Yes, a rounded lateral ventricle in a near-term infant warrants immediate radiologist communication with the treating physician.
A lateral ventricle that has lost its normal C-shaped, slit-like contour and become rounded represents early ventricular dilation and is an important early indicator of developing hydrocephalus that requires prompt clinical correlation and management decisions 1.
Why This Finding Requires Immediate Communication
Early Sign of Increased Intracranial Pressure
The transformation from a slit-like to rounded ventricular contour is specifically recognized as an early warning sign that precedes measurable increases in ventricular dimensions 1. In normal premature neonates (25-35 weeks gestation), lateral ventricles appear as slit-like structures on coronal ultrasound scans. When intraventricular hemorrhage occurs, mild hydrocephalus first manifests as the lateral ventricle becoming rounded rather than slit-like—this morphological change occurs before the midline-lateral dimension of the ventricle actually increases 1.
This is clinically significant because the anterior horn width (AHW) may be a more accurate reflection of early ventricular expansion than the traditional Levene ventricular index, which can be a relatively late sign of increased intracranial pressure 2.
Clinical Decision-Making Implications
The rounded ventricle finding triggers several urgent clinical considerations:
Assessment for symptomatic hydrocephalus: The treating team needs to immediately correlate imaging with clinical signs including fontanel fullness, suture splaying (particularly sagittal suture width), head circumference trends, and nonspecific signs like apnea, bradycardia, lethargy, and decreased activity 2
Serial monitoring requirements: Once ventricular rounding is identified, the infant requires close serial ultrasound monitoring to track progression 2
Intervention threshold considerations: Clinical decisions about surgical intervention are based on the combination of history, physical examination, and ultrasonographic findings—not imaging alone 2. The treating physician needs this information promptly to integrate it with clinical assessment
Standard Practice for Critical Findings
Point-of-care ultrasound (POCUS) should be used to detect germinal matrix and intraventricular hemorrhage in neonates (strong agreement, quality of evidence A) 3. This guideline emphasizes that cranial ultrasound findings in neonates, particularly those suggesting evolving hydrocephalus, are considered actionable findings requiring clinical correlation.
Common Pitfall to Avoid
Do not wait for quantitative measurements to exceed specific thresholds before communicating. The morphological change from slit-like to rounded is itself the critical finding 1. While normal AHW is less than 3 mm and values greater than 6 mm are generally considered abnormal 2, the shape change can precede these numerical thresholds.
Risk Context
In preterm infants with intraventricular hemorrhage, approximately 76% develop posthemorrhagic ventricular dilation (PHVD), and a significant proportion progress to symptomatic hydrocephalus requiring intervention 2. Early identification through morphological changes allows for:
- Optimization of timing for potential interventions (ventricular access devices, external ventricular drains, ventriculosubgaleal shunts, or lumbar punctures) 4
- Prevention of complications from unrecognized increased intracranial pressure
- Improved neurodevelopmental outcomes through timely management
The radiologist should directly communicate this finding to the treating neonatologist or pediatrician immediately, as it represents a potentially evolving neurological emergency requiring clinical correlation and possible intervention.