The Difference Of MR Scans In Different Positions Between Ankle Ligaments And Tendons

Objective:To discuss the difference of MR scans in different positions between ligaments and tendons of ankle, for clinical injure to provide accurate, fast diagnosis based on 3.0T magnetic resonance instrument.Materials and methods:30 healthy volunteers'ankles were selected for the study, all volunteers were supine, ankle full dorsal flexion, full plantar flexion and natural position scans. Collect coronal, sagittal and transverse images of different position. Choose T1WI as sequences. And two experienced radiologists score the different images. Rating criteria: continuous display of ligaments in 2 to 3 levels, who can only see part of the ligament as 1 point; continuous display of ligament in 2 or 3 level ,who can see most of the ligaments, at least the beginning or the ending as 2 points; at least more than one level can show full-length comment to 3 points. Make the different positions on the same scan for X2 test to P<0.05 indicate significant difference.Results:Ankle ligaments make a obvious contrast with surrounding high signal fat tissue in TWI image, showing two basic signals. ATFL, CFL, CTL and the superficial medial ligament show the uniform linear or point-like low signal. PTFL, PiTFL and the deep medial ligament show the heterogeneous strip signals.The results show that the ATFL shows the high rate in the natural position- transverse images and full dorsal flexion- transverse images, accounting for 42% and 39% of group 3 points, There is no determinate difference between the two groups (P>0.05). And there are no determinate differences between in natural position– coronal images and full dorsal flexion- coronal images, and all sagittal images (P>0.05). PTFL shows best in the full dorsal flexion - transverse images and natural position- coronal, accounting for 48% and 32% of group 3 points. There is determinate difference between the two groups (P<0.05). And there are no determinate differences between all sagittal images (P>0.05). CFL shows best in the natural position-transverse, accounting for 47% of group 3 points.And there are no determinate differences between all sagittal images (P>0.05)NTL shows best in the full plantar flexion - coronal image and full dorsal flexion- transverse image, accounting for 35% and 31% of group 3 points. There is determinate difference between the two groups (P<0.05). And there are no determinate differences between in natural position– coronal images and full dorsal flexion- coronal images, and all sagittal images (P>0.05).CTL shows best in the full dorsal flexion- coronal images, and full dorsal flexion- transverse image, accounting for 35% and 26% of group 3 points, There is determinate difference between the two groups (P<0.05). And there are no determinate differences between in natural position–coronal images and full plantar flexion - coronal images, natural position–transverse images and full plantar flexion - coronal images, and all sagittal images (P>0.05). ATTL shows best in the full plantar flexion - coronal images, and natural position - coronal images, accounting for 36% and 25% of group 3 points, There is no determinate difference between the two groups (P>0.05). And there are no determinate differences between in natural position–coronal images and the full dorsal flexion - coronal images, natural position–transverse images and the full dorsal flexion - transverse images, and all sagittal images (P>0.05). PTTL shows best in the full dorsal flexion - transverse images, accounting for 70% of group 3 points, There are no determinate differences between in natural position–coronal images and the full dorsal flexion - coronal images, natural position–transverse images and the full plantar flexion n - transverse images, and all sagittal images (P>0.05)AiTFL and PiTFL show well in transverse image of all positions. There are no determinate differences between the different positions. Coronal and sagottal plane is difficult to identify the ligament structure. Interosseous ligament shows well both in transverse and coronal image of all positions. In T1WI, Interosseous ligament can be seen at the distal tibia and fibula as a linear low signal. TrTFL shows best in the dorsal flexion - transverse image, and the natural position- transverse image, accounting for 34% and 31% of group 3 points, There is determinate difference between the two groups (P<0.05). And there are no determinate differences between in natural position–coronal images and the full dorsal flexion - coronal images, natural position–transverse images and the full dorsal flexion - transverse images, and all sagittal images (P>0.05).The continuity of the AT is the most important evidence to diagnosis its injure. The natural position- sagittal image showsthe complete AT, which can benefit the diagnosis of the injure of AT. The tendons around the ankle show round or oval low signals in MR image, which related with their different function.The sagittal planes of different positions all can go around the tendons, which can show the most part.Conclusion:1.Lateral collateral ligament: ATFL in the natural position- transverse images and full dorsal flexion- transverse images shows the best and the same effect. PTFL shows the best in full dorsal flexion- transverse images, and comes second in natural position– coronal images, CFL shows best in natural position- transverse images.2. Medial collateral ligament: NTL shows best in the plantar flexion - coronal image, comes the second in full dorsal flexion- transverse image. CTL shows best in the dorsal flexion - transverse image, comes second in the dorsal flexion–transverse image. ATTL in the natural position- transverse image and full plantar flexion-coronal image shows the best and the same effect. PTTL shows best in the dorsal flexion- transverse image.3.Tibofibular syndesmosis ligament: AiTFL and PiTFL show well in transverse image of all positions. Interosseous ligament shows well both in transverse and coronal image of all positions. TrTFL shows best in the dorsal flexion - transverse image, comes second in the natural position- transverse image.4.AT shows best in the natural position- sagittal image.5. The Difference of MR scans in different positions between ankle ligaments and tendons.