Noncontrast Functional MRI of the Kidneys

Abstract

Functional magnetic resonance imaging (fMRI) techniques enable noninvasive assessment of renal function. Diffusion-weighted imaging, diffusion tensor imaging, blood oxygen level-dependent MRI, magnetic resonance elastography, and arterial spin labeling are some of the emerging techniques that have potential to investigate renal function without the use of exogenous gadolinium contrast. This article discusses the principles of these techniques, as well as their possible applications and limitations. This will introduce the readers to these novel imaging tools, which appear to have promising futures.

Time course study on the effects of iodinated contrast medium on intrarenal water transport function using diffusion‐weighted MRI

“…Although DW-MRI is already routinely used and is valuable for the detection of acute vascular lesions in patients with stroke symptoms, its application in abdominal organs is challenging due to respiration, peristalsis and magnetic susceptibility artifacts (15,16). Only in recent years it reveals an appreciable progress in DW-MRI of the kidneys (13,17,18), but to the best of our knowledge, little work has been done to evaluate the renal function sequentially under the insult produced by radiographic contrast agents using a noninvasive DW-MR technique. In this study, as with available preparation to limit the respiratory movements, the DW-MR images were almost free of motion artifacts.…”

Evaluation of renal oxygenation change under the influence of carbogen breathing using a dynamic R2, R2′ and R2* quantification approach

“…Absolute measurement of R 2 / R 2 ′/ R 2 * is less reliable than the relative changes observed in response to various physiological challenges; thus, the evaluation of Δ R 2 /Δ R 2 ′/Δ R 2 * before and after a challenge may be more helpful . So far, BOLD imaging during the respiratory challenge has been shown to indicate changes in vascular density, vessel reactivity and tissue perfusion, and enables the analysis of alterations in vascular architecture, functionality and maturation in intact and malignant tissues .…”

Contrast Media Use in Pediatrics: Safety Issues

“…Gadolinium-based contrast media should only be used in children when the clinical problem cannot be solved using other imaging methods, such as ultrasonography, or unenhanced MRI techniques, such as MR angiography or perfusion imaging based on Time-of-Flight or arterial spin labeling techniques (Mannelli et al 2012;Penfield and Reilly 2008). 2.…”