Diagnostic ultrasound ( PDFDrive )

576 PART II Abdominal and Pelvic Sonography
A
B
FIG. 16.12 Decidualization of Endometrioma in Pregnancy. (A) and (B) Sagittal gray-scale and color Doppler TVS images of a cyst containing
low-level echoes and a peripheral echogenic nodule. The nodule demonstrates color Doppler low, a inding seen in a borderline neoplasm or a
decidualized endometrioma in a pregnant patient.
broad ligament, pouch of Douglas, bladder, rectum, or peritoneum.
he use of the sliding sign on TVS has been described
to diagnose the obliteration of the pouch of Douglas. 91,92 his
procedure entails the placement of gentle pressure against the
cervix with the TVS probe to determine if the posterior cervix
slides easily along the anterior rectal and vaginal wall. Additionally,
if luid is present within the pelvis, ine linear structures representing
adhesions may be seen joining the ovary with attached
endometrioma, uterus and cul-de-sac peritoneum.
Deep iniltrating endometriosis is the most severe form of
the disease although the extent of disease based laparoscopic
staging may not correlate with the severity of symptoms. 78 Variable
accuracy of TVS in the identiication of deep iniltrating endometriosis
has been reported. Most implants are found in dependent
areas of the pelvis that is divided into the anterior and posterior
compartment according to the deep iniltrating endometriosis
classiication by Chapron et al. 93 he anterior compartment is
composed of the urinary bladder, and the posterior compartment
includes the cul-de-sac, the uterosacral ligament, bowel wall,
rectum and recto-sigmoid junction, vagina, and rectovaginal
septum. Sonographically, implants appear as hypoechoic nodules
or as difuse or nodular retroperitoneal thickening. Within the
bowel wall, the lesion oten takes on the appearance of a fusiform
swelling (Fig. 16.11E and F, Video 16.5). Few, if any, vessels are
apparent using color Doppler evaluation. 94-97
Adnexal Torsion
Adnexal torsion is a relatively infrequent gynecologic emergency
requiring prompt surgical intervention with a reported incidence
of 3% in some series. he process primarily afects women of
reproductive age or younger and is uncommon in the postmenopausal
age group. 98,99 Initially, there is twisting of the ovary, the
fallopian tube, or both structures, causing venous and lymphatic
compromise with resulting ovarian edema and adnexal enlargement.
However, until venous and arterial thrombosis has occurred,
reperfusion may permit complete recovery. Complete and unalleviated
torsion can progress rapidly from interference with
venous and lymphatic drainage to arterial occlusion and eventually
necrosis. Torsion may be partial or complete, and acute or chronic.
Not infrequently, torsion may be intermittent with periods of
spontaneous remission of symptoms. he diagnosis of torsion
is complicated by its vague clinical presentation. he most
consistent presenting symptom is abdominal and pelvic pain,
with other nonspeciic signs and symptoms such as fever and
nausea and vomiting more variably present. Early diagnosis
and intervention prior to infarction permit ovarian preservation
and prevent peritonitis.
Because the only consistent symptom cited in most
studies is abdominal pain, usually intense and progressive,
and localized to a lower quadrant, diferential considerations
include other gynecologic causes such as PID, ovarian cysts,
and ectopic pregnancy as well as nongynecologic causes.
Although oten diicult to palpate, a demonstrable mass may
be present. A right-sided predominance also exists that is
attributed to the protective presence of the sigmoid colon on
the let and the hypermobility of the right-sided cecum. As a
result, the presentation of ovarian torsion may mimic that of
appendicitis. 100,101
Most cases of ovarian torsion (50%-80%) are associated with
adnexal pathologic conditions such as ovarian tumors or cysts.
his usually involves an ipsilateral ovarian mass 5 to 10 cm in
diameter that acts as a fulcrum to potentiate torsion due to
increased ovarian volume or weight within adnexal structures.
Although associated with a neoplasm in as many as 50% of cases,
previous studies have indicated that the lesions are usually benign
since the inlammatory and invasive changes caused by malignant
lesions may be protective against ovarian mobility. 102 It is associated
with 1 in 1800 pregnancies, most commonly in the irst
trimester or immediately postpartum. 103 Women undergoing
ovulation induction are at high risk secondary to the development
of large theca lutein cysts. 100
he initial role of sonography in the evaluation of patients at
risk for ovarian torsion is to not only diagnose torsion but also
exclude other causes of acute abdominal pain such as appendicitis,