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Introduction and Tutorial |
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This atlas has been designed as an introduction to cross-sectional cardiac anatomy. It contains five separate cross-sectional views of the heart at end-diastole and just over 750 labels. Within each view is a series of sequential images making a total of 98 anatomical images. The number of images according to each view is shown here.
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The images were obtained in one imaging session from a 1.5 Tesla Siemens Vision MRI scanner at Manukau Radiology Institute in New Zealand. The subject was 28 year old male with normal cardiac anatomy and function. The labelling has been reviewed and confirmed by Dr Chris Occleshaw, a consultant radiologist and cardiac MRI specialist from the Department of Radiology at Green Lane Hospital in New Zealand.
The anatomical images are displayed using a Java applet developed by Warren Hedley of the Department of Engineering Science at the University of Auckland. This enables the viewer to zoom in on the image (to a magnitude of 300%) by clicking on the right mouse button and dragging downwards over the image. The viewer can then to pan around the image by holding down the shift key and the right mouse button and dragging the image in the desired direction. As anatomical structures disappear from view the corresponding label disappears as well.
By turning the button on the bottom left of the applet (named labels on/off) on and off (named draw labels) the viewer is able to display the labels (Figure 1). The labels are default set to on.
(Figure 1. As can be seen from the label at the top of
the figure the draw labels button is switched on.)
The applet also enables the viewer to change the brightness and contrast of the image. For some monitors the the viewer might also have to adjust the brightness and contrast of the monitor as well. To practice using the cardiac atlas applet click on this sentence.
There are a number of ways to navigate around the atlas. First is the control panel at the top and bottom of each page. From this one can select one of the five image series. Once one of these is selected the user can then move from image to image through the sequence using the back and forward arrows on the top and bottom of each page until the user reaches the first or last image in the series. After this the user can either select another series or go back to view a particular image in the series they have just examined.
An alternative means of navigation within each series is by using the multislice image which appears on the bottom left of the page (Figure 2). This image shows in blue the plane of the images within the series. By clicking on the blue line the user can go to that image plane. These images were generated by the Cardiac Image Modellor (CIM) developed by Warren Hedley for the Auckland Cardiac MRI Research Group. A wide ranging tool used extensively for MRI investigations of ventricular mechanics, CIM in this case was used to read the header of the MRI DICOM files and to display the imaged planes against the plan view.
(Figure 2. A CIM-generated multi-slice plan view.
Click on the blue line to go to the image plane you are interested in
and use the back button of the browser to return to this page)
The plan view is a scout image used in MR imaging. It is perpendicular to the image of interest and it is from this image that the radiographer selects an anatomical plane to image. On the bottom right of the page the scanner generated plan view (as opposed to CIM's multislice plan view) is displayed (Figure 3). As can be deduced from the white bar on this image the image plane itself is not two-dimensional, rather it is three-dimensional. Each anatomical image represents in fact data gathered through a section 7mm in depth.
(Figure 3. The white bar indicates the location and width of the
relevant anatomical image which in this case is axial slice 10)
For technical detail on the MR imaging sequences used in the production of this atlas please go to the image details page.
You can practise using the applet here. The image below is axial slice 10.
First, turn the labels off and on by clicking the button named 'labels on/off' on the botton left of the panel.
Second, adjust the brightness and contrast of the image to a desirable level.
Third, zoom in on the image or an anatomical structure on the heart that you particularly wish to see. Do this by right clicking the mouse button over the image itself and, still with the button held down, drag the cursor downwards over the image. If you are using a Macintosh computer to view the atlas click on the only mouse button and drag similarly.
Fourth, When you have zoomed in and want to pan around the image, press the SHIFT key on your keyboard and again hold the right mouse button down, dragging in the direction you would like to go. Notice that as anatomical structures disappear from view, so too do the corresponding labels.
Please be aware that the applet retains changes to settings that the user has made. When the user changes to a different image the brightness, contrast, zoom and pan settings remain the same as on the image currently being viewed. To return to the discussion above click on this sentence.
This is the end of the tutorial. For a brief discussion of some of the MRI and radiological aspects of the atlas please go to the discussion page. We hope this atlas is both informative and user-friendly and are always interested in ways of improving it. Please contact me with any suggestions for improvements.
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Last Modified Sun Jan 14 15:33:30 NZDT 2001
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1998 - 2001. All rights reserved.
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