{
  "abstract": "Introduction/Purpose Accurate quantification of subdural hematoma (SDH) volume is critical for clinical decision-making and monitoring disease progression. The ABC/2 formula has frequently been used for estimating intracranial hemorrhage volume within published literature, including subdural hematomas, but is limited by geometric assumptions that may not apply to the crescent-shaped morphology of SDHs. This study aimed to compare the accuracy of ABC/2 with computer-assisted volumetric analysis (CAVA) in estimating SDH volume.Materials and Methods We conducted a retrospective review of adult patients that presented with SDH to a single institution between January 2021 and December 2023. Admission CT scans were used to calculate SDH volume via ABC/2 and CAVA for the first 200 SDH. Agreement and correlation between methods were assessed using Spearman’s correlation, Lin’s concordance correlation coefficient (CCC), and Bland-Altman plots. Differences were evaluated with Kruskal-Wallis and chi-squared tests. Associations with clinical outcomes were analyzed using logistic and linear regression models.Results A total of 192 patients with 200 hematomas were included; 37% had bilateral SDH. ABC/2 consistently overestimated SDH volume compared to CAVA (median 79 mL vs 64 mL; p<0.05 across thickness groups). The median deviation was 26% (IQR: 12-49%), with 23% of all cases exceeding 51% deviation. Deviation did not differ by hematoma thickness (p=0.810), although large discrepancies were less frequent in thicker SDHs. Despite systematic overestimation by ABC/2, correlation and agreement between methods were strong (Spearman’s ρ = 0.87; Lin’s CCC = 0.82). Both methods demonstrated limited predictive value for clinical outcomes. For SDH resolution, CAVA showed marginally improved predictability (Nagelkerke’s R 2 = 0.038, AUC = 0.609) than ABC/2 (R2 = 0.028, AUC = 0.598), without significant difference (p = 0.451). Predictive ability was similarly weak for recurrence requiring readmission (CAVA: R2 = 0, AUC = 0.481; ABC/2: R2 = 0.001, AUC = 0.549; p = 0.592) and predicting need for surgical evacuation post-discharge (CAVA: R2 = 0.004, AUC = 0.605; ABC/2: R2 = 0.01, AUC = 0.611; p = 0.633). In contrast, both approaches more effectively predicted midline shift, with CAVA demonstrating higher explanatory power (adjusted R2 = 0.235 vs 0.196), though direct statistical comparison was not applicable for this continuous outcome.Conclusion ABC/2 systematically overestimates SDH volume, with a median deviation of 26%. Twenty-three percent of all cases had deviations larger than 51%. Despite this, strong correlation with CAVA is maintained, as demonstrated though Spearman’s correlation, particularly in larger hematomas. Regardless of measurement method and despite moderate correlation with midline shift, SDH volume has limited utility as a standalone predictor of clinical outcomes. These findings support continued clinical use of ABC/2 for rapid or relative estimation, while highlighting the superior accuracy of CAVA and limitations of volume metrics in outcome prediction.Disclosures H. Cherian: None. A. Cummings: None. S. Chowdhury: None. E.M. Kunz: None. R. Solorzano: None. P. Kumar: None. N. Mahmoud: None. A. Saxena: None. L. Zhou: None. W. Gilmour: None. M. McDermott: None. I. Linfante: None. G. Dabus: None. R. Wicks: None.",
  "authors": [
    {
      "affiliations": [
        "Florida International University Herbert Wertheim College of Medicine, Miami, FL"
      ],
      "name": "H Cherian"
    },
    {
      "affiliations": [
        "Florida International University Herbert Wertheim College of Medicine, Miami, FL"
      ],
      "name": "A Cummings"
    },
    {
      "affiliations": [
        "Baptist Health South Florida, Miami, FL"
      ],
      "name": "S Chowdhury"
    },
    {
      "affiliations": [
        "Florida International University Herbert Wertheim College of Medicine, Miami, FL"
      ],
      "name": "EM Kunz"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "KM Hassan"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "R Solorzano"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "P Kumar"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "N Mahmoud"
    },
    {
      "affiliations": [
        "Baptist Health South Florida, Miami, FL"
      ],
      "name": "A Saxena"
    },
    {
      "affiliations": [
        "Baptist Health South Florida, Miami, FL"
      ],
      "name": "L Zhou"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "W Gilmour"
    },
    {
      "affiliations": [
        "Florida International University Herbert Wertheim College of Medicine, Miami, FL",
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "M McDermott"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "I Linfante"
    },
    {
      "affiliations": [
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "G Dabus"
    },
    {
      "affiliations": [
        "Florida International University Herbert Wertheim College of Medicine, Miami, FL",
        "Miami Neuroscience Institute, Baptist Health South Florida, Miami, FL"
      ],
      "name": "R Wicks"
    }
  ],
  "title": "E-080 Pre-embolization subdural hematoma volume assessment: agreement between computer-assisted volumetric analysis and the ABC/2 formula",
  "uid": "bec781b6-99b9-5d86-9d29-062e22860664"
}