Multidetector-row Computed Tomography Research Articles

Optimizing Coronary Computed Tomography Angiography Using a Novel Deep Learning-Based Algorithm.

Coronary computed tomography angiography (CCTA) is an essential part of the diagnosis of chronic coronary syndrome (CCS) in patients with low-to-intermediate pre-test probability. The minimum technical requirement is 64-row multidetector CT (64-MDCT), which is still frequently used, although it is prone to motion artifacts because of its limited temporal resolution and z-coverage. In this study, we evaluate the potential of a deep-learning-based motion correction algorithm (MCA) to eliminate these motion artifacts.124 64-MDCT-acquired CCTA examinations with at least minor motion artifacts were included. Images were reconstructed using a conventional reconstruction algorithm (CA)and a MCA. Image quality (IQ), according to a 5-point Likert score, was evaluated per-segment, per-artery, and per-patient and was correlated with potentially disturbing factors (heart rate (HR), intra-cycle HR changes, BMI, age, and sex). Comparison was done by Wilcoxon-Signed-Rank test, and correlation by Spearman's Rho.Per-patient, insufficient IQ decreased by 5.26%, and sufficient IQ increased by 9.66% with MCA. Per-artery, insufficient IQ of the right coronary artery (RCA) decreased by 18.18%, and sufficient IQ increased by 27.27%. Per-segment, insufficient IQ in segments 1 and 2 decreased by 11.51% and 24.78%, respectively, and sufficient IQ increased by 10.62% and 18.58%, respectively. Total artifacts per-artery decreased in the RCA from 3.11 ± 1.65 to 2.26 ± 1.52. HR dependence of RCA IQ decreased to intermediate correlation in images with MCA reconstruction.The applied MCA improves the IQ of 64-MDCT-acquired images and reduces the influence of HR on IQ, increasing 64-MDCT validity in the diagnosis of CCS.

Thoracic Aortic Plaque Burden and Prediction of Cardiovascular Events in Patients Undergoing 320-row Multidetector CT Coronary Angiography.

Wide volume scan (WVS) coronary computed tomography angiography (CCTA) enables aortic arch visualization. This study assessed whether the thoracic aortic plaque burden (TAPB) score can predict major cardiovascular adverse events (MACE) in addition to and independently of other obstructive coronary artery disease (CAD) attributes. This study included patients with suspected CAD who underwent CCTA (n=455). CCTA-WVS was used to assess CAD and the prognostic capacity of TAPB scores. Data analysis included the coronary artery calcification score (CACS), CAD status and extent, and TAPB score, calculated as the sum of plaque thickness and plaque angle at five thoracic aortic segments. The primary endpoint was MACE defined as a composite event comprised of ischemic stroke, acute coronary syndrome, and cardiovascular death. During a mean follow-up period of 2.8±0.9 years, 40 of 455 (8.8%) patients experienced MACE. In the Cox proportional hazards model adjusted for clinical risks (Suita cardiovascular disease risk score), we identified TAPB score (T3) as a predictor of MACE independent of CACS ＞400 (hazards ratio [HR], 2.91; 95% confidence interval [CI], 1.26-6.72; p=0.012) or obstructive CAD (HR, 2.83; 95% CI, 1.30-6.18; p=0.009). The area under the curve for predicting MACE improved from 0.75 to 0.795 (p value=0.008) when TAPB score was added to CACS ＞400 and obstructive CAD. We found that comprehensive non-invasive evaluation of TAPB and CAD has prognostic value in MACE risk stratification for suspected CAD patients undergoing CCTA.

Association of Anthropometric and CT-Based Obesity Indices with Subclinical Atherosclerosis.

Few studies have compared the strength in the associations of anthropometric and computed tomography (CT)-based obesity indices with coronary artery calcification (CAC), aortic artery calcification (AoAC), and aortic valve calcification (AVC). We assessed cross-sectcional associations of anthropometric and CT-based obesity indices with CAC, AoAC, and AVC. Anthropometric measures included body mass index (BMI), waist circumference, hip ircumference, waist-to-hip circumference ratio, and waist-to-height ratio in 931 men (mean age, 63.7 years) from a population-based cohort. CT images at the L4/5 level were obtained to calculate the areas of abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), total adipose tissue (TAT), VAT-to-SAT ratio (VSR), and VAT-to-TAT ratio (VTR). CAC, AoAC, and AVC were quantified using the Agatston score based on CT scanning. CAC, AVC, and AoAC were present in 348 (62.6%), 173 (18.6%), and 769 (82.6%) participants, respectively. In multivariable models adjusting for age, lifestyle factors, and CT types (electron beam CT and multidetector row CT), anthropometric and CT-based obesity indices were positively associated with CAC (p＜0.01). Conversely, VAT-to-SAT ratio and VAT-to-TAT ratio were positively associated with AoAC (p＜0.01). Any obesity indices were not associated with AVC. The strength of the associations of obesity indices with subclinical atherosclerosis varied according to the anatomically distinct atherosclerotic lesions, among men.

The Probability of Multidetector Row Computed Tomography (MDCT) for Assessment of Transmitral Flow Velocities and Transannular flow Velocities in Comparison with 2-Dimensional (2D) Echocardiography

Two-Dimensions (2D) echocardiography using TDI has been used most commonly to evaluate diastolic LV function. Although the role of MDCT imaging for evaluation of coronary atherosclerosis has been explored extensively. Moreover, assessment of LV volumes and systolic function using MDCT were studied before and showing accurate myocardial border delineation despite its clinical significance use regarding radiation and contrast. The probability to evaluate diastolic function using MDCT has not been studied well yet. The present study was aimed to evaluate the probability of cardiac CT for assessment of diastolic function in a direct comparison with 2-dimensional (2D) echocardiography using combined assessment of transmitral velocity and transannular mitral velocity. One hundred and twenty patients’ consecutive patients who had been referred for 64-MDCT imaging were prospectively selected from our clinical registry. After exclusion criteria had been applied, forty patients who had undergone 64-MDCT and 2D echocardiography with TDI were enrolled. MDCT and 2D echocardiography were performed within the same day and no acute coronary events or worsening of angina occurred between the examinations and no changes in the use of medication occurred between both examinations. A good correlation was found for demonstrate the probability of multidetector row computed tomography (MDCT) for assessment of trans-mitral flow velocities and trans-annular flow velocities in comparison with 2-dimensional (2D) echocardiography using tissue Doppler imaging (TDI).

Automated and semi-automated 3D echocardiographic software for aortic annulus sizing in transcatheter aortic valve implantation helps bridge the gap between expert and novice operators.

3D-transesophageal echocardiography (3D-TEE) is an alternative to multidetector row computed tomography (MDCT) for aortic annulus (AoA) sizing in preparation for Transcatheter aortic valve implantation (TAVI). We aim to evaluate how the fully automated (auto) and semi-automated (SA) TEE methods perform compared to conventional manual TEE method and the gold standard MDCT for annulus sizing both in expert and novice operators. In this prospective cohort study, eighty-nine patients with severe aortic stenosis underwent multimodality imaging with 3D-TEE and MDCT. Annular measurements were collected by expert echocardiographers using 3D auto, SA and manual methods and compared to MDCT. A novice in the field of echocardiography retrospectively measured the AoA for all patients using the same methods. TEE measurements, independently of the method used, had good to very good agreement to MDCT. They significantly underestimated aortic annular area and circumference vs. MDCT with the auto method underestimating it the most and the manual method the least (6.5% and 1.3% respectively for area and circumference). For experts, the manual TEE method offered the least systematic bias while the SA method had narrower limits of agreement (LOA). For the novice operator, SA method provided the least bias and narrower LOA vs. MDCT. There is good agreement between novice and experts for all 3 TEE methods but better agreement with auto and SA methods as opposed to manual one. Our study supports the use of 3D-TEE as a complementary method to MDCT for aortic annular sizing. The newer auto and SA software, that requires minimal operator intervention, is an easy to use, reliable and reproducible tool for aortic annulus sizing for experienced operators, and especially less experienced ones.

Computed tomographic manifestations of celiac ganglia between hypertensive and non-hypertensive population.

The celiac ganglion (CG) is associated with the sympathetic nervous system (SNS) and plays an important role in the pathogenesis of hypertension. The characteristics of the CG in patients with hypertension remain unknown. The aim of our study was to explore the differences in celiac ganglia (CGs) characteristics between hypertensive and non-hypertensive populations using computed tomography (CT). CGs manifestations on multidetector row CT in 1003 patients with and without hypertension were retrospectively analyzed. The morphological characteristics and CT values of the left CGs were recorded. The CT values of the ipsilateral adrenal gland (AG) and crus of the diaphragm (CD) were also measured. The left CG was located between the left AG and CD, and most CGs were long strips. The frequency of visualization of the left CGs was higher in the hypertension group than in the non-hypertension group (p<.05). There were no significant differences in the maximum diameter, size, and shape ratio of the left CGs between the two groups (p>.05). Except for the left CG in the arterial phase, the CT values of the left CG and AG in the non-hypertensive group were higher than those in the hypertension group (p<.05). The venous phase enhancement of the left CG in the non-hypertension group was significantly higher than that in the hypertension group (p<.05). Our findings reveal that CGs have characteristic manifestations in the hypertensive population. As important targets of the SNS, CGs have the potential to regulate blood pressure.

Multidetector CT-derived tricuspid annulus measurements predict tricuspid regurgitation reduction after transcatheter aortic valve replacement

To use multidetector row computed tomography (MDCT)-derived tricuspid annulus (TA) measurements to identify predictors for tricuspid regurgitation (TR) reduction after transcatheter aortic valve replacement (TAVR), and to investigate the impact of TR change on prognosis. A retrospective, single-centre study was conducted on consecutive patients who underwent TAVR with concomitant baseline mild or more severe TR from April 2012 to April 2022. TA parameters were measured using MDCT. The study comprised 266 patients (mean age 74.2±7.6 years, 147 men) and 45.1% had more than one grade of TR reduction at follow-up. Independent predictors of TR reduction at follow-up were distance between TA centroid and antero-septal commissure (odd ratio [OR] 0.776; 95% confidence interval [CI]: 0.672-0.896, p=0.001), baseline TR of moderate or worse (OR 4.599; 95% CI: 2.193-9.648, p<0.001), systolic pulmonary artery pressure (OR 1.018; 95% CI: 1.002-1.035, p=0.027), age (OR 0.955; 95% CI: 0.920-0.993, p=0.019), and pre-existing atrial fibrillation (OR 0.209; 95% CI: 0.101-0.433, p<0.001). Patients without TR reduction had higher rates of rehospitalisation (hazard ratio [HR] 0.642; 95% CI: 0.413-0.998, p=0.049). The MDCT-derived TA parameter was predictive of TR reduction after TAVR. Persistent TR after TAVR was associated with higher rates of rehospitalisation.

Study of the Intersegmental Veins Between S5 and S8 Based on 3D Reconstruction

BackgroundAnatomic resection (AR) is a surgical method for treating hepatocellular carcinoma, and identifying intersegmental planes between segments 5 (S5) and 8 (S8) remains challenging. This study aims to find reliable intersegmental veins (IVs) between them as anatomical landmarks using 3D reconstruction analysis. MethodsWe retrospectively evaluated 57 patients who underwent multidetector-row CT scans from September 2021 to January 2023. The portal vein watershed of S5 and S8 and hepatic veins were reconstructed using 3D reconstruction analysis software. We counted and analyzed the IVs running within the intersegmental plane between S5 and S8, examined their features, and analyzed the location of the junctions between IVs and middle hepatic veins (MHVs). ResultsAmong the 57 patients, 43 patients (75.4%) had IVs between S5 and S8. Most patients (81.4%) had a single IV joining the MHV, while 13.9% had two IVs, one joining the MHV and the other joining the right hepatic vein (RHV). The majority of IV-MHV junctions were found in the lower part of the MHVs. The most clearly identifiable junctions between the IVs and MHVs occurred slightly below the midpoint of the horizontal planes of the second hepatic portal and the center of the gallbladder bed. ConclusionOur study identified IVs between S5 and S8 in the liver as potential anatomical landmarks during AR for hepatocellular carcinoma surgery. We found three types of IVs and provided insights on how to locate their junctions with MHVs for easier surgical navigation. However, individual anatomical variations must be considered, and preoperative 3D reconstruction and personalized surgical planning are crucial for success. More research with larger sample sizes is needed to validate our findings and establish the clinical significance of these IVs as landmarks for AR.

MCR toolkit: A GPU-based toolkit for multi-channel reconstruction of preclinical and clinical x-ray CT data.

The advancement of x-ray CT into the domains of photon counting spectral imaging and dynamic cardiac and perfusion imaging has created many new challenges and opportunities for clinicians and researchers. To address challenges such as dose constraints and scanning times while capitalizing on opportunities such as multi-contrast imaging and low-dose coronary angiography, these multi-channel imaging applications require a new generation of CT reconstruction tools. These new tools should exploit the relationships between imaging channels during reconstruction to set new image quality standards while serving as a platform for direct translation between the preclinical and clinical domains. We outline and demonstrate a new Multi-Channel Reconstruction (MCR) Toolkit for GPU-based analytical and iterative reconstruction of preclinical and clinical multi-energy and dynamic x-ray CT data. To promote open science, open-source distribution of the Toolkit will coincide with the release of this publication (GPL v3; gitlab.oit.duke.edu/dpc18/mcr-toolkit-public). The MCR Toolkit source code is implemented in C/C++ and NVIDIA's CUDA GPU programming interface, with scripting support from MATLAB and Python. The Toolkit implements matched, separable footprint CT reconstruction operators for projection and backprojection in two geometries: planar, cone-beam CT (CBCT) and 3rd generation, cylindrical multi-detector row CT (MDCT). Analytical reconstruction is performed using filtered backprojection (FBP) for circular CBCT, weighted FBP (WFBP) for helical CBCT, and cone-parallel projection rebinning followed by WFBP for MDCT. Arbitrary combinations of energy and temporal channels are iteratively reconstructed under a generalized multi-channel signal model for joint reconstruction. We solve this generalized model algebraically using the split Bregman optimization method and the BiCGSTAB(l) linear solver interchangeably for both CBCT and MDCT data. Rank-sparse kernel regression (RSKR) and patch-based singular value thresholding (pSVT) are used to regularize the energy and time dimensions, respectively. Under a Gaussian noise model, regularization parameters are estimated automatically from the input data, dramatically reducing algorithm complexity for end users. Multi-GPU parallelization of the reconstruction operators is supported to manage reconstruction times. Denoising with RSKR and pSVT and post-reconstruction material decomposition are illustrated with preclinical and clinical cardiac photon-counting (PC)CT data. A digital MOBY mouse phantom with cardiac motion is used to illustrate single energy (SE), multi-energy (ME), time resolved (TR), and combined multi-energy and time-resolved (METR) helical, CBCT reconstruction. A fixed set of projection data is used across all reconstruction cases to demonstrate the Toolkit's robustness to increasing data dimensionality. Identical reconstruction code is applied to in vivo cardiac PCCT data acquired in a mouse model of atherosclerosis (METR). Clinical cardiac CT reconstruction is illustrated using the XCAT phantom and the DukeSim CT simulator, while dual-source, dual-energy CT reconstruction is illustrated for data acquired with a Siemens Flash scanner. Benchmarking results with NVIDIA RTX 8000 GPU hardware demonstrate 61%-99% efficiency in scaling computation from one to four GPUs for these reconstruction problems. The MCR Toolkit provides a robust solution for temporal and spectral x-ray CT reconstruction problems and was built from the ground up to facilitate translation of CT research and development between preclinical and clinical applications.

Multidetector-row CT features and histopathological analysis of pericardial recesses in dogs.

At the level of pericardial reflections and near the great thoracic vessels, pericardial recesses (PRs) are present, where fluid can collect to increase the pericardial reserve volume. To date, these structures have not been described in vivo in veterinary patients. The aims of this observational and descriptive study were to describe the location and appearance of PRs in dogs, as seen with multidetector-row CT (MDCT), and to develop a dedicated imaging technique for their best visualization. Dogs who underwent MDCT examination of the whole body were included in the study and CT data were retrospectively evaluated. Dogs with any thoracic abnormality were excluded. MDCT analysis of the PR's was compared with the pathological features of PRs. PRs were identified as fluid-attenuating (10-30 HU), non-enhancing structures showing varied appearance. Two types of PRs were identified at the level of the transverse sinus of the pericardium and classified on the basis of their anatomic location: the aortic recess and the pulmonic recess. A third pericardial fluid-containing structure was seen in a little number of cases, at the level of the termination of the caudal vena cava into the right atrium. A dorsal, slight oblique multiplanar section through the aortic bulb resulted the best technique for visualization of all the recesses. Anatomo-pathological evaluation confirmed the location and the presence of pocket-like reflections of the pericardium identified with 3D-CT models. Knowledge of the CT appearance of the pericardial recesses is necessary in order to avoid their misinterpretation and subsequent unnecessary invasive investigations.

Number of computed tomography scanners and regional disparities based on population and medical resources in Japan.

This study aimed to discover the associations between the number of computed tomography (CT) scanners and the population, as well as number of medical resources to identify regional disparities in Japan. The number of CT scanners was tabulated for each detector row of CT scanners for hospitals and clinics in each prefecture. The number of CT scanners, patients, medical doctors, radiological technologists, facilities, and beds per 100,000 population was compared. Additionally, the number of hospitals with ≥ 200 beds and multidetector-row CT scanners with ≥ 64 rows were tabulated, and their ratios were calculated. Medical institutions in Japan have installed 14,595 scanners. CT scanners per 100,000 population were the highest in Kochi Prefecture, although the number of CT scanners in hospitals was the highest in Tokyo Prefecture. Multivariate analysis revealed the number of radiological technologists (β coefficient: 0.49; P = 0.03), facilities (β coefficient: 0.12; P < 0.01) and beds (β coefficient: 0.46; P < 0.01) as independent factors for the number of CT scanners. Prefectures with a high proportion of hospitals with ≥ 200 beds also had a relatively high proportion of CT scanners with ≥ 64 rows (P < 0.01). Our survey revealed an association between regional disparities in the number of CT scanners in Japan, the population, and number of medical resources. A positive correlation was found between hospital size and number of CT scanners with ≥ 64 rows.

AB-453070-1 NOVEL INSIGHTS OF GANGLIONATED PLEXI ABLATION FOR ATRIAL FIBRILLATION: FINDINGS FROM RECURRENCE CASES

Epicardial adipose tissue (EAT) containing ganglionated plexi (GP) plays an important role in the presence of atrial fibrillation (AF), but the effect of GP ablation remains controversial. This study aimed to investigate whether the effect of GP ablation on eliminated vagal response and EAT volume persisted after ablation. In 17 patients (70.7± 6.5years, 11 males, 13 persistent AF) who had AF recurrence after 1st pulmonary vein isolation (PVI) and GP ablation, high-frequency stimulation (HFS) at 5 major left atrial (LA)-GP sites (i.e., superior left, inferior left, anterior right, inferior right, and Marshall tract GP) was again performed to detect a vagal response at the 2nd session. The 320-row multidetector CT was performed within 2 weeks before each ablation. The acquired CT images were transferred to a workstation. EAT was defined as -50 to -200 Hounsfield units. The CT-derived EAT volume (around the whole heart and LA) at the 1st session was compared to that at the 2nd session. Despite the elimination of vagal response in all 5 LA-GP sites by GP ablation at the 1st ablation, the percentage of patients in whom a vagal response was elicited was significantly increased in IRGP at 2nd session compared to at 1st session (IRGP; 1st, 42% [7/17] vs. 2nd, 76% [13/17], P=0.009), and there was no significant difference in the other GP sites between initial ablation and the 2nd session (Marshal tract GP; 53% [9/17] vs. 47% [8/17], P=0.79, SLGP; 65% [11/17] vs. 41% [7/17], P=0.16, ILGP; 24% [4/17] vs. 53% [9/17], P=0.06, ARGP; 82% [14/17] vs. 65% [11/17], P=0.27). There was no significant difference in the maximum R-R intervals recorded during HFS between 1st ablation and the 2nd session in all GP sites (Marshal tract GP; 1296 [792-1806] vs. 1020 [772-1294] ms, P=0.12, SLGP; 1064 [760-1560] vs. 1244 [738-1444] ms, P=0.47, ILGP; 1000 [930-1472] vs. 1124 [748-1412] ms, P=0.92, ARGP; 1872 [1128-2880] vs. 1284 [960-1886] ms, P=0.24, IRGP; 1064 [808-1424] vs. 1280 [886-1736] ms, P=0.34). EAT volume increased significantly from the 1st ablation to the 2nd session (whole EAT: 143±78 ml vs. 165±94 ml; P=0.029, LA-EAT: 38± 21 ml vs. 46±28 ml; P=0.007). The elimination of vagal response by GP ablation did not persist and EAT volume increased in AF recurrence cases, suggesting that the effect of GP ablation is transient and GP ablation does not have any favorable effect on EAT in those cases.

Gumbel distribution-based technique enables quantitative comparison between streak metal artifacts of multidetector row CT and cone-beam CT: a phantom study

Cone-beam computed tomography (CBCT), derived from multidetector row CT (MDCT), has a high spatial resolution and has recently been applied to various organs. One of the severe limitations common to CBCT and MDCT is metal artifacts. In particular, streak metal artifacts (SMAs) between multiple metal materials often hinder diagnosis. However, no studies have quantitatively compared the strength of SMAs in MDCT and CBCT. Nomura et al. reported an evaluation method specialized in SMAs of CBCT using the Gumbel distribution (GD), which can also be applied to SMAs of MDCT (Oral Surg Oral Med Oral Pathol Oral Radiol 131: 494-502,2021, https://doi.org/10.1016/J.OOOO.2020.08.031 ). This study aimed to quantitatively compare SMAs occurring between titanium materials on MDCT and CBCT images using the GD-based method. The SMAs were investigated as follows: A hydroxyapatite block was sandwiched between two titanium rods to generate an SMA. They were placed in an acrylic phantom, simulating a human head, and scanned using an MDCT scanner and two CBCT scanners. The obtained images were analyzed using Gumbel plots and location parameters, and the SMA strength was calculated. The results showed that the SMAs on the MDCT images were significantly weaker than those on the CBCT images. In the CBCT scans, a smaller volume CT dose indexvalue caused stronger SMAs. These results indicate that MDCT is more advantageous than CBCT in terms of SMA reduction when bone morphology between titanium materials must be evaluated. The characteristic should be considered in clinical cases.

Image-quality characteristics in the longitudinal direction from different image-reconstruction algorithms during single-rotation volume acquisition on head computed tomography: A phantom study

A multi detector computed tomography (CT) scanner with wide-area coverage enables whole-brain volumetric scanning in a single rotation. To investigate variations in image-quality characteristics in the longitudinal direction for different image-reconstruction algorithms and strengths with phantoms. Single-rotation volume scans were performed on a 320-row multidetector CT volume scanner using three types of phantoms. Tube current was set to 200mA (standard dose) and 50mA (low dose). All images were reconstructed with filtered back projection (FBP), mild and strong levels with hybrid iterative reconstruction (HIR), and model-based IR (MBIR). Computed tomography numbers, image noise, noise power spectrum (NPS), task-based transfer function (TTF), and visual spatial resolution were used to evaluate uniformity of image quality in the longitudinal direction (Z-axis). The MBIR images showed smaller variation in CT numbers in the Z-axis. The difference in the highest and lowest CT numbers was smaller (5.0 Hounsfield units [HU]) for MBIR than for FBP (6.6 HU) and HIR (6.8 HU). The variations in image noise were the smallest for strong MBIR and the largest for FBP. The low-frequency component at NPS0.2 was lower for strong MBIR than for other algorithms. The high-frequency component at NPS0.8 was low in all reconstructions. For MBIR, the image resolution and TTFs were higher in the outer portion than in the center. Model-based IR is the optimal image-reconstruction algorithm for single-volume scan of spherical subjects owing to its high in-plane resolution and uniformity of CT numbers, image noise, and NPS in the Z-axis.

Anterior versus posterior radical antegrade modular pancreatosplenectomy for pancreatic body and tail cancer: an inverse probability of treatment weighting with survival analysis.

Radical antegrade modular pancreatosplenectomy (RAMPS) is a standard procedure for patients with pancreatic body and tail cancer. There are two types of RAMPS: anterior and posterior, but their indications and surgical outcomes remain unclear. We compared the surgical outcomes, postoperative course, and prognosis between anterior and posterior RAMPS. Between 2007 and 2020, 105 consecutive patients who underwent RAMPS for pancreatic body and tail cancers were divided into an anterior RAMPS group (n = 30) and a posterior RAMPS group (n = 75). To adjust for differences in preoperative characteristics and intraoperative procedures, an inverse probability of treatment weighting (IPTW) analysis was done, using propensity scores. After IPTW adjustment, the postoperative body temperature of the posterior RAMPS group and the amount of drain discharge in the anterior RAMPS group were significantly lower, from postoperative days (PODs) 1 to 3, but there were no differences in postoperative complications, recurrence patterns, or prognosis between the two groups. Regarding the diagnostic ability of multidetector-row computed tomography (MD-CT) for direct tumor involvement of the left adrenal gland, the sensitivity and specificity were 100% and 90.0%, respectively. Pancreatic body and tail cancer without apparent preoperative direct tumor involvement of the left adrenal gland on MD-CT may be sufficient indication for anterior RAMPS.

Assessment of Utility of Computed Tomography Pulmonary Angiography in Pulmonary Embolism

Background: Among all the available diagnostic tools, computed tomography (CT) is the preferred diagnostic tool for clinically suspected pulmonary embolism (PE) cases. Further, with the development of multi–detector row CT (MDCT) technology, previous limitations of CT have been overcome effectively. For patients with clinical suspicion of PE, MDCT pulmonary angiography has become the first line of modality for the diagnosis. Aims and Objectives: To evaluate various common observations of CT pulmonary angiography (CTPA) in suspected cases of PE that could accurately determine the choice of management. Materials and Methods: Fifty patients with clinically suspected PE referred to the department of Radiodiagnosis for CTPA from various departments were studied in the cross-sectional study. CT images were obtained with a SIEMENS 64-slice multi-detector CT scanner (somatom definition AS). Images were reconstructed into 3D, axial, coronal, sagittal maximum intensity projection sections, and volume rendering techniques. The axial as well as reformatted coronal and sagittal images were evaluated. Results: The incidence of PE was 52%. The incidence of PE was highest in patients older than 60 years (30.8%) and males (30.3%; p=0.662). The most common symptoms evoking a suspicion of pulmonary embolism were dyspnea (69.2%), followed by chest pain (15.4%), cough (11.5%), and hemoptysis (3.8%). Out of 26 patients who had PE, 61.5% had right ventricular enlargement. DVT (23.1%) was the most common past history. The majority of the patients had thrombus in the right main pulmonary artery (21.1 %), followed by the left main pulmonary artery (19.3 %). Conclusion: In clinically suspected cases of PE, MDCT pulmonary angiography was a useful diagnostic tool. CTPA is the modality of choice for its rapid, minimally invasive, and well-tolerated nature.

Secondary Budd-Chiari syndrome occurred after adjuvant radiotherapy for perihilar cholangiocarcinoma: a case report

BackgroundBudd–Chiari syndrome (BCS) is a rare vascular disorder of the liver, and acute and secondary BCS is even rarer.Case presentationA 62-year-old man with perihilar cholangiocarcinoma of Bismuth type IIIa underwent right hemi-hepatectomy with caudate lobectomy and pancreatoduodenectomy. Adjuvant chemoradiotherapy was performed due to a positive hepatic ductal margin. Subsequently, the disease passed without recurrence. The patient visited for acute onset abdominal pain at the 32nd postoperative month. Multidetector-row computed tomography (MDCT) showed stenosis of the left hepatic vein (LHV) root, which was the irradiated field, and thrombotic occlusion of the LHV. The patient was diagnosed with acute BCS caused by adjuvant radiotherapy. Although anticoagulation therapy was performed, the patient complained of sudden upper abdominal pain again. MDCT showed an enlarged LHV thrombus and hepatomegaly. The patient was diagnosed with exacerbated acute BCS, and stenting for the stenotic LHV root was performed with a bare stent. Although stenting for the LHV root was very effective, restenosis occurred twice due to thrombus in the existing stent, so re-stenting was performed twice. The subsequent clinical course was acceptable without recurrence or restenosis of the LHV root as of 6 months after the last stenting using a stent graft.ConclusionAlthough no case of BCS caused by radiotherapy has yet been reported, the present case showed that late side effect of radiotherapy can cause hepatic vein stenosis and secondary BCS.

Radiation exposure in cardiac computed tomography imaging in Mie prefecture in 2021

PurposeSeveral effective radiation dose reduction methods have been developed for coronary computed tomography angiography (CTA); however, their use in daily clinical practice remains unknown. We aimed to investigate radiation exposure and the utilization of dose-saving strategies for coronary CTA in hospitals in Mie Prefecture, Japan.Materials and methodsImage acquisition details and dose reports of 30 consecutive cardiac CT examinations performed in 2021 were obtained from 18 hospitals. The inclusion criteria were patients aged 20–80 years who weighed 50–70 kg and underwent coronary CTA using ≥ 64-row multidetector CT. The doses for the overall cardiac CT examination and coronary CTA were analyzed using the dose-length product (DLP) and CT dose index (CTDIvol), respectively. Multivariate analysis was performed to determine independent predictors that affect the radiation dose in coronary CTA.ResultsThe median DLP of cardiac CT was 774 (interquartile range [IQR]: 538–1119) mGy*cm, and the median CTDIvol of coronary CTA was 33 (IQR: 25–48) mGy. The 75th percentile values of DLP for cardiac CT and that of CTDIvol for coronary CTA were slightly lower than the values recorded in the Japan Diagnostic Reference Level (DRLs) 2020 report (1285 mGy*cm and 66.4 mGy, respectively) but were substantially higher than those reported in a previous large international dose survey (402 mGy*cm and 24 mGy, respectively). Iterative reconstruction was performed during all examinations. Only six hospitals (33%) used a low tube potential (≤ 100 kVp), and nine hospitals (50%) used electrocardiogram-triggered prospective scanning. Multivariate analysis revealed low heart rate, low tube potential, and use of electrocardiogram-triggered prospective scanning as independent predictors of CTDIvol ≤ 24 mGy (p < 0.001, respectively).ConclusionAs of 2021, low tube potential and prospective scanning are underutilized, whereas iterative reconstruction is used in every coronary CTA in Mie Prefecture. Further efforts to optimize the radiation exposure from cardiac CT scans are necessary.

Deep Learning Reconstruction to Improve the Quality of MR Imaging: Evaluating the Best Sequence for T-category Assessment in Non-small Cell Lung Cancer Patients.

Deep learning reconstruction (DLR) has been recommended as useful for improving image quality. Moreover, compressed sensing (CS) or DLR has been proposed as useful for improving temporal resolution and image quality on MR sequences in different body fields. However, there have been no reports regarding the utility of DLR for image quality and T-factor assessment improvements on T2-weighted imaging (T2WI), short inversion time (TI) inversion recovery (STIR) imaging, and unenhanced- and contrast-enhanced (CE) 3D fast spoiled gradient echo (GRE) imaging with and without CS in comparison with thin-section multidetector-row CT (MDCT) for non-small cell lung cancer (NSCLC) patients. The purpose of this study was to determine the utility of DLR for improving image quality and the appropriate sequence for T-category assessment for NSCLC patients. As subjects for this study, 213 pathologically diagnosed NSCLC patients who underwent thin-section MDCT and MR imaging as well as T-factor diagnosis were retrospectively enrolled. SNR of each tumor was calculated and compared by paired t-test for each sequence with and without DLR. T-factor for each patient was assessed with thin-section MDCT and all MR sequences, and the accuracy for T-factor diagnosis was compared among all sequences and thin-section CT by means of McNemar's test. SNRs of T2WI, STIR imaging, unenhanced thin-section Quick 3D imaging, and CE-thin-section Quick 3D imaging with DLR were significantly higher than SNRs of those without DLR (P < 0.05). Diagnostic accuracy of STIR imaging and CE-thick- or thin-section Quick 3D imaging was significantly higher than that of thin-section CT, T2WI, and unenhanced thick- or thin-section Quick 3D imaging (P < 0.05). DLR is thus considered useful for image quality improvement on MR imaging. STIR imaging and CE-Quick 3D imaging with or without CS were validated as appropriate MR sequences for T-factor evaluation in NSCLC patients.

Diagnostic accuracy and safety of CT-guided Lung and Mediastinal biopsies: a single center study

Background: Computed tomography (CT)-guided percutaneous needle biopsy plays a critical role in establishing tissue diagnosis of malignancy, guiding staging, and planning treatment for pulmonary abnormalities. Aim: To determine diagnostic accuracy and incidence of complications occurring after taking percutaneous CT-guided lung biopsy. Methodology: In this retrospective study, we evaluated 44 CT-guided chest biopsies (31 lung biopsies and 13 mediastinal biopsies) performed at our institution between September 2019 and March 2022. A coaxial core biopsy needle technique was used for all CT-guided biopsies. All procedures were performed by an experienced consultant interventional radiologist using using a commercially available helical multidetector-row CT scanner. Results: There were 29 men and 15 women among the 44 patients, ranging in age from 25 to 65 years. We found technical accuracy (described as tip of core biopsy needle within centre of lesion) of 100% (44/44) and diagnostic accuracy (described as adequate sample for histological assessment) of 97.7% (43/44) in our study. The overall incidence of complications during the procedure were recorded including pneumothorax (n = 2, 4.5%),pulmonary hemorrhage (n = 1, 2.3%), hemoptysis (n = 1, 2.3%). Conclusion: CT-guided chest biopsy is a safe procedure and has good diagnostic accuracy. However, radiologists approaching such interventional procedures must be experienced and well trained so that there are less chances of developing complications after the procedure. Practical implications: We suggest physicians performing chest biopsies to adopt better techniques and use shortest path to the lesion during needle insertion. Although CT-guided chest biopsy has fewer chances of complications, however, interventional radiologists should be conscious of potential complications. Keywords: CT-guided biopsy; Percutaneous biopsy; Imaging, Interventional radiology; Diagnosis.