1. RECIST - Definitions
2. Measure the longest in plane diameter
3. Target Measurement Rules
4. Selecting Target Lesions
5. Importance of Imaging Consistency
6. Importance of IV-Contrast
7. Importance of i.v.-contrast and proper timing, scanning delay
8. Imaging: Anatomy for CT/MRI
9. Target Measurement Rules at Follow-up
10. Progression by Non-Targets only
11. Reappearing Lesion
12. Splitting Lesions
13. Merging Lesions
14. Merging lesions example
15. Variable Enhancement
16. Lung Lesion develops cavity
17. Lymph Node Measurements, CT
18. Lymph Node Measurements, MRI
19. Bone mets
20. MRI
21. PET
22. Overview: RECIST vs. RECIST 1.1

First you need to identify the longest diameter of a lymph node or nodal mass (here 56.0mm) and then choose the longest perpendicular diameter to that as the short axis (here 45.3mm). This lesion here would qualify as a measurable target lesion.