An evaluation of the contribution of routine ultrasound when performed with multiphase CT in renal donor imaging assessment.

OBJECTIVES

We sought to examine the contribution of routine ultrasound when performed with computed tomography in identifying exclusion criteria in potential living kidney donors.

METHODS

We performed a 10-year retrospective cohort study including all cases of potential renal donors at our center. For each case, the donor workup ultrasound (US) and multiphase computed tomography (MPCT) original reports and imaging were reviewed by a fellowship-trained abdominal radiologist in consultation with a transplant urologist and placed into one of 3 groups: (1) no significant US contribution, (2) US was useful to characterize an incidental finding (either US exclusive or US aided in CT interpretation) but did not impact donor eligibility, and (3) an US exclusive finding contributed to donor exclusion.

RESULTS

A total of 432 potential live renal donors were evaluated (mean age 41, 263 women). In total, 340 (78.7%, group 1) cases had no significant US contribution. In 90 cases (20.8%, group 2), US helped to characterize one or more incidental findings but did not contribute to donor exclusion. In 1 (0.2%, group 3) case, an US exclusive finding (suspected medullary nephrocalcinosis) contributed towards donor exclusion.

CONCLUSION

US provided limited contribution to renal donor eligibility decisions when performed routinely with MPCT.

CLINICAL RELEVANCE

Routine ultrasound could potentially be omitted in the live renal donor workup, with alternative strategies including a selective approach to incorporating ultrasound and an expanded role of dual-energy CT.

KEY POINTS

• Ultrasound is performed routinely with CT for renal donor assessment in some jurisdictions; however, this practice has come into question particularly with advances in dual-energy CT. • Our study found that routine use of ultrasound provided limited contribution, primarily assisting CT in characterization of benign findings with only 1/432 (0.2%) potential donors in a 10-year period excluded based in part on an ultrasound exclusive finding. • The role of ultrasound can be narrowed to a targeted approach for certain at-risk patients, and can be further reduced if dual-energy CT is utilized.