# C.18.9.1 3D Spatial Coordinates Macro Attribute Descriptions

## C.18.9.1.1 Graphic Data

Graphic Data may be used to associate an anatomic or spatial Concept with a defined set of patient relative 3D locations in a defined frame of reference, independent of any image. Graphic Data may be defined explicitly as a single point (i.e. to denote the epicenter of an anatomic site or lesion) or more than one point (i.e. representing a set of points or an open or closed polygon).

## C.18.9.1.2 Graphic Type

This attribute defines the type of geometry of the region of interest. The following Enumerated Values are specified for 3D spatial coordinate geometries:

POINT = a single location denoted by a single (x,y,z) triplet.

MULTIPOINT = multiple locations each denoted by an (x,y,z) triplet; the points need not be coplanar.

POLYLINE = a series of connected line segments with ordered vertices denoted by (x,y,z) triplets; the points need not be coplanar.

POLYGON = a series of connected line segments with ordered vertices denoted by (x,y,z) triplets, where the first and last vertices shall be the same forming a polygon; the points shall be coplanar.

ELLIPSE = an ellipse defined by four (x,y,z) triplets, the first two triplets specifying the endpoints of the major axis and the second two triplets specifying the endpoints of the minor axis.

ELLIPSOID = A three-dimensional geometric surface whose plane sections are either ellipses or circles and contains three intersecting orthogonal axes, “a”, “b”, and “c”. The ellipsoid is defined by six (x,y,z) triplets, the first and second triplets specifying the endpoints of axis “a”, the third and fourth triplets specifying the endpoints of axis “b”, and the fifth and sixth triplets specifying the endpoints of axis “c”.

Notes: 1. A circle is a special case of ELLIPSE where the major and minor axis points are equidistant from the center.

2. Coplanar is in the mathematical sense and is not necessarily related to a specific image instance.