Diagnostic ultrasound ( PDFDrive )

1896 PART V Pediatric Sonography
RT Testis
SAG
RT Testis
SAG
RT Testis
A
B
C
FIG. 54.39 Acute Epididymitis in 8-Year-Old Boy With Right Scrotal Pain. (A) Sagittal sonogram of the right testis shows a normal-appearing
testis surrounded posterolaterally by a prominent, hypoechoic heterogeneous epididymis (arrows). (B) Longitudinal color Doppler image of the
scrotum reveals increased low in the head of the epididymis with normal low in the testis. (C) Marked hypervascularity is noted throughout the
body and tail of the epididymis. Skin thickening is also present.
constitutional symptoms compared with patients with testicular
or appendiceal torsion. 115,133
On sonography, the inlamed epididymis may be focally or
difusely enlarged with coarse echoes. he overall echo pattern
is usually decreased, but normal or increased echogenicity may
be observed. 134 Associated orchitis is more oten difuse; when
focal, however, it is usually close to the inlamed epididymis.
he involved portion of the testis is usually hypoechoic and
enlarged. On color Doppler imaging, the inlamed epididymis
and testis are typically hyperemic (Fig. 54.39), although occasionally,
normal low may be seen in the involved organs. 14,133,134
Pulsed Doppler evaluation is not necessary to establish the
diagnosis of acute epididymitis, but when performed, there is
elevated diastolic low in the epididymal arteries, a low-resistance
waveform (RI < 0.7 for epididymal arteries), and detectable venous
low. 134,135
With orchitis there may also be abnormally decreased vascular
resistance (RI < 0.5) for testicular arteries. In testicular tumors,
there may be hyperemia, but the RI is usually greater than 0.5.
herefore pulsed Doppler may be useful to diferentiate hyperemic
tumor from testicular hyperemia. 133,135 Associated sonographic
indings include reactive simple or complex hydrocele
and skin thickening. Complications of severe epididymo-orchitis
include abscess formation and ischemia leading to infarction.
Testicular infarction secondary to severe epididymo-orchitis is
indistinguishable from infarction secondary to torsion.
Torsion on Color Doppler Ultrasound
Decreased or absent low
Spontaneous detorsion—normal or increased low
Incomplete torsion—normal or decreased low
Because there is overlap in the gray-scale appearance of both
testicular torsion and epididymo-orchitis, their diferentiation
depends on color Doppler imaging. 127,136 Torsion typically is
characterized on Doppler imaging by decreased or absent low
within the involved testis. he classic appearance of epididymitis
and orchitis is increased low within the epididymis and the
involved testis if orchitis is present.
Epididymitis on Color Doppler Ultrasound
Increased low in epididymis
Increased low in testes if also infected
Ischemia may cause decreased low
However, the overlap between the two may lead to false-positive
or false-negative diagnoses. he hyperemia or normal color low
seen in testes with spontaneous detorsion may be confused for
epididymitis. 133 Incomplete torsion of the testis may reveal normal
or decreased color low. 116 Ischemia and infarction may also be
seen with severe epididymitis, although this is usually less of a
diagnostic dilemma because these patients also require surgery.
Because Doppler imaging is limited in young patients with testes
less than 1 mL, power and contrast agents may be helpful in
distinguishing between torsed and normal testes. 124,127
With chronic epididymitis the epididymis becomes enlarged
and heterogeneous, and the testicular tunica becomes thickened,
appearing as an echogenic hyperemic rim around the testis. Small
calciications may develop in the epididymis and the tunica
albuginea. Ultimately, the testis may atrophy and become difusely
or focally hypoechoic. 97 Isolated orchitis is unusual and in general
has a viral etiology. Mumps orchitis is seen in about 30% of
prepubertal boys infected with mumps. he testes are usually
enlarged and hyperechoic bilaterally during the initial phase,
resulting in testicular atrophy and reduced fertility.
Clinical indings should aid in the diferentiation of detorsion
and scrotal inlammation. Detorsion is more likely in the presence
of spontaneously resolved acute scrotal pain and hyperemia
on color Doppler imaging. Pulsed Doppler waveform analysis
is not necessary to establish the diagnosis of epididymitis,
but if used, it shows elevated diastolic low in the epididymal
arteries, a low-resistance waveform (RI < 0.7 for epididymal
arteries), and detectable venous low. Abnormally decreased
vascular resistance (RI < 0.5 for testicular arteries) is also seen
in orchitis. 135 When surgery is not done to remove an infarcted
testis, the infarcted testis will begin to atrophy ater 14 days.
During this chronic phase, the testis may be hypoechoic, but
when ibrosis and calciication develop, the gonad may become
hyperechoic.