Table 4.

Comparison of IST-3 angiography scores from 15 scans as assessed by seven members of the IST-3 expert panel

Scan	Reader 1	Reader 2	Reader 3	Reader 4	Reader 5	Reader 6	Reader 7
1	1	0	0	1	0	0	1
2	4	4	4	4	4	4	4
3	2b	0	1	2a	0	0	0
4	2b	0	0	2b	0	0	0
5	2a	0	0	2b	0	2a	2b
6	3	2b	1	3	4	3	4
7	1	1	0	2b	0	0	1
8	3	4	4	3	4	3	4
9	4	4	4	4	4	4	4
10	2a	1	4	2b	0	3	1
11	2b	0	1	2b	0	0	0
12	1	4	3	3	1	0	4
13	1	0	0	1	0	0	0
14	2b	1	2b	2b	0	0	2a
15	3	4	4	4	4	4	4

K-alpha for this inter-observer analysis (315 pairs of readings) is 0.60 (95 % CI = 0.53–0.66). 0 = No patency, 1 = contrast penetrates obstruction but minimal enters the distal artery, 2a = luminal patency of <50 % with partial filling (<half) of major branches, 2b = luminal patency of <50 % with partial filling (>half) of major branches, 3 = patency of >50 % of lumen and filling of most branches and 4 = complete patency