MRI of Right-Sided Abdominal Pain in Pregnancy

Diagnosis of a sigmoid volvulus in pregnancy: ultrasonography and magnetic resonance imaging findings

Sigmoid volvulus complicating pregnancy is a rare, non-obstetric cause of abdominal pain that requires prompt surgical intervention (decompression) to avoid intestinal ischemia and perforation. We report the case of a 31-week pregnant woman with abdominal pain and subsequent development of constipation. Preoperative diagnosis was achieved using magnetic resonance imaging and ultrasonography: the large bowel distension and a typical whirl sign - near a sigmoid colon transition point - suggested the diagnosis of sigmoid volvulus. The decision to refer the patient for emergency laparotomy was adopted without any ionizing radiation exposure, and the pre-operative diagnosis was confirmed after surgery. Imaging features of sigmoid volvulus and differential diagnosis from other non-obstetric abdominal emergencies in pregnancy are discussed in our report, with special emphasis on the diagnostic capabilities of ultrasonography and magnetic resonance imaging.

Ultrafast 3-T MRI in the evaluation of children with acute lower abdominal pain for the detection of appendicitis

OBJECTIVE

The purpose of this study is to evaluate the feasibility of ultrafast 3-T MRI in the evaluation of children with acute lower abdominal pain for the detection of appendicitis.

SUBJECTS AND METHODS

Forty-two pediatric patients (30 girls and 12 boys; mean age, 11.5 years; age range, 4-17 years) with acute abdominal pain were prospectively studied. Ultrafast 3-T MRI was performed with a three-plane single-shot turbo spin-echo sequence and an axial T2-weighted turbo spin-echo sequence with fat suppression. All scans were performed without sedation or oral or IV contrast agent. Scan times were less than 8 minutes 45 seconds (median, 5 minutes 40 seconds). Patients underwent CT or ultrasound or both as a comparison study to the MRI examination. The MRI, CT, and ultrasound examinations were interpreted independently by four board-certified radiologists who were blinded to patient information, study interpretations, surgical pathologic findings, and final diagnosis.

RESULTS

Twelve of 42 cases of acute appendicitis were detected with 100% sensitivity, 99% specificity, 100% negative predictive value, and 98% positive predictive value, all of which were statistically significant (p < 0.01). The pooled and individual receiver operating characteristic curves for radiologists' interpretation of the diagnosis of acute appendicitis were greater than 0.95 in all cases (p < 0.01)

CONCLUSION

Ultrafast 3-T MRI is a feasible alternative imaging modality for the diagnosis of acute appendicitis in children, particularly in cases where ultrasound is equivocal or nondiagnostic, as an alternative to CT. Ultrafast MRI requires no sedation and no oral or IV contrast agent and has no associated radiation exposure risks.

Practice patterns in imaging of the pregnant patient with abdominal pain: a survey of academic centers

OBJECTIVE

The purpose of our study was to evaluate current practice patterns in the imaging of pregnant women with abdominal complaints.

MATERIALS AND METHODS

A survey was sent to the abdominal imaging division of 183 radiology residency programs in the United States. The survey asked for information regarding CT and MRI of abdominal complaints in pregnant patients.

RESULTS

Eighty-five surveys (46%) were returned. Sixty-three (74%) of 85 of respondents have a written departmental policy regarding imaging pregnant women. Eighty-two (96%) of 85 perform CT in pregnant women when benefits outweigh risks, with 58 (68%) obtaining written informed consent before CT examination. Eighty (94%) of 85 perform MRI in pregnant women, and 43 (51%) obtain written consent before MRI. Fifty-seven (67%) of 85 respondents do not administer gadolinium in pregnancy. In the setting of trauma, respondents choose CT over MRI for imaging in all three trimesters (75% vs 5%, 85% vs 5%, and 88% vs 4%). In the second and third trimesters, respondents prefer CT to MRI to evaluate for maternal renal calculus (35% vs 20% and 48% vs 18%, respectively), appendicitis (48% vs 38% and 58% vs 29%), and abscess (49% vs 41% and 58% vs 35%). However, MRI is preferred for imaging of appendicitis and abscesses in the first trimester (39% vs 32% and 46% vs 32%).

CONCLUSION

Most academic radiology departments have written policies regarding imaging of pregnant women. Academic radiologists prefer CT to MRI for imaging abdominal complaints in pregnant women, especially in the second and third trimesters.

MR imaging of acute right lower quadrant pain in pregnant and nonpregnant patients

The use of magnetic resonance (MR) imaging in the evaluation of acute abdominal pain is increasing, particularly in those circumstances where computed tomography (CT) is not desirable (eg, pregnancy, allergy to iodinated contrast material). Although ultrasonography (US) is considered the imaging study of choice for evaluation of abdominal pain in pregnant patients, MR imaging is a valuable adjunct to US in evaluation of pregnant patients with acute right lower quadrant (RLQ) pain who have inconclusive US results. MR imaging is also frequently used in patients with renal failure, in whom the use of iodinated contrast material is contraindicated, as well as in cases where CT results are inconclusive. In patients with acute RLQ pain, the breadth of abnormalities visible at MR imaging is very broad, with pathologic conditions potentially originating from multiple organ systems, but most commonly from the gastrointestinal and genitourinary systems. MR imaging is an excellent imaging modality for evaluation of RLQ pain and should be strongly considered in those patients in whom use of iodinated contrast media or radiation is not desirable.

Imaging of pelvic pain in the first trimester of pregnancy

Pelvic pain during the first trimester of pregnancy can pose a challenge to the clinician. The noninvasive nature, safety, and reliability of ultrasonography make it the diagnostic method of choice for pregnant patients who have pelvic pain. Sonography provides information that allows for diagnosis of both pregnancy-related pain, such as a ruptured ectopic pregnancy, miscarriage, or threatened abortion; and may be useful in the diagnosis of pain unrelated to pregnancy, such as that seen in appendicitis and nephrolithiasis.

MR Imaging Evaluation of Acute Abdominal Pain During Pregnancy

MR imaging enables diagnosis of a variety of maternal diseases presenting as acute abdominal pain in pregnant patients. MR imaging is a valuable complement to ultrasound in the determination of the exact etiology of acute abdominal pain, and it is important for the radiologist to recognize the MR imaging appearance of common causes of acute abdominal pain during pregnancy. This article reviews the MR imaging technique and findings of various abnormalities causing acute abdominal pain in pregnant patients.

Solving the Problem Pelvic Ultrasound With Magnetic Resonance Imaging

Ultrasound is the screening method of choice for evaluation of pelvic anatomy and abnormalities of the female pelvis. It allows for detailed assessment of the uterus, endometrium, and ovaries. However, there are times when the sonographic diagnosis is nonspecific. This review article details the use of magnetic resonance imaging for assessment of uterine duplication anomalies, adnexal and uterine masses, and for aiding in the assessment of pregnant patients with nonspecific sonographic findings in the pelvis.

The value of magnetic resonance imagingin the diagnosis and management of extra-uterine abdominal pregnancy

AIM

To determine the value of magnetic resonance imaging (MRI) in the detection of the location of the placenta and placental adherence in patients with extra-uterine or abdominal pregnancy.

METHODS

A retrospective study of patients with a suspected diagnosis of extra-uterine pregnancy was performed over a 12-month period. MRI images on hard and soft copy were reviewed by two radiologists blinded to the clinical and operative findings.

RESULTS

Nine patients with 10 foetuses were imaged. Nine foetuses were in an extra-uterine position; three were delivered dead, one from intrauterine growth retardation and one from a fatal congenital anomaly. The placenta was located correctly in all nine patients with placental adherence demonstrated in four patients. The placenta was safely delivered in six patients and left in situ in three in which there was MRI evidence of placental adherence.

CONCLUSIONS

MRI is valuable in accurately demonstrating the location of the placenta within the abdomen and the presence of placental adherence, which directly affects the decision whether to remove or leave the placenta in situ.

Obstetric MRI

Ultrasound is the imaging modality of choice for pregnant patients. However, MRI is increasingly utilized in patients in whom the sonographic diagnosis is unclear. These include maternal conditions unique to pregnancy such as ectopic pregnancy, placenta accreta, and uterine dehiscence. MRI is also being increasingly utilized in the assessment of abdominopelvic pain in pregnancy, in particular in assessment for appendicitis. Fetal MRI is performed to assess central nervous system (CNS) abnormalities and patients who are considering fetal surgery for conditions such as neural tube defects, congenital diaphragmatic hernia, and masses that obstruct the airway. In the future, functional MRI and fetal volumetry may provide additional information that can aid in our care of complicated pregnancies.

Magnetic resonance evaluation of pregnant patients with acute abdominal pain

Acute abdominal pain in a pregnant patient is associated with a long differential diagnosis, and diagnostic imaging is often required to guide management. Ultrasound is safe and widely available; however, maternal structures may be difficult to evaluate during pregnancy due to anatomic changes. Computed tomography is accurate but exposes the fetus to ionizing radiation. Magnetic resonance (MR) imaging provides excellent anatomic resolution and tissue characterization without ionizing radiation, and MR diagnosis frequently requires no contrast administration. Using an appropriate combination of sequences, MR imaging can reliably demonstrate many causes of acute abdominal pain during pregnancy.

Female Pelvis

MR is the diagnostic imaging modality of choice for many disorders of the female pelvis. Benign uterine disease is well-demonstrated using rapid sequences and minimal examination time,whereas evaluation of malignancy is best performed with high-resolution techniques. Wide-spread availability of ultrafast sequences has expanded MR imaging applications to include evaluation of pelvic floor relaxation and fetal anomalies. Promising developments, such as new contrast agents, MR-guided focused ultrasound,and 3 tesla imaging, suggest continued advancement of MR imaging in the care of patients who have gynecologic disease.