[Structural MRI study of the Achilles tendon. Correlation with microanatomy and histology]

On T1 and T2 weighted MR Imaging, normal Achilles tendon is generally described as a homogeneous low signal structure. However, punctuate and/or short linear high signal foci are often seen, especially on the anterior part of axial sections. These images are not artifacts. The aim of this study was to correlate MR images of 20 normal Achilles tendons with micro-anatomic and histologic studies of 2 cadaver tendons. Intratendinous vessels were found in connective tissue septa called mesotenon. Foci of high signals result from this mesotenon. On T1 weighted images, a normal Achilles tendon can present high signal images without any disease process.