260. Preoperative Computed Tomography Perfusion in Pediatric Moyamoya Disease: A Single-Institution Experience

Authors: Vijay Mysore Ravindra, MD; Stephen Kralik, MD; Julius Griauzde, MD; Nisha Gadgil, MD; Melissa Lopresti, MD; Sandi Lam, MD, MBA (Salt Lake City, UT)

Objective: Moyamoya disease is a progressive occlusive arteriopathy for which surgical revascularization is indicated; we investigate the use of preoperative computed tomography (CT) perfusion and establish pathological data references.

Methods: Children with Moyamoya disease treated surgically between 2016 and 2019 were reviewed. Preoperative CT perfusion studies were used to quantify mean transit time (MTT), cerebral blood volume (CBV), cerebral blood flow (CBF), and time to peak (TTP) for the anterior, middle, and posterior cerebral artery vascular territories for each patient. CT perfusion parameter ratios (diseased/healthy) and absolute differences were compared between diseased and normal vascular territories. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values for CT perfusion parameters for severe disease were calculated.

Results: Nine children (89% female) had preoperative CT perfusion data; 5 of these had evidence of unilateral hemispheric disease and 4 had bilateral disease. The mean age at revascularization was 77 months (range 40–144 months). The etiology of disease was NF-1 (3 patients), Down syndrome (2), primary Moyamoya disease (2), cerebral proliferative angiopathy (1), and sickle cell disease (1). Five patients underwent unilateral revascularization. Pathological vascular territories demonstrated increased MTT in 66%, increased TTP in 66%, decreased CBF in 47%, and increased CBV in 87%. Severe Moyamoya (Suzuki grade ≥4) had diseased/healthy ratios ≥1 for MTT in 78% , TTP in 89%, CBF in 67%, and CBV in 89%. MTT and TTP region of interest ratio ≥1 demonstrated 89% sensitivity, 67% specificity, 80% PPV 80%, and NPV 80% for prediction of severe angiographic Moyamoya disease.

Conclusions: Pathological hemispheres in children with Moyamoya demonstrate increased MTT, TTP, CBV, and decreased CBF. Preoperative CT perfusion can be useful in deciphering perfusion mismatch in brain tissue in children with Moyamoya disease with a high sensitivity; more severe angiographic disease displays a more distinct correlation.