Corona enhancement can substitute enhancing capsule in the imaging diagnosis of small (≤ 3 cm) HCCs on gadoxetic acid-enhanced MRI.

Objectives: This study aimed to elucidate the relationship between gadoxetic acid-enhanced magnetic resonance imaging (MRI) features-enhancing capsule, corona enhancement or hypointense rim-observed in hepatocellular carcinomas (HCCs).

Methods: Of the HCCs surgically confirmed during a 5-year period (2013-2017), ≤ 3-cm lesions (n = 83) in 78 patients were evaluated. Presence of corona enhancement and enhancing capsule on multiphasic dynamic imaging and presence of hypointense rim on hepatobiliary phase imaging were determined retrospectively by two independent observers.

A radiomics-based model for predicting prognosis of locally advanced gastric cancer in the preoperative setting.

This study aims to evaluate the performance of a radiomic signature-based model for predicting recurrence-free survival (RFS) of locally advanced gastric cancer (LAGC) using preoperative contrast-enhanced CT. This retrospective study included a training cohort (349 patients) and an external validation cohort (61 patients) who underwent curative resection for LAGC in 2010 without neoadjuvant therapies. Available preoperative clinical factors, including conventional CT staging and endoscopic data, and 438 radiomic features from the preoperative CT were obtained.

Texture Analysis of Hepatocellular Carcinoma on Magnetic Resonance Imaging: Assessment for Performance in Predicting Histopathologic Grade.

Objective: The aim of the study was to evaluate the performance of texture analysis for discriminating the histopathological grade of hepatocellular carcinoma (HCC) on magnetic resonance imaging.

Methods: Preoperative magnetic resonance imaging data from 101 patients with HCC, including T2-weighted imaging, arterial phase, and apparent diffusion coefficient mapping, were analyzed using texture analysis software (TexRAD). Differences among the histological groups were analyzed using the Mann-Whitney U test.

Sclerotic changes of cavernous hemangioma in the cirrhotic liver: long-term follow-up using dynamic contrast-enhanced computed tomography.

Purpose: To determine the intra- and extralesional factors that predict sclerotic degeneration of hepatic hemangiomas in the cirrhotic liver on long-term follow-up computed tomography (CT) examinations.

Materials And Methods: Fifty-seven hepatic hemangiomas (> 5 mm in diameter) in 41 cirrhotic patients, recruited over a 5-year period (January 2005-December 2009), were subjected to CT to determine which factors predict sclerotic contraction or degeneration in hemangiomas. Prior and follow-up CT examinations (from 2000 to 2018) were included to observe time-related changes.

Subtraction Images From Portal Venous Phase Gadoxetic Acid-Enhanced MRI for Observing Washout and Enhancing Capsule Features in LI-RADS Version 2018.

The purpose of this study is to validate the use of subtraction images derived from gadoxetic acid-enhanced MRI for observation of washout and enhancing capsule in the diagnosis of hepatocellular carcinoma (HCC). For 120 histologically verified HCCs in 115 high-risk patients, the presence of washout and enhancing capsule in the portal venous phase (PVP) on conventional MR images with and without corresponding subtraction images was determined by two independent observers. The incremental value of subtraction imaging in upgrading the categories outlined in the Liver Imaging Reporting and Data System (LI-RADS) version 2018 for the diagnosis of HCC was analyzed for different subgroups of patients classified on the basis of lesion size (< 10 mm, 10-19 mm, ≥ 20 mm), unenhanced T1-weighted signal intensity, and arterial phase hyperenhancement (APHE) of the lesions.

Apparent diffusion coefficient of hepatocellular carcinoma on diffusion-weighted imaging: Histopathologic tumor grade versus arterial vascularity during dynamic magnetic resonance imaging.

Objectives: Apparent diffusion coefficient (ADC) has been suggested to reflect the tumor grades of hepatocellular carcinomas (HCCs); i.e., it can be used as a biomarker to predict the patients' prognosis.

Serous Cystic Neoplasms of the Pancreas: Endoscopic Ultrasonographic Versus Computed Tomography and Magnetic Resonance Imaging Features of Surgically Removed Masses.

Our purpose was to assess the endoscopic ultrasonography (EUS) features of serous cystic neoplasms (SCNs) of the pancreas in determining the surgical removal compared with computed tomography (CT) and magnetic resonance imaging (MRI) features. For 33 consecutive patients with 34 surgically confirmed SCNs over the past 11 years, preoperative EUS features were compared with those of CT and MRI (CT&MRI). Besides the lesion size and location, a retrospective analysis of the various imaging features was performed by 2 observers to understand the characteristics that determine the need for surgical intervention in terms of multiplicity of locules, calcification, mural thickening, mural nodules, ductal communication, and main pancreatic duct dilatation in addition to the gross morphologic type: microcystic, macrocystic (>1 cm), mixed, or solid.

Hepatic cavernous hemangiomas: long-term (> 5 years) follow-up changes on contrast-enhanced dynamic computed tomography or magnetic resonance imaging and determinant factors of the size change.

Purpose: To investigate the very long-term (> 5 years) follow-up changes of hepatic cavernous hemangiomas and to evaluate possible determinant factors for the changes.

Materials And Methods: Among 1115 consecutive patients suspected of having hepatic hemangiomas based on imaging features, 101 patients with comparable computed tomography or magnetic resonance imaging data during a 5-year follow-up interval in the Picture Archiving and Communication System were analyzed. Two radiologists independently determined the largest dimension of each lesion on axial images.

Prediction of pancreatic fistula after pancreatoduodenectomy by preoperative dynamic CT and fecal elastase-1 levels.

Objective: To validate preoperative dynamic CT and fecal elastase-1 level in predicting the development of pancreatic fistulae after pancreatoduodenectomy.

Materials And Methods: For 146 consecutive patients, CT attenuation values of the nontumorous pancreatic parenchyma were retrospectively measured on precontrast, arterial and equilibrium phase images for calculation of enhancement ratios. CT enhancement ratios and preoperative fecal elastase-1 levels were correlated with the development of pancreatic fistulae using independent t-test, logistic regression models, ROC analysis, Youden method and tree analysis.

Optimization of Split-Bolus CT Urography: Effect of Differences in Allocation of Contrast Medium and Prolongation of Imaging Delay.

Objective: The purpose of this study was to find the optimal allocation ratio of contrast medium (CM) in split-bolus CT urography (CTU) and to investigate the effect of increased imaging delays for synchronous nephrographic-excretory phase imaging.

Subjects And Methods: One hundred ninety-two patients were randomly assigned to one of three protocols with different allocation ratios of CM: group A, 30% of CM at first bolus and 70% of CM at second bolus; group B, 70% and 30%; or group C, 50% and 50%. Saline (250 mL) was administered after the first CM bolus.

Multidetector CT findings of histopathologically proven peritoneal tuberculous cold abscesses.

Purpose: To evaluate the characteristic multidetector CT findings of peritoneal tuberculous (TB) cold abscesses.

Patients And Methods: The morphological characteristics of 48 peritoneal TB cold abscesses in 29 patients (male:female = 13:16; age range 16-75 years) were retrospectively evaluated. TB infection was histologically proven by acid fast bacilli (AFB) smear or culture, TB-polymerase chain reaction (PCR), or histopathological specimen diagnosis.

Feasibility of 10-Minute Delayed Hepatocyte Phase Imaging Using a 30° Flip Angle in Gd-EOB-DTPA-Enhanced Liver MRI for the Detection of Hepatocellular Carcinoma in Patients with Chronic Hepatitis or Cirrhosis.

Objectives: To compare 10-minute (min) delayed hepatocyte phase imaging (HPI) using a 30° flip angle (FA) (10m-FA30) and 20-min delayed HPI using a 10° FA (20m-FA10) or 30° FA (20m-FA30) in Gd-EOB-DTPA-enhanced MRI in patients with chronic hepatitis or cirrhosis, in terms of lesion-to-liver contrast-to-noise ratio (CNR) for hepatocellular carcinoma (HCC) and detection sensitivity for focal hepatic lesions (FHLs).

Materials And Methods: One hundred and four patients with 168 HCCs and 55 benign FHLs who underwent Gd-EOB-DTPA-enhanced MRI with 10m-FA30, 20m-FA10, and 20m-FA30 were enrolled. Patients were divided into two groups according to the Child-Pugh classification: group A with chronic hepatitis or Child-Pugh A cirrhosis and group B with Child-Pugh B or C cirrhosis.

Diffusion-Weighted MRI of Malignant versus Benign Portal Vein Thrombosis.

Objective: To validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis.

Materials And Methods: The Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40-85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed.

Radiation Doses of Various CT Protocols: a Multicenter Longitudinal Observation Study.

Emerging concerns regarding the hazard from medical radiation including CT examinations has been suggested. The purpose of this study was to observe the longitudinal changes of CT radiation doses of various CT protocols and to estimate the long-term efforts of supervising radiologists to reduce medical radiation. Radiation dose data from 11 representative CT protocols were collected from 12 hospitals.

Validation of 10-Minute Delayed Hepatocyte Phase Imaging with 30° Flip Angle in Gadoxetic Acid-Enhanced MRI for the Detection of Liver Metastasis.

Objectives: To compare 10-minute delayed hepatocyte phase imaging using a 30° flip angle (10 min-FA30) and 20-minute hepatocyte phase imaging using a 10° FA (20 min-FA10) in gadoxetic acid-enhanced MRI of patients with possible liver metastases, regarding lesion-to-liver contrast-to-noise ratio (CNR) and focal hepatic lesion (FHL) detection to evaluate whether 10 min-FA30 would be superior to 20 min-FA10.

Materials And Methods: Eighty-three patients with 248 liver metastases and 78 benign FHLs who underwent gadoxetic acid-enhanced MRI with 10 min-FA30 and 20 min-FA10 were enrolled. Lesion-to-liver CNRs were compared between the two image groups.

Prognostic value of gallbladder wall thickening in patients with acute hepatitis A.

Purpose: To investigate the clinical significance of gallbladder (GB) wall thickening frequently observed in patients with acute hepatitis A.

Methods: A total of 328 consecutive patients who were diagnosed with acute hepatitis A and underwent abdominal ultrasonography were enrolled retrospectively. Patients were divided into two groups: GB wall thickening (≥3 mm, group A) and no thickening (group B).

Feasibility of 5-minute delayed transition phase imaging with 30° flip angle in gadoxetic acid-enhanced 3D gradient-echo MRI of liver, compared with 20-minute delayed hepatocyte phase MRI with standard 10° flip angle.

Objective: The purpose of this study was to compare 5-minute delayed transitional phase imaging using a 30° flip angle (hereafter, 5 min-FA30) and 20-minute hepatocyte phase imaging using a 10° flip angle (hereafter, 20 min-FA10) in gadoxetic acid-enhanced MRI for focal hepatic lesion detection and lesion-to-liver contrast-to-noise ratio (CNR), and to determine whether 5 min-FA30 could replace 20 min-FA10 with a 15-minute time saving.

Materials And Methods: One hundred sixteen patients with 282 focal hepatic lesions (size range, 0.2-12.

Comparison of abdominal ultrasonographic findings with endoscopic ultrasonographic findings of solid pseudopapillary neoplasms of the pancreas.

To compare abdominal ultrasonographic (AU) findings with endoscopic ultrasonographic (EUS) findings of solid pseudopapillary neoplasm (SPN) of the pancreas, 13 patients (male-to-female ratio, 3:10; mean age, 36 years) with surgically proven SPN who underwent both preoperative AU and EUS were included in the study. Ultrasonographic findings of the 2 modalities were compared according to internal echogenicity, calcification, demarcation, internal septum, and main pancreatic duct dilatation. Nine cases showed hypoechogenicity on both AU and EUS.

Usefulness of a lead shielding device for reducing the radiation dose to tissues outside the primary beams during CT.

Purpose: This study was done to investigate the efficacy of a lead shield in protecting the tissues outside the primary beams, such as the breast and thyroid, by measurement of the entrance skin dose during CT of the brain, neck, abdomen, and lumbar spine.

Materials And Methods: Institutional Review Board approval was obtained. This study included 150 patients (male:female 25:125, age range 15-45 years).

Evaluation of lateral pelvic nodes in patients with advanced rectal cancer.

Objective: The purpose of this article is to discuss the importance of lateral pelvic lymph node metastasis as a predictor of local recurrence and survival in patients with advanced rectal cancer.

Conclusion: Prediction of lateral pelvic nodal staging on MRI shows high accuracy compared with the other imaging modalities. Diffusion-weighted MRI or (18)F-FDG PET/CT may be helpful to assesses lateral pelvic lymph node metastasis.

Preoperative evaluation of lymphovascular invasion using high-resolution pelvic magnetic resonance in patients with rectal cancer: a 2-year follow-up study.

Objectives: The objectives of this study were to preoperatively evaluate lymphovascular invasion (LVI) using pelvic magnetic resonance (MR) in patients with rectal cancer and to determine the correlation with distant metastasis rate.

Methods: If the mesorectal perivascular infiltrative signal was visible on pelvic MR imaging, the possibility of LVI was recorded. Distant metastatic lesions were also recorded at the time of the initial diagnostic workup and over a 2-year follow-up period.

CT venography for deep vein thrombosis using a low tube voltage (100 kVp) setting could increase venous enhancement and reduce the amount of administered iodine.

Objective: To investigate the validity of the 100 kVp setting in CT venography (CTV) in the diagnosis of deep vein thrombosis (DVT), and to evaluate the feasibility of reducing the amount of administered iodine in this setting.

Materials And Methods: After receiving the contrast medium (CM) of 2.0 mL/kg, 88 patients underwent CTV of the pelvis and lower extremities by using one of four protocols: Group A, 120 kVp setting and 370 mgI/mL CM; group B, 120 kVp and 300 mgI/mL; group C, 100 kVp and 370 mgI/mL; group D, 100 kVp and 300 mgI/mL.

Hepatic cavernous hemangiomas: relationship between speed of intratumoral enhancement during dynamic MRI and apparent diffusion coefficient on diffusion-weighted imaging.

Objective: To investigate the relationships between the apparent diffusion coefficients (ADCs) on diffusion-weighted imaging (DWI) and the speed of contrast-enhancement in hepatic hemangiomas.

Materials And Methods: Sixty-nine hepatic hemangiomas (≥ 1 cm) were evaluated with DWI, by using multiple b values (b = 50, 400, 800 s/mm(2)), followed by a gadolinium-enhanced dynamic MRI. The lesions were classified into three groups, according to the speed of contrast-enhancement on the portal phase.

Computed tomographic venography for varicose veins of the lower extremities: prospective comparison of 80-kVp and conventional 120-kVp protocols.

Objective: To prospectively investigate the feasibility of an 80-kilovolt (peak) (kVp) protocol in computed tomographic venography for varicose veins of the lower extremities by comparison with conventional 120-kVp protocol.

Methods: Attenuation values and signal-to-noise ratio of iodine contrast medium (CM) were determined in a water phantom for 2 tube voltages (80 kVp and 120 kVp). Among 100 patients, 50 patients were scanned with 120 kVp and 150 effective milliampere second (mAs(eff)), and the other 50 patients were scanned with 80 kVp and 390 mAs(eff) after the administration of 1.