LI-RADS v2014 categorization of hepatocellular carcinoma: Intraindividual comparison between gadopentetate dimeglumine-enhanced MRI and gadoxetic acid-enhanced MRI.

OBJECTIVES: To use Liver Imaging Reporting and Data System (LI-RADS) categorization and features of hepatocellular carcinomas (HCCs) to intraindividually compare gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-DTPA-MRI) and gadoxetic acid-enhanced MRI (Gd-EOB-MRI), before and after applying modified major features. METHODS: Of 77 HCCs in 64 patients analysed, 17 HCCs were confirmed histopathologically and 46 patients had cirrhosis. Gd-EOB-MRI and Gd-DTPA-MRI were evaluated for the presence of major and ancillary features by two radiologists. LI-RADS categorization was done for Gd-DTPA-MRI (LI-RADS-DTPA) and for Gd-EOB-MRI before and after applying modified major features (hepatobiliary phase [HBP] hypointensity as an additional major feature, LI-RADS-EOBm1; HBP hypointense rim as capsule appearance, LI-RADS-EOBm2; and transitional phase [TP] hypointensity as washout appearance, LI-RADS-EOBm3). Sensitivities of LR-5 categorization for the diagnosis of HCC were compared. RESULTS: Washout (p=0.012) and capsule appearance (p<0.001) were less frequently observed on Gd-EOB-MRI. Sensitivity for LR-5 categorization was significantly higher with LI-RADS-DTPA compared with LI-RADS-EOB (p=0.001) and LI-RADS-EOBm2 (p=0.004), while sensitivity for LR-5 categorization with LI-RADS-EOBm1 (p=0.210) and LI-RADS-EOBm3 (p=0.727) was comparable. CONCLUSION: Modifying LI-RADS for use with Gd-EOB-MRI, such as applying HBP hypointensity as an additional major feature or using TP hypointensity as washout appearance, can improve the sensitivity for the detection of HCC. KEY POINTS: • Adding HBP hypointensity as additional major feature improved sensitivity of LR-5 categorization. • Adding TP hypointensity as modified washout appearance improved sensitivity of LR-5 categorization. • Sensitivities for LR-5 classification were comparable between LI-RADS-DTPA, LI-RADS-EOBm1, and LI-RADS-EOBm3.

3-Dimensional Volumetric Analysis of Relationship Between the Orbital Volume Ratio and Enophthalmos in Unoperated Blowout Fractures.

PURPOSE: Blowout fractures are common in midfacial trauma and often involve other parts of facial bones. Sometimes, patients have complications caused by inadequate management. Surgical indications, such as clinical symptoms, can be inaccurate owing to post-traumatic swelling or hematoma formation. Previous studies on the prediction of enophthalmos used the orbital volume ratio (OVR) or only the volume of herniated tissue. This study examined which of these values is more predictive of the degree of enophthalmos. In addition, the predictive values for a 2-mm enophthalmos in unoperated blowout fractures were assessed. PATIENTS AND METHODS: A total of 191 patients underwent nonoperative treatment for blowout fractures at our institution; they were divided into 2 groups according to the degree of enophthalmos (>2 mm vs 0 to 2 mm) and were further divided into 3 subgroups according to the location of the fracture (inferior, medial, or inferomedial). Multifactor logistic regression analysis was performed to determine the relationship between the degree of enophthalmos and these values. RESULTS: We observed a correlation between the OVR and the degree of enophthalmos, as well as a correlation between the volume of herniated tissue and the degree of enophthalmos. Regarding the anatomic location of herniation, the orbital floor was found to be more correlated with the amount of enophthalmos. CONCLUSIONS: The OVR is a more reliable predictor than measurement of the volume of herniated tissue. The relationship found between radiologic examination findings and the degree of enophthalmos can be used as a surgical indication in addition to consideration of the anatomic location.

Leptomeningeal collateral vessels are a major risk factor for intracranial hemorrhage after carotid stenting in patients with carotid atherosclerotic plaque.

AIM: To evaluate the relationship between leptomeningeal collaterals and intracranial hemorrhage (ICH) after carotid artery stenting (CAS). METHODS: A retrospective study was undertaken of 228 patients (median age 75 years (range 44-90); 187 men and 41 women) who underwent CAS due to unilateral carotid atherosclerotic plaque from January 2009 to December 2013. Cerebral angiographic findings were classified into three patterns: type I, normal visualization of the anterior and middle cerebral arteries without leptomeningeal collaterals; type II, visualization of the middle cerebral artery only without leptomeningeal collaterals; and type III, visualization of leptomeningeal collateral flow. RESULTS: For all cerebral angiographic findings, 146 (64.0%) were type I, 61 (26.8%) were type II, and 21 (9.2%) were type III. Four patients (1.8%) died with fatal ICH after CAS and had type III angiographic findings (19%). The prevalence of ICH in patients with leptomeningeal collateral vessels was significantly higher than in patients without leptomeningeal collateral vessels (19% vs 0%, p<0.0001). The percentage of carotid stenosis in patients with ICH based on North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria was significantly higher than in patients without ICH (89.8±3.6% vs 72.8±12.8%, p=0.014). CONCLUSIONS: Leptomeningeal collateral vessels are a major risk factor for ICH after CAS in patients with carotid atherosclerotic plaque.

Retropharyngeal spindle cell/pleomorphic lipoma.

Spindle cell/pleomorphic lipoma is an uncommon benign adipose tissue tumor most frequently arising from the subcutaneous tissue of the back, shoulder, head and neck, and extremities. The deep cervical spaces are the rarely affected locations. Herein we report on the imaging findings of spindle cell/pleomorphic lipoma involving the retropharyngeal space in an elderly woman.

Myoid angioendothelioma of the spleen mimicking metastatic disease in a patient with rectal cancer: a radiologic-pathologic correlation.

Myoid angioendothelioma of the spleen is an uncommon, benign vascular tumor that is morphologically characterized by a composite of vascular spaces and stromal cells with myoid feature. Herein, we report a case of the myoid angioendothelioma of the spleen, concurrent with rectal adenocarcinoma. A 41-year-old woman presented with hematochezia for several weeks. Grossly, the rectal mass was a 2.5 × 2-cm ulcerative fungating lesion. The splenic mass was a 2.2 × 2-cm well-circumscribed lesion. Microscopically, the rectal mass was a well-differentiated adenocarcinoma that invaded into the pericolic adipose tissue. The splenic mass was composed of slit-like vascular spaces and fascicles of elongated stromal cells. Vascular endothelial cells were immunopositive for CD31, factor VIII-related antigen, and CD34 but negative for CD8. Stromal cells were immunopositive for smooth muscle actin but negative for desmin.

Ocular vestibular evoked myogenic potentials induced by air-conducted sound in patients with acute brainstem lesions.

OBJECTIVE: The ocular vestibular-evoked myogenic potential (oVEMP), a recently documented otolith-ocular reflex, is considered to reflect the central projections of the primary otolithic afferent fibers to the oculomotor nuclei. The aim of our study is to define air-conducted sound oVEMP abnormality in patients with acute brainstem lesions and to determine the brainstem structures involved in the generation of oVEMPs. METHODS: In response to air-conducted tone burst sounds (ACS), oVEMP was measured in 52 patients with acute brainstem lesions. Individualized brainstem lesions were analyzed by means of MRI-based voxel-wise lesion-behavior mapping, and the probabilistic lesion maps were constructed. RESULTS: More than half (n=28, 53.8%) of the patients with acute brainstem lesions showed abnormal oVEMP in response to ACS. The majority of patients with abnormal oVEMPs had lesions in the dorsomedial brainstem that contains the medial longitudinal fasciculus (MLF), the crossed ventral tegmental tract (CVTT), and the oculomotor nuclei and nerves. CONCLUSION: MLF, CVTT, and the oculomotor nuclei and nerves appear to be responsible for otolith-ocular responses in the brainstem. SIGNIFICANCE: Complemented to cervical VEMP for the uncrossed otolith-spinal function, oVEMP to ACS may be applied to evaluate the crossed otolith-ocular function in central vestibulopathies.

Detection of hepatocellular carcinoma: gadoxetic acid-enhanced 3-dimensional magnetic resonance imaging versus multi-detector row computed tomography.

PURPOSE: The aim of this study was to compare the diagnostic accuracy and sensitivity of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with multi-detector row computed tomography (MDCT) for the detection of hepatocellular carcinomas (HCCs). MATERIALS: Sixty-two patients (81 HCCs) who underwent MDCT and gadoxetic acid-enhanced MRI using a 3-dimensional volumetric interpolated technique with a mean interval of 7 days (range, 3-11 days) were included in this study. Two observers reached a consensus on 2 sets of images: the gadoxetic acid set (unenhanced, early dynamic, 10-minute, and 20-minute hepatocyte phase images) and the 3-phase MDCT. Diagnostic accuracy and sensitivity were evaluated using the alternative-free response receiver operating characteristic method. RESULTS: There was a trend toward increased area under the receiver operating characteristic curve (Az value) for the gadoxetic acid set (0.963) as compared with the MDCT (0.930), but no significant difference was found (P = 0.41). Sensitivity of the gadoxetic acid set (91.4%) was better than that of the MDCT (71.6%; P = 0.0001). There were 12 lesions that showed only arterial hypervascularization on MDCT but showed arterial hypervascularization and delayed hypointensity on the gadoxetic acid set. CONCLUSIONS: Gadoxetic acid-enhanced MRI, including hepatocyte phase imaging, is more sensitive than MDCT for the detection of HCCs.

Double-dose 1.0-M gadobutrol versus standard-dose 0.5-M gadopentetate dimeglumine in revealing small hypervascular hepatocellular carcinomas.

The purpose of this study was to compare the diagnostic efficacy of double-dose 1.0-M gadobutrol with that of standard-dose 0.5-M gadopentetate dimeglumine for revealing small hypervascular hepatocellular carcinomas (HCCs). Twenty-three patients with 37 HCCs (mean size: 1.2 cm) that were diagnosed by histology (n = 13) or imaging findings (n = 10) underwent two separate 3D dynamic MRIs with 0.2 mmol/kg of gadobutrol and 0.1 mmol/kg of gadopentetate dimeglumine. Three observers interpreted both MRIs in terms of lesion detection using the alternative-free response receiver operating characteristic method and lesion-to-liver contrast using matched pairs analysis. The two MRIs were also compared quantitatively by measuring the signal-to-noise ratio (SNR) of the liver and lesion as well as the lesion-liver contrast-to-noise ratio (CNR). The SNR of the liver and lesion and lesion-liver CNR with gadobutrol were better than those with gadopentetate dimeglumine (p < 0.01). However, in terms of the diagnostic accuracy (mean Az for gadobutrol: 0.878, and mean Az for gadopentate dimeglumine: 0.873), the sensitivity (92.8%), positive predictive value (92.8% vs. 93.7%) and lesion-liver contrast, the two dynamic MRIs were equivalent. Gadobutrol showed a superior degree of enhancement for hypervascular HCC than did gadopentetate dimeglumine, but the diagnostic capabilities of the two agents for revealing HCCs were equivalent.

Detection and characterization of liver metastases: 16-slice multidetector computed tomography versus superparamagnetic iron oxide-enhanced magnetic resonance imaging.

The aim of our study was to compare the diagnostic performance of 16--slice multidetector computed tomography with that of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the detection of small hepatic metastases and in the differentiation of hepatic metastases from cysts. Twenty-three patients with 55 liver metastases and 14 liver cysts underwent SPIO-enhanced MR imaging and multiphasic CT using 16-MDCT. Two observers independently analyzed each image, in random order. Sensitivity and diagnostic accuracy for lesion detection and differentiation as metastases or cysts for MDCT and SPIO-enhanced MR imaging were calculated using receiver operating characteristic analysis. For all observers, the Az values of SPIO-enhanced MR imaging for lesion detection and differentiation of liver metastases from cysts (mean 0.955, 0.999) were higher than those of MDCT (mean 0.925, 0.982), but not statistically significantly so (P > 0.05). Sensitivity of SPIO-enhanced MR imaging with regard to the detection of liver metastases (mean 94.5%) was significantly higher than that of MDCT (mean 80.0%) (P < 0.05). SPIO-enhanced MR imaging and 16-MDCT showed similar diagnostic accuracies for detection and differentiation of liver metastases from cysts, but sensitivity of SPIO-enhanced imaging in the detection of liver metastases was superior to that of 16-MDCT.

Polyurethane-covered self-expandable nitinol stent for malignant biliary obstruction: preliminary results.

PURPOSE: To evaluate the immediate and long-term results in ten patients with malignant biliary obstruction using a polyurethane-covered, self-expandable nitinol stent. METHODS: A nitinol stent, fully covered with high-elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 60-80 mm, was placed transhepatically under fluoroscopic guidance in ten patients. The length of the biliary obstruction varied between 30-50 mm. The follow-up examination included a clinical assessment, serum bilirubin measurement, and ultrasound examinations at one-month intervals in all patients. RESULTS: Initial stent deployment was successful in eight patients. Two patients experienced proximal migration, which was solved by insertion of two, uncovered Wallstents. One patient had the stent removed after two weeks because of severe nausea and vomiting. One patient had delayed migration of the covered stent after 40 weeks. The follow-up duration was 3-40 weeks (Mean: 16.9 weeks). Seven patients died (3-26 weeks) and three patients survived (24-40 weeks). The bilirubin measurements in all patients had significantly decreased one week after stent insertion. The levels of amylase and lipase had did not increase after stent insertion. CONCLUSIONS: A polyurethane-covered, self-expandable nitinol stent can be used effectively and safely in the treatment of malignant biliary obstruction. The preliminary results are favorable, but there is a need for further large studies to determine both long-term survival and patency.