Table 2. Top 10 countries and institutions according to the number of articles published in the IAMRA field from 2004 to 2020.
| Rank | Country | Counts (%) | Average IF | Centrality† | Half-life | Institution | Counts (%) | Average IF | Centrality | Half-life |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | USA | 347 (27.28) | 3.14 | 0.75 | 8 | Mayo Clinic | 33 (2.59) | 4.302 | 0.03 | 8 |
| 2 | Japan | 242 (19.03) | 2.38 | 0 | 9 | Shanghai Jiao Tong University | 25 (1.97) | 3.964 | 0 | 4 |
| 3 | Germany | 135 (10.61) | 3.21 | 0.33 | 9 | Seoul Natl Univ | 23 (1.81) | 2.892 | 0 | 3 |
| 4 | China | 101 (7.94) | 2.86 | 0 | 7 | Univ Med Ctr Utrecht | 19 (1.49) | 8.437 | 0 | 2 |
| 5 | South Korea | 96 (7.55) | 2.64 | 0 | 9 | Univ Amsterdam | 17 (1.34) | 4.072 | 0.02 | 9 |
| 6 | France | 74 (5.82) | 3.54 | 0.13 | 8 | Univ Calif San Francisco | 17 (1.34) | 3.781 | 0.02 | 2 |
| 7 | The Netherlands | 56 (4.40) | 5.07 | 0.14 | 7 | Saitama Med Univ | 16 (1.26) | 1.538 | 0.04 | 4 |
| 8 | Canada | 38 (2.99) | 3.95 | 0.02 | 5 | Univ Hosp Essen | 16 (1.26) | 3.438 | 0.05 | 1 |
| 9 | Italy | 38 (2.99) | 2.95 | 0.07 | 7 | Univ Calif Los Angeles | 15 (1.18) | 4.227 | 0.04 | 3 |
| 10 | UK | 36 (2.83) | 4.09 | 0.13 | 5 | Univ Cincinnati | 14 (1.10) | 5.608 | 0 | 2 |
†, an index used to quantify the importance of points in the network. Value of centrality is proportional to the mediating effect half-life; that is, the number of years in which an organization’s forward calculated citations from the current year account for 50% of the total citations. IF, impactor factor (Journal Citation Reports 2018, released on June 6, 2019). IAMRA, intracranial aneurysms magnetic resonance angiography.