Microvascular morphology alteration using relaxation rate change with gadolinium-based magnetic resonance imaging contrast agent in patients with Alzheimer's disease

Xiao-Yi Guo; Hyeok Jung Kwon; Hak Young Rhee; Soonchan Park; Ah Rang Cho; Chang-Woo Ryu; Geon-Ho Jahng

doi:10.21037/qims-22-524

Microvascular morphology alteration using relaxation rate change with gadolinium-based magnetic resonance imaging contrast agent in patients with Alzheimer's disease

Quant Imaging Med Surg. 2023 Jan 1;13(1):1-16. doi: 10.21037/qims-22-524. Epub 2022 Nov 1.

Authors

Xiao-Yi Guo¹, Hyeok Jung Kwon², Hak Young Rhee³, Soonchan Park⁴, Ah Rang Cho⁵, Chang-Woo Ryu⁴, Geon-Ho Jahng⁴

Affiliations

¹ Department of Medicine, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
² Department of Medicine, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
³ Department of Neurology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
⁴ Department of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
⁵ Department of Psychiatry, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.

Abstract

Background: Conventional magnetic resonance imaging (MRI) techniques cannot demonstrate microvascular alterations in mild Alzheimer's disease (AD). Thus, the diagnosis of microvascular pathology commonly relies on postmortem. The purpose of this study was to evaluate alterations of microvascular structures in patients with AD using a 3T clinical MRI system with a commercially available contrast agent.

Methods: Eleven patients with AD and 11 cognitively normal (CN) controls were included in this cross-sectional prospective study. R2 and R2* relaxation rate changes (∆R2 and ∆R2*) before and after a Gadolinium (Gd)-based contrast agent injection were calculated from images obtained with a multi-echo turbo spin-echo sequence and multi-echo gradient-echo sequence to obtain microvascular index maps of blood volume fraction (BVf), mean vessel diameter (mVD), vessel size index (VSI), mean vessel density (Q), and microvessel-weighted imaging (MvWI). Two-sample t-test was used to compare those values between the two groups. Correlation analysis was performed to evaluate the relationship between those values and age.

Results: BVfs at the corpus callosum and at the thalamus were significantly increased in the AD group (P=0.024 and P=0.005, respectively). BVf at the gray matter (P=0.020) and white matter area (P=0.012) were also significantly increased in the AD group compared with the CN group. MvWIs at the hippocampus and parahippocampal gyrus were significantly increased in the AD group compared with the CN group (P=0.020 and P=0.006, respectively). Voxel-based analysis showed both mVD and VSI were significantly decreased at the prefrontal lobe in the AD group. Q were not significant difference between CN and AD groups. MvWI were significantly positively correlated with age.

Conclusions: Microvascular index was a useful non-invasive method to evaluate microvascular morphology alteration. The microvascular morphology of AD was manifested as increasing BVf and microvessel-weighted.

Keywords: 3T magnetic resonance imaging (3T MRI); Alzheimer’s disease (AD); Gd-based contrast agent; Microvascular index.