Imaging for Retrograde Ejaculation

Clinical Diagnosis and Imaging Indications

The American College of Radiology recommends transrectal ultrasound (TRUS) as the first-line imaging modality for evaluating anatomic causes of retrograde ejaculation, with MRI reserved for cases where TRUS is inconclusive or unsatisfactory 1
Low or absent ejaculate volume (<1.4 mL) with normal testosterone and palpable vas deferens suggests possible ejaculatory duct obstruction, and TRUS is indicated for anatomic evaluation 1

TRUS is safe, inexpensive, radiation-free, and effective for evaluating the prostate gland and seminal tract, and can identify ejaculatory duct obstruction with dilated ejaculatory ducts (>2.3 mm), dilated seminal vesicles (>15 mm), or prostatic cysts 2, 3, 1
MRI provides superior soft tissue contrast for multiplanar, high-resolution anatomic evaluation of the prostate, seminal vesicles, and ejaculatory ducts, and is reserved for cases where TRUS is negative, inconclusive, or technically unsatisfactory 4, 5, 1
The American College of Radiology recommends against using CT for evaluating retrograde ejaculation due to poor soft tissue contrast and inability to differentiate structural changes in the prostate and seminal tract 2, 3

The clinical algorithm for imaging selection involves confirming clinical diagnosis first, assessing for anatomic causes, and using TRUS as the first-line imaging modality, with MRI reserved for cases where TRUS is inconclusive or unsatisfactory 1, 4, 5