Clinical Application Of CT Perfusion In Patients With Ischemic Cerebrovascular Disease And In The Operation Of Balloon Occlusion Test

Objective: To explore the diagnostic value of CT perfusion (CTP) on cerebral ischemia.Methods: Part 1 25 patients involved 18 males and 7 females, average 36.2ys, with cerebral arteries stenosis diagnosed by DSA were performed CT perfusion, CBF(cerebral blood flow), CBV(cerebral blood volume) and TTP(time to peak) color maps were generated with software, then 201 pairs of ROI were selected using image method, and 201 groups of rCBF, rCBV and rTTP were calculated by comparing bilateral ROI. 20 of the patients received IC+EC bypass + EDMS (encephaloduromyosynangiosis), 4 of them underwent stenting, and after operation 20 of them received re-CTP.Part 2 17 patients with giant ICA aneurysm or CCF were performed CTP during balloon occlusion test (BOT), CBF, CBV and TTP color maps were also generated.Results: Part 1 Every CTP parameter map showed no ischemia changes in 40 pairs of ROI, otherwise, showed ischemia in various degrees in the other pairs. In the rest 161 pairs, rTTP value of all pairs delayed, average 1.32±0.16(P <0.01); rCBF of 2 pairs ascended, average 1.24±0.11(P =0.105), 18 pairs were normal, average 1.01±0.05(P =0.038), of 141 pairs descended, average 0.56±0.18(P <0.01); and rCBV of 13 pairs were normal , average 1.01±0.04(P =0.112), of 15 pairs descended, average 0.76±0.06(P <0.01); of 133 pairs ascended, average 1.51±0.32(P <0.01). Of 20 patients who received both surgical treatment and post-operative CT scan, follow-up CTP demonstrated improvement of perfusion in various degrees.Part 2 Of 17 patients who were performed CTP during balloon occlusion test (BOT), CTP showed no ischemia changes in 10 cases, all of them underwent ICA occlusion and no late ischemia complications during 2～9 months' follow up. The other 7 cases showed ischemia in various degrees, 6 of them were performed aneurysm or fistulae embolization or bypass and with good prognosis, one of them refused further treatment.Conclusion: CTP is an effective method for cerebral ischemic changes, which can clearly presents the abnormal hemodynamics that routine CT or MRI can't display, and is useful in BOT.