Tag | (0070,030A) |
---|---|

Type | Required (1) |

Keyword | MatrixSequence |

Value Multiplicity | 1 |

Value Representation | Sequence (SQ) |

Specifies one transformation, that registers the Source RCS/images to the Registered RCS. It is expressible as multiple matrices, each in a separate Item of the Sequence.

One or more Items shall be included in this Sequence.

The Item order is significant and corresponds to matrix multiplication order. See Section C.20.2.1.1.

The Frame of Reference Transformation Matrix (3006,00C6) ^{A}M_{B} describes how to transform a point (^{B}x,^{B}y,^{B}z) with respect to RCS_{B} into (^{A}x,^{A}y,^{A}z) with respect to RCS_{A} according to Equation C.20.2-1.

**Equation C.20.2-1. **

The Matrix Registration is expressible as multiple matrices, each in a separate Item of Matrix Sequence (0070,030A). Equation C.20.2-2 specifies the order of the matrix multiplication where
**M _{1}
**
,

**Equation C.20.2-2. **

where

Registration often involves two or more RCS, each with a corresponding Frame of Reference Transformation Matrix. For example, another Frame of Reference Transformation Matrix ^{A}M_{C} can describe how to transform a point (
^{C}x,^{C}y,^{C}z) with respect to RCS
_{C}
into (
^{A}x,^{A}y,^{A}z) with respect to RCS_{A}. It is straightforward to find the Frame of Reference Transformation Matrix
^{B}
M
_{C}
that describes how to transform the point (
^{C}x,^{C}y,^{C}z) with respect to RCS_{C} into the point (
^{B}x,^{B}y,^{B}z) with respect to RCS_{B}. The solution is to invert ^{A}M_{B} and multiply by ^{A}M_{C}, as shown in Equation C.20.2-3.

**Equation C.20.2-3. **

If two or more transformation matrices describe the relation between Patient coordinates and a device-centric Well-known Frame of Reference, any calculations assuming transitivity via the Well-known Frame of Reference must be performed with great care to assure that both registrations reflect the same positioning of the patient with respect to the common Well-known Frame of Reference.