Microstructural visual pathway abnormalities in patients with primary glaucoma: 3 T diffusion kurtosis imaging study.

AIM: To evaluate microstructural visual pathway damage in patients with primary glaucoma (PG) by using 3 T diffusion kurtosis imaging (DKI). MATERIALS AND METHODS: The study was approved by the ethics committee, and all participants provided written informed consent. Ten patients with PG were examined. Twenty healthy individuals served as control subjects. DKI was performed with a GE Silent 3 T magnetic resonance imaging (MRI) unit. Mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK) maps were automatically created. Mean MK, MD, and FA values were calculated for each part of the visual pathway. RESULTS: No abnormalities in the shape and signal intensity were observed along the entire visual pathway in patients and the control group on the conventional MRI. Higher MD, and lower MK and FA were observed in the optic nerves (ON), lateral geniculate nucleus (LGN), optic radiations (OR), and visual cortex (VCx) of PG patients, as compared with control subjects. A significantly higher MD was observed in the ON (p<0.01), and significantly lower FA was observed in OR (p<0.05). Additionally, significantly lower MK was observed in the ON, LGN, and VCx, except for OR (p<0.01). Changes of DKI parameters in the ON were the most distinct. CONCLUSION: Glaucoma is a complex neurological disease that affects the entire visual pathway. MK derived from DKI would be a better biomarkers than FA and MD in detecting microstructural damage.

Preoperative assessment and staging of hilar cholangiocarcinoma with 16-multidetector computed tomography cholangiography and angiography.

BACKGROUND/AIMS: To evaluate prospectively the preoperative use of 16-multidetector computed tomography (MDCT) with cholangiography and angiography in determining the resectability of hilar cholangiocarcinoma. METHODOLOGY: From January 2002 to January 2008, 75 consecutive patients with hilar cholangiocarcinoma underwent preoperative MDCT with cholangiography and angiography. 3D images of the portal vein, hepatic artery, and bile ducts were created and viewed simultaneously. The accuracy of MDCT with cholangiography and angiography was determined by comparison with intraoperative and pathologic findings. RESULTS: All patients tolerated the CT imaging well and without serious complication. The sensitivity, specificity, and accuracy rates were 92.9%, 100%, and 96% for portal vein invasion and 83.3%, 100%, and 93.3% for hepatic arterial invasion. The accuracy rate of longitudinal tumor extension, using the modified Bismuth-Corlette classification, was 96%. The sensitivity, specificity, and accuracy of prediction of resectability were 95.7%, 82.1%, and 90.7%, respectively. CONCLUSIONS: Preoperative MDCT with cholangiography and angiography gave a good assessment of the degree of biliary and vascular involvement of hilar cholangiocarcinoma. It also accurately predicted resectability.

Preoperative evaluation of resectability of Klatskin tumor with 16-MDCT angiography and cholangiography.

OBJECTIVE: The objective of our study was to evaluate prospectively the preoperative use of 16-MDCT angiography and cholangiography in determining the resectability of Klatskin tumors. CONCLUSION: Preoperative MDCT angiography and cholangiography gave a good assessment of the degree of vascular and biliary involvement of the Klatskin tumor.