Incremental dynamic computed tomography: practical method of imaging the carotid bifurcation.

A simple, practical method of applying incremental dynamic computed tomography (CT) to the imaging of 20 carotid bifurcations is described. The results are compared with those obtained by conventional carotid angiography and intravenous digital subtraction angiography (DSA). Conventional angiography provided additional information about the carotid bifurcation in only one of 14 cases, while incremental dynamic CT provided information not available from intravenous DSA in two of eight cases. Conventional brain CT is being used increasingly in the workup of patients with transient ischemic symptoms, and dynamic CT scanning at 3-mm increments requires only an extra 5 min of scanner time. The addition of incremental dynamic CT through the carotid bifurcation to the conventional brain CT scan procedure may obviate other screening tests before more definitive angiographic procedures.