Role for MRI in Secondary Screening for Placenta Accreta.

Area of Science:

• Obstetrics and Gynecology
• Diagnostic Imaging

Background:

• Placenta praevia and placenta accreta spectrum (PAS) are increasing.
• Antenatal detection of PAS is crucial for reducing maternal morbidity.
• Centralization of PAS care in the UK requires effective pre-referral diagnostics.

Purpose of the Study:

• To evaluate the role of Magnetic Resonance Imaging (MRI) as an adjunct diagnostic tool for placenta accreta spectrum (PAS).
• To assess the accuracy of MRI compared to ultrasound (US) in diagnosing PAS in a non-specialist setting.
• To understand the trend of MRI demand for PAS evaluation.

Main Methods:

• Retrospective analysis of 41 cases referred for MRI after initial US evaluation for suspected PAS over 13 years.
• Assessment of MRI accuracy (sensitivity, specificity) in diagnosing PAS.
• Comparison of diagnostic outcomes between US alone and US with MRI.

Main Results:

• Eleven cases of PAS were identified.
• MRI demonstrated high accuracy (sensitivity 81.8%, specificity 86.6%) for PAS diagnosis.
• MRI correctly reclassified 2 cases initially deemed normal by US, while 2 PAS cases were missed by both modalities.

Conclusions:

• There is an increasing demand for MRI in evaluating suspected PAS.
• Adding MRI as a secondary diagnostic test improves overall accuracy compared to US alone.
• MRI serves a valuable role in secondary screening for PAS in non-specialist units prior to referral.