Non-hypervascular Hypointense Nodules on Hepatocyte Phase Gadoxetic Acid-Enhanced MR Images: Transformation of MR Hepatobiliary Hypointense Nodules into Hypervascular Hepatocellular Carcinomas

BACKGROUND/AIMS: The annual risk of transformation of non-hypervascular magnetic resonance (MR) hepatobiliary phase imaging (HBPI) hypointense nodules into hypervascular hepatocellular carcinomas (HCCs) was evaluated. METHODS: Cirrhotic patients with non-hypervascular HBPI hypointense nodules were retrospectively analyzed if they were diagnosed as HCC and MR followed up longer than 1 year during the period from January 2010 to October 2016 with regular intervals of 3 to 6 months. Risk factors for transformation into hypervascular HCCs were analyzed using the Cox proportional hazard model. RESULTS: Among the 103 non-hypervascular HBPI hypointense nodules meeting the inclusion criteria, transformation into hypervascular HCCs occurred in 44 tumors (42.7%). The median follow-up period was 24 months. Multivariate analysis revealed that hyperintensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI) were the two independent predictors of transformation into hypervascular HCCs (p=0.036 and p=0.041, respectively). Most tumors with hyperintensity on T2WI or DWI on the initial or follow-up MR were transformed into hypervascular HCCs within the first year. Among the 22 nodules (21.3%) showing a new change in dynamic phases during follow-up, 14 nodules (13.6%) showed malignant transformations. CONCLUSIONS: The transformation rates of HBPI hypointense nodules into hypervascular HCCs could be predicted according to the initial or serial MRI findings.

Tumor Recurrence in Hepatocellular Carcinoma Patients after Radiofrequency Ablation: Portal Hypertension as an Indicator of Recurrence of Hepatocellular Carcinoma

PURPOSE@#To evaluate the effect of portal hypertension on the tumor recurrence in patients with hepatocellular carcinoma (HCC) and without hepatic decompression following radiofrequency ablation (RFA).@*MATERIALS AND METHODS@#Treatment-naïve HCC patients within the Milan criteria and with Child-Pugh class A were included in this study, who had performed RFA in our hospital between January 2010 and March 2017. Univariate and multivariate analyses using the Cox proportional hazard model were performed to find the predictors of local or distant tumor recurrence.@*RESULTS@#Overall, 178 patients were included in this study. Median follow-up period was 40.2 months. The difference in the local tumor progression rates depending on the absence or presence of portal hypertension was not statistically significant (p = 0.195). The 1-, 3-, and 5-year distant intrahepatic tumor spread rates were 6.6%, 29.5%, and 537% in patients without portal hypertension, and 23.4%, 51.9%, and 63.6% in patients with portal hypertension, respectively. The difference was statistically significant (p = 0.011). Univariate and multivariate analysis showed that portal hypertension was an independent predictor for distant intrahepatic tumor spread (p = 0.008).@*CONCLUSION@#For HCC patients with Child-Pugh class A, portal hypertension adversely affected distant intrahepatic tumor progression.

Deep Femoral Vessel Injury Following Subtrochanteric Hip Fracture: A Case Report

Arterial trauma associated with hip fracture treatment is still a rare complication. We present a case in which an arterial injury was discovered during closed reduction and intramedullary nail fixation of a subtrochanteric hip fracture. The preoperative thigh circumference was increased due to severe swelling, and the vascular injury was located substantially proximal to the fracture and the instrumentation area. An interventional angiogram revealed a damaged vessel originating from one of the minor proximal branches of the right deep femoral artery while filling a 2 cm-sized pseudoaneurysm. Embolization was performed without further complications.

Combined Anomaly of the Right Hepatic Lobe Agenesis and Absence of the Inferior Vena Cava: a Case Report

The absence of the inferior vena cava is an uncommon congenital anomaly that has recently been identified as an important risk factor contributing to the development of deep venous thrombosis. Congenital agenesis of the right hepatic lobe is a rare anomaly which is found incidentally in radiologic examinations. We present a case of a congenital absence of the infrarenal inferior vena cava, combined with agenesis of the right hepatic lobe in a 62-year-old man presented with symptoms of deep venous thrombosis.

A Covered Nitinol Stent Fracture in a Patient with a Malignant Esophageal Stricture: A Case Report

Self-expanding metallic stent insertion has been widely applied for the palliative treatment of malignant esophageal strictures. Although it is known as an easy, safe, and effective procedure, complications are well known and include things such as stent migration and esophageal stent occlusion caused by tumor ingrowth. However, metallic stent fractures have been rarely reported in the esophagus, especially for nitinol stents. We report a case of a stent fracture associated with migration in a patient with a malignant esophageal stricture near the gastroesophageal junction. It is highly probable that the stent fracture was due to chemical erosion of the stent caused by gastric juice.

Multivariate Analysis of the Predictors of Survival for Patients with Hepatocellular Carcinoma Undergoing Transarterial Chemoembolization: Focusing on Superselective Chemoembolization

OBJECTIVE: While the prognostic factors of survival for patients with hepatocellular carcinoma (HCC) who underwent transarterial chemoembolization (TACE) are well known, the clinical significance of performing selective TACE for HCC patients has not been clearly documented. We tried to analyze the potential factors of disease-free survival for these patients, including the performance of selective TACE. MATERIALS AND METHODS: A total of 151 patients with HCC who underwent TACE were retrospectively analyzed for their disease-free survival (a median follow-up of 23 months, range: 1-88 months). Univariate and multivariate analyses were performed for 20 potential factors by using the Cox proportional hazard model, including 19 baseline factors and one procedure-related factor (conventional versus selective TACE). The parameters that proved to be significant on the univariate analysis were subsequently tested with the multivariate model. RESULTS: Conventional or selective TACE was performed for 40 and 111 patients, respectively. Univariate and multivariate analyses revealed that tumor multiplicity, venous tumor thrombosis and selective TACE were the only three independent significant prognostic factors of disease-free survival (p = 0.002, 0.015 and 0.019, respectively). CONCLUSION: In our study, selective TACE was a favorable prognostic factor for the disease-free survival of patients with HCC who underwent TACE.

A Metastatic Adrenal Tumor from a Hepatocellular Carcinoma: Combination Therapy with Transarterial Chemoembolization and Radiofrequency Ablation

The adrenal gland is the second most common site of metastasis from a hepatocellular carcinoma (HCC). Radiofrequency ablation (RFA) for these tumors has been reported to be a potentially effective alternative to an adrenalectomy, especially for inoperable patients. However, for intermediate or large adrenal tumors, combination therapy of transarterial chemoembolization (TACE) and RFA can be attempted as it may reduce the heat sink effect. A 74-year-old patient presented with abdominal discomfort. Abdominal CT images revealed a 5.0 cm sized right adrenal mass. A percutaneous biopsy of the adrenal mass revealed a metastatic hepatocellular carcinoma. TACE was performed on the adrenal mass. However, a one-month follow-up CT image revealed a residual viable tumor. RFA was performed for the adrenal tumor six weeks after the TACE. No procedure-related major complications were noted. The serum alpha-fetoprotein level had also been normalized after the treatment, and 10-month follow-up CT images showed no definite evidence of viable adrenal tumor.

Radiologic Findings of Bilateral Elastofibroma Dorsi: A Case Report

Elastofibroma dorsi is a rare, slow-growing, ill defined soft tissue tumor that's typically found between the inferior scapula and chest wall. The characteristic findings on ultrasonography, MRI and CT usually allow the correct diagnosis and so prevent unnecessary surgical procedure. We experienced a case of bilateral elastofibroma dorsi in an 87-year-old man, and we report on this case along with a review of the literature.

Local Recurrence of Hepatocellular Carcinoma after Segmental Transarterial Chemoembolization: Risk Estimates Based on Multiple Prognostic Factors

OBJECTIVE: To determine the prognostic factors for local recurrence of nodular hepatocellular carcinoma after segmental transarterial chemoembolization. MATERIALS AND METHODS: Seventy-four nodular hepatocellular carcinoma tumors < or = 5 cm were retrospectively analyzed for local recurrence after segmental transarterial chemoembolization using follow-up CT images (median follow-up of 17 months, 4-77 months in range). The tumors were divided into four groups (IA, IB, IIA, and IIB) according to whether the one-month follow-up CT imaging, after segmental transarterial chemoembolization, showed homogeneous (Group I) or inhomogeneous (Group II) iodized oil accumulation, or whether the tumors were located within the liver segment (Group A) or in a segmental border zone (Group B). Comparison of tumor characteristics between Group IA and the other three groups was performed using the chi-square test. Local recurrence rates were compared among the groups using the Kaplan-Meier estimation and log rank test. RESULTS: Local tumor recurrence occurred in 19 hepatocellular carcinoma tumors (25.7%). There were: 28, 18, 17, and 11 tumors in Group IA, IB, IIA, and IIB, respectively. One of 28 (3.6%) tumors in Group IA, and 18 of 46 (39.1%) tumors in the other three groups showed local recurrence. Comparisons between Group IA and the other three groups showed that the tumor characteristics were similar. One-, two-, and three-year estimated local recurrence rates in Group IA were 0%, 11.1%, and 11.1%, respectively. The difference between Group IA and the other three groups was statistically significant (p = 0.000). CONCLUSION: An acceptably low rate of local recurrence was observed for small or intermediate nodular tumors located within the liver segment with homogeneous iodized oil accumulation.

Risk Factors for Local Tumor Recurrence after Segmental Transarterial Chemoembolization for Hepatocellular Carcinoma: the Importance of Tumor Located in the Segmental Border Zone

OBJECTIVE: We wanted to evaluate whether tumors located in a segmental border zone are predisposed to local recurrence after performing segmental transarterial chemoembolization for hepatocellular carcinoma. MATERIALS AND METHODS: Seventy-three hepatocellular carcinoma nodules were retrospectively analyzed for local tumor recurrence after performing segmental transarterial chemoembolization by using follow-up CT studies (median follow-up period: 20 months, range: 4-77 months). The tumors were divided into two groups according to whether the lesions were located at the segmental border zone (Group I) or not (Group II). Comparison of the tumor characteristics and chemoembolization methods between the two groups was performed using the chi-square test. The local recurrence rates were compared by Kaplan-Meyer method and analyzed with the log rank test. RESULTS: Local tumor recurrence occurred for 25 hepatocellular carcinoma nodules (42.9%). The follow-up periods, tumor characteristics and chemoembolization methods between Groups l and ll were comparable. The local recurrence rate was 64.0% (16/25) in Group I and 18.8% (9/48) in Group II. The difference was statistically significant on the univariate and multivariate analyses (p = 0.000 for both). CONCLUSION: Tumor location in a segmental border zone was a significant risk factor for local tumor recurrence after performing segmental transarterial chemoembolization for hepatocellular carcinoma.

Comparison of FSE and EPI with Brain MR Imaging

PURPOSE: To compare the usefulness of echo-planar imaging (EPI) and fast spin-echo (FSE) in routine brain MR imaging. MATERIALS AND METHODS: Twenty-five patients with various intracranial diseases were prospectively examined with T2-weighted MR imaging on a 1.5T unit using FSE, spin echo singl-shot EPI (SS-EPI) and multi-shot EPI (MS-EPI) techniques. For qualitative assessment, overall image quality, discrimination between cortical gray-white matter and between basal ganglia-white matter, lesion conspicuity, image distortion and artifacts (motion, ghost, flow, and susceptibility) were all evaluated using a subjective scoring system ranging from 1 to 4 (1 for the worst and 4 for the best). For quantitative assessment, contrast and contrast-to-noise ratio (CNR) were calculated for cortical gray-white matter, basal ganglia-white matter, and lesion-white matter. RESULTS: Overall image quality, discrimination between cortical gray-white matter, basal ganglia-white matter, and lesion-white matter, lesion conspicuity, image distortion and susceptibility artifacts showed the highest value in FSE and the lowest in SS-EPI. Motion artifacts were seen only in FSE, while flow and ghost artifacts were most commonly seen in SS-EPI. Contrast and CNR of anatomical and pathologic structures showed the highest value in FSE, especially for cortical gray-white matter and basal ganglia-white matter . CONCLUSION: With regard to overall image quality, image distortion, susceptibility artifacts, contrast and CNR, EPI is far inferior to FSE. In routine brain MR imaging., the usefulness of EPI techniques would therefore be very limited.

Thin Section Helical CT Findings of Klatskin Tumor and Benign Stricture: Cholangiographic Correlation

PURPOSE: The purpose of this study was 1) to describe the thin section helical CT findings of hilar cholangiocarcinoma and of benign stricture, and to discuss the differential points between the two disease entities and 2) using cholangiographic correlation, to evaluate the diagnostic accuracy of helical CT in determining the extent of hilar cholangiocarcinoma. MATERIALS AND METHODS: Twenty-seven patients with hilar cholangiocarcinoma and eight with benign biliary dilatation were studied. All except four with hilar cholangiocarcinoma, who underwent CT using a conventional scanner, were studied with two-phase helical CT. In all patients, cholangiographs were obtained by digital fluoroscopy after the injection of contrast materials into PTBD catheters. The level of obstruction was classified according to Bismuth, and 35 CT scans were studied blindly and retrospectively by two radiologists. The findings were analyzed for the presence of tumor, and then divided into two groups (cholangiocarcinomas and benign strictures), and the positive predictive value was calculated. The CT images of klatskin tumor were analyzed with special emphasis on the level and shape of the hilar obstruction. The level of biliary obstruction and extent of the tumor were carefully correlated with the results of cholangiography. RESULTS: Thin-section spiral CT correctly identified all tumor mass as a focal wall thickening obliterating the lumen. On arterial/portal phase CT scanning, 81% of infilterative tumors showed high attenuation. In all patients, differentiation between benign stricture and klatskin tumor was possible ; correct identification of the level of obstruction and extent of tumor, according to Bismuth's classification, was possible in 63% of cases. CONCLUSION: For correct diagnosis of hilar cholangiocarcinoma and differentiation of benign stricture, helical CT was highly accurate and effective. Because of limital Z-axis resolution, however, the exact intraductalextent of the tumor was less accorately diagnosed.

Liver Neoplasms: Atypical CT and MR Imaging Findings

The use of advanced imaging techniques in computed tomography(CT) and magnetic resonance imaging (MRI) has established the appearance of most common liver neoplasms. There are, however, considerable overlaps In the appearances of various pathologic entities on CT and MRI, and certain hepatic lesions can show unusual characteristics that may lead to misinterpretation, so it is important for the radiologist to be aware of these uncommon appearances. The purpose of this article is to illustrate the spectra of uncommon patterns and various diagnostic pitfalls encountered on CT and MRI of liver neoplasms.

MR Imaging of Intramedullary Tumors of the Spinal Cord

PURPOSE: The purpose of this study was to evaluate the characteristic MR findings of intramedullary spinal cord tumors according to histologic diagnosis. MATERIALS AND METHODS: MR images of 34 patients with surgically-proven intramedullary spinal cord tumor were retrospectively reviewed. Histologic diagnosis revealed 15 ependymomas, ten astrocytomas, three hemangioblastomas, two oligidendrogliomas, one malignant schwannoma, one glioblastoma multiforme, one neuroblastoma and one ganglioglioma. MR images were analyzed for location, size, shape, signal intensity, and degree and pattern of contrast enhancement of the tumors. RESULTS: All tumors showed cord expansion and a varying extent of involvement ranging from 1.5 to 30cm. Variable degrees of contrast enhancement were seen in all cases. Cervical, cervico-thoracic, thoracic, and thoraco-lumbar spinal ependymomas accounted for three, two, six, and four cases, respectively, while four, two, and four cases of cervical, cervico-thoracic, and thoracic spinal astrocytomas respectively, were seen. Other tumors were located most commonly in the thoracic spinal cord. A sharply-defined tumor margin was seen in 13 of 15 ependymomas, in all three hemangioblastomas, one neuroblastoma and one ganglioglioma. Tumors usually showed slightly low- or iso-signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Peritumoral cysts were seen in nine ependymomas, one hemangioblastoma, and one astrocytoma, while peritumoral hemorrhage was seen only in three ependymomas. Relatively homogeneous enhancement was seen in nine of 13 ependymomas, all hemangioblastomas and one neuroblastoma. All ten astrocytomas showed a poorly defined tumor margin and heterogeneous enhancement. CONCLUSION: On the basis of characteristic MR findings, intramedullary cord tumors may be histopathologically diagnosed.