Childhood moyamoya disease: quantitative evaluation of perfusion MR imaging--correlation with clinical outcome after revascularization surgery.

PURPOSE

To evaluate whether perfusion magnetic resonance (MR) imaging can depict hemodynamic status after revascularization surgery and whether changes at perfusion MR imaging after revascularization surgery correspond with clinical outcome in moyamoya disease.

MATERIALS AND METHODS

An institutional review board approved this retrospective study; informed consent was waived. Pre- and postoperative perfusion MR imaging data in 67 children with moyamoya disease (mean age, 7.2 years; range, 2-13 years) were included. Regional time to peak (rTTP) and regional cerebral blood volume (rCBV) were calculated by adjusting cerebral time to peak (TTP) and cerebral blood volume (CBV) values by using cerebellar reference values. For quantitative regional analysis, pixel values were divided into five categories (>0, >2, >4, >6, and >8 seconds), and percentages of pixels in rTTP meeting these time conditions were calculated. Changes in the values after revascularization were calculated. Postoperative clinical outcomes were categorized as follows: 1 indicated excellent; 2, good; 3, fair; and 4, poor. Pre- and postoperative perfusion parameters were compared by using a paired t test; relationships between perfusion parameters and clinical outcomes were investigated by using one-way analysis of variance, with a significance level of .05.

RESULTS

rTTP, rCBV, and percentage of pixels of rTTP decreased significantly after revascularization surgery. Pre- and postoperative rTTP were significantly different for the clinical outcome categories. Change in rTTP and change in percentage of pixels of rTTP (>0 seconds to >6 seconds) were significantly different for the clinical outcome categories.

CONCLUSION

TTP and CBV perfusion maps can depict hemodynamic status after revascularization surgery in moyamoya disease. Furthermore, changes in TTP perfusion maps after revascularization surgery correspond with clinical outcome in patients with moyamoya disease.