Multiparametric MRI Features of Plasmacytoid Urothelial Carcinoma of the Urinary Bladder.

Objective: Plasmacytoid urothelial carcinoma (PUC) is a rare aggressive bladder cancer subtype with limited imaging data owing to its low incidence. This study aimed to report the characteristic features of PUC on multiparametric MRI (mpMRI).

Materials And Methods: We retrospectively analyzed 13 patients with histologically confirmed PUC who underwent preoperative mpMRI between January 2019 and August 2024.

Preoperative Computed Tomography-Based Prediction and Patterns of Lymph Node Metastasis in Renal Pelvis and Ureteral Urothelial Carcinomas.

The accurate preoperative prediction of lymph node (LN) metastasis is essential to optimizing surgical management in renal pelvis urothelial carcinoma (RPUC) and ureteral urothelial carcinoma (UUC). This study evaluates the predictive value of preoperative computed tomography (CT) findings in detecting LN metastasis and determining primary metastatic LN location based on the tumor site. This retrospective study included 48 RPUC and 97 UUC patients who underwent surgery with lymph node dissection (LND) between 2005 and 2023.

Assessing Image Quality in Multiplexed Sensitivity-Encoding Diffusion-Weighted Imaging with Deep Learning-Based Reconstruction in Bladder MRI.

This study compared the image quality of conventional multiplexed sensitivity-encoding diffusion-weighted imaging (MUSE-DWI) and deep learning MUSE-DWI with that of vendor-specific deep learning (DL) reconstruction applied to bladder MRI. This retrospective study included 57 patients with a visible bladder mass. DWI images were reconstructed using a vendor-provided DL algorithm (AIR Recon DL; GE Healthcare)-a CNN-based algorithm that reduces noise and enhances image quality-applied here as a prototype for MUSE-DWI.

Development and multicenter validation of deep convolutional neural network-based detection of colorectal cancer on abdominal CT.

Objectives: This study aims to develop computer-aided detection (CAD) for colorectal cancer (CRC) using abdominal CT based on a deep convolutional neural network.

Methods: This retrospective study included consecutive patients with colorectal adenocarcinoma who underwent abdominal CT before CRC resection surgery (training set = 379, test set = 103). We customized the 3D U-Net of nnU-Net (CUNET) for CRC detection, which was trained with fivefold cross-validation using annotated CT images.

Machine Learning-Based Magnetic Resonance Radiomics Analysis for Predicting Low- and High-Grade Clear Cell Renal Cell Carcinoma.

Purpose: To explore whether high- and low-grade clear cell renal cell carcinomas (ccRCC) can be distinguished using radiomics features extracted from magnetic resonance imaging.

Methods: In this retrospective study, 154 patients with pathologically proven clear ccRCC underwent contrast-enhanced 3 T magnetic resonance imaging and were assigned to the development (n = 122) and test (n = 32) cohorts in a temporal-split setup. A total of 834 radiomics features were extracted from whole-tumor volumes using 3 sequences: T2-weighted imaging (T2WI), diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging.

Development and validation of CT‑based radiomics model of PET-negative residual CT masses: a potential biomarker for predicting relapse‑free survival in non-Hodgkin lymphoma patients showing complete metabolic response.

Purpose: PET-negative residual CT masses (PnRCMs) are usually dismissed as nonviable post-treatment lesions in non-Hodgkin lymphoma (NHL) patients showing complete metabolic response (CMR). We aimed to develop and validate computed tomography (CT)-based radiomics model of PET-negative residual CT mass (PnRCM) for predicting relapse-free survival (RFS) in NHL patients showing CMR.

Methods: A total of 224 patients who showed CMR after completing first-line chemotherapy for PET-avid NHL were recruited for model development.

Radiomics Analysis of Magnetic Resonance Proton Density Fat Fraction for the Diagnosis of Hepatic Steatosis in Patients With Suspected Non-Alcoholic Fatty Liver Disease.

Background: This study aimed to assess the diagnostic feasibility of radiomics analysis based on magnetic resonance (MR)-proton density fat fraction (PDFF) for grading hepatic steatosis in patients with suspected non-alcoholic fatty liver disease (NAFLD).

Methods: This retrospective study included 106 patients with suspected NAFLD who underwent a hepatic parenchymal biopsy. MR-PDFF and MR spectroscopy were performed on all patients using a 3.

Comparison between biparametric and multiparametric MRI in predicting muscle invasion by bladder cancer based on the VI-RADS.

This study aimed to compare the diagnostic validity of biparametric magnetic resonance imaging (bpMRI) with that of multiparametric MRI (mpMRI) based on the Vesicle Imaging-Reporting and Data System (VI-RADS) in predicting muscle invasion by bladder cancer (BCa). We retrospectively examined 357 patients with an initial diagnosis of BCa who underwent preoperative MRI; 257 and 100 patients underwent mpMRI and bpMRI, respectively. Two urogenital radiologists evaluated all bpMRI and mpMRI scans using VI-RADS, and the diagnostic validity of VI-RADS for predicting muscle invasion by BCa was analyzed based on histopathology of the first and/or second transurethral resection of bladder tumors and radical cystectomy.

Metastatic Renal Cell Carcinoma Manifesting as a Gastric Polyp on CT: A Case Report and Literature Review.

Gastric metastasis from renal cell carcinoma (RCC) is extremely rare, occurring in 0.2% of all RCC cases. Owing to its low prevalence, metachronous gastric metastasis from RCC may be underdiagnosed, and the imaging findings have not been well-established.

Dual-Layer Spectral CT of Pancreas Ductal Adenocarcinoma: Can Virtual Monoenergetic Images of the Portal Venous Phase Be an Alternative to the Pancreatic-Phase Scan?

Objectives: To determine the performance of virtual monoenergetic images (VMIs) of the portal venous phase (PVP) compared with the pancreatic-phase image for pancreatic ductal adenocarcinoma (PDAC) evaluation.

Materials And Methods: This retrospective study enrolled 64 patients with PDAC who underwent pancreatic CT with dual-layer spectral CT between February 2018 and January 2020. A polychromatic pancreatic-phase image and VMIs at 40 (VMI), 55 (VMI), and 70 keV (VMI) of the PVP were generated.

Hepatocellular carcinoma pathologic grade prediction using radiomics and machine learning models of gadoxetic acid-enhanced MRI: a two-center study.

Purpose: To develop a radiomics-based hepatocellular carcinoma (HCC) grade classifier model based on data from gadoxetic acid-enhanced MRI.

Methods: This retrospective study included 137 patients who underwent hepatectomy for a single HCC and gadoxetic acid-enhanced MRI within 60 days before surgery. HCC grade was categorized as low or high (modified Edmondson-Steiner grade I-II vs.

Computer-aided hepatocellular carcinoma detection on the hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging using a convolutional neural network: Feasibility evaluation with multi-sequence data.

Background And Objectives: Diagnosis of hepatocellular carcinoma (HCC) on liver MRI needs analysis of multi-sequence images. However, developing computer-aided detection (CAD) for every single sequence requires considerable time and labor for image segmentation. Therefore, we developed CAD for HCC on the hepatobiliary phase (HBP) of gadoxetic acid-enhanced magnetic resonance imaging (MRI) using a convolutional neural network (CNN) and evaluated its feasibility on multi-sequence, multi-unit, and multi-center data.

Diagnostic Feasibility of Magnetic Resonance Elastography Radiomics Analysis for the Assessment of Hepatic Fibrosis in Patients With Nonalcoholic Fatty Liver Disease.

Objective: The aim of the study was to investigate the diagnostic feasibility of radiomics analysis using magnetic resonance elastography (MRE) to assess hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

Methods: One hundred patients with suspected NAFLD were retrospectively enrolled. All patients underwent a liver parenchymal biopsy.

Ectopic lesions in the abdomen and pelvis: a multimodality pictorial review.

Various ectopic lesions occur in the abdomen and pelvis and affect multiple organs including liver, gallbladder, pancreas, spleen, and organs of the genitourinary system. Ectopic organs may be present outside their normal positions, or ectopic tissues may develop while the original organ exists in its normal position. Both benign and malignant lesions can occur in ectopic organs and tissues.

Accuracy of MRI for predicting anterior peritoneal reflection involvement in locally advanced rectal cancer: a comparison with operative findings.

Purpose: To assess the diagnostic accuracy of preoperative rectal MRI for anterior peritoneal reflection (APR) involvement in rectal cancer through comparison with the surgeon's operative findings.

Methods: This retrospective study was approved by the institutional review board; informed consent was waived. We enrolled 55 consecutive patients with suspected locally advanced mid-to-upper rectal cancer.

Active Learning for Efficient Segmentation of Liver with Convolutional Neural Network-Corrected Labeling in Magnetic Resonance Imaging-Derived Proton Density Fat Fraction.

This study aimed to propose an efficient method for self-automated segmentation of the liver using magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) through deep active learning. We developed an active learning framework for liver segmentation using labeled and unlabeled data in MRI-PDFF. A total of 77 liver samples on MRI-PDFF were obtained from patients with nonalcoholic fatty liver disease.

Role of magnetic resonance imaging in tumor staging and follow-up for bladder cancer.

Urothelial carcinoma of the bladder is a common urologic malignancy. Complex factors, such as local stage, tumor grade, biologic potential, and various conditions, can affect the treatment strategy for bladder cancer. However, the local stage-in particular, the presence or absence of muscle invasion-significantly influences decisions regarding treatment strategy.

How to accurately measure the distance from the anal verge to rectal cancer on MRI: a prospective study using anal verge markers.

Purpose: To determine an accurate method for localizing rectal cancer using the distance from the anal verge on preoperative MRI.

Methods: This prospective study included 50 patients scheduled for MRI evaluation of rectal cancer. After rectal filling with gel, MRI was performed with two markers attached at the anal verge.

Efficacy of ZOOMit coronal diffusion-weighted imaging and MR texture analysis for differentiating between benign and malignant distal bile duct strictures.

Purpose: To investigate the diagnostic efficacy of ZOOMit coronal diffusion-weighted imaging (Z-DWI) and MR texture analysis (MRTA) for differentiating benign from malignant distal bile duct strictures.

Methods: We retrospectively enrolled a total of 71 patients with distal bile duct stricture who underwent magnetic resonance cholangiopancreatography (MRCP). For quantitative analysis, the average apparent diffusion coefficient (ADC) value at suspected stricture sites was assessed on both Z-DWI and conventional DWI (C-DWI).

Ectopic Prostatic Tissue in the Right Paracolic Gutter: A Case Report.

Ectopic prostatic tissue (EPT) is fairly uncommon; however, when reported, it is most often found in the male genitourinary tract. Since extragenitourinary EPT is very rare, it is extremely difficult to properly diagnose preoperatively.(1-3) This article describes a unique case of EPT found in the right paracolic gutter.

Predicting cannulation difficulty in endoscopic retrograde cholangiopancreatography using CT image findings: a decision-tree analysis.

Background: Difficult cannulation during endoscopic retrograde cholangiopancreatography (ERCP) is associated with increased complications; therefore, its prediction is important.

Purpose: To identify radiologic risk factors of difficult cannulation during ERCP based on computed tomography (CT) findings and to develop a predictive model for a difficult cannulation.

Material And Methods: A total of 171 patients with native papilla who underwent both enhanced CT and ERCP were recruited.

Effects of gadoxetic acid on image quality of arterial multiphase magnetic resonance imaging of liver: comparison study with gadoteric acid-enhanced MRI.

Purpose: To compare the effects of gadoxetic acid and gadoteric acid on the image quality of single-breath-hold, triple (first, second, and third) arterial hepatic magnetic resonance imaging (MRI).

Methods: Two hundred and eleven patients were divided into two groups according to the contrast materials used (gadoxetic acid, 108 patients and gadoteric acid, 103 patients). All 3.