A standardized method to measure brain shifts with decompressive hemicraniectomy

Area of Science:

• Neurosurgery
• Radiology
• Stroke Imaging

Background:

• Malignant middle cerebral artery (MCA) territory infarction often requires decompressive hemicraniectomy (DHC).
• Standardized, reliable measurement of DHC defects and brain shifts on computed tomography (CT) scans is crucial for research.
• Existing methods lack consistency and do not account for head size variations.

Purpose of the Study:

• To introduce and validate a practical, standardized method for measuring DHC defects and brain shifts on CT scans.
• To facilitate reliable comparisons of DHC effects in malignant MCA infarction.

Main Methods:

• A novel measurement technique was applied to 25 patients with malignant MCA infarction.
• Measurements included DHC size index (head size-adjusted), midline brain shift, outward brain herniation, and contralateral lateral ventricle diameter.
• Utilized standard radiology platforms and volume-acquired helical CT scans.

Main Results:

• The method demonstrated excellent inter-rater reliability (correlation coefficients 0.90-0.98) in a subset of 15 subjects.
• Measurements are adjusted for head size variations and standardize CT slice orientation.
• The technique incorporates midline brain shift and ventricular system measurements.

Conclusions:

• A practical and consistent method for measuring DHC size and brain shifts on CT scans has been developed.
• This method enables reliable comparisons across serial scans, patients, and studies.
• The technique is valuable for research in brain herniation associated with malignant MCA infarction and potentially other conditions.