Preliminary Diagnosis: Meningioma

I. What imaging technique is first-line for this diagnosis

  • MRI with contrast of the brain and spine

II. Describe the advantages and disadvantages of this technique for diagnosis of meningioma.

Advantages
  • Very sensitive and specific for the diagnosis of meningioma

  • Able to localize the lesion and detail its extent

  • Depicts degree of vasogenic edema created by lesion and can be used for preoperative planning

  • Does not use ionizing radiation

Disadvantages
  • Time-consuming

  • Expensive imaging modality

  • Requires significant patient cooperation to minimize motion artifact

  • Cannot be used on patients with poor kidney function (i.e., GFR <30)

III. What are the contraindications for the first-line imaging technique?

  • Contraindicated in patients with non-MR compatible hardware or foreign bodies

IV. What alternative imaging techniques are available?

  • Enhanced and non-enhanced CT

  • PET/CT

  • Digital subtraction angiography

V. Describe the advantages and disadvantages of the alternative techniques for diagnosis of meningioma.

Enhanced and nonenhanced CT imaging
Advantages
  • Can evaluate for secondary bony involvement better than MRI

  • Specific for the diagnosis of meningioma, unlike most intracranial neoplasms

  • Fast, efficient, and less susceptible to motion artifact

Disadvantages
  • Not as specific as MRI

  • Not as effective or preoperative planning as MRI

  • Does not demonstrate cranial anatomic detail as well as MRI

  • Uses ionizing radiation

PET/CT
Advantages
  • Often able differentiate typical meningioma from atypical/malignant based on degree of glucose metabolism

  • Can depict distant metastatic disease

Disadvantages
  • Lacks anatomic detail of MRI

  • Expensive and time-consuming modality

  • High radiation dose to the patient

Digital subtraction angiography
Advantages
  • Evaluates dural/pial vessels that supply the meningioma better than any other imaging modality

  • Can be used for preoperative embolization

Disadvantages
  • Lacks anatomic detail since it mainly evaluates lesion vascularity

  • Is invasive and entails all the risks inherent to an invasive procedure

VI. What are the contraindications for the alternative imaging techniques?

Enhanced and nonenhanced CT
  • Pregnant patients, especially within the first two trimesters

  • Contrast cannot be used on those with poor renal function

PET/CT
  • Pregnant patients cannot be scanned secondary to a high radiation dose.

Digital subtraction angiography
  • Contraindicated in patients in a hypocoagulable state ( i.e., platelets <50,000 and INR >2)

  • High radiation dose with contrast also prohibits pregnant patients and those with severe renal dysfunction from being imaged