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Updated: May 14, 2026
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Contrast-Enhanced Subharmonic Aided Pressure Estimation (SHAPE) Using Ultrasound Imaging with a Focus on Identifying Portal Hypertension
Published on: December 5, 2020
On the implementation of an automated acoustic output optimization algorithm for subharmonic aided pressure
J K Dave1, V G Halldorsdottir, J R Eisenbrey
1Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Ultrasonics
|January 26, 2013
Summary
This study introduces an automated algorithm to optimize ultrasound acoustic output for improved subharmonic signal analysis, enhancing pressure estimation accuracy. The findings support real-time clinical applications for monitoring portal vein pressures.
Area of Science:
- Ultrasound physics and biomedical imaging
- Medical instrumentation and signal processing
- Diagnostic ultrasound applications
Background:
- Subharmonic aided pressure estimation (SHAPE) relies on specific ultrasound acoustic output (IAO) levels for accurate hydrostatic pressure measurements.
- Current SHAPE methods require offline data acquisition and analysis across all IAO levels, limiting clinical applicability.
- Optimizing IAO is crucial for enhancing the reliability and efficiency of SHAPE.
Purpose of the Study:
- To develop and validate an automated algorithm for identifying optimal IAO levels for SHAPE.
- To investigate the impact of pulse length on SHAPE performance at optimized IAO levels.
- To assess the feasibility of real-time clinical pressure monitoring using the developed SHAPE optimization approach.
Main Methods:
- An automated IAO optimization algorithm was developed and implemented on a Logiq 9 ultrasound scanner.
- A logistic equation fitting function was used to determine the optimal IAO level based on subharmonic signal amplitudes.
- The optimized IAO level's efficacy was evaluated in vivo for monitoring canine portal vein pressures using Sonazoid microbubbles, with varying pulse lengths (4, 8, 16 cycles).
Main Results:
- The automated algorithm successfully identified optimal IAO levels for SHAPE in canines, ranging from 6% to 40%.
- The best correlation between portal vein pressures and subharmonic amplitudes was achieved with the optimized IAO and 4 transmit cycles (r=-0.89, p<0.01).
- Subharmonic amplitudes showed significant differences (p<0.01) before and after pressure changes only with the optimized IAO and 4 transmit cycles.
Conclusions:
- A novel algorithm for optimizing IAO levels for SHAPE has been developed and validated.
- The optimized IAO level, particularly with 4 transmit cycles, significantly improves the accuracy and reliability of ultrasound-based pressure estimation.
- This advancement holds promise for enabling real-time clinical applications of SHAPE for pressure monitoring.
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