Digital Fluoroscopic Angiography in the Diagnosis of Central Nervous System Diseases

Abstract

Listen

Translate article

Digital fluoroscopic angiography (DFA) is a recently developed non-invasive intravenous angiography which has become possible through real-time digital subtraction of X-ray transmission data from an image intensifier and television fluoroscopic system. Prototype units were developed and installed. The output signal of the image intensifier-television camera system was digitized by an analog-digital converter. The digital information, 512×512 pixels and 9 bits deep, was fed into the image processing assembly after logarithmic amplification, where 2-8 frames were added and subtracted from the mask images for the final digital images. Up to 32 serial digital images could be stored in real time in the frame memories, while additional images were transfered to other recording units as necessary. Fifty-five examinations were performed on 49 patients with various clinical symptoms referable to the central nervous system. Diagnostic information was obtained in 26 of the 55 examinations (47.3%), which included brain tumors, aneurysms, and atherosclerotic diseases in the neck. Examinations of “fair” quality were obtained 19 times (34.5%), most being intracranial arterial occlusive diseases. No information was obtained in 10 examinations (18.2%), mostly due to technical failures or misregistration artifacts. Although spatial resolution of DFA is inferior to conventional angiography, this technique will replace it in certain conditions such as: 1) screening and postoperative follow-up of cervical diseases; 2) visualization of carotid arteries in contemplated transsphenoidal hypophysectomy; 3) diagnosis of large tumors or vascular tumors; 4) visualization of faint tumor stains; 5) diagnosis of sinus occlusions; 6) screening of vascular lesions such as subarachnoid hemorrhage and megadolichobasilar artery; and 7) patency of STA-MCA anastomosis. Future development of DFA should be directed towards improvement of spatial resolution and removal of misregistration artifacts.