Scoring system for periventricular leukomalacia in infants with congenital heart disease

BACKGROUND: Currently two magnetic resonance imaging (MRI) methods have been used to assess periventricular leukomalacia (PVL) severity in infants with congenital heart disease: manual volumetric lesion segmentation and an observational categorical scale. Volumetric classification is labor intensive and the categorical scale is quick but unreliable. We propose the quartered point system (QPS) as a novel, intuitive, time-efficient metric with high interrater agreement. METHODS: QPS is an observational scale that asks the rater to score MRIs on the basis of lesion size, number, and distribution. Pre- and postoperative, brain MRIs were obtained on term congenital heart disease infants. Three independent observers scored PVL severity using all three methods: volumetric segmentation, categorical scale, and QPS. RESULTS: One-hundred and thirty-five MR's were obtained from 72 infants; PVL was seen in 48 MRIs. Volumetric measurements among the three raters were highly concordant (pc = 0.94-0.96). Categorical scale severity scores were in poor agreement between observers (K = 0.17) and fair agreement with volumetrically determined severity (K = 0.26). QPS scores were in very good agreement between observers (K = 0.82) and with volumetric severity (K = 0.81). CONCLUSION: QPS minimizes training and sophisticated radiologic analysis and increases interrater reliability. QPS offers greater sensitivity to stratify PVL severity and has the potential to more accurately correlate with neurodevelopmental outcomes.