In-vivo cerebral artery pulsation assessment with Dynamic computed tomography angiography
Lotte B Stam1, Sabine M L Linden1, René Aquarius1
1Department of Neurosurgery, Radboud University Medical Center, Nijmegen, the Netherlands.
Insights
Four-Dimensional Computed Tomography Angiography (4D CTA) shows potential for assessing cerebral artery motion in aneurysm patients. However, this study found pulsations were undetectable, likely due to motion below the detection threshold.
Area of Science:
- Medical Imaging
- Neurology
- Cardiovascular Research
Background:
- Four-Dimensional Computed Tomography Angiography (4D CTA) is a developing technique for visualizing cerebral artery motion.
- Assessing vessel motion may aid in diagnosing conditions like intracranial aneurysms.
Purpose of the Study:
- To capture cerebral artery lumen diameter over three cardiac cycles using 4D CTA.
- To assess vessel motion and identify consistent expansion patterns within cardiac cycles in patients with intracranial aneurysms.
Main Methods:
- An observational study involving 18 adult patients with unruptured intracranial aneurysms.
- ECG-gated 4D CTA was performed on a wide detector CT system to capture three cardiac cycles.
- Rigid-body registration was used to minimize head movement artifacts, and deformable registration calculated vessel lumen deformation as a measure of motion.
Main Results:
- No arterial pulsations were successfully registered during the 4D CTA acquisition.
- The lack of detected pulsations is attributed to motion below the system's detection threshold and insufficient signal-to-noise ratio.
Conclusions:
- Current 4D CTA methods may not be sensitive enough to detect cerebral artery pulsations in patients with intracranial aneurysms.
- Future research should explore advanced scanners with higher spatial resolution for reproducible measurements of small intracranial arteries.
Abstract:
Four-Dimensional Computed Tomography Angiography (4D CTA) seems a promising technique for capturing vessel motion of cerebral arteries, which may help to assess pathological conditions such as intracranial aneurysms. The goal of our current observational study is to capture the lumen diameter of cerebral arteries during three subsequent cardiac cycles with 4D CTA and to assess vessel motion, anticipating consistent expansion patterns within each cardiac cycle. Eighteen adult patients with unruptured and untreated intracranial aneurysms were recruited at Radboud University Medical Center. Three cardiac cycles were captured, on a wide detector CT system, using ECG-gated 4D CTA. To reduce the impact of small head movements during the acquisition, a rigid-body registration was employed. Three 10 mm segments of cerebral arteries were selected. The total deformation of the vessel lumen was calculated using a deformable registration algorithm and was used as a substitute measure for vessel motion. No pulsations could be registered, which was probably caused by pulsation motion below threshold of detection in combination with insufficient Signal-to-Noise Ratio. Further studies need to investigate if large intracranial structures can be evaluated and if using a novel scanner with a high spatial resolution would result in reproducible measurements of arteries this size.
