C.8.27.4 Intravascular OCT Processing Parameters Module

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.8.27.4.1 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.8.27.4.2.
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.

C.8.27.4.1 Refractive Index Applied

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).

C.8.27.4.2 Pixel Intensity Relationship

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.