Unenhanced ECG‐gated fast spin‐echo MR digital subtraction angiography (MRDSA) using short echo‐spacing three‐dimensional sequence of femoral arteries: Initial experience

Purpose: To compare the image qualities of unenhanced electrocardiographically (ECG)-gated fast spin-echo magnetic resonance digital subtraction angiography (MRDSA) using a short echo-spacing three-dimensional (3D) sequence, known as sampling perfection with application-optimized contrasts using different flip angle evolutions (SPACE), and the conventional half-Fourier single-shot turbo spin-echo (HASTE) sequence. Materials and Methods: Unenhanced ECG-gated MRDSA using SPACE and HASTE of the femoral arteries were prospectively acquired in 13 healthy volunteers at 1.5 Tesla (T) MRI. Sequential frontal maximum-intensity-projection images produced by subtracting each of 10 systolic images from a diastolic image were evaluated quantitatively using paired t-test and qualitatively by two blinded radiologists using the Mann-Whitney U-test. Results: Quantitatively, relative contrast against the background, contour sharpness index, and slope of the sequential signal changes of the superficial femoral artery of MRDSA using SPACE were significantly better than those of HASTE (P = 0.005, P = 0.001, and P < 0.0001, respectively). Qualitatively, the overall subjective image quality and sequential appearance changes of MRDSA using SPACE were significantly better than those of HASTE (P < 0.0001 and P < 0.0001, respectively). Conclusion: Unenhanced ECG-gated fast spin-echo MRDSA using SPACE produces increments in signal intensity, which reflect arterial pulse wave transmission, more clearly than the conventional HASTE sequence. J. Magn. Reson. Imaging 2011;. © 2011 Wiley-Liss, Inc.