Optimizing the scan protocol in whole-brain perfusion imaging with 320-MDCT

Objective To evaluate the feasibility of optimized scan protocol in whole-brain perfusion imaging with 320-MDCT scanner.Methods Twenty healthy volunteers were randomly divided into control group (13 patients) and test group (7 patients).The standard perfusion scan protocol (collecting 19 volumes)was applied in control group.The optimized perfusion CT scan protocol(collecting ll volumes)formulated by reducing scanning phases reasonably and changing the collection intervals was applied in test group.The regions of interest(ROI) with area of(20 ± 2)mm2 were located in the bilateral frontal white matter,parietal white matter,centrum semiovate,basal ganglia,occipital lobe and cerebellum.Bilateral perfusion values from ROI were measured,including cerebral blood volume(CBV),mean transit time (TTP),cerebral blood flow (CBF),mean transit time (MTT) and delay time (DT).Results Dose length product (DLP)and effective dose (ED)in optimized protocol were decreased 42.02％ as compared to control group.Every relative perfusion value of both sides from both groups were not statistically significant (P ＞ 0.05).Every relative perfusion parameters from individual territory in both groups showed no significant differences (P ＞ 0.05).Conclusions Using the optimized scan protocol,we could obtain the same whole-brain perfusion values could be obtained with the default standard protocol and less radiation dose. Key words: Tomography;  Radiation dose;  Whole brain CT perfusion;  Scan protocol