The main objectives of the original application were as follows: 1) to re-program the Prosound carotid IMT assessment method to utilize more compact hardware; and 2) to test longitudinal transducer positioning with stacking (modified Beach method) of the carotid artery and jugular vein to obtain more reproducible IMT measurements have been completed. Technology for on-line display of baseline and real-time images and a mechanical rotation transducer holding device have been developed. The investigators have reduced IMT measurement variability by 50% (coefficient of variation, CV, from 3.25% to 1.60%) using these newest developments to acquire IMT images. Preliminary data indicate that using the transducer holding device with head in-line anatomical body positioning and lateral scanning, reduces the IMT measurement CV to 0.58%. Additionally, they have developed prototypal software for multiple sequential-frame IMT analysis over full cardiac cycles which further reduces IMT measurement variability. As a continuation of their findings, the investigators propose to develop a carotid artery IMT assessment technique that will be more reproducible than any currently available technique with special application to multicenter image acquisition by: 1) more fully automating IMT image acquisition by developing an electro/mechanical rotational transducer device; and 2) developing an easily deployed automated multiple sequential-frame IMT analysis system. These improvements will effectively maximize IMT measurement reproducibility for a single center and are easily applied to a multicenter clinical setting. A major goal of this continuation application is to deploy their newest and most highly reproducible IMT image acquisition and processing methodology across three clinical sites and determine the cross-sectional and longitudinal variability of this new standardized automated methodology for measuring IMT in a multicenter setting. The investigators state that this methodology has important implications since reduced IMT measurement variability will result in reduced sample size requirements and costs for conducting multicenter studies.
| Selzer, R H; Mack, W J; Lee, P L et al. (2001) Improved common carotid elasticity and intima-media thickness measurements from computer analysis of sequential ultrasound frames. Atherosclerosis 154:185-93 |
