Evaluating microvascular obstruction after acute myocardial infarction using cardiac magnetic resonance imaging and 201-thallium and 99m-technetium pyrophosphate scintigraphy.
BACKGROUND
Few studies have compared the ability of cardiac magnetic resonance (CMR) with that of scintigraphy using 201-thallium (201-Tl) and 99m-technetium pyrophosphate (99m-Tc PYP) to evaluate microvascular obstructions (MOs). In the present study the relationship between the scintigraphic and CMR characteristics of MOs after acute myocardial infarction (MI) was examined.


RESULTS
The 14 patients (age 69±8 years, 11 males) underwent 201-Tl/99m-Tc PYP SPECT 7±3 days, initial CMR 16±12 days, and follow-up CMR 193±20 days after a reperfused first acute MI. Each image was analyzed using a 17-segment model. Segmental extent of delayed enhancement (DE), wall motion (WM) and degree of 201-Tl uptake were scored in 238 segments. Of 91 MI segments, MO was recognized in 22 (25%) segments on CMR. WM was significantly better in proportion to 201-Tl uptake (P=0.01) in MO segments. All 8 MO segments with WM improvement at follow-up had 99m-Tc PYP uptake, although only 3 (21%) of 14 MO segments that did not show WM improvement at follow-up had 99m-Tc PYP uptake (P=0.001).


CONCLUSIONS
99m-Tc PYP and 201-Tl scintigraphy have the potential to predict WM status and improvement of the MO region after reperfused acute MI.
Department of Cardiology, Hiratsuka Kyosai Hospital, Hiratsuka, Japan. ohnishi-t@kkr.hiratsuka.kanagawa.jp
Takayuki
T
Onishi
Isshi
I
Kobayashi
Yuko
Y
Onishi
Tomoyuki
T
Kawashima
Hirotaka
H
Muramoto
Hiroaki
H
Nakamura
Yasutoshi
Y
Nagata
Shigeo
S
Umezawa
Akihiro
A
Niwa
D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011859:Radiography; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D016698:Technetium Tc 99m Pyrophosphate / Q000008:administration & dosage*; D013794:Thallium Radioisotopes
D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D016698:Technetium Tc 99m Pyrophosphate