Basic as well as detailed neurosonogram can be performed by an off-line analysis of 3D fetal brain volumes.

OBJECTIVES:: To evaluate the feasibility and the processing time using off-line analysis of 3D brain volumes to perform basic as well as detailed, targeted, fetal neurosonogram METHODS:: 3D fetal brain volumes were obtained in 103 consecutive healthy fetuses that underwent routine anatomical survey at 20 to 23 post menstrual weeks. Transabdominal gray scale and power Doppler volumes of the fetal brain were acquired by one of three experienced sonographers (average of 7 volumes per fetus). Acquisition was first attempted in the sagittal and coronal planes. When fetal position did not enable easy and rapid access to these planes, axial acquisition at the level of the bi-parietal diameter was performed. Off-line analysis of each volume was performed by two of the authors in blinded fashion. A systematic technique of "volume manipulation" was used to identify a list of 25 brain structures comprising a complete basic evaluation, intra-cranial biometry as well as detailed targeted fetal neurosonogram. The feasibility and reproducibility of obtaining diagnostic quality images of the different structures was evaluated and processing times recorded by the two examiners. RESULTS:: Diagnostic quality visualization was feasible in all of the 25 structures with excellent visualization rate (85%-100%) reported in 18 structures, good visualization rate (69%-97%) in 5 structures, and low visualization rate (38%-54%) reported in 2 structures by the two examiners. Average of 4.3 and 5.4 volumes were used to complete the examination by the two examiners with a mean processing time of 7.2 and 8.8 minutes, respectively. The overall agreement rate for diagnostic visualization of the different brain structures between the two examiners was 89.9%, with a Kappa coefficient of 0.5 (p<0.001). CONCLUSIONS:: In experienced hands, off-line analysis of 3D brain volumes is a reproducible modality that can identify all of the structures necessary to complete both basic and detailed second trimester fetal neurosonogram. Copyright (c) 2009 ISUOG. Published by John Wiley & Sons, Ltd.