Diffusion-weighted imaging of adnexal torsion

The Diagnostic Accuracy of Magnetic Resonance Imaging for Maternal Acute Adnexal Torsion during Pregnancy: Single-Institution Clinical Performance Review

Background: For acute adnexal torsion of pregnant women, appropriate treatment based on an accurate diagnosis is especially important for fertility preservation and timely treatment. The 2017 American College of Obstetricians and Gynecologists (ACOG) Committee Opinion No. 723 announced its practice-changing guidelines to ensure that diagnostic magnetic resonance imaging (MRI) conducted during the first trimester and gadolinium exposure at any time during pregnancy are safe for fetal stability. Unfortunately, few studies have been performed to evaluate the usefulness of the diagnostic accuracy of MRI for acute adnexal torsion during pregnancy. Objective: We sought to determine the efficacy of diagnostic MRI modality using multiparameter for maternal adnexal torsion during pregnancy. Methods: From 1 January 2007 to 31 January 2019, 131 pregnant with MRI tests were reviewed. In this retrospective cohort study, 94 women were excluded due to conditions other than an adnexal mass, and 37 were identified through MRI analyses conducted before surgery for suspected adnexal torsion. The primary outcome was the diagnostic accuracy of sonography and MRI, and the secondary outcome was the usefulness of Apparent diffusion coefficient (ADC) values for predicting the severity of hemorrhagic infarction between the medulla and cortex of the torsed ovarian parenchyma. Results: Our study demonstrates that in the diagnosis of adnexal torsion during pregnancy, the sensitivity, specificity, positive predictive value, and negative predictive value are 62.5%, 83.3%, 90.9%, and 45.5% for sonography and 100%, 77.8%, 90.5%, and 100% for MRI. MRI results in surgical-proven adnexal torsion patients revealed unilocular ovarian cysts (36.8% (7/19)), multilocular ovarian cysts (31.6% (6/19)), and near normal-appearing ovaries (31.6% (6/19)). Pathology in adnexal torsion revealed a corpus luteal ovarian cyst (63.2% (12/19)) and underlying adnexal pathology (46.8% (7/19)). Maternal adnexal torsion during pregnancy was more likely to occur in corpus luteal ovarian cysts than in underlying adnexal masses (odds ratio, 2.14; 95% confidence interval (CI), 0.428–10.738). MRI features for adnexal torsion were as follows: tubal wall thickness, 100% (19/19); ovarian stromal (medullary) edema, 100% (19/19); symmetrical or asymmetrical ovarian cystic wall, 100%(19/19); prominent follicles in the ovarian parenchyma periphery, 57.9% (11/19); periadenxal fat stranding, 84.2% (16/19); uterine deviation to the twisted side, 21.1% (4/19); and peritoneal fluid, 42.1% (8/19). The signal intensity of the ADC values of the ovarian medulla and cortex were compared between the cystectomy and detorsion (CD) and salpingo-oophorectomy (SO) groups. The ADC values of the CD and SO groups were 1.81 ± 0.09 × 10⁻³ mm²/s and 1.91 ± 0.18 × 10⁻³ mm²/s, respectively (P = 0.209), in the ovarian medulla and 1.37 ± 0.32 × 10⁻³ mm²/s and 0.96 ± 0.36 × 10⁻³ mm²/s, respectively (P = 0.022), in the ovarian cortex. The optimal cut-off value of ADC values for predictable total necrosis in the torsed ovarian cortex was ≤ 1.31 × 10⁻³ mm²/s (area under the curve (AUC) = 0.81; 95% CI 0.611–1.0; P = 0.028). Conclusion: Our data showed that maternal adnexal torsion during pregnancy occurred in most corpus luteal cystic ovary cases and some normal-appearing ovary during the 1st and 2nd trimesters of gestation. Therefore, this study is the first study to elaborate on the existence or usefulness of the diagnostic MRI for acute maternal adnexal torsion during pregnancy and to provide a predictive diagnosis of the severity of hemorrhagic infarction for deciding surgical radicality.

[Sudden chest pain and lower abdominal pain : The usual suspects]

CLINICAL PROBLEM

Sudden chest pain and sudden abdominal pain are among the most common reasons that lead patients to the emergency room. The heterogeneous field of possible, sometimes serious diagnoses requires a structured and rapid interdisciplinary clarification in order to be able to promptly provide patients with an adequate therapy.

STANDARD RADIOLOGICAL PROCEDURES

Knowing the "usual suspects" of sudden chest and abdominal pain enables the radiologist to quickly select the appropriate imaging method that allows a diagnosis to be made without delay. In addition to pain localization and character, age, gender, any previous illnesses and laboratory results are taken into account in the differential diagnosis.

METHODICAL INNOVATION AND EVALUATION

The technical state of computer tomography (CT) now ensures that most diagnoses can be clarified due to its excellent spatial and temporal resolution. In the abdomen, however, ultrasound should continue to be used at least for primary evaluation. Only if there is a further need for abdominal imaging afterwards is CT indicated for clarification. Magnetic resonance imaging is rarely used in the emergency setting of abdominal pain except to avoid radiation exposure in children or pregnant women.

RECOMMENDATION FOR THE PRACTICE

Knowledge of the usual diagnoses that cause sudden chest or abdominal pain, as well as knowledge of the appropriate examination procedures and classic radiological signs are essential to avoid errors and delays in the emergency diagnosis of sudden chest and abdominal pain.

Multimodality imaging of acute locoregional and systemic complications in the setting of assisted reproduction

Over the past 40 years since the first in vitro fertilization was performed, both the role of assisted reproductive technology (ART) in establishing viable pregnancy as well as the available treatment options have expanded enormously. Annually in the USA, nearly 2% of pregnancies now employ some form of ART assistance, with in vitro fertilization (IVF) being the most commonly utilized methodology. Both maternal and fetal risks are elevated in ART pregnancies, the latter including adverse outcome due to both increased gestational number as well as advanced maternal age. Maternal risks may be divided into locoregional and systemic complications. Adverse pelvic complications include those relating to gamete harvesting and transfer, ovarian hyperstimulation, the sequela of ectopic and heterotopic pregnancies, as well as ovarian torsion, all of which are elevated in the ART cohort. Ovarian hyperstimulation syndrome is the most commonly encountered complication, with both systemic and pelvic features relating to increased vascular permeability, hemoconcentration, and ascites. While life-threatening cases are relatively rare, moderate and severe manifestations may occur in up to 10% of ART cycles and, as such, are a not infrequent cause for ER visitation. Familiarity with the clinical and imaging manifestations of ART complications as well as their prognostic implications will facilitate a timely diagnosis and assist the interpreting radiologist in best expediting appropriate clinical care. In this article, we will briefly discuss the current methodology of ART then present an imaging-based multimodality review of the potentially encountered adverse maternal sequela, highlighting key diagnostic features and differential considerations as well as potential prognostic implications.

Pitfalls of diffusion-weighted imaging of the female pelvis

Diffusion-weighted imaging (DWI) is widely used in protocols for magnetic resonance imaging (MRI) of the female pelvis. It provides functional and structural information about biological tissues, without the use of ionizing radiation or intravenous administration of contrast medium. High signal intensity on DWI with simultaneous low signal intensity on apparent diffusion coefficient maps is usually associated with malignancy. However, that pattern can also be seen in many benign lesions, a fact that should be recognized by radiologists. Correlating DWI findings with those of conventional (T1- and T2-weighted) MRI sequences and those of contrast-enhanced MRI sequences is mandatory in order to avoid potential pitfalls. The aim of this review article is the description of the most relevant physiological and benign pathological conditions of the female pelvis that can show restricted diffusion on DWI.

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.

High-field magnetic resonance imaging of the pelvis: uterus, ovary, and prostate gland

Today, magnetic resonance imaging (MRI) is a standard imaging modality for various pathologic disorders in the human pelvis. It has given proof of its usefulness in the diagnosis of several benign and malignant disorders, and it is routinely used for the local staging of different tumors even when confined to specific parts of a pelvic organ. Signal-to-noise ratio and motion artifacts of the examined organ and adjacent bowel structures are major factors for image quality. Setting at 3 T with surface coils avoids technical limitations and discomfort of additional endovaginal or endorectal coils. Definition of high field seems fuzzy because of the availability of MRI machines with 3, 7 T, or higher; therefore, the general aspects of MRI of pelvic structures with emphasis on uterus, ovary, and prostate gland and attention to promising newer techniques such as 3 T, dynamic contrast imaging, and diffusion-weighted imaging are reviewed in this article.