The Testicles: Trauma, Inflammation and Testicular Torsion

Fig. 41.1

At longitudinal greyscale ultrasound evaluation, the right twisted testis appears enlarged and oedematous with initial diffuse hypoechogenicity compared to the left healthy testis

After 4 h, the testis is enlarged with a more spherical morphology and diffuse hypoechogenicity.

It should be kept in mind that a partial infarct may result in a focal or partially hypoechoic pattern (Fig. 41.2a, b).

Fig. 41.2

(a, b) US appearance of partial infarct. Longitudinal greyscale US examination shows focal hypoechoic areas interspersed with normal testicular parenchyma and hyperechoic scar

As time passes, heterogeneous testis is seen due to focal haemorrhage and necrosis. In the late phases of torsion, the number of hyperechoic areas increases, a sign of intraparenchymal bleeding (Fig. 41.3a, b).

Fig. 41.3

(a) Testicular torsion. In transverse greyscale US, imaging shows heterogeneous testis due to focal haemorrhage and necrosis. Colour Doppler shows absence of flow. (b) Intraoperative image shows ischaemic testis with haemorrhage and necrosis. Usually also the epididymis could be involved in the ischaemic process

As the testicular arteries supply the epididymis, also this structure could be involved in the ischaemic process. If the epididymis is involved, it also became enlarged with heterogeneous and with hyperechoic areas due to haemorrhage.

Reactive hydrocele and thickening of scrotal skin are also seen (Fig. 41.4). Scrotal hyperaemia also known as the ‘rim sign’ is the cause of pitfalls of the major Doppler ultrasound. The collateral blood supply to paratesticular tissues, which is reactively increased, should not be erroneous.

Fig. 41.4

In testicular torsion, the transverse greyscale US shows reactive hydrocele (*) and thickening of the scrotal skin (#)

On greyscale US, the testis appears more horizontal that than the contralateral testis, and the mediastinum could be in abnormal position (Fig. 41.5a, b).

Fig. 41.5

In testicular torsion, the mediastinum (*) of the twisted testis (a) is in different position compared to the contralateral healthy testis (b)

In chronic torsion, the testis appears small, hard and markedly hypoechoic to anechoic, and colour Doppler shows no flow in the testis and increases the flow in the paratesticular tissue, including the epididymis complex and dartos fascia.

At the accurate US scrotal analysis in patient with testicular torsion, as a consequence, the sonographic ‘whirlpool sign’ could be detected and appear as a mass with concentric layers formed by coiling of the cord vessels secondary to the twisting of the spermatic cord (Fig. 41.6a, b) [11].

Fig. 41.6

(a) At the US scrotal analysis of the twisted testis, the spermatic cord presents a spiral aspect also known as ‘whirlpool sign’. (b) At colour Doppler ultrasound, flow can be detected in the vessels of the ‘whirlpool mass’

41.3.2 Colour Doppler Ultrasonographic appearances

Colour and power Doppler are the modality of choice to assess the testicular perfusion.

The impossibility to detect any blood flow in the interested testis is the most important criteria for the diagnosis of testicular torsion; furthermore, the flow can easily be detected in the normal contralateral testis (Fig. 41.7a, b) [11].

Fig. 41.7

(a) In testicular torsion, the longitudinal US shows the absence of blood flow in the right twisted testis. (b) Flow can easily be detected in the normal contralateral testis

As said before, the presence of blood flow into the testis does not exclude the possibility of torsion. Again the contralateral same testis should be used as control and the examination should be repeated in a second time (Fig. 41.8a, b).

Fig. 41.8

(a) The US evaluation shows the presence of blood in the normal testis; (b) flow can also be detected in the contralateral testis with incomplete torsion

In suspected cases, where the blood flow is present, the blood flow resistance should be evaluated.

High-resistance blood flow pattern characterised by a decrease or reversal of diastolic flow in the spermatic cord suggests an impending testicular infarction.

In general the presence of testicular blood flow should always been studied using quantitative spectral Doppler evaluation.

In normal testis, the spectral waveform of the intratesticular arteries shows low-resistance pattern with high level of diastolic flow.

The mean resistive index (RI) value obtained in normal intratesticular arteries is 0.62 (range, 0.48–0.75) [12].

The possibility of the diagnosis of prenatal torsion with colour Doppler ultrasonography was described [13].

41.3.3 Incomplete or Partial Torsion

Incomplete torsion or partial torsion is a very challenging diagnosis because the blood flow appears normal; therefore, this condition is very difficult to discriminate with orchitis which can also cause partial ischaemia of the testicular parenchyma (Fig. 41.9).

Fig. 41.9

US obtained in postoperative follow-up shows focal area of survived testicular parenchyma and hyperechoic foci of fibrosis. Power Doppler shows presence of vascular flow only in small part of tissue

Frequently it resolves spontaneously and the detorsion is characterised by increased reactive perfusion of the testis. Again clinical history and laboratory finding help to interpret this problematic condition [2].

41.3.4 Torsion of the Appendices

Torsion of the appendix testis and appendix epididymis can also cause acute scrotal pain, and the clinical presentation may be similar to that of testicular torsion. More than 90 % of twisted appendices involve the appendix testis. During childhood appendiceal torsion is nearly frequent as the testicular torsion. Appendiceal torsion can be asymptomatic. The so-called blue dot sign may be found in appendiceal torsion and consists of small (5 mm) tender mass on the upper pole of the testis with a visible chrematistic blue dot through the scrotal skin. The twisted appendage has been described on US as a small mass onto the upper pole of the testis with no internal blood flow and increased periappendiceal vascular signals. Colour Doppler US aspect of the testis and epididymis is normal, and the only accompanying sign is reactive hydrocele [2].

41.4 Trauma

Scrotal injuries most commonly occur in young men between 15 and 40 years and may result from either penetrating or blunt traumas.

Penetrating injuries include wounds from sharp objects and missiles as well as animal bites and self-mutilation [14].

Penetrating injuries to the scrotum require surgical exploration with conservative debridement of non-viable tissue and reconstruction of the testis and scrotum.

In blunt trauma management, the assessment of the tunica albuginea integrity is essential because if it is intact the lesion can be usually managed conservatively, while immediate operation is necessary if albugineal disruption is suspected [15].

In the assessment of patient that present with scrotal trauma, ultrasound is the first-line imaging modality to evaluate testis integrity. US examinations would be considered also in polytraumatic patient that present with scrotal swelling because often in these patients the examinations of the external genitalia are underestimated and often excessively delayed.

Today’s approach of early operative exploration and repair in case of albugineal disruption is based on evidence that early diagnosis and intervention result in salvage of the testis in a high percent of cases [16].

Imaging helps urologists because clinical examination is difficult because scrotal swelling and pain could prevent evaluation of the scrotal content.

Colour Doppler examination allows direct evaluation of testicular perfusion and detection of ischaemic changes following contusion or posttraumatic torsion.

Assessment of the tunica albuginea integrity is particularly important because if it is intact the lesion can be usually managed conservatively, while immediate surgery is necessary if albugineal disruption is suspected [15].

41.4.1 Testicular Rupture

This severe condition is characterised by traumatic disruption of the tunica albuginea and extrusion of the testicular parenchyma into the scrotal sac (Fig. 41.10a, b).

Fig. 41.10

Testicular rupture. (a) US shows irregularity in the contour of the upper testis pole with extrusion of the parenchyma. (b) Surrending haematocele is present

Differently from the past, recent series, in which high-frequency probe is used, show that ultrasound is the imaging modality of choice in identification of testicular rupture for the diagnostic high sensitivity and specificity [17].

Irregularity of the testis is the most significant predictor for diagnosis of testicular rupture, with sensitivity, specificity and accuracy of 90 % [18].

In patients with testicular rupture, as well as those 136 with other testicular parenchymal injuries in which the tunica albuginea is not interrupted, testicular echotexture may appear heterogeneous, with focal hyperechoic or hypoechoic regions corresponding to haemorrhagic or ischaemic areas.

On ultrasound, the normal tunica albuginea appears as a hyperechoic line outlining the testis. Colour Doppler interrogation is useful to determine viability of the injured testis. Tunica albuginea rupture is almost always associated with a disruption of the tunica vasculosa. As a result, testicular rupture results in ischaemia at a portion of the parenchyma of variable extension, which must be removed during surgical repair. CEUS may be performed in equivocal cases to confirm partial or complete testicular ischaemia [19] (Fig. 41.11). Limitations have been described for ultrasound in assessing patients with testicular rupture. False-negative assessment may result from lack of contour irregularity in patients with small albugineal disruption. Conversely, intratesticular and extratesticular haematomas may be isoechoic to the testis and mimic contour irregularity, leading to a false-positive diagnosis of rupture.

Fig. 41.11

In testicular rupture, the power Doppler shows a portion of ischaemic parenchyma

41.4.2 Testicular Fracture

In this injury, the tunica albuginea is intact but one or more fracture lines break the testicular parenchyma. Similar to injuries of other parenchymas, such as liver, kidney and spleen fracture, lines in the testis are often difficult to identify at greyscale ultrasound. Only about 17 % of cases are seen. When visible, fractures appear as linear hypoechoic avascular bands extending across the testis (Fig. 41.12) [20]. Testicular shape and ultrasound appearance of the tunica albuginea are normal. Colour Doppler examination of the injured testis has achieved a very important role in the assessment and the management of this patient.