Although mri is the ideal imaging modality to evaluate the optic nerve ct is better at showing erosion or expansion of the optic canal meningioma the primary differential diagnostic consideration is characterized by peripheral enhancement of the optic nerve sheath aka tram track sign whereas enhancement of optic gliomas is more uniform. Tram track sign refers to the parallel thickening and enhancement around the optic nerve and is most frequently seen in the setting of optic nerve meningioma.
Straightening squaring of anterior vertebral margins.
Tram track sign mri. Prone to fracture resulting in pseudarthrosis. The dilated airway lies adjacent to a pulmonary artery branch giving the appearance of a ring varicose. Basics of radiology ct chest pathology including pneumonia pleural effusion malignancy lymphoma bronchiectasis fibrosis emphysema.
Evaluation of the tram track sign. Signet ring sign. It may however also be seen in 1.
It should not be confused with other tram track signs elsewhere in the body. This describes airways viewed in a transverse plane. The tree in bud sign and the signet ring sign can be seen on ct.
This description applies to dilated airways seen in a horizontal orientation. T1 weighted mri showed a mass lesion in the left orbital apex. 820 jorie blvd suite 200 oak brook il 60523 2251 u s.
Cylindrical tram track sign. Analogous to intrameniscal cysts which are isointense to fluid in only 8 4 of the cases 12 the majority of pcl intrasubstance signal intensity particularly in our tram track pcl group was not fluid signal intensity. Tram track sign can be seen on ct and cxr.
Trolley track sign on ap view central line of ossification supraspinous and interspinous ligaments with two lateral lines of ossification apophyseal joints bamboo spine on ap view undulating contour due to syndesmophytes. Tram track sign may be used in chest radiography or ct to denote the thickened non tapering parallel walls of cylindrical bronchiectasis. Fat suppressed t2 weighted mri showed a hyperintense parallel linear lesion on the left optic nerve and a ring lesion around it producing the tram track sign on the axial view and the donut configuration on the coronal view.
Orbital pseudotumor perioptic neuritis orbital. 3 rothfus we curtin hd slamovits tl kennerdell js. A differential approach based on high resolution ct morphology.
Ct evaluation of perineural orbital lesions. Ajnr am j neuroradiol 1984. Implies non uniform bronchial dilatation.
The tram track appearance was the best mri finding for distinguishing between pcl mucoid degeneration and pcl tears in this small series.