IS case 444: Dural ectasia
Imaging Sciences URMC 2010
Publication Date: 2010-08-30
The scalloping sign represents increased concavity of the posterior vertebral bodies on plain film or MR. Over half of the population demonstrates mild scalloping, however the effect can be more pronounced in musculoskeletal and neurologic diseases. Causes include neuropathic diseases such as Neurofibromatosis, Marfan's syndrome, congenital skeletal disease such as Morquio syndrome, soft tissue bony remodeling from acromegaly and increased intraspinal pressure.
Predominant lumbar scalloping occurs in cases of dural ectasia where the deep dural layer of connective tissue is weakened secondary to a connective tissue disease such as Marfan's syndrome or secondary to Neurofibromatosis type 1. Interpediculate widening and deformity is another manifestation of this ectasia. MRI of the spine may be indicated in neurofibromatosis to determine whether the scalloping is primarily due to dural ectasia or compression from expansile neurofibromas or meningoceles. In Neurofibromatosis type 2, scalloping is more often caused by expansile masses such as schwannomas or ependemomas rather than dural ectasia. MR demonstrates expansile dural pulsations without space occupying lesions compressing the vertebrae.
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