Ultrasound‐based sensors to monitor physiological motion

2021 ◽  
Author(s):  
Bruno Madore ◽  
Frank Preiswerk ◽  
Jeremy Bredfeldt ◽  
Shenyan Zong ◽  
Cheng‐Chieh Cheng
Keyword(s):  
Author(s):  
Johannes Mayer ◽  
Thomas-Heinrich Wurster ◽  
Tobias Schaeffter ◽  
Ulf Landmesser ◽  
Andreas Morguet ◽  
...  

Abstract Background Cardiac PET has recently found novel applications in coronary atherosclerosis imaging using [18F]NaF as a radiotracer, highlighting vulnerable plaques. However, the resulting uptakes are relatively small, and cardiac motion and respiration-induced movement of the heart can impair the reconstructed images due to motion blurring and attenuation correction mismatches. This study aimed to apply an MR-based motion compensation framework to [18F]NaF data yielding high-resolution motion-compensated PET and MR images. Methods Free-breathing 3-dimensional Dixon MR data were acquired, retrospectively binned into multiple respiratory and cardiac motion states, and split into fat and water fraction using a model-based reconstruction framework. From the dynamic MR reconstructions, both a non-rigid cardiorespiratory motion model and a motion-resolved attenuation map were generated and applied to the PET data to improve image quality. The approach was tested in 10 patients and focal tracer hotspots were evaluated concerning their target-to-background ratio, contrast-to-background ratio, and their diameter. Results MR-based motion models were successfully applied to compensate for physiological motion in both PET and MR. Target-to-background ratios of identified plaques improved by 7 ± 7%, contrast-to-background ratios by 26 ± 38%, and the plaque diameter decreased by −22 ± 18%. MR-based dynamic attenuation correction strongly reduced attenuation correction artefacts and was not affected by stent-related signal voids in the underlying MR reconstructions. Conclusions The MR-based motion correction framework presented here can improve the target-to-background, contrast-to-background, and width of focal tracer hotspots in the coronary system. The dynamic attenuation correction could effectively mitigate the risk of attenuation correction artefacts in the coronaries at the lung-soft tissue boundary. In combination, this could enable a more reproducible and reliable plaque localisation.


2007 ◽  
Vol 33 (7) ◽  
pp. 1149-1166 ◽  
Author(s):  
Brian J. Fahey ◽  
Mark L. Palmeri ◽  
Gregg E. Trahey

1971 ◽  
Vol 9 (4) ◽  
pp. 401-402
Author(s):  
R. N. Stiles ◽  
R. S. Pozos ◽  
A. C. York

10.2196/14741 ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. e14741
Author(s):  
Inge J M H Caelers ◽  
Toon F M Boselie ◽  
Kim Rijkers ◽  
Wouter L W Van Hemert ◽  
Rob A De Bie ◽  
...  

Background Physiological motion of the lumbar spine is a subject of interest for musculoskeletal health care professionals, as abnormal motion is believed to be related to lumbar conditions and complaints. Many researchers have described ranges of motion for the lumbar spine, but only a few have mentioned specific motion patterns of each individual segment during flexion and extension. These motion patterns mostly comprise the sequence of segmental initiation in sagittal rotation. However, an adequate definition of physiological motion of the lumbar spine is still lacking. The reason for this is the reporting of different ranges of motion and sequences of segmental initiation in previous studies. Furthermore, due to insufficient fields of view, none of these papers have reported on maximum flexion and extension motion patterns of L1 to S1. In the lower cervical spine, a consistent pattern of segmental contributions was recently described. In order to understand physiological motion of the lumbar spine, it is necessary to systematically study motion patterns, including the sequence of segmental contribution, of vertebrae L1 to S1 in healthy individuals during maximum flexion and extension. Objective This study aims to define the lumbar spines’ physiological motion pattern of vertebrae L1, L2, L3, L4, L5, and S1 by determining the sequence of segmental contribution and the sequence of segmental initiation of motion in sagittal rotation of each vertebra during maximum flexion and extension. The secondary endpoint will be exploring the possibility of analyzing the intervertebral horizontal and vertical translation of each vertebra during maximum flexion and extension. Methods Cinematographic recordings will be performed on 11 healthy male participants, aged 18-25 years, without a history of spine problems. Cinematographic flexion and extension recordings will be made at two time points with a minimum 2-week interval in between. Results The study has been approved by the local institutional medical ethical committee (Medical Research Ethics Committee of Zuyderland and Zuyd University of Applied Sciences) on September 24, 2018. Inclusion of participants will be completed in 2020. Conclusions If successful, these physiological motion patterns can be compared with motion patterns of patients with lumbar conditions before or after surgery. Ultimately, researchers may be able to determine differences in biomechanics that can potentially be linked to physical complaints like low back pain. Trial Registration ClinicalTrials.gov NCT03737227; https://clinicaltrials.gov/ct2/show/NCT03737227 International Registered Report Identifier (IRRID) DERR1-10.2196/14741


2018 ◽  
Author(s):  
Sean C Warren ◽  
Max Nobis ◽  
Astrid Magenau ◽  
Yousuf H Mohammed ◽  
David Herrmann ◽  
...  

Author(s):  
Amy D. Droitcour ◽  
Olga Boric-Lubecke
Keyword(s):  

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