Applications - what contrast agent to use and when

Masahiro Tanabe¹
¹Radiology, Yamaguchi University Graduate School of Medicine, Ube, Japan

Synopsis

Keywords: Contrast mechanisms: Contrast agents, Body: Liver

We discuss properties of contrast agents, as well as their advantages and disadvantages, and present the recent research advances for improving this promising imaging method. Knowledge of these specific mechanisms, and typical and atypical enhancement pattern is important not only for accurate imaging-based diagnoses but also for understanding the pathogenesis of hepatic mass lesions.

The major classes of contrast agents currently used for magnetic resonance (MR) imaging of the liver include extracellular agents, hepatobiliary agents, and reticuloendothelial agents. This course will identify common clinical applications of contrast-enhanced imaging of the liver and what contrast agent is commonly used and when.Dynamic contrast-enhanced MRI (DCE-MRI) is a noninvasive method to evaluate angiogenesis, which is widely used in clinical applications including lesion detection, differential diagnosis, monitoring therapy response and prognosis estimation in cancer patients. Contrast agents play a pivotal role in DCE-MRI and should be carefully selected in order to improve accuracy in DCE-MRI examination.
Hepatobiliary agents are taken up by functioning hepatocytes and the liver parenchyma is strongly enhanced in the hepatobiliary phase (HBP), during which hepatic mass lesions without functioning hepatocytes typically show hypointensity. Hepatobiliary agents can be used to improve lesion detection and characterize mass lesions as hepatocellular or nonhepatocellular. Some hepatic mass lesions such as focal nodular hyperplasia (FNH) and moderately differentiated hepatocellular carcinoma (HCC) with OATP1b3 expression show hyperintensity in the HBP and are specifically characterized while early HCC or dysplastic nodules tend to show hypointensity in the HBP without arterial enhancement. In addition, hepatobiliary contrast agents can be used to quantify liver function and estimate the degree of cirrhosis.
In this course, we discuss properties of contrast agents, as well as their advantages and disadvantages, and present the recent research advances for improving this promising imaging method. Knowledge of these specific mechanisms, and typical and atypical enhancement pattern of benign and malignant focal liver lesions, is important not only for accurate imaging-based diagnoses but also for understanding the pathogenesis of hepatic mass lesions.

Acknowledgements

No acknowledgement found.

References

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Proc. Intl. Soc. Mag. Reson. Med. 31 (2023)