FFF. X-Ray Field of View Macro Recommendations

The usage of this macro is recommended to specify the characteristics of the field of view.

When the field of view characteristics change across the multi-frame image, this macro is encoded on a per-frame basis.

The field of view region is defined by a shape, origin and dimension. The region of irradiated pixels corresponds to the interior of the field of view region.

When the X-Ray Receptor Type (0018,9420) equals “IMG_INTENSIFIER”, the intensifier TLHC is undefined. Therefore the field of view origin cannot be related to the physical area of the receptor. It is commonly understood that the field of view area corresponds to the intensifier active area, but there is no definition in the DICOM standard that forces a manufacturer to do so. As a consequence, it is impossible to relate the position of the pixels of the stored area to the isocenter reference system.

Table FFF.2.1-44 X-RAY FIELD OF VIEW MACRO Recommendations

Attribute Name Tag Comment
Field of View Sequence (0018,9432)
>Field of View Shape (0018,1147) Applicable in this scenario.
>Field of View Dimension(s) in Float (0018,9461) Applicable in this scenario.
>Field of View Origin (0018,7030) Applicable only in the case of digital detector.
>Field of View Rotation (0018,7032) Applicable regardless the type of receptor.
>Field of View Horizontal Flip (0018,7034) Applicable regardless the type of receptor.
>Field of View Description (0018,9433) Free text defining the type of field of view as displayed by the manufacturer on the acquisition system. For display purposes.