A Feasibility Study on Model-based Evaluation of Kidney Perfusion Measured by Means of FAIR Prepared True-FISP Arterial Spin Labeling (ASL) on a 3-T MR Scanner1

Rationale and Objectives

A feasibility study on measuring kidney perfusion by a contrast-free magnetic resonance (MR) imaging technique is presented.

Materials and methods

A flow-sensitive alternating inversion recovery (FAIR) prepared true fast imaging with steady-state precession (TrueFISP) arterial spin labeling sequence was used on a 3.0-T MR-scanner. The basis for quantification is a two-compartment exchange model proposed by Parkes that corrects for diverse assumptions in single-compartment standard models.

Results

Eleven healthy volunteers (mean age, 42.3 years; range 24–55) were examined. The calculated mean renal blood flow values for the exchange model (109 ± 5 [medulla] and 245 ± 11 [cortex] ml/min − 100 g) are in good agreement with the literature. Most important, the two-compartment exchange model exhibits a stabilizing effect on the evaluation of perfusion values if the finite permeability of the vessel wall and the venous outflow (fast solution) are considered: the values for the one-compartment standard model were 93 ± 18 (medulla) and 208 ± 37 (cortex) ml/min − 100 g.

Conclusion

This improvement will increase the accuracy of contrast-free imaging of kidney perfusion in treatment renovascular disease.

Key Words: ASL, FAIR, True-FISP, compartment, exchange, kidney