Visualization of ureters on standard gynecological transvaginal scan: a feasibility study

OBJECTIVE: To investigate the feasibility of identifying pelvic segments of normal ureters and measuring their size on standard transvaginal ultrasound examination. METHODS: This was a prospective observational study from June to July 2012. All women in the study underwent a transvaginal ultrasound examination performed for various indications either by an expert or by an intermediate-level operator. A standardized assessment of the pelvic organs was performed, recording any congenital or acquired uterine pathology and ovarian abnormalities. Visualization of pelvic segments of both ureters was attempted in all cases. The success in finding the ureters, the time required to identify them and their dimensions at rest and while exhibiting peristalsis were all recorded. RESULTS: A total of 245 consecutive women were included in the study. In all women at least one ureter was successfully identified. Both ureters were seen in 227 women (92.7% (95% CI, 89.4-96.0%)). In 17 (6.9% (95% CI, 3.7-10.1%)) the left ureter was not seen and in one woman (0.4% (95% CI, 0.0-1.2%)) the right ureter could not be visualized (P < 0.001). There were no significant differences in the median time required to visualize the right and left ureters (9.0 (interquartile range (IQR), 6.0-14.0) s vs 8.0 (IQR, 6.0 -14.0) s, respectively; P = 0.9). The median diameter of the right ureter was 1.7 (IQR, 1.4-2.2) mm at rest and 2.9 (IQR, 2.4-3.6) mm during peristalsis. The median diameter of the left ureter was 1.9 (IQR, 1.6-2.3) mm at rest and 2.9 (IQR, 2.4-3.6) mm during peristalsis. CONCLUSION: Pelvic segments of normal ureters can be identified in most women on transvaginal ultrasound examination. Visualization of the ureters could be integrated into the routine pelvic ultrasound examination, particularly in women presenting with pelvic pain or in those with suspected pelvic endometriosis.