Prospective motion correction for magnetic resonance spectroscopy using single camera retro‐grate reflector optical tracking

Andrews-Shigaki, Brian; Armstrong, B.; Zaitsev, Maxim; Ernst, Thomas

doi:10.1002/jmri.22467

Cited by 51 publications

(65 citation statements)

References 18 publications

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“…These results are consistent with recent manuscripts reporting the interest of optical information measures using different apparatus, either for prospective [31] or retrospective [32] motion correction. The optical sensor may also possess a major advantage to study cardiovascular disease on animal models with heart failure.…”

Section: Discussionsupporting

confidence: 93%

An Optical Fiber-Based Gating Device for Prospective Mouse Cardiac MRI

Sablong

Rengle

Ramgolam

et al. 2014

IEEE Trans. Biomed. Eng.

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Abstract-Prospective synchronization of MRI acquisitions on living organisms involves the monitoring of respiratory and heart motions. The electrocardiogram (ECG) signal is conventionally used to measure the cardiac cycle. However, in some circumstances, obtaining an uncorrupted ECG signal recorded on small animals with RF pulses and gradient switching is challenging. To monitor respiratory motion, an air cushion associated with a pressure sensor is commonly used but the system suffers from bulkiness. For many applications, the physiological gating information can also be derived from an MR navigated-signal. However, a compact device that can simultaneously provide respiratory and cardiac information, for both prospective gating and physiological monitoring, is desirable. This is particularly valid since small volume coils or dedicated cardiac RF coil arrays placed directly against the chest wall are required to maximize measurement sensitivity. An optic-based device designed to synchronize MRI acquisitions on small animal's respiratory and heart motion was developed using a transmit-receive pair of optical fibers. The suitability of the developed device was assessed on mice (n=10) and was based on two sets of experiments with dual cardiac and respiratory synchronization. Images acquired with prospective triggering using the opticalbased signal, ECG and the pressure sensor during the same experiment were compared between themselves in the first set. The second set compared prospective technique using optical-based device and ECG to a retrospective technique. The optical signal which was correlated to both respiratory and heart motion was totally unaffected by radiofrequency pulses or currents induced by the magnetic field gradients used for imaging. Mice heart MR images depict low visible motion artifacts with all sensors or techniques used. No significant SNR differences were found between each series of image. Full fiber optic based signal derived from heart and respiratory motion was suitable for prospective triggering of heart MR imaging. The fiber optic device performed similarly to the ECG and air pressure sensors, while providing an advantage for imaging with dedicated cardiac array coils by reducing bulk. It can be an attractive alternative for small animal MRI in difficult environments such as limited space and strong gradient switching.

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Section: Discussionsupporting

confidence: 93%

An Optical Fiber-Based Gating Device for Prospective Mouse Cardiac MRI

Sablong

Rengle

Ramgolam

et al. 2014

IEEE Trans. Biomed. Eng.

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“…Several studies have reported significantly improved spectral quality for both single-voxel spectroscopy (SVS) and 2D-MRSI, when retrospective, prospective, or a combination of both motion corrections is used (Andrews-Shigaki et al, 2011; Boer et al, 2012; de Nijs et al, 2009; Ernst and Li, 2011; Hess et al, 2012; Hess et al, 2011; Keating and Ernst, 2012; Lange et al, 2012; Lin et al, 2009; Thiel et al, 2002; Zaitsev et al, 2010). While retrospective correction alone (e.g., frequency/phase alignment of separately saved averages) can improve data quality to a certain degree (Helms and Piringer, 2001; Kim et al, 2004; Posse et al, 1993), prospective real-time motion correction (i.e., updating the MR sequence in real-time) can further improve data quality (Andrews-Shigaki et al, 2011; Hess et al, 2012; Hess et al, 2011; Lange et al, 2012; Zaitsev et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…While retrospective correction alone (e.g., frequency/phase alignment of separately saved averages) can improve data quality to a certain degree (Helms and Piringer, 2001; Kim et al, 2004; Posse et al, 1993), prospective real-time motion correction (i.e., updating the MR sequence in real-time) can further improve data quality (Andrews-Shigaki et al, 2011; Hess et al, 2012; Hess et al, 2011; Lange et al, 2012; Zaitsev et al, 2010). …”

Section: Introductionmentioning

confidence: 99%

Real-time motion- and B0-correction for LASER-localized spiral-accelerated 3D-MRSI of the brain at 3T

et al. 2014

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The full potential of magnetic resonance spectroscopic imaging (MRSI) is often limited by localization artifacts, motion-related artifacts, scanner instabilities, and long measurement times. Localized adiabatic selective refocusing (LASER) provides accurate B1-insensitive spatial excitation even at high magnetic fields. Spiral encoding accelerates MRSI acquisition, and thus, enables 3D-coverage without compromising spatial resolution. Real-time position-and shim/frequency-tracking using MR navigators correct motion- and scanner instability-related artifacts. Each of these three advanced MRI techniques provides superior MRSI data compared to commonly used methods. In this work, we integrated in a single pulse sequence these three promising approaches. Real-time correction of motion, shim, and frequency-drifts using volumetric dual-contrast echo planar imaging-based navigators were implemented in an MRSI sequence that uses low-power gradient modulated short-echo time LASER localization and time efficient spiral readouts, in order to provide fast and robust 3D-MRSI in the human brain at 3T. The proposed sequence was demonstrated to be insensitive to motion- and scanner drift-related degradations of MRSI data in both phantoms and volunteers. Motion and scanner drift artifacts were eliminated and excellent spectral quality was recovered in the presence of strong movement. Our results confirm the expected benefits of combining a spiral 3D-LASER-MRSI sequence with real-time correction. The new sequence provides accurate, fast, and robust 3D metabolic imaging of the human brain at 3T. This will further facilitate the use of 3D-MRSI for neuroscience and clinical applications.

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“…These methods are more difficult to apply in the clinical situation due to the additional hardware, calibration, and markers affixed to the patient. However, in the research setting, extremely high-resolution imaging is possible under ideal conditions (Andrews-Shigaki et al, 2011;Schulz et al, 2012;Zaitsev et al, 2006).…”

Section: Motion Correctionmentioning

confidence: 99%

“…If extrinsic sensors are used, customization of the sequence is much reduced and motion can be estimated more rapidly and not necessarily at intervals dictated by the sequence structure. Optical systems using reflective markers (Zaitsev, Dold, Sakas, Hennig, & Speck, 2006) or retrograte reflectors (Andrews-Shigaki, Armstrong, Zaitsev, & Ernst, 2011) can be used to rapidly estimate head pose. The sequence is modified to track the head position, without affecting total acquisition time.…”

Section: Motion Correctionmentioning

confidence: 99%