Learning objectives
To educate regarding the importance of accurate diagnosis of appendicitis in pregnancy, and the role for MRI in this emergency clinical scenario. A sample MRI scanning protocol and a stepwise approach for the diagnosis of appendicitis is described.
Background
Acute appendicitis is the primary reason for non-obstetric surgical intervention during pregnancy, with an estimated incidence of 1/1500 pregnancies. Appendicitis can be a challenging clinical diagnosis in pregnancy due to multiple confounding factors: caecal displacement and abdominal distension from the gravid uterus, as well as pregnancy-related physiological leucocytosis can all confuse the clinical picture.
Early identification of appendicitis is critical due to significantly increased morbidity and mortality to both the fetus and mother associated with delayed diagnosis. Overdiagnosis is also problematic, as negative laparotomy rates...
Imaging findings OR Procedure details
Step 1. Localise the appendix.
As with CT, localising the appendix can be a difficult task given its wide variation in position. The caecal tilt angle can be assessed on sagittal T2 – an angle of at least 90 ° localizes the appendix to the right upper quadrant with high specificity irrespective of gestational age[3].[Fig 1]
Subsequent localisation of the appendix may require concurrent use of multiple planes. The T2 non-fat saturated HASTE sequence often provides sufficient spatial resolution to identify the appendix, while T2...
Conclusion
MRI is an accurate modality for the diagnosis of appendicitis in pregnancy. We outline a stepwise process for appendicitis interpretation on MRI: tips for appendix localisation, assessment of primary and secondary signs of appendicitis and important alternative pathologies for exclusion.
With the increasing utilisation of emergency MRI and relatively high incidence of abdominal pain in pregnancy, interpretation of acute abdominal pathology in an obstetric patient on MRI is becoming an increasingly relevant skill for the radiologist covering tertiary centre out of hours call, and one...
Personal information
C. Jeavons:
Nothing to disclose
References
Kave M, Paroorie F, Salarzaei M. Pregnancy and appendicitis: a systematic review and meta-analysis on the clinical use of MRI in diagnosis of appendicitis in pregnant women. World J Emerg Surg 14, 37(2019).
Shetty MK, Garrett NM, Carpenter WS, Shah YP, Roberts C. Abdominal Computed tomography during pregnancy for suspected appendicitis: a 5 year experience at a maternity hospital. In seminars in Ultrasound, CT and MRI. Philadelphia: WB Saunders; 2010;31(1):8-13.
Lee KS, Rofsky NM, Pedrosa I. Localization of the appendix at MR imaging during pregnancy:...