Correlation Between Thrombus Signal Intensity and Aneurysm Wall Thickness in Partially Thrombosed Intracranial Aneurysms Using 7T Magnetization-Prepared Rapid Acquisition Gradient Echo Magnetic Resonance Imaging

Taku Sato; Toshinori Matsushige; Bixia Chen; Oliver Gembruch; Philipp Dammann; Ramazan Jabbarli; Michael Forsting; Andreas Junker; Stefan Maderwald; Harald H Quick; Mark E Ladd; Ulrich Sure; Karsten H Wrede

doi:10.3389/fneur.2022.758126

Correlation Between Thrombus Signal Intensity and Aneurysm Wall Thickness in Partially Thrombosed Intracranial Aneurysms Using 7T Magnetization-Prepared Rapid Acquisition Gradient Echo Magnetic Resonance Imaging

Front Neurol. 2022 Feb 18:13:758126. doi: 10.3389/fneur.2022.758126. eCollection 2022.

Authors

Taku Sato^{1

2

3}, Toshinori Matsushige^{1

2

4

5}, Bixia Chen^{1

2}, Oliver Gembruch^{1

2}, Philipp Dammann^{1

2}, Ramazan Jabbarli¹, Michael Forsting⁶, Andreas Junker⁷, Stefan Maderwald², Harald H Quick^{2

8}, Mark E Ladd^{2

9

10}, Ulrich Sure¹, Karsten H Wrede^{1

2}

Affiliations

¹ Department of Neurosurgery, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
² Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany.
³ Department of Neurosurgery, Fukushima Medical University, Fukushima, Japan.
⁴ Department of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
⁵ Department of Neurosurgery and Interventional Neuroradiology, Hiroshima City Asa Citizens Hospital, Hiroshima, Japan.
⁶ Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
⁷ Institute of Neuropathology, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
⁸ High Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
⁹ Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
¹⁰ Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany.

Abstract

Objective: The objective of this study is to investigate the relationship between the thrombus signal intensity and aneurysm wall thickness in partially thrombosed intracranial aneurysms in vivo with magnetization-prepared rapid acquisition gradient echo (MPRAGE) taken using 7T magnetic resonance imaging (MRI) and correlate the findings to wall instability.

Methods: Sixteen partially thrombosed intracranial aneurysms were evaluated using a 7T whole-body MR system with nonenhanced MPRAGE. To normalize the thrombus signal intensity, its highest signal intensity was compared to that of the anterior corpus callosum of the same subject, and the signal intensity ratio was calculated. The correlation between the thrombus signal intensity ratio and the thickness of the aneurysm wall was analyzed. Furthermore, aneurysmal histopathological specimens from six tissue samples were compared with radiological findings to detect any correlation.

Results: The mean thrombus signal intensity ratio was 0.57 (standard error of the mean [SEM] 0.06, range 0.25-1.01). The mean thickness of the aneurysm wall was 1.25 (SEM 0.08, range 0.84-1.55) mm. The thrombus signal intensity ratio significantly correlated with the aneurysm wall thickness (p < 0.01). The aneurysm walls with the high thrombus signal intensity ratio were significantly thicker. In histopathological examinations, three patients with a hypointense thrombus had fewer macrophages infiltrating the thrombus and a thin degenerated aneurysmal wall. In contrast, three patients with a hyperintense thrombus had abundant macrophages infiltrating the thrombus.

Conclusion: The thrombus signal intensity ratio in partially thrombosed intracranial aneurysms correlated with aneurysm wall thickness and histologic features, indicating wall instability.

Keywords: 7T magnetic resonance imaging; aneurysm wall; magnetization-prepared rapid acquisition gradient echo; partially thrombosed intracranial aneurysm; thrombus.