Does patient position alter attenuation effects in multipinhole cardiac SPECT?
Translation of a source relative to a multipinhole camera caused only small changes in homogeneous phantoms with SPS changing <1.5. Inhomogeneous attenuating media cause much larger changes to occur when the source is translated. Changes in SPS of up to six were seen in an anthropomorphic phantom for axial translations. Attenuation correction removes the position-dependent changes in attenuation.
LV lead sensing delay is the only independent predictor for significant reduction in LVESV and was found to be significantly associated with LVEF increase and QRS narrowing after CRT treatment. We suggest that LV lead sensing delay may be used as a marker to predict the favorable response to CRT.