Longitudinal-positioning indicator and marking grid

1. A longitudinal-positioning indicator comprising:

a substrate including a first side and a second side, wherein the second side is at least partially coated with an adhesive, and wherein the substrate has a length and a width; and

a set of longitudinal-positioning guidelines secured with the substrate, wherein the set of longitudinal-positioning guidelines is configured to indicate a position along the length of the substrate based on a cross-section of the longitudinal-positioning indicator taken along the width of the substrate.

2. The longitudinal-positioning indicator of claim 1 , wherein the set of longitudinal-positioning guidelines includes a plurality of parallel guidelines of different lengths, and wherein each of the plurality of parallel guidelines extends in a direction parallel to the length.

3. The longitudinal-positioning indicator of claim 2 , wherein:

the plurality of guidelines of different lengths are spaced apart and oriented substantially parallel to each other; and

each of the plurality of guidelines is aligned at one end and arranged based on length.

4. The longitudinal-positioning indicator of claim 3 , further comprising:

an index with a plurality of demarcations, each of the plurality of demarcations corresponding to a length of a guideline in the plurality of guidelines.

5. The longitudinal-positioning indicator of claim 2 , wherein the position along the length of the substrate is indicated by a number of the plurality of parallel guidelines appear in the cross-section of the substrate.

6. The longitudinal-positioning indicator of claim 1 , wherein the set of longitudinal-positioning guidelines is disposed on the first side of the substrate.

7. The longitudinal-positioning indicator of claim 1 , wherein:

the substrate has a first radiopacity; and

the set of longitudinal-positioning guidelines has a second radiopacity that is greater than the first radiopacity.

8. The longitudinal-positioning indicator of claim 1 , wherein the substrate further comprises:

an elongated body portion for the set of longitudinal-positioning guidelines; and

a margin portion extending from the elongated body portion.

9. The longitudinal-positioning indicator of claim/wherein the margin portion includes a set of tabs.

10. The longitudinal-positioning indicator of claim 8 , wherein the elongated body portion is separated from the margin portion by a perforation line.

11. The longitudinal-positioning indicator of claim 1 , further comprising:

a releasable backing secured to the substrate by the adhesive.

12. A marking grid for use in radiographic imaging, the marking grid comprising:

a substrate including a first side and a second side, wherein the second side is at least partially coated with an adhesive, and wherein the substrate includes a length and a width;

a set of lateral-positioning guidelines supported by the substrate and extending in a direction of the length; and

a set of longitudinal-positioning guidelines supported by the substrate, and

wherein the set of lateral-positioning guidelines and the set of longitudinal-positioning guidelines are configured to identify a location within an area bounded by the marking grid, the location based on a cross-section of the marking grid taken substantially orthogonally to the length of the substrate.

13. The longitudinal-positioning indicator of claim 12 , wherein the set of longitudinal-positioning guidelines includes at least one reference guideline extending in a direction parallel to the length and an auxiliary guideline at a predetermined angle relative to the at least one reference guideline.

14. The longitudinal-positioning indicator of claim 13 , wherein the auxiliary guideline intersects at least some of the set of lateral positioning guidelines.

15. The marking grid of claim 12 , wherein the substrate comprises a set of elongated apertures interspersed with the set of lateral-positioning guidelines in alternating fashion.

16. The marking grid of claim 12 , wherein the set of longitudinal-positioning guidelines includes a plurality of guidelines, and wherein the set of longitudinal-positioning guidelines is configured to indicate a longitudinal position within the area bounded by the marking grid based on a number of guidelines that appear in the cross-section of the marking grid.

17. The marking grid of claim 16 , wherein the plurality of guidelines includes guidelines of a different length, arranged in a stair-step configuration.

18. The marking grid of claim 16 , wherein the marking grid further comprises:

an index with a plurality of demarcations, each of the plurality of demarcations corresponding to a length of a guideline in the plurality of guidelines.

19. The marking grid of claim 12 , further comprising a releasable backing secured to the substrate by the adhesive.