DIGITAL SUBTRACTION ROTATIONAL ANGIOGRAPHY FOR ANEURYSMS OF THE INTRACRANIAL ANTERIOR CIRCULATION - INJECTION METHOD AND OPTIMIZATION

PURPOSE: To optimize parameters of rotational angiography for examinat ion of the internal carotid circulation; to compare rotational angiogr aphy with standard digital subtraction angiography (DSA) in the evalua tion of aneurysms of the intracranial internal carotid circulation; an d to determine tolerance and safety limits of prolonged internal carot id injection angiography, METHODS: Rotational angiograms were obtained during injection of the internal carotid circulation as part of the c linical angiographic evaluation of aneurysms in 41 patients. Injection rates, X-ray delays, and fields of view were studied retrospectively. Findings at rotational angiography and standard DSA were compared. No nionic contrast material was injected over 6 seconds, and patients wer e studied before and after prolonged injection angiography by physical and laboratory examination, including measurement of blood pressure, pulse, and intracranial pressure. RESULTS: Vascular conspicuity was eq uivalent at carotid injection rates of 4 and 5 mL/s delivered over 6 s econds. At 3 mL/s, more image manipulation was required to see small v ascular structures. One-second X-ray delay combined with 6-second inje ction duration provided the best arterial depiction of intracranial Ve ssels from start to end of rotational angiography. Maximal rotational resolution was with a 17-cm field of view. Identification of aneurysms and small vessels was equivalent at all injection rates. Aneurysm det ection was equivalent with rotational angiography and DSA, In 9 of 31 aneurysms, the neck was defined more clearly with rotational angiograp hy than with DSA, compared with 2 of 31 that were seen better with DSA . Aneurysms of the intracranial internal carotid circulation were seen with rotational angiography and not DSA in 12 of 41 cases. No change was noted in clinical or laboratory findings. CONCLUSION: Rotational a ngiography provided better definition of the aneurysmal neck and great er clarity of aneurysms than did DSA; it also improved the level of co nfidence in predicting the presence or absence of aneurysms, especiall y in the anterior communicating artery; however, in our small series i t did not significantly increase the detection of aneurysms. Prolonged injection angiography was well tolerated in all patients.