Ultrasound of the spleen

Ultrasound (US) is a very useful means of noninvasively examining the spleen. Imaging is generally achieved via an intercostal approach using gray scale US supplemented by color flow to assess vasculature. Normal spleen appears uniform with vessels radiating and converging at the hilum. US readily identifies accessory spleens, a common congenital variation. Splenomegaly can be identified by US, however, it is not useful in differentiating the many causes of an enlarged spleen. Focal splenic masses are identified as cystic or solid by US, and features such as calcification, wall thickening, internal debris, and gas may be demonstrated in cystic type masses. Granulomatous calcification may be seen with US and cavernous hemangiomata typically have a characteristic US appearance. US can demonstrate typical features of splenic infarction. Splenic injury can be detected with US, however, whether US is the most appropriate first line investigation for suspected splenic injury is yet to be determined. It is a very useful follow-up modality for monitoring splenic injuries detected by either US or computed tomography which are treated conservatively.