Adnexal torsion

Ghossain MA, Buy JN, Bazot M, Haddad S, Guinet C, Malbec L, Hugol D, True JB, Poitout P, Vadrot D (1994) CT in adnexal torsion with emphasis on tubal findings correlation with US. J Comput Assist Tomogr 18 619-625... 

Differential diagnosis differential diagnosis of an unilateral missing ovary includes ectopic ovary and atrophy resulting from adnexal torsion. 

The finding of a cystic ovarian tiunor, especially a dermoid cyst in young women who present with acute pain and vomiting is highly suspicious of adnexal torsion. 

Clinically, ruptured ovarian cysts may resemble ovarian torsion. In a patient with acute pelvic pain, a hemorrhagic lesion within a normal size ovary is typically a ruptured ovarian cyst. Furthermore, unlike in most cases of ovarian torsion, clotted blood may be detected in the lesser pelvis. Wall edema of an adnexal mass, engorged adnexal vessels or dilatation of the fallopian tube are missing. TUboovarian abscess and hydrosalpinx may resemble advanced adnexal torsion. Lack of enhancement supports the diagnosis of ovarian torsion. In children, sonography usually allows the diagnosis of appendicitis as a cause of acute pelvic pain. In case of a suspected abscess or an ovarian mass, MRI may aid in further assessment of the adnexa. Rarely, a calcified mass may result from chronic infarction which cannot reliably be differentiated from a calcified ovarian tumor [19]. 

Koonings PP, Grimes DA (1989) Adnexal torsion in postmenopausal women. Obstet Gynecol 73 11-12... 

Haque TL, Togashi K, Kobayashi H et al (2000) Adnexal torsion MR findings of viable ovary. Eur Radiol 10 1954-1957... 

Pain or an acute abdomen should alert to complications due to hemorrhage, rupture, and torsion of the adnexal mass (Fig. 9.17) or caused by nongyne-cological pelvic diseases. 

Fig. 9.29. Dermoid torsion in CT. Noncontrast transaxial CT in a 37-year-old female who presented with acute pelvic pain. A well-demarcated left adnexal lesion with fatty attenuation values ( s-terisk) is located adjacent to the uterus. Linear calcifications are found at its medial wall. An area of higher density within the fatty tissue correlated with floating hair in the macroscopic specimen. The homogenous wall thickening (arrow) is caused by edema due to torsion of the dermoid...

In adults, most commonly a mass with hyperin-tense signal on Tl and T2 due to hemorrhage has been described [16]. Smooth wall thickening of the twisted adnexal cystic mass and a thin hyperintense rim at the periphery of the lesion on Tl-weighted images are further signs in ovarian torsion. 

Fig. 17.8. Torsion of a normal ovary. Transaxial T2WI at umbilical level. In a 14-year-old girl with excessive intermittent pelvic pain for several days, sonography detected an indeterminate solid right adnexal mass. MRI shows a predominantly low-signal-intensity mass with numerous small peripheral cysts (small arrows), representing displaced follicles. Normal left ovary( ) At surgery, the right ovary had undergone complete hemorrhagic infarction. Courtesy of Dr. K. Kinkel, Geneva...

Incompetent and dilated ovarian veins are frequently seen on CT in asymptomatic parous women (Fig. 17.11) [31]. Congenital or acquired vascular malformations of the uterus or parametria present also as vascular lesions. Contrast-enhanced CT or MRI may aid in the differentiation by the early enhancement of arteriovenous malformations in contrast to a more delayed enhancement in varicosities [32]. Adnexal masses with torsion or rare uterine tumors, especially choriocarcinomas may also be surrounded by thick, tortuous, well-enhanced vessels. The clinical background and imaging findings of an adnexal or uterine mass aid in the differential diagnosis. 

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