Analysis of dynamic antral scintigraphy using empirical mode decomposition

Area of Science:

• Gastroenterology
• Signal Processing
• Medical Imaging

Background:

• Accurate estimation of antral contraction rate is crucial for assessing gastric motility.
• Conventional Fourier methods for analyzing dynamic antral scintigraphy (DAS) signals have limitations in precision.

Purpose of the Study:

• To introduce and validate a novel Empirical Mode Decomposition (EMD)-Fourier method for enhanced antral contraction rate estimation.
• To compare the performance of the EMD-Fourier method against the conventional Fourier method using DAS signals.

Main Methods:

• Applied Empirical Mode Decomposition (EMD) to decompose DAS time-activity curves (TACs) into intrinsic mode functions (IMFs).
• Estimated frequencies from the Fourier transform of each IMF to derive multiple frequency values per TAC.
• Analyzed 23 DAS TACs from healthy volunteers using both EMD-Fourier and conventional Fourier methods.

Main Results:

• The EMD-Fourier method demonstrated a significant reduction in the standard deviation (SD)-to-mean ratio, ranging from 64.3% to 85.8%.
• Mean frequencies from the third IMF (2.76 cycles/min) closely matched the normal antral contraction rate (3.0 cycles/min), with a substantial SD reduction (4.77 to 0.57, p < 0.0001).
• Other IMFs identified frequencies consistent with duodenal (11.26 ± 2.2 cycles/min) and large intestine (4.3 ± 1.3 cycles/min) contraction rates.

Conclusions:

• The EMD-Fourier method offers a more robust and precise approach for estimating antral contraction rates from DAS signals.
• This technique provides valuable insights into gastric and intestinal motility patterns.
• EMD-Fourier analysis enhances the diagnostic potential of dynamic antral scintigraphy.