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Accelerometer-Based Method for Extracting Respiratory and Cardiac Gating Information for Dual Gating during Nuclear Medicine Imaging.

Jafari Tadi M, Koivisto T, Pänkäälä M, Paasio A - Int J Biomed Imaging (2014)

Bottom Line: Both respiratory and cardiac motions reduce the quality and consistency of medical imaging specifically in nuclear medicine imaging.The correct information about the status of ventricles and atria helps us to create an improved estimate for quiescent phases within a cardiac cycle.The correlation of ADR signals with the reference respiration belt was investigated using Pearson correlation.

View Article: PubMed Central - PubMed

Affiliation: Technology Research Center, Brahea Center, University of Turku, 20520 Turku, Finland ; Department of Clinical Physiology and Nuclear Medicine, Faculty of Medicine, University of Turku, 20520 Turku, Finland.

ABSTRACT
Both respiratory and cardiac motions reduce the quality and consistency of medical imaging specifically in nuclear medicine imaging. Motion artifacts can be eliminated by gating the image acquisition based on the respiratory phase and cardiac contractions throughout the medical imaging procedure. Electrocardiography (ECG), 3-axis accelerometer, and respiration belt data were processed and analyzed from ten healthy volunteers. Seismocardiography (SCG) is a noninvasive accelerometer-based method that measures accelerations caused by respiration and myocardial movements. This study was conducted to investigate the feasibility of the accelerometer-based method in dual gating technique. The SCG provides accelerometer-derived respiratory (ADR) data and accurate information about quiescent phases within the cardiac cycle. The correct information about the status of ventricles and atria helps us to create an improved estimate for quiescent phases within a cardiac cycle. The correlation of ADR signals with the reference respiration belt was investigated using Pearson correlation. High linear correlation was observed between accelerometer-based measurement and reference measurement methods (ECG and Respiration belt). Above all, due to the simplicity of the proposed method, the technique has high potential to be applied in dual gating in clinical cardiac positron emission tomography (PET) to obtain motion-free images in the future.

No MeSH data available.


Related in: MedlinePlus

The windowing technique for detecting AO and AC peaks.
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Related In: Results  -  Collection


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fig5: The windowing technique for detecting AO and AC peaks.

Mentions: Figure 5 represents the basis of windowing method in time domain. Since detection of the R peaks across the ECG signal was straightforward, the R peaks were found applicable to be used as reliable time points for detecting the cardiac events throughout the SCG signal. Thus, detection of R peaks allowed us to detect the AO peaks by using time-domain windows before and after each R peak. The length of the windows varies case by case based on the heart rate of the subjects. Across the first taken window, the maximum value of the signal was calculated in order to find the AO peak. Then, the second window was taken few hundred milliseconds before and after the next R peak and the current detected AO, respectively. The length of the second window was longer than the first one due to uncertainty to find the exact location of the AC time point after AO point. The AC peaks were detected by calculating the minimum value of the signal within the taken window based on what [4] has determined for the location of AC. With detection of the exact locations of cardiac phases, reliable precise measurements were performed to obtain the electromechanical cardiac intervals such as R-R, R-AO, R-AC, AO-AO, and AO-AC intervals.


Accelerometer-Based Method for Extracting Respiratory and Cardiac Gating Information for Dual Gating during Nuclear Medicine Imaging.

Jafari Tadi M, Koivisto T, Pänkäälä M, Paasio A - Int J Biomed Imaging (2014)

The windowing technique for detecting AO and AC peaks.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4120481&req=5

fig5: The windowing technique for detecting AO and AC peaks.
Mentions: Figure 5 represents the basis of windowing method in time domain. Since detection of the R peaks across the ECG signal was straightforward, the R peaks were found applicable to be used as reliable time points for detecting the cardiac events throughout the SCG signal. Thus, detection of R peaks allowed us to detect the AO peaks by using time-domain windows before and after each R peak. The length of the windows varies case by case based on the heart rate of the subjects. Across the first taken window, the maximum value of the signal was calculated in order to find the AO peak. Then, the second window was taken few hundred milliseconds before and after the next R peak and the current detected AO, respectively. The length of the second window was longer than the first one due to uncertainty to find the exact location of the AC time point after AO point. The AC peaks were detected by calculating the minimum value of the signal within the taken window based on what [4] has determined for the location of AC. With detection of the exact locations of cardiac phases, reliable precise measurements were performed to obtain the electromechanical cardiac intervals such as R-R, R-AO, R-AC, AO-AO, and AO-AC intervals.

Bottom Line: Both respiratory and cardiac motions reduce the quality and consistency of medical imaging specifically in nuclear medicine imaging.The correct information about the status of ventricles and atria helps us to create an improved estimate for quiescent phases within a cardiac cycle.The correlation of ADR signals with the reference respiration belt was investigated using Pearson correlation.

View Article: PubMed Central - PubMed

Affiliation: Technology Research Center, Brahea Center, University of Turku, 20520 Turku, Finland ; Department of Clinical Physiology and Nuclear Medicine, Faculty of Medicine, University of Turku, 20520 Turku, Finland.

ABSTRACT
Both respiratory and cardiac motions reduce the quality and consistency of medical imaging specifically in nuclear medicine imaging. Motion artifacts can be eliminated by gating the image acquisition based on the respiratory phase and cardiac contractions throughout the medical imaging procedure. Electrocardiography (ECG), 3-axis accelerometer, and respiration belt data were processed and analyzed from ten healthy volunteers. Seismocardiography (SCG) is a noninvasive accelerometer-based method that measures accelerations caused by respiration and myocardial movements. This study was conducted to investigate the feasibility of the accelerometer-based method in dual gating technique. The SCG provides accelerometer-derived respiratory (ADR) data and accurate information about quiescent phases within the cardiac cycle. The correct information about the status of ventricles and atria helps us to create an improved estimate for quiescent phases within a cardiac cycle. The correlation of ADR signals with the reference respiration belt was investigated using Pearson correlation. High linear correlation was observed between accelerometer-based measurement and reference measurement methods (ECG and Respiration belt). Above all, due to the simplicity of the proposed method, the technique has high potential to be applied in dual gating in clinical cardiac positron emission tomography (PET) to obtain motion-free images in the future.

No MeSH data available.


Related in: MedlinePlus