Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging

doi:10.1002/mp.16551

CORC > 自动化研究所 > 中国科学院自动化研究所 > 中国科学院分子影像重点实验室

	Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging
	Feng, Xin 5; Jia, Guang 1; Peng, Jiaming ; Huang, Liyu 4; Liang, Xiaofeng 1; Zhang, Haoran 3; Liu, Yanjun 3; Zhang, Bo 3; Zhang, Yifei 1; Sun, Meng 1
刊名	MEDICAL PHYSICS
	2023-06-09
页码	13
关键词	magnetic particle imaging magnetic nanoparticles relaxation time viscosity mapping
ISSN号	0094-2405
DOI	10.1002/mp.16551
通讯作者	Jia, Guang(gjia@xidian.edu.cn) ; Li, Tanping(tpli@xidian.edu.cn) ; Tian, Jie(tian@ieee.org)
英文摘要	BackgroundMagnetic nanoparticles (MNPs) are used as tracers without ionizing radiation in vascular imaging, molecular imaging, and neuroimaging. The relaxation mechanisms of magnetization in response to excitation magnetic fields are important features of MNPs. The basic relaxation mechanisms include internal rotation (Neel relaxation) and external physical rotation (Brownian relaxation). Accurate measurement of these relaxation times may provide high sensitivity for predicting MNP types and viscosity-based hydrodynamic states. It is challenging to separately measure the Neel and Brownian relaxation components using sinusoidal excitation in conventional MPI. PurposeWe developed a multi-exponential relaxation spectral analysis method to separately measure the Neel and Brownian relaxation times in the magnetization recovery process in pulsed vascular MPI. MethodsSynomag-D samples with different viscosities were excited using pulsed excitation in a trapezoidal-waveform relaxometer. The samples were excited at different field amplitudes ranging from 0.5 to 10 mT at intervals of 0.5 mT. The inverse Laplace transform-based spectral analysis of the relaxation-induced decay signal in the field-flat phase was performed by using PDCO, a primal-dual interior method for convex objectives. Neel and Brownian relaxation peaks were elucidated and measured on samples with various glycerol and gelatin concentrations. The sensitivity of viscosity prediction of the decoupled relaxation times was evaluated. A digital vascular phantom was designed to mimic a plaque with viscous MNPs and a catheter with immobilized MNPs. Spectral imaging of the digital vascular phantom was simulated by combining a field-free point with homogeneous pulsed excitation. The relationship between the Brownian relaxation time from different tissues and the number of periods for signal averages was evaluated for a scan time estimation in the simulation. ResultsThe relaxation spectra of synomag-D samples with different viscosity levels exhibited two relaxation time peaks. The Brownian relaxation time had a positive linear relationship with the viscosity in the range 0.9 to 3.2 mPa center dot s. When the viscosity was >3.2 mPa center dot s, the Brownian relaxation time saturated and did not change with increasing viscosity. The Neel relaxation time decreased slightly with an increase in the viscosity. The Neel relaxation time exhibited a similar saturation effect when the viscosity level was >3.2 mPa center dot s for all field amplitudes. The sensitivity of the Brownian relaxation time increased with the field amplitude and was maximized at approximately 4.5 mT. The plaque and catheter regions were differentiated from the vessel region in the simulated Brownian relaxation time map. The simulation results show that the Neel relaxation time was 8.33 +/- 0.09 mu s in the plaque region, 8.30 +/- 0.08 mu s in the catheter region, and 8.46 +/- 0.11 mu s in the vessel region. The Brownian relaxation time was 36.60 +/- 2.31 mu s in the plaque region, 30.17 +/- 1.24 mu s in the catheter region, and 31.21 +/- 1.53 mu s in the vessel region. If we used 20 excitation periods for image acquisition in the simulation, the total scan time of the digital phantom was approximately 100 s. ConclusionQuantitative assessment of the Neel and Brownian relaxation times through inverse Laplace transform-based spectral analysis in pulsed excitation, highlighting their potential for use in multi-contrast vascular MPI.
资助项目	National Key Research and Development Program of China[2022YFB3203800] ; National Key Research and Development Program of China[2017YFA0700401] ; National Natural Science Foundation of China[62027901] ; National Natural Science Foundation of China[11974267] ; National Key Scientific Instrument and Equipment Development Projects of China[82227802]
WOS关键词	INVERSION ; RESOLUTION ; VISCOSITY
WOS研究方向	Radiology, Nuclear Medicine & Medical Imaging
语种	英语
出版者	WILEY
WOS记录号	WOS:001004545200001
资助机构	National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Key Scientific Instrument and Equipment Development Projects of China
内容类型	期刊论文
源URL	[http://ir.ia.ac.cn/handle/173211/53474]
专题	自动化研究所_中国科学院分子影像重点实验室
通讯作者	Jia, Guang; Li, Tanping; Tian, Jie
作者单位	1.Xidian Univ, Sch Comp Sci & Technol, 2 South Taibai Rd, Xian 710071, Shaanxi, Peoples R China 2.Lanzhou Univ, Sch Phys Sci & Technol, Lanzhou, Gansu, Peoples R China 3.Beihang Univ, Sch Biol Sci & Med Engn, Beijing, Peoples R China 4.Xidian Univ, Sch Life Sci & Technol, Xian, Shaanxi, Peoples R China 5.Chinese Acad Sci, Inst Automat, CAS Key Lab Mol Imaging, Beijing Key Lab Mol Imaging,State Key Lab Manageme, Beijing 100190, Peoples R China 6.Xidian Univ, Sch Phys, Xian 710071, Shaanxi, Peoples R China
推荐引用方式 GB/T 7714	Feng, Xin,Jia, Guang,Peng, Jiaming,et al. Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging[J]. MEDICAL PHYSICS,2023:13.
APA	Feng, Xin.,Jia, Guang.,Peng, Jiaming.,Huang, Liyu.,Liang, Xiaofeng.,...&Tian, Jie.(2023).Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging.MEDICAL PHYSICS,13.
MLA	Feng, Xin,et al."Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging".MEDICAL PHYSICS (2023):13.