Department of Radiology and Research Institute of Radiological Science, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Republic of Korea.
Eur J Radiol. 2012 Oct;81(10):2783-7. doi: 10.1016/j.ejrad.2011.12.028. Epub 2012 Jan 18.
To describe the appearance of the infrapatellar plica (IPP) on magnetic resonance arthrography (MRA) taken in 70° knee flexion, corresponding to the arthroscopic posture.
Twenty-two patients (23 knee joints) who underwent MRA with 70° knee flexion were enrolled. All patients underwent MRA with 70° knee flexion to simulate operative arthroscopy. The images included fat-suppressed T1-weighted spin echo axial, sagittal, and coronal images. The visualization and morphology of the IPP were retrospectively assessed by two musculoskeletal radiologists.
The IPP was demonstrated in 78.3% (n=18/23) and was best visualized on the sagittal section through the intercondylar notch. The IPP manifested as a linear hypointense structure with variable thicknesses. The intercondylar component was delineated clearly, arising from the anterior intercondylar notch in parallel with the ACL and curving gently downward to attach to the infrapatellar fat pad. On the other hand, the Hoffa's fat pad component was not depicted clearly. The morphology of the IPP was either a separate type (60.9%) or a split type (17.4%).
The IPPs can be visualized with a high rate of detection and various morphologic appearances must be appreciated under the review of a flexed knee MRA.
描述在 70°膝关节屈曲位（对应关节镜检查体位）磁共振关节造影（MRA）上观察到的髌下隐襞（IPP）的外观。
共纳入 22 例（23 个膝关节）接受 70°膝关节屈曲 MRA 的患者。所有患者均接受 70°膝关节屈曲 MRA 以模拟手术关节镜检查。图像包括脂肪抑制 T1 加权自旋回波轴位、矢状位和冠状位。两名肌肉骨骼放射科医生回顾性评估 IPP 的可视化和形态。
IPP 在 78.3%（n=18/23）的膝关节中显示，在经髁间切迹的矢状位图像上显示最佳。IPP 表现为线性低信号结构，厚度不一。髁间成分清晰显示，从前交叉韧带（ACL）起始于前髁间切迹，呈平缓向下弯曲，附着于髌下脂肪垫。另一方面，Hoffa's 脂肪垫成分显示不清。IPP 的形态为单独型（60.9%）或分裂型（17.4%）。
在膝关节弯曲 MRA 检查下，IPP 可以被高概率检测到，并且必须评估其各种形态表现。
