NEURO NUCLEAR MEDICINE

CEREBRAL RADIONUCLIDE ANGIOGRAM

AND BRAIN SCAN (PLANAR)

INDICATIONS:

1. Confirmatory evidence of brain death
2. Evaluation of meningitis, encephalitis, and other intracranial infections; follow up of response to therapy.
3. Detection of brain tumors, abscesses, and strokes when computed tomography and magnetic resonance imaging are not available.

PATIENT PREPARATION:

No special preparation is necessary.

RADIOPHARMACEUTICAL:

Tc-99m DTPA is given (20 mCi I.V.). The critical organ is the urinary bladder (0.07-0.6 rad/mCi depending on frequency of voiding).

SCANNING TIME:

15 minutes for initial perfusion images. Blood pool or static views are obtained at 20 minutes post injection. Routine delayed images are obtained 2-3 hours after injection.

OTHER CONSIDERATIONS/RATIONALE:

The flow study is a simple, non-invasive method of determining the presence or absence of cerebral perfusion and thus is useful in documenting brain death. On static images Tc-99m DTPA localizes in and around lesions by crossing a blood-brain barrier damaged by various pathologic processes (infection, neoplasm, vascular accidents, hematomas, etc.). Lesions with increased vascularity will also show increased uptake of radiotracer. Detection of pathology depends on size, location, and the degree of blood-brain barrier breakdown.