Echo-planar perfusion MR of moyamoya disease

Our goal was to assess the value of perfusion MR imaging by using a single-shot echo-planar technique to evaluate the hemodynamics of moyamoya disease.

We performed echo-planar perfusion studies in 19 patients with a 1.5-T unit, using a free-induction-decay echo-planar sequence for 14 examinations and a turbo-gradient-spin-echo echo-planar sequence for five examinations. After a bolus injection of contrast material, 30 consecutive scans were done in 10 sections every 2 seconds. The data were analyzed to yield time-intensity curves for a region of interest set in the territory of the bilateral middle and/or anterior cerebral arteries in all examinations and to produce semiquantitative flow maps of each section, representing the signal decrease due to passage of contrast material in 17 examinations. The semiquantitative flow maps were compared with single-photon emission CT (SPECT) findings in 11 cases.

We detected differences between the cerebral hemispheres and/or focal perfusion abnormalities by the time-intensity curves and semiquantitative flow maps in 15 of the 19 examinations and in 11 of the 17 examinations, respectively. Results of one or both these examinations corresponded with the SPECT findings in nine of the 11 examinations.

Our results indicate that single-shot echo-planar perfusion MR imaging can sensitively depict hemodynamic abnormalities in moyamoya disease.