A Simplified Quantitative Method to Measure Brain Shifts in Patients with Middle Cerebral Artery Stroke.

BACKGROUND AND PURPOSE: A standardized and validated method to measure brain shifts in malignant middle cerebral artery (MCA) stroke with decompressive hemicraniectomy (DHC) could facilitate clinical decision making, prognostication, and comparison of results between studies. METHODS: We tested for reliability simplified methods to measure transcalvarial herniation, midline brain shift, and the contralateral cerebral ventricular atrium in malignant MCA stroke after DHC. Multiple raters measured brain shifts on post-DHC computed tomography (CT) scans with aligned and unaligned slice orientations in 25 patients. We compared the simplified measurements to previously reported more meticulous measurements. RESULTS: The simplified measurements correlate well with the more meticulous measurements on both aligned and unaligned CTs (intraclass correlation coefficients .72-.89). CONCLUSIONS: These simplified and expedient methods of measuring brain shifts in malignant MCA stroke after DHC correlate well with the more meticulous methods.

A standardized method to measure brain shifts with decompressive hemicraniectomy.

BACKGROUND: A standardized, reliable, and practical method for measuring decompressive hemicraniectomy (DHC) defects and brain shifts in malignant middle cerebral artery (MCA) territory infarction is needed for reliable comparisons between computed tomography (CT) scans. Such a method could facilitate further studies on the effects of DHC. NEW METHOD: We describe and apply a method for measuring DHC defects and brain shifts on CT scans in 25 patients with malignant MCA territory infarction. Craniectomy area is adjusted for variations in head size, CT slice orientation is standardized, and the site of each measurement is defined. This method uses standard radiology platforms and volume-acquired helical CT scans. RESULTS: The measurements include a DHC size index (adjusted for variations in head size), midline brain shift (subfalcine), outward brain herniation (transcalvarial), and the diameter of the contralateral atrium of the lateral ventricle. Inter-rater agreement for these measurements in a sample of 15 subjects is excellent (correlation coefficients 0.90-0.98). COMPARISON WITH EXISTING METHODS: In contrast to previously reported methods, this method is tested in acute stroke patients, compensates for variability in head size, and includes a midline brain shift (subfalcine) and brain ventricular system measurements. CONCLUSIONS: A practical method for measuring DHC size and brain shifts designed to be consistent between scans is proposed. This method should facilitate comparisons of measurements between serial scans, between patients, and perhaps between studies. This method could be useful in medical and surgical studies of brain herniations in malignant MCA territory infarction, and possibly other conditions.