Magnetic resonance imaging during warm ex vivo kidney perfusion

Abstract

Background The shortage of donor organs for transplantation remains a worldwide problem. The utilization of suboptimal deceased donors enlarges the pool of potential organs, yet consequently, clinicians face the difficult decision of whether these sub‐optimal organs are of sufficient quality for transplantation. Novel technologies could play a pivotal role in making pre‐transplant organ assessment more objective and reliable. Methods Ex vivo normothermic machine perfusion (NMP) at temperatures around 35–37°C allows organ quality assessment in a near‐physiological environment. Advanced magnetic resonance imaging (MRI) techniques convey unique information about an organ's structural and functional integrity. The concept of applying magnetic resonance imaging during renal normothermic machine perfusion is novel in both renal and radiological research and we have developed the first MRI‐compatible NMP setup for human‐sized kidneys. Results We were able to obtain a detailed and real‐time view of ongoing processes inside renal grafts during ex vivo perfusion. This new technique can visualize structural abnormalities, quantify regional flow distribution, renal metabolism, and local oxygen availability, and track the distribution of ex vivo administered cellular therapy. Conclusion This platform allows for advanced pre‐transplant organ assessment, provides a new realistic tool for studies into renal physiology and metabolism, and may facilitate therapeutic tracing of pharmacological and cellular interventions to an isolated kidney.

Renal cortex microperfusion evaluated by laser speckle contrast imaging in an ex vivo perfused kidney model—A proof‐of‐concept study

“…Even though MRI has shown promise for measuring renal physiological parameters during NMP, it is practical challenging, and therefore, new methods should be introduced. 27 We demonstrated that LSCI has potential for both renal cortex microperfusion visualization and quantification in human-sized kidneys. Thus, although further validation studies are needed LSCI is a promising technique for assessment of kidney viability during NMP.…”

“…To utilize NMP as a platform for continuous organ monitoring, there is a need for real time, non‐contacting, rapid, and sensitive technology suitable for real time assessment of renal overall vitality. Even though MRI has shown promise for measuring renal physiological parameters during NMP, it is practical challenging, and therefore, new methods should be introduced 27 . We demonstrated that LSCI has potential for both renal cortex microperfusion visualization and quantification in human‐sized kidneys.…”

Gépi perfúzió a vesetranszplantációban

“…A fenti módszereken kívül számos egyéb lehetőség is felmerült, amelyek közül megemlítendő a képalkotó di agnosztika használata. Az első tanulmányok az MR spektroszkópia alkalmazásáról szóltak [54], legújabban pedig Schutter és mtsai [56] mutatták be eredményeiket ÖSSZEFOGLALÓ KÖZLEMÉNY sertés és humán vesék NMP alatti MRvizsgálatáról, amelynek során a szerkezeti analízisen kívül elemezték a regionális áramlási eloszlást, a metabolizmust, illetve kö vették a perfúzió alatt adott őssejtek útvonalát.…”

Oxidation of hyperpolarized [1‐13C]pyruvate in isolated rat kidneys

“…25,26 Isolated perfused rat kidneys have been used in metabolism studies [27][28][29][30] for many decades but assessment of real-time metabolism by HP 13 C MR has only recently been reported in isolated perfused rat kidneys 31 and porcine kidneys. 32,33 However, HP 13 C MR studies are commonly performed in isolated perfused hearts [34][35][36] and livers. 37,38 We aimed to establish isolated perfused rat kidneys as an experimental model for evaluating the metabolism of HP 13 C substrates.…”

“…These preparations enable precise control over substrate compositions and concentrations, as well as pharmacological and physiological interventions 25,26 . Isolated perfused rat kidneys have been used in metabolism studies 27–30 for many decades but assessment of real‐time metabolism by HP 13 C MR has only recently been reported in isolated perfused rat kidneys 31 and porcine kidneys 32,33 . However, HP 13 C MR studies are commonly performed in isolated perfused hearts 34–36 and livers 37,38 .…”