Diagnosing and grading heart failure with tomographic perfusion lung scintigraphy: validation with right heart catheterization

Although not as available as chest X-ray, V/P SPECT is a feasible alternative, especially because the introduction of SPECT and new ventilation tracers (i.e. Technegas) has lowered the number of non-diagnostic studies to <3%, even in the presence of obstructive lung disease.