Table 2.

Suggested timelines and modality for routine imaging by GA¹

GA	First imaging	Repeat imaging*	Term-corrected imaging
≤31+6 weeks	HUS 4 to 7 days postbirth	4–6 weeks postbirth	Routinely for neonates born before 26 weeks Not routinely for neonates born between 26+0 and ≤31+6 weeks †
≥32+0 to 36+6 weeks with additional risk factors‡	HUS 4 to 7 days postbirth	4–6 weeks postbirth, and only if first image is abnormal	Not routinely

¹This HUS schedule is for routine surveillance of preterm infants with uncomplicated clinical course and should be intensified if clinically indicated or in the presence of anomalies detected on HUS.

GA Gestational age; HUS Head ultrasound; IVH Intraventricular hemorrhage; NEC Necrotizing enterocolitis; PHVD Post-hemorrhagic ventricular dilation; PVL Periventricular leukomalacia; WMI White matter injury.

*If an abnormality (Grade 2 or higher IVH or WMI) is detected on first imaging, a repeat HUS should be performed 7–10 days later. If ventricular dilation or worsening IVH/WMI is detected, the frequency of HUS should be intensified (at least weekly initially and as clinically indicated thereafter). A repeat HUS should also be conducted in the weeks following acute illness (e.g., NEC or sepsis).

^†HUS between 37 and 42 weeks corrected GA if previous moderate-to-severe anomalies (Grade 3 or higher IVH, PHVD, or Grade 3–4 PVL) on HUS, or presence of additional risk factors (e.g., critical illness requiring mechanical ventilation or vasopressors, NEC, major surgery).

^‡Additional risk factors for the late and moderately preterm infant include: need for critical care out of keeping with the usual neonatal course, complicated monochorionic twin pregnancy, microcephaly, complicated postnatal course: sepsis, NEC, major surgery, or abnormal neurological symptoms.