ACQUISITION

ENERGY SETTING: 99mTc-140 KeV, 20% Window

• Always acquire Pelvic SPECT first…Planars next…Liver SPECT last
• Start Pelvic SPECT 2½ hours post-infusion

PELVIS & LIVER SPECT GUIDELINES:

• When indicated-Chest SPECT is ideally performed about 18 hours post-infusion

CHEST SPECT GUIDELINES:

PLANAR ACQUISITION GUIDELINES:

WHOLE BODY MODE

or

SPOT VIEWS

PLANAR IMAGE AND RAW SPECT DATA DISPLAY

Vary the intensity of the images to check for suspicious areas. Use a linear gray scale. Take care not to remove any background. Review the images at two intensities-one light and the other dark enough to display the blood vessels intensely.

Raw Data Cine Display:

• From the screen behind the Image Display Screen-Right Click, Hold & Slide Right to select "CLINICAL UTILITIES", release
• Right Click, Hold & Slide Right to select "CINE TOOL", release
• Select the desired raw data set from the Image Review Menu
• ***The cine will be generated and displayed***
• Check each SPECT for motion
• Vary the intensity to look for any suspicious areas of uptake

OBTAIN CLAMP VALUE

If the kidneys are extremely hot on the SPECT images, "clamping" may be helpful to reduce SPECT artifacts and identify subtle lesions near hot structures. The program "clamps off" all pixel values over the upper limit of relevant data by replacing them with the lower limit of non-relevant data supplied by user-the "Clamp Value". Obtain the "Clamp Value" with extreme care-too high a value yields no effect and too low a value eliminates relevant data.

• Display the entire study, or at least include the frames with the hottest structures-these most likely will be the projections that include the posterior kidneys
• Ensure the cursors displayed are "Window" and "Center Scale"
• Change the window cursor from 200% to 1%
• Adjust the center scale cursor so the only structures observable are those to be clamped
• For the Pelvis & Abdomen SPECT-clamp the kidneys and/or bladder
• For the Chest SPECT-clamp the heart
• Read the center scale value and record
• This is your "Clamp Value" to which all counts above this value will be re-assigned

OBTAIN OPTIMAL FILTER VALUES

• From the Menu Manager, Single Left Click on "FILTER"
• Load the study to be reconstructed: Single Left Click on the raw "ECT" file
• Single Left Click on "PROCESS"
• Single Left Click on "2D SMOOTH" to apply a pre-reconstruction filter
• Choose the Butterworth filter: move the cursor into the circle, Right Mouse Click, Hold and Drag onto "BUTTERWORTH", release
• Select the test slice: Position the cursor over the green horizontal line-Middle Click, Hold & Drag the green horizontal line to the desired level, release
• Reconstruct at default settings: Single Right Click anywhere on the Display Screen
• The Menu Page will refresh
• Adjust the high cut frequency to 0.40
• Adjust the roll-off to 5.0
• Adjust the difference or D to 0.02
• Strike the return key
• Initiate the preview filters of the test slice: Single Left Click on "GO"

*** Seven transverse cuts of the test slice will be generated***

Review the images:

• If Images are too smooth, use a filter with a higher cut-off
• If the images are too grainy, use a filter with a lower cut-off
• If needed, generate a new set of test images with a higher or lower frequency cut-off and/or adjust the roll-off from 5 to 10
• When the optimal image is obtained, record the cut-off & roll-off values
• Close the Filter Application Window

SPECT RECONSTRUCTION

• From the "MENU MANAGER", Single Left Click on "RECON"
• Select the raw data set to be processed
• Single Left Click on "PROCESS"
• Single Left Click on " REVIEW PROTOCOL"
• *** The Default Form Editor Menu Opens ***
• Single Left Click on "EDIT" at line labeled " PATIENT INFO"
• Under study type-enter a descriptive name For example: "ABD,45,5" for a data set of the abdomen reconstructed with a Butterworth filter, cut-off=0.45, roll-off=5 with no attenuation correction applied
• Single Left Click on "EDIT" at line labeled "PRE-PROCESS INFO"
• Check off "Clamp as Needed"
• Enter the number from "OBTAIN CLAMP VALUE" on page 3
• Single Left Click on "EDIT" at line labeled "2D Smooth"
• Choose Butterworth
• Enter the cut-off and roll-off values from "When the optimal image is obtained" above on this page
• Single Left Click on "EDIT" at line labeled "BACK-PROJECTION INFO"
• Single Left Click on "EDIT" at line labeled "FILTER INFO"
• Edit the above menus to reflect those parameters obtained from previous steps and factors listed on the next page

SPECT RECONSTRUCTION FACTORS

• At the top of the Default Form Editor, Single Left Click on "SAVE"
• Quit the Default Form Editor-all the daughter windows will close and be saved
• *** 2 Horizontal lines will appear on the Display Screen***
• Define the volume to be reconstructed: Middle Mouse Point, Click & Drag the superior and inferior blue lines to include the entire field of view
• Single Right Click anywhere on the Display Screen
• From the RECON Menu, Single Left Click on "PERFORM RECON"
• ***Reconstruction will proceed; the study will be saved automatically***

SAVING SPECT IMAGES

The newly reconstructed and re-named data set has been saved automatically

ATTENUATION CORRECTION

Occasionally the liver will display a dark rim particularly on lateral edge of the right lobe. If there is question of a lesion at the edge, attenuation correction may help differentiate between a reconstruction artifact and disease. Process the SPECT with and without attenuation correction.

Follow the procedure found on page 4 titled "SPECT RECONSTRUCTION" and make the following changes

• Single Left Click on "EDIT" at line labeled " PATIENT INFO"
• Under study type, enter a descriptive name. For example:"ABD,47,5,AC" for a data set of the abdomen reconstructed with a Butterworth filter, cut-off = 0.47, roll-off = 5 with attenuation correction applied
• Single Left Click on "EDIT" at line labeled "2D Smooth"
• Choose Butterworth
• Increase the cut-off value from "When the optimal image is obtained" by 0.02-0.04
• Enter the identical roll-off value from "When the optimal image is obtained"
• Single Left Click on "EDIT" at line labeled "BACK-PROJECTION INFO"
• Attenuation Correction: Right Click, Hold & Drag to "4-Point Ellipse", release
• Attenuation Coefficient: Single Left Click on existing value, delete and enter 0.110
• Continue as outlined under "SPECT RECONSTRUCTION" to the point where lines that define the volume to be reconstructed have been established

Define the 4-Point Ellipse:

• ***An anterior projection will appear on the display screen accompanied by 2 yellow vertical lines adjacent to the left and right lateral aspects of the projection***
• Middle Click, Hold & Drag the yellow lines to define the lateral margins of the body …These yellow lines will define the long axis of the ellipse…
• Single Right Click anywhere on the Display Screen
• ***A lateral projection will appear on the display screen accompanied by 2 yellow vertical lines adjacent to the posterior and anterior aspects of the projection***
• Middle Click, Hold & Drag the yellow lines to define the posterior and anterior margins of the body …These yellow lines will define the short axis of the ellipse…
• Single Right Click anywhere on the Display Screen
• From the Recon Menu, Single Left Click on "PERFORM RECON"
• ***Reconstruction will proceed; the data will be saved automatically***

SAVING ATTENUATION CORRECTED IMAGES

The newly reconstructed and re-named data set has been saved automatically

SPECT REVIEW

Investigate all structures by triangulation

• From the Image Review Screen, Single Left Click on the study to be reviewed
• From the RECON Menu, Single Left Click on "PROCESS"
• Activate "Cursor Mode"
• From the Black Menu Box-Right Click, Hold & Slide Right to "CURSOR", release
• *** "Cursor Mode" is activated when ("Cursor") is at the top of the RECON Menu***
• Point & Left Click on a suspicious area on any orthogonal plane to display the other two corresponding orthogonal planes simultaneously-investigate/review all structures
• Deactivate "Cursor Mode"
• From the Black Menu Box-Right Click, Hold & Slide Right to "CURSOR", release
• ***"Cursor Mode" is deactivated when ( ) is at the top of the RECON Menu***

3D VOLUME IMAGE GENERATION & REVIEW

• From the Menu Manager Box-Single Left Click on "REPRJ"
• ***The Image Review & Reprojection Menus will open***
• From the Image Review Menu-Left Single Click to choose the TRANS data set
• From the Reprojection Menu-Single Left Click on "PROCESS"
• Change the number of frames to 36
• Ensure the weighting option is defaulted to "LINEAR"
• Single Left Click on "GO"
• ***The Cine will be generated***
• When finished, Single Left Click on "SAVE"
• Close the Reprojection Menu
• To view images immediately

• Position the cursor on the Display Screen, Right Click, Hold & Slide Right to "CINE", release
• Adjust speed and intensity as needed

• To view images at a later time

• Open the Image Review Window
• Single Left Click on the data set RPJ
• Single Left Click on "READ"
• Close the Image Review Window
• From the Display Screen, Right Click, Hold & Slide Right to "CINE", release
• Adjust speed and intensity as needed

FILMING THE STUDY

• Change the slice thickness to 2 pixels

• Single Lt. Click on the boxes marked DSP/TRANS, DSP/SAG & DSP/COR in turns

•     Display a maximum of 16 images/8 X10 hardcopy
•     Use a linear gray scale
•     Adjust the intensity as needed-obtain hardcopies as desired
•     Some images may require hardcopies of two or more intensities

• Change the slice thickness back to 1 pixel

• Quit the RECON Menu 

HELPFUL TIPS: 

• Do not use Zoom during the acquisition
• Read the study from the computer screen and document the abnormalities on hardcopies
• Use a linear gray scale for image review/display
• Display a maximum of 16 images/8 X10 cut film for hardcopies
• Some images may require hardcopies of two or more intensities
• The use of 3D Volume Display may be helpful

DISCLAIMER:

Please refer to the full product prescribing information and consult you equipment manufacturer's updated user's manual prior to the first use of CEA-Scan. The suggested parameters above are based on the experience of various users and are not a substitute for the physician's or technologist's professional experience or knowledge. Users are ultimately responsible for determining if this procedure is usable with their equipment and standard practices. It is assumed that Quality Control of the imaging equipment is performed according to the manufacturer's recommendations. This procedure was not developed by, nor is meant as an endorsement by Trionix of CEA-Scan.