Multiple metallic stents placement for malignant hilar biliary obstruction: Perspective of a radiologist

In the palliative setting, the necessity of biliary drainage of both liver lobes for malignant hilar biliary obstruction remains controversial. However, bilateral biliary drainage is a reasonable option to prevent cholangitis of the undrained lobe and to preserve liver function during the course of chemotherapy. Bilateral biliary drainage can be accomplished by the percutaneous or endoscopic placement of multiple self-expandable metallic stents (SEMS). Although SEMS placement via bilateral (multiple) percutaneous routes is technically simple, multiple percutaneous transhepatic biliary drainage (PTBD) may lead to additional morbidity. SEMS placement via a single percutaneous route is a useful method; however, negotiation of a guidewire into the contralateral bile duct is occasionally impossible if the hilar angle between the right hepatic duct and left hepatic duct is acute. Percutaneous dual SEMS placement is generally performed using the stent-in-stent technique (T configuration or Y configuration) or the side-by-side technique. In addition, the crisscross technique has been reported as being a useful method for trisegmental drainage. The side-to-end technique is also useful for multiple SEMS placement. In the future, the combination of percutaneous intervention and endoscopic ultrasonography-guided procedures may be effective in the management of malignant hilar biliary obstruction.

Preoperative Estimation of Future Remnant Liver Function Following Portal Vein Embolization Using Relative Enhancement on Gadoxetic Acid Disodium-Enhanced Magnetic Resonance Imaging

OBJECTIVE: To retrospectively evaluate relative enhancement (RE) in the hepatobiliary phase of gadoxetic acid disodium-enhanced magnetic resonance (MR) imaging as a preoperative estimation of future remnant liver (FRL) function in a patients who underwent portal vein embolization (PVE). MATERIALS AND METHODS: In 53 patients, the correlation between the indocyanine green clearance (ICG-K) and RE imaging was analyzed before hepatectomy (first analysis). Twenty-three of the 53 patients underwent PVE followed by a repeat RE imaging and ICG test before an extended hepatectomy and their results were further analyzed (second analysis). Whole liver function and FRL function were calculated on the MR imaging as follows: RE x total liver volume (RE Index) and FRL-RE x FRL volume (Rem RE Index), respectively. Regarding clinical outcome, posthepatectomy liver failure (PHLF) was evaluated in patients undergoing PVE. RESULTS: Indocyanine green clearance correlated with the RE Index (r = 0.365, p = 0.007), and ICG-K of FRL (ICG-Krem) strongly correlated with the Rem RE Index (r = 0.738, p < 0.001) in the first analysis. Both the ICG-Krem and the Rem RE Index were significantly correlated after PVE (r = 0.508, p = 0.013) at the second analysis. The rate of improvement of the Rem RE Index from before PVE to after PVE was significantly higher than that of ICG-Krem (p = 0.014). Patients with PHLF had a significantly lower Rem RE Index than patients without PHLF (p = 0.023). CONCLUSION: Relative enhancement imaging can be used to estimate FRL function after PVE.

Clinical Value of CT-Guided Needle Biopsy for Retroperitoneal Lesions

OBJECTIVE: The purpose of this study was to investigate retrospectively the clinical procedural performance of CT-guided needle biopsy for retroperitoneal lesions. MATERIALS AND METHODS: CT-guided needle biopsy was performed in 74 consecutive patients (M:F = 44:30; mean age, 59.7 years) with retroperitoneal lesions between April 1998 and June 2009. The target lesion ranged from 1.5 to 12.5 cm in size. The biopsy access path ranged from 3.5 to 11.5 cm in depth. A biopsy specimen was obtained using an 18-gauge core needle under a CT or CT-fluoroscopy guidance and with the patient under local anesthesia. The histopathological diagnoses from the biopsies were obtained. The diagnostic confirmation of the subtype of lymphoma was evaluated. RESULTS: Satisfactory biopsy samples were obtained in 73 (99%) of 74 patients and a pathological diagnosis was made in 70 (95%) of 74 patients. Sixty three lesions were malignant (45 lymphomas, nine primary tumors, nine lymph node metastases) and seven were benign. The subtype of lymphoma was specified in 43 (96%) of 45 patients who were diagnosed with lymphoma. Analysis of the value of CT-guided biopsy in this series indicated 63 true positives, zero false positive, six true negatives and five false negatives. This test had a sensitivity of 93%, a specificity of 100% and an accuracy of 93%. No major complications were seen and minor complications were noted in seven patients (five with local hematomas, two with transient pain at the puncture site). CONCLUSION: CT-guided needle biopsy for retroperitoneal lesions is highly practical and useful, and particularly for determining the subtypes in patients with lymphoma.

Cellular Density Evaluation for Malignant Lymphoma Using Equivalent Cross-Relaxation Rate Imaging - Initial Experience

OBJECTIVE: Equivalent cross-relaxation rate (ECR) imaging is an MRI technique used to evaluate quantitatively a change in the protein-water interaction. We aimed to evaluate retrospectively the usefulness of ECR imaging for the histologic classification of malignant lymphoma (ML). MATERIALS AND METHODS: Institutional Review Board approval was obtained and all patients provided informed consent. The study subjects included 15 patients with untreated ML who were histologically diagnosed with follicular lymphoma (FL; n = 8) or diffuse large B-cell lymphoma (DLBCL; n = 7). All patients underwent ECR imaging and the offset frequency was set at 7 ppm. RESULTS: The median ECR values were 71% (range; 60.7 to 75.5) in FL and 54% (50.8 to 59.4) in DLBCL (p = 0.001). The median cellular density was 1.5 +/- 0.17 x 10(6) / mm2 in FL and 1.0 +/- 0.70 x 10(6) / mm2 in DLBCL (p = 0.001). The correlation coefficient between the ECR values and cellular density in ML was 0.88 (p = 0.001). In FL and DLBCL, assuming ECR value cut-off points of 60%, both sensitivity and specificity were 100%. CONCLUSION: A strong correlation between ECR and cellular density in ML is demonstrated and the ECR may be a useful technique to differentiate between FL and DLBCL.