Quasi-diffusion magnetic resonance imaging (QDI): A fast, high b-value diffusion imaging technique

NeuroImage

卷:211

Catherine A. Spilling¹  Richard L. Magin²  Jeremy D. Isaacs³  Jeremy Madigan⁴  Matt G. Hall⁵  Philip Rich⁵  Franklyn A. Howe⁶  Carson Ingo⁷  Timothy L. Jones⁷  Thomas R. Barrick⁷ 

[1] Corresponding author. Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George’s, University of London, Cranmer Terrace, London, SW17 0RE, UK.;

[2] Department of Neurology, St George’s University Hospitals NHS Foundation Trust, London, UK;

[3] Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, USA;

[4] Department of Neurology, Northwestern University, Chicago, USA;

[5] Department of Neuroradiology, St George’s University Hospitals NHS Foundation Trust, London, UK;

[6] Department of Neurosurgery, St George’s University Hospitals NHS Foundation Trust, London, UK;

[7] Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George’s, University of London, London, UK;

关键词: Magnetic resonance imaging;    Brain;    Continuous time random walk;    Non-Gaussian diffusion;    Diffusional kurtosis imaging;    High b-value;   

DOI  :  

来源: DOAJ

【 摘 要 】

To enable application of non-Gaussian diffusion magnetic resonance imaging (dMRI) techniques in large-scale clinical trials and facilitate translation to clinical practice there is a requirement for fast, high contrast, techniques that are sensitive to changes in tissue structure which provide diagnostic signatures at the early stages of disease. Here we describe a new way to compress the acquisition of multi-shell b-value diffusion data, Quasi-Diffusion MRI (QDI), which provides a probe of subvoxel tissue complexity using short acquisition times (1–4 ​min). We also describe a coherent framework for multi-directional diffusion gradient acquisition and data processing that allows computation of rotationally invariant quasi-diffusion tensor imaging (QDTI) maps.QDI is a quantitative technique that is based on a special case of the Continuous Time Random Walk model of diffusion dynamics and assumes the presence of non-Gaussian diffusion properties within tissue microstructure. QDI parameterises the diffusion signal attenuation according to the rate of decay (i.e. diffusion coefficient, D in mm2 s−1) and the shape of the power law tail (i.e. the fractional exponent, α). QDI provides analogous tissue contrast to Diffusional Kurtosis Imaging (DKI) by calculation of normalised entropy of the parameterised diffusion signal decay curve, Hn, but does so without the limitations of a maximum b-value.We show that QDI generates images with superior tissue contrast to conventional diffusion imaging within clinically acceptable acquisition times of between 84 and 228 ​s. We show that QDI provides clinically meaningful images in cerebral small vessel disease and brain tumour case studies. Our initial findings suggest that QDI may be added to routine conventional dMRI acquisitions allowing simple application in clinical trials and translation to the clinical arena.

【 授权许可】

Unknown