Magnetic Resonance of Pelvic and Gastrointestinal Emergencies

Magnetic Resonance Imaging in Gastrointestinal and Genitourinary Emergencies

While computed tomography (CT) offers faster cross-sectional imaging in the emergency department, owing to its concerns for higher radiation exposure, magnetic resonance imaging (MRI) applications in acute settings are increasingly validated. A significant proportion of patients present to the emergency department with abdominopelvic symptoms, most commonly acute abdominal pain. Early detection with imaging and timely intervention can significantly decrease morbidity and mortality in conditions such as acute pancreatitis or ovarian torsion. MRI encompasses better soft-tissue resolution, nonusage of ionizing radiation and iodinated contrast media, nonoperator dependency, and higher reproducibility. This review discusses the MRI protocols and applications in abdominopelvic emergencies.

Problem-solving with MRI in acute abdominopelvic conditions, part 1: gastrointestinal, hepatobiliary, and pancreatic diseases

The purpose of this article is to review the benefit and added value and advantages of magnetic resonance imaging (MRI) compared with other cross-sectional imaging in patients presenting with abdominopelvic emergencies. During the past decade, there has been increased utilization of MRI in the emergency department with widespread availability of MR scanners, improvement in rapid imaging techniques, and methods to overcome motion-related artifacts. This has benefited patients at higher risk of radiation, particularly children and pregnant women, and patients with contraindications to iodinated contrast including allergy and renal dysfunction. Still the challenges are: on site MR scanner in the emergency department, after-hour services, as well as availability of time slot to rapidly scan emergency patient. MRI has additional advantages over other imaging modalities due to its high contrast resolution, which allows it to better characterize tissue and fluid collections, and may avoid the need for intravenous contrast. Radiologists must be familiar with the role and added value of MRI, spectrum of imaging findings, and problem-oriented modified MR protocols in abdominal and pelvic emergencies. In part 1, we will discuss the utility of MRI in gastrointestinal, hepatobiliary, and pancreatic diseases. In part 2, the authors will focus on the key MR imaging features of female pelvic gynecological diseases, pregnancy related complications, abdominal vascular complications, and renal diseases.

Ischaemic bowel perforation secondary to a gravid uterus in a patient with treated inflammatory bowel disease and an ileoanal pouch: a case report

The diagnosis of visceral perforation during pregnancy is often delayed and the management complex. A 32-year-old primigravid woman in her second trimester presented with abdominal pain and a pre-existing ileoanal pouch. Initial imaging was negative but later imaging was suggestive of serious pathology. At laparotomy, a caesarean section was performed. Peritonitis was encountered secondary to two discrete perforations in the small bowel separate from her pouch. Histology found an ischaemic perforation secondary to a pressure effect from the gravid uterus. In pregnancy, ileoanal pouches may make the interconnected bowel vulnerable to the pressure effect of the gravid uterus and perforation. Pregnant women with such a surgical history who develop symptoms suggestive of bowel perforation should have rapid imaging and their clinical team should consider early definitive surgical intervention.

Contribution of diffusion-weighted imaging to conventional MRI for detection of haemorrhagic infarction in ovary torsion

Background

To assess the role of DWI in differentiation haemorrhagic ovary infarction from non-haemorrhagic one.

Methods

For this prospectively designed study, of 117 female patients who presented with acute lower quadrant pain and underwent MRI for suspicion of ovary torsion, results of only 29 patients (mean age, 24.7; SD, ±5.7; age range, 18–37), with surgical and pathological confirmation of adnexal torsion, were included to the study. All patients underwent DWI after conventional MRI. Quantitative and qualitative analysis of both the torsed and contralateral normal ovary were performed. Results of conventional MRI and DWI were noted.

Results

At operation 15 patients were found to have haemorrhagic infarction while 14 had non-haemorrhagic infarction. Of the 29 patients, 17 torsed ovaries could be salvaged in a viable state. We found statistically significant correlation of the ADC values, between haemorrhagic and non-haemorrhagic ovary infarction. The ADC values were significantly lower in patients with haemorrhagic infarction than non-haemorrhagic ones (p < 0.001). Using an ADC threshold of 1.27, the sensitivity of DWI for haemorrhagic infarction was 0.93 and specificity 0.85.

Conclusion

DWI may be used with a significant success for the preoperative diagnosis of haemorrhagic infarction. This may be alerting for pre-emptive surgery in avoiding serious complications and preventing irreversible structural damage of the ovary.