Table C.8.27.4-1 describes the parameters used for processing an Intravascular Optical Coherence Tomography polar data image.
Table C.8.27.4-1INTRAVASCULAR OCT PROCESSING PARAMETERS MODULE ATTRIBUTES
|Attribute Name||Tag||Type||Attribute Description|
|OCT Z Offset Applied||(0052,0026)||1||Indicates whether or not Z offset correction was applied to the OCT image frames. Enumerated Values: YES NO|
|Refractive Index Applied||(0052,003A)||1||Indicates whether or not Refractive Index correction was applied. Enumerated Values: YES NO See section C.188.8.131.52 for further explanation.|
|A-line Pixel Spacing||(0052,0014)||1||Spacing of pixels in the A-line (X-axis), in mm.|
|Pixel Intensity Relationship||(0028,1040)||1||The relationship between the pixel sample values and the IVOCT A-line intensity. See Section C.184.108.40.206.|
|First A-line Location||(0052,0034)||1||Orientation in degrees at which the 1st A-line in the frame should be displayed. Value shall be between 0 and 360, with zero representing vertical.|
For Refractive Index Applied (0052,003A) a value of YES indicates that Effective Refractive Index (0052,0004) correction has been applied to the reported A-line Pixel Spacing (0052,0014) attribute. A value of NO indicates that Effective Refractive Index (0052,0004) correction has not been applied (i.e. A-line Pixel Spacing corresponds to the pixel spacing in air).
Pixel Intensity Relationship (0028,1040) shall identify the relationship of the pixel values to the IVOCT A-line intensity. Defined terms are:
|LIN||Approximately proportional to A-line intensity.|
|LOG||Non-linear “Log Function”; A Pixel Intensity Relationship LUT shall be included with the image to allow it to be scaled back to its proportional A-line intensity value.|