Loading Image Files

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Single Files

Choosing Read DICOM in the File menu or the open toolbar button shows the Windows file selection box for choosing a DICOM file to read. The expected file suffix is .dcm. The image contained in the file is displayed if the file is read successfully. If the image contains multiple frames, the first frame is shown. IMG files are loaded by selecting Read IMG File in the File menu.

Multiple Files & 3D Data Sets

Selecting Read Multiple DICOMS in the File menu or the read multiple toolbar button shows the Windows file selection box in which multiple files may be chosen. Hold down the <shift> key to select a range of files or hold down the <control> key to select individual files. Display of the images following a multiple read is controlled by settings on the Options dialog. All, none, or the first file read can be displayed.

Following a multiple read, the files are checked to see if they constitute a valid 3D data set. The following must hold for a collection of images to be a 3D set:

• The vectors specifying the vertical and horizontal directions of each 2D image must be orthogonal and must be the same for each file.
• The position of the upper left pixel in the 2 directions parallel to the scan plane must be the same.
• The position in the direction perpendicular to the image plane must match the value given by the "Slice Location" data element.
• The Series UID (Unique Identifier), Reference Frame UID, and Series Number must be the same in all files.
• The number of rows, number of columns, pixel spacing, window width & center, slope, and intercept must be the same for all files.

The information used for these checks is shown on the Image Properties dialog.

The transcript window reports whether or not the multiple files read constitute a valid 3D set. If a single or multiple files are read once a valid 3D set has been established, the checks are performed again using all loaded files. If a file is loaded that invalidates a 3D data set, the 3D data set is not recognized as valid if the nonconforming file is deleted. Gener ating a 3D MCNP model from multiple files requires the existence of valid 3D data set. The checks are not made, and a 3D data set is not recognized, if the files are loaded one at a time with Read DICOM.

The Loaded Images dialog (invoked with Loaded Images in the Image menu) presents a list of DICOM files present in memory. From the dialog, one can hide or show an image, list its properties, and delete an image.

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