Magnetic Resonance Imaging of Blood Flow with a Phase Subtraction Technique

Evans, Avery J.; Iwai, F.; Grist, Thomas A.; Sostman, Henry Dirk; Hedlund, Laurence W.; Spritzer, Charles E.; Negro-Vilar, Rosa; Beam, Craig A.; Pelc, Norbert J.

doi:10.1097/00004424-199302000-00004

Cited by 143 publications

(80 citation statements)

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“…With a recent TRUST MRI technique that was developed by our laboratory, the quantification of global venous oxygenation becomes more feasible (Lu and Ge, 2008). The TRUST technique has been validated in humans against a gold-standard pulse oximetry method (Bakker et al, 1999;Evans et al, 1993;Zananiri et al, 1991). Since changes in alertness during the experiment may alter CMRO 2 (in addition to any O 2 effect) (Braun et al, 1997;Nofzinger et al, 2002), the subjects of this study were allowed to view a movie while in the scanner.…”

Section: Technical Considerationsmentioning

confidence: 99%

Effect of Hypoxia and Hyperoxia on Cerebral Blood Flow, Blood Oxygenation, and Oxidative Metabolism

Liu

Pascual

et al. 2012

J Cereb Blood Flow Metab

149

182

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Characterizing the effect of oxygen (O 2 ) modulation on the brain may provide a better understanding of several clinically relevant problems, including acute mountain sickness and hyperoxic therapy in patients with traumatic brain injury or ischemia. Quantifying the O 2 effects on brain metabolism is also critical when using this physiologic maneuver to calibrate functional magnetic resonance imaging (fMRI) signals. Although intuitively crucial, the question of whether the brain's metabolic rate depends on the amount of O 2 available has not been addressed in detail previously. This can be largely attributed to the scarcity and complexity of measurement techniques. Recently, we have developed an MR method that provides a noninvasive (devoid of exogenous agents), rapid ( < 5 minutes), and reliable (coefficient of variant, CoV < 3%) measurement of the global cerebral metabolic rate of O 2 (CMRO 2 ). In the present study, we evaluated metabolic and vascular responses to manipulation of the fraction of inspired O 2 (FiO 2 ). Hypoxia with 14% FiO 2 was found to increase both CMRO 2 (5.0±2.0%, N = 16, P = 0.02) and cerebral blood flow (CBF) (9.8±2.3%, P < 0.001). However, hyperoxia decreased CMRO 2 by 10.3 ± 1.5% (P < 0.001) and 16.9 ± 2.7% (P < 0.001) for FiO 2 of 50% and 98%, respectively. The CBF showed minimal changes with hyperoxia. Our results suggest that modulation of inspired O 2 alters brain metabolism in a dose-dependent manner.

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Section: Technical Considerationsmentioning

confidence: 99%

Effect of Hypoxia and Hyperoxia on Cerebral Blood Flow, Blood Oxygenation, and Oxidative Metabolism

Liu

Pascual

et al. 2012

J Cereb Blood Flow Metab

149

182

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“…Phase contrast magnetic resonance imaging (PC-MRI) is a technique which has been extensively used at 1.5 Tesla to determine blood velocity or flow within vessels such as the aorta, carotid arteries, and renal arteries (Bakker et al, 1995;Chatzimavroudis et al, 2001;Evans et al, 1993;Hoogeveen et al, 1998;Pelc et al, 1991;Rebergen et al, 1993). Few studies, however, have used PC-MRI to measure coronary flow due to; 1) the large degree of cardiac motion of the vessels, 2) the large amount and respiratory motion of the vessels, and 3) the small diameter of the vessels.…”

Section: Introductionmentioning

confidence: 99%

Coronary artery flow measurement using navigator echo gated phase contrast magnetic resonance velocity mapping at 3.0 T

Johnson

Sharma

Oshinski

2008

Journal of Biomechanics

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A validation study and early results for noninvasive, in vivo measurement of coronary artery blood flow using phase contrast magnetic resonance imaging (PC-MRI) at 3.0 Tesla is presented. Accuracy of coronary artery blood flow measurements by phase contrast MRI is limited by heart and respiratory motion as well as the small size of the coronary arteries. In this study, a navigator-echo gated, cine phase velocity mapping technique is described to obtain time-resolved velocity and flow waveforms of small diameter vessels at 3.0 Tesla. Phantom experiments using steady, laminar flow are presented to validate the technique and show flow rates measured by 3.0 Tesla phase contrast MRI to be accurate within 15% of true flow rates. Subsequently, in vivo scans on healthy volunteers yield velocity measurements for blood flow in the right, left anterior descending, and left circumflex arteries. Measurements of average, cross-sectional velocity were obtainable in 224/243 (92%) of the cardiac phases. Time-averaged, cross-sectional velocity of the blood flow was 6.8±4.3 cm/s in the LAD, 8.0 ±3.8 cm/s in the LCX, and 6.0±1.6 cm/s in the RCA.

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“…Velocity and flow rate measurements with PC MRI have been repeatedly validated (e.g. Evans et al, 1993;Pelc et al, 1992). The principal source of error on the measured velocity is eddy currents induced by switched gradients, which can introduce a non-zero baseline.…”

Section: Discussionmentioning

confidence: 99%

Stroke volume and cardiac output in juvenile elephant seals during forced dives

Thornton

Hochachka

Crocker

et al. 2005

Journal of Experimental Biology

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SUMMARY The aim of this study was to examine the effect of forced diving on cardiac dynamics in a diving mammal by evaluating cardiac output and heart rate. We used MR Imaging and phase contrast flow analysis to obtain accurate flow measurements from the base of the aorta. Heart rate (fh)and cardiac output (Q̇) were measured before, during and after dives in four restrained juvenile northern elephant seals, Mirounga angustirostris, and stroke volume(Vs) was calculated(Vs=Q̇/fh). Mean Q̇ during diving (4011±387 ml min-1) and resting (6530±1018 ml min-1) was not significantly different (paired t-test; P<0.055). Diving was accompanied by a 20% increase in Vs over the pre-dive level. Pre-dive, post-dive or diving fh was not significantly correlated with Vs during any state. Diving Vs correlated negatively with the bradycardic ratio(diving fh to pre-dive fh). In this study, the degree of bradycardia during diving was less than in previous pinniped studies, suggesting that the reduction in vagal input may contribute to the observed increase in Vs.

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Magnetic Resonance Imaging of Blood Flow with a Phase Subtraction Technique

Cited by 143 publications

References 0 publications

Effect of Hypoxia and Hyperoxia on Cerebral Blood Flow, Blood Oxygenation, and Oxidative Metabolism

Effect of Hypoxia and Hyperoxia on Cerebral Blood Flow, Blood Oxygenation, and Oxidative Metabolism

Coronary artery flow measurement using navigator echo gated phase contrast magnetic resonance velocity mapping at 3.0 T

Stroke volume and cardiac output in juvenile elephant seals during forced dives

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