Quantitative density profiling with pure phase encoding and a dedicated 1D gradient

Deka, Kumud; MacMillan, M.B.; Ouriadov, Alexei; Mastikhin, Igor V.; Young, J.J.; Glover, Paul; Ziegler, Gregory R.; Balcom, Bruce J.

doi:10.1016/j.jmr.2005.08.009

Cited by 35 publications

(16 citation statements)

References 17 publications

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“…Hence, our raw images were T 2 * -weighted even with the shortest available encoding delay. This effect was corrected for by extrapolating the relation S(z,s) = s(z) exp[À(s/T 2 * ) 2 ]sina to zero encoding delay; a is the rf flip angle [17,18]. Hence, a series of images were collected with different encoding delays s and correspondingly adjusted gradient strength to maintain a constant k-space step [19].…”

Section: Mri Methodologymentioning

confidence: 99%

MRI profiles over very wide concentration ranges: Application to swelling of a bentonite clay

Dvinskikh

Szutkowski

Furó

2009

Journal of Magnetic Resonance

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Section: Mri Methodologymentioning

confidence: 99%

MRI profiles over very wide concentration ranges: Application to swelling of a bentonite clay

Dvinskikh

Szutkowski

Furó

2009

Journal of Magnetic Resonance

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“…1D Double half-k (DHK) SPRITE (Deka et al, 2005) is so called because it is a one-dimensional SPRITE sequence (Balcom et al, 1996), which covers each half of k-space separately. When coupled with a custom high strength magnetic field gradient and a novel application of zero filling, it enables us to acquire images of very short lived signals such as the solid fat component in chocolate.…”

Section: Introductionmentioning

confidence: 99%

Spatial mapping of solid and liquid lipid in confectionery products using a 1D centric SPRITE MRI technique

Deka

MacMillan

Ziegler

et al. 2006

Food Research International

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“…The double half k-space 1D SPRITE imaging method (DHK SPRITE) has proven to be a robust and general method to generate fluid content images (spin density images) in porous media [25]. However broad filter widths, and low flip angle RF pulses, yield sub-optimal S/N images.…”

Section: Image Sensitivitymentioning

confidence: 99%

Spin echo SPI methods for quantitative analysis of fluids in porous media

Li¹,

Han²,

Balcom³

2009

Journal of Magnetic Resonance

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Fluid density imaging is highly desirable in a wide variety of porous media measurements. The SPRITE class of MRI methods has proven to be robust and general in their ability to generate density images in porous media, however the short encoding times required, with correspondingly high magnetic field gradient strengths and filter widths, and low flip angle RF pulses, yield sub-optimal S/N images, especially at low static field strength. This paper explores two implementations of pure phase encode spin echo 1D imaging, with application to a proposed new petroleum reservoir core analysis measurement. In the first implementation of the pulse sequence, we modify the spin echo single point imaging (SE-SPI) technique to acquire the k-space origin data point, with a near zero evolution time, from the free induction decay (FID) following a 90 degrees excitation pulse. Subsequent k-space data points are acquired by separately phase encoding individual echoes in a multi-echo acquisition. T(2) attenuation of the echo train yields an image convolution which causes blurring. The T(2) blur effect is moderate for porous media with T(2) lifetime distributions longer than 5 ms. As a robust, high S/N, and fast 1D imaging method, this method will be highly complementary to SPRITE techniques for the quantitative analysis of fluid content in porous media. In the second implementation of the SE-SPI pulse sequence, modification of the basic measurement permits fast determination of spatially resolved T(2) distributions in porous media through separately phase encoding each echo in a multi-echo CPMG pulse train. An individual T(2) weighted image may be acquired from each echo. The echo time (TE) of each T(2) weighted image may be reduced to 500 micros or less. These profiles can be fit to extract a T(2) distribution from each pixel employing a variety of standard inverse Laplace transform methods. Fluid content 1D images are produced as an essential by product of determining the spatially resolved T(2) distribution. These 1D images do not suffer from a T(2) related blurring. The above SE-SPI measurements are combined to generate 1D images of the local saturation and T(2) distribution as a function of saturation, upon centrifugation of petroleum reservoir core samples. The logarithm mean T(2) is observed to shift linearly with water saturation. This new reservoir core analysis measurement may provide a valuable calibration of the Coates equation for irreducible water saturation, which has been widely implemented in NMR well logging measurements.

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Quantitative density profiling with pure phase encoding and a dedicated 1D gradient

Cited by 35 publications

References 17 publications

MRI profiles over very wide concentration ranges: Application to swelling of a bentonite clay

MRI profiles over very wide concentration ranges: Application to swelling of a bentonite clay

Spatial mapping of solid and liquid lipid in confectionery products using a 1D centric SPRITE MRI technique

Spin echo SPI methods for quantitative analysis of fluids in porous media

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