Assessment of skeletal muscle perfusion by contrast medium first-pass magnetic resonance imaging: Technical feasibility and preliminary experience in healthy volunteers

Purpose: To probe the potential and pitfalls of contrast medium first-pass skeletal muscle perfusion imaging under reproducible stress conditions. Materials and Methods: Magnetic resonance (MR) signal dynamics in calf muscle and lower-leg arteries of 20 healthy volunteers were analyzed under postarterial occlusion reactive hyperemia and concurrent contrast medium first pass, using a saturation recovery spoiled gradient-echo type sequence without heartbeat synchronization. The signal vs. time curves were analyzed descriptively and by two-compartment deconvolution analysis. Results: Highly significant changes in calf muscle signal dynamics in the hyperemic leg vs. those in the contralateral leg at rest were found in phenomenological and deconvolution analysis. Although a distortion of the arterial signal derived input function by inflow effects was found to cause large variations of the deconvolution results, the magnitude of the observed effects suggested a potential for immediate visual detection of areas with reduced tissue perfusion. Conclusion: The first-pass approach appeared promising for visual evaluation. However, a disentanglement of inflow and contrast medium-induced effects on arterial signal intensity was deemed a prerequisite for input function-based numerical assessment.