Once the
dural sac was incised, the MEPs' amplitude suddenly dropped significantly because of the instant release of high-intradural pressure.
On MR images, a mid-sagittal diameter of the
dural sac less than 10mm is also consistent with stenosis (Figure 19).
Digital subtraction angiography showed the feeding artery and dilated tortuous draining vein within the
dural sac.
MRI shows atrophy of the lower cervical cord in a neutral position and there will be abnormal cervical curvature (straight or kyphotic) and loss of attachment between the posterior
dural sac and subjacent lamina, which is most valuable in Hirayama disease.
MRI showed a deformity of the
dural sac at the L4-S1 levels consistent with fatty tissue compression and signs of disc degeneration (Pfirrmann IV and Modic I) at the L4-L5 level (Figure 1).
Surprisingly, worm-like appearance of flow void signal intensity markedly noted at C1-2 level of the
dural sac and extending into C7 level.
Analysis of
dural sac thickness in human spine--gcadaver study with confocal infrared laser microscope.
Magnetic resonance imaging (MRI) of her abdomen and thorax 1 year earlier for evaluation of her cardiac pathology revealed extensive ectasia of the
dural sac at the sacral level (Fig.
Contrast agent uptake was observed, especially at the
dural sac, with edema in the nerve roots.
The aim of this study was to determine the volumes of both CSF and nerve roots within the human lumbar
dural sac and estimate the degree of vulnerability at different vertebral levels.
The partial damage of the
dural sac was noted in 2 patients.
Under chloroform anaesthesia, and in the prone position, the spines and laminae of the thoracic vertebrae 4, 5 and 6 were resected (laminectomy), and the
dural sac exposed and opened--nothing abnormal was found.
