## 5 Discussion  
The attachment areas of ankle and subtalar ligaments were identified using 1.5 T and 3.0 T MRI systems via both 2D and 3D sequences, and also via direct observations used as a reference. After relevant redistribution of the ligament fibres, a dynamic analysis of an ankle complex model showed load-displacement curves based on the 3.0 T MRI observations more consistent with those curves based on direct observations of the specimen.  
A number of papers in radiologic anatomy have addressed MRI imaging for ankle complex ligaments [40; 41; 42; 43]. However, these have not dealt with careful definition of origin and insertion areas of the ligaments, and this is particularly true for the subtalar ligaments. Additionally, not a single paper has compared geometrical and morphological features of these ligaments with corresponding direct observations. Also very limited is the analysis of the effects of resulting ligament mapping on dynamic computer models of the ankle joint complex. A recent paper from these authors has addressed medical imaging of the ankle complex by different modalities [44], but with a focus on the articular cartilage.  
Figure 3: Superimposition of the load–displacement curves resulting from the three mappings of the ligament attachment sites obtained via 1.5 T (red curves), 3.0 T (blue curves), and direct observation from the dissection of the specimen (green curves). Curves associated to Internal–External Rotation (**A**,**C**,**E**) and Inversion–Eversion (**B**,**D**,**F**) are reported for the AJC (**A**,**B**), TTJ (**C**,**D**), and STJ (**E**,**F**).  
The comparison of the ligament attachment sites obtained using the two MRI modalities with the direct observations demonstrated the superiority of the 3.0 T MRI over the 1.5 T MRI in imaging ligaments and identifying their regions of origin and insertion on bones. The main reason for these differences was that the 3D Cube sequence in 3.0 T MRI allows for a clearer visualization and revisualization of the ligaments and their attachment areas without losing resolution. In addition, 3.0 T MRI provides twice the signal-to-noise ratio compared to 1.5 T MRI, resulting in better image quality and higher spatial resolution [35].  
Visualization through imaging of the subtalar ligament morphology is very difficult [23; 40]. This study demonstrated that this difficulty may be overcome by more advanced imaging modalities and may offer a solution for accurate diagnosis of subtalar ligament injuries [8; 24]. Furthermore, this study demonstrated that visualizing the subtalar ligaments from different orientations without loss of resolution provides an important imaging advantage over non-cubic sequences where high resolution is only available in one direction.  
The 3.0 T MRI-based dynamic model produced load-displacement behaviour similar to that resulting from the model based on direct observations of the ligaments attachment sites. The 1.5 T MRI-based model, on the other hand, produced different results. This demonstrates the importance of using higher resolution 3D Cube sequence, as by 3.0 T MRI, in developing accurate models of the ankle complex and its ligamentous support.  
This study is not without limitations. The study relied on one single specimen so that inter-subject variability was not considered. In addition, direct observation, even from very careful anatomical dissections by experienced anatomists and surgeons, is difficult and subject to controversies due to the complex structure of these ligaments and their hard-to-access location. This also applies to identification by radiologists in image-based observations. In addition, no inter-observer assessment was included. The present relevant findings can be certainly strengthened in the future with other specimens, other MRI devices, and other ligament mapping definitions.