Temperature-corrected proton density fat fraction estimation using chemical shift-encoded MRI in phantoms.

Purpose: Chemical shift-encoded MRI (CSE-MRI) is well-established to quantify proton density fat fraction (PDFF) as a quantitative biomarker of hepatic steatosis. However, temperature is known to bias PDFF estimation in phantom studies. In this study, strategies were developed and evaluated to correct for the effects of temperature on PDFF estimation through simulations, temperature-controlled experiments, and a multi-center, multi-vendor phantom study.

Technical Note: Investigating internal-external motion correlation using fast helical CT.

Purpose: To quantify the use of anterior torso skin surface position measurement as a breathing surrogate.

Methods: Fourteen patients were scanned 25 times in alternating directions using a free-breathing low-mA fast helical CT protocol. Simultaneously, an abdominal pneumatic bellows was used as a real-time breathing surrogate.