Digital subtraction angiography: principles and potential applications in emergency medicine

Digital subtraction angiography (DSA) is a new computer-assisted process which enables visualization of arterial structures after intravenous injection of contrast material. Technical requirements of the process mandate total patient cooperation during the filming sequence, which generally lasts five to ten seconds. Because of lower spatial resolution compared with conventional angiography, and difficulty with vessel overlap as a result of nonselective opacification, DSA has not supplanted conventional angiography in evaluation of traumatic vascular injuries. The technology of DSA, currently accepted uses, and potential future uses of DSA are discussed. Future improvements in DSA promise to make it more amenable to the evaluation of traumatic vascular injuries.