Masahiro Tanabe

Imaging Outcomes of Liver Imaging Reporting and Data System Version 2014 Category 2, 3, and 4 Observations Detected at CT and MR Imaging

Purpose To determine the proportion of untreated Liver Imaging Reporting and Data System (LI-RADS) version 2014 category 2, 3, and 4 observations that progress, remain stable, or decrease in category and to compare the cumulative incidence of progression in category. Materials and Methods In this retrospective, longitudinal, single-center, HIPAA-compliant, institutional review board-approved study, 157 patients (86 men and 71 women; mean age ± standard deviation, 59.0 years ± 9.7) underwent two or more multiphasic computed tomographic (CT) or magnetic resonance (MR) imaging examinations for hepatocellular carcinoma surveillance, with the first examination in 2011 or 2012. One radiologist reviewed baseline and follow-up CT and MR images (mean follow-up, 614 days). LI-RADS categories issued in the clinical reports by using version 1.0 or version 2013 were converted to version 2014 retrospectively; category modifications were verified with another radiologist. For index category LR-2, LR-3, and LR-4 observations, the proportions that progressed, remained stable, or decreased in category were calculated. Cumulative incidence curves for progression were compared according to baseline LI-RADS category (by using log-rank tests). Results All 63 index LR-2 observations remained stable or decreased in category. Among 166 index LR-3 observations, seven (4%) progressed to LR-5, and eight (5%) progressed to LR-4. Among 52 index LR-4 observations, 20 (38%) progressed to a malignant category. The cumulative incidence of progression to a malignant category was higher for index LR-4 observations than for index LR-3 or LR-2 observations (each P < .001) but was not different between LR-3 and LR-2 observations (P = .155). The cumulative incidence of progression to at least category LR-4 was trend-level higher for index LR-3 observations than for LR-2 observations (P = .0502). Conclusion Observations classified according to LI-RADS version 2014 categories are associated with different imaging outcomes. (©) RSNA, 2016 Online supplemental material is available for this article.

Iodized oil accumulation in hypervascular hepatocellular carcinoma after transcatheter arterial chemoembolization: comparison of imaging findings with CT during hepatic arteriography.

PURPOSE To compare the degree of tumor enhancement seen on computed tomography (CT) during hepatic arteriography (CT/HA) performed before transcatheter arterial chemoembolization (TACE) versus that determined based on the accumulation of iodized oil seen on CT images obtained after TACE in patients with hypervascular hepatocellular carcinoma (HCC) and evaluate the discrepancy in findings between the two imaging modalities (more or less oil accumulation after TACE compared with enhancement on CT/HA). MATERIALS AND METHODS CT/HA, TACE, and iodized oil CT after TACE were performed in 69 patients with 83 hypervascular HCCs with use of an interventional CT system. The degree of contrast enhancement of the lesion on CT/HA and the iodized oil accumulation on unenhanced CT after TACE were compared. RESULTS Among 83 HCCs, the degree of enhancement on CT/HA before TACE corresponded to the iodized oil accumulation on CT in 56 (67.5%). Fifteen of 83 HCCs (18%) showed incomplete or poor accumulation of iodized oil despite good enhancement on CT/HA images. Twelve of 83 HCCs (14.5%) showed moderate or complete accumulation of iodized oil despite poor or no enhancement on CT/HA images. In particular, in two patients with occluded portal veins, iodized oil did not accumulate in the tumor despite good visualization on CT/HA. CONCLUSIONS Although iodized oil accumulation in hypervascular HCCs correlates with the degree of lesion enhancement on CT/HA in most cases, a discrepancy may occur in a substantial number of cases, which likely affects the prediction of therapeutic effects in hypervascular HCCs.

Imaging findings of unusual intra- and extrahepatic portosystemic collaterals.

We describe unusual portosystemic shunts demonstrated using computed tomography (CT) and magnetic resonance imaging (MRI), including gallbladder varices, aberrant left gastric vein to left portal vein collaterals, intrahepatic and transhepatic portosystemic venous shunt, and mesenteric varices. Familiarity with the CT and MRI features of unusual portosystemic shunts will help in making the correct diagnosis for affected patients.

Portal Venous System: Evaluation with Unenhanced MR Angiography with a Single-Breath-Hold ECG-Synchronized 3D Half-Fourier Fast Spin-Echo Sequence

OBJECTIVE Eighteen healthy persons underwent unenhanced MR angiography with a breath-hold ECG-synchronized 3D half-Fourier fast spin-echo technique to evaluate the visibility of the portal vein and its branches. CONCLUSION Our results indicated that unenhanced MR angiography with a singlebreath-hold ECG-synchronized 3D half-Fourier fast spin-echo sequence facilitates precise visualization of the anatomic features of the portal vein and its branches without the use of contrast agents.

Immediate and late outcomes of bronchial and systemic artery embolization for palliative treatment of patients with nonsmall-cell lung cancer having hemoptysis.

Background: Hemoptysis in patients with advanced lung cancer can be a life threatening. Objectives: To evaluate immediate outcomes and late outcomes of bronchial artery embolization (BAE) for palliative treatment in patients with advanced nonsmall-cell lung cancer (NSCLC) having hemoptysis. Methods: The BAE was performed in 28 patients with NSCLC. Hemoptysis was defined as follows: massive bleeding greater than 300 mL within 24 hours (n = 8), moderate bleeding of 100 to 300 mL within 24 hours (n =12), and slight bleeding less than100 mL within 24 hours (n = 8). Results: Success rate was 96%. Immediate clinical success within 24 hours after BAE was achieved in 22 of the 27 patients who underwent embolization. Conclusions: The BAE with gelatin sponge particles can provide good management of hemoptysis as a palliative treatment in patients with advanced NSCLC.

Small hepatic lesions found on single-phase helical CT in patients with malignancy: Diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) MR imaging using a half-fourier acquisition single-shot turbo spin-echo (HASTE) sequence

To evaluate the diagnostic capability of breath‐hold, multisection fluid‐attenuated inversion‐recovery (FLAIR) imaging using a half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE) sequence in combination with T2‐weighted fast spin‐echo (FSE) magnetic resonance (MR) sequences for small hepatic lesions found on CT in patients with malignancy.

Cisterna chyli in patients with portal hypertension: Evaluation with MR imaging

To evaluate the difference in the caliber of cisterna chyli between patients with and without portal hypertension on magnetic resonance imaging (MRI) and to assess the alteration of the caliber of cisterna chyli related to contraction waves during serial T2‐weighted MRI.

Evaluation of intraportal venous flow distribution by unenhanced MR angiography using three-dimensional fast spin-echo with a selective tagging pulse: Efficacy of subtraction of tag-on and tag-off images acquired during a single breath-hold

To evaluate the efficacy of subtracted MR images from two sets of unenhanced three‐dimensional (3D) MR angiography data (tag‐on and tag‐off images) acquired simultaneously during a single breath‐hold in assessing the intraportal venous flow distribution to the distal branches from the superior mesenteric vein (SMV) and the splenic vein (SpV).

Hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide-enhanced magnetic resonance imaging in cirrhosis or chronic hepatitis: comparison of four magnetic resonance sequences for lesion conspicuity

PURPOSE The aim of this study was to determine the adequate MR sequence for the lesion conspicuity of hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide (SPIO)-enhanced MRI. MATERIALS AND METHODS SPIO-enhanced MRI was performed using a 1.5-T system. Among 25 patients with hypovascular hepatocellular nodules on contrast-enhanced dynamic CT (no early enhancement at arterial phase and hypoattenuation at equilibrium phase), 39 lesions with increased iron uptake on SPIO-enhanced MRI were evaluated. SPIO-enhanced MRI included (1) T1-weighted in-phase gradient recalled echo (GRE) images, (2) T2-weighted fast spin echo (FSE) images, (3) T2*-weighted GRE with moderate TE (7 ms) and (4) long TE (12 ms). The lesion-to-liver contrast-to-noise ratios of the hepatocellular nodule and the signal-to-noise ratio (SNR) of the hepatic parenchyma were calculated by one radiologist for a quantitative assessment. MR images were reviewed retrospectively by two independent radiologists to compare the subjective lesion conspicuity in each image set based on a four-point rating scale. RESULT The mean lesion-to-liver contrast-to-noise ratios with T2*-weighted GRE with moderate TE (7 ms) was highest (5.79+/-3.71) and was significantly higher than those with T1-weighted, in-phase images (3.79+/-3.23, P<.01), T2-weighted images (2.72+/-1.52, P<.001) and T2*-weighted GRE with long TE (12 ms) (3.93+/-2.69, P<.05). The subjective rating of lesion conspicuity was best on the T2*-weighted GRE with moderate TE (7 ms), followed by that on the T2*-weighted GRE with moderate TE (7 ms; P<.05). CONCLUSION T2*-weighted GRE sequence with moderate TE (7 ms) showed high lesion-to-liver contrast-to-noise ratios in hepatocellular lesions with increased iron uptake on SPIO-enhanced MRI, indicating better lesion conspicuity of hypointense hepatocellular nodules in cirrhosis or chronic hepatitis.

Percutaneous Gastrostomy Tube Placement Using a Balloon Catheter in Patients With Head and Neck Cancer

BACKGROUND Patients with head and neck cancer frequently require gastrostomy feeding. The aim of this study was to evaluate the safety and feasibility of percutaneous radiologic gastrostomy with push-type gastrostomy tubes using a rupture-free balloon (RFB) catheter under computed tomography (CT) and fluoroscopic guidance in patients with head and neck cancer with swallowing disturbance or trismus. METHODS Percutaneous CT and fluoroscopic gastrostomy placement of push-type gastrostomy tubes using a RFB catheter was performed in consecutive patients with head and neck cancer between April 2007 and July 2010. The technical success, procedure duration, and major or minor complications were evaluated. RESULTS Twenty-one patients (14 men, 7 women; age range, 55-78 years; mean age, 69.3 years) underwent gastrostomy tube placement. The tumor location was the pharynx (n = 8), oral cavity (n = 7), and gingiva (n = 6). Gastrostomy was performed in 15 patients during treatment and 6 patients after treatment. Percutaneous radiologic gastrostomy was technically successful in all patients. The median procedure time was 35 ± 19 (interquartile range) minutes (range, 25-75). The average follow-up time interval was 221 days (range, 10-920 days). No major complications related to the procedure were encountered. No tubes failed because of blockage, and neither tube dislodgement nor intraperitoneal leakage occurred during the follow-up periods. CONCLUSION Percutaneous CT and fluoroscopic-guided gastrostomy with push-type tubes using a RFB catheter is a relatively safe and effective means of gastric feeding, with high success and low complication rates in patients with head and neck cancer in whom endoscopy was not feasible.