Development of an Ultrasound Scoring System to Describe Brain Maturation in Preterm Infants

Abstract

Background and purpose: Cerebral maturation in preterm infants predominantly occurs postnatally, necessitating the development of objective bedside markers to monitor this process. This study aimed to develop a straightforward objective Ultrasound Score of Brain Development to assess cortical development in preterm infants.

Materials and methods: A total of 344 serial ultrasound examinations from 94 preterm infants born at ≤ 32 weeks of gestation were analyzed to identify brain structures suitable for a scoring system.

Results: Among 11 candidate structures, 3 cerebral landmarks were selected due to their correlation with gestational age: the interopercular opening (P < .001), the height of the insular cortex (P < .001), and the depth of the cingulate sulcus (P < .001). These structures can be easily visualized in a single midcoronal view in the plane through the third ventricle and the foramina of Monro. A score point from 0 to 2 was assigned to each measurement, culminating in a total score ranging from 0 to 6. The Ultrasound Score of Brain Development correlated significantly with gestational age (P < .001).

Conclusions: The proposed Ultrasound Score of Brain Development has the potential for application as an objective indicator of brain maturation in correlation with gestational age, circumventing the need to rely on individual growth trajectories and percentiles for each specific structure.

FIG 1.

Flowchart of patient recruitment.

FIG 2.

Ultrasound identification of the structures evaluated for the USBD in an infant with a PMA of 26 weeks. A, Midcoronal view at the level of the foramina of Monro: interopercular opening* (1), height of the insular cortex—curved measurement (2) and straight measurement* (3), depth of the Sylvian fissure (4), thickness of the corpus callosum (5), height of the cingulate gyrus (6), depth of cingulate sulcus* (7). B, Midsagittal view: circumferent length of corpus callosum (8), thickness of corpus callosum (midsagittal) at the genu (9a) and at the body (9b), and height of cingulate gyrus (10). Asterisks indicate structures selected for the USBD (bold lines, A).

FIG 3.

Progression of opercularization with lengthening of insular cortex and closure of interopercular opening in the midcoronal view at different PMAs. A, PMA 22 + 6/7 weeks. B, PMA 30 + 0/7 weeks. C, PMA 34 + 2/7 weeks.

FIG 4.

Scatterplot of measurements of selected structures for the USBD and trajectories with 25th and 75th percentiles, regression curves, and selected cutoff values for USBD marked as lines. A, Interopercular opening. B, Height of insular cortex. C, Depth of cingulate sulcus in the midcoronal plane.

FIG 5.

Boxplot of USBD score points by postmenstrual age grouped by day of scan: light gray including only scorable scans from DOL 1–3 (n = 88); dark gray including all scorable scans (n = 312).