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In coronavirus disease 2019 (COVID-19), endothelial cells play a central role and inadequate response is associated with vascular complications. PET imaging with gallium-68 labelled RGD-peptide (68Ga-RGD) targets αvβ3 integrin expression which allows quantification of endothelial activation. In this single-center, prospective observational study, we included ten hospitalized patients with COVID-19 between October 2020 and January 2021. Patients underwent 68Ga-RGD PET/CT followed by iodine mapping of lung parenchyma. CT-based segmentation of lung parenchyma, carotid arteries and myocardium was used to quantify tracer uptake by calculating standardized uptake values (SUV). Five non-COVID-19 patients were used as reference. The study population was 68.5 (IQR 52.0-74.5) years old, with median oxygen need of 3 l/min (IQR 0.9-4.0). 68Ga-RGD uptake quantified as SUV ± SD was increased in lungs (0.99 ± 0.32 versus 0.45 ± 0.18, p ) and myocardium (3.44 ± 1.59 versus 0.65 ± 0.22, p ) of COVID-19 patients compared to reference but not in the carotid arteries. Iodine maps showed local variations in parenchymal perfusion but no correlation with SUV. In conclusion, using 68Ga-RGD PET/CT in COVID-19 patients admitted with respiratory symptoms, we demonstrated increased endothelial activation in the lung parenchyma and myocardium. Our findings indicate the involvement of increased and localized endothelial cell activation in the cardiopulmonary system in COVID-19 patients. Trail registration NCT04596943

Background Dynamic myocardial computed tomography perfusion (CTP) is a novel technique able to depict cardiac ischemia. Purpose To evaluate the impact of a four-dimensional noise reduction filter (similarity filter [4D-SF]) on image quality in dynamic CTP imaging, allowing for substantial radiation dose reduction. Material and Methods Dynamic CTP datasets of 30 patients (16 women) with suspected coronary artery disease, acquired with a 320-slice CT system, were retrieved, reconstructed with the deep learning-based algorithm of the system (DLR), and filtered with the 4D-SF. For each case, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in six regions of interest (33–38mm2) were calculated before and after filtering, in four-chamber and short-axis views, and t-tested. Furthermore, six radiologists of different expertise evaluated subjective image preference by answering five visual grading analysis-type questions (regarding acceptable level of noise, absence of artifacts, natural appearance, cardiac contour sharpness, diagnostic acceptability) using a 5-point scale. The results were analyzed using visual grade characteristics (VGC) and intraclass correlation coefficient (ICC). Results Mean SNR in four-chamber view (unfiltered vs. filtered) were: septum=4.1 ± 2.1 versus 7.6 ± 5.6; lateral wall=4.5 ± 2.0 versus 8.0 ± 4.9; CNRseptum=16.6 ± 8.9 versus 31.7 ± 28; lateral wall=16.2 ± 8.9 versus 31.3 ± 28.9. Similar results were obtained in short-axis view. The perceived filtered image quality indicated decreased noise (VGCAUC=0.96) and artifacts (0.65), improved natural appearance (0.59), cardiac contour sharpness (0.74), and diagnostic acceptability (0.78). The inter-observer variability was excellent (ICC=0.79). All results were statistically significant ( P Conclusion Similarity filtering after DLR improves image quality, possibly enabling dose reduction in dynamic CTP imaging in patient with suspected chronic coronary syndrome.

Objectives To evaluate the technical performance of an ultra-high-resolution CT (UHRCT) system. Methods The physico-technical capabilities of a novel commercial UHRCT system were assessed and compared with those of a current-generation multi-detector (MDCT) system. The super-high-resolution (SHR) mode of the system uses 0.25 mm (at isocentre) detector elements (dels) in the in-plane and longitudinal directions, while the high-resolution (HR) mode bins two dels in the longitudinal direction. The normal-resolution (NR) mode bins dels 2 × 2, resulting in a del-size equivalent to that of the MDCT system. In general, standard procedures and phantoms were used to perform these assessments. Results The UHRCT MTF (10% MTF 4.1 lp/mm) is twice as high as that of the MDCT (10% MTF 1.9 lp/mm), which is comparable to the MTF in the NR mode (10% MTF 1.7 lp/mm). The width of the slice sensitivity profile in the SHR mode (FWHM 0.45 mm) is about 60% of that of the MDCT (FWHM 0.77 mm). Uniformity and CT numbers are within the expected range. Noise in the high-resolution modes has a higher magnitude and higher frequency components compared with MDCT. Low-contrast visibility is lower for the NR, HR and SHR modes compared with MDCT, but about a 14%, for NR, and 23%, for HR and SHR, dose increase gives the same results. Conclusions HR and SHR mode scanning results in double the spatial resolution, with about a 23% increase in dose required to achieve the same low-contrast detectability. Key Points • Resolution on UHRCT is up to twice as high as for the tested MDCT. • With abdominal settings, UHRCT needs higher dose for the same low-contrast detectability as MDCT, but dose is still below achievable levels as defined by current diagnostic reference levels. • The UHRCT system used in normal-resolution mode yields comparable resolution and noise characteristics as the MDCT system.

Background A categorical CT assessment scheme for suspicion of pulmonary involvement of coronavirus disease 2019 (COVID-19 provides a basis for gathering scientific evidence and improved communication with referring physicians. Purpose To introduce the COVID-19 Reporting and Data System (CO-RADS) for use in the standardized assessment of pulmonary involvement of COVID-19 on unenhanced chest CT images and to report its initial interobserver agreement and performance. Materials and Methods The Dutch Radiological Society developed CO-RADS based on other efforts for standardization, such as the Lung Imaging Reporting and Data System or Breast Imaging Reporting and Data System. CO-RADS assesses the suspicion for pulmonary involvement of COVID-19 on a scale from 1 (very low) to 5 (very high). The system is meant to be used in patients with moderate to severe symptoms of COVID-19. The system was evaluated by using 105 chest CT scans of patients admitted to the hospital with clinical suspicion of COVID-19 and in whom reverse transcription-polymerase chain reaction (RT-PCR) was performed (mean, 62 years ± 16 [standard deviation]; 61 men, 53 with positive RT-PCR results). Eight observers used CO-RADS to assess the scans. Fleiss κ value was calculated, and scores of individual observers were compared with the median of the remaining seven observers. The resulting area under the receiver operating characteristics curve (AUC) was compared with results from RT-PCR and clinical diagnosis of COVID-19. Results There was absolute agreement among observers in 573 (68.2%) of 840 observations. Fleiss κ value was 0.47 (95% confidence interval [CI]: 0.45, 0.47), with the highest κ value for CO-RADS categories 1 (0.58, 95% CI: 0.54, 0.62) and 5 (0.68, 95% CI: 0.65, 0.72). The average AUC was 0.91 (95% CI: 0.85, 0.97) for predicting RT-PCR outcome and 0.95 (95% CI: 0.91, 0.99) for clinical diagnosis. The false-negative rate for CO-RADS 1 was nine of 161 cases (5.6%; 95% CI: 1.0%, 10%), and the false-positive rate for CO-RADS category 5 was one of 286 (0.3%; 95% CI: 0%, 1.0%). Conclusion The coronavirus disease 2019 (COVID-19) Reporting and Data System (CO-RADS) is a categorical assessment scheme for pulmonary involvement of COVID-19 at unenhanced chest CT that performs very well in predicting COVID-19 in patients with moderate to severe symptoms and has substantial interobserver agreement, especially for categories 1 and 5. © RSNA, 2020 Online supplemental material is available for this article.

Purpose The purpose of this study was to assess, using an anthropomorphic digital phantom, the accuracy of algorithms in registering precontrast and contrast‐enhanced computed tomography (CT) chest images for generation of iodine maps of the pulmonary parenchyma via temporal subtraction. Materials and methods The XCAT phantom, with enhanced airway and pulmonary vessel structures, was used to simulate precontrast and contrast‐enhanced chest images at various inspiration levels and added CT simulation for realistic system noise. Differences in diaphragm position were varied between 0 and 20 mm, with the maximum chosen to exceed the 95th percentile found in a dataset of 100 clinical subtraction CTs. In addition, the influence of whole body movement, degree of iodine enhancement, beam hardening artifacts, presence of nodules and perfusion defects in the pulmonary parenchyma, and variation in noise on the registration were also investigated. Registration was performed using three lung registration algorithms - a commercial (algorithm A) and a prototype (algorithm B) version from Canon Medical Systems and an algorithm from the MEVIS Fraunhofer institute (algorithm C). For each algorithm, we calculated the voxel‐by‐voxel difference between the true deformation and the algorithm‐estimated deformation in the lungs. Results The median absolute residual error for all three algorithms was smaller than the voxel size (1.0 × 1.0 × 1.0 mm3) for up to an 8 mm diaphragm difference, which is the average difference in diaphragm levels found clinically, and increased with increasing difference in diaphragm position. At 20 mm diaphragm displacement, the median absolute residual error after registration was 0.85 mm (interquartile range, 0.51-1.47 mm) for algorithm A, 0.82 mm (0.50-1.40 mm) for algorithm B, and 0.91 mm (0.54-1.52 mm) for algorithm C. The largest errors were seen in the paracardiac regions and close to the diaphragm. The impact of all other evaluated conditions on the residual error varied, resulting in an increase in the median residual error lower than 0.1 mm for all algorithms, except in the case of whole body displacements for algorithm B, and with increased noise for algorithm C. Conclusion Motion correction software can compensate for respiratory and cardiac motion with a median residual error below 1 mm, which was smaller than the voxel size, with small differences among the tested registration algorithms for different conditions. Perfusion defects above 50 mm will be visible with the commercially available subtraction CT software, even in poorly registered areas, where the median residual error in that area was 7.7 mm.

The objective of this study was to compare the image quality of iodine maps derived from subtraction CT and from dual-energy CT (DECT) in patients with suspected pulmonary embolism (PE).In this prospective study conducted between July 2016 and April 2017, consecutive patients with suspected PE underwent unenhanced CT at 100 kV and dual-energy pulmonary CT angiography at 100 and 140 kV on a dual-source scanner. The scanner was set to generate subtraction and DECT iodine maps at similar radiation doses. In 55 patients (30 women, 25 men; mean age ± SD, 63.4 ± 11.9 years old), various subjective image quality criteria including diagnostic acceptability were rated on a 5-point scale by four radiologists and a radiology resident. In 29 patients (17 women, 12 men; mean age, 62.4 ± 11.7 years old) with confirmed perfusion defects, the signal-difference-to-noise ratio (SDNR) between perfusion defects and adjacent normally perfused parenchyma was measured in corresponding ROIs on subtraction and DECT iodine maps. McNemar and Wilcoxon signed-rank tests were used for statistical comparisons.Diagnostic acceptability was rated excellent or good in a mean of 67% (range, 31-80%) of subtraction CT studies and 36% (5-69%) of DECT studies (p0.05 for four of the five radiologists), mainly because of fewer artifacts on subtraction CT. Mean SDNR was marginally higher for subtraction CT than for DECT (18.6 vs 17.1, p = 0.06) and was significantly higher in the upper lobes (21.8 vs 17.9, p0.05).Radiologist-judged image quality of pulmonary iodine maps was higher for subtraction CT than for DECT with similar to higher SDNR. Subtraction CT is a software-only solution, so it may be an attractive alternative to DECT for depicting perfusion defects.

Contains fulltext : 229492.pdf (Publisher’s version ) (Open Access) OBJECTIVE: To compare nodule enhancement on subtraction CT iodine maps to that on dual-energy CT iodine maps using CT datasets acquired simultaneously. METHODS: A previously-acquired set of lung subtraction and dual-energy CT maps consisting of thirty patients with 95solid pulmonary nodules (>/=4mm diameter) was used. Nodules were annotated and segmented on CT angiography, and mean nodule enhancement in the iodine maps calculated. Three radiologists scored nodule visibility with both techniques on a 4-point scale. RESULTS: Mean nodule enhancement was higher (p

An observer study showed that two of the three top-performing algorithms from a public competition (Kaggle Data Science Bowl 2017) attained performances that were not significantly worse than that of 11 radiologists for estimating lung cancer risk on low-dose CT scans. Purpose. To determine whether deep learning algorithms developed in a public competition could identify lung cancer on low-dose CT scans with a performance similar to that of radiologists. Materials and Methods. In this retrospective study, a dataset consisting of 300 patient scans was used for model assessment; 150 patient scans were from the competition set and 150 were from an independent dataset. Both test datasets contained 50 cancer-positive scans and 100 cancer-negative scans. The reference standard was set by histopathologic examination for cancer-positive scans and imaging follow-up for at least 2 years for cancer-negative scans. The test datasets were applied to the three top-performing algorithms from the Kaggle Data Science Bowl 2017 public competition: grt123, Julian de Wit and Daniel Hammack (JWDH), and Aidence. Model outputs were compared with an observer study of 11 radiologists that assessed the same test datasets. Each scan was scored on a continuous scale by both the deep learning algorithms and the radiologists. Performance was measured using multireader, multicase receiver operating characteristic analysis. Results. The area under the receiver operating characteristic curve (AUC) was 0.877 (95% CI: 0.842, 0.910) for grt123, 0.902 (95% CI: 0.871, 0.932) for JWDH, and 0.900 (95% CI: 0.870, 0.928) for Aidence. The average AUC of the radiologists was 0.917 (95% CI: 0.889, 0.945), which was significantly higher than grt123 (P = .02); however, no significant difference was found between the radiologists and JWDH (P = .29) or Aidence (P = .26). Conclusion. Deep learning algorithms developed in a public competition for lung cancer detection in low-dose CT scans reached performance close to that of radiologists.

Background The coronavirus disease 2019 (COVID-19) pandemic has spread across the globe with alarming speed, morbidity, and mortality. Immediate triage of patients with chest infections suspected to be caused by COVID-19 using chest CT may be of assistance when results from definitive viral testing are delayed. Purpose To develop and validate an artificial intelligence (AI) system to score the likelihood and extent of pulmonary COVID-19 on chest CT scans using the COVID-19 Reporting and Data System (CO-RADS) and CT severity scoring systems. Materials and Methods The CO-RADS AI system consists of three deep-learning algorithms that automatically segment the five pulmonary lobes, assign a CO-RADS score for the suspicion of COVID-19, and assign a CT severity score for the degree of parenchymal involvement per lobe. This study retrospectively included patients who underwent a nonenhanced chest CT examination because of clinical suspicion of COVID-19 at two medical centers. The system was trained, validated, and tested with data from one of the centers. Data from the second center served as an external test set. Diagnostic performance and agreement with scores assigned by eight independent observers were measured using receiver operating characteristic analysis, linearly weighted κ values, and classification accuracy. Results A total of 105 patients (mean age, 62 years ± 16 [standard deviation]; 61 men) and 262 patients (mean age, 64 years ± 16; 154 men) were evaluated in the internal and external test sets, respectively. The system discriminated between patients with COVID-19 and those without COVID-19, with areas under the receiver operating characteristic curve of 0.95 (95% CI: 0.91, 0.98) and 0.88 (95% CI: 0.84, 0.93), for the internal and external test sets, respectively. Agreement with the eight human observers was moderate to substantial, with mean linearly weighted κ values of 0.60 ± 0.01 for CO-RADS scores and 0.54 ± 0.01 for CT severity scores. Conclusion With high diagnostic performance, the CO-RADS AI system correctly identified patients with COVID-19 using chest CT scans and assigned standardized CO-RADS and CT severity scores that demonstrated good agreement with findings from eight independent observers and generalized well to external data. © RSNA, 2020 Supplemental material is available for this article.

Background Long-term health sequelae of coronavirus disease 2019 (COVID-19) may be multiple but have thus far not been systematically studied. Methods All patients discharged after COVID-19 from the Radboud University Medical Center, Nijmegen, the Netherlands, were consecutively invited to a multidisciplinary outpatient facility. Also, nonadmitted patients with mild disease but with symptoms persisting >6 weeks could be referred by general practitioners. Patients underwent a standardized assessment including measurements of lung function, chest computed tomography (CT)/X-ray, 6-minute walking test, body composition, and questionnaires on mental, cognitive, health status, and quality of life (QoL). Results 124 patients (59 ± 14 years, 60% male) were included: 27 with mild, 51 with moderate, 26 with severe, and 20 with critical disease. Lung diffusion capacity was below the lower limit of normal in 42% of discharged patients. 99% of discharged patients had reduced ground-glass opacification on repeat CT imaging, and normal chest X-rays were found in 93% of patients with mild disease. Residual pulmonary parenchymal abnormalities were present in 91% of discharged patients and correlated with reduced lung diffusion capacity. Twenty-two percent had low exercise capacity, 19% low fat-free mass index, and problems in mental and/or cognitive function were found in 36% of patients. Health status was generally poor, particularly in the domains functional impairment (64%), fatigue (69%), and QoL (72%). Conclusions This comprehensive health assessment revealed severe problems in several health domains in a substantial number of ex–COVID-19 patients. Longer follow-up studies are warranted to elucidate natural trajectories and to find predictors of complicated long-term trajectories of recovery.

Objectives To compare contrast-to-noise ratios (CNRs) and iodine discrimination thresholds on iodine maps derived from dual energy CT (DECT) and subtraction CT (SCT). Methods A contrast-detail phantom experiment was performed with 2 to 15 mm diameter tubes containing water or iodinated contrast concentrations ranging from 0.5 mg/mL to 20 mg/mL. DECT scans were acquired at 100 kVp and at 140 kVp+Sn filtration. SCT scans were acquired at 100 kVp. Iodine maps were created by material decomposition (DECT) or by subtraction of water scans from iodine scans (SCT). Matched exposure levels varied from 8 to 15 mGy. Iodine discrimination thresholds (Cr) and response times were determined by eight observers. Results The adjusted mean CNR was 1.9 times higher for SCT than for DECT. Exposure level had no effect on CNR. All observers discriminated all details ≥10 mm at 12 and 15 mGy. For sub-centimetre details, the lowest calculated Cr was ≤ 0.50 mg/mL for SCT and 0.64 mg/mL for DECT. The smallest detail was discriminated at ≥4.4 mg/mL with SCT and at ≥7.4 mg/mL with DECT. Response times were lower for SCT than DECT. Conclusions SCT results in higher CNR and reduced iodine discrimination thresholds compared to DECT for sub-centimetre details. Key Points • Subtraction CT iodine maps exhibit higher CNR than dual-energy iodine maps • Lower iodine concentrations can be discriminated for sub-cm details with SCT • Response times are lower using SCT compared to dual-energy CT Electronic supplementary material The online version of this article (10.1007/s00330-018-5496-x) contains supplementary material, which is available to authorized users.

To evaluate the technical performance of an ultra-high-resolution CT (UHRCT) system.The physico-technical capabilities of a novel commercial UHRCT system were assessed and compared with those of a current-generation multi-detector (MDCT) system. The super-high-resolution (SHR) mode of the system uses 0.25 mm (at isocentre) detector elements (dels) in the in-plane and longitudinal directions, while the high-resolution (HR) mode bins two dels in the longitudinal direction. The normal-resolution (NR) mode bins dels 2 × 2, resulting in a del-size equivalent to that of the MDCT system. In general, standard procedures and phantoms were used to perform these assessments.The UHRCT MTF (10% MTF 4.1 lp/mm) is twice as high as that of the MDCT (10% MTF 1.9 lp/mm), which is comparable to the MTF in the NR mode (10% MTF 1.7 lp/mm). The width of the slice sensitivity profile in the SHR mode (FWHM 0.45 mm) is about 60% of that of the MDCT (FWHM 0.77 mm). Uniformity and CT numbers are within the expected range. Noise in the high-resolution modes has a higher magnitude and higher frequency components compared with MDCT. Low-contrast visibility is lower for the NR, HR and SHR modes compared with MDCT, but about a 14%, for NR, and 23%, for HR and SHR, dose increase gives the same results.HR and SHR mode scanning results in double the spatial resolution, with about a 23% increase in dose required to achieve the same low-contrast detectability.• Resolution on UHRCT is up to twice as high as for the tested MDCT. • With abdominal settings, UHRCT needs higher dose for the same low-contrast detectability as MDCT, but dose is still below achievable levels as defined by current diagnostic reference levels. • The UHRCT system used in normal-resolution mode yields comparable resolution and noise characteristics as the MDCT system.

Objective To evaluate accuracy of fracture detection and therapeutic impact of a single-shot CT protocol as a primary imaging tool in all patients with clinical suspicion of wrist injury, and evaluate the resulting impact on therapy. Materials and methods We performed a single-institution study on all patients with suspicion of fractures of the wrist and carpus. All patients underwent conventional radiography, thereafter single-shot wrist CT, and then 1-year follow-up. Physicians and radiologists prospectively scored likelihood of fracture presence on a five-point scale before and after CT. Three surgeons proposed a treatment regimen (functional, cast, reduction, or operative) based on clinical and radiological data, first with knowledge of conventional radiography, and then with knowledge of CT. The reference standard for fracture presence was based on all data. We performed receiver operating characteristic (ROC) analyses and calculated proportion of wrists with treatment changes due to CT imaging. Results Ninety-eight patients participated (63% female, mean age 53, range, 18–87 years old) with 100 wrist CTs. Conventional radiography detected true-positive fractures in 45, and CT in 61 wrists. The areas under the curve for fracture detection were 0.85 (95% CI 0.77–0.93) for conventional radiography and 0.97 (95% CI 0.93–1.00) for CT. Treatment changed in 24 (24%, 95% CI 16–33%) - 31 (31%, 95% CI 23–41%) wrists, mostly involving a decrease in the rate of cast immobilization. Conclusions Single-shot CT in patients with clinical suspicion of wrist injury increases accuracy of fracture detection. This has a significant impact therapy in this population, mainly on cast immobilization. Trial Registration We registered the study at www.clinicaltrials.gov, NL43482.091.13.

Background Dual-energy CT iodine maps are used to detect pulmonary embolism (PE) with CT angiography but require dedicated hardware. Subtraction CT, a software-only solution, results in iodine maps with high contrast-to-noise ratios. Purpose To compare the use of subtraction CT versus dual-energy CT iodine maps to CT angiography for PE detection. Materials and Methods In this prospective study ( https://clinicaltrials.gov , NCT02890706), 274 participants suspected of having PE underwent precontrast CT followed by contrast material-enhanced dual-energy CT angiography between July 2016 and April 2017. Iodine maps from dual-energy CT were derived. Subtraction maps (contrast-enhanced CT minus precontrast CT) were calculated after motion correction. Truth was established by expert consensus. A total of 75 randomly selected participants with and without PE (1:1 ratio) were evaluated by three radiologists and six radiology residents (blinded to final diagnosis) for the presence of PE using three types of CT: CT angiography alone, dual-energy CT, and subtraction CT. The partial area under the receiver operating characteristic curve (AUC) for the clinically relevant specificity region (maximum partial AUC, 0.11) was compared by using multireader multicase variance. A P value less than or equal to .025 was considered indicative of a significant difference due to multiple comparisons. Results There were 35 men and 40 women in the reader study (mean age, 63 years ± 12 [standard deviation]). The pooled sensitivities were not different (P ≥ .31 among techniques) (95% confidence intervals [CIs]: 67%, 89% for CT angiography; 72%, 91% for dual-energy CT; 70%, 91% for subtraction CT). However, pooled specificity was higher for subtraction CT (95% CI: 100%, 100%) than for CT angiography (95% CI: 89%, 97%) or dual-energy CT (95% CI: 89%, 98%) (P < .001). Partial AUCs for the average observer improved equally when adding iodine maps (subtraction CT [0.093] vs CT angiography [0.088], P = .03; dual-energy CT [0.094] vs CT angiography, P = .01; dual-energy CT vs subtraction CT, P = .68). Average reading times were equivalent (range, 97-101 seconds; P ≥ .41) among techniques. Conclusion Subtraction CT iodine maps had greater specificity than CT angiography alone in pulmonary embolism detection. Subtraction CT had comparable diagnostic performance to that of dual-energy CT, without the need for dedicated hardware. © RSNA, 2019 Online supplemental material is available for this article.

Context: No consensus about classification, treatment, and clinical relevance of occipital condyle fractures (OCFs) exists. Aims: The aim of the study was to determine radiological, clinical, and functional outcome of OCFs and thereby determine its clinical relevance. Settings and Design: This was a retrospective analysis of a prospective follow-up study. Materials and Methods: From May 2005 to May 2008, all OCFs were included from a Level-1 trauma center. Patient files were reviewed for patient and fracture characteristics. Fracture classification was done according to the Anderson criteria. Clinical outcome was assessed by completing two questionnaires, radiological outcome by computed tomography imaging, and functional outcome by measuring active cervical range of motion using a Cybex EDI-320. Statistical Analysis Used: A Fisher's exact Test was used in categorical variables and a one-sample t-test for comparing means of active cervical range of motion in occipital fracture patients with normal values. An independent samples t-test was carried out to compare the means of groups with and without accompanying cervical fractures for each motion. Results: Thirty-nine patients were included (4 type I, 16 type II, and 19 type III). Twenty-seven patients completed follow-up, of whom 26 were treated conservatively. Fracture healing was established in 25 of 28 fractures at a median follow-up of 19 months. Eleven patients had none to minimal pain or disability at follow-up, 12 had mild, and two had moderate pain or disability on questionnaires. No statistically significant difference in active cervical range of motion was identified comparing means stratified for accompanying cervical fractures. Conclusions: Conservatively treated patients with an OCF generally show favorable radiological and clinical outcome.

PURPOSE: To compare human observers to a mathematically derived computer model for differentiation between malignant and benign pulmonary nodules detected on baseline screening computed tomography (CT) scans.METHODS: A case-cohort study design was chosen. The study group consisted of 300 chest CT scans from the Danish Lung Cancer Screening Trial (DLCST). It included all scans with proven malignancies (n = 62) and two subsets of randomly selected baseline scans with benign nodules of all sizes (n = 120) and matched in size to the cancers, respectively (n = 118). Eleven observers and the computer model (PanCan) assigned a malignancy probability score to each nodule. Performances were expressed by area under the ROC curve (AUC). Performance differences were tested using the Dorfman, Berbaum and Metz method. Seven observers assessed morphological nodule characteristics using a predefined list. Differences in morphological features between malignant and size-matched benign nodules were analyzed using chi-square analysis with Bonferroni correction. A significant difference was defined at p < 0.004.RESULTS: Performances of the model and observers were equivalent (AUC 0.932 versus 0.910, p = 0.184) for risk-assessment of malignant and benign nodules of all sizes. However, human readers performed superior to the computer model for differentiating malignant nodules from size-matched benign nodules (AUC 0.819 versus 0.706, p < 0.001). Large variations between observers were seen for ROC areas and ranges of risk scores. Morphological findings indicative of malignancy referred to border characteristics (spiculation, p < 0.001) and perinodular architectural deformation (distortion of surrounding lung parenchyma architecture, p < 0.001; pleural retraction, p = 0.002).CONCLUSIONS: Computer model and human observers perform equivalent for differentiating malignant from randomly selected benign nodules, confirming the high potential of computer models for nodule risk estimation in population based screening studies. However, computer models highly rely on size as discriminator. Incorporation of other morphological criteria used by human observers to superiorly discriminate size-matched malignant from benign nodules, will further improve computer performance.

Pulmonary embolism is a fairly common and serious entity, so rapid diagnosis and treatment has a significant impact on morbidity and mortality rates. Iodine maps representing tissue perfusion enhancement are commonly generated by dual-energy CT acquisitions to provide information about the effect of the embolism on pulmonary perfusion. Alternatively, the iodine map can be generated by subtracting pre- from post-contrast CT scans as previously reported. Although accurate image registration is essential, subtraction has the advantage of a higher signal-to-noise ratio and suppression of bone. This paper presents an improvement over the previously reported registration algorithm. Significantly, allowance for sliding motion at tissue boundaries is included in the regularization. Pre- and post-contrast helical CT scans were acquired for thirty subjects using a Toshiba Aquilion ONE scanner. Ten of these subjects were designated for algorithm development, while the remaining twenty were reserved for qualitative clinical evaluation. Quantitative evaluation was performed against the previously reported method and using publicly available data for comparison against other methods. Comparison of 100 landmarks in seven datasets shows no change in the mean Euclidean error of 0.48 mm, compared to the previous method. Evaluation in the publicly available DIR-Lab data with 300 annotations results in a mean Euclidean error of 1.17 mm in the ten 4DCT cases and 3.37 mm in the ten COPDGene cases. Clinical evaluation on a sliding scale from 1 (excellent) to 5 (non-diagnostic) indicates a slight, but non-significant, improvement in registration adequacy from 3.1 to 2.9.

Contains fulltext : 167183.pdf (Publisher’s version ) (Open Access) We present a method for automatic separation and classification of pulmonary arteries and veins in computed tomography. Our method takes advantage of local information to separate segmented vessels, and global information to perform the artery-vein classification. Given a vessel segmentation, a geometric graph is constructed that represents both the topology and the spatial distribution of the vessels. All nodes in the geometric graph where arteries and veins are potentially merged are identified based on graph pruning and individual branching patterns. At the identified nodes, the graph is split into subgraphs that each contain only arteries or veins. Based on the anatomical information that arteries and veins approach a common alveolar sag, an arterial subgraph is expected to be intertwined with a venous subgraph in the periphery of the lung. This relationship is quantified using periphery matching and is used to group subgraphs of the same artery-vein class. Artery-vein classification is performed on these grouped subgraphs based on the volumetric difference between arteries and veins. A quantitative evaluation was performed on 55 publicly available non-contrast CT scans. In all scans, two observers manually annotated randomly selected vessels as artery or vein. Our method was able to separate and classify arteries and veins with a median accuracy of 89%, closely approximating the inter-observer agreement. All CT scans used in this study, including all results of our system and all manual annotations, are publicly available at "http://www.w3.org/1999/xlink">http://arteryvein.grand-challenge.org".

Purpose To determine the accuracy of registration algorithms, using an anthropomorphic digital phantom, in registering unenhanced and enhanced computed tomography (CT) chest images. Methods Lung subtraction CT generates pulmonary iodine maps by subtracting an unenhanced scan from an enhanced scan after image registration. This technique can be useful for detection of pulmonary embolism, characterization of nodule or mass perfusion, or for evaluation of pulmonary lesion growth at follow-up. The LUMIC challenge is aimed at comparing the performance of algorithms in registering simulated enhanced and unenhanced CT images of the XCAT anthropomorphic digital phantom (Duke University, Durham, North Carolina, U.S.A.). The simulated scans are available with two voxel sizes (anisotropic, 0.6 × 0.6 × 1.0 mm3, and isotropic, 1.0 × 1.0 × 1.0 mm3), and with varying differences in diaphragm levels between the CT scans: 3 mm (small difference), 8 mm (average clinical difference), and 20 mm (large difference), all without pulmonary pathology. Since the voxel-by-voxel true displacement between the unenhanced and enhanced phantom realizations is known, the residual error between the estimated displacement field and the known truth can be determined for all lung voxels. Results The results submitted in response to this challenge will be calculated as the median, 25th and 75th percentile of the residual values. Besides these values, whole residual error images will be generated, which will provide position-specific information on the performance of each algorithm. Three algorithms have already been evaluated, resulting in the following residual errors for the large diaphragm-position difference [median (25th – 75th percentile)]: 0.93 mm (0.52 mm – 1.58 mm), 0.92 mm (0.51 mm – 1.57 mm), and 0.93 mm (0.52 mm – 1.60 mm). For all three algorithms, the largest errors were seen in the paracardiac regions and close to the diaphragm. Conclusions This challenge, based on the use of a digital anthropomorphic phantom, is a useful way to not only determine the current performance level of registration algorithms world-wide, but also to directly compare their performance. In addition, given the availability of the resulting error location information, the participants will be able to identify problematic areas for their registration algorithms that might need further improvement. The challenge is available on https://lumic.grand-challenge.org .

Purpose To determine the impact of patient and acquisition parameters on the quantification of the enhancement of pulmonary parenchyma in subtraction computed tomography pulmonary angiography (CTPA) imaging in patients without pulmonary pathology. Methods 2515 patients underwent clinical CTPA with subtraction imaging on a 320-multidetector row CT scanner (Aquilion ONE VISION or GENESIS, Canon Medical Systems Corporation, Japan) between January 2013 and August 2017 for suspicion of pulmonary embolism. In subtraction CT, an unenhanced chest CT is subtracted from an enhanced CT after motion correction, resulting in an iodine map representing pulmonary perfusion. After examination of patient records and images, 74 patients (2.9 %) without any apparent pulmonary or systemic pathology were selected. The mean enhancement in circular regions of interest (ROI) in all lung lobes of the iodine maps, placed to avoid vessels depicted in the CTPA images, were calculated. Patient age, sex, BMI, and smoking habits, as well as CT scan time, diaphragm position and lung volume changes between the unenhanced and enhanced CT, type and volume of contrast, and enhancement in the aortic arch, pulmonary trunk and left atrium were collected. Linear regression analysis was used to evaluate the correlation between the parameters and the measured enhancement. Results The mean enhancement of the ROIs throughout the whole lung was 32.2 ± 21.6 HU. The enhancement in the lower lobes (39.4 ± 24.3 HU) was significantly higher than in the upper lobes (31.7 ± 22.3 HU, p r 2 = 0.54 p 0.001 ) , and with lung volume changes ( r 2 = 0.73 p 0.001 ) between the scans. No correlation was found between the mean enhancement and all other variables studied. Conclusions The enhancement of the pulmonary parenchyma on subtraction CT imaging in patients without pulmonary pathology varies widely. However, normal enhancement values correlate strongly with changes in diaphragm position and in pulmonary volume between scans. This implies that normalization of lung enhancement based on lung volume changes could improve clinical interpretation and would be the first step towards quantification of enhancement in subtraction CT imaging.

Contains fulltext : 89655.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To select parameters that can predict which patients should receive abdominal computed tomography (CT) after high-energy blunt trauma. SUMMARY BACKGROUND DATA: Abdominal CT accurately detects injuries of the abdomen, pelvis, and lumbar spine, but has important disadvantages. More evidence for an appropriate patient selection for CT is required. METHODS: A prospective observational study was performed on consecutive adult high-energy blunt trauma patients. All patients received primary and secondary surveys according to the advanced trauma life support, sonography (focused assessment with sonography for trauma [FAST]), conventional radiography (CR) of the chest, pelvis, and spine and routine abdominal CT. Parameters from prehospital information, physical examination, laboratory investigations, FAST, and CR were prospectively recorded for all patients. Independent predictors for the presence of > or =1 injuries on abdominal CT were determined using a multivariate logistic regression analysis. RESULTS: A total of 1040 patients were included, 309 had injuries on abdominal CT. Nine parameters were independent predictors for injuries on CT: abnormal CR of the pelvis (odds ratio [OR], 46.8), lumbar spine (OR, 16.2), and chest (OR, 2.37), abnormal FAST (OR, 26.7), abnormalities in physical examination of the abdomen/pelvis (OR, 2.41) or lumbar spine (OR 2.53), base excess

BACKGROUND: Discussion still remains which polytraumatized patients require radiologic thoracolumbar spine (TL spine) screening. The purpose of this study is to determine whether pelvic fractures are associated with TL spine fractures after a blunt trauma. Additionally, the sensitivity of conventional TL spine radiographs and pelvic radiographs (PXRs) is evaluated. METHODS: We prospectively studied 721 consecutive patients who had sustained a high-energy blunt trauma. The diagnostic workup in these patients included routine conventional radiographs of the pelvis and TL spine followed by a computed tomography (CT) analysis. All patients with pelvic fractures and TL spine fractures identified on conventional radiographs and CT were analyzed. A relative risk (RR) was calculated for the association between pelvic fractures and TL spine fractures. The sensitivity for conventional TL spine radiographs and PXRs in identifying fractures was calculated. RESULTS: Of the 721 patients studied, 620 were included in our diagnostic high-energy trauma protocol. Of these 620 included patients, 86 (14%) suffered a pelvic fracture and 126 (20%) suffered a TL spine fracture. Thirty-three patients (5%) suffered both a pelvic fracture and a TL spine fracture. The RR for a TL spine fracture in the presence of a pelvic fracture identified on PXR is 2.14 (95% confidence interval, 1.54-2.98) and identified on CT this RR is 2.20 (95% confidence interval, 1.59-3.05). However, this association diminishes to a nonsignificant level when the transverse process and spinous process fractures are excluded. Overall sensitivity for conventional TL spine radiographs and PXRs is 22% and 69%, respectively. CONCLUSION: Our data suggest that a pelvic fracture is not a predictor for clinically relevant TL spine fractures. Furthermore, our data confirm the superior sensitivity of CT for detecting TL spine injury and pelvic fractures.

Contains fulltext : 81423.pdf (Publisher’s version ) (Closed access) The need for prospective studies in trauma radiology emerges as knowledge on the appropriate use of imaging becomes increasingly important in this field. Prospective observational studies enroll patients after research questions are articulated but only observe medical practice and should not compromise or change patient treatment. However, controversy exists regarding the requirement of informed consent from trauma patients in this type of study. This is reflected not only in differences in reporting informed consent in recent scientific publications on trauma radiology but also by the fact that policies regarding this topic vary in different parts of the world. The authors consider whether requesting informed consent is appropriate in prospective observational studies in trauma radiology from practical and different ethical perspectives.

Contains fulltext : 81609.pdf (Publisher’s version ) (Closed access) INTRODUCTION: This study was performed to determine the agreement between and within surgeons concerning the influence on treatment plan of routine versus selective multidetector-row computed tomography (MDCT) findings in blunt trauma patients. PATIENTS: For this study, 50 patients were randomly selected from a customized database that was originally used to compare a diagnostic algorithm with a selective use of MDCT with an algorithm with routine MDCT of the spine, chest, and abdomen within the same population. In all 50 patients, routine MDCT found additional diagnoses as compared with the selective MDCT algorithm. Of all patients, paper cases were created with detailed information on clinical parameters, findings by physical examination, and radiologic findings. The cases were independently presented to three different trauma surgeons. First, the surgeons were asked for their treatment plan based upon diagnoses found by physical examination, conventional radiography, and selective MDCT alone. Subsequently they were asked for their treatment plan with knowledge of the injuries additionally found by routine MDCT. This procedure was repeated after 3 months. The agreement between and within surgeons was determined for the change of patient management because of additional findings by routine MDCT. RESULTS: The agreement on the influence of routine MDCT findings on patient management between surgeons was moderate ([kappa] = 0.46) in the first procedure and substantial in the second ([kappa] = 0.67). The agreement within surgeons ranged from moderate ([kappa] = 0.60) to excellent ([kappa] = 0.87). CONCLUSION: All surgeons agreed that the traumatic injuries additionally found by routine MDCT, frequently resulted in a change of treatment plan. There was a moderate-to-excellent agreement between and within surgeons that these additional findings resulted in a change of treatment plan.

Contains fulltext : 69921.pdf (Publisher’s version ) (Closed access) PURPOSE: To evaluate the effect of arm position on image quality and effective radiation dose in an automatic exposure-controlled (AEC) multidetector thoracoabdominal computed tomography (CT) protocol in trauma patients. MATERIALS AND METHODS: This retrospective study of the data of 177 trauma patients (117 male; median age, 39 years) was approved by the institutional ethics board, with informed patient consent waived. Patients underwent scanning by using an AEC 16-detector thoracoabdominal CT protocol in which both arms were raised above the shoulder region (standard-position group, 132 patients), one arm was raised and the other was down (one-arm group, 27 patients), or both arms were down (two-arm group, 18 patients). Objective and subjective image quality was assessed. Individual effective radiation dose was calculated from the effective tube current-time product per exposed section. For this purpose, section location-dependent conversion factors were derived by using a CT dosimetry calculator. The effect of arm position on effective dose was quantified by using linear regression analysis with correction for patient volume and attenuation. RESULTS: Compared with the image quality in the standard-position group, the image quality in the one- and two-arm groups was decreased but within acceptable diagnostic limits. The median corrected effective dose in the standard-position group was 18.6 mSv; the dose in the one-arm group was 18% (95% confidence interval: 11%, 25%) higher than this, and that in the two-arm group was 45% (95% confidence interval: 34%, 57%) higher. CONCLUSION: Omitting arm raising results in lower but acceptable image quality and a substantially higher effective radiation dose. Hence, effort should be made to position the arms above the shoulder when scanning trauma patients. Clinical trial registration no. NCT00228111.

Contains fulltext : 69546.pdf (Publisher’s version ) (Closed access) OBJECTIVE: The objective of our study was to evaluate the added value of a low-threshold routine thoracic MDCT algorithm compared with a selective MDCT algorithm in adult blunt trauma patients. SUBJECTS AND METHODS: A prospective cohort study was conducted in 464 consecutive blunt trauma patients who met criteria indicative of severe blunt trauma (66% male; age range, 16-93 years; median injury severity score, 13). After clinical evaluation and conventional radiography of the chest and thoracic spine, all patients underwent routine thoracic MDCT with an IV contrast agent (routine MDCT algorithm). Within this routine MDCT group, a subgroup was prospectively defined with abnormal or inconclusive clinical or conventional radiography evaluation (selective MDCT group). Two investigators determined the type, extent, and clinical impact of additional injuries found on MDCT as compared to conventional radiography for both MDCT groups. RESULTS: Of all 464 patients within the routine MDCT group, 164 patients underwent selective MDCT, which resulted in detection of additional diagnoses compared with conventional radiography in 97 (59%) patients. The routine MDCT algorithm detected additional diagnoses compared with conventional radiography in 201 of 464 patients (43%). Compared with the selective MDCT algorithm, this was an absolute increase of 104 of 464 (22%) extra patients, resulting in a change in patient management in 34 (7%; 95% CI, 5-9.7%), mostly because of additional findings of pulmonary and mediastinal injury. CONCLUSION: Routine MDCT has relatively lower, though still substantial, added diagnostic value compared with selective MDCT of the chest.

Patients with familial pulmonary arterial hypertension inherit heterozygous mutations of the type 2 bone morphogenetic protein (BMP) receptor BMPR2. To explore the cellular mechanisms of this disease, we evaluated the pulmonary vascular responses to chronic hypoxia in mice carrying heterozygous hypomorphic Bmpr2 mutations ( Bmpr2ΔEx2/+). These mice develop more severe pulmonary hypertension after prolonged exposure to hypoxia without an associated increase in pulmonary vascular remodeling or proliferation compared with wild-type mice. This is associated with defective endothelial-dependent vasodilatation and enhanced vasoconstriction in isolated intrapulmonary artery preparations. In addition, there is a selective decrease in hypoxia-induced, BMP-dependent, endothelial nitric oxide synthase expression and Smad signaling in the intact lungs and in cultured pulmonary microvascular endothelial cells from Bmpr2ΔEx2/+ mutant mice. These findings indicate that the pulmonary endothelium is a target of abnormal BMP signaling in Bmpr2ΔEx2/+ mutant mice and suggest that endothelial dysfunction contributes to their increased susceptibility to hypoxic pulmonary hypertension.

Contains fulltext : 139472.pdf (Publisher’s version ) (Open Access) BACKGROUND: CT is increasingly used during the initial evaluation of blunt trauma patients. In this era of increasing cost-awareness, the pros and cons of CT have to be assessed. OBJECTIVES: This study was performed to evaluate cost-consequences of different diagnostic algorithms that use thoracoabdominal CT in primary evaluation of adult patients with high-energy blunt trauma. MATERIALS AND METHODS: We compared three different algorithms in which CT was applied as an immediate diagnostic tool (rush CT), a diagnostic tool after limited conventional work-up (routine CT), and a selective tool (selective CT). Probabilities of detecting and missing clinically relevant injuries were retrospectively derived. We collected data on radiation exposure and performed a micro-cost analysis on a reference case-based approach. RESULTS: Both rush and routine CT detected all thoracoabdominal injuries in 99.1% of the patients during primary evaluation (n = 1040). Selective CT missed one or more diagnoses in 11% of the patients in which a change of treatment was necessary in 4.8%. Rush CT algorithm costed euro 2676 (US$ 3660) per patient with a mean radiation dose of 26.40 mSv per patient. Routine CT costed euro 2815 (US$ 3850) and resulted in the same radiation exposure. Selective CT resulted in less radiation dose (23.23 mSv) and costed euro 2771 (US$ 3790). CONCLUSIONS: Rush CT seems to result in the least costs and is comparable in terms of radiation dose exposure and diagnostic certainty with routine CT after a limited conventional work-up. However, selective CT results in less radiation dose exposure but a slightly higher cost and less certainty.

Objective Currently CT is rapidly implemented in the evaluation of trauma patients. In anticipation of a large international multicentre trial, this study9s aim was to evaluate the clinical feasibility of a new diagnostic protocol, used for the primary radiological evaluation in adult blunt high-energy trauma patients, especially for the use of CT. Methods An evidence-based flow chart was created with criteria based on trauma mechanism, physical examination and laboratory analyses to indicate appropriateness of conventional radiography (CR), sonography and CT of head, cervical spine and trunk. To evaluate this protocol, the authors prospectively included 81 consecutive patients. Collected data included protocol adherence and number and type of performed CR and CT scans. The authors also determined the time needed to perform radiological investigations, adverse events in the CT room and clinically relevant missed injuries after 1-month clinical follow-up. Results There was 99% adherence to the protocol concerning CT. Seventy-nine patients (98%) received one or more CT scans: 72 (89%) had thoracoabdominal, 78 (96%) cervical spine and 54 (67%) had cranial CT. In 30 patients, one or more CT scans of body regions could be omitted. In 38%, CR was wrongly omitted or performed incorrectly at a variance with the protocol. No major adverse events occurred in the CT room and no clinically relevant injuries were missed. Conclusions The authors introduced a diagnostic protocol that seems feasible and safe for the evaluation of adult blunt high-energy trauma patients. Implementation of this protocol has the potential to reduce unnecessary radiological investigations, especially CT scans.

BACKGROUND:: Thoracoabdominal MultiDetector-row Computed Tomography (MDCT) is frequently used as a diagnostic tool in trauma patients. One potential side-effect of performing MDCT is the detection of incidental findings and their subsequent consequences on medical treatment. The objective was to evaluate frequency and effects of incidental findings in trauma patients. METHODS:: The reports of 1,047 consecutive blunt trauma patients (mean age, 40 years) who underwent routine contrast-enhanced thoracoabdominal MDCT were evaluated. Incidental findings were categorized by a trauma radiologist into four hierarchic categories based on their clinical consequences. We recorded additional diagnostic workup and treatment performed in conjunction with these incidental findings. RESULTS:: Of the 1,047 patients, 372 (mean age, 56 years; 61% male) had one or more incidental findings on thoracoabdominal MDCT. Complementary investigation or therapy was performed in 72 of these 372 patients; 29 of these patients required additional invasive evaluation or treatment. Nineteen patients underwent surgery due to an incidental finding. Nine patients were diagnosed with a not previously identified malignancy. CONCLUSIONS:: Routine thoracoabdominal MDCT in the evaluation of trauma patients revealed a significant number of incidental findings. Based on radiologic findings it is possible to decide whether additional follow-up or treatment is necessary.

Contains fulltext : 87857.pdf (Publisher’s version ) (Closed access) PURPOSE: The purpose of this study was to derive parameters that predict which high-energy blunt trauma patients should undergo computed tomography (CT) for detection of chest injury. METHODS: This observational study prospectively included consecutive patients (>or=16 years old) who underwent multidetector CT of the chest after a high-energy mechanism of blunt trauma in one trauma centre. RESULTS: We included 1,047 patients (median age, 37; 70% male), of whom 508 had chest injuries identified by CT. Using logistic regression, we identified nine predictors of chest injury presence on CT (age >or=55 years, abnormal chest physical examination, altered sensorium, abnormal thoracic spine physical examination, abnormal chest conventional radiography (CR), abnormal thoracic spine CR, abnormal pelvic CR or abdominal ultrasound, base excess or=1 positive predictors, 484 had injury on CT (95% of all 508 patients with injury). Of all 192 patients with no positive predictor, 24 (13%) had chest injury, of whom 4 (2%) had injuries that were considered clinically relevant. CONCLUSION: Omission of CT in patients without any positive predictor could reduce imaging frequency by 18%, while most clinically relevant chest injuries remain adequately detected. 01 april 2010

Contains fulltext : 88962.pdf (Publisher’s version ) (Closed access) BACKGROUND: Multidetector-row computed tomography (MDCT) is a more sensitive modality as compared with conventional radiography (CR) in detecting pulmonary injuries. MDCT often detects pulmonary contusion that is not visualized by CR, defined as occult pulmonary contusion (OPC). The aim of this study was to investigate whether OPC on MDCT has implications for the outcome in blunt trauma patients. METHODS: We used prospectively collected data from 1,040 adult high-energy blunt trauma patients who were primarily presented at our emergency department and who underwent CR and MDCT of the chest. All patients with pulmonary contusion were identified and divided into two groups: The "CR/computed tomography (CT) group" consisted of patients with pulmonary contusion visible on both CR and MDCT. The "CT-only" group consisted of patients with OPC, visible exclusively on MDCT. The control group consisted of blunt trauma patients without pulmonary contusion. These groups were compared with respect to difference in mortality and other outcome measures. In addition, a multivariate analysis was performed. RESULTS: Two hundred fifty-five patients suffered pulmonary contusion: The CT-only group consisted of 157 and the CR/CT group of 98 patients. The CT-only group did not differ from the control group with respect to mortality rate and other outcome measures. However, compared with the CR/CT group, mortality rate was significantly lower (8% versus 16%, p = 0.039) and most other outcome measures were significantly better in the CT-only group. CONCLUSION: OPC on MDCT is not associated with a worse outcome as compared with patients without pulmonary contusion. OPC has a better outcome as compared with pulmonary contusion visible on both CR and MDCT. 01 februari 2010

Contains fulltext : 81608.pdf (Publisher’s version ) (Closed access) BACKGROUND: Discussion still remains whether computed tomography (CT) of the abdomen, pelvis, and lumbar spine should be performed routinely after blunt trauma with high energy impact or only in restricted situations. The purpose of this study was to evaluate the additional value of a routine CT algorithm as compared with a more restricted, selective CT algorithm. MATERIALS: This prospective study consisted of 465 patients that met the inclusion criteria of our high-energy trauma protocol. All patients underwent physical examination, abdominal ultrasound (AUS), and conventional radiography (CR) of the pelvis and lumbar spine and subsequently routine CT of the abdomen, pelvis, and lumbar spine. Before CT, a subgroup of patients with abnormal physical examination or CR or AUS was prospectively defined as the selective CT group. Type and extent of injuries and impact on treatment were recorded for both the routine CT group and the selective CT subgroup. RESULTS: Of all patients, 42 received selective CT of the abdomen, 71 of the pelvis, and 48 of the lumbar spine. Compared with the algorithm with selective CT, routine CT revealed additional traumatic injuries in 15% of the patients in the abdomen, in 2.4% in the pelvis and in 8.2% in the lumbar spine. This resulted in an overall change of treatment in 6.4% (95% confidence interval, 3.7-9.0) of the patients who would not have received CT in a selective CT algorithm. CONCLUSIONS: Compared with an algorithm with selective CT, an algorithm with routine CT finds substantially more clinically relevant diagnoses, even in patients with unsuspicious clinical examination, normal CR, and normal AUS.

Contains fulltext : 80538.pdf (Publisher’s version ) (Closed access) AIM: To identify and to evaluate predictors that determine whether chest computed tomography (CT) is likely to reveal relevant injuries in adult blunt trauma patients. METHODS: After a comprehensive literature search for original studies on blunt chest injury diagnosis, two independent observers included studies on the accuracy of parameters derived from history, physical examination, or diagnostic imaging that might predict injuries at (multidetector row) CT in adults and that allowed construction of 2x2 contingency tables. For each article, methodological quality was scored and relevant predictors for injuries at CT were extracted. For each predictor, sensitivity, specificity, positive and negative likelihood ratio and diagnostic odds ratio (DOR) including 95% confidence intervals were calculated. RESULTS: Of 147 articles initially identified, the observers included 10 original studies in consensus. Abnormalities at physical examination (abnormal respiratory effort, need for assisted ventilation, reduced airentry, coma, chest wall tenderness) and pelvic fractures were significant predictors (DOR: 2.1-6.7). The presence of any injuries at conventional radiography of the chest (eight articles) was a more powerful significant predictor (DOR: 2.2-37). Abnormal chest ultrasonography (four articles) was the most accurate predictor for chest injury at CT (DOR: 491-infinite). CONCLUSION: The current literature indicates that in blunt trauma patients with abnormal physical examination, abnormal conventional radiography, or abnormal ultrasonography of the chest, CT was likely to reveal relevant chest injuries. However, there was no strong evidence to suggest that CT could be omitted in patients without these criteria, or whether these findings are beneficial for patients.

Contains fulltext : 52750.pdf (Publisher’s version ) (Closed access) BACKGROUND: Multidetector computed tomography (CT) is more sensitive and specific in detecting traumatic injuries than conventional radiology is. However, still little is known about the diagnostic value and the therapeutic impact of indicated thoraco-abdominal CT scan when it is performed in addition to the complete conventional radiologic work-up for blunt trauma patients. METHODS: Clinical and radiologic data from 106 consecutive blunt trauma patients were reviewed. Diagnoses revealed by conventional work-up of the chest, abdomen, pelvis, and thoracolumbar spine were compared with that detected by CT scan of the chest and abdomen. Unexpected findings by CT scan and rejected diagnoses by CT scan were collected. Therapeutic consequences of these diagnoses were determined both theoretically and collected from the medical records. RESULTS: In 74% (95% confidence interval [CI] 65-82) of the 106 patients, 1 or more diagnoses were demonstrated by chest or abdominal CT scan, whereas they had not been revealed by preceding conventional work-up. This resulted in an actual change of treatment in 34% (95% CI 25-43) of the patients. CT scan of the chest resulted in a change of treatment in 33% (95% CI 23-44) and abdominal CT scan in 16% (95% CI 9-24). CONCLUSIONS: CT scan of the chest and abdomen has a high diagnostic value in the evaluation of blunt trauma patients, when it is selectively performed in addition to the early conventional radiologic work-up. Unexpected pathologic findings are detected by CT scan in the majority of the patients. These findings result in an adaptation of treatment in a substantial number of the patients.

Contains fulltext : 136386.pdf (Publisher’s version ) (Open Access) Objective: To investigate two new methods of using computer-aided detection (CAD) system information for the detection of lung nodules on chest radiographs. We evaluated an interactive CAD application and an independent combination of radiologists and CAD scores. Methods: 300 posteroanterior and lateral digital chest radiographs were selected, including 111 with a solitary pulmonary nodule (average diameter, 16 mm). Both nodule and control cases were verified by CT. Six radiologists and six residents reviewed the chest radiographs without CAD and with CAD (ClearRead +Detect™ 5.2; Riverain Technologies, Miamisburg, OH) in two reading sessions. The CAD system was used in an interactive manner; CAD marks, accompanied by a score of suspicion, remained hidden unless the location was queried by the radiologist. Jackknife alternative free response receiver operating characteristics multireader multicase analysis was used to measure detection performance. Area under the curve (AUC) and partial AUC (pAUC) between a specificity of 80\% and 100\% served as the measure for detection performance. We also evaluated the results of a weighted combination of CAD scores and reader scores, at the location of reader findings. Results: AUC for the observers without CAD was 0.824. No significant improvement was seen with interactive use of CAD (AUC = 0.834; p = 0.15). Independent combination significantly improved detection performance (AUC = 0.834; p = 0.006). pAUCs without and with interactive CAD were similar (0.128), but improved with independent combination (0.137). Conclusion: Interactive CAD did not improve reader performance for the detection of lung nodules on chest radiographs. Independent combination of reader and CAD scores improved the detection performance of lung nodules. Advances in knowledge: (1) Interactive use of currently available CAD software did not improve the radiologists' detection performance of lung nodules on chest radiographs. (2) Independently combining the interpretations of the radiologist and the CAD system improved detection of lung nodules on chest radiographs.

Brink, Monique Dekker, Helena M de Lange, Frank Edwards, Michael J R Comment Letter United States J Trauma. 2011 Apr;70(4):1016; author reply 1016-7.

Item does not contain fulltext INTRODUCTION: Many scoring systems have been proposed to predict the survival of trauma patients. This study was performed to evaluate the influence of routine thoracoabdominal computed tomography (CT) on the predicted survival according to the trauma injury severity score (TRISS). PATIENTS AND METHODS: 1,047 patients who had sustained a high-energy blunt trauma over a 3-year period were prospectively included in the study. All patients underwent physical examination, conventional radiography of the chest, thoracolumbar spine and pelvis, abdominal sonography, and routine thoracoabdominal CT. From this group with routine CT, we prospectively defined a selective CT (sub)group for cases with abnormal physical examination and/or conventional radiography and/or sonography. Type and extent of injuries were recorded for both the selective and the routine CT groups. Based on the injuries found by the two different CT algorithms, we calculated the injury severity scores (ISS) and predicted survivals according to the TRISS methodology for the routine and the selective CT algorithms. RESULTS: Based on injuries detected by the selective CT algorithm, the mean ISS was 14.6, resulting in a predicted mortality of 12.5%. Because additional injuries were found by the routine CT algorithm, the mean ISS increased to 16.9, resulting in a predicted mortality of 13.7%. The actual observed mortality was 5.4%. CONCLUSION: Routine thoracoabdominal CT in high-energy blunt trauma patients reveals more injuries than a selective CT algorithm, resulting in a higher ISS. According to the TRISS, this results in higher predicted mortalities. Observed mortality, however, was significantly lower than predicted. The predicted survival according to MTOS seems to underestimate the actual survival when routine CT is used.