DENSITOMETRIC ASSESSMENT OF REGIONAL LEFT-VENTRICULAR SYSTOLIC FUNCTION DURING GRADED ISCHEMIA IN THE DOG BY USE OF DUAL-ENERGY DIGITAL SUBTRACTION VENTRICULOGRAPHY
Ch. Mccollough et al., DENSITOMETRIC ASSESSMENT OF REGIONAL LEFT-VENTRICULAR SYSTOLIC FUNCTION DURING GRADED ISCHEMIA IN THE DOG BY USE OF DUAL-ENERGY DIGITAL SUBTRACTION VENTRICULOGRAPHY, The American heart journal, 125(6), 1993, pp. 1667-1675
Densitometric analysis of images obtained by digital subtraction angio
graphy (DSA) allows for more reproducible and less operator-dependent
quantitation of ventricular function. Conventional DSA uses temporal s
ubtraction but is limited by misregistration artifacts. Dual-energy di
gital subtraction angiography (DE-DSA) is immune to such misregistrati
on artifacts. The ability of DE-DSA to quantitate changes in regional
ventricular volume resulting from ischemia was tested. Densitometric a
nalysis of both phase-matched and ejection fraction DE-DSA images was
used to quantitate regional left ventricular systolic function during
four levels of ischemia ranging from mild to severe in open-chest dogs
(n = 10). DE-DSA left ventriculograms were obtained by means of centr
al venous injections of iodinated contrast medium. Ischemia was graded
according to percentage of systolic wall thickening as measured by so
nomicrometry. Phase-matched end-systolic images were obtained at each
of four levels of ischemia by subtracting an end-systolic control imag
e from each end-systolic ischemic image. Ejection fraction images were
obtained at the control level and at each level of ischemia by subtra
cting an end-systolic image from an end-diastolic image of the same ca
rdiac cycle. The resulting wall motion difference signals represent th
e changes in regional ventricular volumes and were quantitated by dens
itometry. Densitometry was able to detect the effect of all levels of
ischemia on regional function, even the mildest. Densitometric analysi
s of both phase-matched and ejection fraction DE-DSA images provides a
sensitive technique for detecting and quantitating the changes in reg
ional left ventricular systolic volume that occur with ischemia.