Antenatal diagnosis of agenesis of the corpus callosum.

AIM: To estimate the diagnostic performance of ultrasound in detecting agenesis of the corpus callosum (ACC).

MATERIALS AND METHODS: A retrospective review was performed of 1722 in utero MRI examinations. All cases were identified in which the fetus had been referred from ultrasonography with a diagnosis of ACC and those in which ACC was given as a diagnosis on the in utero MRI study. The MRI was assumed to provide the correct diagnosis of ACC and descriptive statistics of diagnostic accuracy for ultrasound were calculated.

RESULTS: Of the 1722 ultrasound examinations performed, 121 had a diagnosis of ACC and approximately 50% were confirmed at MRI. Forty-two fetuses with ACC not suspected at ultrasonography were also identified at MRI. Ultrasonography had a positive predictive value of 47% (95% CI: 38-56%) and a negative predictive value of 97% (95% CI: 96-98%) for detecting ACC.

CONCLUSION: Ultrasound is poor in diagnosing ACC and in utero MRI should be performed if there is any suspicion on antenatal ultrasonography.