Quantomo: validation of a computer-assisted methodology for the volumetric analysis of intracerebral haemorrhage.

ABSTRACT

BACKGROUND: Volume measurements of intracerebral haemorrhage are prognostically important and are increasingly used in clinical trials to measure the effects of potential interventions. The purpose of this work is to establish the reliability of haematoma volume measurements obtained using a computer-assisted method called Quantomo (for quantitative tomography) and the ABC/2 method. Hypothesis Quantomo reliably detects smaller changes in intracerebral haemorrhage volume as compared with the ABC/2 method because computer-assisted volume measurements are tailored to measure the geometry of individual haematoma volumes whereas the ABC/2 method approximates all haematoma volumes as ellipsoids. METHODS: Thirty randomly selected computed tomography scans with intracerebral haemorrhage were measured by four raters a total of four times each (two sessions using Quantomo and two using the ABC/2 method). Interrater and intrarater reliability for both techniques were calculated simultaneously using a two-way random-effects analysis of variance model. The precision of intracerebral haemorrhage volume measurement was quantified as the minimum detectable difference with 95% confidence intervals. RESULTS: The median (first quartile and third quartile) intracerebral haemorrhage volume measurements of all rater and sessions for Quantomo were 32.7 ml (6.2 and 54.4 ml) and for ABC/2 40.7 ml (8.6 and 76.0 ml). Quantomo intracerebral haemorrhage volume measurements were more precise, having an inter- and intrarater minimum detectable difference of 8.1 and 5.3 ml, while the inter- and intrarater minimum detectable difference for ABC/2 were 37.0 and 15.7 ml. CONCLUSIONS: Quantomo is a computer-assisted methodology that is more reliable for quantifying intracerebral haemorrhage volume as compared with the ABC/2 method.