IMAGING OF TESTICULER TORSION

2. • Testicular torsion refers to the torsion of the
spermatic cord structures and subsequent
loss of the blood supply to the ipsilateral
testicle.
• This is a urological emergency; early
diagnosis and treatment are vital to saving
the testicle and preserving future fertility.
• Testicular torsion is primarily a disease of
adolescents and neonates. It is the most
common cause of testicular loss in these
age groups.
INTRODUCTION

3. Normal anatomy
• The tunica vaginalis does not
completely surround the testis and
epididymis, which are attached to the
posterior scrotal wall.
Anatomy review

4. • Bell-clapper anomaly.
The tunica vaginalis completely surrounds
the testis, epididymis, and part of the
spermatic cord, predisposing to torsion.
Anatomy review

5. TESTICULAR ARTERIAL ANATOMY
Testicular artery
– Branch off aorta
– Major intra-testicular blood supply
• Cremaster and deferential artery
– Extra-testicular
Anatomy review

6. • Colour Doppler should reveal bilaterally symmetric and relatively
uniform flow through both testes and epididymides.
NORMAL ULTRASOUND AND DOPPLER FINDINGS

7. • Spectral Doppler tracings of testicular arterial inflow demonstrate
relatively low resistance
NORMAL ULTRASOUND AND DOPPLER FINDINGS

8. • The cremasteric and deferential arteries which have relatively
high resistance to flow.
• The normal testicular artery resistive indices in adults range from
46% to 78%, with a mean of 64%.
NORMAL ULTRASOUND AND DOPPLER FINDINGS

9. ULTRASOUND: SPECTRAL
DOPPLER
Extratesticular blood flow-
High resistance, low flow
Intratesticular blood flow-
Low resistance, high flow

10. • Torsion occurs as the testicle rotates between 90° and 180°,
compromising blood flow to and from the testicle.
• Complete torsion usually occurs when the testicle twists 360° or more;
incomplete or partial torsion occurs with lesser degrees of rotation.
The degree of torsion may extend to 720°.
• The twisting of the testicle causes venous occlusion and engorgement
as well as arterial ischemia and infarction of the testicle.
• The degree of torsion the testicle endures may play a role in the
viability of the testicle over time.
• In addition to the extent of torsion, the duration of torsion prominently
influences the rates of both immediate salvage and late testicular
atrophy. Testicular salvage is most likely if the duration of torsion is less
than 6-8 hours.
• If 24 hours or more elapse, testicular necrosis develops in most
patients.
PATHOPHYSIOLOGY

11. Intravaginal torsion
Is the more common type, occurring
most frequently at puberty. It results
from anomalous suspension of the testis
by a long stalk of spermatic cord,
resulting in complete investment of the
testis and epididymis by the tunica
vaginalis.
• This anomaly has been likened to a
bell-clapper
TWO TYPES OF TESTICULAR
TORSION

12. Extravaginal torsion
• Most often occurs in newborns
without the “bell clapper”
deformity.
• It is thought to result from a poor or
absent attachment of the testis to
the scrotal wall, allowing rotation of
the testis, epididymis, and tunica
vaginalis as a unit and causing
torsion of the cord at the level of
the external ring
TWO TYPES OF TESTICULAR
TORSION

13. Testicle rotates on spermatic
cord

Venous occlusion, edema

Arterial ischemia

Infarction

14. • Severe unilateral scrotal pain
• Previous episodes, spontaneous resolution
• Related to activity, trauma, during sleep
• Nausea, vomiting, abdominal pain, fever
HISTORY

15. • Prenatal torsion, firm, hard, scrotal
mass, which does not transilluminate
in an otherwise asymptomatic
newborn male. The scrotal skin
characteristically fixes to the
necrotic gonad.
• Older patient, swollen, tender, high-
riding testis with abnormal transverse
lie and loss of the cremasteric reflex
PHYSICAL EXAMINATION

16. • CLINICAL SUSPICION
• Nuclear scintigraphy
– Radiation, limited availability
• Ultrasound
– Altered echotexture (B-mode)
– Vascular flow (Color / Spectral / Power Doppler)
• Infrared scrotal Spectroscopy
DIAGNOSIS

17. • Sensitivity 86%, specificity 100% experienced provider using color /
power doppler1
• Gray-scale findings on ultrasound depend on how much time has
passed since the torsion occurred.
• The gray-scale findings of acute and subacute torsion are not
specific and may be seen in testicular infarction caused by
epididymitis, epididymo-orchitis, and traumatic testicular rupture or
infarction.
ULTRASOUND FOR TESTICULAR TORSION

18. • Early stages, scrotal contents may have a normal sonographic
appearance.
• After 4 to 6 hours, the testis becomes swollen and hypoechoic,
• After 24 hours, the testis becomes heterogeneous as a result of
hemorrhage, infarction, necrosis, and vascular congestion
• The epididymal head appears enlarged and may have
decreased echogenicity or may become heterogeneous.
• The spermatic cord immediately cranial to the testis and
epididymis is twisted, causing a characteristic torsion knot or
“whirlpool pattern” of concentric layers
ULTRASOUND FOR TESTICULAR TORSION

19. • A reactive hydrocele and scrotal skin thickening are often seen
with torsion.
Large, echogenic or complex extratesticular masses caused by
hemorrhage in the tunica vaginalis or epididymis may be seen in
patients with undiagnosed torsion.
ULTRASOUND FOR TESTICULAR TORSION

20. ULTRASOUND – B-MODE
– Early ischemia: enlargement, no Δ echogenicity
– Hemorrhage: hyperechoic areas in an
infarcted testis, heterogenous
• Late ischemia/infarct:
hypoechoic

21. • Color/power Doppler sonography is the most useful and
most rapid technique to establish the diagnosis of
testicular torsion and to help distinguish torsion from
epididymo-orchitis
• Blood flow is absent in the affected testicle or
significantly less than in the normal, contralateral testicle.
COLOR/POWER DOPPLER SONOGRAPHY

22. ULTRASOUND: COLOR DOPPLER
• Early Torsion
– No flow, echogenicity similar
• Late Torsion
– Heterogenous echotexture
– Increased extra testicular
blood flow

24. Meticulous scanning of the testicular parenchyma with
the use of low-flow detection Doppler settings
(low pulse repetition frequency, low wall filter, high
Doppler gain)
is important because testicular vessels are small and
have low flow velocities, especially in prepubertal
boys.

25. DIFFERENTIAL DIAGNOSIS OF ACUTE SCROTUM
• Epididymitis
• Scrotal abscess
• Torsion of epididymal appendage
• Intratesticular hematoma

26. • Is a common cause of acute scrotal pain and may mimic
testicular torsion clinically.
• Patients are rarely referred for imaging because the pain is
usually not severe, and the twisted appendage may be evident
clinically as the “blue dot” sign.
• The sonographic appearance of the twisted testicular
appendage has been described as an avascular hypoechoic
mass adjacent to a normally perfused testis and surrounded by
an area of increased color Doppler perfusion.
• However, the twisted appendage may appear as an echogenic
extratesticular mass situated between the head of the
epididymis and the upper pole of the testis.
TORSION OF THE TESTICULAR APPENDAGE

28. • Technetium-99m pertechnetate is the agent of choice.
• Immediate radionuclide angiograms are obtained, with
subsequent static images as well.
• In the healthy patient, images show symmetric flow to the
testes, and delayed images show uniformly symmetric
activity.
NUCLEAR IMAGING

29. • Static images demonstrate a photopenic area in the
involved testis.
• In the subacute and late phases of torsion (missed torsion),
there is often increased flow to the affected hemiscrotum
via the pudendal artery with a photopenic testis and a rim
of surrounding increased activity on static images. This has
been called a rim, doughnut, or bull's-eye sign.
NUCLEAR IMAGING

32. • Near-infrared spectroscopy (NIRS) is an emerging tool to assess
testicular torsion.
• It can measure oxygen saturation 3-4 cm deep in the skin, is rapid
(lasting 20 seconds), and is noninvasive.
• Aydogdu et al performed a small prospective study evaluating 16
adult patients with testicular torsion and found NIRS to be 100%
sensitive and specific for torsion when compared with the
contralateral testis.
NEAR-INFRARED SPECTROSCOPY

33. TREATMENT
• Definitive treatment: surgical
detorsion and orchioplexy
• Manual detorsion: medial to
lateral; “opening a book”
– May need to rotate 2-3 times for
complete detorsion
Roberts: Clinical Procedures in Emergency Medicine