Temporal constraints in renal perfusion imaging with a 2-compartment model

Area of Science:

• Medical Imaging
• Renal Physiology
• Quantitative MRI

Background:

• Accurate assessment of renal perfusion and filtration is crucial for diagnosing kidney diseases.
• Quantitative MRI techniques offer non-invasive methods for evaluating renal function.
• A 2-compartment model is commonly used to analyze dynamic contrast-enhanced MRI data for renal parameters.

Purpose of the Study:

• To determine the optimal temporal resolution and total acquisition time for renal perfusion and filtration measurements using a 2-compartment model.
• To establish imaging parameter guidelines for accurate quantitative MRI of the kidneys.

Main Methods:

• Saturation-recovery TurboFLASH MRI was performed on 15 healthy volunteers at 1.5 T.
• Data were acquired with 1-second temporal resolution and analyzed after regridding and truncation to various resolutions (1-30s) and acquisition times (30-270s).
• A 2-compartment model was fitted to quantify plasma volume (PV), plasma flow (PF), tubular volume (TV), and tubular flow (TF), with discretization error (DE) and truncation error (TE) <10%.

Main Results:

• Plasma flow (PF) and tubular flow (TF) require temporal resolutions of at least 4 and 5 seconds, respectively.
• Plasma volume (PV) and tubular volume (TV) require temporal resolutions of at least 9 seconds.
• Required total acquisition times were 35s (PF), 85s (PV), 230s (TF), and 255s (TV).

Conclusions:

• Renal perfusion MRI should utilize a temporal resolution of at least 4 seconds.
• Evaluating renal excretory function with MRI necessitates a total acquisition time of at least 255 seconds.
• These findings provide essential parameters for optimizing quantitative MRI protocols for renal studies.