Материал: part03

The Patient-Based Coordinate System is a right handed system, i.e., the vector cross product of a unit vector along the positive x-​ axis and a unit vector along the positive y-axis is equal to a unit vector along the positive z-axis.​

Note​

If a patient is positioned parallel to the ground, in dorsal recumbency (i.e., for humans, face-up on the table), with the caudo-​ cranial(i.e.,forhumans,feet-to-head)directionthesameasthefront-to-backdirectionoftheimagingequipment,thedirection​ of the axes of this Patient-Based Coordinate System and the Equipment-Based Coordinate System in previous versions of​ this Standard will coincide.​

The Image Plane Attributes, in conjunction with the Pixel Spacing Attribute, describe the position and orientation of the image slices​ relative to the Patient-Based Coordinate System. In each image frame Image Position (Patient) (0020,0032) specifies the origin of​ the image with respect to the Patient-Based Coordinate System. RCS and Image Orientation (Patient) (0020,0037) values specify​ the orientation of the image frame rows and columns. The mapping of pixel location (i,j) to the RCS is calculated as follows:​

Where:​

Pxyz The coordinates of the voxel (i,j) in the frame's image plane in units of mm.​

Sxyz The three values of Image Position (Patient) (0020,0032). It is the location in mm from the origin of the RCS.​

Xxyz The values from the row (X) direction cosine of Image Orientation (Patient) (0020,0037).​

Yxyz The values from the column (Y) direction cosine of Image Orientation (Patient) (0020,0037).​

i Column index to the image plane. The first column is index zero.​

i Column pixel resolution of Pixel Spacing (0028,0030) in units of mm.​

j Row index to the image plane. The first row index is zero.​

j Row pixel resolution of Pixel Spacing (0028,0030) in units of mm.​

Additional constraints apply:​

1.​The row and column direction cosine vectors shall be orthogonal, i.e., their dot product shall be zero.​

2.​The row and column direction cosine vectors shall be normal, i.e., the dot product of each direction cosine vector with itself shall​ be unity.​

C.7.6.2.1.2 Slice Location​

Slice Location (0020,1041) is defined as the relative position of the image plane expressed in mm. This information is relative to an​ unspecified implementation specific reference point.​

C.7.6.3 Image Pixel Module​

Table C.7-11a describes the Image Pixel Module.​

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Page 522​ DICOM PS3.3 2020a - Information Object Definitions​

Table C.7-11a. Image Pixel Module Attributes​

Attribute Name​ Tag​ Type​ Attribute Description​

Include Table C.7-11c “Image Pixel Description​Required if the IOD is not being transferred in a STOW-RS Request and is not​

Module. See Section C.7.5.1.1.2 for further explanation.​

Required if pixel padding is to be defined as a range rather than a single value.​

Note​

1.​The Value Representation of this Attribute is determined by the value​ of Pixel Representation (0028,0103).​

2.​Pixel Padding Value (0028,0120) is also required when this Attribute​ is present.​

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See Section C.7.6.3.1.8.​

Required if Extended Offset Table (7FE0,0001) is present and every frame is​ encoded as a single fragment.​

Note​

The length information is not sent when there are multiple fragments per​ frame, since it is necessary to assemble the frame from fragments with​ delimiters rather than assuming a single contiguous span of bytes.​

Table C.7-11b specifies the common Attributes that describe and encode the pixel data of the image.​

Table C.7-11b. Image Pixel Macro Attributes​

Table C.7-11c specifies the common Attributes that describe the pixel data of the image.​

Table C.7-11c. Image Pixel Description Macro Attributes​

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See Section C.11.15.1.2.​

C.7.6.3.1 Image Pixel Attribute Descriptions​

C.7.6.3.1.1 Samples Per Pixel​

Samples per Pixel (0028,0002) is the number of separate planes in this image. One and three image planes are defined. Other​ numbers of image planes are allowed, but their meaning is not defined by this Standard.​

For monochrome (gray scale) and palette color images, the number of planes is 1. For RGB and other three vector color models, the​ value of this Attribute is 3.​

Note​

The use of a value of 4 was previously described, but the Photometric Interpretations that used it have been retired.​

All image planes shall have the same number of Rows (0028,0010), Columns (0028,0011), Bits Allocated (0028,0100), Bits Stored​ (0028,0101), High Bit (0028,0102), Pixel Representation (0028,0103), and Pixel Aspect Ratio (0028,0034).​

Note​

Downsampled chrominance planes of a color Photometric Interpretation are a special case, e.g., for a Photometric Interpret-​ ation (0028,0004) of YBR_FULL_422. In such cases, Samples per Pixel (0028,0002) describes the nominal number of​ channels (i.e., 3), and does not reflect that two chrominance samples are shared between four luminance samples. For​ YBR_FULL_422,Rows(0028,0010)andColumns(0028,0011)describethesizeoftheluminanceplane,notthedownsampled​ chrominance planes.​

The data in each pixel may be represented as a "Composite Pixel Code". If Samples Per Pixel is one, the Composite Pixel Code is​ just the "n" bit pixel sample, where "n" = Bits Allocated. If Samples Per Pixel is greater than one, Composite Pixel Code is a "k" bit​ concatenation of samples, where "k" = Bits Allocated multiplied by Samples Per Pixel, and with the sample representing the vector​

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