Related Experiment Video
Updated: Dec 31, 2025
06:37
Quantifying Cytoskeleton Dynamics Using Differential Dynamic Microscopy
Published on: June 15, 2022
4.0K
Are SPECT MPI measures of dyssynchrony dyssynchronous?
Omaima Ali1, Maithili Shenoy2, Anas Alani3
1Department of Cardiology, Penn State Health Milton S Hershey Medical Center, Hershey, USA. oali@pennstatehealth.psu.edu.
Summary
Left ventricular mechanical dyssynchrony (LVMD) assessment using gated SPECT MPI is influenced by test type and patient alignment. Consider these factors for accurate cardiac resynchronization therapy selection.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Gated SPECT MPI assesses left ventricular mechanical dyssynchrony (LVMD) to guide cardiac resynchronization therapy (CRT) selection.
- Current LVMD assessment criteria include phase standard deviation (PSD) ≥ 43° or phase histogram bandwidth (HBW) > 38° (males) and > 30.6° (females).
- Preliminary observations suggest test type and patient alignment may impact LVMD parameter values.
Purpose of the Study:
- To evaluate the influence of test type (rest vs. stress) and valve plane alignment on LVMD parameters derived from gated SPECT MPI.
- To compare PSD and HBW values between rest and stress conditions.
- To assess the substitutability of PSD and HBW measurements using Bland-Altman analysis.
Main Methods:
- Retrospective review of 242 patients undergoing gated SPECT MPI.
- Utilized the Emory Cardiac Toolbox for LVMD parameter analysis.
- Compared PSD and HBW at rest and stress using Pearson correlation and Bland-Altman analysis.
Main Results:
- Statistically significant differences were observed in mean PSD and HBW between rest and stress conditions (P < 0.001).
- Proper valve plane alignment resulted in significantly lower PSD and HBW values, indicating reduced dyssynchrony (P = 0.011 for PSD, P = 0.023 for HBW).
- Resting measurements showed lower dyssynchrony compared to stress measurements.
Conclusions:
- Test type, specifically low-dose rest versus high-dose stress imaging, significantly affects LVMD assessment.
- Proper patient alignment during gated SPECT MPI is crucial for accurate LVMD quantification.
- These factors must be considered for reliable patient selection for CRT.
More Related Videos
09:04Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks
Published on: March 16, 2015
13.2K
08:54Performing Spectroscopy on Plasmonic Nanoparticles with Transmission-Based Nomarski-Type Differential Interference Contrast Microscopy
Published on: June 5, 2019
7.9K
Related Concept Videos
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.4K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.4K
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
1.7K
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
1.7K
01:13¹H NMR Signal Multiplicity: Splitting Patterns
6.5K
When protons A and X are coupled, their nuclear spin energy levels are slightly modified. This is because the energy required to excite proton A to a spin state parallel to proton X is slightly different from the energy required for it to become anti-parallel to spin X. Consequently, there are two possible excitation frequencies for A (A1 and A2), depending on the spin state of X, and vice versa. The mutual nature of coupling implies that the difference between frequencies A1 and A2, indicated...
6.5K
01:14NMR Spectrometers: Resolution and Error Correction
993
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
993
01:16Spectrophotometry: Introduction
6.4K
Spectrophotometry is the quantitative measurement of the absorption, reflection, diffraction, or transmission of electromagnetic radiation through a material as a function of the intensity and wavelength of the radiation. A spectrophotometer is a device used to measure the change in the radiation intensity caused by its interaction with the material.
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...
6.4K
01:21Tandem Mass Spectrometry
2.2K
Tandem mass spectrometry is a technique that uses multiple mass analyzers in series to obtain a higher selectivity and reduce chemical noise during analyte detection. Instruments with multiple analyzers separated by an interaction cell enable secondary fragmentation and selected study of the fragment ions.Secondary fragmentations occur in the interaction cell and can be induced by various factors. Fragmentation induced by collision with inert gases, such as N2, Ar, He, etc., is called...
2.2K