AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Sep 2009
Motion of the cerebellar tonsils in the foramen magnum during the cardiac cycle.
Tonsil motion was measured with cine MR imaging in patients clinically suspected of having Chiari I malformation. Cardiac-gated sagittal 2D fast imaging employing steady-state acquisition (2D FIESTA) was performed in 11 patients with a Chiari I malformation and in 6 subjects without tonsil ectopia. Tonsil motion was measured through the cardiac cycle with a pixel-shift program designed for that purpose. ⋯ In patients with Chiari I and subjects with normal cerebellar tonsils, 2D FIESTA showed small-amplitude tonsil movement in cephalad and caudad directions during the cardiac cycle. The average total magnitude of motion was 0.43 mm in subjects with normal tonsils (controls) and 0.57 mm in patients with Chiari malformations, 33% greater than that in controls. Tonsil motion was 0.61 mm in the patients with syringomyelia and 0.50 mm in those without it (22% difference).
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Loeys-Dietz syndrome (LDS) is a recently described entity that has the triad of arterial tortuosity and aneurysms, hypertelorism, and bifid uvula or cleft palate. Its neuroradiologic manifestations have not been well delineated. We sought to describe the neuroradiologic features of LDS and to assess the manifestations that would warrant follow-up imaging. ⋯ Significant neuroradiologic manifestations are associated with LDS, predominantly arterial tortuosity. Most of the patients in this series were young and, therefore, may require serial CTA monitoring for development of intra- and extracranial dissections and aneurysms, on the basis of the fact that most of the patients with pseudoaneurysms and dissection were older at the time of imaging. Other findings of LDS such as craniosynostosis, Chiari malformation, and spinal instability may also need to be addressed.