Role of 4D Ultrasound in the Diagnosis of Intra-Uterine Cranio-Facial Anomalies

Abstract
Background: Craniofacial anomalies account for approx-imately one-third of all birth defects and are a significant cause of infant mortality. They include brain, cranial bone & facial anomalies. Ultrasound examination is an effective modality for the prenatal diagnosis of these anomalies. 3D/4D US offers several image displays for precise demonstration of the normal and abnormal anatomy of the fetus. Subtle or inconclusive Ultrasound abnormalities can be confirmed or ruled out by MRI.
Aim of the Work: To evaluate role of the 4D ultrasound in diagnosis of in utero congenital cranio-facial anomalies.
Patients and Methods: The study was conducted on 20 pregnant females with suspected congenital head anomalies by 2D ultrasound in Tanta University Hospitals at the Radio-diagnosis department. The cases were collected during a period starting from December 2015 to January 2017. All patients were subjected to 2D and 4D ultrasound examination.
Results: As regards to brain anomalies, sensitivity of 4D ultrasound = 94.74%, specificity of 4D ultrasound = 100%, PPV = 100%, NPV = 50.0 % & accuracy = 95%. As regards to cranial bone anomalies, sensitivity of 4D ultrasound = 100%, specificity = 100 %, PPV = 100%, NPV = 100 % & accuracy = 100%. As regards to facial anomalies, sensitivity of 4D ultrasound = 100%, specificity = 100 %, PPV = 100%, NPV = 100 % & accuracy = 100%. So 4D ultrasound is more superior to 2D ultrasound in demonstrating anomalies of the face, cranial bone (mainly through surface rendering mode) and brain (through multiplanar & tomographic views) which may affect the post natal outcome.
Conclusion: 4D US is considered now an important diagnostic tool in fetal medicine as it provides many advanced diagnostic options like multiplanar, multiview or tomographic imaging, volume calculation and surface rendering mode which aided in early diagnosis of fetal anomalies and improved postnatal outcome.