Undescended testes is the most common congenital genitourinary anomaly in boys. Diagnosis is made on physical examination and if necessary, imaging. The evidence shows that it is not necessary to order a routine ultrasound in children with suspected undescended testes before referring to a pediatric surgeon.
Sources:
Tasian GE, et al. Diagnostic performance of ultrasound in nonpalpable cryptorchidism: a systematic review and meta-analysis. Pediatrics. 2011 Jan;127(1):119-28. PMID: 21149435.
Tasian GE, et al. Imaging use and cryptorchidism: determinants of practice patterns. J Urol. 2011 May;185(5):1882-7. PMID: 21421239.