OBJECTIVES: To determine which 3-D techniques are most effective for "real time" prenatal ultrasound assessment of the corpus callosum and cerebellar vermis. METHODS: A prospective study involving 100 consecutive normal singleton pregnancies attending routine anomaly scan at 19-23 weeks' gestation. Midsagittal structures of the fetal brain were assessed using six different methods of 3-D image acquisition and three post-processing techniques. The quality of the resulting images were then assessed and scored by a second operator. The significance of the difference between various techniques was assessed using the Friedman test. RESULTS: The best method for visualization of both corpus callosum and cerebellar vermis in one image involved 3-D acquisition in a sagittal plane through the sagittal suture with manipulated 3-D OVIX™ (Oblique View eXtended Imaging) reconstruction. Five other methods scored closely and were not significantly different; all were based on 3-D acquisition in the sagittal plane through either sagittal suture or anterior fontanel. CONCLUSIONS: We have applied described techniques for 3-D central nervous system volume acquisition and have shown that the best method of assessment, allowing assessment of both the corpus callosum and the cerebellar vermis, involves midsagittal acquisition through the sagittal suture with 3-D OVIX reconstruction. This technique can be applied successfully in 83% of cases.
OBJECTIVES: To determine which 3-D techniques are most effective for "real time" prenatal ultrasound assessment of the corpus callosum and cerebellar vermis. METHODS: A prospective study involving 100 consecutive normal singleton pregnancies attending routine anomaly scan at 19-23 weeks' gestation. Midsagittal structures of the fetal brain were assessed using six different methods of 3-D image acquisition and three post-processing techniques. The quality of the resulting images were then assessed and scored by a second operator. The significance of the difference between various techniques was assessed using the Friedman test. RESULTS: The best method for visualization of both corpus callosum and cerebellar vermis in one image involved 3-D acquisition in a sagittal plane through the sagittal suture with manipulated 3-D OVIX™ (Oblique View eXtended Imaging) reconstruction. Five other methods scored closely and were not significantly different; all were based on 3-D acquisition in the sagittal plane through either sagittal suture or anterior fontanel. CONCLUSIONS: We have applied described techniques for 3-D central nervous system volume acquisition and have shown that the best method of assessment, allowing assessment of both the corpus callosum and the cerebellar vermis, involves midsagittal acquisition through the sagittal suture with 3-D OVIX reconstruction. This technique can be applied successfully in 83% of cases.
Keywords:
2-D ultrasound; 3-D ultrasound; Central nervous system examination; Cerebellar vermis; Corpus callosum; Median plane; Neurosonogram; Prenatal diagnosis; Second trimester