Ultrasound of scrotal and penile emergency: how, why and when

Abstract

High-resolution ultrasound is the most common imaging technique used to supplement the physical examination of scrotum and penis with great accuracy in assisting the diagnosis of the various pathologies of male genital system, with the highest diagnostic potential in emergency conditions. Technical advancements in real-time high-resolution, color flow Doppler sonography and contrast enhanced ultrasonography (CEUS) have led to an increase in the clinical applications of scrotal and penile sonography. In this pictorial review we focus on common and uncommon male genitalia emergency with special emphasis on the role of ultrasound assessment and its specific findings to improve diagnostic accuracy.

Keywords: CEUS; Color-doppler; Emergency; Penis; Testis; Ultrasound.

Fig. 1

a, b. PRF setting. High (a) and low (b) PRF setting show a better evidence of intra-testicular flow at low setting (white box; a, b). c, d, e Trans-mediastinal testicular vessels. Longitudinal scans of testis with power-Doppler (c), color-Doppler (d) and superb microvascular imaging (SMI) (e) mode show an artery branching from the mediastinum testis and running within the parenchyma. f Mediastinum testis and albuginea. Longitudinal B-mode scan of testis shows a normal homogeneous echotexture of testis with a mediastinum testis (arrow) as a linear echogenic band of fibrofatty tissue; a thin echoic line surrounds the testis and corresponds to the tunica albuginea (arrowheads). g Head of epididymis. Longitudinal B-mode scan of testis with virtual convex field of view shows the head of epididymis (arrows) with a normal homogeneous echotexture. T: testis. h, i Flow of trans-testicular arteries. Longitudinal scan of testis shows normal testicular arteries representation at color-Doppler mode (h) with low-impedance waveform with large amount of end diastolic flow at pulse-Doppler mode as well as low resistance pattern (i). l, m, n Normal testicular anatomy at CEUS. Longitudinal scans of testis after contrast agent administration show: Testicular arteries enhance first (l) followed by a complete fill-in of the parenchyma and a progressive late washout (n). (white box: time of the scans; l, m, n). o Normal penis anatomy. Transverse B-mode ventral scans of the penis at the basis shows two hypoechoic images (C) corresponding to the corpora cavernosa with a thin echoic line that surrounds them and corresponds to the tunica albuginea (arrowheads); the corpus spongiosum (S) is adjacent to the corpora cavernosa. p Cavernous artery. Longitudinal, ventral scan of the penis, with color-Doppler and pulsed mode shows a normal flow pattern of the cavernous artery (arrow) in a flaccid penis

Fig. 2

a Acute torsion. Longitudinal color-Doppler scan of the right and left testis shows no flow in the right testis (arrow; R: right) compared to the left (L: left). However, the parenchyma still shows a preserved ecostructure. b Sub-acute torsion. Longitudinal B-mode scan of testis shows a fine inhomogeneity of the parenchyma with poor evidence of the mediastinum testis (arrow). c, d Sub-acute torsion. Transverse B-mode scan (c) and color-Doppler scan (d) of testis show an enlarged hypoechoic testis (c) and absent flow within the testis with surrounding hyperemia. e Intermittent torsion. Longitudinal color-Doppler scan of testis shows a widely uneven eco-structure as a result of intermittent twisting but with represented flow. f Chronic torsion. Longitudinal B-mode scan of both testis shows heterogenous echotexture of the torsed right testis (arrow) which also appears increased in volume compared to the left as a result of hemorrhagic infarction. g Flow pattern in incomplete torsion. Longitudinal color-Doppler scan of testis with pulse mode shows increase in flow’s resistance of the intra-testicular arteries with reversal of flow in diastole caused by edema impeding venous flow. h, i, l After detorsion parenchymal testis viability. Longitudinal B-mode (h) and transverse scans with superbe microvascular imaging (i) and after contrast agent administration (l) show an inhomogeneously hypoechoic area (arrows; h) not vascularized at superbe microvascular imaging (arrows; i) which however appears much more extensive at CEUS (arrow; l) with peritesticular hyperemia

Fig. 3

a, b Torsion of appendage. Longitudinal B-mode (a) and color-Doppler mode (b) scans of the upper pole of testis show an enlarged and avascularized appendage (arrows; a, b)

Fig. 4

a, b Acute epididymitis. Longitudinal B-mode (a) and color-Doppler mode (b) scans of the tail of the epididymis show an enlargement and a heterogeneous echotexture (arrows; a) with an increased flow. c, d, e, f Acute epididymitis with spermatic cord extension. Longitudinal color-Doppler mode scans (c, d) of the head (c) and tail of epididymis and longitudinal B-mode (e) and color-Doppler mode scans (f) of the spermatic cord show an enlargement and increased flow of the epididymis extended to the spermatic cord that appears congested (arrows; e). g, h Orchitis. Transverse B-mode (g) and color-Doppler mode (h) scans of the testis show an enlargement and a heterogeneous echotexture of testis (g) with an increased flow (h). i, l Epididymal abscess. Transverse B-mode (i) and color-Doppler mode (l) scans of the tail of the epididymis (stars, i, l) shows a focal low reflective area (arrows; i, l) without vascularity within and with increased surrounding vascularity

Fig. 5

a, b, c Epididymitis-related testicular infarction. Longitudinal (a) and transverse (b) color-Doppler mode scans of testis show a focal avascularized area of low reflectivity (arrows, b) at the upper aspect of the testis surrounded by a perilesional hyperemia (star; b). The transverse scans obtained after administration of contrast medium (c) confirms that the area is completely avascular (arrows; c) and identifies a perilesional rim of enhancement (stars; c)

Fig. 6

a, b, c, d, e Testicular ischemia after inguinal hernia repair. Longitudinal color-Doppler mode scans of testis (a, b, c) and the spermatic cord (d) show a focal low reflective necrotic area (star; a, b, c) into a diffuse avascularised testis and haemorrhagic infarction of the cord (arrows; d) after inguinal hernia repair. The operative exploration confirms the US finding and haemorrhagic infarction of the cord (arrows; e—case of dr. Antonio Brillantino)

Fig. 7

a, b, c, d Fournier’s gangrene. Longitudinal B-mode scan of the scrotal sac (a) shows scrotal wall thickening with multiple areas of high reflectivity (arrows; a) in the subcutaneous tissue representing gas formation. Longitudinal color-Doppler scan (b) of the onside testis shows normal parenchymal echotexture with flow pattern within. Computed tomography on axial view and lung window (c) confirms the scrotal wall thickening and subcutaneous gas (arrows; c), consistent with Fournier’s gangrene. Perineal and scrotal region after necrosectomy (d—case of dr. Giuseppe Romano). From Di Serafino et al. [16]

Fig. 8

a, b, c, d Compartment syndrome. Longitudinal B-mode (a), color-Doppler (b) and power-Doppler (c) scans of right testis (arrows; a, b, c) in neonate with hypertensive hydrocele (star; a) show homogenous echotexture of testis without any vascular flow within compared to the left side (b); the testis is also marginalized. Transverse color-Doppler (e) scan after decompression shows an increased blood flow within right testis (arrow; d)

Fig. 9

a, b Injury of the scrotal wall. Transverse B-mode (a) and color-Doppler (b) scans show diffuse, inhomeogeneous thickening of the scrotal wall (arrows; a, b), consistent with blood extravasation. The testis (T; a, b) is intact with normal blood flow within (b). c, d Extra-testicular hematoma. Longitudinal B-mode (c) and color-Doppler (d) mode scans in two different patient show a hyperechoic subacute hematoma on sub-albuginea side (arrows; c) and chronic hypoechoic hematoma on extra-albuginea side (arrows; d) without albuginea tears (arrowheads; c, d). e Intra-testicular hematoma without tunica tears. Longitudinal color-Doppler mode scan (e) of upper pole of the testis shows an avascularized hypoechoic heterogeneous area referred to hematoma (arrows) with tunica intact (arrowheads). f Intra-testicular hematoma with tunica tear. Longitudinal color-Doppler mode scan (f) of the anterior surface of the testis shows an avascularized hypoechoic heterogeneous area referred to hematoma (arrows) with disruption of the tunica (arrowheads). Surgery confirmed testicular rupture. g, h, i, l Testicular rupture. Longitudinal B-mode scans of the right (R; g) and left testis (L; h) after a motorcycle accident, a well defined hematoma of the right testis (arrows; g) and diffuse parenchymal distortion of the left testis with contour irregularity referred to rupture (arrows; h) is shown; the corresponding CEUS findings of the right (i) and left testis (l) define better the areas of avascular traumatic impairment (caliper; i, l) with a large part of the right parenchyma vital (star; i) unlike the left. The right testis was rescued at surgery while the left has been removed

Fig. 10

a Extra-albuginea hematoma. Transverse B-mode scan shows a hematoma (arrows) adjacent to the left corpus cavernosum (C); no fracture was identified in the tunica albuginea (arrowheads). b Intra-cavernosus hematoma without tunica tears. Longitudinal color-Doppler mode scan on right lateral view shows an avascularized intra-cevernosus hematoma (arrow) without tunica albuginea tear (arrowhead). c Intra-cavernosus hematoma with tunica tear. Longitudinal B-mode scan on left lateral view shows rupture of the tunica albuginea (arrowhead) with an adjacent hematoma (arrow) due to trauma. d Urethral leak. Transverse B-mode scan at the basis of the penis shows a large corpuscolate collection suggestive for hemo-urinoma (arrows) due to post-traumatic urethral leak. (U: urethra). e, f Pseudoaneurysm. Transverse B-mode and color-Doppler mode (e) scan show a hypoechoic collection (star; e) referred to hematoma with pseudoaneurysm (arrows; e) secondary to traumatic injury of the penis. Digital subtraction angiogram (f) shows an area of abnormal blush at the penile base that corresponds to the pseudoaneurysm (arrow; f—case of dr. Giuseppe de Magistris)

Fig. 11

a Low flow priapism. Transverse color-Doppler mode scan shows the corpora cavernosa (C) with a coarsened heterogeneous echotexture, a finding consistent with congestion without blood flow in the substance of the corpora. b High flow priapism. Transverse color-Doppler mode with pulse mode scan shows a right arterio-venous cavernous fistulas (arrow) with turbulent high-flow pulse pattern. c, d Mondor disease. Transverse (c) and longitudinal (d) dorsal color-Doppler mode scan of the penis at the basis show an increased calibre of the superficial dorsal vein (arrows; c, d), which is filled with echogenic material (arrows; d) without blood flow referred to thrombosis in leukemic patient

Fig. 12

a, b, c, d Penis abscess. Transverse ventral B-mode scan of the penis at the basis shows an extensive collection (arrows; a) with a mixed ecostructure engaging the extra-albugine space, imprinting the left cavernous body. Longitudinal color-Doppler mode (b) scans shows the perineal extension of the collection (arrows; b) without any blood flow within. Magnetic resonance images on axial T2w (a) and T1w post-contrast media on axial (d) and coronal (e) view confirm the extent and heterogeneity of the collection (arrows; c, d, e) which appears non-vascularized and suggestive for extra-albugine abscess. C corpora cavernosa. S corpus spongiosum