MRI of Intramedullary Spinal Cord Astrocytoma

General Findings

  • Spinal cord diameter:  The diameter of the spinal cord will be enlarged.  If it is not, a disease other than neoplasia should be suspected.
  • Eccentric: The epicenter for tumor will be off the midline involving one side of the cord more than another to a variable degree.
  • Smaller average length: The length of the spinal cord involved by the tumor is, on average 4 spinal segments.
  • Malignant tumors: These tumors can appear similar to benign.

T1-Weighted Sequence

  • Hypointense: 80% of time the tumor will appear slightly hypointense with the remaining 20% being isointense.
  • Blurred margins: The margins of the tumor will appear slightly blurred  due to the infiltrative nature of astrocytomas.
  • Gadolinium enhances: In almost all cases there will be uptake of gadolinium but the degree will vary.  The enhancement can be homogeneous or heterogeneous.

T2-Weighted Sequence

  • Hyperintense:  There is a variable degree of T2 hyperintensity in astrocytomas of the spinal cord.
  • Nonhomogeneous: The degree T2 hyperintensity within the tumor will vary (as opposed to edema, which is homogeneous).
  • Size matches T1-weighted sequence:  The size of the tumor seen on T2 imaging will match that seen on T1 imaging with benign tumors.