Choose Wisely: Benefits and Drawbacks of Radiopharmaceuticals (3,5–8)
| Nondiffusible, non–brain-specific radiopharmaceutical | Diffusible, brain-specific radiopharmaceutical | ||
|---|---|---|---|
| Benefit | Drawback | Benefit | Drawback |
| Rapid renal excretion facilitates repeat examinations if necessary | Primarily planar imaging is performed | Planar imaging and SPECT or SPECT/CT can be performed if patient condition allows and is needed | Repeat examination on same day is often not possible because of parenchymal retention |
| There is greater dependency on injection technique | No significant redistribution occurs for several hours, making it easy to perform and interpret imaging | High radiochemical stability and purity are essential to prevent false-positive interpretation | |
| Delayed images may show superior sagittal sinus activity even in presence of brain death in as many as 50% of patients. | Procedure is more technically forgiving—dynamic imaging is noncritical step in image acquisition | ||
| Superficial scalp blood flow interferes | Parenchymal trapping appears preserved even in presence of metabolic disturbances | ||