Evaluation of Appropriate Readout Sequence for Renal MRI Perfusion Using ASTAR (ASL) Technique

Area of Science:

• Medical Imaging
• Radiology
• Magnetic Resonance Imaging

Background:

• Renal arterial spin labeling (ASL) is crucial for assessing kidney perfusion.
• Optimizing readout sequences is essential for improving ASL image quality and diagnostic utility.
• Comparing True-SSFP and FFE sequences can identify the most effective method for renal ASL.

Purpose of the Study:

• To compare the efficacy of True-SSFP and FFE as readout sequences for renal ASL.
• To optimize imaging parameters for renal ASL using these sequences.
• To evaluate quantitative and qualitative aspects of image quality.

Main Methods:

• Renal ASL perfusion images acquired at 3T using ASTAR technique with respiratory triggering.
• 3D True-SSFP and FFE sequences were used as readout.
• Inversion time (TI) was varied, and flip angles were optimized via simulation.
• Quantitative (contrast ratio) and qualitative (image quality, suppression, misregistration) assessments were performed.

Main Results:

• True-SSFP demonstrated higher average cortical contrast ratios across all inversion times compared to FFE.
• Qualitative evaluation revealed significantly better image quality with True-SSFP readout.
• True-SSFP provided superior background signal suppression and reduced misregistration.

Conclusions:

• True-SSFP is recommended as the preferred readout sequence for renal ASL.
• True-SSFP yields improved quantitative and qualitative performance over FFE for renal ASL.
• This finding supports enhanced diagnostic capabilities in renal perfusion imaging.