DEXA (GE Lunar PIXImus) Scanning Protocol

A. Run Quality Control before you scan the animals:

1.  Turn on the DEXA computer

2.  Open the DEXA program by clicking on the LUNAR PIXI icon twice.

3.  Press F6 and select quality control.

4.  You will be prompted to place the QC phantom in the path of the x-ray beam.

5.  Press F3 to start the measurement.

6.  You may begin to scan your animals only after QC scan is passed.

7.  Press F8 to escape and return to the main menu screen.

B.  Prepare animals:
Weigh the first mouse to be scanned and anesthetize the animal by injecting the proper amount of Avertin (0.02 ml per gram of body weight), and measure its body length (nose to anus).

C. Scan animals:

1.  Press F3 in the main screen to start the measurements. Enter the animal information (ID, DOB, body weight, body length, etc.) and click Enter after it is done.

2.  Put the sleeping animal on the sticky tray, make sure the animal is within the blue line and in straight position. Also position the tail within the blue line.

3.  Place the tray with animal on the DEXA machine under the beam path and begin the measurement by pressing F3.

4.  When the measurement is completed, you will see a colored outline of the subject. You can adjust the region of interest (ROI) by clicking F3 twice. The green area is the one you want to delete, and the red area is the one you want to keep. You may use the arrow keys to adjust the circle to the desired size. Using the Shift key and arrow key at the same time will allow you to do this rapidly.

5.  Click Enter when desired ROI is achieved. You may press F5 to print the result.

6.  Clicking F8 twice will bring you back to the main menu screen. You are now ready to begin the next subject by repeating these steps.
 

Flag Values for mouse models:
Male adults:

a) Weight >32g.

b) Body Fat Composition less than 12% or greater than 21%.

c) BMD .0432-.0537 g/cm2 at 12 weeks of age, .0435-.0503 g/cm2 at 18 weeks of age, and .0449-.0565 g/cm2 at 20 weeks of age.

d) BMC .358-.609 g at 12 weeks of age, .356-.678 g at 18 weeks of age, and 391-.702 g at 20 weeks of age.

Female adults:

a) Weight >34g.

b) Body Fat Composition less than 15% or greater than 29%.

c) BMD .0437-.0501 g/cm2 at 12 weeks of age, .0435-.0503 g/cm2 at 18 weeks of age, .0445-.0505 g/cm2 at 20 weeks of age.

d) BMC .344-.464g at 12 weeks of age, .385-.513 g at 18 weeks of age, .417-.489 g at 20 weeks of age.