Advances in obstetric ultrasound.

(a) More sophisticated The latest generation of ultrasound machines in the upper range have become more complicated. A few machines already have 256 grey levels incorporated into the monitor giving more differentiation between tissues l . Three dimensional ultrasound has also arrived at the scene and this is mainly by reconstruction from the scanning data of the fetus. It is hoped that this will be useful in detecting anomalies as well as aid in estimation of fetal weight. With the advent of better software to drive these sophisticated machines the capabilities are enhanced. Currently some machines have 128 channels for incorporation of data from the probes. This may be increased in the near future to give rise to better images. Incorporation of different colours (B colour) to give better resolution to the image has been introduced by an ultrasound company Storage of data can now be done on video in the machine itself in most upper range models but now a model has come out where it is possible to store it on a floppy disc. (b) New probes There has been a plethora of probes recently and the move is to make smaller probes with better resolution(spatial and lateral) due to advances in the computer software. The transvaginal probe has remarkably changed gynaecological scanning and has undergone changes from basic 5-7mHz probes to those with capabilities for transvaginal colour doppler incorporation of duplex scanners with doppler mode has enhanced the location of the vessels where sampling is required. With the advent of colour doppler vessels which previously were inaccessible can now be sampled easily. Furthermore visualisation of structural defects particularly in the fetal heart has been enhanced by this modality. Introduction of zoom facilities enhance the visualisation of a suspicious area for structural defects.