Improved liver lesion conspicuity by increasing the flip angle during hepatocyte phase MR imaging.

摘要

OBJECTIVE: One of the advantages of using hepatobiliary contrast agents in liver MRI is the ability to acquire a delayed, "hepatocyte phase" dataset. This phase highlights many types of lesions as hypointense compared with the liver, because of the accumulation of contrast material in functioning hepatocytes and non-retention within most lesions. METHOD: Increasing the flip angle of the T1-weighted pulse sequence used to acquire the hepatocyte phase is a simple parameter change that increases the contrast-to-noise ratio of focal lesions compared with the hepatic parenchyma. RESULT: This technique increases the sensitivity for detection and conspicuity of focal liver lesions. CONCLUSION: High flip angle delayed hepatocyte phase imaging is a useful adjunct to standard enhanced MRI of the liver. It allows for better sensitivity in focal lesion detection, particularly for small lesions. Secondarily, this technique increases the conspicuity of the biliary system, which is an additional benefit of delayed imaging with hepatobiliary contrast agents.