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.