[Quantitative analysis of 123I-metaiodobenzylguanidine myocardial imaging: assessment of its usefulness in patients with congestive heart failure].
To investigate the usefulness of the quantitative analysis of 123I-metaiodobenzylguanidine (123I-MIBG) myocardial uptake, we studied 9 normal subjects and 18 patients with congestive heart failure (CHF). Rest myocardial imaging with 123I-MIBG was performed at 20 minutes and 3 hours (delayed image) after 123I-MIBG injection. Rest 201Tl imaging was obtained at 20 minutes after 201Tl injection. In addition to ordinary tomograms, a planar anterior image and a whole body image were supplemented in each imaging. In patients with CHF fractional shortening (%FS) was calculated from echocardiography and left ventricular ejection fraction was obtained from cardiac blood pool imaging with 99mTc at rest. We calculated H/M (heart to mediastinum count ratio) from the anterior planar image and %Uptake (percentage of cardiac uptake of the isotope to total injected dose) from the whole body image. H/M of 123I-MIBG in delayed images separated patients with CHF from normal subjects (2.00 +/- 0.19 vs. 2.56 +/- 0.13, p < 0.01). H/M Ratio (H/M of 123I-MIBG divided by H/M of 201Tl) in delayed image could distinguish these two groups poorly (0.72 +/- 0.12 vs. 0.88 +/- 0.14, p < 0.05). On the other hand, %Uptake of 123I-MIBG was not different between two groups (3.49 +/- 0.60% in CHF, 3.54 +/- 0.34% in normal). But %Uptake of 201Tl was greater in CHF than in normal (5.96 +/- 1.09% vs. 4.70 +/- 0.30%, p < 0.05). When myocardial 123I-MIBG uptake was normalized by myocardial perfusion (%Uptake of 123I-MIBG divided by %Uptake of 201Tl, Uptake Ratio), Uptake Ratio in delayed image could distinguish theses two groups as same as H/M (0.60 +/- 0.05 in CHF, 0.75 +/- 0.05 in normal, p < 0.01). In patients with CHF, H/M of 123I-MIBG did not reflect LV function and serum norepinephrine (NE) level. But Uptake Ratio and H/M Ratio in delayed image correlated well with %FS (r = 0.88, r = 0.65), EF (r = 0.80, r = 0.68) and NE level (r = -0.77, r = -0.75). Although the calculation of Uptake Ratio is time consuming and expensive, it was assumed that Uptake Ratio is an useful index to quantitate myocardial 123I-MIBG uptake.
Narita
M
M
Department of Internal Medicine, Sumitomo Hospital.
Kurihara
T
T
Murano
K
K
Usami
M
M
Honda
M
M
D019797:3-Iodobenzylguanidine; D000328:Adult; D000368:Aged; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006333:Heart Failure / Q000000981:diagnostic imaging*; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine