Comparative study of the relative signal intensity on DWI, FLAIR, and T2 images in identifying the onset time of stroke in an embolic canine model.
In acute stroke magnetic resonance imaging, many attempts have been made to identify the onset time of ischemic events using the simply quantitative judgment of relative signal intensity (rSI) from various MR images. However, no uniform opinion has been achieved broadly till now. The controversy might derive from the potential patients' selection bias of clinical retrospective study, the discrepant MR parameters, and the various sample sizes among different studies. Thus, we evaluated the temporal change of the relative DWI signal intensity (rDWI), relative ADC value (rADC), relative FLAIR signal intensity (rFLAIR), and relative T2 signal intensity (rT2), and further compare their diagnostic value in identifying the hyperacute lesions based on our embolic canine model with clear onset time. Twenty ischemic models were successfully established. All rSI values were linearly correlated to time with significance until 24 h after model establishment (P < 0.05). Paired comparison of ROC curves showed that significant difference was found between rADC and other three rSIs (P < 0.0001). However, no significant difference was found among rDWI, rT2 and rFLAIR. Our results indicated that rDWI, rFLAIR and rT2 may be helpful to predict the onset time of ischemic events with the similar diagnostic value. However, the rADC does not have comparable predictive value in our embolic canine model.
Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
Xiao-Quan
XQ
Xu
Qi-Guang
QG
Cheng
Qing-Quan
QQ
Zu
Shan-Shan
SS
Lu
Jing
J
Yu
Ye
Y
Sheng
Hai-Bin
HB
Shi
Sheng
S
Liu
D015901:Angiography, Digital Subtraction; D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D007090:Image Interpretation, Computer-Assisted; D020766:Intracranial Embolism / Q000150:complications*; D008279:Magnetic Resonance Imaging / Q000145:classification / Q000379:methods*; D008297:Male; D012372:ROC Curve; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology*; D013997:Time Factors