ULTRASOUND USE IN THE PEDIATRIC POPULATION
By Susan (Flevares) Duffek, MD
Ultrasound is an ideal imaging modality for children. It is painless, does not expose the child to radiation and does not require contrast or sedation. In recent years, ultrasound has become the preferred imaging modality for those infants suspected of having pyloric stenosis. In the past, this was diagnosed with an upper GI. Using ultrasound, we are able to image not only the length and width of the pyloric channel, but also the actual width of the pyloric muscle. These measurements can then be used to calculate the pyloric volume. A pyloric volume greater than 1.4 cm3 is considered positive for pyloric stenosis.
Ultrasound has also become the preferred modality for diagnosing early appendicitis in children. Because children have very little mesenteric fat, appendicitis (particularly early appendicitis) is often very difficult to diagnose with computed tomography. In the hands of an experienced sonsographer, the edematous appendix can often be visualized. The sonographer is looking for an enlarged appendix which is noncompressible. Appendicoliths can also be visualized. Free fluid in the right lower quadrant or pelvis is another helpful, but nonspecific finding. In those patients who are suspected of having an abscess, computed tomography with good oral contrast remains most useful.
In newborns with sacral dimple, hairy tuft, or skin tag, we also offer ultrasound of the spinal cord. The infant is imaged in a prone position and ultrasound of the lumbosacral spine is performed to identify the level of the conus medullaris and to exclude a tethered cord. This is a nice alternative to MRI which would require sedation.
Up to approximately 6 months of age, ultrasound can also be used to image the hips in those babies with hip click who may have developed dysplasia of the hip. Coronal and axial images are obtained both in a neutral position and with stress maneuvers. We prefer to image these infants after one month of age when maternal hormones are less likely to contribute to ligamentous laxity.
If you are interested in obtaining an imaging procedure on a child and are uncertain of which study to order please do not hesitate to contact me at Medical X-Ray Center 605-336-0515 or toll free at 1-800-473-0271.
