Correlation between imaging signs and DO in OLF
| OLF with DO | OLF without DO | Total | |
|---|---|---|---|
| TTS | 47 | 11 | 58 |
| CS | 7 (CS=1, CS+TTS=6)* | 0 | 7 (CS=1, CS+TTS=6)* |
| BS | 7 (BS=1, BS+TTS=6)* | 0 | 7 (BS=1, BS+TTS=6)* |
| No TTS, CS or BS | 3 | 179 | 182 |
| Total | 52 | 190 | 242 |
*CS/BS existed alone for one segment and was accompanied by TTS in six segments.
BS, bridge sign; CS, comma sign; DO, dural ossification; OLF, ossification of ligamentum flavum; TTS, tram track sign.