Cleveland Family Study

10.14 Post-Occlusion Image Acquisition

1. The PW Doppler will be immediately turned off (i.e., duplex off).
2. The scanhead will be adjusted to maximize the color flow image and the color flow function will be turned off.
3. The artery will be horizontally displayed. If the artery is diagonally displayed, “toe” or “heel” will be added so that it becomes horizontally displayed.
4. The artery will be vertically centered on the screen and the anterior and posterior intima will be parallel to each other. The lumen will be relatively echo-free and the artery will still be in the focal zone.
5. The 1 cm zoom box will then be activated and care will be taken to ensure that it is located in the same horizontal position along the artery for accurate comparison to baseline images. The zoom function will be engaged.
6. The scanhead angle will be fine turned to optimize the anterior and posterior intima so that when the resultant image is measured there will be no ambiguity about where to place the calipers to accurately measure the inside diameter of the artery. Ideally the intima will look like a railroad track occupying the full width of the screen. The receive gain may have to be increased slightly by 1 to 2 clicks.
7. A stable image will be maintained from 45 to 75 seconds post-release. This will be the critical period of maximum dilatation. Post-stimulus image acquisition will be recorded until three minutes after the cuff released.
8. The gel will then be wiped off the patient’s arm and a magic marker (ex. Sanford “Sharpie”) will be used to trace the imprint of the scanhead on the patient’s skin.