A Novel Method to Suppress the Effect of Subdiaphragmatic Activity in Tc Myocardial Perfusion SPECT and Evaluation of Its Usefulness Using a Myocardial Phantom.

: Smoothing in Tc myocardial perfusion single-photon emission computed tomography (SPECT) often increases myocardial artifacts due to subdiaphragmatic activity near the heart. To reduce these artifacts, we developed a new process flow, masking on unsmoothed images (MUS), that includes the extraction of the myocardium by masking before smoothing. : This study evaluated the relationships between matrix sizes and distances to the subdiaphragmatic activity using the MUS method compared to conventional methods using a combination of image reconstruction methods (filtered back-projection [FBP] and ordered subset expectation maximization [OSEM]) with or without corrections (attenuation [AC], scatter [SC], and resolution recovery [RR]) using a myocardial phantom.

Vasoconstrictive response in the vascular beds of the non-exercising forearm during leg exercise in patients with mild chronic heart failure.

Background: Reduced exercise capacity may be related to decreased redistribution of blood flow from the non-exercising tissues to the exercising skeletal muscle in patients with mild chronic heart failure (CHF).

Methods And Results: In the present study 14 patients with mild CHF and 10 healthy subjects (N) underwent symptom-limited multistage-ergometer exercise, during which forearm vascular resistance (FVR), cardiac index (CI), systemic vascular resistance index (SVRI), and oxygen uptake (VO(2)) were measured non-invasively using the plethysmograph, impedance, and respiratory gas analysis methods, respectively. The VO(2) and CI at peak exercise were lower (p<0.