Miniaturized multi-coil arrays for functional planar imaging with a single-sided NMR sensor

Oligschläger, Dirk; Lehmkuhl, Sören; Watzlaw, Jan; Benders, Stefan; Boever, Eva De; Rehorn, Christian; Vossel, Manuel; Schnakenberg, Uwe; Blümich, Bernhard

doi:10.1016/j.jmr.2015.02.001

Cited by 21 publications

(11 citation statements)

References 23 publications

(34 reference statements)

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“…Although all the samples displayed good agreement between measurements taken at different depths, it is conceivable that in some situations measurements could be sensitive to the precise positioning of the sensor. Alternative designs of portable‐NMR instrumentation may be able to alleviate both these issues by enabling a larger sensing volume …”

Section: Discussionmentioning

confidence: 99%

Transverse relaxation‐based assessment of mammographic density and breast tissue composition by single‐sided portable NMR

Ali

Tourell

Hugo

et al. 2019

Magnetic Resonance in Med

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Purpose: Elevated mammographic density (MD) is an independent risk factor for breast cancer (BC) as well as a source of masking in X-ray mammography.High-frequency longitudinal monitoring of MD could also be beneficial in hormonal BC prevention, where early MD changes herald the treatment's success. We present a novel approach to quantification of MD in breast tissue using single-sided portable NMR. Its development was motivated by the low cost of portable-NMR instrumentation, the suitability for measurements in vivo, and the absence of ionizing radiation. Methods: Five breast slices were obtained from three patients undergoing prophylactic mastectomy or breast reduction surgery. Carr-Purcell-Meiboom-Gill (CPMG) relaxation curves were measured from (1) regions of high and low MD (HMD and LMD, respectively) in the full breast slices; (2) the same regions excised from the full slices; and (3) excised samples after H 2 O-D 2 O replacement. T 2 distributions were reconstructed from the CPMG decays using inverse Laplace transform. Results: Two major peaks, identified as fat and water, were consistently observed in the T 2 distributions of HMD regions. The LMD T 2 distributions were dominated by the fat peak. The relative areas of the two peaks exhibited statistically significant (P < .005) differences between HMD and LMD regions, enabling their classification as HMD or LMD. The relative-area distributions exhibited no statistically significant differences between full slices and excised samples. Conclusion: T 2 -based portable-NMR analysis is a novel approach to MD quantification. The ability to quantify tissue composition, combined with the low cost of instrumentation, make this approach promising for clinical applications. 1200 | ALI et AL. K E Y W O R D S breast cancer, mammographic density, NMR-MOUSE, nuclear magnetic resonance, single-sided portable NMR, transverse spin relaxation time constant (T 2 )

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Section: Discussionmentioning

confidence: 99%

Transverse relaxation‐based assessment of mammographic density and breast tissue composition by single‐sided portable NMR

Ali

Tourell

Hugo

et al. 2019

Magnetic Resonance in Med

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“…The NMR-MOUSE has also been miniaturized and fitted with multilayered micro-coils (Fig. 2j, k) (Watzlaw et al, 2013;Oligschläger et al, 2014Oligschläger et al, , 2015a, by which, on the expense of 7.6-fold lower sensitivity compared to the PM5 NMR-MOUSE at 1 mm access depth, the dead time of the measurement could be reduced to a record 10 µs echo time. With its small coil, the signal from the cement regions be- tween the stone aggregate in cuts of concrete could be focused on, and with an echo time ≤ 20 µs, the hitherto hidden signals from bound water in the dry gray cement could be measured (Fig.…”

Section: The Nmr-mouse In the Housementioning

confidence: 99%

When the MOUSE leaves the house

Blümich

Anders

2021

Magn. Reson.

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Abstract. Change is inherent to time being transient. With the NMR-MOUSE (MObile Universal Surface Explorer) having matured into an established NMR tool for nondestructive testing of materials, this forward-looking retrospective assesses the challenges the NMR-MOUSE faced when deployed outside a protected laboratory and how its performance quality can be maintained and improved when operated under adverse conditions in foreign environments. This work is dedicated to my dear colleague and friend Geoffrey Bodenhausen on the occasion of his crossing an honorable timeline in appreciation of his ever-continuing success of fueling the dynamics of magnetic resonance.

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“…Therefore, each new technique utilized for single-sided devices is often evaluated in terms of its sensitivity. The relative SNR

\propto \frac{B_{1}}{i \cdot \sqrt{R}}

[20] was used in this study to evaluate the designed RF coil, where

B_{1} / i

is the coil sensitivity that is defined by the law of reciprocity as the magnetic flux density B 1 caused by an RF current

i

passes through the coil, and

R

is the alternating-current impedance resistance of the coil. A common printed circuit board (PCB) coil with the same size as the designed RF coil was available for comparison.…”

Section: Sensor Designmentioning

confidence: 99%

“…The most common design of RF coils explored for UMRI sensors is a single current loop in the plane for a B 1 field perpendicular to the face of the coil and a figure-of-eight-like coil with two opposing current loops for a B 1 field parallel to the face of the coil [4]. Despite several special RF coils, such as microstructured [20] and arc-shaped spiral RF coils [21], adopted for a signal-to-noise ratio (SNR) and sensitivity improvement, the RF coil design considerations for UMRI systems have been largely overshadowed by the attention given to single-sided magnet design. RF coil efficiency is critical at low fields typical of single-sided systems.…”

Section: Introductionmentioning

confidence: 99%

The Novel Design of a Single-Sided MRI Probe for Assessing Burn Depth

et al. 2017

Sensors

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Burn depth assessment in clinics is still inaccurate because of the lack of feasible and practical testing devices and methods. Therefore, this process often depends on subjective judgment of burn surgeons. In this study, a new unilateral magnetic resonance imaging (UMRI) sensor equipped with a 2D gradient coil system was established, and we attempted to assess burns using unilateral nuclear magnetic resonance devices. A reduced Halbach magnet was utilized to generate a magnetic field that was relatively homogeneous on a target plane with a suitable field of view for 2D spatial localization. A uniplanar gradient coil system was designed by utilizing the mainstream target field method, and a uniplanar RF (radio frequency) coil was designed by using a time-harmonic inverse method for the UMRI sensor. A 2D image of the cross sections of a simple burn model was obtained by a fast 2D pure-phase encoding imaging method. The design details of the novel single-sided MRI probe and imaging tests are also presented.

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Miniaturized multi-coil arrays for functional planar imaging with a single-sided NMR sensor

Cited by 21 publications

References 23 publications

Transverse relaxation‐based assessment of mammographic density and breast tissue composition by single‐sided portable NMR

Transverse relaxation‐based assessment of mammographic density and breast tissue composition by single‐sided portable NMR

When the MOUSE leaves the house

The Novel Design of a Single-Sided MRI Probe for Assessing Burn Depth

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