Optimized scanning protocol for whole-brain perfusion by third generation dual-source computed tomography: A feasibility study / 第二军医大学学报

ABSTRACT

Objective To assess the influence of different time sampling modes on perfusion parameters and radiation dose of whole-brain computed tomography perfusion imaging (CTP), and to formulate an optimized scanning protocol for clinical diagnosis requirements. Methods Forty-seven consecutive patients, who underwent cerebral CTP scanning in our hospital between Nov. 2016 and Jun. 2017, were included in this study. Nineteen of them had acute ischemic stroke (AIS) and 28 had AIS symptoms, but no lesions were found by computed tomography or CTP. According to the time-attenuation curve, four scanning protocols were obtained standard control group (group 1), sampling interval of 3 s (group 2), sampling interval of 3 s in pre-ascending and pro-descending period, and sampling interval of 1.5 s in the intermediate period (group 3), and smapling interval of 1.5 s between the peak of artery and vein and other sampling interval of 3 s (group 4). The perfusion parameters of all subjects were quantitatively measured. Subjective image quality was analyzed and radiation dose was calculated. Results In AIS and non-AIS groups, a total of 10 region of interests were placed in the ischemic area and contralateral brain parenchyma of each patient, and the total numbers of data points of perfusion parameters were 190 and 280, respectively. There were significant differences in blood flow, blood volume and mean transit time (MTT) between the AIS group and non-AIS group (all P0.01). However, inter-group analysis showed that there were no significant differences in the above perfusion parameters between group 3 and group 1 in both the AIS group and non-AIS group (all P0.05). Bland-Altman consistency analysis showed that group 3 and group 1 had good consistency of blood flow, blood volume and MTT in both the AIS group and non-AIS group. Compared with group 1 (standard control group), group 3 had better subjective score and lower radiation dose. Based on the sampling mode of group 3, 2 recommended scanning protocols were established and validated. The perfusion parameters of the 2 recommended scanning protocols were well correlated with those of group 1 in AIS patients and non-AIS patients (all P0.01). Conclusion The scanning protocol, in which sampling interval is 3 s in pre-ascending and pro-descending period and 1.5 s in intermediate period, is in good agreement with the standard scanning mode, and can reduce radiation dose. It may be a whole-brain CTP scanning protocol for the clinical settings.