Characterization of tubo-ovarian abscess mimicking adnexal masses: Comparison between contrast-enhanced CT, 18F-FDG PET/CT and MRI

O-RADS MRI risk stratification system: pearls and pitfalls

In 2021, the American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System (O-RADS) MRI Committee developed a risk stratification system and lexicon for assessing adnexal lesions using MRI. Like the BI-RADS classification, O-RADS MRI provides a standardized language for communication between radiologists and clinicians. It is essential for radiologists to be familiar with the O-RADS algorithmic approach to avoid misclassifications. Training, like that offered by International Ovarian Tumor Analysis (IOTA), is essential to ensure accurate and consistent application of the O-RADS MRI system. Tools such as the O-RADS MRI calculator aim to ensure an algorithmic approach. This review highlights the key teaching points, pearls, and pitfalls when using the O-RADS MRI risk stratification system.Critical relevance statement This article highlights the pearls and pitfalls of using the O-RADS MRI scoring system in clinical practice.Key points• Solid tissue is described as displaying post- contrast enhancement.• Endosalpingeal folds, fimbriated end of the tube, smooth wall, or septa are not solid tissue.• Low-risk TIC has no shoulder or plateau. An intermediate-risk TIC has a shoulder and plateau, though the shoulder is less steep compared to outer myometrium.

Huge uterine abscess after myomectomy: A case report

RATIONALE

Uterine abscess is a rare gynecologic entity and only a few cases have been reported so far. This study aimed to describe our clinical experience in this case. Initially, hematoma was diagnosed without detail previous medical record. Finally, laparotomy was performed due to refractory fever and highly possible diagnosis of uterine abscess. We successfully performed a hysterectomy and the patient had an uneventful recovery.

PATIENT CONCERNS

A 44-year-old nulliparous woman underwent myomectomy in the local hospital, 45 days ago. She complained of irregular fever (up to 40 °C) without abdominal pain since the surgery.

DIAGNOSES

Due to lack of her detail medical record, equivocal images and her strong intention to preserve uterus, she was misdiagnosed with hematoma and treated with antibiotic treatment. Finally, intraoperative findings revealed that the huge myometrial abscess contained a mass of pus.

INTERVENTIONS

Laparotomy was performed due to refractory high-grade fever and highly possible diagnosis of uterine abscess. Total hysterectomy was performed to avoid the possibility of life-threatening sepsis.

OUTCOMES

The postoperative course was uneventful and the patient was discharged 10 days after surgery.

LESSONS

Complete imaging examinations are recommended prior myomectomy to facilitate the differential diagnosis of postoperative complications. In addition, several measures, such as maintaining aseptic conditions during surgery and postoperative drainage, play a critical role in preventing nosocomial infections. Rare uterine abscess is often mistaken for hematoma with fever. If the patient develops high fever after myomectomy, accompanied by a mass in the myometrium, the possibility of infection or even abscess formation should not be excluded. For women who need to preserve their fertility, the early diagnosis and timely administration of appropriate medication is crucial for preventing uterine loss.

Systematic review and meta-analysis of imaging differential diagnosis of benign and malignant ovarian tumors

BACKGROUND

With the increasing incidence of gynecological ovarian tumors, the differential diagnosis of benign and malignant ovarian tumors is of great significance for subsequent treatment. Currently, ovarian examinations commonly use computed tomography (CT) or magnetic resonance imaging (MRI). This study sought to compare the value of CT and MRI in differentiating between benign and malignant ovarian tumors.

METHODS

The PubMed, Cochrane Central Register of Controlled Trials, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, and Weipu databases were searched for published articles using the following terms "CT" or "Computed Tomography" or "MRI" or "Magnetic Resonance imaging" and "ovarian cancer" or "ovarian tumor" or "ovarian neoplasm" or "adnexal mass" or "adnexal lesion". The articles were screened and the data were extracted based on the inclusion and exclusion criteria. The Quality Assessment of Diagnostic Accuracy Studies-2 recommended by the Cochrane Collaboration was used to assess the methodological quality of the included studies, and the network meta-analysis was performed by Stata 15.0.

RESULTS

The results showed that the overall sensitivity and specificity of CT were 0.79 [95% confidence intervals (CI): 0.70-0.87] and 0.87 (95% CI: 0.80-0.92), respectively. The overall sensitivity and specificity of MRI were 0.94 (95% CI: 0.91-0.95) and 0.91 (95% CI: 0.90-0.93), respectively. The area under the curve of the CT and MRI summary receiver operating characteristics were 0.9016 and 0.9764, respectively. The positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of CT were 5.26 (95% CI: 2.78-9.93), 0.26 (95% CI: 0.13-0.50), and 22.19 (95% CI: 7.54-65.30), respectively. The positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of MRI were 8.69 (95% CI: 5.06-14.92), 0.07 (95% CI: 0.04-0.13), and 146.19 (95% CI: 68.88-310.24), respectively.

CONCLUSIONS

Compared to CT, MRI has a stronger ability to differentiate between benign and malignant ovarian tumors. It's a promising non-radiological imaging technique and a more favorable choice for patients with ovarian tumors. However, in the future, large-sample, multi-center prospective studies need to be conducted to compare the performance of MRI and CT in distinguishing between benign and malignant ovarian tumors.

The role of "penumbra sign" and diffusion-weighted imaging in adnexal masses: do they provide a clue in differentiating tubo-ovarian abscess from ovarian malignancy?

Purpose

To evaluate the role of “penumbra sign”, diffusion-weighted imaging (DWI), and the apparent diffusion coefficient (ADC) value in differentiating tubo-ovarian abscess (TOA) from ovarian malignancy.

Material and methods

Thirty-six patients with 50 adnexal masses (tubo-ovarian abscess, n = 24; ovarian malignancy, n = 26), who underwent magnetic resonance imaging (MRI) with DWI, were retrospectively evaluated. “Penumbra sign” (hyperintense rim on T1W images), diffusion restriction, and mean apparent diffusion coefficient (ADC) values from cystic (c-ADC) and solid (s-ADC) components were evaluated for all the masses.

Results

“Penumbra sign” on T1W images was significantly more common in the TOA group (n = 21, 87.5%) than in the ovarian malignancy group (n = 2, 7.7%) (p < 0.001). Similarly, diffusion restriction in the cystic component was more frequent in the TOA group (n = 24, 100% vs. n = 2, 10.5%; p < 0.001). In contrast, diffusion restriction in the solid component was more common in the ovarian malignancy group (n = 5, 20.8% vs. n = 26, 100%; p < 0.001). The mean c-ADC value was significantly lower in TOAs (p < 0.001). A c-ADC value of 1.31 × 10^-3 mm²/s may be an optimal cut-off in distinguishing TOAs from ovarian malignancies. Conversely, the mean s-ADC value was significantly lower in the ovarian malignancy group (p < 0.001). An s-ADC value of 0.869 × 10^-3 mm²/s may be an optimal cut-off in differentiating ovarian malignancies from TOAs (p < 0.001). ROC curve analysis showed that c-ADC values had a higher diagnostic accuracy than s-ADC values.

Conclusions

“Penumbra sign” on T1W images, diffusion characteristics, and ADC values provide important clues in addition to conventional MR imaging features in differentiating TOA from ovarian malignancy.

Successful laparoscopic resection of ovarian abscess caused by Staphylococcus aureus in a 13-year-old girl: a case report and review of literature

Background

Ovarian abscesses, which occur mostly in sexually active women via recurrent salpingitis, occur rarely in virginal adolescent girls. Here, we present a case of an ovarian abscess in a virginal adolescent girl who was diagnosed and treated by laparoscopy.

Case presentation

A 13-year-old healthy girl presented with fever lasting for a month without abdominal pain. Computed tomography scan and magnetic resonance imaging indicated a right ovarian abscess. Laparoscopic surgery revealed a right ovarian abscess with intact uterus and fallopian tubes. The abscess was caused by Staphylococcus aureus. The patient recovered completely after excision of the abscess, followed by antibiotic treatment.

Conclusions

Ovarian abscess may occur in virginal adolescent girls; Staphylococcus aureus, an uncommon species causing ovarian abscess, may cause the infection.