The quantification of rapid hemodynamic reactions to wide and slow breathing movements has been performed, by two modalities (gamma) -left ventriculography of ^99mTc-labeled blood volume, in anterior oblique incidence on standing and even exercising healthy volunteers and cardiac patients. A highly sensitive stethoscope delivered whole (gamma) -counts acquired at 30 msec intervals in a square field of view including the left ventricle, in a one dimensional low resolution imaging mode for beat to beat analysis. A planar 2D (gamma) -camera imaging of the same cardiac area was then performed without cardiac gating for alternate acquisitions during deep inspiration and deep expiration, completed by a 3D MRI assessment of the stethoscope detection field. Young healthy volunteers displayed wide variations of diastolic times and stroke volumes, as a result of enhanced baroreflex control, together with +/- 16% variations of the stethoscope's background blood volume counts. Any of the components of these responses were shifted, abolished or even inverted as a result of either obesity, hypertension, aging or cardiac pathologies. The assessment of breathing control of the cardiovascular system by the beat to beat (gamma) -ventriculography combined with nuclear 2D and 3D MRI imaging is a kinetic method allowing the detection of functional anomalies in still ambulatory patients.

Date Published: 24 April 2002
PDF: 10 pages
Proc. SPIE 4683, Medical Imaging 2002: Physiology and Function from Multidimensional Images, (24 April 2002); doi: 10.1117/12.463621

Published in SPIE Proceedings Vol. 4683:
Medical Imaging 2002: Physiology and Function from Multidimensional Images
Anne V. Clough; Chin-Tu Chen, Editor(s)