U Ultrasonography

Imaging Studies

· Ultrasonography can be useful in distinguishing torsion of a testicle and torsion of an appendix testis (Image 8.5).

· Better results were reported using high-resolution ultrasonography (HRUS) for direct visualization of the spermatic cord twist with a sensitivity of 97.3% and a specificity of 99% (29, 33) (Level of evidence: 2; Grade of recommendation: C).

u Color Doppler ultrasonography

· Color Doppler sonography (CDS) is the imaging modality of choice for evaluation of the acute scrotum (Image 8.5).

· In torsion of the testicular appendage, CDS shows normal blood flow to the testis, with an occasional increase on the affected side that possibly is due to inflammation.

· In prepubertal patients, this method of imaging is somewhat controversial because the prepubertal testis has low-velocity blood flow, and CDS is less accurate in these instances.

· Doppler ultrasound is useful to evaluate an acute scrotum, with a sensitivity of 63.6-100% and a specificity of 97-100%, and a positive predictive value of 100% and negative predictive value 97.5% (Level of evidence: 3; Grade of recommendation: C).

u Radionuclide imaging (Scintigraphy)

· The positive sign for testicular appendix torsion is the hot-dot sign, which is an area of increased tracer uptake. This sign is pathognomonic for testicular appendix torsion.

· Radionuclide images do not show a positive result if symptoms have been present for fewer than 5 hours. Positive results are seen in only 45% of patients whose symptoms have lasted 5-24 hours.

· The test is reported to be 68% sensitive and 79% accurate.

Note! Scintigraphy and, more recently, dynamic contrast-enhanced subtraction MRI of the scrotum also provide a comparable sensitivity and specificity to ultrasound. These investigations may be used when diagnosis is less likely.

Image 8.5 Torsion of testicular appendages of the left testis. A – Color Doppler sonography; B – Ultrasonography; C – Left scrotum is erythematous and edematous, D – Intraoperative photo demonstrating the torsion of testicular appendages.

Дата добавления: 2014-10-15