Diagnostic Yield of Whole-Body Fetal MRI in Fetuses Referred for Suspected Brain Abnormalities

Purpose: While fetal MRI primarily evaluates suspected brain abnormalities, systematic whole-body assessment can identify additional extracranial findings. This study aimed to determine the prevalence, distribution, and referral indications associated with extracranial abnormalities detected on whole-body fetal MRI in fetuses referred for suspected brain abnormalities.

Methods: This retrospective single-center study included consecutive 3-T fetal MRI examinations performed for suspected brain abnormalities detected on ultrasound. Examinations referred for known extracranial abnormalities were excluded. All cases underwent dedicated neuroimaging and systematic whole-body assessment. Associations between referral indications (ventricular, biometric, parenchymal, suspected TORCH, spinal, or multiple brain abnormalities) and extracranial findings were evaluated using logistic regression.

Results: Of 423 examinations, 314 were analyzed after exclusions. Extracranial abnormalities were identified in 40/314 fetuses (12.7%). The highest rate occurred in fetuses with multiple brain abnormalities (8/28, 28.6%) compared with the rest of the cohort (11.2%; OR 3.18, p=0.015). On multivariable logistic regression, multiple brain abnormalities remained significantly associated with extracranial findings compared to ventricular abnormalities (OR 3.20, p=0.025). The genitourinary system was most frequently affected (52.5%), followed by gastrointestinal (12.5%), umbilical cord (10.0%), and pulmonary abnormalities (7.5%).

Conclusion: Systematic whole-body assessment during fetal MRI for suspected brain abnormalities detects additional extracranial findings in approximately one in eight fetuses. The diagnostic yield is particularly high in fetuses with multiple brain abnormalities, emphasizing the value of comprehensive fetal evaluation beyond targeted neuroimaging.