SMV Camera Protocol

CEA-SCAN ACQUISITION AND PROCESSING
FOR THE SMV SYSTEM

ACQUISITION

ENERGY SETTING: Tc99m - 140 Kev with a 20% Window.

PLANARS:

Use Frame Format: 256 Word
Static Acquisition: Anterior and Posterior views of the chest, abdomen and pelvis
at a preset time of 10 minutes.

Whole-body sweep: Starting at the head, scan at 8-10 cm/minute stopping at the level of the mid-thigh

SPECTs: (Always acquire pelvis SPECT first)

Single-head camera:

Use a 128 matrix
64 steps for 30-40 seconds/step.

Dual-head camera:

Use a 128 matrix
64 steps per head for 30-40 seconds per step.
Pelvis SPECT: Position the camera to include from the groin to above the bifurcation.
Abdominal SPECT: Position the camera to include the entire liver allowing for Some overlap from the Pelvic SPECT.
Chest SPECT: (May be acquired if clinically indicated) Image at 18-24 hours post injection. Position the camera to include the entire chest and axilla
Use 64 matrix
6-degree stops for 60-70 seconds per stop.

SPECT PROCESSING
VISION POWERSTATION

SELECT: SPECT RECONSTRUCTION PROGRAM

Use gray colorscale; set gamma to zero "0" and lower scale to zero "0" to avoid removing any background.
Adjust brightness as needed by changing upper scale.
Click on slice reconstruction.
Click with cursor on the projection data (third quadrant) to select a different test slice (if necessary) to allow filter evaluation.
Click on slice thickness and select 2.
Click on Pre-filter Projections and select Butterworth filter at the following parameters:

Order: 6-10 (use lower order if study appears count deficient).

Cut-off: .10-.30 (select cut-off, which displays sharp edges of vessels).

Check set each time the filter values are changed to update test slice.
Select slice range for reconstruction by adjusting Begin and End slice slider bar to include entire FOV.
Click on Sagittal Coronal setup. Adjust rectangle (middle button resizes, left button moves) to include entire body.

**Attenuation correction for liver images (if needed):

Select Isotope: Tc99m.
Click on Attenuation Correction Set-up.
Use ellipse to follow body contours.
Click on Setup Complete.
Continue Reconstruction Process

Click Complete Reconstruction.
Page through TV, SAG, COR slices to determine if satisfactory (using MAG and Page Options).
Select Save as Default.
Create and save 3D Maximum Activity Projection images.

**Attenuation correction (Use only for abdominal SPECT if necessary)

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

SPECT PROCESSING
XT.1

Select Tomography

Check raw data cine for motion and vary the intensity to look for any suspicious areas of uptake.
Use Butterworth filter

Order 6 – 10.

Cutoff .10 - .30 (if this filter does not exist, generate and save).

To generate a new filter – From SPECT Processing program, go into Filter Selection.

Generate Filter

Generate Analytic Filter

Butterworth

SQRT with Order 6 – 10 and Critical Frequency of .10 - .30

Kernel length 9

Validate

Save User Kernel

Name Filter

Click on any "None Box".

Save reconstruction.

**Attenuation correction (Use only for abdominal SPECT if necessary).

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

IMAGE DISPLAY
VISION POWERSTATION

PLANAR DISPLAY:

To check each image, adjust the intensity by using the Upper scale to look for any suspicious areas of uptake.
Set the lower scale to zero "0" to avoid removing any background
Use a gray scale with the gamma set to zero "0".
Film the images at two intensities; one lighter and the other dark enough to display the blood vessels intensely.

CINE DISPLAY, RAW DATA OR PROCESSED DATA:

Select display applications
Select SPECT
Mag of 4
Click on cine

SPECT DISPLAY:

In display applications desktop choose SPECT
Select: Transverse, Sagittal and Coronal files
Select MULTIVIEW to triangulate structures

Starting with one image (the transverse, for example) slowly move the crosshairs through the image from top to bottom

When a suspicious structure appears, move the crosshairs to the area in question and the corresponding other two planes will appear.

Repeat this method to triangulate structures in question, remember to vary intensity to bring out any subtle structures.

To film the entire study, click on Transverse, then Sagittal, then Coronal

Change the beginning and end slices to include the entire file

Use the Mag option to select the desired size for review (typically 3 or 4)

Use the Pg+, Frm+, Scr + options to step through the entire range of slices

Turn on Overlay Reference images for reference slice above each image

IMAGE DISPLAY
XT.1

Planar

Use the display menu to display planar images.
Change the Gamma Scale to Linear through the B & W menu.
Film images at two intensities: one lighter and the other dark enough to display the blood vessels intensely.

SPECT

Choose volume cube, change pixel thickness to 2.
Scroll through planes and vary intensity to bring out subtle structures.

Snake display

Change pixel thickness to 2.
Change gamma scale to Linear using B & W menu.

SPECT 3D

Select Processing

Use 3D Processing and Display
Select Volume Rendering
Threshold: try different % to determine best level
Light Attenuation: Try different % to determine best level
Proceed with 3D volume

HELPFUL HINTS

Do not use any Zoom during the acquisition.
Display a maximum of 16 images for filming.
Read the study on the computer screen, document the abnormalities on film.
Some images may require filming with two or more intensities.
The use of 3D Volume Display may be helpful.

DISCLAIMER:

This procedure was not developed by, or is not meant as an endorsement by SMV of CEA-Scan. These suggested parameters are based on the experience of various users with this type of equipment 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. Please refer to the full product prescribing information and consult your equipment manufacturer's updated user's manual prior to the first use of CEA-Scan.

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