Normal Pressure Hydrocephalus

Preliminary Diagnosis: Normal Pressure Hydrocephalus

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

• Non-contrast CT of the brain

II. Describe the advantages and disadvantages of this technique for diagnosis of normal pressure hydrocephalus.

Advantages

• Relatively inexpensive, fast imaging modality compared with companion MR imaging

• Able to evaluate osseous structures

Disadvantages

• Exposes the patient to ionizing radiation

• Less specific and sensitive in characterizing the gray and white matter and cannot well detail any specific soft tissue abnormalities

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

• May be contraindicated in pregnant patients.

IV. What alternative imaging techniques are available?

• MRI of the brain without contrast

V. Describe the advantages and disadvantages of the alternative techniques for diagnosis of normal pressure hydrocephalus.

MRI of the brain without contrast

Advantages

• Offers exquisite detail of both gray and white matter.

• Better able to evaluate for any associated soft tissue abnormalities and is less specific for any osseous abnormalities

Disadvantages

• Expensive

• Time consuming

• Requires significant patient cooperation to minimize motion artifact

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

MRI of the brain without contrast

• Contraindicated in patients with non–MR-compatible hardware.