Hepatocellular Carcinoma Arising in a Non-cirrhotic Liver with Secondary Hemochromatosis.

A 70-year-old man was admitted for treatment of a single liver nodule that was detected by contrast-enhanced computed tomography. Twenty years earlier, the patient had been diagnosed with myelodysplastic syndrome-refractory anemia and secondary hemochromatosis but had not received erythrocyte transfusions. The current histological, computed tomography, and magnetic resonance imaging findings revealed hepatocellular carcinoma (HCC) and non-cirrhotic liver hemochromatosis. The liver tumor was treated using radiofrequency ablation therapy. Secondary hemochromatosis may be a risk factor for HCC, even if the liver is not cirrhotic. In such cases, additional surveillance may be required to detect the development of HCC.

Usefulness of new subtraction algorithm in estimating degree of liver fibrosis by calculating extracellular volume fraction obtained from routine liver CT protocol equilibrium phase data: Preliminary experience.

OBJECTIVES: To assess whether extracellular volume fraction (ECV) obtained from routine liver CT equilibrium phase data utilizing new subtraction algorithm is useful in estimating the degree of liver fibrosis. MATERIALS AND METHODS: Consecutive 41 patients, 21 men and 20 women, with chronic liver diseases who underwent quadri-phase liver CT and MR elastography within 3 months were retrospectively enrolled. Subtraction image of unenhanced from equilibrium phase (240 s) images using conventional and new algorithms were made. We firstly assessed the quality of these subtraction algorithms using patients in whom anatomical misregistration between the two image sets were prominent. Then, ECVs were calculated using both subtraction data sets (ECV-convSub, and ECV-newSub, respectively). ECV were also calculated by traditional manual method (ECV-man). Correlation coefficients of 3 types of ECV were compared using liver stiffness (kPa) as measured by MR elastography and pathologically proven fibrosis grades as reference standards. RESULTS: For eleven patients with prominent anatomical misregistration between the unenhanced and equilibrium phases, new algorithm provided significantly better subtraction images than the conventional one (p = 0.001, Wilcoxon's signed rank test). As for correlation with liver stiffness, R2 for ECV-man, ECV-convSub, and ECV-newSub, were 0.57, 0.59, and 0.66, respectively (all p < 0.0001, Pearson's correlation). Histological assessment for fibrosis grades were available in 20 patients, and rho values for these three ECVs were 0.66, 0.61, and 0.71, respectively (all p < 0.01, Spearman's rank correlation). CONCLUSION: ECV-newSub showed better correlation to liver stiffness and pathological fibrosis grades than ECV-convSub and ECV-man, which could be a reliable biomarker of liver fibrosis obtained from routine clinical diagnostic imaging data, where equilibrium phase delay time was set at 240 s.

Hepatic Hodgkin lymphoma with delayed enhancement on CT and MRI.

Hepatic Hodgkin lymphoma is a rare disease, characterized by the presence of abundant granulofibrous stroma, and its radiological features have rarely been described. We report a 67-year-old man, who presented with liver masses that showed apparent delayed enhancement, along with systemic lymphadenopathy and musculoskeletal lesions. Repeated percutaneous needle biopsy, however, failed to confirm the diagnosis, and surgical biopsy finally revealed small amount of Hodgkin cells and Reed-Sternberg cells. In this report, the radiological features of hepatic Hodgkin lymphoma will be presented and discussed, in correlation with its histological findings.

A case of porphyria cutanea tarda of the liver exhibiting multifocal macrovesicular steatosis in the background of microvesicular steatosis, probably caused by uneven iron accumulation.

A 61-year-old man with chronic hepatitis B and a history of alcohol overconsumption was admitted to our hospital for the scrutiny of multiple echogenic liver nodules. CT and hepatobiliary phase of gadoxetate-enhanced MR imaging revealed no nodular lesions. Quantitative fat fraction images and R2* map of MR imaging suggested homogeneous steatosis and uneven iron deposition in the liver, namely moderately and severely elevated R2* values at the nodules and surrounding background liver, respectively. Biopsy specimens showed macrovesicular fatty liver and less iron deposition at the echogenic nodules, and microvesicular fatty change and more prominent iron deposition at the surrounding liver tissue. The patient's urinary uroporphyrin level was elevated, and the final diagnosis of porphyria cutanea tarda was made. In patients with history of excessive alcohol intake or viral hepatitis, echogenic nodules on ultrasonography along with radiological evidence of absence of space occupying lesions, and presence of excessive intrahepatic fat and iron, might suggest a possible diagnosis of porphyria cutanea tarda.

Preliminary Comparison of Multi-scale and Multi-model Direct Inversion Algorithms for 3T MR Elastography.

PURPOSE: To elucidate whether any differences are present in the stiffness map obtained with a multiscale direct inversion algorithm (MSDI) vs that with a multimodel direct inversion algorithm (MMDI), both qualitatively and quantitatively. MATERIALS AND METHODS: The MR elastography (MRE) data of 37 consecutive patients who underwent liver MR elastography between September and October 2014 were retrospectively analyzed by using both MSDI and MMDI. Two radiologists qualitatively assessed the stiffness maps for the image quality in consensus, and the measured liver stiffness and measurable areas were quantitatively compared between MSDI and MMDI. RESULTS: MMDI provided a stiffness map of better image quality, with comparable or slightly less artifacts. Measurable areas by MMDI (43.7 ± 17.8 cm2) was larger than that by MSDI (37.5 ± 14.7 cm2) (P < 0.05). Liver stiffness measured by MMDI (4.51 ± 2.32 kPa) was slightly (7%), but significantly less than that by MSDI (4.86 ± 2.44 kPa) (P < 0.05). CONCLUSION: MMDI can provide stiffness map of better image quality, and slightly lower stiffness values as compared to MSDI at 3T MRE, which radiologists should be aware of.

Homogeneously enhancing breast lesions on contrast enhanced US: differential diagnosis by conventional and contrast enhanced US findings.

OBJECTIVE: To clarify the details of homogeneously enhancing lesions on contrast-enhanced ultrasonography (CEUS) and also to elucidate whether their differential diagnosis is possible. METHODS: Seventy-three homogeneously enhancing lesions on CEUS were retrospectively selected. Two radiologists first assessed conventional US findings alone in consensus to differentiate malignant vs. benign lesions. Then, qualitative and quantitative CEUS findings were analyzed to determine the useful findings for the differential diagnosis. Determined CEUS findings were applied to the indeterminate lesions based on conventional US findings to see whether CEUS can improve the diagnostic performance. RESULTS: There were 42 cancers (58 %) out of 73. Sensitivity and specificity using conventional US findings alone were 91 and 55 %, respectively. Among the CEUS findings tested, multivariate analysis revealed only the type 3 enhancement pattern, which indicates a larger enhancing area than the precontrast hypoechoic lesion, was related to malignancy (p < 0.05). By adding this information, however, no improvement was achieved in the diagnostic performance as determined by conventional US findings. CONCLUSIONS: Approximately half of the homogeneously enhancing lesions on CEUS are malignant, and differentiation of malignant from benign lesions may be possible, at least to some extent, by meticulous assessment of the conventional US rather than CEUS findings.

Biochemical and Clinical Predictive Approach and Time Point Analysis of Hepatobiliary Phase Liver Enhancement on Gd-EOB-DTPA-enhanced MR Images: A Multicenter Study.

Purpose To identify biochemical factors associated with liver enhancement over time on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) images and predict the optimal time point of the hepatobiliary phase in various clinical settings. Materials and Methods This study was approved by the institutional review boards, and written informed consent was obtained from the 1903 patients enrolled. Simple and multiple logistic regression analyses were performed to investigate the biochemical factors associated with liver-to-spleen contrast (LSC) of at least 1.5 in the hepatobiliary phase. Changes in LSC and lesion-to-liver contrast (LLC) of lesions over time (at 5, 10, 15, and 20 minutes) were investigated with a linear mixed-effects model in patients and lesions. For LSC, the optimal cutoff value was determined with receiver operating characteristic analysis of the most significant variable. Differences in LSC and LLC were analyzed in various clinical settings. Results Ultimately, 1870 patients were evaluated, as 33 were excluded according to study criteria. Prothrombin (PT) activity, total bilirubin level (P = .020), and total cholesterol level (P = .005) were significantly associated with LSC of at least 1.5 at 20 minutes, and PT activity was identified as the most significant factor (odds ratio, 1.271; 95% confidence interval: 1.109, 1.455; P = .001). LSC of at least 1.5 at 20 minutes with PT activity of at least 86.9% and less than 86.9% occurred in 555 of 626 patients (88.6%) and 388 of 575 patients (67.5%), respectively. Satisfactory liver enhancement at 20 minutes was significantly more likely to be achieved by patients with hepatitis B virus than by those with hepatitis C virus (P < .001) and by patients with metastasis than by those with hepatocellular carcinoma (P < .001). No significant difference in LLC was observed in patients examined at 1.5 and 3.0 T (P = .133). Conclusion Hepatic enhancement is significantly associated with PT activity, total bilirubin level, and total cholesterol level. PT activity of at least 86.9% could be used to shorten examination times at Gd-EOB-DTPA-enhanced MR imaging. © RSNA, 2016 Online supplemental material is available for this article.

Obliteration of the Biliary System after Administration of an Oral Contrast Medium Is Probably due to Regurgitation: A Pitfall on MRCP.

PURPOSE: We retrospectively evaluated the incidence and related factors of obliteration of the lower bile duct after oral administration of contrast medium (OCM) probably resulting from its regurgitation into the biliary system (OCMRB) as observed on images of MR cholangiopancreatography (MRCP). METHODS: We retrospectively analyzed 305 MRCP images in 278 patients obtained between February 2010 and March 2011 using negative OCM with 1.0- and 1.5-tesla clinical units. OCMRB was defined as positive when visualization of the common bile duct was clear on precontrast 2-dimensional (2D) MRCP but obliterated on postcontrast 3-dimensional (3D) MRCP. Two abdominal radiologists reviewed all images in consensus. The incidence of OCMRB was correlated to various clinicoradiological factors. RESULTS: We observed OCMRB on 11 MRCP images in 10 patients (3.6%). Among various clinicoradiological factors, the presence of juxtapapillary diverticula, pneumobilia, and history of intervention to the papilla were suggested as significant factors related to positive OCMRB with multivariate analysis (P < 0.05). CONCLUSION: OCMRB occurs in about 4% of the patients who undergo MRCP, typically in those with juxtapapillary diverticula, pneumobilia, and history of papillary intervention. Acquisition of MRCP images before OCM may secure visualization of the common bile duct in these patients.

MR elastography of the liver at 3.0 T in diagnosing liver fibrosis grades; preliminary clinical experience.

OBJECTIVES: To clarify the usefulness of 3.0-T MR elastography (MRE) in diagnosing the histological grades of liver fibrosis using preliminary clinical data. MATERIALS AND METHODS: Between November 2012 and March 2014, MRE was applied to all patients who underwent liver MR study at a 3.0-T clinical unit. Among them, those who had pathological evaluation of liver tissue within 3 months from MR examinations were retrospectively recruited, and the liver stiffness measured by MRE was correlated with histological results. Institutional review board approved this study, waiving informed consent. RESULTS: There were 70 patients who met the inclusion criteria. Liver stiffness showed significant correlation with the pathological grades of liver fibrosis (rho = 0.89, p < 0.0001, Spearman's rank correlation). Areas under the receiver operating characteristic curve were 0.93, 0.95, 0.99 and 0.95 for fibrosis score greater than or equal to F1, F2, F3 and F4, with cut-off values of 3.13, 3.85, 4.28 and 5.38 kPa, respectively. Multivariate analysis suggested that grades of necroinflammation also affected liver stiffness, but to a significantly lesser degree as compared to fibrosis. CONCLUSIONS: 3.0-T clinical MRE was suggested to be sufficiently useful in assessing the grades of liver fibrosis. KEY POINTS: MR elastography may help clinicians assess patients with chronic liver diseases. Usefulness of 3.0-T MR elastography has rarely been reported. Measured liver stiffness correlated well with the histological grades of liver fibrosis. Measured liver stiffness was also affected by necroinflammation, but to a lesser degree. 3.0-T MRE could be a non-invasive alternative to liver biopsy.

Optimization of scanning parameters for MR elastography at 3.0 T clinical unit: volunteer study.

PURPOSE: We sought to optimize scanning parameters for MR elastography at 3.0 T clinical unit. MATERIALS AND METHODS: 10 volunteers were scanned with various magnetization encoding gradient (MEG) frequencies from 60 to 120 Hz at every 10 Hz, with otherwise fixed parameters (external driver frequency/amplitude = 60 Hz/50 %, 10 mm slice thickness, etc.). Images were qualitatively assessed for the degree of image defects, and also quantitatively for the areas without cross-hatching. After determining optimal MEG frequency, external driver amplitudes of 70 % (vs 50 %) and slice thickness of 8 mm (vs 10 mm) were also tested. With the optimized parameters, scans were repeated 1 week after the initial scan, and the repeatability of the liver stiffness measurement was validated. RESULTS: 80 or 90 Hz was shown to be the best MEG frequency. There were no significant differences in the qualitative and quantitative assessment between the two amplitudes and two slice thicknesses; however, 70 % amplitude resulted in discomfort at the chest wall beneath the external acoustic driver. Thus, MEG 80 (or 90) Hz, amplitude 50 %, and thickness 10 (or 8) mm were considered optimal. Repeatability of the liver stiffness measurement was ±10 % (95 % confidence interval). CONCLUSIONS: With the optimized parameters, repeatability of ±10 % in liver stiffness measurement was obtained.

Measurement consistency of MR elastography at 3.0 T: comparison among three different region-of-interest placement methods.

PURPOSE: To test inter- and intraobserver consistency of liver stiffness measurement on MR elastography (MRE) at 3.0 T. MATERIALS AND METHODS: Two abdominal radiologists independently measured stiffness of the liver on MRE in three volunteers and seven patients with chronic liver diseases using three different region-of-interest (ROI) placement methods. Methods 1 and 2 involved placing circular and free-hand-drawn ROIs, respectively, visually referring to anatomical (three-dimensional T1-weighted) and wave images. Method 3 involved placing ROIs on the fused images of MRE and anatomical images developed on a work station, visually referring to wave images. The inter- and intraobserver consistency was assessed with regression and Bland-Altman analysis. RESULTS: Thirty-eight images were available for measurement in total. As for interobserver consistency, method 3 showed the best regression coefficient, correlation coefficient, and y intercept. The absolute values of the interobserver differences for method 3 were significantly smaller than those of method 1 or method 2 (p < 0.05, each). Intraobserver consistency of method 3 was excellent for both observers. CONCLUSION: Stiffness measurement of the liver on MRE performed with the fusion method at 3.0 T provides the highest inter- and intraobserver consistency.

Pseudolesion of the liver on gadoxetate disodium-enhanced MR images obtained after transarterial chemoembolization for hepatocellular carcinoma: clinicoradiologic correlation.

OBJECTIVE: The purpose of this study was to elucidate the clinicoradiologic characteristics of pseudolesions of the liver in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE) as observed on gadoxetate disodium-enhanced MR images. A particular interest was correlation between the pseudolesion characteristics and TACE-MRI interval, during which sequential changes in pseudolesions may be revealed after TACE. MATERIALS AND METHODS: Forty-eight patients with HCC who underwent gadoxetate disodium-enhanced MRI after TACE were retrospectively recruited. Pseudolesions were defined as areas of decreased signal intensity in treated areas on hepatocellular phase images that were confirmed to be nontumorous areas at follow-up. The prevalence and MRI features of pseudolesions were correlated with various clinical parameters, including TACE-MRI interval. RESULTS: Pseudolesions were found in 14 patients (29%). Within 1 month of TACE, the prevalence of pseudolesions was 83%. All of the pseudolesions had arterial enhancement, mimicking residual HCC. After 1 month, the prevalence of pseudolesions decreased, and these pseudolesions tended to exhibit no abnormality in any sequence other than the hepatocellular phase. Results of multivariate analysis suggested that size of HCC (p < 0.0001), duration of postembolization syndrome (p = 0.012), and TACE-MRI interval (p = 0.038) are independent indicators of the presence of pseudolesions. CONCLUSION: The prevalence and appearance of pseudolesions differ at different intervals from TACE. Radiologists need to recognize the clinicoradiologic characteristics to differentiate pseudolesions from true residual or recurrent HCC.

Pseudolesion of the liver observed on gadoxetate disodium-enhanced magnetic resonance imaging obtained shortly after transarterial chemoembolization for hepatocellular carcinoma.

The purpose of this report was to describe pseudolesions of the liver that mimicked residual hypervascular hepatocellular carcinoma (HCC), as observed on gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI) obtained shortly after transarterial chemoembolization (TACE). Between June 2008 and December 2008, three patients underwent MRI within 12 days after TACE to rule out remaining viable cancerous tissue or to assess the treatment effect. In all three patients, nontumorous liver tissue adjacent to the treated HCC exhibited focal arterial enhancement on dynamic phase and subsequent diminished uptake of gadoxetate disodium on hepatocellular phase images, which mimicked residual HCC. All three patients had mild postembolization syndrome at the time of EOB-MRI and showed no evidence of residual or recurrent tumors on follow-up. The findings of these areas may represent transient focal hyperemia and damage to the liver cell function caused by TACE. Radiologists should be aware that EOB-MRI obtained shortly after TACE may show pseudolesions around the treated tumors and should not mistake them for residual or recurrent tumors.

Clinico-roentogenologic findings in hepatocellular carcinoma fed by the right inferior phrenic artery at the initial chemoembolization.

BACKGROUND/AIMS: The purpose of this study was to investigate factors that may predict the development of the right inferior phrenic artery (RIPA) as a feeding artery in hepatocellular carcinoma (HCC) at the initial (first session) chemoembolization. METHODOLOGY: From January 1997 to June 2002, 538 patients with HCC were treated with a first session of transcatheter arterial chemoembolization (TACE). Twenty-six of these patients underwent TACE via both the Hepatic artery (HA) and RIPA at the initial TACE. We retrospectively analyzed the Child-Pugh's classification, macroscopic tumor type, location and size of the tumor, past history of intervention, complications and outcome in these 26 patients with HCC fed by the RIPA. RESULTS: The incidence of HCC fed by both the HA and RIPA at the initial TACE was 4.8% (26/538 patients). No hepatic arterial occlusion or attenuation was found in any of these 26 patients. All of the tumors abutted the diaphragm and were located at the surface of the liver. All of the tumors that were larger than 5 cm in diameter protruded from the surface of the liver. Seven of the 9 patients with HCC smaller than 5 cm in diameter had a defect in the liver capsule induced by previous intervention for the treatment of a different tumor, such as hepatic resection or percutaneous ablation therapy. There were no serious complications after TACE. CONCLUSION: The RIPA can be an extrahepatic feeding artery for HCC even at the initial TACE. A high incidence of HCC fed by the RIPA was recognized in cases in which a large tumor protruded from the surface of the liver, and when the liver capsule was damaged due to previous intervention such as hepatic resection or in ruptured HCC even at the initial TACE.

Successful embolization of pancreaticoduodenal artery pseudoaneurysm in a patient with common hepatic arterial occlusion after modified pancreatoduodenectomy with preservation of arteries in the head of pancreas.

Pancreaticoduodenectomy (PD) with preservation of the arcade in the head of the pancreas was performed in a 73-year-old male with ampullary adenocarcinoma associated with occlusion of the common hepatic artery (CHA) in another hospital. He developed active bleeding from his drain site, at 18 days after the operation. He was transferred to our hospital for emergent embolization. Celiac arteriogram showed complete occlusion of the CHA, posterior superior pancreaticoduodenal artery (PSPDA) pseudoaneurysm 1.7 cm in diameter and development of an enlarged tortuous dorsal pancreatic artery (DPA), posterior pancreatico-duodenal artery (PPDA), and gastroduodenal artery (GDA). Complete hemostasis was obtained without major complications by the transcatheter arterial embolization (TAE) with microcoils.