MR Imaging of Acute Abdomen and Pelvis

Imaging in Acute Obstetric Conditions: A Pictorial Essay

Acute abdominopelvic pain during pregnancy and the postpartum period is a diagnostic challenge owing to the overlapping symptoms of obstetric, gastrointestinal, and urinary conditions coupled with pregnancy-induced physiological changes. This pictorial essay reviews critical obstetric emergencies and categorizes cases into two phases: the first covers the preconception-to-pregnancy period, while the second focuses on the postpartum period. This essay covers key obstetric emergencies, such as ovarian hyperstimulation syndrome, hyperreactio luteinalis, ectopic pregnancy, red degeneration of fibroids, placenta accreta spectrum disorders, placental abruption, uterine rupture, retained products of conception, and uterine arteriovenous malformations, with an emphasis on their clinical and imaging characteristics. While ultrasound remains the first-line modality, MRI offers superior soft tissue contrast for more complex cases, and CT is reserved for critical scenarios in which the radiation risk is outweighed by diagnostic necessity. Timely and accurate imaging is essential for differentiating these conditions, guiding interventions, such as uterine arterial embolization and surgery, and minimizing maternal and fetal morbidity. This work aims to enhance the diagnostic precision and multidisciplinary management of obstetric emergencies, ensuring optimal clinical outcomes.

"Renal emergencies: a comprehensive pictorial review with MR imaging"

Superior soft-tissue contrast and high sensitivity of magnetic resonance imaging (MRI) for detecting and characterizing disease may provide an expanded role in acute abdominal and pelvic imaging. Although MRI has traditionally not been exploited in acute care settings, commonly used in biliary obstruction and during pregnancy, there are several conditions in which MRI can go above and beyond other modalities in diagnosis, characterization, and providing functional and prognostic information. In this manuscript, we highlight how MRI can help in further assessment and characterization of acute renal emergencies. Currently, renal emergencies are predominantly evaluated with ultrasound (US) or computed tomography (CT) scanning. US may be limited by various patient factors and technologist experience while CT imaging with intravenous contrast administration can further compromise renal function. With the advent of rapid, robust non-contrast MRI, and magnetic resonance angiography (MRA) imaging studies with short scan times, free-breathing techniques, and lack of ionization radiation, the utility of MRI for renal evaluation might be superior to CT not only in diagnosing an emergent renal process but also by providing functional and prognostic information. This review outlines the clinical manifestations and the key imaging findings for acute renal processes including acute renal infarction, hemorrhage, and renal obstruction, among other entities, to highlight the added value of MRI in evaluating the finer nuances in acute renal emergencies.

MRI of Acute Gynecologic Conditions

Although usually not a first-line imaging modality in the setting of acute pelvic pain, magnetic resonance imaging (MRI) is able to depict and characterize a wide range gynecologic diagnoses with high accuracy. Lack of ionizing radiation renders MRI particularly useful for assessment of pregnant women and children. Furthermore, inherent high soft-tissue resolution of MRI allows accurate diagnosis without intravenous contrast use, which is advantageous for patients with renal insufficiency and pregnant patients. Familiarity with the typical MRI appearance of various acute gynecologic conditions helps establish the correct diagnosis. This article reviews the common MRI findings of acute gynecologic processes, in both pregnant and nonpregnant patients. Level of Evidence: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:1291-1309.