Hemorragia Subaracnoidea

Hemorragia subaracnoidea

n EVIDENCE-BASED PRACTICE

Intracranial Aneurysms in
Patients with Subarachnoid
Hemorrhage: CT Angiography
as a Primary Examination Tool for
Diagnosis—Systematic Review and
Meta-Analysis1
Henriëtte E. Westerlaan, MD
J. M. C. van Dijk, MD, PhD
Marijke C. Jansen-van der Weide, PhD
Jan Cees de Groot, MD, PhD
Rob J. M. Groen, MD, PhD
Jan Jakob A. Mooij, MD,PhD
Matthijs Oudkerk, MD, PhD

From the Departments of Radiology (H.E.W., J.C.d.G.,
M.O.), Neurosurgery (M.J.v.D., R.J.M.G., J.J.A.M.), and
Epidemiology (M.C.J.), University Medical Center Groningen,
PO Box 30.001, Hanzeplein 1, 9700 RB Groningen, the
Netherlands. Received December 23, 2009; revision
requested February 6, 2010; revision received May 27;
accepted June 2; final versionaccepted August 2. Address
correspondence to H.E.W. (e-mail: H.E.Westerlaan@rad.
umcg.nl ).
q

To calculate the sensitivity and specificity of computed tomographic (CT) angiography in the diagnosis of cerebral
aneurysms in patients with acute subarachnoid hemorrhage (SAH) at presentation.

Materials and
Methods:

A systematic search for relevant studies was performed of
the PubMed/MEDLINE andEMBASE databases. Two reviewers independently assessed the methodologic quality
of each study by using the Quality Assessment of Diagnostic Accuracy Studies tool. The inclusion criteria were met
by 50 studies. Heterogeneity was tested, and the presence
of publication bias was visually assessed (by using a funnel plot). A meta-analysis of the reported sensitivity and
specificity of each studywith 95% confidence intervals
(CIs) was performed on a per-patient level.

Results:

1

Purpose:

Concerning sensitivity, the selected studies showed moderate heterogeneity. For specificity, low heterogeneity was
observed. Moderate-heterogeneity studies that investigated only sensitivity or specificity were excluded from
the pooled analyses by using a bivariate random effects
model. Themajority of the studies (n = 30) used a four–
detector row CT scanner. The studies had good methodologic
quality. Pooled sensitivity was 98% (95% CI: 97%, 99%),
and pooled specificity was 100% (95% CI: 97%, 100%).
Potential sources of variability among the studies were
variations in the methodologic features (quality score),
CT examination procedure (number of rows on the multidetector CTscanner), the standard of reference used,
and the prevalence of ruptured intracranial aneurysms.
There was evidence for publication bias, which may have
led to overestimation of the diagnostic accuracy of CT
angiography.

Conclusion:

Multidetector CT angiography can be used as a primary
examination tool in the diagnostic work-up of patients
with SAH.
q

RSNA, 2010

RSNA, 2010

134radiology.rsna.org

n

Radiology: Volume 258: Number 1—January 2011

EVIDENCE-BASED PRACTICE: Meta-Analysis of CT Angiography for Aneurysms in Patients with Hemorrhage

S

pontaneous subarachnoid hemorrhage (SAH) is caused by rupture
of an intracranial aneurysm in
80%–90% of cases (1,2). The mortality
for untreated aneurysmal SAH is up to
50% in the 1st month, mainly because
ofrerupture (3). Early identification and
definitive treatment of underlying ruptured aneurysms is generally advocated
to reduce the risk of rebleeding (4–6).
Computed tomographic (CT) angiography of the intracranial vessels is now
a routine examination that has become
fully integrated into the imaging and treatment algorithm for patients with SAH at
presentation in many centers in Europe.
The aimof this systematic review
and meta-analysis was to calculate the
sensitivity and specificity of CT angiography in the diagnosis of cerebral aneurysms in patients with acute SAH at
presentation.

Materials and Methods
Literature Review
A computerized search was performed
in MEDLINE and EMBASE to identify
relevant articles published from January
1, 1997, through September 1, 2009. In...