Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
Orthop J Sports Med. 2013 Dec 5;1(7):2325967113513423. doi: 10.1177/2325967113513423. eCollection 2013 Dec.
In recent years, few studies have evaluated low-field magnetic resonance imaging (MRI) diagnoses compared with intraoperative findings of the knee.
To determine the accuracy and sensitivity of low-field MRI scanners in diagnosing pathology of the menisci, cruciate ligaments, and osteochondral surfaces.
Cohort study (diagnosis); Level of evidence, 2.
MRI examinations without intra-articular contrast were performed on 379 patients for knee pathologies over a 4-year period. The MRI examinations were done using a 0.2-tesla scanner utilizing a dedicated knee coil and read by 1 of 3 board-certified, musculoskeletal fellowship-trained radiologists. Within a mean time of 50 days after MRI, all patients underwent knee arthroscopy performed by 1 of 2 sports fellowship-trained orthopaedic surgeons. Operative notes from the knee arthroscopies were then reviewed by a single independent observer, and the intraoperative findings were compared with the MRI reports.
For medial meniscus tears, the sensitivity, specificity, positive predictive value, and negative predictive value were 83%, 81%, 89%, and 71%, respectively. For lateral meniscus tears, the values were 51%, 93%, 84%, and 73%, respectively. For anterior cruciate ligament (ACL) tears, the values were 85%, 94%, 69%, and 97%, respectively. For osteochondral lesions, the values were 8%, 99%, 29%, and 94%, respectively. For posterior cruciate ligament (PCL) tears, the specificity and negative predictive value were 99% and 100%, respectively.
Low-field MRI was an accurate tool for evaluation of medial meniscus and ACL tears. However, within the study population, it is not as effective in diagnosing lateral meniscus tears and showed a poor ability to detect osteochondral lesions. More information is needed to properly assess its ability to diagnose PCL tears.
近年来，与膝关节术中发现相比，很少有研究评估低场磁共振成像（MRI）诊断。
确定低场 MRI 扫描仪诊断半月板、交叉韧带和骨软骨表面病变的准确性和敏感性。
队列研究（诊断）；证据水平，2。
在 4 年期间，对 379 例膝关节病变患者进行了无关节内对比的 MRI 检查。MRI 检查使用 0.2 特斯拉扫描仪，使用专用膝关节线圈，由 3 名经过董事会认证的、有肌肉骨骼专科培训的放射科医生中的 1 名进行阅读。在 MRI 后平均 50 天内，所有患者均由 2 名运动专科培训的骨科医生中的 1 名进行膝关节镜检查。然后由 1 名独立观察者审查膝关节镜手术记录，并将术中发现与 MRI 报告进行比较。
对于内侧半月板撕裂，敏感性、特异性、阳性预测值和阴性预测值分别为 83%、81%、89%和 71%。对于外侧半月板撕裂，值分别为 51%、93%、84%和 73%。对于前交叉韧带（ACL）撕裂，值分别为 85%、94%、69%和 97%。对于骨软骨病变，值分别为 8%、99%、29%和 94%。对于后交叉韧带（PCL）撕裂，特异性和阴性预测值分别为 99%和 100%。
低场 MRI 是评估内侧半月板和 ACL 撕裂的准确工具。然而，在研究人群中，它在诊断外侧半月板撕裂方面效果不佳，并且在检测骨软骨病变方面能力较差。需要更多信息来正确评估其诊断 PCL 撕裂的能力。
