Mn-DPDP-enhanced MR Imaging: the Optimal Pulse Sequence for Detection of Focal Hepatic Tumor

PURPOSE: To assess the diagnostic value of Mn-DPDP for the detection of focal hepatic tumors on MR images and to determine the optimal pulse sequence to maximize its effect. MATERIALS AND METHODS: Twenty-three patients with 32 focal hepatic tumors were examined by means of 1.5-T MRI. Before and after the intravenous administration of Mn-DPDP, five pulse sequences were used to obtain T1-weighted images: two-dimensional fast low-angle shot (2D FLASH) with/without fat saturation (FS), spinecho (SE), and three-dimensional fast low angle shot reconstruction (3D FLASH) with/without FS. Quantitative assessment involved determination of the signal-to-noise ratio (SNR) of the liver and the tumor, the percentage signal enhancement ratio (PSER) of the liver, and tumor-to-liver contrast to noise ratio (CNR). Pulse sequences were also evaluated subjectively for tumor conspicuity, delineation, and image artifact. In addition, two experienced radiologists compared tumor detection rates between precontrast and postcontrast images. RESULTS: Mn-DPDP had a marked effect on liver SNR and absolute CNR at all pulse sequences (p<0.05). On postcontrast images, PSER and absolute CNR of the liver were highest at 3D FLASH and 2D FLASH FS, respectively, and significantly higher at GRE than at SE (p<0.05). On postcontrast images, the CNR of focal nodular hyperplasia and hepatocellular carcinoma was positive, while that of hemangioma, metastasis and cholangiocarcinoma was negative. The postcontrast CNR of all tumors except hepatocellular carcinoma increased more than 100%. Qualitative studies showed that tumor conspicuity increased significantly at all sequences except SE, and delineation increased significantly except at SE and postcontrast 2D GRE FS. After Mn-DPDP, GRE more effectively demonstrated tumor conspicuity and image artifact than did SE, and GRE other than 2D FLASH FS was also better than SE for tumor dilineation (p<0.05). The sensitivity of all postcontrast images increased and the tumor detection rate at GRE was significantly higher than at SE. CONCLUSION: Mn-DPDP favorably affects tumor-to-liver contrast, and may be useful in the imaging of focal hepatic tumors, more so with 2D or 3D FLASH pulse sequences than with SE.

A Case of Common Bile Duct Cancer with Mucosal and Submucosal Spread to Gallbladder and Common Hepatic Duct / 대한소화기내시경학회지

Cholangiocarcinoma is a form of adenocarcinoma arising from the intrahepatic or extrahepatic biliary epithelium. Apparent predisposing factors include some chronic hepatobiliary parasitic infsttations, congenital anomalies with ectatic ducts, sclerosing cholangitis and chronic ulcerative colitis and occupational exposure to possible biliary tract carcinogens. Patients with cholangiocarcinoma usually present with biliary obstruction, painless jaundice, pruritus, weight loss and acholic stools. Because the obstructing process is gradua1, the cholangiocarcinoma is often far advanced by the time it presents clinically. The diagnosis is most frequently made by cholangiography following ultrasound demonstration of dilated intrahepatic bile ducts. We report a case of common bile duct cancer spreading to gallbladder and common hepatic duct along the biliary mucosal epitherium and submucosal tissue in 68-year-old female patient along with a review of literature.