NEURORADIOLOGIC APPLICATIONS OF CENTRAL-NERVOUS-SYSTEM SPECT

Single photon emission computed tomography (SPECT) of the central nerv ous system (CNS) has many potentially useful interventional neuroradio logic applications, CNS SPECT allows easy and safe evaluation of the c ollateral circulation during internal carotid balloon test occlusion. The cerebrovascular distribution of intracarotid amobarbital sodium, w hich is used in the Wada test, can be accurately determined with sif m ultaneous injection of a radiopharmaceutical. Easy and safe evaluation of the extent and distribution of vasospasm associated with subarachn oid hemorrhage or cerebral angiography is also possible with CNS SPECT . Images obtained after administration of acetazolamide can be compare d with baseline images to evaluate cerebrovascular reserve before caro tid endarterectomy. Seizure foci can be identified if peripheral intra venous injection is performed during an ictus, Thallium-201 imaging ca n be used to direct stereotactic brain biopsy to check for tumor recur rence. Radiologists need to familiarize themselves and their clinical colleagues with the many uses of this imaging technique.