Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1895
Testis
Hydrocele
Epididymis
A B C
FIG. 54.38 “Missed” Testicular Torsion. (A) This 18-year-old male patient had a 2-day history of left scrotal pain and swelling. Sagittal sonogram
demonstrates an enlarged (volume, 22.6 mL), hypoechoic, heterogeneous left testis and epididymis with increased echogenicity and thickening of
the tunica albuginea. There is no arterial or venous low within the left testis or epididymis, although there is hyperemia around the testis. This
constellation of indings is consistent with a missed testicular torsion of a subacute nature. A reactive hydrocele is seen around the left testis,
which contains complicated luid. (B) and (C) Sagittal and transverse sonograms in 5-month-old male infant with missed torsion of the left testis,
with history since birth of a normal size right testis (not shown) and a small hard left testis. The tiny left testis (volume, 0.1 mL) is shown in the
left hemiscrotum, with the tunica albuginea appearing brightly echoic and demonstrating partial shadowing of the ultrasound beam, consistent with
delayed (missed) torsion, the insult presumably having occurred in utero.
he gray-scale appearance of the torsed testis ranges from
normal (early) to enlarged and hypoechoic secondary to
edema (usually ater 4-6 hours) and then to a heterogeneous
appearance with areas of increased echogenicity secondary to
vascular congestion, hemorrhage, and ischemia (usually ater
24 hours) 89,115 (Fig. 54.38). he last appearance is also known
as “missed” torsion. Surgical removal is recommended if the
testis is clearly necrotic because if let in situ, the contralateral
testis may be adversely afected because of a presumed antibodyinduced
immunologic process. 97 Other gray-scale indings in the
presence of torsion include abnormal orientation of the testis
within the scrotum (e.g., transverse lie) as well as abnormally
thickened paratesticular structures. he epididymis is usually
enlarged because of vascular congestion and may be isoechoic,
hypoechoic, or hyperechoic to the testis. here may be scrotal
wall thickening and reactive hydrocele formation. Another
associated inding includes an enlarged, twisted spermatic
cord. 116
Color Doppler Sonography in
Testicular Torsion
To make the diagnosis of acute testicular torsion, the clinician
must unequivocally demonstrate absent blood low in the painful
testis and normal blood low in the contralateral asymptomatic
testis. he color low examination includes careful comparison
of the symmetry of low in both testes. he sensitivity of color
Doppler for detecting acute testicular torsion in pediatric patients
is 90% to 100%, whereas the sensitivity of scintigraphy approaches
100%. 124,125,127 In technically adequate studies performed on
state-of-the-art equipment, the speciicity of color low imaging
is almost 100%. 115 Important to note, presence of low in the
painful testis does not exclude the diagnosis of torsion. 126,128,129
In patients with incomplete or partial spermatic cord torsion
(≤360 degrees), arterial low may be demonstrated, although
diminished in quantity compared with the asymptomatic testis. 126
Power Doppler, with its greater sensitivity to minimal low, may
be helpful. 120
In cases of detorsion, color Doppler may demonstrate
increased low within the painful testis and paratesticular sot
tissues caused by reactive hyperemia. his phenomenon may
mimic the reactive hyperemia that occurs in inlammatory
conditions such as epididymo-orchitis. 126 he clinical indings
should help to diferentiate between torsion and inlammation.
In the patient with acute scrotal pain that spontaneously resolves
and in whom color Doppler imaging shows hyperemia, detorsion
is likely. Spontaneously or manually reduced torsion does
not require emergency surgery, but these patients are at risk
for subsequent torsion and can beneit from orchiopexy. 126,130
In cases of late torsion (>24 hours), color Doppler typically
shows marked hyperemia of the scrotal wall and paratesticular
sot tissues with absent testicular low, analogous to the scintigraphic
doughnut sign. Pulsed Doppler waveform analysis
is unnecessary for the diagnosis of torsion. he sensitivity
of pulsed Doppler for detecting torsion ranges from 67% to
100%. In small children, identiication of low can be diicult in
normal testes because of the small size of the testicular arteries.
In addition, it may be diicult to distinguish between paratesticular
and intratesticular arterial pulsations, and thus scrotal
wall hyperemia associated with torsion may be mistaken for
normal low.
With chronic torsion the testis will begin to atrophy ater 14
days. During this phase, the testis may remain hypoechoic, or
it may become hyperechoic if ibrosis or calciication develops. 126
he ipsilateral epididymis is oten enlarged and echogenic, oten
with an accompanying hydrocele. Other causes of testicular
infarction include trauma, polyarteritis nodosa, and subacute
bacterial endocarditis. Extrinsic compression of the cord or testis
leading to testicular infarction can occur with hernias, 115 hydroceles,
131,132 and epididymitis.
Acute epididymitis accounts for 28% to 47% of cases of acute
scrotal pain in children and is more common in pubertal than
prepubertal boys. It is thought that many cases of prepubertal
epididymitis are actually cases of appendiceal torsion, especially
in patients with a negative urine culture. 114 Patients with epididymitis
typically have a more gradual onset of pain with fewer