Preliminary Diagnosis: Neurofibromatosis

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

  • MRI imaging of the brain and spine with contrast

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

Advantages
  • Diagnostic in the appropriate clinical setting

  • Able to determine both the extent and type of intracranial anomaly associated with NF1/NF2


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  • Does not utilize ionizing radiation

Disadvantages
  • Expensive

  • Time consuming

  • Requires significant patient cooperation to minimize motion artifact

  • Requires the patient have adequate renal function (ie, GFR > 30 )

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

  • Contraindicated in patients with poor renal function (ie, GFR < 30)

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

IV. What alternative imaging techniques are available?

  • Contrast-enhanced CT

  • Catheter-based angiography

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

Contrast-enhanced CT
Advantages
  • Quicker and less expensive than MR imaging

  • Less prone to motion artifact

  • More adept than MR at detecting associated osseous abnormalities such as sphenoid and occipital bone dysplasias, spinal scoliosis, etc

Disadvantages
  • Has both a lower sensitivity and specificity in detecting associated intracranial abnormalities

  • Not able to depict early parenchymal brain changes associated with neurofibromatosis and has less anatomic detail than MRI

  • Exposes the patient to ionizing radiation

Catheter Angiography
Advantages
  • Gold standard in detecting associated vascular lesions of NF such as aneurysms/AVMs, stenoses, etc

  • Can be used as both diagnostic and therapeutic modality

Disadvantages
  • Invasive procedure

  • Limited to only vascular findings associated with NF

  • Time consuming

  • Exposes the patient to a high degree of ionizing radiation

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

Contrast-enhanced CT
  • Contraindicated in pregnant patients, especially during the first two trimesters

  • Contraindicated in patients with poor renal function

Catheter Angiography
  • Contraindicated in patients in a hypocoagulable state (ie, platelets < 50,000 and INR > 2)

  • Contraindicated in pregnant patients

  • Contraindicated in patients with poor renal function