Purpose: Assessing renal perfusion in-vivo is challenging and quantitativeinformation regarding renal hemodynamics is hardly incorporated in medicaldecision-making while abnormal renal hemodynamics... Show morePurpose: Assessing renal perfusion in-vivo is challenging and quantitativeinformation regarding renal hemodynamics is hardly incorporated in medicaldecision-making while abnormal renal hemodynamics might play a crucial rolein the onset and progression of renal disease. Combining physiological stimuliwith rubidium-82 positron emission tomography/computed tomography (82 RbPET/CT) offers opportunities to test the kidney perfusion under various condi-tions. The aim of this study is: (1) to investigate the application of a one-tissuecompartment model for measuring renal hemodynamics with dynamic 82 RbPET/CT imaging, and (2) to evaluate whether dynamic PET/CT is sensitiveto detect differences in renal hemodynamics in stress conditions compared toresting state.Methods: A one-tissue compartment model for the kidney was applied to car-diac 82 Rb PET/CT scans that were obtained for ischemia detection as part ofclinical care. Retrospective data, collected from 17 patients undergoing dynamicmyocardial 82 Rb PET/CT imaging in rest, were used to evaluate various CT-based volumes of interest (VOIs) of the kidney. Subsequently, retrospectivedata, collected from 10 patients (five impaired kidney functions and five controls)undergoing dynamic myocardial 82 Rb PET/CT imaging, were used to evaluateimage-derived input functions (IDIFs), PET-based VOIs of the kidney, extractionfractions, and whether dynamic 82 Rb PET/CT can measure renal hemodynam-ics differences using the renal blood flow (RBF) values in rest and after exposureto adenosine pharmacological stress.Results: The delivery rate (K1 ) values showed no significant (p = 0.14) differ-ence between the mean standard deviation (SD) K1 values using one CT-basedVOI and the use of two, three, and four CT-based VOIs, respectively 2.01(0.32),1.90(0.40), 1.93(0.39), and 1.94(0.40) mL/min/mL. The ratio between RBF inrest and RBF in pharmacological stress for the controls were overall significantlylower compared to the impaired kidney function group for both PET-based delin-eation methods (region growing and iso-contouring), with the smallest medianinterquartile range (IQR) of 0.40(0.28–0.66) and 0.96(0.62–1.15), respectively(p < 0.05). The K1 of the impaired kidney function group were close to1.0 mL/min/mL. Show less
Boer, A. de; Villa, G.; Bane, O.; Bock, M.; Cox, E.F.; Dekkers, I.A.; ... ; Caroli, A. 2020
Background Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However... Show moreBackground Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PC-MRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PC-MRI as a clinically useful tool.Purpose To build technical recommendations for the acquisition, processing, and analysis of renal 2D PC-MRI data in human subjects to promote standardization of renal blood flow measurements and facilitate the comparability of results across scanners and in multicenter clinical studies.Study Type Systematic consensus process using a modified Delphi method.Population Not applicable.Sequence Field/Strength Renal fast gradient echo-based 2D PC-MRI.Assessment An international panel of 27 experts from Europe, the USA, Australia, and Japan with 6 (interquartile range 4-10) years of experience in 2D PC-MRI formulated consensus statements on renal 2D PC-MRI in two rounds of surveys. Starting from a recently published systematic review article, literature-based and data-driven statements regarding patient preparation, hardware, acquisition protocol, analysis steps, and data reporting were formulated.Statistical Tests Consensus was defined as >= 75% unanimity in response, and a clear preference was defined as 60-74% agreement among the experts.Results Among 60 statements, 57 (95%) achieved consensus after the second-round survey, while the remaining three showed a clear preference. Consensus statements resulted in specific recommendations for subject preparation, 2D renal PC-MRI data acquisition, processing, and reporting.Data Conclusion These recommendations might promote a widespread adoption of renal PC-MRI, and may help foster the set-up of multicenter studies aimed at defining reference values and building larger and more definitive evidence, and will facilitate clinical translation of PC-MRI.Level of Evidence 1Technical Efficacy Stage 1 Show less
