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Sample records for chest ct radiation

  1. Evaluation of radiation doses delivered in different chest CT protocols

    OpenAIRE

    Gorycki, Tomasz; Lasek, Iwona; Kamiński, Kamil; Studniarek, Michał

    2014-01-01

    Summary Background There are differences in the reference diagnostic levels for the computed tomography (CT) of the chest as cited in different literature sources. The doses are expressed either in weighted CT dose index (CTDIVOL) used to express the dose per slice, dose-length product (DLP), and effective dose (E). The purpose of this study was to assess the radiation dose used in Low Dose Computer Tomography (LDCT) of the chest in comparison with routine chest CT examinations as well as to ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

  4. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  6. Excess radiation and organ dose in chest and abdominal CT due to CT acquisition beyond expected anatomical boundaries

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    Zanca, Federica; Demeter, Martine; Oyen, Raymond; Bosmans, Hilde [University Hospitals Leuven, Department of Radiology, Leuven (Belgium)

    2012-04-15

    To assess the extent of extra imaging beyond the prescribed anatomical margins for chest and abdominal CT and to determine associated extra patient and organ dose estimates. For 167 consecutive patients undergoing routine chest and/or abdominal examination with 128-slice CT, extra imaging length was evaluated on coronal images. Effective and organ doses (thyroid, liver, breasts, testes) were calculated. Paired t-test was applied to evaluate statistically significant differences between prescribed and actual imaging length, and associated doses. 133 (80%) examinations had extra coverage (mean 4.6 cm, range 1-19.5 cm). Significantly higher (P < 0.05) effective doses for chest CT (mean 4.8 mSv vs 4.2 mSv for actual vs prescribed volume of interest), abdominal CT (8.4 mSv vs 7.9 mSv) or thorax-abdominal CT (12.8 mSv vs 11.9 mSv) were found. A significantly higher (P < 0.001) organ dose was estimated for thyroid (extra dose 99% corresponding to 5.1 mSv), liver (56%, 2.2 mSv), testes (115%, 7.6 mSv), and breasts (163%, 1.5 mSv). Imaging beyond anatomical limits during routine chest and abdominal CT results in higher organ and effective doses. Continuous training of the technologists remains important. Physicians and technologists must be kept aware of the additional dose associated with extra imaging. (orig.)

  7. Patient-specific radiation dose and cancer risk estimation in pediatric chest CT: a study in 30 patients

    Science.gov (United States)

    Li, Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P.

    2010-04-01

    Radiation-dose awareness and optimization in CT can greatly benefit from a dosereporting system that provides radiation dose and cancer risk estimates specific to each patient and each CT examination. Recently, we reported a method for estimating patientspecific dose from pediatric chest CT. The purpose of this study is to extend that effort to patient-specific risk estimation and to a population of pediatric CT patients. Our study included thirty pediatric CT patients (16 males and 14 females; 0-16 years old), for whom full-body computer models were recently created based on the patients' clinical CT data. Using a validated Monte Carlo program, organ dose received by the thirty patients from a chest scan protocol (LightSpeed VCT, 120 kVp, 1.375 pitch, 40-mm collimation, pediatric body scan field-of-view) was simulated and used to estimate patient-specific effective dose. Risks of cancer incidence were calculated for radiosensitive organs using gender-, age-, and tissue-specific risk coefficients and were used to derive patientspecific effective risk. The thirty patients had normalized effective dose of 3.7-10.4 mSv/100 mAs and normalized effective risk of 0.5-5.8 cases/1000 exposed persons/100 mAs. Normalized lung dose and risk of lung cancer correlated strongly with average chest diameter (correlation coefficient: r = -0.98 to -0.99). Normalized effective risk also correlated strongly with average chest diameter (r = -0.97 to -0.98). These strong correlations can be used to estimate patient-specific dose and risk prior to or after an imaging study to potentially guide healthcare providers in justifying CT examinations and to guide individualized protocol design and optimization.

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

    International Nuclear Information System (INIS)

    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. (authors)

  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

    Institute of Scientific and Technical Information of China (English)

    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. Actinomycosis involving the chest wall: CT findings

    International Nuclear Information System (INIS)

    Two cases of pulmonary actinomycosis with extension to involve the chest wall that were evaluated using computerized tomography are reported. In both cases, the relation of pulmonary and chest wall disease was best shown using CT

  12. Response to the argument on the risk of cancer with chest CT screening. Is low-dose chest CT safe?

    International Nuclear Information System (INIS)

    The steady increase in the annual number of chest CT screening has become a worldwide concern because of its associated risk of lung cancer. Epidemiological studies, however, have shown that repeated exposure to low-dose radiation does not increase the risk of lung cancer. In addition, a recent randomized controlled study on chest CT screening has shown its usefulness for reducing lung cancer mortality. We reviewed the risk of lung cancer after repeated exposure to low-dose radiation, the efficacy of chest CT screening, and device technology for reducing the irradiation dose. (author)

  13. Chest CT in children: anesthesia and atelectasis

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. Chest CT in children: anesthesia and atelectasis

    International Nuclear Information System (INIS)

    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

  15. CT of blunt chest trauma in children

    International Nuclear Information System (INIS)

    While trauma is still the leading cause of death in the pediatric age range, it is surprising how little the CT appearances of pediatric chest injury have been investigated in the literature. We have reviewed the CT findings of blunt chest trauma in 44 children for whom chest CT examinations were requested to investigate the extent of intrathoracic injury. We noted a propensity for pulmonary contusions to be located posteriorly or posteromedially, and for them to be anatomically nonsegmental and crescentic in shape. This is possibly attributable to the relatively compliant anterior chest wall in children. The CT appearances of other major thoracic injuries are described, including pulmonary lacerations, pneumothoraces, malpositioned chest tubes, mediastinal hematomas, aortic injury, tracheobronchial injury, hemopericardium, and spinal injuries with paraspinal fluid collections. Children demonstrating findings incidental to the actual injury yet important to the subsequent therapy are also presented. We conclude that, in the event of clinically significant blunt chest trauma, the single supine chest examination in the trauma room is insufficient to adequately identify the extent of intrathoracic injury. With the exception of concern for aortic injury for which aortography is indicated, a dynamically enhanced CT scan of the thorax should be performed as clinically significant findings may result in altered therapy. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    International Nuclear Information System (INIS)

    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 CTDIvol, 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.)

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Evaluation of time-related changes in lung detail findings after radiation therapy to the chest using multidetector-row CT. Usefulness of precision scanning

    International Nuclear Information System (INIS)

    Time-related changes in lung detail findings after radiation therapy to the chest were evaluated using multidetector-row CT. The frequency of individual findings and time-related changes in percent incidence of findings were compared between ordinary scanning at 3 mm raw thickness and 8 mm recon thickness, and precision scanning set at 0.5 mm for both parameters. For both scanning methods, the most frequently detected finding was ground-glass opacity (GGO). For all findings other than GGO and consolidation, the frequency of detection was greater with precision scanning than with ordinary scanning. GGO was also the finding showing the greatest difference in frequency of detection between the two scanning methods; because ordinary scanning tended to overvalue GGO, a demonstrative experiment was conducted using a lung detail phantom. Regarding time-related changes in percent incidence of findings, precision scanning was equivalent or superior to ordinary scanning at all time points except after 3 months. These results, combined with the more accurate evaluation of various lung detail changes after radiation therapy to the chest, including GGO (reversible lesion), suggest the usefulness of precision scanning in combination with ordinary scanning. (author)

  20. Chest radiation - discharge

    Science.gov (United States)

    ... during cancer treatment Eating extra calories when sick - adults Lymphedema - self-care Radiation therapy - questions to ask your doctor Safe eating during cancer treatment When you have diarrhea When you have nausea and vomiting Update Date ...

  1. 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

  2. Anteroposterior chest radiograph vs. chest CT scan in early detection of pneumothorax in trauma patients

    OpenAIRE

    Omar, Hesham R.; Mangar, Devanand; Khetarpal, Suneel; Shapiro, David H; Kolla, Jaya; Rashad, Rania; Helal, Engy; Camporesi, Enrico M

    2011-01-01

    Pneumothorax is a common complication following blunt chest wall trauma. In these patients, because of the restrictions regarding immobilization of the cervical spine, Anteroposterior (AP) chest radiograph is usually the most feasible initial study which is not as sensitive as the erect chest X-ray or CT chest for detection of a pneumothorax. We will present 3 case reports which serve for better understanding of the entity of occult pneumothorax. The first case is an example of a true occult ...

  3. Derivation and validation of two decision instruments for selective chest CT in blunt trauma: a multicenter prospective observational study (NEXUS Chest CT.

    Directory of Open Access Journals (Sweden)

    Robert M Rodriguez

    2015-10-01

    Full Text Available Unnecessary diagnostic imaging leads to higher costs, longer emergency department stays, and increased patient exposure to ionizing radiation. We sought to prospectively derive and validate two decision instruments (DIs for selective chest computed tomography (CT in adult blunt trauma patients.From September 2011 to May 2014, we prospectively enrolled blunt trauma patients over 14 y of age presenting to eight US, urban level 1 trauma centers in this observational study. During the derivation phase, physicians recorded the presence or absence of 14 clinical criteria before viewing chest imaging results. We determined injury outcomes by CT radiology readings and categorized injuries as major or minor according to an expert-panel-derived clinical classification scheme. We then employed recursive partitioning to derive two DIs: Chest CT-All maximized sensitivity for all injuries, and Chest CT-Major maximized sensitivity for only major thoracic injuries (while increasing specificity. In the validation phase, we employed similar methodology to prospectively test the performance of both DIs. We enrolled 11,477 patients-6,002 patients in the derivation phase and 5,475 patients in the validation phase. The derived Chest CT-All DI consisted of (1 abnormal chest X-ray, (2 rapid deceleration mechanism, (3 distracting injury, (4 chest wall tenderness, (5 sternal tenderness, (6 thoracic spine tenderness, and (7 scapular tenderness. The Chest CT-Major DI had the same criteria without rapid deceleration mechanism. In the validation phase, Chest CT-All had a sensitivity of 99.2% (95% CI 95.4%-100%, a specificity of 20.8% (95% CI 19.2%-22.4%, and a negative predictive value (NPV of 99.8% (95% CI 98.9%-100% for major injury, and a sensitivity of 95.4% (95% CI 93.6%-96.9%, a specificity of 25.5% (95% CI 23.5%-27.5%, and a NPV of 93.9% (95% CI 91.5%-95.8% for either major or minor injury. Chest CT-Major had a sensitivity of 99.2% (95% CI 95.4%-100%, a specificity of

  4. Patient-specific dose estimation for pediatric chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P. [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Global Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham North Carolina 27710 (United States)

    2008-12-15

    Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ

  5. Estimation of breast dose and cancer risk in chest and abdomen CT procedures

    International Nuclear Information System (INIS)

    The use of CT in medical diagnosis delivers radiation doses to patents that are higher than those from other radiological procedures. Lack of optimized protocols be an additional source of increased dose in developing countries. The aims of this study are first, to measure patient doses during CT chest and abdomen procedures, second, to estimate the radiation dose to the breast, and third to quantify the radiation risks during the procedures. Patient doses from two common CT examinations were obtained from four hospitals in Khartoum.The patient doses were estimated using measurement of CT dose indexes (CTDI), exposure-related parameters, and the IMPACT spreadsheet based on NRPB conversion factors. A large variation of mean organ doses among hospitals was observed for similar CT examinations. These variations largely originated from different CT scanning protocols used in different hospitals and scanner type. The largest range was found for CT of the chest, for which the dose varied from 2.3 to 47 (average 24.7) mSv and for abdomen CT, it was 1.6 to 18.8 (average 10.2) mSv. Radiation dose to the breast ranged from 1.6 to 32.9 mSv for the chest and 1.1 to 13.2 mSv for the abdomen. The radiation risk per procedure was high. The obtained values were mostly higher than the values of organ doses reported from the other studies. It was concluded that current clinical chest and abdomen protocols result in variable radiation doses to the breast. The magnitude of exposure may have implications for imaging strategies.(Author)

  6. Radiation induced osteosarcoma of the chest wall

    Energy Technology Data Exchange (ETDEWEB)

    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)

  7. Computed tomography of the chest with model-based iterative reconstruction using a radiation exposure similar to chest X-ray examination: preliminary observations

    Energy Technology Data Exchange (ETDEWEB)

    Neroladaki, Angeliki; Botsikas, Diomidis; Boudabbous, Sana; Becker, Christoph D.; Montet, Xavier [Geneva University Hospital, Department of Radiology, Geneva 4 (Switzerland)

    2013-02-15

    The purpose of this study was to assess the diagnostic image quality of ultra-low-dose chest computed tomography (ULD-CT) obtained with a radiation dose comparable to chest radiography and reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) in comparison with standard dose diagnostic CT (SDD-CT) or low-dose diagnostic CT (LDD-CT) reconstructed with FBP alone. Unenhanced chest CT images of 42 patients acquired with ULD-CT were compared with images obtained with SDD-CT or LDD-CT in the same examination. Noise measurements and image quality, based on conspicuity of chest lesions on all CT data sets were assessed on a five-point scale. The radiation dose of ULD-CT was 0.16 {+-} 0.006 mSv compared with 11.2 {+-} 2.7 mSv for SDD-CT (P < 0.0001) and 2.7 {+-} 0.9 mSv for LDD-CT. Image quality of ULD-CT increased significantly when using MBIR compared with FBP or ASIR (P < 0.001). ULD-CT reconstructed with MBIR enabled to detect as many non-calcified pulmonary nodules as seen on SDD-CT or LDD-CT. However, image quality of ULD-CT was clearly inferior for characterisation of ground glass opacities or emphysema. Model-based iterative reconstruction allows detection of pulmonary nodules with ULD-CT with radiation exposure in the range of a posterior to anterior (PA) and lateral chest X-ray. (orig.)

  8. CT and MR findings of chest wall masses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Woo; Kim, Jin Hee; Lee, Eun Suk; Kwon, Sun Young; Ko, Eun Ju [Eul Ji General Hospital, Daejeon (Korea, Republic of); Lee, Sang Young [Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kang, Hye Jeong [Eul Ji General Hospital, Seoul (Korea, Republic of)

    1995-07-15

    To evaluate the characteristic radiological findings of various diseases forming chest wall masses by CT and MR. We retrospectively reviewed CT and MR findings of the chest wall masses in 31 patients. Morphology, density, features of contrast enhancement, and location of the mass within the bony thorax or soft tissue were analyzed. Benign lesions of bony thorax were osteochondritis (n = 2), tuberculosis (n = 1), and osteochon droma (n = 1). Malignant lesions of bony thorax were Ewing's sarcoma (n = 1) and metastasis (n = 3). Benign lesions of soft tissue were abscess (n = 1), tuberculosis (n = 7), lipoma (n = 1), cavernous hemangioma (n = 2), cavernous lymphangioma (n = 1), and neurofibroma (n = 1). Malignant lesions of soft tissue were lymphoma (n = 1), spindle cell sarcoma (n = 1), metastasis (n = 8). Tuberculosis of the chest wall (n = 8) were ill-defined hypodense (n = 7) or isodense (n = 1) mass than surrounding muscle on pre-enhanced CT scan. All massess showed peripheral rim enhancement after contrast enhancement. Five cases were associated with pulmonary or pleural tuberculosis. All malignant lesions of bony thorax showed bone destruction, but inflammatory processes also showed bone destruction. MR showed characteristic signal intensity in the case of lipoma (n = 1) and hemangioma (n = 1). We conclude that CT and MR are helpful for differential diagnosis of chest wall masses.

  9. Generalities of anomalous CT chest non tumoral

    International Nuclear Information System (INIS)

    This presentation is about the generalities of multidetector CT in the pulmonary, the diaphragmatic, the pleural and the mediastinum pathology.These techniques as well as the virtual endoscopy allow visualize volumetric thorax reconstructions, brain diseases, opacities, radiolucent images, respiratory and vascular diseases, pneumonia, embolism, AIDS stage, tuberculosis, tumors, etc

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Chest wall tuberculosis; CT findings in 14 patients

    International Nuclear Information System (INIS)

    To present CT findings of chest wall tuberculosis. CT scans were obtained in 14 patients with proven chest wall tuberculosis. Diagnosis was confirmed by means of right open thoracostomy with abscess evacuation (n=1), excision and curettage (n=11) or excision and curettage along with resection of the involved lung (n=2). The images were assessed with emphasis for the extrapleural, pleural, and pulmonary lesions. All patients showed juxtacostal soft tissue mass with central low attenuation and peripheral rim enhancement. The lesions were located in the left hemithorax in eight patients and in the right in six. Multiple lesions were found in three patients (two in one and three in two). Rib destruction was observed in four patients. Intercostal muscle involvement of thickening and enhancement were shown in all patients. Thirteen patients (93%) had evidence of pulmonary tuberculosis: active pulmonary tuberculosis in nine and stable tuberculosis in four. Pleural lesions, including empyema necessitatis in six, were observed in eleven (79%). On CT scan, chest wall tuberculosis is characterized by juxtacostal soft tissue lesion with central low attenuation and peripheral rim enhancement. Rib destruction may be associated. Additionally, enhancing intercostal muscle suggest direct inflammatory process of tuberculosis and spread channel to the chest wall involvement of pleuropulmonary tuberculosis

  12. Segmentation of individual ribs from low-dose chest CT

    Science.gov (United States)

    Lee, Jaesung; Reeves, Anthony P.

    2010-03-01

    Segmentation of individual ribs and other bone structures in chest CT images is important for anatomical analysis, as the segmented ribs may be used as a baseline reference for locating organs within a chest as well as for identification and measurement of any geometric abnormalities in the bone. In this paper we present a fully automated algorithm to segment the individual ribs from low-dose chest CT scans. The proposed algorithm consists of four main stages. First, all the high-intensity bone structure present in the scan is segmented. Second, the centerline of the spinal canal is identified using a distance transform of the bone segmentation. Then, the seed region for every rib is detected based on the identified centerline, and each rib is grown from the seed region and separated from the corresponding vertebra. This algorithm was evaluated using 115 low-dose chest CT scans from public databases with various slice thicknesses. The algorithm parameters were determined using 5 scans, and remaining 110 scans were used to evaluate the performance of the segmentation algorithm. The outcome of the algorithm was inspected by an author for the correctness of the segmentation. The results indicate that over 98% of the individual ribs were correctly segmented with the proposed algorithm.

  13. Case report: Pulmonary syphilis mimicking pulmonary hematogenous metastases on chest CT and integrated PET/CT

    Directory of Open Access Journals (Sweden)

    Hyung Jun Kim

    2011-01-01

    Full Text Available We report a case of syphilis with pulmonary involvement. Chest CT scan and 18 F-fluorodeoxyglucose (FDG PET/CT showed multiple pulmonary nodules mimicking pulmonary hematogenous metastases. This was confirmed on follow-up images that showed therapeutic response to penicillin.

  14. Case report: Pulmonary syphilis mimicking pulmonary hematogenous metastases on chest CT and integrated PET/CT

    International Nuclear Information System (INIS)

    We report a case of syphilis with pulmonary involvement. Chest CT scan and 18F-fluorodeoxyglucose (FDG) PET/CT showed multiple pulmonary nodules mimicking pulmonary hematogenous metastases. This was confirmed on follow-up images that showed therapeutic response to penicillin

  15. 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

  16. Chest Computed Tomography (CT) Immediately after CT-Guided Transthoracic Needle Aspiration Biopsy as a Predictor of Overt Pneumothorax

    OpenAIRE

    Noh, Tae June; Lee, Chang Hoon; Kang, Young Ae; Kwon, Sung-Youn; Yoon, Ho-Il; Kim, Tae Jung; Lee, Kyung Won; Lee, Jae Ho; Lee, Choon-Taek

    2009-01-01

    Background/Aims This study examined the correlation between pneumothorax detected by immediate post-transthoracic needle aspiration-biopsy (TTNB) chest computed tomography (CT) and overt pneumothorax detected by chest PA, and investigated factors that might influence the correlation. Methods Adult patients who had undergone CT-guided TTNB for lung lesions from May 2003 to June 2007 at Seoul National University Bundang Hospital were included. Immediate post-TTNB CT and chest PA follow-up at 4 ...

  17. 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.

  18. 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、

  19. 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.

  20. Evaluation of the efficiency of bismuth breast shield in CT chest paediatric examinations

    International Nuclear Information System (INIS)

    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)

  1. Abnormal chest shadow on CT in immunosuppressed patients

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Nobuyuki; Matsumoto, Tsuneo; Nakamura, Hiroshi (Yamaguchi Univ., Ube (Japan). School of Medicine) (and others)

    1992-12-01

    An abnormal chest shadow was observed on CT scans in 25 cases of 23 immunosuppressed patients. Pulmonary disease was pathologically confirmed to be pneumocystis carinii pneumonia (PC pneumonia) in four patients, cytomegalovirus pneumonia (CMV pneumonia) in one, bacterial pneumonia in seven, fungal infection in three, miliary tuberculosis in one, leukemic infiltration in two, lymphangitis carcinomatosa in three, drug-induced pneumonitis in three, and ARDS in one. In almost all patients, especially those with infectious diseases such as PC pneumonia, CMV pneumonia, and bacterial pneumonia, the abnormal shadow was wide and visible in the bilateral lung fields. We presumed that such findings as lobular shadow, centrilobular shadow, and mosaic pattern reflected the extension of disease via the respiratory tract, and that those findings are typical of infectious diseases. Because such findings as abnormal linear shadow and swelling of a broncho-vascular bundle were very frequently recognized in patients with lymphangitis carcinomatosa and frequently recognized in those with drug-induced pneumonitis, these diseases may be distinguished from other diseases. An area of slightly increased density was frequently recognized in patients with PC pneumonia, bacterial pneumonia, and drug-induced pneumonitis. Such lesions were pathologically confirmed to be located in the interstitium and/or alveolus. CT was extremely useful in comprehending the character and extension of particular diseases among various diseases. As the number of patients studied was small, the utility of CT in immunosuppressed patients requires further investigation in a larger number of patients. (author).

  2. An audit of CT chest surveillance following oral cancer treatment.

    Science.gov (United States)

    Nugent, G; Hughes, T; Hanlon, R; Jones, H Lewis; Rogers, S N

    2016-07-01

    Computed tomography (CT) of the chest is an integral part of the staging of patients with oral cancer. It identifies metastases, synchronous pulmonary primaries, and detects small nodules of indeterminate character that require a follow-up scan. We aimed to find out how many patients with small nodules had had subsequent scans, and the outcome of those who did. Between 2010 and 2013, 413 patients with oral squamous cell carcinoma (SCC) were treated with curative intent or were actively monitored at the Merseyside and Cheshire Regional Surgical Head and Neck Unit. A total of 324 (78%) had CT at diagnosis. The scans of 246 were clear, metastases were detected in 4, and 51 showed abnormalities. Forty-nine of the patients with abnormalities were recommended for further interval scans but only 20 (41%) actually had them. Further pathological findings were found in 11 (increase in the size of the nodule n=2; metastatic disease n=5; and primary pulmonary tumour n=4). A substantial number of patients did not have the recommended follow-up scans and potentially serious disease was found in some who did. As a result of this audit we have changed the process regarding the booking of CT surveillance scans, and we now check periodically that they have been done. The audit will be repeated to include other sites in the head and neck. PMID:27156437

  3. Clinical utility of coronary CT angiography with low-dose chest CT in the evaluation of patients with atypical chest pain: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Soo Jin [Kimhae Bokum Hospital, Kimhae (Korea, Republic of); Choo, Ki Seok; Kim, Chang Won [Pusan National University Hospital, Busan (Korea, Republic of)] (and others)

    2008-04-15

    To determine the clinical utility of coronary CT angiography (CCTA) with low-dose chest CT in the evaluation of patients with atypical chest pain. Ninety-six patients (mean age 60.2 years; age range, 41-68 years; 70 males) were referred for CCTA with low-dose chest CT (16-slice MDCT, Siemens) for an evaluation of atypical chest pain. When significant stenoses (lumen diameter reduction > 50%) were detected on CCTA, invasive coronary angiography (CA) was performed as the standard of reference. In all patients, medical chart review or telephone contact with patients was used to evaluate the contribution of CCTA with low-dose chest CT to the final clinical diagnosis, at least 6 months after performing CCTA. Among 96 patients, seven patients (7%) had significant stenoses as detected on CCTA, whereas two patients (2%) had significant stenoses and five patients had insignificant stenoses or no stenosis, as detected on conventional catheter angiography. In 18 (19%) of the 89 patients without significant stenosis detected on CCTA, this protocol provided additional information that suggested or confirmed an alternate clinical diagnosis. In patients with atypical chest pain, CCTA with low-dose chest CT could help to exclude ischemic heart disease and could provide important ancillary information for the final diagnosis.

  4. 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.)

  5. 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.

  6. [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.

  7. 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.)

  8. 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.

  9. Children, CT Scan and Radiation

    OpenAIRE

    Morteza Bajoghli; Farshad Bajoghli; Nazila Tayari; Reza Rouzbahani

    2010-01-01

    Children are more sensitive to radiation than adults. Computer-ized tomography (CT) consists of 25 % of all medical imaging. It was estimated that more than 2% of all carcinomas in the USA are due to CT scans. There is an ongoing focus on the reduction of CT scan radiation dose. Awareness about risk-benefits of CT has increased. Reduction of radiological exam is an important issue because the accumulation effects of radiation can be hazardous. In addition, proper protocol should be followed f...

  10. 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.)

  11. 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.

  12. Children, CT scan and radiation

    Directory of Open Access Journals (Sweden)

    Morteza Bajoghli

    2010-01-01

    Full Text Available Children are more sensitive to radiation than adults. Computer-ized tomography (CT consists of 25 % of all medical imaging. It was estimated that more than 2% of all carcinomas in the USA are due to CT scans. There is an ongoing focus on the reduction of CT scan radiation dose. Awareness about risk-benefits of CT has increased. Reduction of radiological exam is an important issue because the accumulation effects of radiation can be hazardous. In addition, proper protocol should be followed for diagnostic pro-cedures of ionization radiation and computerized tomography. Effective radiation dose should range from 0.8 to 10.5 millisievert. The same protocol should be followed in different hospitals as well. Basic principles of radiation protection should be monitored. As much as possible, both technician and radiologist must be pre-sent during computerized tomography for children, and MRI and ultrasound should be replaced if possible.

  13. Role of Multidetector CT in Evaluation of Acute Chest Pain: Non-Cardiac Vascular and Pulmonary Causes

    Directory of Open Access Journals (Sweden)

    Rania S Sayed *, Hisham M Mansour **, Mohammad H Khaleel ***, Sherif H Abo Gamra ** and Merhan A Nasr

    2013-04-01

    Full Text Available Background: Triage of patients with acute chest pain is one of the most important issues currently facing physicians in the emergency department. Acute chest pain may be a symptom of a number of serious conditions and is generally considered a medical emergency. The causes of acute chest pain range from non-serious to life threatening. A rapid, accurate and cost-effective approach for the evaluation of emergency department patients with chest pain is needed. Aim of the work: This work aims to emphasize the role of multidetector CT in assessment of non-cardiac vascular and pulmonary causes of acute chest pain.Method: The studied group included 89 patients (59 men and 30 women presented by acute chest pain. All patients were subjected to MDCT and/or MDCT angiography using a Toshiba 64 detectors CT scanner. Results: The high spatial resolution and relatively non-invasive nature make MSCT angiography a strong and serious competitor to established vascular imaging techniques. Having the additional ability to simultaneously acquire information on other organs, which enables the early diagnosis of complications. Conclusion: Continued technical improvements in acquisition speed and spatial resolution of computed tomography images, and development of more efficient image reconstruction algorithms which reduce patient exposure to radiation and contrast result in increased popularity of MDCT.

  14. 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.

  15. 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.

  16. 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.

  17. Evaluation of variation of voltage (kV) absorbed dose in chest CT scans

    International Nuclear Information System (INIS)

    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

  18. 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.

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

    International Nuclear Information System (INIS)

    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

  20. 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

  1. Attenuation and image quality in the use of protective bismuth in chest CT scans

    International Nuclear Information System (INIS)

    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.

  2. 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)

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

    International Nuclear Information System (INIS)

    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

  4. 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.)

  5. Techniques and radiation dose in CT examinations of adult patients

    International Nuclear Information System (INIS)

    The use of CT in medical diagnosis delivers radiation dose to patients that are higher than those from other radiological procedures. Lake of optimized protocols could be an additional source of increased dose. The aim of this study was to measure radiation doses in CT examination of the adults in three Sudanese hospitals. Details were obtained from approximately 160 CT examination carried out in 3 hospitals (3 CT scanners). Effective dose was calculated for each examination using CT dose indices. exposure related parameters and CT D1- to- effective dose conversion factors. CT air kerma index (CT D1) and dose length products (DLP) determined were below the established international reference dose levels. The mean effective doses in this study for the head, chest, and abdomen are 0.82, 3.7 and 5.4 mGy respectively. These values were observed that the effective dose per examination was lower in Sudan than in other countries. The report of a CT survey done in these centers indicates that the mean DLP values for adult patients were ranged from 272-460 mGy cm (head) 195-995 mGy cm (chest), 270-459 mGy cm (abdomen). There are a number of observed parameters that greatly need optimization, such as minimize the scan length, without missing any vital anatomical regions, modulation of exposure parameters (kV, mA, exposure time, and slice thickness) based on patient size and age. Another possible method is through use of contrast media only to optimize diagnostic yield. The last possible method is the use of radio protective materials for protection however, in order to achieve the above optimization strategies: there is great demand to educate CT personnel on the effects of scan parameter settings on radiation dose to patients and image quality required for accurate diagnosis. (Author)

  6. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  8. Radiation dose optimization in CT planning of corrective scoliosis surgery. A phantom study.

    OpenAIRE

    Abul-Kasim, Kasim; Gunnarsson, Mikael; Maly, Pavel; Ohlin, Acke; Sundgren, Pia

    2008-01-01

    The aim of the study was to explore the possibility of obtaining a helical CT scan of a long segment of vertebral column, optimally reduce the radiation dose, compare the radiation dose of the low dose helical CT with that of some of the CT protocols used in clinical practice and finally assess the impact of such a dose reduction on the image quality. A chest phantom was examined with a 16-slice CT scanner. Six scans were performed with different radiation doses. The lowest radiation dose whi...

  9. Simple pulmonary eosinophilia (loeffler's syndrome): chest radiographic and CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung Jae; Lee, Kyung Soo; Kim, Tae Sung; Chung, Man Pyo; Choi, Dong Chull; Kwon, O Jung [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2000-01-01

    The purpose of our study is to describe the chest radiographic and CT findings of simple pulmonary eosinophilia. Twenty-six patients with simple pulmonary eosinophilia underwent chest radiography and CT scanning; the results were analyzed retrospectively by two chest radiologists, focusing on the patterns and distribution of the parenchymal abnormalities. The chest radiographs were normal in eight patients (31%), while among the remaining 18 patients, they showed subtle opacity (n=3D9), nodules (n=3D8), consolidation (n=3D2), and mass (n=3D1). Follow-up chest radiographs (m=3D18) demonstrated complete (n=3D16) or partial (n=3D1) resolution of parenchymal lesions or migratory lesions (n=3D1). On CT, nodule(s) (n=3D19) were most commonly seen, followed by ground-glass opacity (n=3D16), consolidation (n=3D3), and mass (n=3D1). A peripheral halo surrounding a nodule or an area of consolidation was seen in 18 patients. The nodules(s) (n=3D19) were subpleural (n=3D13) or random (=3D6). Areas of ground-glass opacity (n=3D16) were subpleural (n=3D13), random (n=3D2), or central (n=3D1). All lesions were patchy rather than diffuse. Follow-up CT in nine patients showed complete (n=3D7) or partial (n=3D2) resolution of parenchymal lesions. Chest radiographs of patients with simple pulmonary eosinophilia often reveal no abnormality. The most common finding is subtle opacity or nodule(s), while CT reveals transient nodule(s) with a surrounding halo or transient areas of ground glass opacity. (author)

  10. High-resolution chest CT in the evaluation of dyspneic smokers with pulmonary fibrosis and normal spirometry

    International Nuclear Information System (INIS)

    This paper evaluates the utility of high- resolution CT (HRCT) of the chest in dyspneic smokers who present with normal or near-normal spirometric measurement and a reduced diffusing capacity. Eight dyspneic smokers with near-normal spirometric measurements were imaged with a Picker Fastrac scanner. Prone 3-mm images and supine 10-mm images of the chest were obtained. All CT scans and concurrently obtained plain chest radiographs were reviewed by two chest radiologists and two pulmonologists. One outside CT scan and plain film of a ventilator-dependent, postpneumonectomy patient was also included

  11. 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

  12. 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

  13. Computer-Aided Segmentation and Volumetry of Artificial Ground-Glass Nodules at Chest CT

    NARCIS (Netherlands)

    Scholten, E.T.; Jacobs, C.; Ginneken, B. van; Willemink, M.J.; Kuhnigk, J.-M.; Ooijen, PM van; Oudkerk, M.; Mali, W.P.Th.; Jong, P.A. de

    2013-01-01

    OBJECTIVE. The purpose of this study was to investigate a new software program for semiautomatic measurement of the volume and mass of ground-glass nodules (GGNs) in a chest phantom and to investigate the influence of CT scanner, reconstruction filter, tube voltage, and tube current. MATERIALS AND M

  14. 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.

  15. 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.)

  16. Quantification of Emphysema with a Three-Dimensional Chest CT Scan: Correlation with the Visual Emphysema Scoring on Chest CT, Pulmonary Function Tests and Dyspnea Severity

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Jeong; Hwang, Jung Hwa [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2011-09-15

    We wanted to prospectively evaluate the correlation between the quantification of emphysema using 3D CT densitometry with the visual emphysema score, pulmonary function tests (PFT) and the dyspnea score in patients with chronic obstructive pulmonary disease (COPD). Non-enhanced chest CT with 3D reconstruction was performed in 28 men with COPD (age 54-88 years). With histogram analysis, the total lung volume, mean lung density and proportion of low attenuation lung volume below predetermined thresholds were measured. The CT parameters were compared with the visual emphysema score, the PFT and the dyspnea score. A low attenuation lung volume below -950 HU was well correlated with the DLco and FEV{sub 1}/FVC. A Low attenuation lung volume below -950 HU and -930 HU was correlated with visual the emphysema score. A low attenuation lung volume below -950 HU was correlated with the dyspnea score, although the correlations between the other CT parameters and the dyspnea score were not significant. Objective quantification of emphysema using 3D CT densitometry was correlated with the visual emphysema score. A low attenuation lung volume below -950 HU was correlated with the DLco, the FEV{sub 1}/FVC and the dyspnea score.

  17. Quantification of Emphysema with a Three-Dimensional Chest CT Scan: Correlation with the Visual Emphysema Scoring on Chest CT, Pulmonary Function Tests and Dyspnea Severity

    International Nuclear Information System (INIS)

    We wanted to prospectively evaluate the correlation between the quantification of emphysema using 3D CT densitometry with the visual emphysema score, pulmonary function tests (PFT) and the dyspnea score in patients with chronic obstructive pulmonary disease (COPD). Non-enhanced chest CT with 3D reconstruction was performed in 28 men with COPD (age 54-88 years). With histogram analysis, the total lung volume, mean lung density and proportion of low attenuation lung volume below predetermined thresholds were measured. The CT parameters were compared with the visual emphysema score, the PFT and the dyspnea score. A low attenuation lung volume below -950 HU was well correlated with the DLco and FEV1/FVC. A Low attenuation lung volume below -950 HU and -930 HU was correlated with visual the emphysema score. A low attenuation lung volume below -950 HU was correlated with the dyspnea score, although the correlations between the other CT parameters and the dyspnea score were not significant. Objective quantification of emphysema using 3D CT densitometry was correlated with the visual emphysema score. A low attenuation lung volume below -950 HU was correlated with the DLco, the FEV1/FVC and the dyspnea score.

  18. The measurement of organic radiation dose of multi-slice CT scanning by using the Chinese anthropomorphic chest phantom%中国人仿真胸部体模检测多层螺旋CT扫描组织器官剂量的研究

    Institute of Scientific and Technical Information of China (English)

    彭刚; 曾勇明; 罗天友; 赵峰; 张志伟; 郁仁强; 彭盛坤

    2011-01-01

    目的 利用中国人仿真胸部模型来测量不同噪声指数下胸部各组织器官的吸收剂量,计算有效剂量(ED)并对MSCT胸部扫描进行剂量评估.方法 对CDP-1C型中国人仿真胸部体模在CT体层解剖和X线衰减两方面进行等效性论证;通过在体模内布放热释光剂量计(TLD)来测量不同噪声水平下各组织器官的吸收剂量,并记录相应的剂量长度乘积(DLP);将两者分别换算为ED后选择单因素t检验方法进行对比研究,分析自动管电流调制(ATCM)技术时不同噪声指数胸部CT扫描的剂量水平.结果 中国人仿真胸部体模与成人CT胸部图像的结构相似.体模主要器官平均CT值为肺-788.04 HU、心脏45.64 HU、肝脏65.84 HU、脊柱254.32 HU,与成人偏差程度分别为肺0.10%、心脏3.04%、肝脏4.49%、脊柱4.36%.肝脏的平均CT值差异有统计学意义(t=-8.705,P<0.05);肺、心脏和脊柱平均CT值与人体差异无统计学意义(t值分别为-0.752、-1.219、-1.138,P>0.05).当噪声指数从8.5逐渐增至22.5时,DLP从393.57 mGy·cm递减至78.75 mGy·cm,各器官吸收剂量呈下降趋势(以肺为例,平均吸收剂量从22.38 mGy递减至3.66 mGy).应用DLP所计算的ED较器官吸收剂量计算的ED偏低(以噪声指数为8.5为例,两种方法的ED分别为6.69和8.77 mSv).结论 应用中国人仿真体模来进行CT剂量评估更为准确;基于ATCM技术的胸部CT扫描噪声指数设定至少应大于8.5.%Objective Using the Chinese anthropomorphic chest phantom to measure the absorbed dose of various tissues and organs under different noise index, and to assess the radiation dose of MSCT chest scanning with the effective dose(ED). Methods The equivalence of the Chinese anthropomorphic chest phantom(CDP-1C) and the adult chest on CT sectional anatomy and X-ray attenuation was demonstrated. The absorbed doses of various tissues and organs under different noise index were measured by laying thermoluminescent

  19. 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.

  20. Evaluation of automated attenuation-based tube potential selection in combination with organ-specific dose reduction for contrast-enhanced chest CT examinations

    International Nuclear Information System (INIS)

    Aim: To evaluate the influence of attenuation-based tube potential selection (ATPS) in combination with organ-specific dose reduction (OSDR) on radiation dose and image quality of contrast-enhanced chest computed tomography (CT) examinations. Material and methods: Seventy consecutive patients (59.2 ± 16.1 years; 49 men; 21 women) were randomized into two groups and underwent contrast-enhanced chest CT using a 128 section CT scanner. CT examinations were performed as standard protocol in group A (n = 35) and with the activated novel dose-saving devices, OSDR and ATPS, in group B (n = 35). Objective [signal-to-noise (SNR) and contrast-to-noise ratio (CNR)] and subjective image quality (five-point scale; 1 = non diagnostic; 5 = excellent) as well as radiation dose (CTDIvol) were analysed. Results: CTDIvol of the protocol using OSDR and ATPS was significantly lower than in standard chest CT examinations (3.4 ± 1 versus 6.1 ± 2.3 mGy; p < 0.001). Although the level of noise was slightly elevated in group B (14.1 ± 1.7 versus 11.4 ± 1.9 HU; p < 0.01), no significant differences in SNR (17.1 ± 5 versus 16.3 ± 4.7) or subjective image quality (mean score of 4.6 versus 4.4) were observed between both imaging protocols. Conclusion: Attenuation-based tube potential selection in combination with organ-specific dose reduction essentially reduces the dose of chest CT in patients with normal body mass index (BMI) in clinical routine while maintaining subjective and objective image quality. - Highlights: • ATPS in combination with OSDR essentially reduces radiation exposure in chest CT. • ATPS combined with OSDR does not compromise image quality of chest CT examinations. • ATPS and OSDR can be recommended for clinical routine

  1. Association between Image Characteristics on Chest CT and Severe Pleural Adhesion during Lung Cancer Surgery.

    Directory of Open Access Journals (Sweden)

    Kwang Nam Jin

    Full Text Available The aim of this study was to investigate the association between image characteristics on preoperative chest CT and severe pleural adhesion during surgery in lung cancer patients. We included consecutive 124 patients who underwent lung cancer surgeries. Preoperative chest CT was retrospectively reviewed to assess pleural thickening or calcification, pulmonary calcified nodules, active pulmonary inflammation, extent of emphysema, interstitial pneumonitis, and bronchiectasis in the operated thorax. The extent of pleural thickening or calcification was visually estimated and categorized into two groups: localized and diffuse. We measured total size of pulmonary calcified nodules. The extent of emphysema, interstitial pneumonitis, and bronchiectasis was also evaluated with a visual scoring system. The occurrence of severe pleural adhesion during lung cancer surgery was retrospectively investigated from the electrical medical records. We performed logistic regression analysis to determine the association of image characteristic on chest CT with severe pleural adhesion. Localized pleural thickening was found in 8 patients (6.5%, localized pleural calcification in 8 (6.5%, pulmonary calcified nodules in 28 (22.6%, and active pulmonary inflammation in 22 (17.7%. There was no patient with diffuse pleural thickening or calcification in this study. Trivial, mild, and moderate emphysema was found in 31 (25.0%, 21 (16.9%, and 12 (9.7% patients, respectively. Severe pleural adhesion was found in 31 (25.0% patients. The association of localized pleural thickening or calcification on CT with severe pleural adhesion was not found (P = 0.405 and 0.107, respectively. Size of pulmonary calcified nodules and extent of emphysema were significant variables in a univariate analysis (P = 0.045 and 0.005, respectively. In a multivariate analysis, moderate emphysema was significantly associated with severe pleural adhesion (odds ratio of 11.202, P = 0.001. In conclusion

  2. A case of radiation ulcer of chest wall with osteomyelitis

    International Nuclear Information System (INIS)

    We report a case of anterior chest skin ulcer with rib and sternum osteomyelitis following radiation therapy for post operative mammary carcinoma. Operation was performed six times including debridement with sternum and rib resection reconstruction and skin grafting. It took about one and a half years after first operation to heal the ulcer with osteomyelitis. Principle of treatment for radiation ulcer accompanied by osteomyelitis is complete resection of the damaged lesion. However, it is difficult to evaluate the exact area of the damaged lesion. Therefore it is not rare to repeat its recurrence and have trouble with its treatment. In this case, it was considered that the resected area was insufficient on the initial operation. In order to treat for radiation ulcers accompanied by osteomyelitis, enough resection of the damaged lesion in the initial operation is necessary. Ultimately, in our case, the resection of all sternum, part of the right second to fifth rib and part of left second to seventh rib was necessary. It is generally said that reconstructing bone structure is required in the case of wide defect of chest wall. Though, we did not perform reconstruction of the bone structures, there is no problem in the condition of respiratory system. The surrounding soft tissues changed to hard enough to avoid paradoxical breathing. (author)

  3. Radiation Load of Children by Chest Radiodiagnostic Measurements

    International Nuclear Information System (INIS)

    Radiodiagnostic examinations of children present particular importance from the radiation hygiene point of view. The estimation of the radiation load of pediatric patient is not easy, because of the lack of information about organ weighting factors for various ages of patients, as well as due to the differences in applied X-ray examination parameters. In the district of Slovak Republic, in which also the working Nuclear Power Plant Jaslovske Bohunice is included, efforts were done to estimate the radiation load of children to 15 years by chest radiodiagnostic examinations. The data of entrance surface doses were collected using measurements with TLD for 100 patients divided in 5 age categories at six radiodiagnostic departments. The calculations of the total absorbed dose were performed using the measured ESD values (entrance surface dose in mGy) integrated over the X-ray beam area, the conversion factors between the imparted energy and the dose-area product and the known irradiation parameters (kV, HVL, mass, etc.). The analysis of the obtained absorbed doses (Ea) as a function of age for chest PA radiodiagnostic examinations has shown, that the investigated Slovak radiodiagnostic centres use rather lower voltage techniques and the entrance surface doses are much higher than the proposed value of European Communities. (author)

  4. Where Does It Lead? Imaging Features of Cardiovascular Implantable Electronic Devices on Chest Radiograph and CT

    Energy Technology Data Exchange (ETDEWEB)

    Lanzman, Rotem S.; Blondin, Dirk; Furst, Gunter; Scherer, Axel; R Miese, Falk; Kroepil, Patric [University of Duesseldorf, Medical Faculty, 40225 Duesseldorf (Germany); Winter, Joachim [University Hospital Duesseldorf, 40225 Duesseldorf (Germany); Abbara, Suhny [Massachusetts General Hospital, Boston, MA (US)

    2011-10-15

    Pacemakers and implantable cardioverter defibrillators (ICDs) are being increasingly employed in patients suffering from cardiac rhythm disturbances. The principal objective of this article is to familiarize radiologists with pacemakers and ICDs on chest radiographs and CT scans. Therefore, the preferred lead positions according to pacemaker types and anatomic variants are introduced in this study. Additionally, the imaging features of incorrect lead positions and defects, as well as complications subsequent to pacemaker implantation are demonstrated herein.

  5. Where Does It Lead? Imaging Features of Cardiovascular Implantable Electronic Devices on Chest Radiograph and CT

    OpenAIRE

    Lanzman, Rotem S.; Winter, Joachim; Blondin, Dirk; Fürst, Günter; Scherer, Axel; Miese, Falk R; Abbara, Suhny; Kröpil, Patric

    2011-01-01

    Pacemakers and implantable cardioverter defibrillators (ICDs) are being increasingly employed in patients suffering from cardiac rhythm disturbances. The principal objective of this article is to familiarize radiologists with pacemakers and ICDs on chest radiographs and CT scans. Therefore, the preferred lead positions according to pacemaker types and anatomic variants are introduced in this study. Additionally, the imaging features of incorrect lead positions and defects, as well as complica...

  6. Low grade coal worker's pneumoconiosis. Comparison of CT and chest radiography

    International Nuclear Information System (INIS)

    We compared CT with chest radiography (CR) in the assessment of low grade coal worker's pneumoconiosis (CWP) in a population of 83 subjects. All subjects had a high-voltage p.a. CR, graded according to the ILO classification between 0/0 and 1/1, a conventional CT (CCT) using contiguous 1-cm-thick sections on the entire thorax and a set of 10 high-resolution CT (HRCT) images. CR and CT were separately read by consensus by 2 teams of 2 trained readers. CR were coded 0/0 in 9 subjects; 0/1 in 31; 1/0 in 28; 1/1 in 15. Among these groups of patients, micronodules were detected by CT in respectively 2 (22%), 14 (45%), 17 (61%) and 10 (67%) patients. In all groups, micronodules were more often detected by CT when the opacities detected on CR were scored as rounded (p, q) than irregular (s, t). Among the patients graded 0/0 or 0/1, CT showed micronodules in 40%. By contrast, among the patients graded 1/0 or 1/1, CT did not show micronodules in 37%, but revealed in numerous patients that opacities detected on CR were related to bronchiectasis and/or emphysema only. Comparative analysis of HRCT and CCT showed that both techniques are complementary and proved the usefulness of CCT in the detection or confirmation of low profusion of micronodules. (orig.)

  7. Classification of pulmonary emphysema from chest CT scans using integral geometry descriptors

    Science.gov (United States)

    van Rikxoort, E. M.; Goldin, J. G.; Galperin-Aizenberg, M.; Brown, M. S.

    2011-03-01

    To gain insight into the underlying pathways of emphysema and monitor the effect of treatment, methods to quantify and phenotype the different types of emphysema from chest CT scans are of crucial importance. Current standard measures rely on density thresholds for individual voxels, which is influenced by inspiration level and does not take into account the spatial relationship between voxels. Measures based on texture analysis do take the interrelation between voxels into account and therefore might be useful for distinguishing different types of emphysema. In this study, we propose to use Minkowski functionals combined with rotation invariant Gaussian features to distinguish between healthy and emphysematous tissue and classify three different types of emphysema. Minkowski functionals characterize binary images in terms of geometry and topology. In 3D, four Minkowski functionals are defined. By varying the threshold and size of neighborhood around a voxel, a set of Minkowski functionals can be defined for each voxel. Ten chest CT scans with 1810 annotated regions were used to train the method. A set of 108 features was calculated for each training sample from which 10 features were selected to be most informative. A linear discriminant classifier was trained to classify each voxel in the lungs into a subtype of emphysema or normal lung. The method was applied to an independent test set of 30 chest CT scans with varying amounts and types of emphysema with 4347 annotated regions of interest. The method is shown to perform well, with an overall accuracy of 95%.

  8. 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

  9. 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.

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

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    Graham L Hall

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

  12. 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

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

    Science.gov (United States)

    Phillips, Michael; Bauer, Thomas L.; Cataneo, Renee N.; Lebauer, Cassie; Mundada, Mayur; Pass, Harvey I.; Ramakrishna, Naren; Rom, William N.; Vallières, Eric

    2015-01-01

    Background 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. Methods 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. Results 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. Conclusions Breath VOC mass ion biomarkers identified lung cancer in a

  14. 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.

  15. A study of chest CT examinations by 8 DAS multi detector row CT

    International Nuclear Information System (INIS)

    High-resolution CT images of 1.25 mm in slice thickness and routine images of 7.5 mm in slice thickness are usually obtained for lung examinations in our hospital. However these can't be obtained in one scan, and lead to increase CT dose. We considered that we could obtain their images in one scan and could decrease CT dose, if we scan the whole lung field by detector row 1.25 mm. We confirmed availability of thin detector row scans in consideration of Slice Sensitivity Profiles in z-direction (SSPz) and Standard Deviation (SD), and CT Dose Index (CTDI) under each condition. (author)

  16. Radiation exposure in CT-guided interventions

    International Nuclear Information System (INIS)

    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

  17. 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.

  18. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  20. Proton MRI in the evaluation of pulmonary sarcoidosis: Comparison to chest CT

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to determine the feasibility of proton MRI of the lung in sarcoidosis patients and the agreement between the imaging appearance of pulmonary sarcoidosis on MRI and CT. Materials and methods: Chest CT scans and dedicated pulmonary MRI scans (including HASTE, VIBE, and TrueFISP sequences) were performed within 90 days of each other in 29 patients. The scans were scored for gross parenchymal opacification, reticulation, nodules, and masses using a 3-point lobar scale. Total and subset scores for corresponding MRI and CT scans were compared using the Spearman correlation test, Bland–Altman plots, and Cohen's quadratic-weighted kappa analysis. MRI scores were compared to CT by lobe and disease category, using percentage agreement, Spearman rank correlation, and Cohen's quadratic-weighted kappa. Results: The mean (±s.d.) time between MRI and CT scans was 33 ± 32 days. There was substantial correlation and agreement between total disease scoring on MRI and CT with a Spearman correlation coefficient of 0.774 (p < 0.0001) and a Cohen's weighted kappa score of 0.646. Correlation and agreement were highest for gross parenchymal opacification (0.695, 0.528) and reticulation (0.609, 0.445), and lowest in the setting of nodules (0.501, 0.305). Agreement testing was not performed for mass scores due to low prevalence. Upper lobe scoring on MRI and CT demonstrated greater agreement compared to the lower lobes (average difference in Cohen's weighted kappa score of 0.112). Conclusion: There is substantial correlation and agreement between MRI and CT in the scoring of pulmonary sarcoidosis, though MRI evaluation in the upper lobes may be more accurate than in the lower lobes

  1. Influenza A (H1N1) pneumonia: an analysis of 63 cases by chest CT

    Institute of Scientific and Technical Information of China (English)

    LI Min; ZHU Jian-bing; CHEN Guang-qiang; YANG Wei-ye; TAO Cheng; WANG Xiao-hui

    2011-01-01

    Background In early April 2009,cases of human infection with 2009 pandemic influenza A (H1N 1) virus were identified in Mexico.The virus then spread rapidly to other regions of the world.From October 2009,sporadic imported cases of novel influenza A (H1N1) were continuously confirmed in Suzhou.The aim of the study was to review the chest CT findings in 63 patients with laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection.Methods Chest CT examinations were collected from 63 S-OIV infected patients during their hospital stay.Three experienced radiologists inspected images to qualitatively and quantitatively characterize S-OIV induced image changes.CT scores of lesion severity were calculated based on the percentage of affected area to determine severity of infectious lesions.Patients were divided into two groups based on the leukocyte counts.Lesion patterns,local distributions,and quantitative measures were investigated and compared between the two groups.Results Various degrees of bilateral multifocal lesions of ground-glass opacities were found with or without consolidations on the chest CT images.The lesions were both bronchocentric and centrilobular.Patients with elevated leukocyte counts had more extensive lesions,in terms of severity and affected area,than the patients with normal leukocyte counts.The lesion severity scores of patients in the elevated leukocyte group were significantly higher than those of the normal leukocyte group in terms of the entire lung area (P <0.01),and upper (P <0.05) and lower (P <0.01)lobes as well.There were changes in the CT characteristics seen at follow-up as demonstrated by lesions absorption (P<0.01),especially in the upper lobe of the lung (P <0.01),but less so in the middle lobe/lingual and lower lobe of the lung (P>0.05).Conclusions The most common CT findings in S-OIV infection patients were bilateral multifocal distributed ground-glass opacities and consolidations.The lesions were

  2. Comparison between plain chest film and CT in estimating the size of pneumothorax

    International Nuclear Information System (INIS)

    Regarding the patients diagnosed as having traumatic and spontaneous pneumothorax at our emergency center within the past 6 years we examined the distribution of pneumothorax shown by plain chest film and CT, and compared the pneumothorax rate evaluated by Kircher's method with plain chest film and that by one slice method with CT, which was based on full slice integration method with CT. Occult pneumothorax was found in 47.6% of traumatic cases and 11.1% of spontaneous cases. The distribution of pneumothoraces showed no significant differences. However, as compared with classical pneumothorax, the ratio of pneumothoraces in the apicolateral recess in the occult pneumothoraces tended to be lower, whereas the ratio of the ones in the anteromedial recess and in the subpulmonic recess tended to be comparatively high. The plain chest film of occult pneumothorax had been taken on supine position in most cases of traumatic pneumothorax and in more than half the cases of spontaneous pneumothorax. This was considered to be the cause of the unique distribution of pneumothorax. The pneumothorax rate evaluated by Kircher's method tended to be underestimated in comparison with the basic rate, where the correlation coefficient was R=0.84 for traumatic pneumothorax and R=0.14 for spontaneous pneumothorax. Especially in the cases of low pneumothorax rate the correlation was poor. The pneumothorax rate calculated by one slice method produced better figures with the correlation coefficient of R=0.92 for traumatic pneumothorax and R=0.85 for spontaneous pneumothorax. The one slice method was considered to be effective in evaluation of the degree of serious cases, and also for the choice of treatment modality for pneumothorax. (author)

  3. Comparison between plain chest film and CT in estimating the size of pneumothorax

    Energy Technology Data Exchange (ETDEWEB)

    Seto, Yuichi [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1995-08-01

    Regarding the patients diagnosed as having traumatic and spontaneous pneumothorax at our emergency center within the past 6 years we examined the distribution of pneumothorax shown by plain chest film and CT, and compared the pneumothorax rate evaluated by Kircher`s method with plain chest film and that by one slice method with CT, which was based on full slice integration method with CT. Occult pneumothorax was found in 47.6% of traumatic cases and 11.1% of spontaneous cases. The distribution of pneumothoraces showed no significant differences. However, as compared with classical pneumothorax, the ratio of pneumothoraces in the apicolateral recess in the occult pneumothoraces tended to be lower, whereas the ratio of the ones in the anteromedial recess and in the subpulmonic recess tended to be comparatively high. The plain chest film of occult pneumothorax had been taken on supine position in most cases of traumatic pneumothorax and in more than half the cases of spontaneous pneumothorax. This was considered to be the cause of the unique distribution of pneumothorax. The pneumothorax rate evaluated by Kircher`s method tended to be underestimated in comparison with the basic rate, where the correlation coefficient was R=0.84 for traumatic pneumothorax and R=0.14 for spontaneous pneumothorax. Especially in the cases of low pneumothorax rate the correlation was poor. The pneumothorax rate calculated by one slice method produced better figures with the correlation coefficient of R=0.92 for traumatic pneumothorax and R=0.85 for spontaneous pneumothorax. The one slice method was considered to be effective in evaluation of the degree of serious cases, and also for the choice of treatment modality for pneumothorax. (author).

  4. 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.)

  5. 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.)

  6. Automated quantification of bronchiectasis, airway wall thickening and lumen tapering in chest CT

    DEFF Research Database (Denmark)

    Perez-Rovira, Adria; Kuo, Wieying; Petersen, Jens;

    were obtained using a fully automatic, in-house developed, segmentation method. Subsequently, for each detected airway branch, the Airway-Artery Ratio (AAR, ratio between airway outer wall and accompanying artery radius, a bronchiectasis measurement), Wall-Artery Ratio (WAR, ratio between airway wall...... measurement for each subject. Results: Spirometer-guided inspiratory chest CTs of 12 CF patients (median age 10.6 years, 5 females) and 12 age and gender matched controls - lungs evaluated as normal on CT - (median age 12.4 years, 5 females) were retrospectively selected in the Sophia Children’s Hospital.......632, pdetect and quantify CF-related structural changes of the airways....

  7. Automated detection system for pulmonary emphysema on 3D chest CT images

    Science.gov (United States)

    Hara, Takeshi; Yamamoto, Akira; Zhou, Xiangrong; Iwano, Shingo; Itoh, Shigeki; Fujita, Hiroshi; Ishigaki, Takeo

    2004-05-01

    An automatic extraction of pulmonary emphysema area on 3-D chest CT images was performed using an adaptive thresholding technique. We proposed a method to estimate the ratio of the emphysema area to the whole lung volume. We employed 32 cases (15 normal and 17 abnormal) which had been already diagnosed by radiologists prior to the study. The ratio in all the normal cases was less than 0.02, and in abnormal cases, it ranged from 0.01 to 0.26. The effectiveness of our approach was confirmed through the results of the present study.

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

    International Nuclear Information System (INIS)

    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

  11. Three-dimensional automatic computer-aided evaluation of pleural effusions on chest CT images

    Science.gov (United States)

    Bi, Mark; Summers, Ronald M.; Yao, Jianhua

    2011-03-01

    The ability to estimate the volume of pleural effusions is desirable as it can provide information about the severity of the condition and the need for thoracentesis. We present here an improved version of an automated program to measure the volume of pleural effusions using regular chest CT images. First, the lungs are segmented using region growing, mathematical morphology, and anatomical knowledge. The visceral and parietal layers of the pleura are then extracted based on anatomical landmarks, curve fitting and active contour models. The liver and compressed tissues are segmented out using thresholding. The pleural space is then fitted to a Bezier surface which is subsequently projected onto the individual two-dimensional slices. Finally, the volume of the pleural effusion is quantified. Our method was tested on 15 chest CT studies and validated against three separate manual tracings. The Dice coefficients were 0.74+/-0.07, 0.74+/-0.08, and 0.75+/-0.07 respectively, comparable to the variation between two different manual tracings.

  12. 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.

  13. 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

  14. 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.

  15. 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)

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

    International Nuclear Information System (INIS)

    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 FEV1/FVC ratio 69.7±12.7%, mean MEF25 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 DLCO 57.4±21.2 and 52.0±8.0%). Significant correlation (pCO (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.)

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

    International Nuclear Information System (INIS)

    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 cm2, 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

  18. CT evaluation of pulmonary parenchymal injury due to blunt chest trauma and its clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Niimi, Hiroshi (St. Marianna University School of Medicine, Kawasaki, Kanagawa (Japan))

    1990-10-01

    The CT findings of pulmonary parenchymal injury due to blunt chest trauma in 73 patients and their clinical significance were analyzed. CT was obtained within 6 hours after trauma. Findings were analyzed according to the number of injured segments and severity which was classified into three grades. A correlation was also made with arterial blood PaO{sub 2} and thoracic complications. Pulmonary parenchymal injury was identified in multisegmental portions bilaterally in most cases. It was most frequently observed in the posterior portion of the lung such as segment 6. More than 50% of lesions were classified as Grade 1. Pulmonary laceration, defined as patchy density with the cavitary lesion (Grade 3), was noted in 9.2%. There was a good correlation between extent of pulmonary injury and degree of hypoxia. The correlation of pneumothorax was also found with extensive lesion and frequency of Grade 3 lesion. Cases with pulmonary laceration tend to have extensive injury, and be related to the degree of hypoxia. In conclusion, CT evaluation of pulmonary parenchymal injury is valuable not only for morphological evaluation but also for estimation of hypoxia. (author).

  19. 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.

  20. Ultra low-dose chest CT using filtered back projection: Comparison of 80-, 100- and 120 kVp protocols in a prospective randomized study

    Energy Technology Data Exchange (ETDEWEB)

    Khawaja, Ranish Deedar Ali, E-mail: rkhawaja@mgh.harvard.edu [Division of Thoracic Radiology, MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston (United States); Singh, Sarabjeet [Division of Thoracic Radiology, MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston (United States); Madan, Rachna [Division of Thoracic Radiology, Brigham and Women' s Hospital and Harvard Medical School, Boston (United States); Sharma, Amita; Padole, Atul; Pourjabbar, Sarvenaz; Digumarthy, Subba; Shepard, Jo-Anne; Kalra, Mannudeep K. [Division of Thoracic Radiology, MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston (United States)

    2014-10-15

    Highlights: • Filtered back projection technique enables acceptable image quality for chest CT examinations at 0.9 mGy (estimated effective dose of 0.5 mSv) for selected sizes of patients. • Lesion detection (such as solid non-calcified lung nodules) in lung parenchyma is optimal at 0.9 mGy, with limited visualization of thyroid nodules in FBP images. • Further dose reduction down to 0.4 mGy is possible for most patients undergoing follow-up chest CT for evaluation of larger lung nodules and GGOs. • Our results may help set the reference ALARA dose for chest CT examinations reconstructed with filtered back projection technique using the minimum possible radiation dose with acceptable image quality and lesion detection. - Abstract: Purpose: To assess lesion detection and diagnostic image quality of filtered back projection (FBP) reconstruction technique in ultra low-dose chest CT examinations. Methods and materials: In this IRB-approved ongoing prospective clinical study, 116 CT-image-series at four different radiation-doses were performed for 29 patients (age, 57–87 years; F:M – 15:12; BMI 16–32 kg/m{sup 2}). All patients provided written-informed-consent for the acquisitions of additional ultra low-dose (ULD) series on a 256-slice MDCT (iCT, Philips Healthcare). In-addition to their clinical standard-dose chest CT (SD, 120 kV mean CTDI{sub vol}, 6 ± 1 mGy), ULD-CT was subsequently performed at three-dose-levels (0.9 mGy [120 kV]; 0.5 mGy [100 kV] and 0.2 mGy [80 kV]). Images were reconstructed with FBP (2.5 mm * 1.25 mm) resulting into four-stacks: SD-FBP (reference-standard), FBP{sub 0.9}, FBP{sub 0.5}, and FBP{sub 0.2}. Four thoracic-radiologists from two-teaching-hospitals independently-evaluated data for lesion-detection and visibility-of-small-structures. Friedman's-non-parametric-test with post hoc Dunn's-test was used for data-analysis. Results: Interobserver-agreement was substantial between radiologists (k = 0.6–0.8). With

  1. 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. PMID:26262345

  2. 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.

  3. 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

    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...... to treatment guided by either coronary CTA or standard care (bicycle exercise electrocardiogram or myocardial perfusion imaging). In the coronary CTA-guided group, a functional test was included in cases of nondiagnostic coronary CTA images or coronary stenoses of borderline severity. The primary endpoint...... electrocardiograms and troponin values compared to standard care with a functional test. (Cardiac-CT in the Treatment of Acute Chest Pain [CATCH]; NCT01534000)....

  4. 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.)

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

    International Nuclear Information System (INIS)

    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 CTDIvol 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.)

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

    NARCIS (Netherlands)

    C. Wang (Cathy); G.H. de Bock (Geertruida); R.J. van Klaveren (Rob); P. van Ooyen (Peter); W. Tukker (Wim); Y. Zhao (Yingru); M.D. Dorrius (Monique); R.V. Proença; W.J. Post (Wendy); M. Oudkerk (Matthijs)

    2010-01-01

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

  7. Chest wall deformity and respiratory distress in a 17-year-old patient with achondroplasia: CT and MRI evaluation

    International Nuclear Information System (INIS)

    A marked thoracic deformity associated with intrathoracic tracheal narrowing was seen in a 17-year old with achondroplasia and dyspnea. The role of chest deformity and its evaluation by CT and MRI in achondroplastic patients with respiratory symptoms are considered. (orig.)

  8. Image Subtraction Facilitates Assessment of Volume and Density Change in Ground-Glass Opacities in Chest CT

    NARCIS (Netherlands)

    M. Staring; J.P.W. Pluim; B. de Hoop; S. Klein; B. van Ginneken; H. Gietema; G. Nossent; C. Schaefer-Prokop; S. van de Vorst; M. Prokop

    2009-01-01

    OBJECTIVES:: To study the impact of image subtraction of registered images on the detection of change in pulmonary ground-glass nodules identified on chest CT. MATERIALS AND METHODS:: A cohort of 33 individuals (25 men, 8 women; age range 51-75 years) with 37 focal ground-glass opacities (GGO) were

  9. Image subtraction facilitates assessment of volume and density change in ground-glass opacities in chest CT.

    NARCIS (Netherlands)

    Staring, M.; Pluim, J.P.; Hoop, B. de; Klein, S.; Ginneken, B. van; Gietema, H.; Nossent, G.; Schaefer-Prokop, C.M.; Vorst, S. van de; Prokop, M.

    2009-01-01

    OBJECTIVES: To study the impact of image subtraction of registered images on the detection of change in pulmonary ground-glass nodules identified on chest CT. MATERIALS AND METHODS: A cohort of 33 individuals (25 men, 8 women; age range 51-75 years) with 37 focal ground-glass opacities (GGO) were re

  10. Radiodiagnostic measurements radiation load of children by chest

    International Nuclear Information System (INIS)

    With the aim of optimisation of the radiographic examinations in paediatric radiology the entrance surface doses measured by chest examinations, as the most frequent procedure for children in Slovakia were surveyed. In this paper the results of measurements and calculations of doses obtained by paediatric patients with ages ranging from newborn to 15 years, who undergone chest radiodiagnostic examinations during the year 1996 are presented.. The obtained results are compared with dose assessment procedures based on total absorbed dose calculations using the published conversion factors between energy impaired to the patient and and entrance surface doses integrated over the beam area

  11. Radiation Exposure in X-Ray and CT Examinations

    Science.gov (United States)

    ... A-Z Radiation Dose in X-Ray and CT Exams What are x-rays and what do ... natural background radiation for: ABDOMINAL REGION: Computed Tomography (CT)-Abdomen and Pelvis 10 mSv 3 years Computed ...

  12. Estimated radiation exposure and cancer risk from CT and PET/CT scans in patients with lymphoma

    International Nuclear Information System (INIS)

    Introduction: The purpose of this study was to estimate total effective dose and cancer risk related to treatment monitoring and surveillance computed tomography (CT) scans in a cohort of patients diagnosed with lymphoma. Methods: 76 patients with head, neck, chest, abdomen or pelvis CT and whole-body positron emission tomography (PET)/CT were identified from an institutional lymphoma database; this included 54 (71%) patients with non-Hodgkin and 22 (29%) patients with classical Hodgkin lymphoma. Average treatment and surveillance periods were 8 months (range, 3–14 mo) and 23 months (range, 1–40 mo), respectively. Radiation exposure was estimated from the dose-length product (DLP) for CT scans and milli-Curies and DLP for PET/CT scans. Cancer risk was estimated using the Biological Effects of Ionizing Radiation model. Results: During their treatment period, 45 patients had 161 CT exams and 39 patients had 73 PET/CT exams. Mean effective dose was 39.3 mSv (range, 7.1–100 mSv). During the surveillance period, 60 patients had 378 CT exams and 25 patients had 39 PET/CT exams. Mean effective dose was 53.2 mSv (range, 2.6–154 mSv). Seventeen of 76 (22.4%) patients had total cumulative doses greater than 100 mSv. The mean increase in estimated cancer risk was 0.40%; the greatest estimated risk to any one patient was 1.19%. Conclusion: Mean total effective dose and mean estimated cancer risk were low in patients with lymphoma undergoing serial imaging, suggesting that theoretical risks of radiation-induced cancer need not be a major consideration in radiologic follow-up

  13. Estimated radiation exposure and cancer risk from CT and PET/CT scans in patients with lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Guttikonda, Ravi [Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Herts, Brian R., E-mail: hertsb@ccf.org [Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Dong, Frank [Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Baker, Mark E. [Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Fenner, Kathleen B.; Pohlman, Brad [Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195 (United States)

    2014-06-15

    Introduction: The purpose of this study was to estimate total effective dose and cancer risk related to treatment monitoring and surveillance computed tomography (CT) scans in a cohort of patients diagnosed with lymphoma. Methods: 76 patients with head, neck, chest, abdomen or pelvis CT and whole-body positron emission tomography (PET)/CT were identified from an institutional lymphoma database; this included 54 (71%) patients with non-Hodgkin and 22 (29%) patients with classical Hodgkin lymphoma. Average treatment and surveillance periods were 8 months (range, 3–14 mo) and 23 months (range, 1–40 mo), respectively. Radiation exposure was estimated from the dose-length product (DLP) for CT scans and milli-Curies and DLP for PET/CT scans. Cancer risk was estimated using the Biological Effects of Ionizing Radiation model. Results: During their treatment period, 45 patients had 161 CT exams and 39 patients had 73 PET/CT exams. Mean effective dose was 39.3 mSv (range, 7.1–100 mSv). During the surveillance period, 60 patients had 378 CT exams and 25 patients had 39 PET/CT exams. Mean effective dose was 53.2 mSv (range, 2.6–154 mSv). Seventeen of 76 (22.4%) patients had total cumulative doses greater than 100 mSv. The mean increase in estimated cancer risk was 0.40%; the greatest estimated risk to any one patient was 1.19%. Conclusion: Mean total effective dose and mean estimated cancer risk were low in patients with lymphoma undergoing serial imaging, suggesting that theoretical risks of radiation-induced cancer need not be a major consideration in radiologic follow-up.

  14. 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.

  15. 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.

  16. Distribution of the radiation dose in multislice computer tomography of the chest – phantom study

    International Nuclear Information System (INIS)

    The most commonly used form of reporting doses in multislice computed tomography involves a CT dose index per slice and dose-length product for the whole series. The purpose of this study was to analyze the actual dose distribution in routine chest CT examination protocols using an antropomorphic phantom. We included in the analysis readings from a phantom filled with thermoluminescent detectors (Art Phantom Canberra) during routine chest CT examinations (64 MDCT TK LIGHT SPEED GE Medical System) performed using three protocols: low-dose, helical and angio-CT. Mean dose values (mSv) reported from anterior parts of the phantom sections in low-dose/helical/angio-CT protocols were as follows: 3.74; 16.95; 30.17; from central parts: 3.18; 14.15; 26.71; from posterior parts: 3.01; 12.47; 24.98 respectively. Correlation coefficients for mean doses registered in anterior parts of the phantom between low-dose/helical, low-dose/angio-CT and helical/angio-CT protocols were 0.49; 0.63; 0.36; from central parts: 0.73; 0.66; 0.83, while in posterior parts values were as follows: 0.06; 0.21; 0.57. The greatest doses were recorded in anterior parts of all phantom sections in all protocols in reference to largest doses absorbed in the anterior part of the chest during CT examination. The doses were decreasing from anterior to posterior parts of all sections. In the long axis of the phantom, in all protocols, lower doses were measured in the upper part of the phantom and at the very lowest part

  17. Measurements of patient chest dose for multi-slice X-ray CT examinations using PIN photodiode dosimeters

    International Nuclear Information System (INIS)

    Organ and tissue doses delivered during chest CT examinations were measured as a function of scanning parameters including tube current, slice thickness, and pitch of the multi-slice CT scanner. Measurements were carried out by using a chest dosimetry phantom that incorporated lung and vertebra models, and by putting PIN photodiode dosimeters into the phantom at sites of the esophagus or stomach, lung, bone marrow, and skin. Absorbed doses at each site in the phantom measured for a constant scan area indicated that these values could be precisely calculated from the value obtained at any scanning parameter by using inverse proportionality of dose to pitch and the data of x-ray intensity as a function of tube current and slice thickness measured for the CT scanner used. Relative dose at each site was found to be constant regardless of the scanning parameters, indicating that the dose value at each site could be calculated from that measured at only one point in the phantom. Effective doses and effective dose equivalents were estimated from organ or tissue doses for chest CT examinations, and were found to be 1.5 to 3 times larger than the average values of effective dose equivalent appearing in the literature. (author)

  18. Adaptive wiener filter based on Gaussian mixture distribution model for denoising chest X-ray CT image

    International Nuclear Information System (INIS)

    In recent decades, X-ray CT imaging has become more important as a result of its high-resolution performance. However, it is well known that the X-ray dose is insufficient in the techniques that use low-dose imaging in health screening or thin-slice imaging in work-up. Therefore, the degradation of CT images caused by the streak artifact frequently becomes problematic. In this study, we applied a Wiener filter (WF) using the universal Gaussian mixture distribution model (UNI-GMM) as a statistical model to remove streak artifact. In designing the WF, it is necessary to estimate the statistical model and the precise co-variances of the original image. In the proposed method, we obtained a variety of chest X-ray CT images using a phantom simulating a chest organ, and we estimated the statistical information using the images for training. The results of simulation showed that it is possible to fit the UNI-GMM to the chest X-ray CT images and reduce the specific noise. (author)

  19. 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.)

  20. Reduced volume of contrast media; effect on vascular opacification and image quality in spiral CT of the chest

    International Nuclear Information System (INIS)

    To evaluate the effect of reduced volume of contrast media on vascular opacification and image quality in spiral CT of the chest. Sixty patients referred for chest CT were examined with spiral CT with 60ml (n=30) or 90ml(n=30) of 30% ionic contrast media(Rayvist 300r, Schering, Germany) alternately. Injection rate of each group was as follows; 2.0ml/sec for 20 seconds followed by 1.0ml/sec for 20 seconds in 60ml group and 2.0ml/sec for 45 seconds in 90ml group. Twenty-five seconds scanning delay was employed. For the objective comparison of vascular opacification, CT numbers were measured at superior vena cava, ascending and descending aorta, right and left pulmonary artery, left atrium, and inferior vena cava. For the subjective comparison three radiologists scored the grade of vascular opacification and image quality blindly and independently. All data were analyzed statistically. The mean values of measured CT numbers in 90ml group were higher than those in 60ml group (p<.05) at the same level. The overall mean score of vascular opacification in 90ml group was 2.86, and 2.31 in 60ml group(p<.0001). In the overall mean score of image quality, there was no statistically significant difference between 90ml group(2.46) and 60ml group(2.40). Although there is some degradation of vascular opacification in 60ml group, overall image quality is not degraded. Therefore, 60ml of contrast media can be used in spiral CT of the chest without degradation of overall image quality except in spiral CT angiography

  1. 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

  2. Radiation exposure of children during radiodiagnostic examination of chest

    International Nuclear Information System (INIS)

    Organ doses in a tissue-equivalent anthropomorphous child phantom (corresponding to the age of 1 to 3 years) were measured during chest radiography by thermoluminescence dosimetry. The effective dose obtained by children of selected age was 0.044 mSv. The reproducibility of dose determination on phantom and on patient are compared. The obtained results are analyzed from the standpoint of optimization and reduction of patient doses. (author)

  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. Automated aortic calcification detection in low-dose chest CT images

    Science.gov (United States)

    Xie, Yiting; Htwe, Yu Maw; Padgett, Jennifer; Henschke, Claudia; Yankelevitz, David; Reeves, Anthony P.

    2014-03-01

    The extent of aortic calcification has been shown to be a risk indicator for vascular events including cardiac events. We have developed a fully automated computer algorithm to segment and measure aortic calcification in low-dose noncontrast, non-ECG gated, chest CT scans. The algorithm first segments the aorta using a pre-computed Anatomy Label Map (ALM). Then based on the segmented aorta, aortic calcification is detected and measured in terms of the Agatston score, mass score, and volume score. The automated scores are compared with reference scores obtained from manual markings. For aorta segmentation, the aorta is modeled as a series of discrete overlapping cylinders and the aortic centerline is determined using a cylinder-tracking algorithm. Then the aortic surface location is detected using the centerline and a triangular mesh model. The segmented aorta is used as a mask for the detection of aortic calcification. For calcification detection, the image is first filtered, then an elevated threshold of 160 Hounsfield units (HU) is used within the aorta mask region to reduce the effect of noise in low-dose scans, and finally non-aortic calcification voxels (bony structures, calcification in other organs) are eliminated. The remaining candidates are considered as true aortic calcification. The computer algorithm was evaluated on 45 low-dose non-contrast CT scans. Using linear regression, the automated Agatston score is 98.42% correlated with the reference Agatston score. The automated mass and volume score is respectively 98.46% and 98.28% correlated with the reference mass and volume score.

  5. Chest computed tomography

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  6. Obesity Increases the Risk of Chest Wall Pain From Thoracic Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Purpose: Stereotactic body radiation therapy (SBRT) is increasingly being used to treat thoracic tumors. We attempted here to identify dose-volume parameters that predict chest wall toxicity (pain and skin reactions) in patients receiving thoracic SBRT. Patients and Methods: We screened a database of patients treated with SBRT between August 2004 and August 2008 to find patients with pulmonary tumors within 2.5 cm of the chest wall. All patients received a total dose of 50 Gy in four daily 12.5-Gy fractions. Toxicity was scored according to the NCI-CTCAE V3.0. Results: Of 360 patients in the database, 265 (268 tumors) had tumors within 30, or volume of the chest wall receiving 30 Gy. Body mass index (BMI) was also strongly associated with the development of chest pain: patients with BMI ≥29 had almost twice the risk of chronic pain (p = 0.03). Among patients with BMI >29, diabetes mellitus was a significant contributing factor to the development of chest pain. Conclusion: Safe use of SBRT with 50 Gy in four fractions for lesions close to the chest wall requires consideration of the chest wall volume receiving 30 Gy and the patient's BMI and diabetic state.

  7. 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.

  8. 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

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

    International Nuclear Information System (INIS)

    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

  10. 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

  11. Pulmonary tuberculosis mimicking lung cancer on radiological findings: Evaluation of chest CT findings in pathologically proven 76 patients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Daun; Shin, Sang Soo; Kim, Yun Hyeon [Chonnam National Univ. Hospital, Gwangju, (Korea, Republic of); Kim, Hyoung Ook; Seon, Hyun Ju; Kang, Heoung Keun [Chonnam National Univ. Hwasun Hospital, Hwasun (Korea, Republic of)

    2012-09-15

    To evaluate chest CT features of pulmonary tuberculosis mimicking lung malignancy. We retrospectively reviewed chest CT findings for 76 consecutive patients (21-84 years, average: 63 years; M : F = 30 : 46) who underwent an invasive diagnostic procedure under the suspicion of lung cancer and were pathologically diagnosed as pulmonary tuberculosis by bronchoscopic biopsy (n = 49), transthoracic needle biopsy (n = 17), and surgical resection (n = 10). We categorized the chest CT patterns of those lesions as follows: bronchial narrowing or obstruction without a central mass like lesion (pattern 1), central mass-like lesion with distal atelectasis or obstructive pneumonia (pattern 2), peripheral nodule or mass including mass-like consolidation (pattern 3), and cavitary lesion (pattern 4). CT findings were reviewed with respect to the patterns and the locations of the lesions, parenchymal abnormalities adjacent to the lesions, the size, the border and pattern of enhancement for the peripheral nodule or mass and the thickness of the cavitary wall in the cavitary lesion. We also evaluated the abnormalities regarding the lymph node and pleura. Pattern 1 was the most common finding (n = 34), followed by pattern 3 (n = 23), pattern 2 (n = 11) and finally, pattern 4 (n = 8). The most frequently involving site in pattern 1 and 2 was the right middle lobe (n = 14/45). However, in pattern 3 and 4, the superior segment of right lower lobe (n = 5/31) was most frequently involved. Ill-defined small nodules and/or larger confluent nodules were found in the adjacent lung and at the other segment of the lung in 31 patients (40.8%). Enlarged lymph nodes were most commonly detected in the right paratracheal area (n = 9/18). Pleural effusion was demonstrated in 10 patients. On the CT, pulmonary tuberculosis mimicking lung cancer most commonly presented with bronchial narrowing or obstruction without a central mass-like lesion, which resulted in distal atelectasis and obstructive

  12. Pulmonary tuberculosis mimicking lung cancer on radiological findings: Evaluation of chest CT findings in pathologically proven 76 patients

    International Nuclear Information System (INIS)

    To evaluate chest CT features of pulmonary tuberculosis mimicking lung malignancy. We retrospectively reviewed chest CT findings for 76 consecutive patients (21-84 years, average: 63 years; M : F = 30 : 46) who underwent an invasive diagnostic procedure under the suspicion of lung cancer and were pathologically diagnosed as pulmonary tuberculosis by bronchoscopic biopsy (n = 49), transthoracic needle biopsy (n = 17), and surgical resection (n = 10). We categorized the chest CT patterns of those lesions as follows: bronchial narrowing or obstruction without a central mass like lesion (pattern 1), central mass-like lesion with distal atelectasis or obstructive pneumonia (pattern 2), peripheral nodule or mass including mass-like consolidation (pattern 3), and cavitary lesion (pattern 4). CT findings were reviewed with respect to the patterns and the locations of the lesions, parenchymal abnormalities adjacent to the lesions, the size, the border and pattern of enhancement for the peripheral nodule or mass and the thickness of the cavitary wall in the cavitary lesion. We also evaluated the abnormalities regarding the lymph node and pleura. Pattern 1 was the most common finding (n = 34), followed by pattern 3 (n = 23), pattern 2 (n = 11) and finally, pattern 4 (n = 8). The most frequently involving site in pattern 1 and 2 was the right middle lobe (n = 14/45). However, in pattern 3 and 4, the superior segment of right lower lobe (n = 5/31) was most frequently involved. Ill-defined small nodules and/or larger confluent nodules were found in the adjacent lung and at the other segment of the lung in 31 patients (40.8%). Enlarged lymph nodes were most commonly detected in the right paratracheal area (n = 9/18). Pleural effusion was demonstrated in 10 patients. On the CT, pulmonary tuberculosis mimicking lung cancer most commonly presented with bronchial narrowing or obstruction without a central mass-like lesion, which resulted in distal atelectasis and obstructive

  13. Dual-source chest CT angiography with high temporal resolution and high pitch modes: evaluation of image quality in 140 patients

    Energy Technology Data Exchange (ETDEWEB)

    Tacelli, Nunzia; Remy-Jardin, Martine; Faivre, Jean-Baptiste; Remy, Jacques [University Centre of Lille (EA 2694), Department of Thoracic Imaging, Hospital Calmette, Lille (France); Flohr, Thomas [Siemens Healthcare, Computed Tomography, Forchheim (Germany); Delannoy, Valerie; Duhamel, Alain [University Centre of Lille (EA 2694), Department of Biostatistics, Lille (France)

    2010-05-15

    To evaluate image quality of dual-source computed tomography (CT) angiograms acquired with high temporal resolution and high pitch modes. Two groups of 70 consecutive patients underwent chest CT angiography with dual-source, single-energy CT, with an 83-ms temporal resolution and a pitch of 2 (group 1) or a pitch of 3 (group 2). Subjective and objective image quality and the diagnostic value were assessed by two radiologists in consensus. The radiation dose was recorded. The image quality was always diagnostic in both groups, rated as excellent in 97% of group 1 (68/70) and 98.5% of group 2 (69/70) examinations. Although no statistically significant difference in subjective image noise was found between the two groups (p = 0.3055), objective noise was found to be statistically higher in group 2 (p<0.0001). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were found to be significantly higher in group 1 than in group 2 (p=0.0014). The acquisition time was significantly shorter in group 2 than in group 1 (p<0.0001). The dose-length product was significantly lower in group 2 than in group 1 (p < 0.0001). High temporal resolution and high pitch modes provided standard CT angiographic examinations of excellent quality for thoracic applications in routine clinical practice. (orig.)

  14. The Value and Prognostic Role of the CT Scan versus Chest Radiography in the Follow-up of Intubated Burn Patients with Possible Inhalation Injury

    OpenAIRE

    Spyropoulou, G.A.; Iconomou, T.; Tsagarakis, M.; Tsoutsos, D.

    2005-01-01

    The admission and follow-up chest radiographs as well as the follow-up CT scans of 13 burn patients admitted to our clinic requiring ventilatory support were analysed for signs of inhalation injury and pulmonary complications. The findings were compared with the results of the clinical examination, the blood gas tests, and bronchoscopy. Eleven out of the 13 patients underwent bronchoscopy revealing inhalation injury. The CT scan detected pleural effusion in two patients with a normal chest ra...

  15. 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.

  16. Computer-aided recognition of emphysema on digital chest radiography.

    OpenAIRE

    Miniati, Massimo; Coppini, Giuseppe; Monti, Simonetta; Bottai, Matteo; Paterni, Marco; Ferdeghini, Ezio Maria

    2011-01-01

    Background Computed tomography (CT) is the benchmark for diagnosis emphysema, but is costly and imparts a substantial radiation burden to the patient. Objective To develop a computer-aided procedure that allows recognition of emphysema on digital chest radiography by using simple descriptors of the lung shape. The procedure was tested against CT. Methods Patients (N=225), who had undergone postero-anterior and lateral digital chest radiographs and CT for diagnostic purposes, were studied and ...

  17. 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.

  18. Influence of model based iterative reconstruction algorithm on image quality of multiplanar reformations in reduced dose chest CT

    Science.gov (United States)

    Dunet, Vincent; Hachulla, Anne-Lise; Grimm, Jochen; Beigelman-Aubry, Catherine

    2016-01-01

    Background Model-based iterative reconstruction (MBIR) reduces image noise and improves image quality (IQ) but its influence on post-processing tools including maximal intensity projection (MIP) and minimal intensity projection (mIP) remains unknown. Purpose To evaluate the influence on IQ of MBIR on native, mIP, MIP axial and coronal reformats of reduced dose computed tomography (RD-CT) chest acquisition. Material and Methods Raw data of 50 patients, who underwent a standard dose CT (SD-CT) and a follow-up RD-CT with a CT dose index (CTDI) of 2–3 mGy, were reconstructed by MBIR and FBP. Native slices, 4-mm-thick MIP, and 3-mm-thick mIP axial and coronal reformats were generated. The relative IQ, subjective IQ, image noise, and number of artifacts were determined in order to compare different reconstructions of RD-CT with reference SD-CT. Results The lowest noise was observed with MBIR. RD-CT reconstructed by MBIR exhibited the best relative and subjective IQ on coronal view regardless of the post-processing tool. MBIR generated the lowest rate of artefacts on coronal mIP/MIP reformats and the highest one on axial reformats, mainly represented by distortions and stairsteps artifacts. Conclusion The MBIR algorithm reduces image noise but generates more artifacts than FBP on axial mIP and MIP reformats of RD-CT. Conversely, it significantly improves IQ on coronal views, without increasing artifacts, regardless of the post-processing technique.

  19. An education and training programme for radiological institutes: impact on the reduction of the CT radiation dose

    International Nuclear Information System (INIS)

    To establish an education and training programme for the reduction of CT radiation doses and to assess this programme's efficacy. Ten radiological institutes were counselled. The optimisation programme included a small group workshop and a lecture on radiation dose reduction strategies. The radiation dose used for five CT protocols (paranasal sinuses, brain, chest, pulmonary angiography and abdomen) was assessed using the dose-length product (DLP) before and after the optimisation programme. The mean DLP values were compared with national diagnostic reference levels (DRLs). The average reduction of the DLP after optimisation was 37% for the sinuses (180 vs. 113 mGycm, P < 0.001), 9% for the brain (982 vs. 896 mGycm, P < 0.05), 24% for the chest (425 vs. 322 mGycm, P < 0.05) and 42% for the pulmonary arteries (352 vs. 203 mGycm, P < 0.001). No significant change in DLP was found for abdominal CT. The post-optimisation DLP values of the sinuses, brain, chest, pulmonary arteries and abdomen were 68%, 10%, 20%, 55% and 15% below the DRL, respectively. The education and training programme for radiological institutes is effective in achieving a substantial reduction in CT radiation dose. (orig.)

  20. An education and training programme for radiological institutes: impact on the reduction of the CT radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Schindera, Sebastian T.; Allmen, Gabriel von; Vock, Peter; Szucs-Farkas, Zsolt [University of Berne, University Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital Berne, Berne (Switzerland); Treier, Reto; Trueb, Philipp R. [Federal Office of Public Health, Radiation Protection Division, Berne (Switzerland); Nauer, Claude [University of Berne, University Institute of Diagnostic and Interventional Neuroradiology, University Hospital Berne, Berne (Switzerland)

    2011-10-15

    To establish an education and training programme for the reduction of CT radiation doses and to assess this programme's efficacy. Ten radiological institutes were counselled. The optimisation programme included a small group workshop and a lecture on radiation dose reduction strategies. The radiation dose used for five CT protocols (paranasal sinuses, brain, chest, pulmonary angiography and abdomen) was assessed using the dose-length product (DLP) before and after the optimisation programme. The mean DLP values were compared with national diagnostic reference levels (DRLs). The average reduction of the DLP after optimisation was 37% for the sinuses (180 vs. 113 mGycm, P < 0.001), 9% for the brain (982 vs. 896 mGycm, P < 0.05), 24% for the chest (425 vs. 322 mGycm, P < 0.05) and 42% for the pulmonary arteries (352 vs. 203 mGycm, P < 0.001). No significant change in DLP was found for abdominal CT. The post-optimisation DLP values of the sinuses, brain, chest, pulmonary arteries and abdomen were 68%, 10%, 20%, 55% and 15% below the DRL, respectively. The education and training programme for radiological institutes is effective in achieving a substantial reduction in CT radiation dose. (orig.)

  1. 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

  2. Automated Coronary Artery Calcification Scoring in Non-Gated Chest CT: Agreement and Reliability

    Science.gov (United States)

    Takx, Richard A. P.; de Jong, Pim A.; Leiner, Tim; Oudkerk, Matthijs; de Koning, Harry J.; Mol, Christian P.; Viergever, Max A.; Išgum, Ivana

    2014-01-01

    Objective To determine the agreement and reliability of fully automated coronary artery calcium (CAC) scoring in a lung cancer screening population. Materials and Methods 1793 low-dose chest CT scans were analyzed (non-contrast-enhanced, non-gated). To establish the reference standard for CAC, first automated calcium scoring was performed using a preliminary version of a method employing coronary calcium atlas and machine learning approach. Thereafter, each scan was inspected by one of four trained raters. When needed, the raters corrected initially automaticity-identified results. In addition, an independent observer subsequently inspected manually corrected results and discarded scans with gross segmentation errors. Subsequently, fully automatic coronary calcium scoring was performed. Agatston score, CAC volume and number of calcifications were computed. Agreement was determined by calculating proportion of agreement and examining Bland-Altman plots. Reliability was determined by calculating linearly weighted kappa (κ) for Agatston strata and intraclass correlation coefficient (ICC) for continuous values. Results 44 (2.5%) scans were excluded due to metal artifacts or gross segmentation errors. In the remaining 1749 scans, median Agatston score was 39.6 (P25–P75∶0–345.9), median volume score was 60.4 mm3 (P25–P75∶0–361.4) and median number of calcifications was 2 (P25–P75∶0–4) for the automated scores. The κ demonstrated very good reliability (0.85) for Agatston risk categories between the automated and reference scores. The Bland-Altman plots showed underestimation of calcium score values by automated quantification. Median difference was 2.5 (p25–p75∶0.0–53.2) for Agatston score, 7.6 (p25–p75∶0.0–94.4) for CAC volume and 1 (p25–p75∶0–5) for number of calcifications. The ICC was very good for Agatston score (0.90), very good for calcium volume (0.88) and good for number of calcifications (0.64). Discussion Fully automated

  3. 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.

  4. 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。

  5. Multidisciplinary approach to treatment of radiation-induced chest wall sarcoma.

    Science.gov (United States)

    Kara, H Volkan; Gandolfi, Brad M; Williams, Judson B; D'Amico, Thomas A; Zenn, Michael R

    2016-08-01

    Radiation-induced sarcoma (RIS) is a rare complication following therapeutic external irradiation for lung cancer patients. Patients with RIS may develop recurrence or metastasis of the previous disease and also at high risk for early chest wall complications following operation, which requires close follow-up and multidisciplinary approach. We present a challenging case of RIS with a multidisciplinary teamwork in the decision-making and successful management. PMID:25663293

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

    International Nuclear Information System (INIS)

    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). IA of the large airways was well correlated with basal TXVI, FEV1 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.)

  8. 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.

  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. Radiation exposure during chest X-ray examinations in a premature intensive care unit: phantom studies

    International Nuclear Information System (INIS)

    Background. There are few reports on the radiation dose received by infants, their family and radiographers exposed to scatter radiation in a premature baby intensive care unit. Objective. To evaluate the degree of radiation exposure from diagnostic X-ray examinations with mobile X-ray machines in a premature intensive care unit. Materials and methods. The radiation exposure of an adjacent newborn, the radiographer and other persons in the room was simulated using phantoms during X-ray examination of the chest using vertical and horizontal beams. Results. Most of the measured doses were below the registration limit of the measuring apparatus and had to be extrapolated by multiple exposures. Without exception, the maximal doses were significantly lower than the permitted limit for persons not professionally exposed to X-rays. Conclusions. Recommendations to avoid unnecessary radiation exposure are given. (orig.)

  11. 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)

  12. 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

  13. 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.

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

    International Nuclear Information System (INIS)

    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. CTDIvol 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.)

  15. 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.)

  16. 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.)

  17. Registration of chest PET and CT images. Fusion technique using the PET/Tr image by the respiration compensation

    International Nuclear Information System (INIS)

    The conventional registration of PET images of the chest with CT images is performed by rotating and shifting those images while used median lines and contours on axial images as the reference indexes. For the thoracic and the abdominal regions, therefore, the respiratory movements have prevented us from achieving satisfactory levels of registration reproducibility and accuracy. In order to solve this, we have analyzed respiratory movements of the chest and derived an image fusion method. Respiratory movements of the lung along each axis (X-axis: left-right, Y-axis: dorsoventral, and Z-axis: craniocaudal) during deep breathing were analyzed using CT-3D images. In addition, respiratory movements of the lung and thorax in the Y-axis and Z-axis directions during deep breathing and at rest were also analyzed by using an MR system that is the non-invasive method and allows for acquiring arbitrary tomographic images. Respiratory movements were compensated for on PET images of the lung. Moving average deviations in the Y-axis and Z-axis directions, which were obtained from the analytical result of respiration (30 samples), were used to derive the compensatory values. The analysis of CT-3D images showed that the movements in the X-axis direction were negligible. Registration of PET images with CT images was found useful when it performed on the sagittal planes. The analysis of MR images on sagittal planes revealed that the region extending from the apex of the lung to the posterior wall of the lung was useful for reference indexes for registration. The PET image by the compensation of the respiration transfer difference in the pulmonary hilum division was fusion on the CT image. In the pulmonary hilum division, the improvement in the accuracy of 3.6 mm in the dorsoventral and 6.1 mm in the craniocaudal direction was obtained in comparison with the fusion only of the reference index. The developed image fusion technique compensating the respiratory movements was found to be

  18. Pulmonary intimal sarcoma: a rare differential diagnosis for arterial filling defects on a chest CT

    International Nuclear Information System (INIS)

    We present a rare case of pulmonary intimal sarcoma mimicking pulmonary embolism in a 40-year-old woman. Although extremely rare, these tumors must be considered in patients who present inappropriate imaging findings that suggest embolism. Chest computed tomography is the modality of choice to determine the extent of the tumor. We present a female patient with suspected embolism that was in fact found to be an endothelial sarcoma of the pulmonary arteries

  19. 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.

  20. 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.

  1. Radiation safety education reduces the incidence of adult fingers on neonatal chest radiographs

    International Nuclear Information System (INIS)

    A previous audit revealed a high frequency of adult fingers visualised on neonatal intensive care unit (NICU) chest radiographs—representing an example of inappropriate occupational radiation exposure. Radiation safety education was provided to staff and we hypothesised that the education would reduce the frequency of adult fingers visualised on NICU chest radiographs. Two cross-sectional samples taken before and after the administration of the education were compared. We examined fingers visualised directly in the beam, fingers in the direct beam but eliminated by technologists editing the image, and fingers under the cones of the portable x-ray machine. There was a 46.2% reduction in fingers directly in the beam, 50.0% reduction in fingers directly in the beam but cropped out, and 68.4% reduction in fingers in the coned area. There was a 57.1% overall reduction in adult fingers visualised, which was statistically significant (Z value − 7.48, P < 0.0001). This study supports radiation safety education in minimising inappropriate occupational radiation exposure. (paper)

  2. Radiation exposure of children during radiodiagnostic examinations of chest in Slovakia

    International Nuclear Information System (INIS)

    Higher individual somatic radiation risk in the younger age groups has been until now inadequately considered in radiation protection. It is therefore essential to develop appropriate radiation protection measures also in the field of diagnostic radiology for paediatric patients. The European Communities elaborated Guidelines on 'Quality Criteria for Radiodiagnostic Radiographic Images in Paediatrics'. Reference dose values for selected types of examinations and for 5 year old children were proposed. In our contribution we have tried to estimate the radiation load of children to 15 years, which underwent chest radiodiagnostic examinations during 1996 in a Slovak district. Our data of entrance surface doses were collected using measurements with TLD for 149 patients divided into 5 age categories at nine radiodiagnostic departments. The calculations of the total absorbed dose were performed using the measured ESD values integrated over the X-ray beam area, the conversion factors between the imparted energy and the dose-area product and the known irradiation parameters (kV, HVL, mass, etc.). The analysis of the obtained absorbed doses as a function of age for chest PA radiodiagnostic examinations has shown that the investigated Slovak radiodiagnostic centres use rather lower voltage techniques and the entrance surface doses are much higher than the proposed value of the EC. (author)

  3. 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.

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

    International Nuclear Information System (INIS)

    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

  5. 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

  6. The optimization of low-dose scanning protocols of 64-slice spiral CT in the adult chest: a multicenter study

    International Nuclear Information System (INIS)

    Objective: To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current. control (CCC) and explore a more reasonable scanning protocol. Methods: Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (Al) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (Cl) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols. The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically. Differences of radiation dose and noise among groups were determined with variance analysis and t test, image quality with Mann- Whitney test and the consistency of diagnosis with Kappa test. Results: There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31) vs (110.81±18.21) mGy · cm (F=56.88, P 0.05]. The noisy of AEC group was higher than that of CCC group both on lung window (41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference (Flung=0.835, P=0.476, Fwediastinum=1.910, P=0.128). The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49± 0.56 vs 4.38±0.64, superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32, the right superior lobar bronchus Level: 4.87±0.27 vs 4.84±0.22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level (4.92±0.25 vs 4.93±0.17) and superior margin of the left diaphragmatic dome level (4.91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P>0.05) were observed. A significant higher

  7. 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.

  8. Examination of the chest computed tomography scan condition optimization in consideration of the influence of the position of the arms

    International Nuclear Information System (INIS)

    Computed tomography automatic exposure control (CT-AEC) technique is calculated from a localizer radiograph. When we perform neck and chest CT examination, at first, we acquire localizer radiograph and neck images by placing the arm in a lowered position. Next, the arm is raised for the chest scan. Therefore, the localizer radiograph and subject information are different in the chest scan. In this situation, the chest scan with the use of the CT-AEC causes radiation over-dose. The purpose of this study is to optimize the CT-AEC by controlling noise index (NI), and make a chest CT scan condition considering the position of the arms. We measured the image noise (SD) in the phantom by using CT-AEC. In addition, dose length product (DLP) was recorded. Moreover, we examined the correlation with the clinical images. The results of our experiments show that radiation dose can be reduced with the image quality kept by controlling NI. (author)

  9. 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.

  10. Radiation Protection Challenges and Trends in PET/CT

    International Nuclear Information System (INIS)

    Positron emission tomography (PET)/computed tomography (CT) is now an essential imaging modality in various clinical circumstances, especially in the management of oncology patients. Customization of therapy through PET/CT imaging is actually becoming an indispensable process in the strategy of oncological management, that is, initial diagnosis and staging, treatment selection, planning of external beam radiation therapy, and follow-up and detection of recurrence after therapy. Standardization of PET/CT images for therapy response assessment and application of high precision radiation therapy planning will require strict quality control of the imaging. Considering the increasing number of PET/CT procedures and such higher imaging quality, measures of radiation protection for both patients and staff members should evolve to sustain the application of this modality in medical practices

  11. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... time! Spotlight Recently posted: Pediatric MRI Intravascular Ultrasound Video: Chest CT Video:Thyroid Ultrasound Video: Head CT ...

  12. 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.

  13. Study on scan conditions in the chest by four multi detector-row CT

    International Nuclear Information System (INIS)

    In our hospital, Toshiba's Aquilion (AQ) and Siemens' Volume Zoom (VZ) that are both four multi detector-row CT (MDCT) are working at present. In the lung CT, when pulmonary nodules or diffuse lung diseases are detected on CT images obtained by the use of beam collimation of 2.0 mm x 4 in AQ or 2.5 mm x 4 in VZ, the patient needs additional scans by using thinner beam collimation. However, this technique involves a problem that cannot scan the same target region as the first examination. High-resolution CT (HRCT) is generally defined to an image obtained by slice thickness of 1 mm to 3 mm. In this paper, however, we especially refers HRCT as an image obtained by slice thickness of 1 mm or less in the case of acquiring more detailed patient's data. Beam collimation of two MDCT scanners was set to 1.0 mm x 4 in order to efficiently employ a feature of MDCT that images of various slice thickness obtained by one scan can be reconstructed. We compared the images reconstructed from 5 mm slice-thickness images and 1 mm slice-thickness images in terms of changing of standard deviation (SD) and the occurrence of artifacts. As the results, the increase of SD and streak artifacts were confirmed under some conditions. The beam collimation of 1 mm x 4 needed to increase helical pitch, allowing for the patient's breath-holding time. We conclude to be useful for setting the beam collimation to 1 mm x 4, considering the reduction of the patient's exposure dose, the improvement of shape reappearance, and a shortening in examination time. (author)

  14. Emphysema Quantification Using Low Dose Chest CT: Changes in Follow-Up Examinations of Asymptomatic Smokers

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Eun Ho; Sun, Joo Sung; Kang, Doo Kyung [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Park, Kwang Joo; Park, Kyung Joo [Dept. of Pulmolary Medicine, Ajou University School of Medicine, Suwon (Korea, Republic of)

    2012-01-15

    To evaluate the changes of emphysema quantification in a follow-up low dose CT compared with pulmonary function test (PFT) results in asymptomatic smokers. We selected 66 asymptomatic smokers (> 40 years old) who underwent a follow-up low dose CT at least one year after the first CT as well as PFT within the same time period. Emphysema quantification was performed using an automated measurement software and an emphysema index (EI) was calculated using multiple threshold values (-970--900 HU). The interval change of EI ({Delta} EI) was compared with the change in the PFT values. Mean follow-up %forced expiratory volume in 1 second (88.1), %forced vital capacity (FVC) (89.5) and forced expiratory flow between 25 and 75% of vital capacity (3.21) were significantly lower compared with the values of initial tests (93.3, 93.1, 3.48). The mean EIs (2.4-25.6%) increased on follow-up CTs compared with initial EIs (2.1-24.5%), though the increase was not statistically significant. In a group with a follow-up period of 2 years or more (n = 32), EI significantly increased when using -900 HU as the threshold. The ({Delta} EIs were poorly correlated with the ({Delta} PFT values, but significantly correlated with ({Delta} FVC (r = -0.32--0.27). Emphysema quantification using low dose CT was not effective for the evaluation of short-term changes in less than a 2-year period, but may be used for long term follow-up series in asymptomatic smokers.

  15. 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).

  16. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  18. Quantification of pneumothorax volume on chest radiographs: comparison between the collins' and the axel's methods with three-dimensional CT as the standard of reference

    International Nuclear Information System (INIS)

    The purpose of this study was twofold. In a preliminary study, we evaluated the accuracy of 3-D (three-dimensional) CT for the estimation of pneumothorax volume and for providing the optimal postprocessing method for clinical study. In the clinical study, we determined which of the two methods, Collins' and Axel's, was more accurate for the estimation of pneumothorax volume, as seen on chest radiographs, using 3-D CT as the standard of reference. In the preliminary study, 3-D CT was applied to phantoms and to four patients with pneumothorax using two different postprocessing methods, manual contour delineation and thresholding. In the clinical study, 3-D CT was performed in 13 patients with pneumothorax. For the purpose of evaluating conventional radiographs, a localizer scan was used for comparing the accuracy of Collins' method with that of Axel's method, with 3-D CT as the standard of reference. The preliminary study revealed that 3-D CT estimated pneumothorax volume with great accuracy and that manual contour delineation and thresholding measured volume equally well. Because of the shorter postprocessing time required with thresholding than with manual contour delineation (5 min versus 30 min), the former was used during clinical study. The results of this indicated close correlation between the measurements obtained using Collins' method on chest radiographs and those obtained by 3-D CT(r=0.95, p0.05). 3-D CT can estimate pneumothorax volume with great accuracy. Collins' method is superior to Axel's method for the quantification of pneumothorax volume as seen on chest radiographs

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

    International Nuclear Information System (INIS)

    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 (CTDIvol) (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 CTDIvol 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 CTDIvol, 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. CTDIvol 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.)

  20. 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.)

  1. Image quality of thickened slabs in multislice CT chest examinations: postprocessing vs. direct reconstruction

    International Nuclear Information System (INIS)

    Purpose: Postprocessing offers the possibility of real-time creation of thickened slabs from a set of thin slices. This allows the interactive change from thick to thin slices for better evaluation of unclear lesions. As a result the clinical workflow of MSCT evaluation can be improved. However, to be able to apply this postprocessing software in the clinical routine, degradations in the image quality (compared to standard original reconstructed images) have to be avoided. The purpose of this study was to compare the image quality of thickened slabs from MSCT chest examinations that have either been directly reconstructed from the raw data or have been retrospectively generated via postprocessing. Materials and Methods: Chest MSCT examinations of 20 patients (mean age: 56 years) were performed on a 16-slice MSCT scanner (Mx8000IDT16, Philips, Best, Netherlands) using the following scan parameters: 120 kV, 94 effective mAs, 16 x 1.5 mm collimation, 512 x 512 matrix, field of view 371 x 371 mm, (CTDI-vol 6.3 mGy, DLP = 210 mGyxcm). Slices with a thickness of 3 and 5 mm were generated for each examination both directly from the raw data and via postprocessing. Corresponding images from postprocessing and direct reconstruction (lung/soft tissue window) were evaluated by two radiologists with respect to 5 criteria on the basis of a five-point scale: organ structure, contour of small objects, contrast, image noise and artifacts. Differences between both data sets regarding image quality were assessed for each of the 5 criteria using a Wilcoxon test with Bonferroni correction. In addition, image noise was analyzed quantitatively in a region of interest in the aorta. Results: For the lung and soft tissue window, both reviewers and all criteria, no differences in image quality were detected between the thickened slices obtained via direct reconstruction and the postprocessing method. In 96 % and 95 % of the cases images of the two reconstruction methods were graded

  2. 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.

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

    International Nuclear Information System (INIS)

    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

  4. Automatic classication of pulmonary function in COPD patients using trachea analysis in chest CT scans

    Science.gov (United States)

    van Rikxoort, E. M.; de Jong, P. A.; Mets, O. M.; van Ginneken, B.

    2012-03-01

    Chronic Obstructive Pulmonary Disease (COPD) is a chronic lung disease that is characterized by airflow limitation. COPD is clinically diagnosed and monitored using pulmonary function testing (PFT), which measures global inspiration and expiration capabilities of patients and is time-consuming and labor-intensive. It is becoming standard practice to obtain paired inspiration-expiration CT scans of COPD patients. Predicting the PFT results from the CT scans would alleviate the need for PFT testing. It is hypothesized that the change of the trachea during breathing might be an indicator of tracheomalacia in COPD patients and correlate with COPD severity. In this paper, we propose to automatically measure morphological changes in the trachea from paired inspiration and expiration CT scans and investigate the influence on COPD GOLD stage classification. The trachea is automatically segmented and the trachea shape is encoded using the lengths of rays cast from the center of gravity of the trachea. These features are used in a classifier, combined with emphysema scoring, to attempt to classify subjects into their COPD stage. A database of 187 subjects, well distributed over the COPD GOLD stages 0 through 4 was used for this study. The data was randomly divided into training and test set. Using the training scans, a nearest mean classifier was trained to classify the subjects into their correct GOLD stage using either emphysema score, tracheal shape features, or a combination. Combining the proposed trachea shape features with emphysema score, the classification performance into GOLD stages improved with 11% to 51%. In addition, an 80% accuracy was achieved in distinguishing healthy subjects from COPD patients.

  5. Attenuation-based automatic kilovolt (kV)-selection in computed tomography of the chest: Effects on radiation exposure and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Eller, Achim; Wuest, Wolfgang; Scharf, Michael; Brand, Michael [Department of Radiology, University Erlangen (Germany); Achenbach, Stephan [Department of Cardiology, University Erlangen (Germany); Uder, Michael [Department of Radiology, University Erlangen (Germany); Imaging Science Institute, Erlangen (Germany); Lell, Michael M., E-mail: Michael.lell@uk-erlangen.de [Department of Radiology, University Erlangen (Germany); Imaging Science Institute, Erlangen (Germany)

    2013-12-01

    Objectives: To evaluate an automated attenuation-based kV-selection in computed tomography of the chest in respect to radiation dose and image quality, compared to a standard 120 kV protocol. Materials and methods: 104 patients were examined using a 128-slice scanner. Fifty examinations (58 ± 15 years, study group) were performed using the automated adaption of tube potential (100–140 kV), based on the attenuation profile of the scout scan, 54 examinations (62 ± 14 years, control group) with fixed 120 kV. Estimated CT dose index (CTDI) of the software-proposed setting was compared with a 120 kV protocol. After the scan CTDI volume (CTDIvol) and dose length product (DLP) were recorded. Image quality was assessed by region of interest (ROI) measurements, subjective image quality by two observers with a 4-point scale (3 – excellent, 0 – not diagnostic). Results: The algorithm selected 100 kV in 78% and 120 kV in 22%. Overall CTDIvol reduction was 26.6% (34% in 100 kV) overall DLP reduction was 22.8% (32.1% in 100 kV) (all p < 0.001). Subjective image quality was excellent in both groups. Conclusion: The attenuation based kV-selection algorithm enables relevant dose reduction (∼27%) in chest-CT while keeping image quality parameters at high levels.

  6. The relationship between aortic calcification on chest radiography and ionizing radiation in RERF's Adult Health Study

    International Nuclear Information System (INIS)

    Aortic calcification has been reported to be an indicator of atherosclerosis and a predictor of coronary heart disease. However, the relationship between aortic calcification and conventional coronary risk factors or recently reported coronary risk factors including ionizing radiation, which is one kind of oxidative stress, has not been established. Objective: To investigate the relationship between aortic calcification and ionizing radiation in a longitudinal study design. The study cohort comprises the Radiation Effects Research Foundation's Adult Health Study participants which include atomic-bomb survivors and sex- and age-matched controls. A total of 522 men and 938 women identified as not having aortic calcification based on plain chest X-ray examinations at baseline examination between 1991 and 1993 were assessed regarding the presence of aortic calcification (mild/ severe calcification) about 10 years later. The relationship between cumulative incidence of aortic calcification and atomic-bomb radiation was analyzed using logistic regression analysis after adjusting for sex, age, and other coronary risk factors such as blood pressure, total cholesterol, and inflammation markers. Age-adjusted cumulative incidence of aortic calcification showed a possible increase with atomic-bomb radiation dose for both total aortic calcification and severe aortic calcification. But after adjusting for other coronary risk factors such as smoking, SBP, total cholesterol, HDL-cholesterol, hemoglobin A1c, and leukocyte neutropils, radiation dose was not a significant predictor of cumulative incidence of severe aortic calcification. Age-adjusted increase of cumulative incidence of aortic calcification with atomic-bomb radiation dose suggests ionizing radiation is one predictor of atheroscelerosis. Nevertheless, its predictive impact may not be as significant as conventional coronary risk factors

  7. Options for radiation dose reduction in CT; Moeglichkeiten der Strahlenreduktion bei der CT des Koerperstamms

    Energy Technology Data Exchange (ETDEWEB)

    Euler, Andre; Schindera, Sebastian [Universitaetsspital Basel (Switzerland). Klinik fuer Radiologie und Nuklearmedizin; Szuecs-Farkas, Zsolt [Spitalzentrum Biel (Switzerland). Radiologie

    2014-06-15

    The use of a computed tomography (CT) scan for the diagnostic workup of various diseases has increased tremendously within the last 10 years. One major cause of this development is related to the technical advances of the CT scanners, resulting in a growing number of clinical CT indications. Besides the diagnostic benefit for the patient population, the overall radiation exposure to the patient has increased. Thus, to slow down the increase in radiation exposure, methods for dose optimization are necessary. Radiologists and technicians are liable for a responsible utilization of the CT scan, which goes along with the ALARA principle ('as low as reasonably achievable'). In the present article, we present various practicable strategies for a dose optimization. (orig.)

  8. Technique and clinical applications of full-inflation and end-exhalation controlled-ventilation chest CT in infants and young children

    International Nuclear Information System (INIS)

    Background. The inability of young children to cooperate with breath holding limits the usefulness of chest CT. Objective. To describe the technique and utility of a non-invasive method called controlled-ventilation CT (CVCT) for obtaining motion-free full-inflation and end-exhalation images of the lung in infants and young children. Materials and methods. Eighty-seven children (ages 1 week to 5 years, mean 2 years) underwent CVCT of the chest during suspended respiration at full-lung inflation and end-exhalation for a variety of clinical indications. Respiratory pauses were produced using conscious sedation and positive-pressure face-mask ventilation. Forty-one of 87 children had recordings of respiratory motion during CVCT. Results. Respiratory pause lengths increased with age (P < 0.003), were highly reproducible (r = 0.85), and lasted sufficiently long to be practical for full-inflation (24 ± 9 s) and end-exhalation (12 ± 5 s) CT scanning. Full-inflation CVCT was useful in evaluating tracheal and bronchial stenosis, bronchial wall thickening, early bronchiectasis, bronchial fistula, extent of interstitial fibrosis, and lung nodules. End-exhalation CVCT was useful in evaluating tracheomalacia and air trapping. Conclusion. Controlled-ventilation chest CT is a practical and reliable technique that promises to be clinically useful for a number of clinical indications in infants and young children. (orig.)

  9. 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.)

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

    International Nuclear Information System (INIS)

    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

  11. 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

  12. Thin-section chest CT findings in systemic lupus erythematosus with antiphospholipid syndrome: A comparison with systemic lupus erythematosus without antiphospholipid syndrome

    International Nuclear Information System (INIS)

    Purpose: To assess thin-section chest CT findings in systemic lupus erythematosus (SLE) with antiphospholipid syndrome (APS), in comparison with SLE without APS. Materials and methods: We retrospectively reviewed the medical records and thin-section CT findings of 17 consecutive patients with an established diagnosis of SLE with APS, comparing with 37 consecutive SLE patients without APS, between 2004 and 2008, and patients who had other autoimmune disease, such as Sjögren syndrome, were excluded. No significant differences were seen between the two groups in age, gender, smoking habits, or history of steroid pulse and biological therapy. CT images of 2 mm thickness obtained with a 16- or 64-detector row CT were retrospectively evaluated by two radiologists in consensus on ultra high-resolution gray-scale monitors. Results: The frequency of thin-section CT abnormalities was higher in SLE with APS group (82%) than in SLE without APS group (43%). Ground-glass opacity (59%), architectural distortion (47%), reticulation (41%), enlarged peripheral pulmonary artery (29%), and mosaic attenuation (29%) were significantly more common in the SLE with APS group than in the SLE without APS group (Fisher's exact test, p < 0.01). Conclusion: SLE patients with APS have increased prevalence of thin-section chest CT abnormalities than those without APS.

  13. Intracranial germinoma; typical CT appearances and radiation therapy

    International Nuclear Information System (INIS)

    The typical CT appearances of intracranial germinomas are described in three cases. These consist of an isodense or hyperdense tumour in the mid-line, originating from the pineal body or infundibulum, with marked increase in density on contrast enhancement. Periventricular tumour expansion in relation to the entire supratentorial ventricular system is characteristic. The rapid tumour regression after small doses of radiation is stressed and complete regression of the tumour, as seen on CT, is a sign of its radio-curability. (orig.)

  14. 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.)

  15. The impact of iterative reconstruction on image quality and radiation dose in thoracic and abdominal CT

    International Nuclear Information System (INIS)

    Purpose: To compare the image quality and radiation dose between iterative reconstruction (IR) and standard filtered back projection (FBP) in CT of the chest and abdomen. Materials and methods: Thoracic CT was performed in 50 patients (38 male, 12 female; mean age, 51 ± 23 yrs; range, 7–85 yrs) and abdominal CT was performed in 50 patients (36 male, 14 female; mean age, 62 ± 13 yrs; range, 20–85 yrs), using IR as well as FBP for image reconstruction. Image noise was quantitatively assessed measuring standard deviation of Hounsfield Units (HU) in defined regions of interest in subcutaneous tissue. Scan length and Computed Tomography Dose Index (CTDI) were documented. Scan length, image noise, and CTDI of both reconstruction techniques were compared by using paired tests according to the nature of variables (McNemar test or Student t test). Overall subjective image quality and subjective image noise were compared. Results: There was no significant difference between the protocols in terms of mean scan length (p > 0.05). Image noise was statistically significantly higher with IR, although the difference was clinically insignificant (13.3 ± 3.0 HU and 13.6 ± 3.0 HU for thoracic CT and 11.5 ± 3.1 HU and 11.7 ± 3.0 HU for abdominal CT, p < 0.05). There was no significant difference in overall subjective image quality and subjective image noise. The radiation dose was significantly lower with IR. Volume-weighted CTDI decreased by 64% (6.2 ± 2.5 mGy versus 17.1 ± 9.5 mGy, p < 0.001) for thoracic CT and by 58% (7.8 ± 4.6 mGy versus 18.5 ± 8.6 mGy, p < 0.001) for abdominal CT. Conclusions: Our study shows that in thoracic and abdominal CT with IR, there is no clinically significant impact on image quality, yet a significant radiation dose reduction compared to FBP

  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. Chest CT findings in patients with inflammatory myopathy and Jo1 antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Karadimitrakis, Stylianos; Plastiras, Sotiris C. [University of Athens Medical School, Department of Pathophysiology, Laiko University Hospital, 75 M. Asias Street, 11527 Athens (Greece); Zormpala, Alexandra; Chatzikonstantinou, Konstantinos [Department of Radiology, Laiko University Hospital, Athens (Greece); Boki, Kyriaki A. [University of Athens Medical School, Department of Pathophysiology, Laiko University Hospital, 75 M. Asias Street, 11527 Athens (Greece); Tzelepis, George E. [University of Athens Medical School, Department of Pathophysiology, Laiko University Hospital, 75 M. Asias Street, 11527 Athens (Greece)], E-mail: gtzelep@med.uoa.gr; Moutsopoulos, Haralampos M. [University of Athens Medical School, Department of Pathophysiology, Laiko University Hospital, 75 M. Asias Street, 11527 Athens (Greece)

    2008-04-15

    Thoracic high-resolution computed tomography scans (HRCT) of 17 patients with inflammatory muscle disorders (IMD) and positive Jo1 antibodies were retrospectively reviewed regarding presence, extension, and distribution of pathological findings. Abnormal findings were found in 14 (82.3%) patients. The predominant CT abnormality was ground glass attenuation, which was present in seven patients (41.1%), having a bilateral and diffuse distribution. In general, lesions tended to appear in the lower lobes and more specifically in the lung bases. Interlobular septal thickening was found in six patients (35.3%); it was seen in the upper and lower lobes with peripheral distribution and bilateral localization in five out of six patients. Bronchiectases, reticular opacities, and honeycombing were found in six patients (35.3%). Air space consolidation was seen in about 17% of the patients. Lung involvement is a frequent feature of IMD patients with positive Jo1 antibodies and its most common radiological pattern is that of nonspecific interstitial pneumonia.

  19. Chest CT findings in patients with inflammatory myopathy and Jo1 antibodies

    International Nuclear Information System (INIS)

    Thoracic high-resolution computed tomography scans (HRCT) of 17 patients with inflammatory muscle disorders (IMD) and positive Jo1 antibodies were retrospectively reviewed regarding presence, extension, and distribution of pathological findings. Abnormal findings were found in 14 (82.3%) patients. The predominant CT abnormality was ground glass attenuation, which was present in seven patients (41.1%), having a bilateral and diffuse distribution. In general, lesions tended to appear in the lower lobes and more specifically in the lung bases. Interlobular septal thickening was found in six patients (35.3%); it was seen in the upper and lower lobes with peripheral distribution and bilateral localization in five out of six patients. Bronchiectases, reticular opacities, and honeycombing were found in six patients (35.3%). Air space consolidation was seen in about 17% of the patients. Lung involvement is a frequent feature of IMD patients with positive Jo1 antibodies and its most common radiological pattern is that of nonspecific interstitial pneumonia

  20. 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.)

  1. 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

    International Nuclear Information System (INIS)

    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 (RVV/LVV) were calculated. RVV/LVV 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 RVV/LVV and PASP (R = 0.82, p V/LVV were 0.990 and 0.892. RVV/LVV 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 V/LVV, 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.)

  2. 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.

  3. Low-dose CT scan screening for lung cancer: comparison of images and radiation doses between low-dose CT and follow-up standard diagnostic CT

    OpenAIRE

    ONO, KOJI; Hiraoka, Toru; Ono, Asami; Komatsu, Eiji; Shigenaga, Takehiko; Takaki, Hajime; Maeda, Toru; Ogusu, Hiroyuki; Yoshida, Shintaro; Fukushima, Kiyoyasu; Kai, Michiaki

    2013-01-01

    Objectives This study aim to compare image quality and radiation doses between low-dose CT and follow-up standard diagnostic CT for lung cancer screening. Methods In a single medical institution, 19 subjects who had been screened for lung cancer by low-dose CT before going through follow-up standard diagnostic CT were randomly selected. Both CT image sets for all subjects were independently evaluated by five specialized physicians. Results There were no significant differences between low-dos...

  4. 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

  5. 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.

  6. Bone scan findings of chest wall pain syndrome after stereotactic body radiation therapy: implications for the pathophysiology of the syndrome

    OpenAIRE

    Lloyd, Shane; Decker, Roy H.; Evans, Suzanne B.

    2013-01-01

    We present a case of a 72-year-old woman treated with stereotactic body radiation therapy (SBRT) for peripherally located stage I non-small cell lung cancer (NSCLC). After treatment she developed ipsilateral grade II chest wall pain. A bone scan showed nonspecific and heterogeneous increased radiotracer uptake in the volume of ribs receiving 30% of the prescription dose of radiation (V30). We present a color wash image demonstrating excellent concordance between the V30 and the area of scinti...

  7. Reduction of patient radiation dose in Spiral CT scan

    International Nuclear Information System (INIS)

    To optimize patient radiation dose in Spiral CT scan of dento-maxillo-facial region by measuring the absorbed dose in the phantom and to evaluate reliability of dose estimation methods using CTDI (CT Dose Index, FDA, USA). Spiral CT scanning with 'pitchs' (ratio of table speed to slice thickness per rotation) more than 1 was used for dose measurements. The dose was measured using a human phantom (Alderson Research Laboratories, USA) in the CT scan with a 3rd generation CT scanner of Somatom Plus (Siemens, Germany) for bone imaging. CTDI for this CT scanner were 9.2 mGy/100 mA at the center in an acrylic resin phantom with diameter of 16 cm and 8.5 mGy/100 mA at 1 cm depth from the phantom surface. X-ray tube voltage of 120 kV and tube current of 85 mA was used. Slice thickness was varied from 1 to 3 mm and table speed per rotation was also varied from 1 to 5 mm per rotation. X-Omat-V (Eastman Kodak, USA) films and TLD (Thermo-Luminescent-Dosimetry) dosimeters of the type of MSO-S (Kyokko, Japan) were used in the dosimetry. Patients radiation dose reduced with increasing the pitch of SPIRAL scan. Measured dose was uniformly distributed and well corresponded to the dose calculated using CTDI. However, measured doses on scanning with 1 mm slice thickness were always higher than those with 2 to 5 mm slice thickness. The lowest radiation dose was obtained with scanning with 2 mm slice thickness and table speed of 4 mm per rotation which give the dose of about 4 mGy per one CT examination in the imaged tissues. The highest dose per one CT examination was measured in 'dental CT' for the mandibular region with 1 mm slice thickness and table speed of 1 mm per rotation which gave 12 mGy by film dosimetry and 9 mGy by TLD dosimetry. SPIRAL scan with pitch more than 1 was effective for reduction of patient radiation dose without reducing the image quality. CTDI was also useful to estimate the dose except scans with 1 mm slice thickness. (author)

  8. Screening for distant metastases in head and neck cancer patients using FDG-PET and chest CT: validation of an algorithm.

    Science.gov (United States)

    Senft, Asaf; Hoekstra, Otto S; Witte, Birgit I; Leemans, C René; de Bree, Remco

    2016-09-01

    In patients with head and neck squamous cell carcinoma and high-risk factors, the combination of whole body FDG-PET and contrast-enhanced chest CT has the highest sensitivity and accuracy when screening for distant metastases. The aim of the present study was to retrospectively validate an earlier developed algorithm for interpreting the combination of screening PET and CT. The test cohort consisted of 47 consecutive HNSCC patients with high-risk factors for distant metastases, who had previously undergone FDG-PET and CT and had a minimum 12 months of follow-up. In 12 (26 %) patients, distant metastases were detected during screening or within 12-month follow-up. In patients with locoregional control during follow-up, the sensitivity and specificity were 55 % (95 % CI 23-83 %) and 97 % (95 % CI 82-99 %), respectively, for chest CT, 55 % (95 % CI 23-83 %) and 100 % (95 % CI 88-100 %), respectively, for PET and 73 % (95 % CI 39-94 %) and 100 % (95 % CI 88-100 %), respectively, for the combination of PET and CT. The proposed algorithm was considered to have been validated. In this algorithm, all FDG-PET positive scans for distant metastases (regardless of interpretation of a solid lung lesion on CT) and CT scans with suspicious pulmonary lesions of less than 5-mm diameter (regardless of FDG-PET findings) are considered positive for distant metastases. PMID:26350882

  9. 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.

  10. Toward high-contrast breast CT at low radiation dose.

    Science.gov (United States)

    Keyriläinen, Jani; Fernández, Manuel; Karjalainen-Lindsberg, Marja-Liisa; Virkkunen, Pekka; Leidenius, Marjut; von Smitten, Karl; Sipilä, Petri; Fiedler, Stefan; Suhonen, Heikki; Suortti, Pekka; Bravin, Alberto

    2008-10-01

    This study was approved by the local research ethics committee, and patient informed consent was obtained. The purpose of this study was to demonstrate that high-spatial-resolution low-dose analyzer-based x-ray computed tomography (CT) can substantially improve the radiographic contrast of breast tissue in vitro when compared with that attained by using diagnostic mammography and CT. An excised human breast tumor was examined by using analyzer-based x-ray imaging with synchrotron radiation. The correspondence between analyzer-based x-ray images and diagnostic mammograms, CT images, and histopathologic findings was determined. Calcifications and fine details of soft tissue, which are at the contrast detection limit on diagnostic mammograms, are clearly visible on planar analyzer-based x-ray images. Analyzer-based x-ray CT yields high contrast from smoothly varying internal structures, such as tumorous mass lesions, corresponding to information on actual structures seen at histopathologic analysis. The mean glandular dose of 1.9 mGy in analyzer-based x-ray CT is approximately equivalent to the dose administered during single-view screening mammography. The improved visibility of mammographically indistinguishable lesions in vitro suggests that analyzer-based x-ray CT may be a valuable method in radiographic evaluation of the breast, thereby justifying further investigations. PMID:18796684

  11. 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.

  12. 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.

  13. Coronary computed tomography and triple rule out CT in patients with acute chest pain and an intermediate cardiac risk profile. Part 1: Impact on patient management

    Energy Technology Data Exchange (ETDEWEB)

    Gruettner, Joachim, E-mail: joachim.gruettner@umm.de [Emergency Department, University Medical Center, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Fink, Christian, E-mail: Christian.Fink@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Walter, Thomas, E-mail: thomas.walter@umm.de [Emergency Department, University Medical Center, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Meyer, Mathias, E-mail: mr.meyer.mathias@gmail.com [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Apfaltrer, Paul, E-mail: Paul.Apfaltrer@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, Ashley River Tower, 25 Courtenay Drive, Charleston, SC 29425-2260 (United States); Saur, Joachim, E-mail: joachim.saur@umm.de [1st Department of Medicine (Cardiology), University Medical Center, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Sueselbeck, Tim, E-mail: tim.sueselbeck@umm.de [1st Department of Medicine (Cardiology), University Medical Center, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Traunwieser, Dominik, E-mail: dominik.traunwieser@umm.de [1st Department of Medicine (Cardiology), University Medical Center, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Takx, Richard, E-mail: richard.takx@gmail.com [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, Ashley River Tower, 25 Courtenay Drive, Charleston, SC 29425-2260 (United States); and others

    2013-01-15

    Objective: To evaluate the impact of coronary CT angiography (coronary CTA) or “triple-rule-out” CT angiography (TRO-CTA) on patient management in the work-up of patients with acute chest pain and an intermediate cardiac risk profile. Materials and methods: 100 patients with acute chest pain and an intermediate cardiac risk for acute coronary syndrome (ACS) underwent coronary CTA or TRO-CTA for the evaluation of chest pain. Patients with a high and low cardiac risk profile were not included in this study. All patients with significant coronary stenosis >50% on coronary CTA underwent invasive coronary catheterization (ICC). Important other pathological findings were recorded. All patients had a 90-day follow-up period for major adverse cardiac events (MACE). Results: Based on a negative coronary CTA 60 of 100 patients were discharged on the same day. None of the discharged patients showed MACE during the 90-day follow-up. Coronary CTA revealed a coronary stenosis >50% in 19 of 100 patients. ICC confirmed significant coronary stenosis in 17/19 patients. Among the 17 true positive patients, 9 underwent percutaneous coronary intervention with stent implantation, 7 were received intensified medical therapy, and 1 patient underwent coronary artery bypass surgery. A TRO-CTA protocol was performed in 36/100 patients due to elevated D-dimer levels. Pulmonary embolism was present in 5 patients, pleural effusion of unknown etiology in 3 patients, severe right ventricular dysfunction with pericardial effusion in 1 patient, and an incidental bronchial carcinoma was diagnosed in 1 patient. Conclusion: Coronary CTA and TRO-CTA allow a rapid and safe discharge in the majority of patients presenting with acute chest pain and an intermediate risk for ACS while at the same time identifies those with significant coronary artery stenosis.

  14. Application of Dual-source CT High-pitch Spiral in the Chest Screening%双源CT大螺距扫描在胸部筛查的应用

    Institute of Scientific and Technical Information of China (English)

    李贞旭; 殷洁; 吕国义; 李建灵; 向旭; 陈怡帆; 司尚干

    2015-01-01

    目的:分析双源 CT 大螺距扫描在胸部筛查的辐射剂量。方法选择180例行双源 CT 胸部扫描的患者随机分为三组,用螺距行胸部平扫并记录 CTDIvol、DLP 值,使用独立样本 t 检验比较3组扫描模式的辐射剂量间差异。结果三组病例中,图像 SD 值无统计学差异(P>0.05);三组病例的 CTDIvol 值、DLP 值差异均有统计学意义(P0.05);The three groups of cases CTDIvol value DLP, value dif erences were statistical y significant (P<0.05), and the radiation dose in group A to group B, C 64.2%、49.7%. Conclusion Dual-source spiral CT pitch scan is a new model under the premise of the clinical diagnosis for chest screening.

  15. Hyperthermia combined with radiation therapy for superficial breast cancer and chest wall recurrence: A review of the randomised data

    OpenAIRE

    Zagar, Timothy M.; OLESON, JAMES R.; Vujaskovic, Zeljko; Dewhirst, Mark W.; Craciunescu, Oana I; BLACKWELL, KIMBERLY L.; Prosnitz, Leonard R.; Jones, Ellen L.

    2010-01-01

    Hyperthermia has long been used in combination with radiation for the treatment of superficial malignancies, in part due to its radiosensitising capabilities. Patients who suffer superficial recurrences of breast cancer, be it in their chest wall following mastectomy, or in their breast after breast conservation, typically have poor clinical outcomes. They often develop distant metastatic disease, but one must not overlook the problems associated with an uncontrolled local failure. Morbidity ...

  16. Deformable image registration of CT and truncated cone-beam CT for adaptive radiation therapy

    Science.gov (United States)

    Zhen, Xin; Yan, Hao; Zhou, Linghong; Jia, Xun; Jiang, Steve B.

    2013-11-01

    Truncation of a cone-beam computed tomography (CBCT) image, mainly caused by the limited field of view (FOV) of CBCT imaging, poses challenges to the problem of deformable image registration (DIR) between computed tomography (CT) and CBCT images in adaptive radiation therapy (ART). The missing information outside the CBCT FOV usually causes incorrect deformations when a conventional DIR algorithm is utilized, which may introduce significant errors in subsequent operations such as dose calculation. In this paper, based on the observation that the missing information in the CBCT image domain does exist in the projection image domain, we propose to solve this problem by developing a hybrid deformation/reconstruction algorithm. As opposed to deforming the CT image to match the truncated CBCT image, the CT image is deformed such that its projections match all the corresponding projection images for the CBCT image. An iterative forward-backward projection algorithm is developed. Six head-and-neck cancer patient cases are used to evaluate our algorithm, five with simulated truncation and one with real truncation. It is found that our method can accurately register the CT image to the truncated CBCT image and is robust against image truncation when the portion of the truncated image is less than 40% of the total image. Part of this work was presented at the 54th AAPM Annual Meeting (Charlotte, NC, USA, 29 July-2 August 2012).

  17. Virtual monochromatic imaging in dual-source dual-energy CT: Radiation dose and image quality

    OpenAIRE

    Yu, Lifeng; Christner, Jodie A.; Leng, Shuai; Wang, Jia; Fletcher, Joel G.; McCollough, Cynthia H.

    2011-01-01

    Purpose: To evaluate the image quality of virtual monochromatic images synthesized from dual-source dual-energy computed tomography (CT) in comparison with conventional polychromatic single-energy CT for the same radiation dose.

  18. Overview of two years of clinical experience of chest tomo-synthesis at Sahlgrenska university hospital

    International Nuclear Information System (INIS)

    Since December 2006, ∼ 3800 clinical chest tomo-synthesis examinations have been performed at our department at Sahlgrenska Univ. Hospital. A subset of the examinations has been included in studies of the detectability of pulmonary nodules, using computed tomography (CT) as the gold standard. Visibility studies, in which chest tomo-synthesis and CT have been compared side-by side, have been used to determine the depiction potential of chest tomo-synthesis. Comparisons with conventional chest radiography have been made. In the clinical setting, chest tomo-synthesis has mostly been used as an additional examination. The most frequent indication for chest tomo-synthesis has been suspicion of a nodule or tumour. In visibility studies, tomo-synthesis has depicted over 90% of the nodules seen on the CT scan. The corresponding figure for chest radiography has been <30%. In the detection studies, the lesion-level sensitivity has been ∼ 60% for tomo-synthesis and 20% for chest radiography. In one of the detection studies, an analysis of all false-positive nodules was performed. This analysis showed that all findings had morphological correlates on the CT examinations. The majority of the false-positive nodules were localised in the immediate sub-pleural region. In conclusion, chest tomo-synthesis is an improved chest radiography method, which can be used to optimise the use of CT resources, thereby reducing the radiation dose to the patient population. However, there are some limitations with chest tomo-synthesis. For example, patients undergoing tomo-synthesis have to be able to stand still and hold their breath firmly for 10 s. Also, chest tomo-synthesis has a limited depth resolution, which may explain why pathology in the sub-pleural region is more difficult to interpret and artefacts from medical devices may occur. (authors)

  19. Radiographic and CT features of radiation-induced organizing pneumonia syndrome after breast-conserving therapy

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate radiographic and computed tomography features of radiation-induced organizing pneumonia syndrome after breast-conserving surgery. The appearances and distribution of lung parenchymal abnormalities were retrospectively analyzed on chest radiographs (n=12) and computed tomography scan images (n=10) of 12 women (range 37-78 years, mean 55.8 years) with radiation-induced organizing pneumonia syndrome after breast-conserving surgery. The principal radiographic feature was an airspace filling pattern in all patients that involved the middle and lower lung zones in 10 of the 12 patients. Multi-focal lesions manifesting airspace consolidation surrounded by ground-glass opacities were the predominant CT finding in all 10 of these patients. The main lesion was predominantly located in the lung periphery in nine patients and contiguously extended to the central portion of the lung in seven patients. Frequent ancillary findings were airway dilation within the consolidation and lobar volume loss in nine and eight patients, respectively. All had solitary (6/10) or multifocal (4/10) distant lung opacities, mostly consistent with the finding of ground-glass opacities (9/10). Migration of the lung disease was observed in ten patients on subsequent radiographs. The cardinal radiologic feature of this syndrome is airspace consolidation surrounded by ground-glass opacification with airway dilation and volume loss, involving primarily the irradiated, subpleural area, along with distant opacities. (author)

  20. 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 ...

  1. 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.

  2. Chest Wall Thickness Measurements and the Dosimetric Implications for Male Radiation Workers at the KAERI

    International Nuclear Information System (INIS)

    Using ultrasound techniques, the Korea Atomic Energy Research Institute has measured chest wall thicknesses of a group of male workers at the Korea Atomic Energy Research Institute. A site-specific biometric equation has been developed for these workers. Chest wall thickness is an important modifier on lung counting efficiency. These data have been put into the perspective of the ICRP recommended dose limits for occupationally exposed workers:100 mSv in a 5-year period with a maximum of 50 mSv in any one year. For measured chest wall thicknesses of 1.9 cm to 4.1 cm and a 30 min counting time, the achievable MDAs for natural uranium in the KAERI lung counter vary from 5.75 mg to 11.28 mg. These values are close to, or even exceed, the predicted amounts of natural uranium that will remain in the lung (absorption type M and S) after an intake equal to the Annual Limit on Intake corresponding to a committed dose of 20 mSv. This paper shows that the KAERI lung counter probably cannot detect an intake of Type S natural uranium in a worker with a chest wall thickness equal to the average value (2.7 cm) under routine counting conditions

  3. Chest radiography and CT characteristics analysis of infantile pulmonary tuberculosis%婴儿肺结核胸部X线和CT影像学特征分析

    Institute of Scientific and Technical Information of China (English)

    龚春竹; 朱朝敏

    2012-01-01

    目的 分析婴儿肺结核的胸部X线和CT的影像学特征.方法 回顾性收集重庆医科大学附属儿童医院(我院)2001年1月至2011年12月确诊和临床诊断为婴儿肺结核的病例资料,提取胸部X线和CT的影像学资料用于分析.结果 研究期间共诊断203例婴儿肺结核,其中188例在我院行胸部X线或CT检查纳入分析.132例行胸部X线检查、144例行胸部CT检查,其中88例同时行CT和胸部X线检查.①132例胸部X线片示肺实质浸润115例(87.1%),纵隔增宽33例(25.0%),肺门增大9例(6.8%).②144例胸部CT示肺实质浸润143例(99.3%),纵隔、肺门淋巴结肿大120例(83.3%).143例肺实质浸润部位分布中双肺109例,右肺上叶132例,右肺中叶124例,右肺下叶124例,左肺上叶118例,左肺下叶118例;120例淋巴结肿大患儿中,常见肿大淋巴结部位依次为右肺门(72例)、腔静脉后(58例)、左肺门(49例)和隆突下(44例).肺门和纵隔淋巴结同时受累88例(73.3%).③胸部CT在提示肺实质浸润、空洞、淋巴结肿大、支气管病变、胸膜病变和钙化等方面均优于胸部X线片.结论 肺实质浸润伴淋巴结肿大是婴儿肺结核影像学的基本特征.胸部CT对婴儿肺结核的诊断优于胸部X线片.%Objective The purpose of this shirty was to analyze the features of radiographic and CT findings of pulmonary tuberculosis in infants. Methods Clinical data of infants diagnosed as pulmonary tuberculosis in chongqing medical university affiliated children's hospital from January 2001 to December 2011 were retrospectively collected, and chest X-ray and CT imaging data were analyzed. Results A total of 203 cases were diagnosed as infantile pulmonary tuberculosis in study period , 188 finished chest X-ray or CT examination cases in our hospital were brought into the analysis, 132 finished chest X-ray examination, 144 finished chest CT examination and 88 cases finished both of them. Chest radiographs showed pulmonary

  4. 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

  5. Coronary computed tomography and triple rule out CT in patients with acute chest pain and an intermediate cardiac risk for acute coronary syndrome

    International Nuclear Information System (INIS)

    Objective: To evaluate the economic impact of integrating coronary CT angiography (cCTA) or whole chest “triple-rule-out” CTA (TRO-CTA) in the work-up of patients with acute chest pain. Materials and methods: 100 consecutive emergency department patients with acute chest pain and an intermediate cardiac risk for ACS underwent cCTA or TRO-CTA (cCTA group). Diagnostic performance, rate and length of hospitalization, hospital costs, hospital reimbursement and hospital profit were analyzed. All findings were compared to those of 100 different patients with acute chest pain that were evaluated with a standard of care (SOC) diagnostic algorithm (SOC group) that did not include cCTA. Diagnostic performance (“safety”) of both algorithms was defined as the absence of major adverse cardiac events (MACE) over a 90-day follow-up period. Results: In the cCTA group 60/100 patients were safely discharged at the same day. 19/100 patients were hospitalized due to significant coronary stenosis on cCTA, which was confirmed by invasive coronary catheterization (ICC) in 17/19 patients. Relevant non-coronary disease that led to hospitalization were found in 21 patients of the cCTA group. In the SOC group all patients were hospitalized. 87 of these hospitalized patients underwent ICC for exclusion of coronary artery stenosis. A significant coronary artery stenosis was found in only 25 of these patients. Within the cCTA group no patient suffered from MACE over the 90-day follow-up period. In the SOC group 2 patients were rehospitalized during the 90-day follow-up period due to recurrent chest pain and 1 patient because of a pseudoaneurym of the left femoral artery after ICC. The median hospital costs per patient were significantly lower in the cCTA group than in the SOC group (428.9€ vs. 1575.0€, p < 0.001). The median reimbursement of the cCTA group was less compared to the SOC group (589.8€ vs. 2412.1€, p < 0.001) and patients in the cCTA group gained less profit than

  6. Radiation protection in newer medical imaging techniques: CT colonography

    International Nuclear Information System (INIS)

    Multislice/detector computed tomography (CT) scanning, applied to visualization of the colon in CT colonography (CTC), also known as virtual colonoscopy (VC), is a relatively new application of CT introduced in recent years. The possibility of its application in population screening techniques raises a number of questions. Effort is required to ensure that the benefit of this new practice will not pose an undue level of detriment to the individual in multiple examinations. For practitioners and regulators, it is evident that innovation has been driven by both the imaging industry and by an ever increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practice lag (inevitably) behind the industrial and clinical innovations being achieved. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill this growing vacuum, by bringing up to date and timely advice to bear on the problems involved. Under its statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for worldwide application of these standards, the IAEA has developed the Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS). The BSS was issued by the IAEA and co-sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organisation (ILO), the OECD Nuclear Energy Agency (OECD/NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO), and requires radiation protection of patients undergoing medical exposures through justification of the procedures involved and through optimization. The IAEA programme on radiation protection of patients encourages the reduction of patient doses without losing diagnostic benefits. To facilitate this

  7. 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

  8. Estimation of frequency and pretest probability of CAD in patients presenting with recent onset chest pain by multi-detector CT angiography

    Directory of Open Access Journals (Sweden)

    Omar Muayad Sultan

    2016-03-01

    Conclusion: CAD was seen in 77.5% in those with recent onset chest pain. Higher incidence of significant CAD was seen in hypertensive and diabetic patients. Family history is still not a reliable factor in our society. Male patient <60 years old has higher incidence of CAD than female in same age group. Pretest probability for CAD is a simple and important test as all patients in higher probability have CAD and most of them have significant disease so it is better to direct referral of them to conventional angiography to gain a benefit from direct intervention, radiation and cost benefit.

  9. Influence of 'optical illusion' on the detectability of pneumothorax in diagnosis for chest CT images. Substantiation by visual psychological simulation images

    International Nuclear Information System (INIS)

    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. (author)

  10. Radiation protection in newer medical imaging techniques: Cardiac CT

    International Nuclear Information System (INIS)

    Medical imaging has seen many developments as it has evolved since the mid-1890s. In the last 30-40 years, the pace of innovation has increased, starting with the introduction of computed tomography (CT) in the early 1970s. During the last decade, the rate of change has accelerated further, in terms of continuing innovation and its global application. Most patient exposure now arises from practices that barely existed two decades ago. These developments are evident in the technology on which this volume is based - multislice/detector CT scanning and its application in cardiac imaging. However, this advance is achieved at the cost of a radiation burden to the individual patient, and possibly to the community, if its screening potential is exploited. Much effort will be required to ensure that the undoubted benefit of this new practice will not pose an undue level of detriment to the individual in multiple examinations. For practitioners and regulators, it is evident that innovation has been driven by both the imaging industry and an increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practices lag (inevitably) behind the industrial and clinical innovations. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill this growing vacuum, by bringing up to date and timely advice from experienced practitioners to bear on the problems involved. The advice in this report has been developed as part of the IAEA's statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for the worldwide application of these standards. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) were issued by the IAEA and co-sponsored by organizations including the Food and Agriculture

  11. The chest features of patients with the novel influenza type A H1N1 on high resolution CT

    International Nuclear Information System (INIS)

    Objective: To explore the chest features of patients with the novel influenza type A H1N1 on HRCT. Methods: One hundred and seventy-two chest HRCT examinations on 163 cases with Influenza type A H1N1 (9 cases were reexamed) were retrospectively analyzed using standard pulmonary window and mediastinal window, respectively. HRCT imaging appearances were summarized. Results: Ninety-seven cases showed normal on chest HRCT, while the others showed abnormalities of parenchymal and interstitial. Among them, HRCT identified ground-glass opacity in 35 cases (53.0%), centrilobular nodules in 30 cases (45.5%), thickening of intralobular septa in 31 cases (47.0%), intralobular thin reticulation and micro-nodule in 8 cases (12.1%), single-lobular inflammation in 19 cases (28.8%), consolidation of lung (the large consolidation and multiple small consolidations) in 15 cases (22.7%), pulmonary atelectasis in 3 cases (4.5%), and irregular lines in 2 cases (3.0%). Pleurisy was also revealed including 8 cases with right pleurisy, 5 cases with left pleurisy, 5 cases with left pleurisy, and 19 cases with bilateral pleurisy. Mediastinal and axillary lymphadenopathy were found in 7 cases, who were spared of pleural effusion. All above abnormalities resolved quickly after anti-virus treatment. Conclusion: Parenchymal and interstitial abnormalities, mediastinum and axillary fossa lymphadenopathy, and pleural effusion were the common findings on HRCT in patients with Influenza type A H1N1, which were similar to those of other viral pneumonia. (authors)

  12. Observation of Allende and Antarctic meteorites by monochromatic X-ray CT based on synchrotron radiation

    OpenAIRE

    Hirano,Tatsumi/Funaki,Minoru/Nagata,Takesi/Taguchi,Isamu/ Hamada,Hiroki/Usami,Katsuhisa/Hayakawa,Kazunobu

    1990-01-01

    Three-dimensional CT images of the Allende meteorite with a high resolution of 10μm have been obtained nondestructively by a monochromatic X-ray computed tomography (CT) based on synchrotron radiation (SR). The metallic minerals, matrix and chondrules can be clearly observed in the CT images. The CT values, which express the image intensity, allow a quantitative elemental analysis including such as difference in the metallic minerals, i. e., pentlandite and troilite, using the comparison of C...

  13. 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.)

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

    International Nuclear Information System (INIS)

    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 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.)

  15. Robotically Driven Interventions: A Method of Using CT Fluoroscopy without Radiation Exposure to the Physician1

    OpenAIRE

    Solomon, Stephen B.; Patriciu, Alexandru; Bohlman, Mark E.; Kavoussi, Louis R.; Stoianovici, Dan

    2002-01-01

    Radiation exposure to physicians’ hands during interventional procedures with computed tomography (CT) fluoroscopic guidance may be high. A robot was developed that could hold, orient, and advance a needle, with CT fluoroscopic guidance. This robot could be either computer or joystick controlled. Twenty-three robotically guided percutaneous interventions were performed without complication. Physician radiation exposure was negligible during the CT fluoroscopy–guided procedures.

  16. Chest X-Ray

    Medline Plus

    Full Text Available ... However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. ...

  17. 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.

  18. 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).

  19. [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.

  20. Low dose multi-detector CT of the chest (iLEAD Study): Visual ranking of different simulated mAs levels

    Energy Technology Data Exchange (ETDEWEB)

    Ley-Zaporozhan, Julia [Department of Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg (Germany); Department of Radiology (E010), German Cancer Research Center, Heidelberg (Germany)], E-mail: julia.leyzaporozhan@gmail.com; Ley, Sebastian [Department of Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg (Germany); Department of Radiology (E010), German Cancer Research Center, Heidelberg (Germany); Krummenauer, Frank [Clinical Epidemiology and Health Economy Unit, Carl Gustav Carus University Hospital, Dresden (Germany); Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Hatabu, Hiroto [Department of Radiology, Brigham and Women' s Hospital, Boston, MA (United States); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg (Germany)

    2010-02-15

    Purpose: Detailed evaluation of the lung parenchyma might be impaired by use of low dose CT as image noise increases and subsequently image quality decreases. The aim of our study was to determine the accuracy of visual perception of differences in image quality and noise at low dose chest CT. Materials and methods: Forty-four patients suffering from emphysema underwent CT (Aquilion-16, 120 kV, 150 mAs, 1 mm-collimation). Original raw data were used for simulation of 10 different mAs settings from 10 mAs to 100 mAs in 10 mAs increments. Three representative hard copy images (carina, 4 cm above, 5 cm below) were printed for evaluation of lung parenchyma (high-resolution kernel, lung window) and mediastinum (soft-kernel, soft tissue window). Ranking of expected low mAs level was performed for lung and soft tissue separately based on visual perception by three-blinded chest radiologist independently. Results were compared to the real simulated mAs. Results: The accuracy for correct ranking of the original 150 mAs scan was 89% for lung and 86% for soft tissue while it was 99% for the simulated 10 mAs for both windows. In comparison to the lowest mAs a significant error increase was found for the lung at 60-100 mAs (with error increase of 30-47%) for reader-I; 60-100 mAs for (33-64%) for reader-II and 70-100 mAs (38-57%) for reader-III. For the soft tissue: 60-150 mAs (with error increase of 28-63%) for reader-I; 50-100 mAs (35-56%) for reader-II and 50-90 mAs (35-40%) for reader-III. Conclusion: Simulated dose levels below 60 mAs (=42 mAs{sub eff}) were clearly differentiated from higher dose levels by all readers. Therefore, imaging doses could be lowered down to 60 mAs without a diagnostically relevant increase in noise impairing image quali0008.

  1. Coronary artery calcification in clinical practice: what we have learned and why should it routinely be reported on chest CT?

    Science.gov (United States)

    Shemesh, Joseph

    2016-04-01

    The recent acceptance of low dose chest computed tomography (LDCT) as a screening modality for early lung cancer detection will significantly increase the number of LDCT among high risk population. The target subjects are at the same time at high risk to develop cardiovascular (CV) events. The routine report on coronary artery calcification (CAC) will therefore, enhances the screening benefit by providing the clinicians with an additive powerful risk stratification tool for the management or primary prevention of CV events. This review will provide the radiologists with helpful information for the daily practice regarding on what is CAC, its clinical applications and how to diagnose, quantify and report on CAC while reading the LDCT. PMID:27195277

  2. 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.)

  3. 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

  4. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine. Pt. 1. The radiation risk from CT

    International Nuclear Information System (INIS)

    The theory of radiation carcinogenesis has been debated for decades. Most estimates of the radiation risks from CT have been based on extrapolations from the lifespan follow-up study of atomic bomb survivors and on follow-up studies after therapeutic radiation, using the linear no-threshold theory. Based on this, many population-based projections of induction of future cancers by CT have been published that should not be used to estimate the risk to an individual because of their large margin of error. This has changed recently with the publication of three large international cohort follow-up studies, which link observed cancers to CT scans received in childhood. A fourth ongoing multi-country study in Europe is expected to have enough statistical power to address the limitations of the prior studies. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) report released in 2013 specifically addresses variability in response of the pediatric population exposed to ionizing radiation. Most authorities now conclude that there is enough evidence to link future cancers to the radiation exposure from a single CT scan in childhood but that cancer risk estimates for individuals must be based on the specifics of exposure, age at exposure and absorbed dose to certain tissues. Generalizations are not appropriate, and the communication of the CT risk to individuals should be conducted within the framework of personalized medicine. (orig.)

  5. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine. Pt. 1. The radiation risk from CT

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-15

    The theory of radiation carcinogenesis has been debated for decades. Most estimates of the radiation risks from CT have been based on extrapolations from the lifespan follow-up study of atomic bomb survivors and on follow-up studies after therapeutic radiation, using the linear no-threshold theory. Based on this, many population-based projections of induction of future cancers by CT have been published that should not be used to estimate the risk to an individual because of their large margin of error. This has changed recently with the publication of three large international cohort follow-up studies, which link observed cancers to CT scans received in childhood. A fourth ongoing multi-country study in Europe is expected to have enough statistical power to address the limitations of the prior studies. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) report released in 2013 specifically addresses variability in response of the pediatric population exposed to ionizing radiation. Most authorities now conclude that there is enough evidence to link future cancers to the radiation exposure from a single CT scan in childhood but that cancer risk estimates for individuals must be based on the specifics of exposure, age at exposure and absorbed dose to certain tissues. Generalizations are not appropriate, and the communication of the CT risk to individuals should be conducted within the framework of personalized medicine. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, S [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Bravin, A [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Keyrilaeinen, J [Department of Physical Sciences, POB 64, FIN-00014 Helsinki University (Finland); Fernandez, M [Department of Physical Sciences, POB 64, FIN-00014 Helsinki University (Finland); Suortti, P [Department of Physical Sciences, POB 64, FIN-00014 Helsinki University (Finland); Thomlinson, W [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Tenhunen, M [Department of Oncology, Helsinki University Central Hospital, POB 180, FIN-00029 HUS (Finland); Virkkunen, P [Department of Oncology, Helsinki University Central Hospital, POB 180, FIN-00029 HUS (Finland); Karjalainen-Lindsberg, M-L [Department of Pathology, HUCH Laboratory Diagnostics, Helsinki University Central Hospital, POB 400, FIN-00029 HUS (Finland)

    2004-01-21

    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.

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

    International Nuclear Information System (INIS)

    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.)

  8. 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.)

  9. SU-E-I-31: Differences Observed in Radiation Doses Across 2 Similar CT Scanners From Adult Brain-Neck CT Angiography

    International Nuclear Information System (INIS)

    Purpose: The aim of this study is to evaluate the difference in radiation doses from adult Brain-Neck CT angiography (CTA) between two CT scanners. Methods: We collected CT dose index data (CTDIvol, DLP) from adult Brain-Neck CTA performed with two CT scanners (Sensation 64 (S64) and Definition AS (AS), Siemens Healthcare) performed at two of our facilities from Jan 1st to Dec 31th, 2014. X-ray dose management software (Radmetrics, Bayer Healthcare) was used to mine these data. All exams were performed with Tube Current Modulation (Care Dose 4D), tube voltage of 120 kVp, quality reference mAs of 300, beam collimation of 64*0.6 mm. The rotation time was set to 0.5 sec for S64 and 1.0 sec for AS. We also scanned an anthropomorphic skull and chest phantom under routine Brain-Neck CTA protocol with the two scanners and extracted the tube current values from the raw projection data. Results: The mean CTDIvol and DLP in Brain-Neck CTA was 72 mGy and 2554 mGy*cm for AS, which was substantially larger than the mean values of 46 mGy and 1699 mGy*cm for S64. The maximum tube current was 583 mA for most cases on the S64 while the maximum was 666 mA for AS even though the rotation time set for AS was 1.0 sec. Measurements obtained with the anthropomorphic phantom showed that the tube current reached 583 mA at the shoulder region for S64 while it reached to 666 mA for AS. Conclusion: The results of this study showed that substantially different CT doses can Result from Brain-Neck CTA protocols even when similar scanners and similar settings are used. Though both scanners have a similar maximum mA rating, differences in mA were observed through the shoulders, resulting in substantially different CTDIvol values

  10. SU-E-I-31: Differences Observed in Radiation Doses Across 2 Similar CT Scanners From Adult Brain-Neck CT Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K [Graduate School of Medicine, Nagoya University, Nagoya, JP (Japan); UCLA School of Medicine, Los Angeles, CA (United States); McMillan, K; Bostani, M; Cagnon, C; McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2015-06-15

    Purpose: The aim of this study is to evaluate the difference in radiation doses from adult Brain-Neck CT angiography (CTA) between two CT scanners. Methods: We collected CT dose index data (CTDIvol, DLP) from adult Brain-Neck CTA performed with two CT scanners (Sensation 64 (S64) and Definition AS (AS), Siemens Healthcare) performed at two of our facilities from Jan 1st to Dec 31th, 2014. X-ray dose management software (Radmetrics, Bayer Healthcare) was used to mine these data. All exams were performed with Tube Current Modulation (Care Dose 4D), tube voltage of 120 kVp, quality reference mAs of 300, beam collimation of 64*0.6 mm. The rotation time was set to 0.5 sec for S64 and 1.0 sec for AS. We also scanned an anthropomorphic skull and chest phantom under routine Brain-Neck CTA protocol with the two scanners and extracted the tube current values from the raw projection data. Results: The mean CTDIvol and DLP in Brain-Neck CTA was 72 mGy and 2554 mGy*cm for AS, which was substantially larger than the mean values of 46 mGy and 1699 mGy*cm for S64. The maximum tube current was 583 mA for most cases on the S64 while the maximum was 666 mA for AS even though the rotation time set for AS was 1.0 sec. Measurements obtained with the anthropomorphic phantom showed that the tube current reached 583 mA at the shoulder region for S64 while it reached to 666 mA for AS. Conclusion: The results of this study showed that substantially different CT doses can Result from Brain-Neck CTA protocols even when similar scanners and similar settings are used. Though both scanners have a similar maximum mA rating, differences in mA were observed through the shoulders, resulting in substantially different CTDIvol values.

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

    International Nuclear Information System (INIS)

    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 μGy). 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.)

  12. 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.)

  13. 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.

  14. 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.

  15. 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.

  16. Reducing CT radiation dose with iterative reconstruction algorithms: The influence of scan and reconstruction parameters on image quality and CTDIvol

    International Nuclear Information System (INIS)

    Highlights: • Iterative reconstruction (IR) and filtered back projection (FBP) were compared. • CT image noise was reduced by 12.4%–52.2% using IR in comparison to FBP. • IR did not affect high- and low-contrast resolution. • CTDIvol was reduced by 26–50% using hybrid IR at comparable image quality levels. • IR produced good to excellent image quality in patients. - Abstract: Objectives: In this phantom CT study, we investigated whether images reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) with reduced tube voltage and current have equivalent quality. We evaluated the effects of different acquisition and reconstruction parameter settings on image quality and radiation doses. Additionally, patient CT studies were evaluated to confirm our phantom results. Methods: Helical and axial 256 multi-slice computed tomography scans of the phantom (Catphan®) were performed with varying tube voltages (80–140 kV) and currents (30–200 mAs). 198 phantom data sets were reconstructed applying FBP and IR with increasing iterations, and soft and sharp kernels. Further, 25 chest and abdomen CT scans, performed with high and low exposure per patient, were reconstructed with IR and FBP. Two independent observers evaluated image quality and radiation doses of both phantom and patient scans. Results: In phantom scans, noise reduction was significantly improved using IR with increasing iterations, independent from tissue, scan-mode, tube-voltage, current, and kernel. IR did not affect high-contrast resolution. Low-contrast resolution was also not negatively affected, but improved in scans with doses <5 mGy, although object detectability generally decreased with the lowering of exposure. At comparable image quality levels, CTDIvol was reduced by 26–50% using IR. In patients, applying IR vs. FBP resulted in good to excellent image quality, while tube voltage and current settings could be significantly decreased. Conclusions: Our

  17. 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.)

  18. 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.

  19. 儿童慢性肉芽肿病胸部CT表现%Chest CT manifestations of chronic granulomatous disease in children

    Institute of Scientific and Technical Information of China (English)

    赵晶; 彭芸; 贺建新

    2012-01-01

    Objective To describe the thoracic CT features of chronic granulomatous disease in children. Methods The chest CT and Laboratory test were retrospectively analyzed and summarized in 30 diagnosed CGD between June 2004 and December 2009. Results Most patients presented with respiratory infections. 23 patients were younger than 2 years old. CT discovered mediastinal and/or hilar lymphadcnopathy in 27 patients, lymph nodes calcification in 17 patients, including 14 patients with ipsilateral axillary lymph node calcification after BCG vaccine. CT findings also included areas of consolidation in 19 paticnts, nodules and masses in 24 cases. Cavities in consolidation and nodules were found in 12 patients, in-terlobular septal thickening in 11 cases, pleural thickening in 10 patients, small amount of pleural effusion in 10 patients, bronchiectasis in 9 patients. These children had a total of 33 tests. 5 times were aspergillus infections in 21 clear tests of pathogen review. This result was coincided with CT findings . Imaging tips for aspergillus infections accounted for 4 times in 12 unclear pathogen review. Conclusion Thoracic CT manifestations of chronic granulomatous disease in children include consolidation, nodules, masses and cavities, with interstitial changes in common. Nodules and masses are highly suggestive of aspergillus infection, especially when pathogen tests are not clear, and imagings on the tips of aspergillus infections will be of great help. Mediastinal and/or hilar lymphadenopathy. ipsilateral axillary lymph node calcification after BCG vaccine has certain particularity, which is very useful for clinician to make diagnosis.%目的 分析儿童慢性肉芽肿病(CGD)胸部CT的特征性表现.方法 搜集我院2004年6月~2009年12月确诊的30例CGD患儿,对其胸部CT及实验室检查进行回顾性分析和总结.结果 30例CGD患儿,发病年龄小于2岁的有23例,大多数患儿以呼吸道感染来诊,CT发

  20. CT-assisted evaluation of the results of radiation and surgical treatment of paranasal and nasopharyngeal tumors

    International Nuclear Information System (INIS)

    A total of 40 patients with bening and malignant paranasal sinusal and nasopharyngeal tumors were examined to evaluate the effectiveness of radiation and surgical treatment with the help of computerized tomography (CT). The aim of CT examinations was to reveal CT-findings of radiation pathomorphosis of a tumor mass and contiguous tissue, to determine their CT-structure, and to find residual masses after the treatment. CT-findings of three stages of tumor radiation pathomorphosis were determined. Some criteria of objective assessment of the rsults of radiation and surgical treatment of paranasal sinusal and nasopharyngeal tumors were proposed

  1. Dose reduction using Bismuth protectors in chest computed tomography

    International Nuclear Information System (INIS)

    This monography is about the Dose reduction using Bismuth protectors in chest CT. The radiation protection of specific areas is necessary when the tissues or radiosensitive organs are near the path of light beam. The correct use of protection represents a challenge for the radiologist because of the time and materials required. The method used was a prospective investigatio in CHPR (TC service) and the doses was measured with TLD dosimeters. It is important to use these protectors in children hospitals.

  2. Patient dose simulation in X-ray CT using a radiation treatment-planning system

    International Nuclear Information System (INIS)

    Medical irradiation dosage has been increasing with the development of new radiological equipment and new techniques like interventional radiology. It is fair to say that patient dose has been increased as a result of the development of multi-slice CT. A number of studies on the irradiation dose of CT have been reported, and the computed tomography dose index (CTDI) is now used as a general means of determining CT dose. However, patient dose distribution in the body varies with the patient's constitution, bowel gas in the body, and conditions of exposure. In this study, patient dose was analyzed from the viewpoint of dose distribution, using a radiation treatment-planning computer. Percent depth dose (PDD) and the off-center ratio (OCR) of the CT beam are needed to calculate dose distribution by the planning computer. Therefore, X-ray CT data were measured with various apparatuses, and beam data were sent to the planning computer. Measurement and simulation doses in the elliptical phantom (Mix-Dp: water equivalent material) were collated, and the CT irradiation dose was determined for patient dose simulation. The rotational radiation treatment technique was used to obtain the patient dose distribution of CT, and patient dose was evaluated through simulation of the dose distribution. CT images of the thorax were sent to the planning computer and simulated. The result was that the patient dose distribution of the thorax was obtained for CT examination. (author)

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

    Science.gov (United States)

    Dhalisa, H.; Mohamad, A. S.; Rafidah, Z.

    2016-01-01

    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.

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

    International Nuclear Information System (INIS)

    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

  6. 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

    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......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....... Multivariate linear regression was performed to find predictors for a high contribution to life years lost from the radiation therapy planning diagnostics. RESULTS: 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...

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

    International Nuclear Information System (INIS)

    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.

  8. Management of chest keloids

    Directory of Open Access Journals (Sweden)

    Kim June Kyu

    2011-04-01

    Full Text Available Abstract Keloid formation is one of the most challenging clinical problems in wound healing. With increasing frequency of open heart surgery, chest keloid formations are not infrequent in the clinical practice. The numerous treatment methods including surgical excision, intralesional steroid injection, radiation therapy, laser therapy, silicone gel sheeting, and pressure therapy underscore how little is understood about keloids. Keloids have a tendency to recur after surgical excision as a single treatment. Stretching tension is clearly associated with keloid generation, as keloids tend to occur on high tension sites such as chest region. The authors treated 58 chest keloid patients with surgical excision followed by intraoperative and postoperative intralesional steroid injection. Even with minor complications and recurrences, our protocol results in excellent outcomes in cases of chest keloids.

  9. The diagnostic value of X-ray and CT scan of the chest trauma%X线平片和CT扫描对胸部创伤的诊断价值

    Institute of Scientific and Technical Information of China (English)

    陈志勇; 陈俊

    2016-01-01

    Objective:To discuss the diagnostic value of X-ray and CT scan of the chest trauma.Methods:30 patients with chest trauma were selected,doing X-ray,CT examination. Results: 13 cases were pulmonary exudative change, in which X-ray showed normal in 2 cases, while CT lung found pale patchy and high-density shadow.6 cases were pneumothorax,in which it was difficult to see very little pneumothorax for X-ray, while CT scan was clear.In addition, X-ray and CT could clear diagnosis of pneumohemothorax in 6 cases,pulmonary hematoma in 5 cases,hemothorax in 8 cases,rib fracture in 9 cases, mediastinal and subcutaneous emphysema in 6 cases,pulmonary atelectasis in 1 case.Conclusion:X-ray and CT scan are important methods in diagnosis of chest trauma,and CT is superior to X-ray.%目的:探讨 X 线平片和 CT 扫描对胸部创伤的诊断价值。方法:收治胸部创伤患者30例,行 X 线、CT 检查。结果:肺部渗出性改变13例,平片显示正常2例,而CT检查则均发现肺部的浅淡斑片状、云絮状高密度影。气胸6例,极少量的气胸,用平片很难看到,而CT扫描却十分清晰。另外,血气胸6例,肺血肿5例,胸腔积血8例,肋骨骨折9例,纵隔及皮下气肿6例,肺不张1例,X线和CT均能明确诊断。结论:X线平片和CT扫描是诊断胸部创伤的重要方法,而CT扫描明显优于X线平片。

  10. Radiation exposure with spiral CT of the paranasal sinuses; Strahlenexposition bei der Spiral-CT der Nasennebenhoehlen

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, F.; Momino-Traserra, E.; Remy, C.; Claussen, C.D. [Radiologische Universitaetsklinik Tuebingen (Germany). Abt. fuer Radiologische Diagnostik; Pereira, P.L.; Baumann, I.; Koitschev, A. [Universitaetsklinik Tuebingen (Germany). Klinik fuer Hals-Nasen-Ohrenheilkunde

    2000-03-01

    Purpose: Determination of the radiation doses in spiral CT of the paranasal sinuses using a variety of mAs values and scan protocols. Material and methods: CT examinations of the paranasal sinuses were performed using an Alderson-Rando phantom. Radiation dose was determined by LiF-TLD at the level of high risk organs in the head and neck region for combinations of different scan parameters (2/3, 3/3, 3/4 mm) and decreasing charges (200, 150, 100, 50, 25 mAs) on a spiral CT. Additional measurements were performed on three other CT scanners using the 2/3 mm protocol at 50 mAs, and a single slice technique (5/5 mm) on one scanner. Results: The lowest dose values found were 1.88 mGy for the eye lenses, 1.35 mGy for the parotid gland, 0.03 mGy for the thyroid gland and 0.1 mGy for the medulla oblongata using 2 mm collimation and 3 mm table feed at 25 mAs. Maximal dose values resulted using the 3/3 mm protocol at 200 mAs (31.00 mGy for the eye lense, 0.65 mGy for the thyroid gland). There were no significant differences found between the different CT scanners. Conclusions: Using up-to-date CT scanners, radiation exposure may be reduced by a factor of 15-20 compared to that of conventional CT technique. Thus, the exposure of the eye lens comes to only a thousandth of the value supposedly inducing a cataract, as published by the ICRP. (orig.) [German] Ziel: Systematische Erfassung der Strahlenexposition bei der Spiral-CT der Nasennebenhoehlen bei unterschiedlichen Dosen und Scanprotokollen. Material und Methoden: Am Alderson-Rando-Phantom wurden die Dosen an Risikoorganen im Kopf-Halsbereich mittels LiF-TLD-Sonden fuer Kombinationen aus unterschiedlichen Scanparametern (2/3, 3/3, 3/4 mm) und absteigender Ladung (200, 150, 100, 50, 25 mAs) an einem Spiral-CT gemessen. Zusaetzlich wurden Messungen an drei weiteren CT-Geraeten mit dem 2/3-Protokoll bei 50 mAs sowie an einem dieser Geraete im Einzelschicht-Modus mit 5/5 mm durchgefuehrt. Ergebnisse: Die niedrigsten Dosen

  11. Relationship of Image Quality and Radiation Dose for Chest Radiography in the Medical Institutions for Pneumoconiosis: A Comparison to the Korean Diagnostic Reference Level

    International Nuclear Information System (INIS)

    To evaluate the relationship of image quality to the measurement of radiation dose for chest radiography in the medical institutions for pneumoconiosis (MIPs). Film-screen radiography (FSR) (n = 24) and digital radiography (DR) (n = 5) were used as chest radiography modalities. The entrance surface dose (ESD) was measured from the exposure conditions routinely used for chest radiography using an ionization chamber dosimeter. All images were randomly selected for evaluating image quality from each of the MIPs, and independently rated by two experienced radiologists using a 3-point scale. ESD of DR was higher than FSR, excluding flat panel. However, image quality of DR was significantly higher than that of FSR, especially in flat panel and the charge-coupled device. ESD and tube voltage were not significantly correlated with image quality. DR more frequently exceeded the Korean diagnostic reference level for ESD than FSR (41.7% vs. 20.0%), though the difference was not statistically significant. DR used a higher radiation dose than FSR; however, there was a possibility of a radiation dose reduction in relation to image quality. We suggest that the MIPs transfer to a flat panel with automatic exposure control for a more effective radiation dose management.

  12. Relationship of Image Quality and Radiation Dose for Chest Radiography in the Medical Institutions for Pneumoconiosis: A Comparison to the Korean Diagnostic Reference Level

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jeong [Clincal Research Team, Occupational Lung Diseases Institute, Ansan (Korea, Republic of); Kim, Sung Jin [Dept. of Radiology, Chungbuk National University Hospital, Cheongju (Korea, Republic of); Park, Jai Soung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Seon, Jong Ryul [Dept. of Radiological Technology, Daejeon Health Science College, Daejeon (Korea, Republic of)

    2012-03-15

    To evaluate the relationship of image quality to the measurement of radiation dose for chest radiography in the medical institutions for pneumoconiosis (MIPs). Film-screen radiography (FSR) (n = 24) and digital radiography (DR) (n = 5) were used as chest radiography modalities. The entrance surface dose (ESD) was measured from the exposure conditions routinely used for chest radiography using an ionization chamber dosimeter. All images were randomly selected for evaluating image quality from each of the MIPs, and independently rated by two experienced radiologists using a 3-point scale. ESD of DR was higher than FSR, excluding flat panel. However, image quality of DR was significantly higher than that of FSR, especially in flat panel and the charge-coupled device. ESD and tube voltage were not significantly correlated with image quality. DR more frequently exceeded the Korean diagnostic reference level for ESD than FSR (41.7% vs. 20.0%), though the difference was not statistically significant. DR used a higher radiation dose than FSR; however, there was a possibility of a radiation dose reduction in relation to image quality. We suggest that the MIPs transfer to a flat panel with automatic exposure control for a more effective radiation dose management.

  13. 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

  14. Focused radiation hepatitis after Bragg-peak proton therapy for hepatocellular carcinoma: CT findings

    International Nuclear Information System (INIS)

    Radiation hepatitis is clearly demonstrated by noncontrast and contrast enhanced CT following radiotherapy for liver diseases. Radiation hepatitis is dependent on dose distribution and is usually demonstrated as nonsegmental bandlike lesion after photon therapy. We report a case of focused, oval-shaped radiation hepatitis that was induced by photon therapy. The attenuation difference was localized in a high-dose area caused by Bragg-peak proton therapy. 17 refs., 2 figs

  15. 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.

  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. Radiation Dose to the Thyroid and Gonads in Patients Undergoing Cardiac CT Angiography

    OpenAIRE

    Behroozi, Hamid; Davoodi, Mohammad; Aghasi, Shahriar

    2015-01-01

    Background: The present data show a global increase in the rate of cardiovascular disease. Cardiac CT angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. Objectives: The aim of this study was to measure the radiation dose to the thyroid and pelvis regions in patients undergoing cardiac CT angiography using the Care Dose 4D method of 64-slice scanner. Patients and Methods: Eighty-one patients (41 males an...

  18. CT dosimetry and risk estimates

    International Nuclear Information System (INIS)

    Conventional approaches to CT dosimetry are inadequate because they fail to evaluate the risk to the patient. A risk related approach to CT dosimetry is developed which explicitly takes into account the non-uniform dose distribution in the body and the relative sensitivities of different organs and tissues. The principal radiological risks to patients undergoing CT examinations are the stochastic processes of carcinogenesis and genetic effects. Radiation risk estimates have been obtained for an EMI 5005 CT scanner by measuring the mean organ doses in a Rando phantom for CT studies on the head, chest, abdomen and pelvis. The application of these risk estimates to the population served by this CT scanner indicates that during the lifetime of the CT scanner, approximately 50,000 patients will undergo CT scanning and 60% will result in a positive diagnosis. The radiation detriment is estimated to be about 1 induced cancer and a negligible genetic effect. The radiation detriment is considerably smaller than the total detriment associated with contrast material used in 76% of the CT studies. (author)

  19. Chest drainage.

    Science.gov (United States)

    Carter, Chris

    2014-07-15

    As an intensive care nurse with experience of caring for critically ill patients in the UK and on deployed operations overseas, I found the CPD article useful in reviewing the pathophysiology of a pneumothorax, use of intrapleural chest drains, observations that should be recorded, and nursing care and management of a patient with an intrapleural chest drain. Reflecting on the time out activities in the CPD article was valuable. PMID:25005418

  20. Study of dosimetric quantities applied to patient undergoing routine chest examinations by computed tomography

    International Nuclear Information System (INIS)

    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 (PK,L), organ equivalent dose (HT) 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 HT and E and acceptable agreement for CW ,CVOL and PK,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)

  1. CT radiation profile width measurement using CR imaging plate raw data.

    Science.gov (United States)

    Bjarnason, Thorarin Albert; Yang, Chang-Ying Joseph

    2015-01-01

    This technical note demonstrates computed tomography (CT) radiation profile measurement using computed radiography (CR) imaging plate raw data showing it is possible to perform the CT collimation width measurement using a single scan without saturating the imaging plate. Previously described methods require careful adjustments to the CR reader settings in order to avoid signal clipping in the CR processed image. CT radiation profile measurements were taken as part of routine quality control on 14 CT scanners from four vendors. CR cassettes were placed on the CT scanner bed, raised to isocenter, and leveled. Axial scans were taken at all available collimations, advancing the cassette for each scan. The CR plates were processed and raw CR data were analyzed using MATLAB scripts to measure collimation widths. The raw data approach was compared with previously established methodology. The quality control analysis scripts are released as open source using creative commons licensing. A log-linear relationship was found between raw pixel value and air kerma, and raw data collimation width measurements were in agreement with CR-processed, bit-reduced data, using previously described methodology. The raw data approach, with intrinsically wider dynamic range, allows improved measurement flexibility and precision. As a result, we demonstrate a methodology for CT collimation width measurements using a single CT scan and without the need for CR scanning parameter adjustments which is more convenient for routine quality control work. PMID:26699559

  2. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  4. 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)

  5. RADIANCE: An automated, enterprise-wide solution for archiving and reporting CT radiation dose estimates.

    Science.gov (United States)

    Cook, Tessa S; Zimmerman, Stefan L; Steingall, Scott R; Maidment, Andrew D A; Kim, Woojin; Boonn, William W

    2011-01-01

    There is growing interest in the ability to monitor, track, and report exposure to radiation from medical imaging. Historically, however, dose information has been stored on an image-based dose sheet, an arrangement that precludes widespread indexing. Although scanner manufacturers are beginning to include dose-related parameters in the Digital Imaging and Communications in Medicine (DICOM) headers of imaging studies, there remains a vast repository of retrospective computed tomographic (CT) data with image-based dose sheets. Consequently, it is difficult for imaging centers to monitor their dose estimates or participate in the American College of Radiology (ACR) Dose Index Registry. An automated extraction software pipeline known as Radiation Dose Intelligent Analytics for CT Examinations (RADIANCE) has been designed that quickly and accurately parses CT dose sheets to extract and archive dose-related parameters. Optical character recognition of information in the dose sheet leads to creation of a text file, which along with the DICOM study header is parsed to extract dose-related data. The data are then stored in a relational database that can be queried for dose monitoring and report creation. RADIANCE allows efficient dose analysis of CT examinations and more effective education of technologists, radiologists, and referring physicians regarding patient exposure to radiation at CT. RADIANCE also allows compliance with the ACR's dose reporting guidelines and greater awareness of patient radiation dose, ultimately resulting in improved patient care and treatment. PMID:21969661

  6. 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)

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

    International Nuclear Information System (INIS)

    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 CaSO4: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)

  8. 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.)

  9. Radiation dose to the patient and the radiologist while performing on chest computed tomography: a program of early diagnosis of lung cancer, biopsy and treatment simulation guided radiation oncologist breast cancer

    International Nuclear Information System (INIS)

    In this paper we determine the equivalent dose received by the operator and patient lung biopsies using thermoluminescence dosimeters, are established recommendations that this dose is as low as possible. It also reviews the acquisition protocols in both CT scans in early diagnosis program cited as the acquisition of CT for treatment planning dosimetric radiation oncologist in breast cancer.

  10. Radiation doses and image quality in pediatric chest X-ray for the diagnosis of pneumonia in selected Latin American countries

    International Nuclear Information System (INIS)

    Full text: Pneumonia and acute lower respiratory infections in general, is the leading cause of child death in developing countries. According to the World Health Organization (WHO), 4 millions of children die annually due to this disease. Despite the growing use of vaccination as an alternate approach to reduce mortality, the increasing antimicrobial resistance and the high costs of vaccines remain important obstacles in the global struggle against the disease. The usual treatment strategy begins with a clinical examination of the patient followed by the prescription of a chest X-ray. Radiography would appear as the best available method for diagnosing pneumonia only if radiologists (and other health professionals such as pediatricians) knew how to interpret the images showed in the radiographs, and these meeting the standards of quality (anatomic structures, image contrast and optical density, and patient dose among other factors). On the other hand, special attention should be paid on patient doses due to children's specific radiosensitivity, repeated and extended use of chest x-ray in all Radiology Departments, and high rejection rate due to both equipment malfunction and to human skills shortcomings. Patient doses of chest X-ray performed to children less than 5 years old in PAHO Sentinel Hospitals for surveillance of bacterial pneumonias in various Latin American countries were estimated using technical parameters and equipment specifications. Image quality was compared to WHO criteria for chest X-rays quality. Results showing differences in patient doses translates on one hand the impact of specific characteristics of the radiological equipment, including equipment limitations and performance of the radiographs and on the other various and divers levels of health professionals skills and training on image quality interpretation and dose optimization. The study concludes that professionals' training and education on chest radiographs image quality constitutes

  11. 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.

  12. 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.)

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

    International Nuclear Information System (INIS)

    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.)

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

    Science.gov (United States)

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

    2014-04-01

    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 radiation-induced cancer compared with adults and have a long lifespan to express harmful effects which may offset clinical benefits of performing a scan. This paper describes the design and methodology of a nationwide study, the Dutch Pediatric CT Study, regarding risk of leukemia and brain tumors in children after radiation exposure from CT scans. It is a retrospective record-linkage cohort study with an expected number of 100,000 children who received at least one electronically archived CT scan covering the calendar period since the introduction of digital archiving until 2012. Information on all archived CT scans of these children will be obtained, including date of examination, scanned body part and radiologist's report, as well as the machine settings required for organ dose estimation. We will obtain cancer incidence by record linkage with external databases. In this article, we describe several approaches to the collection of data on archived CT scans, the estimation of radiation doses and the assessment of confounding. The proposed approaches provide useful strategies for data collection and confounder assessment for general retrospective record-linkage studies, particular those using hospital databases on radiological procedures for the assessment of exposure to ionizing or non-ionizing radiation. PMID:24748424

  15. Radiation Protection in Paediatric Computed Tomography

    International Nuclear Information System (INIS)

    The number of examinations with radiation exposure has been increasing mainly due to advances in computed tomography (CT) technology, with a rapid expansion of CT utilization. Annually, 3.6 billion diagnostic and medical and dental examinations involving radiation are performed worldwide. The contribution of CT to collective dose due to medical X rays is up to 47–59%. A 2009 report of the National Council on Radiation Protection and Measurements (NCRP) estimates that 8–10% of CT examinations in the United States of America are performed on children; the growth in CT utilization is higher in the paediatric than adult population in the USA; and there is a particularly pronounced rise in adolescents undergoing chest CT in the emergency department setting for suspected pulmonary embolism or trauma. The reasons for the growing incidence of CT are new indications for CT with the advent of multidetector CT, overcautious ordering related to medico-legal problems and probably financial incentive systems

  16. Radiation risk to critical organ during brain CT

    International Nuclear Information System (INIS)

    Study was performed to evaluate dose to critical organ for patient undergoing CT brain in modern medical center a total of 61 patient were examined in this study. The data collected from Modern Medical Center for brain. The data collected from Modern Medical Center for brain. The eye lens dose was 31.31 mSv, skin 29.23 mSv, cranium 30.01 mSv, brain 34.50 mSv, mandible 4.39 mSv, thyroid 2.59 mSv. The organ dose value were comparable to the previous studies. (Author)

  17. 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.

  18. Absorbed radiation doses in women undergone to PET-CT exams for cancer diagnosis

    International Nuclear Information System (INIS)

    The absorbed dose in several organs and the effective dose in patients submitted to PET-CT exams with the radiopharmaceutical 18F-FDG were assessed. The ICRP-106 biokinetic model and thermoluminescent detectors in a anthropomorphic phantom were used. The use of the PET-CT image acquisition protocol, with the CT protocol for anatomical mapping, showed that 60% of effective dose was from the radiotracer administration, being the effective dose values for a female patient of (5.80 ± 1.57) mSv. In conclusion, patient doses can be reduced by using appropriate imaging acquisition in 18F-FDG PET-CT examinations and promoting the compliance with the radiation protection principles. (author)

  19. Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

    OpenAIRE

    Nievelstein, R. A. J.; Quarles van Ufford, H.M.E.; Kwee, T. C.; Bierings, M.B.; Ludwig, I.; Beek, F. J. A.; de Klerk, J. M. H.; Mali, W P Th M; de Bruin, P.W.; Geleijns, J.

    2012-01-01

    Objective To quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with 18F-fluorodeoxyglucose (18F-FDG) in patients with malignant lymphoma (Hodgkin’s disease [HD] or non-Hodgkin’s lymphoma [NHL]). Methods First, organ doses were assessed for a typical diagnostic work-up in children with HD and adults with NHL. Subsequently, life tables were constructed for assessment of radiation risks, also taking into account the diseas...

  20. Study on radiation dose caused by 18F-FDG in PET/CT examination

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to investigate the radiation dose caused by 18F-flu- orodeoxyglucose (FDG) in PET/CT examination and to optimize the concerned radiation protection. Methods: Thirty patients from our conventional PET/CT examination were simple randomly selected, and they all underwent whole body PET/CT imaging. The radioactive dose of injected 18F-FDG was recorded. The internal radiation dose was calculated and the external radiation dose from patients was measured with the 451P-DE-SI ion chamber survey meter. The staff's dose was recorded with thermoluminescent detector (TLD). All dosimetry data were processed and analyzed statistically with Excel 2003. Results: The injected radioactive dose of 18F-FDG was (432.9 ± 51.8) MBq, and effective dose equivalent received per patient was (8.23 ± 0.99) mSv. The correlation coefficient (r) of the dose equivalent rate and distance was -0.994 by power function curve fitting, and that of dose equivalent rate and time was -0.988 by exponential curve fitting. The staff's dose was lower than the annual dose limit. Conclusions: The patient's internal radiation dose caused by 18F-FDG in PET/CT examination is low, nonetheless, the clinician should always consider optimizing and minimizing the necessary radiation received by the patients. The patients having been injected with 18F-FDG should stay in one place to decrease their radiation to the public. From the medical point of view in optimizing radiation exposure, there may still be a potential to lower the injected 18F-FDG activity. (authors)

  1. Individualized volume CT dose index determined by cross-sectional area and mean density of the body to achieve uniform image noise of contrast-enhanced pediatric chest CT obtained at variable kV levels and with combined tube current modulation

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2011-07-15

    A practical body-size adaptive protocol providing uniform image noise at various kV levels is not available for pediatric CT. To develop a practical contrast-enhanced pediatric chest CT protocol providing uniform image noise by using an individualized volume CT dose index (CTDIvol) determined by the cross-sectional area and density of the body at variable kV levels and with combined tube current modulation. A total of 137 patients (mean age, 7.6 years) underwent contrast-enhanced pediatric chest CT based on body weight. From the CTDIvol, image noise, and area and mean density of the cross-section at the lung base in the weight-based group, the best fit equation was estimated with a very high correlation coefficient ({gamma}{sup 2} = 0.86, P < 0.001). For the next study, 177 patients (mean age, 7.9 years; the CTDIvol group) underwent contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the best fit equation. CTDIvol values on the dose report after CT scanning, noise differences from the target noise, areas, and mean densities were compared between these two groups. The CTDIvol values (mean{+-}standard deviation, 1.6 {+-} 0.7 mGy) and the noise differences from the target noise (1.1 {+-} 0.9 HU) of the CTDIvol group were significantly lower than those of the weight-based group (2.0 {+-} 1.0 mGy, 1.8 {+-} 1.4 HU) (P < 0.001). In contrast, no statistically significant difference was found in area (317.0 {+-} 136.8 cm{sup 2} vs. 326.3 {+-} 124.8 cm{sup 2}), mean density (-212.9 {+-} 53.1 HU vs. -221.1 {+-} 56.3 HU), and image noise (13.8 {+-} 2.3 vs. 13.6 {+-} 1.7 HU) between the weight-based and the CTDIvol groups (P > 0.05). Contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the cross-sectional area and density of the body provides more uniform noise and better dose adaptation to body habitus than does weight-based CT at variable kV levels and with combined tube current modulation. (orig.)

  2. 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.)

  3. Scan Quality and Entrance Skin Dose in Thoracic CT: A Comparison between Bismuth Breast Shield and Posteriorly Centered Partial CT Scans

    International Nuclear Information System (INIS)

    Objectives. To compare the effectiveness of the bismuth breast shield and partial CT scan in reducing entrance skin dose and to evaluate the effect of the breast shield on image quality (IQ). Methods. Nanodots were placed on an adult anthropomorphic phantom. Standard chest CT, CT with shield, and partial CT were performed. Nanodot readings and effective doses were recorded. 50 patients with chest CTs obtained both with and without breast shields were reviewed. IQ was evaluated by two radiologists and by measuring Hounsfield units (HUs) and standard deviation (SD) of HU in anterior subcutaneous region. Results. Breast shield and the partial CT scans reduced radiation to the anterior chest by 38% and 16%, respectively. Partial CT increased dose to the posterior chest by 37% and effective dose by 8%. Change in IQ in shield CT was observed in the anterior chest wall. Significant change in IQ was observed in 5/50 cases. The shield caused an increase of 20 HU (P = 0.021) and a 1.86 reduction in SD of HU (P = 0.027) in the anterior compared to posterior subcutaneous regions. Summary. Bismuth breast shield is more effective than the partial CT in reducing entrance skin dose while maintaining image quality

  4. 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...

  5. Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

    NARCIS (Netherlands)

    Nievelstein, R. A. J.; van Ufford, H. M. E. Quarles; Kwee, T. C.; Bierings, M. B.; Ludwig, I.; Beek, F. J. A.; de Klerk, J. M. H.; Mali, W. P. Th. M.; de Bruin, P. W.; Geleijns, J.

    2012-01-01

    Objective To quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with F-18-fluorodeoxyglucose (F-18-FDG) in patients with malignant lymphoma (Hodgkin's disease [HD] or non-Hodgkin's lymphoma [NHL]). Methods First, organ doses we

  6. Large mediastinal tumor mass as a prognostic factor in Hodgkin's lymphoma. Is the definition on the basis of a chest radiograph in the era of CT obsolete?

    Energy Technology Data Exchange (ETDEWEB)

    Kriz, J.; Haverkamp, U.; Eich, H.T. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Mueller, R.P. [Koeln Univ. (Germany). Dept. of Radiation Oncology; Mueller, H.; Engert, A. [Koeln Univ. (Germany). Dept. of Medical Oncology; Kuhnert, G.; Kobe, C. [Koeln Univ. (Germany). Dept. of Nuclear Medicine

    2012-11-15

    Purpose: The risk factor 'large mediastinal tumor mass' is an internationally accepted unfavorable prognostic factor in the staging of Hodgkin's lymphoma (HL). The definition of this risk factor varies considerably between large cooperative study groups. The purpose of the present analysis was to determine to which degree data obtained from chest radiograph (CRX) give the same results as those from CT scans (CT). Methods: A total of 145 de novo HL patients in early unfavorable and advanced stages were included in this study. A total of 94 patients had a large mediastinal tumor mass according to the guidelines of the German Hodgkin Study Group (GHSG), while 51 had mediastinal lymph node involvement only. The size of mediastinal involvement and the thoracic diameter were measured on CRX and CT. Agreement between CRX and CT was determined by sensitivity and specificity analysis as well as descriptive statistics and correlations. Results: The correlation of the diameters on CRX with those of CT was 0.95 for the tumor size and 0.77 for the thoracic diameter. The diagnostic decision - large mediastinal mass or not - correlated with 0.81 between CRX and CT and was identical in 90.3% of cases. The sensitivity was 0.87 and the specificity 0.96 for CRX, which is considered the current standard. Conclusion: The results show that there is a high agreement between the measurements of CRX and CT. Diagnosis of a large mediastinal mass disagreed in 10% of patients. Since the correct diagnosis of this risk factor is decisive for the adequate multimodal treatment choice, CRX should not be omitted. (orig.)

  7. 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.

  8. 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.

  9. Comparison between x-ray tube-based and synchrotron radiation-based μCT

    Science.gov (United States)

    Brunke, Oliver; Brockdorf, Kathleen; Drews, Susanne; Müller, Bert; Donath, Tilman; Herzen, Julia; Beckmann, Felix

    2008-08-01

    Nowadays, X-ray tube-based high-resolution CT systems are widely used in scientific research and industrial applications. But the potential, convenience and economy of these lab systems is often underestimated. The present paper shows the comparison of sophisticated conventional μCT with synchrotron radiation-based μCT (SRμCT). The different aspects and characteristics of both approaches like spatial and density resolution, penetration depth, scanning time or sample size is described in detail. The tube-based μCT measurements were performed with a granite-based nanotom®-CT system (phoenix|x-ray, Wunstorf, Germany) equipped with a 180 kV - 15 W high-power nanofocus® tube with tungsten or molybdenum targets. The tube offers a wide range of applications from scanning low absorbing samples in nanofocus® mode with voxel sizes below 500 nm and highly absorbing objects in the high power mode with focal spot and voxel sizes of a few microns. The SRμCT measurements were carried out with the absorption contrast set-up at the beamlines W 2 and BW 2 at HASYLAB/DESY, operated by the GKSS Research Center. The range of samples examined covers materials of very different absorption levels and related photon energies for the CT scans. Both quantitative and qualitative comparisons of CT scans using biomedical specimens with rather low X-ray absorption such as parts of the human spine as well as using composites from the field of materials science are shown.

  10. 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.

  11. 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)

  12. 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

    International Nuclear Information System (INIS)

    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)

  13. Is PET/CT efficient tool to evaluate the response after stereotactic radiation therapy for pancreas cancer?

    International Nuclear Information System (INIS)

    In pancreas cancer, to evaluate the efficacy of PET/CT as tool to check the response after stereotactic radiation therapy and to define functional imaging role of PET/CT as alterative tool of computed tomography. From November 2003 to December 2004, among locally advanced pancreas cancer patients treated by stereotactic radiation therapy using CyberKnife(CK), 14 were evaluated by PET/CT before and after treatment. Four patients took PET/CT one month after CK, 4 patients 2 months after CK, and 6 patients 3 months after CK as the first evaluation of treatment. All of patients were also evaluated by CT or CA19-9 tumor antigen with the range of 1-2 months after CK. In addition of PET/CT to CT, lymph node metastasis were revealed as positive in 4 patients who had negative finding on CT. Furthermore, patients who showed partial or complete response on PET/CT findings that checked within 3 months after CK have significantly longer median survival time than patients who showed no response or disease progression(13 months and 9 months, respectively). Responses based on CA19-9 tumor antigen or CT, however, showed no significant difference in terms of median survival time. PET/CT can provide more information for lymph node metastasis compared to CT alone. It is very helpful for delineation of tumor extent for CK planning. And initial response on PET/CT scan could be a significant prognostic factor rather than response on CA19-9 level or CT. In the future, more study is necessary to evaluate if PET/CT could substitute CT and finally CT could be omitted during follow-up period after CK

  14. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction

    International Nuclear Information System (INIS)

    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.)

  15. 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.

  16. 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.)

  17. An experimental study of dual-energy CT imaging using synchrotron radiation

    International Nuclear Information System (INIS)

    The measurement of electron density is important for medical diagnosis and charged particle radiotherapy treatment planning. Traditionally, electron density is obtained by CT imaging using the relationship between CT-number and electron densities established beforehand. However, the measurement is not accurate due to the beam hardening effect. In this paper, we propose a simple and practical electron density acquisition method based on dual-energy CT technique. For each sample, the CT imaging is conducted using two selected X-ray energy from synchrotron radiation. A post-processing dual-energy reconstruction method is used. Linear attenuation coefficients of the scanned samples are obtained by FBP reconstruction. The effective atomic number and electron density are got by solving the dual-energy simultaneous equations. Different phantoms and breast tissues were scanned in this experimental study under 10 keV and 30 keV monochromatic X-rays. The distribution of effective atomic numbers and electron densities of the scanned phantoms were obtained by Dual-energy CT image reconstruction, which agrees well with the theoretical values. Compared with conventional methods, the measurement accuracy is greatly improved, and the measurement error is reduced to about 1%, This experimental study demonstrates that DECT imaging based on synchrotron radiation source is applicable to medical diagnosis for quantitative measurement with high accuracy. (authors)

  18. 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

  19. A method for estimating radiation interaction coefficients for tissues from single energy CT

    Science.gov (United States)

    Midgley, S. M.

    2014-12-01

    A parametric model for the x-ray linear attenuation coefficient is used to describe the compositional dependence of Hounsfield numbers measured by medical CT scanners. Measurements with materials of known density and composition, that span and evenly sample the compositional range of tissues, are written as linear simultaneous equations and solved for model coefficients. An algorithm is identified for this purpose. Results are expressed as atomic cross-sections in units of barn per electron divided by the attenuation coefficient for water. With the CT scanner characterised, a virtual CT scan can be simulated to predict HN for tissues based upon their known density and composition. Similar calculations using the tabulations and mixture rule deliver attenuation coefficients and mass energy absorption coefficients for mono-energetic radiation 10 keV to 20 MeV. Results are presented for measurements with a radiotherapy CT simulator, the RMI-467 phantom with tissue substitute materials, plus common polymer materials and silicon. Published measurements with earlier generations of the phantom and tissue substitutes using different CT scanners are also considered. Measured atomic cross-sections differ from expectations for mono-energetic radiation due to the use of a filtered spectrum and energy integrating detection system. The cross-sections for different CT scanners are similar, without large variations with kVp. Results are presented showing the relationship between predicted HN for tissues, electron density and photon interaction coefficients for healthy tissues and mono-energetic radiation. A strategy is suggested for accommodating strongly attenuating materials such as calculi and metallic implants.

  20. 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.

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

    International Nuclear Information System (INIS)

    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 (R2=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. 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.

  3. 4D PET-CT guided radiation therapy

    OpenAIRE

    Geets, X

    2013-01-01

    Tremendous technological progress in the field of imaging and computation have been revolutionizing radiotherapy of non-small cell lung cancer (NSCLC). Tumor biology can now be characterized by functional imaging for modifying treatment management and dose delivered in better accordance with the radiobiology of solid tumors and normal tissues. Specific radiation therapy (RT) strategies can further address the tumor motion issue, ensuring optimal tumor coverage with small safety margins.

  4. 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.

  5. 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.

  6. What Is Chest MRI?

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Chest MRI? Chest MRI (magnetic resonance imaging) is a safe, noninvasive test. "Noninvasive" means that ... your chest wall, heart, and blood vessels. Chest MRI uses radio waves, magnets, and a computer to ...

  7. 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.

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

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. CT in ureterolithiasis with a radiation dose equal to intravenous urography: results in 209 patients; CT der Ureterolithiasis mit der Strahlendosis einer Ausscheidungsurographie: Ergebnisse bei 209 Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Knoepfle, E.; Bohndorf, K. [Klinikum Augsburg (Germany). Klinik fuer Diagnostische Radiologie und Neuroradiologie; Hamm, M.; Wartenberg, S. [Klinikum Augsburg (Germany). Klinik fuer Urologie

    2003-12-01

    Purpose: To evaluate a low-dose, nonenhanced helical CT protocol for the diagnosis of renal colic using an effective dose equivalent of radiation not higher than that of intravenous urography. Materials and Methods: A new low-dose helical-CT protocol (120 kV; 70 mA; rotation time 0.75 s; collimation 5 mm, pitch=2) was used to examine 209 consecutive patients with symptoms of renal colic. The initial CT reports were compared with retrograde ureterography, ureteral endoscopy, stone retrieval, surgical or clinical findings. The effective radiation dose was calculated by the method published by Nagel. The prevalence of ureterolithiasis was 70%. Results: Sensitivity and specificity of the low-dose-helical CT in detecting ureteral calculi were 97.7% and 96.8%, respectively. The positive predictive value was 99.3% and negative predictive value 92.4%. The mean effective radiation dose equivalent was 0.97 mSv in male and 1.35 mSv in female patients. Conclusions: the diagnostic value of the reported CT protocol does no differ from previously published protocols. However, the effective radiation dose equivalent is at least 50% lower than stated in the published protocols. We recommend the low-dose helical CT protocol as the method of choice. (orig.) [German] Fragestellung: Pruefung der diagnostischen Aussagekraft eines nativen Spiral-CT-Protokolls mit einer niedrigen, einer Ausscheidungsurographie aequivalenten Strahlendosis bei der Abklaerung einer Harnleiterkolik. Methode: 209 konsekutive Patienten mit der klinischen Verdachtsdiagnose einer Harnleiterkolik wurden mit einem neuen CT-Protokoll untersucht (120 kV; 70 mA; Rotationszeit 0,75 s; Kollimation 5 mm; Pitch=2). Die prospektiv erhobenen CT-Befunde wurden mittels retrograder Ureterdarstellung, Ureterendoskopie, Steinasservierung, operativ oder im klinischen Verlauf validiert. Die effektive Dosis der CT-Untersuchung wurde nach Nagel berechnet. Die Praevalenz der Ureterolithiasis betrug 70%. Ergebnisse: Die Niedrig-Dosis-CT

  11. 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

  12. 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.

  13. 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...

  14. 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 (ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of 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. PMID:26271472

  15. 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

  16. 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.

  17. Reducing CT radiation dose with iterative reconstruction algorithms: The influence of scan and reconstruction parameters on image quality and CTDI{sub vol}

    Energy Technology Data Exchange (ETDEWEB)

    Klink, Thorsten, E-mail: klink_t1@ukw.de [Inselspital – Bern University Hospital, University Institute of Diagnostic, Interventional, and Pediatric Radiology, Freiburgstrasse 10, 3010 Bern (Switzerland); University of Würzburg, Insitute of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg (Germany); Obmann, Verena, E-mail: verena.obmann@insel.ch [Inselspital – Bern University Hospital, University Institute of Diagnostic, Interventional, and Pediatric Radiology, Freiburgstrasse 10, 3010 Bern (Switzerland); Heverhagen, Johannes, E-mail: johannes.heverhagen@insel.ch [Inselspital – Bern University Hospital, University Institute of Diagnostic, Interventional, and Pediatric Radiology, Freiburgstrasse 10, 3010 Bern (Switzerland); Stork, Alexander, E-mail: a.stork@roentgeninstitut.de [Roentgeninstitut Duesseldorf, Kaiserswerterstrasse 89, 40476 Duesseldorf (Germany); Adam, Gerhard, E-mail: g.adam@uke.de [University Medical Center Hamburg Eppendorf, Department of Diagnostic and Interventional Radiology, Martinistrasse 52, 20246 Hamburg (Germany); Begemann, Philipp, E-mail: p.begemann@roentgeninstitut.de [Roentgeninstitut Duesseldorf, Kaiserswerterstrasse 89, 40476 Duesseldorf (Germany)

    2014-09-15

    Highlights: • Iterative reconstruction (IR) and filtered back projection (FBP) were compared. • CT image noise was reduced by 12.4%–52.2% using IR in comparison to FBP. • IR did not affect high- and low-contrast resolution. • CTDI{sub vol} was reduced by 26–50% using hybrid IR at comparable image quality levels. • IR produced good to excellent image quality in patients. - Abstract: Objectives: In this phantom CT study, we investigated whether images reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) with reduced tube voltage and current have equivalent quality. We evaluated the effects of different acquisition and reconstruction parameter settings on image quality and radiation doses. Additionally, patient CT studies were evaluated to confirm our phantom results. Methods: Helical and axial 256 multi-slice computed tomography scans of the phantom (Catphan{sup ®}) were performed with varying tube voltages (80–140 kV) and currents (30–200 mAs). 198 phantom data sets were reconstructed applying FBP and IR with increasing iterations, and soft and sharp kernels. Further, 25 chest and abdomen CT scans, performed with high and low exposure per patient, were reconstructed with IR and FBP. Two independent observers evaluated image quality and radiation doses of both phantom and patient scans. Results: In phantom scans, noise reduction was significantly improved using IR with increasing iterations, independent from tissue, scan-mode, tube-voltage, current, and kernel. IR did not affect high-contrast resolution. Low-contrast resolution was also not negatively affected, but improved in scans with doses <5 mGy, although object detectability generally decreased with the lowering of exposure. At comparable image quality levels, CTDI{sub vol} was reduced by 26–50% using IR. In patients, applying IR vs. FBP resulted in good to excellent image quality, while tube voltage and current settings could be significantly decreased

  18. 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

  19. Radiation Dose to the Thyroid and Gonads in Patients Undergoing Cardiac CT Angiography

    International Nuclear Information System (INIS)

    The present data show a global increase in the rate of cardiovascular disease. Cardiac CT angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. The aim of this study was to measure the radiation dose to the thyroid and pelvis regions in patients undergoing cardiac CT angiography using the Care Dose 4D method of 64-slice scanner. Eighty-one patients (41 males and 40 females) who were diagnosed with suspected coronary artery disease and were referred to Golestan Hospital, Imaging Department were recruited. Inclusion criteria were based on the protocol of multi-slice CT coronary angiography. The radiation dose to the thyroid and pelvis regions was measured using thermo luminescent dosimeters (TLDs). The mean radiation dose to the thyroid in male and female subjects was 0.32 mSv and 0.41 mSv, respectively (P = 0.032) (total mean, 0.36 mSv). The mean radiation dose to the pelvis in male and female subjects was 81 μSv and 112 μSv, respectively (P = 0.026) (total mean, 96.5 μSv), The total mean radiation dose to the thyroid and gonads was 0.36 mSv, and 96.5 μSv, respectively for the subjects. These values were high for one organ in a single study. Gender can affect the radiation dose to the thyroid and gonads. This can be attributed to the anatomical characteristic differences of the male and female subjects

  20. Radiation Exposure of Patients by Cone Beam CT during Endobronchial Navigation - A Phantom Study

    OpenAIRE

    Hohenforst-Schmidt, Wolfgang; Banckwitz, Rosemarie; Zarogoulidis, Paul; Vogl, Thomas; Darwiche, Kaid; Goldberg, Eugene; Huang, Haidong; Simoff, Michael; Li, Qiang; Browning, Robert; Freitag, Lutz; Turner, J. Francis; Pivert, Patrick Le; Yarmus, Lonny; Zarogoulidis, Konstantinos

    2014-01-01

    Rationale: Cone Beam Computed Tomography imaging has become increasingly important in many fields of interventional therapies. Objective: Lung navigation study which is an uncommon soft tissue approach. Methods: As no effective organ radiation dose levels were available for this kind of Cone Beam Computed Tomography application we simulated in our DynaCT (Siemens AG, Forchheim, Germany) suite 2 measurements including 3D acquisition and again for 3D acquisition and 4 endobronchial navigation m...

  1. 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...

  2. 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

  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.; 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

  4. Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Nievelstein, R.A.J.; Kwee, T.C.; Beek, F.J.A.; Mali, W.P.T.M. [University Medical Center, Department of Radiology (E 01.132), Utrecht (Netherlands); Quarles van Ufford, H.M.E. [Medical Center Haaglanden, Department of Radiology, The Hague (Netherlands); Bierings, M.B. [University Medical Center, Department of Pediatric Hematology, Utrecht (Netherlands); Ludwig, I. [University Medical Center, Department of Hematology, Utrecht (Netherlands); Klerk, J.M.H. de [Meander Medical Center, Department of Nuclear Medicine, Amersfoort (Netherlands); Bruin, P.W. de; Geleijns, J. [University Medical Center, Department of Radiology, Leiden (Netherlands)

    2012-09-15

    To quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) in patients with malignant lymphoma (Hodgkin's disease [HD] or non-Hodgkin's lymphoma [NHL]). First, organ doses were assessed for a typical diagnostic work-up in children with HD and adults with NHL. Subsequently, life tables were constructed for assessment of radiation risks, also taking into account the disease-related mortality. In children with HD, cumulative effective dose from medical imaging ranged from 66 mSv (newborn) to 113 mSv (15 years old). In adults with NHL the cumulative effective dose from medical imaging was 97 mSv. Average fractions of radiation-induced deaths for children with HD [without correction for disease-related mortality in brackets] were 0.4% [0.6%] for boys and 0.7% [1.1%] for girls, and for adults with NHL 0.07% [0.28%] for men and 0.09% [0.37%] for women. Taking into account the disease-related reduction in life expectancy of patients with malignant lymphoma results in a higher overall mortality but substantial lower incidence of radiation induced deaths. The modest radiation risk that results from imaging with CT and {sup 18}F-FDG PET can be considered as justified, but imaging should be performed with care, especially in children. (orig.)

  5. Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

    International Nuclear Information System (INIS)

    To quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with 18F-fluorodeoxyglucose (18F-FDG) in patients with malignant lymphoma (Hodgkin's disease [HD] or non-Hodgkin's lymphoma [NHL]). First, organ doses were assessed for a typical diagnostic work-up in children with HD and adults with NHL. Subsequently, life tables were constructed for assessment of radiation risks, also taking into account the disease-related mortality. In children with HD, cumulative effective dose from medical imaging ranged from 66 mSv (newborn) to 113 mSv (15 years old). In adults with NHL the cumulative effective dose from medical imaging was 97 mSv. Average fractions of radiation-induced deaths for children with HD [without correction for disease-related mortality in brackets] were 0.4% [0.6%] for boys and 0.7% [1.1%] for girls, and for adults with NHL 0.07% [0.28%] for men and 0.09% [0.37%] for women. Taking into account the disease-related reduction in life expectancy of patients with malignant lymphoma results in a higher overall mortality but substantial lower incidence of radiation induced deaths. The modest radiation risk that results from imaging with CT and 18F-FDG PET can be considered as justified, but imaging should be performed with care, especially in children. (orig.)

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

    International Nuclear Information System (INIS)

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

  8. Patient Vertical Centering and Correlation with Radiation Output in Adult Abdominopelvic CT.

    Science.gov (United States)

    Cheng, Phillip M

    2016-08-01

    The purpose of this study was to determine if there is a significant effect, independent of patient size, of patient vertical centering on the current-modulated CT scanner radiation output in adult abdominopelvic CT. A phantom was used to evaluate calculation of vertical positioning and effective diameter at five different table heights. In addition, 656 consecutive contrast-enhanced abdominopelvic scans using the same protocol and automatic tube current modulation settings on a Philips Brilliance 64 MDCT scanner were retrospectively evaluated. The vertical position of the patient center of mass and the average effective diameter of the scanned patient were computed using the reconstructed images. The average volume CT dose index (CTDIvol) for each scan was recorded. The mean patient center of mass y coordinate ranged from -3.7 to 6.7 cm (mean ± SD, 2.8 ± 1.2 cm), indicating that patients were on average positioned slightly below the scanner isocenter. There was a slight tendency for smaller patients to be mis-centered lower than larger patients. Average CTDIvol closely fit a quadratic regression curve with respect to mean effective diameter. However, the value of the regression coefficient relating CTDIvol to the patient's vertical position was nearly zero, indicating only a very slight increase in CTDIvol with patient mis-centering for the scanner used in this study. The techniques used here may be useful both for automated evaluation of proper patient positioning in CT and for estimating the radiation dose effects of patient mis-centering for any CT scanner. PMID:26810981

  9. 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.)

  10. 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.

  11. Analysis of the Characteristics of CT in the Chest of Patients with HIV/AIDS Complicated with Pneumonia%艾滋病合并肺孢子菌肺炎胸部CT特点的分析

    Institute of Scientific and Technical Information of China (English)

    鲜龚兵; 李文全

    2015-01-01

    目的通过对我科艾滋病并肺孢子菌肺炎患者胸部CT特点,提高对肺孢子菌肺炎的诊断水平。方法回顾分析30例艾滋病合并肺孢子菌肺炎患者的胸部CT改变。结果①双肺局灶磨玻璃样密度增高影5例;②双肺弥漫性磨玻璃样密度增高影12例;③双肺弥漫性网织状纹理增粗伴磨玻璃样密度增高影7例;榆典型"碎石路征"伴磨玻璃样密度增高影2例;虞双肺散布多发气囊影4例。%Objective To analyse the characteristics of chest CT for AIDS complicate with pneumocystis pneumonia (PCP) patients, improve the PCP diagnositic level.Methods Retrospect 30 cases changes in chest CT of AIDS complicate with pneumocystis pneumonia (PCP).Results ①bilateral pulmonary of focal ground-glass opacity had 5.②bilateral pulmonary of dif use ground-glass opacity had 12. ③bilateral pulmonary of lung markings thickening merged ground-glass opacity had 7. crazy-paving pat ern merged ground-glass opacity had 2. ⑤air space opacification in bilateral pulmonary had 4.

  12. Development of a Radiation Dose Reporting Software for X-ray Computed Tomography (CT)

    Science.gov (United States)

    Ding, Aiping

    X-ray computed tomography (CT) has experienced tremendous technological advances in recent years and has established itself as one of the most popular diagnostic imaging tools. While CT imaging clearly plays an invaluable role in modern medicine, its rapid adoption has resulted in a dramatic increase in the average medical radiation exposure to the worldwide and United States populations. Existing software tools for CT dose estimation and reporting are mostly based on patient phantoms that contain overly simplified anatomies insufficient in meeting the current and future needs. This dissertation describes the development of an easy-to-use software platform, “VirtualDose”, as a service to estimate and report the organ dose and effective dose values for patients undergoing the CT examinations. “VirtualDose” incorporates advanced models for the adult male and female, pregnant women, and children. To cover a large portion of the ignored obese patients that frequents the radiology clinics, a new set of obese male and female phantoms are also developed and applied to study the effects of the fat tissues on the CT radiation dose. Multi-detector CT scanners (MDCT) and clinical protocols, as well as the most recent effective dose algorithms from the International Commission on Radiological Protection (ICRP) Publication 103 are adopted in “VirtualDose” to keep pace with the MDCT development and regulatory requirements. A new MDCT scanner model with both body and head bowtie filter is developed to cover both the head and body scanning modes. This model was validated through the clinical measurements. A comprehensive slice-by-slice database is established by deriving the data from a larger number of single axial scans simulated on the patient phantoms using different CT bowtie filters, beam thicknesses, and different tube voltages in the Monte Carlo N-Particle Extended (MCNPX) code. When compared to the existing CT dose software packages, organ dose data in this

  13. Virtual monochromatic imaging in dual-source dual-energy CT: Radiation dose and image quality

    International Nuclear Information System (INIS)

    Purpose: To evaluate the image quality of virtual monochromatic images synthesized from dual-source dual-energy computed tomography (CT) in comparison with conventional polychromatic single-energy CT for the same radiation dose. Methods: In dual-energy CT, besides the material-specific information, one may also synthesize monochromatic images at different energies, which can be used for routine diagnosis similar to conventional polychromatic single-energy images. In this work, the authors assessed whether virtual monochromatic images generated from dual-source CT scanners had an image quality similar to that of polychromatic single-energy images for the same radiation dose. First, the authors provided a theoretical analysis of the optimal monochromatic energy for either the minimum noise level or the highest iodine contrast to noise ratio (CNR) for a given patient size and dose partitioning between the low- and high-energy scans. Second, the authors performed an experimental study on a dual-source CT scanner to evaluate the noise and iodine CNR in monochromatic images. A thoracic phantom with three sizes of attenuating rings was used to represent four adult sizes. For each phantom size, three dose partitionings between the low-energy (80 kV) and the high-energy (140 kV) scans were used in the dual-energy scan. Monochromatic images at eight energies (40 to 110 keV) were generated for each scan. Phantoms were also scanned at each of the four polychromatic single energy (80, 100, 120, and 140 kV) with the same radiation dose. Results: The optimal virtual monochromatic energy depends on several factors: phantom size, partitioning of the radiation dose between low- and high-energy scans, and the image quality metrics to be optimized. With the increase of phantom size, the optimal monochromatic energy increased. With the increased percentage of radiation dose on the low energy scan, the optimal monochromatic energy decreased. When maximizing the iodine CNR in

  14. 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.)

  15. Radiation Dose and Image Quality at High-Pitch CT Angiography of the Aorta : Intraindividual and Interindividual Comparisons With Conventional CT Angiography

    NARCIS (Netherlands)

    Apfaltrer, Paul; Hanna, E. Lexworth; Schoepf, U. Joseph; Spears, J. Reid; Schoenberg, Stefan O.; Fink, Christian; Vliegenthart, Rozemarijn

    2012-01-01

    OBJECTIVE. The objective of our study was to evaluate radiation dose and quantitative image quality parameters at high-pitch CT angiography (CTA) of the aorta compared with conventional CTA. MATERIALS AND METHODS. We studied the examinations of 110 patients (65 men and 45 women; mean age +/- SD, 64

  16. Estimation of exposed radiation dose in radiography of the chest. Mainly on the dose at health examination on automobiles

    International Nuclear Information System (INIS)

    The exposure doses in radiography and photofluorography of the chest at health examination on automobiles were estimated and compared with those using other hospital equipments. The tube voltage, effective energy and half value layer under ordinary conditions for radiography and fluorography were measured by KYOKKO model 100 X-ray analyzer and output pulse shape was confirmed by the fluorometer (TOREKEY-1001 C). The dose at the body surface was measured by the ionization chambers (VICTOREEN RADCON 500 and 30-330) which had been equipped in the WAC chest phantom (JIS Z 4915, Kyoto Kagaku). Nine automobiles of 3 facilities were used, of which X-ray generating apparatuses of either condenser or inverter type were manufactured by Hitachi (5 machines), Toshiba (1) and Shimadzu (3). The examined apparatuses not for the automobile were Toshiba-20 and Hitachi SIRIUS-100 portable ones and Hitachi DH-1520 TM high-voltage one. The effective energy was found dependent on the tube voltage (100-130 kV) and X-ray generating system (35.1-54.37 keV in the condenser type and 41.1-43.9 keV in the inverter type). Pulse shape analysis revealed that the pulse height and area under the pulse height-time curve were larger in the inverter system. The mean doses in photofluorography and radiography on automobiles were 0.525 and 0.297 mGy, respectively. The mean dose of 0.61 mGy in radiography at home with the portable apparatus was the highest even when compared with that of 0.525 mGy for fluorography on the automobile. Thus, the inverter system on the car can guarantee the level of 0.4 mGy defined by IAEA guideline (Safety series No. 115, 1996). (K.H.)

  17. Synchrotron radiation based microtomography (SR{mu}CT) and neutron tomography (NCT) for materials science

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Felix; Herzen, Julia; Donath, Tilman; Haibel, Astrid; Dose, Thomas; Vollbrandt, Juergen; Schmitz, Heinz-Werner; Pranzas, Philipp Klaus; Schreyer, Andreas [GKSS-Research Centre, Geesthacht (Germany)

    2008-07-01

    The GKSS-Research Centre Geesthacht, Germany, is operating the user experiment for microtomography using synchrotron radiation at the storage ring DORIS 3 at DESY Hamburg. In the recents years the beamline W2 was rebuilt. The outstanding feature of this synchrotron radiation beamline HARWI II is the use of high energy X-rays from 20 to 250 keV for materials science experiments. The features for microtomography at HARWI II and new enhancements and applications using lower photon energies at the wiggler beamline BW2 are presented. Furthermore at the research reactor FRG-1 the neutron radiography facility GENRA 3 was extended by a setup for neutron tomography. Results performing SR{mu}CT at HARWI 2 and NCT at GENRA 3 are presented. The combination of neutron and synchrotron radiation techniques will give new insight into the three-dimensional behavior of samples in materials science.

  18. 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

  19. 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

  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. Anatomical database generation for radiation transport modeling from computed tomography (CT) scan data

    Energy Technology Data Exchange (ETDEWEB)

    Margle, S.M.; Tinnel, E.P.; Till, L.E.; Eckerman, K.F.; Durfee, R.C.

    1989-01-01

    Geometric models of the anatomy are used routinely in calculations of the radiation dose in organs and tissues of the body. Development of such models has been hampered by lack of detailed anatomical information on children, and models themselves have been limited to quadratic conic sections. This summary reviews the development of an image processing workstation used to extract anatomical information from routine diagnostic CT procedure. A standard IBM PC/AT microcomputer has been augmented with an automatically loading 9-track magnetic tape drive, an 8-bit 1024 {times} 1024 pixel graphics adapter/monitor/film recording package, a mouse/trackball assembly, dual 20 MB removable cartridge media, a 72 MB disk drive, and a printer. Software utilized by the workstation includes a Geographic Information System (modified for manipulation of CT images), CAD software, imaging software, and various modules to ease data transfer among the software packages. 5 refs., 3 figs.

  2. 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.

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

    International Nuclear Information System (INIS)

    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

  4. 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

  5. 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.

  6. Incidentally Detected Enhancing Breast Lesions on Chest Computed Tomography

    OpenAIRE

    Lin, Wen-Chiung; Hsu, Hsian-He; Li, Chao-Shiang; Yu, Jyh-Cherng; Hsu, Giu-Cheng; Yu, Cheng-Ping; Chang, Tsun-Hou; Huang, Guo-Shu

    2011-01-01

    Objective To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. Materials and Methods Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-te...

  7. Pediatric chest imaging. Chest imaging in infants and children. 2. rev. ed.

    International Nuclear Information System (INIS)

    Imaging of the pediatric chest continues to evolve rapidly. All chapters in this 2nd edition of Pediatric Chest Imaging have been extensively updated, with additional disease-specific information and numerous new illustrations. The book thus presents the state of the art in the diagnosis of pediatric chest disorders, highlighting the role played by advanced technology. As the conventional features of most of these disorders are extremely well known, special attention is devoted to the technical aspects of the modern imaging modalities, their indications, and the diagnostic information that they supply. Individual chapters focus on chest ultrasound, nuclear medicine imaging, high-resolution chest CT, helical CT, and pediatric cardiac CT and pediatric cardiacMRI. Others are directed towards specific disorders, including congenital malformations of the chest, chest tumors, pulmonary infection, trauma, the lung in systemic diseases, the pediatric airway, foreign bodies, the thymus, and the chest wall. Without exception, the authors of this book are internationally known specialists with great expertise in the field. This book will serve as a handy, superbly illustrated reference for all who routinely image children, as well as for those who need access to information on how best to image them. (orig.)

  8. 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.

  9. TH-C-18A-04: Validation of Dosimetric Measurement of CT Radiation Profile Width

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, D; Al-Senan, R [UAB Medical Center, Birmingham, AL (United Kingdom)

    2014-06-15

    Purpose: The ACR now requires that the CT radiation profile width be measured at all clinically used collimations. We developed a method for measuring the profile width using dosimetry alone to allow a faster and simpler measurement of beam widths. Methods: A pencil ionization chamber is used to take two dose-length product measurements in air for a wide collimation. One of these is taken with a 1cm tungsten mask on the pencil chamber. The difference between these measurements is the calibration factor, or the DLP in air per unit length. By dividing the doselength product for any given collimation by this factor, we can rapidly determine the beam profile width.We measured the beam width for all available detector configurations and focal spot sizes on three different CT scanners from two different manufacturers. The measurements were done using film, CR cassette, and the present dosimetric method. Results: The beam widths measured dosimetrically are approximately 2% wider than those measured using film or computed radiography; this difference is believed due to off-focus or scattered radiation. After correcting for this, the dosimetric beam widths match the film and CR widths with an RMS difference of approximately 0.2mm. The measured beam widths are largely insensitive to errors in positioning of the mask, or to tilt errors in the pencil chamber. Conclusion: Using the present method, radiation profile widths can be measured quickly, with an accuracy better than 1mm.

  10. 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.)

  11. Imaging of blunt chest trauma

    Energy Technology Data Exchange (ETDEWEB)

    Wicky, S.; Wintermark, M.; Schnyder, P.; Capasso, P.; Denys, A. [Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland). Dept. of Radiology

    2000-10-01

    In western European countries most blunt chest traumas are associated with motor vehicle and sport-related accidents. In Switzerland, 39 of 10,000 inhabitants were involved and severely injured in road accidents in 1998. Fifty two percent of them suffered from blunt chest trauma. According to the Swiss Federal Office of Statistics, traumas represented in men the fourth major cause of death (4 %) after cardiovascular disease (38 %), cancer (28 %), and respiratory disease (7 %) in 1998. The outcome of chest trauma patients is determined mainly by the severity of the lesions, the prompt appropriate treatment delivered on the scene of the accident, the time needed to transport the patient to a trauma center, and the immediate recognition of the lesions by a trained emergency team. Other determining factors include age as well as coexisting cardiac, pulmonary, and renal diseases. Our purpose was to review the wide spectrum of pathologies related to blunt chest trauma involving the chest wall, pleura, lungs, trachea and bronchi, aorta, aortic arch vessels, and diaphragm. A particular focus on the diagnostic impact of CT is demonstrated. (orig.)

  12. 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

  13. Variation in CT pediatric head examination radiation dose: results from a national survey.

    Science.gov (United States)

    Kanal, Kalpana M; Graves, Janessa M; Vavilala, Monica S; Applegate, Kimberly E; Jarvik, Jeffrey G; Rivara, Frederick P

    2015-03-01

    OBJECTIVE. The purpose of this article is to examine the variation in radiation dose, CT dose index volume (CTDIvol), and dose-length product (DLP) for pediatric head CT examinations as a function of hospital characteristics across the United States. MATERIALS AND METHODS. A survey inquiring about hospital information, CT scanners, pediatric head examination protocol, CTDIvol, and DLP was mailed to a representative sample of U.S. hospitals. Follow-up mailings were sent to nonrespondents. Descriptive characteristics of respondents and nonrespondents were compared using design-based Pearson chi-square tests. Dose estimates were compared across hospital characteristics using Bonferroni-adjusted Wald test. Hospital-level factors associated with dose estimates were evaluated using multiple linear regressions and modified Poisson regression models. RESULTS. Surveys were sent out to 751 hospitals; 292 responded to the survey, of which 253 were eligible (35.5% response rate, calculated as number of hospitals who completed surveys [n = 253] divided by sum of number who were eligible and initially consented [n = 712] plus estimated number who were eligible among those who refused [n = 1]). Most respondents reported using MDCT scanners (99.2%) and having a dedicated pediatric head CT protocol (93%). Estimated mean reported CTDIvol values were 27.3 mGy (95% CI, 24.4-30.1 mGy), and DLP values were 390.9 mGy × cm (95% CI, 346.6-435.1 mGy × cm). These values did not vary significantly by region, trauma level, teaching status, CT accreditation, number of CT scanners, or report of a dedicated pediatric CT protocol. However, estimated CTDIvol reported by children's hospitals was 19% lower than that reported by general hospitals (p < 0.01). CONCLUSION. Most hospitals (82%) report doses that meet American College of Radiology accreditation levels. However, [corrected] the mean CTDI(vol) at children's hospitals was approximately 7 mGy (21%, adjusted for covariates), lower than that

  14. Presentation of the project EPI-CT: A cohort study of children with substantial diagnostic medical exposure to ionizing radiation

    International Nuclear Information System (INIS)

    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.

  15. Can low-dose CT with iterative reconstruction reduce both the radiation dose and the amount of iodine contrast medium in a dynamic CT study of the liver?

    International Nuclear Information System (INIS)

    Purpose: To investigate whether low-dose dynamic CT of the liver with iterative reconstruction can reduce both the radiation dose and the amount of contrast medium. Materials and methods: This study was approved by our institutional review board. 113 patients were randomly assigned to one of two groups. Group A/group B (fifty-eight/fifty-five patients) underwent liver dynamic CT at 120/100 kV, with 0/40% adaptive statistical iterative reconstruction (ASIR), with a contrast dose of 600/480 mg I/kg, respectively. Radiation exposure was estimated based on the manufacturer's phantom data. The enhancement value of the hepatic parenchyma, vessels and the tumor-to-liver contrast of hepatocellular carcinomas (HCCs) were compared between two groups. Two readers independently assessed the CT images of the hepatic parenchyma and HCCs. Results: The mean CT dose indices: 6.38/4.04 mGy, the dose-length products: 194.54/124.57 mGy cm, for group A/group B. The mean enhancement value of the hepatic parenchyma and the tumor-to-liver contrast of HCCs with diameters greater than 1 cm in the post-contrast all phases did not differ significantly between two groups (P > 0.05). The enhancement values of vessels in group B were significantly higher than that in group A in the delayed phases (P < 0.05). Two reader's confidence levels for the hepatic parenchyma in the delayed phases and HCCs did not differ significantly between the groups (P > 0.05). Conclusions: Low-dose dynamic CT with ASIR can reduce both the radiation dose and the amount of contrast medium without image quality degradation, compared to conventional dynamic CT without ASIR

  16. 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.

  17. Can low-dose CT with iterative reconstruction reduce both the radiation dose and the amount of iodine contrast medium in a dynamic CT study of the liver?

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroto; Okada, Masahiro; Hyodo, Tomoko; Hidaka, Syojiro; Kagawa, Yuki; Matsuki, Mitsuru; Tsurusaki, Masakatsu; Murakami, Takamichi, E-mail: murakami@med.kindai.ac.jp

    2014-04-15

    Purpose: To investigate whether low-dose dynamic CT of the liver with iterative reconstruction can reduce both the radiation dose and the amount of contrast medium. Materials and methods: This study was approved by our institutional review board. 113 patients were randomly assigned to one of two groups. Group A/group B (fifty-eight/fifty-five patients) underwent liver dynamic CT at 120/100 kV, with 0/40% adaptive statistical iterative reconstruction (ASIR), with a contrast dose of 600/480 mg I/kg, respectively. Radiation exposure was estimated based on the manufacturer's phantom data. The enhancement value of the hepatic parenchyma, vessels and the tumor-to-liver contrast of hepatocellular carcinomas (HCCs) were compared between two groups. Two readers independently assessed the CT images of the hepatic parenchyma and HCCs. Results: The mean CT dose indices: 6.38/4.04 mGy, the dose-length products: 194.54/124.57 mGy cm, for group A/group B. The mean enhancement value of the hepatic parenchyma and the tumor-to-liver contrast of HCCs with diameters greater than 1 cm in the post-contrast all phases did not differ significantly between two groups (P > 0.05). The enhancement values of vessels in group B were significantly higher than that in group A in the delayed phases (P < 0.05). Two reader's confidence levels for the hepatic parenchyma in the delayed phases and HCCs did not differ significantly between the groups (P > 0.05). Conclusions: Low-dose dynamic CT with ASIR can reduce both the radiation dose and the amount of contrast medium without image quality degradation, compared to conventional dynamic CT without ASIR.

  18. Assess results of PET/CT in cancer diagnosis, follow up treatment and simulation for radiation therapy

    International Nuclear Information System (INIS)

    PET/CT (Positron Emission Computed Tomography) has been studied and established as routine at the Nuclear Medicine and Oncology Center, Bach Mai hospital. From 8/2009 to 5/2015, 6223 patients have been undergone PET/CT scan. Among them, diagnostic and simulation PET/CT scan for cancer patients accounted to 5833 (93.8%). Researches about value of PET/CT for most common cancers have been done. Results: PET/CT can help the primary tumor diagnosis, metastases detection, staging, simulation for radiation therapy, response to treatment assessment, and relapses after treatment identification. Percentage accordance between PET / CT and histopathology was 96% (esophagus cancer), 94.7% (lung cancer). Average maxSUV value of primary tumor of the esophagus cancer, colorectal cancer, nasopharynx cancer, lung cancer, and NHL respectively 9.50, 9.78, 11.08, 9.17, 10.21. MaxSUV value increased with histological grade and tumor size. After undergone PET / CT, stage of disease changed in 28% esophagus cancer; 22.7% colorectal cancer; stage of disease increased in 23.5% of NHL, 32.0% of lung cancer, and 25.0% of nasopharynx cancer. PET / CT simulation for radiation therapy target volume reduced in 28% of nasopharynx cancer, which helped the radioactive dose concentrate exactly in the target lesions, minimize effect to healthy tissues, improved the effectiveness of treatment and reduced complications. (author)

  19. 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

  20. Improving Image Quality of On-Board Cone-Beam CT in Radiation Therapy Using Image Information Provided by Planning Multi-Detector CT: A Phantom Study

    OpenAIRE

    Yang, Ching-Ching; Chen, Fong-Lin; Lo, Yeh-Chi

    2016-01-01

    Purpose The aim of this study was to improve the image quality of cone-beam computed tomography (CBCT) mounted on the gantry of a linear accelerator used in radiation therapy based on the image information provided by planning multi-detector CT (MDCT). Methods MDCT-based shading correction for CBCT and virtual monochromatic CT (VMCT) synthesized using the dual-energy method were performed. In VMCT, the high-energy data were obtained from CBCT, while the low-energy data were obtained from MDCT...

  1. 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

  2. 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

    International Nuclear Information System (INIS)

    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

  3. Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose

    OpenAIRE

    Wenz, Holger; Máté E Maros; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; HENZLER, THOMAS

    2015-01-01

    Objectives To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. Methods 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was recon...

  4. 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.

  5. The chest

    International Nuclear Information System (INIS)

    Radiographic interpretation of chest films of newborns in respiratory distress remains one of the most difficult aspects of pediatric radiology. Complex pulmonary and cardiac adjustments to extrauterine life are rapidly taking place. The small, fluid-filled fetal lung must rid itself of fluid and fill with air. The high vascular resistance of the fetal pulmonary bed and the open ductus arteriosus allow shunting of blood in both directions. Films taken in this period of time may show lungs that resemble those seen in congestive heart failure or fluid overload. When these findings are observed in infants who may appear dusky or even cyanotic, the result may be the diagnosis of disease in normal infants passing through a stormy transition period. To make things worse, the films are taken as portable surpine films, usually in an isolette in the intensive care unit (ICU). The phase of respiration is difficult, if not impossible, to control, and lateral films are usually not obtained. Many of the infants are on assisted ventilation either by tube or nasal prongs-nasal continuous positive airway pressure (CPAP)-and lungs can appear over-inflated or whited out, depending on the pressures used and the phase of the respiratory cycle. Prolonged crying itself can make lungs appear semiopaque; the next breath may show such a dramatic reinflation that it is hard to believe the two films are of the same infant, made only seconds apart. Is the heart large? Or is it the thymus? Are the lungs ''wet''? Is there infection? Is there pulmonary vascular engorgement? Why are these films so hard to interpret? They have no easy answers. The radiologist must realize that the neonatal intensive care personnel, armed though they may be with blood gas values, are no better at interpreting films. If anything, they read into them what they wish to see

  6. Three-dimensional dosimetry of small megavoltage radiation fields using radiochromic gels and optical CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Babic, Steven; Battista, Jerry; Jordan, Kevin [Department of Physics and Engineering, London Regional Cancer Program at London Health Sciences Centre, 790 Commissioners Road East, London, Ontario N6 A 4L6 (Canada); McNiven, Andrea [Princess Margret Hospital/University Health Network, Toronto, Ontario (Canada)], E-mail: steven.babic@lhsc.on.ca

    2009-04-21

    The dosimetry of small fields as used in stereotactic radiotherapy, radiosurgery and intensity-modulated radiation therapy can be challenging and inaccurate due to partial volume averaging effects and possible disruption of charged particle equilibrium. Consequently, there exists a need for an integrating, tissue equivalent dosimeter with high spatial resolution to avoid perturbing the radiation beam and artificially broadening the measured beam penumbra. In this work, radiochromic ferrous xylenol-orange (FX) and leuco crystal violet (LCV) micelle gels were used to measure relative dose factors (RDFs), percent depth dose profiles and relative lateral beam profiles of 6 MV x-ray pencil beams of diameter 28.1, 9.8 and 4.9 mm. The pencil beams were produced via stereotactic collimators mounted on a Varian 2100 EX linear accelerator. The gels were read using optical computed tomography (CT). Data sets were compared quantitatively with dosimetric measurements made with radiographic (Kodak EDR2) and radiochromic (GAFChromic (registered) EBT) film, respectively. Using a fast cone-beam optical CT scanner (Vista(TM)), corrections for diffusion in the FX gel data yielded RDFs that were comparable to those obtained by minimally diffusing LCV gels. Considering EBT film-measured RDF data as reference, cone-beam CT-scanned LCV gel data, corrected for scattered stray light, were found to be in agreement within 0.5% and -0.6% for the 9.8 and 4.9 mm diameter fields, respectively. The validity of the scattered stray light correction was confirmed by general agreement with RDF data obtained from the same LCV gel read out with a laser CT scanner that is less prone to the acceptance of scattered stray light. Percent depth dose profiles and lateral beam profiles were found to agree within experimental error for the FX gel (corrected for diffusion), LCV gel (corrected for scattered stray light), and EBT and EDR2 films. The results from this study reveal that a three-dimensional dosimetry

  7. Three-dimensional dosimetry of small megavoltage radiation fields using radiochromic gels and optical CT scanning

    Science.gov (United States)

    Babic, Steven; McNiven, Andrea; Battista, Jerry; Jordan, Kevin

    2009-04-01

    The dosimetry of small fields as used in stereotactic radiotherapy, radiosurgery and intensity-modulated radiation therapy can be challenging and inaccurate due to partial volume averaging effects and possible disruption of charged particle equilibrium. Consequently, there exists a need for an integrating, tissue equivalent dosimeter with high spatial resolution to avoid perturbing the radiation beam and artificially broadening the measured beam penumbra. In this work, radiochromic ferrous xylenol-orange (FX) and leuco crystal violet (LCV) micelle gels were used to measure relative dose factors (RDFs), percent depth dose profiles and relative lateral beam profiles of 6 MV x-ray pencil beams of diameter 28.1, 9.8 and 4.9 mm. The pencil beams were produced via stereotactic collimators mounted on a Varian 2100 EX linear accelerator. The gels were read using optical computed tomography (CT). Data sets were compared quantitatively with dosimetric measurements made with radiographic (Kodak EDR2) and radiochromic (GAFChromic® EBT) film, respectively. Using a fast cone-beam optical CT scanner (Vista™), corrections for diffusion in the FX gel data yielded RDFs that were comparable to those obtained by minimally diffusing LCV gels. Considering EBT film-measured RDF data as reference, cone-beam CT-scanned LCV gel data, corrected for scattered stray light, were found to be in agreement within 0.5% and -0.6% for the 9.8 and 4.9 mm diameter fields, respectively. The validity of the scattered stray light correction was confirmed by general agreement with RDF data obtained from the same LCV gel read out with a laser CT scanner that is less prone to the acceptance of scattered stray light. Percent depth dose profiles and lateral beam profiles were found to agree within experimental error for the FX gel (corrected for diffusion), LCV gel (corrected for scattered stray light), and EBT and EDR2 films. The results from this study reveal that a three-dimensional dosimetry method

  8. Radiation dose calculations for CT scans with tube current modulation using the approach to equilibrium function

    International Nuclear Information System (INIS)

    Purpose: The approach to equilibrium function has been used previously to calculate the radiation dose to a shift-invariant medium undergoing CT scans with constant tube current [Li, Zhang, and Liu, Med. Phys. 39, 5347–5352 (2012)]. The authors have adapted this method to CT scans with tube current modulation (TCM). Methods: For a scan with variable tube current, the scan range was divided into multiple subscan ranges, each with a nearly constant tube current. Then the dose calculation algorithm presented previously was applied. For a clinical CT scan series that presented tube current per slice, the authors adopted an efficient approach that computed the longitudinal dose distribution for one scan length equal to the slice thickness, which center was at z = 0. The cumulative dose at a specific point was a summation of the contributions from all slices and the overscan. Results: The dose calculations performed for a total of four constant and variable tube current distributions agreed with the published results of Dixon and Boone [Med. Phys. 40, 111920 (14pp.) (2013)]. For an abdomen/pelvis scan of an anthropomorphic phantom (model ATOM 701-B, CIRS, Inc., VA) on a GE Lightspeed Pro 16 scanner with 120 kV, N × T = 20 mm, pitch = 1.375, z axis current modulation (auto mA), and angular current modulation (smart mA), dose measurements were performed using two lines of optically stimulated luminescence dosimeters, one of which was placed near the phantom center and the other on the surface. Dose calculations were performed on the central and peripheral axes of a cylinder containing water, whose cross-sectional mass was about equal to that of the ATOM phantom in its abdominal region, and the results agreed with the measurements within 28.4%. Conclusions: The described method provides an effective approach that takes into account subject size, scan length, and constant or variable tube current to evaluate CT dose to a shift-invariant medium. For a clinical CT scan

  9. 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.

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  11. Initial experience with single-source dual-energy CT abdominal angiography and comparison with single-energy CT angiography: image quality, enhancement, diagnosis and radiation dose

    International Nuclear Information System (INIS)

    To assess image quality of virtual monochromatic spectral (VMS) images, compared to single-energy (SE) CT, and to evaluate the feasibility of material density imaging in abdominal aortic disease. In this retrospective study, single-source (ss) dual-energy (DE) CT of the aorto-iliac system in 35 patients (32 male, mean age 76.5 years) was compared to SE-CT. By post-processing the data from ssDECT, VMS images at different energies and material density water (WD) images were generated. The image quality parameters were rated on 5-point scales. The aorto-iliac attenuation and contrast-to-noise ratio (CNR) were recorded. Quality of WD images was compared to true unenhanced (TNE) images. Radiation dose was recorded and statistical analysis was performed. Image quality and noise were better at 70 keV (P < 0.01). Renal artery branch visualisation was better at 50 keV (P < 0.005). Attenuation and CNR were higher at 50 and 70 keV (P < 0.0001). The WD images had diagnostic quality but higher noise than TNE images (P < 0.0001). Radiation dose was lower using single-phase ssDECT compared to dual-phase SE-CT (P < 0.0001). 70-keV images from ssDECT provide higher contrast enhancement and improved image quality for aorto-iliac CT when compared to SE-CT at 120 kVp. WD images are an effective substitute for TNE images with a potential for dose reduction. (orig.)

  12. Poster — Thur Eve — 02: Measurement of CT radiation profile width using Fuji CR imaging plate raw data

    International Nuclear Information System (INIS)

    Measuring the CT collimation width and assessing the shape of the overall profile is a relatively straightforward quality control (QC) measure that impacts both image quality and patient dose, and is often required at acceptance and routine testing. Most CT facilities have access to computed radiography (CR) systems, so performing CT collimation profile assessments using CR plates requires no additional equipment. Previous studies have shown how to effectively use CR plates to measure the radiation profile width. However, a major limitation of the previous work is that the full dynamic range of CR detector plates are not used, since the CR processing technology reduces the dynamic range of the DICOM output to 210, requiring the sensitivity and latitude settings of CR reader to be adjusted to prevent clipping of the CT profile data. Such adjustments to CR readers unnecessarily complicate the QC procedure. These clipping artefacts hinder the ability to accurately assess CT collimation width because the full-width at half maximum value of the penumbras are not properly determined if the maximum dose of the profile is not available. Furthermore, any inconsistencies in the radiation profile shape are lost if the profile plateau is clipped off. In this work we developed an opensource Matlab script for straightforward CT profile width measurements using raw CR data that also allows assessment of the profile shape without clipping, and applied this approach during CT QC

  13. Poster — Thur Eve — 02: Measurement of CT radiation profile width using Fuji CR imaging plate raw data

    Energy Technology Data Exchange (ETDEWEB)

    Bjarnason, T A [Diagnostic Imaging Services, Interior Health, Kelowna (Canada); Department of Radiology, University of British Columbia, Vancouver (Canada); Yang, C J [Sindi Ahluwalia Hawkins Centre for the Southern Interior, British Columbia Cancer Agency, Kelowna (Canada)

    2014-08-15

    Measuring the CT collimation width and assessing the shape of the overall profile is a relatively straightforward quality control (QC) measure that impacts both image quality and patient dose, and is often required at acceptance and routine testing. Most CT facilities have access to computed radiography (CR) systems, so performing CT collimation profile assessments using CR plates requires no additional equipment. Previous studies have shown how to effectively use CR plates to measure the radiation profile width. However, a major limitation of the previous work is that the full dynamic range of CR detector plates are not used, since the CR processing technology reduces the dynamic range of the DICOM output to 2{sup 10}, requiring the sensitivity and latitude settings of CR reader to be adjusted to prevent clipping of the CT profile data. Such adjustments to CR readers unnecessarily complicate the QC procedure. These clipping artefacts hinder the ability to accurately assess CT collimation width because the full-width at half maximum value of the penumbras are not properly determined if the maximum dose of the profile is not available. Furthermore, any inconsistencies in the radiation profile shape are lost if the profile plateau is clipped off. In this work we developed an opensource Matlab script for straightforward CT profile width measurements using raw CR data that also allows assessment of the profile shape without clipping, and applied this approach during CT QC.

  14. Clinical Utility of 4D FDG-PET/CT Scans in Radiation Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Aristophanous, Michalis, E-mail: maristophanous@lroc.harvard.edu [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center and Harvard Medical School, Boston, MA (United States); Berbeco, Ross I.; Killoran, Joseph H. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center and Harvard Medical School, Boston, MA (United States); Yap, Jeffrey T. [Department of Radiology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA (United States); Sher, David J.; Allen, Aaron M.; Larson, Elysia; Chen, Aileen B. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center and Harvard Medical School, Boston, MA (United States)

    2012-01-01

    Purpose: The potential role of four-dimensional (4D) positron emission tomography (PET)/computed tomography (CT) in radiation treatment planning, relative to standard three-dimensional (3D) PET/CT, was examined. Methods and Materials: Ten patients with non-small-cell lung cancer had sequential 3D and 4D [{sup 18}F]fluorodeoxyglucose PET/CT scans in the treatment position prior to radiation therapy. The gross tumor volume and involved lymph nodes were contoured on the PET scan by use of three different techniques: manual contouring by an experienced radiation oncologist using a predetermined protocol; a technique with a constant threshold of standardized uptake value (SUV) greater than 2.5; and an automatic segmentation technique. For each technique, the tumor volume was defined on the 3D scan (VOL3D) and on the 4D scan (VOL4D) by combining the volume defined on each of the five breathing phases individually. The range of tumor motion and the location of each lesion were also recorded, and their influence on the differences observed between VOL3D and VOL4D was investigated. Results: We identified and analyzed 22 distinct lesions, including 9 primary tumors and 13 mediastinal lymph nodes. Mean VOL4D was larger than mean VOL3D with all three techniques, and the difference was statistically significant (p < 0.01). The range of tumor motion and the location of the tumor affected the magnitude of the difference. For one case, all three tumor definition techniques identified volume of moderate uptake of approximately 1 mL in the hilar region on the 4D scan (SUV maximum, 3.3) but not on the 3D scan (SUV maximum, 2.3). Conclusions: In comparison to 3D PET, 4D PET may better define the full physiologic extent of moving tumors and improve radiation treatment planning for lung tumors. In addition, reduction of blurring from free-breathing images may reveal additional information regarding regional disease.

  15. 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.

  16. 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.

  17. Infant Cardiac CT Angiography with 64-Slice and 256-Slice CT: Comparison of Radiation Dose and Image Quality Using a Pediatric Phantom

    OpenAIRE

    Lee, Yi-Wei; Yang, Ching-Ching; Mok, Greta S. P.; Wu, Tung-Hsin

    2012-01-01

    Background The aims of this study were to investigate the image quality and radiation exposure of pediatric protocols for cardiac CT angiography (CTA) in infants under one year of age. Methodology/Principal Findings Cardiac CTA examinations were performed using an anthropomorphic phantom representing a 1-year-old child scanned with non-electrocardiogram-gated (NG), retrospectively electrocardiogram-gated helical (RGH) and prospectively electrocardiogram-gated axial (PGA) techniques in 64-slic...

  18. 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

  19. 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

  20. Evaluation of three commercial metal artifact reduction methods for CT simulations in radiation therapy

    Directory of Open Access Journals (Sweden)

    Jessie Y Huang

    2014-03-01

    Full Text Available Purpose: To evaluate the success of three commercial metal artifact reduction methods (MAR in the context of radiation therapy treatment planning.Methods: Three MAR strategies were evaluated: Philips O-MAR, monochromatic imaging using Gemstone Spectral Imaging (GSI dual energy CT, and monochromatic imaging with metal artifact reduction software (GSI-MARs. The Gammex RMI 467 tissue characterization phantom with several metal rods and two anthropomorphic phantoms (pelvic phantom with hip prosthesis and head phantom with dental fillings, were scanned with and without metals (baseline. Each MAR method was evaluated based on CT number accuracy, metal size accuracy, and reduction in the severity of streak artifacts. CT number difference maps between the baseline and metal scan images were calculated, and the severity of streak artifacts was quantified using the percentage of pixels with > 40 HU error (“bad pixels”.Results: Philips O-MAR generally reduced HU errors in the RMI phantom. However, increased errors and induced artifacts were observed for lung materials. GSI monochromatic 70keV images generally showed similar HU errors as conventional 120kVp imaging, while 140keV images reduced HU errors. All the imaging techniques represented the diameter of a stainless steel rod to within ±1.6mm (2 pixels. For the hip prosthesis, O-MAR reduced the average % bad pixels from 47% to 32%. For GSI 140keV imaging, the % bad pixels was reduced from 37% to 29% compared to 120kVp imaging, and GSI-MARs further reduced it to 12%. For the head phantom, none of the MAR methods was particularly successful.Conclusion: O-MAR resulted in consistent artifact reduction but exhibited induced artifacts for metals located near lung tissue. GSI imaging at 140keV gave consistent reduction in HU errors and severity of artifacts. GSI-MARs at 140keV was the most successful MAR method for the hip prosthesis but exhibited induced artifacts at the edges of metals in some cases

  1. CT detection of occult pneumothorax in head trauma

    International Nuclear Information System (INIS)

    A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneuomothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia

  2. 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.

  3. The Addition of SPECT/CT Lymphoscintigraphy to Breast Cancer Radiation Planning Spares Lymph Nodes Critical for Arm Drainage

    International Nuclear Information System (INIS)

    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

  4. Biometric estimation of chest wall thickness of female radiation workers as an aid in in-vivo detection of the actinides

    International Nuclear Information System (INIS)

    An equation was derived to estimate female chest wall thickness from a series of biometric measurements. This technique will result in improved performance for actinide detection in females by accounting for variations in chest wall thickness in derivation of calibration factors

  5. Chest Wall tumor: combined management

    International Nuclear Information System (INIS)

    Cancer is relatively rare disease among children and adolescents. The incidence of solid tumors other than CNS is less than 2/100,000. Tumors of the chest wall can arise either from the somatic tissue or ribs. These are rare, so either institutional reviews or multi institutional studies should determine optimal therapeutic management. Of the bony chest wall, Ewing's sarcoma or the family of tumor (peripheral neuro epithelioma, Askin tumor), are the most common. These lesions are lytic and have associated large extra pleural component. This large extra pleural component often necessitates major chest wall resection (3 or more ribs), and when lower ribs are involved, this entails resection of portion of diaphragm. Despite this resection, survival in the early 1970 was 10-20%. Since 1970 multi agent chemotherapy has increased survival rates. of importance, however, is these regimens have caused significant reduction of these extra pleural components so that major chest wall resections have become a rarity. With improved survival and decreased morbidity preoperative chemotherapy followed by surgery is now the accepted modality of treatment. Another major advantage of this regimen is that potential radiation therapy may be obviated. The most common chest wall lesion is rhabdomyosarcoma. In the IRS study of 1620 RMS patients, in 141 (9%) the primary lesion was in the chest wall. these are primarily alveolar histology. when lesions were superficial, wide local excision with supplemental radiation therapy was associated with low morbidity and good overall survival. however, a majority have significant intra- thoracic components. in these circumstances the resectability rate is less than 30% and the survival poor. Other lesions include non rhabdomyosarcomas, eosinophilic granuloma, chondrosarcoma, and osteomyelitis. The management of these lesions varies according to extent, histology, and patient characteristics

  6. 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.

  7. Reducing radiation dose in adult head CT using iterative reconstruction. A clinical study in 177 patients

    International Nuclear Information System (INIS)

    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.

  8. Low radiation dose imaging of myocardial perfusion and coronary angiography with a hybrid PET/CT scanner

    OpenAIRE

    Kajander, S; Ukkonen, H; Sipilä, H.; Teräs, M.; Knuuti, J

    2009-01-01

    Objectives: To test the image quality and feasibility of a sequential low radiation dose protocol for hybrid cardiac PET/CT angiography (CTA). Background: Multidetector computed tomography (MDCT) is a non-invasive method for coronary angiography. The negative predictive value of MDCT is high but perfusion imaging has a role in detecting functional significance of coronary lesions. This has encouraged combining these techniques. However, radiation dose is of concern. We report our first experi...

  9. 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.

  10. Risk Factors for Brain Metastases in Locally Advanced Non-Small Cell Lung Cancer With Definitive Chest Radiation

    International Nuclear Information System (INIS)

    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

  11. 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.)

  12. The application value of low-dose of high-pitch scan mode of dual-source computed tomography in the chest of children%双源 CT 大螺距扫描模式在儿童胸部低剂量成像中的应用价值

    Institute of Scientific and Technical Information of China (English)

    翟峰; 李泉; 许昌; 王萍; 张成周

    2015-01-01

    目的:探讨双源C T 大螺距扫描模式在儿童胸部成像中的辐射剂量及图像质量的应用价值。方法将80例行双源C T胸部检查的患儿随机分为A、B两组。其中A组40例,行大螺距模式扫描,螺距3.0;B组40例,行常规模式扫描,螺距1.2。对A、B两组图像质量、辐射剂量(CT容积剂量指数CTDIvol值、剂量长度乘积DLP值及有效剂量 E)及扫描时间进行对比分析。结果 A、B两组均获得了满足临床诊断的图像,图像质量差异无统计学意义(Z=-1.75,P=0.08);A、B两组患儿的CTDIvol值分别平均为1.82 mGy、4.50 mGy ,差异具有统计学意义(t=-32.50,P=0.00),A组患儿较B组患儿下降59.56%。A、B两组患儿的DLP值分别平均为38.41 mGy/cm、82.74 mGy/cm ,差异具有统计学意义(t=-37.94,P=0.00), A组患儿的DLP值较B组患儿下降53.58%。A组患儿的平均扫描时间(0.27 s)明显短于B组患儿(2.60 s),差异有统计学意义(t=41.31,P=0.00),A组扫描时间仅为B组的10.38%。结论双源CT 大螺距扫描模式具有扫描速度快、辐射剂量低等优点,在儿童胸部低剂量扫描中具有重要价值。%Objective To evaluate the radiation dose and image quality of the application of high‐pitch scan mode of dual -source computed tomography in the chest of children .Methods 80 sick children who were going to do chest CT examination by dual‐source CT system were randomly divided into two groups of A B .40 children of group A were examined with a in high‐pitch scan mode(pitch=3.0);40 patients of group B were examined with in conventional pitch mode(pitch=1.2) .The image quality ,radiation dose(CTDIvol ,DLP) and scaning time between the two groups were analysed .Results The Image quality of group A and B meet the requirements of the clinical diagnosis .There is no significant difference in the image quality of group A and B(Z= -1.75 ,P=0

  13. Cardiovascular CT angiography in neonates and children : Image quality and potential for radiation dose reduction with iterative image reconstruction techniques

    NARCIS (Netherlands)

    Tricarico, Francesco; Hlavacek, Anthony M.; Schoepf, U. Joseph; Ebersberger, Ullrich; Nance, John W.; Vliegenthart, Rozemarijn; Cho, Young Jun; Spears, J. Reid; Secchi, Francesco; Savino, Giancarlo; Marano, Riccardo; Schoenberg, Stefan O.; Bonomo, Lorenzo; Apfaltrer, Paul

    2013-01-01

    To evaluate image quality (IQ) of low-radiation-dose paediatric cardiovascular CT angiography (CTA), comparing iterative reconstruction in image space (IRIS) and sinogram-affirmed iterative reconstruction (SAFIRE) with filtered back-projection (FBP) and estimate the potential for further dose reduct

  14. 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.

  15. An experimental study of comparing digital tomosynthesis and multi-slice CT scanning for the detection of pulmonary nodules using the anthropomorphic chest phantom%数字断层融合技术与多层CT胸部扫描病变检出及辐射剂量的体模研究

    Institute of Scientific and Technical Information of China (English)

    赵峰; 曾勇明; 彭盛坤; 彭刚; 郁仁强; 谭欢; 蔡文晶

    2012-01-01

    ). Three radiologists of different clinical experiences independently reviewed and recorded the density,diameter and position of pulmonary nodules.The sensitivity of nodule detection by DTS and MSCT were compared by Fisher exact test and Chi-square test. The paired t test was conducted to analyze the dose levels of DTS and MSCT.Results The sensitivity of detection nodule by DTS and MSCT were 66.7% (30/45) and 91.1% (41/45) respectively.Statistically significant difference between the two examinations existed ( x2 =8.073,P < 0.05).The sensitivity of detection - 650 HU ground glass opacity pulmonary nodule by MSCT and DTS were 93.3% (14/15) and 73.3% (11/15) respectively.There was no significant difference between DTS and MSCT ( P > 0.05 ).The sensitivity of detection - 800 HU ground glass opacity nodule and ground glass opacity nodule (d < 8 mm) by DTS were 33.3% (5/15) and 16.7% (2/12) respectively,which were lower than those by CT[80.0% (12/15) and 66.7% (8/12)].The radiation doses of DTS for various organs in the chest were lower than those of CT. Statistical significant difference between DTS and MSCT existed ( lung t =19.69,thoracic vertebral t =30.01,heart t =16.33,liver t =5.06,breast t =9.43,thyroid gland t =8.05 ;P < 0.05).The effective doses of the DTS and MSCT were 0.65 and 7.71 mSv respectively.Conclusions There is no difference between the DTS and MSCT in the detection rate of -650 HU ground glass opacity nodule.For detecting the ground glass opacity nodule ( - 800 HU) and ground glass opacity nodule (d < 8 mm),MSCT is superior to DTS. However,the radiation dosage of DTS is 8.41% of the MSCT scanning.

  16. [18F]fluoroethylcholine-PET/CT imaging for radiation treatment planning of recurrent and primary prostate cancer with dose escalation to PET/CT-positive lymph nodes

    International Nuclear Information System (INIS)

    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. 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. 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