MRI assessment of biliary ductal obstruction: is there added value of T1-weighted gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MR cholangiography?

OBJECTIVE: The goal of the present study was to determine the added value of gadolium-ethoxybenzyl-diethylenetriamine pentaacetic acid (gadoxetate disodium)-enhanced magnetic resonance cholangiography (MRC) to standard liver MRI including T2-weighted MRCP in assessment of biliary ductal obstruction. MATERIALS AND METHODS: Thirty-eight patients (mean age, 48.1 ± 16.7 years) (40 total examinations) who underwent liver MRI (including T2-weighted MRCP and gadoxetate disodium-enhanced MRC) for suspicion of biliary disease were included in this institutional review board-approved, HIPAA-compliant retrospective study. Three blinded radiologists first evaluated MR images without gadoxetate disodium-enhanced MRC for presence and significance of biliary obstruction, underlying cause for obstruction, and confidence in final diagnosis. After inclusion of gadoxetate disodium-enhanced MRC, readers again determined presence and significance of biliary obstruction and confidence in final diagnosis. Reference standard was established using MRI along with ERCP, percutaneous transhepatic cholangiography, intraoperative cholangiography, or a combination thereof. RESULTS: Overall sensitivity across all readers in diagnosing significance of obstruction was 60% without gadoxetate disodium-enhanced MRC and 91% with gadoxetate disodium- enhanced MRC (p < 0.001). Across all readers, assessment of significance of obstruction was changed when adding gadoxetate disodium-enhanced MRC in 40 of 120 cases (33%); significance of obstruction was correctly changed in 35 of 40 cases (87.5%). Biliary obstruction was graded of unknown significance in 27 of 120 cases (22.5%) across all readers when gadoxetate disodium-enhanced MRC was not reviewed. Significance of biliary obstruction was classified correctly after adding gadoxetate disodium-enhanced MRC in 25 of these 27 cases (93%). Confidence in final diagnosis was significantly higher with addition of gadoxetate di-sodium-enhanced MRC for two of three readers (p < 0.003). CONCLUSION: Addition of gadoxetate disodium-enhanced MRC to liver MRI significantly improves sensitivity in assessing significance of biliary obstruction and can improve reader confidence in establishing a final diagnosis. This added information could have a substantial impact in the determination of the most appropriate therapeutic options.

Metastatic Malignant Paraganglioma: A Case Report and Review of Literature.

Metastasis is a rare presentation of non-secretory paraganglioma. Consequently, there is no standard of care for the treatment of metastatic malignant paraganglioma. The most widely used chemotherapy regimen for non-resectable cases includes cyclophosphamide, vincristine, and dacarbazine (CVD). CVD has been previously studied with variable therapeutic response. However, yttrium-90 (Y90) radioembolization has not been previously studied in the treatment of hepatic metastasis in patients diagnosed with malignant paraganglioma. This case report follows the treatment of a patient with stage IV mediastinal paraganglioma with metastasis to the liver. Treatment consisted of the CVD chemotherapy regimen and Y90 radioembolization of the hepatic lesions. After 10 cycles of CVD, the tumor size has decreased from 6.0 × 8.8 to 5.5 × 3.0 × 3.4 cm on computed tomography scan. The prominent metastatic liver lesions responded after Y90 radioembolization of both the right and left hepatic arteries. The prominent right hepatic lobe lesion has decreased in size from 2.6 × 3.4 × 3.0 cm to 2.6 × 2.8 × 2.9 cm. The prominent left hepatic lobe lesion originally measuring 1.6 cm in diameter completely resolved on follow-up imaging studies. After completion of 12 cycles of chemotherapy, the most recent positron emission testing scan determined no evidence of disease regarding both the primary mass and the hepatic lesions. This study demonstrates the first case of combination chemotherapy and Y90 radioembolization with a complete response per response evaluation criteria in solid tumors criteria. The approaches toward diagnosis and treatment corresponding to this case of malignant metastatic paraganglioma are also reviewed in this study.