Metabolic imaging of in vivo myocardium
نویسندگان
چکیده
Background The equilibrium cellular water efflux rate constant [kio; mean water lifetime inverse] from contrast agent [CA]enhanced MRI measures on-going cellular Na,K-ATPase activity [turnover]. Good literature [4 different labs] agreement shows substantial kio decreases in myocardial ischemia, hypertension, or infarct regions (Table). The 3 methods used differ in extracellular ("outside”) CAo level manipulation to change the MR shutter-speed relative to kio and the MR exchange condition reached: A) CAo steady-state, slow-exchange-regime; B) CAo titration, fastexchange-regime [FXR]; and C) CAo wash-out, FXR. The independent intracellular volume fraction [ICV] cell density • volume product and ≈ 1 ECV [extracellular volume fraction] also decreases in pathology. We hypothesize that kio mapping shows metabolic compromise most effectively. We report initial experience with tissue near a repaired ventricular septal defect [VSD].
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