***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: Eleven studies (n = 927 participants) met our inclusion criteria. Eight studies compared CTA with IADSA (n = 526) and three studies compared MRA with IADSA (n = 401). Methodological quality varied considerably among studies, with partial verification bias in 7/11 (64%) and retrospective designs in 5/10 (50%). In studies of CTA, the pooled estimate of sensitivity was 0.95 (95% confidence interval (CI) 0.90 to 0.97) and specificity was 0.99 (95% CI 0.95 to 1.00). The results remained robust in a sensitivity analysis in which only studies evaluating adult patients (≥ 16 years of age) were included. In studies of MRA, the pooled estimate of sensitivity was 0.98 (95% CI 0.80 to 1.00) and specificity was 0.99 (95% CI 0.97 to 1.00). An indirect comparison of CTA and MRA using a bivariate model incorporating test type as one of the parameters failed to reveal a statistically significant difference in sensitivity or specificity between the two imaging modalities (P value = 0.6). CTA and MRA appear to have good sensitivity and specificity following ICH for the detection of intracranial vascular malformations, although several of the included studies had methodological shortcomings (retrospective designs and partial verification bias in particular) that may have increased apparent test accuracy.
Output:

This review looked at different tests used to identify blood vessel abnormalities in the brain. Intra-arterial digital subtraction angiography (IADSA) is the standard test used and involves positioning a tube, introduced through a blood vessel in the groin, into blood vessels near the brain. Dye is directly injected into the brain's blood vessels using this tube. Computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) are newer tests that may be done without any injections (MRA) or only through an injection into the arm (CTA and MRA). This review investigated the accuracy of CTA or MRA, or both, compared with IADSA after intracerebral haemorrhage. We found eight studies (involving 526 participants) that compared CTA with IADSA and three studies (involving 401 participants) that compared MRA with IADSA. Both CTA and MRA appear to have good accuracy when compared with IADSA. However, the studies were small and were limited in many cases by their design. Further research that looks at accuracy, practicality, and costs is needed.