Sonography in male infertility: a look beyond the obvious

Abstract

Infertility affects 15-20% of the reproductive age range population; the male factor accounts for up to 40-60% of these. With female factor infertility catching most of the limelight in research, diagnosis and treatment, the other half of the problem has not been duly addressed. Imaging has an important role to play in the evaluation of male infertility, especially to identify correctible (obstructive) causes. We review the scrotal, trans-rectal sonographic and Doppler findings in infertile men to aid in the accurate diagnosis and proper management of such patients.

Keywords: Azoospermia; Male infertility; Reproductive system; Scrotal sonography; TRUS.

Conflict of interest statement

Conflict of interest

We have no conflict of interest to declare.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Figures

Fig. 1

Normal testes showing uniform homogeneous echogenicity

Fig. 2

a Axial section on TRUS shows seminal vesicles as hypo-echoic bow-tie-shaped structures. Parasagittal TRUS in normal adult showing the vas in long section (b), seminal vesicle, vas deferens (c) and ejaculatory duct (d)

Fig. 3

Characteristic sonographic findings in infertile men with obstructive etiology. Ductal ectasia and dilated channels in epididymis, visualized as multiple anechoic tubular structures in rete testis (a) and epididymal head (b) and body (c), respectively

Fig. 4

Chronic infective epididymitis causing proximal obstruction: a dilated rete testis with b bulky heterogeneous epididymis showing c increased vascularity on Doppler. Another patient with chronic tubercular epididymitis shows d epididymal tail calciication visualized as echogenic foci with distal shadowing

Fig. 5

a Anechoic round lesion with posterior acoustic enhancement involving the head of the epididymis represents an epididymal cyst. b Spermatocele in another patient with obstructive cause of infertility seen as hypo-echoic cystic lesion with fine internal echoes. c Dilated rete testis in right testis of same patient (b)

Fig. 6

Proximal obstruction (CBAVD). a, b Scrotal USG showing ectatic rete testis and tubules in epididymal head (c, d); dilated tubules in epididymal body and abrupt decrease in size with transformation into thin cord-like structure; e bilateral hypo-plastic seminal vesicle with non-visualization of distal vas

Fig. 7

A diffusely bulky epididymis with a fine speckled appearance due to ectatic tubules in a patient previous vasectomy

Fig. 8

Secondary signs of distal genital tract obstruction as seen on TRUS: a bulky seminal vesicle with AP diameter > 15 mm and b dilated distal vas with a diameter > 6 mm

Fig. 9

ED calcification; parasagittal TRUS images showing (a) hyper-echoic foci with distal shadowing seen along the course of ejaculatory duct. b Seminal vesicle is bulky and has multiple small cysts due to the retention of secretions secondary to ED calculi

Fig. 10

Distal obstruction due to chronic prostatic abscess; a, b focal hypo-echoic lesion in prostate showing increased peripheral vascularity; c parasagittal TRUS image showing dilated distal vas deferens

Fig. 11

Common findings in infertile men with non-obstructive etiology (a–c). Reduced testicular volume with heterogeneous echotexture and reduced vascularity in different patients

Fig. 12

Varicocele; a gray-scale USG images showing dilated venous channels in scrotal sac. b Doppler confirmed the presence of varicoceles with increased diameter of venous channels on Valsalva

Fig. 13

Cryptorchidism; a empty scrotal sac; b, c undescended right and left testis lying intra-abdominally along postero-lateral aspects of the urinary bladder

Fig. 14

Grey-scale sonographic images showing multiple non-shadowing hyper-echoic foci representing diffuse microlithiasis

Fig. 15

Hypo-plastic seminal vesicle with an AP diameter 

Fig. 16

A comparison of Doppler flow patterns in intra-testicular vessels in patients with obstructive (a) and non-obstructive etiologies (b). The last group shows increased resistance and consequently a raised resistive index