Cheol Min Park

Typical and atypical imaging findings of intrahepatic cholangiocarcinoma using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging.

Purpose The objective of this study was to examine the imaging features of classic mass-forming intrahepatic cholangiocarcinoma (MICC) and nonclassic hypervascular MICC on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid–enhanced magnetic resonance imaging. Methods Twenty pathologically confirmed MICCs were included. Two radiologists retrospectively reviewed the imaging characteristics on T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced images, and hepatobiliary phase (HBP) of each MICC. For the morphologic feature of defect, HBP signal intensity (SI) ratio was calculated by dividing the SI of the MICC by nearby normal liver parenchyma SI. Results Classic MICCs (n = 14) showed classic rim or peripheral enhancement at arterial dominant phase with centripetal enhance in the delayed phases. Hypervascular MICCs (n = 6) showed complete (n = 4) or near-complete (n = 2) arterial enhancement and washout (n = 6) on delayed phases. On HBP, 13 classic MICCs (93%) and 2 hypervascular MICCs (33%) showed cloud-like SI in the center (“EOB cloud”) with peripheral defect. Mean SI ratio was 0.77 in classic MICCs and 0.59 in hypervascular MICC (P = 0.057). Conclusions Classic MICCs (70%) frequently showed progressive centripetal enhancement on dynamic phase, and central EOB-cloud appearance with distinct peripheral defect on HBP. Nonclassic hypervascular MICCs comprised 30% of the MICCs in this study. Compared with classic MICCs, hypervascular MICCs showed wash-in on arterial dominant phase and washout on delayed phase.

Usefulness of controlled aliasing in parallel imaging results in higher acceleration in gadoxetic acid-enhanced liver magnetic resonance imaging to clarify the hepatic arterial phase.

PurposeWe aimed to determine whether the controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique could improve the image quality of the hepatic arterial phase of gadoxetic acid–enhanced liver magnetic resonance (MR) imaging. Materials and MethodsA total of 320 patients underwent gadoxetic acid–enhanced liver MR imaging: a conventional protocol (a fixed scan delay and 2-mL/s injection) using a standard 3-T MR system (Trio-Tim; Siemens, commercialized since 2005) (group A), an optimized protocol (bolus tracking and 1-mL/s injection) using a standard 3-T MR (group B), an optimized protocol using a new 3-T MR (Skyra; Siemens, commercialized since 2012) (group C), and an optimized protocol with CAIPIRINHA using a new 3-T MR (group D). The image quality of the hepatic arterial phase was graded using a 4-point rating scale from 1 (no artifacts) to 4 points (non–diagnostic images with severe artifacts). The differences in image quality scores among the 4 groups were evaluated. In addition, the detection rates of hypervascular hepatocellular carcinomas among the 4 groups were evaluated. ResultsScores of 4 points were observed in groups A (n = 7), B (n = 5), and C (n = 3) but not in group D. The median image quality score was 2 in groups A and B and 1 in groups C and D. From group A to group D, the median image quality score decreased significantly (P = 0.0001). The median image quality score was significantly lower in group D than in groups A and B (P = 0.0001 and 0.001, respectively), whereas there was no significant difference observed between groups C and D (P = 0.656). The detection rates of hypervascular hepatocellular carcinomas on the hepatic arterial phase were not significantly different among the groups (all P > 0.03), except between groups A and D (P = 0.007). ConclusionsThe CAIPIRINHA technique improved the image quality of hepatic arterial phase imaging with gadoxetic acid, reducing the number of non–diagnostic arterial phase studies.

An interesting hepatic mass: Splenosis mimicking a hepatocellular carcinoma (2003:9b)

We report a splenosis mimicking hepatocellular carcinoma in a patient with chronic liver disease. Knowledge of these imaging findings, including helical CT, angiography, CT hepatic arteriogram, CT arterioportogram, and iodized-oil CT, may obviate unnecessary surgery.

Prediction of liver cirrhosis, using diagnostic imaging tools

Early diagnosis of liver cirrhosis is important. Ultrasound-guided liver biopsy is the gold standard for diagnosis of liver cirrhosis. However, its invasiveness and sampling bias limit the applicability of the method. Basic imaging for the diagnosis of liver cirrhosis has developed over the last few decades, enabling early detection of morphological changes of the liver by ultrasonography (US), computed tomography, and magnetic resonance imaging (MRI). They are also accurate diagnostic methods for advanced liver cirrhosis, for which early diagnosis is difficult. There are a number of ways to compensate for this difficulty, including texture analysis to more closely identify the homogeneity of hepatic parenchyma, elastography to measure the stiffness and elasticity of the liver, and perfusion studies to determine the blood flow volume, transit time, and velocity. Amongst these methods, elastography using US and MRI was found to be slightly easier, faster, and able to provide an accurate diagnosis. Early diagnosis of liver cirrhosis using MRI or US elastography is therefore a realistic alternative, but further research is still needed.

The short breath-hold technique, controlled aliasing in parallel imaging results in higher acceleration, can be the first step to overcoming a degraded hepatic arterial phase in liver magnetic resonance imaging: A prospective randomized control study

ObjectiveThe aim of this study was to assess whether a short breath-hold technique can improve hepatic arterial phase (HAP) image quality in gadoxetic acid–enhanced magnetic resonance (MR) imaging compared with a conventional long breath-hold technique. Materials and MethodsInstitutional review board approval and patient consent were obtained for this prospective randomized control study. One hundred nineteen patients undergoing gadoxetic acid–enhanced MR imaging were randomly assigned to groups A or B. Group A patients underwent an 18-second long breath-hold MR technique (conventional VIBE [volumetric interpolated breath-hold examination] technique with GRAPPA [generalized autocalibrating partially parallel acquisition]), and group B patients underwent a 13-second short breath-hold MR technique (VIBE technique with CAIPIRINHA [controlled aliasing in parallel imaging results in higher acceleration]). Respiratory-related graphs of the precontrast and HAP were acquired. The breath-hold degree was graded based on the standard deviation (SD) value of respiratory waveforms. Gadoxetic acid–related dyspnea was defined as when the SD value of the HAP was 200 greater than that of the precontrast phase without degraded image quality in the portal and transitional phases (SD value of the HAP − SD value of the precontrast phase). The overall image quality and motion artifacts of the precontrast and HAP images were evaluated. The groups were compared using the Student t or Fisher exact test, as appropriate. ResultsThe incidence of breath-holding difficulty (breath-hold grades 3 and 4) during the HAP was 43.6% (27/62) and 36.8% (21/57) for group A and B, respectively. The SD value during the precontrast phase and the SD value difference between the precontrast and HAP were both significantly higher in group A than in group B (P = 0.047 and P = 0.023, respectively). Gadoxetic acid–related dyspnea was seen in 19.4% (12/62) of group A and 7.0% (4/57) of group B. Group B showed better precontrast and HAP image quality than group A (P < 0.001). Degraded HAP (overall image quality ≥4) was observed in 9.7% (6/62) and 3.5% (2/57) of group A and B, respectively. ConclusionsThe short breath-hold MR technique, CAIPIRINHA, showed better HAP image quality with less degraded HAP and a lower incidence of breath-hold difficulty and gadoxetic acid–related dyspnea than the conventional long breath-hold technique.

Hepatic Arterial Phase in Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging: Analysis of Respiratory Patterns and Their Effect on Image Quality.

ObjectiveThe aims of this study were to objectively evaluate patient respiration and breathing change after contrast injection and to assess its potential impact on image quality for the hepatic arterial phase in gadoxetic acid–enhanced magnetic resonance imaging. Materials and MethodsThis retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. One hundred fifty-four patients underwent gadoxetic acid–enhanced liver magnetic resonance imaging with a 13-second breath-hold hepatic arterial phase. During the acquisition of precontrast and hepatic arterial phases, the respiratory motion signal was acquired and graded on a 4-point scale based on the SD of the respiratory waveform, with the highest grade indicating the worst breath-hold. Breath-holding grades 3 and 4 for the hepatic arterial phases were considered as breath-holding difficulty during the hepatic arterial phase. Gadoxetic acid–related dyspnea was defined as when the SD value of respiratory waveform during the hepatic arterial phase was 200 greater than that of the precontrast image. Then, the precontrast and hepatic arterial phase images were evaluated with respect to overall image quality and motion artifact using a 5-point scale, with the highest score indicating the worst image quality. In the hepatic arterial phase, the correlation between breath-holding degree and image quality parameters was evaluated using Pearson correlation. The differences in mean image quality scores between patients with and without gadoxetic acid–related dyspnea were evaluated using Student t test. ResultsBased on the analysis of the respiratory waveforms, the incidence of breath-holding difficulty during the hepatic arterial phase was 23.4% (33/154), and the incidence of gadoxetic acid–related dyspnea was 6.5% (10/154). By image analysis, the incidence of a degraded hepatic arterial phase (overall image quality score ≥4) was 5.2% (8/154). During the hepatic arterial phase, the breath-holding degree correlated with overall image quality and motion artifacts (r = 0.564 and 0.578, respectively). Patients with gadoxetic acid–related dyspnea showed significantly worse image qualities of the hepatic arterial phase than patients without gadoxetic acid–related dyspnea (all, P < 0.001), although image qualities for the precontrast image were not statistically significant between the 2 groups (all, P > 0.05). ConclusionsThe objective analysis of respiratory patterns during a breath-hold is feasible and useful for evaluating gadoxetic acid–related dyspnea and its effect on image quality analysis.

Correlation of fatty liver and abdominal fat distribution using a simple fat computed tomography protocol

AIM To evaluate the relationship between hepatic fat infiltration and abdominal fat volume by using computed tomography (CT). METHODS Three hundred and six patients who visited our obesity clinic between November 2007 and April 2008 underwent fat protocol CT scans. The age range of the patients was 19 to 79 years and the mean age was 49 years. The male to female ratio was 116:190. Liver and spleen attenuation measurements were taken with three regions of interests (ROIs) from the liver and two ROIs from the spleen. Hepatic attenuation indices (HAIs) were measured as follows: (1) hepatic parenchymal attenuation (CT(LP)); (2) liver to spleen attenuation ratio (LS ratio); and (3) difference between hepatic and splenic attenuation (LS(dif)). Abdominal fat volume was measured using a 3 mm slice CT scan starting at the level of the umbilicus and was automatically calculated by a workstation. Abdominal fat was classified into total fat (TF), visceral fat (VF), and subcutaneous fat (SF). We used a bivariate correlation method to assess the relationship between the three HAIs and TF, VF, and SF. RESULTS There were significant negative correlations between CT(LP), LS ratio, and LS(dif) with TF, VF, and SF, respectively. The CT(LP) showed a strong negative correlation with TF and VF (r = -0.415 and -0.434, respectively, P < 0.001). The correlation between CT(LP) and SF was less significant (r = -0.313, P < 0.001). CONCLUSION Fatty infiltration of the liver was correlated with amount of abdominal fat and VF was more strongly associated with fatty liver than SF.

C-furanoside synthesis via radical cyclisation of β-alkoxyacrylates

Stereoselective synthesis of C-furanosides is accomplished via tributylstannane-mediated radical cyclisation of β-alkoxyacrylates.

Differentiation of hepatocellular carcinoma from its various mimickers in liver magnetic resonance imaging: What are the tips when using hepatocyte-specific agents?

Hepatocellular carcinoma is the most common primary hepatic malignant tumor. With widespread use of liver imaging, various cirrhosis-related nodules are frequently detected in patients with chronic liver disease, while diverse hypervascular hepatic lesions are incidentally detected but undiagnosed on dynamic computed tomography and magnetic resonance imaging (MRI). However, use of hepatocyte-specific MR contrast agents with combined perfusion and hepatocyte-selective properties have improved diagnostic performance in detection and characterization of focal liver lesions. Meanwhile, the enhancement patterns observed during dynamic phases using hepatocyte-specific agents may be different from those observed during MRI using conventional extracellular fluid agents, leading to confusion in diagnosis. Therefore, we discuss useful tips for the differentiation of hepatocellular carcinoma from similar lesions in patients with and without chronic liver disease using liver MRI with hepatocyte-specific agents.

Synchronous Bilateral Primary Breast Lymphoma: MRI and Pathologic Findings

A 46-year-old woman was referred to our hospital with bilateral breast masses and localized edema. She had no medical history of note, no family history of breast, colon, or ovarian cancer, and was not on any medication. Physical examination revealed firm and immobile masses in both breasts without axillary lymphadenopathy. Mammography, ultrasonography and MRI of both breasts using a 1.5 Tesla MRI system and a dedicated breast coil were performed. Contrast-enhanced transverse MR images of both breasts (Figs. 1a, b) showed well-enhanced masses with Impending skin ulceration