Table 3. Subgroup assessment of accuracy of BAVM characterization and grading on silent MRA and TOF MRA.
| Subgroup grading criteria | Nidus size grading | Pattern of venous drainage | Associated aneurysm | Spetzler-Martin grading | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Silent MRA | TOF MRA | P value | Silent MRA | TOF MRA | P value | Silent MRA | TOF MRA | P value | Silent MRA | TOF MRA | P value | ||||
| Total (n=80) | 0.963 (77/80) | 0.675 (54/80) | <0.01* | 0.938 (75/80) | 0.888 (71/80) | 0.402 | 0.975 (78/80) | 0.90 (72/80) | 0.098 | 0.913 (73/80) | 0.625 (50/80) | <0.01* | |||
| New hemorrhage | |||||||||||||||
| + (n=19) | 1 (19/19) | 0.684 (13/19) | 0.020* | 1 (19/19) | 0.789 (15/19) | 0.105 | 1 (19/19) | 0.842 (16/19) | 0.230 | 0.947 (18/19) | 0.632 (12/19) | 0.042* | |||
| – (n=61) | 0.951 (58/61) | 0.672 (41/61) | <0.001* | 0.918 (56/61) | 0.918 (56/61) | 1 | 0.967 (59/61) | 0.918 (56/61) | 0.439 | 0.902 (55/61) | 0.623 (38/61) | 0.001* | |||
| P value | 0.438 | 0.579 | 0.247 | 0.130 | 0.579 | 0.285 | 0.469 | 0.585 | |||||||
| Embolization | |||||||||||||||
| + (n=33) | 0.909 (30/33) | 0.667 (22/33) | 0.033* | 0.939 (31/33) | 0.909 (30/33) | 0.5 | 1 (33/33) | 0.969 (32/33) | 0.5 | 0.939 (31/33) | 0/576 (19/33) | 0.002* | |||
| – (n=47) | 1 (47/47) | 0.681 (32/47) | <0.001* | 0.936 (44/47) | 0.872 (41/47) | 0.486 | 0.957 (45/47) | 0.851 (40/47) | 0.158 | 0.894 (42/47) | 0.660 (31/47) | 0.012* | |||
| P value | 0.066 | 0.541 | 0.665 | 0.446 | 0.342 | 0.082 | 0.386 | 0.298 | |||||||
| Nidus size | |||||||||||||||
| <3 cm (n=22) | 1 (22/22) | 0.955 (21/22) | 0.5 | 1 (22/22) | 0.909 (20/22) | 0.488 | 1 (22/22) | 0.909 (20/22) | 0.488 | 0.909 (20/22) | 0.727 (16/22) | 0.240 | |||
| 3–6 cm (n=49) | 0.939 (46/49) | 0.531 (26/49) | <0.001* | 0.939 (46/49) | 0.898 (44/49) | 0.715 | 0.959 (47/49) | 0.898 (44/49) | 0.436 | 0.939 (46/49) | 0.612 (30/49) | <0.001* | |||
| >6 cm (n=9) | 1 (9/9) | 0.778 (7/9) | 0.471 | 0.778 (7/9) | 0.778 (7/9) | 1 | 1 (9/9) | 0.889 (8/9) | 0.5 | 0.778 (7/9) | 0.444 (4/9) | 0.335 | |||
| P value | 0.373 | 0.002 | 0.068 | 0.538 | 0.523 | 0.983 | 0.290 | 0.322 | |||||||
| Compactness | |||||||||||||||
| + (n=65) | 0.969 (63/65) | 0.662 (43/65) | <0.001* | 0.954 (62/65) | 0.877 (57/65) | 0.206 | 0.969 (63/65) | 0.877 (57/65) | 0.096 | 0.923 (60/65) | 0.615 (40/65) | <0.001* | |||
| – (n=15) | 0.933 (14/15) | 0.733 (11/15) | 0.330 | 0.867 (13/15) | 0.933 (14/15) | 0.5 | 1 (15/15) | 1 (15/15) | 1 | 0.867 (13/15) | 0.667 (10/15) | 0.390 | |||
| P value | 0.468 | 0.418 | 0.234 | 0.464 | 0.658 | 0.174 | 0.391 | 0.477 | |||||||
Values are presented as accuracy rate with the ratio of the accurate number to the total number in parentheses. *, statistical significance. BAVM, brain arteriovenous malformation; MRA, magnetic resonance angiography; TOF MRA, time-of-flight magnetic resonance angiography.