Using intravoxel incoherent motion MR imaging to study the renal pathophysiological process of contrast-induced acute kidney injury in rats: Comparison with conventional DWI and arterial spin labelling

Abstract

• IVIM analysis permits separate quantification of diffusion and perfusion. • IVIM can provide useful biomarkers ifor changes in renal pathophysiology. • IVIM can be useful for monitoring progress in renal pathophysiology undergoing CIAKI.

Severe bilateral ischemic-reperfusion renal injury: hyperacute and acute changes in apparent diffusion coefficient, T1, and T2 mapping with immunohistochemical correlations

“…Diffusion-weighted imaging and ADC measurement can offer quantitative information on the microstructure and water motion on a molecular level 10, 13, 14, 18, 19 . Although ADC measurement with conventional monoexponential model delivers signals from both capillary perfusion and extracellular diffusion, measurement of ADC with b -values > 400 sec/mm 2 primarily referring to molecular water diffusion for blood perfusion signals are substantially suppressed by the large diffusion gradients 13, 14, 26, 27 .…”

“…Although ADC measurement with conventional monoexponential model delivers signals from both capillary perfusion and extracellular diffusion, measurement of ADC with b -values > 400 sec/mm 2 primarily referring to molecular water diffusion for blood perfusion signals are substantially suppressed by the large diffusion gradients 13, 14, 26, 27 . In the present study, 7 b-valves (0, 50, 150, 450, 650, 850, and 1000 sec/mm 2 ) were used for calculating ADC avg , and the gradients were applied in three orthogonal directions and subsequently averaged so that the effects of diffusion anisotropy could be eliminated 26, 27 .…”

“…Liang et al . advocated that intravoxel incoherent motion could further permit separate quantification of diffusion and perfusion for evaluating of renal pathophysiological process in contrast-induced AKI 14 . Pohlmann et al .…”

Intravoxel incoherent motion MRI as a means to measure in vivo perfusion: A review of the evidence

“…Studies comparing IVIM fD * and ASL blood flow are sparse and inconclusive. In the rat kidney cortex Liang et al found an excellent correlation between fD * and ASL blood flow (0.803, p < 0.0001), while in stroke patients Yao et al found a weak correlation between fD * and ASL cerebral blood flow ( r = 0.39, p = 0.0002), and in the brain of healthy volunteers Wu et al found no correlation between these two parameters.…”

Renal Functional MRI and Its Application

“…IVIM is a four‐parameter model that assumes two compartments with pure water diffusion and directional flow. Variations in the diffusion and perfusion parameters over time may provide a means for uncovering early pathophysiological changes in acute renal injury after transplantation or contrast injection . Although perfusion parameters can be acquired from IVIM models, they are weakly correlated with the parameters derived from DCE‐MRI, such as the GFR and the mean transit time (MTT).…”