The Fourier reconstruction of a head section

Shepp, Larry; Logan, B. F.

doi:10.1109/tns.1974.6499235

Cited by 1,875 publications

(822 citation statements)

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“…In the Bayesian estimation framework, the Fisher information matrix I F is the sum of two terms: I M due to measurements and I P from the prior information [23], where the (i; j) th elements of I M and I P are given by (15) and…”

Section: Cramér-rao Bound On Error Variancementioning

confidence: 99%

“…The strength and the orientation of the gradient vector are varied from projection to projection to encode the spectral and spatial information of the spins. Once an adequate number of projections are acquired, an image can be reconstructed using filtered backprojection (FBP) [15], which is based on the direct inversion of the Radon transform. To image the spectral dimension, projections are acquired at different gradient strengths.…”

Section: Introductionmentioning

confidence: 99%

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A parametric approach to spectral–spatial EPR imaging

Som

Potter

Ahmad

et al. 2007

Journal of Magnetic Resonance

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Continuous wave electron paramagnetic resonance imaging for in vivo mapping of spin distribution and spectral shape requires rapid data acquisition. A spectral-spatial imaging technique is presented that provides an order of magnitude reduction in acquisition time, compared to iterative tomographic reprojection. The proposed approach assumes that spectral shapes in the sample are wellapproximated by members from a parametric family of functions. A model is developed for the spectra measured with magnetic field modulation. Parameters defining the spin distribution and spectral shapes are then determined directly from the measurements using maximum a posteriori probability estimation. The approach does not suffer approximation error from limited sweep width of the main magnetic field and explicitly incorporates the variability in signal-to-noise ratio versus strength of magnetic field gradient. The processing technique is experimentally demonstrated on a one-dimensional phantom containing a nitroxide spin label with constant g-factor. Using an L-band EPR spectrometer, spectral shapes and spin distribution are accurately recovered from two projections and a spectral window which is comparable to the maximum linewidth of the sample.

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Section: Cramér-rao Bound On Error Variancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A parametric approach to spectral–spatial EPR imaging

Som

Potter

Ahmad

et al. 2007

Journal of Magnetic Resonance

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“…The resolution is 24 mm full width at half-maximum at the center and 20 mm at a 10 cm radius of the reconstructed slice in the high speed scan. Every 12 s tomographic images were reconstructed using the fil tered backprojection method (Shepp and Logan, 1974) with an attenuation correction program (Sorenson, 1974).…”

Section: Determination Of Flow and Rate Constantsmentioning

confidence: 99%

Determination of Flow and Rate Constants in a Kinetic Model of [^99mTc]-Hexamethyl-Propylene Amine Oxime in the Human Brain

Oba

Seki

Higashi

et al. 1988

J Cereb Blood Flow Metab

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Summary:The values for flow and rate constants for a kinetic model of [99mTc]-hexamethylpropyleneamine ox ime (HM-PAO) distribution in the human brain were de termined. The single-pass extraction ratio of HM-PAO was also determined in the rat brain by the indicator dif fusion method; a value of 0.90 ± 0.02 (mean ± SEM, n = 5) was obtained. Time course data of brain activity and arterial blood activity of the tracer were fitted to a four compartment model: Values of blood flow and the first order rate constants for backdiffusion of the diffusible tracer from brain to blood (k2), conversion of the li pophilic tracer to the hydrophilic one in brain (k3), and conversion of the diffusible tracer to the nondiffusible one in blood (ks) were determined. Conversion of hydrophilic tracer back to a lipophilic form in both blood and brain was assumed to be negligible during the course of the this poor contrast, we describe here the direct de termination of cerebral blood flow values in the hu man brain along with the rate constants for a kinetic model describing the in vivo distribution of HM PAO as presented by Lassen et aI. (1987a). THEORYThe model for quantitating cerebral blood flow using HM-PAO that is examined in this study is shown in Fig. 1 (Lassen et aI. , 1987a). In this model, the first compartment is the diffusible tracer in the arterial blood at concentration CaD and the second compartment is the nondiffusible tracer that is trapped in the blood (Sharp et aI. , 1986; Matsuda et aI. , 1987 Matsuda et aI. , , 1988 Neirinckx et aI. , 1987a Neirinckx et aI. , , 1987b) at concentration CaNDo The third compartment is the lipophilic diffusible tracer inside the brain tissue at concentration CbD and the fourth compartment is

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“…2. The filtered backprojection algorithm with the Shepp filter (Shepp et al, 1974) was used for PCT reconstruction. Images were reconstructed to a 100 x 100 array size with pixel-to-pixel dis tance of 0.25 cm.…”

Section: Simulation Studiesmentioning

confidence: 99%

Measurement of Local Blood Flow and Distribution Volume with Short-Lived Isotopes: A General Input Technique

Huang

Carson

Phelps

1982

J Cereb Blood Flow Metab

119

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Summary: A new technique for measuring local blood flow and distribution volume is proposed. The technique uses short-lived isotopes but is different from the equilibrium method in that no constant input is necessary, and no as sumption about distribution volume is needed. The theoretical basis of the technique is developed, and the results of a computer-simulation study are pre sented to show the potential of the technique. The technique is expected to be easier to perform and to give more accurate flow values than the equilibrium method.

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The Fourier reconstruction of a head section

Cited by 1,875 publications

References 0 publications

A parametric approach to spectral–spatial EPR imaging

A parametric approach to spectral–spatial EPR imaging

Determination of Flow and Rate Constants in a Kinetic Model of [^99mTc]-Hexamethyl-Propylene Amine Oxime in the Human Brain

Measurement of Local Blood Flow and Distribution Volume with Short-Lived Isotopes: A General Input Technique

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The Fourier reconstruction of a head section

Cited by 1,875 publications

References 0 publications

A parametric approach to spectral–spatial EPR imaging

A parametric approach to spectral–spatial EPR imaging

Determination of Flow and Rate Constants in a Kinetic Model of [99mTc]-Hexamethyl-Propylene Amine Oxime in the Human Brain

Measurement of Local Blood Flow and Distribution Volume with Short-Lived Isotopes: A General Input Technique

Contact Info

Product

Resources

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Determination of Flow and Rate Constants in a Kinetic Model of [^99mTc]-Hexamethyl-Propylene Amine Oxime in the Human Brain