[Perfusion MR imaging of the heart with TrueFISP]

Development and test of a saturation-recovery TrueFISP (SR-Trufi) pulse sequence for myocardial perfusion MR imaging (MRI) using improved gradient hardware.

Measurements were performed on a 1.5 T scanner with prototype gradients (50 mT/m, minimum rise time 300 microseconds). T1-weighted first-pass MRI of Gd-DTPA (0.025 mumol/kg) kinetics in the myocardium was performed using an SR-Trufi pulse sequence (TR/TE/alpha = 2.6 ms/1.4 ms/55 degrees) with a saturation preparation of TD = 30 ms before the TrueFISP readout. Measurements were performed in volunteers (n = 4) and in a pig model of chronic ischemia (n = 1).

In phantoms, the signal intensity was linear with contrast concentration up to 0.9 mmol/kg Gd-DTPA. MR images obtained with SR-Trufi had a good image quality and high spatial resolution of 2.1 mm x 2.1 mm. Differences of the contrast agent's kinetics between a subendocardial perfusion deficit and neighboring myocardium were well visible on both MR images and signal-time curves derived from the region-of-interest analysis.

SR-Trufi appears to be an interesting new technique for the assessment of myocardial microcirculation using dedicated cardiovascular MR systems.