteoporosis likelihood by using helical CT scanner for the lung cancer mass screening. The function to observe suspicious shadow in detail are provided in computer-aided diagnosis workstation with these screening algorithms. We also have developed the telemedicine network by using Web medical image conference system with the security improvement of images transmission, Biometric fingerprint authentication system and Biometric face authentication system. Biometric face authentication used on site of telemedicine makes "Encryption of file" and Success in login" effective. As a result, patients' private information is protected. Based on these diagnostic assistance methods, we have developed a new computer-aided workstation and a new telemedicine network that can display suspected lesions three-dimensionally in a short time. The results of this study indicate that our radiological information system without film by using computer-aided diagnosis workstation and our telemedicine network system can increase diagnostic speed, diagnostic accuracy and security improvement of medical information.

  5. Effect of staff training on radiation dose in pediatric CT

    Energy Technology Data Exchange (ETDEWEB)

    Hojreh, Azadeh, E-mail: azadeh.hojreh@meduniwien.ac.at [Medical University of Vienna, Department of Biological Imaging and Image-guided Therapy, Division of General and Paediatric Radiology, Waehringer Guertel 18–20, A-1090 Vienna (Austria); Weber, Michael, E-mail: michael.Weber@Meduniwien.Ac.At [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of General and Paediatric Radiology, Waehringer Guertel 18–20, A-1090 Vienna (Austria); Homolka, Peter, E-mail: peter.Homolka@Meduniwien.Ac.At [Medical University of Vienna, Centre for Medical Physics and Biomedical Engineering, Waehringer Guertel 18–20, A-1090 Vienna (Austria)

    2015-08-15

    Highlights: • Pediatric patient CT doses were compared before and after staff training. • Staff training increasing dose awareness resulted in patient dose reduction. • Application of DRL reduced number of CT's with unusually high doses. • Continuous education and training are effective regarding dose optimization. - Abstract: Objective: To evaluate the efficacy of staff training on radiation doses applied in pediatric CT scans. Methods: Pediatric patient doses from five CT scanners before (1426 scans) and after staff training (2566 scans) were compared statistically. Examinations included cranial CT (CCT), thoracic, abdomen–pelvis, and trunk scans. Dose length products (DLPs) per series were extracted from CT dose reports archived in the PACS. Results: A pooled analysis of non-traumatic scans revealed a statistically significant reduction in the dose for cranial, thoracic, and abdomen/pelvis scans (p < 0.01). This trend could be demonstrated also for trunk scans, however, significance could not be established due to low patient frequencies (p > 0.05). The percentage of scans performed with DLPs exceeding the German DRLs was reduced from 41% to 7% (CCT), 19% to 5% (thorax-CT), from 9% to zero (abdominal–pelvis CT), and 26% to zero (trunk; DRL taken as summed DRLs for thorax plus abdomen–pelvis, reduced by 20% accounting for overlap). Comparison with Austrian DRLs – available only for CCT and thorax CT – showed a reduction from 21% to 3% (CCT), and 15 to 2% (thorax CT). Conclusions: Staff training together with application of DRLs provide an efficient approach for optimizing radiation dose in pediatric CT practice.

  6. Computer-aided diagnosis for osteoporosis using chest 3D CT images

    Science.gov (United States)

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

    2016-03-01

    The patients of osteoporosis comprised of about 13 million people in Japan and it is one of the problems the aging society has. In order to prevent the osteoporosis, it is necessary to do early detection and treatment. Multi-slice CT technology has been improving the three dimensional (3-D) image analysis with higher body axis resolution and shorter scan time. The 3-D image analysis using multi-slice CT images of thoracic vertebra can be used as a support to diagnose osteoporosis and at the same time can be used for lung cancer diagnosis which may lead to early detection. We develop automatic extraction and partitioning algorithm for spinal column by analyzing vertebral body structure, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the diagnosis of osteoporosis. Osteoporosis diagnosis support system obtained high extraction rate of the thoracic vertebral in both normal and low doses.

  7. CT saber-sheath trachea. Correlation with clinical, chest radiographic and functional findings

    Energy Technology Data Exchange (ETDEWEB)

    Trigaux, J.P. (Services de Radiologie, de Pneumologie, Cliniques Universitaires UCL Mont-Godinne, Yvoir (Belgium)); Hermes, G. (Services de Radiologie, de Pneumologie, Cliniques Universitaires UCL Mont-Godinne, Yvoir (Belgium)); Dubois, P. (Services de Radiologie, de Pneumologie, Cliniques Universitaires UCL Mont-Godinne, Yvoir (Belgium)); Beers, B. van (Services de Radiologie, de Pneumologie, Cliniques Universitaires UCL Mont-Godinne, Yvoir (Belgium)); Delaunois, L. (Services de Radiologie, de Pneumologie, Cliniques Universitaires UCL Mont-Godinne, Yvoir (Belgium)); Jamart, J. (Services de Radiologie, de Pneumologie, Cliniques Universitaires UCL Mont-Godinne, Yvoir (Belgium))

    1994-05-01

    The diagnosis of saber-sheath trachea is easy at CT due to its cross-sectional imaging, but the significance of this CT sign has not been evaluated in the diagnosis of chronic obstructive pulmonary disease (COPD). Various signs of COPD were compared between a series of 20 patients with a saber-sheath trachea at CT (tracheal index [<=]66%) and a group of 20 pneumologic control patients without saber-sheath trachea (tracheal index [>=]70%). These signs include clinical and standard radiographic indices of COPD, sternum-spine distance and 3 functional tests of COPD: forced expiratory volume in one second, carbon monoxide diffusing lung capacity, and funtional residual capacity (FRC). A significant difference was found between the 2 groups, concerning the values of FRC and of sternum-spine distance (p<10[sup -2]). The tracheal index was significantly correlated with the FRC values and with the sternum-spine distance. No other significant difference was observed. It is concluded that saber-sheath trachea is basically a sign of hyperinflation. (orig./MG).

  8. Volume-monitored chest CT: a simplified method for obtaining motion-free images near full inspiratory and end expiratory lung volumes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Kathryn S. [The Ohio State University College of Medicine, Columbus, OH (United States); Long, Frederick R. [Nationwide Children' s Hospital, The Children' s Radiological Institute, Columbus, OH (United States); Flucke, Robert L. [Nationwide Children' s Hospital, Department of Pulmonary Medicine, Columbus, OH (United States); Castile, Robert G. [The Research Institute at Nationwide Children' s Hospital, Center for Perinatal Research, Columbus, OH (United States)

    2010-10-15

    Lung inflation and respiratory motion during chest CT affect diagnostic accuracy and reproducibility. To describe a simple volume-monitored (VM) method for performing reproducible, motion-free full inspiratory and end expiratory chest CT examinations in children. Fifty-two children with cystic fibrosis (mean age 8.8 {+-} 2.2 years) underwent pulmonary function tests and inspiratory and expiratory VM-CT scans (1.25-mm slices, 80-120 kVp, 16-40 mAs) according to an IRB-approved protocol. The VM-CT technique utilizes instruction from a respiratory therapist, a portable spirometer and real-time documentation of lung volume on a computer. CT image quality was evaluated for achievement of targeted lung-volume levels and for respiratory motion. Children achieved 95% of vital capacity during full inspiratory imaging. For end expiratory scans, 92% were at or below the child's end expiratory level. Two expiratory exams were judged to be at suboptimal volumes. Two inspiratory (4%) and three expiratory (6%) exams showed respiratory motion. Overall, 94% of scans were performed at optimal volumes without respiratory motion. The VM-CT technique is a simple, feasible method in children as young as 4 years to achieve reproducible high-quality full inspiratory and end expiratory lung CT images. (orig.)

  9. Radiation induced skin cancer the chest wall 30 years later from breast cancer operation

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Kouji; Togawa, Tamotsu; Hasegawa, Takeshi; Matsunami, Hidetoshi; Ikeda, Tsuneko [Matsunami General Hospital, Kasamatsu, Gifu (Japan); Matsuo, Youichi

    1998-10-01

    This paper describes the skin cancer on the frontal chest wall induced by postoperative irradiation 30 years later from mastectomy. The patients was a 62-year-old woman, who received mastectomy of the right breast cancer (invasive ductal carcinoma, comedo type) at 31 years old, and received the postoperative radiotherapy of total 11,628 rad over 38 times. On the first medical examination in author`s hospital, the patient had an ulcer of about 10 cm diameter and was diagnosed the radiation induced skin cancer (well differentiated squamous cell carcinoma) in the biopsy. Because of the general condition of the patient was extremely bad and the skin cancer had highly developed, the excision was thought to be impossible. The radiotherapy (16 Gy) and combined local chemotherapy by OK 432 and Bleomycin were performed. In spite of the short term treatment, these therapies were effective on the reduction of the tumor size and the hemostasis, and brought the patient the improvement of QOL. The general condition of the patient improved to be stable and she recovered enough to go out from the hospital for 6 months. After 10 months, she showed anorexia and dyspnea and died after about 1 year from the admission. The present case is extremely rare, and it is required the radical therapy like the excision of chest wall at early stage. (K.H.)

  10. Serial chest CT findings in interstitial lung disease associated with polymyositis-dermatomyositis

    Energy Technology Data Exchange (ETDEWEB)

    Bonnefoy, Olivier; Ferretti, Gilbert; Calaque, Olivier; Coulomb, Max; Begueret, Hugues; Beylot-Barry, Marie; Laurent, Francois E-mail: francois.laurent@chu-bordeaux.fr

    2004-03-01

    Objective: A retrospective study was carried out in two institutions to determine serial changes in the pattern, distribution, and extent of interstitial lung disease (ILD) associated with polymyositis (PM)-dermatomyositis (DM) using HRCT. Subjects and methods: Twenty patients with PM-DM and clinical suspicion of ILD who underwent at least two serial HRCT examinations were retrospectively evaluated by two readers. Patients were classified according to the dominant CT pattern which was correlated with clinical evolution and underlying histology when available (n=6). Results: Patients were classified into four groups according to the dominant pattern: ground-glass attenuation and reticulation (group 1, n=9); honeycombing (group 2, n=4); airspace consolidation (group 3, n=4), and normal or almost normal lung (group 4, n=3). Under medical treatment, serial HRCT showed that the extent of areas of ground-glass opacities (group 1) decreased in five patients, stabilized in two, and increased in two. Pathologic findings demonstrated usual interstitial pneumonia (UIP) in two cases and unspecified interstitial pneumonia in one. In group 2, extent of honeycombing increased in three cases and stabilized in one. In group 3, dramatic resolution of airspace consolidation occurred in three cases. Clinical deterioration with extensive consolidation at CT and diffuse alveolar damage (DAD) at histology occurred in one patient of each of the three previous groups. Lesions stayed invisible or progressed slightly in the fourth group. Conclusion: In ILD associated with PM-DM, clinical deterioration and DAD in the follow-up can be observed whatever the HRCT pattern. However, unfavorable evolution is constant when honeycombing is present at the initial CT.

  11. Admission Chest CT Complements Fiberoptic Bronchoscopy in Prediction of Adverse Outcomes in Thermally Injured Patients

    Science.gov (United States)

    2012-08-01

    full-thickness burn (% FT), injury severity score (ISS), presence of tracheos- tomy, arterial carboxyhemoglobin levels (COHb), and the ratio ( PFR ) of...146) 57 (12, 126) .03 No. CT slices 17 (16, 20) 17 (16, 19) .87 RADS per slice 7.1 (4.4, 9.7) 3.0 (0.2, 7.2) .03 RADS ≥ 8 36 (9) 16 (3) .181 PFR 252...113, 407) 284 (130, 504) .32 * Expressed as median (Q1, Q3) or % (total). RADS, radiologist score; PFR , arterial oxygen tension to fraction of

  12. PET/CT-guided Interventions: Personnel Radiation Dose

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, E. Ronan, E-mail: ronan@ronanryan.com; Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States); Hsu, Meier [Memorial Sloan-Kettering Cancer Center, Department of Epidemiology and Biostatistics (United States); Quinn, Brian; Dauer, Lawrence T. [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics (United States); Solomon, Stephen B. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States)

    2013-08-01

    PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.

  13. Thoracic CT

    Science.gov (United States)

    ... lungs; CT scan - chest Images CT scan Thyroid cancer - CT scan Pulmonary nodule, solitary - CT scan Lung mass, right upper ... Chest Injuries and Disorders CT Scans Emphysema Lung Cancer Lung Diseases Pleural Disorders Pneumonia Pulmonary Embolism Tuberculosis Browse the Encyclopedia A.D.A. ...

  14. Comparison of chest-CT findings of Influenza virus-associated pneumonia in immunocompetent vs. immunocompromised patients

    Energy Technology Data Exchange (ETDEWEB)

    Kloth, C., E-mail: christopher.kloth@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tübingen (Germany); Forler, S.; Gatidis, S. [Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tübingen (Germany); Beck, R. [Institute of Medical Virology and Epidemiology of Viral Diseases, Eberhard-Karls-University, Elfriede-Aulhorn-Straße 6, 72076 Tübingen (Germany); Spira, D.; Nikolaou, K.; Horger, M. [Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tübingen (Germany)

    2015-06-15

    Highlights: • Patterns of pulmonary infiltration caused by Influenza viruses do not significantly differ between immunocompetent and immunocompromised patients or between different types and subtypes of Influenza virus. • Patterns of pulmonary infiltration caused by Influenza viruses seem to be interchangeable which might in part explain the great overlap in CT-imaging findings that has been reported in the past. • Interestingly, pattern transition from interstitial into airway-centric pattern seems to be frequent in immunocompromised patients receiving specific antiviral therapy, whereas the conversion of the airway-centric pattern into an interstitial pattern was observed more frequent in immunocompetent patients developing ARDS. - Abstract: Purpose: To retrospectively compare CT-patterns of pulmonary infiltration caused by different Influenza virus types and subtypes in immunocompetent and immunocompromised patients for possible discrimination. Materials and methods: Retrospective database search at our institution yielded 237 patients who were tested positive for Influenza virus type A or type B by bronchoalveolar lavage between January 2009 and April 2014. Fifty-six of these patients (female 26; male 30; median age 55.8 y, range 17–86 y; SD ± 14.4 y) underwent chest-HRCT due to a more severe clinical course of pulmonary infection. We registered all CT-findings compatible with pulmonary infection classifying them as airway predominant (tree-in-bud, centrilobular nodules, bronchial wall thickening ± peribronchial ground-glass opacity and consolidation) vs. interstitial-parenchymal predominant (bilateral, symmetrical GGO, consolidation, crazy paving and/or interlobular septal thickening). Twenty-six patients (46.4%) had follow-up CT-studies (0.78 mean, SD ± 5.8 scans). Results: Thirty-six patients were immunocompromised (group I) whereas 20 patients were immunocompetent (group II). An airway-centric pattern of infection was found in 15 patients (group

  15. Chest computed tomography using iterative reconstruction vs filtered back projection (Part 2): image quality of low-dose CT examinations in 80 patients

    Energy Technology Data Exchange (ETDEWEB)

    Pontana, Francois; Pagniez, Julien; Faivre, Jean-Baptiste; Hachulla, Anne-Lise; Remy, Jacques [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain [University Lille Nord de France, Department of Medical Statistics, Lille (France); Flohr, Thomas [Computed Tomography Division, Siemens Healthcare, Forchheim (Germany); Remy-Jardin, Martine [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Hospital Calmette, Department of Thoracic Imaging, Lille cedex (France)

    2011-03-15

    To evaluate the image quality of an iterative reconstruction algorithm (IRIS) in low-dose chest CT in comparison with standard-dose filtered back projection (FBP) CT. Eighty consecutive patients referred for a follow-up chest CT examination of the chest, underwent a low-dose CT examination (Group 2) in similar technical conditions to those of the initial examination, (Group 1) except for the milliamperage selection and the replacement of regular FBP reconstruction by iterative reconstructions using three (Group 2a) and five iterations (Group 2b). Despite a mean decrease of 35.5% in the dose-length-product, there was no statistically significant difference between Group 2a and Group 1 in the objective noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios and distribution of the overall image quality scores. Compared to Group 1, objective image noise in Group 2b was significantly reduced with increased SNR and CNR and a trend towards improved image quality. Iterative reconstructions using three iterations provide similar image quality compared with the conventionally used FBP reconstruction at 35% less dose, thus enabling dose reduction without loss of diagnostic information. According to our preliminary results, even higher dose reductions than 35% may be feasible by using more than three iterations. (orig.)

  16. Is diagnostic accuracy for detecting pulmonary nodules in chest CT reduced after a long day of reading?

    Science.gov (United States)

    Krupinski, Elizabeth A.; Berbaum, Kevin S.; Caldwell, Robert; Schartz, Kevin M.

    2012-02-01

    Radiologists are reading more cases with more images, especially in CT and MRI and thus working longer hours than ever before. There have been concerns raised regarding fatigue and whether it impacts diagnostic accuracy. This study measured the impact of reader visual fatigue by assessing symptoms, visual strain via dark focus of accommodation, and diagnostic accuracy. Twenty radiologists and 20 radiology residents were given two diagnostic performance tests searching CT chest sequences for a solitary pulmonary nodule before (rested) and after (tired) a day of clinical reading. 10 cases used free search and navigation, and the other 100 cases used preset scrolling speed and duration. Subjects filled out the Swedish Occupational Fatigue Inventory (SOFI) and the oculomotor strain subscale of the Simulator Sickness Questionnaire (SSQ) before each session. Accuracy was measured using ROC techniques. Using Swensson's technique yields an ROC area = 0.86 rested vs. 0.83 tired, p (one-tailed) = 0.09. Using Swensson's LROC technique yields an area = 0.73 rested vs. 0.66 tired, p (one-tailed) = 0.09. Using Swensson's Loc Accuracy technique yields an area = 0.77 rested vs. 0.72 tired, p (one-tailed) = 0.13). Subjective measures of fatigue increased significantly from early to late reading. To date, the results support our findings with static images and detection of bone fractures. Radiologists at the end of a long work day experience greater levels of measurable visual fatigue or strain, contributing to a decrease in diagnostic accuracy. The decrease in accuracy was not as great however as with static images.

  17. Assessment of Acute Chest Pain with Dual-Source CT%双源CT对急性胸痛的诊断价值

    Institute of Scientific and Technical Information of China (English)

    李宇; 范占明; 余婧; 耿冀; 叶红; 晏子旭; 张兆琪

    2011-01-01

    Objective To assess the accuracy of triple rule out protocol for acute chest pain with dual-source CT in emergency department. Methods 56 consecutive patients with acute chest pain were examined with triple rule out protocol on a dual-source scanner (Siemens) at a temporal resolution of 83 ms using a body-mass-adapted contrast material injection. The scanning range included the whole chest from the first ribs to the diaphragm. The level of the carina was defined as the trigger point where the second tube was switched on additionally. The tri-phase injection protocol was used to get enough enhancement of coronary arteries,pulmonary arteries and aortas. One patient was excluded because he was unable to hold breath during scanning. The remaining subjects underwent more than 30 days follow-up. Results All examinations showed an adequate contrast enhancement of the pulmonary arteries, coronary arteries and aortas. The mean volume of contrast medium was (88±5 ) ml. The median radiation exposure was 11.6 mSy (95 %CI 6.9-13.1 ). 14 patients showed coronary arteries atherosclerosis, including coronary arterial stenosis more than 50% in 13 and 12 patients underwent the coronary stent implantation. 11 patients suffered from aortic dissection(Stanford type A), and 11 patients with pulmonary embolism (PE). In brief, the reasons of the chest pain were complex. 7 of the patients suffered from several kinds of chest diseases. The sensitivity and specificity in diagnosing acute chest pain were 98% and 96% ,respectively with CTA. There were no adverse outcomes follow-up for 30 days in this group. Conclusion Triple rule out coronary CT angiography in evaluation of the patients with acute chest pain presented to the emergency department is very helpful, safety and effective way.%目的 评价双源CT胸痛三联扫描计划对急诊胸痛诊断的准确性.方法 按照入选标准连续选取急性胸痛患者56例,采用西门子双源CT扫描仪胸痛三联扫描计划

  18. Automatic CT simulation optimization for radiation therapy: A general strategy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hua, E-mail: huli@radonc.wustl.edu; Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M.; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Yu, Lifeng [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2014-03-15

    Purpose: In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. Methods: The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Results: Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube

  19. Potential of right to left ventricular volume ratio measured on chest CT for the prediction of pulmonary hypertension: correlation with pulmonary arterial systolic pressure estimated by echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Heon [Soon Chun Hyang University, Department of Radiology, Bucheon (Korea, Republic of); Kim, Seok Yeon [Seoul Medical Center, Department of Cardiology, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Kim, Jae Kyun [Chung-Ang University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Reddy, Ryan P.; Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science and Division of Cardiology, Department of Medicine, Charleston, SC (United States)

    2012-09-15

    To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio measured by chest CT with pulmonary arterial systolic pressure (PASP) estimated by echocardiography. 104 patients (72.47 {+-} 13.64 years; 39 male) who had undergone chest CT and echocardiography were divided into two groups (hypertensive and normotensive) based upon an echocardiography-derived PASP of 25 mmHg. RV to LV volume ratios (RV{sub V}/LV{sub V}) were calculated. RV{sub V}/LV{sub V} was then correlated with PASP using regression analysis. The Area Under the Curve (AUC) for predicting pulmonary hypertension on chest CT was calculated. In the hypertensive group, the mean PASP was 46.29 {+-} 14.42 mmHg (29-98 mmHg) and there was strong correlation between the RV{sub V}/LV{sub V} and PASP (R = 0.82, p < 0.001). The intraobserver and interobserver correlation coefficients for RV{sub V}/LV{sub V} were 0.990 and 0.892. RV{sub V}/LV{sub V} was 1.01 {+-} 0.44 (0.51-2.77) in the hypertensive and 0.72 {+-} 0.14 (0.52-1.11) in the normotensive group (P <0.05). With 0.9 as the cutoff for RV{sub V}/LV{sub V}, sensitivity and specificity for predicting pulmonary hypertension over 40 mmHg were 79.5 % and 90 %, respectively. The AUC for predicting pulmonary hypertension was 0.87 RV/LV volume ratios on chest CT correlate well with PASP estimated by echocardiography and can be used to predict pulmonary hypertension over 40 mmHg with high sensitivity and specificity. (orig.)

  20. SU-D-BRA-06: Dual-Energy Chest CT: The Effects of Virtual Monochromatic Reconstructions On Texture Analysis Features

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J; Duran, C; Stingo, F; Wei, W; Rao, A; Zhang, L; Court, L; Erasmus, J; Godoy, M [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To characterize the effect of virtual monochromatic reconstructions on several commonly used texture analysis features in DECT of the chest. Further, to assess the effect of monochromatic energy levels on the ability of these textural features to identify tissue types. Methods: 20 consecutive patients underwent chest CTs for evaluation of lung nodules using Siemens Somatom Definition Flash DECT. Virtual monochromatic images were constructed at 10keV intervals from 40–190keV. For each patient, an ROI delineated the lesion under investigation, and cylindrical ROI’s were placed within 5 different healthy tissues (blood, fat, muscle, lung, and liver). Several histogram- and Grey Level Cooccurrence Matrix (GLCM)-based texture features were then evaluated in each ROI at each energy level. As a means of validation, these feature values were then used in a random forest classifier to attempt to identify the tissue types present within each ROI. Their predictive accuracy at each energy level was recorded. Results: All textural features changed considerably with virtual monochromatic energy, particularly below 70keV. Most features exhibited a global minimum or maximum around 80keV, and while feature values changed with energy above this, patient ranking was generally unaffected. As expected, blood demonstrated the lowest inter-patient variability, for all features, while lung lesions (encompassing many different pathologies) exhibited the highest. The accuracy of these features in identifying tissues (76% accuracy) was highest at 80keV, but no clear relationship between energy and classification accuracy was found. Two common misclassifications (blood vs liver and muscle vs fat) accounted for the majority (24 of the 28) errors observed. Conclusion: All textural features were highly dependent on virtual monochromatic energy level, especially below 80keV, and were more stable above this energy. However, in a random forest model, these commonly used features were

  1. Evaluation of variation of voltage (kV) absorbed dose in chest CT scans; Avaliacao da variacao da tensao (kV) na dose absorvida em varreduras de TC torax

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Bruna G.A.; Mourao, Arnaldo P., E-mail: brunabgam@gmail.com [Centro Federal de Educacao Tecnologica de Minas Gerais (CENEB/CEFET-MG), Belo Horionte, MG, (Brazil)

    2013-07-01

    Computed tomography (CT) is one of the most important diagnostic techniques images today. The increasing utilization of CT implies a significant increase of population exposure to ionizing radiation. Optimization of practice aims to reduce doses to patients because the image quality is directly related to the diagnosis. You can decrease the amount of dose to the patient, and maintain the quality of the image. There are several parameters that can be manipulated in a CT scan and these parameters can be used to reduce the energy deposited in the patient. Based on this, we analyzed the variation of dose deposited in the lungs, breasts and thyroid, by varying the supply voltage of the tube. Scans of the thorax were performed following the protocol of routine chest with constant and variable current for the same applied voltage. Moreover, a female phantom was used and thermoluminescent dosimeters (TLD-100), model bat, were used to record the specific organ doses. Scans were performed on a GE CT scanner, model 64 Discovery channels. Higher doses were recorded for the voltage of 120 kV with 200 mAs in the lungs (22.46 mGy) and thyroid (32.22 mGy). For scans with automatic mAs, variable between 100 and 440, this same tension contributed to the higher doses. The best examination in terms of the dose that was used with automatic 80 kV mAs, whose lungs and thyroid received lower dose. For the best breast exam was 100 kV. Since the increase in the 80 kV to 100 kV no impact so much the dose deposited in the lungs, it can be concluded that lowering the applied voltage to 100 kV resulted in a reduction in the dose absorbed by the patient. These results can contribute to optimizing scans of the chest computed tomography.

  2. Chest computed tomography

    DEFF Research Database (Denmark)

    Loeve, Martine; Krestin, Gabriel P.; Rosenfeld, Margaret

    2013-01-01

    Clinical trials for the treatment of cystic fibrosis (CF) lung disease are important to test and optimize new therapeutic interventions. To evaluate the effect of these interventions, sensitive and accurate outcome measures are needed. The most commonly used endpoints are spirometric variables...... are not suitable to study CF lung disease in young children. Chest computed tomography (CT) holds great promise for use as a sensitive surrogate endpoint in CF. A large body of evidence has been produced to validate the use of chest CT as primary endpoint to study CF lung disease. However, before chest CT can...

  3. Characteristics of pulmonary cysts in Birt-Hogg-Dube syndrome: Thin-section CT findings of the chest in 12 patients

    Energy Technology Data Exchange (ETDEWEB)

    Tobino, Kazunori, E-mail: tobino@juntendo.ac.jp [Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Gunji, Yoko [Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Kurihara, Masatoshi [Pneumothorax Center, Nissan Tamagawa Hospital, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Kunogi, Makiko; Koike, Kengo [Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Tomiyama, Noriyuki [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Johkoh, Takeshi [Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Kurumazuka 3-1, Itami, Hyogo 664-0872 (Japan); Kodama, Yuzo [Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Iwakami, Shin-ichiro [Department of Respiratory Medicine, Juntendo University, Shizuoka Hospital, 1129 Nagaoka, Izunokuni, Shizuoka 410-2295 (Japan); Kikkawa, Mika [Biochemical Research Center, Division of Proteomics and Biomolecular Sciences, Juntendo University, Graduate School of Medicine, Bunkyo-Ku, Tokyo (Japan); Takahashi, Kazuhisa [Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Seyama, Kuniaki [Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan)

    2011-03-15

    Purpose: To describe in detail the characteristic chest computed tomography (CT) findings of Birt-Hogg-Dube (BHD) syndrome. Materials and methods: Thin-section chest CT scans of consecutive 12 patients with genetically diagnosed BHD syndrome were retrospectively evaluated by two observers, especially about the characteristics (distribution, number, size, shape and relation to pleura) of pulmonary cysts. Interobserver agreement in the identification of abnormalities on the CT images was achieved using the {kappa} statistic, and the degree of interobserver correlation for the characterization of pulmonary cysts was assessed using the Spearman rank correlation coefficient. Results: Multiple pulmonary cysts were seen in all patients. The number of cysts in each patient was various (range, 29-407), and cysts of various sizes (from a few mm to 2 cm or more) were seen in all patient. 76.6% (mean) of cysts were irregular-shaped, and 40.5% (mean) of cysts were located along the pleura. The mean extent score of cysts was 13% of the whole lung, and the distribution of cysts was predominantly in the lower medial zone. Finally, cysts abutting or including the proximal portions of lower pulmonary arteries or veins were also seen in all patients. Conclusion: Multiple, irregular-shaped cysts of various sizes with lower medial lung zone predominance are characteristic CT findings of BHD syndrome. Cysts abutting or including the proximal portions of lower pulmonary arteries or veins may also exist in this syndrome in a high probability.

  4. Impact of the scout view orientation on the radiation exposure and image quality in thoracic and abdominal CT

    Energy Technology Data Exchange (ETDEWEB)

    Suntharalingam, S.; Wetter, A.; Guberina, N.; Theysohn, J.; Ringelstein, A.; Schlosser, T.; Forsting, M.; Nassenstein, K. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2016-11-15

    To assess the impact of the scout view orientation on radiation exposure and image quality in thoracoabdominal CT, when automated tube voltage selection (ATVS) and automated tube current modulation (ATCM) are used in combination with scan planning on a single scout view. Fifty patients underwent two thoracoabdominal CT examinations, one planned on an anteroposterior scout view, one planned on a lateral scout view. Both examinations included contrast-enhanced imaging of chest (CH) and abdomen (AB) and non-contrast-enhanced imaging of the liver (LI). For all examinations the same imaging protocol was used on the same dual-source CT scanner. The radiation exposure was recorded and objective as well as visual image quality was assessed for all examinations. The median dose-length product was significantly lower in scans planned on a lateral scout view (CH: 179 vs. 218 mGy*cm, LI: 148 vs. 178 mGy*cm, AB: 324 vs. 370 mGy*cm, p < 0.0001). Objective image quality was marginal lower in scans planned on a lateral scout view, whereas the visual image quality was rated as equal. At the tested radiation doses, the orientation of the scout view has a significant impact on the radiation exposure but no clinically relevant impact on the image quality. (orig.)

  5. Triple-rule-out dual-source CT angiography of patients with acute chest pain: Dose reduction potential of 100 kV scanning

    Energy Technology Data Exchange (ETDEWEB)

    Krissak, Radko, E-mail: radko.krissak@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Henzler, Thomas; Prechel, Anne; Reichert, Miriam [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Gruettner, Joachim; Sueselbeck, Tim [1st Department of Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Schoenberg, Stefan O.; Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: To investigate the dose reduction potential of low kV triple-rule-out dual-source CT angiography (TRO-CTA) in non-obese (BMI ≤ 25 kg/m{sup 2}) patients with acute chest pain. Materials and methods: Sixty consecutive patients were randomly assigned to two different retrospectively ECG-gated TRO-CTA protocols in this prospective trial: Thirty patients were examined with a 120-kV standard protocol (320 reference mAs with automatic tube current modulation, automatically adapted pitch and ECG-pulsing) and served as the control group (group 1), an otherwise identical 100 kV protocol was used in the other thirty patients (group 2) for a radiation dose reduction. Subjective image quality was assessed on a 5 point scale (1: excellent, 5: non-diagnostic) by two blinded observers. Quantitative image analysis assessed vascular attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in different vascular segments. The effective dose was calculated from the dose length product (DLP) using a conversion coefficient of 0.017 mSv mGy{sup −1} cm{sup −1}. Results: There was no significant difference of age, BMI, heart rate, pitch or scan length between both patient groups. Subjective image quality was rated similar in both groups (group 1: 1.2 ± 0.4, group 2: average score = 1.3 ± 0.5). Vessel attenuation was significantly higher in group 2 than in group 1 (ascending aorta: 456 ± 83 HU vs. 370 ± 78 HU, p < 0.001; pulmonary artery: 468 ± 118 HU vs. 411 ± 91 HU, p = 0.03; left coronary artery: 437 ± 110 HU vs. 348 ± 89 HU, p < 0.001), however, there was no significant difference in SNR (13.2 ± 7.6 vs. 14.5 ± 7.5, p = 0.49) or CNR (13.8 ± 6.6 vs. 15.9 ± 7.7, p = 0.25). The effective radiation dose of the 100 kV protocol was significantly lower (9.6 ± 3.2 mSv vs. 18.1 ± 9.4 mSv, p < 0.0001). Conclusion: TRO-CTA with 100 kV is feasible in non-obese patients and results in diagnostic image quality and significantly reduced radiation dose.

  6. Prevalence and clinical significance of incidental cardiac findings in non-ECG-gated chest CT scans; Praevalenz und klinische Bedeutung inzidenteller Herzbefunde im nicht EKG-getriggerten Thorax-CT

    Energy Technology Data Exchange (ETDEWEB)

    Quentin, M.; Kroepil, P.; Lanzman, R.S.; Blondin, D.; Miese, F.; Scherer, A. [Heinrich-Heine-Universitaet Duesseldorf, Institut fuer Radiologie, Duesseldorf (Germany); Steiner, S. [Klinikum der Heinrich-Heine-Universitaet Duesseldorf, Klinik fuer Kardiologie, Pneumologie und Angiologie, Duesseldorf (Germany); Choy, G.; Abbara, S. [Massachusetts General Hospital, Harvard Medical School, Cardiovascular Imaging Section, Boston (United States)

    2011-01-15

    The purpose of this study was to evaluate the prevalence and clinical significance of incidental cardiac findings in non-ECG-gated chest CT. Non-ECG-gated chest CT examinations of 300 patients were retrospectively analyzed for incidental cardiac findings. Subsequently, these findings were evaluated for their clinical relevance by a cardiologist. A total of 107 out of 300 examined patients had 174 incidental cardiac findings including coronary calcification (90), aortic/mitral valve calcification (42), iatrogenic changes (23), pericardial effusion (6), dilatation of the heart (4), myocardial changes (3), thrombus in the left ventricle (2), constrictive pericarditis (2) and atrial myxoma (1). Of the cardiac findings 51% were described in the written report and in 53 out of the 107 patients the cardiac findings were unknown. Newly detected incidental findings from 8 patients were rated as clinically significant: pericardial effusion (4), constrictive pericarditis (1), thrombus in the left ventricle (1), atrial myxoma (1) and dilatation of the heart (1). Incidental cardiac findings are frequent in non-ECG-gated chest CT and may have a high clinical relevance. (orig.) [German] Ziel dieser Studie war es, die Praevalenz und klinische Bedeutung inzidenteller Herzbefunde im nicht EKG-getriggerten Thorax-CT ohne primaer kardiale Fragestellung zu evaluieren. Dreihundert nicht EKG-getriggerte Thorax-CT-Untersuchungen wurden retrospektiv bzgl. inzidenteller Herzbefunde analysiert. Die klinische Bedeutung wurde von einem Kardiologen bewertet. Von 300 Patienten hatten 107 insgesamt 174 Herzbefunde: Koronarsklerose (90), Aorten-/Mitralklappenverkalkung (42), iatrogene Veraenderungen (23), Perikarderguss (6), Herzvergroesserung (4), Myokardpathologien (3), Perikardverkalkungen (2), Thrombus im linken Ventrikel (2) und Myxom (1). Im radiologischen Bericht wurden 51% aller Herzbefunde beschrieben. Bei 53 der 107 Patienten mit Herzbefund waren diese klinisch nicht bekannt. Als

  7. 胸腹部局限性Castleman病的CT特征%CT Features of Localized Castleman Disease of the Chest and Abdomen

    Institute of Scientific and Technical Information of China (English)

    王洪洋

    2015-01-01

    Objective To analyze the CT features of thoracic and abdominal localized castleman disease and its clinical signiifcance. Methods Collected 80 patients with thoracoabdominal localized castleman disease, including 32 patients in chest, 48 cases in abdomen. All underwent CT scan, and analyzed by two physicians. Results All the patients underwent CT scanning, three types of CT appeared to have different types, type I in 48 cases, the lesion with clear edge accounted for 5 cases, mild leaf cases accounted for 43 of cases, type II in 25 cases,type III in 7 cases. Conclusion The CT features of localized castleman disease of the chest and abdomen and related pathology are closely linked to learning, CT features can provide a powerful imaging data for the clinical treatment of pretreatment.%目的:分析胸腹部局限性Castleman病的CT特征及临床意义。方法通过收集近年胸腹部局限性Castleman病的患者80例,其中胸部患者占32例、腹部患者占48例。所有患者都经过CT扫描后由两名医师进行分析。结果所有患者分别CT扫描后,CT的三种类型显现均有不同,I型有48例,其中病灶边缘清晰占5例,轻度分叶情况占43例;II型有25例;III型有7例。结论胸腹部局限性Castleman病的CT特征和相关病理学之间有密切联系,CT特征可以为临床治疗的预处理提供有力的影像学资料。

  8. A Survey of Pediatric CT Protocols and Radiation Doses in South Korean Hospitals to Optimize the Radiation Dose for Pediatric CT Scanning

    OpenAIRE

    Hwang, Jae-Yeon; Do, Kyung-Hyun; Yang, Dong Hyun; Cho, Young Ah; Yoon, Hye-Kyung; Lee, Jin Seong; KOO, HYUN JUNG

    2015-01-01

    Abstract Children are at greater risk of radiation exposure than adults because the rapidly dividing cells of children tend to be more radiosensitive and they have a longer expected life time in which to develop potential radiation injury. Some studies have surveyed computed tomography (CT) radiation doses and several studies have established diagnostic reference levels according to patient age or body size; however, no survey of CT radiation doses with a large number of patients has yet been...

  9. Attenuation and image quality in the use of protective bismuth in chest CT scans; Atenuacion y calidad de imagen en el empleo de protectores de bismuto en exploraciones de TC de torax

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Ruiz-Zorrila, J.; Fernandez Leton, P.; Martinez Gomez, L. C.; Casa de Julian, M. A. de la; Gilarranz Moreno, R.; Zucca Aparicio, D.; Minambres Moro, A.; Perez Moreno, J. M.

    2011-07-01

    For chest CT scans are protective of bismuth (Bi) with the aim of reducing the dose in the breast. The aim of this study was to evaluate the attenuation with thermoluminescent dosimeters in the glandular dose average when using these protective breast CT scans and to evaluate the image quality with and without protective Bismuth.

  10. 16排CT胸部平扫与重建临床运用分析%Clinical application of 16-slices CT to chest plain scan and reconstruction

    Institute of Scientific and Technical Information of China (English)

    王家荣; 肖化石

    2012-01-01

    目的 探讨16排CT胸部平扫与重建在胸部疾病的诊断和临床应用价值.方法 选取60例诊断为胸部疾病的住院患者进行16排CT薄层连续扫描,对结果进行容积重建、多平面重建和曲面重建分析.结果 60例患者的胸部疾病都在VR、MPR和CPR图像中得到清楚的显示.结论 16排CT胸部平扫与重建在胸部疾病的诊断中有重要应用价值.%Objective To discuss the clinical application value of 16 - slices CT to chest plain scan and reconstruction in the diagnosis of thoracopathy. Methods Sixty hospitalized patients who were diagnosed as thoracopathy were selected to receive the 16 -slices CT thin continuous scanning. According to the examination results, volume reconstruction, multiplanar reconstruction, and surface reconstruction analysis were made. Results The thoracopathy of the 60 patients were clearly shown on the VR, MPR, and CPR images. Conclusion The 16 - slices CT chest plain scan and reconstruction has important application value in the diagnosis of thoracopathy.

  11. Human infection with a novel avian-origin influenza A (H7N9) virus: serial chest radiographic and CT findings

    Institute of Scientific and Technical Information of China (English)

    Dai Jian; Zhou Xianmei; Dong Danjiang; Liu Yin; Gu Qin; Zhu Bin; Wu Chao

    2014-01-01

    Background Rapidly progressive pneumonia infection with H7N9 virus is a novel disease,and limited information is available concerning serial chest radiographic and computed tomography (CT) findings.The aim of this study was to evaluate the changes in serial radiologic findings in patients with H7N9 pneumonia.Methods The two institutional ethics review boards approved this retrospective study.This study included 10 patients with H7N9 pneumonia.All patients underwent chest radiologic examinations at different time points.Serial radiologic images were systematically analyzed.Results All patients showed abnormal results on initial chest radiography and CT.The initial radiographic abnormalities were unilateral (n=9) and bilateral (n=1),including ground-glass opacities (GGOs) (n=5) and consolidation (n=5).The initial CT findings consisted of unilateral (n=6) and bilateral (n=4),including consolidation (n=10),GGOs (n=10),reticular opacities (n=2),and pleural effusion (n=3).Follow-up radiologic findings showed rapid development of consolidation or GGOs within two weeks after illness onset.Pneumomediastinum with secondary subcutaneous emphysema and pneumothorax were noted in two patients.Follow-up high resolution computed tomography (HRCT) after two weeks showed slow improvement in both size and opacity of the lesions.On HRCT after discharge,patients had substantial residual lesions such as irregular linear opacities,reticular opacities,parenchymal bands,traction bronchiectasis,and cystic lesions.Conclusions The most common radiologic findings at presentation are multifocal or diffuse areas of consolidation and GGOs in H7N9 pneumonia.HRCT in sequence can show more changes in rapid progression of disease and a slow decrease of both size and opacity of the lesions plays an important role in the evaluation of H7N9 pneumonia.

  12. Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

    Energy Technology Data Exchange (ETDEWEB)

    Schertler, T.; Wildermuth, S.; Willmann, J.K.; Crook, D.W.; Marincek, B.; Boehm, T. [Dept. Medical Radiology, Inst. of Diagnostic Radiology, Univ. Hospital Zurich (Switzerland)

    2004-04-01

    Purpose: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. Materials and Methods: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of -400 msec in all patients. In 10 patients additional reconstructions at -200 msec, -300 msec, and -500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. Results: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P<0.05). The summary scores for visualization of bronchial segments for different diastolic reconstructions did not differ significantly. The effective radiation dose and the SNR were significantly higher with the ECG-gated acquisition technique (P<0.05). Conclusion: The bronchial tree is significantly better visualized when using non-ECG-gated MDCT compared to ECG-gated MDCT. Additionally, non-ECG-gated techniques require less radiation exposure. Thus, the current retrospective ECG-gating technique does not provide any additional benefit for 3D visualization of the bronchial tree and VB. (orig.) [German] Ziel: Untersuchung des Einflusses der retrospektiven EKG-Synchronisierung auf

  13. Accuracy of dual-source CT to identify significant coronary artery disease in patients with uncontrolled hypertension presenting with chest pain: comparison with coronary angiography.

    Science.gov (United States)

    Marwan, Mohamed; Pflederer, Tobias; Schepis, Tiziano; Seltmann, Martin; Klinghammer, Lutz; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G; Achenbach, Stephan

    2012-06-01

    It has been previously reported that the sensitivity and specificity of multislice CT for detecting significant CAD (coronary artery disease) is high. Chest pain is a common presentation in patients with uncontrolled hypertension. We investigated the sensitivity and specificity of dual-source CT to detect and rule out significant CAD in patients presenting with uncontrolled hypertension accompanied by chest pain. 260 consecutive patients presenting with acute chest pain in the context of stage 2 hypertension (systolic pressure ≥160 and/or diastolic pressure ≥100) were enrolled in the study. After admission, control of blood pressure and risk stratification, 82 patients were excluded due to renal insufficiency, prior coronary revascularisation or refused participation in the study. 90 further patients with low pre-test probability of CAD were also excluded. 88 remaining patients were subjected to CT coronary angiography using dual-source CT (Definition, Siemens Medical Solutions, Forchheim, Germany) within 24 h before invasive coronary angiography. A contrast-enhanced volume dataset was acquired (120 kV, 400 mAs/rot, collimation 2 × 64 × 0.6 mm, retrospective ECG gating). Data sets were evaluated concerning the presence or absence of significant coronary stenoses and validated against invasive coronary angiography. A significant stenosis was assumed if the diameter reduction was ≥50%. 88 patients (mean age 66 ± 11 years, mean heart rate 61 ± 9 bpm) were evaluated regarding the presence or absence of significant CAD (at least one stenosis ≥50% diameter reduction). Mean systolic blood pressure on presentation was 203 ± 20 mmHg and mean diastolic blood pressure was 103 ± 13 mmHg. On a per patient basis, the sensitivity and specificity for dual-source CT to detect significant CAD in vessels >1.5 mm diameter was 100% (36/36, 95% CI 90-100) and 90% (47/52, 95% CI 79-97), respectively with a negative predictive value (NPV) of 100% (47/47, 95% CI 92-100) and a

  14. Computed and conventional chest radiography: a comparison of image quality and radiation dose.

    Science.gov (United States)

    Ramli, K; Abdullah, B J J; Ng, K-H; Mahmud, R; Hussain, A F

    2005-12-01

    The aim of this study was to compare the image quality and entrance skin dose (ESD) for film-screen and computed chest radiography. Analysis of the image quality and dose on chest radiography was carried out on a conventional X-ray unit using film-screen, storage phosphor plates and selenium drum direct chest radiography. For each receptor, ESD was measured in 60 patients using thermoluminescent dosemeters. Images were printed on 35 x 43 cm films. Image quality was assessed subjectively by evaluation of anatomic features and estimation of the image quality, following the guidelines established by the protocols of the Commission of the European Communities. There was no statistically significant difference noted between the computed and conventional images (Wilcoxon rank sum test, P > 0.05). Imaging of the mediastinum and peripheral lung structures were better visualized with the storage phosphor and selenium drum technique than with the film-screen combination. The patients' mean ESD for chest radiography using the storage phosphor, film-screen combination and selenium drum was 0.20, 0.20 and 0.25 mGy, respectively, with no statistically significant difference with P > 0.05 (chi(2) tests).

  15. CT Diagnosis and Clinical Manifestations of Chest Malignant Lymphoma%胸部恶性淋巴瘤的CT诊断及临床表现

    Institute of Scientific and Technical Information of China (English)

    阮丽萍

    2015-01-01

    Objective: lymphoma of chest CT diagnosis and clinical manifestations of method retrospective analysis of 43 cases with pathologically proved pulmonary lymphoma clinical and CT (HRCT) data. Results:pulmonary lymphoma CT basic performance can be classified as mass, nodule type;inflammatory alveolar type;bronchial lymph vessels tube type;miliary hematogenous dissemi-nated. According to the performance of the image:mass and nodular type in 18 cases (43%);inflammatory alveolar type in 12 cases (28%), bronchial lymph vessels tube type in 5 cases (accounted for 11%);3 cases of miliary (7%);mixed type in 5 cases (11%), which its mass and nodular type. The most common. Conclusion: lymphoma of chest CT manifestations, but has some characteristics. CT plain scan and multi-phase enhanced scanning is helpful to the diagnosis.%目的:探讨胸部淋巴瘤的CT诊断及临床表现特征.方法:回顾分析43例经病理证实的肺淋巴瘤的临床及CT (部分HRCT)资料.结果:肺淋巴瘤的CT基本表现可以分为肿块、结节型;炎症肺泡型;支气管血管淋巴管型;粟粒型血行播散型.根据影像表现:肿块、结节型18例(占43%);炎症肺泡型12例(占28%),支气管血管淋巴管型5例(占11%);粟粒型3例(占7%);混合型5例(占11%),其中以肿块结节型最多见.结论:胸部淋巴瘤的CT表现形式多样,但具有一定特征性,CT平扫及多期增强扫描有助于诊断.

  16. Application Analysis of Low Dose Chest CT scan%低剂量胸部CT扫描技术的应用分析

    Institute of Scientific and Technical Information of China (English)

    李晶; 周珏榕; 黄雨琴; 续晋铭; 钱琳琳

    2013-01-01

    Objective To probe into the value of low dose chest CT in clinical application. Methods 100 cases are randomly classified into 2 groups. Each includes 18 males and 32 females. The height is between 1.60~1.78 m and the weight is between 50~80 kg. The tube current of regular group A is 90 mAs, and control group B is 70 mAs. The tube voltages are both 120 Kv and the scanned images are compared by using t test and are supervised by 2 advanced doctors for blind peer review between the two groups. Results CTDI decreases by 23.3%, from 6.84 mGy to 5.32 mGy when the tube current changed from 90 mAs to 70 mAs. The average effective tube ball dose, total tube ball dose, and CT dose index volume are (75.83±4.92) mAs, (2092±128.14) mAs and (5.77±0.42) mGy in regular group A, and the data are (56.24±5.87) mAs, (1592±114.02) mAs and (4.29±0.69) mGy in low dose group. Both of them have statistical significance (t=20.62, t=35.41, t=5.48,p < 0.05). The image noises are (11.4±2.97) HU in standard group and (14.22±3.39) HU in low dose group, there is statistical significance is (t=6.71,p < 0.05 ). Conclusion The low dose chest CT can remarkably reduce the radiation dose, and provide satisfactory images for diagnosis.%目的 探讨低剂量CT胸部扫描技术的临床应用价值.方法 将100例患者随机分2组,各50例,均为男18例,女32例.身高1.60~1.78 m,体重50~80 kg.常规A组采用管电流90 mAs,对照B组管电流70 mAs.管电压均为120 kV,两组胸部扫描的差异对比采用t 检验进行比较.扫描图像质量由2名高年资诊断医师进行盲审.结果 两组对比单次扫描剂量CTDI分别为6.84 mGy、5.32 mGy,降幅为23.3%.常规组的平均有效管球剂量、总管球剂量和放射容积剂量指数分别为(75.83±4.92)mAs、(2092±128.14)mAs和(5.77±0.42)mGy.低剂量组分别为(56.24±5.87)mAs、(1592±114.02)mAs和(4.29±0.69)mGy,两者差异有统计学意义(t =20.62,t =35.41,t =5.48,p <0.05).常规组的图像噪声为(11.4

  17. Chest MRI

    Science.gov (United States)

    Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax; Thoracic MRI ... healthy enough to filter the contrast. During the MRI, the person who operates the machine will watch ...

  18. Plasmacytoma presenting as missing rib on chest film: a case report and review of the literature.

    Science.gov (United States)

    Caffery, Terrell; Foy, Matthew

    2014-01-01

    A 33-year-old man presented to the emergency department (ED) with chief complaint of chest pain, persisting for approximately one year. Chest X-ray revealed he was missing the right posterior fifth rib. Physical examination showed no surgical scars, and he reported no history of chest trauma. A CT of his chest demonstrated a mass involving the posterior aspect of the right fifth rib, and subsequent biopsy revealed plasma cells. Laboratory results indicated the tumor was a solitary plasmacytoma of the rib. He was referred to oncology and treated with radiation therapy. This case report illustrates an unusual presentation of a solitary plasmacytoma of the rib.

  19. The application value of 64 layers CT low-dose scanning technology in the chest check%64层螺旋 CT低剂量扫描技术在胸部检查中的应用价值

    Institute of Scientific and Technical Information of China (English)

    陈绵荣; 陈志远; 吴辉

    2016-01-01

    Objective Through this research we aimed to explore the application value of 64 layers CT low-dose scanning technology in the chest check.Methods Totally 84 cases of people, who received chest examination by 64 layers CT for medical examination in our hospital during July 2014 and July 2016, were selected as the research objects, according to random number table method all selected objects were divided into low dose group, forty cases in each group.The people in low dose group received low dose 64 layers CT scan, those in routine dose group adopted regular doses of 64 layer CT scan, comparing the diagnosed rate of chest lesions of the two dose groups.Results The diagnosis rate of low dose group was 92.00%, and it was 92.50%of the conventional dose group, the difference between the two groups has no statistical significance (P>0.05). Image quality of both low dose group and conventional dose group are excellent, air-filled bronchi, pleural adhesion, spicule sign, sign of lobulation, nodular density cavity, uneven and calcification can clear display in both groups.Conclusions Diagnose rate of routine dose 64 spiral CT scans was equal to that of low dose 64 spiral CT scans.Compared to conventional treatment, low dose scan can reduce the radiation hazards, reduce the loss of the ball tube, has important application value in clinical.%目的:通过本研究探讨64层螺旋CT低剂量扫描技术在胸部检查中的应用价值。方法选取2013年7月至2016年7月期间在本院行胸部64层螺旋CT检查的80例体检者作为研究对象,按照随机法将所有入选对象分为低剂量组与常规剂量组(各40例),低剂量组行低剂量64层螺旋CT扫描,常规剂量组行常规剂量64层螺旋CT扫描,比较两种剂量对胸部病变的诊出率。结果两组分别经低剂量和常规剂量64层螺旋CT扫描诊断后,低剂量组诊出率为92.00%,常规剂量组诊出率为92.50%,两组间诊出率比

  20. Chest radiographic and CT features of acute inhaled mercury poisoning%急性吸入性汞中毒胸部X线及CT表现

    Institute of Scientific and Technical Information of China (English)

    刘雨峰

    2012-01-01

    Objective To analyze chest radiographic and CT features of acute inhaled mercury poisoning. Methods 23 cases with high concentration of mercury vapour inhaled acutely were included in this study. Among them, 81 cases underwent chest radio-graphics (61 times) and 11 cases underwent CT scanning(17 times). Radiographic and CT features were analysed. Results Chest radiographs showed pneumonia in 10 cases, the lesions appeared as multiple and scattered patchy high density in bilateral lung field with obscure border, and 3 cases combined with emphysema. There were 7 cases of interstitial pneumonia, radiographs showed lung markings increased and disorder, patchy, strip and gridding high dense shadows. 6 cases had toxic bubble pulmonary edema, which presented as large patchy dense shadows, and 4 cases of interstitial pulmonary edema, K's A,B lines were seen. On CT images, pneumonia appeared as multiple and scattered patchy shadows in bilateral lung field with bullous emphysemas which were low dense thin-wall bubbly shadows. Interstitial pneumonia appeared as lung weight lung markings in creased and blurred, resulted in massive, stripe net-like dense shadows with exudative changes around the lesions. Bullous pulmonary edema appeared as large patchy or butterfly wing-like dense shadow with undefinitive borders. Conclusion The chest X-ray and CT manifestations arc of certain characteristics in acute inhalation of mercury-induced pneumonia, combined with the clinical history and laboratory examination the diagnosis may be done.%目的 分析急性吸入性汞中毒性肺炎胸部X线及CT表现.方法 23例急性吸入性汞中毒患者,拍摄胸部平片61次,其中11例行胸部CT扫描17次,分析其X线及CT表现.结果 23例入院时X线片示汞毒性实质性肺炎10例,表现为双肺野多发片状密度增高影,边缘模糊,散在分布,3例伴有泡性肺气肿.汞毒性肺间质性炎症7例,表现为肺纹理增重模糊及紊乱,呈

  1. Low-dose ECG-gated 64-slices helical CT angiography of the chest: evaluation of image quality in 105 patients

    Energy Technology Data Exchange (ETDEWEB)

    D' Agostino, A.G.; Remy-Jardin, M.; Khalil, C.; Remy, J. [University Center of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Delannoy-Deken, V.; Duhamel, A. [University of Lille, Department of Medical Statistics, Lille (France); Flohr, T. [Siemens Medical, Research and Development Department, CT Division, Forchheim (Germany)

    2006-10-15

    The purpose of this study was to evaluate image quality of low-dose electrocardiogram (ECG)-gated multislice helical computed tomography (CT) angiograms of the chest. One hundred and five consecutive patients with a regular sinus rhythm (72 men; 33 women) underwent ECG-gated CT angiographic examination of the chest without administration of beta blockers using the following parameters: (a) collimation 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices, rotation time 0.33 s, pitch 0.3; (b) 120 kV, 200 mAs; (c) use of two dose modulation systems, including adjustment of the mAs setting to the patient's size and anatomical shape and an ECG-controlled tube current. Subjective and objective image quality was evaluated by two radiologists in consensus on 3-mm-thick scans reconstructed at 55% of the response rate (RR) interval. The population and protocol characteristics included: (a) a mean [{+-}standard deviation (SD)] body mass index (BMI) of 24.47 ({+-}4.64); (b) a mean ({+-}SD) heart rate of 72.04 ({+-}15.76) bpm; (c) a mean ({+-}SD) scanning time of 18.3 ({+-}2.73) s; (d) a mean ({+-}SD) dose-length product (DLP) value of 260.57 ({+-}83.67) mGy/cm; (e) an estimated average effective dose of 4.95 ({+-}1.59) mSv. Subjective noise was depicted in a total of nine examinations (8.5%), always rated as mild. Objective noise was assessed by measuring the standard deviation of pixel values in a homogeneous region of interest within the trachea and descending aorta; SD was 15.91 HU in the trachea and 22.16 HU in the descending aorta, with no significant difference in the mean value of the standard deviations between the four categories of BMI except for obese patients, who had a higher mean SD within the aorta. Interpolation artefacts were depicted in 22 patients, with a mean heart rate significantly lower than that of patients without interpolation artifacts, rated as mild in 11 patients and severe in 11 patients. The severity of

  2. Chemo-thermotherapy for radiation-induced squamous cell carcinoma in anterior chest wall

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Ken; Doi, Osamu; Higashiyama, Masahiko; Yokouchi, Hideki; Noguchi, Shinzaburo; Koyama, Hiroki (Osaka Prefectural Center for Adult Diseases (Japan))

    1992-09-01

    A 62 years-old woman had visited our hospital with the large and deep ulcer formation on the left anterior chest wall. A biopsy of the ulcerous lesion established the diagnosis of a squamous cell carcinoma which might be induced by the irradiation after mastectomy. Although a wide resection of the chest wall including left arm was performed, it was impossible to resect completely. After then, she had operations for local recurrence three times in three years. However, cure was not obtained, and residual lesions gradually enlarged and all layers of the anterior chest wall were replaced with tumor tissues. Conventional chemotherapy using futraful and mytomycin C was not effective. Therefore, we tried combined therapy with intravenous administration of cisplatin (CDDP) and vindesine (VDS), and local hyperthermia using radiofrequency (RF) wave. A total number of 11 courses of this treatment modality was carried out at once a week intervals. The tumor-temperature was maintained at the range of 40-43degC for 40 min in each treatment session. Chemotherapeutic agents were administered simultaneously with hyperthermia. After these treatment, the recurrent tumor was markedly reduced, and epithelization of the ulcer was recognized from the surrounding normal skin. The residual tumor was then resected completely. The operative wound was successfully closed by surrounding normal tissue mobilization. She is in good postoperative condition. We concluded that the chemo-thermotherapy is safe and promising therapeutic modality for such invasive squamous cell carcinoma, and the normal tissues are not affected. Furthermore, this approach will expand the scope of radical resection for such an uncontrollable tumor. (author).

  3. [Chemo-thermotherapy of radiation-induced squamous cell carcinoma in anterior chest wall].

    Science.gov (United States)

    Kodama, K; Doi, O; Higashiyama, M; Yokouchi, H; Noguchi, S; Koyama, H

    1992-09-01

    A 62-year-old woman had visited our hospital with the large and deep ulcer formation on the left anterior chest wall. A biopsy of the ulcerous lesion established the diagnosis of a squamous cell carcinoma which might be induced by the irradiation after mastectomy. Although a wide resection of the chest wall including left arm was performed, it was impossible to resect completely. After then, she had operations for local recurrence for three times in three years. However, cure was not obtained, and residual lesions gradually enlarged and all layers of the anterior chest wall was replaced with tumor tissues. Conventional chemotherapy using ftorafur and mitomycin C was not effective. Therefore, we tried combined therapy with intravenous administration of cisplatin (CDDP) and vindesine (VDS), and local hyperthermia using radiofrequency (RF) wave. A total number of 11 courses of this treatment modality was carried out at once a week intervals. The tumor-temperature was maintained at the range of 40-43 degrees C for 40 min in each treatment session. Chemotherapeutic agents were administered simultaneously with hyperthermia. After these treatments, the recurrent tumor was markedly reduced, and epithelization of the ulcer was recognized from the surrounding normal skin. The residual tumor was then resected completely. The operative wound was successfully closed by surrounding normal tissue mobilization. She is in good postoperative condition. We concluded that the chemo-thermotherapy is safe and promising therapeutic modality for such invasive squamous cell carcinoma, and the normal tissues are not affected. Furthermore, this approach will expand the scope of radical resection for such an uncontrollable tumor.

  4. [Influence of "optical illusion" on the detectability of pneumothorax in diagnosis for chest CT images: substantiation by visual psychological simulation images].

    Science.gov (United States)

    Henmi, Shuichi

    2008-10-20

    Some cases have been reported in which an optical illusion of lightness perception influences the detectability in diagnosis of low-density hematoma in head CT images in addition to the visual impression of the photographic density of the brain. Therefore, in this study, the author attempted to compare the detectability in diagnosis for chest images with pneumothorax using visual subjective evaluation, and investigated the influence of optical illusion on that detectability in diagnosis. Results indicated that in the window setting of lung, on such an occasion when the low-absorption free space with pneumothorax forms a crescent or the reduced lung borders on the chest-wall, an optical illusion in which the visual impression on the difference of the film contrast between the lung and the low-absorption free space with pneumothorax was psychologically emphasized when contrast was observed. In all cases the detectability in diagnosis for original images with the white thorax and mediastinum was superior to virtual images. Further, in case of the virtual double window setting of lung, thorax, and mediastinum, under the influence of the difference in the radiological anatomy of thorax and mediastinum as a result of the grouping theories of lightness computation, an optical illusion different from the original images was observed.

  5. PET/CT in radiation therapy planning; PET/CT in der Strahlentherapieplanung

    Energy Technology Data Exchange (ETDEWEB)

    Grosu, A.L. [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Krause, B.J. [Klinik fuer Nuklearmedizin, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Nestle, U. [Klinik fuer Nuklearmedizin, Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany)

    2006-09-15

    Regarding treatment planning in radiotherapy PET offers advantages in terms of tumor delineation and the description of biological processes. To define the real impact of this investigation in radiation treatment planning, following experimental, clinical and cost/benefit analysis are required. FDG-PET has a significant impact on GTV and PTV delineation in lung cancer and can detect lymph node involvement and differentiation of malignant tissue from atelectasis. In high-grade gliomas and meningiomas, methionine-PET helps to define the GTV and differentiate tumor from normal tissue. In head and neck cancer, cervix cancer and prostate cancer the value of FDG-PET for radiation treatment planning is still under investigation. For example, FDG-PET can be superior to CT and MRI in the detection of lymph node metastases in head and neck, unknown primary cancer and differentiation of viable tumor tissue after treatment. Therefore, it could play an important role in GTV definition and sparing of normal tissue. For other entities like gastro-intestinal cancer, lymphomas, sarcoma etc., the data of the literature are yet insufficient. The imaging of hypoxia, cell proliferation, angiogenesis, apoptosis and gene expression leads to the identification of different areas of a biologically heterogeneous tumor mass that can be individually targeted using IMRT. In addition, a biological dose distribution can be generated, the so-called dose painting. However, systematical experimental and clinical trials are necessary to validate this hypothesis. (orig.)

  6. Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT; Radiologische Bildgebung beim Polytrauma: Dosisvergleich von Ganzkoerper-MSCT und konventionellem Roentgen mit organspezifischer CT

    Energy Technology Data Exchange (ETDEWEB)

    Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Nagel, H.D. [Philips Medizin Systeme GmbH, Hamburg (Germany)

    2004-07-01

    Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [German] Ziel: Dosisvergleich von Ganzkoerper-MSCT und konventioneller Basisdiagnostik mit organspezifischen Ct-Untersuchungen beim Polytrauma. Material und Methoden: Die Ganzkoerper-MSCT-Untersuchung von Schaedel, Mittelgesicht, HWS sowie Thorax, Abdomen und Becken erfolgte an einem Somatom-Volume-Zoom (Siemens). Die konventionelle Bildgebung, bestehend aus Thorax, Becken, HWS, BWS und LWs, wurde an einem Siemens-Polymat durchgefuehrt. Fuer die organspezifischen CT-Untersuchungen wurden 3 Kombinationen ausgewaehlt: (1) CCT + HWS, (2) CCT + HWS

  7. Detailed analysis of the density change on chest CT of COPD using non-rigid registration of inspiration/expiration CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Young [Chonbuk National University Medical School and Hospital, Research Institute of Clinical Medicine, Department of Radiology, Jeollabuk-do (Korea, Republic of); University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Seo, Joon Beom; Lee, Hyun Joo; Kim, Namkug; Lee, Eunsol; Lee, Sang Min; Oh, Sang Young [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Hwang, Hye Jeon [Hallym University Sacred Heart Hospital, Department of Radiology, Hallym University College of Medicine, Gyeonggi-do (Korea, Republic of); Oh, Yeon-Mok; Lee, Sang-Do [University of Ulsan College of Medicine, Asan Medical Center, Department of Pulmonary and Critical Care Medicine, and Clinical Research Center for Chronic Obstructive Airway Diseases, Seoul (Korea, Republic of)

    2014-09-14

    One objective was to evaluate the air trapping index (ATI), measured by inspiration/expiration CT, in COPD patients and nonsmokers. Another objective was to assess the association between the pulmonary function test (PFT) and CT parameters such as ATI or other indices, separately in the whole lung, in emphysema, and in hyperinflated and normal lung areas. One hundred and thirty-eight COPD patients and 29 nonsmokers were included in our study. The ATI, the emphysema index (EI), the gas trapping index (Exp -856) and expiration/inspiration ratio of mean lung density (E/Iratio of MLD) were measured on CT. The values of the whole lung, of emphysema, and of hyperinflated and normal lung areas were compared and then correlated with various PFT parameters. Compared with nonsmokers, COPD patients showed a higher ATI in the whole lung and in each lung lesion (all P < 0.05). The ATI showed a higher correlation than EI with FEF{sub 25-75%}, RV and RV/TLC, and was comparable to Exp -856 and the E/I ratio of MLD. The ATI of emphysema and hyperinflated areas on CT showed better correlation than the normal lung area with PFT parameters. Detailed analysis of density change at inspiration and expiration CT of COPD can provide new insights into pulmonary functional impairment in each lung area. (orig.)

  8. Radiation risk and protection of patients in clinical SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Brix, Gunnar; Nekolla, Elke A.; Nosske, Dietmar [Federal Office for Radiation Protection, Department of Medical and Occupational Radiation Protection, Oberschleissheim (Germany); Borowski, Markus [Klinikum Braunschweig, Institute of Radiation Diagnostics and Nuclear Medicine, Braunschweig (Germany)

    2014-05-15

    Clinical studies have demonstrated that hybrid single photon emission computed tomography (SPECT)/CT for various diagnostic issues has an added value as compared to SPECT alone. However, the combined acquisition of functional and anatomical images can substantially increase radiation exposure to patients, in particular when using a hybrid system with diagnostic CT capabilities. It is, therefore, essential to carefully balance the diagnostic needs and radiation protection requirements. To this end, the evidence on health effects induced by ionizing radiation is outlined. In addition, the essential concepts for estimating radiation doses and lifetime attributable cancer risks associated with SPECT/CT examinations are presented taking into account both the new recommendations of the International Commission on Radiological Protection (ICRP) as well as the most recent radiation risk models. Representative values of effective dose and lifetime attributable risk are reported for ten frequently used SPECT radiopharmaceuticals and five fully diagnostic partial-body CT examinations. A diagnostic CT scan acquired as part of a combined SPECT/CT examination contributes considerably to, and for some applications even dominates, the total patient exposure. For the common SPECT and CT examinations considered in this study, the lifetime attributable risk of developing a radiation-related cancer is less than 0.27 %/0.37 % for men/women older than 16 years, respectively, and decreases markedly with increasing age at exposure. Since there is no clinical indication for a SPECT/CT examination unless an emission scan has been indicated, the issue on justification comes down to the question of whether it is necessary to additionally acquire a low-dose CT for attenuation correction and anatomical localization of tracer uptake or even a fully diagnostic CT. In any case, SPECT/CT studies have to be optimized, e.g. by adapting dose reduction measures from state-of-the-art CT practice, and

  9. Chest wall, lung, and pleural space trauma.

    Science.gov (United States)

    Miller, Lisa A

    2006-03-01

    Chest radiographs frequently underestimate the severity and extent of chest trauma and, in some cases, fail to detect the presence of injury. CT is more sensitive than chest radiography in the detection of pulmonary, pleural, and osseous abnormalities in the patient who has chest trauma. With the advent of multidetector CT (MDCT), high-quality multiplanar reformations are obtained easily and add to the diagnostic capabilities of MDCT. This article reviews the radiographic and CT findings of chest wall, pleural, and pulmonary injuries that are seen in the patient who has experienced blunt thoracic trauma.

  10. CT在诊断胸部创伤中的应用价值%The application value of CT in diagnosis of chest trauma

    Institute of Scientific and Technical Information of China (English)

    王青; 唐育红

    2014-01-01

    目的:探讨CT在诊断胸部创伤中的应用价值。方法:2012年1月-2014年9月收治胸部创伤患者90例,致伤原因:交通事故30例(33.3%),建筑物高空坠落10例(11.1%),殴打伤28例(31.1%),挤压伤18例(20.0%),其他4例(4.4%)。所有患者均采用螺旋CT检查。结果:诊断为创伤性湿肺60例(66.7%),患者主要表现为病变均为多发,小点状、小片状、斑点状模糊影,病变多为磨玻璃影,似一层薄纱覆盖肺野。本组90例患者发现肋骨骨折88例(97.8%),多发性骨折64例,胸骨骨折67例(74.4%),胸椎骨折39例(43.3%)。发生胸膜损伤86例(95.6%),其中表现为气胸52例,血气胸34例,发生肺挫裂伤78例(86.7%)。诊断纵膈气肿24例,主要表现为纵膈气肿及胸壁皮下软组织内积气。结论:CT在诊断胸部创伤具有分辨率高,显像清晰,患者无痛苦,诊断符合率高等优点,值得临床推广。%Objective:To explore the application value of CT in diagnosis of chest trauma.Methods:90 patients with chest trauma were selected from January 2012 to September 2014.The cause of injury including:30 cases with traffic accident,accounting for 33.3%;10 cases were falled from the buildings,accounting for 11.1%;28 cases were injury by beating,accounting for 31.1%;18 cases were crush injury,accounting for 20%;4 cases with other injury,accounting for 4.4%.All patients were examined by spiral CT. Results:60 cases were diagnosised as traumatic wet lung,accounting for 66.7%;the patients mainly manifested:multiple lesions, small punctate,patchy,small punctate opacities,and the lesions were ground glass shadow,like a layer of gauze covered lung field. Among those 90 patients in this group,there were 88 cases with rib fracture,accounting for 97.8%;64 cases with multiple fractures and 67 cases with sternum fracture,accounting for 74.4%;39 cases with thoracic vertebral fracture,accounting for 43.3%.86 cases with pleura injury

  11. Imaging lobular breast carcinoma: comparison of synchrotron radiation DEI-CT technique with clinical CT, mammography and histology

    Science.gov (United States)

    Fiedler, S.; Bravin, A.; Keyriläinen, J.; Fernández, M.; Suortti, P.; Thomlinson, W.; Tenhunen, M.; Virkkunen, P.; Karjalainen-Lindsberg, M.-L.

    2004-01-01

    Different modalities for imaging cancer-bearing breast tissue samples are described and compared. The images include clinical mammograms and computed tomography (CT) images, CT images with partly coherent synchrotron radiation (SR), and CT and radiography images taken with SR using the diffraction enhanced imaging (DEI) method. The images are evaluated by a radiologist and compared with histopathological examination of the samples. Two cases of lobular carcinoma are studied in detail. The indications of cancer are very weak or invisible in the conventional images, but the morphological changes due to invasion of cancer become pronounced in the images taken by the DEI method. The strands penetrating adipose tissue are seen clearly in the DEI-CT images, and the histopathology confirms that some strands contain the so-called 'Indian file' formations of cancer cells. The radiation dose is carefully measured for each of the imaging modalities. The mean glandular dose (MGD) for 50% glandular breast tissue is about 1 mGy in conventional mammography and less than 0.25 mGy in projection DEI, while in the clinical CT imaging the MGD is very high, about 45 mGy. The entrance dose of 95 mGy in DEI-CT imaging gives rise to an MGD of 40 mGy, but the dose may be reduced by an order of magnitude, because the contrast is very large in most images.

  12. The effect of pitch and collimation on radiation dose in spiral CT

    Institute of Scientific and Technical Information of China (English)

    CHENG Qi-Jun; TSANG Cheung; FENG Ding-Hua

    2005-01-01

    Measurements of radiation dose to patients in spiral computed tomography (CT) were completed for various collimations, table speeds and pitch. A standard CT head dosimetry phantom and thermoluminescent dosimeters (TLD) were used for the measurement. The.effect of collimation and pitch on radiation dose was studied. The results indicated that the radiation dose at the given tube current, voltage and rotation speed was inversely proportional to pitch. And the increasing times of dose were as decreasing times of pitch. This regular pattern was tenable for radiation dose at both central holes and peripheral holes of the phantom at pitch = 1, >1 and <1. The collimation had no impact on the radiation dose. The results also indicated that radiation dose at central holes was nearly equal to that at peripheral holes. There was no significant difference between them statistically. The study demonstrates that the pitch in spiral CT scans is the primary parameter and has significant impact on radiation dose.

  13. Scatter radiation from chest radiographs: is there a risk to infants in a typical NICU?

    Energy Technology Data Exchange (ETDEWEB)

    Trinh, Angela M. [Albert Einstein/Yeshiva University, College of Medicine, Bronx, NY (United States); Schoenfeld, Alan H.; Levin, Terry L. [Montefiore Medical Center, Department of Radiology, Bronx, NY (United States)

    2010-05-15

    To evaluate the dose of scatter radiation to infants in a NICU in order to determine the minimal safe distance between isolettes. Dose secondary to scattered radiation from an acrylic phantom exposed to vertical and horizontal beam exposures at 56 kVp was measured at 93 cm and 125 cm from the center of the phantom. This corresponds to 2 and 3 ft between standard isolettes, respectively. For horizontal exposures, the dosimeter was placed directly behind a CR plate and scatter dose at 90-degrees and 135-degrees from the incident beam was also measured. Exposures were obtained at 160 mAs and the results were extrapolated to correspond to 2.5 mAs. Four measurements were taken at each point and averaged. At 125 cm and 93 cm there was minimal scatter compared to daily natural background radiation dose (8.493 {mu}Gy). Greatest scatter dose obtained from a horizontal beam exposure at 135 from the incident beam was still far below background radiation. Scatter radiation dose from a single exposure as well as cumulative scatter dose from numerous exposures is significantly below natural background radiation. Infants in neighboring isolettes are not at added risk from radiation scatter as long as the isolettes are separated by at least 2 ft. (orig.)

  14. Current concepts in F18 FDG PET/CT-based Radiation Therapy planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Percy eLee

    2012-07-01

    Full Text Available Radiation therapy is an important component of cancer therapy for early stage as well as locally advanced lung cancer. The use of F18 FDG PET/CT has come to the forefront of lung cancer staging and overall treatment decision-making. FDG PET/CT parameters such as standard uptake value and metabolic tumor volume provide important prognostic and predictive information in lung cancer. Importantly, FDG PET/CT for radiation planning has added biological information in defining the gross tumor volume as well as involved nodal disease. For example, accurate target delineation between tumor and atelectasis is facilitated by utilizing PET and CT imaging. Furthermore, there has been meaningful progress in incorporating metabolic information from FDG PET/CT imaging in radiation treatment planning strategies such as radiation dose escalation based on standard uptake value thresholds as well as using respiratory gated PET and CT planning for improved target delineation of moving targets. In addition, PET/CT based follow-up after radiation therapy has provided the possibility of early detection of local as well as distant recurrences after treatment. More research is needed to incorporate other biomarkers such as proliferative and hypoxia biomarkers in PET as well as integrating metabolic information in adaptive, patient-centered, tailored radiation therapy.

  15. Computer-aided diagnosis workstation and telemedicine network system for chest diagnosis based on multislice CT images

    Science.gov (United States)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Ohmatsu, Hironobu; Kakinuma, Ryutaru; Moriyama, Noriyuki

    2009-02-01

    Mass screening based on multi-helical CT images requires a considerable number of images to be read. It is this time-consuming step that makes the use of helical CT for mass screening impractical at present. Moreover, the doctor who diagnoses a medical image is insufficient in Japan. To overcome these problems, we have provided diagnostic assistance methods to medical screening specialists by developing a lung cancer screening algorithm that automatically detects suspected lung cancers in helical CT images, a coronary artery calcification screening algorithm that automatically detects suspected coronary artery calcification and a vertebra body analysis algorithm for quantitative evaluation of osteoporosis likelihood by using helical CT scanner for the lung cancer mass screening. The functions to observe suspicious shadow in detail are provided in computer-aided diagnosis workstation with these screening algorithms. We also have developed the telemedicine network by using Web medical image conference system with the security improvement of images transmission, Biometric fingerprint authentication system and Biometric face authentication system. Biometric face authentication used on site of telemedicine makes "Encryption of file" and "Success in login" effective. As a result, patients' private information is protected. We can share the screen of Web medical image conference system from two or more web conference terminals at the same time. An opinion can be exchanged mutually by using a camera and a microphone that are connected with workstation. Based on these diagnostic assistance methods, we have developed a new computer-aided workstation and a new telemedicine network that can display suspected lesions three-dimensionally in a short time. The results of this study indicate that our radiological information system without film by using computer-aided diagnosis workstation and our telemedicine network system can increase diagnostic speed, diagnostic accuracy and

  16. Radiochromic film use to record dose profile variations in chest CT scan; Utilizacao do filme radiocromico para registro da variacao do perfil de dose em varredura de TC de torax

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, Arnaldo P.; Santana, Priscila C., E-mail: aprata@des.cefetmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Silva, Teogenes A. da; Alonso, Thessa C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-12-15

    The CT scans generate higher doses in patients than those caused by other types of diagnostic radiology using the attenuation of X-ray beams. Technological advances have increased the clinical applications of computed tomography (CT) and consequently the demand for these exams. Dose reduction strategies are difficult to implement because of a lack of proper guidance on the CT scanning. However, CT offers the possibility of adjusting the image acquisition parameters according to the patient physical profile and the diagnostic application for which it is intended to scan. Knowledge of the dose distribution is important when thinking about varying the acquisition parameters to reduce the dose. In this work was used a PMMA chest phantom to observe the dose deposition in 5 areas. Radiochromic film strips were placed inside the chest phantom, in peripheral and in the central region. The phantom was placed in the scanner isocenter and it was performed the irradiation of its central region using a chest acquisition protocol. After the phantom CT scan the radiochromic film strips were processed for obtaining digital images. Digital images were reworked to obtain the dose variation profiles for each position. The results showed a wide variation in absorbed dose by the phantom, either within a same position along the length of the film strip, as in the comparison among the five regions which the strips are placed. In this second case the dose variations were even greater. (author)

  17. Treatment techniques for 3D conformal radiation to breast and chest wall including the internal mammary chain.

    Science.gov (United States)

    Sonnik, Deborah; Selvaraj, Raj N; Faul, Clare; Gerszten, Kristina; Heron, Dwight E; King, Gwendolyn C

    2007-01-01

    Breast, chest wall, and regional nodal irradiation have been associated with an improved outcome in high-risk breast cancer patients. Complex treatment planning is often utilized to ensure complete coverage of the target volume while minimizing the dose to surrounding normal tissues. The 2 techniques evaluated in this report are the partially wide tangent fields (PWTFs) and the 4-field photon/electron combination (the modified "Kuske Technique"). These 2 techniques were evaluated in 10 consecutive breast cancer patients. All patients had computerized tomographic (CT) scans for 3D planning supine on a breast board. The breast was defined clinically by the physician and confirmed radiographically with radiopaque bebes. The resulting dose-volume histograms (DVHs) of normal and target tissues were then compared. The deep tangent field with blocks resulted in optimal coverage of the target and the upper internal mammary chain (IMC) while sparing of critical and nontarget tissues. The wide tangent technique required less treatment planning and delivery time. We compared the 2 techniques and their resultant DVHs and feasibility in a busy clinic.

  18. A national survey on radiation dose in CT in The Netherlands

    NARCIS (Netherlands)

    Molen, A.J. van der; Schilham, A.; Stoop, P.; Prokop, M.; Geleijns, J.

    2013-01-01

    Objectives To assess radiation exposure due to CT in the Netherlands. Methods Twenty-one hospitals participated in a dose survey for the 21 most frequently used CT protocols. Hospitals completed a Web survey with detailed parameters for one patient per protocol, including the dose length product (

  19. The impact of CT radiation dose reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring

    Energy Technology Data Exchange (ETDEWEB)

    Willemink, Martin J.; Takx, Richard A.P.; Jong, Pim A. de; Budde, Ricardo P.J.; Schilham, Arnold M.R.; Leiner, Tim [Utrecht University Medical Center, Department of Radiology, Utrecht (Netherlands); Bleys, Ronald L.A.W. [Utrecht University Medical Center, Department of Anatomy, Utrecht (Netherlands); Das, Marco; Wildberger, Joachim E. [Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Center, Department of Radiology, Nijmegen (Netherlands); Buls, Nico; Mey, Johan de [UZ Brussel, Department of Radiology, Brussels (Belgium)

    2014-09-15

    To analyse the effects of radiation dose reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS). Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four dose levels using unenhanced prospectively ECG-triggered protocols. Tube voltage was 120 kV and tube current differed between protocols. CT data were reconstructed with filtered back projection (FBP) and reduced dose CT data with IR. CCS was quantified with Agatston scores, calcification mass and calcification volume. Differences were analysed with the Friedman test. Fourteen hearts showed coronary calcifications. Dose reduction with FBP did not significantly change Agatston scores, calcification volumes and calcification masses (P > 0.05). Maximum differences in Agatston scores were 76, 26, 51 and 161 units, in calcification volume 97, 27, 42 and 162 mm{sup 3}, and in calcification mass 23, 23, 20 and 48 mg, respectively. IR resulted in a trend towards lower Agatston scores and calcification volumes with significant differences for one vendor (P < 0.05). Median relative differences between reference FBP and reduced dose IR for Agatston scores remained within 2.0-4.6 %, 1.0-5.3 %, 1.2-7.7 % and 2.6-4.5 %, for calcification volumes within 2.4-3.9 %, 1.0-5.6 %, 1.1-6.4 % and 3.7-4.7 %, for calcification masses within 1.9-4.1 %, 0.9-7.8 %, 2.9-4.7 % and 2.5-3.9 %, respectively. IR resulted in increased, decreased or similar calcification masses. CCS derived from standard FBP acquisitions was not affected by radiation dose reductions up to 80 %. IR resulted in a trend towards lower Agatston scores and calcification volumes. (orig.)

  20. Calcified pulmonary thromboembolism in a child with sickle cell disease: value of multidetector CT in patients with acute chest syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Staser, Jonathan A. [Indiana University Medical Center, Department of Radiology, Indianapolis, IN (United States); Alam, Tariq [Medical College of Ohio, Department of Radiology, Toledo, OH (United States); Applegate, Kimberly [Indiana University Medical Center, Sections of Pediatric Radiology and Health Services Research, Indianapolis, IN (United States); Indiana University Medical Center, Department of Radiology, Riley Hospital for Children, Indianapolis, IN (United States)

    2006-06-15

    The incidence of pulmonary embolism in children is not clearly known, but is believed to be low. Risk factors for pulmonary thromboembolism include central venous catheter, malignancy, surgery, infection, trauma, and congenital hypercoagulable disorders. Children with sickle cell disease are prothrombotic and are at an increased risk of thromboembolism. The incidence of this event is unknown because these children are often not thoroughly imaged. We report here a case of a calcified pulmonary thromboembolism in a child with sickle cell disease and emphasize the use of multidetector CT in detection of pulmonary thromboembolism in children with sickle cell disease. (orig.)

  1. Impact of Fractionation and Dose in a Multivariate Model for Radiation-Induced Chest Wall Pain

    Energy Technology Data Exchange (ETDEWEB)

    Din, Shaun U. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Williams, Eric L.; Jackson, Andrew [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Rosenzweig, Kenneth E. [Department of Radiation Oncology, Mount Sinai Medical Center, New York, New York (United States); Wu, Abraham J.; Foster, Amanda [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Rimner, Andreas, E-mail: rimnera@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2015-10-01

    Purpose: To determine the role of patient/tumor characteristics, radiation dose, and fractionation using the linear-quadratic (LQ) model to predict stereotactic body radiation therapy–induced grade ≥2 chest wall pain (CWP2) in a larger series and develop clinically useful constraints for patients treated with different fraction numbers. Methods and Materials: A total of 316 lung tumors in 295 patients were treated with stereotactic body radiation therapy in 3 to 5 fractions to 39 to 60 Gy. Absolute dose–absolute volume chest wall (CW) histograms were acquired. The raw dose-volume histograms (α/β = ∞ Gy) were converted via the LQ model to equivalent doses in 2-Gy fractions (normalized total dose, NTD) with α/β from 0 to 25 Gy in 0.1-Gy steps. The Cox proportional hazards (CPH) model was used in univariate and multivariate models to identify and assess CWP2 exposed to a given physical and NTD. Results: The median follow-up was 15.4 months, and the median time to development of CWP2 was 7.4 months. On a univariate CPH model, prescription dose, prescription dose per fraction, number of fractions, D83cc, distance of tumor to CW, and body mass index were all statistically significant for the development of CWP2. Linear-quadratic correction improved the CPH model significance over the physical dose. The best-fit α/β was 2.1 Gy, and the physical dose (α/β = ∞ Gy) was outside the upper 95% confidence limit. With α/β = 2.1 Gy, V{sub NTD99Gy} was most significant, with median V{sub NTD99Gy} = 31.5 cm{sup 3} (hazard ratio 3.87, P<.001). Conclusion: There were several predictive factors for the development of CWP2. The LQ-adjusted doses using the best-fit α/β = 2.1 Gy is a better predictor of CWP2 than the physical dose. To aid dosimetrists, we have calculated the physical dose equivalent corresponding to V{sub NTD99Gy} = 31.5 cm{sup 3} for the 3- to 5-fraction groups.

  2. Diagnostic value of CT scan for closed chest injury%胸部闭合性损伤的CT诊断及临床价值

    Institute of Scientific and Technical Information of China (English)

    于武江; 颜志红; 万云飞

    2011-01-01

    回顾性分析185例胸部闭合性损伤患者的临床、X线及CT表现.胸部闭合性损伤包括肺挫伤185例,其中合并肺撕裂伤35例,Macklin效应5例,肺疝1例.肺挫伤CT表现为肺纹理增粗、模糊9例,小点状影12例,斑片状影48例,小片状影10例,磨玻璃影16例,大片状或肺段影5例,广泛性云絮状影17例,混合性病灶68例.肺撕裂伤表现为肺血肿8例(12个病灶),肺气囊腔14例(19个病灶),液气囊腔25例(53个病灶).支气管血管束周围条状气体密度影5例;含气的肺组织疝入右侧前胸壁皮下组织内1例.首次CT漏诊肺挫伤1例,肺撕裂伤2例.%CT findings and complete clinical data of 185 cases with closed chest injuries were retrospectively analyzed.The diagnosis of 185 cases were pulmonary contusion ( n = 185 ),pulmonary laceration ( n = 35 ),Macklin effect ( n = 5 ) and lung herniation ( n = 1 ).CT findings of lung contusion appeared as thick and vagur lung marking (n =9),small points shadows (n = 12 ),blotchy shadows (n =48),small pieces shadows (n=10),ground-glass shadows (n=16),large pieces shadows (n =5),diffuse patchy clouding shadows (n = 17) or mixed lesions (n = 68).CT appearance of lung laceration included pulmonary hematomas (n = 12),cavitary lesions with air ( n = 19),cavitary lesions with air-fluid levels ( n = 53 ).Macklin effect appeared as bronchus-,pulmonary vessel-adjacent air collection and mediastinal air collection (n=5).Traumatic pulmonary hernia appeared as lung herniation through an intercostal space.Initial CT scan missed one case of pulmonary contusion and 2 cases of pulmonary laceration.

  3. Digital chest radiography

    DEFF Research Database (Denmark)

    Debess, Jeanne Elisabeth; Johnsen, Karen Kirstine; Thomsen, Henrik

    2015-01-01

    on collimation and dose reduction in digital chest radiography Methods and Materials A retrospective study of digital chest radiography is performed to evaluate the primary x-ray tube collimation of the PA and lateral radiographs. Data from one hundred fifty self-reliant female patients between 15 and 55 years...... collimations depending on side of radiograph. Results from dose reduction will be presented on the congress Conclusion: Correct positioning and collimation of digital chest radiographs can reduce the radiation dose significant to the patients and by that improve the quality of basic radiography....

  4. Radiation assessment to paediatric with F-18-FDG undergo whole-body PET/CT examination

    Energy Technology Data Exchange (ETDEWEB)

    Dhalisa, H., E-mail: dhalisa82@gmail.com; Rafidah, Z. [Kluster Oncology Science and Radiology, Advanced Medical Dental Institute, Universiti Sains Malaysia (USM), Bertam, Penang (Malaysia); Mohamad, A. S. [Department of Nuclear Medicine, National Cancer Institute, No 4 Jalan P7, Presint 7, Putrajaya (Malaysia)

    2016-01-22

    This study was carried out on wholebody radiation dose assessment to paediatrics patient who undergo PET/CT scanner at Institut Kanser Negara. Consist of 68 patients with varies of malignancies and epilepsy disease case covering age between 2 years to 12 years old. This is a retrospective study from 2010-2014. The use of PET/CT scanner as an advanced tool has been proven to give an extra radiation dose to the patient. It is because of the radiation exposure from the combination of both CT and PET scans rather than a single CT or PET scan. Furthermore, a study on radiation dose to paediatric patient undergoing PET/CT is rare in Malaysia. So, the aim of this study is to estimate the wholebody effective dose to paediatric patient in Malaysia. Effective dose from PET scan was calculated based on the activity of F18 FDG and dose coefficient reported in International Commission on Radiological Protection (ICRP) Publication 106. Effective dose from CT was determined using k coefficient as reported in ICRP publication 102 and Dose Length Product (DLP) value. The average effective dose from PET and CT were found to be 7.05mSv and 5.77mSv respectively. The mean wholebody effective dose received by a patient with combined PETCT examination was 12.78mSv. These results could be used as reference for dosimetry of a patient undergoing PETCT examination in Malaysia.

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

    Medline Plus

    Full Text Available ... for the chest x-ray, CT is the most commonly used imaging procedure for evaluating the chest. ... scanning, especially if the chest is being scanned. Most children older than six years are able to ...

  6. Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Morgane; Jacob, Sophie [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France); Roger, Gilles [Otolaryngology Department, Trousseau Hospital, Paris (France); Pelosse, Beatrice [Ophthalmology Department, Trousseau Hospital, Paris (France); Laurier, Dominique [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France); Le Pointe, Hubert Ducou [Radiology Department, Trousseau Hospital, Paris (France); Bernier, Marie-Odile, E-mail: marie-odile.bernier@irsn.fr [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France)

    2012-08-15

    Objectives: The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study. Methods: Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews. Results: Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7 mSv and 168 mGy, respectively. Conclusion: A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients' families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.

  7. A new CT-based method to quantify radiation-induced lung damage in patients.

    Science.gov (United States)

    Ghobadi, Ghazaleh; Wiegman, Erwin M; Langendijk, Johannes A; Widder, Joachim; Coppes, Robert P; van Luijk, Peter

    2015-10-01

    A new method to assess radiation-induced lung toxicity (RILT) using CT-scans was developed. It is more sensitive in detecting damage and corresponds better to physician-rated radiation pneumonitis than routinely-used methods. Use of this method may improve lung toxicity assessment and thereby facilitate development of more accurate predictive models for RILT.

  8. 基于数字模拟技术胸部CT扫描不同组织的噪声%Noise of different tissues in chest CT scanning based on digital simulated technique

    Institute of Scientific and Technical Information of China (English)

    赵峰; 曾勇明; 彭刚; 曹会志; 廖静敏; 郁仁强; 彭盛坤; 谭欢

    2012-01-01

    (P < 0.05), which had linear correlation. The noise of differenttissues increased significant in groups of 10-50 mA, and decreased gradually with the increase of current in groups of 80-240 mA.There was no statistical difference of the estimated noise value between the noise of 120 and 180 mA groups (P < 0.05). Theestimated noise of noise addition tool can be used to evaluate the image noise of different tissues. The tube current of 120 mA to180 mA in low dose chest CT scan can reduce radiation dose and keep the image quality of different tissues.

  9. Evaluation of the radiation doses in newborn patients submitted to CT examinations

    Energy Technology Data Exchange (ETDEWEB)

    De Souza Santos, William; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear (IPENCNEN/SP), Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP, (Brazil); Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA, (Brazil); Pereira Neves, Lucio; Perini, Ana Paula [Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG, (Brazil)

    2015-07-01

    The number of computed tomography (CT) scans available to the population is increasing, as well as the complexity of such exams. As a result, the radiation doses are increasing as well. Considering the population exposed to CT exams, pediatric patients are considerably more sensitive to radiation than adults. They have a longer life expectancy than adults, and may receive a higher radiation dose than necessary if the CT scan settings are not adjusted for their smaller body size. As a result of these considerations, the risk of developing cancer is of great concern when newborn patients are involved. The objective of this work was to study the radiation doses on radiosensitive organs of newborn patients undergoing a whole body CT examination, utilizing Monte Carlo simulations. The novelty of this work is the use of pediatric virtual anthropomorphic phantoms, developed at the Department of Nuclear Energy at the Federal University of Pernambuco (DEN/UFPE). The CT equipment utilized during the simulations was a Discovery VCT GE PET/CT system, with a tube voltage of 140 kVp. The X-ray spectrum of this CT scanner was generated by the SRS-78 software, which takes into account the X-ray beam energy used in PET/CT procedures. The absorbed organ doses were computed employing the F6 tally (MeV/g). The results were converted to dose coefficients (mGy/100 mA) for all the structures, considering all employed beams. The highest dose coefficients values were obtained for the brain and the thyroid. This work provides useful information regarding the risks involving ionizing radiation in newborn patients, employing a new and reliable technique. (authors)

  10. 螺旋CT不同机型胸部平扫对贫血的诊断价值%Value of chest CT plain scanning performed on different types of scanners in diagnosing anemia

    Institute of Scientific and Technical Information of China (English)

    仝开军; 舒荣宝; 张克健

    2013-01-01

    Objective To investigate the value of chest CT plain scanning performed on different types of scanners in diagnosing anemia. Methods A total of 266 patients were evenly divided into two groups and were performed chest plain scanning on GE HiSpeed NX/I double—slice CT scanner (hereafter was referred to as 2 SCT) and GE LightSpeed VCT 64—slice CT scanner (hereafter is referred to as 64 SCT) respectively. The images were objectively examined by measuring the CT value at the endovascular area of the aorta and comparing the difference of CT values between interventricular septum and atrioventricular cavity, and subjectively examined with naked eyes by differentiating the interventricular septum and the atrioventricular cavity as well as density difference between the walls and the endovascular area of the aorta. The objective and subjective findings of both anemic patients and non— anemic patients were put into comparison and analysis so that the value of chest plain scanning in diagnosing anemia, particularly that in relation to different types of scanners, can be fully assessed. Results The CT value of the endovascular area of the aorta was positively correlated with the quantitative determination of hemoglobin (r2 sct=0.82,r64 sct=0.90,P= 0.00) while the difference of CT values between the interventricular septum and the atrioventricular cavity was negatively correlated with the quantitative determination of hemoglobin (r2 sct=—0.71,r64 sct=-0.81,P=0.00). The comparison between the anemic patients and the non—anemic patients in respect of the CT value at the endovascular area of the aorta and the difference of CT values between the interventricular septum and the atrioventricular cavity presented statistic significance (P=0.00), regardless of the specific type of scanners (t value of 2 SCT were 12.17 and—11.08 respectively; t value of 64 SCT were 13.14 and —13.086 respectively). When such subjective evidence as the low—density sign of the

  11. Evaluation of ambient radiation levels in positron emission tomography/computed tomography in microPET/CT laboratory; Avaliacao dos niveis de radiacao ambiental no laboratorio de tomografia por emissao de positrons acoplada a tomografia computadorizada, microPET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Sarmento, Daniele Martins

    2016-11-01

    Micro PET/CT scanner is an essential tool generally used for small animal molecular imaging. Fluorine-18-labeled fluorodeoxyglucose is the most widely used radioisotope in this technique. The present study aimed to evaluate the radiation levels in a micro PET/CT research laboratory of the Radiopharmacy Center at IPEN-CNEN / SP, in order to accomplish both national standards and international recommendations. The radioprotection team has classified the laboratory as supervised area; even this laboratory does not require the adoption of specific measures for protection and safety, should be done regular re-evaluation of the conditions of occupational exposures. Workplace monitoring and individual control assessment were carried out to ensure the radiological protection of all workers directly involved in handling the scanner. Initially, there was conducted a radiometric survey, as well as measurements of the external radiation level in the workplace and its surroundings. To achieve this goal, there were placed nine thermoluminescent dosimeters of CaSO{sub 4}:Dy in preselected locations. Monthly evaluations of the occupationally exposed individuals were carried out through the use of TL dosimeters, ported in the workers' chest. Moreover, whole body measurements were performed every six months. The study period was about two-years which started in April 2014. All tests to evaluate micro PET/CT performance were based on the standard protocol of the equipment in accordance with the standard developed by the Animal PET Standard Task Force. Present study's results demonstrated that the ambient radiation levels (ambient and effective estimated radiation dose), as well as the effective shielding equipment are both adequate. This study emphasizes that it is essential to strictly follow the principles of radioprotection in workplace, whenever researches involve radioactive unsealed sources. (author)

  12. Decreasing the effective radiation dose in pediatric craniofacial CT by changing head position

    Energy Technology Data Exchange (ETDEWEB)

    Didier, Ryne A. [Oregon Health and Science University, School of Medicine, Portland, OR (United States); Kuang, Anna A. [Oregon Health and Science University, Department of Plastic and Reconstructive Surgery, Portland, OR (United States); Schwartz, Daniel L. [Oregon Health and Science University, Department of Psychiatry, Portland, OR (United States); Selden, Nathan R. [Oregon Health and Science University, Department of Neurological Surgery, Portland, OR (United States); Stevens, Donna M. [Oregon Health and Science University, Department of Diagnostic Radiology, Portland, OR (United States); Bardo, Dianna M.E. [Oregon Health and Science University, Department of Diagnostic Radiology, Portland, OR (United States); Oregon Health and Science University, Department of Neuroradiology, Portland, OR (United States)

    2010-12-15

    Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery. The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study. In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49). When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images. Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images. (orig.)

  13. Using of CT in diagnosis and operation instruction for chest wall tuberculosis%胸壁结核的CT诊断及其对手术治疗的指导价值

    Institute of Scientific and Technical Information of China (English)

    王钧; 张捷; 吴万鹏

    2011-01-01

    目的 探讨CT对胸壁结核的诊断价值和对手术的指导意义.方法 本组120例病人均经手术、病理证实为胸壁结核,术前均行胸部常规CT扫描.结果 120例病人胸部CT表现,其中病变局限于胸壁软组织者44例,占36.67%;肋间肌里外各形成一脓腔,中间有窦道相通呈哑铃形病变者76例,占63.33%;有72例液化区周围及脓腔壁可见钙化,占60%;肋骨呈骨质破坏者42例,占35%,78例CT未发现肋骨破坏者中有34例手术中发现存在不同程度的肋骨骨膜破坏;并发活动性或陈旧性肺及胸膜结核病灶者88例,占73.33%.全组病人术后伤口均一期愈合,随访半年至5年无1例复发.结论 胸部CT可以同时观察肺内病变、胸膜病变、肋骨病变和胸壁软组织病变,及其相互关系,指导手术治疗;病灶的液化与钙化并存,哑铃形病变对胸壁结核的诊断有一定特异性;CT对肋骨骨质破坏较敏感,但不易发现单纯骨膜破坏.%Objective To discuss the using of CT in diagnosis and operation instruction for chest wall tuberculosis.Methods All the 120 patients were confirmed by surgery and pathology, preoperative for chest wall tuberculosis were performed conventional chest CT scans.Results Chest CT manifestations of 120 patients, one of the lesions limited to 44 cases of soft organizers of chest wall, accounting for 36.67%; formation an abscess inside and outside of the intercostal muscles, dumbbell-shaped sinus in the middle of lesion was in 76 cases, accounting for 63.33%; calcification can be seen around liquefied area and the abscess wall in 72 cases, accounting for 60%; db bone destroyed was in 42 cases, accounting for 35%, 34 cases in 78 patients CT found no spoilers in the ribs, surgery found there are different degrees of rib periosteum damage; concurrent active or obsolete pulmonary tuberculosis and pleural tuberculosis in 88 cases, accounting for 73.33%.After surgery all patients achieve the primary wound

  14. Ambient radiation levels in positron emission tomography/computed tomography (PET/CT imaging center

    Directory of Open Access Journals (Sweden)

    Priscila do Carmo Santana

    2015-02-01

    Full Text Available Objective: To evaluate the level of ambient radiation in a PET/CT center. Materials and Methods: Previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results: In none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/year or free area (0.5 mSv/year as recommended by the Brazilian regulations. Conclusion: In the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed.

  15. Ambient radiation levels in positron emission tomography/computed tomography (PET/CT) imaging center

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Priscila do Carmo; Oliveira, Paulo Marcio Campos de; Mamede, Marcelo; Silveira, Mariana de Castro; Aguiar, Polyanna; Real, Raphaela Vila, E-mail: pridili@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Silva, Teogenes Augusto da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-01-15

    Objective: to evaluate the level of ambient radiation in a PET/CT center. Materials and methods: previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results: in none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/ year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion: in the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed. (author)

  16. Quantitative evaluation of correlation of dose and FDG-PET uptake value with clinical chest wall complications in patients with lung cancer treated with stereotactic body radiation therapy.

    Science.gov (United States)

    Algan, O; Confer, M; Algan, S; Matthiesen, C; Herman, T; Ahmad, S; Ali, I

    2015-01-01

    The aim of this study was to investigate quantitatively the dosimetric factors that increase the risk of clinical complications of rib fractures or chest wall pain after stereotactic body radiation therapy (SBRT) to the lung. The correlations of clinical complications with standard-uptake values (SUV) and FDG-PET activity distributions from post-treatment PET-imaging were studied. Mean and maximum doses from treatment plans, FDG-PET activity values on post-SBRT PET scans and the presence of clinical complications were determined in fifteen patients undergoing 16 SBRT treatments for lung cancer. SBRT treatments were delivered in 3 to 5 fractions using 5 to 7 fields to prescription doses in the range from 39.0 to 60.0 Gy. The dose and FDG-PET activity values were extracted from regions of interest in the chest wall that matched anatomically. Quantitative evaluation of the correlation between dose deposition and FDG-PET activity was performed by calculating the Pearson correlation coefficient using pixel-by-pixel analysis of dose and FDG-PET activity maps in selected regions of interest associated with clinical complications. Overall, three of fifteen patients developed rib fractures with chest wall pain, and two patients developed pain symptoms without fracture. The mean dose to the rib cage in patients with fractures was 37.53 Gy compared to 33.35 Gy in patients without fractures. Increased chest wall activity as determined by FDG-uptake was noted in patients who developed rib fractures. Enhanced activity from PET-images correlated strongly with high doses deposited to the chest wall which could be predicted by a linear relationship. The local enhanced activity was associated with the development of clinical complications such as chest wall inflammation and rib fracture. This study demonstrates that rib fractures and chest wall pain can occur after SBRT treatments to the lung and is associated with increased activity on subsequent PET scans. The FDG-PET activity

  17. Cavitary Lesions and Nodular Infiltration Patterns in Multi-Drug Resistant TB and Non-Tuberculosis Mycobacterium: Comparison of Chest CT

    Directory of Open Access Journals (Sweden)

    Shahram Kahkouee

    2010-05-01

    Full Text Available Background/Objective: By increasing of HIV frequency, MDRTB has also increased. Clinical and laboratory findings of multi-drug resistant TB (MDRTB and non-tuberculosis mycobacterium (NTM are very similar. Maybe imaging findings help early differentiation before culture result. This study has compared cavitary lesions and nodular infiltration patterns in the chest CT of MDRTB and NTM."nPatients and Methods: A retrospective study was performed on 66 hospitalized patients (43 MDRTB and 23 NTM in Masih Daneshvari Hospital (from 2006-2009. Lung CT scans were evaluated by a radiologist and two radiology residents without any information about the culture result. Nodular infiltrations were classified into 6 patterns (tree in bud, scattered nodule, lobar nodular infiltration, cavitary nodule, macronodule, miliary pattern and cavitary lesions to thick and thin, single and multiple with lobar distribution and satellite nodule adjacent to cavity. Chi-square statistics analysis was performed."nResult: Respectively in NTM and MDRTB: Mean age (51.5%-44.8%, sex (34.8% M and 65.2 F, 58.1% M and 41.9% F, treatment history (56.5%,83.7%, scattered nodular infiltration (47.8%, 60.5%, lobar nodular infiltration (13%, 9.3%, TIB (47.8%, 46.5%, miliary pattern (0%, 0%, cavitary nodule (21.7%, 27.9%, macro nodule (nodule≥10mm (43.5%, 25.6%, cavity (69.6%, 76.7%, thin wall cavity (65.2%, 46.5%, thick wall cavity (26.1%, 58.1%, satellite nodule adjacent to cavity (39.1%, 9.3%, single cavity (13%, 14%, lobar distribution of single cavity: RUL (8.7%, 4.7%, RML (0%, 0%, RLL (0%, 0%, LUL (4.3%, 4.7%, lingual (0%, 0%, LLL (0%, 4.7%, multiple cavity (56.5%, 60.5%, lobar distribution of multiple cavity: RUL (26.1%, 51.2%, RML (21.7%, 9.3%, RLL (26.1%, 23.3%, LUL (47.8%, 44.2%, lingual (26.1%, 18.6%, LLL (30.4%, 16.3%."nConclusion: Treatment history (p=0.016, satellite nodule adjacent to cavity (p=0.004, thick wall cavity (p=0.013 and multiple cavity in RUL (p=0.05 are more

  18. Low incidence of chest wall pain with a risk-adapted lung stereotactic body radiation therapy approach using three or five fractions based on chest wall dosimetry.

    Directory of Open Access Journals (Sweden)

    Thibaud P Coroller

    Full Text Available PURPOSE: To examine the frequency and potential of dose-volume predictors for chest wall (CW toxicity (pain and/or rib fracture for patients receiving lung stereotactic body radiotherapy (SBRT using treatment planning methods to minimize CW dose and a risk-adapted fractionation scheme. METHODS: We reviewed data from 72 treatment plans, from 69 lung SBRT patients with at least one year of follow-up or CW toxicity, who were treated at our center between 2010 and 2013. Treatment plans were optimized to reduce CW dose and patients received a risk-adapted fractionation of 18 Gy×3 fractions (54 Gy total if the CW V30 was less than 30 mL or 10-12 Gy×5 fractions (50-60 Gy total otherwise. The association between CW toxicity and patient characteristics, treatment parameters and dose metrics, including biologically equivalent dose, were analyzed using logistic regression. RESULTS: With a median follow-up of 20 months, 6 (8.3% patients developed CW pain including three (4.2% grade 1, two (2.8% grade 2 and one (1.4% grade 3. Five (6.9% patients developed rib fractures, one of which was symptomatic. No significant associations between CW toxicity and patient and dosimetric variables were identified on univariate nor multivariate analysis. CONCLUSIONS: Optimization of treatment plans to reduce CW dose and a risk-adapted fractionation strategy of three or five fractions based on the CW V30 resulted in a low incidence of CW toxicity. Under these conditions, none of the patient characteristics or dose metrics we examined appeared to be predictive of CW pain.

  19. Ambient radiation levels in a microPET/CT research laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sarmento, D.M.; Rodrigues, D.L.; Sanches, M.P.; Carneiro, J.C.G.G., E-mail: janetegc@ipen.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This study focuses on initial radiological evaluation and the exposure situation related to the worker task in a micro-positron emission tomography/computed tomography laboratory (microPET/CT). Selected and calibrated thermoluminescent dosimeters, TLD, of CaSO{sub 4}:Dy were used to measure room radiation levels. The detectors were placed in several selected points inside the microPET/CT laboratory and adjacent rooms. In addition, the occupationally exposed workers were monthly evaluated for external and internal exposures. In none of the selected points the dose values exceeded the radiation dose limit established for supervised area, as well as the values obtained in individual monitoring. (author)

  20. The applications of low tube voltage combined with dual-source CT new technology in early childhood chest examination%低管电压结合双源 CT 新技术在幼儿胸部检查中的应用研究

    Institute of Scientific and Technical Information of China (English)

    王宁; 孙建; 冯艳; 董景敏; 司晓静

    2014-01-01

    Objective To explore a more reasonable voltage parameters in early childhood chest examination with dual‐source CT new technology .Methods Selected 150 children product dual‐source CT chest scans which ages 1 to 3 years old ,the tube voltage of 80Kv group ( 50 cases ) ,100Kv group ( 50 cases ) ,120Kv group ( 50 cases ) ,with flash chest scan mode ,using real‐time online mA second adjustment techniques (CARE Dose 4D) and SAFIRE technology for image reconstruction .Two physi‐cians using 5‐point double‐blind method ,evaluated interobserver consistency with Kappa test ,recorded objective noise of ima‐ges ,CT dose index volume (CTDIvol) and dose length product (DLP) .Compared different voltage group subjective image quali‐ty ,objective noise and radiation dose .Results As the tube voltage value increased ,mediastinal and lung windows were improved image quality ,lung window image quality are more than four points ,able to meet the clinical diagnosis requires .Mediastinal win‐dow image score lower than the lung window ,which 80kV mediastinal image quality were less than 3 minutes ,unable to meet the diagnostic needs ,100kV and 120kV mediastinal image able to meet clinical needs .With tube voltage increases The objective noise significantly reduced .CT dose index volume ,dose length product value and the effective dose increases with the voltage in‐creased significantly .The group 80kV and 100kV CT dose index for the group 120kV of 24.2% ,55% .The group 80kV and 100kV effective dose for the group 120kV of 26.9% ,58.1% .Conclusion Chest examination with dual‐source CT in early childhood should be based on clinical needs to choose the right tube voltage .For lung and bronchial lesions ,80kV is able to meet clinical diagnostic needs and significantly reduce radiation measurement ,while for mediastinal lesions ,you need to select a high‐er tube voltage value .%目的:探讨应用双源C T新技术后,在幼儿胸部检查中较为合理

  1. A feasibility study of using ultra-low tube voltage (70 kVp) combined with iterative reconstruction in low weight children chest CT scan%超低管电压(70 kVp)结合迭代重建技术在低体重儿童胸部检查中的可行性研究

    Institute of Scientific and Technical Information of China (English)

    刘艳

    2015-01-01

    Objective:To assess radiation dose and image quality of chest CT examinations in low weight (0.05) compared to control group. hTere were no signiifcant differences between the overall subjective image quality grades of FBP groups.Conclusion: Ultra-low tube voltage (70 kVp) combined with iterative reconstruction technique the of the chest can obtain image with the clinical acceptable image noise in low weight children, meanwhile reduce radiation does signiifcantly.%目的:研究超低管电压(70 kVp)与迭代重建联合应用对低体重(0.05),图像主观评分无统计学差异。结论:超低管电压(70 kVp)与迭代重建联合应用较传统螺旋扫描获得临床可以接受的图像质量,同时显著减少了辐射剂量。

  2. Use of PET/CT instead of CT-only when planning for radiation therapy does not notably increase life years lost in children being treated for cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kornerup, Josefine S.; Munck af Rosenschoeld, Per [Rigshospitalet, Section of Radiotherapy, Department of Oncology, Copenhagen (Denmark); The Niels Bohr Institute, Faculty of Science, University of Copenhagen, Copenhagen (Denmark); Brodin, Patrik [Rigshospitalet, Section of Radiotherapy, Department of Oncology, Copenhagen (Denmark); Institute for Onco-Physics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (United States); Birk Christensen, Charlotte; Borgwardt, Lise [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Bjoerk-Eriksson, Thomas [Sahlgrenska University Hospital, Department of Oncology, Gothenburg (Sweden); Kiil-Berthelsen, Anne [Rigshospitalet, Section of Radiotherapy, Department of Oncology, Copenhagen (Denmark); Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark)

    2015-04-01

    PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans used for radiation therapy planning in children with cancer, and compare to the risks attributable to the cancer treatment. Organ doses and effective doses were estimated for 40 children (2-18 years old) who had been scanned using PET/CT as part of radiation therapy planning. The risk of inducing secondary cancer was estimated using the models in BEIR VII. The prognosis of an induced cancer was taken into account and the reduction in life expectancy, in terms of life years lost, was estimated for the diagnostics and compared to the life years lost attributable to the therapy. Multivariate linear regression was performed to find predictors for a high contribution to life years lost from the radiation therapy planning diagnostics. The mean contribution from PET to the effective dose from one PET/CT scan was 24% (range: 7-64%). The average proportion of life years lost attributable to the nuclear medicine dose component from one PET/CT scan was 15% (range: 3-41%). The ratio of life years lost from the radiation therapy planning PET/CT scans and that of the cancer treatment was on average 0.02 (range: 0.01-0.09). Female gender was associated with increased life years lost from the scans (P < 0.001). Using FDG-PET/CT instead of CT only when defining the target volumes for radiation therapy of children with cancer does not notably increase the number of life years lost attributable to diagnostic examinations. (orig.)

  3. Use of PET/CT instead of CT-only when planning for radiation therapy does not notably increase life years lost in children being treated for cancer

    DEFF Research Database (Denmark)

    Kornerup, Josefine S.; Brodin, Nils Patrik; Christensen, Charlotte Birk

    2015-01-01

    BACKGROUND: PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. OBJECTIVE: To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans...... used for radiation therapy planning in children with cancer, and compare to the risks attributable to the cancer treatment. MATERIALS AND METHODS: Organ doses and effective doses were estimated for 40 children (2-18 years old) who had been scanned using PET/CT as part of radiation therapy planning....... The risk of inducing secondary cancer was estimated using the models in BEIR VII. The prognosis of an induced cancer was taken into account and the reduction in life expectancy, in terms of life years lost, was estimated for the diagnostics and compared to the life years lost attributable to the therapy...

  4. [Chest trauma].

    Science.gov (United States)

    Freixinet Gilart, Jorge; Ramírez Gil, María Elena; Gallardo Valera, Gregorio; Moreno Casado, Paula

    2011-01-01

    Chest trauma is a frequent problem arising from lesions caused by domestic and occupational activities and especially road traffic accidents. These injuries can be analyzed from distinct points of view, ranging from consideration of the most severe injuries, especially in the context of multiple trauma, to the specific characteristics of blunt and open trauma. In the present article, these injuries are discussed according to the involvement of the various thoracic structures. Rib fractures are the most frequent chest injuries and their diagnosis and treatment is straightforward, although these injuries can be severe if more than three ribs are affected and when there is major associated morbidity. Lung contusion is the most common visceral lesion. These injuries are usually found in severe chest trauma and are often associated with other thoracic and intrathoracic lesions. Treatment is based on general support measures. Pleural complications, such as hemothorax and pneumothorax, are also frequent. Their diagnosis is also straightforward and treatment is based on pleural drainage. This article also analyzes other complex situations, notably airway trauma, which is usually very severe in blunt chest trauma and less severe and even suitable for conservative treatment in iatrogenic injury due to tracheal intubation. Rupture of the diaphragm usually causes a diaphragmatic hernia. Treatment is always surgical. Myocardial contusions should be suspected in anterior chest trauma and in sternal fractures. Treatment is conservative. Other chest injuries, such as those of the great thoracic and esophageal vessels, are less frequent but are especially severe.

  5. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    Science.gov (United States)

    Gu, Jin; Shi, He-Shui; Han, Ping; Yu, Jie; Ma, Gui-Na; Wu, Sheng

    2016-10-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose.

  6. Reversed halo sign: chest CT findings in 5 patients and cause analysis%胸部CT表现为反晕征五例并文献复习

    Institute of Scientific and Technical Information of China (English)

    路明; 陈亚红; 韩翔; 杨薇; 张静; 朱翔; 朱红; 贺蓓; 孙伯章

    2016-01-01

    Objective To describe diseases that may present with the reversed halo sign (RHS) on high-resolution CT,and therefore to improve the recognition of this thoracic radiological feature.Methods We retrospectively reviewed the HRCT scans and medical records of 5 patients who presented with RHS on chest CT from Peking University Third Hospital.With "reversed halo sign,fairy ring,atoll sign" as the Chinese and English keywords,420 cases from the literatures were also reviewed through PubMed,Wanfang and CNKI databases until August 2015.Results The 5 patients were all males,aging 19-55 years.The diagnosis of the diseases included cryptogenic organizing pneumonia (patient 1),pulmonary tuberculosis (patient 2),pulmonary infarction (patient 3),pulmonary edema (patient 4) and mycoplasma pneumonia (patient 5).Literature review showed that RHS was observed in 206 cases of infectious pulmonary diseases and 219 cases of noninfectious pulmonary diseases.Invasive fungal infection (including 59 cases of mucormycosis and 27 aspergillosis) and pulmonary tuberculosis (79 cases) predominated in infectious pulmonary diseases.However,in non-infectious pulmonary diseases,RHS was most frequently observed in organizing pneumonia (66%),sarcoidosis,lung cancer,pulmonary infarction,pulmonary edema and other interstitial lung diseases.There were some differences in the morphologic findings of RHS among invasive fungal infection,pulmonary tuberculosis and organizing pneumonia.In addition,our patient with mycoplasma pneumonia was the first case reported to present with RHS on HRCT.Condusions Although a wide spectrum of pulmonary diseases may present with RHS on chest CT,this sign is stilla characteristic thoracic radiological feature,which is more commonly found in organizing pneumonia,pulmonary tuberculosis and invasive fungal infection,and is helpful in differential diagnosis.%目的 探讨反晕征在不同肺部疾病谱的分布,提高对这一影像征的认识.方法 报道北京大学第

  7. Diagnostic Accuracy and Radiation Dose of CT Coronary Angiography in Atrial Fibrillation

    DEFF Research Database (Denmark)

    Vorre, Mette Medom; Abdulla, Jawdat

    2013-01-01

    Purpose:To determine by means of a systematic review and meta-analysis the diagnostic accuracy, associated radiation dose, and technical challenges of computed tomographic (CT) coronary angiography in patients with atrial fibrillation.Materials and Methods:A systematic literature search was perfo...

  8. Characterization of a CT ionization chamber for radiation field mapping.

    Science.gov (United States)

    Perini, Ana P; Neves, Lucio P; Vivolo, Vitor; Xavier, Marcos; Khoury, Helen J; Caldas, Linda V E

    2012-07-01

    A pencil-type ionization chamber, developed at Instituto de Pesquisas Energéticas e Nucleares (IPEN), was characterized with the objective to verify the possibility of its application in radiation field mapping procedures. The characterization tests were evaluated, and the results were satisfactory. The results obtained for the X radiation field mapping with the homemade chamber were compared with those of a PTW Farmer-type chamber (TN 30011-1). The maximum difference observed in this comparison was only 1.25%, showing good agreement.

  9. Multicenter study assessing ophthalmologist's knowledge towards radiation dose when prescribing CT scans for pediatric patients: A Saudi Arabian perspective

    Directory of Open Access Journals (Sweden)

    Hussain Almohiy

    2016-01-01

    Conclusion: Knowledge of Ophthalmologists towards the risk of radiation exposure in pediatric CT is poor and suggest a propensity of misappropriate radiation use and under-utilization of alternative radiation-free methods. Structured education sessions and deliberation of the radiation dangers with patients are recommended.

  10. CT outperforms radiographs at a comparable radiation dose in the assessment for spondylolysis

    Energy Technology Data Exchange (ETDEWEB)

    Fadell, Michael F.; Stewart, Jaime R.; Harned, Roger K.; Ingram, James D.; Miller, Angie L.; Strain, John D.; Weinman, Jason P. [Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States); University of Colorado Hospital, Department of Radiology, Aurora, CO (United States); Gralla, Jane [University of Colorado Denver, Department of Pediatrics, Aurora, CO (United States); Bercha, Istiaq [Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States)

    2015-07-15

    Lumbar spondylolysis, a unilateral or bilateral fracture at pars interarticularis, is a common cause of low back pain in children. The initial imaging study in the diagnosis of lumbar spondylolysis has historically been lumbar spine radiographs; however, radiographs can be equivocal or false-negative. Definitive diagnosis can be achieved with computed tomography (CT), but its use has been limited due to the dose of ionizing radiation to the patient. By limiting the z-axis coverage to the relevant anatomy and optimizing the CT protocol, we are able to provide a definitive diagnosis of fractures of the pars interarticularis at comparable or lower radiation dose than commonly performed lumbar spine radiographs. As there is no gold standard for the diagnosis of spondylolysis besides surgery, we compared interobserver agreement and degree of confidence to determine which modality is preferable. Sixty-two patients with low back pain ages 5-18 years were assessed for the presence of spondylolysis. Forty-seven patients were evaluated by radiography and 15 patients were evaluated by limited field-of-view CT. Both radiographic and CT examinations were assessed anonymously in random order for the presence or absence of spondylolysis by six raters. Agreement was assessed among raters using a Fleiss Kappa statistic for multiple raters. CT provided a significantly higher level of agreement among raters than radiographs (P < 0.001). The overall Kappa for rater agreement with radiographs was 0.24, 0.34 and 0.40 for 2, 3 or 4 views, respectively, and 0.88 with CT. Interobserver agreement is significantly greater using limited z-axis coverage CT when compared with radiographs. Radiologist confidence improved significantly with CT compared to radiographs regardless of the number of views. (orig.)

  11. Evaluation of radiation dose in 64-row whole-body CT of multiple injured patients compared to 4-row CT; Evaluation der Strahlendosis bei Polytrauma-CT-Untersuchungen eines 64-Zeilen-CT im Vergleich zur 4-Zeilen-CT

    Energy Technology Data Exchange (ETDEWEB)

    Harrieder, A.; Geyer, L.L.; Koerner, M.; Deak, Z.; Wirth, S.; Reiser, M.; Linsenmaier, U. [Ludwig-Maximilians-Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie

    2012-05-15

    Purpose: To evaluate radiation exposure in whole-body CT (WBCT) of multiple injured patients comparing 4-row multidetector computed tomography (MDCT) to 64-row MDCT. Materials and Methods: 200 WBCT studies were retrospectively evaluated: 92 4-row MDCT scans and 108 64-row MDCT scans. Each CT protocol was optimized for the particular CT system. The scan length, CT dose index (CTDI), and dose length product (DLP) were recorded and analyzed for radiation exposure. The mean effective dose was estimated based on conversion factors. Student's t-test was used for statistical analysis. Results: The mean CTDI{sub vol} values (mGy) of the thorax and abdomen were significantly reduced with 64-row MDCT (10.2 {+-} 2.5 vs. 11.4 {+-} 1.4, p < 0.001; 14.2 {+-} 3.7 vs. 16.1 {+-} 1.7, p < 0.001). The DLP values (mGy x cm) of the head and thorax were significantly increased with 64-row MDCT (1305.9 {+-} 201.1 vs. 849.8 {+-} 90.9, p < 0,001; 504.4 {+-} 134.4 vs. 471.5 {+-} 74.1, p = 0.030). The scan lengths (mm) were significantly increased with 64-row MDCT: head 223.6 {+-} 35.8 vs. 155.5 {+-} 12.3 (p < 0.001), thorax 427.4 {+-} 44.5 vs. 388.3 {+-} 57.5 (p < 0.001), abdomen 520.3 {+-} 50.2 vs. 490.8 {+-} 51.6 (p < 0.001). The estimated mean effective doses (mSv) were 22.4 {+-} 2.6 (4-row MDCT) and 24.1 {+-} 4.6 (64-row MDCT; p = 0.001), resulting in a percentage increase of 8 %. Conclusion: The radiation dose per slice of the thorax and abdomen can be significantly decreased by using 64-row MDCT. Due to the technical advances of modern 64-row MDCT systems, the scan field can be adapted to the clinical demands and, if necessary, enlarged without time loss. As a result, the estimated mean effective dose might be increased in WBCT. (orig.)

  12. Accuracy of chest radiography versus chest computed tomography in hemodynamically stable patients with blunt chest trauma

    Institute of Scientific and Technical Information of China (English)

    Mojtaba Chardoli; Toktam Hasan-Ghaliaee; Hesam Akbari; Vafa Rahimi-Movaghar

    2013-01-01

    Objective:Thoracic injuries are responsible for 25% of deaths of blunt traumas.Chest X-ray (CXR) is the first diagnostic method in patients with blunt trauma.The aim of this study was to detect the accuracy of CXR versus chest computed tomograpgy (CT) in hemodynamically stable patients with blunt chest trauma.Methods:Study was conducted at the emergency department of S ina Hospital from March 2011 to March 2012.Hemodynamically stable patients with at least 16 years of age who had blunt chest trauma were included.All patients underwent the same diagnostic protocol which consisted of physical examination,CXR and CT scan respectively.Results:Two hundreds patients (84% male and 16% female) were included with a mean age of(37.9±13.7) years.Rib fracture was the most common finding of CXR (12.5%) and CT scan (25.5%).The sensitivity of CXR for hemothorax,thoracolumbar vertebra fractures and rib fractures were 20%,49% and 49%,respectively.Pneumothorax,foreign body,emphysema,pulmonary contusion,liver hematoma and sternum fracture were not diagnosed with CXR alone.Conclusion:Applying CT scan as the first-line diagnostic modality in hemodynamically stable patients with blunt chest trauma can detect pathologies which may change management and outcome.

  13. Accuracy of chest radiography versus chest computed tomography in hemodynamically stable patients with blunt chest trauma

    Directory of Open Access Journals (Sweden)

    Chardoli Mojtaba

    2013-12-01

    Full Text Available 【Abstract】 Objective: Thoracic injuries are respon- sible for 25% of deaths of blunt traumas. Chest X-ray (CXR is the first diagnostic method in patients with blunt trauma. The aim of this study was to detect the accuracy of CXR versus chest computed tomograpgy (CT in hemodynami- cally stable patients with blunt chest trauma. Methods: Study was conducted at the emergency department of Sina Hospital from March 2011 to March 2012. Hemodynamically stable patients with at least 16 years of age who had blunt chest trauma were included. All patients underwent the same diagnostic protocol which consisted of physical examination, CXR and CT scan respectively. Results: Two hundreds patients (84% male and 16% female were included with a mean age of (37.9±13.7 years. Chin J Traumatol 2013;16(6:351-354 Rib fracture was the most common finding of CXR (12.5% and CT scan (25.5%. The sensitivity of CXR for hemothorax, thoracolumbar vertebra fractures and rib fractures were 20%, 49% and 49%, respectively. Pneumothorax, foreign body, emphysema, pulmonary contusion, liver hematoma and ster- num fracture were not diagnosed with CXR alone. Conclusion: Applying CT scan as the first-line diag- nostic modality in hemodynamically stable patients with blunt chest trauma can detect pathologies which may change management and outcome. Key words: Radiography; Thoracic injuries; Tomography, X-ray computed

  14. Dual-source CT Low-dose Technology Used in Suspected Lesions in Patients with Chest CT Examination%双源CT低剂量技术在疑是胸部病变患者CT检查中的应用

    Institute of Scientific and Technical Information of China (English)

    刘素芝; 郭占林; 张颖

    2016-01-01

    . Results With the reduction of radiation dose, the signal-to-noise ratio of the pulmonary artery and the descending aorta gradually reduced (P<0.05). Each image quality score and decreased with the decrease of the bulb electricity flow (P<0.05), 80 mas electric flow of low duct lesion detection rate of 81.25%from the rest of the group was significantly lower (P<0.05). Conclusion Dual-source CT low-dose technique can in suspected lesions in patients with chest CT examination to give accurate judgment, can effectively reduce the radiation damage to human body, suggested that dual-source CT examination with 85 mas reference pipe flow, both can obtain accurate diagnostic images clearly and can significantly reduce the radiation dose.

  15. Characterization of a CT ionization chamber for radiation field mapping

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana P., E-mail: aperini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Neves, Lucio P., E-mail: lpneves@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Vivolo, Vitor, E-mail: vivolo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Xavier, Marcos, E-mail: mxavier@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil); Khoury, Helen J., E-mail: hjkhoury@gmail.com [Universidade Federal de Pernambuco, Departamento de Energia Nuclear, Av. Prof. Luiz Freire 1000, 50740-540, Recife, PE (Brazil); Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil)

    2012-07-15

    A pencil-type ionization chamber, developed at Instituto de Pesquisas Energeticas e Nucleares (IPEN), was characterized with the objective to verify the possibility of its application in radiation field mapping procedures. The characterization tests were evaluated, and the results were satisfactory. The results obtained for the X radiation field mapping with the homemade chamber were compared with those of a PTW Farmer-type chamber (TN 30011-1). The maximum difference observed in this comparison was only 1.25%, showing good agreement. - Highlights: Black-Right-Pointing-Pointer A new ionization chamber was made and tested for radiation field mapping. Black-Right-Pointing-Pointer This ionization chamber was made using only accessible low cost materials. Black-Right-Pointing-Pointer The operational tests were made and the results were within the recommended limits. Black-Right-Pointing-Pointer The field map was compared with a commercial chamber presenting a 1.25% difference. Black-Right-Pointing-Pointer Our chamber presents potential for assurance reliability in calibration procedures.

  16. National Survey of Radiation Dose and Image Quality in Adult CT Head Scans in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chung-Jung Lin

    Full Text Available The purpose of the present study was to evaluate the influence of different variables on radiation dose and image quality based on a national database.Taiwan's Ministry of Health and Welfare requested all radiology departments to complete a questionnaire for each of their CT scanners. Information gathered included all scanning parameters for CT head scans. For the present analysis, CT machines were divided into three subgroups: single slice CT (Group A; multi-detector CT (MDCT with 2-64 slices (Group B; and MDCT with more than 64 slices (Group C. Correlations between computed tomography dose index (CTDI and signal-to-noise ratio (SNR with cumulated tube rotation number (CTW(n and cumulated tube rotation time (CTW(s, and sub group analyses of CTDI and SNR across the three groups were performed.CTDI values demonstrated a weak correlation (r = 0.33 with CTW(n in Group A. SNR values demonstrated a weak negative correlation (r = -0.46 with CTW(n in Group C. MDCT with higher slice numbers used more tube potential resulting in higher effective doses. There were both significantly lower CTDI and SNR values in helical mode than in axial mode in Group B, but not Group C.CTW(n and CTW(s did not influence radiation output. Helical mode is more often used in MDCT and results in both lower CTDI and SNR compared to axial mode in MDCT with less than 64 slices.

  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. Weekly monitoring of the effects of conventional external beam radiation therapy on patients with head and neck, chest, and pelvis cancer by means of blood cells count

    Energy Technology Data Exchange (ETDEWEB)

    Lundgren, Maria da Salete Fonseca dos Santos [Hospital Universitario Oswaldo Cruz, Recife, PE (Brazil). Radiotherapy Unit]. E-mail: salete@lundgren.med.br; Cavalcanti, Maria do Socorro de Mendonca [Universidade de Pernambuco, Recife, PE (Brazil); Sampaio, Divaldo de Almeida [Centro de Hematologia de Pernambuco (Hemope), Recife, PE (Brazil)

    2008-01-15

    Objective: To evaluate the necessity of weekly monitoring by means of leukocyte and platelet counts of patients with head and neck, chest, and pelvis cancer submitted to conventional radiotherapy. Materials and methods: A hundred and one adult patients with cancer of head and neck (n = 11), chest (n = 35) and pelvis (n = 55), submitted to radiotherapy were assessed by means of leukocyte and platelet counts on a weekly basis, with a comparison between the results before and during the treatment and in correlation with the area treated, patient's sex and age group. Results: The most significant decrease in leukocytes was observed in the fourth week, when lymphocytes, total leukocytes, neutrophils, monocytes and platelets presented a decrease of 53.5%, 26.8%, 19.4%, 22.2% and 14.6%, respectively, in comparison with the values found before the beginning of the therapy. Geometric means for pelvis during the treatment were lower than those for chest, and head and neck. Lymphocytes demonstrated to be more sensitive to radiation therapy. No alteration was found in leukocyte or platelet counts in correlation with patients' sex or age. Conclusion: Based on the results of the present study, weekly leukocyte and platelet counts do not seem to be useful in the assessment patients submitted to conventional radiotherapy for localized cancer. (author)

  19. Leukemia and brain tumors among children after radiation exposure from CT scans : design and methodological opportunities of the Dutch Pediatric CT Study

    NARCIS (Netherlands)

    Meulepas, Johanna M.; Ronckers, Cecile M.; Smets, Anne M. J. B.; Nievelstein, Rutger A. J.; Jahnen, Andreas; Lee, Choonsik; Kieft, Mariette; Lameris, Johan S.; van Herk, Marcel; Greuter, Marcel J. W.; Jeukens, Cecile R. L. P. N.; van Straten, Marcel; Visser, Otto; van Leeuwen, Flora E.; Hauptmann, Michael

    2014-01-01

    Computed tomography (CT) scans are indispensable in modern medicine; however, the spectacular rise in global use coupled with relatively high doses of ionizing radiation per examination have raised radiation protection concerns. Children are of particular concern because they are more sensitive to r

  20. What did we learn from two decades of chest computed tomography in cystic fibrosis?

    Energy Technology Data Exchange (ETDEWEB)

    Tiddens, Harm A.W.M. [Erasmus MC-Sophia Children' s Hospital, Department of Pediatric Pulmonology, Rotterdam (Netherlands); Erasmus MC, Department of Radiology, Rotterdam (Netherlands); Rosenow, Tim [Erasmus MC-Sophia Children' s Hospital, Department of Pediatric Pulmonology, Rotterdam (Netherlands); The University of Western Australia, Telethon Institute for Child Health Research, Perth (Australia); The University of Western Australia, School of Paediatrics and Child Health Research, Perth (Australia)

    2014-12-15

    Despite our current treatment, many cystic fibrosis (CF) patients still show progressive bronchiectasis and small airways disease. Adequate detection and monitoring of progression of these structural abnormalities is needed to personalize treatment to the severity of CF lung disease of the patient. Chest computed tomography (CT) is the gold standard to diagnose and monitor bronchiectasis. Many studies have been done to validate the role of chest CT in CF and to improve the protocols. From these studies it became clear that for correct interpretation of the severity of bronchiectasis and small airways disease standardization of lung volume for the inspiratory and expiratory CT scan acquisition is needed. The risk related to the radiation exposure of a chest CT scan every second year is considered low. Automated and quantitative image analysis systems are developed to improve the reliability and sensitivity of assessments of structural lung changes in CF, particularly in early life. In this paper an overview is given of the lessons learned from two decades of monitoring CF lung disease using chest CT. (orig.)

  1. SU-E-J-267: Change in Mean CT Intensity of Lung Tumors During Radiation Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, R; Tennyson, N; Weiss, E; Hugo, G [Virginia Commonwealth University, Richmond, VA (United States)

    2015-06-15

    Purpose: To evaluate CT intensity change of lung tumors during radiation therapy. Methods: Repeated 4D CT images were acquired on a CT simulator during the course of therapy for 27 lung cancer patients on IRB approved protocols. All subjects received definitive radiation treatment ± chemotherapy. CT scans were completed prior to treatment, and 2–7 times during the treatment course. Primary tumor was delineated by an experienced Radiation Oncologist. Contours were thresholded between −100 HU and 200 HU to remove airways and bone. Correlations between the change in the mean tumor intensity and initial tumor intensity, SUVmax, and tumor volume change rate were investigated. Reproducibility was assessed by evaluating the variation in mean intensity over all phases in 4DCT, for a subgroup of 19 subjects. Results: Reproducibility of tumor intensity between phases as characterized by the root mean square of standard deviation across 19 subjects was 1.8 HU. Subjects had a mean initial tumor intensity of 16.5 ± 11.6 HU and an overall reduction in HU by 10.3 ± 8.5 HU. Evaluation of the changes in tumor intensity during treatment showed a decrease of 0.3 ± 0.3 HU/day for all subjects, except three. No significant correlation was found between change in HU/day and initial HU intensity (p=0.53), initial PET SUVmax (p=0.69), or initial tumor volume (p=0.70). The rate of tumor volume change was weakly correlated (R{sup 2}=0.05) with HU change (p=0.01). Conclusion: Most lung cancer subjects showed a marked trend of decreasing mean tumor CT intensity throughout radiotherapy, including early in the treatment course. Change in HU/day is not correlated with other potential early predictors for response, such as SUV and tumor volume change. This Result supports future studies to evaluate change in tumor intensity on CT as an early predictor of response.

  2. Soft-tissue changes after head and neck radiation: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Bronstein, A.D.; Nyberg, D.A.; Schwartz, A.N.; Shuman, W.P.; Griffin, B.R.

    1989-01-01

    To identify possible soft-tissue changes of the head and neck after radiation therapy, 102 CT scans from 78 patients with head and neck tumors were reviewed to assess (1) skin thickening, (2) epiglottic thickening, (3) stranding of subcutaneous fat, and (4) stranding of deep cervical fat. Scans were obtained after radiation therapy alone (10 cases), after radiation and surgery (27 cases), after surgery alone (24 cases), or before either surgery or radiation (41 cases). Skin thickening, epiglottic thickening, and stranding of subcutaneous fat were seen more frequently after radiation therapy than before such treatment. However, skin thickening and stranding of subcutaneous fat were sometimes also associated with tumor involvement and/or previous surgery, while epiglottic thickening was only occasionally associated with tumor involvement. Stranding of deep cervical fat was noted with increased frequency after radiation or surgery, but postradiation effects could not be reliably distinguished from postsurgical or tumor effects. We conclude that soft-tissue changes of the head and neck on CT may commonly be associated with previous radiation therapy, but these postradiation effects are not always distinguishable from postsurgical effects or tumor.

  3. Etoposide sensitizes CT26 colorectal adenocarcinoma to radiation therapy in BALB/c mice

    Institute of Scientific and Technical Information of China (English)

    Chia-Yuan Liu; Hui-Fen Liao; Tsang-En Wang; Shee-Chan Lin; Shou-Chuan Shih; Wen-Hsuing Chang; Yuh-Cheng Yang; Ching-Chung Lin; Yu-Jen Chen

    2005-01-01

    AIM: To investigate the combined effect of etoposide and radiation on CT26 colorectal adenocarcinoma implanted into BALB/c mice.METHODS: We evaluated the radiosensitizing effect of etoposide on CT26 colorectal adenocarcinoma in a syngeneic animal model. BALB/c mice were subcutaneously implanted with CT26 cells and divided into four groups:control (intra-peritoneal salinex2) group, etoposide (5 mg/kgintra-peritoneallyx2) group, radiation therapy (RT 5 Gyx2fractions) group, and combination therapy with etoposide (5 mg/kg intra-peritoneally 1 h before radiation) group.RESULTS: Tumor growth was significantly inhibited by RT and combination therapy. The effect of combination therapy was better than that of RT. No significant changes were noted in body weight, plasma alanine aminotransferase,or creatinine in any group. The leukocyte count significantly but transiently decreased in the RT and combination therapy groups, but not in the etoposide and control groups. There was no skin change or hair loss in the RT and combination therapy groups.CONCLUSION: Etoposide can sensitize CT26 colorectal adenocarcinoma in BALB/c mice to RT without significant toxicity.

  4. Calculation of the Scattered Radiation Profile in 64 Slice CT Scanners Using Experimental Measurement

    Directory of Open Access Journals (Sweden)

    Afshin Akbarzadeh

    2009-06-01

    Full Text Available Introduction: One of the most important parameters in x-ray CT imaging is the noise induced by detected scattered radiation. The detected scattered radiation is completely dependent on the scanner geometry as well as size, shape and material of the scanned object. The magnitude and spatial distribution of the scattered radiation in x-ray CT should be quantified for development of robust scatter correction techniques. Empirical methods based on blocking the primary photons in a small region are not able to extract scatter in all elements of the detector array while the scatter profile is required for a scatter correction procedure. In this study, we measured scatter profiles in 64 slice CT scanners using a new experimental measurement. Material and Methods: To measure the scatter profile, a lead block array was inserted under the collimator and the phantom was exposed at the isocenter. The raw data file, which contained detector array readouts, was transferred to a PC and was read using a dedicated GUI running under MatLab 7.5. The scatter profile was extracted by interpolating the shadowed area. Results: The scatter and SPR profiles were measured. Increasing the tube voltage from 80 to 140 kVp resulted in an 80% fall off in SPR for a water phantom (d=210 mm and 86% for a polypropylene phantom (d = 350 mm. Increasing the air gap to 20.9 cm caused a 30% decrease in SPR. Conclusion: In this study, we presented a novel approach for measurement of scattered radiation distribution and SPR in a CT scanner with 64-slice capability using a lead block array. The method can also be used on other multi-slice CT scanners. The proposed technique can accurately estimate scatter profiles. It is relatively straightforward, easy to use, and can be used for any related measurement.

  5. Radiology illustrated. Chest radiology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Soo [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of). Dept. of Radiology; Han, Joungho [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of). Dept. of Pathology; Chung, Man Pyo [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of). Dept. of Medicine; Jeong, Yeon Joo [Pusan National Univ. Hospital, Busan (Korea, Republic of). Dept. of Radiology

    2014-04-01

    Pattern approach to the diagnosis of lung diseases based on CT scan appearances. Guide to quick and reliable differential diagnosis. CT-pathology correlation. Emphasis on state-of-the-art MDCT. The purpose of this atlas is to illustrate how to achieve reliable diagnoses when confronted by the different abnormalities, or ''disease patterns'', that may be visualized on CT scans of the chest. The task of pattern recognition has been greatly facilitated by the advent of multidetector CT (MDCT), and the focus of the book is very much on the role of state-of-the-art MDCT. A wide range of disease patterns and distributions are covered, with emphasis on the typical imaging characteristics of the various focal and diffuse lung diseases. In addition, clinical information relevant to differential diagnosis is provided and the underlying gross and microscopic pathology is depicted, permitting CT-pathology correlation. The entire information relevant to each disease pattern is also tabulated for ease of reference. This book will be an invaluable handy tool that will enable the reader to quickly and easily reach a diagnosis appropriate to the pattern of lung abnormality identified on CT scans.

  6. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Liao, S; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  7. Radiation dose reduction in perfusion CT imaging of the brain: A review of the literature.

    Science.gov (United States)

    Othman, Ahmed E; Afat, Saif; Brockmann, Marc A; Nikoubashman, Omid; Brockmann, Carolin; Nikolaou, Konstantin; Wiesmann, Martin

    2016-02-01

    Perfusion CT (PCT) of the brain is widely used in the settings of acute ischemic stroke and vasospasm monitoring. The high radiation dose associated with PCT is a central topic and has been a focus of interest for many researchers. Many studies have examined the effect of radiation dose reduction in PCT using different approaches. Reduction of tube current and tube voltage can be efficient and lead to a remarkable reduction of effective radiation dose while preserving acceptable image quality. The use of novel noise reduction techniques such as iterative reconstruction or spatiotemporal smoothing can produce sufficient image quality from low-dose perfusion protocols. Reduction of sampling frequency of perfusion images has only little potential to reduce radiation dose. In the present article we aimed to summarize the available data on radiation dose reduction in PCT imaging of the brain.

  8. Patient-size-dependent radiation dose optimisation technique for abdominal CT examinations.

    Science.gov (United States)

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

    2012-01-01

    Since patient doses from computed tomography (CT) are relatively high, risk-benefit analysis requires dose to patients and image quality be optimised. The aim of this study was to develop a patient-dependent optimisation technique that uses patient diameter to select a combination of CT scanning parameters that minimise dose delivered to patients undergoing abdominal CT examinations. The study was performed using cylindrical phantoms of diameters ranging from 16 to 40 cm in order to establish the relationship between image degradation, CT scanning techniques, patient dose and patient size from two CT scanners. These relationships were established by scanning the phantoms using standard scanning technique followed by selected combinations of scanning parameters. The image noises through phantom images were determined using region of interest software available in both scanners. The energy depositions to the X-ray detector through phantoms were determined from measurements of CT dose index in air corrected for attenuation of the phantom materials. The results demonstrate that exposure settings (milliampere seconds) could be reduced by up to 82 % for smaller phantom relative to standard milliampere seconds, while detector signal could be reduced by up to 93 % for smaller phantom relative to energy depositions required when scanned using standard scanning protocols. It was further revealed that the use of the object-specific scanning parameters on studies performed with phantom of different diameters could reduce the incident radiation to small size object by up to 86 % to obtain the same image quality required for standard adult object. In view of the earlier mentioned fact, substantial dose saving from small-sized adults and children patients undergoing abdomen CT examinations could be achieved through optimal adjustment of CT scanning technique based on the patient transverse diameter.

  9. Sandstorm in the chest?

    Directory of Open Access Journals (Sweden)

    Talluri MR

    2011-07-01

    Full Text Available A 32 year old female presented with dry cough and progressive breathlessness of one year duration. There was no history suggestive of collagen vascular disease, lung parenchymal infection or allergic airway disease. Clinical evaluation showed basal fine inspiratory crepitations. Radiographic examination of the chest revealed a black pleura line and lung parenchymal calcification. CT scan of the chest demonstrated nodular calcification of lung parenchyma with a “crazy pavement” pattern, which is suggestive of alveolar calcification. Pulmonary function test showed a severe restrictive defect. On transbronchial lung biopsy calcific spherules suggestive of the alveolar microlithiasis were seen. Diagnosis of pulmonary alveolar microlithiasis was made and symptomatic treatment was given, as there is no specific therapy available. The case illustrates an unusual cause of shortness of breath in a young female with striking radiographic features.

  10. Cardiac CT Scan

    Science.gov (United States)

    ... combine these pictures to create a three-dimensional (3D) model of the whole heart. This imaging test ... findings from earlier chest x rays. Different CT scanners are used for different purposes. A multidetector CT ...

  11. Application of high resolution synchrotron micro-CT radiation in dental implant osseointegration

    DEFF Research Database (Denmark)

    Neldam, Camilla Albeck; Lauridsen, Torsten; Rack, Alexander

    2015-01-01

    The purpose of this study was to describe a refined method using high-resolution synchrotron radiation microtomography (SRmicro-CT) to evaluate osseointegration and peri-implant bone volume fraction after titanium dental implant insertion. SRmicro-CT is considered gold standard evaluating bone...... microarchitecture. Its high resolution, high contrast, and excellent high signal-to-noise-ratio all contribute to the highest spatial resolutions achievable today. Using SRmicro-CT at a voxel size of 5 μm in an experimental goat mandible model, the peri-implant bone volume fraction was found to quickly increase...... to 50% as the radial distance from the implant surface increased, and levelled out to approximately 80% at a distance of 400 μm. This method has been successful in depicting the bone and cavities in three dimensions thereby enabling us to give a more precise answer to the fraction of the bone-to-implant...

  12. Tube current modulation based on the lateral chest diameter and CT value on a scout view in prospectively ECG-gated CT coronary angiography%定位像胸部横径与CT值调制前瞻性序列扫描冠状动脉成像管电流的研究

    Institute of Scientific and Technical Information of China (English)

    舒荣宝; 仝开军; 王岳松; 严芳; 罗潇; 董学滨; 周华飞; 章聪

    2015-01-01

    0.05).Conclusions Using the tube current determined by the individual chest LD and CTchest on the scout AP view would help to control the radiation in PG CTCA without damage of image quality and diagnostic accuracy.%目的 探讨定位像胸部横径(LD)与平均CT值(CTchest)在前瞻性心电触发序列扫描冠状动脉成像(Prospective ECG-gated CT coronary angiography,PG CTCA)管电流调制中的临床应用价值.方法 将连续进行CTCA扫描的194例患者按例数不等的完全随机区段分组法分为3组,即回顾性心电触发序列组(RG组)69例,前瞻性心电触发序列组(PG1组)68例及PG2对照组57例.其中RG组固定600 mA扫描,于前后位定位像上测量第10胸椎椎体上缘水平LD、右侧膈肌上方锁骨中线处肋间隙的CTchest;相同高度侧位像胸部前后径(APD),以及CTCA图像冠状动脉左主干层面的升主动脉噪声(SD);拟合各测量参数与SD的关系,推算管电流换算公式及速查表.PG1组扫描管电流依据推导的管电流速查表进行选择.PG2组依据体质量固定选择管电流(<77 kg者取400 mA,≥77 kg者取500 mA).对3组图像质量评分、SD、CTDIvol、DLP、有效剂量(E)进行比较和评估.SD与LD、APD及CTchest的关系采用多元回归分析;3组间定位像胸部LD、CTchest、SD,以及CTDIvol、E比较均采用单因素方差分析;图像质量评分比较采用R×2列联表的x2检验.结果 管电流换算公式:mA=600/282·(0.487LD+0.064CTchest+13.7)2(R2 =0.53,F=36.13,P=0.00).3组胸部LD及CTchest大小比较,差异均无统计学意义(P >0.05);SD、扫描毫安值和CTDIvol差异均有统计学意义(F=44.96、167.37和1 071.26,P<0.05);但图像质量评分及可评估血管差异无统计学意义(x2=6.89,2.54,P>0.05).结论 根据胸部定位像LD及CTchest选择PG CTCA个体化管电流,可在满足诊断需求的前提下,更科学合理地控制X射线剂量.

  13. Computation of thyroid doses and carcinogenic radiation risks to patients undergoing neck CT examinations.

    Science.gov (United States)

    Huda, Walter; Spampinato, Maria V; Tipnis, Sameer V; Magill, Dennise

    2013-10-01

    The aim of the study was to investigate how differences in patient anatomy and CT technical factors in neck CT impact on thyroid doses and the corresponding carcinogenic risks. The CTDIvol and dose-length product used in 11 consecutive neck CT studies, as well as data on automatic exposure control (AEC) tube current variation(s) from the image DICOM header, were recorded. For each CT image that included the thyroid, the mass equivalent water cylinder was estimated based on the patient cross-sectional area and average relative attenuation coefficient (Hounsfield unit, HU). Patient thyroid doses were estimated by accounting for radiation intensity at the location of the patient's thyroid, patient size and the scan length. Thyroid doses were used to estimate thyroid cancer risks as a function of patient demographics using risk factors in BEIR VII. The length of the thyroid glands ranged from 21 to 54 mm with an average length of 42 ± 12 mm. Water cylinder diameters corresponding to the central slice through the patient thyroid ranged from 18 to 32 cm with a mean of 25 ± 5 cm. The average CTDIvol (32-cm phantom) used to perform these scans was 26 ± 6 mGy, but the use of an AEC increased the tube current by an average of 44 % at the thyroid mid-point. Thyroid doses ranged from 29 to 80 mGy, with an average of 55 ± 19 mGy. A 20-y-old female receiving the highest thyroid dose of 80 mGy would have a thyroid cancer risk of nearly 0.1 %, but radiation risks decreased very rapidly with increasing patient age. The key factors that affect thyroid doses in neck CT examinations are the radiation intensity at the thyroid location and the size of the patient. The corresponding patient thyroid cancer risk is markedly influenced by patient sex and age.

  14. Detecting Radiation-Induced Injury Using Rapid 3D Variogram Analysis of CT Images of Rat Lungs

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Rick E.; Murphy, Mark K.; Creim, Jeffrey A.; Carson, James P.

    2013-10-01

    A new heterogeneity analysis approach to discern radiation-induced lung damage was tested on CT images of irradiated rats. The method, combining octree decomposition with variogram analysis, demonstrated a significant correlation with radiation exposure levels, whereas conventional measurements and pulmonary function tests did not. The results suggest the new approach may be highly sensitive for assessing even subtle radiation-induced changes

  15. A comparative study for Triple-Rule-out with different tube voltage technique of Dual-Source CT in acute chest pain%双源 CT不同管电压技术诊断急性胸痛三联症效果比较

    Institute of Scientific and Technical Information of China (English)

    王皆欢; 陈东风; 王少春; 孙占国; 王林省; 张谷青

    2014-01-01

    目的:对比双源CT胸痛三联检查在两种不同电压下显示急性胸痛患者肺动脉、主动脉及冠状动脉的图像质量以及患者所受的辐射剂量,以评估低电压扫描在急性胸痛患者推广应用的可行性。方法利用双源C T胸痛三联扫描模式,结合回顾性心电门控技术对361例胸痛三联检查患者进行统计分析,比较主动脉、肺动脉及冠状动脉的图像质量及辐射的有效剂量。结果120kV组与100kV组在图像质量的主观评分对比中差异无统计学意义(P>0.05),在患者辐射剂量的对比中,120kV组的辐射剂量大于100kV组,差异有统计学意义(P<0.05)。结论双源CT胸痛三联检查两种不同管电压扫描对急性胸痛患者的肺动脉、主动脉及冠状动脉的成像质量无影响,并且应用100kV 管电压扫描可以降低患者所受的辐射剂量,可以作为急性胸痛患者的首选。%Objective To compare the value of triple-rule-out (TRO) dual-source computed tomography angiog-raphy in acute chest pain patients with diseases of pulmonary artery ,aortic and coronary artery and radiation dose in two different voltage as well as the feasibility of generalizing and applying in patients with acute chest pain . Methods 361 patients with chest pain were analyzed statistically underwent triple-rule-out (TRO) dual-source CT combined with retrospective ECG-gated technique ,and then compare with image quality of aorta ,pulmonary artery and coronary artery and effective radiation dose .Results Subjective score of image quality of the voltage 120kV and 100kV group had no statistical significance(P>0.05) .The difference was statistically significant(P<0.05)in comparison of radiation dose .The effective radiation dose of the voltage 100kV group was lower than that of the voltage 120kV group .Conclusion The quality of pictures of pulmonary artery ,coronary artery and aorta are not affected in different tube tension

  16. Initial clinical evaluation of stationary digital chest tomosynthesis

    Science.gov (United States)

    Hartman, Allison E.; Shan, Jing; Wu, Gongting; Lee, Yueh Z.; Zhou, Otto; Lu, Jianping; Heath, Michael; Wang, Xiaohui; Foos, David

    2016-03-01

    Computed Tomography (CT) is the gold standard for image evaluation of lung disease, including lung cancer and cystic fibrosis. It provides detailed information of the lung anatomy and lesions, but at a relatively high cost and high dose of radiation. Chest radiography is a low dose imaging modality but it has low sensitivity. Digital chest tomosynthesis (DCT) is an imaging modality that produces 3D images by collecting x-ray projection images over a limited angle. DCT is less expensive than CT and requires about 1/10th the dose of radiation. Commercial DCT systems acquire the projection images by mechanically scanning an x-ray tube. The movement of the tube head limits acquisition speed. We recently demonstrated the feasibility of stationary digital chest tomosynthesis (s-DCT) using a carbon nanotube (CNT) x-ray source array in benchtop phantom studies. The stationary x-ray source allows for fast image acquisition. The objective of this study is to demonstrate the feasibility of s-DCT for patient imaging. We have successfully imaged 31 patients. Preliminary evaluation by board certified radiologists suggests good depiction of thoracic anatomy and pathology.

  17. The Survey for Awareness of Radiation Dose of CT and General X-ray Examination

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Cheol; Cho, Han Byul [Dept. of Diagnostic Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Lim, Cheong Hwan; Jung, Hong Ryang; You, In Gyu; Yang, Oh Nam; Kim, Min Cheol [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Yoon, Joon [Dept. of Radiotechnolgy, Dongnam Health College, Suwon (Korea, Republic of)

    2012-03-15

    The goal of this study is to awaken about risk occurred by CT examination. For radio-technologists working at 'S medical center' located in Seoul, we investigated a recognition about dose and risk CT and normal X-ray examination according by working experience in hospital, experience about CT examination and radiation source. For subjects of investigation, radio-technologists working at 'S medical center' located in Seoul helped us. We collected 131 questionnaires for a test of hypothesis. Cronbach coefficients of questionnaires were 0.825988 and 0.767161 and a rejection rate of p-value was below 0.05. SAS 9.1(SAS Institute Inc., Cary, NC, USA.) statistic package was used for hypothesis test. We used Mann-Whitney test, Kruskai-Wallis test, Two sample T-test, Two sample T-test with Bonferroni's Correction and One-way ANOVA methods. P-values of hypothesis about dose of CT and normal X-ray examination were 0.2291-0.9663. p-values of hypothesis about risk were 0.1924-1.0000. All of hypothesis is over rejection rate(<0.05). This study shows that radio-technologists of S medical center recognized that CT has higher dose and risk than general X-ray examination.

  18. PET/CT imaging of delayed radiation encephalopathy following radiotherapy for nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-lu; YIN Ji-lin; LI Hua; LI Xiang-dong; QUAN Jiang-tao

    2007-01-01

    Background With the significant improvement in the survival of patients with nasopharyngeal carcinoma (NPC)undergoing radiotherapy and the growing availability of the sophisticated imaging modalities, the number of radiation encephalopathy (RE) cases relating to NPC radiotherapy is increasing. In this study, we investigated the metabolic and density changes of the compromised brain tissues during delayed RE using a positron-emission tomography-computed tomography (PET/CT) to provide clinical evidences for the diagnosis of delayed RE following radiotherapy for NPC.Methods The PET/CT manifestations and the clinical data of 53 pathologically confirmed NPC patients with delayed RE following radical radiotherapy and 15 healthy volunteers were investigated. The standardized uptake values (SUV) of the bilateral temporal lobes, the occipital lobe and the brain stem were measured respectively; and then the metabolic reduction rate of 88 temporal lobes and 13 brain stems were calculated for a statistical comparison between the two groups.Results The earliest case of delayed RE in the investigated patients occurred 1.5 years after radiotherapy. Delayed RE frequently involved the inferior temporal lobe. For patients with delayed RE confirmed by clinical symptoms and imaging findings, PET maintained a 100% coincidence rate with CT; however, in the 25 temporal lobes of the 35 delayed RE patients, PET revealed obvious hypometabolic changes whereas CT displayed normal density. The incidence of brain stem metabolic reductions was 24.5% (13/53) in the investigated patients, including 4 patients with hypometabolic changes shown by PET and negative finding shown by CT. The incidence of granuloma adjacent to the hypometabolic region in the temporal lobe was 12.5% (11/88).Conclusion Delayed RE patients exhibit significant hypometabolic changes in the inferior temporal lobe, captured by PET much earlier than by CT. PET/CT offers a valuable means for the diagnosis of delayed RE in

  19. Feasibility of Nanoparticle-Guided Radiation Therapy (NGRT) Using a Conventional CT Scanner

    Science.gov (United States)

    2010-10-01

    created and used as the input geometry for dose calculations within the Monte Carlo N-Particle eXtended ( MCNPX ) program. MCNPX is a generalized...conventional CT scanners (SOW 1b).11,12 The energy spectra were input into MCNPX for radiation energy deposition calculations (SOW 1c-d). An example of...the program developed to perform the dose calculations is shown within the appendix. Because the programming language used within MCNPX is Fortran

  20. Radiation exposure from pediatric head CT: a bi-institutional study

    Energy Technology Data Exchange (ETDEWEB)

    King, Mary A. [University of Washington, Department of Pediatrics, Harborview Medical Center, Seattle, WA (United States); Seattle Children' s Hospital, Seattle, WA (United States); Kanal, Kalpana M.; Relyea-Chew, Annemarie [University of Washington, Department of Radiology, Harborview Medical Center, Seattle, WA (United States); Bittles, Mark [Vanderbilt Children' s Hospital, Department of Radiology, Nashville, TN (United States); Vavilala, Monica S. [University of Washington, Departments of Anesthesiology and Pediatrics, Harborview Medical Center, 325 Ninth Avenue, Box 359724, Seattle, WA (United States); Hollingworth, William [University of Bristol, Department of Social Medicine, Bristol (United Kingdom)

    2009-10-15

    Medical radiation from CT should be kept as low as reasonably achievable (ALARA), particularly in young patients. To examine radiation dose from head CT in children in a trauma center (TC) and a regional children's hospital (RCH). A random sample of 240 children (0-3, 4-9, 10-14 years of age) from the TC were compared with a similar cohort from the RCH. All children had undergone at least one head CT scan without contrast enhancement; data from PACS and Department of Radiology Information System were used to estimate normalized effective dose (ED). Lifetime attributable risk of cancer incidence was estimated using the Biologic Effects of Ionizing Radiation (BEIR) VII report. The mean normalized ED was significantly higher in the youngest children at the TC (2.74 mSv in those aged 0-3 years vs. 2.23 mSv in those aged 10-14 years; P<0.001) and at the RCH (2.44 mSv in those aged 0-3 years vs. 1.71 mSv in those aged 10-14 years; P<0.001). Each decreasing year of age was independently associated with a 0.06 mSv higher mean normalized ED (P<0.001). After adjusting for the age difference between the institutions, the mean normalized ED was 0.44 mSv lower at the RCH than at the TC across all ages (95% CI 0.31-0.58, P<0.001). A higher lifetime attributable risk of cancer was associated with younger age. The radiation dose from head CT in children as defined by the normalized ED was highest in the youngest children and varied significantly between institutions in this bi-institutional study. (orig.)

  1. Clinical evaluation of a commercial orthopedic metal artifact reduction tool for CT simulations in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Li Hua; Noel, Camille; Chen, Haijian; Harold Li, H.; Low, Daniel; Moore, Kevin; Klahr, Paul; Michalski, Jeff; Gay, Hiram A.; Thorstad, Wade; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States); Department of Radiation Oncology, University of California San Diego, San Diego, California 92093 (United States); Philips Healthcare System, Cleveland, Ohio 44143 (United States); Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States)

    2012-12-15

    Purpose: Severe artifacts in kilovoltage-CT simulation images caused by large metallic implants can significantly degrade the conspicuity and apparent CT Hounsfield number of targets and anatomic structures, jeopardize the confidence of anatomical segmentation, and introduce inaccuracies into the radiation therapy treatment planning process. This study evaluated the performance of the first commercial orthopedic metal artifact reduction function (O-MAR) for radiation therapy, and investigated its clinical applications in treatment planning. Methods: Both phantom and clinical data were used for the evaluation. The CIRS electron density phantom with known physical (and electron) density plugs and removable titanium implants was scanned on a Philips Brilliance Big Bore 16-slice CT simulator. The CT Hounsfield numbers of density plugs on both uncorrected and O-MAR corrected images were compared. Treatment planning accuracy was evaluated by comparing simulated dose distributions computed using the true density images, uncorrected images, and O-MAR corrected images. Ten CT image sets of patients with large hip implants were processed with the O-MAR function and evaluated by two radiation oncologists using a five-point score for overall image quality, anatomical conspicuity, and CT Hounsfield number accuracy. By utilizing the same structure contours delineated from the O-MAR corrected images, clinical IMRT treatment plans for five patients were computed on the uncorrected and O-MAR corrected images, respectively, and compared. Results: Results of the phantom study indicated that CT Hounsfield number accuracy and noise were improved on the O-MAR corrected images, especially for images with bilateral metal implants. The {gamma} pass rates of the simulated dose distributions computed on the uncorrected and O-MAR corrected images referenced to those of the true densities were higher than 99.9% (even when using 1% and 3 mm distance-to-agreement criterion), suggesting that dose

  2. Low-Radiation-Dose Modified Small Bowel CT for Evaluation of Recurrent Crohn's Disease

    Directory of Open Access Journals (Sweden)

    A. Z. Kielar

    2012-01-01

    Full Text Available Crohn's disease affects any part of the GI tract, commonly the terminal ileum. To decrease radiation exposure we developed a low-radiation-dose unenhanced CT (modified small Bowel CT, MBCT to evaluate the small bowel using hyperdense oral contrast. Technique. MBCT was investigated in patients with pathologically proven Crohn's disease presenting with new symptoms from recurrent inflammation or stricture. After ethics board approval, 98 consecutive patients were retrospectively evaluated. Kappa values from two independent reviewers were calculated for presence of obstruction, active inflammation versus chronic stricture, and ancillary findings. Forty-two patients underwent surgery or colonoscopy within 3 months. Results. Kappa was 0.84 for presence of abnormality versus a normal exam and 0.89 for differentiating active inflammation from chronic stricture. Level of agreement for presence of skip areas, abscess formation, and fistula was 0.62, 0.75, and 0.78, respectively. In the subset with “gold standard” follow-up, there was 83% agreement. Conclusions. MBCT is a low-radiation technique with good to very good interobserver agreement for determining presence of obstruction and degree of disease activity in patients with Crohn's disease. Further investigation is required to refine parameters of disease activity compared to CT enterography and small bowel follow through.

  3. Integration of FDG-PET/CT into external beam radiation therapy planning Technical aspects and recommendations on methodological approaches

    NARCIS (Netherlands)

    Thorwarth, D.; Beyer, T.; Boellaard, R.; De Ruysscher, D.; Grgic, A.; Lee, J. A.; Pietrzyk, U.; Sattler, B.; Schaefer, A.; van Elmpt, W.; Vogel, W.; Oyen, W. J. G.; Nestle, U.

    2012-01-01

    This work addresses the clinical adoption of FDG-PET/CT for image-guided radiation therapy planning (RIP). As such, important technical and methodological aspects of PET/CT-based RIP are reviewed and practical recommendations are given for routine patient management and clinical studies. First, rece

  4. Integration of FDG-PET/CT into external beam radiation therapy planning. Technical aspects and recommendations on methodological approaches.

    NARCIS (Netherlands)

    Thorwarth, D.; Beyer, T.; Boellaard, R.; Ruysscher, D. de; Grgic, A.; Lee, J.A.; Pietrzyk, U.; Sattler, B.; Schaefer, A.; Elmpt, W. van; Vogel, W.; Oyen, W.J.G.; Nestle, U.

    2012-01-01

    This work addresses the clinical adoption of FDG-PET/CT for image-guided radiation therapy planning (RTP). As such, important technical and methodological aspects of PET/CT-based RTP are reviewed and practical recommendations are given for routine patient management and clinical studies. First, rece

  5. 胸部X线、CT和纤维支气管镜对肺癌诊断的应用研究%Study of Diagnosis of Chest X ray, CT and Bronchoscopy in Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    董乐; 张锡海; 韩璐璐; 刘钊

    2015-01-01

    Objective To analyze and discuss the meaning and value of chest X-ray, CT and fibrobronchoscope. Methods Select-ed 140 cases of patients with lung cancer in our hospital from January 2013 to January 2015 as a study object, according to the different of imaging detection scheme divided into CT group, X-gray group and fibrobronchoscope group, and analysis of the effect of the three detection methods in the treatment of patients. Results The accuracy rate of X-ray was 171/235 (72.77%), accuracy of CT examination for 211/235 (89.79%), the accuracy rate of fiberoptic bronchoscopy for 221/235 (94.04%) was higher than that of X-ray, CT, there was significant difference(χ2=5.37, P<0.05); fiberoptic bronchoscopy was higher than that of X-ray, there were statistically significant differences (χ2=6.81,P<0.05);fiberoptic bronchoscopy the mirror is higher than that of CT, but the difference was not statistically significant(χ2=0.67, P<0.05).Over 60% lung cancer patients can be clinically diagnosed only by chest X-ray, the accurate rate of peripheral lung cancer can be diagnosed by CT while central lung cancer can be diagnosed by fibrobroncho-scope. Conclusion It was showed that Chest X-ray should be used firstly in the diagnosis of lung cancer, and CT or fibrobroncho-scope can greatly improve the diagnostic accuracy of lung cancer, which is worthy of promotion and application.%目的 分析和研究胸部X线、 螺旋 CT及纤维支气管镜在诊断中的价值和意义. 方法 随机抽取于 2013年1月-2015年1月间在该院就诊的140例肺癌患者作为研究对象,并根据检查方法的不同分为X线、CT、支气管镜,所有患者均进行以上检查,对比和分析各种方法在诊断中的准确性. 结果 X线检查的准确率为171/235(72.77%),CT检查的准确率为211/235(89.79%),纤维支气管镜的准确率为221/235(94.04%),CT高于X线,差异有统计学意义(χ2=5.37,P<0.05);纤维支气管镜高于X线,差异有统计学意义(χ2=6.81,P<0

  6. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    Science.gov (United States)

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.

  7. Improved image quality and radiation dose reduction in liver dynamic CT scan with the protocol change

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yu Jin; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5-24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120 kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100 kVp, apply SAFIRE strength 0-5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120 kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100 kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100 kVp than 120 kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality

  8. Query Expansion Using SNOMED-CT and Weighing Schemes

    Science.gov (United States)

    2014-11-01

    to improve performance because with the SNOMED-CT ontology in place they were just not looking for key words , but concepts. This was a semantic...for the first query. Query #1 58-year-old woman with hypertension and obesity presents with exercise-related episodic chest pain radiating to the...back The first three terms that were identified in SNOMED-CT were: Hyperpiesia Hypertensive Systemic arterial hypertension Each one of the terms

  9. Radiation dose to radiosensitive organs in PET/CT myocardial perfusion examination using versatile optical fibre

    Science.gov (United States)

    Salasiah, M.; Nordin, A. J.; Fathinul Fikri, A. S.; Hishar, H.; Tamchek, N.; Taiman, K.; Ahmad Bazli, A. K.; Abdul-Rashid, H. A.; Mahdiraji, G. A.; Mizanur, R.; Noor, Noramaliza M.

    2013-05-01

    Cardiac positron emission tomography (PET) provides a precise method in order to diagnose obstructive coronary artery disease (CAD), compared to single photon emission tomography (SPECT). PET is suitable for obese and patients who underwent pharmacologic stress procedures. It has the ability to evaluate multivessel coronary artery disease by recording changes in left ventricular function from rest to peak stress and quantifying myocardial perfusion (in mL/min/g of tissue). However, the radiation dose to the radiosensitive organs has become crucial issues in the Positron Emission Tomography/Computed Tomography(PET/CT) scanning procedure. The objective of this study was to estimate radiation dose to radiosensitive organs of patients who underwent PET/CT myocardial perfusion examination at Centre for Diagnostic Nuclear Imaging, Universiti Putra Malaysia in one month period using versatile optical fibres (Ge-B-doped Flat Fibre) and LiF (TLD-100 chips). All stress and rest paired myocardial perfusion PET/CT scans will be performed with the use of Rubidium-82 (82Rb). The optic fibres were loaded into plastic capsules and attached to patient's eyes, thyroid and breasts prior to the infusion of 82Rb, to accommodate the ten cases for the rest and stress PET scans. The results were compared with established thermoluminescence material, TLD-100 chips. The result shows that radiation dose given by TLD-100 and Germanium-Boron-doped Flat Fiber (Ge-B-doped Flat Fiber) for these five organs were comparable to each other where the p>0.05. For CT scans,thyroid received the highest dose compared to other organs. Meanwhile, for PET scans, breasts received the highest dose.

  10. Microstructure analysis of the secondary pulmonary lobules by 3D synchrotron radiation CT

    Science.gov (United States)

    Fukuoka, Y.; Kawata, Y.; Niki, N.; Umetani, K.; Nakano, Y.; Ohmatsu, H.; Moriyama, N.; Itoh, H.

    2014-03-01

    Recognition of abnormalities related to the lobular anatomy has become increasingly important in the diagnosis and differential diagnosis of lung abnormalities at clinical routines of CT examinations. This paper aims a 3-D microstructural analysis of the pulmonary acinus with isotropic spatial resolution in the range of several micrometers by using micro CT. Previously, we demonstrated the ability of synchrotron radiation micro CT (SRμCT) using offset scan mode in microstructural analysis of the whole part of the secondary pulmonary lobule. In this paper, we present a semiautomatic method to segment the acinar and subacinar airspaces from the secondary pulmonary lobule and to track small vessels running inside alveolar walls in human acinus imaged by the SRμCT. The method beains with and segmentation of the tissues such as pleural surface, interlobular septa, alveola wall, or vessel using a threshold technique and 3-D connected component analysis. 3-D air space are then conustructed separated by tissues and represented branching patterns of airways and airspaces distal to the terminal bronchiole. A graph-partitioning approach isolated acini whose stems are interactively defined as the terminal bronchiole in the secondary pulmonary lobule. Finally, we performed vessel tracking using a non-linear sate space which captures both smoothness of the trajectories and intensity coherence along vessel orientations. Results demonstrate that the proposed method can extract several acinar airspaces from the 3-D SRμCT image of secondary pulmonary lobule and that the extracted acinar airspace enable an accurate quantitative description of the anatomy of the human acinus for interpretation of the basic unit of pulmonary structure and function.

  11. Dual guidance (CT and fluoroscopy) vertebroplasty: radiation dose to radiologists. How much and where?

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Lesbats, Virginie; Marcy, Pierre-Yves; Amoretti, Marie-eve; Maratos, Yvonne; Ianessi, Antoine; Boileau, Pascal [Centre hospitalier universitaire, Radiology Department, Nice (France); Hauger, Olivier [CHU de Bordeaux, Unite d' Imagerie Osteo-articulaire, Hopital Pellegrin, Bordeaux (France)

    2010-12-15

    The goal of this study was to evaluate the radiation received by the practitioner when performing percutaneous vertebroplasty guided by CT and fluoroscopy for specific anatomical sites: orbits, hands, ankles, and thorax (under lead-lined apron). Twenty-four vertebroplasties were performed on 18 patients. The anatomical site that was most exposed to radiation was the right hand (0.37 mSv on average). This study demonstrates a significant correlation between the irradiation dose and fluoroscopy duration, reflecting both the quantity of primary-beam radiation and backscattered radiation. The right hand (P = 0.03), left hand (P = 0.02), and the left orbit (P < 0.0001) are the anatomical zones that are the most affected by the combination of these two types of radiation, with cumulative irradiation doses of 0.45, 0.2, and 0.14 mSv, respectively. There was a significant correlation between the patient weight and radiation of the left hand (P = 0.03), the left orbit (P = 0.03), and the thorax (P = 0.02), confirming the major influence of backscattered radiation. The most irradiated anatomical sites limiting the number of interventions are the left orbit and the right hand. (orig.)

  12. Blood pressure is associated with occult cardiovascular disease in prospectively studied Hodgkin lymphoma survivors after chest radiation.

    Science.gov (United States)

    Chen, Ming Hui; Blackington, Lauren H; Zhou, Jing; Chu, Tammy F; Gauvreau, Kimberlee; Marcus, Karen J; Fisher, David C; Diller, Lisa R; Ng, Andrea K

    2014-11-01

    The objectives of this study were to prospectively screen a cohort of asymptomatic long-term survivors of Hodgkin lymphoma (HL) treated with chest irradiation for occult cardiovascular disease (CVD), and correlate screen-detected disease with prospectively measured cardiovascular risk factors (CRFs). A total of 182 HL survivors treated with chest irradiation (median follow-up time 14.8 years) were enrolled and underwent prospective CRF measurement and resting and stress echocardiography to assess coronary artery disease (CAD)/valve disease and left ventricular systolic dysfunction (LVSD). Forty-seven (26%) patients had occult CAD/valve disease and/or LVSD. LVSD was not correlated with CRFs. Controlling for treatment factors, hypertension (odds ratio [OR] = 3.0) and elevated high-sensitivity C-reactive protein (hs-CRP) (OR = 2.7) increased the likelihood of occult CAD/valve disease. Risk of CAD/valve disease rose exponentially with increasing blood pressure (BP) values, even in the normal range. Our findings suggest that BP screening may be useful in determining those survivors at greatest risk for occult CVD.

  13. Quality assurance: using the exposure index and the deviation index to monitor radiation exposure for portable chest radiographs in neonates

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Mervyn D. [Indiana University School of Medicine, Department of Radiology, Riley Children' s Hospital, Indianapolis, IN (United States); Riley Hospital for Children, Department of Radiology, Indianapolis, IN (United States); Cooper, Matt L.; Piersall, Kelly [Indiana University School of Medicine, Department of Radiology, Riley Children' s Hospital, Indianapolis, IN (United States); Apgar, Bruce K. [Agfa HealthCare Corporation, Greenville, SC (United States)

    2011-05-15

    Many methods are used to track patient exposure during acquisition of plain film radiographs. A uniform international standard would aid this process. To evaluate and describe a new, simple quality-assurance method for monitoring patient exposure. This method uses the ''exposure index'' and the ''deviation index,'' recently developed by the International Electrotechnical Commission (IEC) and American Association of Physicists in Medicine (AAPM). The deviation index measures variation from an ideal target exposure index value. Our objective was to determine whether the exposure index and the deviation index can be used to monitor and control exposure drift over time. Our Agfa workstation automatically keeps a record of the exposure index for every patient. The exposure index and deviation index were calculated on 1,884 consecutive neonatal chest images. Exposure of a neonatal chest phantom was performed as a control. Acquisition of the exposure index and calculation of the deviation index was easily achieved. The weekly mean exposure index of the phantom and the patients was stable and showed <10% change during the study, indicating no exposure drift during the study period. The exposure index is an excellent tool to monitor the consistency of patient exposures. It does not indicate the exposure value used, but is an index to track compliance with a pre-determined target exposure. (orig.)

  14. Observation on Chest Big Vascular System of Rhesus Monkey by Three-dimensional Spiral CT Reconstruction%螺旋CT三维重建观察实验猕猴胸部大血管系统

    Institute of Scientific and Technical Information of China (English)

    范春梅; 李志雄; 车敏

    2012-01-01

    目的 利用256层螺旋CT三维重建观察实验猕猴胸部大血管,为猕猴血管系统的研究、数字化猴的建立及科学研究提供资料.方法 (1)选择实验猕猴10只,雌雄各半,年龄6~10岁,进行胸部CT断层扫描试验.(2)动物全身麻醉后,采用平扫及增强扫描技术,进行容积数据采集,获取正常猕猴胸部CT横断面影像.(3)利用CT图像后处理技术对扫描获得的容积数据进行三维的图像重组处理.结果 获得了良好的主动脉、肺动静脉等胸部大血管三维重建的立体影像,本文展示了2幅三维重组图像.从比较解剖学的角度,观察到了猕猴胸部血管的结构特点及与人类的区别.结论 CT三维重建能很好地反映了猕猴胸部血管系统的解剖结构、走行及与周围结构的位置关系,它是有效的、无创伤性的、直观的观察血管系统的理想方法.%Objective Observing rhesus monkey big vascular system of chest by 256 layer spiral CT and providing scientific materials for studying rhesus monkey vascular and digitization system. Methods Five male and five female rhesus monkeys aging at 6 to 10 years old were selected and obtained for CT scanning experiment. Rhesus monkey chest CT cross-sectional images were acquired through flat and strengthen scanning technique to collect volume data. Rhesus monkey volume data were processed by 3D image restruction using CT image post-processing technology. Results Rhesus monkey stereoscopic images of aorta, pulmonary artery and vein and chest big vascular were obtained by Three-dimensional reconstruction. From the point of comparative anatomy the difference of chest big vascular system between rhesus monkey and human being were found. Conclusion The anatomical and tissue structures of rhesus monkey among the big vascular system were reflected perfectly by Three-dimensional CT reconstruction. It is an effective, non-invasive and direct ideal way of observation of the vascular system.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    A comprehensive artefact correction method for clinical cone beam CT (CBCT) images acquired for image guided radiation therapy (IGRT) on a commercial system is presented. The method is demonstrated to reduce artefacts and recover CT-like Hounsfield units (HU) in reconstructed CBCT images of five......-correspondence with the planning CT images, and total volume HU error. Artefacts are reduced and CT-like HUs are recovered in the artefact corrected CBCT images. Visual inspection confirms that artefacts are indeed suppressed by the proposed method, and the HU root mean square difference between reconstructed CBCTs...

  16. Chest Pain

    Directory of Open Access Journals (Sweden)

    Samad Shams-Vahdati

    2014-03-01

    Full Text Available Introduction: Acute chest pain is an important and frequently occurring symptom in patients. Chest pain is often a sign of ischemic heart disease. Associated findings of electrocardiograph (ECG are rather heterogeneous, and traditional cardiac biomarkers such as Creatine Kinase-MB (CK-MB suffer from low cardiac specificity and sensitivity. In this study cost effectiveness of cardiac biomarkers single quantitative measurement was examined.Methods: The present descriptive-analytic study conducted on patients who were asked for troponin I and CK-MB. All patients who referred to Emergency unit of Tabriz Imam Reza educational-medical center during January 2012 to July the 2013 were included in study. All patients included in the study were documented in terms of age, sex, working shift of referring, main complaint of patient, symptoms in referring, ECG findings, and results of troponin I and CK-MB tests.Results: In this study, 2900 patients were studied including 1440 (49.7% males and 1460 (50.3% females. Mean age of patients was 62.91 (SD=14.36. Of all patients 1880 (64.8% of patients referred during 8 a.m. to 8 p.m. and 1020 (35.2% patients were referred during 8 p.m. to 8 a.m. The sensitivity of cardiac biomarkers’ test in diagnosing Acute Coronary Syndrome (ACS disease was calculated as 44.8% and its specificity was 86.6%. For diagnosing Acute Myocardial Infarction (AMI, sensitivity of cardiac biomarkers’ test was 72.2% and its specificity was 86%. None of patients who were finally underwent unstable angina diagnosis showed increase in cardiac enzymes.Conclusion: In conclusion, cardiac biomarkers can be used for screening acute chest pains, also cost effectiveness of cardiac biomarkers, appropriate specificity and sensitivity can guarantee their usefulness in emergency room.

  17. Chest Traumatic Pulmonary Hemorrhage of X-Ray Plain Film, CT Diagnosis Analysis%胸部损伤性肺出血的X线平片、CT诊断分析

    Institute of Scientific and Technical Information of China (English)

    陆忠才

    2013-01-01

    Objective:To study the chest traumatic pulmonary hemorrhage of X-ray plain film, CT diagnosis application value. Methods:The diagnosis and treatment in our hospital of 66 cases of chest injury patients with pulmonary hemorrhage, the implement X-ray plain film and CT diagnosis, to the patient to diagnose. Results:Through to all patients in X-ray plain film and CT diagnosis, image display performance for pulmonary interstitial change have 23 cases, accounting for 34.8%, affects the performance show for lung parenchyma real variable shadow of 24 cases, accounting for 36.4%, display for traumatic pulmonary cyst of 11 cases, accounting for 16.7%, shown as the lungs hematoma of 8 cases, accounting for 12.1%. Conclusion:The chest traumatic pulmonary hemorrhage disease.%目的:探讨胸部损伤性肺出血的X线平片、CT诊断应用价值。方法:选取在我院诊治的66例胸部损伤性肺出血患者,对其实行X线平片及CT诊断,以对患者的病情进行确诊。结果:通过对所有患者实行X线平片及CT诊断,影像表现显示为肺间质性改变的有23例,占34.8%,影响表现显示为肺实质实变影的有24例,占36.4%,显示为创伤性肺囊肿的有11例,占16.7%,显示为肺内血肿的有8例,占12.1%。结论:胸部损伤性肺出血疾病。

  18. Utility of CT angiography in cervical spine trauma: analysis of radiation and cost

    Directory of Open Access Journals (Sweden)

    Waqas Shuaib

    2014-12-01

    Full Text Available Purpose: Vertebral artery injuries (VAIs can be seen in cervical injuries. This investigation was conducted to assess the impact of head and neck computed tomography (CT angiography (CTA on planning treatment of vertebral artery injuries, if these tests were ordered appropriately, and to estimate cost and associated exposure to radiation and contrast material. Methods: This retrospective review included all patients who underwent CT of the cervical spine and CTA of the head and neck from March 2011 to October 2012 at a single institution. Patients were divided into two groups, those with and those without cervical spine fracture appreciated on CT of the cervical spine. The frequency of vascular injury on CTA in those with a cervical fracture was assessed. The frequency of vascular injury treatment and modifications owed to a positive CTA of head and neck were also assessed. A study was considered appropriate if it was ordered in accordance with the modified Denver Screening criteria. Effective radiation dose (mSv was calculated by multiplying dose length product (DLP from the scanner with the standard conversion coefficient (k (k = 0.0021 mSv/mGy x cm.Results: In the 387 CTAs of head and neck, a cervical injury was recorded in 128 patients. Twenty CTA scans were correctly ordered for non-spinal indications, and 19 were ordered off protocol. CTA was found positive in 1 patient for whom the imaging was off protocol and 1 for whom the clinical indication was non-cervical. There were 19 positive CTA cases of head and neck, none of which underwent surgical intervention. CTA was positive in 13 of 48 patients who had suffered a C2 fracture; this accounted for 13 of the 19 positive CTA studies (p < 0.01. Estimated fee for CTA was $3783, and radiation exposure was 4 mSv with a standard deviation (±1.3. Conclusion: CTA of head and neck ordered off an institutional imaging protocol has a low probability of being positive. Adherence to protocols for CTA of

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

    Directory of Open Access Journals (Sweden)

    Zhichao Xie

    2016-01-01

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

  20. Experimental measurement of radiation dose in a dedicated breast CT system

    CERN Document Server

    Shan-Wei, Shen; Hang, Shu; Xiao, Tang; Cun-Feng, Wei; Yu-Shou, Song; Rong-Jian, Shi; Long, Wei

    2013-01-01

    Radiation dose is an important performance indicator of a dedicated breast CT (DBCT). In this paper, the method of putting thermoluminescent dosimeters (TLD) into a breast shaped PMMA phantom to study the dose distribution in breasts was improved by using smaller TLDs and a new half-ellipsoid PMMA phantom. Then the weighted CT dose index (CTDIw) was introduced to average glandular assessment in DBCT for the first time and two measurement modes were proposed for different sizes of breasts. The dose deviations caused by using cylindrical phantoms were simulated using the Monte Carlo method and a set of correction factors were calculated. The results of the confirmatory measurement with a cylindrical phantom (11cm/8cm) show that CTDIw gives a relatively conservative overestimate of the average glandular dose comparing to the results of Monte Carlo simulation and TLDs measurement. But with better practicability and stability, the CTDIw is suitable for dose evaluations in daily clinical practice. Both of the TLDs ...

  1. X-ray phase-contrast CT imaging of the acupoints based on synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chenglin, Liu, E-mail: lclyctc@163.com [Physics Department of Yancheng Teachers’ College, Yancheng 224051 (China); Xiaohua, Wang; Hua, Xu [Physics Department of Yancheng Teachers’ College, Yancheng 224051 (China); Fang, Liu; Ruishan, Dang [Anatomy Department of Second Military Medical University, Shanghai 200433 (China); Dongming, Zhang; Xinyi, Zhang [Synchrotron Radiation Research Center of Fudan University, Shanghai 200433 (China); Honglan, Xie; Tiqiao, Xiao [Shanghai Synchrotron Radiation Facility of Shanghai Institute of Applied Physics, CAS, Shanghai 201800 (China)

    2014-10-15

    In this paper, the morphology of the acupuncture point (abbreviated as acupoint hereafter) or tissue where there were no acupoints in the fractional rabbit hind limb was studied by in-line phase contrast CT imaging (PCI-CT) methods based on synchrotron radiation. The density of micro-vessels was calculated for tissues with acupoints or without acupoints. Differences between acupoints area and non-acupoint areas determined by the density of the micro-vessels propose a strong evidence of the existence of acupoints. Our results showed that there were two significantly higher densities of the micro-vessels, where two acupoints were located, respectively. In addition, there were large numbers of involutedly microvascular structure in the acupoint areas. Nevertheless, in non-acupoints area, the microvascular structure was relatively simple and flat.

  2. Evaluating applicability of metal artifact reduction algorithm for head and neck radiation treatment planning CT

    Energy Technology Data Exchange (ETDEWEB)

    Son, Sang Jun; Park, Jang Pil; Kim, Min Jeong; Yoo, Suk Hyun [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-06-15

    The purpose of this study is evaluation for the applicability of O-MAR(Metal artifact Reduction for Orthopedic Implants)(ver. 3.6.0, Philips, Netherlands) in head and neck radiation treatment planning CT with metal artifact created by dental implant. All of the in this study's CT images were scanned by Brilliance Big Bore CT(Philips, Netherlands) at 120 kVp, 2 mm sliced and Metal artifact reduced by O-MAR. To compare the original and reconstructed CT images worked on RTPS(Eclipse ver 10.0.42, Varian, USA). In order to test the basic performance of the O-MAR, The phantom was made to create metal artifact by dental implant and other phantoms used for without artifact images. To measure a difference of HU in with artifact images and without artifact images, homogeneous phantom and inhomogeneous phantoms were used with cerrobend rods. Each of images were compared a difference of HU in ROIs. And also, 1 case of patient's original CT image applied O-MAR and density corrected CT were evaluated for dose distributions with SNC Patient(Sun Nuclear Co., USA). In cases of head and neck phantom, the difference of dose distribution is appeared 99.8% gamma passing rate(criteria 2 mm / 2%) between original and CT images applied O-MAR. And 98.5% appeared in patient case, among original CT, O-MAR and density corrected CT. The difference of total dose distribution is less than 2% that appeared both phantom and patient case study. Though the dose deviations are little, there are still matters to discuss that the dose deviations are concentrated so locally. In this study, The quality of all images applied O-MAR was improved. Unexpectedly, Increase of max. HU was founded in air cavity of the O-MAR images compare to cavity of the original images and wrong corrections were appeared, too. The result of study assuming restrained case of O-MAR adapted to near skin and low density area, it appeared image distortion and artifact correction simultaneously. In O-MAR CT, air cavity area

  3. Radiation Safety Management Guidelines for PET-CT: Focus on Behavior and Environment

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Wook [Cancer Imaging Center, National University Cancer Hospital, Seoul (Korea, Republic of); Han, Eun Ok [Dept. of Radiological Technology, Daegu Health College, Seoul (Korea, Republic of)

    2011-09-15

    Our purpose is to specify behavior and environmental factors aimed at reducing the exposed dosage caused by PET-CT and to develop radiation safety management guidelines adequate for domestic circumstances. We have used a multistep-multimethod as the methodological approach to design and to carry out the research both in quality and quantity, including an analysis on previous studies, professional consultations and a survey. The survey includes responses from 139 practitioners in charged of 109 PET-CTs installed throughout Korea(reported by the Korean Society of Nuclear Medicine, 2010). The research use 156 questions using Cronbach's {alpha} (alpha) coefficients which were: 0.818 for 'the necessity of setting and installing the radiation protective environment'; 0.916 for 'the necessity of radiation protection', 'setting and installing the radiation protective environment'; and 0.885 for 'radiation protection'. The check list, derived from the radiation safety management guidelines focused on behavior and environment, was composed of 20 items for the radiation protective environment: including 5 items for the patient; 4 items for the guardian; 3 items for the radiologist; and 8 items applied to everyone involved; for a total of 26 items for the radiation protective behavior including: 12 items for the patient; 1 item for the guardian, 7 items for the radiologist; and 6 items applied to everyone involved. The specific check list is shown in (Table 5-6). Since our country has no safety management guidelines of its own to reduce the exposed dosage caused by PET-CTs, we believe the guidelines developed through this study means great deal to the field as it is not only appropriate for domestic circumstances, but also contains specific check lists for each target who may be exposed to radiation in regards to behavior and environment.

  4. Reducing radiation in CT urography for hematuria: Effect of using 100 kilovoltage protocol

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungwon, E-mail: sungwonlee8@gmail.com [Department of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701 (Korea, Republic of); Jung, Seung Eun, E-mail: sejung@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701 (Korea, Republic of); Rha, Sung Eun, E-mail: serha@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701 (Korea, Republic of); Byun, Jae Young, E-mail: jybyun@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701 (Korea, Republic of)

    2012-08-15

    Objective: To compare 128-slice multidetector computed tomography (MDCT) at 100 kVp and 120 kVp for image quality and radiation dose. Materials and methods: Our study had approval of our institutional review board. We retrospectively selected 25 patients who underwent CT urography for the evaluation of hematuria. The CT scans were taken with 128-slice MDCT, with three phases (precontrast, nephrographic, and excretory), using an automatic tube current modulation with reference tube level of 180 mA s and tube voltages of either 100 kVp (n = 14, mean age 26.71) or 120 kVp (n = 11, mean age 25.54). The signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) of the urinary tract, the subjective image quality of the urinary tract evaluated with a five point scale by two radiologists and the effective dose calculated on the basis of dose-length-product (DLP) and volume-CT-dose-index (CTDIvol) were compared between the groups with Student's t test or Mann-Whitney U test. Results: There was no significant difference in the SNR (p = 0.358), CNR (p = 0.303) and the subjective image quality (p = 0.486) between the two protocols. The mean CTDIvol, DLP and the effective dose in the 100 kVp protocol were significantly lower than the 120 kVp protocol (p = 0.000, 0.000). Conclusion: CT urography using 100 kVp protocol resulted in reduction of radiation dose without loss of objective or subjective image quality.

  5. Quantitative assessment of global lung inflammation following radiation therapy using FDG PET/CT: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Abdulla, Sarah; Salavati, Ali; Saboury, Babak; Torigian, Drew A. [University of Pennsylvania, and Hospital of the University of Pennsylvania, Department of Radiology, Perelman School of Medicine, Philadelphia, PA (United States); Basu, Sandip [Bhabha Atomic Research Center, Tata Memorial Center Annexe, Radiation Medicine Center, Bombay (India); Alavi, Abass [University of Pennsylvania, and Hospital of the University of Pennsylvania, Department of Radiology, Perelman School of Medicine, Philadelphia, PA (United States); Hospital of the University of Pennsylvania, Department of Radiology, Division of Nuclear Medicine, Philadelphia, PA (United States)

    2014-02-15

    Radiation pneumonitis is the most severe dose-limiting complication in patients receiving thoracic radiation therapy. The aim of this study was to quantify global lung inflammation following radiation therapy using FDG PET/CT. We studied 20 subjects with stage III non-small-cell lung carcinoma who had undergone FDG PET/CT imaging before and after radiation therapy. On all PET/CT studies, the sectional lung volume (sLV) of each lung was calculated from each slice by multiplying the lung area by slice thickness. The sectional lung glycolysis (sLG) was calculated by multiplying the sLV and the lung sectional mean standardized uptake value (sSUVmean) on each slice passing through the lung. The lung volume (LV) was calculated by adding all sLVs from the lung, and the global lung glycolysis (GLG) was calculated by adding all sLGs from the lung. Finally, the lung SUVmean was calculated by dividing the GLG by the LV. The amount of inflammation in the lung parenchyma directly receiving radiation therapy was calculated by subtracting tumor measurements from GLG. In the lung directly receiving radiation therapy, the lung parenchyma SUVmean and global lung parenchymal glycolysis were significantly increased following therapy. In the contralateral lung (internal control), no significant changes were observed in lung SUVmean or GLG following radiation therapy. Global lung parenchymal glycolysis and lung parenchymal SUVmean may serve as potentially useful biomarkers to quantify lung inflammation on FDG PET/CT following thoracic radiation therapy. (orig.)

  6. Estimation of radiation exposure of retrospective gated and prospective triggered 128-slice triple-rule-out CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin (Dept. of Diagnostic and Interventional Radiology, Univ. Hospital Tuebingen, Tuebingen (Germany)), email: dominik.ketelsen@med.uni-tuebingen.de; Buchgeister, Markus (Depts. of Radiotherapy and Radiooncology, Univ. Hospital Tuebingen, Tuebingen (Germany))

    2011-09-15

    Background: CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. Purpose: To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). Material and Methods: An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). Results: The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4-13.4 mSv and from 10.1-17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% +- 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% +- 6.5% in comparison to standard ECG-pulsing (p < 0.001). The effective dose increased significantly with lower heart rates (p < 0.001). Prospective ECG-triggered TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Conclusion: Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner

  7. Diagnostic accuracy at several reduced radiation dose levels for CT imaging in the diagnosis of appendicitis

    Science.gov (United States)

    Zhang, Di; Khatonabadi, Maryam; Kim, Hyun; Jude, Matilda; Zaragoza, Edward; Lee, Margaret; Patel, Maitraya; Poon, Cheryce; Douek, Michael; Andrews-Tang, Denise; Doepke, Laura; McNitt-Gray, Shawn; Cagnon, Chris; DeMarco, John; McNitt-Gray, Michael

    2012-03-01

    Purpose: While several studies have investigated the tradeoffs between radiation dose and image quality (noise) in CT imaging, the purpose of this study was to take this analysis a step further by investigating the tradeoffs between patient radiation dose (including organ dose) and diagnostic accuracy in diagnosis of appendicitis using CT. Methods: This study was IRB approved and utilized data from 20 patients who underwent clinical CT exams for indications of appendicitis. Medical record review established true diagnosis of appendicitis, with 10 positives and 10 negatives. A validated software tool used raw projection data from each scan to create simulated images at lower dose levels (70%, 50%, 30%, 20% of original). An observer study was performed with 6 radiologists reviewing each case at each dose level in random order over several sessions. Readers assessed image quality and provided confidence in their diagnosis of appendicitis, each on a 5 point scale. Liver doses at each case and each dose level were estimated using Monte Carlo simulation based methods. Results: Overall diagnostic accuracy varies across dose levels: 92%, 93%, 91%, 90% and 90% across the 100%, 70%, 50%, 30% and 20% dose levels respectively. And it is 93%, 95%, 88%, 90% and 90% across the 13.5-22mGy, 9.6-13.5mGy, 6.4-9.6mGy, 4-6.4mGy, and 2-4mGy liver dose ranges respectively. Only 4 out of 600 observations were rated "unacceptable" for image quality. Conclusion: The results from this pilot study indicate that the diagnostic accuracy does not change dramatically even at significantly reduced radiation dose.

  8. Hepatic CT perfusion measurements: A feasibility study for radiation dose reduction using new image reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Negi, Noriyuki, E-mail: noriyuki@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Yoshikawa, Takeshi, E-mail: yoshikawa0816@aol.com [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Somiya, Yuichiro, E-mail: somiya13@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Sekitani, Toshinori, E-mail: atieinks-toshi@nifty.com [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Sugihara, Naoki, E-mail: naoki.sugihara@toshiba.co.jp [Toshiba Medical Systems Co., 1385 Shimoishigami, Otawara 324-0036 (Japan); Koyama, Hisanobu, E-mail: hkoyama@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kanda, Tomonori, E-mail: k_a@hotmail.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kanata, Naoki, E-mail: takikina12345@yahoo.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Murakami, Tohru, E-mail: mura@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kawamitsu, Hideaki, E-mail: kawamitu@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Sugimura, Kazuro, E-mail: sugimura@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan)

    2012-11-15

    Objectives: To assess the effects of image reconstruction method on hepatic CT perfusion (CTP) values using two CT protocols with different radiation doses. Materials and methods: Sixty patients underwent hepatic CTP and were randomly divided into two groups. Tube currents of 210 or 250 mA were used for the standard dose group and 120 or 140 mA for the low dose group. The higher currents were selected for large patients. Demographic features of the groups were compared. CT images were reconstructed by using filtered back projection (FBP), image filter (quantum de-noising, QDS), and adaptive iterative dose reduction (AIDR). Hepatic arterial and portal perfusion (HAP and HPP, ml/min/100 ml) and arterial perfusion fraction (APF, %) were calculated using the dual-input maximum slope method. ROIs were placed on each hepatic segment. Perfusion and Hounsfield unit (HU) values, and image noises (standard deviations of HU value, SD) were measured and compared between the groups and among the methods. Results: There were no significant differences in the demographic features of the groups, nor were there any significant differences in mean perfusion and HU values for either the groups or the image reconstruction methods. Mean SDs of each of the image reconstruction methods were significantly lower (p < 0.0001) for the standard dose group than the low dose group, while mean SDs for AIDR were significantly lower than those for FBP for both groups (p = 0.0006 and 0.013). Radiation dose reductions were approximately 45%. Conclusions: Image reconstruction method did not affect hepatic perfusion values calculated by dual-input maximum slope method with or without radiation dose reductions. AIDR significantly reduced images noises.

  9. Estimation of organ-absorbed radiation doses during 64-detector CT coronary angiography using different acquisition techniques and heart rates: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, Kosuke; Koshida, Kichiro; Kawashima, Hiroko (Dept. of Quantum Medical Technology, Faculty of Health Sciences, Kanazawa Univ., Kanazawa (Japan)), email: matsuk@mhs.mp.kanazawa-u.ac.jp; Noto, Kimiya; Takata, Tadanori; Yamamoto, Tomoyuki (Dept. of Radiological Technology, Kanazawa Univ. Hospital, Kanazawa (Japan)); Shimono, Tetsunori (Dept. of Radiology, Hoshigaoka Koseinenkin Hospital, Hirakata (Japan)); Matsui, Osamu (Dept. of Radiology, Faculty of Medicine, Kanazawa Univ., Kanazawa (Japan))

    2011-07-15

    Background: Though appropriate image acquisition parameters allow an effective dose below 1 mSv for CT coronary angiography (CTCA) performed with the latest dual-source CT scanners, a single-source 64-detector CT procedure results in a significant radiation dose due to its technical limitations. Therefore, estimating the radiation doses absorbed by an organ during 64-detector CTCA is important. Purpose: To estimate the radiation doses absorbed by organs located in the chest region during 64-detector CTCA using different acquisition techniques and heart rates. Material and Methods: Absorbed doses for breast, heart, lung, red bone marrow, thymus, and skin were evaluated using an anthropomorphic phantom and radiophotoluminescence glass dosimeters (RPLDs). Electrocardiogram (ECG)-gated helical and ECG-triggered non-helical acquisitions were performed by applying a simulated heart rate of 60 beats per minute (bpm) and ECG-gated helical acquisitions using ECG modulation (ECGM) of the tube current were performed by applying simulated heart rates of 40, 60, and 90 bpm after placing RPLDs on the anatomic location of each organ. The absorbed dose for each organ was calculated by multiplying the calibrated mean dose values of RPLDs with the mass energy coefficient ratio. Results: For all acquisitions, the highest absorbed dose was observed for the heart. When the helical and non-helical acquisitions were performed by applying a simulated heart rate of 60 bpm, the absorbed doses for heart were 215.5, 202.2, and 66.8 mGy for helical, helical with ECGM, and non-helical acquisitions, respectively. When the helical acquisitions using ECGM were performed by applying simulated heart rates of 40, 60, and 90 bpm, the absorbed doses for heart were 178.6, 139.1, and 159.3 mGy, respectively. Conclusion: ECG-triggered non-helical acquisition is recommended to reduce the radiation dose. Also, controlling the patients' heart rate appropriately during ECG-gated helical acquisition with

  10. Evaluation of an initiative to reduce radiation exposure from CT to children in a non-pediatric-focused facility.

    Science.gov (United States)

    Blumfield, Einat; Zember, Jonathan; Guelfguat, Mark; Blumfield, Amit; Goldman, Harold

    2015-12-01

    We would like to share our experience of reducing pediatric radiation exposure. Much of the recent literature regarding successes of reducing radiation exposure has come from dedicated children's hospitals. Nonetheless, over the past two decades, there has been a considerable increase in CT imaging of children in the USA, predominantly in non-pediatric-focused facilities where the majority of children are treated. In our institution, two general hospitals with limited pediatric services, a dedicated initiative intended to reduce children's exposure to CT radiation was started by pediatric radiologists in 2005. The initiative addressed multiple issues including eliminating multiphase studies, decreasing inappropriate scans, educating referring providers, training residents and technologists, replacing CT with ultrasound or MRI, and ensuring availability of pediatric radiologists for consultation. During the study period, the total number of CT scans decreased by 24 %. When accounting for the number of scans per visit to the emergency department (ED), the numbers of abdominal and head CT scans decreased by 37.2 and 35.2 %, respectively. For abdominal scans, the average number of phases per scan decreased from 1.70 to 1.04. Upon surveying the pediatric ED staff, it was revealed that the most influential factors on ordering of scans were daily communication with pediatric radiologists, followed by journal articles and lectures by pediatric radiologists. We concluded that a non-pediatric-focused facility can achieve dramatic reduction in CT radiation exposure to children; however, this is most effectively achieved through a dedicated, multidisciplinary process led by pediatric radiologists.

  11. Improvement of internal tumor volumes of non-small cell lung cancer patients for radiation treatment planning using interpolated average CT in PET/CT.

    Directory of Open Access Journals (Sweden)

    Yao-Ching Wang

    Full Text Available Respiratory motion causes uncertainties in tumor edges on either computed tomography (CT or positron emission tomography (PET images and causes misalignment when registering PET and CT images. This phenomenon may cause radiation oncologists to delineate tumor volume inaccurately in radiotherapy treatment planning. The purpose of this study was to analyze radiology applications using interpolated average CT (IACT as attenuation correction (AC to diminish the occurrence of this scenario. Thirteen non-small cell lung cancer patients were recruited for the present comparison study. Each patient had full-inspiration, full-expiration CT images and free breathing PET images by an integrated PET/CT scan. IACT for AC in PET(IACT was used to reduce the PET/CT misalignment. The standardized uptake value (SUV correction with a low radiation dose was applied, and its tumor volume delineation was compared to those from HCT/PET(HCT. The misalignment between the PET(IACT and IACT was reduced when compared to the difference between PET(HCT and HCT. The range of tumor motion was from 4 to 17 mm in the patient cohort. For HCT and PET(HCT, correction was from 72% to 91%, while for IACT and PET(IACT, correction was from 73% to 93% (*p<0.0001. The maximum and minimum differences in SUVmax were 0.18% and 27.27% for PET(HCT and PET(IACT, respectively. The largest percentage differences in the tumor volumes between HCT/PET and IACT/PET were observed in tumors located in the lowest lobe of the lung. Internal tumor volume defined by functional information using IACT/PET(IACT fusion images for lung cancer would reduce the inaccuracy of tumor delineation in radiation therapy planning.

  12. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine: part 2: benefits versus risk of CT.

    Science.gov (United States)

    Westra, Sjirk J

    2014-10-01

    In order to personalize the communication of the CT risk, we need to describe the risk in the context of the clinical benefit of CT, which will generally be much higher, provided a CT scan has a well-established clinical indication. However as pediatric radiologists we should be careful not to overstate the benefit of CT, being aware that medico-legal pressures and the realities of health care economics have led to overutilization of the technology. And even though we should not use previously accumulated radiation dose to a child as an argument against conducting a clinically indicated scan (the "sunk-cost" bias), we should consider patients' radiation history in the diagnostic decision process. As a contribution to future public health, it makes more sense to look for non-radiating alternatives to CT in the much larger group of basically healthy children who are receiving occasional scans for widely prevalent conditions such as appendicitis and trauma than to attempt lowering CT use in the smaller group of patients with chronic conditions with a limited life expectancy. When communicating the CT risk with individual patients and their parents, we should acknowledge and address their concerns within the framework of informed decision-making. When appropriate, we may express the individual radiation risk, based on estimates of summated absorbed organ dose, as an order of magnitude rather than as an absolute number, and compare this with the much larger natural cancer incidence over a child's lifetime, and with other risks in medicine and daily life. We should anticipate that many patients cannot make informed decisions on their own in this complex matter, and we should offer our guidance while maintaining respect for patient autonomy. Proper documentation of the informed decision process is important for future reference. In concert with our referring physicians, pediatric radiologists are well-equipped to tackle the complexities associated with the communication

  13. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine. Pt. 2. Benefits versus risk of CT

    Energy Technology Data Exchange (ETDEWEB)

    Westra, Sjirk J. [Massachusetts General Hospital, Division of Pediatric Radiology, Boston, MA (United States)

    2014-10-15

    In order to personalize the communication of the CT risk, we need to describe the risk in the context of the clinical benefit of CT, which will generally be much higher, provided a CT scan has a well-established clinical indication. However as pediatric radiologists we should be careful not to overstate the benefit of CT, being aware that medico-legal pressures and the realities of health care economics have led to overutilization of the technology. And even though we should not use previously accumulated radiation dose to a child as an argument against conducting a clinically indicated scan (the ''sunk-cost'' bias), we should consider patients' radiation history in the diagnostic decision process. As a contribution to future public health, it makes more sense to look for non-radiating alternatives to CT in the much larger group of basically healthy children who are receiving occasional scans for widely prevalent conditions such as appendicitis and trauma than to attempt lowering CT use in the smaller group of patients with chronic conditions with a limited life expectancy. When communicating the CT risk with individual patients and their parents, we should acknowledge and address their concerns within the framework of informed decision-making. When appropriate, we may express the individual radiation risk, based on estimates of summated absorbed organ dose, as an order of magnitude rather than as an absolute number, and compare this with the much larger natural cancer incidence over a child's lifetime, and with other risks in medicine and daily life. We should anticipate that many patients cannot make informed decisions on their own in this complex matter, and we should offer our guidance while maintaining respect for patient autonomy. Proper documentation of the informed decision process is important for future reference. In concert with our referring physicians, pediatric radiologists are well-equipped to tackle the complexities

  14. Actinomycosis of the Chest X-ray Plain Film and CT Imaging Features%胸部放线菌病的X线平片和CT影像特点研究

    Institute of Scientific and Technical Information of China (English)

    岳莉; 闫国梁

    2015-01-01

    Objective Analysis actinomycosis of the chest X-ray plain film and CT tomography imaging characteristics, the evaluation of the value of X-ray and CT in the diagnosis of the disease.Methods Choose from January 2005 to February 2015, in our hospital during the period, confirmed by laboratory tests for patients with thoracic actinomycosis 10 cases as the research object, all patients were performed X-ray plain film and CT tomography; CT images with a standard algorithm, multi plane restructuring image, image characteristics.Results This group of 10 cases with X-ray is, lateral chest plain film are displayed as mass and large dense shadow, but did not show empty, liquefied gas and lesions; CT examination results showed that 52 actinomycetes lesions involving 18 normal; 8 cases of patients with CT images show that mass as the main lesions, lung see more spots or patch around the lesions and the funicular fuzzy shadow; Mass in the thin wall, and hollow, thin wall smooth, hollow with low density liquefaction and scattered suspended gas oven shadow; CT scan showed to see gas-liquid surface; CT images of 10 cases were showed lesion adjacent pleural thickening, 8 cases of patients with lung CT images showed the door increases and/or mediastinal lymph nodes, 2 cases of right lung CT images showed patchy shadow merge mediastinal abscess.Conclusion X-ray plain film to check the chest actinomycosis cannot view demonstrates the focal area of cavity, liquid and gas, limited diagnostic value and CT tomography can display the details of the lesion, has the characteristic, has high diagnostic value.%目的:分析胸部放线菌病的X线平片和CT体层摄影术影像特点,评价X线及CT在诊断该病中的价值。方法选择2005年1月至2015年2月期间我院收治,经实验室检查证实为胸部放线菌病的患者10例为研究对象,所有患者均行X线平片和CT体层摄影术检查;CT影像采用标准算法、多平面重组图像,观

  15. Chest X Ray?

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Chest X Ray A chest x ray is a fast and painless imaging test ... tissue scarring, called fibrosis. Doctors may use chest x rays to see how well certain treatments are ...

  16. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI of the Chest? What is MRI of the Chest? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the chest is performed ...

  17. Comparison of gonadal radiation doses from CT enterography and small-bowel follow-through in pediatric patients.

    Science.gov (United States)

    Reid, Janet R; Pozzuto, Jessica; Morrison, Stuart; Obuchowski, Nancy; Davros, William

    2015-03-01

    OBJECTIVE. CT enterography is superior to small-bowel follow-through (SBFT) for diagnosis of inflammatory bowel disease (IBD). It is widely assumed that the radiation dose from CT enterography is greater than that from SBFT in the pediatric patient. This study was designed to compare gonadal doses from CT enterography and SBFT to verify the best imaging choice for IBD evaluation in children. This study also challenges the assumption that CT enterography imparts a higher radiation dose through comparison of calculated radiation doses from CT enterography and SBFT. MATERIALS AND METHODS. Patients 0-18 years old who underwent either CT enterography or SBFT over a 2-year period were included. The CT enterography group consisted of 39 boys and 51 girls, whereas the SBFT group consisted of 89 boys and 113 girls. CT enterography was performed at 120 kVp and approximately 132 mAs (range, 54-330 mAs) using weight-based protocols. SBFT used automated control of kilovoltage and tube current-exposure time product. Patient demographics and technical parameters were collected for CT enterography and SBFT, data were cross-paired between CT enterography and SBFT, and gonadal dose was calculated. RESULTS. Mean (± SD) CT enterography testis and ovarian doses were 0.93 ± 0.3 cGy (n = 39) and 0.64 ± 0.2 cGy (n = 51), respectively. Mean SBFT testis and ovarian doses were 2.3 ± 1.6 cGy (n = 89) and 1.49 ± 0.3 cGy (n = 113), respectively. Mean fluoroscopy time for SBFT was 2.6 ± 2 minutes. Gonadal dose for CT enterography was significantly lower than that for SBFT in boys and girls (p enterography dose was higher in boys than girls (p enterography was lower than that for SBFT for boys and girls of all sizes and age. Controlled exposure time made CT enterography dose more consistent, whereas the range of dose for SBFT was highly operator dependent and related to extent of disease. Thus, for IBD, CT enterography is preferred over SBFT for all children.

  18. Does iterative reconstruction lower CT radiation dose: evaluation of 15,000 examinations.

    Directory of Open Access Journals (Sweden)

    Peter B Noël

    Full Text Available PURPOSE: Evaluation of 15,000 computed tomography (CT examinations to investigate if iterative reconstruction (IR reduces sustainably radiation exposure. METHOD AND MATERIALS: Information from 15,000 CT examinations was collected, including all aspects of the exams such as scan parameter, patient information, and reconstruction instructions. The examinations were acquired between January 2010 and December 2012, while after 15 months a first generation IR algorithm was installed. To collect the necessary information from PACS, RIS, MPPS and structured reports a Dose Monitoring System was developed. To harvest all possible information an optical character recognition system was integrated, for example to collect information from the screenshot CT-dose report. The tool transfers all data to a database for further processing such as the calculation of effective dose and organ doses. To evaluate if IR provides a sustainable dose reduction, the effective dose values were statistically analyzed with respect to protocol type, diagnostic indication, and patient population. RESULTS: IR has the potential to reduce radiation dose significantly. Before clinical introduction of IR the average effective dose was 10.1±7.8mSv and with IR 8.9±7.1mSv (p*=0.01. Especially in CTA, with the possibility to use kV reduction protocols, such as in aortic CTAs (before IR: average14.2±7.8mSv; median11.4mSv /with IR:average9.9±7.4mSv; median7.4mSv, or pulmonary CTAs (before IR: average9.7±6.2mSV; median7.7mSv /with IR: average6.4±4.7mSv; median4.8mSv the dose reduction effect is significant(p*=0.01. On the contrary for unenhanced low-dose scans of the cranial (for example sinuses the reduction is not significant (before IR:average6.6±5.8mSv; median3.9mSv/with IR:average6.0±3.1mSV; median3.2mSv. CONCLUSION: The dose aspect remains a priority in CT research. Iterative reconstruction algorithms reduce sustainably and significantly radiation dose in the clinical routine

  19. TU-CD-BRB-01: Normal Lung CT Texture Features Improve Predictive Models for Radiation Pneumonitis

    Energy Technology Data Exchange (ETDEWEB)

    Krafft, S [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); The University of Texas Graduate School of Biomedical Sciences, Houston, TX (United States); Briere, T; Court, L; Martel, M [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: Existing normal tissue complication probability (NTCP) models for radiation pneumonitis (RP) traditionally rely on dosimetric and clinical data but are limited in terms of performance and generalizability. Extraction of pre-treatment image features provides a potential new category of data that can improve NTCP models for RP. We consider quantitative measures of total lung CT intensity and texture in a framework for prediction of RP. Methods: Available clinical and dosimetric data was collected for 198 NSCLC patients treated with definitive radiotherapy. Intensity- and texture-based image features were extracted from the T50 phase of the 4D-CT acquired for treatment planning. A total of 3888 features (15 clinical, 175 dosimetric, and 3698 image features) were gathered and considered candidate predictors for modeling of RP grade≥3. A baseline logistic regression model with mean lung dose (MLD) was first considered. Additionally, a least absolute shrinkage and selection operator (LASSO) logistic regression was applied to the set of clinical and dosimetric features, and subsequently to the full set of clinical, dosimetric, and image features. Model performance was assessed by comparing area under the curve (AUC). Results: A simple logistic fit of MLD was an inadequate model of the data (AUC∼0.5). Including clinical and dosimetric parameters within the framework of the LASSO resulted in improved performance (AUC=0.648). Analysis of the full cohort of clinical, dosimetric, and image features provided further and significant improvement in model performance (AUC=0.727). Conclusions: To achieve significant gains in predictive modeling of RP, new categories of data should be considered in addition to clinical and dosimetric features. We have successfully incorporated CT image features into a framework for modeling RP and have demonstrated improved predictive performance. Validation and further investigation of CT image features in the context of RP NTCP

  20. 胸部CT检查对乳腺癌临床早期诊断的价值分析%The value of chest CT scan for early diagnosis of breast cancer

    Institute of Scientific and Technical Information of China (English)

    马荣国

    2015-01-01

    目的:探讨胸部CT检查对乳腺癌临床早期诊断的临床价值。方法:收治乳腺癌患者60例,所有患者均经针吸细胞学检查或手术病理证实。所有患者均采用双层螺旋CT检查,分析检查结果。结果:早期乳腺癌的CT影像学特征,本组60例早期乳腺癌病理类型:小管癌3例,小叶癌3例,单纯癌4例,导管内癌13例,浸润性导管癌37例。早期乳腺癌的主要影像学征象:肿块有毛刺影,长短不一,偶见伪足,形肿块状不规则,质地不均匀且有明显钙化,见局部皮肤增厚,钙化灶呈泥沙样、针尖样或条索样,若侵犯胸壁可见肿块周围腺体密度增高、腋下淋巴结肿大、乳腺后脂肪间隙完全消失。结论:胸部CT检查具有灵敏度高、检查无痛苦,是诊断早期乳腺癌的重要手段之一。%Objective:To explore the value of chest CT scan for early diagnosis of breast cancer.Methods:60 patients with breast cancer were selected.All patients were diagnosed by needle aspiration cytology or surgical pathology.All patients were given double helical CT examination,and we analyzed the results of the examination.Results:CT imaging features of early breast cancer:early breast cancer pathological type of 60 cases in this group:3 cases of tubular carcinoma,3 cases of small tumor,4 cases of simple carcinoma,13 cases of catheter carcinoma,37 cases of invasive ductal carcinoma.Imaging appearances of early breast cancer:the mass had burr shadow,the length was different,pseudopod were rare,occasionally pseudopodia and swollen lump shape were irregular,the texture was not uniform and it had calcification.The local skin was thickened,and the calcification was the sediment sample,the needle tip sample or the cord like.If the tumor invaded the chest wall,the density of the gland around the tumor increased,the axillary lymph nodes were enlarged,and the fat clearance after the mammary gland was disappeared

  1. 胸部CT与钡餐透视检查对食管癌诊断价值研究%Research on Value of Chest CT and Barium Meal Fluoroscopic Examination in Diagnosis of Esophagus Cancer

    Institute of Scientific and Technical Information of China (English)

    李北平

    2016-01-01

    Objective To discuss the application value of chest barium meal fluoroscopy, CT and gastroscope in diagnosis of esophagus cancer. Methods 76 cases of patients with esophagus cancer diagnosed in our hospital from January 2014 to De-cember 2015 were selected, 44 cases of patients with benign lesions of pars oesophagea treated at the same period were se-lected for comparison, the different examination methods included barium meal fluoroscopy, CT and bronchoscope, all pa-tients received the above examinations, and the diagnostic accuracy of various methods was compared and analyzed. Results The diagnostic accuracy rates of barium meal fluoroscopy, CT and gastroscope for esophagus cancer were respectively 67.11%, 90.79% and 92.11%, the diagnostic accuracy rate of CT and gastroscope for esophagus cancer was higher than that of barium meal fluoroscopic diagnosis, the diagnostic accuracy rate of CT for lesions of pars oesophagea was higher than that of barium meal fluoroscopy with statistical difference(χ2=5.37, P0.05). Conclusion Chest barium meal fluoroscopy can be in the first place in the initial diagnosis and screening of esophagus cancer in clinic, and the CT and gastroscope can be used for further examination, which is of impor-tant significance to improve the diagnosis rate of esophagus cancer in clinic.%目的:探讨胸部钡餐透视、CT和胃镜对食管癌诊断的应用价值。方法整群选取该医院2014年1月—2015年12月间就诊的76例食管癌患者作为研究对象,选取同期44例食管部良性病变患者作为对照,并根据检查方法的不同分为钡餐透视、CT、支气管镜,所有患者均进行以上检查,对比和分析各种方法在诊断中的准确性。结果钡餐透视对食管癌的诊断准确率为67.11%,CT为90.79%,胃镜为92.11%,CT与胃镜对食管癌的诊断准确率高于钡餐透视诊断,对食管部病变的诊断准确率CT高于钡餐透视,差异有统计学意义(χ2=5.37,P0.05

  2. PET/CT alignment calibration with a non-radioactive phantom and the intrinsic 176Lu radiation of PET detector

    Science.gov (United States)

    Wei, Qingyang; Ma, Tianyu; Wang, Shi; Liu, Yaqiang; Gu, Yu; Dai, Tiantian

    2016-11-01

    Positron emission tomography/computed tomography (PET/CT) is an important tool for clinical studies and pre-clinical researches which provides both functional and anatomical images. To achieve high quality co-registered PET/CT images, alignment calibration of PET and CT scanner is a critical procedure. The existing methods reported use positron source phantoms imaged both by PET and CT scanner and then derive the transformation matrix from the reconstructed images of the two modalities. In this paper, a novel PET/CT alignment calibration method with a non-radioactive phantom and the intrinsic 176Lu radiation of the PET detector was developed. Firstly, a multi-tungsten-alloy-sphere phantom without positron source was designed and imaged by CT and the PET scanner using intrinsic 176Lu radiation included in LYSO. Secondly, the centroids of the spheres were derived and matched by an automatic program. Lastly, the rotation matrix and the translation vector were calculated by least-square fitting of the centroid data. The proposed method was employed in an animal PET/CT system (InliView-3000) developed in our lab. Experimental results showed that the proposed method achieves high accuracy and is feasible to replace the conventional positron source based methods.

  3. Radiation dose assessment in a 320-detector-row CT scanner used in cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goma, Carles; Ruiz, Agustin; Jornet, Nuria; Latorre, Artur; Pallerol, Rosa M.; Carrasco, Pablo; Eudaldo, Teresa; Ribas, Montserrat [Servei de Radiofisica i Radioproteccio, Hospital de la Santa Creu i Sant Pau, Sant Antoni Maria Claret 167, 08025 Barcelona (Spain)

    2011-03-15

    Purpose: In the present era of cone-beam CT scanners, the use of the standardized CTDI{sub 100} as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI{sub 100} is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. Methods: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, {sigma}. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI{sub 100} calculated analytically to the measurement made with a 100 mm pencil ion chamber. Results: For the central and weighted dose profiles, the authors found a good

  4. Quantifying the Increase in Radiation Exposure Associated with SPECT/CT Compared to SPECT Alone for Routine Nuclear Medicine Examinations

    Directory of Open Access Journals (Sweden)

    Ann M. Larkin

    2011-01-01

    Full Text Available Purpose. We quantify the additional radiation exposure in terms of effective dose incurred by patients in the CT portion of SPECT/CT examinations. Methods. The effective dose from a variety of common nuclear medicine procedures is calculated and summarized. The extra exposure from the CT portion of the examination is summarized by examination and body part. Two hundred forty-eight scans from 221 patients are included in this study. The effective dose from the CT examination is also compared to average background radiation. Results. We found that the extra effective dose is not sufficient to cause deterministic effects. However, the stochastic effects may be significant, especially in patients undergoing numerous follow-up studies. The cumulative effect might increase the radiation exposure compared to patient management with SPECT alone. Conclusions. While the relative increase in radiation exposure associated with SPECT/CT is generally considered acceptable when compared with the benefits to the patient, physicians should make every effort to minimize this effect by using proper technical procedures and educating patients about the exposure they will receive.

  5. Environmental Radiation Monitoring in PET-CT facilities; Vigilancia radiologica ambiental en instalaciones de PET-CT

    Energy Technology Data Exchange (ETDEWEB)

    Casa, M. A. de la; Gilarranz, R.; Adaimi, P.; Martinez, L. C.; Ruiz, M. A.; Rot, M. J.; Clemente, F.; Milanes, A.; Delgado, J. M.; Manzanas, M. J.

    2012-11-01

    We have made radiological surveillance measures in three PET-CT facilities during thirteen months. The results of our measures confirm the validity of the shielding calculation and safety studies performed in each one of the facilities. (Author) 3 refs.

  6. High-resolution three-dimensional visualization of the rat spinal cord microvasculature by synchrotron radiation micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jianzhong; Cao, Yong; Wu, Tianding; Li, Dongzhe [Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008 (China); Lu, Hongbin, E-mail: hongbinlu@hotmail.com [Department of Sports Medicine, Research Centre of Sports Medicine, Xiangya Hospital, Central South University, Changsha 410008 (China)

    2014-10-15

    Purpose: Understanding the three-dimensional (3D) morphology of the spinal cord microvasculature has been limited by the lack of an effective high-resolution imaging technique. In this study, synchrotron radiation microcomputed tomography (SRµCT), a novel imaging technique based on absorption imaging, was evaluated with regard to the detection of the 3D morphology of the rat spinal cord microvasculature. Methods: Ten Sprague-Dawley rats were used in this ex vivo study. After contrast agent perfusion, their spinal cords were isolated and scanned using conventional x-rays, conventional micro-CT (CµCT), and SRµCT. Results: Based on contrast agent perfusion, the microvasculature of the rat spinal cord was clearly visualized for the first time ex vivo in 3D by means of SRµCT scanning. Compared to conventional imaging techniques, SRµCT achieved higher resolution 3D vascular imaging, with the smallest vessel that could be distinguished approximately 7.4 μm in diameter. Additionally, a 3D pseudocolored image of the spinal cord microvasculature was generated in a single session of SRµCT imaging, which was conducive to detailed observation of the vessel morphology. Conclusions: The results of this study indicated that SRµCT scanning could provide higher resolution images of the vascular network of the spinal cord. This modality also has the potential to serve as a powerful imaging tool for the investigation of morphology changes in the 3D angioarchitecture of the neurovasculature in preclinical research.

  7. Application of a computed tomography based cystic fibrosis scoring system to chest tomosynthesis

    Science.gov (United States)

    Söderman, Christina; Johnsson, Åse; Vikgren, Jenny; Rystedt, Hans; Ivarsson, Jonas; Rossi Norrlund, Rauni; Nyberg Andersson, Lena; Bâth, Magnus

    2013-03-01

    In the monitoring of progression of lung disease in patients with cystic fibrosis (CF), recurrent computed tomography (CT) examinations are often used. The relatively new imaging technique chest tomosynthesis (CTS) may be an interesting alternative in the follow-up of these patients due to its visualization of the chest in slices at radiation doses and costs significantly lower than is the case with CT. A first step towards introducing CTS imaging in the diagnostics of CF patients is to establish a scoring system appropriate for evaluating the severity of CF pulmonary disease based on findings in CTS images. Previously, several such CF scoring systems based on CT imaging have been published. The purpose of the present study was to develop a CF scoring system for CTS, by starting from an existing scoring system dedicated for CT images and making modifications regarded necessary to make it appropriate for use with CTS images. In order to determine any necessary changes, three thoracic radiologists independently used a scoring system dedicated for CT on both CT and CTS images from CF patients. The results of the scoring were jointly evaluated by all the observers, which lead to suggestions for changes to the scoring system. Suggested modifications include excluding the scoring of air trapping and doing the scoring of the findings in quadrants of the image instead of in each lung lobe.

  8. The Addition of SPECT/CT Lymphoscintigraphy to Breast Cancer Radiation Planning Spares Lymph Nodes Critical for Arm Drainage

    Energy Technology Data Exchange (ETDEWEB)

    Cheville, Andrea L., E-mail: Cheville.andrea@mayo.edu [Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota (United States); Brinkmann, Debra H.; Ward, Shelly B. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Durski, Jolanta [Department of Radiology, Nuclear Medicine Program, Mayo Clinic, Rochester, Minnesota (United States); Laack, Nadia N.; Yan, Elizabeth; Schomberg, Paula J.; Garces, Yolanda I. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Suman, Vera J. [Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota (United States); Petersen, Ivy A. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2013-03-15

    Background: This prospective cohort study was designed to determine whether the amount of radiation delivered to the nonpathological lymph nodes (LNs) that drain the arm can be significantly reduced by integrating single-photon emission computed tomography (SPECT)/computed tomography (CT) scans into radiation treatment planning. Methods: SPECT-CT scans were acquired for the 28 patients with stage I or II breast cancer and fused with the routinely obtained radiation oncology planning CT scans. Arm-draining LNs were contoured with 0.5-cm margins automatically using a threshold of 50% maximum intensity. Two treatment plans were generated: 1 per routine clinical practice (standard; STD) and the second (modified; MOD) with treatment fields modified to minimize dose to the arm-draining LNs visible on SPECT/CT images without interfering with the dosage delivered to target tissues. Participants were treated per the MOD plans. Arm volumes were measured prior to radiation and thereafter at least three subsequent 6-month intervals. Results: Sixty-eight level I-III arm-draining LNs were identified, 57% of which were inside the STD plan fields but could be blocked in the MOD plan fields. Sixty-five percent of arm-draining LNs in the STD versus 16% in the MOD plans received a mean of ≥10 Gy, and 26% in the STD versus 4% in the MOD plans received a mean of ≥40 Gy. Mean LN radiation exposure was 23.6 Gy (standard deviation 18.2) with the STD and 7.7 Gy (standard deviation 11.3) with the MOD plans (P<.001). No participant developed lymphedema. Conclusions: The integration of SPECT/CT scans into breast cancer radiation treatment planning reduces unnecessary arm-draining LN radiation exposure and may lessen the risk of lymphedema.

  9. Impact of 64-slice coronary CT on the management of patients presenting with acute chest pain: results of a prospective two-centre study

    Energy Technology Data Exchange (ETDEWEB)

    Christiaens, Luc [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); CHU de Poitiers, Departement de Cardiologie, Poitiers (France); Duchat, Florent; Boudiaf, Mourad; Fargeaudou, Yann; Ledref, Olivier; Soyer, Philippe [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); Tasu, Jean-Pierre [CHU de Poitiers, Departement de Radiologie, Poitiers (France); Sirol, Marc [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); INSERM UFR U942, Insuffisance Cardiaque et Biomarqueurs, Universite Paris 7 - Denis Diderot, Hopital Lariboisiere, Paris (France); Universite Paris VII - Denis Diderot, Assistance Publique - Hopitaux de Paris, Service de Radiologie Vasculaire, Hopital Lariboisiere, Paris (France)

    2012-05-15

    Our two-centre prospective study evaluates the usefulness of 64-slice coronary computed tomography (CCT) to rule out significant coronary artery stenosis in patients admitted in emergency departments (ED) for acute coronary syndromes (ACS) with low-to-intermediate risk score. Patients (175) admitted for acute chest pain (ACP), unmodified electrocardiogram and first troponin measurement within normal ranges were included. A second troponin measurement and a 64-slice CCT within 24 h were performed. Major adverse cardiac events (MACE) were recorded during follow-up (6 months {+-} 2). 64-slice CCT was either normal or showed non-significant coronary stenosis in the majority of patients (78%). 64-slice CCT depicted significant stenosis (>50% diameter) in 22% of patient whereas initial clinical and biological evaluation was reassuring. For negative CCTs, elevated troponin at second measurement did not modify the strategy or treatment of patients. No MACEs were noted during follow up. In 12% of patients CCT identified unsuspected non-coronary abnormalities. Our study confirms 64-slice CCT utility to rule out significant coronary artery stenosis in 8/10 patients admitted in ED with ACP or ACS with low-to-intermediate risk score. Early discharge with a negative 64-slice CCT is associated with very low risk of cardiac events at 6 months. (orig.)

  10. Stationary digital chest tomosynthesis for coronary artery calcium scoring

    Science.gov (United States)

    Wu, Gongting; Wang, Jiong; Potuzko, Marci; Harman, Allison; Pearce, Caleb; Shan, Jing; Lee, Yueh Z.; Zhou, Otto; Lu, Jianping

    2016-03-01

    The coronary artery calcium score (CACS) measures the buildup of calcium on the coronary artery wall and has been shown to be an important predictor of the risk of coronary artery diseases (CAD). Currently CACS is measured using CT, though the relatively high cost and high radiation dose has limited its adoption as a routine screening procedure. Digital Chest Tomosynthesis (DCT), a low dose and low cost alternative to CT, and has been shown to achieve 90% of sensitivity of CT in lung disease screening. However commercial DCT requires long scanning time and cannot be adapted for high resolution gated cardiac imaging, necessary for CACS. The stationary DCT system (s- DCT), developed in our lab, has the potential to significantly shorten the scanning time and enables high resolution cardiac gated imaging. Here we report the preliminary results of using s-DCT to estimate the CACS. A phantom heart model was developed and scanned by the s-DCT system and a clinical CT in a phantom model with realistic coronary calcifications. The adapted fan-beam volume reconstruction (AFVR) method, developed specifically for stationary tomosynthesis systems, is used to obtain high resolution tomosynthesis images. A trained cardiologist segmented out the calcifications and the CACS was obtained. We observed a strong correlation between the tomosynthesis derived CACS and CT CACS (r2 = 0.88). Our results shows s-DCT imaging has the potential to estimate CACS, thus providing a possible low cost and low dose imaging protocol for screening and monitoring CAD.

  11. MRI of the Chest

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Chest Magnetic resonance imaging (MRI) of the chest ... limitations of MRI of the Chest? What is MRI of the Chest? Magnetic resonance imaging (MRI) is ...

  12. Reducing radiation dose in adult head CT using iterative reconstruction. A clinical study in 177 patients

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, D. [Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiology; Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiation Oncology; Kahn, J.; Huizing, L.; Wiener, E.; Grupp, U.; Boening, G.; Streitparth, F. [Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiology; Ghadjar, P. [Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiation Oncology; Renz, D.M. [Jena University Hospital (Germany). Dept. of Radiology

    2016-02-15

    To assess how ASIR (adaptive statistical iterative reconstruction) contributes to dose reduction and affects image quality of non-contrast cranial computed tomography (cCT). Non-contrast emergency CT scans of the head acquired in 177 patients were evaluated. The scans were acquired and processed using four different protocols: Group A (control): 120 kV, FBP (filtered back projection) n=71; group B1: 120 kV, scan and reconstruction performed with 20 % ASIR (blending of 20 % ASIR and 80 % FBP), n=86; group B2: raw data from group B1 reconstructed using a blending of 40 % ASIR and 60 % FBP, n=74; group C1: 120 kV, scan and reconstruction performed with 30 % ASIR, n=20; group C2: raw data from group C1 reconstructed using a blending of 50 % ASIR and 50 % FBP, n=20. The effective dose was calculated. Image quality was assessed quantitatively and qualitatively. Compared to group A, groups B1/2 and C1/2 showed a significantly reduced effective dose of 40.4 % and 73.3 % (p < 0.0001), respectively. Group B1 and group C1/2 also showed significantly reduced quantitative and qualitative image quality parameters. In group B2, quantitative measures were comparable to group A, and qualitative scores were lower compared to group A but higher compared to group B1. Diagnostic confidence grading showed groups B1/2 to be adequate for everyday clinical practice. Group C2 was considered acceptable for follow-up imaging of severe acute events such as bleeding or subacute stroke. Conclusion: Use of ASIR makes it possible to reduce radiation significantly while maintaining adequate image quality in non-contrast head CT, which may be particularly useful for younger patients in an emergency setting and in follow-up.

  13. Low radiation dose protocol in cardiac CT with 100 kVp: usefulness of display preset optimization.

    Science.gov (United States)

    Nakaura, Takeshi; Kidoh, Masafumi; Sakaino, Naritsugu; Nakamura, Shota; Nozaki, Toshimitsu; Izumi, Akari; Harada, Kazunori; Yamashita, Yasuyuki

    2013-08-01

    To evaluate the radiation dose and image quality of 100 kVp cardiac CT, and the effects of display setting optimization. We randomly assigned 100 patients undergoing cardiac CT to one of following two protocols. Fifty patients underwent our conventional protocol with 120 kVp, and the other 50 patients underwent our low radiation dose protocol with 100 kVp. We compared effective dose (ED); CT number, image noise, and contrast noise ratio (CNR) of ascending aorta at 120 and 100 kVp protocol. We also performed quantitative analysis and qualitative analysis for bitmap image of 120, 100 kVp, and display preset optimization for 100 kVp images. The estimated ED was 48 % lower with the 100 kVp protocol than the 120 kVp protocol (2.8 vs. 5.5 mSv, p protocol (18.5 ± 3.6 vs. 18.6 ± 3.8, p = 0.84). Display preset optimization significantly improved image quality of 100 kVp cardiac CT, and there is no significant difference in qualitative analysis and quantitative analysis between 100 kVp scan with optimized display preset and 120 kVp scan (p > 0.05). The 100 kVp scanning with optimized display preset offers almost same image quality at cardiac CT of thin adults under 48 % decreased radiation dose.

  14. Quantification of radiation-induced lung damage with CT scans - The possible benefit for radiogenomics

    Energy Technology Data Exchange (ETDEWEB)

    De Ruysscher, Dirk [Radiation Oncology, Univ. Hospitals Leuven/KU Leuven, Leuven (Belgium); Dept. of Radiation Oncology (Maastro clinic), Maastricht Univ. Medical Center, Maastricht (Netherlands)], e-mail: dirk.deruysscher@uzleuven.be; Sharifi, Hoda [Dept. of Radiation Oncology (Maastro clinic), Maastricht Univ. Medical Center, Maastricht (Netherlands); Defraene, Gilles [Radiation Oncology, Univ. Hospitals Leuven/KU Leuven, Leuven (Belgium)] [and others

    2013-10-15

    Background: Radiation-induced lung damage (RILD) is an important problem. Although physical parameters such as the mean lung dose are used in clinical practice, they are not suited for individualised radiotherapy. Objective, quantitative measurements of RILD on a continuous instead of on an ordinal, semi-quantitative, semi-subjective scale, are needed. Methods: Hounsfield unit (HU) changes before versus three months post-radiotherapy were correlated per voxel with the radiotherapy dose in 95 lung cancer patients. Deformable registration was used to register pre- and post-CT scans and the density increase was quantified for various dose bins. The dose-response curve for increased HU was quantified using the slope of a linear regression (HU/Gy). The end-point for the toxicity analysis was dyspnoea = grade 2. Results: Radiation dose was linearly correlated with the change in HU (mean R2 = 0.74 {+-} 0.28). No differences in HU/Gy between groups treated with stereotactic radiotherapy, conventional radiotherapy alone, sequential or concurrent chemo-radiotherapy were observed. In the whole patient group, 33/95 (34.7%) had dyspnoea {>=} G2. Of the 48 patients with a HU/Gy below the median, 16 (33.3%) developed dyspnoea = G2, while in the 47 patients with a HU/Gy above the median, 17 (36.1%) had dyspnoea {>=}G2 (not significant). Individual patients showed a nearly 21-fold difference in radiosensitivity, with HU/Gy ranging from 0 to 10 HU/Gy. Conclusions: HU changes identify objectively the whole range of individual radiosensitivity on a continuous, quantitative scale. CT density changes may allow more robust and accurate radiogenomics studies.

  15. Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Poonam [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); School of Advance Sciences, Vellore Institue of Technology University, Vellore, Tamil Nadu (India); Kozak, Kevin [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Tolakanahalli, Ranjini [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); Ramasubramanian, V. [School of Advance Sciences, Vellore Institue of Technology University, Vellore, Tamil Nadu (India); Paliwal, Bhudatt R. [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); University of Wisconsin, Riverview Cancer Centre, Wisconsin Rapids, WI (United States); Welsh, James S. [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); Rong, Yi, E-mail: rong@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); University of Wisconsin, Riverview Cancer Centre, Wisconsin Rapids, WI (United States)

    2012-07-01

    This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for sperm banking and lead shields were used to minimize testicular dose during radiation therapy. To minimize imaging artifacts, kilovoltage CT (kVCT) treatment planning was conducted without shielding. Generous hypothetical contours were generated on each 'planning scan' to estimate the location of the lead shield and generate a directionally blocked helical tomotherapy plan. To ensure the accuracy of each plan, megavoltage fan-beam CT (MVCT) scans were obtained at the first treatment and adaptive planning was performed to account for lead shield placement. Two important regions of interest in these cases were femurs and femoral heads. During adaptive planning for the first patient, it was observed that the virtual lead shield contour on kVCT planning images was significantly larger than the actual lead shield used for treatment. However, for the second patient, it was noted that the size of the virtual lead shield contoured on the kVCT image was significantly smaller than the actual shield size. Thus, new adaptive plans based on MVCT images were generated and used for treatment. The planning target volume was underdosed up to 2% and had higher maximum doses without adaptive planning. In conclusion, the treatment of the upper thigh, particularly in young men, presents several clinical challenges, including preservation of gonadal function. In such circumstances, adaptive planning using MVCT can ensure accurate dose delivery even in the presence of high-density testicular shields.

  16. Radiation exposure of patients during {sup 68}Ga-DOTATOC PET/CT examinations

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Holger; Freudenberg, R.; Oehme, L.; Andreeff, M.; Wunderlich, G. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Zoephel, K. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Oncoray, Center for Radiation Research in Oncology, Medizinische Fakultaet Carl Gustav Carus, Technische Univ. Dresden (Germany); Eisenhofer, G. [Medizinische Klinik III, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Kotzerke, J. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); PET-Zentrum, Forschungszentrum Dresden-Rossendorf (Germany)

    2009-07-01

    Investigation of the biodistribution and calculation of dosimetry of Ga-68-DOTATOC-for patients imaged in the routine clinical setting for diagnosis or exclusion of neuroendocrine tumours. Patients methods: Dynamic PET/CT-imaging (Biograph 16) was performed over 20 min in 14 patients (8 men, 6 women) after injection of (112 {+-} 22) MBq {sup 68}Ga-DOTATOC followed by whole body 3D-acquisition (8 bed positions, 3 or 4 min each) 30 min p.i. and 120 min p.i., Urinary tracer elimination was measured and blood activity was derived non-invasively from the blood pool of the heart. The relevant organs for dosimetry were spleen, kidneys, liver, adrenals, urinary bladder and pituitary gland. Dosimetry was performed using OLINDA/EXM 1.0 software and specific organ uptake was expressed as standardized uptake values (SUVs). Results Rapid physiological uptake of the radiotracer could be demonstrated in liver, spleen and kidneys, adrenals and pituitary gland (mean SUVs were 6, 20, 16, 10, and 4, respectively). Radiotracer elimination was exclusively via urine (16% of injected dose within 2h); no redistribution could be observed. The spleen and the kidneys received the highest radiation exposure (0.24 mSv/MBq, 0.22 mSv/MBq resp.), mean effective dose yielded 0.023 mSv/MBq. Conclusion: {sup 68}Ga-DOTATOC is used extensively for diagnosis of somatostatin receptor positive tumours because it has several advantages over the {sup 111}In-labelled ligand. The derived dosimetric values are lower than first approximations from the biological data of OctreoScan. The use of CT for transmission correction of the PET data delivers radiation exposure up to 1 mSv (low dose). (orig.)

  17. 18F-FDG PET/CT显像在肺部恶性肿瘤治疗中的疗效评价%Assessment of therapy effect for chest malignity lesions with 18 F-FDG PET/CT imaging

    Institute of Scientific and Technical Information of China (English)

    陈翼; 彭艳梅; 潘兴华; 董丽华; 徐昕明; 李懿; 杨洪文

    2016-01-01

    目的:探讨18 F-FDG PET/CT显像观察98例胸部恶性肿瘤治疗后疗效的作用。方法18 F-FDG PET/CT显像检查了98例手术+放化疗、放化疗和氩氦刀3类治疗后的胸部恶性肿瘤患者,分析3种治疗方法的疗效;并对比同机CT病灶分布的特征,分析与18 F-FDG PET显像的异同。结果受检患者98例中阳性87例,阴性11例,其中手术+放化疗44例(阳性34例,阴性10例);放化疗组15例(阳性14例,阴性1例);氩氦刀组39例(阳性39例)。各治疗组之间18 F-FDG PET/CT显示的治疗后残存病灶数量差异有显著意义(礸2=24.40, P <0.001)。18 F-FDG PET显示病灶130个,病灶最大横径2.2~9.4cm,平均(5.20±1.73)cm;同机CT显示病灶132个,最大横径1.0~10.6cm,平均(4.48±2.19)cm,18 F-FDG PET与同机CT显示的病灶大小基本一致,差异无显著意义( t =0.079, P >0.05),二者正相关性关系( r =0.85, P <0.01)。但是PET反应的是残留恶性组织的活性而CT仅是解剖改变。18 F-FDG PET病灶的T/NT比值1.3~26.07,平均6.32±5.48。结论18 F-FDG PET/CT在观察胸部恶性肿瘤疗效中有较大临床价值。%Objective This study was performed to evaluate the ability of 18 F-FDG PET/CT to assess therapy effect for chest lesion.Methods Ninety-nine cases with chest cancer were performed using 18 F-FDG PET/CT.Those imagings were compared between 18 F-FDG PET and CT on the same instrument .Results There were Eighty-seven cases in positive and eleven cases in negative in this study.Forty-four cases (34 in positive and 10 in negative) were surgery and chemotherapy and radiotherapy treat-ment.Fifteen cases (14 in positive and 1 in negative) were treated using radio-chemotherapy methods.Thirty-nine patients were treated by argon-helium cryotherapy (positive 39 cases).There were different in residual mass among 3

  18. Risk Factors for Brain Metastases in Locally Advanced Non-Small Cell Lung Cancer With Definitive Chest Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Zhe; Bi, Nan; Wang, Jingbo; Hui, Zhouguang; Xiao, Zefen; Feng, Qinfu; Zhou, Zongmei; Chen, Dongfu; Lv, Jima; Liang, Jun; Fan, Chengcheng; Liu, Lipin; Wang, Luhua, E-mail: wlhwq@yahoo.com

    2014-06-01

    Purpose: We intended to identify risk factors that affect brain metastases (BM) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) receiving definitive radiation therapy, which may guide the choice of selective prevention strategies. Methods and Materials: The characteristics of 346 patients with stage III NSCLC treated with thoracic radiation therapy from January 2008 to December 2010 in our institution were retrospectively reviewed. BM rates were analyzed by the Kaplan-Meier method. Multivariate Cox regression analysis was performed to determine independent risk factors for BM. Results: The median follow-up time was 48.3 months in surviving patients. A total of 74 patients (21.4%) experienced BM at the time of analysis, and for 40 (11.7%) of them, the brain was the first site of failure. The 1-year and 3-year brain metastasis rates were 15% and 28.1%, respectively. In univariate analysis, female sex, age ≤60 years, non-squamous cell carcinoma, T3-4, N3, >3 areas of lymph node metastasis, high lactate dehydrogenase and serum levels of tumor markers (CEA, NSE, CA125) before treatment were significantly associated with BM (P<.05). In multivariate analysis, age ≤60 years (P=.004, hazard ratio [HR] = 0.491), non-squamous cell carcinoma (P=.000, HR=3.726), NSE >18 ng/mL (P=.008, HR=1.968) and CA125 ≥ 35 U/mL (P=.002, HR=2.129) were independent risk factors for BM. For patients with 0, 1, 2, and 3 to 4 risk factors, the 3-year BM rates were 7.3%, 18.9%, 35.8%, and 70.3%, respectively (P<.001). Conclusions: Age ≤60 years, non-squamous cell carcinoma, serum NSE >18 ng/mL, and CA125 ≥ 35 U/mL were independent risk factors for brain metastasis. The possibilities of selectively using prophylactic cranial irradiation in higher-risk patients with LA-NSCLC should be further explored in the future.

  19. Anatomical decomposition in dual energy chest digital tomosynthesis

    Science.gov (United States)

    Lee, Donghoon; Kim, Ye-seul; Choi, Sunghoon; Lee, Haenghwa; Choi, Seungyeon; Kim, Hee-Joung

    2016-03-01

    Lung cancer is the leading cause of cancer death worldwide and the early diagnosis of lung cancer has recently become more important. For early screening lung cancer, computed tomography (CT) has been used as a gold standard for early diagnosis of lung cancer [1]. The major advantage of CT is that it is not susceptible to the problem of misdiagnosis caused by anatomical overlapping while CT has extremely high radiation dose and cost compared to chest radiography. Chest digital tomosynthesis (CDT) is a recently introduced new modality for lung cancer screening with relatively low radiation dose compared to CT [2] and also showing high sensitivity and specificity to prevent anatomical overlapping occurred in chest radiography. Dual energy material decomposition method has been proposed for better detection of pulmonary nodules as means of reducing the anatomical noise [3]. In this study, possibility of material decomposition in CDT was tested by simulation study and actual experiment using prototype CDT. Furthermore organ absorbed dose and effective dose were compared with single energy CDT. The Gate v6 (Geant4 application for tomographic emission), and TASMIP (Tungsten anode spectral model using the interpolating polynomial) code were used for simulation study and simulated cylinder shape phantom consisted of 4 inner beads which were filled with spine, rib, muscle and lung equivalent materials. The patient dose was estimated by PCXMC 1.5 Monte Carlo simulation tool [4]. The tomosynthesis scan was performed with a linear movement and 21 projection images were obtained over 30 degree of angular range with 1.5° degree of angular interval. The proto type CDT system has same geometry with simulation study and composed of E7869X (Toshiba, Japan) x-ray tube and FDX3543RPW (Toshiba, Japan) detector. The result images showed that reconstructed with dual energy clearly visualize lung filed by removing unnecessary bony structure. Furthermore, dual energy CDT could enhance

  20. SU-E-J-190: Characterization of Radiation Induced CT Number Changes in Tumor and Normal Lung During Radiation Therapy for Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C; Liu, F; Tai, A; Gore, E; Johnstone, C; Li, X [Medical College of Wisconsin Milwaukee WI (United States)

    2014-06-01

    Purpose: To measure CT number (CTN) changes in tumor and normal lung as a function of radiation therapy (RT) dose during the course of RT delivery for lung cancer using daily IGRT CT images and single respiration phase CT images. Methods: 4D CT acquired during planning simulation and daily 3D CT acquired during daily IGRT for 10 lung cancer cases randomly selected in terms of age, caner type and stage, were analyzed using an in-house developed software tool. All patients were treated in 2 Gy fractions to primary tumors and involved nodal regions. Regions enclosed by a series of isodose surfaces in normal lung were delineated. The obtained contours along with target contours (GTVs) were populated to each singlephase planning CT and daily CT. CTN in term of Hounsfield Unit (HU) of each voxel in these delineated regions were collectively analyzed using histogram, mean, mode and linear correlation. Results: Respiration induced normal lung CTN change, as analyzed from single-phase planning CTs, ranged from 9 to 23 (±2) HU for the patients studied. Normal lung CTN change was as large as 50 (±12) HU over the entire treatment course, was dose and patient dependent and was measurable with dose changes as low as 1.5 Gy. For patients with obvious tumor volume regression, CTN within the GTV drops monotonically as much as 10 (±1) HU during the early fractions with a total dose of 20 Gy delivered. The GTV and CTN reductions are significantly correlated with correlation coefficient >0.95. Conclusion: Significant RT dose induced CTN changes in lung tissue and tumor region can be observed during even the early phase of RT delivery, and may potentially be used for early prediction of radiation response. Single respiration phase CT images have dramatically reduced statistical noise in ROIs, making daily dose response evaluation possible.

  1. A dual energy CT study on vascular effects of gold nanoparticles in radiation therapy

    Science.gov (United States)

    Ashton, Jeffrey R.; Hoye, Jocelyn; Deland, Katherine; Whitley, Melodi; Qi, Yi; Moding, Everett; Kirsch, David G.; West, Jennifer; Badea, Cristian T.

    2016-03-01

    Gold nanoparticles (AuNPs) are emerging as promising agents for both cancer therapy and CT imaging. AuNPs are delivered to tumors via the enhanced permeability and retention effect and they preferentially accumulate in close proximity to the tumor blood vessels. AuNPs produce low-energy, short-range photoelectrons during external beam radiation therapy (RT), boosting dose. This work is focused on understanding how tumor vascular permeability is influenced by AuNP-augmented radiation therapy (RT), and how this knowledge can potentially improve the delivery of additional nanoparticle-based chemotherapeutics. We use dual energy (DE) CT to detect accumulation of AuNPs and increased vascular permeability to liposomal iodine (i.e. a surrogate for chemotherapeutics with liposome encapsulation) following RT. We used sarcoma tumors generated in LSL-KrasG12D; p53FL/FL conditional mutant mice. A total of n=37 mice were used in this study. The treated mice were injected with 20 mg AuNP (0.1 ml/25 g mouse) 24 hours before delivery of 5 Gy RT (n=5), 10 Gy RT (n=3) or 20 Gy RT (n=6). The control mice received no AuNP injection and either no RT (n=6), 5 Gy RT (n=3), 10 Gy RT (n=3), 20 Gy RT (n=11). Twenty four hours post-RT, the mice were injected with liposomal iodine (0.3 ml/25 mouse) and imaged with DE-CT three days later. The results suggest that independent of any AuNP usage, RT levels of 10 Gy and 20 Gy increase the permeability of tumor vasculature to liposomal iodine and that the increase in permeability is dose-dependent. We found that the effect of RT on vasculature may already be at its maximum response i.e. saturated at 20 Gy, and therefore the addition of AuNPs had almost no added benefit. Similarly, at 5 Gy RT, our data suggests that there was no effect of AuNP augmentation on tumor vascular permeability. However, by using AuNPs with 10 Gy RT, we observed an increase in the vascular permeability, however this is not yet statistically significant due to the small

  2. Analysis of clinical application of percutaneous chest lesion puncture under CT guided%CT引导下经皮胸部病灶穿刺的临床应用分析

    Institute of Scientific and Technical Information of China (English)

    熊丽纹; 滕家俊; 李榕; 张雪艳; 楼煜清; 顾爱琴; 韩宝惠

    2013-01-01

    Background and purpose:Percutaneous transthoracic needle biopsy with computed tomographic (CT) guidance, following two diagnostic methods of needle biopsy and needle aspiration cytology, is a widely used non-vascular interventional technique, regarded as an extremely important technique for clinical qualitative diagnosis, treatment and the prognosis. This study aimed to evaluate and to compare the diagnostic value of needle biopsy and needle aspiration cytology in CT-guided percutaneous chest lesion puncture, and to analyze the variables affecting the diagnostic accuracy and rates of complications. Methods:A retrospective study was conducted of 1 027 patients who underwent CT-guided percutaneous thoracopathy puncture from Apr. 2006 to Mar. 2012. Results:There were no significant differences in diagnostic positive rate and accuracy between needle biopsy and needle aspiration cytology in CT-guided percutaneous chest lesion puncture (P>0.05). There were 859 malignant and 168 benign lesions. Overall diagnostic accuracy was 90.6%. The diagnostic accuracy for malignancy was 89.1%and for benign was 98.2%. There was significant correlation among the diagnostic accuracy and the final diagnosis (benign and malignant), lesion site, and lesion type (P0.05).1027例患者中,恶性病变859例,良性病变168例,诊断正确率为90.6%,其中对恶性肿瘤的诊断正确率为89.1%,良性病变的诊断正确率为98.2%.病灶的良恶性、疾病部位和病灶形态对诊断正确率的影响差异有统计学意义(P<0.05).不良反应(气胸和出血)的发生率为19.9%,与穿刺深度和病灶至胸膜距离密切相关(P<0.05).结论:CT引导下胸部穿刺术是安全、可靠的微创诊断方法.在某些条件下,CT引导下胸部穿刺针吸脱落细胞学检测可以代替活检,以避免那些需要通过增加穿刺风险获取足够组织进行的活检.诊断正确率与病灶的良恶性、发生部位和形态相关.并发症的发生与穿刺深度和

  3. Head CT: Image quality improvement of posterior fossa and radiation dose reduction with ASiR - comparative studies of CT head examinations

    Energy Technology Data Exchange (ETDEWEB)

    Guzinski, Maciej; Waszczuk, Lukasz; Sasiadek, Marek J. [Wroclaw Medical University, Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw (Poland)

    2016-10-15

    To evaluate head CT protocol developed to improve visibility of the brainstem and cerebellum, lower bone-related artefacts in the posterior fossa and maintain patient radioprotection. A paired comparison of head CT performed without Adaptive Statistical Iterative Reconstruction (ASiR) and a clinically indicated follow-up with 40 % ASiR was acquired in one group of 55 patients. Patients were scanned in the axial mode with different scanner settings for the brain and the posterior fossa. Objective image quality analysis was performed with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality analysis was based on brain structure visibility and evaluation of the artefacts. We achieved 19 % reduction of total DLP and significantly better image quality of posterior fossa structures. SNR for white and grey matter in the cerebellum were 34 % to 36 % higher, respectively, CNR was improved by 142 % and subjective analyses were better for images with ASiR. When imaging parameters are set independently for the brain and the posterior fossa imaging, ASiR has a great potential to improve CT performance: image quality of the brainstem and cerebellum is improved, and radiation dose for the brain as well as total radiation dose are reduced. (orig.)

  4. 艾滋病合并播散性隐球菌病的胸腹部CT表现%The Chest and Abdomen CT Findings of the Disseminated Cryptococcosis in Patients with AIDS

    Institute of Scientific and Technical Information of China (English)

    张烈光; 刘晋新; 江松峰; 陈碧华; 黄德扬

    2013-01-01

    Objective To study the chest and abdomen CT findings of the disseminated cryptococcosis in patients with AIDS.Materials and Methods The chest and abdomen CT imaging features of the disseminated cryptococcosis in 28 patients with AIDS were retro spectively analyzed.Results 28 cases underwent chest CT scan.Pulmonary nodules were seen in 27 (96.43%,27/28) cases.Cavitation in nodule was present in 19 (67.86%,19/28) cases.Ground-glass opacities were seen in 14(50%,14/28) cases.Patch opacities were seen in 2(7.14%,2/28) cases.The enlarged mediastinal and hilar lymph nodes were seen in 11 (40.74%,11/28) cases.Pleural effusion was seen in 6(21.43%,6/28)cases,pericardial effusion was seen in 4(14.29%,4/28) cases.11 of 28 cases underwent abdominal CT scan.Hepatosplenomegaly were seen in 8(72.73%,8/11) cases.Lesions in liver and spleen were found in 2(18.18%,2/11) cases which involved mass and diffused micro-nodules in liver in 1 case and low density node in spleen in 1 case.Abdominal lymph adenopathy were seen in 4(36.36%,4/11)cases and sandwich sign in the small bowel mesentery was seen in 3(27.27%,3/11) cases.Nodule in adrenal gland was seen in 1(9.09%,1/11) case.Ascites were seen in 1(9.09%,1/11) case.Conclusion Pulmonary nodules were the most common CT findings of the disseminated cryptococcosis in patients with AIDS.Cavitation in nodule was characteristic CT findings.Multiple organs can be involved in the abdomen.%目的 探讨艾滋病(Acquired immunodeficiency syndrome,AIDS)合并播散性隐球菌病的胸腹部CT表现.方法 回顾性分析28例艾滋病合并播散性隐球菌病的胸腹部CT表现.结果 28例艾滋病合并播散性隐球菌病胸部CT示肺内结节2 7例(96.43%,27/28),其中19例(67.86%,19/28)结节内可见空洞;肺内磨玻璃样改变14例(50%,14/28);肺内片状实变2例(7.14%,2/28);纵隔肺门淋巴结肿大11例(40.74%,11/28);胸腔积液6例(21.43%,6/28);心包积液4例(14.29%,4/28).11

  5. [18F]fluoroethylcholine-PET/CT imaging for radiation treatment planning of recurrent and primary prostate cancer with dose escalation to PET/CT-positive lymph nodes

    Directory of Open Access Journals (Sweden)

    Wahl Andreas

    2011-05-01

    Full Text Available Abstract Background At present there is no consensus on irradiation treatment volumes for intermediate to high-risk primary cancers or recurrent disease. Conventional imaging modalities, such as CT, MRI and transrectal ultrasound, are considered suboptimal for treatment decisions. Choline-PET/CT might be considered as the imaging modality in radiooncology to select and delineate clinical target volumes extending the prostate gland or prostate fossa. In conjunction with intensity modulated radiotherapy (IMRT and imaged guided radiotherapy (IGRT, it might offer the opportunity of dose escalation to selected sites while avoiding unnecessary irradiation of healthy tissues. Methods Twenty-six patients with primary (n = 7 or recurrent (n = 19 prostate cancer received Choline-PET/CT planned 3D conformal or intensity modulated radiotherapy. The median age of the patients was 65 yrs (range 45 to 78 yrs. PET/CT-scans with F18-fluoroethylcholine (FEC were performed on a combined PET/CT-scanner equipped for radiation therapy planning. The majority of patients had intermediate to high risk prostate cancer. All patients received 3D conformal or intensity modulated and imaged guided radiotherapy with megavoltage cone beam CT. The median dose to primary tumours was 75.6 Gy and to FEC-positive recurrent lymph nodal sites 66,6 Gy. The median follow-up time was 28.8 months. Results The mean SUVmax in primary cancer was 5,97 in the prostate gland and 3,2 in pelvic lymph nodes. Patients with recurrent cancer had a mean SUVmax of 4,38. Two patients had negative PET/CT scans. At 28 months the overall survival rate is 94%. Biochemical relapse free survival is 83% for primary cancer and 49% for recurrent tumours. Distant disease free survival is 100% and 75% for primary and recurrent cancer, respectively. Acute normal tissue toxicity was mild in 85% and moderate (grade 2 in 15%. No or mild late side effects were observed in the majority of patients (84%. One patient had

  6. Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sohi; Kim, Myung-Joon; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Kim, Dong Wook; Hong, Jung Hwa [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

    2014-12-15

    Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

  7. Effects of radiation dose reduction in Volume Perfusion CT imaging of acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikobashman, Omid; Brockmann, Marc A.; Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Yang, Zepa; Kim, Changwon [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Kim, Jong Hyo [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Center for Medical-IT Convergence Technology Research, Advanced Institute of Convergence Technology, Suwon (Korea, Republic of)

    2015-12-15

    To examine the influence of radiation dose reduction on image quality and sensitivity of Volume Perfusion CT (VPCT) maps regarding the detection of ischemic brain lesions. VPCT data of 20 patients with suspected ischemic stroke acquired at 80 kV and 180 mAs were included. Using realistic reduced-dose simulation, low-dose VPCT datasets with 144 mAs, 108 mAs, 72 mAs and 36 mAs (80 %, 60 %, 40 % and 20 % of the original levels) were generated, resulting in a total of 100 datasets. Perfusion maps were created and signal-to-noise-ratio (SNR) measurements were performed. Qualitative analyses were conducted by two blinded readers, who also assessed the presence/absence of ischemic lesions and scored CBV and CBF maps using a modified ASPECTS-score. SNR of all low-dose datasets were significantly lower than those of the original datasets (p <.05). All datasets down to 72 mAs (40 %) yielded sufficient image quality and high sensitivity with excellent inter-observer-agreements, whereas 36 mAs datasets (20 %) yielded poor image quality in 15 % of the cases with lower sensitivity and inter-observer-agreements. Low-dose VPCT using decreased tube currents down to 72 mAs (40 % of original radiation dose) produces sufficient perfusion maps for the detection of ischemic brain lesions. (orig.)

  8. Chest high resolution CT features of extrinsic allergic alveolitis and its diagnostic value%外源性过敏性肺泡炎高分辨率CT特点及其诊断价值

    Institute of Scientific and Technical Information of China (English)

    班承钧; 代华平; 张曙; 张镭; 叶俏; 朱敏

    2010-01-01

    Objective To summarize the chest high-resolution CT(HRCT) features of the patients with extrinsic allergic alveolitis (EAA). Methods We analyzed the images of chest HRCT of 34 patients diagnosed as EAA at our hospital from February 2001 to August 2009. Results All patients had a history of environmental exposure. The duration of intermittent or continuous antigen exposure was from 3 months to 13 years. Two patients showed acute clinical manifestations. There were 22 sub-acute and 10 chronic cases.Acute EAA was characterized by ground-glass opacities, air trapping and/or mosaic sign on HRCT. The HRCT features of subacute EAA included patchy ground-glass opacities with mosaic sign (n =11, 50. 0% )and diffusely distributed centrilobular nodules ( n = 7, 31.8% ) with mosaic sign ( n = 4, 18. 2% ). All patients with chronic EAA had reticular and honeycombing lesions on HRCT. There were 3 cases with ground-glass opacities, 3 with mosaic sign, and 3 with centrilobular nodules. Conclusion The typical findings of chest HRCT are helpful for making a diagnosis and differential diagnosis of EAA.%目的 探讨外源性过敏性肺泡炎(EAA)的高分辨率CT(HRCT)特征及其诊断价值.方法 回顾性分析2001年2月至2009年8月在首都医科大学附属北京朝阳医院确诊的34例EAA患者的胸部HRCT影像学表现及相关临床资料.结果 34例患者均有明确的环境抗原暴露史,间歇或持续抗原暴露时间为3个月~13年.临床表现2例呈急性,22例呈亚急性,10例呈慢性.2例急性EAA胸部HRCT分别表现弥漫磨玻璃影和磨玻璃影伴马赛克征;亚急性者主要表现弥漫分布的斑片磨玻璃影伴马赛克征(11例,50.0%)、弥漫分布的小叶中心结节(7例,31.8%)和马赛克征(4例,18.2%);慢性者均表现网格影或伴蜂窝肺,其中3例伴斑片磨玻璃影,3例伴马赛克征,3例伴小叶中心结节.结论 EAA的胸部HRCT有比较特征性的表现,对EAA的诊断和鉴别诊断具有重要的提示作用.

  9. MO-C-18C-01: Radiation Risks at Level of Few CT Scans: How Real?- Science to Practice

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M [International Atomic Energy Agency, Vienna (Austria); Samei, E [Duke University Medical Center, Durham, NC (United States); Morgan, W [Pacific Northwest National Laboratory, Richland, WA (United States); Goske, M [Cincinnati Childrens Hospital, Cincinnati, OH (United States); Shore, R

    2014-06-15

    There are controversies surrounding radiation effects in human population in the range of radiation doses encountered by patients resulting from one to several CT scans. While it is understandable why the effects from low levels of diagnostic radiation are controversial, the situation is complicated by the media which may distort the known facts. There is need to understand the state of science regarding low-level radiation effects and also to understand how to communicate the potential risk with patients, the public and media. This session will seek to come to a consensus in order to speak with one voice to the media and the public. This session will review radiation effects known so far from a variety of exposed groups since the nuclear holocaust, provide clarification where effects are certain and where they are not, at what level extrapolation is the only way and at what level there is weak but agreeable acceptance. We will depict where and why there is agreement among organizations responsible for studying radiation effects, and how to deal with situations where effects are uncertain. Specific focus on radiation effects in children will be provided.Finally, the session will attempt to bridge the communication gap from the science to how to be an effective communicator with patients, parents, and media about ionizing radiation. Learning Objectives: To have a clear understanding about certainties and uncertainties of radiation effects at the level of a few CT scans To understand the results and limitations from 3 major pediatric CT scientific studies on childhood exposures published recently. To understand successful strategies used in risk communication.

  10. Case of chronic progressive radiation myelopathy with a CT myelogram simulating intramedullary tumor

    Energy Technology Data Exchange (ETDEWEB)

    Kanemaru, Kazutomi; Kamo, Hisaki; Yamao, Satoshi; Akiguchi, Ichiro; Kameyama, Masakuni

    1985-05-01

    A 58-year-old man underwent a right middle lobectomy in June, 1975, for poorly differentiated adenocarcinoma of the lung. Postoperative irradiation was given to the hilus (6100 rads), and to the right supraclavicular area (6000 rads). In 1980, 60 months after completion of irradiation, the patient noticed weakness of his legs particularly on the left side. In 1982, he noticed the girdle sensation in the upper thoracic region, and paresthesia in the lateral side of the right thigh. In Dec 1983, micturition disturbance appeared, and gait disturbance progressed, he was admitted to the Kyoto University Hospital. Neurological examination revealed an incomplete left Brown-Sequard syndrome with diminution of pain and thermal sensation on the right lower limb, and weakness and spasticity particularly on the left lower limb. Conventional myelogram with CT myelogram showed spinal cord swelling from T-2 through T-5. No extramedullary lesion was found. Laminectomy was performed through T-1 to T-6. When the dura was opened, the cord was swollen and necrotic with a cyst formation. Microscopic examination of the thickened part of the cord showed necrosis and gliosis. The lesion was correspond to the cord segments exposed to the radiation, and a diagnosis of radiation myelopathy was made. Several cases of radiation myelopathy with definite swelling of the cord at myelography were reported, but myelography in these cases was performed at most within 11 months after the onset. In this case, myelography was performed three years after the onset, and revealed difinite swelling of the cord due to a cyst formation. (author).

  11. Whole-organ CT perfusion of the pancreas: impact of iterative reconstruction on image quality, perfusion parameters and radiation dose in 256-slice CT-preliminary findings.

    Directory of Open Access Journals (Sweden)

    Qian Xie

    Full Text Available BACKGROUND: This study was performed to assess whether iterative reconstruction can reduce radiation dose while maintaining acceptable image quality, and to investigate whether perfusion parameters vary from conventional filtered back projection (FBP at the low-tube-voltage (80-kVp during whole-pancreas perfusion examination using a 256-slice CT. METHODS: 76 patients with known or suspected pancreatic mass underwent whole-pancreas perfusion by a 256-slice CT. High- and low-tube-voltage CT images were acquired. 120-kVp image data (protocol A and 80-kVp image data (protocol B were reconstructed with conventional FBP, and 80-kVp image data were reconstructed with iDose(4 (protocol C iterative reconstruction. The image noise; contrast-to-noise ratio (CNR relative to muscle for the pancreas, liver, and aorta; and radiation dose of each protocol were assessed quantitatively. Overall image quality was assessed qualitatively. Among 76 patients, 23 were eventually proven to have a normal pancreas. Perfusion parameters of normal pancreas in each protocol including blood volume, blood flow, and permeability-surface area product were measured. RESULTS: In the quantitative study, protocol C reduced image noise by 36.8% compared to protocol B (P<0.001. Protocol C yielded significantly higher CNR relative to muscle for the aorta, pancreas and liver compared to protocol B (P<0.001, and offered no significant difference compared to protocol A. In the qualitative study, protocols C and A gained similar scores and protocol B gained the lowest score for overall image quality (P<0.001. Mean effective doses were 23.37 mSv for protocol A and 10.81 mSv for protocols B and C. There were no significant differences in the normal pancreas perfusion values among three different protocols. CONCLUSION: Low-tube-voltage and iDose(4 iterative reconstruction can dramatically decrease the radiation dose with acceptable image quality during whole-pancreas CT perfusion and have no

  12. Radiation dose reduction sinogram affirmed iterative reconstruction and automatic tube voltage modulation(CARE kV) in abdominal CT

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyun Joo; Chung, Yong Eun; Lee, Young Han; Choi, Jin Young; Park, Mi Suk; Kim, Myeong Jin; Kim, Ki Whang [Dept. of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2013-12-15

    To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination. This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups. Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p ≥ 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE. Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images.

  13. Scatter radiation breast exposure during head CT: impact of scanning conditions and anthropometric parameters on shielded and unshielded breast dose

    Energy Technology Data Exchange (ETDEWEB)

    Klasic, B. [Hospital for pulmonary diseases, Zagreb (Croatia); Knezevic, Z.; Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Brnic, Z.; Novacic, K. [Merkur Univ. Hospital, Zagreb (Croatia)

    2006-07-01

    Constantly increasing clinical requests for CT scanning of the head on our facility continue to raise concern regarding radiation exposure of patients, especially radiosensitive tissues positioned close to the scanning plane. The aim of our prospective study was to estimate scatter radiation doses to the breast from routine head CT scans, both with and without use of lead shielding, and to establish influence of various technical and anthropometric factors on doses using statistical data analysis. In 85 patient referred to head CT for objective medical reasons, one breast was covered with lead apron during CT scanning. Radiation doses were measured at skin of both breasts and over the apron simultaneously, by the use of thermo luminescent dosimeters. The doses showed a mean reduction by 37% due to lead shielding. After we statistically analyzed our data, we observed significant correlation between under-the-shield dose and values of technical parameters. We used multiple linear regression model to describe the relationships of doses to unshielded and shielded breast respectively, with anthropometric and technical factors. Our study proved lead shielding of the breast to be effective, easy to use and leading to a significant reduction in scatter dose. (author)

  14. SU-E-J-260: Quantitative Image Feature Analysis of Multiphase Liver CT for Hepatocellular Carcinoma (HCC) in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, W; Wang, J; Lu, W [University of Maryland School of Medicine, Baltimore, MD (United States); Kang, M [University of Maryland School of Medicine, Baltimore, MD (United States); Yeungnam University Medical Center, Daegu (Korea, Republic of)

    2015-06-15

    Purpose: To identify the effective quantitative image features (radiomics features) for prediction of response, survival, recurrence and metastasis of hepatocellular carcinoma (HCC) in radiotherapy. Methods: Multiphase contrast enhanced liver CT images were acquired in 16 patients with HCC on pre and post radiation therapy (RT). In this study, arterial phase CT images were selected to analyze the effectiveness of image features for the prediction of treatment outcome of HCC to RT. Response evaluated by RECIST criteria, survival, local recurrence (LR), distant metastasis (DM) and liver metastasis (LM) were examined. A radiation oncologist manually delineated the tumor and normal liver on pre and post CT scans, respectively. Quantitative image features were extracted to characterize the intensity distribution (n=8), spatial patterns (texture, n=36), and shape (n=16) of the tumor and liver, respectively. Moreover, differences between pre and post image features were calculated (n=120). A total of 360 features were extracted and then analyzed by unpaired student’s t-test to rank the effectiveness of features for the prediction of response. Results: The five most effective features were selected for prediction of each outcome. Significant predictors for tumor response and survival are changes in tumor shape (Second Major Axes Length, p= 0.002; Eccentricity, p=0.0002), for LR, liver texture (Standard Deviation (SD) of High Grey Level Run Emphasis and SD of Entropy, both p=0.005) on pre and post CT images, for DM, tumor texture (SD of Entropy, p=0.01) on pre CT image and for LM, liver (Mean of Cluster Shade, p=0.004) and tumor texture (SD of Entropy, p=0.006) on pre CT image. Intensity distribution features were not significant (p>0.09). Conclusion: Quantitative CT image features were found to be potential predictors of the five endpoints of HCC in RT. This work was supported in part by the National Cancer Institute Grant R01CA172638.

  15. Reduction in radiation dose with reconstruction technique in the brain perfusion CT

    Science.gov (United States)

    Kim, H. J.; Lee, H. K.; Song, H.; Ju, M. S.; Dong, K. R.; Chung, W. K.; Cho, M. S.; Cho, J. H.

    2011-12-01

    The principal objective of this study was to verify the utility of the reconstruction imaging technique in the brain perfusion computed tomography (PCT) scan by assessing reductions in the radiation dose and analyzing the generated images. The setting used for image acquisition had a detector coverage of 40 mm, a helical thickness of 0.625 mm, a helical shuttle mode scan type and a rotation time of 0.5 s as the image parameters used for the brain PCT scan. Additionally, a phantom experiment and an animal experiment were carried out. In the phantom and animal experiments, noise was measured in the scanning with the tube voltage fixed at 80 kVp (kilovolt peak) and the level of the adaptive statistical iterative reconstruction (ASIR) was changed from 0% to 100% at 10% intervals. The standard deviation of the CT coefficient was measured three times to calculate the mean value. In the phantom and animal experiments, the absorbed dose was measured 10 times under the same conditions as the ones for noise measurement before the mean value was calculated. In the animal experiment, pencil-type and CT-dedicated ionization chambers were inserted into the central portion of pig heads for measurement. In the phantom study, as the level of the ASIR changed from 0% to 100% under identical scanning conditions, the noise value and dose were proportionally reduced. In our animal experiment, the noise value was lowest when the ASIR level was 50%, unlike in the phantom study. The dose was reduced as in the phantom study.

  16. Accurate tissue area measurements with considerably reduced radiation dose achieved by patient-specific CT scan parameters

    DEFF Research Database (Denmark)

    Brandberg, J.; Bergelin, E.; Sjostrom, L.;

    2008-01-01

    to cover a wide range of diameters (31-47 cm) for both abdomen and thighs - were examined using both techniques. Tissue areas were compared, as were CT numbers...... for muscle tissue. Image noise was quantified by standard deviation measurements. The area deviation was ... as compared with the integral dose by the standard diagnostic technique. The CT numbers of muscle tissue remained unchanged with reduced radiation dose. Image noise was on average 20.9 HU (Hounsfield units) for subjects with diameters of 31-35 cm and 11.2 HU for subjects with diameters in the range of 36...

  17. WE-A-BRF-01: Dual-Energy CT Imaging in Diagnostic Imaging and Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Molloi, S [University of California, Irvine, CA (United States); Li, B [Boston University Medical Center, Boston, MA (United States); Yin, F [Duke University Medical Center, Durham, NC (United States); Chen, H [New York Presbyterian Hospital, New York, NY (United States)

    2014-06-15

    classification based on calcium scores shows excellent agreement with classification on the basis of conventional coronary artery calcium scoring. These studies demonstrate dual-energy cardiovascular CT can potentially be a noninvasive and sensitive modality in high risk patients. On-board KV/MV Imaging. To enhance soft tissue contrast and reduce metal artifacts, we have developed a dual-energy CBCT technique and a novel on-board kV/MV imaging technique based on hardware available on modern linear accelerators. We have also evaluated the feasibility of these two techniques in various phantom studies. Optimal techniques (energy, beam filtration, # of overlapping projections, etc) have been investigated with unique calibration procedures, which leads to successful decomposition of imaged material into acrylic-aluminum basis material pair. This enables the synthesis of virtual monochromatic (VM) CBCT images that demonstrate much less beam hardening, significantly reduced metal artifacts, and/or higher soft tissue CNR compared to single-energy CBCT. Adaptive Radiation Therapy. DECT could actually contribute to the area of Dose-Guided Radiation Therapy (or Adaptive Therapy). The application of DECT imaging using 80kV and 140 kV combinations could potentially increase the image quality by reducing the bone or high density material artifacts and also increase the soft tissue contrast by a light contrast agent. The result of this higher contrast / quality images is beneficial for deformable image registration / segmentation algorithm to improve its accuracy hence to make adaptive therapy less time consuming in its recontouring process. The real time re-planning prior to per treatment fraction could become more realistic with this improvement especially in hypofractional SBRT cases. Learning Objectives: Learn recent developments of dual-energy imaging in diagnosis and radiation therapy; Understand the unique clinical problem and required quantification accuracy in each application

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  19. Age- and gender-specific estimates of cumulative CT dose over 5 years using real radiation dose tracking data in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunsol; Goo, Hyun Woo; Lee, Jae-Yeong [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

    2015-08-15

    It is necessary to develop a mechanism to estimate and analyze cumulative radiation risks from multiple CT exams in various clinical scenarios in children. To identify major contributors to high cumulative CT dose estimates using actual dose-length product values collected for 5 years in children. Between August 2006 and July 2011 we reviewed 26,937 CT exams in 13,803 children. Among them, we included 931 children (median age 3.5 years, age range 0 days-15 years; M:F = 533:398) who had 5,339 CT exams. Each child underwent at least three CT scans and had accessible radiation dose reports. Dose-length product values were automatically extracted from DICOM files and we used recently updated conversion factors for age, gender, anatomical region and tube voltage to estimate CT radiation dose. We tracked the calculated CT dose estimates to obtain a 5-year cumulative value for each child. The study population was divided into three groups according to the cumulative CT dose estimates: high, ≥30 mSv; moderate, 10-30 mSv; and low, <10 mSv. We reviewed clinical data and CT protocols to identify major contributors to high and moderate cumulative CT dose estimates. Median cumulative CT dose estimate was 5.4 mSv (range 0.5-71.1 mSv), and median number of CT scans was 4 (range 3-36). High cumulative CT dose estimates were most common in children with malignant tumors (57.9%, 11/19). High frequency of CT scans was attributed to high cumulative CT dose estimates in children with ventriculoperitoneal shunt (35 in 1 child) and malignant tumors (range 18-49). Moreover, high-dose CT protocols, such as multiphase abdomen CT (median 4.7 mSv) contributed to high cumulative CT dose estimates even in children with a low number of CT scans. Disease group, number of CT scans, and high-dose CT protocols are major contributors to higher cumulative CT dose estimates in children. (orig.)

  20. Spiral CT in diagnosis and follow-up evaluation of chest closed pulmonary contusion%胸部闭合性肺挫伤的螺旋CT诊断和随访评价

    Institute of Scientific and Technical Information of China (English)

    陶海慧; 吴茂铸; 徐昌茶

    2013-01-01

    Objective To investigate CT findings and diagnosis,follow-up value in the chest closed pulmonary contusion.Methods The clinical and imaging data of 56 patients with pulmonary contusion were retrospectively analyzed.Results 23caseswithX-raycheck,18caseswerefoundpulmonarycontusion,and five cases were negative.CT found 56 cases of pulmonary contusion involving 13 cases of the right lung,8 cases of the left lung,35 cases of both lungs involved,a total of 135 lung lobes involvement.CT performance can be divided into three types,interstitial pulmonary contusion in 13 cases(23.2%),the substance of the pulmonary contusion in 31 cases(55.4%),the mixed pulmonary contusion in 12 patients (21.4%).After treatment,interstitial pulmonary contusion lesions were completely absorbed after 1 ~ 3 days,lesions began to absorb in the substance and mixed pulmonary contusion after 1 week and absorbed completely 3 weeks after treatment.Six cases left over from fibrosis lesions and pleural adhesions hypertrophic changes.Conclusion CT is helpful for early diagnosis of pulmonary contusion,it is the best imaging method in understanding its severity and dynamic track review of pulmonary contusion,the CT classification has important guiding value in clinical conditions and duration judgment.%目的 探讨胸部闭合性肺挫伤的CT表现及其诊断、随访价值.方法 回顾性分析56例肺挫伤病例的临床及影像学资料.结果 X 线检查23例,发现肺挫伤18例,5例为阴性;CT发现56例肺挫伤涉及右肺13例,左肺8例,两肺均受累35例,共计135叶肺叶受累,CT表现可分为3型,即间质型肺挫伤13例(23.2%),实质型肺挫伤31例(55.4%),混合型肺挫伤12例(21.4%),治疗后复查间质型肺挫伤1~3d病灶均完全吸收,实质型和混合型肺挫伤1周后病灶开始吸收,3周后病灶基本吸收,6例遗留纤维化病灶和胸膜粘连肥厚改变.结论 CT能早期诊断肺挫伤、了解其严重程度而且是动态追踪复查

  1. Management of flail chest.

    OpenAIRE

    Miller, H A; Taylor, G.A.; Harrison, A. W.; Maggisano, R.; Hanna, S.; de Lacy, J. L.; Shulman, H.

    1983-01-01

    This paper compares the management of two groups of patients with flail chest. The 25 patients in group 1 had a flail chest without other significant injuries or shock, whereas the 57 in group 2 had a flail chest with multiple injuries, shock or both. The group 1 patients were treated with repeated multiple intercostal nerve blocks or high segmental epidural analgesia, oxygen, intensive chest physiotherapy, fluid restriction, furosemide diuretics, methylprednisolone sodium succinate and collo...

  2. Establishment of a semi-biological phantom model for the study of the effect of dose reducing measures on radiation-induced DNA double strand breaks in CT using the example of risk organ based tube current modulation; Etablierung eines semibiologischen Phantommodells zur Untersuchung des Effekts dosisreduzierender Massnahmen auf strahleninduzierte DNA-Doppelstrangbrueche in der CT am Beispiel der risikoorganbasierten Roehrenstrommodulation

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Matthias

    2013-12-12

    The number of computed tomography (CT) examinations has been rising during the last decades. Therefore techniques for dose reduction receive increasing attention. Risk organ-based tube current modulation (RCM) in CT is a new approach and works by lowering the tube current, while the tube is in front of the patient's body. Therefore it should lead to a dose reduction for radiosensitive organs like the female breast, the eye lenses and the thyroid gland. Biological radiation effects cannot be estimated by physical-based dose measurements. γ-H2AX is a sensitive marker for the determination of x-ray induced DNA double-strand breaks (DSB). Hence the aim of this study was to establish a biological phantom model based on the γ-H2AX immunofluorescence microscopy method and to investigate the effect of RCM on radiation induced DNA damages. The γ-H2AX method is based on the phosphorylation of the histone variant H2AX. The phosphorylated histone γ-H2AX can be visualised using antibodies and is specific for radiation induced DSB. Blood lymphocytes from healthy volunteers, skin fibroblasts (LN) and mammary epithelial cells (HMEpC-p) were placed in different positions of an Alderson-phantom and exposed to x-rays using a 128-slice dual-source CT scanner. Standard head, neck and chest-CT scan protocols either with or without risk-organ based tube current modulation were used. RCM reduces the tube current to 20 percent at an angle of 130 degree anterior to the body, whereas tube current is increased at an angle of 230 degree posterior to the body. Afterwards cells were isolated, fixed on slides und stained with specific primary γ-H2AX antibodies and fluorescent secondary antibodies. Tiny green dots (named foci) can be detected and quantified with a fluorescence microscope and represent distinct DSB. Non-irradiated samples served as controls and CT-induced DSB were calculated by subtraction of pre- from post-exposure values. In this study a semibiological phantom model

  3. A technique for multi-dimensional optimization of radiation dose, contrast dose, and image quality in CT imaging

    Science.gov (United States)

    Sahbaee, Pooyan; Abadi, Ehsan; Sanders, Jeremiah; Becchetti, Marc; Zhang, Yakun; Agasthya, Greeshma; Segars, Paul; Samei, Ehsan

    2016-03-01

    The purpose of this study was to substantiate the interdependency of image quality, radiation dose, and contrast material dose in CT towards the patient-specific optimization of the imaging protocols. The study deployed two phantom platforms. First, a variable sized phantom containing an iodinated insert was imaged on a representative CT scanner at multiple CTDI values. The contrast and noise were measured from the reconstructed images for each phantom diameter. Linearly related to iodine-concentration, contrast to noise ratio (CNR), was calculated for different iodine-concentration levels. Second, the analysis was extended to a recently developed suit of 58 virtual human models (5D-XCAT) with added contrast dynamics. Emulating a contrast-enhanced abdominal image procedure and targeting a peak-enhancement in aorta, each XCAT phantom was "imaged" using a CT simulation platform. 3D surfaces for each patient/size established the relationship between iodine-concentration, dose, and CNR. The Sensitivity of Ratio (SR), defined as ratio of change in iodine-concentration versus dose to yield a constant change in CNR was calculated and compared at high and low radiation dose for both phantom platforms. The results show that sensitivity of CNR to iodine concentration is larger at high radiation dose (up to 73%). The SR results were highly affected by radiation dose metric; CTDI or organ dose. Furthermore, results showed that the presence of contrast material could have a profound impact on optimization results (up to 45%).

  4. Optimizing radiation dose by using advanced modelled iterative reconstruction in high-pitch coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Gordic, Sonja; Husarik, Daniela B.; Alkadhi, Hatem [University Hospital Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Desbiolles, Lotus; Leschka, Sebastian [University Hospital Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Kantonsspital, Divison of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Sedlmair, Martin; Schmidt, Bernhard [Siemens Healthcare, Computed Tomography Division, Forchheim (Germany); Manka, Robert [University Hospital Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); University Hospital Zurich, University of Zurich, Clinic of Cardiology, Zurich (Switzerland); University and ETH Zurich, Institute for Biomedical Engineering, Zurich (Switzerland); Plass, Andre; Maisano, Francesco [University Hospital Zurich, University of Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland); Wildermuth, Simon [Kantonsspital, Divison of Radiology and Nuclear Medicine, St. Gallen (Switzerland)

    2016-02-15

    To evaluate the potential of advanced modeled iterative reconstruction (ADMIRE) for optimizing radiation dose of high-pitch coronary CT angiography (CCTA). High-pitch 192-slice dual-source CCTA was performed in 25 patients (group 1) according to standard settings (ref. 100 kVp, ref. 270 mAs/rot). Images were reconstructed with filtered back projection (FBP) and ADMIRE (strength levels 1-5). In another 25 patients (group 2), high-pitch CCTA protocol parameters were adapted according to results from group 1 (ref. 160 mAs/rot), and images were reconstructed with ADMIRE level 4. In ten patients of group 1, vessel sharpness using full width at half maximum (FWHM) analysis was determined. Image quality was assessed by two independent, blinded readers. Interobserver agreements for attenuation and noise were excellent (r = 0.88/0.85, p < 0.01). In group 1, ADMIRE level 4 images were most often selected (84 %, 21/25) as preferred data set; at this level noise reduction was 40 % compared to FBP. Vessel borders showed increasing sharpness (FWHM) at increasing ADMIRE levels (p < 0.05). Image quality in group 2 was similar to that of group 1 at ADMIRE levels 2-3. Radiation dose in group 2 (0.3 ± 0.1 mSv) was significantly lower than in group 1 (0.5 ± 0.3 mSv; p < 0.05). In a selected population, ADMIRE can be used for optimizing high-pitch CCTA to an effective dose of 0.3 mSv. (orig.)

  5. American College of Chest Physicians

    Science.gov (United States)

    ... Master Fellows Staff & Contact Us CHEST Newsroom Staff Job Opportunities at CHEST Contact Us Industry Support Industry Support ... of Global Governors Master Fellows CHEST Newsroom Staff Job Opportunities at CHEST Contact Us Industry Support Industry Advisory ...

  6. Application of Low-dose Chest 16-slice Spiral CT Scan in Examination of Foreign Bodies in Bronchi of Children%16层螺旋CT低剂量胸部扫描在小儿气道异物检查中的应用

    Institute of Scientific and Technical Information of China (English)

    曹治婷

    2011-01-01

    目的:探讨16层螺旋CT低剂量胸部扫描在小儿气道异物检查中的应用价值.方法:对48例经纤维支气管镜证实有气道异物的患儿行不同荆量检查,其中28倒为低剂量(30 mAs)扫描,20例为常规(100 mAs)剂量扫描,将轴位薄层原始数据传至工作站分别行多平面重组(MPR)、最小密度投影(MinIP)、容积再现(VR)及CT仿真内镜(CTVE)后处理重建成像、分析其敏感性和准确性.结果:28例低剂量扫描患儿中发现异物27例,诊断准确率为96.4%;20例常规刺量扫描患儿中发现异物20例,诊断准确率为100%.两者无显著性差异(P>0.05).结论:16层螺旋CT低剂量胸部扫描不仅减少小儿接受的辐射剂量,后处理图像重建后可清楚显示异物的部位、形态、大小及阻塞部位,是诊断小儿气道异物无创并实用的检查方法.%Objective To discuss the value of low-dose chest 16-slice spiral CT scan in the examination of foreign hodies in bronchi of children. Methods Forty-eight children with foreign bodies aspiration were scanned transversely and reconstructed in different doses of the line check, twenty-eight were scanned witb low-dose, the others were scanned with conventional dose. Then the original axial data were transferred to workstation for image reconsruction by multi-planar reconstruction (MPR), minimum intensity projection (MinIP), volume rendering (VR) and CT virtual endoscopy (CTVE) respectively. The sensitivity and accuracy were analyzed. Results Twenty-seven cases were diagnosed with foreign bodies in those scanned with low-dose, diagnostic accuracy was 96.4%. Twenty cases were diagnosed with foreign bodies diagnostic accuracy was 100%. The difference was not statistically significant (P>0.05). Conclusion Low-dose chest 16-slice spiral CT scan can not only reduce the radiation dose received but also clearly show the site, the shape and the size of foreign body, and even the position of obstruction after post

  7. Adenosine-stress dynamic myocardial perfusion imaging using 128-slice dual-source CT: optimization of the CT protocol to reduce the radiation dose.

    Science.gov (United States)

    Kim, Sung Mok; Kim, Yoo Na; Choe, Yeon Hyeon

    2013-04-01

    The aim of this study was to compare the radiation dose and image quality of different adenosine-stress dynamic myocardial perfusion CT protocols using a 128-slice dual-source computed tomography (DSCT) scanner. We included 330 consecutive patients with suspected coronary artery disease. Protocols employed the following dynamic scan parameters: protocol I, a 30-s scan with a fixed tube current (FTC, n = 172); protocol II, a 30-s scan using an automatic tube current modulation (ATCM) technique (n = 108); protocol III, a 14-s scan using an ATCM (n = 50). To determine the scan interval for protocol III, we analyzed time-attenuation curves of 26 patients with myocardial perfusion who had been scanned using protocol I or II. The maximum attenuation difference between normal and abnormal myocardium occurred at 18.0 s to 30.3 s after initiation of contrast injection. Myocardial perfusion images of FTC and ATCM were of diagnostic image quality based on visual analysis. The mean radiation dose associated with protocols I, II, and III was 12.1 ± 1.6 mSv, 7.7 ± 2.5 mSv, and 3.8 ± 1.3 mSv, respectively (p < 0.01). Use of a dose-modulation technique and a 14-s scan duration for adenosine-stress CT enables significant dose reduction while maintaining diagnostic image quality.

  8. A comparison study of radiation exposure to patients during EVAR and Dyna CT in an angiosuite vs. an operating theatre.

    Science.gov (United States)

    Bruschi, Andrea; Michelagnoli, Stefano; Chisci, Emiliano; Mazzocchi, Silvia; Panci, Simone; Didona, Annamaria; Ghirelli, Alessandro; Zatelli, Giovanna

    2015-03-01

    The aim of this study was to assess the patient dosimetric impact of endovascular abdominal aortic aneurysm repair (EVAR), both in an operating theatre (OR) and in an angiosuite (AS), with the facility of Dynamic CT (Dyna CT, Siemens AG, Berlin, Germany). One hundred and forty-six consecutive EVAR procedures dating from May 2011 to March 2013 were analysed. These were performed either in an OR (n = 97) using a mobile C-arm or in an AS (n = 49) equipped with a ceiling-mounted angiography system. Air kerma area product (P(KA)) and total air kerma at reference point (K(a,r)) values were reported for all procedures and Dyna CT. Radiation exposure during EVAR was quite low in the majority of patients but nearly 50 % higher if performed in AS vs. OR. Median Dyna CT K(a,r) was the same as an entire EVAR procedure in OR. The higher patient's radiation exposure recorded in the AS should be balanced with the technical advantages given to the EVAR procedure.

  9. Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields

    CERN Document Server

    Seoung, Youl-Hun

    2015-01-01

    The purpose of the present study was to evaluate radiation dose reduction and image quality during CT scanning by using a new dose reduction fiber sheet (DRFS) with commercially available bismuth shields. These DRFS were composed of nano-barium sulfate (BaSO4), filling the gaps left by the large oxide bismuth (Bi2O3) particle sizes. The radiation dose was measured five times at directionss of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom to calculate an average value using a CT ionization chamber. The image quality measured CT transverse images of the PMMA head phantom depending on X-ray tube voltages and the type of shielding. Two regions of interest in CT transverse images were chosen from the right and left areas under the surface of the PMMA head phantom and from ion chamber holes located at directions of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce dosages to 15.61%, 23.05%, and 22.71% more in ...

  10. Estimating cancer risks to adults undergoing body CT examinations.

    Science.gov (United States)

    Huda, Walter; He, Wenjun

    2012-06-01

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

  11. Investigation of the accuracy of MV radiation isocentre calculations in the Elekta cone-beam CT software XVI

    DEFF Research Database (Denmark)

    Zimmermann, S. J.; Rowshanfarzad, P.; Ebert, M. A.

    2015-01-01

    ) and the radiation field centre (RFC) is calculated. A software package was developed for accurate calculation of the linac isocentre position. This requires precise determination of the position of the ball bearing and the RFC. Results: Data were acquired for 6 MV, 18 MV and flattening filter free (FFF) 6 MV FFF...... radiation isocentre prior to routine use of the cone-beam CT system. The isocentre determination method used in the XVI software is not available to users. The aim of this work is to perform an independent evaluation of the Elekta XVI 4.5 software for isocentre verification with focus on the robustness...... iView GT software. Two images were acquired at each cardinal gantry angle (-180o, -90o , 0o, 90o) at two opposing collimator angles. The images were exported to the conebeam CT software XVI 4.5 where the difference between the ball bearing position in the XYZ-room coordinates (IEC61217...

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

    Science.gov (United States)

    Slot Thing, Rune; Bernchou, Uffe; Mainegra-Hing, Ernesto; Hansen, Olfred; Brink, Carsten

    2016-08-01

    A comprehensive artefact correction method for clinical cone beam CT (CBCT) images acquired for image guided radiation therapy (IGRT) on a commercial system is presented. The method is demonstrated to reduce artefacts and recover CT-like Hounsfield units (HU) in reconstructed CBCT images of five lung cancer patients. Projection image based artefact corrections of image lag, detector scatter, body scatter and beam hardening are described and applied to CBCT images of five lung cancer patients. Image quality is evaluated through visual appearance of the reconstructed images, HU-correspondence with the planning CT images, and total volume HU error. Artefacts are reduced and CT-like HUs are recovered in the artefact corrected CBCT images. Visual inspection confirms that artefacts are indeed suppressed by the proposed method, and the HU root mean square difference between reconstructed CBCTs and the reference CT images are reduced by 31% when using the artefact corrections compared to the standard clinical CBCT reconstruction. A versatile artefact correction method for clinical CBCT images acquired for IGRT has been developed. HU values are recovered in the corrected CBCT images. The proposed method relies on post processing of clinical projection images, and does not require patient specific optimisation. It is thus a powerful tool for image quality improvement of large numbers of CBCT images.

  13. The One-step Imaging Study of Acute Chest Pain Trilogy by 64 Slice Spiral CT%急性胸痛三联症64层螺旋CT“一站式成像”的研究

    Institute of Scientific and Technical Information of China (English)

    李欣; 孙吉林; 戴国华; 付英杰; 李志远; 柳溪

    2011-01-01

    [Abstract] Objective To investigate the image quality and ability of one-time unified examination of the 64-slice spiral CT(MSCT)in showing coronary artery, pulmonary artery and aorta. Materials and Methods 60 patients with acute chest pain received unified examination of coronary artery .pulmonary artery, aorta with 64-slice MSCT using ECG-gated function respectively. The coronary artery,pulmonary artery and aorta were imaged by using a variety of reconstruction techniques compare to 50 cases with pure 64-slice MSCT coronary angiography ,30 cases with pulmonary artery imaging and 20 cases with aortic imaging. The results from the above examinations were analyzed to evaluate whether or not the quality of the images could meet the need of the clinical diagnosis. Results The average scan time of one step examination was(8.0 ± 1.5)S,and the dose of contrast medium injected was 100 ml,and the injection flow rate of 4.0 -4.5 ml/s. There was significant difference between the chest pain group and the control group in the images of the coronary artery (P 0.05;P=0.44, >0.05;P =0.068, >0.05).The image quality of the chest pain group was as good as the one of the control group. There was significant difference between two groups and intragroup in the images of the central, peripheral and whole pulmonary artery in chest pain group and the control group (P<0.01 ;P<0.01 ;P<0.01).The image quality of the chest pain group was better than the one of the control group. Conclusion The one-step examination of coronary artery .pulmonary artery,aorta by 64-slice MSCT can be finished within 10 seconds. The image quality of aorta, pulmonary artery is excellent. There is no significant difference between the image quality of the single aorta imaging and the unified examination of the MSCT,of which image quality is better than that of single pulmonary artery MSCT. The image of the coronary artery in one time unified examination is good,can meet the needs of the clinical diagnosis,but is

  14. Study of dosimetric quantities applied to patient undergoing routine chest examinations by computed tomography; Estudo de grandezas dosimetricas aplicadas em pacientes submetidos a exames de torax rotina em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Gonzaga, Natalia Barbosa

    2012-07-01

    The radiological protection system has established a standard to protect persons against the harmful effects caused by ionizing radiation that is based on the justification, optimization and dose limitation principles. The increasing use of radiation in medicine and the related risks have stressed the discussion on patient radiation protection. The computed tomography (CT) is the diagnostic radiology technique that most contributes to patient doses and it requires optimization efforts. Diagnostic reference levels (DRL) has been established in many countries in terms of CT dosimetric quantities; in Brazil, the DRLs are still under investigation since the culture of patient protection is not very strong yet. The objective of this work was to investigate the dosimetric and protection quantities related to patients undergoing CT routine chest examinations. The ImPACT CT, CT Expo and ImpactDose softwares were used for calculations of the weight and volumetric air-kerma indexes (CW and CVOL), the air kerma - length product (P{sub K,L}), organ equivalent dose (H{sub T}) and the effective dose (E) for CT routine chest protocols in 19 tomographs in Belo Horizonte city. The CT Expo was selected to be validated against experimental measurements in three hospitals with thermoluminescent dosimeters and CT pencil ionization chamber in anthropomorphic and standard CT body phantoms. Experimental and calculated results indicated differences up to 97% for H{sub T} and E and acceptable agreement for C{sub W} ,C{sub VOL} and P{sub K,L}. All data from 19 tomographs showed that local DRLs for CT routine chest examinations may be chosen smaller than DRLs adopted in other countries; this would contribute to increase the radiological protection of patients. (author)

  15. Significance of findings of both emergency chest X-ray and thoracic computed tomography routinely performed at the emergency unit in 102 polytrauma patients. A prospective study; Relevanz der Befunde von Thoraxroentgen und Thorax-CT im routinemaessigen Schockraumeinsatz bei 102 polytraumatisierten Patienten. Eine prospektive Studie

    Energy Technology Data Exchange (ETDEWEB)

    Grieser, T.; Buehne, K.H.; Haeuser, H.; Bohndorf, K. [Zentralklinikum Augsburg (Germany). Klinik fuer Diagnostische Radiologie und Neuroradiologie

    2001-01-01

    Purpose: To evaluate prospectively whether and to what extent both thoracic computed tomography (Tx-CT) and supine X-ray of the chest (Rx-Tx) are able to show additional findings that are therapeutically relevant. Patients and Methods: According to a fixed study protocol, we performed Rx-Tx and Tx-CT in 102 consecutive, haemodynamically stable polytrauma patients (mean age, 41.2 yrs; age range, 12-93 yrs). Findings of therapeutical relevance drawn from both Tx-CT and Rx-Tx, and urgent interventions indicated by an attending trauma team were documented on a standardized evaluation sheet immediately. Any change in the patient's management that is different from routine life-saving procedures, and any therapeutical intervention done in the emergency room or elsewhere (operating theatre, angiographic facility) were considered therapeutically relevant. Results: Of 102 patients, 43 (42.2%) had a total of 51 therapeutically relevant findings. Rx-Tx alone yielded 23 relevant findings (45.1%) in 23 patients (22.5%). Of them, Tx-CT has shown additional important findings in 7 patients (30.4%). When Tx-CT alone is considered, it revealed 22 new findings of therapeutical relevance (43.2%) in 20 patients (46.5%). Altogether, Tx-CT was able to show 30 relevant findings in 27 patients, i.e., there was a therapeutical benefit for 26.5% of all polytrauma patients included. Most frequently, there was a need for chest-tube insertion (n=29). Conclusions: Polytrauma patients if haemodynamically stable may profit from computed tomography of the chest when therapeutically relevant thoracic injuries are looked for or early therapeutical interventions are to be checked. However, chest X-ray should stay as a 'front-line' screening method because of its superbly quick feasibility and availability. (orig.) [German] Ziel: Die prospektive Studie soll klaeren, ob und inwieweit eine Thoraxcomputertomographie (Tx-CT) unter Schockraumbedingungen gegenueber der Roentgen

  16. 双源CT前瞻性心电门控扫描在急性胸痛诊断中应用的可行性%Feasibility of Prospective EGG-Dual-Source CT in the Diagnosis of Patients with Acute Chest Pain

    Institute of Scientific and Technical Information of China (English)

    陈丹; 周嘉慧; 史雅文

    2012-01-01

    Objective To evaluate the feasibility of prospective ECG gated dual-source CT (DSCT)in patients with acute chest pain in different heart rate. Methods Forty two patients with acute chest pain underwent prospective ECG-ga ted DSCT scan. The patients were divided into two groups. In group A, the heart rate of patients was = 75 beats / min, data set was reconstructed in 70% R-R interval, ECG pulse window was set to 62% -78% . In group B, the heart rate of patients was > 75 beats / min, data set was reconstructed in 40% R-R interval, ECG pulse window was set to 32% -48%. Two experienced radiologists assessed the image quality of two groups, The images were target reconstructed on pul monary artery, aorta, coronary arteries, and the radiation dose was calculated. \\2 test was used to explore significant differ ences in assessable segments coronary artery . Two independent samples t-test was used to explore significant differences in vessel attenuation of ascending aorta and pulmonary trunk. As well as, the CT coronary angiographic images of 16 cases were compared with DSA. Results Only one case, the attenuation of ascending aorta did not meet the diagnostic criteria. The attenuation of ascending aorta and pulmonary trunk had not statistical difference between group A and B (t values were 0.254,0. 700, P values were > 0. 05). The assessable segments of coronary arteries of group A and B were 278/284 (97. 89% ) , 297/307 {96. 74% ) , and there was no statistical difference between two groups. There was good consistency between CT coronary angiographic images and DSA images. The average effective dose was (8. 67 ±2. 54)mSv. Conclu sion Prospective ECG gated DSCT angiography offers a very good image quality without heart rate control in patients with acute chest pain.%目的 探讨应用双源CT( dual-source CT,DSCT)前瞻性心电门控扫描对不同心率的急性胸痛患者诊断的可行性.方法 对42例急性胸痛患者进行DSCT前瞻性心电门控心胸联合

  17. Monte Carlo modeling in CT-based geometries: dosimetry for biological modeling experiments with particle beam radiation.

    Science.gov (United States)

    Diffenderfer, Eric S; Dolney, Derek; Schaettler, Maximilian; Sanzari, Jenine K; McDonough, James; Cengel, Keith A

    2014-03-01

    The space radiation environment imposes increased dangers of exposure to ionizing radiation, particularly during a solar particle event (SPE). These events consist primarily of low energy protons that produce a highly inhomogeneous dose distribution. Due to this inherent dose heterogeneity, experiments designed to investigate the radiobiological effects of SPE radiation present difficulties in evaluating and interpreting dose to sensitive organs. To address this challenge, we used the Geant4 Monte Carlo simulation framework to develop dosimetry software that uses computed tomography (CT) images and provides radiation transport simulations incorporating all relevant physical interaction processes. We found that this simulation accurately predicts measured data in phantoms and can be applied to model dose in radiobiological experiments with animal models exposed to charged particle (electron and proton) beams. This study clearly demonstrates the value of Monte Carlo radiation transport methods for two critically interrelated uses: (i) determining the overall dose distribution and dose levels to specific organ systems for animal experiments with SPE-like radiation, and (ii) interpreting the effect of random and systematic variations in experimental variables (e.g. animal movement during long exposures) on the dose distributions and consequent biological effects from SPE-like radiation exposure. The software developed and validated in this study represents a critically important new tool that allows integration of computational and biological modeling for evaluating the biological outcomes of exposures to inhomogeneous SPE-like radiation dose distributions, and has potential applications for other environmental and therapeutic exposure simulations.

  18. Radiation monitoring in facilities of PET-CT thermoluminescence dosimetry; Vigilancia radiologica en instalaciones de PET-TC con dosimetria de termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Casa de Julian, M. A. de la; Gilarranz Moreno, R.; Martinez Gomez, L. C.; Clemente Gutierrez, F.; Manzanas Artigas, M. J.

    2011-07-01

    The PET-CT is a powerful diagnostic tool of relatively recent introduction, Following the opening of two PET-CT facilities, the CSN requested to do radiological monitoring of both facilities for a year to check the shields. These shields were calculated according the formalism proposed in the AAPM TG 108 of the. Here we review data from radiation monitoring.

  19. Presentation of the project EPI-CT: A cohort study of children with substantial diagnostic medical exposure to ionizing radiation; Presentacion del proyecto EPI-CT: Estudio de cohorte de ninos con exposicion medica diagnostica substancia a radiaciones ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    Bosch de Basea, M.; Cardis, E.; Vrijheid, M.

    2011-07-01

    Ionizing radiation for diagnostic purposes are an indispensable tool in modern medicine. The increasing use of computed tomography (CT) in children and adolescents is of concern both from the point of view of radio-protection and public health. children are more sensitive to the carcinogenic effects of ionizing radiation than adults. Children also have a higher life expectancy to show any detrimental effect. Furthermore, because of their smaller mass, CT scans in children receiving higher doses of radiation in specific organs in adults.

  20. Diagnosis and Treatment of Chest Injury and Emergency Diseases of Chest Organs

    Directory of Open Access Journals (Sweden)

    A. M. Khadjibaev

    2016-01-01

    Full Text Available Goal of research: to evaluate efficiency of videothoracoscopy in diagnosis and treatment of patients with injuries and emergency diseases ща chest organs.Material and methods: Study wasbased on treatment results analysis of 2111 patients with injuries and chest organs emergency diseases, who were treated at Republican Research Centre of Emergency Medicine in 2001-2014. Chest trauma made up 1396 (66,1% victims. There were 477 (22,6% patients with spontaneous pneumothorax. At the stages of initial diagnosis, the radiologic evaluations, CT investigations and videothoracoscopies were performed. In chest trauma patients the videothoracoscopy underwent in 844 cases, in spontaneous pneu#mothorax this method was employed in 290 patients. Complicated forms of lung echinococcosis were observed in 238 (11,3% patients and complicated forms of lung echinococcosis were evident in 72 patients.Results. Videothoracoscopy and video-assisted interventions allowed to eliminate lungs and pleura pathology in 1206 (57,1% patients, whereas the traditional methods were effective only in 905 cases (42,9%.Conclusions. Investigation methods such as multiplanar radioscopy, radiography, chest CT and videothora-coscopy must be included into algorithm of diagnosis and surgical treatment of chest injuries and emergency diseases of chest organs. At chest trauma the videothoracoscopy allows to avoid broad thoracotomy from 9,4% to 4,7% of cases, to reduce the frequency of repeated interventions from 17,4% to 0,5% and diminish a number of early postsurgery complications from 25,4% to 10,9%. Videothoracoscopy of chest traumas allows to reduce frequency of repeated interventions from 19,8 to 1,7%.

  1. Radiation exposure to nuclear medicine staffs during 18F-FDG PET/CT procedures at Ramathibodi Hospital

    Science.gov (United States)

    Donmoon, T.; Chamroonrat, W.; Tuntawiroon, M.

    2016-03-01

    The aim of this study is to estimate the whole body and finger radiation doses per study received by nuclear medicine staff involved in dispensing, administration of 18F-FDG and interacting with radioactive patients during PET/CT imaging procedures in a PET/CT facility. The whole-body doses received by radiopharmacists, technologists and nurses were measured by electronic dosimeter and the finger doses by ring dosimeter during a period of 4 months. In 70 PET/CT studies, the mean whole-body dose per study to radiopharmacist, technologist, and nurse were 1.07±0.09, 1.77±0.46, μSv, and not detectable respectively. The mean finger doses per study received by radiopharmacist, technologist, and nurse were 265.65±107.55, 4.84±1.08 and 19.22±2.59 μSv, respectively. The average time in contact with 18F-FDG was 5.88±0.03, 39.06±1.89 and 1.21±0.02 minutes per study for radiopharmacist, technologist and nurse respectively. Technologists received highest mean effective whole- body dose per study and radiopharmacist received the highest finger dose per study. When compared with the ICRP dose limit, each individual worker can work with many more 18F- FDG PET/CT studies for a whole year without exceeding the occupational dose limits. This study confirmed that low levels of radiation does are received by our medical personnel involved in 18F-FDG PET/CT procedures.

  2. Feature of clinic and imageology in patients with unstable angina pectoris after radiation therapy to chest%经胸放射治疗后的不稳定型心绞痛患者冠状动脉影像学及临床特点分析

    Institute of Scientific and Technical Information of China (English)

    隋春兴; 刘文民; 周旭晨; 郑晓群

    2009-01-01

    目的 观察经胸放射治疗后冠心病患者的冠状动脉影像学及临床特点.方法 选择不稳定型心绞痛(UAP)患者58例,其中经胸放射治疗后的UAP患者28例(经胸放疗后组);普通UAP患者30例(普通心绞痛组).全部患者行冠状动脉多排螺旋CT(MSCT)检查、冠状动脉造影术(CAG)及经皮冠状动脉介入治疗(PCI),随访1年,测定两组患者脑钠尿肽(BNP)水平,观察心血管事件的发生率,并进行比较.结果 经胸放疗后组冠状动脉病变特点与普通心绞痛组比较,钙化病变、多支病变、血栓病变以及PCI术中夹层发生率明显升高,1年随访时BNP水平较普通心绞痛组高[(234.31±121.39)ng/L比(124.74±37.81)ng/L],室壁运动指数、新发心功能不全及再发心绞痛、再次血运重建的比例也较普通心绞痛组高,差异均有统计学意义(P<0.05).结论 经胸放射治疗后患者冠状动脉病变以复杂病变为主,同时因放射性心肌及瓣膜损伤,使得该类患者远期预后更差.%Objective To observe feature of clinic and imageology in patients with unstable angina pectoris after radiation therapy to chest. Methods The study enrolled 58 patients who had unstable angina pectoris. Twenty-eight patients were in the postradiation therapy to chest group, 30 patients were in the common unstable angina pectoris group. All patients underwent multislice spiral CT(MSCT) examination and coronary angiography (CAG). After one year follow-up, the levels of brain natriuretic peptide (BNP) and ventricular wall motion score index (WMSI) were measured , the incidence of cardiovascular events were observed in all patients. Results Calcific, multi-vessel, thrombotic disease and dissection were significantly different between the two groups, when one year follow-up , the levels of BNP were higher in the postradiation therapy to chest group than those in the common unstable angina pectoris group [ (234.31 ± 121.39) ng/L vs (124.74 ±37.81) ng/L] WMST

  3. Prospectively ECG Gated CT pulmonary angiography versus helical ungated CT pulmonary angiography: Impact on cardiac related motion artifacts and patient radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Shuman, William P., E-mail: wshuman@u.washington.edu [Department of Radiology, 1959 NE Pacific Street, Box 357115, Seattle, WA 98195 (United States); Leipsic, Jonathon A., E-mail: JLeipsic@providencehealth.bc.ca [University of British Columbia and St. Paul' s Hospital, Department of Radiology, 1081 Burrard Street, Vancouver, BC, V6Z1Y6 (Canada); Busey, Janet M., E-mail: jbonny@u.washington.edu [Department of Radiology, 1959 NE Pacific Street, Box 357115, Seattle, WA 98195 (United States); Green, Douglas E., E-mail: dougreen@uw.edu [Department of Radiology, 1959 NE Pacific Street, Box 357115, Seattle, WA 98195 (United States); Pipavath, Sudhakar N., E-mail: snjp@u.wwashington.edu [Department of Radiology, 1959 NE Pacific Street, Box 357115, Seattle, WA 98195 (United States); Hague, Cameron J., E-mail: cjhague@interchange.ubc.ca [University of British Columbia and St. Paul' s Hospital, Department of Radiology, 1081 Burrard Street, Vancouver, BC, V6Z1Y6 (Canada); Koprowicz, Kent M., E-mail: kentk@u.washington.edu [Department of Radiology, 1959 NE Pacific Street, Box 357115, Seattle, WA 98195 (United States)

    2012-09-15

    Objective: To compare prospectively ECG gated CT pulmonary angiography (CTPA) with routine helical ungated CTPA for cardiac related motion artifacts and patient radiation dose. Subjects and methods: Twenty patients with signs and symptoms suspicious for pulmonary embolism and who had a heart rate below 85 were scanned with prospectively ECG gated CTPA. These gated exams were matched for several clinical parameters to exams from twenty similar clinical patients scanned with routine ungated helical CTPA. Three blinded independent reviewers subjectively evaluated all exams for overall pulmonary artery enhancement and for several cardiac motion related artifacts, including vessel blurring, intravascular shading, and double line. Reviewers also measured pulmonary artery intravascular density and image noise. Patient radiation dose for each technique was compared. Fourteen clinical prospectively ECG gated CTPA exams from a second institution were evaluated for the same parameters. Results: Prospectively ECG gated CTPA resulted in significantly decreased motion-related image artifact scores in lung segments adjacent to the heart compared to ungated CTPA. Measured image noise was not significantly different between the two types of CTPA exams. Effective dose was 28% less for prospectively ECG gated CTPA (4.9 mSv versus 6.8 mSv, p = 0.02). Similar results were found in the prospectively ECG gated exams from the second institution. Conclusion: Compared to routine helical ungated CTPA, prospectively ECG gated CTPA may result in less cardiac related motion artifact in lung segments adjacent to the heart and significantly less patient radiation dose.

  4. Radiation dose reduction at a price: the effectiveness of a male gonadal shield during helical CT scans

    Directory of Open Access Journals (Sweden)

    Erdi Yusuf E

    2007-03-01

    Full Text Available Abstract Background It is estimated that 60 million computed tomography (CT scans were performed during 2006, with approximately 11% of those performed on children age 0–15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-around male pediatric gonad shield was used during CT scanning. This information is obtained to assist the attending radiologist in the decision to utilize such male gonadal shields in pediatric imaging practice. Methods The dose reduction to the gonads was measured for both direct radiation and for indirect scattered radiation from the abdomen. A 6 cm3 ion chamber (Model 10X5-6, Radcal Corporation, Monrovia, CA was placed on a Humanoid real bone pelvic phantom at a position of the male gonads. When exposure measurements with shielding were made, a 1 mm lead wrap-around gonadal shield was placed around the ion chamber sensitive volume. Results The use of the shields reduced scatter dose to the gonads by a factor of about 2 with no appreciable loss of image quality. The shields reduced the direct beam dose by a factor of about 35 at the expense of extremely poor CT image quality due to severe streak artifacts. Conclusion Images in the direct exposure case are not useful due to these severe artifacts and the difficulties in positioning these shields on patients in the scatter exposure case may not be warranted by the small absolute reduction in scatter dose unless it is expected that the patient will be subjected to numerous future CT scans.

  5. Investigation of a method for generating synthetic CT models from MRI scans of the head and neck for radiation therapy

    Science.gov (United States)

    Hsu, Shu-Hui; Cao, Yue; Huang, Ke; Feng, Mary; Balter, James M.

    2013-12-01

    Magnetic resonance (MR) images often provide superior anatomic and functional information over computed tomography (CT) images, but generally are not used alone without CT images for radiotherapy treatment planning and image guidance. This study aims to investigate the potential of probabilistic classification of voxels from multiple MRI contrasts to generate synthetic CT (‘MRCT’) images. The method consists of (1) acquiring multiple MRI volumes: T1-weighted, T2-weighted, two echoes from a ultra-short echo time (UTE) sequence, and calculated fat and water image volumes using a Dixon method, (2) classifying tissues using fuzzy c-means clustering with a spatial constraint, (3) assigning attenuation properties with weights based on the probability of individual tissue classes being present in each voxel, and (4) generating a MRCT image volume from the sum of attenuation properties in each voxel. The capability of each MRI contrast to differentiate tissues of interest was investigated based on a retrospective analysis of ten patients. For one prospective patient, the correlation of skull intensities between CT and MR was investigated, the discriminatory power of MRI in separating air from bone was evaluated, and the generated MRCT image volume was qualitatively evaluated. Our analyses showed that one MRI volume was not sufficient to separate all tissue types, and T2-weighted images was more sensitive to bone density variation compared to other MRI image types. The short echo UTE image showed significant improvement in contrasting air versus bone, but could not completely separate air from bone without false labeling. Generated MRCT and CT images showed similar contrast between bone and soft/solid tissues. These results demonstrate the potential of the presented method to generate synthetic CT images to support the workflow of radiation oncology treatment planning and image guidance.

  6. A model-based approach of scatter dose contributions and efficiency of apron shielding for radiation protection in CT.

    Science.gov (United States)

    Weber, N; Monnin, P; Elandoy, C; Ding, S

    2015-12-01

    Given the contribution of scattered radiations to patient dose in CT, apron shielding is often used for radiation protection. In this study the efficiency of apron was assessed with a model-based approach of the contributions of the four scatter sources in CT, i.e. external scattered radiations from the tube and table, internal scatter from the patient and backscatter from the shielding. For this purpose, CTDI phantoms filled with thermoluminescent dosimeters were scanned without apron, and then with an apron at 0, 2.5 and 5 cm from the primary field. Scatter from the tube was measured separately in air. The scatter contributions were separated and mathematically modelled. The protective efficiency of the apron was low, only 1.5% in scatter dose reduction on average. The apron at 0 cm from the beam lowered the dose by 7.5% at the phantom bottom but increased the dose by 2% at the top (backscatter) and did not affect the centre. When the apron was placed at 2.5 or 5 cm, the results were intermediate to the one obtained with the shielding at 0 cm and without shielding. The apron effectiveness is finally limited to the small fraction of external scattered radiation.

  7. Analysis of biological tissues in infant chest for the development of an equivalent radiographic phantom

    Energy Technology Data Exchange (ETDEWEB)

    Pina, D. R.; Souza, Rafael T. F.; Duarte, Sergio B.; Alvarez, Matheus; Miranda, Jose R. A. [Faculdade de Medicina de Botucatu, Departamento de Doencas Tropicais e Diagnostico por Imagem, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil); Instituto de Biociencias de Botucatu, Departamento de Fisica e Biofisica, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil); Centro Brasileiro de Pesquisas Fisicas-CBPF/MCT, Rio de Janeiro 22290-180 (Brazil); Instituto de Biociencias de Botucatu, Departamento de Fisica e Biofisica, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil); Instituto de Biociencias de Botucatu, Departamento de Fisica e Biofisica, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil)

    2012-03-15

    Purpose: The main purpose of the present study was to determine the amounts of different tissues in the chest of the newborn patient (age {<=}1 year), with the aim of developing a homogeneous phantom chest equivalent. This type of phantom is indispensable in the development of optimization procedures for radiographic techniques, including dosimetric control, which is a crucial aspect of pediatric radiology. The authors present a systematic set of procedures, including a computational algorithm, to estimate the amounts of tissues and thicknesses of the corresponding simulator material plates used to construct the phantom. Methods: The Gaussian fit of computed tomographic (CT) analysis was applied to classify and quantify different biological tissues. The methodology is summarized with a computational algorithm, which was used to quantify tissues through automated CT analysis. The thicknesses of the equivalent homogeneous simulator material plates were determined to construct the phantom. Results: A total of 180 retrospective CT examinations with anterior-posterior diameter values ranging 8.5-13.0 cm were examined. The amounts of different tissues were evaluated. The results provided elements to construct a phantom to simulate the infant chest in the posterior-anterior or anterior-posterior (PA/AP) view. Conclusions: To our knowledge, this report represents the first demonstration of an infant chest phantom dedicated to the radiology of children younger than one year. This phantom is a key element in the development of clinical charts for optimizing radiographic technique in pediatric patients. Optimization procedures for nonstandard patients were reported previously [Pina et al., Phys. Med. Biol. 49, N215-N226 (2004) and Pina et al., Appl. Radiat. Isot. 67, 61-69 (2009)]. The constructed phantom represents a starting point to obtain radiologic protocols for the infant patient.

  8. Automated tube voltage selection for radiation dose and contrast medium reduction at coronary CT angiography using 3{sup rd} generation dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Poole, Zachary B.; Varga-Szemes, Akos; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Canstein, Christian [Siemens Medical Solutions, Malvern, PA (United States); Caruso, Damiano [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Bamberg, Fabian; Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2016-10-15

    To investigate the relationship between automated tube voltage selection (ATVS) and body mass index (BMI) and its effect on image quality and radiation dose of coronary CT angiography (CCTA). We evaluated 272 patients who underwent CCTA with 3{sup rd} generation dual-source CT (DSCT). Prospectively ECG-triggered spiral acquisition was performed with automated tube current selection and advanced iterative reconstruction. Tube voltages were selected by ATVS (70-120 kV). BMI, effective dose (ED), and vascular attenuation in the coronary arteries were recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used for subjective image quality analysis. Image quality was rated good to excellent in 98.9 % of examinations without significant differences for proximal and distal attenuation (all p ≥.0516), whereas image noise was rated significantly higher at 70 kV compared to ≥100 kV (all p <.0266). However, no significant differences were observed in SNR or CNR at 70-120 kV (all p ≥.0829). Mean ED at 70-120 kV was 1.5 ± 1.2 mSv, 2.4 ± 1.5 mSv, 3.6 ± 2.7 mSv, 5.9 ± 4.0 mSv, 7.9 ± 4.2 mSv, and 10.7 ± 4.1 mSv, respectively (all p ≤.0414). Correlation analysis showed a moderate association between tube voltage and BMI (r =.639). ATVS allows individual tube voltage adaptation for CCTA performed with 3{sup rd} generation DSCT, resulting in significantly decreased radiation exposure while maintaining image quality. (orig.)

  9. Triple rule-out CT in the emergency department: protocols and spectrum of imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Frauenfelder, Thomas; Appenzeller, Philippe; Karlo, Christoph; Scheffel, Hans; Desbiolles, Lotus; Stolzmann, Paul; Marincek, Borut; Alkadhi, Hatem; Schertler, Thomas [University Hospital Zurich, Department of Medical Radiology, Institute of Diagnostic Radiology, Zurich (Switzerland)

    2009-04-15

    Triage decisions in patients suffering from acute chest pain remain a challenge. The patient's history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated. (orig.)

  10. Study of the radiation dose reduction capability of a CT reconstruction algorithm: LCD performance assessment using mathematical model observers

    Science.gov (United States)

    Fan, Jiahua; Tseng, Hsin-Wu; Kupinski, Matthew; Cao, Guangzhi; Sainath, Paavana; Hsieh, Jiang

    2013-03-01

    Radiation dose on patient has become a major concern today for Computed Tomography (CT) imaging in clinical practice. Various hardware and algorithm solutions have been designed to reduce dose. Among them, iterative reconstruction (IR) has been widely expected to be an effective dose reduction approach for CT. However, there is no clear understanding on the exact amount of dose saving an IR approach can offer for various clinical applications. We know that quantitative image quality assessment should be task-based. This work applied mathematical model observers to study detectability performance of CT scan data reconstructed using an advanced IR approach as well as the conventional filtered back-projection (FBP) approach. The purpose of this work is to establish a practical and robust approach for CT IR detectability image quality evaluation and to assess the dose saving capability of the IR method under study. Low contrast (LC) objects imbedded in head size and body size phantoms were imaged multiple times with different dose levels. Independent signal present and absent pairs were generated for model observer study training and testing. Receiver Operating Characteristic (ROC) curves for location known exact and location ROC (LROC) curves for location unknown as well as their corresponding the area under the curve (AUC) values were calculated. Results showed approximately 3 times dose reduction has been achieved using the IR method under study.

  11. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Geisel, Dominik; Zimmermann, Elke; Rief, Matthias; Greupner, Johannes; Hamm, Bernd [Charite Medical School, Department of Radiology, Berlin (Germany); Laule, Michael; Knebel, Fabian [Charite Medical School, Department of Cardiology, Berlin (Germany); Dewey, Marc [Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2012-08-15

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 {+-} 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 {+-} 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  12. 3D dosimetry estimation for selective internal radiation therapy (SIRT) using SPECT/CT images: a phantom study

    Science.gov (United States)

    Debebe, Senait A.; Franquiz, Juan; McGoron, Anthony J.

    2015-03-01

    Selective Internal Radiation Therapy (SIRT) is a common way to treat liver cancer that cannot be treated surgically. SIRT involves administration of Yttrium - 90 (90Y) microspheres via the hepatic artery after a diagnostic procedure using 99mTechnetium (Tc)-macroaggregated albumin (MAA) to detect extrahepatic shunting to the lung or the gastrointestinal tract. Accurate quantification of radionuclide administered to patients and radiation dose absorbed by different organs is of importance in SIRT. Accurate dosimetry for SIRT allows optimization of dose delivery to the target tumor and may allow for the ability to assess the efficacy of the treatment. In this study, we proposed a method that can efficiently estimate radiation absorbed dose from 90Y bremsstrahlung SPECT/CT images of liver and the surrounding organs. Bremsstrahlung radiation from 90Y was simulated using the Compton window of 99mTc (78keV at 57%). 99mTc images acquired at the photopeak energy window were used as a standard to examine the accuracy of dosimetry prediction by the simulated bremsstrahlung images. A Liqui-Phil abdominal phantom with liver, stomach and two tumor inserts was imaged using a Philips SPECT/CT scanner. The Dose Point Kernel convolution method was used to find the radiation absorbed dose at a voxel level for a three dimensional dose distribution. This method will allow for a complete estimate of the distribution of radiation absorbed dose by tumors, liver, stomach and other surrounding organs at the voxel level. The method provides a quantitative predictive method for SIRT treatment outcome and administered dose response for patients who undergo the treatment.

  13. An automated technique for estimating patient-specific regional imparted energy and dose in TCM CT exams

    Science.gov (United States)

    Sanders, Jeremiah W.; Tian, Xiaoyu; Segars, W. Paul; Boone, John; Samei, Ehsan

    2016-03-01

    Currently computed tomography (CT) dosimetry relies on CT dose index (CTDI) and size specific dose estimates (SSDE). Organ dose is a better metric of radiation burden. However, organ dose estimation requires precise knowledge of organ locations. Regional imparted energy and dose can also be used to quantify radiation burden. Estimating the imparted energy from CT exams is beneficial in that it does not require precise estimates of the organ size or location. This work investigated an automated technique for retrospectively estimating the imparted energy from chest and abdominopelvic tube current modulated (TCM) CT exams. Monte Carlo simulations of chest and abdominopelvic TCM CT examinations across various tube potentials and TCM strengths were performed on 58 adult computational extended cardiac-torso (XCAT) phantoms to develop relationships between scanned mass and imparted energy normalized by dose length product (DLP). An automated algorithm for calculating the scanned patient volume was further developed using an open source mesh generation toolbox. The scanned patient volume was then used to estimate the scanned mass accounting for diverse density within the scan region. The scanned mass and DLP from the exam were used to estimate the imparted energy to the patient using the knowledgebase developed from the Monte Carlo simulations. Patientspecific imparted energy estimates were made from 20 chest and 20 abdominopelvic clinical CT exams. The average imparted energy was 274 +/- 141 mJ and 681 +/- 376 mJ for the chest and abdominopelvic exams, respectively. This method can be used to estimate the regional imparted energy and/or regional dose in chest and abdominopelvic TCM CT exams across clinical operations.

  14. Respiratory-gated segment reconstruction for radiation treatment planning using 256-slice CT-scanner during free breathing

    Science.gov (United States)

    Mori, Shinichiro; Endo, Masahiro; Kohno, Ryosuke; Minohara, Shinichi; Kohno, Kazutoshi; Asakura, Hiroshi; Fujiwara, Hideaki; Murase, Kenya

    2005-04-01

    The conventional respiratory-gated CT scan technique includes anatomic motion induced artifacts due to the low temporal resolution. They are a significant source of error in radiotherapy treatment planning for the thorax and upper abdomen. Temporal resolution and image quality are important factors to minimize planning target volume margin due to the respiratory motion. To achieve high temporal resolution and high signal-to-noise ratio, we developed a respiratory gated segment reconstruction algorithm and adapted it to Feldkamp-Davis-Kress algorithm (FDK) with a 256-detector row CT. The 256-detector row CT could scan approximately 100 mm in the cranio-caudal direction with 0.5 mm slice thickness in one rotation. Data acquisition for the RS-FDK relies on the assistance of the respiratory sensing system by a cine scan mode (table remains stationary). We evaluated RS-FDK in phantom study with the 256-detector row CT and compared it with full scan (FS-FDK) and HS-FDK results with regard to volume accuracy and image noise, and finally adapted the RS-FDK to an animal study. The RS-FDK gave a more accurate volume than the others and it had the same signal-to-noise ratio as the FS-FDK. In the animal study, the RS-FDK visualized the clearest edges of the liver and pulmonary vessels of all the algorithms. In conclusion, the RS-FDK algorithm has a capability of high temporal resolution and high signal-to-noise ratio. Therefore it will be useful when combined with new radiotherapy techniques including image guided radiation therapy (IGRT) and 4D radiation therapy.

  15. PET Motion Compensation for Radiation Therapy Using a CT-Based Mid-Position Motion Model: Methodology and Clinical Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kruis, Matthijs F.; Kamer, Jeroen B. van de; Houweling, Antonetta C.; Sonke, Jan-Jakob; Belderbos, José S.A.; Herk, Marcel van, E-mail: m.v.herk@nki.nl

    2013-10-01

    Purpose: Four-dimensional positron emission tomography (4D PET) imaging of the thorax produces sharper images with reduced motion artifacts. Current radiation therapy planning systems, however, do not facilitate 4D plan optimization. When images are acquired in a 2-minute time slot, the signal-to-noise ratio of each 4D frame is low, compromising image quality. The purpose of this study was to implement and evaluate the construction of mid-position 3D PET scans, with motion compensated using a 4D computed tomography (CT)-derived motion model. Methods and Materials: All voxels of 4D PET were registered to the time-averaged position by using a motion model derived from the 4D CT frames. After the registration the scans were summed, resulting in a motion-compensated 3D mid-position PET scan. The method was tested with a phantom dataset as well as data from 27 lung cancer patients. Results: PET motion compensation using a CT-based motion model improved image quality of both phantoms and patients in terms of increased maximum SUV (SUV{sub max}) values and decreased apparent volumes. In homogenous phantom data, a strong relationship was found between the amplitude-to-diameter ratio and the effects of the method. In heterogeneous patient data, the effect correlated better with the motion amplitude. In case of large amplitudes, motion compensation may increase SUV{sub max} up to 25% and reduce the diameter of the 50% SUV{sub max} volume by 10%. Conclusions: 4D CT-based motion-compensated mid-position PET scans provide improved quantitative data in terms of uptake values and volumes at the time-averaged position, thereby facilitating more accurate radiation therapy treatment planning of pulmonary lesions.

  16. Radiation dose response of normal lung assessed by Cone Beam CT - a potential tool for biologically adaptive radiation therapy

    DEFF Research Database (Denmark)

    Bertelsen, Anders; Schytte, Tine; Bentzen, Søren M;

    2011-01-01

    Density changes of healthy lung tissue during radiotherapy as observed by Cone Beam CT (CBCT) might be an early indicator of patient specific lung toxicity. This study investigates the time course of CBCT density changes and tests for a possible correlation with locally delivered dose....

  17. 胸部低剂量CT定量指标与肺气流受限的相关性分析%Correlation between the parameters quantified by chest low-dose CT scan and airflow limitation examined by spirometry

    Institute of Scientific and Technical Information of China (English)

    陈淑靖; 白春学; 顾宇彤; 张静; 余勇夫; 计海婴; 王桂芳; 李丽; 龚颖; 陈刚

    2012-01-01

    目的 探讨胸部低剂量CT(LDCT)定量指标和肺气流受限及其严重程度的相关性,建立初步相关模型.方法 纳入2008年7月至2012年2月在我院同步完成LDCT和肺功能检查的48例40岁以上有吸烟史的患者,对LDCT定量指标和肺功能指标进行相关性分析,并结合年龄、性别等因素建立回归模型.通过绘制受试者工作特征曲线(ROC曲线)确定对气流受限的判断作用最佳的LDCT定量指标.结果 经调整年龄、性别及BMI校正后,EV和El与FEV1、FEV1% pred、FEV1/FVC和TLC% pred呈负相关(P<0.05).但与RV/TLC% pred则无明显相关性(P>0.05);确定最佳回归模型为FEV1/FVC%=94.17+25.31×性别(gender)-0.58×年龄(age)-l0.84×In(El(%));FEV1% pred=141.76-0.78×年龄(age)-14.07×In(EI(%)).经ROC曲线确定对气流受限的判断作用最佳的LDCT定量指标为El.结论 El可用于判别有无气流受限,通过回归方程计算可估测气流受限和肺气肿严重程度.LDCT有望用于COPD的早期诊断.%Objective The purpose of the current study was to deternmine the correlation between the parameters quantified by chest low-dose CT scan (LDCT) and airflow limitation examined by spirometry.Methods This study included 48 patients above 40 years old and with smoking history who underwent LDCT and spirometry on the same day.The regression model was generated on the base of the LDCT value which correlated best to airflow limitation using ROC curve.Results With age,gender and body mass index adjusted,EV and El significantly correlated negatively with FEV1,FEV1%predieted,FEV1/FVC and TLC% predicted (P<0.05),but had no correlation with RV/TLC% predicted ( P>0.05).The regression model were FEV1/FVC%=94.17+25.31 X<gender-0.58×age-10.84×In (EI (%)),FEV1%predicted=141.76-0.78×age-14.07×In (EI(%)).The best LDCT value for airflow limitation estimation was EI.Conclusions El may be used to estimate whether airflow limitation exited and to

  18. Cumulative radiation exposure in children with cystic fibrosis.

    LENUS (Irish Health Repository)

    O'Reilly, R

    2010-02-01

    This retrospective study calculated the cumulative radiation dose for children with cystic fibrosis (CF) attending a tertiary CF centre. Information on 77 children with a mean age of 9.5 years, a follow up time of 658 person years and 1757 studies including 1485 chest radiographs, 215 abdominal radiographs and 57 computed tomography (CT) scans, of which 51 were thoracic CT scans, were analysed. The average cumulative radiation dose was 6.2 (0.04-25) mSv per CF patient. Cumulative radiation dose increased with increasing age and number of CT scans and was greater in children who presented with meconium ileus. No correlation was identified between cumulative radiation dose and either lung function or patient microbiology cultures. Radiation carries a risk of malignancy and children are particularly susceptible. Every effort must be made to avoid unnecessary radiation exposure in these patients whose life expectancy is increasing.

  19. Analyzing radiation absorption difference of dental substance by using Dual CT

    Science.gov (United States)

    Yu, H.; Lee, H. K.; Cho, J. H.; Yang, H. J.; Ju, Y. S.

    2015-07-01

    The purpose of this study was to evaluate the changes of noise and computer tomography (CT) number in each dental substance, by using the metal artefact reduction algorithm; we used dual CT for this study. For the study, we produced resin, titanium, gypsum, and wax that are widely used by dentists. In addition, we made nickel to increase the artefact. While making the study materials, we made sure that there is no difficulty when inserting the substances inside phantom. In order to study, we scanned before and after using the metal artefact reduction algorithm. We conducted an average analysis of CT number and noise, before and after using the metal artefact reduction algorithm. As a result, there was no difference in CT number and noise before and after using the metal artefact reduction algorithm. However, when it comes to the noise value in each substance, wax's noise value was the lowest whereas titanium's noise value was the highest, after applying the metal artefact reduction algorithm. In nickel, CT number and noise value from artefact area showed a decreased noise value when applying the metal artefact reduction algorithm. In conclusion, we assumed that we could increase the effectiveness of CT examination by applying dual energy's metal artefact reduction algorithm.

  20. Evaluation of radiation exposure with singleslice- and a multislice-spiral CT system (a phantom study); Untersuchungen zur Strahlenexposition bei der Einzelschicht- und Mehrschicht-Spiral-CT (eine Phantom-Studie)

    Energy Technology Data Exchange (ETDEWEB)

    Giacomuzzi, S.M.; Rieger, M.; Lottersberger, C.; Peer, S.; Peer, R.; Buchberger, W.; Bale, R.; Mallouhi, A.; Jaschke, W. [Universitaetsklinik fuer Radiodiagnostik, Innsbruck (Austria); Torbica, P. [Inst. fuer Medizinische Physik, Innsbruck (Austria); Perkmann, R. [Universitaetsklinik fuer Gefaesschirurgie, Innsbruck (Austria)

    2001-07-01

    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.) [German] Es soll im Vergleich die Dosisbelastung bei der Einzelschicht Spiral-CT zur Mehrschicht-Spiral-CT dargestellt werden. Methoden: Die Untersuchungen wurden mit einem Einzelschicht Spiral-CT (ES Spiral-CT) (Highspeed Advantage; Fa. GE Medical Systems; Milwaukee, USA) und einem Mehrschicht-Spiral-CT (MS Spiral-CT) (LightSpeed Qx/l; Fa. GE Medical Systems; Milwaukee, USA) durchgefuehrt. Fuer die Bestimmung der Strahlenexposition (Energiedosis) wurde eine Auswahl der routinemaessig am meisten durchgefuehrten Untersuchungen (Thorax-helical, Abdomen-helical, Felsenbein-axial, Schaedel-axial) an

  1. Effect of deformable registration on the dose calculated in radiation therapy planning CT scans of lung cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Cunliffe, Alexandra R.; Armato, Samuel G.; White, Bradley; Justusson, Julia [Department of Radiology, The University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois 60637 (United States); Contee, Clay; Malik, Renuka; Al-Hallaq, Hania A., E-mail: hal-hallaq@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, The University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois 60637 (United States)

    2015-01-15

    Purpose: To characterize the effects of deformable image registration of serial computed tomography (CT) scans on the radiation dose calculated from a treatment planning scan. Methods: Eighteen patients who received curative doses (≥60 Gy, 2 Gy/fraction) of photon radiation therapy for lung cancer treatment were retrospectively identified. For each patient, a diagnostic-quality pretherapy (4–75 days) CT scan and a treatment planning scan with an associated dose map were collected. To establish correspondence between scan pairs, a researcher manually identified anatomically corresponding landmark point pairs between the two scans. Pretherapy scans then were coregistered with planning scans (and associated dose maps) using the demons deformable registration algorithm and two variants of the Fraunhofer MEVIS algorithm (“Fast” and “EMPIRE10”). Landmark points in each pretherapy scan were automatically mapped to the planning scan using the displacement vector field output from each of the three algorithms. The Euclidean distance between manually and automatically mapped landmark points (d{sub E}) and the absolute difference in planned dose (|ΔD|) were calculated. Using regression modeling, |ΔD| was modeled as a function of d{sub E}, dose (D), dose standard deviation (SD{sub dose}) in an eight-pixel neighborhood, and the registration algorithm used. Results: Over 1400 landmark point pairs were identified, with 58–93 (median: 84) points identified per patient. Average |ΔD| across patients was 3.5 Gy (range: 0.9–10.6 Gy). Registration accuracy was highest using the Fraunhofer MEVIS EMPIRE10 algorithm, with an average d{sub E} across patients of 5.2 mm (compared with >7 mm for the other two algorithms). Consequently, average |ΔD| was also lowest using the Fraunhofer MEVIS EMPIRE10 algorithm. |ΔD| increased significantly as a function of d{sub E} (0.42 Gy/mm), D (0.05 Gy/Gy), SD{sub dose} (1.4 Gy/Gy), and the algorithm used (≤1 Gy). Conclusions: An

  2. 强直性脊柱炎并发肺大疱、气胸的胸部高分辨率 CT 特征及诊治体会%Chest high-resolution CT features, diagnosis and treatment of ankylosing spondylitis complicated with pulmonary bullae and pneumothorax

    Institute of Scientific and Technical Information of China (English)

    孙志强; 左翠云; 陈雷

    2015-01-01

    Objective To investigate the pulmonary complications of ankylosing spondylitis, and the level of recognition and diagnosis of these complications such as pulmonary bullae and pneumothorax. Methods Eight ankylosing spondylitis patients complicated with pulmonary bullae and pneumothorax form the Respiratory Department of the Third Hospital of Xiamen Province from July 2008 to July 2015 were enrolled. The clinic data, laboratory data, radiological data and therapy data were collected and analyzed, especially the chest high-resolution CT ( HRCT) characteristics, the cause of misdiagnosis and curative effects. Results The chest CT scan results showed, all of the 8 patients had double apex of lung fibrosis and lung multiple giant pulmonary bulla, 5 of which complicated with pneumothorax. Sagittal position of three dimensional multi planar reconstruction showed, all of the 8 patients had thoracic spine curvature becomes straight, vertebral hyperplasia were bamboo like change. The clinic data suggests that all of the 8 patients were complicated with pulmonary infection, 3 of which were severe infection. Five cases were cured after treatment, 1 case improved and 2 cases died. Conclusions Screening of atherosclerosis should be strengthened in the elderly patients with bilateral lung giant bullae and / or pneumothorax combined with axial joint inflammation. The therapy of the patients mentioned above is mainly symptomatic treatment, and the prognosis of simple pneumothorax is relatively better: most of which can be cured after thoracic closed drainage. The prognosis is mainly determined by the condition of lung infection and the severity of cardiac and renal function injury.%目的:探讨强制性脊柱炎(AS)并发肺大疱、气胸的胸部高分辨率 CT(HRCT)特征,以提高临床对该症的诊治水平。方法回顾性分析2008年7月—2015年7月福建省厦门市第三医院呼吸一科收住的8例 AS 并发肺大疱、气胸患者的临

  3. 儿童先天性漏斗胸与胸廓扁平程度相关性的多层螺旋CT研究%Relationship of the degree of the congenital pectus excavatum and the flat chest in children:evaluation with multislice helical CT

    Institute of Scientific and Technical Information of China (English)

    路涛; 邓开鸿

    2012-01-01

    目的 评价儿童先天性漏斗胸并发扁平胸的多层螺旋CT表现及其相关性.方法 收集2011年2~10月经临床诊断并行CT检查的漏斗胸患儿34例,在PACS形态图像上,测量漏斗胸的胸骨凹陷深度、Haller指数、CT凹陷指数及胸廓扁平指数,评价它们之间的关系.结果 34例先天性漏斗胸患儿胸骨凹陷深度为(17.12±9.98)mm,Haller指数为4.12±1.48,CT凹陷指数为2.39±0.70,胸廓扁平指数为3.30±0.56.漏斗胸中重度患儿的胸骨凹陷深度及胸廓扁平指数与轻度患儿相比较,差异具有统计学意义,且胸骨凹陷深度、胸廓扁平指数分别与Haller指数、CT凹陷指数间存在正相关关系.不同年龄组间患儿的胸骨凹陷深度、Haller指数、CT凹陷指数、胸廓扁平指数比较,差异均无统计学意义.结论 随着漏斗胸程度的加重,胸骨凹陷深度和胸廓扁平程度增加,其次漏斗胸的严重程度、胸骨凹陷深度及胸廓扁平程度并不随着年龄增长而加重.%Objective To evaluate the CT manifestations of pectus excavatum accompanied by flat chest and their relativity. Methods CT features of 34 children with pectus excavatum were retrospectively reviewed. The sternal depression(SD) ,Haller index(HI) ,CT depression index(CTDI) ,chest flat index( CFI) were measured from the images on the PACS system. The relationships among these indexes were evaluated. Results The SD was( 17. 12 ±9. 98) mm, HI was 4. 12 ±1.48,CT DI was 2.39 ±0.70, CFI was 3. 30 ±0. 56. There were statistical significance of sternal depression and chest flat index between children with modest to severe and slight pectus excavatum. AT the same time, the sternal depression and chest flat index were positively related to the Haller index and CT depression index respectively. There weren't statistical significances of SD, HI, CTDI and CFI among different age groups. Conclusions The degree of sternal depression and flat chest increased with the severity

  4. Radiation-induced Leiomyosarcoma of the Oral Cavity: A Rare Occurrence Detected on 18F-FDG PET/CT

    Science.gov (United States)

    Siraj, Fouzia; Dalal, Varsha; Kaur, Manveen; Suri, Kapil

    2016-01-01

    Radiation-induced sarcomas (RIS) or postirradiation sarcomas have been reported as a rare long-term complication of radiation therapy (RT). The survival benefit offered by radiotherapy has been masked by an increase in the incidence of these sarcomas, thus making radiotherapy a double-edged sword. RIS generally develop with a mean latency period of 10-15 years and encompass different histological types. We report a case of oral leiomyosarcoma with a rather short latency period of 4 years after the radiotherapy of the prior oral squamous cell carcinoma (OSCC) detected on fluorine-18 (18F)-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT). The rarity of occurrence of leiomyosarcoma in the oral cavity is also highlighted. PMID:27651746

  5. Investigation of the accuracy of MV radiation isocentre calculations in the Elekta cone-beam CT software XVI

    DEFF Research Database (Denmark)

    Lynggaard Riis, Hans; Moltke, Lars N; Zimmermann, S. J.

    2016-01-01

    at cardinal angles of the gantry using the electronic portal imaging device (EPID). Eight Elekta linacs with three different types of multileaf collimators (MLCs) were included in the test. The influence of MLC orientation, x-ray energy, and phantom modifications were examined. The acquired images were......Accurate determination of the megavoltage (MV) radiation isocentre of a linear accelerator (linac) is an important task in radiotherapy. The localization of the MV radiation isocentre is crucial for correct calibration of the in-room lasers and the cone-beam CT scanner used for patient positioning...... analysed using the Elekta x-ray volume imaging (XVI) software and in-house developed (IHD) MATLAB code. Results from the two different software were compared. A discrepancy in the longitudinal direction of the isocentre localization was found averaging 0.23 mm up to a maximum of 0.75 mm. The MLC...

  6. 重症甲型H1N1流感患者的胸部X线和CT特征分析%Chest X-ray Radiographic and CT Findings in Severe A(H1N1) Virus Infection

    Institute of Scientific and Technical Information of China (English)

    陈伟; 何波; 袁峰; 孙学进; 赵卫

    2011-01-01

    Objective To study X-ray radiographic and CT findings in patients with severe A (H1N1)virus infection. Method We reviewed the chest X-ray radiographic and CT findings of 24 patients with confrmed severe A (H1N1) virus infection in our hospital from November 2009 to December 2009. Results (1) The initial radiograph was normal in 4 patients among 24 patients with severe A (H1N1) virus infection. (2) Chest radiography and CT found ground-glass opacity in the lungs accounted for 53% and 67%, and mixed groundglass opacity with consolidation accounted for 37% and 62%. Ground-glass is mainly located in the lower part of the pleura around the lung, and ground-glass with consolidation is mainly located in the lower lung and central lung. (3) Chest radiography and CT found 3 cases and 5 cases of pleural effusion, and 2 cases and 9 cases of pleural thickening, respectively. (4) No patients were found with evident hilar or mediastinal lymph node enlargement by radiography or CT scans. Conclusions The predominant radiographic and CT findings are ground-glass opacity, following by ground- glass opacity with consolidation, without mediastinal and hilar lymph node enlargement, and the pleura can be involved on both chest radiography and CT. The findings of chest radiography and CT are consistent, but CT can find the lung lesions earlier than chest radiograph. CT can show the morphology and distribution of the lesions more clearly, so can increase the positive rate of lung lesions in severe A (H1N1). Also the chest radiography and CT can provide more clinical information to help clinicians find lesions in the lung early, give treatment in time, observe disease development and clinical evaluation.%目的 探讨重症甲型H1N1流感患者的胸部X线及CT表现.方法 回顾性分析经确诊的24例重症甲型H1N1流感患者的胸部X线及CT表现.结果 (1)24例中4例患者入院时胸部X线检察无异常发现;(2)X线及CT发现肺部磨玻璃影分别占53%、67

  7. Whole-body CT for lymphoma staging: Feasibility of halving radiation dose and risk by iterative image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M., E-mail: mathias.meyer@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Klein, S.A., E-mail: stefan.klein@umm.de [Department of Hematology and Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Brix, G., E-mail: gbrix@bfs.de [Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Fink, C., E-mail: Christian.Fink@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Pilz, L., E-mail: lothar.pilz@medma.uni-heidelberg.de [Department of Biostatistics, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Jafarov, H., E-mail: Hashim.Jafarov@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Hofmann, W.K., E-mail: w.k.hofmann@umm.de [Department of Hematology and Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Schoenberg, S.O., E-mail: Stefan.Schoenberg@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); and others

    2014-02-15

    Objectives: Patients with lymphoma are at higher-risk of secondary malignancies mainly due to effects of cancer therapy as well as frequent radiological surveillance. We thus aimed to investigate the objective and subjective image quality as well as radiation exposure and risk of full-dose standard (FDS), full-dose iterative (FDI), and half-dose iterative (HDI) image reconstruction in patients with lymphoma. Material and methods: In 100 lymphoma patients, contrast-enhanced whole-body staging was performed on a dual-source CT. To acquire full-dose and half-dose CT data simultaneously, the total current-time product was equally distributed on both tubes operating at 120 kV. HDI reconstructions were calculated by using only data from one tube. Quantitative image quality was assessed by measuring image noise in different tissues of the neck, thorax, and abdomen. Overall diagnostic image quality was assessed using a 5-point Likert scale. Radiation doses and risks were estimated for a male and female reference person. Results: For all anatomical regions apart from the lungs image noise was significantly lower and the overall subjective image quality significantly better when using FDI and HDI instead of FDS reconstruction (p < 0.05). For the half-dose protocol, the risk to develop a radiation-induced cancer was estimated to be less than 0.11/0.19% for an adult male/female. Conclusions: Image quality of FDI and more importantly of HDI is superior to FDS reconstruction, thus enabling to halve radiation dose and risk to lymphoma patients.

  8. Planned FDG PET-CT Scan in Follow-Up Detects Disease Progression in Patients With Locally Advanced NSCLC Receiving Curative Chemoradiotherapy Earlier Than Standard CT

    DEFF Research Database (Denmark)

    Pan, Yi; Brink, Carsten; Schytte, Tine;

    2015-01-01

    The role of positron emission tomography-computed tomography (PET-CT) in surveillance of patients with nonsmall cell lung cancer (NSCLC) treated with curatively intended chemoradiotherapy remains controversial. However, conventional chest X-ray and computed tomography (CT) are of limited value...... in discriminating postradiotherapy changes from tumor relapse. The aim of this study was to evaluate the clinical value of PET-CT scan in the follow-up for patients with locally advanced (LA) NSCLC receiving concomitant chemoradiotherapy (CCRT).Between 2009 and 2013, eligible patients with stages IIB-IIIB NSCLC...... were enrolled in the clinical trial NARLAL and treated in Odense University Hospital (OUH). All patients had a PET-CT scan scheduled 9 months (PET-CT9) after the start of the radiation treatment in addition to standard follow-up (group A). Patients who presented with same clinical stage of NSCLC...

  9. New Developed DR Detector Performs Radiographs of Hand, Pelvic and Premature Chest Anatomies at a Lower Radiation Dose and/or a Higher Image Quality

    DEFF Research Database (Denmark)

    Precht, Helle; Outzen, Claus Bjørn; Tingberg, Anders;

    2013-01-01

    quality compared to previous DR detector versions. To examine whether the newly developed Canon CXDI-70C DR detector provides an improved image quality and/or allows for dose reductions in hand and pelvic bone examinations as well as premature chest examinations, compared to the previous (CXDI-55C) DR...... studies indicated that by using the CXDI-70C detector, diagnostic image quality could be maintained at a dose reduction of in average 30 %, depending on anatomy and kVp level. This indicates that the CXDI-70C detector is significantly more sensitive than the previous model, and supports a better clinical...

  10. The application of metal artifact reduction (MAR) in CT scans for radiation oncology by monoenergetic extrapolation with a DECT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Schwahofer, Andrea [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology; Clinical Center Vivantes, Neukoelln (Germany). Dept. of Radiotherapy and Oncology; Baer, Esther [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology; Kuchenbecker, Stefan; Kachelriess, Marc [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiology; Grossmann, J. Guenter [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology; Ortenau Klinikum Offenburg-Gengenbach (Germany). Dept. of Radiooncology; Sterzing, Florian [Heidelberg Univ. (Germany). Dept. of Radiation Oncology; German Cancer Research Center, Heidelberg (Germany). Dept. of Radiotherapy

    2015-07-01

    Metal artifacts in computed tomography CT images are one of the main problems in radiation oncology as they introduce uncertainties to target and organ at risk delineation as well as dose calculation. This study is devoted to metal artifact reduction (MAR) based on the monoenergetic extrapolation of a dual energy CT (DECT) dataset. In a phantom study the CT artifacts caused by metals with different densities: aluminum (ρ{sub Al} = 2.7 g/cm{sup 3}), titanium (ρ{sub Ti} = 4.5 g/cm{sup 3}), steel (ρ{sub steel} = 7.9 g/cm{sup 3}) and tungsten (ρ{sub W} = 19.3 g/cm{sup 3}) have been investigated. Data were collected using a clinical dual source dual energy CT (DECT) scanner (Siemens Sector Healthcare, Forchheim, Germany) with tube voltages of 100 kV and 140 kV (Sn). For each tube voltage the data set in a given volume was reconstructed. Based on these two data sets a voxel by voxel linear combination was performed to obtain the monoenergetic data sets. The results were evaluated regarding the optical properties of the images as well as the CT values (HU) and the dosimetric consequences in computed treatment plans. A data set without metal substitute served as the reference. Also, a head and neck patient with dental fillings (amalgam ρ = 10 g/cm{sup 3}) was scanned with a single energy CT (SECT) protocol and a DECT protocol. The monoenergetic extrapolation was performed as described above and evaluated in the same way. Visual assessment of all data shows minor reductions of artifacts in the images with aluminum and titanium at a monoenergy of 105 keV. As expected, the higher the densities the more distinctive are the artifacts. For metals with higher densities such as steel or tungsten, no artifact reduction has been achieved. Likewise in the CT values, no improvement by use of the monoenergetic extrapolation can be detected. The dose was evaluated at a point 7 cm behind the isocenter of a static field. Small improvements (around 1%) can be seen with 105 ke

  11. The application of metal artifact reduction (MAR) in CT scans for radiation oncology by monoenergetic extrapolation with a DECT scanner.

    Science.gov (United States)

    Schwahofer, Andrea; Bär, Esther; Kuchenbecker, Stefan; Grossmann, J Günter; Kachelrieß, Marc; Sterzing, Florian

    2015-12-01

    Metal artifacts in computed tomography CT images are one of the main problems in radiation oncology as they introduce uncertainties to target and organ at risk delineation as well as dose calculation. This study is devoted to metal artifact reduction (MAR) based on the monoenergetic extrapolation of a dual energy CT (DECT) dataset. In a phantom study the CT artifacts caused by metals with different densities: aluminum (ρ Al=2.7 g/cm(3)), titanium (ρ Ti=4.5 g/cm(3)), steel (ρ steel=7.9 g/cm(3)) and tungsten (ρ W=19.3g/cm(3)) have been investigated. Data were collected using a clinical dual source dual energy CT (DECT) scanner (Siemens Sector Healthcare, Forchheim, Germany) with tube voltages of 100 kV and 140 kV(Sn). For each tube voltage the data set in a given volume was reconstructed. Based on these two data sets a voxel by voxel linear combination was performed to obtain the monoenergetic data sets. The results were evaluated regarding the optical properties of the images as well as the CT values (HU) and the dosimetric consequences in computed treatment plans. A data set without metal substitute served as the reference. Also, a head and neck patient with dental fillings (amalgam ρ=10 g/cm(3)) was scanned with a single energy CT (SECT) protocol and a DECT protocol. The monoenergetic extrapolation was performed as described above and evaluated in the same way. Visual assessment of all data shows minor reductions of artifacts in the images with aluminum and titanium at a monoenergy of 105 keV. As expected, the higher the densities the more distinctive are the artifacts. For metals with higher densities such as steel or tungsten, no artifact reduction has been achieved. Likewise in the CT values, no improvement by use of the monoenergetic extrapolation can be detected. The dose was evaluated at a point 7 cm behind the isocenter of a static field. Small improvements (around 1%) can be seen with 105 keV. However, the dose uncertainty remains of the order of 10

  12. In vivo reproducibility of robotic probe placement for an integrated US-CT image-guided radiation therapy system

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Sen, H. Tutkun; Iordachita, Iulian; Kazanzides, Peter; Wong, John

    2014-03-01

    Radiation therapy is used to treat cancer by delivering high-dose radiation to a pre-defined target volume. Ultrasound (US) has the potential to provide real-time, image-guidance of radiation therapy to identify when a target moves outside of the treatment volume (e.g. due to breathing), but the associated probe-induced tissue deformation causes local anatomical deviations from the treatment plan. If the US probe is placed to achieve similar tissue deformations in the CT images required for treatment planning, its presence causes streak artifacts that will interfere with treatment planning calculations. To overcome these challenges, we propose robot-assisted placement of a real ultrasound probe, followed by probe removal and replacement with a geometrically-identical, CT-compatible model probe. This work is the first to investigate in vivo deformation reproducibility with the proposed approach. A dog's prostate, liver, and pancreas were each implanted with three 2.38-mm spherical metallic markers, and the US probe was placed to visualize the implanted markers in each organ. The real and model probes were automatically removed and returned to the same position (i.e. position control), and CT images were acquired with each probe placement. The model probe was also removed and returned with the same normal force measured with the real US probe (i.e. force control). Marker positions in CT images were analyzed to determine reproducibility, and a corollary reproducibility study was performed on ex vivo tissue. In vivo results indicate that tissue deformations with the real probe were repeatable under position control for the prostate, liver, and pancreas, with median 3D reproducibility of 0.3 mm, 0.3 mm, and 1.6 mm, respectively, compared to 0.6 mm for the ex vivo tissue. For the prostate, the mean 3D tissue displacement errors between the real and model probes were 0.2 mm under position control and 0.6 mm under force control, which are both within acceptable

  13. Monte Carlo simulation of simultaneous radiation detection in the hybrid tomography system ClearPET-XPAD3/CT

    Science.gov (United States)

    Dávila, H. Olaya; Sevilla, A. C.; Castro, H. F.; Martínez, S. A.

    2016-07-01

    Using the Geant4 based simulation framework SciFW1, a detailed simulation was performed for a detector array in the hybrid tomography prototype for small animals called ClearPET / XPAD, which was built in the Centre de Physique des Particules de Marseille. The detector system consists of an array of phoswich scintillation detectors: LSO (Lutetium Oxy-ortosilicate doped with cerium Lu2SiO5:Ce) and LuYAP (Lutetium Ortoaluminate of Yttrium doped with cerium Lu0.7Y0.3AlO3:Ce) for Positron Emission Tomography (PET) and hybrid pixel detector XPAD for Computed Tomography (CT). Simultaneous acquisition of deposited energy and the corresponding time - position for each recorded event were analyzed, independently, for both detectors. interference between detection modules for PET and CT. Information about amount of radiation reaching each phoswich crystal and XPAD detector using a phantom in order to study the effectiveness by radiation attenuation and influence the positioning of the radioactive source 22Na was obtained. The simulation proposed will improve distribution of detectors rings and interference values will be taken into account in the new versions of detectors.

  14. Estimation of Radiation Exposure of 128-Slice 4D-Perfusion CT for the Assessment of Tumor Vascularity

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik; Horger, Marius; Buchgeister, Markus; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Schulze, Maximilian; Tsiflikas, Ilias; Claussen, Claus D.; Heuschmid, Martin [University Hospital Tuebingen, Tuebingen (Germany)

    2010-10-15

    We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4D Perfusion-CT. Phantom measurements were performed on a 128-slice single source scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue (lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans

  15. Absorbed radiation doses in women undergone to PET-CT exams for cancer diagnosis; Dose absorvida e efetiva em mulheres submetidas a exames de PET-CT para diagnostico oncologico

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Priscila do Carmo;