Mr. Bell et al., Validation of minimally invasive measurement of myocardial perfusion usingelectron beam computed tomography and application in human volunteers, HEART, 81(6), 1999, pp. 628-635
Citations number
41
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Objectives-To measure myocardial perfusion using an estimate of intramyocar
dial vascular volume obtained by electron beam computed tomography (EBCT) i
n an animal model; to assess the feasibility and validity of measuring regi
onal myocardial perfusion in human volunteers using the techniques develope
d and validated in the animal studies.
Methods-Measurements of myocardial perfusion with EBCT employing intravenou
s contrast injections were compared with radioactive microsphere measuremen
ts (flow 57 to 346 ml/100 g/min) in seven closed chest dogs. Fourteen human
volunteers then underwent EBCT scans using intravenous contrast injections
.
Results-Mean (SEM) global intramyocardial vascular volume by EBCT was 7.6 (
1.1)%. The correlation between global EBCT (y) and microsphere (x) perfusio
n was y = 0.59x + 15.56 (r = 0.86) before, and y = 0.72x + 6.06 (r = 0.88)
after correcting for intramyocardial vascular volume. Regional perfusion co
rrelation was y = 0.75x + 23.84 (r = 0.82). Corresponding improvements in a
greement between the two techniques were also seen using Bland-Altman plots
. In the human subjects, mean resting global myocardial flow was 98 (6) ml/
100 g/min, with homogeneous flow across all regions. In 10 of these subject
s, perfusion was studied during coronary vasodilatation using intravenous a
denosine. Global flow increased from 93 (5) ml/100 g/min at rest to 250 (19
) ml/100 g/min during adenosine (p < 0.001), with an average perfusion rese
rve ratio of 2.8 (0.2). Similar changes in regional perfusion were observed
and were uniform throughout all regions, with a mean regional perfusion re
serve ratio of 2.8 (0.3).
Conclusions-Accounting for intramyocardial vascular volume improves the acc
uracy of EBCT measurements of myocardial perfusion when using intravenous c
ontrast injections. The feasibility of providing accurate measurements of g
lobal and regional myocardial perfusion and perfusion reserve in people usi
ng this minimally invasive technique has also been demonstrated.