Software Implementation of Optimized Bicubic Interpolated Scan Conversion in Echocardiography

This paper presents the image-quality-guided strategy for optimization of bicubic interpolation and interpolated scan conversion algorithms. This strategy uses feature selection through line chart data visualization technique and first index of the minimum absolute difference between computed scores and ideal scores to determine the image quality guided coefficient k that changes all sixteen BIC coefficients to new coefficients on which the OBIC interpolation algorithm is based. Perceptual evaluations of cropped sectored images from Matlab software implementation of interpolated scan conversion algorithms are presented. Also, IQA metrics-based evaluation is presented and demonstrates that the overall performance of the OBIC algorithm is 92.22% when compared with BIC alone, but becomes 57.22% with all other methods mentioned.Comment: 10 pages, 9 figures, 6 table

Ultrasound Three- Dimensional Velocity Measurements by Feature Tracking

This article describes a new angle-independent method suitable for three-dimensional (3-D) blood flow velocity measurement that tracks features of the ultrasonic speckle produced by a pulse echo system. In this method, a feature is identified and followed over time to detect motion. Other blood flow velocity measurement methods typically estimate velocity using one- (1-D) or two-dimensional (2-D) spatial and time information. Speckle decorrelation due to motion in the elevation dimension may hinder this estimate of the true 3-D blood flow velocity vector. Feature tracking is a 3-D method with the ability to measure the true blood velocity vector rather than a projection onto a line or plane. Off-line experiments using a tissue phantom and a real-time volumetric ultrasound imaging system have shown that the local maximum detected value of the speckle signal may be identified and tracked for measuring velocities typical of human blood flow. The limitations of feature tracking, including the uncertainty of the peak location and the duration of the local maxima are discussed. An analysis of the expected error using this method is given

Harmonic source wavefront aberration correction for ultrasound imaging

A method is proposed which uses a lower-frequency transmit to create a known harmonic acoustical source in tissue suitable for wavefront correction without a priori assumptions of the target or requiring a transponder. The measurement and imaging steps of this method were implemented on the Duke phased array system with a two-dimensional (2-D) array. The method was tested with multiple electronic aberrators [0.39π to 1.16π radians root-mean-square (rms) at 4.17 MHz] and with a physical aberrator 0.17π radians rms at 4.17 MHz) in a variety of imaging situations. Corrections were quantified in terms of peak beam amplitude compared to the unaberrated case, with restoration between 0.6 and 36.6 dB of peak amplitude with a single correction. Standard phantom images before and after correction were obtained and showed both visible improvement and 14 dB contrast improvement after correction. This method, when combined with previous phase correction methods, may be an important step that leads to improved clinical images