Bias and Precision in Magnetic Resonance Imaging‐Based Estimates of Renal Blood Flow: Assessment by Triangulation

Author(s):  
Bashair A. Alhummiany ◽  
David Shelley ◽  
Margaret Saysell ◽  
Maria‐Alexandra Olaru ◽  
Bernd Kühn ◽  
...  
1992 ◽  
Vol 27 (6) ◽  
pp. 465-470 ◽  
Author(s):  
GRAHAM SOMMER ◽  
BEHZAD NOORBEHESHT ◽  
NORBERT PELC ◽  
REX JAMISON ◽  
A J PINEVICH ◽  
...  

2015 ◽  
Vol 66 (3) ◽  
pp. 402-411 ◽  
Author(s):  
Dinah S. Khatir ◽  
Michael Pedersen ◽  
Bente Jespersen ◽  
Niels H. Buus

2020 ◽  
Vol 319 (6) ◽  
pp. F966-F978
Author(s):  
Per Eckerbom ◽  
Peter Hansell ◽  
Eleanor Cox ◽  
Charlotte Buchanan ◽  
Jan Weis ◽  
...  

Circadian regulation of kidney function is involved in maintaining whole body homeostasis, and dysfunctional circadian rhythm can potentially be involved in disease development. Magnetic resonance imaging (MRI) provides reliable and reproducible repetitive estimates of kidney function noninvasively without the risk of adverse events associated with contrast agents and ionizing radiation. The purpose of this study was to estimate circadian variations in kidney function in healthy human subjects with MRI and to relate the findings to urinary excretions of electrolytes and markers of kidney function. Phase-contrast imaging, arterial spin labeling, and blood oxygen level-dependent transverse relaxation rate (R2*) mapping were used to assess total renal blood flow and regional perfusion as well as intrarenal oxygenation in eight female and eight male healthy volunteers every fourth hour during a 24-h period. Parallel with MRI scans, standard urinary and plasma parameters were quantified. Significant circadian variations of total renal blood flow were found over 24 h, with increasing flow from noon to midnight and decreasing flow during the night. In contrast, no circadian variation in intrarenal oxygenation was detected. Urinary excretions of electrolytes, osmotically active particles, creatinine, and urea all displayed circadian variations, peaking during the afternoon and evening hours. In conclusion, total renal blood flow and kidney function, as estimated from excretion of electrolytes and waste products, display profound circadian variations, whereas intrarenal oxygenation displays significantly less circadian variation.


2018 ◽  
Vol 314 (1) ◽  
pp. F99-F106 ◽  
Author(s):  
Cesar A. Romero ◽  
Glauber Cabral ◽  
Robert A. Knight ◽  
Guangliang Ding ◽  
Edward L. Peterson ◽  
...  

Renal blood flow (RBF) provides important information regarding renal physiology and nephropathies. Arterial spin labeling–magnetic resonance imaging (ASL-MRI) is a noninvasive method of measuring blood flow without exogenous contrast media. However, low signal-to-noise ratio and respiratory motion artifacts are challenges for RBF measurements in small animals. Our objective was to evaluate the feasibility and reproducibility of RBF measurements by ASL-MRI using respiratory-gating and navigator correction methods to reduce motion artifacts. ASL-MRI images were obtained from the kidneys of Sprague-Dawley (SD) rats on a 7-Tesla Varian MRI system with a spin-echo imaging sequence. After 4 days, the study was repeated to evaluate its reproducibility. RBF was also measured in animals under unilateral nephrectomy and in renal artery stenosis (RST) to evaluate the sensitivity in high and low RBF models, respectively. RBF was also evaluated in Dahl salt-sensitive (SS) rats and spontaneous hypertensive rats (SHR). In SD rats, the cortical RBFs (cRBF) were 305 ± 59 and 271.8 ± 39 ml·min−1·100 g tissue−1 in the right and left kidneys, respectively. Retest analysis revealed no differences ( P = 0.2). The test-retest reliability coefficient was 92 ± 5%. The cRBFs before and after the nephrectomy were 296.8 ± 30 and 428.2 ± 45 ml·min−1·100 g tissue−1 ( P = 0.02), respectively. The kidneys with RST exhibited a cRBF decrease compared with sham animals (86 ± 17.6 vs. 198 ± 33.7 ml·min−1·100 g tissue−1; P < 0.01). The cRBFs in SD, Dahl-SS, and SHR rats were not different ( P = 0.35). We conclude that ASL-MRI performed with navigator correction and respiratory gating is a feasible and reliable noninvasive method for measuring RBF in rats.


1998 ◽  
Vol 12 (1) ◽  
pp. 9-12 ◽  
Author(s):  
MOHAMMAD R. MOSTAFAVI ◽  
DAVID R. CHAVEZ ◽  
JOHN CANNILLO ◽  
BRIAN SALTZMAN ◽  
POTTUMARTHI V. PRASAD

2019 ◽  
Vol 316 (4) ◽  
pp. F693-F702 ◽  
Author(s):  
Per Eckerbom ◽  
Peter Hansell ◽  
Eleanor Cox ◽  
Charlotte Buchanan ◽  
Jan Weis ◽  
...  

Noninvasive methods of magnetic resonance imaging (MRI) can quantify parameters of kidney function. The main purpose of this study was to determine baseline values of such parameters in healthy volunteers. In 28 healthy volunteers (15 women and 13 men), arterial spin labeling to estimate regional renal perfusion, blood oxygen level-dependent transverse relaxation rate (R2*) to estimate oxygenation, and apparent diffusion coefficient (ADC), true diffusion (D), and longitudinal relaxation time (T1) to estimate tissue properties were determined bilaterally in the cortex and outer and inner medulla. Additionally, phase-contrast MRI was applied in the renal arteries to quantify total renal blood flow. The results demonstrated profound gradients of perfusion, ADC, and D with highest values in the kidney cortex and a decrease towards the inner medulla. R2* and T1 were lowest in kidney cortex and increased towards the inner medulla. Total renal blood flow correlated with body surface area, body mass index, and renal volume. Similar patterns in all investigated parameters were observed in women and men. In conclusion, noninvasive MRI provides useful tools to evaluate intrarenal differences in blood flow, perfusion, diffusion, oxygenation, and structural properties of the kidney tissue. As such, this experimental approach has the potential to advance our present understanding regarding normal physiology and the pathological processes associated with acute and chronic kidney disease.


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