Angelica Cupertino, Roberta Ninkova, Valentina Miceli, Marco Gennarini, Federica Curti, Carlo Catalano, Lucia Manganaro
Abdominal and pelvic pain are a common symptoms in pregnant woman that may subtend an emergency condition leading to life-threating for the fetus and the woman and a prompt surgical intervention is required. The causes of abdominal pain in pregnancy can be obstetric and non-obstetric, including gynecological, gastrointestinal, hepatobiliary, and genitourinary pathologies. However, an early diagnosis can be challenging due to the several changes occurring in pregnancy, such as a displacement of abdominal and pelvic structures from their normal locations by the enlarged gravid uterus. Ultrasound (US) is the first-line imaging modality, but Magnetic Resonance Imaging (MRI) is gaining favor due to its accuracy, quick acquisition time and safety.
MRI is an important diagnostic tool in pregnancy because of its safety profile due to absence of ionizing radiations exposure, quick acquisition time and excellent multiplanar imaging in emergency setting, especially in cases in which the diagnosis with US is inconclusive and equivocal. The most frequent cause of non-obstetric acute abdominal pain is appendicitis, followed by inflammatory bowel disease and bowel obstruction, adnexal torsion, cholecystitis and pancreatitis, renal causes like nephrolithiasis and pyelonephritis. Obstetrical causes include the spectrum of placenta accreta, ectopic pregnancy and rare cases of implantation on scar of previous cesarian section and uterine rupture.
Acute uncomplicated pyelonephritis with hydronephrosis in pregnancy. Coronal fat- suppressed T2 weighted image (A) and without FS (B) show severe hydroureteronephrosis associated with diffuse signal T2-hyperintensity of peri-renal and peri-ureteral soft tissue due to edema.
A 36 gestational weeks pregnant woman with sudden onset acute abdominal pain and inconclusive US findings. No significant history of abdominal surgery. Axial T2- weighted images show a focal defect of the anterior aspect of myometrial wall with fetus hand outside the uterus (white arrows). Significant abdominal effusion is also present (red stars).
A 27 gestational weeks pregnant patient with epigastric pain and hypertriglyceridemia. MR imaging findings show an interstitial edematous pancreatitis. Axial and coronal T2-weighted images with and without FS (A, B, C, D) demonstrate a diffuse pancreatic edema (hyperintense signal) with peripancreatic fluid and restricted diffusion (E) due to acute inflammation (white arrow and red stars); cholelithiasis (red arrow).
Coronal T2WI (A), axial fat suppressed T2WI (T2 FS; B) and coronal T1WI FS (C) show a thickened and dilated tubular appendix with intraluminal fluid and appendicolith (white arrows and red line) and mild periappendiceal T2 hyperintense signal consistent with inflammation. Inflammation is also visible on DWI image (D).
Cesarean scar pregnancy. Sagittal T2-weighted image (A) shows a gestational sac containing the small fetus (cystic mass-like) within a cesarean delivery scar (typical hypointensity of fibrous tissue; white arrow). The contrast enhancement (B) demarcates the silhouette of the gestational sac.
The aim is to make radiologist familiar with causes of acute abdominal pain in pregnancy and their imaging features.