Phillip Cheng, MD MS

Hepatic Steatosis MRI Calculator

Disclaimer: The author makes no claims of the accuracy of the information contained herein; this information is for educational purposes only and is not a substitute for clinical judgment.

Hepatic SI in-phase:

Spleen SI in-phase:

Hepatic SI out-of-phase:

Spleen SI out-of-phase:

Hepatic fat fraction:

Hepatic fat percentage:

Note: this is a very approximate method which likely underestimates hepatic fat; better methods may be available depending on equipment and technique.

Fat fraction: 100 x liver SIIP-liver SIOP / 2 x liver SIIP

Fat percentage: 100 x liver SIIP/spleen SIIP - liver SIOP/spleen SIOP / 2 x liver SIIP/spleen SIIP

The fat fraction should be used if both echoes are obtained after a single excitation. However, if the echoes are acquired separately, the fat percentage can be used instead, which makes the assumption that liver and spleen have identical T2* values.

Sirlin CB. Invited Commentary on Image-based quantification of hepatic fat: methods and clinical applications. Radiographics 2009; 29:1277-80

USC Department of Radiology

Hepatic Steatosis MRI Calculator