Bowel Angioedema Associated With Iodinated Contrast Media: Incidence and Predisposing Factors.

Objective: Bowel angioedema is an acute adverse reaction to iodinated contrast media (CM) that involves the gastrointestinal tract. We aimed to investigate the incidence and predisposing factors of iodinated CM-associated bowel angioedema during computed tomography (CT) examinations.

Materials And Methods: This study was approved by our institutional review board, and informed consent was waived due to its retrospective design.

Normal Postoperative Computed Tomography Findings after a Variety of Pancreatic Surgeries.

Pancreatic surgery remains the only curative treatment for pancreatic neoplasms, and plays an important role in the management of medically intractable diseases. Since the original Whipple operation in the 20th century, surgical techniques have advanced, resulting in decreased postoperative complications and better clinical outcomes. Normal postoperative imaging findings vary greatly depending on the surgical technique used.

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.

Added value of arterial enhancement fraction color maps for the characterization of small hepatic low-attenuating lesions in patients with colorectal cancer.

Objective: To assess the added value of arterial enhancement fraction (AEF) color maps for the differentiation of small metastases from hepatic benign lesions.

Subjects And Methods: We retrospectively analyzed 46 patients with colorectal cancer who underwent multiphasic liver CT imaging and had low-attenuating liver lesions smaller than 3 cm (123 total lesions; metastasis: benign = 32:91). AEF color maps of the liver were created from multiphasic liver CT images using dedicated software.

Quantitative analysis of the effect of iterative reconstruction using a phantom: determining the appropriate blending percentage.

Purpose: To investigate the optimal blending percentage of adaptive statistical iterative reconstruction (ASIR) in a reduced radiation dose while preserving a degree of image quality and texture that is similar to that of standard-dose computed tomography (CT).

Materials And Methods: The CT performance phantom was scanned with standard and dose reduction protocols including reduced mAs or kVp. Image quality parameters including noise, spatial, and low-contrast resolution, as well as image texture, were quantitatively evaluated after applying various blending percentages of ASIR.

Contrast-enhanced ultrasonography: advance and current status in abdominal imaging.

In the field of contrast-enhanced ultrasonography (US), contrast agents are classified as either first- or second-generation agents depending on the gas within the microbubbles. In the case of first-generation contrast agents, a high-mechanical-index technique is used and only intermittent scanning is possible due to the early destruction of the microbubbles during the scanning. The use of second-generation contrast agents in a low-mechanical-index technique enables continuous scanning.

Metal artifact reduction software used with abdominopelvic dual-energy CT of patients with metal hip prostheses: assessment of image quality and clinical feasibility.

Objective: The objective of our study was to determine the feasibility of using Metal Artifact Reduction (MAR) software for abdominopelvic dual-energy CT in patients with metal hip prostheses.

Materials And Methods: This retrospective study included 33 patients (male-female ratio, 19:14; mean age, 63.7 years) who received total hip replacements and 20 patients who did not have metal prostheses as the control group.

Assessment of angiogenesis of hepatocellular carcinoma using dynamic contrast enhanced MR and histopathologic correlation in an experimental rat model.

Background/aims: To assess the perfusion parameters and angiogenesis of HCC using dynamic contrast enhanced(DCE) MR and to correlate it with histopathologic findings in an experimental rat model.

Methodology: Twenty rats were continuously infused with diethylnitrosamine (DEN) for tumor induction. After 32 to 36 weeks of DEN treatment, the rats underwent MRI of the liver with a 3-T MR imaging system.

Dynamic enhancement pattern of HCC smaller than 3 cm in diameter on gadoxetic acid-enhanced MRI: comparison with multiphasic MDCT.

Background & Aims: The dynamic enhancement pattern of HCCs smaller than 3 cm in diameter on gadoxetic acid-enhanced magnetic resonance imaging (MRI) have not been extensively investigated. We aimed to evaluate the dynamic enhancement patterns of small HCCs (≤3 cm) on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and compare enhancement patterns with multiphasic multidetector computed tomography (MDCT) based on tumour cellular differentiation and size.

Methods: We retrospectively included 55 patients with 67 surgically confirmed small HCCs (≤3 cm) who underwent multiphasic MDCT and gadoxetic acid-enhanced MRI.

Diagnostic radiation exposure of injury patients in the emergency department: a cross-sectional large scaled study.

In contrast to patients with underlying cancer or chronic disease, injury patients are relatively young, and can be expected to live their natural lifespan if injuries are appropriately treated. Multiple and repeated diagnostic scans might be performed in these patients during admission. Nevertheless, radiation exposure in injury patients has been overlooked and underestimated because of the emergent nature of such situations.

Detection of recurrent hepatocellular carcinoma on post-operative surveillance: comparison of MDCT and gadoxetic acid-enhanced MRI.

Objective: To compare the accuracy of multidetector computed tomography (MDCT) and gadoxetic acid-enhanced magnetic resonance imaging (MRI) for the detection of intrahepatic tumor recurrence after curative resection of hepatocellular carcinoma (HCC).

Materials And Methods: Fifty-six patients who underwent MDCT and gadoxetic acid-enhanced MRI for postoperative surveillance after resection of HCC were retrospectively analyzed; 26 patients had a recurrence (36 lesions) and 30 patients did not. Recurrent HCCs were confirmed by histological examinations in two, typical dynamic imaging findings on CT and/or MRI in 28, and by demonstration of growth or tumor staining on angiography on six.

Diffusion and perfusion MRI prediction of progression-free survival in patients with hepatocellular carcinoma treated with concurrent chemoradiotherapy.

Purpose: To assess whether MR perfusion and diffusion parameters taken before concurrent chemoradiotherapy (CCRT) are useful imaging biomarkers for predicting progression-free survival (PFS) in patients with hepatocellular carcinoma (HCC).

Materials And Methods: Twenty patients with locally advanced HCC who had no treatment before CCRT underwent dynamic contrast-enhanced (DCE) and diffusion-weighted MRI. Mean values of the volume transfer constant (K(trans) ), reflex constant (Kep ), extravascular extracellular volume fraction (Ve ) and the apparent diffusion coefficient (ADC) were estimated on a region of interest.

Intraindividual comparison of diagnostic performance in patients with hepatic metastasis of full-dose standard and half-dose iterative reconstructions with dual-source abdominal computed tomography.

Objectives: The objectives of the study were to evaluate the image quality and diagnostic performance of sinogram-affirmed iterative reconstruction (SAFIRE) for detecting hepatic metastasis and to estimate the potential radiation dose reduction at abdominal computed tomography (CT).

Materials And Methods: Fifty-nine consecutive patients (mean age, 59.2 years; range, 42-81 years) who had hepatic metastasis and who underwent dual-source abdominal CT were enrolled in this study.

Radiation dose reduction via sinogram affirmed iterative reconstruction and automatic tube voltage modulation (CARE kV) in abdominal CT.

Objective: To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination.

Materials And Methods: This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e.

Perfusion parameters of dynamic contrast-enhanced magnetic resonance imaging in patients with rectal cancer: correlation with microvascular density and vascular endothelial growth factor expression.

Objective: To determine whether quantitative perfusion parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) correlate with immunohistochemical markers of angiogenesis in rectal cancer.

Materials And Methods: Preoperative DCE-MRI was performed in 63 patients with rectal adenocarcinoma. Transendothelial volume transfer (K(trans) ) and fractional volume of the extravascular-extracellular space (Ve) were measured by Interactive Data Language software in rectal cancer.

Gadoxetate disodium-enhanced MRI of mass-forming intrahepatic cholangiocarcinomas: imaging-histologic correlation.

Objective: The purpose of this study was to describe the enhancement patterns of mass-forming intrahepatic cholangiocarcinomas on gadoxetate disodium-enhanced MR images using imaging-histologic correlation.

Materials And Methods: We retrospectively evaluated the preoperative gadoxetate disodium-enhanced MR images of 19 patients with mass-forming intrahepatic cholangiocarcinomas. Two readers independently interpreted enhancement patterns on arterial (globally high, rimlike), dynamic (washout, progressive), and hepatobiliary (target, nontarget) phase images.

Usefulness of the tensile gallbladder fundus sign in the diagnosis of early acute cholecystitis.

Objective: The purpose of this article is to evaluate the usefulness of the tensile gallbladder fundus sign on CT in diagnosing early acute cholecystitis.

Materials And Methods: The tensile gallbladder fundus sign on CT is defined as the absence of gallbladder fundus flattening by the anterior abdominal wall due to increased gallbladder pressures. Between October 2010 and March 2012, 222 patients with confirmed diagnoses of acute cholecystitis by surgery or follow-up imaging studies underwent CT scans in the emergency department because of right upper quadrant pain.

Characterization of incidental liver lesions: comparison of multidetector CT versus Gd-EOB-DTPA-enhanced MR imaging.

As a result of recent developments in imaging modalities and wide spread routine medical checkups and screening, more incidental liver lesions are found frequently on US these days. When incidental liver lesions are found on US, physicians have to make a decision whether to just follow up or to undergo additional imaging studies for lesion characterization. In order to choose the next appropriate imaging modality, the diagnostic accuracy of each imaging study needs to be considered.

Correlations of dynamic contrast-enhanced magnetic resonance imaging with morphologic, angiogenic, and molecular prognostic factors in rectal cancer.

Purpose: To investigate the correlations between parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and prognostic factors in rectal cancer.

Materials And Methods: We studied 29 patients with rectal cancer who underwent gadolinium contrast-enhanced, T1-weighted DCE-MRI with a three Tesla scanner prior to surgery. Signal intensity on DCE-MRI was independently measured by two observers to examine reproducibility.

Comparison of breathhold, navigator-triggered, and free-breathing diffusion-weighted MRI for focal hepatic lesions.

Purpose: To compare the breathhold, navigator-triggered, and free-breathing techniques in diffusion-weighted magnetic resonance imaging (MRI) for the evaluation of focal liver lesions on a 3.0T system.

Materials And Methods: Fifty-two patients (36 men, 16 women; mean age, 56.

Histological characteristics of small hepatocellular carcinomas showing atypical enhancement patterns on gadoxetic acid-enhanced MR imaging.

Purpose: To define the histological characteristics of hepatocellular carcinomas (HCCs) showing atypical dynamic enhancement patterns on gadoxetic acid-enhanced dynamic magnetic resonance imaging (EOB-MRI).

Materials And Methods: We evaluated a total of 130 small (≤ 3 cm) HCCs from 114 patients that were surgically removed after EOB-MRI. Two radiologists blinded to the histological findings retrospectively classified the HCCs into typical or atypical lesions.

Added value of subtraction imaging in detecting arterial enhancement in small (<3 cm) hepatic nodules on dynamic contrast-enhanced MRI in patients at high risk of hepatocellular carcinoma.

Objectives: To determine the importance of arterial enhancement in diagnosing small (<3 cm) hepatocellular carcinomas (HCCs) and to evaluate the added value of dynamic subtraction magnetic resonance imaging (MRI) in detecting arterial enhancement in small (<3 cm) hepatic nodules in high-risk patients.

Methods: Eighty-six patients with 135 pathologically confirmed small (<3 cm) hepatic nodules (104 HCCs, 31 benign nodules) underwent MRI before curative surgery. Arterial enhancement was determined by three methods: (1) visual assessment of the arterial phase alone, (2) visual comparison of the arterial phase with the unenhanced phase and (3) additional review of subtraction images.

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.

The impact of CT follow-up interval on stages of hepatocellular carcinomas detected during the surveillance of patients with liver cirrhosis.

Objective: The purpose of our study was to assess the relationship between time intervals of CT examinations and the stages of hepatocellular carcinomas (HCCs) detected during the surveillance of patients with liver cirrhosis.

Materials And Methods: In this study, 73 patients with 93 HCCs (reference standard: surgery, n=7 [8 HCCs]; biopsy, n=2 [3 HCCs]; imaging criteria, n=64 [82 HCCs]) who showed no evidence of HCC on prior CT examinations were included. Patients were stratified into three groups based on the time interval between the two CT examinations: groups A (interval≤1 year, n=21), B (interval between 1 and 2 years, n=25), and C (interval≥2 years, n=27).

Preoperative prediction of the microvascular invasion of hepatocellular carcinoma with diffusion-weighted imaging.

The aim of this study was to investigate whether diffusion-weighted imaging (DWI) could be useful in predicting the microvascular invasion (MVI) of hepatocellular carcinoma (HCC). Sixty-seven surgically proven HCCs from 65 patients (54 men and 11 women with an age range of 35-75 years and a mean age of 56.0 years) were retrospectively analyzed.