Nuklearmedizinische Funktionsdiagnostik in der Kardiologie

Abstract

Cardiac nuclear medicine comprises various diagnostic techniques using radiopharmaceuticals for functional imaging in vivo. This article provides an overview of current clinical use of cardiac imaging in nuclear medicine in Germany: Myocardial perfusion imaging using SPECT is a well-established noninvasive tool to semi-quantitatively measure left ventricular myocardial perfusion. Ischemia and chronic myocardial scars can be idenified with a high diagnostic accuracy. Gated SPECT enables measuring left ventricular function. With new dedicated solid-state camera systems examinations have become faster and better while radiation exposure has been minimized. These new camera systems allow quantitative calculations of myocardial blood flow, which will further improve diagnostic accuracy.For patients with severe chronic coronary artery disease and myocardial dysfunction analyzing myocardial viability is crucial for guiding therpeutic decisions. For detection of hibernating myocardium and its differentiation from scar tissue, two nuclear cardiac methods are combined: Rest myocardial perfusion imaging detects perfusion defects and cardiac 18F-FDG-PET/CT detects glucose metabolism in the hypoperfused area. As long as glucose metabolism is intact therapeutic interventions can be beneficial.In general 18F-FDG-PET/CT allows visualization and quantification of celluar glucose metabolism in oncologic and inflammatory processes. For analysis of cardiac inflammation (e. g. endocarditis or sarcoidosis) a no-carb and high-protein diet is needed at leat 24 hours prior to imaging in order to suppress the physiologic myocardial glucose metabolism. Then, specific inflammatory tracer uptake can be assessed.Cardiac amyloidosis is a rare but dangerous condition. With a specific amyloidosis scintigraphy (bone scintigraphy), cardiac ATTR-amyloidosis can be diagnosed with high accuracy. A potenitally harmful myocardial biopsy often is not needed any more and specific therapy can be initiated.In summary, diagnostic methods in cardiac nuclear medicine non-invasively allow visualization and function analysis of biological processes and are essential for diagnosis finding and therapy guidance. The continuous advancement of diagnostic tools makes nuclear cardiology a highly relevant and interesting field.