Impact On Modified TOAST Classification Of Magnetic Resonance Imaging And CT Angiography

Background and objectiveNowadays, people pay more and more attention to the ischemic cerebrovascular disease due to its high incidence rate, high mutilation rate and high recurrence rate. So it is high time for us to take effective measures to prevent stroke. TOAST classification focus on the etiology of ischemic stroke,and it would be helpful to take individual measures. This paper includes two chapters. The first chapter is to analyze the imaging appearance of modified TOAST classification in patients with acute cerebral infarction. The second chapter is to explore the effect of magnetic resonance imaging and CT angiography on modified TOAST classification.MethodsChapter 1:Totally 187 patients with ischemic cerebrovascular disease were permitted to the study according to inclusion criteria. The modified TOAST classification,the imaging appearance on DWI were analyzed and then the relationship between them were analyzed by Pearsonχ2 test.Chapter 2:Totally 121 patients with cerebrovascular disease among 187 case were permitted to the study. Ischemic stroke subtype diagnoses were rendered retrospectively at 3 possible time points:(1) immediately before DWI/CTA imaging(based on history, physical examination, and CT studies) (2)immediately after combined DWI/CTA, and (3) at hospital discharge (final diagnosis). pre-DWI/CTA,post-DWI/CTA diagnoses were cross-tabulated with final diagnoses. Final diagnoses were taken as a gold standard.After final diagnoses, risk factors were compared between AT subtype of stroke and SAD subtype of stroke by x2 test.ResultsChapter 1:The imaging appearance on DWI was significantly related with M-TOAST classification (χ2=242.715, P=0.000).Among of them,14 cases with single cortical-subcortical infarcts,22 cases with multiple infarcts of anterior circulation, were mostly associated with atherothrombosis (χ2=11.987, P=0.001;χ2=33.253, P=0.000); 10 cases with cortical infarcts, were mostly associated with cardiac embolic source (χ2=28.866, P=0.000);and 59 cases with small infarcts in basal ganglion and brain stem were mostly associated with small vessel disease (χ2=147.406, P=0.000)Chapter 2:Of the 121 patients, The percent of cases matching final classification before DWI/CTA imaging was 54.5%; the percent of cases matching final classification with the addition of combined DWI and CTA was 97%. For the modified TOAST diagnostic subtypes of Atherothrombosis, pre-DWI/CTA diagnoses matched final diagnoses in 31.7% and improving to 98% after DWI/CTA. For the modified TOAST diagnostic subtypes of Small-artery occlusion, pre-DWI/CTA diagnoses matched final diagnoses in 55.3% and improving to 100% after DWI/CTA.Ischemic heart disease was significantly different between AT subtype of stroke and SAD subtype of stroke (χ2=3.903, P=0.048).Hypertension (χ2=1.552, P=0.213) Diabetes (χ2=1.272,P=0.259),Hyperlipidemia (χ2=0.001,P=0.975) were of no statistically significant difference between them.Conclusions1. The DWI patterns would be helpful to verify modified TOAST classification in acute cerebral infarction.2. The percent of cases matching final classification with the addition of combined DWI and CTA can be significantly improved.3. The higher prevalence of ischemic heart disease was found in AT subtypes of stroke compared to SAD subtypes of stroke.