Embolic infarction followed by serial bone SPECT and MR fusion images--the door to SPECT/MR-.

We recently experienced a case of cerebral infarction incidentally found by whole body bone scintigraphy for the detection of bone metastasis from renal cell carcinoma. Additional bone SPECT and brain MR fusion images clearly demonstrated the wedge-shaped uptake of tracer corresponded to the abnormal intensity reflecting subacute cerebral infarction. Follow-up bone scan and fused images with MRI showed complete resolution of the abnormal uptake in chronic phase. A breakdown in the normal blood-brain barrier results in abnormal ionic calcium flux into the cells following altered cell membrane integrity leading to precipitation of calcium salts which eventually binds to bone imaging tracer such as (99m)Tc-methylene diphosphonate. That is, increased accumulation of bone seeking agents represents lethal cell death. The recent development of software and hardware has enabled the fusion of functional and anatomic images. Image fusion between SPECT with various tracers and MRI is expected to provide clues as to the underlying cause of diseases and to decide our treatment planning in the near future.