Quantification of liver perfusion using multidelay pseudocontinuous arterial spin labeling

Area of Science:

• Medical Imaging
• Radiology
• Hepatology

Background:

• Accurate measurement of liver perfusion is crucial for diagnosing and managing various liver diseases.
• Existing techniques for liver perfusion imaging have limitations in terms of invasiveness, radiation exposure, or specificity.

Purpose of the Study:

• To develop and validate a free-breathing multidelay pseudocontinuous arterial spin labeling (pCASL) technique for quantitative assessment of liver perfusion.
• To enable selective and noninvasive labeling of the hepatic artery and portal vein for independent perfusion measurement.

Main Methods:

• A navigator-gated pCASL sequence utilizing balanced steady-state free precession (bSSFP) readout was implemented on a 3T MRI scanner.
• Two distinct labeling schemes were employed to selectively target the hepatic artery and portal vein.
• Multidelay acquisitions were performed, followed by offline processing including nonrigid motion correction for robust perfusion and transit time estimation.

Main Results:

• The developed multidelay pCASL technique provided quantitative estimates for hepatic artery perfusion (21.8 ± 1.9 mL/100g/min) and portal vein perfusion (95.1 ± 8.9 mL/100g/min).
• Corresponding transit times were measured as 1227.3 ± 355.5 msec for the hepatic artery and 667.2 ± 85.0 msec for the portal vein.
• Motion correction significantly improved the reliability of perfusion and transit time estimations, reducing residual variance (P < 0.05).

Conclusions:

• Multidelay pCASL offers a reliable method for quantitative liver perfusion measurement, with results aligning with established literature values.
• The ability of pCASL to noninvasively and selectively label both the hepatic artery and portal vein represents a significant advantage over other imaging modalities like CT perfusion and dynamic contrast-enhanced MRI.