A two-pool model to describe the IVIM cerebral perfusion. Issue 8 (August 2017)

• Record Type: Journal Article
• Authors: Fournet, Gabrielle; Li, Jing-Rebecca; Cerjanic, Alex M; Sutton, Bradley P; Ciobanu, Luisa; Le Bihan, Denis
• Is Part Of: Journal of cerebral blood flow & metabolism. Volume 37:Issue 8(2017)
• Page Start: 2987
• Page End: 3000
• Publication Date: 2017-08
• Subjects: Cerebral blood flow -- intravoxel incoherent motion -- magnetic resonance imaging -- microcirculation -- perfusion; Cerebral circulation -- Periodicals; Brain -- Metabolism -- Periodicals; Brain -- Blood-vessels -- Periodicals; Cerebrovascular disease -- Periodicals; 612.824
• DOI: 10.1177/0271678X16681310
• Languages: English
• ISSNs: 0271-678X

Abstract

IntraVoxel Incoherent Motion (IVIM) is a magnetic resonance imaging (MRI) technique capable of measuring perfusion-related parameters. In this manuscript, we show that the mono-exponential model commonly used to process IVIM data might be challenged, especially at short diffusion times. Eleven rat datasets were acquired at 7T using a diffusion-weighted pulsed gradient spin echo sequence with b-values ranging from 7 to 2500 s/mm 2 at three diffusion times. The IVIM signals, obtained by removing the diffusion component from the raw MR signal, were fitted to the standard mono-exponential model, a bi-exponential model and the Kennan model. The Akaike information criterion used to find the best model to fit the data demonstrates that, at short diffusion times, the bi-exponential IVIM model is most appropriate. The results obtained by comparing the experimental data to a dictionary of numerical simulations of the IVIM signal in microvascular networks support the hypothesis that such a bi-exponential behavior can be explained by considering the contribution of two vascular pools: capillaries and somewhat larger vessels.