Magnetic resonance imaging of freely moving objects: prospective real-time motion correction using an external optical motion tracking system

Zaitsev, Maxim; Dold, Christian; Sakas, Georgios; Hennig, Jürgen; Speck, Oliver

doi:10.1016/j.neuroimage.2006.01.039

Cited by 353 publications

(420 citation statements)

References 14 publications

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“…Infrared diodes attached to the camera body illuminate the scene inside the scanner bore. An independent tracking computer processes the captured camera images as described in [8,9]. The patient's pose at the beginning of each scan serves as initial point of reference to describe the motion throughout the scan.…”

Section: Methodsmentioning

confidence: 99%

Self-encoded Marker for Optical Prospective Head Motion Correction in MRI

Forman

Aksoy

Hornegger

et al. 2010

Medical Image Computing and Computer-Assisted Intervention – MICCAI 2010

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Abstract. The tracking and compensation of patient motion during a magnetic resonance imaging (MRI) acqusition is an unsolved problem. For brain MRI, a promising approach recently suggested is to track the patient using an in-bore camera and a checkerboard marker attached to the patient's forehead. However, the possible tracking range of the head pose is limited by the locally attached marker that must be entirely visible inside the camera's narrow field of view (FOV). To overcome this shortcoming, we developed a novel self-encoded marker where each feature on the pattern is augmented with a 2-D barcode. Hence, the marker can be tracked even if it is not completely visible in the camera image. Furthermore, it offers considerable advantages over the checkerboard marker in terms of processing speed, since it makes the correspondence search of feature points and marker-model coordinates, which are required for the pose estimation, redundant. The motion correction with the novel self-encoded marker recovered a rotation of 18 • around the principal axis of the cylindrical phantom in-between two scans. After rigid registration of the resulting volumes, we measured a maximal error of 0.39 mm and 0.15 • in translation and rotation, respectively. In in-vivo experiments, the motion compensated images in scans with large motion during data acquisition indicate a correlation of 0.982 compared to a corresponding motion-free reference.

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Section: Methodsmentioning

confidence: 99%

Self-encoded Marker for Optical Prospective Head Motion Correction in MRI

Forman

Aksoy

Hornegger

et al. 2010

Medical Image Computing and Computer-Assisted Intervention – MICCAI 2010

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show abstract

“…Due to the sensitivity of fMRI to motion artifacts, it would also be necessary to restrict the range of head and body movement made by the participant within the scanner. Freedom of movement could be increased by using an optical tracking system to control for motion artifacts (Zaitsev, Dold, Sakas, Hennig, & Speck, 2006), or alternatively hand movements could be the target mimicry (cf. Guionnet et al, 2012).…”

Section: Neuroimaging Studies Of Mimicrymentioning

confidence: 99%

Cognitive mechanisms for responding to mimicry from others

Hale

Hamilton

2016

Neuroscience & Biobehavioral Reviews

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unclear how the complex behavioural effects of mimicry relate to neural systems which respond to being mimicked. Mimicry activates regions associated with mirror properties, selfother processing and reward. In this review, we outline three potential models linking these regions with cognitive consequences of being mimicked. The models suggest that positive downstream consequences of mimicry may depend upon self-other overlap, detection of contingency or low prediction error. Finally, we highlight limitations with traditional research designs and suggest alternative methods for achieving highly ecological validity and experimental control. We also highlight unanswered questions which may guide future research. Keywords: mimicry, imitation, nonverbal behaviour, neurocognitive modelsIt is often said that imitation is the sincerest form of flattery, and copying what other people do is a central feature of human social interaction (Frith & Frith, 2012; Hamilton, 2014; Meltzoff, 2010; Over & Carpenter, 2013). One way we copy others is through unconscious behavioural mimicry, also described as 'behaviour matching' (Bernieri & Rosenthal, 1991;Chartrand & Bargh, 1999) or the 'chameleon effect' (Chartrand & Bargh, 1999). This kind of mimicry occurs when one person unintentionally and effortlessly copies another person's posture or body movements without either one being aware (Chartrand & Lakin, 2013;Chartrand & van Baaren, 2009). Mimicry may extend to the contagion of facial expressions (Bavelas, Black, Lemery, & Mullett, 1986, 1987 Dimberg, Thunberg, & Elmehed, 2000;Hsee, Hatfield, Carlson, & Chemtob, 1990), moods (Hsee et al., 1990;Neumann & Strack, 2000) and speech (Giles & Powesland, 1975;Neumann & Strack, 2000).As well as mimicry, there are many other ways we coordinate our behaviour with other people during social interactions (Table 1). The umbrella term 'interpersonal coordination' covers a range of coordinated actions between two people, which can be linked in both space and time. Actions occurring at the same time are described as entrained or synchronous; this includes perfect synchrony where actions are matched in form and timing, as well as general synchrony where different actions are coordinated in time (see Table 1, column 1). Actions that occur after a delay but which are contingent on the other are termed imitation or mimicry if the form is the same, and complementary if the form is different (see column 2). There is a distinction between imitation, which is deliberate and goal-directed,and mimicry, which is unconscious and spontaneous. In this paper we will focus specifically on mimicry. For the main part we will limit our review to mimicry of postures and body movements, and we will not include literature on facial, emotional or vocal mimicry. We will also concentrate on adult mimicry rather than developmental literature. At the end, we will return to consider how future research may situate mimicry within a wider framework of interpersonal coordination. Whilst partners in real life social interac...

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“…Different attempts with external devices include locator coils, laser detectors, deuterium crystals, sonography, infrared markers, and, most recently, optical markers. 70 If used prospectively, these techniques can correct for through-plane motion; they are not time-consuming but require additional hardware and calibration of the external-device spatial coordinates to the scanner coordinates. These seem well-suited for imaging the neonatal population because of the excessive throughplane motion, but more research is required to find a safe and practical tracking device for neonates.…”

Section: External Motion-tracking Techniquesmentioning

confidence: 99%

Motion-Compensation Techniques in Neonatal and Fetal MR Imaging

Malamateniou

Malik

Counsell

et al. 2012

AJNR Am J Neuroradiol

111

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SUMMARY:Fetal and neonatal MR imaging is increasingly used as a complementary diagnostic tool to sonography. MR imaging is an ideal technique for imaging fetuses and neonates because of the absence of ionizing radiation, the superior contrast of soft tissues compared with sonography, the availability of different contrast options, and the increased FOV. Motion in the normally mobile fetus and the unsettled, sleeping, or sedated neonate during a long acquisition will decrease image quality in the form of motion artifacts, hamper image interpretation, and often necessitate a repeat MR imaging to establish a diagnosis. This article reviews current techniques of motion compensation in fetal and neonatal MR imaging, including the following: 1) motion-prevention strategies (such as adequate patient preparation, patient coaching, and sedation, when required), 2) motion-artifacts minimization methods (such as fast imaging protocols, data undersampling, and motion-resistant sequences), and 3) motion-detection/correction schemes (such as navigators and self-navigated sequences, external motion-tracking devices, and postprocessing approaches) and their application in fetal and neonatal brain MR imaging. Additionally some background on the repertoire of motion of the fetal and neonatal patient and the resulting artifacts will be presented, as well as insights into future developments and emerging techniques of motion compensation.ABBREVIATIONS: bFFE ϭ balanced fast-field echo; FLASH ϭ fast low-angle shot; G RO ϭ readout gradient; NSA ϭ number of signal averages; PROPELLER ϭ periodically rotated overlapping parallel lines with enhanced reconstruction; RF ϭ radio-frequency M R imaging is an ideal diagnostic technique for the evaluation of infants and fetuses 1-7 because of the absence of ionizing radiation, the superior contrast of soft tissues compared with sonography, and the availability of different contrast options (T1-weighted, T2-weighted, and diffusion-weighted imaging, Fig 1) to improve characterization of both anatomy and pathology. However MR imaging remains a relatively slow technique, with scanning times for most applications in the order of seconds to minutes, leaving them susceptible to motion artifacts. The normally mobile fetus and the unsettled neonate present a major difficulty because the presence of motion during a long acquisition will decrease image quality in the form of motion artifacts (Fig 2), hamper accurate image interpretation, and often necessitate a repeat MR imaging to establish a diagnosis. This may have major emotional implications for parents and can stress the tight budgets of health care providers.

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Magnetic resonance imaging of freely moving objects: prospective real-time motion correction using an external optical motion tracking system

Cited by 353 publications

References 14 publications

Self-encoded Marker for Optical Prospective Head Motion Correction in MRI

Self-encoded Marker for Optical Prospective Head Motion Correction in MRI

Cognitive mechanisms for responding to mimicry from others

Motion-Compensation Techniques in Neonatal and Fetal MR Imaging

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