Adnexal torsion: MR imaging findings of viable ovary

High risk and low prevalence diseases: Ovarian torsion

INTRODUCTION

Ovarian torsion is a rare, frequently misdiagnosed condition that carries with it a high rate of morbidity.

OBJECTIVE

This review highlights the pearls and pitfalls of ovarian torsion, including presentation, evaluation, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Ovarian torsion is one of the most common gynecological surgical emergencies and occurs with complete or partial rotation of the ovary along the supporting ligaments, obstructing vascular flow. Several risk factors include the presence of an ovarian mass or cyst. The most common population affected includes reproductive aged women, though cases also occur in premenarchal females, pregnant women, and postmenopausal women. Abdominal or pelvic pain is common but is not always sudden in onset or severe. Nausea and vomiting occur in 70%. Ultrasound can assist with diagnosis, but a normal ultrasound examination cannot exclude the diagnosis. Computed tomography with intravenous contrast can assist with diagnosis. Treatment includes emergent gynecologic consultation for surgical detorsion, along with symptomatic therapy in the ED.

CONCLUSIONS

An understanding of ovarian torsion can assist emergency clinicians in diagnosing and managing this disease.

Spontaneously infarcted parotid tumours: MRI findings

OBJECTIVES

To report MRI findings of spontaneous infarction in parotid tumours.

METHODS

14 patients (13 male, 1 female; mean age 73 years) with spontaneously infarcted parotid tumours were reviewed retrospectively. MR images were assessed for the location, the presence of synchronous parotid masses, margin characteristics, signal intensity on T ₁ and T ₂ weighted images, and internal architecture according to the distribution of T ₂ signal hyperintensity.

RESULTS

12 tumours were located in the parotid tail and 2 in the superficial lobe. Synchronous parotid masses were seen in four tumours, three of which were located in the ipsilateral parotid tail and one in the contralateral parotid tail. Seven tumours had well-defined margins and seven had ill-defined margins. The signal intensities on T ₁ weighted images were a mixture of high and intermediate in all cases; in 11 tumours, hyperintense areas were dominant. On T ₂ weighted images, all tumours also showed a mixture of high and intermediate signal intensities. Internal architectures on T ₂ weighted images were mosaic hyperintensity in three tumours, central hyperintensity in five, and multiseparated hyperintensity in six.

CONCLUSIONS

Spontaneously infarcted parotid tumours were mostly located in the parotid tail and showed mixed signal intensities with predominant hyperintensity on T ₁ weighted images. Half of the tumours had ill-defined margins, and the internal architectures varied.

Polycystic ovary syndrome with asynchronous bilateral adnexal torsion in a natural cycle

Cases involving polycystic ovaries (PCOs) with adnexal torsion in a natural cycle without ovulation induction are rare, and no reports of such cases have described asynchronous bilateral adnexal torsion. Here, we report a case of PCO syndrome (PCOS) with asynchronous bilateral adnexal torsion in a natural cycle. The patient was a 37-year-old woman with a history of 2 gravidas 1 para. Her primary complaint was left lower abdominal pain. Ultrasonography and MRI identified multiple uterine myomas occupying the pelvis and the left ovary, with oedematous swelling that had moved ventrally to the uterus. She was diagnosed with adnexal torsion and underwent emergency laparoscopic adnexectomy. Nine months after surgery, she experienced right lower abdominal pain. Ultrasonography revealed suspected right adnexal torsion and she underwent emergency surgery. The right ovary was twisted 540° counterclockwise and swollen to 7 cm in size, with partial polycystic changes. She was histopathologically diagnosed with a PCO, and the final diagnosis, which also considered the endocrine test results, was PCOS. In PCOS, adnexal torsion may occur if the swollen ovary moves because of a hysteromyoma or other cause. Accordingly, torsion should be considered during the follow-up of patients with PCOS.

A review of ovary torsion

Ovarian torsion is a rare but emergency condition in women. Early diagnosis is necessary to preserve the function of the ovaries and tubes and prevent severe morbidity. Ovarian torsion refers to complete or partial rotation of the adnexal supporting organ with ischemia. It can affect females of all ages. Ovarian torsion occurs in around 2%-15% of patients who have surgical treatment of adnexal masses. The main risk in ovarian torsion is an ovarian mass. The most common symptom of ovarian torsion is acute onset of pelvic pain, followed by nausea and vomiting. Pelvic ultrasonography can provide information on ovarian cysts. Once ovarian torsion is suspected, surgery or detorsion is the mainstay of diagnosis and treatment.

Midtrimester spontaneous torsion of unruptured gravid rudimentary horn: Presurgical diagnosis on magnetic resonance imaging

Unicornuate uterus with rudimentary horn occurs due to failure of complete development and partial fusion of one of the Müllerian ducts. Pregnancy in a non-communicating rudimentary horn is extremely rare, with a reported incidence of 1 in 76 000-150 000 pregnancies, and usually terminates in rupture during the first or second trimester. Clinical diagnosis of rudimentary horn pregnancy in a woman with history of normal vaginal delivery in prior gestations is difficult. The role of sonography, and more recently, magnetic resonance imaging, in the presurgical diagnosis of rudimentary horn pregnancy is established. We present a case of magnetic resonance imaging diagnosis of 20-week pregnancy in the unruptured non-communicating rudimentary horn in a patient with previous history of two full-term normal vaginal deliveries. The novelty of the case lies in the fact that there was associated torsion of the gravid rudimentary horn and ipsilateral ovary, which has not been reported previously.

Diffusion-weighted imaging of ovarian torsion: usefulness of apparent diffusion coefficient (ADC) values for the detection of hemorrhagic infarction

PURPOSE

We undertook this study to evaluate the need for diffusion-weighted (DW) magnetic resonance (MR) imaging in detecting hemorrhagic infarction following ovarian torsion.

METHODS

The study included 14 consecutive patients aged 12 to 74 years (average age, 36 years) with surgical confirmation of ovarian torsion who underwent 1.5-tesla MR imaging. Pathologically, hemorrhagic infarction was found in 7 patients. We retrospectively reviewed signal intensity on T1-, T2-, and diffusion-weighted images and apparent diffusion coefficients (ADCs) in swollen ovarian stroma.

RESULTS

Fallopian tube thickening was seen in all patients. In patients with ovarian cystic lesion, maximum cyst wall thickness was significantly higher in patients with hemorrhagic infarction (mean, 13.5 ± 4.1 mm) than those without (mean, 5.0 ± 1.0 mm) (P < .05). Signal intensity did not differ significantly on T1-weighted, T2-weighted, and DW images between patients with and without hemorrhagic infarction. ADCs were significantly lower in patients with hemorrhagic infarction (1.20 ± 0.50 [× 10(-3) mm(2)/s]) than those without (2.04 ± 0.26 [× 10(-3) mm(2)/s]) (P < .01). With an ADC threshold of 1.80 [× 10(-3) mm(2)/s], sensitivity for hemorrhagic infarction was 0.88 (7 of 8), and specificity was 1.00 (6 of 6).

CONCLUSION

ADC measurements were useful for detecting hemorrhagic infarction in patients with ovarian torsion.

Massive ovarian edema with torsion: unusual hemorrhage and the recovery of contrast enhancement

We report a case of massive ovarian edema due to left adnexal torsion. On initial magnetic resonance (MR), unusual hemorrhages were demonstrated as several hypointense areas on T2-weighted images. The lack of contrast enhancement was also observed in the left adnexa. Abdominal pain resolved spontaneously, and then follow-up MR demonstrated the recovery of enhancement and hemorrhages as hyperintense signals on T1-weighted images.

Ovarian torsion in a premenarcheal girl: MRI findings

Adnexal torsion is an uncommon cause of severe lower abdominal pain in women and is often difficult to distinguish from other acute abdominal conditions. However, adnexal torsion should be considered in premenarcheal girls admitted with acute abdominal pain and evidence of an ovarian mass. Accurate and early radiological diagnosis is mandatory immediately after onset of clinical symptoms in order to preserve the viability of the ovary. Ultrasound (US) is usually the first line examination performed in an emergency setting, but computed tomography (CT) and magnetic resonance imaging (MRI) can be useful in case of ambiguous US findings, especially in patients with sub-acute symptoms and a suspected adnexal mass. This case report describes the additional value of MRI in a premenarcheal girl with sub-acute right fossa pain.

MR features of physiologic and benign conditions of the ovary

In reproductive women, various physiologic conditions can cause morphologic changes of the ovary, resembling pathologic conditions. Benign ovarian diseases can also simulate malignancies. Magnetic resonance imaging (MRI) can play an important role in establishing accurate diagnosis. Functional cysts should not be confused with cystic neoplasms. Corpus luteum cysts typically have a thick wall and are occasionally hemorrhagic. Multicystic lesions that may mimic cystic neoplasms include hyperreactio luteinalis, ovarian hyperstimulation syndrome, and polycystic ovary syndrome. Recognition of clinical settings can help establish diagnosis. In endometrial cysts, MRI usually provides specific diagnosis; however, decidual change during pregnancy should not be confused with secondary neoplasm. Peritoneal inclusion cysts can be distinguished from cystic neoplasms by recognition of their characteristic configurations. Ovarian torsion and massive ovarian edema may mimic solid malignant tumors. Recognition of normal follicles and anatomic structures is useful in diagnosing these conditions. In pelvic inflammatory diseases, transfascial spread of the lesion should not be confused with invasive malignant tumors. Radiologic identification of abscess formation can be a diagnostic clue. Many benign tumors, including teratoma, Brenner tumor, and sex-cord stromal tumor, frequently show characteristic MRI features. Knowledge of MRI features of these conditions is essential in establishing accurate diagnosis and determining appropriate treatment.

Adnexal torsion: Magnetic resonance findings in the viable adnexa with emphasis on stromal ovarian appearance

PURPOSE

To evaluate ultrasound (US) and magnetic resonance (MR) findings in the viable twisted adnexa.

MATERIALS AND METHODS

Ten patients underwent US and MR studies before surgical detorsion. Corrected cross-sectional area of the ovary was defined as cross-sectional area minus areas of cysts and follicles superior to 1 cm. On T2-weighted images, signal intensity of the stroma was graded as type 1 when it was equal to that of urine and type 2 when it was less than that of urine but markedly more than the contralateral side.

RESULTS

The tube was twisted in six cases and the ovary in nine cases. All adnexa were viable. The largest ovarian cross-sectional area and the largest corrected ovarian cross-sectional area of the twisted ovary were significantly larger than those of the contralateral ovary (P = 0.043 for US; P = 0.012 and 0.017, respectively, for MR). These ovaries contained types 1 and 2 hyperintensity in six cases and only type 2 hyperintensity in three cases. Tubal thickening was seen on MR in five cases.

CONCLUSION

Tubal thickening, enlargement of ovarian stroma as reflected by the corrected cross-sectional area, and hyperintensity of this stroma on T2-weighted images probably related to edema were useful findings in these viable torsions.

Magnetic resonance imaging findings in gynecologic emergencies

Gynecologic emergencies include a variety of gynecologic diseases that manifest with acute lower abdominal pain, fever, and vaginal bleeding. Recent technical advances enable the application of magnetic resonance (MR) imaging to these conditions, which may add clinically useful information in a short enough time for emergent diagnosis. In this study, the acute gynecologic conditions in which MR imaging studies were performed are reviewed, and the characteristic MR findings in gynecologic emergencies, including ovarian hemorrhage, ectopic pregnancy, tumor rupture, torsion, hemorrhage, infarction, and pelvic inflammatory diseases, are demonstrated. Familiarity of these findings aids accurate diagnosis and proper treatment choices in gynecologic emergencies.

MR imaging of the ovaries: normal appearance and benign disease

MR imaging enables a physician to make an accurate diagnosis of various benign adnexal masses and helps to obviate unnecessary surgery.