• Most common non-OB surgical condition

• Fetal loss >30% if ruptured, <2% if not

• Difficult clinical diagnosis:• Majority of cases afebrile

• Physiologic increase WBC6-16,000 & up to 30,000 in labor

• N/V common in pregnancy

• Site of pain may be unusual

APPENDICITIS

Ax T1w: normal appendix

MR SAFETYRECOMMENDATIONS

• No known adverse fetal effects• Safety concern: energy deposition• MR only if US not adequate • Depending on risk/benefit:

• Avoid MR in first trimester• Avoid Gadolinium

(FDA pregnancy category C)

Preparation & Positioning

• NPO x 4 hours

• Supine or decubitus position• LLD: better for IVC compression

• Phased array coil• Large patient: 2 phased array or body coil

Maternal MR: Technique

• 3 plane 6mm T2w HASTE (Seimens) or SSFSE (GE)

• Coronal, axial T2/T1w True-FISP

• Review to determine need for additional sequences or gadolinium

Additional Noncontrast Sequences

• Fat-suppressed T2w• Inflammation, especially if no gad

• T1w or fat-suppressed T1w• Blood products, fat vs. blood, endometriosis

• Thick slab T2w echo train spin echo• MRCP, MR Urography

• Phase contrast/time of flight: vascular

• Dynamic imaging if neededVascular tumor, accreta

• Delayed fat-suppressed T1WInfection, inflammation

Gadolinium

APPENDIX ON MR

Appendix seen in 10/12 pregnant patients with suspected appendicitis(AJR 2004;183:671-5)

Thin slices and cross-referencing tool helpful

APPENDICITIS

Pregnant with abdominal pain

T2w

T2w FS

34 yo RLQ pain

DEGENERATING FIBROID

Courtesy of Aytekin Oto, M.D.

RUPTURED APPENDICITS

Courtesy of Aytekin Oto, M.D.

RUPTURED APPENDICITIS

33 yo at 31 weeks, right-sided pain

10 weeks pregnant, abdominal pain and fever

COLITIS

Courtesy of Aytekin Oto, M.D.

Courtesy of Aytekin Oto, M.D.

PELVIC ABSCESS

DIVERTICULAR ABSCESS

ULCERATIVE COLITIS

PERITONITIS

Pregnant, history of Crohn dz now with pain and fever

DEGENERATING FIBROID

Fibroids & Pregnancy

• Pain during pregnancy can be severe• Rapid growth

• Degeneration

• Torsion

• Degeneration may lead to premature labor

DEGENERATING FIBROID

35 yo 19 weeks pregnant with severe RLQ pain

DEGENERATING FIBROID

SHORT CERVIX

18 yo 17 weeks pregnant, RLQ pain x 2 mos, now acutely worse

TORSED FIBROID

Surgery: pedunculated fibroid, stalk twisted 360 degrees

SMALL BOWEL OBSTRUCTION

• Adhesions > volvulus >> other causes

• High incidence of necrotic bowel

• Fetal mortality 20-26%• Only 1/3 complete to term after surgery

• Most significant contributor to mortality: delayed diagnosis and treatment

• MR: Ultra-fast sequences (HASTE, FISP) helpful due to minimal motion artifact

30 yo at 36 weeks with abdominal & pelvic pain

SMALL BOWEL OBSTRUCTION

Surgery: sbo, multiple adhesions

INTUSSUSCEPTION

Pregnant with abdominal and pelvic pain, nausea and vomiting

CHOLECYSTITIS

• Pregnant women predisposed to torsion

• Ultrasound diagnostic unless ovaries poorly visualized due to pregnancy

• MR appearance: enlarged ovary with increased stromal SI on T2w

• Increased SI on T1w suggests hemorrhage or vascular congestion

• Gadolinium may be diagnostic

OVARIAN TORSION

OVARIAN TORSION

Courtesy of David McFadden, MD

25 yo 15 weeks pregnant with RLQ pain

OVARIAN TORSION

T2w

OVARIAN TORSION

25 yo 15 weeks pregnant with RLQ pain and adnexal mass on ultrasound

PYELONEPHRITIS

19 yo pregnant woman with right-sided pain and fever

Sickle Beta Thalassemia