Key result
[13N]ammonia positron emission tomography yielded estimates of average myocardial blood flow highly correlated with those from [15O]water (r=0.99, P<0.001), supporting its validity in humans.
Why the study?
Does the [13N]ammonia PET technique provide comparable estimates of myocardial blood flow to the [15O]water technique in healthy volunteers?
Observational (n=30)
Does the [13N]ammonia PET technique provide comparable estimates of myocardial blood flow to the [15O]water technique in healthy volunteers?
Effect estimate: r = 0.99
Absolute Event Rate: 0.64% vs 0.66%
p-value: p=< .001
The [13N]ammonia PET technique yields comparable estimates of myocardial blood flow to the [15O]water approach in humans, validating its use for noninvasive quantification.
Supports [13N]ammonia PET for myocardial blood flow quantification in healthy volunteers; leaves open validation and adoption in patients with disease.
BACKGROUND: [13N]Ammonia has been validated in dog studies as a myocardial blood flow tracer. Estimates of myocardial blood flow by [13N]ammonia were highly linearly correlated to those by the microsphere and blood sample techniques. However, estimates of myocardial blood flow with [13N]ammonia in humans have not yet been compared with those by an independent technique. This study therefore tested the hypothesis that the [13N]ammonia positron emission tomographic technique in humans gives estimates of myocardial blood flow comparable to those obtained with the [15O]water technique. METHODS AND RESULTS: A total of 30 pairs of positron emission tomographic flow measurements were performed in 30 healthy volunteers; 15 volunteers were studied at rest and 15 during adenosine-induced hypermia. Estimates of average and of regional myocardial blood flow by the [13N]ammonia and the [15O]water approaches correlated well (y = 0.02 + 1.02x, r = .99, P < .001 SEE = 0.023 for average and y = 0.06 + 1.00x, r = .97, P < .001, SEE = 0.025 for regional values) over a flow range of 0.45 to 4.74 mL.min-1.g-1. At rest, mean myocardial blood flow was 0.64 +/- 0.09 mL.min-1.g-1 for [13N]ammonia and 0.66 +/- 0.12 mL.min-1.g-1 for [15O]water (P = NS). For adenosine-induced hyperemia, mean myocardial blood flow was 2.63 +/- 0.75 mL.min-1.g-1 for [13N]ammonia and 2.73 +/- 0.77 mL.min-1.g-1 for [15O]water (P = NS). The coefficient of variation as an index of the observed heterogeneity of myocardial blood flow averaged, for [13N]ammonia, 9 +/- 4% at rest and 12 +/- 7% during stress and, for [15O]water, 14 +/- 11% at rest and 16 +/- 9% during stress. The coefficients of variation for [15O]water were significantly higher than those for [13N]ammonia (P = .004 at rest and P = .03 during stress). CONCLUSIONS: The two approaches yield comparable estimates of myocardial blood flow in humans, which supports the validity of the [13N]ammonia method in human myocardium previously shown only in animals. However, the [15O]water approach reveals a greater heterogeneity (presumably method-related), which might limit the accuracy of sectorial myocardial blood flow estimates in humans.
No takes yet. Share an insight, caveat, or question.
Nitzsche et al. (1996) conducted an observational in Healthy volunteers (n=30). [13N]ammonia positron emission tomography vs. [15O]water positron emission tomography was evaluated on average myocardial blood flow (r = 0.99, p=< .001). [13N]ammonia positron emission tomography yielded estimates of average myocardial blood flow highly correlated with those from [15O]water (r=0.99, P<0.001), supporting its validity in humans.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: