CT in the diagnosis of adnexal torsion: a retrospective study

Gynaecological Causes of Acute Pelvic Pain: Common and Not-So-Common Imaging Findings

In female patients, acute pelvic pain can be caused by gynaecological, gastrointestinal, and urinary tract pathologies. Due to the variety of diagnostic possibilities, the correct assessment of these patients may be challenging. The most frequent gynaecological causes of acute pelvic pain in non-pregnant women are pelvic inflammatory disease, ruptured ovarian cysts, ovarian torsion, and degeneration or torsion of uterine leiomyomas. On the other hand, spontaneous abortion, ectopic pregnancy, and placental disorders are the most frequent gynaecological entities to cause acute pelvic pain in pregnant patients. Ultrasound (US) is usually the first-line diagnostic technique because of its sensitivity across most common aetiologies and its lack of radiation exposure. Computed tomography (CT) may be performed if ultrasound findings are equivocal or if a gynaecologic disease is not initially suspected. Magnetic resonance imaging (MRI) is an extremely useful second-line technique for further characterisation after US or CT. This pictorial review aims to review the spectrum of gynaecological entities that may manifest as acute pelvic pain in the emergency department and to describe the imaging findings of these gynaecological conditions obtained with different imaging techniques.

Adnexal torsion: a review of diagnosis and management strategies

PURPOSE OF REVIEW

Adnexal torsion remains a diagnostic challenge heavily reliant on high clinical suspicion, with patient presentation and imaging used as adjuncts to aid in its diagnosis. This review summarizes diagnostic and management techniques of adnexal torsion to assist providers when encountering this surgical emergency.

RECENT FINDINGS

Common findings of adnexal torsion include abdominal pain, nausea, vomiting, and adnexal mass or ovarian enlargement. An elevated neutrophil to lymphocyte ratio may be useful for diagnosis. A 'whirlpool' sign, 'follicular ring' sign, enlarged/edematous ovary, and absent Doppler flow to the ovary are highly suggestive of adnexal torsion. Intraoperative visual diagnosis of ovarian death is highly inaccurate, with only 18-20% of ovaries necrotic on pathological examination. Necrotic appearing ovaries have been shown to have follicular activity on ultrasound one year postoperatively.

SUMMARY

Pelvic ultrasound remains the first-line imaging modality. In patients of reproductive age, we recommend performing detorsion with ovarian conservation, even in cases where the tissue appears necrotic, given poor intraoperative diagnostic rates of tissue death. Retention of ovarian function is also reliant on a timely diagnosis and intervention. We emphasize that the risk of ovarian damage/loss outweigh the risk of a diagnostic laparoscopy in patients of reproductive age.

Transvaginal US vs. CT in non-pregnant premenopausal women presenting to the ED: clinical impact of the second examination when both are performed

Objective

To determine the clinical impact of the second examination when both CT and TVUS are obtained in the same ED visit for acute pelvic/lower abdominal symptoms in non-pregnant premenopausal women.

Methods

200 consecutive non-pregnant premenopausal women (mean age, 31.8 years; range, 18–49 years) who underwent both ED-based TVUS and abdominopelvic CT evaluation for acute symptoms over a 12 month period were included; 107 women had TVUS first, followed by CT; 93 women had CT first. All relevant clinical, radiologic, and pathologic findings were reviewed to establish a final diagnosis. Any additional clinical impact provided by the second imaging test was assessed by two experienced abdominal radiologists.

Results

Initial TVUS was interpreted as normal (n = 63) or mentioned incidental findings (n = 11) in 69% (74/107); subsequent CT established a non-gynecologic GI/GU etiology in 25 (34%). For 37% (34/93) of CT exams interpreted as normal, TVUS added no new information. In 32 cases (34%), TVUS further excluded ovarian torsion/adnexal pathology when initial CT was indeterminate/equivocal. Overall, CT following TVUS provided a key new or alternative diagnosis in 26% (28/107), whereas TVUS after CT provided a relevant new/alternative diagnosis in only 1/93 cases (p < 0.001). In nine cases (8%), CT confirmed a positive US diagnosis but detected relevant additional diagnostic information.

Conclusion

CT following negative TVUS frequently identified a non-gynecologic cause of acute pelvic or lower abdominal symptoms in non-pregnant premenopausal women, whereas the main benefit of TVUS after CT was more confident exclusion of ovarian torsion.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-022-03504-6.

Computed Tomography Features of Adnexal Torsion: A Meta-Analysis

OBJECTIVES

We performed a meta-analysis of studies examining the computed tomography (CT) features of adnexal torsion (AT).

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library for studies involving the proportion of CT features in patients with AT and that used surgery as the reference test. Study quality was assessed using the Newcastle-Ottawa scale and the Agency for Healthcare Research and Quality tool.

RESULTS

Twelve articles involving 483 patients were included. The pooled proportion of right-sided adnexal lesion was 54% (95% confidence interval [CI]: 49%-56%). The pooled proportions of the ovarian lesion histopathological types were: benign germ cell tumors, 33% (95% CI: 28%-37%); benign cystic lesions, 26% (95% CI: 21%-30%); benign epithelial neoplasms, 24% (95% CI: 20%-29%); sex cord-stromal tumors, 4% (95% CI: 2%-6%); borderline neoplasms, 3% (95% CI: 1%-6%); and hemorrhagic cysts, 2% (95% CI: 0%-3%). The pooled proportions of CT features were: Adnexal enlargement, 99% (95% CI: 98%-99%); adnexal with mass, 98% (95% CI: 97%-100%); twisted pedicle, 81% (95% CI: 78%-83%); mass with thickened wall, 77% (95% CI: 73%-81%); tubal thickening, 73% (95% CI: 68%-77%); abnormal location of adnexa, 69% (95% CI: 63%-75%), pelvic ascites, 43% (95% CI: 38%-49%); pelvic fat infiltration, 41% (95% CI: 34%-48%); uterine deviation, 37% (95% CI: 31%-42%); and lack of enhancement, 20% (95% CI: 14%-25%).

CONCLUSION

Adnexal enlargement, adnexal mass, and twisted pedicle may be the most important CT features for diagnosing AT.

When is it too late? Ovarian preservation and duration of symptoms in ovarian torsion

This 10-year retrospective study between 2008 and 2018, aims to investigate the duration of symptoms of ovarian torsion and the subsequent rate of ovarian preservation. Eighty-six women with surgically confirmed ovarian torsion were included. The median duration from the onset of pain symptoms to presentation (26.0 vs 6.0 h, p < .001) and from presentation to surgery (11.0 vs 5.5 h, p = .010) were significantly longer in women who required an oophorectomy compared to women who had conservative surgery. There was no significant difference in symptoms, signs or investigations except ultrasound finding of an enlarged ovary (94.9% vs 76.9%, p = .026). Awareness of the condition among the community and healthcare is crucial and routine investigations should not delay management as positive Doppler flow on ultrasound does not exclude an ovarian torsion.Impact StatementWhat is already known on this subject? Ovarian torsion is a gynaecological emergency and may lead to ovarian necrosis, infection and peritonitis. Early recognition is essential in preserving the ovary, particularly in patients with future fertility aspirations. Currently there is no consensus regarding the time period of ovarian viability after the onset of symptoms.What do the results of this study add? We have demonstrated a significant difference in the duration from the onset of symptoms to surgery. Furthermore, the duration from the onset of symptoms to presentation (26.0 vs 6.0 h, p<.001) and from presentation to surgery (11.0 vs 5.5 h, p=.010) were significantly longer in women who required an oophorectomy compared to women who had conservative surgery. There was no significant difference in symptoms, signs or investigations except ultrasound finding of an enlarged ovary.What are the implications of these findings for clinical practice and/or further research? Women with known ovarian cysts in particular should be educated of the risk of ovarian torsion. Routine investigations should not delay management as it does not exclude an ovarian torsion. Although our study suggests that early presentation and management would reduce the risk of oophorectomy, prospective studies are required to confirm the findings.

Adnexal Torsion: Review of Radiologic Appearances

Adnexal torsion is the twisting of the ovary, and often of the fallopian tube, on its ligamental supports, resulting in vascular compromise and ovarian infarction. The definitive management is surgical detorsion, and prompt diagnosis facilitates preservation of the ovary, which is particularly important because this condition predominantly affects premenopausal women. The majority of patients present with severe acute pain, vomiting, and a surgical abdomen, and the diagnosis is often made clinically with corroborative US. However, the symptoms of adnexal torsion can be variable and nonspecific, making an early diagnosis challenging unless this condition is clinically suspected. When adnexal torsion is not clinically suspected, CT or MRI may be performed. Imaging has an important role in identifying adnexal torsion and accelerating definitive treatment, particularly in cases in which the diagnosis is not an early consideration. Several imaging features are characteristic of adnexal torsion and can be seen to varying degrees across different modalities: a massive, edematous ovary migrated to the midline; peripherally displaced ovarian follicles resembling a string of pearls; a benign ovarian lesion acting as a lead mass; surrounding inflammatory change or free fluid; and the uterus pulled toward the side of the affected ovary. Hemorrhage and absence of internal flow or enhancement are suggestive of ovarian infarction. Pertinent conditions to consider in the differential diagnosis are a ruptured hemorrhagic ovarian cyst, massive ovarian edema, ovarian hyperstimulation, and a degenerating leiomyoma. Online supplemental material is available for this article. ^©RSNA, 2021.