Correct High Bit value description in various IODs STATUS Submitted Date of Last Update 2014/06/27 Person Assigned David Clunie Submitter Name Mathieu Malaterre Submission Date 2014/06/21 Correction Number CP-1422 Log Summary: Correct High Bit value description in various IODs Name of Standard PS3.3 Rationale for Correction: High Bit for all DICOM image IODs (since DICOM was first introduced in 1993) is intended to always be one less than Bits Stored and should always be defined as such. This is distinct form the earlier ACR-NEMA standards that permitted "packing"). A few IODs incorrectly describe High Bit when more than one enumerated value is permitted but do not use the consistent "one less than Bits Stored" language, leading to potentially ambiguities if the "obvious" selection is not made. Correct this, and specify the constraint in the general macro. Correction Wording:

Amend PS3.3 Annex C as follows:

... specifies the common attributes that describe the pixel data of the image.

Image Pixel Macro Attributes

Attribute Name	Tag	Type	Attribute Description
Bits Allocated	(0028,0100)	1	Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See PS3.5 for further explanation.
Bits Stored	(0028,0101)	1	Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. See PS3.5 for further explanation.
High Bit	(0028,0102)	1	Most significant bit for pixel sample data. Each sample shall have the same high bit. High Bit (0028,0102) shall be one less than Bits Stored (0028,0101). See PS3.5 for further explanation.
...	...	...	....

contains the Attributes that describe MR images.

MR Image Module Attributes

Attribute Name	Tag	Type	Attribute Description
Bits Allocated	(0028,0100)	1	Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See for specialization.
Bits Stored	(0028,0101)	1	Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored.
High Bit	(0028,0102)	1	Most significant bit for pixel sample data. Each sample shall have the same high bit. High Bit (0028,0102) shall be one less than Bits Stored (0028,0101).

...

16

specifies the Attributes that describe ultrasound images.

US Image Module Attributes

Attribute Name	Tag	Type	Attribute Description
Bits Allocated	(0028,0100)	1	Number of bits allocated for each pixel sample. See for specialization.
Bits Stored	(0028,0101)	1	Number of bits stored for each pixel sample. See for specialization.
High Bit	(0028,0102)	1	Most significant bit for pixel sample data. See for specialization.

...

For US Images, Bits Allocated (0028,0100) is specified to use the following values for specific Photometric Interpretations:

US Bits Allocated

Photometric Interpretation	Bits Allocated Value
MONOCHROME2	8
RGB	8
YBR_FULL	8
YBR_FULL_422	8
YBR_PARTIAL_422	8
YBR_RCT	8
YBR_ICT	8
YBR_PARTIAL_420	8
PALETTE COLOR	8 - 8 bit palette, or 16 - 16 bit palette

For US Images, Bits Stored (0028,0101) shall be equal to Bits Allocated (0028,0100)is specified to use the following values for specific Photometric Interpretations:

US Bits Stored

Photometric Interpretation	Bits Stored Value
MONOCHROME2	8
RGB	8
YBR_FULL	8
YBR_FULL_422	8
YBR_PARTIAL_422	8
YBR_RCT	8
YBR_ICT	8
YBR_PARTIAL_420	8
PALETTE COLOR	8 - 8 bit palette, or 16 - 16 bit palette

For US Images, High Bit (0028,0102) shall be one less than Bits Stored (0028,0101)is specified to use the following values for specific Photometric Interpretations:

US High Bit

Photometric Interpretation	High Bit Value
MONOCHROME2	7
RGB	7
YBR_FULL	7
YBR_FULL_422	7
YBR_PARTIAL_422	7
YBR_RCT	7
YBR_ICT	7
YBR_PARTIAL_420	7
PALETTE COLOR	7 - 8 bit palette, or 15 - 16 bit palette

...

Enhanced US Image Module Attributes

Attribute Name	Tag	Type	Attribute Description
Bits Allocated	(0028,0100)	1	Number of bits allocated for each pixel sample. 8 16
Bits Stored	(0028,0101)	1	Number of bits stored for each pixel sample. Shall be equal to Bits Allocated (0028,0100). 8 16
High Bit	(0028,0102)	1	Most significant bit for pixel sample data. High Bit (0028,0102) shall be one less than Bits Stored (0028,0101). 7 15