Reliability of an Automated Computerized Hematoma Volumetric Analysis Protocol in Patients with Chronic Subdural Hemorrhage

Background Hematoma volume in chronic subdural hematoma (CSDH) may predict neurologic deterioration and need for surgical evacuation. Several computer software–assisted methods exist for accurate volume measurements of intracerebral hemorrhage, but no reliable method has been identified for measurement of CSDH volume. Methods A total of 30 consecutive patients with CSDH from 2018–2019 admitted to our institution were selected. The noncontrast computed tomography head studies were reviewed by 2 residents. The region of interest method on a Horos Open Source Medical Image Viewer (version 3.3.6) was utilized for volume measurement by each resident (resident-1 and resident-2) independently. Resident-1 repeated the protocol on the same studies 1 month later. We calculated the intra- and interobserver reliability of hematoma volume measurements using the Bland–Altman method. Results Mean age of the patients was 79 years (range, 50–92 years). For interobserver analysis, resident-1 mean hematoma volume was 85.46 cm3 (range, 6.40–178.63 cm3) and was 87.15 cm3 (range, 8.79–165.97 cm3) for resident-2. The Bland–Altman coefficient of variation was 13.15% (range, 0.07%–46.29%, 97% within the limits of acceptance). For intraobserver analysis, the initial average volume measured by resident-1 was 85.46 cm3 (range, 6.40–178.63 cm3) and subsequent was 95.26 cm3 (range, 10.48–182.99 cm3). The Bland–Altman coefficient of variation was 13.76% (range, 0.81%–48.34%, 97% within the limits of acceptance). Conclusions We are reporting inter- and intraobserver reliability for a novel volumetric analysis of CSDH volume using Horos Medical Image Viewer region of interest generated volume calculation. This method is accurate and efficient and could have important clinical and research implications for risk stratification.