Myocardial Viability

Rest
	Patient A	Patient B
4 Hour Redistribution
	Viable	Infarction

These two patients illustrate the use of planar ²⁰¹Tl imaging for the assessment of myocardial viability. Each patient underwent planar imaging after injection of 2.5 mCi ²⁰¹Tl at rest. Imaging was repeated 4 hrs. later. The lateral planar views are shown for each patient.

Patient A had severe anterior wall hypokinesis. Thallium imaging showed a moderate anterior wall perfusion defect at rest with evidence of redistribution on delayed imaging. Anterior wall motion was nearly normal after CABG.

Patient B had recurrent CHF. Thallium imaging showed a severe anteroapical perfusion defect without redistribution. Subsequent PET imaging with ¹³NH₃ showed severely reduced anterior wall blood flow. Imaging with ¹⁸FDG also showed severely reduced glucose metabolism confirming infarction of the anterior wall. The patient did not undergo CABG.