Neuroradiologic Applications of Intraarterial Digital Subtraction Angiography

In the neuroradiologic evaluation of 118 patients using intraar-terial digital subtraction angiography definite advantages and disadvantages were defined. Advantages include reduction of contrast medium volume, catheter time, and patient risk and discomfort. It also aids in angiographic planning. The paramount disadvantage is less spatial resolution compared with conven-tional film angiography. Digital subtraction equipment has been developed independently and essentially simultaneously at severeal centers [1-4]. Early neuroradiologic application of digital subtraction angiography (DSA) equipment focused on intravenous injection of radiographic contrast med ium to visu alize the extracranial carotid arteries [5-7]. A large number of arti c les have since explored a variety of uses of intra-venous DSA as it applies to neuroradiology as well as other areas of cardiovascular investigation. However, the use of this same equipment to augment the visual-ization of small volumes of contrast medium delivered via an intraar-terial catheter has been virtually ignored. The use of intraarterial DSA injection was first mentioned by Meaney et al. [6], who de-scribed the comparison of intraarterial DSA and conventional ab-dominal aortography and presented one intraarterial DSA of a selective internal mammary artery. Additional mention of the pos-sible advantages of intraarterial DSA was made by Mistretta et al. [8] , but no images were published. Comparisons of intraarterial DSA images, intravenous DSA images, and conventional angio-grams of the carotid arteries in 50 patients were presented by Weinstein et al. [9]. Subsequently, Hawkins [10] published a single intraarterial DSA image of the abdominal aorta using iodinated contrast medium for comparison with digitally enhanced CO2 arte-riography. Since th e installation of digital subtraction equipment in the neuroangiographic suite at Vanderbilt University Hospital we have had the opportunity to explore various neuroradiologic applications of intraarterial DSA [11, 12]. In the first year of its availability (1981-1982) 302 patients underwent diagnostic neuroangiographic stud-ies. Of these, 118 had a portion or all of their examination conducted using intraarterial DSA techniques