Use of posterior fontanelle in the ultrasound diagnosis of intraventricular/periventricular hemorrhage.

OBJECTIVE To evaluate the use of the posterior fontanelle in premature neonates (< 37 weeks) with a birth weight < 1,500 g in the ultrasound diagnosis of intraventricular/periventricular hemorrhage and to assess whether the use of the anterior fontanelle associated with the posterior fontanelle changes the interrater agreement. METHODS Eighty-five premature neonates were evaluated in this prospective study. Ultrasound was performed using the anterior fontanelle, and later, the posterior fontanelle. A consensus diagnosis between two raters was used to analyze the agreement between the anterior fontanelle alone and in association with the posterior fontanelle. If there was no consensus, a third observer was involved to decide. RESULTS Agreement between the first two raters had a kappa of 0.80 (95%CI 0.76-0.84). However, when the anterior fontanelle was evaluated alone, kappa was 0.74 (95%CI 0.70-0.78). Thirty-seven hemispheres had grade II hemorrhage, of which 17 (45.9%) had their diagnosis performed using the anterior fontanelle; in 10 (27%), diagnosis was suspected by the anterior fontanelle and confirmed by the posterior fontanelle; and in 10 (27%), diagnosis was exclusively performed using the posterior fontanelle. Of the 454 hemispheres, in 20 (4.4%) the diagnosis of intraventricular hemorrhage was performed exclusively by the posterior fontanelle (p < 0.001). CONCLUSIONS In this study, the anterior fontanelle associated with the posterior fontanelle was better than the use of the anterior fontanelle alone in the identification of intraventricular/periventricular hemorrhage. Ultrasound using the posterior fontanelle allowed diagnosis of unsuspected grade II hemorrhage by the anterior fontanelle. Use of the posterior fontanelle was also useful to clarify presence of hemorrhage in inconclusive examinations by the anterior fontanelle.