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Tracheal bronchus (TB) is a very rare condition, which is often associated with some other pathologies. This study was designed to characterize the morphology of tracheal bronchus and associated pathologies in Vietnamese individuals using multidetector-row computed tomography (MDCT). From August 2016 to February 2021, 16, 64-, and 128-detector-row computed tomography scanners were used to perform chest scans of 3663 patients, of whom 32 had tracheal bronchus and associated pathologies. The prevalence of tracheal bronchus was 0.9%, of which 0.6% were male and 0.3% were female. We found that one patient had bilateral tracheal bronchus (3.1%) and 31 patients (96.9%) had right-sided tracheal bronchus. Most patients (75.1%) had type II tracheal bronchus, whereas 15.6% and 6.2% had type III and type I tracheal bronchus, respectively. The average distance from the tracheal bronchus to the carina was 6.6 ± 6.4 mm. The average diameter of the tracheal bronchus was 4.4 ± 2.2 mm; the group with 2-4-mm tracheal bronchus accounted for the highest proportion (46.9%). Associated pathologies included congenital heart diseases (i.e., valvular heart disease, tetralogy of Fallot, cyanotic congenital heart disease-APSO, and aortic coarctation) (43.7%), stenosis of the bilateral pulmonary arteries (15.6%), absent left pulmonary artery (6.2%), stenosis of the right pulmonary artery (3.1%), anomalous pulmonary venous connection (3.1%), stenosis of the trachea (3.1%), stenosis of the left main bronchus (3.1%), bronchogenic cyst (3.1%), and bronchial atresia (3.1%), and the remaining 12.5% had no abnormalities. tracheal bronchus is a very rare abnormality among Vietnamese and is often accompanied by other pathologies. MDCT with a high spatial resolution and a good tissue contrast, along with contrast agent and appropriate scanning protocols, is efficient in detecting tracheal bronchus and associated pathologies. [ABSTRACT FROM AUTHOR]

Background and aims: Evaluating patients of extrahepatic portal hypertension with Colour Doppler and MDCT to study the morphology of splenoportal axis, determining the site of obstruction, the anatomy of portosystemic collaterals, any associated vascular aneurysms, and features of portal biliopathy. Materials and methods: We studied 45 patients (aged 6-55 years) with clinical features of portal hypertension with no identifiable hepatic cause or extrahepatic portal venous occlusion on sonography. All cases underwent Doppler ultrasound and MDCT. The data was compiled and analyzed. A comparative evaluation of Doppler imaging and MDCT was performed with the help of Cohen's kappa test to assess the agreement between the two modalities. Results: MDCT provides better details about the morphology of the splenoportal axis, the site, and cause of block, as well as the extent and distribution of collateral groups. Colour Doppler has an advantage over MDCT in determining the direction and pattern of blood flow within the splenoportal axis, various collaterals, and spontaneous shunts, along with a better depiction of features of portal biliopathy. Colour Doppler is inadequate in the visualization of gastroesophageal and retroperitoneal varices. Identification of spontaneous spleno-adreno-renal and gastrorenal shunts is achieved with the high agreement between Colour Doppler and MDCT. Conclusion: MDCT should be preferred for preoperative evaluation of patients being contemplated for shunt surgery. Colour Doppler imaging of portal biliopathy is sufficiently characteristic to avoid other invasive modalities. The two modalities provide complementary information in the evaluation of patients with extrahepatic portal hypertension.

Background: Facial massage is empirically known to be associated with morphological changes, such as improvements in facial sagging. However, quantified objective evaluations of massage‐induced changes have not been performed to date. This preliminary pilot study aimed to verify the effectiveness of facial massages by using breakthrough computed tomographic technology. Materials and methods: Five healthy adult volunteers (three women and two men; age, 29–37 years) were enrolled, and computed tomography (CT) examinations using a 320 detectors‐spiral CT system known as 320‐multidetector‐row CT (MDCT) were performed before and after facial massages. Each participant performed a self‐massage twice daily for 2 weeks. Massage‐induced changes in the cheeks and the superficial musculoaponeurotic system (SMAS) were analyzed by two radiologists on a workstation with a high‐accuracy imaging analysis system. Results: After facial massage, the malar top became thinner by −0.8% ± 0.45% and shifted cranially and horizontally over a distance of 3.9 ± 1.94 mm. The SMAS‐height, defined as the highest vertical distance of the SMAS, increased by 2.6% ± 2.6%. The change rate in cheek thickness and SMAS‐height showed a significant correlation (r = −0.63; P < 0.05). These changes were attributed to the lifting and tightening effects of facial massage. Conclusion: We conducted a detailed analysis of the effects of facial massages by using the breakthrough CT technology. Our results provide useful information for beauty treatments and could contribute to the collection of objective scientific evidence for facial massages. [ABSTRACT FROM AUTHOR]

The development of ultra-high–resolution CT (U-HRCT) is expected to improve the accuracy of coronary stenosis evaluation. This study aimed to evaluate the accuracy of the stenosis severities of coronary artery phantoms estimated using U-HRCT by comparing them to those estimated with conventional CT. Coronary artery phantoms with non-calcified and calcified lesions were scanned with conventional CT (64-row ​× ​0.625 ​mm) and U-HRCT (32-row ​× ​0.3125 ​mm). The coronary artery phantoms had lumen diameters of 2.0, 3.0, and 4.0 ​mm with non-calcified lesions representing 0%, 25%, 50%, and 75% stenosis and 3.0 and 4.0 ​mm with calcified lesions representing 0%, 25%, 50%, and 75% stenosis. The lumen diameters at the stenotic and non-stenotic regions were measured, and the stenosis severities were compared with the true values. For non-calcified lesions, conventional CT significantly underestimated the stenosis severity in the phantom showing 75% stenosis with lumen diameters of 2.0 and 3.0 ​mm (p ​< ​0.05), while the estimated stenosis severities were not significantly different from the true values at all settings with U-HRCT. For the calcified lesions, conventional CT overestimated the stenosis severities at all settings (p ​< ​0.05), while U-HRCT yielded estimations closer to the true values, although still with some overestimation (p ​< ​0.05). By using U-HRCT, the estimated stenosis severities of the coronary artery with non-calcified lesion become almost equal to the true value, while those with calcified lesion are still overestimated although they become closer to the true value. The accuracy of ultra-high–resolution CT (U-HRCT: 32-row ​× ​0.3125 ​mm) was assessed in comparison with conventional CT (64-row ​× ​0.625 ​mm). In comparison with conventional CT, U-HRCT could more accurately evaluate the stenosis severities of the coronary arteries of non-calcified lesion at 75% stenosis with a 2.0-mm and 3.0-mm lumen diameter than conventional CT. Thus, U-HRCT is appropriate for evaluation of non-calcified lesions. Conversely, although the stenosis severities of calcified lesion have come closer to the true values when using U-HRCT, they are still overestimated. [ABSTRACT FROM AUTHOR]

Objectives: To derive a CT-based scoring system incorporating arterial involvement and resectability status to predict R0 resection in patients with pancreatic ductal adenocarcinoma (PDAC) undergoing neoadjuvant chemoradiation therapy (CRT). Methods: This retrospective study included 112 patients with PDAC who underwent dynamic contrast-enhanced CT before and after neoadjuvant CRT. A 5-point score was used to determine arterial involvement (A score; 1 = no involvement, 2 = haziness, 3 = abutment, 4 = encasement, 5 = deformity) and 4-point score evaluating resectability status (R score; 1 = resectable, 2 = borderline resectable [BR] with venous involvement, 3 = BR with arterial involvement, 4 = locally advanced [LA]). A score before and after CRT were summed with R score before and after CRT to compute the AR score (ARtotal). The associations between ARtotal, R0 resection, overall survival (OS), and disease-free survival (DFS) were assessed. Results: The ARtotal was associated with R0 resection (p <.001) and showed area under the ROC curve of 0.79 for differentiating R0 and R1 resections. Median OS was significantly lower for patients with ARtotal > 9 (median: 35.2 months) compared to patients with ARtotal ≤ 9 (median: not estimable) (p <.001). Similar results were observed for DFS (median, 16.8 months in > 9 vs median, not estimable in ≤ 9; p <.001). Conclusions: A composite score which incorporates degree of arterial involvement and resectability status before and after neoadjuvant CRT is associated with R0 resection and discriminates between R0 and R1 resections in PDAC. Key Points: • A scoring system incorporating arterial involvement and resectability status was associated with R0 resection. • ARtotal > 9 could predict patients' overall and disease-free survival. [ABSTRACT FROM AUTHOR]

Objective: To assess the feasibility of a proposed pancreatic protocol CT generated from portal-venous phase (PVP) dual-energy CT (DECT) acquisition and its impact on image quality, lesion conspicuity, and arterial visualization/involvement. Methods: We included 111 patients (mean age, 66.8 years) who underwent pancreatic protocol DECT (pancreatic phase, PP, and PVP). The original DECT acquisition was used to create two data sets—standard protocol (50 keV PP/65 keV PVP) and proposed protocol (40 keV/65 keV PVP). Three reviewers evaluated the two data sets for image quality, lesion conspicuity, and arterial visualization/involvement using a 5-point scale. The signal-to-noise ratio (SNR) of pancreas and lesion-to-pancreas contrast-to-noise ratio (CNR) was calculated. Qualitative scores, quantitative parameters, and dose-length product (DLP) were compared between standard and proposed protocols. Results: The image quality, SNR of pancreas, and lesion-to-pancreas CNR of the standard and proposed protocol were comparable (p = 0.11–1.00). Lesion conspicuity was comparable between the standard and proposed protocols for pancreatic ductal adenocarcinoma (p = 0.55) and pancreatic cysts (p = 0.28). The visualization of larger arteries and arterial involvement were comparable between the two protocols (p = 0.056–1.00) while the scores were higher for smaller vessels in the standard protocol (p < 0.0001–0.0015). DLP of the proposed protocol (670.4 mGy·cm) showed a projected 42% reduction than the standard protocol (1145.9 mGy·cm) (p < 0.0001). Conclusion: Pancreatic protocol CT generated from a single PVP DECT acquisition is feasible and could potentially be an alternative to the standard pancreatic protocol with PP and PVP. Key Points: • The lesion conspicuity for focal pancreatic lesions was comparable between the proposed protocol and standard dual-phase pancreatic protocol CT. • Qualitative and quantitative image assessments were almost comparable between two protocols. • The radiation dose of a proposed protocol showed a projected 42% reduction from the conventional protocol. [ABSTRACT FROM AUTHOR]

Abstract Background Prediction of nodal involvement in colorectal cancer is an important aspect of preoperative workup to determine the necessity of preoperative treatment and the adequate extent of lymphadenectomy during surgery. This study aimed to investigate newer multidetector-row computed tomography (MDCT) findings for better predicting lymph node (LN) metastasis in colorectal cancer. Methods Seventy patients were enrolled in this study; all underwent MDCT prior to surgery and upfront curative resection for colorectal cancer. LNs with a short-axis diameter (SAD) ≥ 4 mm were identified on MDCT images, and the following measures were recorded by two radiologists independently: two-dimensional (2D) SAD, 2D long-axis diameter (LAD), 2D ratio of SAD to LAD, 2D CT attenuation value, three-dimensional (3D) SAD, 3D LAD, 3D SAD to LAD ratio, 3D CT attenuation value, LN volume, and presence of extranodal neoplastic spread (ENS), as defined by indistinct nodal margin, irregular capsular enhancement, or infiltration into adjacent structures. Results Forty-six patients presented 173 LNs with a SAD ≥ 4 mm, while 24 patients exhibited pathologically confirmed LN metastases. Receiver operating characteristic analysis revealed that 2D LAD was the most sensitive measure for LN metastases with an area under the curve of 0.752 (cut-off value, 7.05 mm). When combined with CT findings indicating ENS, 2D LAD (> or ≤ 7 mm) showed enhanced predictive power for LN metastases (area under the curve, 0.846; p

Purpose: Preoperative and noninvasive prognosis evaluation remains challenging for gastric cancer. Novel preoperative prognostic biomarkers should be investigated. This study aimed to develop multidetector‐row computed tomography (MDCT)‐guided prognostic models to direct follow‐up strategy and improve prognosis. Methods: A retrospective dataset of 353 gastric cancer patients were enrolled from two centers and allocated to three cohorts: training cohort (n = 166), internal validation cohort (n = 83), and external validation cohort (n = 104). Quantitative radiomic features were extracted from MDCT images. The least absolute shrinkage and selection operator penalized Cox regression was adopted to construct a radiomic signature. A radiomic nomogram was established by integrating the radiomic signature and significant clinical risk factors. We also built a preoperative tumor‐node‐metastasis staging model for comparison. All models were evaluated considering the abilities of risk stratification, discrimination, calibration, and clinical use. Results: In the two validation cohorts, the established four‐feature radiomic signature showed robust risk stratification power (P = 0.0260 and 0.0003, log‐rank test). The radiomic nomogram incorporated radiomic signature, extramural vessel invasion, clinical T stage, and clinical N stage, outperforming all the other models (concordance index = 0.720 and 0.727) with good calibration and decision benefits. Also, the 2‐yr disease‐free survival (DFS) prediction was most effective (time‐dependent area under curve = 0.771 and 0.765). Moreover, subgroup analysis indicated that the radiomic signature was more sensitive in risk stratifying patients with advanced clinical T/N stage. Conclusions: The proposed MDCT‐guided radiomic signature was verified as a prognostic factor for gastric cancer. The radiomic nomogram was a noninvasive auxiliary model for preoperative individualized DFS prediction, holding potential in promoting treatment strategy and clinical prognosis. [ABSTRACT FROM AUTHOR]

Objective: Little is known about the prevalence and degree of deformation of surgically implanted aortic biological valve prostheses (bio-sAVRs). We assessed bio-sAVR deformation using multidetector-row computed tomography (MDCT).Methods: Three imaging databases were searched for patients with MDCT performed after bio-sAVR implantation. Minimal and maximal valve ring diameters were obtained in systole and/or diastole, depending on the acquired cardiac phase(s). The eccentricity index (EI) was calculated as a measure of deformation as (1 - (minimal diameter/maximal diameter)) × 100%. EI of < 5% was considered none or trivial deformation, 5-10% mild deformation, and > 10% non-circular. Indications for MDCT and implanted valve type were retrieved.Results: One hundred fifty-two scans of bio-sAVRs were included. One hundred seventeen measurements were performed in systole and 35 in diastole. None or trivial deformation (EI < 5%) was seen in 67/152 (44%) of patients. Mild deformation (EI 5-10%) was seen in 59/152 (39%) and non-circularity was found in 26/152 (17%) of cases. Overall, median EI was 5.5% (IQR 3.4-7.8). In 77 patients, both systolic and diastolic measurements were performed from the same scan. For these scans, the median EI was 6.5% (IQR 3.4-10.2) in systole and 5.1% (IQR3.1-7.6) in diastole, with a significant difference between both groups (p = 0.006).Conclusions: Surgically implanted aortic biological valve prostheses show mild deformation in 39% of cases and were considered non-circular in 17% of studied valves.Key Points: • Deformation of surgically implanted aortic valve bioprostheses (bio-sAVRs) can be adequately assessed using MDCT. • Bio-sAVRs show at least mild deformation (eccentricity index > 5%) in 56% of studied cases and were considered non-circular (eccentricity index > 10%) in 17% of studied valves. • The higher deformity rate found in bio-sAVRs with (suspected) valve pathology could suggest that geometric deformity may play a role in leaflet malformation and thrombus formation similar to that of transcatheter heart valves. [ABSTRACT FROM AUTHOR]

Purpose: To assess quantitative lobar pulmonary perfusion on DECT-PA in patients with and without pulmonary embolism (PE).Materials and Methods: Our retrospective study included 88 adult patients (mean age 56 ± 19 years; 38 men, 50 women) who underwent DECT-PA (40 PE present; 48 PE absent) on a 384-slice, third-generation, dual-source CT. All DECT-PA examinations were reviewed to record the presence and location of occlusive and non-occlusive PE. Transverse thin (1 mm) DECT images (80/150 kV) were de-identified and exported offline for processing on a stand-alone deep learning-based prototype for automatic lung lobe segmentation and to obtain the mean attenuation numbers (in HU), contrast amount (in mg), and normalized iodine concentration per lung and lobe. The zonal volumes and mean enhancement were obtained from the Lung Analysis™ application. Data were analyzed with receiver operating characteristics (ROC) and analysis of variance (ANOVA).Results: The automatic lung lobe segmentation was accurate in all DECT-PA (88; 100%). Both lobar and zonal perfusions were significantly lower in patients with PE compared with those without PE (p < 0.0001). The mean attenuation numbers, contrast amounts, and normalized iodine concentrations in different lobes were significantly lower in the patients with PE compared with those in the patients without PE (AUC 0.70-0.78; p < 0.0001). Patients with occlusive PE had significantly lower quantitative perfusion compared with those without occlusive PE (p < 0.0001).Conclusion: The deep learning-based prototype enables accurate lung lobe segmentation and assessment of quantitative lobar perfusion from DECT-PA.Key Points: • Deep learning-based prototype enables accurate lung lobe segmentation and assessment of quantitative lobar perfusion from DECT-PA. • Quantitative lobar perfusion parameters (AUC up to 0.78) have a higher predicting presence of PE on DECT-PA examinations compared with the zonal perfusion parameters (AUC up to 0.72). • The lobar-normalized iodine concentration has the highest AUC for both presence of PE and for differentiating occlusive and non-occlusive PE. [ABSTRACT FROM AUTHOR]

In patients with cholangiocarcinoma, surgical resection with curative intent is the only way to achieve cure. Since surgical resection of cholangiocarcinomas is technically demanding, determination of resectability and accurate preoperative staging are crucial. For these purposes, high quality imaging including multidetector computed tomography and magnetic resonance imaging with magnetic resonance cholangiopancreaticography, is mandatory. This article will present recent advances in imaging techniques for cholangiocarginomas, potential pitfalls in imaging evaluation, and a checklist for preoperative radiologic assessment of resectability in these patients with an emphasis on perihilar cholangiocarinoma.

Background: Retroperitoneal fibrosis (RPF) and lymphoma presenting as retroperitoneal mass may closely resemble each other and misdiagnosis may occur. This study investigated the differential imaging features of RPF and lymphoma which presented as a retroperitoneal soft tissue using multidetector-row computed tomography (MDCT). Methods: The 42 consecutive patients were included in this retrospective review, including 19 RPF patients (45.2%; including 13 males and 6 females; mean age: 56.7 ± 6.2 years) and 23 patients with lymphoma (54.8%; including 14 males and 9 females; mean age: 57.4 ± 12.3 years). An array of qualitative computed tomography (CT) features of lesions in 42 consecutive patients with newly diagnosed untreated RPF and lymphoma were retrospectively analyzed. The quantitative size of the lesion at the para-aortic region and attenuation in the precontrast, arterial, and portal phases were calculated in regions of interest and compared between the patients with newly diagnosed untreated RPF and with lymphoma. Receiver operating characteristic curve analysis was used to assess the potential diagnostic value of each quantitative parameter. Inter-reader concordance was also calculated. Results: Mean ages between patients with RPF and lymphoma were not significantly different (56.7 ± 6.2 years vs. 57.4 ± 12.3 years P = 0.595). Compared to those in patients with lymphoma, homogeneous enhancement (65.2% vs. 94.7%, P = 0.027) and pelvic extension (52.2% vs. 89.5%, P = 0.017) were significantly more common while the involvement of additional nodes (78.3% vs. 5.3%, P < 0.001), suprarenal extension (60.9% vs. 15.8%, P = 0.004), and aortic displacement (43.5% vs. 5.3%, P = 0.006) were significantly less common in patients with RPF. Lesion size at the para-aorta was significantly greater in patients with lymphoma, compared with RPF patients (3.9 ± 1.2 cm vs. 1.8 ± 0.6 cm; P < 0.001). The attenuation values in three phases were not significantly different between patients with RPF and lymphoma. Inter-reader concordance for subjective features ranged from very good to excellent (range: 85.7–100.0%). Conclusions: This study showed that MDCT can help differentiate between untreated RPF and lymphoma on the basis of qualitative CT features and lesion sizes. Differentiating RPF from lymphoma on the basis of attenuation values in the precontrast, arterial, and portal phases was difficult to accomplish.

Introduction: Axillary lymph nodes (ALN) status is an essential component in tumor staging and treatment planning for patients with breast cancer. The aim of present study was to evaluate the predictive value of preoperative multidetector-row computed tomography (MDCT) for ALN metastasis in breast cancer patients.Methods: A total of 148 cases underwent preoperative MDCT examination and ALN surgery were eligible for the study. Logistic regression analysis of MDCT variates was used to estimate independent predictive factors for ALN metastasis. The prediction of ALN metastasis was determined with MDCT variates through receiver operating characteristic (ROC) analysis.Results: Among the 148 cases, 61 (41.2%) cases had ALN metastasis. The cortical thickness in metastatic ALN was significantly thicker than that in non-metastatic ALN (7.5 ± 5.0 mm vs. 2.6 ± 2.8 mm, P < 0.001). Multi-logistic regression analysis indicated that cortical thickness of >3 mm (OR: 12.32, 95% CI: 4.50–33.75, P < 0.001) and non-fatty hilum (OR: 5.38, 95% CI: 1.51–19.19, P = 0.009) were independent predictors for ALN metastasis. The sensitivity, specificity and AUC of MDCT for ALN metastasis prediction based on combined-variated analysis were 85.3%, 87.4%, and 0.893 (95% CI: 0.832–0.938, P < 0.001), respectively.Conclusions: Cortical thickness (>3 mm) and non-fatty hilum of MDCT were independent predictors for ALN metastasis. MDCT is a potent imaging tool for predicting ALN metastasis in breast cancer. Future prospective study on the value of contrast enhanced MDCT in preoperative ALN evaluation is warranted.

Objectives: The conceptus dose during diagnostic imaging procedures for pregnant patients raises health concerns owing to the high radiosensitivity of the developing embryo/fetus. The aim of this work is to develop a methodology for automated construction of patient-specific computational phantoms based on actual patient CT images to enable accurate estimation of conceptus dose.Methods: We developed a 3D deep convolutional network algorithm for automated segmentation of CT images to build realistic computational phantoms. The neural network architecture consists of analysis and synthesis paths with four resolution levels each, trained on manually labeled CT scans of six identified anatomical structures. Thirty-two CT exams were augmented to 128 datasets and randomly split into 80%/20% for training/testing. The absorbed doses for six segmented organs/tissues from abdominal CT scans were estimated using Monte Carlo calculations. The resulting radiation doses were then compared between the computational models generated using automated segmentation and manual segmentation, serving as reference.Results: The Dice similarity coefficient for identified internal organs between manual segmentation and automated segmentation results varies from 0.92 to 0.98 while the mean Hausdorff distance for the uterus is 16.1 mm. The mean absorbed dose for the uterus is 2.9 mGy whereas the mean organ dose differences between manual and automated segmentation techniques are 0.07%, - 0.45%, - 1.55%, - 0.48%, - 0.12%, and 0.28% for the kidney, liver, lung, skeleton, uterus, and total body, respectively.Conclusion: The proposed methodology allows automated construction of realistic computational models that can be exploited to estimate patient-specific organ radiation doses from radiological imaging procedures.Key Points: • The conceptus dose during diagnostic radiology and nuclear medicine imaging procedures for pregnant patients raises health concerns owing to the high radiosensitivity of the developing embryo/fetus. • The proposed methodology allows automated construction of realistic computational models that can be exploited to estimate patient-specific organ radiation doses from radiological imaging procedures. • The dosimetric results can be used for the risk-benefit analysis of radiation hazards to conceptus from diagnostic imaging procedures, thus guiding the decision-making process. [ABSTRACT FROM AUTHOR]

This meta-analysis investigated the diagnostic values of transthoracic echocardiography (TTE), 2-dimensional (2D) and 3-dimensional (3D) transesophageal echocardiography (TEE), and multidetector-row computed tomography (MDCT) in patients with suspected mechanical prosthetic valve obstruction (PVO) for detecting subprosthetic mass and differentiating its causes. Diagnostic values of advanced imaging modalities, such as MDCT and TEE, for the detection and differentiation of PVO have not been investigated. PubMed and EMBASE were systematically searched for studies that evaluated PVO using imaging modalities. The modified Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate study quality. Pooled sensitivity of each modality for PVO detection and pooled diagnostic accuracy of TEE and MDCT for differentiating the causes of PVO were analyzed. Study heterogeneity was also assessed. Seventeen studies (229 patients) that used at least 1 index tool among TTE, TEE, or MDCT were included. For detecting a subprosthetic mass that caused PVO, 3D TEE and MDCT showed a higher sensitivity of 81% (95% confidence interval [CI]: 40% to 95%) and 88% (95% CI: 81% to 93%), respectively, compared with TTE (20%; 95% CI: 7% to 47%) and 2D TEE (68%; 95% CI: 46% to 84%). Pooled sensitivity and specificity for diagnosing thrombus as a cause of PVO was 75% (95% CI: 54% to 88%) and 75% (95% CI: 40% to 93%), respectively, for TEE and 45% (95% CI: 16% to 77%) and 90% (95% CI: 77% to 96%), respectively, for MDCT. Pooled sensitivity for diagnosing pannus as a cause of PVO was 62% (95% CI: 46% to 76%) for TEE and 85% (95% CI: 70% to 93%) for MDCT. This meta-analysis suggested that MDCT and 3D TEE have higher sensitivity than do TTE and 2D TEE, and can be reliable imaging modalities for detecting a subprosthetic mass that causes PVO. Moreover, MDCT can more accurately differentiate the cause of PVO than does TEE. [ABSTRACT FROM AUTHOR]

Objectives: To determine which clinical or CT imaging factors can help accurately identify complicated sigmoid volvulus (SV), defined as irreversible bowel ischaemia or necrosis requiring emergent surgery in patients with SV.Methods: We performed a retrospective study of 51 patients admitted consecutively to the emergency department for SV. All patients attempted endoscopic detorsion as the first treatment. Clinical and contrast-enhanced CT factors were analysed. A newly described dark torsion knot sign (sudden loss of mucosal enhancement in the volvulus torsion knot) was included as a CT factor. Patients were diagnosed with complicated versus simple SV based on either surgery or follow-up endoscopic findings. Univariate and multivariate analyses were used to identify predictors of complicated SV.Results: Of 51 study patients, 9 patients (17.6%) had complicated SV. Univariate analysis revealed that three clinical factors (sepsis, elevated C-reactive protein, and elevated lactic acid levels) and four CT factors (reduced bowel wall enhancement, increased bowel wall thickness, dark torsion knot sign, and diffuse omental infiltration) were significantly associated with complicated SV. Multivariate analysis identified only dark torsion knot sign (odds ratio = 104.40; p = 0.002) and sepsis (odds ratio = 16.85; p = 0.043) as independent predictive factors of complicated SV.Conclusion: A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can predict complicated SV necessitating emergent surgery instead of colonoscopic detorsion as a primary treatment of choice.Key Points: • A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can be helpful for predicting complicated SV necessitating emergent surgery instead of endoscopic detorsion. [ABSTRACT FROM AUTHOR]

The ability of pro-protein convertase subtilisin/kexin type 9 (PCSK9) levels to predict the presence or severity of coronary artery disease (CAD) remains controversial. The purpose of this study was to investigate these associations. We enrolled 393 patients who were clinically suspected to have CAD or who had at least one cardiac risk factor and underwent multidetector-row computed tomography coronary angiography. The presence of CAD (≥50% coronary stenosis), the number of significantly stenosed coronary vessels, and plasma levels of PCSK9 by ELISA were analyzed. Plasma PCSK9 levels (log-transformed data) were significantly associated with the presence of CAD. Next, we divided the patients into two groups (non-statin and statin groups) according to statin treatment. PCSK9 levels in the non-statin group were significantly lower than those in the statin group. There were no significant differences in PCSK9 levels between the absence and presence of CAD in the statin group. However, in the non-statin group, PCSK9 levels in patients with CAD were significantly higher than those in patients without CAD. PCSK9 levels, in addition to age, gender, BMI, DM and HDL-C, were independently associated with the presence of CAD by a multivariable analysis. In conclusion, our results demonstrated that plasma PCSK9 levels may be a marker for evaluating the presence of CAD. [ABSTRACT FROM AUTHOR]

Although some of the associations between chronic obstructive pulmonary disease (COPD) and atherosclerosis are based on shared risk factors such as smoking, recent epidemiological evidence suggests that COPD is a risk factor for vascular disease due to systemic inflammation. The present study assessed the hypothesis that disease severity (as expressed by the GOLD stage) independently predicts the extent of vascular calcifications. A total of 160 smokers diagnosed with COPD (GOLD I–IV, 40 subjects of each GOLD stage) and 40 smokers at risk (GOLD 0; median age of 60 years old; Q1:56;Q3:65; 135 males and 65 females) underwent non-contrast, non-electrocardiography synchronized chest computerised tomography. The volume of thoracic aortic calcifications was quantified semi-automatically within a region from T1 through T12. Multiparametric associations with GOLD stage, smoking history, sex, age, body mass index and emphysema index were evaluated using generalized linear regression analysis. Thoracic aortic calcifications were highly prevalent in this cohort (187/200 subjects, 709 (Q1:109;Q3:2163) mm3). Analysis of variance on ranks demonstrated a significant difference in calcium between different GOLD-stages as well as patients at risk of COPD (F=36.8, P<0.001). In the multivariable analysis, GOLD-stages were indicated to be predictive of thoracic aortic calcifications (P≤0.0033) besides age (P<0.0001), while age appeared to be the strongest predictor. Other variables were not statistically linked to thoracic aortic calcifications in the multivariable model. COPD severity, as expressed by the GOLD-stage, is a significant predictor of thoracic aortic calcifications, independent of covariates such as age or tobacco consumption. [ABSTRACT FROM AUTHOR]

Aim: To compare pancreatic volume and fat amount, and their associations with glucose homeostasis, in a Korean and a white population. Materials and methods: In 43 healthy Korean and 43 healthy white people, matched for age (±3 years) and body mass index (BMI; ±1 kg/m2), we measured pancreatic volume and fat amount in the pancreas and abdomen using computed tomography. Pancreatic β‐cell function and insulin resistance were estimated according to biochemical characteristics and a 75‐g oral glucose tolerance test. Body composition and resting energy expenditure (REE) were examined using bioimpedance and indirect calorimetry, respectively. Results: The mean ±SD age of the participants was 29.9 ± 5.9 years and 30.0 ± 5.2 years, and BMI was 24.0 ±3.7 and 24.1 ±3.2 kg/m2 in the white participants and the Korean participants, respectively. Pancreatic volume in the white participants was greater than that in Korean participants (77.8 ±11.6 vs 68.2 ±12.1 cm3; P < .001). Pancreatic fat content in Korean participants was 22.8% higher than in white participants (P = .051). Insulinogenic index, disposition index, muscle mass and REE were significantly lower in Korean participants. Pancreatic volume was positively associated with indices linked to β‐cell function; fat content in the pancreas was negatively associated with such indices, and positively with insulin resistance after adjusting for relevant variables including REE. Conclusions: A smaller pancreas and higher fat deposition might be crucial determinants of vulnerability to diabetes in Korean people compared with white people with similar BMI and body fat levels. [ABSTRACT FROM AUTHOR]

Purpose: To assess the reliability of a prototype automated supplying artery tracking software (ASATS) using multidetector-row CT (MDCT) images in emergent TAE.Materials and Methods: Consecutive 53 patients underwent 57 sessions of emergent TAE during 7 months. Twenty-one cases were excluded due to a lack of CT data (n = 12) or negative angiographic findings (n = 9). Remaining 34 sessions of TAE and MDCT images in 32 patients (mean age 62.9 years; age range 37-92 years) were enrolled. ASATS was retrospectively conducted for the identification of supplying arteries which were confirmed with angiography (automated method). Manual modification was added as needed (semi-automated method). Two observers independently reviewed the MDCT images to detect supplying arteries (manual method). Detectability of supplying artery and time to analysis were compared among the automated, semi-automated, and manual methods by both observers.Results: A total of 64 bleeding sites were demonstrated on angiography. The detectability was 28 (43.8%) for automated method, 53 (82.8%) for semi-automated method, 55 (85.9%) for observer 1, and 58 (90.6%) for observer 2. Detectability of semi-automated method was significantly better than of automated method (P = 0.000) and comparable with manual method by both observers (P = 0.193 and 0.081). Average time to analysis was 185.4 s for automated method, 297.2 s for semi-automated method, 186.2 s for observer 1, and 243.7 s for observer 2.Conclusion: ASATS has a sufficient ability to identify supplying arteries of bleeding by adding manual modification as needed and can be used for emergent TAE.Level Of Evidence: Level 4, Case Control Study. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to assess the diagnostic performance of a combined protocol with coronary computed tomography angiography (CCTA) and stress CT perfusion imaging (CTP) in heart transplant patients for comprehensive morphological and functional imaging.Methods: In this prospective study, 13 patients undergoing routine follow-up 8±6 years after heart transplantation underwent CCTA and dynamic adenosine stress CTP using a third-generation dual-source CT scanner, cardiac magnetic resonance (MR) adenosine stress perfusion imaging at 1.5 T, and catheter coronary angiography. In CCTA stenoses >50% luminal diameter narrowing were noted. Myocardial perfusion deficits were documented in CTP and MR. Quantitative myocardial blood flow (MBF) was calculated with CTP. Left ventricular ejection fraction was determined on cardiac MR cine images. Radiation doses of CT were determined.Results: One of the 13 patients had to be excluded because of severe motion artifacts. CCTA identified three patients with stenosis >50%, which were confirmed with catheter coronary angiography. CTP showed four patients with stress-induced myocardial hypoperfusion, which were confirmed by MR stress perfusion imaging. Quantitative analysis of global MBF showed lower mean values as compared to known reference values (MBF under stress 125.5 ± 34.5 ml/100 ml/min). Average left ventricular ejection fraction was preserved (56 ± 5%).Conclusions: In heart transplant patients, a comprehensive CT protocol for the assessment of morphology and function including CCTA and CTP showed good concordance to results from MR perfusion imaging and catheter coronary angiography.Key Points: • Stress CT perfusion imaging enables the detection of myocardial ischemia • CT myocardial perfusion imaging can be combined with coronary computed tomography angiography • Combining perfusion and coronary CT imaging is accurate in heart transplant patients • CT myocardial perfusion imaging can be performed at a reasonable radiation dose. [ABSTRACT FROM AUTHOR]

Backgrounds: We aimed to investigate the diagnostic accuracy of multidetector-row computed tomography (MDCT), mapping biopsy, and other imaging modalities to predict the longitudinal extension and depth of invasion of extrahepatic cholangiocarcinoma at possible surgical ductal margins.Methods: Of 102 patients with surgical resection of extrahepatic cholangiocarcinoma between January 2010 and October 2015, 32 evaluated by multidetector-row computed tomography (MDCT) performed before biliary drainage and mapping biopsy were enrolled. Mapping biopsies were performed at 74 sites to determine the resection point of the bile duct (at 74 possible surgical ductal margins). Diagnostic accuracy was evaluated by histopathology.Results: The diagnostic accuracy of MDCT for longitudinal cancer spread was 79.7%, that of biopsy was 73.0%, and combining the two modalities showed highest accuracy (83.8%). The depth of tumor invasion could be predicted by combination of the ductal wall thickness and contrast enhancement on MDCT, that is, at 11 of 13 sites (84.6%) with submucosal invasion, ductal wall thickness was > 2.5 mm with high contrast enhancement.Conclusions: MDCT demonstrated highest accuracy of diagnosing longitudinal extension at possible surgical ductal margins in patients with extrahepatic cholangiocarcinoma. The depth of tumor invasion could be predicted by ductal wall thickness and contrast enhancement of MDCT. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether computer-based CT quantitation of change can improve on visual change quantification of parenchymal features in IPF.Methods: Sixty-six IPF patients with serial CT imaging (6-24 months apart) had CT features scored visually and with a computer software tool: ground glass opacity, reticulation and honeycombing (all three variables summed as interstitial lung disease extent [ILD]) and emphysema. Pulmonary vessel volume (PVV) was estimated by computer only. Relationships between changes in CT features and forced vital capacity (FVC) were examined using univariate and multivariate linear regression analyses.Results: On univariate analysis, changes in computer variables demonstrated stronger linkages to FVC change than changes in visual scores (CALIPER ILD:R2=0.53, p<0.0001; Visual ILD:R2=0.16, p=0.001). PVV increase correlated most strongly with relative FVC change (R2=0.57). When PVV constituents (vessel size and location) were examined, an increase in middle zone vessels linked most strongly to FVC decline (R2=0.57) and was independent of baseline disease severity (characterised by CT fibrosis extent, FVC, or DLco).Conclusions: An increase in PVV, specifically an increase in middle zone lung vessels, was the strongest CT determinant of FVC decline in IPF and was independent of baseline disease severity.Key Points: • Computer analysis improves on visual CT scoring in evaluating deterioration on CT • Increasing pulmonary vessel volume is the strongest CT predictor of functional deterioration • Increasing pulmonary vessel volume predicts functional decline independent of baseline disease severity. [ABSTRACT FROM AUTHOR]

This case report is about an 85‐year‐old woman with bicuspid aortic stenosis (AS). Although preoperative multimodality imaging showed challenging anatomical aspects, transcatheter aortic valve replacement (TAVR) was selected to be performed as a less invasive alternative treatment approach, owing to her comorbidity. Postoperative transesophageal echocardiography and multidetector‐row computed tomography revealed the presence of “locked‐in leaflet” caused by stent distortion due to pinching by calcified native leaflets, with nodular calcification preventing the full expansion of the valve, which resulted in moderate perivalvular leakage. This is the first reported case of bicuspid AS treated with TAVR that eventually resulted in “locked‐in leaflet.” [ABSTRACT FROM AUTHOR]

This report concerns an 83-year-old woman with aortic stenosis ( AS) who had a history of repetitive hospitalization due to decompensated heart failure. Although her clinical history was compatible with significant AS, findings for aortic valve area, hemodynamics, and valvular calcium burden were discrepant. Multiplanar reconstruction images revealed the membranous structures attached to a subcommissural lesion, which resulted in severe stenosis. The patient had a favorable clinical course after transcatheter aortic valve replacement. This is the first reported case of severe AS due to the subcommissural adhesions, which were successfully visualized by means of echocardiography and computed tomography. [ABSTRACT FROM AUTHOR]

Objectives: Contrast media (CM) extravasation is a well-known complication of CT angiography (CTA). Our prospective randomized control study aimed to assess whether a four-phasic CM administration protocol reduces the risk of extravasation compared to the routinely used three-phasic protocol in coronary CTA.Methods: Patients referred to coronary CTA due to suspected coronary artery disease were included in the study. All patients received 400 mg/ml iomeprol CM injected with dual-syringe automated injector. Patients were randomized into a three-phasic injection-protocol group, with a CM bolus of 85 ml followed by 40 ml of 75%:25% saline/CM mixture and 30 ml saline chaser bolus; and a four-phasic injection-protocol group, with a saline pacer bolus of 10 ml injected at a lower flow rate before the three-phasic protocol.Results: 2,445 consecutive patients were enrolled (mean age 60.6 ± 12.1 years; females 43.6%). Overall rate of extravasation was 0.9% (23/2,445): 1.4% (17/1,229) in the three-phasic group and 0.5% (6/1,216) in the four-phasic group (p = 0.034).Conclusions: Four-phasic CM administration protocol is easy to implement in the clinical routine at no extra cost. The extravasation rate is reduced by 65% with the application of the four-phasic protocol compared to the three-phasic protocol in coronary CTA.Key Points: • Four-phasic CM injection-protocol reduces extravasation rate by 65% compared to three-phasic. • The saline pacer bolus substantially reduces the risk of CM extravasation. • The implementation of four-phasic injection-protocol is at no cost. [ABSTRACT FROM AUTHOR]

The aim of this study is to quantitatively assess radiation comma, and pancreatic enhancement by split-bolus intravenous injection of contrast material using 64-slice CT. Single-pass splitbolus MDCT of the chest and abdomen was performed in 37 patients (female: 18, male: 9; mean age, 66.1±14.2 years; range 17-80 years) without pancreatic disease. Regions of interest in the pancreatic head, body and tail were drawn, and mean attenuation values for pancreatic parenchymal phase (PPP) of the standard MDCT protocol and split-bolus were calculated. P<0.05 was considered statistically significant. Mean effective dose by split-bolus was measured. In all MDCT examinations split-bolus protocol allowed acquisition of optimal images. Mean pancreatic enhancement was higher by split-bolus with respect to PPP of standard triphasic MDCT (131.35 HU±20.63 vs 126.1 HU±20.01). Reduction of dose using MDCT split-bolus was approximately 17%. In conclusion MDCT split-bolus protocol provides an optimal pancreatic enhancement, significantly greater than the enhancement of standard MDCT on PPP which confers an advantage for the detection and staging of pancreatic tumors. [ABSTRACT FROM AUTHOR]

The objective of this study is to compare in vivo, the accuracy of single-energy CT (SECT) and dual-energy CT (DECT) in renal stone characterization. Retrospective study approved by the IRB. 30 patients with symptomatic urolithiasis who underwent CT on a second-generation dual-source scanner with a protocol that included low-dose 120 kV scan followed by 100/Sn140 kV dual-energy scan have been included. Stone composition was classified as uric acid, cystine or calcium oxalates, and phosphates according to attenuation values at 120 kV and to 100/Sn140 kV attenuation ratios and compared with the infrared spectroscopy analysis. 50 stones were detected in 30 patients. SECT correctly assessed stone composition in 52 % of the cases, DECT in 90 %. Sensitivity, specificity, positive predictive value, and negative predictive value in differentiating uric acid vs. non-uric acid stones were 0.94, 0.72, 0.64, and 0.96 for SECT and 1.00, 0.94, 1.00, and 0.96 for DECT, respectively. DECT significantly performs better than SECT in characterising renal stones in vivo, and may represent a useful tool for treatment planning. [ABSTRACT FROM AUTHOR]

Purpose: Fusion angiography using reconstructed multidetector-row computed tomography (MDCT) images, and cholangiography using reconstructed images from MDCT with a cholangiographic agent include an anatomical gap due to the different periods of MDCT scanning. To conquer such gaps, we attempted to develop a cholangiography procedure that automatically reconstructs a cholangiogram from portal-phase MDCT images. Methods: The automatically produced cholangiography procedure utilized an original software program that was developed by the Graduate School of Information Science, Nagoya University. This program structured 5 candidate biliary tracts, and automatically selected one as the candidate for cholangiography. The clinical value of the automatically produced cholangiography procedure was estimated based on a comparison with manually produced cholangiography. Results: Automatically produced cholangiograms were reconstructed for 20 patients who underwent MDCT scanning before biliary drainage for distal biliary obstruction. The procedure showed the ability to extract the 5 main biliary branches and the 21 subsegmental biliary branches in 55 and 25 % of the cases, respectively. The extent of aberrant connections and aberrant extractions outside the biliary tract was acceptable. Among all of the cholangiograms, 5 were clinically applied with no correction, 8 were applied with modest improvements, and 3 produced a correct cholangiography before automatic selection. Conclusions: Although our procedure requires further improvement based on the analysis of additional patient data, it may represent an alternative to direct cholangiography in the future. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate objective and subjective image quality of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique in dual-energy computed tomography (DECT) angiography prior to transcatheter aortic valve replacement (TAVR).Methods: Datasets of 47 patients (35 men; 64.1 ± 10.9 years) who underwent DECT angiography of heart and vascular access prior to TAVR were reconstructed with standard linear blending (F_0.5), VMI+, and traditional monoenergetic (VMI) algorithms in 10-keV intervals from 40-100 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 564 arterial segments were evaluated. Subjective analysis was rated by three blinded observers using a Likert scale.Results: Mean SNR and CNR were highest in 40 keV VMI+ series (SNR, 27.8 ± 13.0; CNR, 26.3 ± 12.7), significantly (all p < 0.001) superior to all VMI series, which showed highest values at 70 keV (SNR, 18.5 ± 7.6; CNR, 16.0 ± 7.4), as well as linearly-blended F_0.5 series (SNR, 16.8 ± 7.3; CNR, 13.6 ± 6.9). Highest subjective image quality scores were observed for 40, 50, and 60 keV VMI+ reconstructions (all p > 0.05), significantly superior to all VMI and standard linearly-blended images (all p < 0.01).Conclusions: Low-keV VMI+ reconstructions significantly increase CNR and SNR compared to VMI and standard linear-blending image reconstruction and improve subjective image quality in preprocedural DECT angiography in the context of TAVR planning.Key Points: • VMI+ combines increased contrast with reduced image noise. • VMI+ shows substantially less image noise than traditional VMI. • 40-keV reconstructions show highest SNR/CNR of the aortic and iliofemoral access route. • Observers overall prefer 60 keV VMI+ images. • VMI+ DECT imaging helps improve image quality for TAVR planning. [ABSTRACT FROM AUTHOR]

Multidetector-row computed tomographic (MDCT) coronary angiography has been validated for noninvasive assessment of coronary anatomy. However, we have less experience in diagnosing children with congenital or acquired coronary artery abnormalities by MDCT. We compared the results of MDCT with invasive coronary angiography (ICA) on identifying coronary abnormalities in infants, children, and adolescents with coronary artery abnormalities, including aneurysm, coronary fistula, or anomalous left coronary artery from pulmonary artery (ALCAPA). Methods: From January 2002 to December 2009, patients with congenital or acquired coronary abnormalities underwent either ICA, MDCT, or both studies for assessment of coronary anatomy. We reviewed all patients’ clinical diagnosis, coronary abnormalities identified by MDCT or ICA, and analyzed the advantages and disadvantages between those two methods. Results: Thirty-three patients (20 males and 13 females) with a mean age of 10.3 years (range: 18 days to 25 years) had coronary abnormalities, including coronary artery aneurysm in Kawasaki disease (n=15), coronary artery fistula (n=12), myocardial bridge (n=2), and ALCAPA (n=4). In 17 patients only referred for ICA, 5 coronary aneurysms (3 on left main coronary artery, 1 on left anterior descending artery segment proximal, 1 on right coronary artery segment proximal), 11 coronary artery fistulas, and 2 ALCAPAs were detected. Sixteen patients received MDCT study, and 14 coronary artery aneurysms (4 on right coronary artery, 5 on left main coronary artery, 4 on left anterior descending artery, 1 on left circumflex artery), 3 myocardial bridges, 1 coronary artery fistulas, and 2 ALCAPAs were assessed. Ten patients with Kawasaki disease-related coronary lesions received MDCT study, and totally 102 (78.5%) segments permitted visualization with accurate diagnostic image quality. In this study, there were 11 patients with indication for conventional ICA spared invasive angiography after precise assessment by MDCT. Conclusion: We conclude that MDCT is a good and useful modality for assessment of congenital or acquired coronary abnormalities in pediatric patients. However, MDCT cannot replace invasive cardiac catheterization and ICA because of lack of therapeutic role.

The coronary sinus is located within the inferior pyramidal space, which is the part of the epicardial visceral fibroadipose tissue wedging between the four cardiac chambers from the bottom of the heart. Therefore, this region is susceptible to the morphological changes of the cardiac chambers. We present a case of slit-like deformation of the coronary sinus orifice due to compression of the inferior pyramidal space by the severely dilated left ventricle, which has not been previously described. [ABSTRACT FROM AUTHOR]

Objectives: To determine the specific CT findings of penetrating neck wound profile predicting aerodigestive injuries, diagnostic performance of CTA and to propose a modified selective management algorithm to reduce nontherapeutic invasive procedures.Methods: We retrospectively evaluated CTAs of 102 patients to determine the presence of various CT signs. "Trajectory"-based signs included trajectory of the wound extending into the aerodigestive tract and trajectory violating the deep neck spaces. "Conventional" signs included transcervical injury; wall defect; air or blood in the deep neck spaces; irregular or thickened aerodigestive tract; and active mucosal bleeding.Results: Trajectory of the wound extending into the aerodigestive tract (sensitivity 76 %, specificity 97 %) and trajectory of the wound violating the suprahyoid deep neck spaces or the infrahyoid visceral space (sensitivity 97 %, specificity 55 %) were the best predictors of injury on regression analysis. The most specific "conventional" CT signs were "wall defect" and "active mucosal bleed", but had very low sensitivity. The sensitivity of CTA for detecting an injury ranged from 89.5 % to 92 %, specificity ranged from 62.5 % to 89 %.Conclusion: CTA can be a useful technique in detecting aerodigestive injury. Our proposed management algorithm can exclude an injury with high degree of confidence (sensitivity 97 %).Key Points: • Trajectory-based CT signs predict aerodigestive injury after penetrating neck trauma. • Surgery should be considered when trajectory extends into the infra-arytenoid aerodigestive tract. • Endoscopy or exploration should be considered when trajectory violates deep neck spaces. • This modified approach can decrease negative explorations and invasive diagnostic procedures. [ABSTRACT FROM AUTHOR]

Purpose: The purpose was to investigate optimal contrast media (CM) injection parameters for lower kVp settings, whilst maintaining diagnostic attenuation levels. Methods and Materials: First, a circulation phantom with physiological parameters (BP 120/80mmHg, HR 60bpm) was used. A fixed CM injection protocol was used for each kVp setting (300mgI/ml [Iopromide], volume=45ml, flow rate=6.0ml/s, iodine delivery rate [IDR]=1.8gI/s, iodine load=13.5gI; at 120, 100, 80 and 70kVp). Then, IDR was decreased by steps of 0.2gI/s for each kVp setting, until diagnostically insufficient attenuation values were reached (<325HU). In order to keep injection time constant (7.5s), total iodine load (TIL) was reduced accordingly. Second, clinical applicability at 120 and 100kVp was evaluated in patients (n=60) referred for coronary CT angiography. A standard and reduced (12% less) CM protocol was used based on weight classes and scan duration ('high-pitch': 1s; 'adaptive sequence' and 'helical': 7s). Attenuation levels of the coronary arteries were measured and compared between protocols. Results: Using a fixed CM injection at each kVp level resulted in the following HU values: 335HU±31 (120kVp); 425HU±30 (100kVp); 587HU±29 (80kVp); 666HU±27 (70kVp). Keeping diagnostic enhancement levels (353HU±28) CM could be reduced as follows: 12% for 100kVp; 45% for 80kVp and 56% for 70kVp. Diagnostic enhancement levels could be reproduced with concurrent CM reduction (-12% at 100kV) in the clinical setting (382HU±35). Conclusion: CM injection parameters can be substantially reduced at low kVp settings (up to 56% at 70kVp), whilst maintaining diagnostic attenuation levels. This may play an important role in CT imaging of the coronary arteries as well as cerebral and peripheral circulations in the future. [ABSTRACT FROM AUTHOR]

Objectives: Recent studies have proposed additional multidetector-row CT (MDCT) for prosthetic heart valve (PHV) dysfunction. References to discriminate physiological from pathological conditions early after implantation are lacking. We present baseline MDCT findings of PHVs 6 weeks post implantation.Methods: Patients were prospectively enrolled and TTE was performed according to clinical guidelines. 256-MDCT images were systematically assessed for leaflet excursions, image quality, valve-related artefacts, and pathological and additional findings.Results: Forty-six patients were included comprising 33 mechanical and 16 biological PHVs. Overall, MDCT image quality was good and relevant regions remained reliably assessable despite mild-moderate PHV-artefacts. MDCT detected three unexpected valve-related pathology cases: (1) prominent subprosthetic tissue, (2) pseudoaneurysm and (3) extensive pseudoaneurysms and valve dehiscence. The latter patient required valve surgery to be redone. TTE only showed trace periprosthetic regurgitation, and no abnormalities in the other cases. Additional findings were: tilted aortic PHV position (n = 3), pericardial haematoma (n = 3) and pericardial effusion (n = 3). Periaortic induration was present in 33/40 (83 %) aortic valve patients.Conclusions: MDCT allowed evaluation of relevant PHV regions in all valves, revealed baseline postsurgical findings and, despite normal TTE findings, detected three cases of unexpected, clinically relevant pathology.Key Points: • Postoperative MDCT presents baseline morphology relevant for prosthetic valve follow-up. • 83 % of patients show periaortic induration 6 weeks after aortic valve replacement. • MDCT detected three cases of clinically relevant pathology not found with TTE. • Valve dehiscence detection by MDCT required redo valve surgery in one patient. • MDCT is a suitable and complementary imaging tool for follow-up purposes. [ABSTRACT FROM AUTHOR]

Gunshot injury has always been an important field of investigation in postmortem forensic radiology. The localization and retrieval of the bullet and of potentially important fragments are vital to these cases. Using postmortem multidetector-row computed tomography (MDCT) prior to forensic autopsy, we sought to illustrate the importance of this modality in the noninvasive characterization of gunshot wounds. We obtained and analyzed MDCT images in three cases of gunshot wounds (accidental close-range shotgun shooting, suicidal contact gunshot to the head and accidental long-range buckshot shooting). We discuss the value of postmortem MDCT findings in gunshot wound cases by comparing with forensic autopsy findings in Japan, a developing country with miserably low autopsy rate. [ABSTRACT FROM AUTHOR]

We present a case of a 12-year-old boy who developed upper gastrointestinal bleeding in the form of hematemesis and melena 1 month after blunt trauma to liver. Computed tomography (CT) angiography with multidetector-row CT demonstrated pseudoaneurysm of right hepatic artery related to old liver laceration to be the cause of the bleeding. Pseudoaneurysm was resected using the roadmap provided by CT angiography findings.

Background: Transarterial chemoembolization (TACE) is an important treatment modality for hepatocellular carcinoma (HCC). Accurate identification of feeding arteries and catheterization are necessary for achieving treatment efficacy, especially with selective TACE. However, this often requires multiple imaging studies. We evaluated the utility of a newly developed apparatus that combines multidetector-row computed tomography (MDCT) and angiography (angio-MDCT) to facilitate TACE for treatment of HCC.Methods: A total of 73 patients who underwent selective TACE with angio-MDCT were compared with 57 patients who had undergone selective TACE with single-row computed tomography assisted by angiography (angio-CT) in terms of the number of imaging studies needed to complete TACE.Results: The mean number of digital subtraction arteriography (DSA) and CT studies required for characterization of feeding arteries before embolization was 3.53 (range 1-8) and 5.16 (range 2-11), respectively, with single-row angio-CT, and 1.67 (range 1-5) and 2.90 (range 1-5), respectively, with angio-MDCT. Fewer studies were needed in patients who underwent TACE with angio-MDCT (p < 0.0001 for both DSA and CT). Whereas single-row angio-CT failed to identify extrahepatic feeders in three patients (37.5%), all extrahepatic feeders could be identified with angio-MDCT.Conclusions: Angio-MDCT facilitates rapid and accurate identification of feeding arteries in patients undergoing TACE through the three-dimensional image analyses by the reconstruction with the workstation. [ABSTRACT FROM AUTHOR]

A 62-year-old female patient underwent mitral valve replacement with a 31/33-mm On-X valve for ischemic mitral valve regurgitation. Three months later, transthoracic echocardiography incidentally showed a blocked leaflet with 6 mmHg of mean pressure gradient and 2.4 cm of mitral valve orifice area. Transesophageal echocardiography could not detect thrombus. Electrocardiographically gated multidetector-row computed tomography (MDCT) clearly demonstrated a blocked leaflet in the close position and thrombus (2 cm in length, 0.4 cm in area) attached onto the atrial aspect of the leaflet. These findings observed by MDCT were confirmed at reoperation. MDCT was useful diagnostic method for visualizing prosthetic valve thrombosis. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to assess the incidence of divided-shaped kidney and the relationship between divided-shaped kidney and collecting system duplication.Subjects and Methods: Between May 1 and June 30, 2012, 857 patients (men:women, 493:364; mean age 39.6 years; age range 2-98 years) with 1699 kidneys underwent enhanced computed tomography of the abdomen and pelvis at our institution. Sixty kidneys were excluded (tumor, 3; percutaneous nephrostomy, 9; polycystic kidney disease, 4; renal injury, 1; infarct, 1; hydronephrosis, 18; parapelvic cyst, 17; artifact, 5; horseshoe kidney, 2). Finally, 845 patients and 1639 kidneys were included. The number of cases of prominent column of Bertin (divided by grade of prominence as either divided-shaped kidney or hypertrophy) and collecting system duplication (bifid, partial, and complete) were evaluated. Fisher exact test was used to determine the relationship between divided-shaped kidney and collecting system duplication, and between hypertrophy and collecting system duplication.Results: Of 1639 kidneys, 66 (4%) were divided-shaped kidneys, and 88 (5%) had collecting system duplication (bifid, 69; partial, 19; complete, 0); among the 66 divided-shaped kidneys, 28 (42%) had collecting system duplication. Among the 429 cases of hypertrophy and 1144 normal kidneys, 51 (11.9%) and 9 (0.8%) had collecting system duplication, respectively.Conclusions: The incidence of divided-shaped kidney was 4%, and there was a significant association between divided-shaped kidney and collecting system duplication. [ABSTRACT FROM AUTHOR]

Clinical Anatomy of the Inferior Pyramidal Space Although many studies have described the detailed anatomy of the inferior pyramidal space, it may not be easy for cardiologists who have few chances to study cadaveric hearts to understand the correct morphology of the structure. The inferior pyramidal space is the part of extracardiac fibro-adipose tissue wedging between the 4 cardiac chambers from the diaphragmatic surface of the heart. Many cardiologists have interests in pericardial adipose tissue, but the inferior pyramidal space seems to have been neglected. A number of important structures, including the coronary sinus, atrioventricular node, atrioventricular nodal artery, membranous septum, muscular atrioventricular sandwich (previously called the 'muscular atrioventricular septum'), atrial septum, ventricular septum, aortic valvar complex, mitral valvar attachment, and tricuspid valvar attachment are associated with the inferior pyramidal space. We previously revealed its 3-dimensional live anatomy using multidetector-row computed tomography. Moreover, the 3-dimensional understanding of the anatomy in association with the cardiac contour is important from the viewpoints of clinical cardiac electrophysiology. The purpose of this article is to demonstrate extended findings regarding the clinical structural anatomy of the inferior pyramidal space, which was reconstructed in combination with the cardiac contour using multidetector-row computed tomography, and discuss the clinical implications of the findings. [ABSTRACT FROM AUTHOR]

Background Because the prevalence of coronary artery calcification is lower among Japanese than among Western individuals, aspects of the Japanese lifestyle might be related to the development of calcification. We aimed to clarify the relationship between coronary artery calcium scores in Japanese patients and various lifestyle factors among the Japanese population. Methods Study subjects were patients aged ≥20 years who underwent multidetector-row computed tomography. A total of 201 patients agreed to take part in this study and answered a questionnaire regarding lifestyle, medical history, and other factors. Results Old age, current and former smoking, sedentary work, short sleep time, coronary artery stenosis, treatment with statins, medical history of cerebrovascular disease, medical history of angina pectoris, medical history of ischemic heart disease, and medical history of dyslipidemia were associated with higher odds ratios than the other factors examined, while the Japanese-style breakfast (e.g. boiled rice, miso soup, grilled fish) was associated with lower odds ratios. Conclusions In this study, smoking, sedentary work, short sleep time, and the Japanese-style breakfast were lifestyle factors related to coronary artery calcification. The lifestyle of Japanese people may be related to coronary calcification. [ABSTRACT FROM AUTHOR]

Objectives: Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). Methods: PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Results: Fifty-one patients were included. In group I ( n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality ( n = 16) or significant stenosis ( n = 3) detection. In group II ( n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. Conclusion: MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. Key Points: • Retrospective MDCT is increasingly used for prosthetic heart valve dysfunction assessment • In case of PHV reoperation, invasive coronary angiography is also required • MDCT can replace CAG in 50 % of patients without coronary artery disease • When conclusive for coronary assessment, MDCT stenosis rule out is highly accurate • Replacing CAG saves associated risks of distant embolization of thrombi or vegetations [ABSTRACT FROM AUTHOR]

Background and aims: Diagnostic imaging has a fundamental contribution to non - invasive diagnosis of the reasons for biliary obstruction and screening the patients at high risk. So, this study was aimed to compare the value of multidetector-row computed tomography (MDCT) in diagnosis of biliary obstruction reasons with the results obtained from invasive procedures. Methods: In this descriptive-analytical study, 50 patients were selected by stratified sampling from January 2010 to May 2011 with diagnosis of biliary obstruction based on per clinical and sonographic results and they were evaluated by MDCT. Their radiology report was compared with the results obtained from other invasive procedures including Percutaneous Transhepatic Cholangiography (PTC), Endoscopic Retrograde Cholangiopancreaticography (ERCP), and/or surgery. Results: Findings indicated that sensitivity, specificity, and accuracy of MDCT was 100%, 88.4%, and 94%, respectively in diagnosis of malignant reasons for biliary obstruction, 75%, 100%, and 96% in diagnosis of benignant reasons for biliary obstruction, and 94.4%, 100%, and 98% in that of gallstones. No significant relationship was found between severity of bile duct dilatation and obstructive agent's benignancy or malignancy (P<0.001). Conclusion: Based on this study findings, MDCT is found a rapid, non-invasive, and highly accurate method in diagnosis of biliary obstruction reasons, differentiation between benignant obstructive agents and malignant ones, and is useful for planning prior to surgery. [ABSTRACT FROM AUTHOR]

Objective : Three-dimensional (3-D) visualization and quantification of vascular calcification (VC) are important to accelerate the multidisciplinary investigation of VC. Agatston scoring is the standard approach for evaluating coronary artery calcification. However, regarding aortic calcification (AC), quantification methods appear to vary among studies. The aim of this study was to introduce a simple technique of simultaneous quantification and 3-D visualization of AC and provide validation data. Methods : The main study comprised of 126 patients who underwent the thoracoabdominal plain computed tomography scan as preoperative general evaluation. AC was quantified using a volume-rendering (VR) method (VR AC volume) by extracting the volume with a density ≥130 HU within the total aorta. The concordance and reproducibility of the VR AC volume were validated in comparison with the conventional slice-by-slice voxel-based AC quantification (volumetric AC score) using the Agatston scoring software. Results : Excellent concordance between the VR AC volume and volumetric AC score was confirmed (Spearman correlation coefficient = 0.9997, mean difference = −0.05 ± 0.23 mL, p <0.0001). Excellent intraobserver and interobserver reliabilities were demonstrated using the Bland–Altman analysis as the mean intraobserver difference was 0.00 mL ( p = 0.9863) and the mean interobserver difference was −0.01 mL ( p = 0.6612). Conclusion : The VR method was validated to be feasible. This simple approach could overcome the limitation of the current method based on slice-by-slice pixel or voxel summation, which lacks 3-D visual information. Accordingly, this approach would be promising for accelerating the investigation of VC. [ABSTRACT FROM AUTHOR]