Visualizing the dynamics of cerebral aneurysms with four-dimensional computed tomographic angiography
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Published on: December 9, 2021
Fujimaro Ishida1, Hiroyuki Ogawa, Takeo Simizu
1Department of Neurosurgery, Mie Prefectural General Medical Center, Yokkaichi, Japan. nsfuji@khaki.plala.or.jp
Insights
Four-dimensional (4-D) computed tomographic (CT) angiography reveals dynamic cerebral aneurysm wall motion and blebs. This advanced imaging provides crucial insights for surgical planning and understanding aneurysm progression.
Area of Science:
- Radiology
- Medical Imaging
- Neurosurgery
Background:
- Cerebral aneurysms pose significant risks, including rupture and subarachnoid hemorrhage.
- Accurate hemodynamic assessment is crucial for effective treatment planning.
- Traditional imaging modalities may not fully capture dynamic aneurysm features.
Purpose of the Study:
- To evaluate the utility of four-dimensional (4-D) computed tomographic (CT) angiography in assessing cerebral aneurysm hemodynamics.
- To visualize and analyze dynamic features of aneurysmal walls, blebs, and dissecting cavities.
- To compare the diagnostic value of 4-D CT angiography with conventional imaging techniques.
Main Methods:
- Utilized multislice computed tomography with retrospective electrocardiography-gated reconstruction.
- Generated 4-D CT movies to visualize the motion of aneurysmal structures.
- Analyzed data from 34 aneurysms in 30 patients.
Main Results:
- 4-D CT angiography successfully visualized dynamic wall motion and pulsating blebs in saccular aneurysms.
- Detected dangerous pulsating blebs in two cases later confirmed as rupture points during surgery.
- Provided detailed information on dissecting aneurysms, including cavities and intimal flaps, surpassing conventional angiography.
- Demonstrated high utility for pre-endovascular surgery anatomical judgment.
Conclusions:
- 4-D CT angiography is valuable for assessing aneurysmal wall dynamics and intracranial aneurysms.
- Offers superior information compared to other imaging modalities for aneurysm evaluation.
- Further research is needed to optimize the application of 4-D CT for pathological characteristics and therapeutic interventions.
Objective:
This study was designed to assess cerebral aneurysm hemodynamics with four-dimensional (4-D) computed tomographic (CT) angiography.
Methods:
Multislice computed tomography with a retrospective electrocardiography-gated reconstruction algorithm was used. The motions of the aneurysmal wall, bleb, and dissecting cavity were rendered observable in a 4-D CT movie.
Results:
The findings for 30 patients with 34 aneurysms who underwent 4-D CT angiography were analyzed. Twenty-three aneurysms were documented in the anterior circulation region, and the remaining 11 aneurysms were in the posterior circulation. The average aneurysm size was 6.4 mm, and there were five large aneurysms. There were 28 saccular, 4 dissecting, and 2 fusiform aneurysms. 4-D CT movies were obtained successfully in all aneurysms. The aneurysm wall motion of two growing aneurysms exhibited a highly irregular pulsation in the 4-D CT movie. Pulsating blebs were detected in nine (32.1%) of the saccular aneurysms. In two patients with subarachnoid hemorrhage, preoperative 4-D CT angiography revealed dangerous pulsating blebs that were confirmed as the ruptured points during the surgical procedure. Specifically, in the dissecting aneurysms, the 4-D CT movie revealed a pulsating line, which provided accurate and detailed information regarding the dissecting cavity and intimal flap. The dissecting cavity revealed by the 4-D CT movie could not be detected with conventional or three-dimensional digital subtraction angiography. The 4-D CT movie images were highly useful in making anatomic judgments for the endovascular surgery procedure.
Conclusion:
4-D CT images are valuable in determining aneurysmal wall dynamics. Highly useful information was obtained regarding intracranial aneurysms with 4-D CT angiography compared with other modalities. Further studies will be necessary to elucidate the optimal application of this new technology to both the pathological characteristics and therapeutic amelioration of aneurysmal features such as dome pulsation, blebs, and growing aneurysms.
