Detection of thrombus size and protein content by ex vivo magnetization transfer and diffusion weighted MRI

Journal of Cardiovascular Magnetic Resonance

Research

Nick Giordano¹  James A Hamilton²  Alkystis Phinikaridou³  Ye Qiao⁴ 

[1] Department of Biomedical Engineering, Boston University, Boston, MA, USA;Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, USA;Department of Biomedical Engineering, Boston University, Boston, MA, USA;Division of Imaging Sciences and Biomedical Engineering, King’s College London, London, UK;Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, USA;The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Hospital, Baltimore, MD, USA;

关键词: Apparent Diffusion Coefficient;    Diffusion Weighted Image;    Magnetization Transfer;    Magnetic Resonance Imaging Sequence;    Diffusion Weighting;   

DOI  :  10.1186/1532-429X-14-45

 received in 2012-04-28, accepted in 2012-06-06,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundTo utilize a rabbit model of plaque disruption to assess the accuracy of different magnetic resonance sequences [T1-weighted (T1W), T2-weighted (T2W), magnetization transfer (MT) and diffusion weighting (DW)] at 11.7 T for the ex vivo detection of size and composition of thrombus associated with disrupted plaques.MethodsAtherosclerosis was induced in the aorta of male New Zealand White rabbits (n = 17) by endothelial denudation and high-cholesterol diet. Subsequently, plaque disruption was induced by pharmacological triggering. Segments of infra-renal aorta were excised fixed in formalin and examined by ex vivo magnetic resonance imaging (MRI) at 11.7 T and histology.ResultsMRI at 11.7 T showed that: (i) magnetization transfer contrast (MTC) and diffusion weighted images (DWI) detected thrombus with higher sensitivity compared to T1W and T2W images [sensitivity: MTC = 88.2%, DWI = 76.5%, T1W = 66.6% and T2W = 43.7%, P < 0.001]. Similarly, the contrast-to-noise (CNR) between the thrombus and the underlying plaque was superior on the MTC and DWI images [CNR: MTC = 8.5 ± 1.1, DWI = 6.0 ± 0.8, T1W = 1.8 ± 0.5, T2W = 3.0 ± 1.0, P < 0.001]; (ii) MTC and DWI provided a more accurate detection of thrombus area with histology as the gold-standard [underestimation of 6% (MTC) and 17.6% (DWI) compared to an overestimation of thrombus area of 53.7% and 46.4% on T1W and T2W images, respectively]; (iii) the percent magnetization transfer rate (MTR) correlated with the fibrin (r = 0.73, P = 0.003) and collagen (r = 0.9, P = 0.004) content of the thrombus.ConclusionsThe conspicuity of the thrombus was increased on MTC and DW compared to T1W and T2W images. Changes in the %MTR and apparent diffusion coefficient can be used to identify the organization stage of the thrombus.

【 授权许可】

CC BY   
© Phinikaridou et al.; licensee BioMed Central Ltd. 2012