Mira M Liu, Jonathan Dyke, Thomas Gladytz, Jonas Jasse, Ian Bolger, Sergio Calle, Swathi Pavaluri, Tanner Crews, Surya Seshan, Steven Salvatore, Isaac Stillman, Thangamani Muthukumar, Bachir Taouli, Samira Farouk, Sara Lewis, Octavia Bane
{"title":"Quantification of Multi-Compartment Flow with Spectral Diffusion MRI.","authors":"Mira M Liu, Jonathan Dyke, Thomas Gladytz, Jonas Jasse, Ian Bolger, Sergio Calle, Swathi Pavaluri, Tanner Crews, Surya Seshan, Steven Salvatore, Isaac Stillman, Thangamani Muthukumar, Bachir Taouli, Samira Farouk, Sara Lewis, Octavia Bane","doi":"","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Estimation of multi-compartment intravoxel 'flow' in <i>fD</i> in ml/100g/min with multi-b-value diffusion weighted imaging and a multi-Gaussian model in the kidneys.</p><p><strong>Theory and methods: </strong>A multi-Gaussian model of intravoxel flow using water transport time to quantify <math><mi>f</mi> <mi>D</mi></math> (ml/100g/min) is presented and simulated. Multi-compartment anisotropic DWI signal is simulated with Rician noise and SNR=50 and analyzed with a rigid bi-exponential, a rigid tri-exponential and diffusion spectrum imaging model of intravoxel incoherent motion (spectral diffusion) to study extraction of multi-compartment flow. The regularization parameter for spectral diffusion is varied to study the impact on the resulting spectrum and computation speed. The application is demonstrated in a two-center study of 54 kidney allografts with 9 b-value advanced DWI that were split by function (CKD-EPI 2021 eGFR<45ml/min/1.73m<sup>2</sup>) and fibrosis (Banff 2017 interstitial fibrosis and tubular atrophy score 0-6) to demonstrate multi-compartment flow of various kidney pathologies.</p><p><strong>Results: </strong>Simulation of anisotropic multi-compartment flow from spectral diffusion demonstrated strong correlation to truth for both three-compartment anisotropic diffusion ( <math><mi>y</mi> <mo>=</mo> <mn>1.08</mn> <mi>x</mi> <mo>+</mo> <mn>0.1</mn> <mo>,</mo> <mspace></mspace> <msup><mrow><mi>R</mi></mrow> <mrow><mn>2</mn></mrow> </msup> <mo>=</mo> <mspace></mspace> <mn>0.71</mn></math> ) and two-compartment anisotropic diffusion ( <math><mi>y</mi> <mo>=</mo> <mn>0.91</mn> <mo>+</mo> <mn>0.6</mn> <mo>,</mo> <mspace></mspace> <msup><mrow><mi>R</mi></mrow> <mrow><mn>2</mn></mrow> </msup> <mo>=</mo> <mn>0.74</mn></math> ), outperforming rigid models in cases of variable compartment number. Use of a fixed regularization parameter set to <math><mi>λ</mi> <mo>=</mo> <mn>0.1</mn></math> increased computation up to 208-fold and agreed with voxel-wise cross-validated regularization (concordance correlation coefficient=0.99). Spectral diffusion of renal allografts showed decreasing trend of tubular and vascular flow with higher levels of fibrosis, and significant increase in tissue parenchyma flow (f-stat=3.86, p=0.02). Tubular <math><mi>f</mi> <mi>D</mi></math> was significantly decreased in allografts with impaired function (eGFR<45ml/min/1.73m<sup>2</sup>)(Mann-Whitney U t-stat=-2.14, p=0.04).</p><p><strong>Conclusions: </strong>Quantitative multi-compartment intravoxel 'flow' can be estimated in ml/100g/min with <math><mi>f</mi> <mi>D</mi></math> from multi-Gaussian diffusion with water transport time, even with moderate anisotropy such as in kidneys. The use of spectral diffusion with a multi-Gaussian model and a fixed regularization parameter is particularly promising in organs such as the kidney with variable numbers of physiologic compartments.</p>","PeriodicalId":93888,"journal":{"name":"ArXiv","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11343220/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ArXiv","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: Estimation of multi-compartment intravoxel 'flow' in fD in ml/100g/min with multi-b-value diffusion weighted imaging and a multi-Gaussian model in the kidneys.
Theory and methods: A multi-Gaussian model of intravoxel flow using water transport time to quantify (ml/100g/min) is presented and simulated. Multi-compartment anisotropic DWI signal is simulated with Rician noise and SNR=50 and analyzed with a rigid bi-exponential, a rigid tri-exponential and diffusion spectrum imaging model of intravoxel incoherent motion (spectral diffusion) to study extraction of multi-compartment flow. The regularization parameter for spectral diffusion is varied to study the impact on the resulting spectrum and computation speed. The application is demonstrated in a two-center study of 54 kidney allografts with 9 b-value advanced DWI that were split by function (CKD-EPI 2021 eGFR<45ml/min/1.73m2) and fibrosis (Banff 2017 interstitial fibrosis and tubular atrophy score 0-6) to demonstrate multi-compartment flow of various kidney pathologies.
Results: Simulation of anisotropic multi-compartment flow from spectral diffusion demonstrated strong correlation to truth for both three-compartment anisotropic diffusion ( ) and two-compartment anisotropic diffusion ( ), outperforming rigid models in cases of variable compartment number. Use of a fixed regularization parameter set to increased computation up to 208-fold and agreed with voxel-wise cross-validated regularization (concordance correlation coefficient=0.99). Spectral diffusion of renal allografts showed decreasing trend of tubular and vascular flow with higher levels of fibrosis, and significant increase in tissue parenchyma flow (f-stat=3.86, p=0.02). Tubular was significantly decreased in allografts with impaired function (eGFR<45ml/min/1.73m2)(Mann-Whitney U t-stat=-2.14, p=0.04).
Conclusions: Quantitative multi-compartment intravoxel 'flow' can be estimated in ml/100g/min with from multi-Gaussian diffusion with water transport time, even with moderate anisotropy such as in kidneys. The use of spectral diffusion with a multi-Gaussian model and a fixed regularization parameter is particularly promising in organs such as the kidney with variable numbers of physiologic compartments.