E1343. Spine Imaging in the Child with a Sacral Dimple
  1. Vincent Parenti; The University of Texas Southwestern Medical Center
  2. Cory Pfeifer; The University of Texas Southwestern Medical Center
Sacral dimples are a common finding on the physical exam of neonates and infants, occurring in 2 - 4% of newborns. Spine ultrasound is often employed as a screening imaging modality for occult spinal dysraphism in patients with sacral dimples or other cutaneous stigmata due to its low cost and lack of radiation. The purpose of the study was to evaluate the utility of using screening ultrasound for the detection of spinal cord tethering in patients with a sacral dimple.

Materials and Methods:
The study retrospectively evaluated 785 spine ultrasounds performed on patients less than 6 months of age with sacral dimples over a 9-year period. Spine ultrasounds suggesting spinal cord tethering were identified as those with a conus medullaris below the L2/L3 intervertebral disc and/or non-dependent nerve roots. Follow-up magnetic resonance imaging (MRI) of patients with a positive screening ultrasound were also reviewed.

The average patient age at screening was 1.6 ± 1.3 months. Of all patients who received a screening spine ultrasound, only 6% had ultrasound imaging findings suggesting possible spinal cord tethering. The positive predictive value of spine ultrasound for the detection of spinal cord tethering was 50% based on MRI confirmation.

The routine use of screening spine ultrasounds for patients with sacral dimples has a low diagnostic yield. Providers should be reminded that sacral dimples within the intergluteal crease do not require imaging in the absence of corroborating clinical symptoms. Decreasing the number of unnecessary spine ultrasounds can serve as an important regulator of healthcare costs in pediatric imaging.