This is the protocol for a review and there is no abstract. The objectives are as follows:
To compare the diagnostic accuracy of CTA and MRA for the detection of intracranial vascular malformations as the cause of ICH assessed by catheter IADSA.
To investigate the influence of the timing of the index and reference tests on diagnostic test accuracy.
We will investigate the differences in diagnostic accuracy in subgroups defined by age distribution, haematoma size distribution, and the timing of the index test(s) after symptom onset, between included studies.
CT and MR technology has advanced rapidly over the last 20 years. Therefore, we will investigate heterogeneity-related variations in CT technology (for example non-helical CT scanners, helical CT scanners, and multi-detector helical CT scanners) and MRI technology (for example MRI magnet strength and the type of angiographic technique used to image the arteries). CTA, MRA, and IADSA are all user-dependent and thus we will also investigate heterogeneity related to the coverage of the brain that is investigated in each study (for example users some may only evaluate the region around the haematoma while others may choose to also evaluate vessels distant from the bleed). Specifically for IADSA, we will investigate how many arterial territories are investigated (the internal carotid artery territory, the external carotid artery territory, the vertebral artery territory, or all three), whether vessels are injected on one side or both sides of the brain, the number of views from different orientations taken per vessel, and whether three-dimensional angiography is employed.
We will describe differences in the qualifications and experience of the radiologists reporting the index tests and reference standards.