MedImage, Inc., 6276 Jackson Rd., Ann Arbor, MI 48103-9579, 313/665-5400
Important Notes
• In order for MedView to function properly the organization of the folder called “DEMO Patients Folder” within the MedView folder should be maintained. Medical image files are grouped together into a visit folder. There are multiple visit folders within the Patients folder.
• MedView requires at least one monitor set to 256 colors (or grays) in order to run. If your monitor is not at this setting when you start, MedView will ask if you want to switch the setting in order to continue. When you quit MedView, it will restore your monitor to its previous setting.
• MedView runs best with 12MB or so of RAM. However, the demo is configured to run in 3MB to 4.5MB of memory. If you have additional RAM, you may wish to increase MedView’s memory partition size via the “Get Info” window in the Finder.
• For quicker loading, the folders “MedView™ Color Palettes” and “MedView™ Preferences” should be kept in the same folder as the MedView application. Otherwise, the application will do a search of the entire hard disk for these folders.
• This demo version of MedView is capable of running fine on both 68K-based Macintosh computers and Power Macintosh computers since it contains code native to both types of machines.
Quick Tour
Launch MedView. “Choose Patient Selection” in blue info bar. Double-click the first patient in the list. Use CINE icon or mouse down when cursor is over a feature in slice studies. Drag sliders on vertical thermometer in upper left corner. Select other patients or Quit. Radiologists often use these few commands to do their job. Of course there are many studies that require more investigation and that is what the bulk of the program is about, so please read on.
What is MedView?
MedView is the display portion of a complete display and reporting system created for use in medical imaging departments and clinics. The complete system is called DELTAmanager® and also includes a file translation program, MedImport™, and the database/reporting software, MedImageDB™. For more information on the whole product, see “More about DELTAmanager” below.
A Little Background
There are numerous methods for acquiring medical images. In this tour, we’ll discuss nuclear medicine imaging.
Nuclear medicine scans are obtained in the hospital or clinic by sophisticated gamma cameras. Instead of photographing visible light, a gamma camera records the radiation produced by gamma rays. Compounds which contain radioactive isotopes are designed to travel to a particular region of the body such as the heart, brain, liver, etc. A typical application of nuclear medicine is to perform a scan on a patient’s heart after a heart attack. The patient is placed beneath a gamma camera and is injected with one of these isotopes. The isotope travels to the heart muscle and gives off radiation. This radiation is noted by the camera and an image of the heart can be generated. Each pixel in the image is essentially a count of the number of gamma rays detected in that area of the organ. We will refer to this information as the pixel value. From these images, then, the physician is able to determine areas of the heart which may have been damaged by the attack.
How do I use the software?
MedView is a complex medical image review application and information about all of its features is beyond the scope of this demo. Instead, we’ll concentrate on describing its general use and elaborate on a couple of features which really take advantage of the increased performance of Macintosh with PowerPC.
General Use
Start by opening the MedView application. After the intro window is briefly displayed, the patient information “bar” appears just below the menu bar. In order to view a patient visit, you can click the button labeled “Patient Selection” (alternatively, you can choose “Select Patient Visit…” from the “Patients” menu). You will then see the patient selection dialog below.
For this first example, choose the “Brain Scan” visit and click the “OK” button. The selection window will disappear and the brain scan images will open. There are 2 files contained in this visit and each will open in a separate window. Windows with multiple images can be resized in order to display more images. Along the left edge of an image window is a series of icon buttons. These icons are also duplicated in the “Tools” menu in the menu bar along with a description of each tool. (You can also use Balloon Help™ to learn more about these tools.) Take a few minutes to see what tools are available.
Take a brief tour through some of the tools, by making the images larger with the “Enlargement” tool. Next, select the “Magnifying Glass” tool and click on the images to examine them in more detail. Now select one of the “ROI” tools. ROI stands for “region of interest” and allows a physician to gather more information about the images in the study. For example, select the rectangular ROI tool, click on an image to select it, and then click and drag to draw a rectangle over an area of the image. In the area beneath the image, you will be able to see information about that region such as the sum of all the pixel values inside the region, the average pixel value, the minimum and maximum pixel values (see “A Little Background” above). Another statistical analysis tool is the “Profile” tool. You can select this tool and draw a line across an area of an image. In the area beneath the image a graph is displayed showing the values of the pixels along the line. This sort of information can assist the physician in making a diagnosis.
We’ll end our brief tour of the tools by selecting the “CINE” tool. All of the images contained in the window should begin quickly cycling from one to the next over and over in the upper-left portion of the window. This “movie” display is particularly useful in gated studies which show motion of a heart wall (try it later with the Gated Cardiac Scan study).
Before we move on to more complex features, take a few minutes and select different items in the “Colors” menu. By default, MedView opened the Brain Scan study with the Brain Colors color table. You can choose other colors to view the data with by selecting a different color table. You should note, however, that these are “false” colors. Since the images were not captured via visible light (but instead by gamma radiation), there is no “actual” color to be assigned. Instead, color simply represents various levels of gamma ray activity. Using the “Grayscale” colors is most like a black and white photograph but instead, black represents low levels of radiation while white is an abundance of radiation.
Contrast/Brightness Control
Another important control in MedView is the contrast/brightness control in the upper-left portion of the window (see the previous illustration). This dual slider allows you to change the brightness and contrast of the images. Click on either slider and move it up and down to see how it works.
Volume Rendering Tutorial
MedView can also create a three-dimensional volume representation commonly known as volume rendering. If it is not still open, reopen the Brain Scan study. Make sure the window titled “TRANSAXIAL” is the active window by clicking on it. Next choose the “Hall Tomo Display” option from the “Format” menu. The window should now look like the one below:
This specialized view of the data is a bit complicated. The original images you were previously viewing are actually transverse “slices” of the brain. In the diagram below, you can see on the left-hand side a representation of these slices stacked vertically.
Stacked in this way, the images actually create a three-dimensional volume of the brain. Once we have the volume, we can then reslice the brain along three orthogonal axes. In the right-hand side of the diagram you can see three examples. You can see that if we pull an image “flat” out of the volume, it is a transverse slice. Likewise, cutting away the front of the volume results in coronal slices, while cutting along the side yields a sagittal slice. These three views are shown in the Hall Tomo window display. The original images are in the transverse box and from there we can create corresponding sagittal and coronal views of the volume.
Move your cursor within one of the three views. Now click and drag around within the image. You will see light hairlines appear in the image you’re in and corresponding lines in the other two views. Now release the mouse button. Immediately, the other two views are updated with the slice at the new location. You can see where you “are” in the volume by the color-coded tick marks on each image. For example, the white tick marks on top and bottom of the sagittal view show the location of the currently-displayed coronal view. Likewise, the green tick marks on the sagittal and coronal views show the location of the transverse view being displayed.
As you can see, the Hall Tomo window allows a more elaborate view of the brain images, but it can also do more. Click the “Reproject Transverse Slices” icon in the tool palette. The lower-left corner of the window will then display a 3-D image, or volume rendering, of the brain.
Now that you’ve had MedView volume render the brain, click the “CINE” button. You will now see the brain “rotate” as your point of view moves in a 360° arc around it. On a Macintosh Quadra 950, this rendering process takes about 16 seconds. On a Power Macintosh, however, the total time is reduced to about 4 seconds!
Beneath the rotating image is a speed control. Moving the indicator to the left slows the rotation while sliding it to the right speeds it up. You’ll also notice that a new tool, “Rock,” is now available. Selecting this tool causes the viewpoint to move back and forth in order to get a good look at one area of the brain.
Rotating the Brain
The final tool we’ll look at is the “3D Volume Rotation Tool.” This tool is available only in Hall Tomo windows and only if you haven’t volume rendered the data. So, follow these steps in order to get to the tool:
1. Click the “Patient Selection” button in the patient information window beneath the menu bar.
2. Select the “Brain Scan” visit in the selection dialog.
3. Select the window “TRANSAXIAL”.
4. Choose “Hall Tomo Display” from the “Format” menu.
You can now choose the “3D Volume Rotation” tool by either clicking the arrow beneath the tools in the window or from the “Tools” menu in the menu bar. (The tool should be the last one listed.) At this point, the 3D rotation dialog will appear.
A physician may wish to rotate a brain study such as this if for some reason the images were acquired slightly off-axis. This allows the physician to reorient the data and view it in a standard fashion.
Select the “Rotate” button in the “Tools” area of the window. Next, move your cursor over one of the images in the window. In our example above, we’re rotating the brain about the transverse axis. As your cursor enters the image area, it turns into a hand. Grab a corner of the image you wish to rotate by clicking on the corner and dragging the mouse around. As you drag, you can see the image rotate. When you’re satisfied with amount of rotation, release the mouse button. The entire volume will now be rotated about the selected axis the amount you specified. You can cancel the rotation by typing command-period on the keyboard.
On Power Macintosh systems, rotating the image by grabbing it is basically instantaneous. In comparison, even on a Quadra 950 there is a slight delay of almost a second between the time you drag the mouse and when the image is rotated. When the actual rotation of the entire volume about the axis is being performed, the Quadra 950 takes about 24 seconds for this brain data set while the Power Macintosh can accomplish the same feat in about five seconds! Power Macintosh transforms many MedView features from being useful tasks on previous Macintosh computers to being effortless tasks.
Gated Cardiac Scan
Another scan included, which is of special note, is the Gated Cardiac Scan. This study constists of two views of a beating heart. You might find these images interesting.
Other Features
There are numerous other features in MedView which we do not have room in this document to discuss. One note, however, is that MedView does support exporting its images in QuickTime™ format. Be aware, though, that MedView cannot open QuickTime movies, so you’ll need to use another QuickTime-capable application to view them.
More about DELTAmanager
In a typical scenario, specialized communication software and hardware bring data from medical imaging computer systems onto the Macintosh computer. MedImport unobtrusively extracts key information about the patient data to enable DELTAmanager to work with the images. Image files from the same patient visit are grouped into a single folder and placed within the “Patients” folder. MedImport allows the Macintosh computer to become the focus of the physician’s activities in the “reading room,” the place the physician actually makes the diagnoses of the medical imaging scans, by bringing data from many different systems (such as ADAC, GE, Picker, and Siemens) on to one central machine.
The physician can then use MedView to view images from up to four visits via the “Select Patient” dialog. MedView allows the user to manipulate these medical images by adjusting their brightness and contrast, viewing them in grayscale or various color scales, and even generating three dimensional renderings from cardiac, brain, or other organ “slices.”
The third aspect of DELTAmanager, MedImageDB, is a database application based on 4th Dimension by ACI US. This database allows the creation and archiving of reports. These reports contain relevant images and the diagnosis of the patient’s visit. Output to a high-quality color printer, these reports are a highly useful addition to a patient’s records. These reports are also a useful marketing tool for the radiologist to his referring physicians. MedImageDB also contains features which assist the physician in generating common reporting information—thus limiting the typing necessary to generate a report—and assist the administrator in collecting information about types of scans, throughput, etc.
How do I learn more?
As an Apple VAR, MedImage sells complete hardware and software solutions for hospitals and clinics. If you would like more information on our medical products, please contact:
