Ultrasound-based Intima-Media Thickness Measurements
Develop a standard technique and demonstrate adequate precision for measurement of intima-media thickness (IMT) for routine clinical use.
Carotid Artery Intima Media Thickness
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Determination of the Precision and Clinical Utility of Ultrasound-based Intima-Media Thickness Measurements|
- The primary statistical endpoint for this study is to determine the standard deviation and 95% confidence interval of IMT measurements obtained using our standard method. [ Time Frame: Four years ] [ Designated as safety issue: No ]
- Standard deviation and 95% confidence interval of our IMT measurement method considering data subsets with variable US image quality levels, and different levels of image plane correlation. [ Time Frame: Two years ] [ Designated as safety issue: No ]
|Study Start Date:||December 2002|
|Study Completion Date:||September 2009|
|Primary Completion Date:||September 2009 (Final data collection date for primary outcome measure)|
Men, age 35 to 65, being seen at the Mayo Clinic Department of Cardiovascular Health clinic, or has an appointment for a carotid duplex ultrasound exam.
Women, age 35 to 65, being seen at the Mayo Clinic Department of Cardiovascular Health clinic, or has an appointment for a carotid duplex ultrasound exam.
IMT is measured using software to analyze ECG-gated US image sequences acquired using a standard protocol. Two sonographers acquire images and measure IMT for 100 vessels. IMT technique standard deviation (SD) is determined by assuming normally distributed measurements, and dividing the SD of the 100 (paired) IMT differences by sqrt(2). This SD will be taken as measures of precision of the IMT technique.