Quantitation of renal perfusion using arterial spin labeling with FAIR-UFLARE

Karger, N.; Biederer, Jürgen; Lüsse, S.; Grimm, John; Steffens, Johann C.; Heller, Martin; Glüer, Claus-Christian

doi:10.1016/s0730-725x(00)00155-7

Cited by 85 publications

(94 citation statements)

References 18 publications

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“…M 0 is the tissue equilibrium magnetization per unit mass of tissue, T1 is the longitudinal relaxation time of tissue, TI is the inversion time, l is the blood-tissue water partition coefficient, which is constant at 80 mL/100 g, and f is the blood flow in milliliters per 100 g per minute. (8).…”

Section: Discussionmentioning

confidence: 99%

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Feasibility of FAIR imaging for evaluating tumor perfusion

Cho

Song

et al. 2010

Magnetic Resonance Imaging

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Purpose: To evaluate the feasibility of flow-sensitive alternating inversion recovery (FAIR) for measuring blood flow in tumor models. Materials and Methods:In eight mice tumor models, FAIR and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed. The reliability for measuring blood flow on FAIR was evaluated using the coefficient of variation of blood flow on psoas muscle. Three regions of interest (ROIs) were drawn in the peripheral, intermediate, and central portions within each tumor. The location of ROI was the same on FAIR and DCE-MR images. The correlation between the blood flow on FAIR and perfusion-related parameters on DCE-MRI was evaluated using the Pearson correlation coefficient.Results: The coefficient of variation for measuring blood flow was 9.8%. Blood flow on FAIR showed a strong correlation with Kep (r ¼ 0.77), percent relative enhancement (r ¼ 0.73), and percent enhancement ratio (r ¼ 0.81). The mean values of blood flow (mL/100 g/min) (358 vs. 207), Kep (sec À1 ) (7.46 vs. 1.31), percent relative enhancement (179% vs. 134%), and percent enhancement ratio (42% vs. 26%) were greater in the peripheral portion than in the central portion (P < 0.01). Conclusion:As blood flow measurement on FAIR is reliable and closely related with that on DCE-MR, FAIR is feasible for measuring tumor blood flow.

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Section: Discussionmentioning

confidence: 99%

“…where R1 sel is the T1 relaxation rate of selective inversion, R1 nonselectivel is the T1 relaxation rate of nonselective inversion, f is the blood flow in milliliters per 100 g per minute and is the blood-tissue water partition coefficient, which is constant at 80 mL/100 g (8).…”

Section: Data Processingmentioning

confidence: 99%

Feasibility of FAIR imaging for evaluating tumor perfusion

Cho

Song

et al. 2010

Magnetic Resonance Imaging

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“…where M 0 represents the tissue equilibrium magnetization per unit mass of the tissue, T 1 is the longitudinal relax-ation time of tissue, f is the perfusion rate (usually in ml/100g/min), and is the blood-tissue water partition coefficient, which is assumed to have a constant value of 80 ml/100g (8,19). Under these conditions perfusion maps can be calculated pixel-by-pixel from the analysis of the difference magnetization ⌬M at time TI, the undisturbed magnetization M 0 , and the relaxation time T 1 by:…”

Section: Quantitative Analysismentioning

confidence: 99%

FAIR true‐FISP perfusion imaging of the kidneys

Martirosian

Klose

Mader

et al. 2004

Magnetic Resonance in Med

179

237

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“…For protons in steady flow with continuous RF labeling, the inversion efficiency can be approximated by Zhernovoi's model (27): [8] where ␤ is the adiabaticity factor (22):…”

Section: Flow Dynamicsmentioning

confidence: 99%

Quantitative analysis of adiabatic fast passage for steady laminar and turbulent flows

Gach

Kam

Reid

et al. 2002

Magnetic Resonance in Med

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Adiabatic fast passage (AFP) is used in noninvasive quantitative perfusion experiments to invert (or label) arterial spins. Continuous arterial spin labeling (CASL) experiments conducted in vivo often assume the inversion efficiency based on the labeling field and steady flow conditions, without direct verification. In practice, the labeling field used in CASL is often amplitude-and duty cycle-limited due to hardware or specific absorption rate constraints. In this study, the effects of the labeling field amplitude and duty cycle, and flow dynamics on the inversion efficiency of AFP were examined under steady flow conditions in a saline flow phantom. The experimental results were in general agreement with models based on Zhernovoi's theory except at high labeling field amplitudes, when the spin inversion times are at least half of the duration of the labeling pulse. The nonlinear relation observed between the inversion efficiency and the labeling duty cycle implies that the practice of linear derating the inversion efficiency with the labeling duty cycle may be prone to significant error. A secondary finding was that the Key words: arterial spin labeling; adiabatic fast passage; inversion efficiency; steady flow; labeling duty cycle During the last decade there has been a significant amount of development in noninvasive quantitative perfusion MRI using arterial spin labeling (ASL), with applications including the human brain (1-5) and kidney (6 -8). Continuous ASL (CASL) employs adiabatic fast passage (AFP) (9) to invert arterial spins (i.e., in blood) prior to their arrival at the tissue region of interest (ROI). The perfusion signal is directly proportional to the inversion (or labeling) efficiency of AFP within a finite inversion region and is attenuated by T 1 relaxation that occurs in transit from the inversion region to the imaging region (5,6,10). It is desirable to maximize the inversion efficiency (and, where possible, minimize T 1 relaxation in transit) since the perfusion signal is small in humans: approximately 1-2% of the image signal for gray matter (11) and 4 -6% in the renal cortex (6,7).Measurement of inversion efficiency in vivo is difficult since it may vary during the cardiac cycle (12) and the ability to synchronize the measurement with the spin labeling (or tagging) is challenging (6). Inversion efficiencies have been measured directly in the rat carotids (13) and rat descending aorta (14), human descending aorta (6) using gated acquisitions, and indirectly in the human brain (4,5,11,15,16) by varying the labeling field.However, the labeling fields and inversion efficiencies are not typically measured in every subject or study (3,17), since such measurements significantly extend the exam time and are prone to large errors. Instead, the inversion efficiency is assumed based on earlier experimental measurements or simulations. Sources of error include the assumptions of the spin hemodynamics (e.g., pulsatile vs. steady flow), relaxation times, labeling field amplitude, and the cycling of the ...

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Quantitation of renal perfusion using arterial spin labeling with FAIR-UFLARE

Cited by 85 publications

References 18 publications

Feasibility of FAIR imaging for evaluating tumor perfusion

Feasibility of FAIR imaging for evaluating tumor perfusion

FAIR true‐FISP perfusion imaging of the kidneys

Quantitative analysis of adiabatic fast passage for steady laminar and turbulent flows

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