Multidetector-row Computed Tomography Research Articles

Prognostic factors for the successful conservative management of nonocclusive mesenteric ischemia

BackgroundThe criteria for deciding upon non-operative management for nonocclusive mesenteric ischemia (NOMI) are poorly defined. The aim of this study is to determine the prognostic factors for survival in conservative treatment of NOMI.MethodsPatients with bowel ischemia were identified by searching for “ICD-10 code K550” in the Diagnosis Procedure Combination database between June 2015 and May 2020. A total of 457 patients were extracted and their medical records, including the clinical factors, imaging findings and outcomes, were analyzed retrospectively. Diagnosis of NOMI was confirmed by the presence of specific findings in contrast-enhanced multidetector-row CT. Twenty-six patients with conservative therapy for NOMI, including four cases of explorative laparotomy or laparoscopy, were enrolled.ResultsAmong the 26 cases without surgical intervention, eight patients (31%) survived to discharge. The level of albumin was significantly higher, and the levels of lactate dehydrogenase, total bilirubin, C-reactive protein, and lactate were significantly lower in the survivors than the non-survivors. Sepsis-related Organ Failure Assessment (SOFA) score was significantly lower in the survivors than the non-survivors. The most reliable predictor of survival for NOMI was SOFA score (cutoff value ≤ 3 points), which had the highest AUC value (0.899) with odds ratio of 0.075 (CI: 0.0096–0.58).ConclusionsThe SOFA score and several biological markers are promising predictors to determine a treatment plan for NOMI and to avoid unnecessary laparotomy.

Endoscopic management of perihilar cholangiocarcinoma.

Endoscopic management for perihilar cholangiocarcinoma (PHCC) is evolving toward more accurate diagnosis and safer drainage. In imaging, it is important to diagnose the entire lesion using multidetector-row computed tomography to determine resectability and optimal surgical planning, followed by local diagnosis using endoscopic retrograde cholangiopancreatography. Video peroral cholangioscopy and probe-based confocal laser endomicroscopy have been newly introduced as diagnostic imaging methods and are being applied clinically. In transpapillary forceps biopsy for PHCC diagnosis, the location in the bile duct (for mapping biopsy) and the number of biopsy samples should be determined depending on resectability, the morphological type, and future surgical planning. Preoperative drainage has shifted from percutaneous transhepatic biliary drainage to endoscopic nasobiliary drainage given the possibility of seeding metastasis. In addition, considering potential patient discomfort from a nasal tube, the usefulness of the placement of a plastic stent above the papilla (inside stent) as a bridging therapy for surgery has been reported. For drainage of unresectable PHCC, the improved prognosis due to advances in chemotherapy has necessitated a strategy that accounts for reintervention. Thus, in addition to uncovered self-expandable metallic stents (SEMS), exchangeable slim fully covered SEMS and inside stents have started to be used. In addition to the conventional transpapillary approach, an endoscopic ultrasonography-guided approach has been introduced, and a combination of both methods has also been proposed. To improve the quality of life and prognosis of PHCC patients, endoscopists need to understand and be able to use the various methods of endoscopic management for PHCC.

Effect of different contrast medium injection protocols for analysis of hepatic computed tomography perfusion in healthy dogs.

To evaluate the hepatic CT perfusion (CTP) for determining the appropriate protocol for the dual-input maximum-slope model in dogs. 5 healthy dogs. Each dog underwent CTP with different contrast medium administration protocols. Combinations of three different injected doses of iohexol (450, 600, and 750 mg/kg) and injection durations (5, 10, and 15 seconds) were used. The CT values at the aorta, portal vein, and hepatic parenchyma were measured to create a time-density curve, and CTP parameters were measured simultaneously on each hepatic lobe using a 320-row multidetector CT scanner. The maximum peak enhancement at the aorta, portal vein, and hepatic parenchyma was greater with the 750-mg/kg dose than with the 450-mg/kg dose. With an injection duration of 15 seconds, the aortic enhancement peak was less, and the arrival time at the aortic enhancement peak was longer compared to that with a 5-second injection duration. The CTP parameters in the caudate process of the caudate lobe and left lateral lobe differed with different injection durations. The CTP parameters in the caudate process of the caudate lobe, left lateral lobe, and right lateral lobe differed with varying injected doses. Our study demonstrated that rapid administration of the contrast medium was required for quantitative analysis of hepatic CTP in healthy dogs. The CTP parameters differed with respect to the contrast medium administration protocol, and it was necessary to administer the contrast medium within a fixed duration and at a fixed dose to evaluate CTP correctly.

Paraffin Fixed Human Trabecular Bone Specimens for Study of Osteoporosis

Examining and quantifying specific measures of trabecular bone to investigate the progression of osteoporosis presents a challenge. Specifically, the development of analytical and computational strategies to interpret computed tomography (CT) generated data sets requires gross anatomical specimens that closely approximate the intraosseous matrix of the marrow while maintaining the structural integrity of the trabecular network. Moreover, these specimens must be durable, easily transported, and stored at room temperature (e.g., do not require freeze/thaw cycles). Here we investigated if paraffin impregnated bone specimens maintained the trabecular network and bone density of prepared fresh‐frozen specimens used in imaging studies for osteoporosis. Standardized fresh‐frozen human distal tibia specimens (n = 12), from the institution’s Deeded Body Program, were scanned using multi‐row detector computed tomography (MDCT) and micro computed tomography (micro‐CT) imaging at different times in the preparation process to evaluate and quantify the preservation of microstructure and continuity of cortical and trabecular bone constituents. Once scanned, the specimens were placed in a series of acetone baths to remove water and marrow. With the de‐marrowing procedure complete, four specimens were rescanned using MDCT and micro‐CT. De‐marrowed specimens were then impregnated, under vacuum controlled conditions, with either a silicone polymer, gelatin matrix solution, or paraffin wax. After impregnation and curing, the specimens were re‐scanned. Analysis demonstrated a high correlation in the region of interest (ROI) for trabecular bone network area density from micro‐CT data sets of the preprocessed and de‐marrowed states (r = 0.99). Quantitatively, wax impregnated specimens demonstrated congruence in MDCT bone volume fraction (r = 0.92) and trabecular network area (r = 0.94) measures when the preprocessed and impregnated states were correlated. Results were more robust in the micro‐CT data in the bone volume fraction (r = 0.97) and the trabecular network area (r = 0.99). MDCT analysis at the (ROI) corresponding to 14‐16% length measured from the distal aspect of specimens demonstrated an increased estimate of bone mineral density (BMD) relative to scans acquired with the unmodified tissue (polymer +160 mg/cc; gelatin +58 mg/cc), whereas the paraffin wax condition slightly underestimated BMD (‐21 mg/cc). Of the impregnating procedures, paraffin wax provided the best qualitative specimens for handling, storage, and processing time. Together these data suggest that the trabecular structure is preserved through the de‐marrowing procedure and demonstrates that specimens can be transferred away from cold storage. Impregnating bone specimens with paraffin wax effectively provides a space occupying matrix that protects the delicate trabecular network without altering the ability to quantify important biomechanical measures in clinical CT as well as micro‐CT imaging for assessing bone integrity for the study of osteoporosis. This procedure creates specimens that are easily stored and transported, can be scanned across various imaging modalities, and effectively retain the trabecular micro‐structure.

A Narrative Review on Current Diagnostic Imaging Tools for Dentomaxillofacial Abnormalities in Children.

The current review narrates the findings and discusses the available diagnostic tools for detecting structural abnormalities. The review discusses several diagnostic tools, such as magnetic resonance imaging, cone beam computed tomography, multi detector row CT and positron emission tomography. The vital findings and comparative analysis of different diagnostic tools are presented in this review. The present review also discusses the advent of newer technologies, such as the HyperionX9 scanner with less field of view and 18F-FDG PET/CT (positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro-D-glucose, integrated with computed tomography), which can give more efficient imaging of dentomaxillofacial structures. The discussion of effective comparative points enables this review to reveal the available diagnostic tools that can be used in the detection of dentomaxillofacial abnormalities in the pediatric population. The advantages and disadvantages of each tool are discussed, and the findings of past publications are also presented. Overall, this review discusses the technical details and provides a comparative analysis of updated diagnostic techniques for dentomaxillofacial diagnosis.

Thoracic Aortic Diameter and Cardiovascular Events and Mortality among Women and Men.

Background Thoracic aortic diameter may have a role as a biomarker for major adverse cardiovascular events. Purpose To evaluate the sex-specific association of the diameters of the ascending (AA) and descending (DA) thoracic aorta with risk of stroke, coronary heart disease, heart failure, cardiovascular mortality, and all-cause mortality. Materials and Methods Study participants from the population-based Rotterdam Study who underwent multidetector-row CT between 2003 and 2006 were evaluated. Cox proportional hazard models were conducted to evaluate the associations of AA and DA diameters indexed and not indexed for body mass index (BMI) with cardiovascular events and mortality for men and women. Hazard ratios (HRs) were calculated per 1-unit greater SD of aortic diameters. Results A total of 2178 participants (mean age, 69 years; 55% women) were included. Mean follow-up was 9 years. Each 0.23-mm/(kg/m2) larger BMI-indexed AA diameter was associated with a 33% higher cardiovascular mortality risk in women (HR, 1.33; 95% CI: 1.03, 1.73). Each 0.16-mm/(kg/m2) larger BMI-indexed DA diameter was associated with a 38% higher risk of stroke (HR, 1.38; 95% CI: 1.07, 1.78) and with a 46% greater risk of cardiovascular mortality (HR, 1.46; 95% CI: 1.10, 1.94) in women. Larger BMI-indexed AA and DA diameters were associated with greater risk of all-cause mortality in both sexes. Conclusion Larger ascending and descending thoracic aortic diameters indexed by body mass index were associated with greater risk of adverse cardiovascular outcomes and mortality in women and men. Clinical trial registration no. NTR6831 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Williams in this issue.

Panorama of multidetector-row computed tomography findings of carcinoma gall bladder - A retrospective observational study.

Carcinoma of the gall bladder (Ca GB) has marked ethnic and geographical variations with a broad spectrum of imaging findings on multidetector-row computed tomography (MDCT). We aim to study the spectrum of the imaging findings of Ca GB on MDCT in an Eastern Indian hospital as these imaging findings help in accurate diagnosis and staging of this lethal disease. The MDCT images of 100 biopsy-proven cases of adenocarcinoma of GB performed from January 1, 2017, to December 31, 2018, in our hospital were retrospectively reviewed by two experienced radiologists blinded to the diagnosis. The CT protocol was a plain scan followed by triple-phase contrast-enhanced CT. Reconstructed images in the form of maximum intensity projection, volume-rendered technology, and minimum intensity projection images were also assessed. Descriptive statistics were used for data analysis. Ca GB showed a female predominance (female:male -1.9:1). The mean age of presentation was 54.7 years (females) and 58 years (males). The morphological patterns were a mass replacing the GB (46%), focal or diffuse wall thickening (26%), and an intraluminal polypoidal mass (28%). Direct extension was to liver (76%), duodenum (32%), colon (19%), pancreas (9%), and abdominal wall (1%). Biliary dilatation (53%), vascular invasion (14%), omental involvement (23%), ascites (22%), N1 (40%), and retroperitoneal lymphadenopathy (33%) were common. Distant metastasis comprised of hepatic (42%), pulmonary (7%), Krukenberg's tumor (6%), and osseous (1%) lesions. The stages at diagnosis were I or II (3%), IIIA (4%), IIIB (16%), IVA (10%), and IVB (67%). Ca GB has a broad spectrum of findings on MDCT and it mostly presents at an advanced stage. MDCT with reconstructions is beneficial in the assessment of locoregional and distant spread and cancer staging which has a direct implication on patient management, survival, and mortality.

Thoracoabdominal aortic aneurysm repair based on pre- and postoperative evaluation of the artery of Adamkiewicz.

The aim of this study was to evaluate our experience with thoraco-abdominal aortic aneurysm repair based on the pre- and postoperative evaluation of the artery of Adamkiewicz (AKA). Between April 2017 and May 2021, 32 patients who underwent thoracoabdominal aortic repair underwent pre- and postoperative multidetector row computed tomography (MDCT) for AKA evaluation. Based on the identification of the AKA on preoperative MDCT, only 1 critical segmental artery was reattached to the AKA (CSA-AKA). Postoperative MDCT was used to evaluate the patency of the reattached CSA-AKA. Pre- and postoperative MDCT helped identify and visualize the AKA in all patients (100%). In 8 patients, alternative continuity to the AKA developed through collateral circulation. The total number of CSA-AKA with collateral circulation was 48 among the 32 cases; the number of reattached segmental arteries per case was 1.3 ± 0.9 (range, 0-4). The overall rate of patency of the reattached CSA-AKA was 53% (23/43). Three patients exhibited spinal cord injuries (paraplegia, 2; paraparesis, 1). In the 2 paraplegia cases exhibiting partial or complete occlusion of the reattached CSA-AKA, the development of collateral circulation was not visualized via postoperative MDCT. In the paraparesis case, postoperative MDCT helped visualize the development of collateral circulation to the CSA-AKA, resulting in full recovery at discharge. The study findings suggest that spinal cord injuries do not occur in the presence of a patent preoperatively identified CSA-AKA or the development of collateral circulation. Pre- and postoperative identification of collateral pathways to the AKA may help reveal paraplegia risk factors.

Comparison of Silicosis and Tuberculosis Involving Mediastinal Lymph Nodes Based on Contrast-Enhanced Multidetector-Row Computed Tomography.

To investigate the different imaging features of contrast-enhanced multidetector-row-computed tomography (MDCT) for distinguishing between silicosis and tuberculosis involving the mediastinal lymph nodes. 86 silicosis patients and 61 tuberculosis patients with mediastinal lymphadenopathy based on contrast-enhanced MDCT were included. The enhanced patterns, anatomical distribution and calcification features of the enlarged lymph nodes were retrospectively compared between the groups using the Pearson chi-square test or Fisher's exact test. Homogeneous enhancement of the mediastinal lymph nodes was more commonly observed in silicosis (94.2%, 81/86) than in tuberculosis (19.7%, 12/61). Peripheral enhancement was more frequent in tuberculosis (n = 44, 72.1%) than in silicosis involving the mediastinal lymph nodes (n = 1, 1.2%), and multilocular appearance was more frequent in TB than in silicosis. Tuberculosis was more likely to affect regions 1R, 2R, 2L, 3A, 5 and 6 than silicosis (all p < 0.05), especially region 2R. Calcification of the lymph nodes was more common in the silicosis group than in tuberculosis group. The sensitivity, specificity, and accuracy of silicosis with lymphadenopathy with homogeneous enhanced pattern were 94.2%, 80.3% and 88.4%, respectively. The sensitivity, specificity, and accuracy of tuberculosis lymphadenopathy with peripheral enhanced pattern were 72.1%, 98.8%, and 87.7%, respectively. The predominant enhanced patterns, anatomical distribution, and calcification features of mediastinal lymph nodes were different between tuberculosis and silicosis. These radiographic features might help differentiate tuberculosis from silicosis, which provides imaging information for the differential diagnosis of the two diseases in a clinical setting.

Submillisievert CT chest for COVID-19 patients in a rural hospital with limited resources

BackgroundThis is a secondary analysis of prospectively acquired data approved by the hospital institutional board committee. We performed a retrospective chart review of 463 patients who underwent a CT Chest for suspected COVID-19 infection between April 1st, 2020, and March 31st, 2021. Patients were grouped based on the CT chest obtained protocol: ultra-low dose or full dose. The likelihood of suspicion of COVID-19 infection was classified on a Likert scale based on the probability of pulmonary involvement. For each group, the sensitivity and specificity of CT were compared to nasopharyngeal swab as standard of reference. The median dose length product and duration of apnea were compared between both groups using two-tailed Mann–Whitney U test. The aim of this study is to share our experience of reducing radiation dose in COVID-19 patients by using an ultra-low dose CT chest protocol on a 16 row multidetector CT scan in a hospital with limited resources.ResultsTwo hundred sixty-nine patients underwent a full dose CT and 194 patients an ultra-low dose CT. In the former group, the median dose length product was 341.11 mGy*cm [Interquartile range (IQR), 239.1–443.2] and the median duration of apnea was 13.29 s [IQR, 10.85–15.73]. In the latter group, the median dose length product was 30.8 mGy*cm [IQR, 28.9–32.7] and median duration of apnea was 8.27 s [IQR, 7.69–8.85]. The sensitivity of the ultra-low dose CT was 91.2% and that of the full dose was 94%.ConclusionA 90% reduction in estimated dose and 38% reduction in apnea duration could be achieved using an ultra-low dose CT chest protocol on a 16-row MDCT without significant loss in the sensitivity of CT to detect COVID-related parenchymal involvement.

Diagnostic performance and inter-observer variability to differentiate between T1- and T2-stage gallbladder cancers using multi-detector row CT.

To evaluate the diagnostic performance and inter-observer variability of differentiating T1 and T2 gallbladder (GB) cancers using multi-detector row CT (MDCT). This retrospective study included 151 patients with surgically confirmed T1 (n = 49)- or T2 (n = 102)-stage GB cancer who underwent contrast-enhanced MDCT from 2016 to 2020. Five radiologists (two experienced and three less experienced) evaluated the T-stage with a confidence level calculated using a six-point scale. GB cancers were morphologically classified into three types: polypoid, polypoid with wall thickening, and wall thickening. The diagnostic performance of T-staging was assessed using receiver operating characteristic (ROC) curve analysis. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated based on a binary scale (T1 = positive). Inter-observer agreement was assessed using Fleiss κ statistics. The area under the receiver operating characteristic (ROC) curve of each reviewer for T-staging ranged from 0.69 to 0.80 (median 0.77). The overall accuracy of the five radiologists was 78% (95% confidence interval [CI] 71-84%). Sensitivity was higher and specificity was lower in experienced radiologists than in less experienced radiologists (P < 0.001). The overall inter-observer agreement was fair (κ = 0.36; 95% CI 0.31, 0.41). The overall accuracy for T-stage was 63% (95% CI 48-76), 78% (95% CI 63-88), and 87% (95% CI 77-93) for polypoid, polypoid with wall thickening, and wall thickening type, respectively. The accuracy of MDCT for differentiating T1 and T2 GB cancer is limited, and there is considerable inter-observer variability.

Low-radiation dose scan protocol for preoperative imaging for dental implant surgery using deep learning-based reconstruction in multidetector CT.

This study aimed to investigate the impact of a deep learning-based reconstruction (DLR) technique on image quality and reduction of radiation exposure, and to propose a low-dose multidetector-row computed tomography (MDCT) scan protocol for preoperative imaging for dental implant surgery. The PB-1 phantom and a Catphan phantom 600 were scanned using volumetric scanning with a 320-row MDCT scanner. All scans were performed with a tube voltage of 120kV, and the tube current varied from 120 to 60 to 40 to 30mA. Images of the mandible were reconstructed using DLR. Additionally, images acquired with the 120-mA protocol were reconstructed using filtered back projection as a reference. Two observers independently graded the image quality of the mandible images using a 4-point scale (4, superior to reference; 1, unacceptable). The system performance function (SPF) was calculated to comprehensively evaluate image quality. The Wilcoxon signed-rank test was employed for statistical analysis, with statistical significance set at p value < 0.05. There was no significant difference between the image quality acquired with the 40-mA tube current and reconstructed with the DLR technique (40DLR), and that acquired with the reference protocol (3.00, 3.00, p = 1.00). The SPF at 1.0 cycles/mm acquired with 40DLR was improved by 156.7% compared to that acquired with the reference protocol. Our proposed protocol, which achieves a two-thirds reduction in radiation dose, can provide a minimally invasive MDCT scan of acceptable image quality for dental implant surgery.

3D-MDCT STUDY OF STYLOID PROCESS OF TEMPORAL BONE AMONG PATIENTS ATTENDING CHITWAN MEDICAL COLLEGE TEACHING HOSPITAL

Background: The styloid process of the temporal bone is clinically significant because differences in length and angulations are linked to the symptoms of stylalgia (Eagle’s syndrome), and surgical removal of the process can help patients with neck and cervico-facial pain. This study aimed to evaluate the length, angulation and distance between bases and tips of the styloid process. Methods: A Hospital based cross-sectional study using observation method was carried out in Department of radiology Chitwan Medical College Teaching Hospital, Nepal from 17th September 2021 to 16th November 2021. A total of 107 patients were enrolled as a sample for the study. The length, distance and angulation were measured during routine 3D Multi-detector row computed tomography (MDCT). Obtained data was evaluated by using descriptive statistics with Statistical Package for the social Science (IBM SPSS) 20.0. Results: Among 107 patients undergoing Computed Tomography (CT) scan, majority i.e 71% have medial angulation of styloid process, 16.80% participants have elongated styloid process on left side and 17.80 % participants have elongated styloid process on right side. Mann Whitney U Test showed that tip to tip and base to base distance are statistically significant between male and female. Conclusions: The styloid process is in close proximity to a number of essential anatomical structures. Because of differences in the shape of the styloid process, these structures may be compressed or inflamed. Even though the existence of an elongated styloid process and its angulation is uncommon, it emphasizes the need of examining the styloid process on a regular basis in clinical practice.

Matching the perforating branch of the internal thoracic artery and the deep inferior epigastric artery for breast reconstruction using multi-detector row computed tomography.

Matching the diameter of the deep inferior epigastric artery (DIEA) and perforating branch (PB) of the internal thoracic artery (ITA) is important for arterial anastomosis during breast reconstruction using the DIEA flap. An anatomic investigation of these arteries was performed using multidetector row computed tomography (MDCT). Contrast-enhanced MDCT data of 50 women (aged 18-90years) covering the neck to the groin were analyzed. The diameter of the PBs of the ITA at their origins from the first to the sixth intercostal space and of the DIEA 20mm from the bifurcation of the external iliac artery were measured. The mean diameters of the right and left DIEAs were 1.53 ± 0.263mm and 1.53 ± 0.306mm, respectively. The diameter of the PBs in the second and third intercoastal spaces was the same as the diameter of the DIEA, bilaterally. It is suggested that anastomosis of the DIEA with PBs of the ITA in the second and third intercoastal spaces is optimal for DIEA flap grafting. Our results could contribute to making vascular anastomosis easier, thereby reducing the burden on both surgeons and patients.

Clinical Impact of Gadoxetic Acid-Enhanced Magnetic Resonance Imaging on Living Donor Liver Transplant

Gadolinium-ethoxybenzyl-diethylene triamine pentaacetic acid (Gd-EOB-DTPA) is a newer magnetic resonance contrast that has the combined effect of conventional and liver-specific contrast. The use of Gd-EOB-DTPA may aid in management of patients with hepatocellular carcinoma (HCC) undergoing living donor liver transplant (LDLT). We retrospectively reviewed all HCC patients who received LDLT with Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) as part of a pretransplant evaluation between October 2012 and October 2016. The detection rate and impact on decision making were assessed between multidetector-row computed tomography (MDCT) and Gd-EOB-DTPA-enhanced MRI with pathology of the explanted liver being the reference standard. We analyzed 25 patients with 80 nodules. Gd-EOB-DTPA-enhanced MRI showed superior detection rate for HCCs than MDCT (76.1% vs 35.8%). Among the 25 patients, 16 had additional HCCs detected by Gd-EOB-DTPA-enhanced MRI, which led to changes in therapeutic decisions in 11 patients. The recurrence rate and mortality rate were 4% (1 of 25). In the same period in our institution, the mortality rate was 13.9% (25 of 180) for those who did not receive Gd-EOB-DTPA-enhanced MRI as part of the pretransplant evaluation. The use of Gd-EOB-DTPA-enhanced MRI can aid in characterization of indeterminate nodules and detect more HCCs and thus more adequate downstaging and pretransplant neoadjuvant treatment ensue, which may lower the recurrence rate after LDLT.

ROLE OF MULTIDETECTOR ROW COMPUTED TOMOGRAPHY ANGIOGRAPHY IN IDENTIFICATION OF THE VASCULAR SOURCE OF BLEEDING IN THE PATIENTS WITH HEMOPTYSIS

We aimed to report our experience with the use of multidetector row computed tomography (MDCT), with angiography in the evaluation of patients with hemoptysis. Role of multidetector row computed tomography angiography in OBJECTIVE: identication of the vascular source of bleeding in the patients with hemoptysis. A prospective study was carried out on 50 patients METHODS: suffering from hemoptysis. They underwent MDCT using a 128-detector row scanner with bronchial and pulmonary angiographic techniques. MDCT identied the RESULTS: cause of hemoptysis in 92% of patients. MDCT angiography was able to detect the site and vascular source of bleeding in 86% of patients. A total of 86 bronchial arteries were detected in 76% of patients; 33% of these arteries (40.74%) were abnormally dilated. Our results CONCLUSION: conrm that MDCT angiography is a useful method to identify and depict the bronchial arteries and to predict the presence of nonbronchial systemic vessels that supply a parenchymal lesion. MDCT angiography allows a rapid and detailed identication of abnormal vasculature and provides a precise road map which can be used to guide therapeutic arterial embolization.

Scientific Research Group Report: Nationwide Survey on Radiation Exposure of Pediatric CT Examination in Japan (2018)

To understand the latest pediatric computed tomography (CT) exposure required for the revision of national DRLs. A questionnaire was sent to 409 facilities where the members of the Japanese Society of Radiological Technology and the Japanese Society of Pediatric Radiology are enrolled. We investigated the imaging conditions, CTDIvol, and DLP of the pediatric head, chest, and abdominal CT examinations. In all, 43 facilities (11%) responded to our survey. multi detector-row CT (MDCT) systems were available in all surveyed facilities. More than 98% of the MDCT systems had more than 64 detector rows. The CTDIvol of all CT protocols was lower than the NDRL due to the progress of updating to MDCTs with radiation exposure reduction functions such as an iterative reconstruction, but the DLP of head and abdominal CT protocols of some age group were higher than NDRL. It is necessary to review the imaging protocol with the attending physician and radiologist and consider further optimization of medical exposure.

Fluid Structure Interaction Analysis of Aorta Using OpenFOAM and CalculiX

Currently, biomechanical simulations of blood vessels and organs are widely used in medical research, and it is expected to realize rapid and accurate medical diagnosis by personalized biological simulations for each individual using high-speed and high-precision 3D modeling of the body internal geometry by Multi Detector-row Computed Tomography (MDCT) and Magnetic Resonance Imaging (MRI). In particular, biomechanical simulation approach using Open Source Software (OSS) has been developed for use in the medical field, and recently, its application to more challenging multiphysics simulation has been studied. However, OSS has many issues such as assurance of accuracy and validity of the analysis, the computation time and stability of Fluid-Structure Interaction (FSI), and the lack of analysis functions for complex phenomena. In particular, blood flow simulation using OpenFOAM, a fluid analysis OSS, has issues in the representation of blood pressure changes caused by pulsation and body movement, and the stability of coupled analysis in conjunction with other structural analysis software. In this study, we added the Windkessel model, which is one of the models for expressing blood pressure changes, to OpenFOAM and developed a two-way coupled multi-physics simulation approach using OpenFOAM and CalculiX. As an example of personalized biomechanical simulation, we applied the method to simulate blood flow in the thoracic aorta and evaluated its effectiveness.

Coronary Artery Visualization by Using the 64-row MDCT in Pediatric Patients

We retrospectively evaluated the visualization of pediatric coronary computed tomography angiography (CCTA) images by using the 64-detector row CT scanner between the electrocardiogram-gated helical scan and non-electrocardiogram-gated helical scan. From January 2015 to March 2019, 100 children who underwent CT angiography examination were retrospectively enrolled. Group A consisted of 50 patients with electrocardiogram-gated helical scan. Group B consisted of 50 patients with non-electrocardiogram-gated helical scan. All patients were scanned using a 64-detector row CT scanner (LightSpeed VCT), and helical scans were acquired. The CT scanning parameters were 0.4-s rotation, 0.625-mm slice thickness, 0.24 (group A) helical pitch (beam pitch), 1.375 (group B) helical pitch (beam pitch), 80 kVp, and 50-300 mA (noise index 40). A retrospective method was used for electrocardiogram gated. To compare the radiation dose, CT volume dose index (CTDIvol) and dose length product (DLP) displayed on the console were recorded. The visualization scores of the coronary artery images were compared between each group. In group A, CTDIvol and DLP values were 6.74 (1.05-11.97) mGy and 79.87 (15.90-146.65) mGy·cm, respectively. In group B, CTDIvol and DLP values were 0.51 (0.39-0.95) mGy and 8.15 (6.30-17.50) mGy·cm, respectively. There were significant differences in CTDIvol and DLP values between both groups (p<0.05). The visualization rates for the proximal and distal coronary arteries were 88% and 54% for the right coronary artery, 84% and 58% for the left anterior descending artery, and 66% and 30% for the left circumflex branch in group A, respectively. The visualization rates for the proximal and distal coronary arteries were 52% and 0% for the right coronary artery, 56% and 0% for the left anterior descending artery, and 32% and 0% for the left circumflex branch in group B. In 64-row multidetector computed tomography (MDCT), the visualization rates for the proximal and distal coronary arteries were significantly higher in the electrocardiogram-gated scan, but the exposure dose was several times higher in the pediatric CCTA. For accurate diagnosis in pediatric coronary arteries, electrocardiogram-gated helical scan should be performed.

Can epicardial and pericardial adipose tissue volume predict the presence and severity of coronary artery disease?

PurposeExcessive accumulation of free fatty acids in the coronary arteries can lead to coronary artery disease (CAD). Quantification of epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT) is beneficial to understand its relationship with CAD, hypertension (HT), and diabetes.Material and methodsThis retrospective study included 54 patients who underwent CT coronary angiogram using a multidetector row CT scanner. The EAT and PAT volumes from cardiac images were quantified using Image J software. The severity of CAD was graded using the CAD-RADS score.ResultsTwenty-nine patients had no CAD, 21 patients had significant CAD, and 4 patients had insignificant CAD. Out of 21 patients with significant CAD, 14 had involvement of multiple coronary arteries. The EAT and PAT volumes were higher in patients with HT, DM, CAD-present group and significant-CAD-present group, but this was not statistically significant except the PAT volume with respect to diabetes. Significant correlation was found between EAT volume and calcium score (p = 0.035) and between EAT volume and total cholesterol level (p = 0.017). Significant differences in the EAT volumes were found in different CAD-RADS categories in the right coronary artery (RCA). From the threshold values, it was observed that CAD can develop in LAD even at lower of EAT and PAT volumes.ConclusionsQuantification of EAT and PAT volumes is beneficial in understanding its relationship with the presence and severity of coronary artery disease and its risk factors.