Presentation Pixel Spacing Attribute
| Tag | (0070,0101) |
|---|---|
| Type | Conditionally Required (1C) |
| Keyword | PresentationPixelSpacing |
| Value Multiplicity | 2 |
| Value Representation | Decimal String (DS) |
Physical distance between the center of each pixel in the referenced image (before spatial transformation), specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See Section 10.7.1.3 for further explanation of the value order.
Note
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This value may be different from Pixel Spacing (0028,0030) or Imager Pixel Spacing (0018,1164) specified in the referenced image, which are ignored, since some form of calibration may have been performed (for example by reference to an object of known size in the image).
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If the row and column spacing are different, then the pixel aspect ratio of the image is not 1:1.
Required if Presentation Size Mode (0070,0100) is TRUE SIZE, in which case the values will correspond to the physical distance between the center of each pixel on the display device.
May be present if Presentation Size Mode (0070,0100) is SCALE TO FIT or MAGNIFY, in which case the values are used to compute the aspect ratio of the image pixels.
Section 10.7.1.3
10.7.1.3 Pixel Spacing Value Order and Valid Values
All pixel spacing related Attributes are encoded as the physical distance between the centers of each two-dimensional pixel, specified by two numeric values.
The first value is the row spacing in mm, that is the spacing between the centers of adjacent rows, or vertical spacing.
The second value is the column spacing in mm, that is the spacing between the centers of adjacent columns, or horizontal spacing.
To illustrate, consider the example shown in Figure 10.7.1.3-1.
Figure 10.7.1.3-1. Example of Pixel Spacing Value Order
Pixel Spacing = Row Spacing \ Column Spacing = 0.30\0.25.
All pixel spacing related Attributes shall have positive non-zero values, except when there is only a single row or column or pixel of data present, in which case the corresponding value may be zero.
Note
A single row or column or "pixel" may occur in MR Spectroscopy Instances.
This description applies to:
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Pixel Spacing (0028,0030)
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Imager Pixel Spacing (0018,1164)
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Nominal Scanned Pixel Spacing (0018,2010)
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Image Plane Pixel Spacing (3002,0011)
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Compensator Pixel Spacing (300A,00E9)
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Detector Element Spacing (0018,7022)
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Presentation Pixel Spacing (0070,0101)
-
Printer Pixel Spacing (2010,0376)
-
Object Pixel Spacing in Center of Beam (0018,9404)