[Serial change of 123I-metaiodobenzylguanidine (MIBG) myocardial concentration in patients with dilated cardiomyopathy].
123I-Metaiodobenzylguanidine (MIBG) is expected to be useful agent for functional evaluation of the myocardial sympathetic innervation. The aim of this paper is to investigate serial change of 123I-MIBG myocardial concentration in patients (pts) with dilated cardiomyopathy (DCM) as compared with 201Tl uptake. Eight pts with DCM and six non-cardiac subjects (controls) were examined. After injection of 111 MBq (3mCi) 201Tl and 111 MBq (3 mCi) 123I-MIBG, simultaneous myocardial imaging in anterior view was performed for both tracers in every 30-60 minutes during 5 hours (6 images). Myocardial uptake ratio per pixel to the injected dose was calculated for each tracer with background and cross-talk correction on each image. In pts with DCM, myocardial uptake ratio of 123I-MIBG did not differ significantly from that of controls. The washout of 123I-MIBG from the myocardium, however, was significantly increased in pts with DCM as compared with controls. The % decrease of the radioactivity in 3 hours was 46.9 +/- 13.8% in DCM, whereas 18.0 +/- 7.7% in controls (p less than 0.05). Especially, the decrease in the early phase (less than 1 hour) was significantly larger in DCM than controls (21.2 +/- 7.5% vs 5.3 +/- 4.0%, p less than 0.01). For 201Tl, on the other hand, neither uptake ratio nor washout rate, differed significantly between the two. In conclusion, the rapid washout of 123I-MIBG in the early phase may reflect some sympathetic dysfunction in pts with DCM.
Yamakado
K
K
Department of Radiology, Mie University School of Medicine, Japan.
Takeda
K
K
Kitano
T
T
Nakagawa
T
T
Futagami
Y
Y
Konishi
T
T
Hamada
M
M
Nakano
T
T
Ichihara
T
T
D019797:3-Iodobenzylguanidine; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000294:innervation; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007462:Iodobenzenes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D012588:Scintillation Counting; D013564:Sympathetic Nervous System / Q000503:physiopathology
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine