Diagnostic Accuracy of Magnetic Resonance Angiography for Cerebral Aneurysms in Correlation With 3D–Digital Subtraction Angiographic Images

Abstract

Background and Purpose-We investigated the sensitivity of 3D-time-of flight (3D-TOF) magnetic resonance angiography (MRA) in the detection of cerebral aneurysms with the use of 3D digital subtraction angiography as the gold standard. We also evaluated the effects of location and number of aneurysms (and experience of the reader) on the sensitivity. Methods-3D-TOF MRA was performed in 82 patients with 133 cerebral aneurysms. Each patient underwent rotational angiography. Three-dimensional reconstructed images were obtained from data of the rotational angiography (as the gold standard). A blind study with 4 readers of different experiences was performed to evaluate the diagnostic accuracy of 3D-TOF MRA for cerebral aneurysms. Results-One hundred five (79%) of all 133 aneurysms were detected with MRA by a neuroradiologist, 100 (75%) were detected by an experienced neurosurgeon, 84 (63%) were detected by a general radiologist, and 80 (60%) were detected by a resident neuroradiologist. For each reader, the detectability was lower for small aneurysms (Ͻ3 mm in maximum diameter) and/or for those located at the internal carotid artery and anterior cerebral artery. False-positive aneurysms were 29 for the neuroradiologist, 19 for the neurosurgeon, 31 for the general radiologist, and 30 for the resident neuroradiologist; most of the aneurysms were at the internal carotid artery. Causes of the false-positive and false-negative results included complex flow in a tortuous artery and susceptibility artifacts. Conclusions-Although MRA is useful in the diagnosis of cerebral aneurysms, sufficient experience and careful attention are necessary for accurate diagnosis of aneurysms located at the internal carotid and anterior cerebral arteries. (Stroke.

Feasibility of a Curvature-based Enhanced Display System for Detecting Cerebral Aneurysms in MR Angiography

“…Although aneurysms less than 3 mm in diameter can be detected with conventional display methods, it has been pointed out that 3 mm is a practical cutoŠ level for detection of cerebral aneurysms on MR angiography, as the detection rate is much lower for smaller aneurysms. 1 However, the same authors also point out that the rupture rate of aneurysms smaller than 3 mm cannot be neglected in cases of subarachnoid hemorrhages. The curvature-based display system may help to increase the low detection rates of these smaller cerebral aneurysms.…”

“…[9][10][11][12] As well, the second smaller aneurysm in the presence of a larger aneurysm is often overlooked. 1 The risk of intervention may also be lowered by new intervention techniques 13 and by better patient management. 14 We believe that low-cost screening for small cerebral aneurysms would have a signiˆcant clinical role in the near future.…”

“…Okahara et al reported that the detection sensitivity of cerebral aneurysms with MR angiography was 60-79z, with digital subtraction 3D angiography used as the standard of reference. 1 A high percentage of false negative aneurysms were simply overlooked. In an eŠort to reduce human error in the detection process, we have developed a curvaturebased display system that displays volume-rendered images with overlaid curvature indices calculated from MR angiography volume data.…”

Rebleeding from Cerebral Aneurysms during 3DCT Angiography

“…Cranial MRA offers inferior diagnostic performance to CTA with respect to the detection of cerebral aneurysm on some points [9,10] but is regarded as a valuable screening method. As MRA also provides less surgical information compared with CTA and the diagnostic concordance rate between different doctors is poor compared with angiography, the technique is most often only used as a supplementary method of diagnosis [11].…”

Ruptured Cerebral Aneurysms: An Update

“…MRA has practical limitations in the characteristics of the aneurysm neck and its relationship to the parent vessels [1,23]. MRA takes considerably longer to perform than does CTA and does not replace CT tomography and cerebral angiography to identify the ruptured cerebral aneurysms before treatment [23,24].…”