Application of computed tomography angiography for evaluating clinical morphology in intracranial aneurysms - monocentric study

Challenges in identifying ruptured aneurysms in cases of multiple aneurysms: Utilizing MRI with contrast for surgical planning-A case report

Key Clinical Message

Accurately identifying the ruptured aneurysm in patients with subarachnoid hemorrhage and multiple aneurysms is critical to prevent rebleeding and optimize outcomes. Vessel wall MRI with contrast can aid in pinpointing the culprit aneurysm, informing a tailored surgical or endovascular management strategy for these complex cases. In patients with subarachnoid hemorrhage (SAH) and multiple intracranial aneurysms, MRI with contrast and DSA are crucial for identifying the ruptured aneurysm, guiding a shift from endovascular to microsurgical clipping. Successful single-session treatment and absence of postsurgical deficits highlight the effectiveness of a multidisciplinary approach. Further research on optimal strategies is needed.

Abstract

Multiple intracranial aneurysms make up approximately 20% of cases of aneurysmal SAH. In patients with aneurysmal SAH and multiple intracranial aneurysms, definite treatment of the ruptured aneurysm causing SAH is of the highest priority. However, identifying the bleeding source can be challenging, and it may not be recognizable by the hemorrhage pattern. Misdiagnosis and mistreatment of a ruptured aneurysm in a patient with multiple aneurysms can lead to bleeding recurrence and an undesirable outcome. We report a 65-year-old woman who presented with severe sudden onset headache. Neuroimaging studies revealed diffuse SAH and concurrent PICA and ACom aneurysm with triplicate A2. However, the ruptured aneurysm responsible for the patient's symptoms was not obvious based on routine neuroimaging studies. Magnetic resonance imaging with contrast was performed, revealing circumferential enhancement of the PICA aneurysm. In this report, we demonstrate the real-world effect of vessel wall MRI with contrast on decision-making regarding identifying the ruptured aneurysm and surgical planning in cases of multiple aneurysms. Furthermore, we show that MRI and aneurysm wall enhancement could be a promising option in detecting ruptured aneurysms in cases of multiple aneurysms.

RAPID aneurysm accurately measures aneurysm size on CT angiography compared to three-dimensional digital subtraction angiography

BACKGROUND

Cerebral aneurysms are often identified and characterized on non-invasive CT Angiography (CTA) images, but digital subtraction angiography (DSA) is the gold standard for aneurysm evaluation.

OBJECTIVE

We compared cerebral aneurysm size measurements as measured from CTA processed by a semi-automated artificial intelligence software program (RAPID Aneurysm) and three-dimensional rotational DSA (3D-DSA).

METHODS

We performed a retrospective cohort study of consecutive patients with a cerebral aneurysm who underwent CTA and DSA with 3D reformations. CTA images were processed by RAPID Aneurysm to determine aneurysm height, width, and neck width. The reference standard was aneurysm measurements on 3D-DSA as measured by two neurointerventionalists. Both readers were blinded to RAPID Aneurysm measurements. Correlation and bias between these measurements were determined.

RESULTS

Results from 50 patients with 50 aneurysms were compared. 32 patients (64%) were female. Median age was 65 (IQR: 56.25-71.75). 37 patients (74%) presented with ruptured aneurysms. The aneurysms represented a range of aneurysm sizes (1.9-33.3 mm; IQR 3.6-7.2 mm). RAPID Aneurysm size measurements showed excellent correlation and low bias (correlation, mean difference) when compared to the reference standard for aneurysm height (0.98, -0.9 mm), width (0.98, 0.1 mm), and neck width (0.94, 1.1 mm). The inter-reader comparison between the two neurointerventionalists was similarly excellent for aneurysm height (0.97, -0.4 mm), width (0.98, -0.2 mm), and neck width (0.89, 0.8 mm).

CONCLUSION

RAPID Aneurysm measurement of cerebral aneurysm height, width, and neck width on CTA is strongly correlated to expert neurointerventionalist measurements on 3D-DSA.

Magnetically assisted soft milli-tools for occluded lumen morphology detection

Methodologies based on intravascular imaging have revolutionized the diagnosis and treatment of endovascular diseases. However, current methods are limited in detecting, i.e., visualizing and crossing, complicated occluded vessels. Therefore, we propose a miniature soft tool comprising a magnet-assisted active deformation segment (ADS) and a fluid drag-driven segment (FDS) to visualize and cross the occlusions with various morphologies. First, via soft-bodied deformation and interaction, the ADS could visualize the structure details of partial occlusions with features as small as 0.5 millimeters. Then, by leveraging the fluidic drag from the pulsatile flow, the FDS could automatically detect an entry point selectively from severe occlusions with complicated microchannels whose diameters are down to 0.2 millimeters. The functions have been validated in both biologically relevant phantoms and organs ex vivo. This soft tool could help enhance the efficacy of minimally invasive medicine for the diagnosis and treatment of occlusions in various circulatory systems.

Enhancing the depth perception of DSA images with 2D-3D registration

Objective

Today, cerebrovascular disease has become an important health hazard. Therefore, it is necessary to perform a more accurate and less time-consuming registration of preoperative three-dimensional (3D) images and intraoperative two-dimensional (2D) projection images which is very important for conducting cerebrovascular disease interventions. The 2D-3D registration method proposed in this study is designed to solve the problems of long registration time and large registration errors in 3D computed tomography angiography (CTA) images and 2D digital subtraction angiography (DSA) images.

Methods

To make a more comprehensive and active diagnosis, treatment and surgery plan for patients with cerebrovascular diseases, we propose a weighted similarity measure function, the normalized mutual information-gradient difference (NMG), which can evaluate the 2D-3D registration results. Then, using a multi-resolution fusion optimization strategy, the multi-resolution fused regular step gradient descent optimization (MR-RSGD) method is presented to attain the optimal value of the registration results in the process of the optimization algorithm.

Result

In this study, we adopt two datasets of the brain vessels to validate and obtain similarity metric values which are 0.0037 and 0.0003, respectively. Using the registration method proposed in this study, the time taken for the experiment was calculated to be 56.55s and 50.8070s, respectively, for the two sets of data. The results show that the registration methods proposed in this study are both better than the Normalized Mutual (NM) and Normalized Mutual Information (NMI).

Conclusion

The experimental results in this study show that in the 2D-3D registration process, to evaluate the registration results more accurately, we can use the similarity metric function containing the image gray information and spatial information. To improve the efficiency of the registration process, we can choose the algorithm with gradient optimization strategy. Our method has great potential to be applied in practical interventional treatment for intuitive 3D navigation.