Detecting High-Resolution Intramural Vascular Wall Strain Signals Using DICOM Data

Abstract

Maintaining dialysis vascular access is a source of considerable morbidity in patients with end-stage renal disease (ESRD). High-resolution radiofrequency (RF) ultrasound vascular strain imaging has been applied experimentally in the vascular access setting to assist in diagnosis and management. Unfortunately, high-resolution RF data are not routinely accessible to clinicians. In contrast, the standard DICOM formatted B-mode ultrasound data are widely accessible. However, B-mode, representing the envelope of the RF signal, is of much lower resolution. If strain imaging could use open-source B-mode data, these imaging techniques could be more broadly investigated. We conducted experiments to detect wall strain signals with submillimeter tracking resolutions ranging from 0.2 mm (3 pixels) to 0.65 mm (10 pixels) using DICOM B-mode data. We compared this submillimeter tracking to the overall vascular distensibility as the reference measurements to see if high-strain resolution strain could be detected using open-source B-Mode data. We measured the best-fit coefficient of determination between signals, expressed as the percentage of strain waveforms that exhibited a correlation with a p value of 0.05 or less. The lowest percentage was 86.7%, and most were 90% and higher. This indicates high-resolution strain signals can be detected within the vessel wall using B-mode DICOM data.

Semiautomated Software to Improve Stability and Reduce Operator‐Induced Variation in Vascular Ultrasound Speckle Tracking

“…7,10,13 Our previous open-source ultrasound software based on speckle tracking algorithms has shown significant potential in detecting changes in vascular mechanics in the postoperative period following dialysis fistula creation. [14][15][16][17][18] To evaluate and enhance the reliability and accuracy of the application of the software in a clinical setting, we conducted this study to understand the effect of user-induced and physiologic (BTB) variation on vascular distensibility. Upon finding significant user input-induced variation, we sought to develop and evaluate methods that may standardize the measurement and allow more widespread testing.…”

“…An important initial finding which corroborates our earlier studies is that the software efficiently determined the circumferential vessel wall strain (distensibility) using the speckle tracking algorithm on standard DICOM images. 14,15,17 The measurement of small changes in the motion of vessel walls with high resolution is encouraging since we used conventional ultrasound scanners and open-source DICOM data available to any clinician.…”

“…7,10,13 We have developed novel ultrasound software that allows investigation of vascular mechanics clinically. [14][15][16][17][18] This software uses standard ultrasound Digital Imaging and Communications in Medicine (DICOM) data to measure circumferential vascular wall strain (distensibility) based on speckle tracking techniques. The software allows measurements of distensibility within single and multiple cardiac cycles and can be used to track changes in wall compliance as the AVF matures.…”

“…In this study, we address the second potential source of variation. To do so, we evaluated the variability of the wall strain (distensibility) measurements as a function of user-induced variation in point selection of the top and bottom edge of arterial vessel walls (using our previously developed method), [14][15][16][17] as well as the physiologic variation in wall strain attributable to beat-to-beat (BTB) variation in pulse pressure. Observing a significant degree in measurement variation arising from the users' variation in point selection, we devised software-assisted measurement systems that implement semiautomated methods for vessel edge detection and strain peak and valley measurement.…”

“…We have developed novel ultrasound software that allows investigation of vascular mechanics clinically 14–18 . This software uses standard ultrasound Digital Imaging and Communications in Medicine (DICOM) data to measure circumferential vascular wall strain (distensibility) based on speckle tracking techniques.…”