TeleFast Rad

☢️MRI in pregnancy — when is it appropriate?☢️

⚠️Short answer: when it will change management and ultrasound isn’t enough. MRI is considered safe in pregnancy when used thoughtfully.

⚠️Safety basics
• No ionizing radiation → unlike CT or X-ray.
• Extensive data show no proven harm to the fetus at 1.5 T (and 3 T when clinically justified).
• Gadolinium contrast: avoid unless there’s a strong, life-saving indication (it crosses the placenta).

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🔺When MRI is appropriate

Use MRI if ultrasound is inconclusive or limited and the result will affect care.

🧠 Fetal indications
• CNS anomalies: ventriculomegaly, agenesis of corpus callosum, posterior fossa abnormalities
• Spinal defects: myelomeningocele, tethered cord
• Thoracic lesions: congenital diaphragmatic hernia, lung masses (CPAM)
• Abdominal/pelvic anomalies: bowel obstruction, renal anomalies
• Suspected placental invasion (accreta spectrum) when US is equivocal

🤰 Maternal indications
• Acute abdomen:
• Suspected appendicitis
• Ovarian torsion
• Biliary or urinary obstruction when US is nondiagnostic
• Neurologic symptoms:
• Stroke, MS relapse, spinal cord compression
• Pelvic masses:
• Characterization of adnexal masses
• Placental disorders:
• Placenta accreta/increta/percreta

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⚠️Timing considerations
• Any trimester: MRI can be done if clinically indicated
• First trimester: avoid unless essential (precautionary, not proven harm)
• Second & third trimesters: commonly used

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🔺When MRI is not first choice
• Routine screening
• When ultrasound provides a clear answer
• If the result won’t change management

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🔺Key take-home points
• ✔ MRI is safe and valuable in pregnancy
• ✔ Use it problem-solving, not routinely
• ❌ Avoid gadolinium unless absolutely necessary
• ✔ Always balance clinical benefit vs necessity