Non-invasive assessment of renal function by dynamic imaging

Abstract Background and Aims Renal ischemia-reperfusion can lead to acute kidney injury (AKI), increasing the risk of developing chronic kidney disease (CKD) through inflammation and vascular lesions. Serum urea or creatinine level routinely used as diagnostic indices of renal function are always delayed from the onset of the disease. Therefore, we currently lack reliable markers to early detect AKI, especially in animals. We aimed to show that non-invasive renal contrast-enhanced ultrasound (CEUS) could be a reliable tool to assess early and chronic changes of renal perfusion after renal ischemia-reperfusion. Method Male C57BL6 mice underwent 15 minutes of unilateral renal ischemia by clamping of the left renal vascular pedicle (n = 7), or a sham procedure (n = 3), under inhaled general anesthesia by Sevoflurane. A renal ultrasound was performed on the left ischemic kidney at baseline 1 week before the surgery, then, 20 minutes after reperfusion to assess early modifications of renal perfusion, and 1 month after reperfusion to follow chronic modifications. CEUS was performed in supine position by using a high-resolution ultrasonic imaging system (VEVO 3100 Fujifilm Visualsonics, Toronto, Canada) with a MX550D probe fixed in place with an iron support, ensuring the constant imaging plane throughout acquisition. First, a continuous infusion of microbubbles (VS-11913, Fujifilm Visualsonics, Toronto, Canada) was done through the tail vein, then a high mechanical index burst was given to destroy microbubbles when the contrast enhancement had reached a steady state, and finally, low mechanical-index imaging mode was used until, and 30 sec after the contrast agent concentration reached the plateau. Images were recorded and were analyzed using the “destruction-replenishment” fitting model of the Vevo LAB software (Fujifilm Visualsonics, Toronto, Canada). Renal perfusion was estimated by the total renal Blood Volume (rBV) parameter and was expressed as percentage of the baseline value for each animal. Renal function was also assessed by serum urea concentration 1 month after reperfusion, and the long axis lengths of both the kidneys were measured ex vivo after the mice were euthanized. Results Renal perfusion of the ischemic kidney measured by CEUS was significantly decreased as soon as 20 minutes of reperfusion compared to baseline (median 28,8% of baseline value; interquartiles [20,1 – 69,8%]). 1 month after reperfusion, renal perfusion recovered partially but was still significantly decreased compared to baseline (median 79,9% of baseline value; interquartiles [52,8 – 99,9%]) (Figure A). In sham operated mice, renal perfusion did not differ from baseline at 20 minutes or 1 month (p > 0.05). The renal function, assessed by serum urea, was mildly but significantly impaired 1 month after ischemia-reperfusion compared with sham (median serum urea 9,8 vs. 7,6 mmol/L) (p = 0.02), and this was consistent with the observed kidney atrophy in the ischemic group when compared to the contralateral kidney (median long axis length 7,5 vs 10,8 mm) (p = 0.03). Moreover, the decrease of renal perfusion 20 minutes after reperfusion was significantly correlated with the impairment of renal perfusion 1 month after reperfusion (Pearson r = 0.836, p = 0.005) and with the serum urea level at 1 month (Pearson r = -0.710, p = 0.03) (Figure B-C). Conclusion Renal CEUS was able to detect early impairment of renal perfusion as soon as 20 minutes after 15 minutes of renal ischemia in mice, and perfusion was still decreased 1 month after reperfusion, compared to baseline. This early impairment of perfusion was correlated with the chronic decrease of renal perfusion and renal function 1 month after reperfusion. This was also associated with a significant kidney atrophy. CEUS is an interesting non-invasive tool to assess renal lesions dynamically after ischemia-reperfusion.

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Non-invasive urinary biomarkers of renal function in sickle cell disease: an overview

Annals of Hematology ◽

10.1007/s00277-019-03813-9 ◽

2019 ◽

Vol 98 (12) ◽

pp. 2653-2660

Author(s):

Marília Rocha Laurentino ◽

Sérgio Luiz Arruda Parente Filho ◽

Lívia Leal Chagas Parente ◽

Geraldo Bezerra da Silva Júnior ◽

Elizabeth De Francesco Daher ◽

...

Keyword(s):

Renal Function ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Urinary Biomarkers ◽

Cell Disease ◽

Non Invasive

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Aluminium Bone Deposits in Normal Renal Function Patients after Long-Term Treatment by Plasma Exchange

The International Journal of Artificial Organs ◽

10.1177/039139888901201012 ◽

1989 ◽

Vol 12 (10) ◽

pp. 664-667 ◽

Cited By ~ 6

Author(s):

C. Mousson ◽

S.A. Charhon ◽

M. Ammar ◽

M. Accominotti ◽

G. Rifle

Keyword(s):

Renal Function ◽

Bone Formation ◽

Plasma Exchange ◽

Normal Renal Function ◽

Bone Biopsy ◽

Term Treatment ◽

Normal Range ◽

Non Invasive ◽

Long Term Treatment

The accumulation of aluminium (AI) can cause AI bone deposits, osteomalacia and encephalopathy. As albumin solutions used as replacement fluid in plasma exchange (PE) are contaminated with AI, we studied AI overload in two symptomless patients with normal renal function, treated by long-term plasma exchange (PE). Total AI loading was calculated at 1750 μmol in patient 1 (178 PE sessions) and 2100 μmol in patient 2 (153 PE sessions). Bone biopsy showed AI deposits and low bone formation without osteomalacia in patient 1 and only osteoporosis in patient 2. Plasma AI levels were useless in detecting early AI overload, because the remained in the normal range, even after PE in both patients. Bone biopsy was the best means of recognizing AI intoxication, but cannot be recommended for frequent evaluations. However, the desferrioxamine mobilization test can be proposed as a repetitive non-invasive investigation method.

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Dynamic imaging of ictal oscillations using non-invasive high-resolution EEG

NeuroImage ◽

10.1016/j.neuroimage.2011.03.043 ◽

2011 ◽

Vol 56 (4) ◽

pp. 1908-1917 ◽

Cited By ~ 57

Author(s):

Lin Yang ◽

Christopher Wilke ◽

Benjamin Brinkmann ◽

Gregory A. Worrell ◽

Bin He

Keyword(s):

High Resolution ◽

Dynamic Imaging ◽

Non Invasive ◽

High Resolution Eeg

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The Application of 99mTc-DTPA Renal Dynamic Imaging to Measuring Renal Function of Children with Acute Lymphoblastic Leukemia after Induction Therapy

BioMed Research International ◽

10.1155/2020/3687134 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Lidan Wang ◽

Kailan Chen ◽

Qiong Xu

Keyword(s):

Renal Function ◽

Acute Lymphoblastic Leukemia ◽

Induction Therapy ◽

Estimated Glomerular Filtration Rate ◽

Lymphoblastic Leukemia ◽

Kidney Injury ◽

Binary Logistic Regression ◽

Dynamic Imaging ◽

High Dose ◽

Renal Functions

Purpose. The study was aimed at assessing renal functions of children with acute lymphoblastic leukemia (ALL) after induction therapy by 99mTc-DTPA renal dynamic imaging Gates method (GFRGates) and investigating whether renal function after induction therapy will affect the occurrence of high-dose methotrexate- (HDMTX-) induced acute kidney injury (AKI). Methods. Children with newly diagnosed ALL were enrolled. Renal functions before the administration of HDMTX were assessed by estimated glomerular filtration rate (eGFR) and GFRGates, respectively, before the first cycle of HDMTX after induction therapy. The areas under the ROC curve were used to assess covariates’ ability to predict HDMTX-induced AKI. Results. 102 children with ALL were included in the study. A stepwise backward binary logistic regression showed that only standardized GFRGates was an independent risk factor for HDMTX-induced AKI ( p = 0.018 , odds ratio 0.985, 95% CI 0.972-0.997). The area under the ROC of standardized GFRGates was 0.679 ( p = 0.012 , 95% CI 0.554-0.804). Conclusion. Standardized GFRGates showed that the normal renal function of children is not enough to be used as a cutoff point to predict HDMTX-induced AKI in ALL children receiving HDMTX. More attention and supportive care should be given to the children with standardized GFRGates lower than the cutoff value to avoid the HDMTX-induced AKI.

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A Novel Creatinine-Based Equation to Estimate Glomerular Filtration Rate in Chinese Population With Chronic Kidney Disease: Implications for DOACs Dosing in Atrial Fibrillation Patients

Frontiers in Pharmacology ◽

10.3389/fphar.2021.615953 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ling-Yun Zhou ◽

Wen-Jun Yin ◽

Jun Zhao ◽

Bi-Kui Zhang ◽

Can Hu ◽

...

Keyword(s):

Atrial Fibrillation ◽

Chronic Kidney Disease ◽

Renal Function ◽

Glomerular Filtration Rate ◽

Kidney Disease ◽

Glomerular Filtration ◽

Filtration Rate ◽

Linear Regression Analysis ◽

Dynamic Imaging ◽

Adverse Outcomes

Background: Over/under-estimating renal function may increase inappropriate dosing strategy associated adverse outcomes; however, previously reported equations to estimate renal function have limited accuracy in chronic kidney disease (CKD) patients. Consequently, we intended to develop a novel equation to precisely estimate renal function and subsequently guide clinical treatment for CKD patients.Methods: A novel approach, Xiangya-s equation, to estimate renal function for CKD patients was derived by linear regression analysis and validated in 1885 patients with measured glomerular filtration rate (mGFR) < 60 ml/min/1.73 m2 by renal dynamic imaging at three representative hospitals in China, with the performance evaluated by accuracy, bias and precision. In the meanwhile, 2,165 atrial fibrillation (AF) patients who initiated direct oral anticoagulants (DOACs) between December 2015 and December 2018 were identified and renal function was assessed by estimated creatinine clearance (eCrCl). Events per 100 patient-years was calculated. Cox proportional hazards regression was applied to compare the incidence of outcomes of each group.Results: Xiangya-s equation demonstrated higher accuracy, lower bias and improved precision when compared with 12 creatinine-based and 2 CysC-based reported equations to estimate GFR in multi-ethnic Chinese CKD patients. When we applied Xiangya-s equation to patients with AF and CKD prescribed DOACs, wide variability was discovered in eCrCl calculated by the Cockcroft-Gault (CG), Modification of Diet in Renal Disease Study (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Xiangya equation which we had developed for generally patients and Xiangya-s equations, which persisted after grouping by different renal function stages. Equation choice affected drug-dosing adjustments, with the formulas agreeing for only 1.19%, 5.52%, 33.22%, 26.32%, and 36.61% of potentially impacted patients for eCrCl cutoffs of <15, <30, 15–49, 30–49, ≥50 ml/min, respectively. Relative to CG equation, accordance in DOACs dosage was 81.08%, 88.54%, 62.25%, and 47.68% for MDRD, CKD-EPI, Xiangya and Xiangya-s equations for patients with CrCl < 50 ml/min (eCrCl cutoffs of <30, 30–49, ≥50 ml/min), respectively. Reclassification of renal function stages by Xiangya-s equation was significantly associated with stroke or systemic embolism, non-major clinically relevant bleeding and any bleeding events.Conclusion: Xiangya-s equation provides more accurate GFR estimates in Chinese CKD patients who need consecutive monitoring of renal function, which may assist clinicians in choosing appropriate drug dosages.

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Non-invasive assessment of early stage diabetic nephropathy by DTI and BOLD MRI

British Journal of Radiology ◽

10.1259/bjr.20190562 ◽

2020 ◽

Vol 93 (1105) ◽

pp. 20190562 ◽

Cited By ~ 5

Author(s):

You-Zhen Feng ◽

Yao-Jiang Ye ◽

Zhong-Yuan Cheng ◽

Jun-Jiao Hu ◽

Chuang-Biao Zhang ◽

...

Keyword(s):

Renal Function ◽

Diabetic Nephropathy ◽

Glomerular Filtration Rate ◽

Diffusion Tensor Imaging ◽

Filtration Rate ◽

Estimated Glomerular Filtration Rate ◽

Diffusion Tensor ◽

Renal Medulla ◽

Non Invasive ◽

Bold Imaging

Objective: Patients with diabetes mellitus, diabetic nephropathy (DN) and healthy donor were analyzed to test whether the early DN patients can be detected using both blood oxygenation level dependent (BOLD) and diffusion tensor imaging. Methods: This study was approved by the Ethics Committee of our hospital. MR images were acquired on a 3.0-Tesla MR system (Discovery MR750, General Electric, Milwaukee, WI). 30 diabetic patients were divided into NAU (normal to mildly increased albuminuria, N = 15) and MAU (moderately increased albuminuria, N = 15) group based on the absence or presence of microalbuminuria. 15 controls with sex- and age-matched were enrolled in the study. Prior to MRI scan, all participants were instructed to collect their fresh morning urine samples for quantitative measurement of urinary microalbumin and urinary creatinine. Then, the estimations of serum creatinine, serum uric acid, HbAlc and fasting plasma glucose as well as fundus examinations were performed in all subjects. Then, the values of albumin–creatinine ratio (ACR) and estimated glomerular filtration rate were also calculated. All subjects underwent renal diffusion tensor imaging (DTI) and BOLD acquisition after fasting for 4 h. Regions of interest were placed in renal medulla and cortex for evaluating apparent diffusion coefficient (ADC), fractional anisotropy (FA) and R2* values by two experienced radiologists. The consistency between the two observations was estimated using intragroup correlation coefficients. To test differences in ADC, FA and R2* values across the three groups, the data were analyzed using separate one-way ANOVAs. Post-hoc pair wise comparisons were then performed using t-test. To investigate the clinical relevance of imaging parameters in both regions across the three groups, the correlations of values of the ACR/estimated glomerular filtration rate and of the ADC/FA/R2* were calculated. Results: There was a high level of consistency of those ADC, FA and R2* values across the three groups on both renal cortex and medulla measured by the two doctors. The FA value of medulla in MAU group was lower than that in control (p < 0.01). The R2* value of medulla in the NAU group was higher than that in the control (p < 0.01), and the R2* value of medulla in the MAU group was lower than that in the control (p = 0.009) . Moreover, the current study revealed a decreasing trend in FA values of the renal medulla from the control group to NAU and MAU groups. Finally, a weak negatively correlation between medullary R2* and ACR was found in current study. Conclusion: Medullary R2* value might be a new more sensitive predictor of early DN. Meanwhile, BOLD imaging detected the medullary hypoxia at the simply diabetic stage, while DTI didn’t identify the medullary directional diffusion changes at this stage. Based on our assumption mentioned above, it’s presumable that BOLD imaging may be more sensitive for assessment of the early renal function changes than DTI. These imaging techniques are more accurate and practical than conventional tests. Advances in knowledge: Non-invasive MRI was used to detect renal function changes at early DN stage.

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Non-invasive methods to measure inter-renal function in aquatic salamanders—correlating fecal corticosterone to the environmental and physiologic conditions of captive Necturus

Conservation Physiology ◽

10.1093/conphys/coz074 ◽

2019 ◽

Vol 7 (1) ◽

Author(s):

Andrew H Nagel ◽

Mark Beshel ◽

Christopher J DeChant ◽

Sarah M Huskisson ◽

Mark K Campbell ◽

...

Keyword(s):

Renal Function ◽

Environmental Changes ◽

Reproductive Activity ◽

Acth Challenge ◽

Non Invasive ◽

Breeding Activity ◽

Faecal Corticosterone Metabolites ◽

Aquatic Salamanders ◽

Corticosterone Metabolites

We measured faecal corticosterone metabolites (fCMs) in aquatic salamander Necturus to understand how inter-renal function changes throughout seasonal environmental changes and associated reproductive activity. fCMs elevated with lower water temperatures and breeding activity. To overcome some challenges associated with faecal hormone collection/analysis, waterborne corticosterone (wCM) was validated through ACTH challenge.

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