Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT02056769 |
Other study ID # |
CT-PIPS |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
April 2014 |
Est. completion date |
February 2024 |
Study information
Verified date |
February 2023 |
Source |
Nova Scotia Health Authority |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Patients with brain hemorrhage resulting from a ruptured aneurysm (SAH) are at risk of
developing a condition called vasospasm, one or two weeks after their hemorrhage. This is a
major cause of stroke and death following SAH. A special type of CT scan, called CT
perfusion, analyzes regional blood flow in the brain. We hypothesize that CT perfusion scans
performed on admission and day 6 post-hemorrhage will enable us to predict which patients
will go on to develop vasospasm.
Description:
Rupture of a brain aneurysm results in a type of bleeding into the brain called subarachnoid
hemorrhage (SAH). This is a substantial cause of morbidity and mortality world-wide: even
with the best possible care, up to half of patients die and many are left disabled. Sometimes
this is because the immediate brain damage from the bleed is very severe. However, many
patients who seem to be doing well at first go on to develop something called "vasospasm":
narrowing of large arteries in the brain. This results in the brain not getting enough blood,
and the patient can suffer a stroke as a result. The lack of blood to the brain is called
delayed cerebral ischemia (DCI), and is the major secondary cause of stroke and death in
patients who survived the initial aneurysm rupture.
Vasospasm can be seen on angiograms (blood vessel imaging) in about two-thirds of SAH
patients, and causes neurological symptoms of DCI in half of those patients. It usually
develops about a week or so after SAH. Early diagnosis and treatment of cerebral vasospasm
and delayed cerebral ischemia (DCI) reduces morbidity and mortality in SAH patients.
CT perfusion imaging is able to identify areas of reduced cerebral blood flow that are at
risk of DCI and stroke. This technique is able to measure cerebral blood flow and blood
volume (CBF, CBV), and calculates two other measures of cerebral perfusion: time to peak
intensity (TTP) and mean transit time (MTT). Taken together, these provide information about
the amount of blood the brain is receiving and whether the brain is compensating for any
reduction in flow. This is helpful because seeing vasospasm on imaging is not enough to
predict brain ischemia and stroke; the additional physiological information provided by the
perfusion assessment strengthens the diagnosis of DCI. Early evidence suggests that CT
perfusion is a fast, accurate, inexpensive and non-invasive method of brain imaging to
identify patients with DCI after SAH, and guide appropriate therapy.
If we were able to successfully predict which patients are at high risk of DCI and/or stroke,
we could intervene early. This could improve patient outcomes, while potentially allowing
better use of limited intensive care and nursing resources. Other studies have shown that
patients with DCI had altered perfusion prior to developing clinical symptoms, but we do not
know whether we can use CT perfusion to predict patients at risk, or which CT perfusion
measurements (e.g., CBF or TTP) are most useful.
The radiation risk associated with CT perfusion imaging is negligible, due to advances in CT
technology which allow for routine simultaneous CT perfusion and CT angiogram (CTA) without a
significant increase in radiation dose over conventional head CT-CTA alone. Judicious use of
CT perfusion, through a structured algorithm that includes routine perfusion scans at
admission and during the peak risk period for vasospasm, may actually decrease cumulative
radiation dose for patients with SAH, by ruling out perfusion deficit and brain ischemia as a
cause of decreased neurological function and limiting repeated angiograms.