Observer variability assessing US scans of the preterm brain: the ELGAN study
Neurosonography can assist clinicians and can provide researchers with documentation of brain lesions. Unfortunately, we know little about the reliability of sonographically derived diagnoses.
We sought to evaluate observer variability among experienced neurosonologists.
Materials and methods
We collected all protocol US scans of 1,450 infants born before the 28th postmenstrual week. Each set of scans was read by two independent sonologists for the presence of intraventricular hemorrhage (IVH) and moderate/severe ventriculomegaly, as well as hyperechoic and hypoechoic lesions in the cerebral white matter. Scans read discordantly for any of these four characteristics were sent to a tie-breaking third sonologist.
Ventriculomegaly, hypoechoic lesions and IVH had similar rates of positive agreement (68–76%), negative agreement (92–97%), and kappa values (0.62 to 0.68). Hyperechoic lesions, however, had considerably lower values of positive agreement (48%), negative agreement (84%), and kappa (0.32). No sonologist identified all abnormalities more or less often than his/her peers. Approximately 40% of the time, the tie-breaking reader agreed with the reader who identified IVH, ventriculomegaly, or a hypoechoic lesion in the white matter. Only about 25% of the time did the third party agree with the reader who reported a white matter hyperechoic lesion.
Obtaining concordance seems to be an acceptable way to assure reasonably high-quality of images needed for clinical research.
KeywordsBrain Newborn Premature
This work was funded by a cooperative agreement with the National Institute of Neurological Disorders and Stroke (1 U01 NS 40069-01A2) and a program project grant form the National Institute of Child Health and Human Development (NIH-P30-HD-18655). The authors are also grateful for the assistance of all their colleagues, and the cooperation of the families of the infants who are the focus of our attention.
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