64‐channel array coil for single echo acquisition magnetic resonance imaging

McDougall, Mary P.; Wright, Steven M.

doi:10.1002/mrm.20568

Cited by 101 publications

(84 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, single-echo-acquisition (SEA) was achieved using a dedicated 64-channel linear planar array that eliminated phase encoding, instead using the spatial information obtained from an array of long and parallel coils. This planar pair element design proved to be crucial for achieving well-localized field sensitivity patterns (McDougall and Wright, 2005). In other work, Hennig developed the one-voxel-one-coil (OVOC) MRencephalography technique, obtaining a reconstructed image by computing the product of a full FOV reference scan and the accelerated acquisition scan where traditional phase and frequency encoding can be selectively omitted.…”

Section: Introductionmentioning

confidence: 99%

“…To this end, dense head coil arrays consisting of 16 de Zwart et al, 2002;de Zwart et al, 2004), 23, 32 and 90 elements (Wiggins et al, 2005a;Wiggins et al, 2005b) have been constructed in support of a range of parallel acquisition applications. In addition, a dedicated 64-channel linear planar array has been developed to achieve 64-fold acceleration (McDougall and Wright, 2005). Notably, the geometric configuration of our 32-channel head array is remarkably similar to that used for electrode and super-conducting quantum interference (SQUID) sensor arrays in modern EEG and MEG systems (Hamalainen et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing

et al. 2008

View full text Add to dashboard Cite

Developments in multi-channel radio-frequency (RF) coil array technology have enabled functional magnetic resonance imaging (fMRI) with higher degrees of spatial and temporal resolution. While modest improvement in temporal acceleration has been achieved by increasing the number of RF coils, in parallel data acquisition techniques, the maximum attainable acceleration is intrinsically limited only by the amount of independent spatial information in the combined array channels. Since the geometric configuration of a large-n MRI head coil array is similar to that used in EEG electrode or MEG SQUID sensor arrays, the source localization algorithms used in MEG or EEG source imaging can be extended to also process MRI coil array data, resulting in greatly improved temporal resolution by minimizing k-space traversal during signal acquisition. Using a novel approach, we acquire multi-channel MRI head coil array data and then apply inverse reconstruction methods to obtain volumetric fMRI estimates of blood oxygenation level dependent (BOLD) contrast at unprecedented whole-brain acquisition rates of 100 ms per sample. We call this combination of techniques magnetic resonance Inverse Imaging (InI), a method that provides estimates of dynamic spatially-resolved signal change that can be used to construct statistical maps of task-related brain activity. We demonstrate the sensitivity and inter-subject reliability of volumetric InI using an eventrelated design to probe the hemodynamic signal modulations in primary visual cortex. Robust results from both single subject and group analyses demonstrate the sensitivity and feasibility of using volumetric InI in high temporal resolution investigations of human brain function.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Although the development of array coils with 32 or more elements has only recently being explored (3)(4)(5), the sensitivity advantages of highly parallel arrays of small surface coils for deep tissue have been demonstrated in theoretical analysis (6 -9). Wright and Wald (8) simulated the sensitivity vs. depth for a square planar array covering given surface area utilizing either an 8 ϫ 8 array (64 elements) or a 4 ϫ 4, 2 ϫ 2 or single coil (1 ϫ 1), all covering the same area above a lossy half plane, using a full-wave approach that assumed ideal decoupling.…”

mentioning

confidence: 99%

32‐channel 3 Tesla receive‐only phased‐array head coil with soccer‐ball element geometry

Wiggins

Triantafyllou

Potthast

et al. 2006

Magnetic Resonance in Med

351

340

View full text Add to dashboard Cite

A 32-channel 3T receive-only phased-array head coil was developed for human brain imaging. The helmet-shaped array was designed to closely fit the head with individual overlapping circular elements arranged in patterns of hexagonal and pentagonal symmetry similar to that of a soccer ball. The signalto-noise ratio (SNR) and noise amplification (g-factor) in accelerated imaging applications were quantitatively evaluated in phantom and human images and compared with commercially available head coils. The 32-channel coil showed SNR gains of up to 3.5-fold in the cortex and 1.4-fold in the corpus callosum compared to a (larger) commercial eight-channel head coil. The experimentally measured g-factor performance of the helmet array showed significant improvement compared to the eightchannel array (peak g-factor 59% and 26% of the eight-channel values for four-and fivefold acceleration).

show abstract

“…It is important to note that HAPI can be implemented on a moderately equipped conventional scanner with an eightchannel coil, unlike other single-echo imaging techniques 5,6 that require RF coil arrays with 64 to 90 elements. The essence of the HAPI technique is to densely sample a projection, which should be acquired at an angle other than 0…”

Section: Discussionmentioning

confidence: 99%

Highly accelerated projection imaging with coil sensitivity encoding for rapid MRI

2013

View full text Add to dashboard Cite

Purpose: Rapid magnetic resonance imaging (MRI) acquisition is typically achieved by acquiring all or most lines of k-space after one radio frequency (RF) excitation. Parallel imaging techniques can further accelerate data acquisition by acquiring fewer phase-encoded lines and utilizing the spatial sensitivity information of the RF coil arrays. The goal of this study was to develop a new MRI data acquisition and reconstruction technique that is capable of reconstructing a two-dimensional (2D) image using highly undersampled k-space data without any special hardware. Such a technique would be very efficient, as it would significantly reduce the time wasted during multiple RF excitations or phase encoding and gradient switching periods. Methods: The essence of this new technique is to densely sample a small number of projections, which should be acquired at an angle other than 0• or multiples of 45• . This results in multiple rays passing through a voxel and provides new and independent measurements for each voxel. Then the images are reconstructed using the unique information coming from these projections combined with RF coil sensitivity profiles. The feasibility of this new technique was investigated with realistic simulations and experimental studies using a phantom and compared with conventional nonuniform fast Fourier transform technique. Eigenvalue analysis and error calculations were conducted to find optimal projection angles and minimum requirements for dense sampling. Results: Reconstruction of 64 × 64 images was done using a single projection from simulated data under different noise levels. Simulated reconstruction was also tested with two projections to assess the improvement. Experimental phantom images were reconstructed at higher resolution using 4, 8, and 16 projections. Cross-sectional profiles illustrate that the new technique resolved compartment boundaries clearly. Conclusions: Simulations demonstrated that only a single k-space line might be sufficient to reconstruct a 2D image using this new technique. Experimental results showed that this is a promising new technique for fast imaging. Using the information from the simulations and fast imaging parameters published in the literature, it could be predicted that a two-dimensional image could be acquired in about 10 ms. One of the major advantages of this new technique is that it does not require any additional hardware and can be implemented on a conventional scanner with an eight-channel coil.

show abstract

64‐channel array coil for single echo acquisition magnetic resonance imaging

Cited by 101 publications

References 37 publications

Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing

Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing

32‐channel 3 Tesla receive‐only phased‐array head coil with soccer‐ball element geometry

Highly accelerated projection imaging with coil sensitivity encoding for rapid MRI

Contact Info

Product

Resources

About