Ultrasound in the diagnosis of injury.

Ultrasound is one of several modalities useful in the work-up of an injured patient. It is a bedside technique which is quick, economical and highly reliable in filtering out the patients who are in urgent need of laparotomy. For the moment, this is the prime and only function of this modality. The US examination can and should be repeated with a very low threshold. Apart from the complication rate, which is zero for US, it shares many virtues with DPL. Ultrasonography in a badly injured victim is a challenging investigation which should be done by an expert. In most situations, this will be a radiologist whose presence in the emergency room could further be used for expert film reading and development as well as the unhampered implementation of a rational follow-up imaging strategy. Follow-up modalities, however impressive, should not be compared with first-line investigations. In expert hands, accuracy figures between DPL and US do not differ decisively but one must bear in mind that DPL spans only one compartment while US gives information about much more vital areas. DPL is complementary to US; it is of paramount importance to understand that DPL spoils the US examination (and CT as well) but is not hindered by repeated US. DPL can and should be used to investigate the nature of free intra-peritoneal fluid when the amount does not warrant laparotomy. Neither US nor DPl are substitutes for sound clinical judgement.