Magnetic resonance imaging of perfusion in the isolated rat heart using spin inversion of arterial water

Williams, Donald S.; Grandis, Donald J.; Zhang, Weiguo; Koretsky, Alan P.

doi:10.1002/mrm.1910300314

Cited by 91 publications

(71 citation statements)

References 9 publications

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“…In several studies attention was paid to the validation of the ASL measurements. For instance, brain perfusion obtained with T 1app sequences was compared with PET results (17) and myocardial perfusion with radioactive microsphere measurements (11,14). The ASL data were found to be in good agreement with the established standards.…”

mentioning

confidence: 67%

“…Second, perfusion maps are generated at excellent temporal and spatial resolutions. Since their introduction by Detre et al (1) and Williams et al (2) in 1992, various ASL protocols, and in particular pulsed ones (3,4), have been increasingly used and have been shown to measure perfusion mainly in the brain (1,3,(5)(6)(7) and also in other organs such as kidney (8 -10), heart (11)(12)(13)(14), and lungs (15,16). In several studies attention was paid to the validation of the ASL measurements.…”

mentioning

confidence: 99%

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Determination of skeletal muscle perfusion using arterial spin labeling NMRI: Validation by comparison with venous occlusion plethysmography

Raynaud

Duteil

Vaughan

et al. 2001

Magnetic Resonance in Med

116

162

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T 1 -based determination of perfusion was performed with the high temporal and spatial resolution that monitoring of exercise physiology requires. As no data were available on the validation of this approach in human muscles, T 1 -based NMRI of perfusion was compared to standard strain-gauge venous occlusion plethysmography performed simultaneously within a 4 T magnet. Two different situations were investigated in 21 healthy young volunteers: 1) a 5-min ischemia of the leg, or 2) a 2-3 min ischemic exercise consisting of a plantar flexion on an amagnetic ergometer. Leg perfusion was monitored over 5-15 min of the recovery phase, after the air-cuff arterial occlusion had been released. The interesting features of the sequence were the use of a saturation-recovery module for the introduction of a T 1 modulation and of single-shot spin echo for imaging. Spatial resolution was 1.7 ؋ 2.0 mm and temporal resolution was 2 s. For data analysis, ROIs were traced on different muscles and perfusion was calculated from the differences in muscle signal intensity in successive images. To allow comparison with the global measurement of perfusion by plethysmography, the T 1 -based NMR measurements in exercising muscles were rescaled to the leg cross-section.

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mentioning

confidence: 67%

mentioning

confidence: 99%

Determination of skeletal muscle perfusion using arterial spin labeling NMRI: Validation by comparison with venous occlusion plethysmography

Raynaud

Duteil

Vaughan

et al. 2001

Magnetic Resonance in Med

116

162

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show abstract

“…In cerebral studies, fast exchange is hindered by the blood-brain barrier, and high cerebral blood flows are underestimated by ASL. Experimental studies conducted on in vitro perfused hearts have demonstrated that the fast exchange condition was not an issue in organs other than the brain (104). Finite and non-instantaneous exchange times are to be taken into account when blood and tissue T 1 s are different, but the correction to be introduced is minor (68).…”

Section: Nmr Determination Of Skeletal Muscle Perfusion: a Key-role Fmentioning

confidence: 99%

Muscle blood flow and oxygenation measured by NMR imaging and spectroscopy

et al. 2006

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Tissue perfusion and oxygenation in many organs can be evaluated by various NMR techniques. This review focuses on the specificities, limitations and adaptations of the NMR tools available to investigate perfusion and oxygenation in the skeletal muscle of humans and animal models. A description of how they may be used simultaneously is provided as well.1 H NMR spectroscopy of myoglobin (Mb) monitors intramyocytic oxygenation. It measures the level of deoxy-Mb, from which Mb concentration, Mb desaturation/resaturation rates, muscle oxygenation changes and intracellular partial oxygen pressure (pO 2 ) can be calculated. Positive and negative blood oxygen level-dependent (BOLD) contrasts exist in skeletal muscle. BOLD contrasts primarily reflect changes in capillary-venous oxygenation, but are also directly or indirectly dependent on muscle blood volume, perfusion, vascular network architecture and angulation, relative to the main magnetic field. Arterial spin labelling (ASL) techniques, having high spatial and temporal resolution, are the methods of choice to quantify and map skeletal muscle perfusion non-invasively. Limitations of ASL are poor contrast-to-noise ratio and sensitivity to movement; however, with the introduction of specific adaptations, it has been proven possible to measure skeletal muscle perfusion at both rest and during exercise. The possibility of combining these NMR measurements with others into a single dynamic protocol is most interesting. The 'multiparametric functional (mpf) NMR' concept can be extended to include the evaluation of muscle energy metabolism simultaneously with 31 P NMR or with lactate double quantum filtered 1 H NMR spectroscopy, an approach which would make NMR an exceptional tool for non-invasive investigations of integrative physiology and biochemistry in skeletal muscle in vivo.

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“…There exist qualitative 11,12 and quantitative [13][14][15][16][17] non-contrastagent perfusion imaging techniques. Most of the latter techniques work with active labeling of the inflowing spins.…”

Section: Development Of Perfusion Imagingmentioning

confidence: 99%

Fast High-Resolution Magnetic Resonance Imaging Demonstrates Fractality of Myocardial Perfusion in Microscopic Dimensions

Bauer¹,

Hiller²,

Galuppo³

et al. 2001

Circulation Research

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Abstract-The fractal nature of heterogeneity of myocardial blood flow and its implications for the healthy and diseased heart is not yet understood. The main hindrance for investigation of blood flow heterogeneity and its role in physiology and pathophysiology is that conventional methods for determination of myocardial perfusion have severe limitations concerning temporal and spatial resolution and invasiveness. In isolated rat hearts, we developed a nuclear magnetic resonance technique that does not depend on contrast agents and in which the apparent longitudinal relaxation time is made perfusion sensitive by selective preparation of the imaging slice. This perfusion-sensitive relaxation time is determined within 40 seconds as a map with a high spatial in-plane resolution of 140ϫ140 m 2 and a thickness of 1.5 mm. Perfusion imaging was validated with the established microsphere technique. Additionally, the congruence between perfusion-sensitive T 1 maps and first-pass perfusion imaging was demonstrated. As an application of high-resolution perfusion imaging, fractal analysis of the spatial distribution of perfusion was performed. We were able to demonstrate that the fractality of this distribution exists even in microscopic dimensions. Vasodilation by nitroglycerin modulated the fractal pattern of perfusion, and the decrease of the fractal dimension indicated a shift toward homogeneity. This implies that parameters of the fractal distribution depend on the microvascular tone rather than on anatomic preformations; ie, fractality is a functional characteristic of perfusion.

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Magnetic resonance imaging of perfusion in the isolated rat heart using spin inversion of arterial water

Cited by 91 publications

References 9 publications

Determination of skeletal muscle perfusion using arterial spin labeling NMRI: Validation by comparison with venous occlusion plethysmography

Determination of skeletal muscle perfusion using arterial spin labeling NMRI: Validation by comparison with venous occlusion plethysmography

Muscle blood flow and oxygenation measured by NMR imaging and spectroscopy

Fast High-Resolution Magnetic Resonance Imaging Demonstrates Fractality of Myocardial Perfusion in Microscopic Dimensions

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