Biology Reference
In-Depth Information
Chapter 32
Neuroimaging Assessment of Subarachnoid Hemorrhage
Andre Obenaus and Sam Barnes
Abstract
Subarachnoid hemorrhage (SAH) is a debilitating disease with signifi cant morbidity and mortality.
Neuroimaging is a critical component for the diagnosis and therapeutic planning in patients. The most
common imaging modality is computed tomography (CT) followed by fl uid-attenuated inversion recov-
ery (FLAIR)-based magnetic resonance imaging (MRI). A new imaging sequence, susceptibility-weighted
imaging (SWI), has been designed that is exquisitely sensitive to extravascular blood. SWI is thus an ideal
imaging sequence to visualize SAH injury. However, while SWI has been extensively used in the diagnosis
of traumatic brain injury only a single report has demonstrated that SWI is better than CT at diagnosis of
SAH. Very few neuroimaging studies of animal models of SAH exist and there are no reports using SWI
for SAH evaluation. However, we describe a robust, easy-to-use protocol for using SWI within the
research setting.
Key words: Magnetic resonance imaging, Susceptibility-weighted imaging, T2*-weighted imaging,
Phase, Intracerebral hemorrhage, Animal models,
1. Introduction
Subarachnoid hemorrhage (SAH) occurs primarily following rupture
of an intracranial aneurysm; however, arterial dissection, infl ammatory
lesions of intracerebral vessels and tumors can also be an underlying
cause of SAH. The most commonly involved vessels for the develop-
ment of aneurysms include the middle cerebral, anterior commu-
nicating, posterior communicating, and posterior inferior cerebellar
and basilar arteries. The incidence of SAH varies 6-20/100,000
person years ( 1 ) and often results in up to 42% mortality ( 2 ).
Recent advances in neuroimaging of SAH have made the diag-
nosis and subsequent intervention more rapid. In addition, critical
care of the SAH patient has also advanced leading to improved
outcomes ( 3, 4 ). Indeed, rapid computed tomography (CT),
advances in angiographic methods and the proliferation of
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