[CLOSED] BOLD review


Aim

This task force delivered a systematic review and statement paper providing an overview of the technique and pitfalls of BOLD-MRI, as well as a summary of all renal BOLD-MRI studies performed in humans so far, identifying gaps in knowledge and providing recommendations about patient preparation, image acquisition and analysis and possible clinical applications.

Deliverable: review paper

Pruijm M, Mendichovszky IA, Liss P, Van der Niepen P, Textor SC, Lerman LO, Krediet CTP, Caroli A, Burnier M, Prasad PV
Renal blood oxygenation level-dependent (BOLD) MRI to measure renal tissue oxygenation: a statement paper and systematic review
Nephrology Dialysis Transplantation, Volume 33, Issue suppl_2, 1 September 2018, Pages ii22–ii28, https://doi.org/10.1093/ndt/gfy243

Abstract. Tissue hypoxia plays a key role in the development and progression of many kidney diseases. Blood oxygenation-level dependent MRI (BOLD-MRI) is the most promising imaging technique to monitor renal tissue oxygenation in humans. BOLD MRI measures renal tissue deoxyhemoglobin levels voxel by voxel. Increases in its outcome measure R2* (transverse relaxation rate expressed as sec-1) correspond to higher deoxyhemoglobin concentrations and suggest lower oxygenation, whereas decreases in R2* indicate higher oxygenation. BOLD-MRI has been validated against micropuncture techniques in animals. Its reproducibility has been demonstrated in humans, provided that physiological and technical conditions are standardized. BOLD-MRI has shown that patients suffering from chronic kidney disease (CKD) or kidneys with severe renal artery stenosis have lower tissue oxygenation than controls.Additionally, CKD patients with the lowest cortical oxygenation have the worst renal outcome. Finally, BOLD-MRI has been used to assess the influence of drugs on renal tissue oxygenation, and may offer the possibility to identify drugs with nephroprotective or nephrotoxic effects at an early stage. Unfortunately, different methods are used to prepare patients, acquire MRI data and analyze the BOLD images. International efforts such as the COST action PARENCHIMA are aiming to harmonize this process, to facilitate the introduction of this technique in clinical practice in the near future.This article represents an extensive overview of the studies performed in this field, summarizes the strengths and weaknesses of the technique, provides recommendations about patient preparation, image acquisition and analysis, and suggests clinical applications and future developments.