Jiyoung Hwang

Differentiating combined hepatocellular and cholangiocarcinoma from mass-forming intrahepatic cholangiocarcinoma using gadoxetic acid-enhanced MRI

To examine the differential features of combined hepatocellular and cholangiocarcinoma (HCC‐CC) from mass‐forming intrahepatic cholangiocarcinoma (ICC) on gadoxetic acid‐enhanced MRI.

Detection of hepatocellular carcinoma in gadoxetic acid-enhanced MRI and diffusion-weighted MRI with respect to the severity of liver cirrhosis

Background As gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) have been widely used for the evaluation of hepatocellular carcinoma (HCC), it is clinically relevant to determine the diagnostic efficacy of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis. Purpose To compare the diagnostic accuracy and sensitivity of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis. Material and Methods A total of 189 patients with 240 HCCs (≤3.0 cm) (Child-Pugh A, 81 patients with 90 HCCs; Child-Pugh B, 65 patients with 85 HCCs; Child-Pugh C, 43 patients with 65 HCCs) underwent DWI and gadoxetic acid-enhanced MRI at 3.0 T. A gadoxetic acid set (dynamic and hepatobiliary phase plus T2-weighted image) and DWI set (DWI plus unenhanced MRIs) for each Child-Pugh class were analyzed independently by two observers for detecting HCCs using receiver-operating characteristic analysis. The diagnostic accuracy and sensitivity were calculated. Results There was a trend toward decreased diagnostic accuracy for gadoxetic acid and DWI set with respect to the severity of cirrhosis (Child-Pugh A [mean 0.974, 0.961], B [mean 0.904, 0.863], C [mean 0.779, 0.760]). For both observers, the sensitivities of both image sets were highest in Child-Pugh class A (mean 95.6%, 93.9%), followed by class B (mean 83.0%, 77.1%), and class C (mean 60.6%, 60.0%) (P < 0.05). Conclusion In HCC detection, the diagnostic accuracy and sensitivity for gadoxetic acid-enhanced MRI and DWI were highest in Child-Pugh class A, followed by Child-Pugh class B, and Child-Pugh class C, indicating a tendency toward decreased diagnostic capability with the severity of cirrhosis.

Importance of voriconazole therapeutic drug monitoring in pediatric cancer patients with invasive aspergillosis

Voriconazole is the drug of choice for invasive aspergillosis (IA) and drug levels are influenced by interactions with other drugs and genetic predisposition. We performed a retrospective analysis of voriconazole drug levels and investigated the adequacy of drug levels in pediatric cancer patients and hematopoietic cell transplant (HCT) recipients with IA.

Gadoxetic acid-enhanced MRI versus multiphase multidetector row computed tomography for evaluating the viable tumor of hepatocellular carcinomas treated with image-guided tumor therapy

To compare the diagnostic performance of gadoxetic acid‐enhanced MRI with that of multi‐phase 40‐ or 64‐multidetector row computed tomography (MDCT) to evaluate viable tumors of hepatocellular carcinomas (HCCs) treated with image‐guided tumor therapy.

Imaging features of small (≤3 cm) pancreatic solid tumors on gadoxetic-acid-enhanced MR imaging and diffusion-weighted imaging: an initial experience

OBJECTIVE The objective was to determine imaging features that distinguish small (≤3cm) solid pancreatic adenocarcinoma, neuroendocrine tumor (NET) and solid pseudopapillary tumor (SPT) on gadoxetic-acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighed imaging (DWI). MATERIALS AND METHODS Twenty-four adenocarcinomas, 10 NETs and 8 SPTs were retrospectively included. Two radiologists analyzed morphologic features, signal intensity of the tumors on MR images including DWI (b=800) and dynamic enhancement pattern with consensus. Tumor-to-parenchyma ratio and tumor apparent diffusion coefficients (ADCs) were quantitatively assessed. RESULTS All adenocarcinomas had an ill-defined margin and irregular shape, and more frequently had pancreatic duct dilatation compared with other tumors (P<.05). All SPTs and all but one of the adenocarcinomas (95.8%) had no arterial enhancement with progressively increased enhancement, whereas seven NETs (70%) had arterial enhancement with progressively decreased enhancement (P<.01). The mean value of tumor-to-parenchyma ratio on arterial and portal phases was significantly higher for NETs, and the mean value of tumor ADCs was significantly lower for SPTs than for other tumors (P<.05). CONCLUSIONS Gadoxetic-acid-enhanced MRI may aid in differentiation between small adenocarcinomas, NETs and SPTs based on morphologic features with dynamic enhancement pattern in adenocarcinomas, dynamic enhancement pattern with tumor-to-parenchyma ration on arterial and portal phases in NETs, and dynamic enhancement pattern with lower ADC value in SPTs.

Scirrhous hepatocellular carcinoma on gadoxetic acid-enhanced magnetic resonance imaging and diffusion-weighted imaging: emphasis on the differentiation of intrahepatic cholangiocarcinoma.

Objective The objective of this study was to determine the features of scirrhous hepatocellular carcinoma (sHCC) on gadoxetic acid–enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) with an emphasis on the differentiation from intrahepatic cholangiocarcinoma (ICC). Materials and Methods A total of 41 patients with sHCCs and 41 patients with ICCs underwent gadoxetic acid–enhanced MRI and DWI. Images were analyzed for shape of lesions, surface retraction, enhancement pattern, proportion of arterial hyperenhancement, target appearance on the hepatobiliary phase and DWI, and presence of necrosis. Results Lobulating shape, rim enhancement, and target appearance on the hepatobiliary phase and DWI were the main features in both tumors. The proportion of arterial hyperenhancement of 20% of tumor diameter or more was the only significant MRI feature for differentiating sHCC from ICC (P ⩽ 0.006 in the multivariate analysis). Conclusions Although the features of sHCC on gadoxetic acid–enhanced MRI and DWI are similar to those of ICC, the proportion of hyperenhancement of 20% or more on the arterial phase is a helpful feature in distinguishing sHCC from ICC.

Gadoxetic acid-enhanced fat suppressed three-dimensional T1-weighted MRI using a multiecho dixon technique at 3 tesla: emphasis on image quality and hepatocellular carcinoma detection.

To compare the image quality between T1 high‐resolution isotropic volume examination using the multi‐echo Dixon technique (mDixon‐eTHRIVE) and that using spectrally adiabatic inversion recovery (SPAIR‐eTHRIVE) in gadoxetic acid‐enhanced liver MRI, and to evaluate the detectability of hepatocellular carcinoma (HCC) on mDixon‐eTHRIVE.

Liver MRI at 3.0 tesla: comparison of image quality and lesion detectability between single-source conventional and dual-source parallel radiofrequency transmissions.

Objective To prospectively and intraindividually compare liver magnetic resonance imaging (MRI) using single-source and dual-source parallel radiofrequency (RF) transmissions at 3.0-T for image quality, lesion detectability, and lesion contrast. Methods Ninety-nine patients with 139 liver lesions underwent liver MRI at 3.0-T. Two radiologists performed a consensus review of T2-weighted images (T2WI), heavily T2WI (HT2WI), gadoxetic acid–enhanced hepatobiliary images, and diffusion-weighted imaging using single-source and dual-source RF transmissions with regard to image quality and lesion detectability. Contrast ratios between liver lesions and liver parenchyma were also calculated. Results Image quality was better with dual-source than with single-source at T2WI and HT2WI (P < 0.05), but lesion detectabilities were similar for all sequences. There was no significant difference in mean contrast ratios for all sequences (P > 0.05). Conclusion Dual-source RF transmission provides a better image quality with T2WI and HT2WI than with single-source. However, 2 techniques showed similar lesion detectability.

Detection and characterization of small focal hepatic lesions (≤2.5 cm in diameter): a comparison of diffusion-weighted images before and after administration of gadoxetic acid disodium at 3.0T

Background As diffusion-weighted imaging (DWI) is routinely incorporated into the standard clinical protocol, it is clinically relevant to determine whether DWI after gadoxetic acid is comparable to pre-contrast DWI, with regard to the detection and characterization of focal liver lesions. Purpose To compare DWI before and after administration of gadoxetic acid in the detection and characterization of small (≤2.5 cm) focal hepatic lesions. Material and Methods One hundred and fifty-eight patients with 237 focal hepatic lesions (≤2.5 cm) (124 HCCs, 50 metastases, 2 cholangiocarcinomas, 43 hemangiomas, and 18 cysts) were included. DWIs were obtained before and after administration of gadoxetic acid. Non-breath-hold DWI was performed with b values of 0, 100, and 800 s/mm2. Signal-to-noise ratio (SNR), lesion-liver contrast-to-noise ratio (CNR), and apparent diffusion coefficients (ADCs) of the liver and lesion were calculated. Lesion detection with each DWI was evaluated with alternative free-response receiver-operating characteristic analysis by two observers. The sensitivity of the characterization of focal hepatic lesions as solid (malignancy) or non-solid (benignity) with each DWI was calculated using a five-point confidence scale. Inter-observer agreement regarding lesion detection and characterization was evaluated using kappa statistics. Results SNRs of the liver on post-contrast DWI were significantly lower than on unenhanced DWI at b = 800 s/mm2 (P < 0.05). SNRs, CNRs, and ADCs of focal hepatic lesions were not significantly different between two DWIs (P > 0.05). The diagnostic accuracy (Az) for lesion detection and the sensitivity for lesion characterization did not show significant difference between two DWIs (P > 0.05). With regard to the detection and characterization of focal hepatic lesions, the kappa values for two DWIs indicated good and excellent inter-observer agreement, respectively. Conclusion Gadoxetic acid-enhanced DWI showed comparable diagnostic capability to unenhanced DWI for the detection and characterization of small focal hepatic lesions.