Ultrasound Protocol
Prepared By Jennifer Labecki
I. Preparation of equipment and instrumentation for beginning of protocol.
A. Windaq blood pressure measurements
1. Turn on computer.
2. Open Windaq
3. Calibrate transducer
Low (0)
High (200)
4. Save file as (date)(rat name)*
5. Allow sufficient file size for experiment (at least 30 min)
6. Record blood pressure on Windaq during duration of the ultrasound measurements
7. Make a marker for each dose and new picture taken
*unique rat name according to PGA database.
B. Ultrasound
1. Turn on GE Medical Systems Vivid 7 ultrasound machine
2. Log on as administrator (ADM)
3. Create patient file. Save as last name (dobutamine), first name (PGA), patient ID** (rat
name)*
4. make sure the sector probe and the MCW-Small Rodent application are selected.
5. Increase the field width until you reach a frame rate of 226.1 fps.
6. Tilt the field one click to the left.
7. Turn up the reject bar until desired level is reached.
8. Change color of field.
9. make sure EKG trace is on bottom of screen if not, press “Physio” button and turn EKG
on.
*unique rat name according to PGA database
**Patient ID field must be unique
C. Infusion Pump
1. Turn pump on.
2. Place 3 mL syringe filled with .1mg/mL dobutamine solution on pump and clamp into
position.
3. Attach 23g stub adapter to syringes and attach a length of PE50 tubing to end of adapter.
4. Attach 23g hollow pin to end of catheter to act as a connector.
5. Advance solution until catheter is filled and small bead collects at end of hollow pin.
II. Surgical implementation of catheters
A. Procedure
1. Prior to inserting the catheters the chest area of the rat is shaved.
2. Nair hair removal cream is placed on the shaved area to remove the rest of the hair. This
creates a clean, smooth surface for the ultrasound probe.
3. A catheter is placed in the carotid artery and jugular vein.
4. A steady state 15 minute blood pressure recording is then collected on a second Windaq
system as part of the Renal protocol.
5. The next rat’s blood pressure is measured while the first rat’s ultrasound is being done.
III. Ultrasound Procedure.
A. Procedure
1. Carotid catheter is hooked up to Windaq and blood pressure is recorded during the
duration of the ultrasound measurements.
2. The short (6 inch) jugular catheter is hooked up to the connecting pin on the infusion
pump to deliver the dobutamine to the rat during the ultrasound.
3. Ekg leads are inserted under the skin of the rat according to the diagram on the machine
and Ekg is recorded during the duration of the ultrasound measurements.
4. Ultrasound gel is placed on the chest area and on the 10S sector probe.
5. Make marker in Windaq (base or control).
a. Take two pairs of base pictures midway through the left ventricle.
b. Use papillary muscles as landmarks.
c. Take each pair of pictures at least one minute apart.
d. Capture a picture that is at least 6 beats.
e. The color should be changed between each dose to avoid confusion during
measurements.
6. Turn on the infusion pump to a rate of 40 ug/kg/min. (Rate for each rat according to
weight is calculated before study begins)
7. Make marker in Windaq that pump is started. Make another marker when drug reaches
rat. (It takes approx 30 seconds for a 6” catheter depending on the rate.)
8. Let pump run for 4 minutes.
9. After 4 minutes, while pump is running:
a. Make marker in Windaq (e.g. 40ug pic1)
b. Take 2 pictures one minute apart for 2 minutes.
c. Change colors between each minute.
10. When done with measurements, there should be 2 pairs of Base pictures and 2 pairs of
40ug pictures.
11. Repeat Ultrasound and dobutamine procedure for each rat.
IV. Measurements/Data analysis
A. Measurements
1. Windaq Dobutamine blood pressure
2. Ultrasound.
a. Two of the base pictures and one from each of the four minute pairs during are
analyzed using the m-mode view and under the Cardiac measurements-LV study
b. Four beats are measured on each picture and HR is also measured under the
Cardiac measurements-HR study
c. The analyzed files are moved from the ultrasound machine and onto the
EchoPAC.
3. Format CD
4. Strain
a. Circumferential Strain and Strain Rate (Circ STR/SRR) are measured for each
picture that ultrasound measurements were taken from.
b. Radial Strain and Strain Rate (Rad STR/SRR) are measured for each picture that
ultrasound measurements were taken from.
B. Windaq Analysis
C. Ultrasound Analysis
1. Push “Archive” button. Highlight rat file you want to analyze.
2. Click “select patient”. Rat file opens with captured ultrasound pictures showing on the
bottom of the screen.
3. Double click on first base picture on bottom left. (Don’t click begin exam, you want to
make measurements on an old exam.)
4. Press “Review” button. (Brings up all 8 pictures)
a. Look at first pair of pictures (first base pair) and pick the best picture to make
measurements on.
5. Push mmode button (MM)
6. Press button under Bcolor maps twice to change color of mmode.
7. Press bottom 2D button to stop beating.
8. Adjust “horizon sweep” knob until trace fills most of the screen.
9. Adjust the 2D knob to get desired darkness/lightness.
10. Press “Image size” button twice to get side by side picture of cross section and mmode
views.
11. Use trackball and “scroll” back to beginning of trace.
a. Scroll until point where ventricle is completely open.
b. Use EKG trace to help find peak.
12. Press bottom 2D button to start picture beating.
a. Check placement of yellow center cursor and green angle cursor.
13. Press “trackball” button to switch to Pos (position)
a. “Pos” in bottom right corner of the screen will be highlighted.
14. Use the trackball to “swing” the green and yellow cursor so that it exactly bisects the
ventricle.
a. Try to miss the papillary muscles with the cursor.
15. Push bottom 2D button to turn on beating scroll with trackball back and forth to check
placement of the cursor.
a. Adjust placement if necessary by going back to the “Pos” button on bottom right.
16. Adjust angle of green cursor by:
a. Push “trackball” button until Pos is highlighted in bottom right.
b. Press large button around trackball.
c. Bottom right screen should change to highlight “angle”.
d. Use the trackball to adjust the angle of the cursor so that you miss the papillary
muscles and bisect the ventricle.
17. Press “trackball” twice to get back to scroll.
18. Press the “img size” button twice to get back to the large view of mmode.
19. Scroll to the point in the trace that you want to measure.
20. Press “measure” button.
21. Click “LV Study” under General folder.
22. A green crosshair and a text box holding the measurements will appear on the mmode
image.
a. Close the text box by clicking on the stop sign on top left of the box.
b. Click on top left arrow of box and move box to blank area so that the time of the
trace is seen on the screen.
c. Click again to place on blank area.
23. Take measurements of the wall thickness on mmode trace.
a. Mark the anterior point of the septum in end diastole. (Use the EKG trace to help
you line up where to put the points.)
i. Click the large trackball button to place the first number. (The number of
the measurement will appear.)
b. Mark the posterior point of the septum in end diastole.
i. Make sure to put the mark exactly on the border between the wall and
ventricle space.
c. Mark the anterior point of the LVPW in end diastole. (Left ventricle posterior wall)
d. Mark the posterior point of the LVPW in end diastole.
e. Mark the anterior point of the septum in systole.
f. Mark the posterior point of the septum in systole.
g. Mark the anterior point of the LVPW in systole.
h. Mark the posterior point of the LVPW in systole.
i. The first measurement is completed and the trace should turn pink.
24. Using the Ekg as a guide, make 3 more measurements. (Total of 4)
25. Press “print” button and b/w picture will print on ultrasound machine printer.
a. Leave pictures attached until all doses have been measured.
b. Pictures can only be printed on the ultrasound machine not on the EchoPAC.
c. During measurement you can use the “undo button” to undo the last point
placement or you can use the “delete” button to delete the whole measurement.
d. You can only delete or undo while you are taking a measurement, once done and
the trace turns pink, you have to delete measurements under the “worksheet”
button.
26. Press the “measure” button twice to get rid of the pink wall measurements. (They will
still be on the worksheet.)
27. Click on “heartrate”. Another crosshair appears.
28. Using the EKG, line up the crosshair and place point by clicking the large trackball
button. Green measurement numbers appear as before.
a. Measure the heartrate of the same beats that you did the wall measurements on.
b. You can use the delete button to get rid of the first point placed.
29. Using the EKG, line up the crosshair and place point by clicking the large trackball
button to complete measurement. (Turns pink)
30. Press “worksheet” button to look at actual measurements.
31. Click “more”
32. Click “page Down” to view heart rates.
a. To delete from worksheet, place cursor over set you want to delete and press
“update/menu” button. Exclude/delete choices will pop up. Select choice by using
trackball and large trackball button.
b. Press worksheet button to get back to mmode.
33. Take 4 measurements from the best view of each set of pictures (2 bases, 2 40ug), for a
total of 16 measurements.
34. Press “measure” to get back to mmode.
35. When done with measurements, press “archive” button then click “end exam”.
36. Transfer files to EchoPAC
a. Press “archive” button.
b. Select rats to send to EchoPAC.
c. Click “export”.
d. Select export pathway: “Remote Import/Export Archive”
e. Click “ok”.
f. Check “delete selected patients after copy box”.
g. Click “copy”, files will transfer to EchoPAC.
h. When finished, click “done” to complete copy procedure. You must do this to
finish the copy operation.
D. Format CD
1. Click “Config”
2. Click “Connectivity”
3. Click “Tools”
a. Must enter a “Label” (name of CD).
4. Click “Format”
5. Click “Yes” you are sure.
6. When media was successfully formatted, click “OK”.
E. Strain Analysis
1. Open rat file under “archive”.
2. Select same picture that other measurements were made on.
3. Select “advanced>>” button.
4. Select “Q Analysis” button (2D strain window will open).
5. Using EKG peaks, select 4 full heart beats (by dragging yellow markers along EKG
trace).
6. Click “2D” strain button.
7. Select “SAX-PM” view (short axis-papillary muscle).
8. Click small animal “ok”.
a. Sector view opens with hand/pencil as cursor.
9. Click “cancel”.
10. Slide bar along the EKG trace to second beat until ventricle is wide open.
11. Click “New ROI” (new region of interest).
12. With mouse pointer outline the inside of the ventricle wall by clicking and dragging the
pointer around the inside perimeter. Double click back on the beginning of the trace to
close the circle (don’t include papillary muscles).
13. Check the heavy dots to make sure they are centered in the middle of the ventricle wall.
If not, expand the “ROI width” until the dots are centered.
14. Click “Process”.
15. System will calculate and show picture of ventricle beating with the strain tracking the
wall movement. Make sure the dots are tracking well; otherwise, you can go back and
change the trace of the inside of the ventricle. By clicking “Re-calc” button.
16. Once satisfied with the tracking, click “Done”.
17. A screen comes up with a graph of the wall movement.
18. Click “store trace”.
a. Under circumferential save:
i. S trace = strain
ii. SR trace = strain rate
b. Under radial save:
i. S trace = strain
ii. SR trace = strain rate
19. Save each kind of strain with a unique name e.g.
CIRC STR BASE 1
CIRC STR 40UG PIC 1
CIRC SRR BASE 1
CIRC SRR 40UG PIC 1
RAD STR BASE 1
RAD STR 40UG PIC 1
RAD SRR BASE 1
RAD SRR 40UG PIC 1
20. Click on “files”, move to bottom box.
21. Under selection criteria highlight “by patient”.
22. Click on “rat name” and “down arrow” to move rat to bottom box.
23. Under “choose action” dropdown, choose “Copy to CD” (writes to disk).
24. Click “exit”
25. Click “exit 2D strain”.
26. Do you want to store loop? Click “Yes”.
27. Once loop is stored, click “ok”.
28. The loop will show up on the bottom at the end of the ultrasound pictures.
29. Repeat for each picture that you took the functional measurements of (4 total).
30. Click “Archive” button to exit rat.
31. Save functional data to disk:
a. Highlight patients to save to disk.
b. Click “Export” tab
c. Export to: “to Excel file”
d. Click “OK”
e. Click “copy” button on top left.
f. When # of items that have been copied pops up, click “OK”.
g. You must click “done” to complete copy operation.
22. When done saving the strain and functional measurements, hit “Alt+E” to eject disk.
Disk will be ejected and reinserted for data verification.