Scrotal Ultrasound Tanya Nolan
Scrotal Anatomy or Globus Major Fused tubules that form efferent ducts Thickened portion of tunica albuginea (multiple septa) Or Globus Minor Covers testes Tunica Vaginalis Lines inner walls of scrotum
Prostate Prostate Gland: secretes a thick alkaline substance that constitutes the largest part of seminal fluid. Alkalinity protects sperm from acid present in the male urethra and female vagina. Seminal Vesicles: Produce fluid rich in fructose (energy source for sperm motility after ejaculation)
Vascular Supply ARTERIES Testicular Arteries Capsular Arteries Centripedal arteries Transmediastinal / Transtesticular Artery Cremasteric and Deferential Arteries Pudendal Artery VEINS Pampiniform plexus Right Testicular Vein: drains into IVC Left Testicular Vein: joins the left renal vein Deferential Vein Cremasteric Vein
Epididymis Head Superior to the upper pole of the testis Contains 10-15 efferent ductules from the rete testes Body, Tail Efferent ductules converge to form Ductus Epididymis and becomes the Vas Deferens which joins the duct of the seminal vesicles and forms the Ejaculatory duct that empties into the Urethra Postvasectomy Changes 40% enlargement, inhomogeneity, spermatoceles, dilation of rete testis, and sperm granulomas
Spermatic Cord • Extends from the scrotum, through the inguinal canal and internal inguinal rings, to the pelvis • Vas Deferens • Testicular Arteries • Venous Pampiniform Plexus • Lymphatics • Autonomic Nerves • Fiber of the Cremaster
Function and Physiology • Spermatogenesis • Testicles • Produce sperm in seminiferous tubules • Epididymis • Serves as a duct through which sperm pass • Stores small quantities of sperm • Secretes a small part of the seminal fluid (Semen) • Secretion of Hormones • Testosterone • Secreted by Leydig cells • Androgen or masculinizing hormone
Sperm Pathway Seminiferous Tubules Produce Sperm Tubuli Recti Rete Testes Efferent Ducts Connect testis to epididymis Vas Deferens Connect epididymis to the ejaculatory duct Ejaculatory Duct Seminal Vesicle ducts join Vas Deferens on each side to form the Ejaculatory Duct Urethra Path by which spermatozoa and urine pass.
Songraphic Technique • Transducer • High frequency (10-14 MHz) Linear • Lower frequency may be considered when wall edema and skin thickening is present. • Trapezoid, virtual convex, and panoramic views may be used in cases of hydroceles, hematomas, or swelling. • Patient Position • Supine with legs slightly apart and support placed underneath scrotum. • Penis and upper thighs are draped and positioned away from scrotum.
Sonographic Technique Rete Testis • Right and left testis and epididymis are examined separately in both sagittal and transverse planes • Transverse plane images include superior, middle, and inferior scrotum. • Measurement is obtained at widest diameter (2-4 cm in width) • Compare echogenicity and scrotal skin thickness • Color Flow Doppler • Sagittal images include medial and lateral borders of scrotum. • Length and AP measurements are obtained at longest axis. (Length 3-5 cm & 3 cm in AP) • If patient has a lump/nodule. Have patient trap it between fingers and then scan the nodule.
Normal Testes & Raphe An image should be taken demonstrating the raphe and comparing size, echogenicity, and texture of each testicle. 12
Color Doppler • Upper frequency range improves sensitivity to slow flow. • Enhance visibility of perfusion • Gain • Scale / Pulse Repetition Frequency (PRF) • Wall Filter • Line Density • Threshold • Packet Size • Color box / Region of Interest • Normal Spectral Doppler • Low resistance waveform in intra-testicular arteries. (A low-resistance waveform demonstrates forward flow during both systole and diastole.)
Indication for Sonographic Examination Painful scrotum Scrotal trauma Enlargement Palpable Mass Search for undescended testicle(s) Follow-up for patients with a previous orchiectomy or recent tumor Trauma Male infertility
Pathology Benign Conditions
Scrotal Trauma • Rupture of the testis is a surgical emergency. • If surgery is performed within 72 hours after injury, 90% of testes can be saved. After 72 hours, only 45% can be saved. • Clinical Findings • Pain • Swelling • Sonographic Findings • Focal alteration of testicular parenchymal pattern; irregular contour • Interruption of the tunica albuginea • Scrotal wall thickening • Hematocele • Blood flow disruption across the surface of the testis
Hydrocele • Abnormal accumulation of fluid in the tunica vaginalis • Clinical Findings • Congenital or idiopathic • Usually due to epididymitis • Associated with orchitis, spermatic cord torsion, and trauma • Sonographic Findings • Located around the anterolateral aspect of the testis • Anechoic or low-level echoes.
Hydrocele and Testicular Appendix The appendix testis is attached to the upper pole of the testis between the epididymis and testis.
Hematocele • Blood in scrotal sac • Sonographic Indications • Acute hematocele is echogenic with many visible echoes that can float or move in real time. • Aged hematoceles become more complex and show low level echoes. They may also develop a fluid-fluid level or septations. • Absent of blood flow
Pyocele • Pus in scrotal sac • Contains internal septations, loculations, & debris • Increased vascular perfussion
Epididymitis • Inflammation of epididymis • Most common cause of acute scrotal pain • Clinical Findings • Fever • Dysuria with possible urethral discharge • Sonographic Findings • Enlarged epididymis • Thickened scrotal skin • Decreased echogenicity with course echo pattern • Associated with hydrocele • Increased Doppler flow
Orchitis • Inflammation of the testis; Infection may be focal or diffuse • Enlarged testis • Severely swollen testis may lead to testicular infarction. • Decreased high resistance, absent blood flow, or Doppler waveforms demonstrating reverse diastolic flow is indicative of testicular infarction. • Sonographic Findings • Affected areas appear hypoechoic
Orchitis 6 months after diagnosis • testicular atrophy • skin thickness • Normal skin wall thickness is 2-8 mm thick
Epidiymo-orchitis • A. Swelling and Edema • B. Hyperemic Perfusion • C. High Resistance Blood Flow
Abscess • Most commonly caused by untreated epidiymo-orchitis • Clinical Findings • Fever • Scrotal Pain • Swelling • Sonographic Findings • Anechoic or complex mass • Increased blood flow around mass periphery • No blood flow in mass • Air within the space indicated abscess
Spermatic Cord Torsion • Spermatic Cord becomes twisted and cuts off blood supply • Medical Emergency • Surgery within 5-6 hours onset of pain (80-100% testes salvaged); 6-12 hours onset of pain (70% testes salvaged); after 12 hours onset of pain (20% testes salvaged) • The degree or number of twists also affects testicular salvage • Acute Symptoms • Scrotal pain and swelling • Nausea and vomiting • Sonographic Findings • Enlarged testicle • Enlarged epididymal head • Decreased echogenicity • Chronic • Sonographic Findings • Small heterogeneous testicle • Scrotal wall thickening • Possible hydrocele • No arterial flow • Partial Torsion • Sonographic Findings • Reduced flow with possilbe increased flow in the peritesticular soft tissue • Must make comparison to contralateral side.
Spermatic Cord Torsion • L testicle enlarged and heterogenous • Mixed echopattern caused by hemorrhage, necrosis, & vascular congestion (torsion > 24 hours) • Absence of detectable Color signal B B
Spermatoceles & Epididymal Cysts Spermatocele • Cyst containing nonviable sperm and proteinaceous fluid. • Always Located in Epididymal Head • More common following vasectomy Epididymal Cyst • Cyst containing serous fluid • Found anywhere within the epididymis Sonographic Findings • Palpable • Clear, Simple, or Multilocular • Thin Walled • Posterior Acoustic Enhancement
Varicocele • Enlargement of Veins of Spermatic Cord • Most common cause of infertility • Majority occur on the left side due to venous drainage (L renal vein) • Large, right-sided varicoceles may be associated with renal tumor
Varicocele • Sonographic Findings • Dilated Veins: More than 2mm in diameter • Valsalva maneuver or having patient stand will increase venous pressure and increase vessel diameter. • Reversal Flow occurs when intra-abdominal pressure increases
Intratesticular Cysts and Tubular Ectasia of the Rete Testis • Intratesticular Cysts • More common in men over 40 • Associated with spermatoceles • Single, multiple, variable size • Tubular Ectasia of the Rete Testis • Dilated tubules of Rete Testis • Associated with spermatoceles, epididymal or testicular cysts, or other epididymal obstruction • Has the appearance of intratesticular varicocele but has NO FLOW
Epidermoid Cyst • Rare benign lesion of testis • Well Circumscribed • Hypoechoic • Lamellated • Little Flow
Scrotal Hernia • Bowel, omentum, or other structures herniated into the scrotum • Sonographic Findings • Peristalsis during real-time • Fluid filled bowel loops easily recognizable
Sperm Granuloma • Chronic inflammatory reaction to extravasation of spermatazoa • Frequently seen in patients with vasectomy • Located anywhere within epididymis or vas deferens • Sonographic Findings • Well defined solid mass • Hypoechoic or isoechoic • Increased flow with color Doppler when inflammation is present
Microlithiasis • Tiny calcifications < 3mm within testis • Bilateral • Associated with testicular malignancy and cryptorchidism, Klinefelter’s syndrome, infertility, varicoceles, testicular atrophy, and male pseudohermaphroditism • Sonographic Finding • Multiple bright non-shadowing foci scattered through testis
Adenomatoid Tumor • Most commonextratesticulartumor • Clinical Findings • Generally asymptomatic • Painless • Small, slow growing • Commonly in 5th decade • Sonographic Findings • Well circumscribed, solid • Unilateral (usually left) • Variable echogenicity • Associated with hydrocele
Pathology Malignant Conditions Approximately 95% of all testicular neoplasms are malignant!
Testicular Cancer • Clinical Findings • Painless; vague discomfort • Unilateral enlargement • Types • Germ Cell Tumors • Associated with elevated human chorionic gonadotropin and alphafetoprotien • Seminoma • Embyonal carcinoma • Teratoma • Choriocarcinoma • Stromal Cell Tumors • Leydig cell • Sertoli • Granulose • Theca cell • Metastasis • Lymphoma and Leukemia
Seminoma • Most common germ cell tumor • Sonographic Findings • Hypoechoic lesion • Smooth border • Cystic components or calcification not common
Embryonal Carcinoma • Invasive; aggressive • Ill defined hypoechoic lesion • Possible capsular distorion • Associated hemorrhage, calcification, • and fibrosis Teratoma • Well defined • Complex Mass • Possible calcification with acoustic shadowing • Usually benign in children
Choriocarcinoma • Mixed appearance depending on dominant cell type • Typically irregular borders
Congenital Anomalies • Cryptochidism • Testicular Ectopia • Anorchia • Scrotum is empty • Polyorchidism • Increased risk of malignancy, cryptorchidism, inguinal hernia, and torsion • Duplicated testis are commonly small & efferent spermatic system is completely absent
Cryptochidism • The testicles do not descend to their normal position • 80% are palpable and located in the inguinal canal region • 2.5-8 more times more likely to develop cancer • 10 times more likely for spermatic cord torsion • Surgical Treatment needed because higher temperature may prohibit spermatogenesis and result in infertility.