Development of a Carotid Vulnerable Plaque Phantom Model Evaluated by Pixel Distribution Analysis

Area of Science:

• Biomedical Imaging
• Vascular Ultrasound
• Medical Device Development

Background:

• Carotid artery plaque vulnerability, characterized by lipids and intra-plaque hemorrhage, is a major contributor to cardiovascular events.
• Ultrasound imaging shows potential for identifying plaque tissue types linked to rupture risk.
• Pixel distribution analysis (PDA) is an imaging method for assessing plaque composition by assigning grayscale ranges to tissue types.

Purpose of the Study:

• To develop an in vitro vulnerable carotid plaque mimic (phantom).
• To establish corresponding PDA grayscale ranges for known rat tissue types (fat, muscle, bone).
• To evaluate the accuracy of different PDA grayscale range sets in identifying tissue composition.

Main Methods:

• Created an in vitro plaque phantom using rat tissue types: fat, muscle, and bone.
• Established two sets of PDA grayscale ranges: a combined tissue set and an individual tissue subtype set.
• Tested PDA ranges on simulated heterogeneous plaque types and analyzed pixel distribution accuracy.

Main Results:

• The individual tissue set grayscale ranges detected significantly more pixels within the correct tissue category compared to the combined set (p < 0.05).
• Established specific PDA grayscale ranges for various tissue subtypes, noting overlapping ranges between certain types.
• Demonstrated the effectiveness of the phantom and PDA method in assessing plaque heterogeneity.

Conclusions:

• The developed phantom and individual tissue set PDA method offer a novel approach to assess carotid plaque heterogeneity.
• This method can potentially infer tissue type composition in clinical ultrasound imaging.
• The plaque phantom serves as a valuable platform for future development and testing of novel composition analysis techniques.