Interrater Agreement for Final Infarct MRI Lesion Delineation

• Published in: Stroke (1970) Vol. 40; no. 12; pp. 3768 - 3771
• Main Authors: NEUMANN, Anders B, JONSDOTTIR, Kristjana Y, KUCINSKI, Thomas, LARSSON, Elna-Marie, SØRENSEN, Leif, ØSTERGAARD, Leif, MOURIDSEN, Kim, HJORT, Niels, GYLDENSTED, Carsten, BIZZI, Alberto, FIEHLER, Jens, GASPAROTTI, Roberto, GILLARD, Jonathan H, HERMIER, Marc
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01.12.2009
• Subjects: Aged; Biological and medical sciences; Brain - blood supply; Brain - pathology; Brain - physiopathology; Brain Infarction - pathology; Brain Infarction - physiopathology; Diagnostic Errors; Disease Progression; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - standards; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Observer Variation; Predictive Value of Tests; Prospective Studies; Retrospective Studies; Sensitivity and Specificity; Vascular diseases and vascular malformations of the nervous system; biostatistics; brain imaging; Cerebral infarction; Stroke; Nervous system diseases; magnetic resonance imaging; Prognosis; Infarct; Cardiovascular disease; clinical trial design; diagnostic methods; Nuclear magnetic resonance imaging; Cerebral disorder; Encephalon; Vascular disease; Interrater agreement; outcomes; Central nervous system disease; Diagnosis; cerebral infarct; Cerebrovascular disease
• ISSN: 0039-2499; 1524-4628
• DOI: 10.1161/STROKEAHA.108.545368

Lesion volume measured on follow-up magnetic resonance imaging (MRI) is commonly used as an outcome parameter in clinical stroke trials. However, few studies have evaluated the optimal sequence choice and the interrater reliability of this outcome measure. The objective of this study was to quantify the geometric interrater agreement for lesion delineation of chronic infarcts on T2-weighted and fluid-attenuated inverse recovery (FLAIR) MRI. In a retrospective study of 14 patients, lesions on 90-day follow-up FLAIR and T2 fast spin echo MRI were outlined by 9 independent, blinded, experienced neuroradiologists. Voxel-wise interrater agreement was measured as (1) the volume of the intersection of individual rater's lesion outlines relative to the mean lesion volume (overlap ratio) and (2) the Hausdorff distance between the lesion markings. Mean patient age was 64.4 years (range, 45 to 79). Lesion volumes on FLAIR were, on average, 2.5 mL greater than were T2 volumes (median; P<0.001). We found considerable differences between raters' lesion markings, but interrater agreement was consistently better on FLAIR than on T2 images, as measured by a greater overlap ratio (P<0.0001) and a smaller Hausdorff distance (P<0.0001) on FLAIR than on T2. FLAIR should be used to quantify follow-up infarct size to minimize interrater variability. Our study suggests that imaging analysis performed by 1 or a few trained readers may be preferred. Future studies should address objective and preferably automated criteria for final lesion delineation.