Image Display and Analysis Protocol

Pulmonary Perfusion

Please Review

This tutorial will attempt to step the user through a specific set of functions within VIDA while by passing a full explanation of the full capabilities of any specific module being used. If the user wishes to find a more detailed discussion of any of these modules, please click on the smiling face.

Starting VIDA

To start VIDA, type vida_start.

Loading Scan

If the image data is not on the computer disk, the user will need to transfer the data to disk before they may load it. For more explicit instructions, please see the Tape Utilities section.

Loading Data into Imatron Blood Flow

To load and make measurements, the Imatron Blood Flow (IBF) program will be used. To call up the Imatron Blood Flow program:

Press the right mouse button down on the Analysis button on the VIDA main panel.

Drag the cursor down to the Imatron Blood Flow menu item.

Release the right mouse button to select Imatron Blood Flow menu item.

The best way to load the data is to use the Load Flow Volume under the file menu and under the load button and select the Load Flow Volume. Then select the disk button because then all the appropriate files will be loaded. If the data is loaded from shared memory then the "*.IMFO" file must be loaded with the Load IMfo.

The best way to load a high resolution data file is to use the Load High Res. Volume button under the file menu and select the Load IMfo button. Then select the disk button because then all the appropriate files will be loaded. If the data is loaded from shared memory then the "*.IMfo" file must be loaded with the Load IMfo entry under the file menu load button.

Making Measurements of Blood Flow using IBF

Choosing a Model

Under the View button the user should select the Blood Flow: Model Criteria menu. This allows the user to choose between three criteria models: Ritman and Weiss for myocardial blood flow and Wolfkeil for pulmonary perfusion. The default values are show in the Criteria window. The user may change the default value of a parameter by left clicking on that parameter. Then type in a new value on the value line and then hitting the apply button. The original values for all the parameters may be retored by left clicking on the default button. In this case Wolfkeil model should be choosen.

Establishing the Arterial Dye Curve

The Imatron Blood Flow main canvas displays the flow volume. The slice line and the phase line on this panel allow the user to view any transverse slice of the image data set at any time point in the scan. The user needs to locate a pulmonary artery where the dye is very visible by changing the slice and the phase. The user may either type in the desired slice and phase on the given lines (remembering to hit return) or use the up and down buttons. The user may select a color scale to help in choosing a pulmonary artery. Also may change the min and max values by typing in a new value or using the up and down buttons in order to better view the image.

Once the user has choosen a pulmonary artery the user hold down the "control" button and the "left mouse" button at the same time. This establishes an aterial dye curve using the sample size.

The sample size is choosen by the user by right clicking on the sample button. Then the user left clicks on the value they wish the sample size to be remembering that the sample size is the number of pixel area to have the program gather data from. The arterial dye curve will appear in its own window. The pointing and clicking produces a graph of the time-intensity curve of that region. The user should continue selecting an arterial dye curve until he sees one he likes. The new dye curve will overwrite the old dye curve.

After designating a curve, all subsequent left clicking will use this curve to calculate blood flow, air content, blood content, tissue content, mean transit time, arrival time, and so on for that region. These calculations are displayed in a text window for the user to view for that particular slice and phrase.

Batch Mode

The user views the data image and locates the region he wishes to study. The user left clicks on the area. Next the user moves the cursor to the batch button and left clicks on it. The batch program works by scanning the box over successive, non-overlapping regions of an entire slice and calculating physiologic data for each sample. The program repeats this for all slices. Samples not meeting the user define criteria are rejected. A text file is generated containing the three dimensional coordinates of all accepted samples along with their calculated corresponding physiologic parameters. The text file may be saved to disk by holding down the left mouse button on the file button and choosing the save button. Then hold down the left mouse button on the save button and select the Save Spreadsheet File menu. In this menu the user picks the location and the name of the file he wishes to contain the text file.

Viewing the Analyzed Data

To view the analyzed functional data with or without the high resolution data the user moves the mouse cursor to the view button and holding down the left mouse button and selects Functional Image menu. The user may display one parameter on the Functional Image canvas.

The user should now select a new color scale choice that has two different color scales in it like split2 in order to see the superimposed high resolution image and the color coded functional data .

The user needs to select the parameter to be displayed in the Functional Image canvas by moving the mouse to the Model Parameters window and left click on the parameter. Use the up and down buttons to scroll the parameters in order to view all the parameters.

Next the user may choose the default scaling by left clicking on the auto button. On the scale factor line the value for the default scaling is shown for the corresponding parameter. Or the user may choose the manual button and type in the scaling value to be used. In some cases, the user will need to increase the scaling factor value in order to better see the color coded functional data mapped onto the high resolution data.

Now left click on the apply button and the functional data will be displayed on the Functional Image canvas. The gathered data from the batch program is colored coded by intensity. The user may view different slices by typing in the new slice number on the slice line or using theup and down buttons.

If the user wants to view both the functional and the high resolution data the user moves the mouse cursor over the High Res Image button and left clicks on the button. Then the user needs to move the mouse cursor over the apply button and left clicks on the button. If the color coded functional data does not appear the use should increase try increasing the scale factor manually. This allows the user to see the detailed visualization of the structure-function relationships.

The color code image file may be saved to an image file to review later or look at it in another VIDA module. The user moves the cursor to the Imatron Blood Flow panel and left clicks on the file button to bring up the file menu. Next, move the cursor over the save button and bring up the save menu. Now left click on the Functional Volume and select the directory and a filename to save the image file.

VIDA Tutorial Sections Relevant to the Blood Flow Module

You may find it helpful to review the relevant VIDA tutorial sections.

Tape Utilities

Loading Image Data

Color Scales

Imatron Blood Flow (IBF)

Load Flow Volume

Load High Resolution Volume

Load IMfo

Load ROI

Save Functional Volume

Save Spread File

Model Criteria

Region of Interest

Properties

Last modified: Fri Jun 4 13:31:12 CDT