The preliminary study of CT cerebral perfusion imaging in transient ischemic attacks

Objective To probe the application of cerebral perfusion imaging on transient ischemic attacks(TIA) Methods Conventional and cerebral perfusion imaging were performed on 5 normal adults and 20 patients with clinically diagnosed TIA After regular examination, dynamic scans of 40 seconds were performed on selected slice (usually on the basal ganglia slice), while 40 ml non ionic contrast material were bolus injected through antecubital vein with These dynamic images were processed with the CT software package on a PC based workstation Cerebral blood flow (CBF) and time to peak (TP) enhancement were measured within specific regions of the brain on perfusion images Quantitative analysis was performed for these images Results A gradient of perfusion between gray matter and white matter was showed on perfusion images in normal adults and TIA patients CBF and TP for normal cortical and white matter were 378 2 ml·min -1 ·L -1 , 7 8 s and 112 5 ml·min -1 ·L -1 , 9 9 s, respectively In 20 cases with TIA, persisting abnormal perfusion changes corresponding to clinical symptoms were found in 15 cases with prolonged TP Other 5 cases showed normal results TP of affected side (11 8±4 4) s compared with that of the contralateral side (9 1±3 1) s was significantly prolonged ( t =5 277, P 0 01) The difference of the CBF was not statistically significant ( t =1 892, P =0 074) between affected side [(223 5±38 7) ml· min -1 ·L -1 ] and contralateral side [(229 1±41 4) ml· min -1 ·L -1 ] Conclusion Perfusion provides valuable hemodynamic information and shows the extent of perfusion disturbances for patients with TIA