12/04/2021 Scrotal Ultrasound Scrotal Ultrasound Paul S. Sidhu CONTENT Professor of Imaging Sciences King’s College Hospital London Scrotal Ultrasound Lecture Content • Background Anatomy • Normal Variants • Extra-testicular pathology • Intra-testicular pathology • Global Abnormalities Scrotal Ultrasound • New US techniques ANATOMY Scrotal Ultrasound Scrotal Ultrasound Anatomy Vascular Anatomy • Testicular artery Low vascular resistance Broad systolic peak High diastolic flow • Cremasteric artery and artery to ductus deferens Epididymis/Peri-testicular tissues Narrower systolic peak Low diastolic flow Aziz ZA, Satchithananda K, Khan M, Sidhu PS. High Frequency Colour Doppler Ultrasound of the Spermatic Cord Arteries: Resistive Index Variation in a Cohort of 51 Healthy Men. Journal of Ultrasound in Medicine 2005;24:905-909. 1 12/04/2021 Scrotal Ultrasound Vascular Anatomy • Pampiniform plexus • Cremasteric plexus • Testicular vein Scrotal Ultrasound NORMAL VARIANTS Scrotal Ultrasound Scrotal Ultrasound Normal Variants Normal Variants Torsion of an Appendix Testis • Testicular appendages are remnants of the paramesonephric ducts, found at the upper pole of the testes in a groove between the testis and the head of the • Age range 7-12 years epididymis. • ‘Blue dot’ sign on a fair skin. • Similar reflectivity to the epididymal head and ovoid shaped, may be cystic. • Torsion of a testicular appendix is a common cause for scrotal pain in children. • Appendix is usually sessile but may be pedunculated and sometimes calcifies. • The presenting features of appendicular torsion and testicular torsion are often similar, • Seen in 92% of post mortems, 90% of cases are appendix testis • Infarcted appendix may form a scrotal pearl though pain localised to the upper pole of the testicle and a tender nodule are suggestive of a torsed appendix. • Differentiation is important as an appendicular torsion may be managed conservatively. • Ultrasound appearances are variable but usually there is a rounded mass at the superior aspect of the testicle with increased surrounding color Doppler flow and an associated hydrocele. Testicular Appendages Paradidymis (Organ of Giraldes) Appendix testis (Hydatid of Mogagni) Appendix epididymis Vas abberrrans of Haller 12 year old boy with 7 day history of left testicular pain with a ‘blue dot’ sign Sellars MEK, Sidhu PS. Ultrasound Appearances of the Testicular Appendages. European Radiology 2003;13:127-135. Scrotal Ultrasound Scrotal Ultrasound Normal Variants Normal Variants Rete Testis • Composed of numerous seminiferous serpiginous tubules which drain to the epididymal head. • Dilatation of the rete testis is common and seen in patients over 50yrs. • Associated with epididymal obstruction, a spermatocele or dilated efferent spermatic ducts. ‘Two-tone’ Testis • The cystic structures usually measure a few millimetres but as large as 7cm. • This describes the appearance of a normal testis where the testis is divided into by an intra-testicular artery. • The portion nearest to the probe is of normal reflectivity whereas the portion distal to the probe is of decreased reflectivity. • The appearance is thought to be due to a refractive artefact caused by scanning obliquely through the walls of the artery. 68 year old man with obstructive azoospermia, which is responsible for 5% of male infertility Bushby LH, Sellars ME, Sidhu PS. The ‘Two-Tone’ Testis: Spectrum of Ultrasound Appearances. Clinical Radiology 2007;62:1119-1123. Sellars MEK, Sidhu PS. Pictorial review: ultrasound appearances of the rete testis. European Journal of Ultrasound 2001;14:115-120. 2 12/04/2021 Scrotal Ultrasound Scrotal Ultrasound Normal Variants Normal Variants Polyorchidism • A rare abnormality described as the presence of three or more testes. SplenogonadalFusion • Occurs following division of the genital ridge at 4-6 weeks of embryonic life. • Reproductive potential of the supernumerary testis is dependant on any attachment • Splenogonadal fusion is a rare congenital abnormality where an to a draining vas and epididymis. accessory spleen exists within the scrotum fused to the testis. • There may be maldescent of the supernumerary testis or the normal testicle and • There are two types, continuous and discontinuous. In the the condition is associated with torsion, inguinal hernia and cryptorchidism. RIGHT continuous type the spleen is connected to the accessory spleen by a cord. • The condition usually presents as a painless mass • Diagnosis is problematic as often the accessory spleen is • The ultrasound features are a well defined rounded lump occurring either at the confused for a testicular tumour. superior or inferior aspect of the ipsilateral testicle with identical reflectivity and • If suspected a sulphur colloid scan is diagnostic demonstrating blood flow. tracer uptake in the spleen and accessory splenic tissue. • The length of the supernumerary testes and ipsilateral testicle added together equates to the length of the contra lateral testicle. • The management is conservative unless there are associated complicated features. LEFT Rajbabu K, Morel JC, Thompson PM, Sidhu PS Multi-cystic (rete testis) supernumerary testis in polyorchidism with underlying microlithiasis: Ultrasound features. Australasian Radiology 2007;51:B56-B58. Stewart VR, Sellars M, Somers S, Muir G, Sidhu PS. Splenogonadal fusion. B-Mode and Color Doppler Sonographic Appearances. J Ultrasound Med 2004; 23:1087-1090. Scrotal Ultrasound Extra-testicular Pathology The para-testicular space contains the epididymis, spermatic cord and the tunica vaginalis cavity and is affected by a variety of inflammatory or tumoral entities. Differential diagnosis based on US criteria is frequently problematic, as the findings are non-specific. Some general rules apply; i) unlike testicular lesions, extra-testicular entities are usually benign in the adult ii) the first steps to accurate diagnosis include careful localization of the lesion and assessment of its consistency (solid or cystic) Scrotal Ultrasound iii) MRI is useful for tissue characterization of lesions suspected to contain fat, but surgical biopsy will often provide the definite diagnosis. EXTRA-TESTICULAR PATHOLOGY iv) Contrast-enhanced ultrasound (CEUS) has been applied with limited experience indicating a narrow role, primarily for the differential diagnosis of echogenic cystic entities and the delineation of a necrotic abscess from a solid neoplasm. Vasileios Rafailidis, Dean Y. Huang, Paul S. Sidhu. Para-testicular lesions: Aetiology and Appearances on Ultrasound. Andrology in press 2021 Scrotal Ultrasound Scrotal Ultrasound Extra-testicular Pathology Extra-testicular Pathology Benign entities Malignant entities • Hydrocele • Rhabdomyosarcoma • Inflammatory lesions: epididymitis and abscess • Liposarcoma • Epididymal and spermatic cord cyst • Leiomyosarcoma • Fibrous pseudo-tumour • Malignant fibrous histiocytoma • Lipoma • Mesothelioma • Adenomatoid tumour • Lymphoma and leukemia • Leiomyoma • Papillary cystadenoma of the epididymis • Para-testicular hemangioma • Hernias A transverse image through the right A longitudinal image through the left scrotal sac, A longitudinal image through the scrotal sac, with the testis (star) demonstrating a normal testis (star) with a • Scrotal calculi right scrotal sac following a road surrounded by a septated pyocoele hydrocoele surrounding the upper aspect of the • Varicocele traffic accident. The testis (star) is (arrowheads and displaced posteriorly by testis, and with an irregular walled abscess within displaced inferiorly by a large thickened inflamed epididymis (long the thickened epididymis and with echogenic debris septated haematocele (arrow). arrow). There is scrotal wall thickening present (arrows). (short arrows). Rafailidis V, Robbie H, KonstantatouE, Huang DY, Deganello A, Sellars ME, Cantisani V, Isidori AM, Sidhu PS. Sonographic imaging of extra-testicular focal lesions: Comparison of grey-scale, colour Doppler sonography and contrast-enhanced ultrasound (CEUS) Ultrasound 2016;24:23-33 3 12/04/2021 Scrotal Ultrasound Scrotal Ultrasound Extra-testicular Pathology Extra-testicular Pathology A longitudinal image through the A longitudinal image through the left scrotal right scrotal sac, with the testis (star) A longitudinal image through the A longitudinal image through the left sac, with the testis (star) superior to a A longitudinal image through the right scrotal A longitudinal image through the left scrotal inferior to a simple cyst of the right scrotal sac, with the testis scrotal sac, with the testis (star) predominantly septated lesion with linear sac, seen at the upper aspect of the testis is a sac, a heterogenous testis (star) is displaced epididymis (long arrow). There is (star) superior to a well superior to a well circumscribed low areas of high reflectivity; a papillary mixed reflective area (arrows); a low grade superiorly by a mixed reflective lesion posterior acoustic enhancement circumscribed high reflectivity reflectivity adenoma (arrow). cystadenoma of the epididymis (arrows). liposarcoma. (arrows), with patchy areas of increased present (short arrows) distal to the lipoma (arrow). reflectivity; epididymal lymphoma. cystic structure, confirming the fluid content. Scrotal Ultrasound Scrotal Ultrasound Extra-testicular Pathology Varicoceles Sarteschi et al Standing and [1] [2] [3] [4] [5] (1993) Supine Inguinal reflux Supra-testicular Peri-testicular Enlarged vessels Enlarged vessels only during varicosities with reflux only during in