Scrotum

Purpose of the sac

Protection and temperature regulation

Two halves are separated by ___ internally

tunica dartos

Two halves are separated by ___

median raphe

Testes endocrine function

produce testosterone

Testes exocrine function

produce sperm (spermatogenesis)

Testes measures how in adults?

3-5 × 2-4 × 3 cm

Each testis divide into over 250-400 conical lobules containing

seminiferous tubules

Seminiferous tubules join at the apex of each lobule and anastomose to form

rete testis in mediastinum

Rete testis drain into 

head of epididymis through efferent ductules

Pathway of Sperm

Seminiferous tubules, tubuli recti, rete testis, efferent ductules, ductus epididymis. vas deferens

How do testicles appear sonographically?

Smooth, medium gray structures with fine echo texture

Epididymis definition

6-7 cm tubular strucure beginning superiorly and then coursing posterolaterally to testis

Epididymis divisions

Head, body and tail

Epididymis contains 10-15 efferent ductules from rete testis

converge to form single duct in body and tail

Epididymis Head

Largest part of the epididymis, superior to upper pole of testicle. Measures 10-12mm in width.

Epididymis Body

Smaller than the epididymal head, follows posterolateral aspect of testis from upper to lower pole 

Epididymis Tail

Slightly larger and positioned posterior to lower pole to testis

Epididymis Sonographic Appearance 

isoechoic or hypoechoic to testicle, echo texture coarser

Each testicle is covered by

dense, fibrous tissue called tunica albuginea

Tunica Albuginea

extended posteriorly and enters the testicle to help form mediastinum testes

Multiple septa are formed from tunica albuginea at the mediastinum and course

through testis and separate into lobules

Mediastinum

supports vessels and ducts coursing through testis

Mediastinum Sonographic Appearance

bright hyperechoic line coursing craniocaudal within testis

Tunica vaginalis 

lines inner walls of scrotum, covering each testis and epididymis

Two layers of tunica vaginalis

parietal and visceral

Tunica vaginalis parietal

inner lining of scrotal wall

Tunica vaginalis parietal

surrounds testis and epididymis

Hydroceles form in space between

layers of tunica vaginalis

What travels through the tunica vaginalis?

Blood vessels, lymphatics, nerves and spermatic ducts

Vas Deferens

a continuation of ductus epididymis, is thicker and less convoluted

Vas deferens joins

duct of seminal vesicles to form the ejaculatory duct which empties into the urethra

Spermatic cord

suspend testis in scrotum and travels through the inguinal canal

Spermatic cord contains

vas deferens, testicular arteries, venous pampiniform plexus, lymphatics, nerves and cremaster muscle

Cremasteric artery

branches from branches of external iliac artery, provides flow to cremaster muscle and peritesticular tissue

Deferential artery

arise from branch of branch of internal iliac artery, supplies epididymis and vas deferens

Intratesticular arteries should have what kind of flow?

Low resistance

Pampiniform plexus

network of veins; where venous drainage of the scrotum occurs through

Pampiniform plexus exits from

mediastinum testis and courses in spermatic cord

Pampiniform plexus converges into

testicular, deferential and cremasteric veins

Right testicular vein drains into _____, left testicular vein drains into _____

IVC, left renal vein

Deferential vein drains into

pelvic veins

Cremasteric vein drains into

tributaries of epigastric and deep pudendal veins

Pt positioning for scrotum ultrasound

Supine position, penis on abdomen covered by towel, legs together to provide support for scrotum and rolled towel between legs to support scrotum

What frequency/probe is used for scrotum ultrasound?

High frequency 10-14 MHz, linear probe

Patient history questions?

Palpable mass, scrotal pain, swollen scrotum, or other reason?

Any symptoms, including history, location, and duration of pain?

Surgical procedure? When?

Any injury or trauma? When did it occur?

I fmass is palpable, ask pt to find lump. Place probe over the exact location and scan

Clinical questions

Is parenchyma homo or heterogeneous?

Is there a mass, if so is it cystic or solid?

Is the mass intra or extratesticular?

Is one testis swollen, larger or smaller than the other?

Is the epididymis normal? Is skin thickened?

Is blood flow normal? How does color doppler compare each side?

When varicocele is suspected, you perform what?

Valsalva maneuver, similar to a sit up

What will a varicocele do when pt performs Valsalva maneuver?

It will dilate

Cryptorchidism

An undescended testicle, testis is usually palpable in the inguinal canal.

Cryptorchidism is bilateral in what % of cases?

10-25%

Cryptorchidism is associated with

future infertility and malignancy

Cryptorchidism treatment

surgery will be done to pull testis down, often done at birth

Cryptorchidism Sonographic Findings

Undescended testicle is smaller and less echogenic than a normal testis, usually oval with homogeneous texture. Mediastinum rarely seen

Testicular Ectopia

very rare condition, testis cannot be manipulated into correct path of descent

Most common site for ectopic testicle to rest

superficial inguinal canal

Other sites ectopic testicle may rest include

perineum, femoral canal, suprapubic area, penis, diaphragm, and other scrotal compartment

Anorchia

rare condition, absence of testicle.

Unilateral anorchia (monorchidism) is found in 4% of patients with

nonpalpable testis

Anorchia is more common on the right or left? How is a definitive diagnosis found?

Left, definitive diagnosis depends on surgical diagnosis

Causes of anorchia

occurs inside mom’s stomach, intrauterine testicular torsion or other forms of decreased vascular supply to testicle in utero

Polyorchidism

testicular duplication, very rare disorder. Extra testicle is usually small

Polyorchidism is more common on the ___ side?

left side (75% of the time)

Polyorchidism is bilateral in ____% of cases?

5%

Polyorchidism is associated with

Malignancy, cryptorchidism, inguinal hernia and torsion

Types of scrotal pathology

Torsion, appendages, fluid collections, trauma, varicocele, inflammation (epididymitis, orchitis, epididymo-orchitis), microlithiasis and masses

Torsion

arterial blood supply to testicle is interrupted secondary to twisting of spermatic cord. Commonly due to Bell Clapper Syndrome

Bell Clapper Syndrome

tunica vaginalis completely surrounds testis, epididymis, distal spermatic cord, allowing them to move and rotate freely within scrotum, is bilateral.

Torsion is most common in

Adolescence, 12-18 years old

Testicular torsion affects

venous flow first with occluded veins, causing swelling of scrotal structures on affected side. If torsion continues, arterial flow is obstructed and testicular ischemia follows. 

360 degree torsion affects?

All vessels

Surgery within 6 hours of onset of pain, what percentage of testes can be saved?

80-100%

Between 6-12 hours of torsion onset salvage rate is?

70%

After 12 hours of torsion only what % will be saved?

20%

24 hours after torsion , testes are typically?

Not salvageable

Torsion Clinical Signs and Symptoms

acute onset pain (often during sleep), possible lower abdomen/inguinal pain, swollen testis/scrotum, nausea/vomiting and malposition of testicle

If testes cannot be saved after torsion, how many are removed?

Typically only one

Torsion Sonographic Appearance

enlargement of spermatic cord, epididymis and testicle, absent/diminished intratesticular flow, heterogeneous hypoechoic testicle, hydrocele, thick scrotal wall

Appendages

normal finding, may not be seen in absence of fluid. Embryologic remnants, small pieces of tissue originating from testicle or epididymis

Most commopn cause of actue scrotal pain in prepubertal boys?

Appendage that has been torsed, gives a blue dot sign on ultrasound. 

Scrotal pearl

After torsion, appendix becomes mobile and calcified

Appendages feel

slightly painful, feels like a pinch, is rarely removed

Fluid Collections (hydrocele, pyocele or hematocele)

potential space exists between visceral and parietal layers of tunica vaginalis

Hydrocele

collection of serous fluid, most common cause of painless swelling

Pyocele

collection of pus, occur with untreated infection or when abscess ruptures. Often due to STDs

Pyocele Sonographic Appearance

hypoechoic, septated

Pyocele Symptoms

fever, high WBC

Hematocele

collection of blood, secondary to trauma. May form after hydrocele surgery or due to STI. Associated with lowered hematocrit

Hematocele Sonographic Appearance General

varies with age of injury

Acute Hematocele Sonographic Appearance

acute hematocele appear echogenic with numerous highly visible echoes that can be seen to float or move in real time

Chronic Hematocele Sonographic Appearance

show low-level echoes and develop fluid-fluid levels or septations

Acute Scrotum Trauma may be result of

MVA, athletic injury, direct blow ton scrotum or straddle injury. Rupture is possible

Testicular Rupture/Fracture Sonographic Appearance

Focal alteration of testicular parenchymal pattern, interruption of tunica albuginea, blood flow disruption across surface of testis, irregular testicular contour, scrotal wall thickening and hematocele.

If surgery is performed within 72 hours following testicular injury, up to ___% of testes can be saved, but only ____% can be saved after 72 hours.

90%, 45%

Hematoma Sonographic Appearance

Appear heterogeneous within the scrotum, becoming more complex with time they develop cystic components. 

Hematomas associated with trauma may be

large and cause displacement of the associated testis

Varicocele definition

An abnormal dilation of veins of pampiniform plexus

Most common cause of correctible male infertility is 

varicocele

Varicocele is more common on the left or right?

Left

Primary Varicocele

Incompetent venous valves of spermatic vein or pampiniform plexus, usually on the left

Nutcracker Syndrome

left renal vein can’t empty into INVC causing backup in the gonadal vein