Table 2.
Frequency of within-institution duplicate imaging 12 months before and 12 months after introduction of PACS
| Frequency of duplicate imaging | |||
| Before PACS | After PACS | P | |
| Duplicate test within less than 7 days | |||
| X-ray | |||
| Chest | 1146/60598 (1.9) | 1070/60366 (1.8) | 0.12 |
| Abdomen | 339/8512(4.0) | 273/8355 (3.3) | 0.01 |
| Total | 1485/69110 (2.2) | 1343/68721 (2.0) | 0.01 |
| Computed tomography | |||
| Abdomen/Pelvis | 275/14213 (1.9) | 351/16060 (2.2) | 0.13 |
| Head | 1099/16523 (6.7) | 1180/18102 (6.5) | 0.62 |
| Chest | 78/6627 (1.2) | 120/8173 (1.5) | 0.13 |
| Total | 1452/37363 (3.9) | 1651/42335 (3.9) | 0.92 |
| Duplicate test within less than 30 days | |||
| X-ray | |||
| Chest | 3948/58212 (6.8) | 3592/58204 (6.2) | <0.001 |
| Abdomen | 667/8248 (8.1) | 595/8123 (7.3) | 0.07 |
| Total | 4615/66460 (6.9) | 4187/66327 (6.3) | <0.001 |
| Computed tomography | |||
| Abdomen/Pelvis | 596/13969 (4.3) | 786/15764 (5.0) | 0.003 |
| Head | 1640/16364 (10.0) | 1856/17868 (10.4) | 0.26 |
| Chest | 200/6525 (3.1) | 309/8019 (3.9) | 0.01 |
| Total | 2436/36858 (6.6) | 2951/41651 (7.1) | 0.01 |
| Duplicate test within less than 60 days | |||
| X-ray | |||
| Chest | 6032/56841 (10.6) | 5519/56902 (9.7) | <0.001 |
| Abdomen | 857/8143 (10.5) | 789/8012 (9.9) | 0.16 |
| Total | 6889/64984 (10.6) | 6308/64914 (9.7) | <0.001 |
| Computed tomography | |||
| Abdomen/Pelvis | 968/13679 (7.1) | 1174/15461 (7.6) | 0.09 |
| Head | 1883/16257 (11.6) | 2157/17736 (12.2) | 0.10 |
| Chest | 341/6405 (5.3) | 498/7857 (6.3) | 0.01 |
| Total | 3192/36341 (8.8) | 3829/41054 (9.3) | 0.01 |
Abbreviations: PACS, picture archiving communication systems.
All numbers reported as no. of index tests associated with a duplicate test/total no. of index tests (%).
All P values are for difference in frequency of duplicate imaging before versus after PACS.