INTEROBSERVER AND INTRAOBSERVER REPRODUCIBILITY OF CEREBRAL ATROPHY ASSESSMENT ON MRI SCANS WITH HEMISPHERIC INFARCTS

Cerebral atrophy (CA) in stroke patients is associated with poststroke dementia and may reflect underlying neurodegenerative pathology. Ther efore, regional CA may be valuable to study in patients who develop po ststroke dementia. The aim of this study was to test the reproducibili ty of a qualitative rating scale of CA on MRI. MRI scans were performe d in 50 consecutive patients (age range 19-81) admitted for an acute h emispheric ischemic stroke. CA was assessed on 2 occasions 24 h apart, on axial T2-weighted sequences by 4 independent observers. We evaluat ed CA in 13 regions on a 0-3 scale. The sum of the subscores was calle d the CA score (range: 0-39). The level of agreement was expressed by kappa statistics as well as by analysis of variance for interexaminer reproducibility studies. The mean CA scores ranged from 2.8 to 11.0, i ndicating the low prevalence of CA in this sample. Complete agreement was reached in 41.7% during the first assessment and in 44.1% in the s econd assessment. The interobserver agreement was moderate in the firs t session (mean overall kappa: 0.48) and substantial in the second (me an overall kappa: 0.67). The intraobserver agreement was good for all raters (mean kappa: 0.65). Standardized to the range of the scale, sta ndard deviations of the differences between CA scores of the 4 raters in the 2 sessions were 11.1 and 11.2%; within raters it was 4.4%. We c onclude that the assessment of CA using this rating scale is possible in stroke patients. It provides regional atrophy measurements and is r eproducible when performed by 1 rater.