Comparison of Diffusion-weighted and T2-weighted Magnetic Resonance Imaging for Ischemic Stroke

Ryu, Seung; Yang, Young Mo; Yoo, In Sool; Kim, Seung Whan; Ha, Young Rok; Chung, Sung Pil

Abstract

PURPOSE: Diffusion-weighted magnetic resonance imaging (DWI) has been known to visualize hyperacute ischemic stroke. And it takes only a few minutes to do. Moreover only a small amount of time and little cost is required to add T2-weighted imaging (T2WI) to DWI. The purpose of this study is to determine the usefulness of T2WI in addition to DWI as a primary imaging modality for patients with suspected ischemic stroke.
METHODS
DWI plus T2WI was performed from January to May 2001 on the patients with suspected ischemic stroke. Two emergency physicians reviewed the films and medical records. The sensitivity and the specificity of DWI and T2WI for acute ischemic stroke were calculated. The agreement between DWI and T2WI was calculated using kappa statistics.
RESULTS
A total of 241 patients were enrolled. Acute ischemic stroke was confirmed in 86 (35.7%) patients. The sensitivity and the specificity of DWI for acute ischemic stroke were 94.2% and 98.7%, and those for T2WI were 60.5% and 94.2%, respectively. The kappa value was 0.721 (p<0.01). Among the 86 acute ischemic stroke patients, the number of cases who presented less than 6 hours after symptom onset was significantly lower in the T2WI positive group (31% vs. 68.7%, p<0.05).
CONCLUSION
This study suggests that the addition of T2WI to DWI as a primary imaging modality for acute ischemic stroke has little benefit compared to DWI alone, especially, when the symptom duration has been less than 6 hours.