SUBTRACTION CT ANGIOGRAPHY WITH CONTROLLED-ORBIT HELICAL SCANNING FORDETECTION OF INTRACRANIAL ANEURYSMS

PURPOSE: Our goal was to evaluate the utility of subtraction three-dim ensional CT angiography for the detection of intracranial aneurysms, M ETHODS: Thirty-six patients with intracranial aneurysms were examined using newly devised controlled-orbit helical scanning and conventional angiography. Three-dimensional CT angiograms and subtraction 3-D CT a ngiograms were compared with conventional angiograms for their charact erization of intracranial aneurysms, RESULTS: Fifty aneurysms were dep icted on conventional angiograms, of which 48 (96%) were seen on the 3 -D CT angiograms, Three-dimensional CT angiography was superior or equ ivalent to conventional angiography for depicting the shape, direction , and location of 33 (66%) of 50 aneurysms; however, it was often less useful than conventional angiography in delineating intracranial aneu rysms adjacent to bone. Subtraction 3-D CT angiograms were obtained in 32 patients with a total of 46 aneurysms (in four cases, aneurysms we re not depicted owing to excessive motion artifacts), and were superio r or equivalent to conventional angiograms in all 46 cases. CONCLUSION S: Subtraction 3-D CT angiography with the use of controlled-orbit hel ical scanning is effective in the detection of intracranial aneurysms.