CT and diffusion-weighted MR imaging in randomized order: diffusion-weighted imaging results in higher accuracy and lower interrater variability in the diagnosis of hyperacute XXXX .

@entity1 @entity64 @entity385 @entity1188
BACKGROUND AND PURPOSE: Diffusion-weighted MRI (DWI) has become a commonly used imaging modality in @entity64 centers. The value of this method as a routine procedure is still being discussed. In previous studies, CT was always performed before DWI. Therefore, @entity1188 progression could be a reason for the better result in DWI. METHODS: All hyperacute (<6 hours) @entity64 @entity1 admitted to our emergency department with a National Institutes of Health @entity64 Scale (NIHSS) score >3 were prospectively randomized for the order in which CT and MRI were performed. Five @entity64 experts and 4 residents blinded to clinical data judged @entity64 signs and lesion size on the images. To determine the interrater variability, we calculated kappa values for both rating groups. RESULTS: A total of 50 @entity1 with @entity385 and 4 @entity1 with transient symptoms of @entity64 (median NIHSS score, 11; range, 3 to 27) were analyzed. Of the 50 @entity1 , 55% were examined with DWI first. The mean delay from symptom onset until CT was 180 minutes; that from symptom onset until DWI was 189 minutes. The mean delay between DWI and CT was 30 minutes. The sensitivity of @entity1188 detection by the experts was significantly better when based on DWI (CT/DWI, 61/91%). Accuracy was 91% when based on DWI (CT, 61%). Interrater variability of lesion detection was also significantly better for DWI (CT/DWI, kappa=0.51/0.84). The assessment of lesion extent was less homogeneous on CT (CT/DWI, kappa=0.38/0.62). The differences between the 2 modalities were stronger in the residents' ratings (CT/DWI: sensitivity, 46/81%; kappa=0.38/0.76). CONCLUSIONS: CT and DWI performed with the same delay after onset of @entity385 resulted in significant differences in diagnostic accuracy. DWI gives good interrater homogeneity and has a substantially better sensitivity and accuracy than CT even if the raters have limited experience.
