Urachal remnants: Sonographic assessment

OBJECTIVE: To evaluate the frequency of the visualization of urachal remnants (UR) with ultrasound and to determine their sonographic patterns. SUBJECTS AND METHODS: Two hundred and fifty consecutive patients were referred for abdominal and/or pelvic ultrasonography, 83 who had urinary tract symptoms. Patient age ranged from 1 month to 91 years (mean = 35 years). Patients were classified into four groups: (1) < 16 years (n = 47) (2) 16-35 years (n = 100), (3) 36-55 years (n = 49), (4) > or = 56 years (n = 54). Ultrasonography was performed using 3.75 MHz and 7.5 MHz transducers. Ultrasound criterion for diagnosis was a midline mass located between the rectus abdominus muscle and the upper part of the anterior bladder wall. RESULTS: UR were found in 90 cases (36%). UR demonstration was more frequent in groups 1 (61.7%) and 2 (49%) and 3 (20.4%) and 4 (3.7%). UR were nodular (87%) or tubular in structure (13%). Echogenicity was similar to or greater than adjacent muscle in 51% and less than in 49%. The length, width, and thickness mean and standard deviation values were 13.5 +/- 4.7 mm, 12.6 +/- 5 mm, and 5.2 +/- 1.5 mm, respectively. UR were observed in 50% of the asymptomatic patients of groups 1 and 2. CONCLUSION: Urachal remnants are commonly demonstrated with ultrasound, particularly in young patients. They should be considered to be a normal variant unless there is an increase in size or they are accompanied by clinical signs, without other possible causes for symptoms.