Comparison of global and regional abnormalities in 99mTc-sestamibi and cardiac magnetic resonance imaging in dilated cardiomyopathy.
OBJECTIVE
The clinical relevance of perfusion defects and increased washout rate (WOR) in (99m)Tc-sestamibi (Tc MIBI) imaging has not been well characterized in dilated cardiomyopathy (DCM). We analyzed abnormalities in Tc MIBI imaging in relation to those in cardiac magnetic resonance (CMR) imaging.


RESULTS
Nineteen DCM patients underwent both Tc MIBI and CMR imaging. The perfusion defects and global and regional MIBI WORs were evaluated with planar and single photon emission computed tomography (SPECT) images. The left ventricular function and the delayed enhancement (DE) were estimated with the cine- and DE-mode CMR. In the DCM patients, the Tc MIBI SPECT showed perfusion defects in 65 segments of 14 patients. The global and regional Tc MIBI WORs were higher than those in 10 normal volunteers (19.4 +/- 9.1% vs. 11.7 +/- 6.8% in global and 13.8 +/- 8.6% vs. 9.6 +/- 8.2% in regional WORs; mean +/- SD, P < .01). The DE-mode CMR demonstrated DE in 103 segments of 14 patients. The severity of perfusion defects was correlated with the extent of DE (r = 0.71, P < .01). The regional Tc MIBI WOR was highest in the segments with perfusion defects or DE, but the Tc MIBI WOR in segments without them was also higher than that in the normal volunteers. There was a weak but significant negative correlation between the regional Tc MIBI WOR and wall thickening (r = -0.23, P < .01).


CONCLUSIONS
In DCM, the severity of perfusion defects and the increase in Tc MIBI WOR reflect the spread of myocardial fibrosis and/or scar. The increase in Tc MIBI WOR is potentially associated with regional dysfunction of LV wall.
Shiraki
Katsunori
K
Division of Cardiology, Internal Medicine III, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan.
Satoh
Hiroshi
H
Saitoh
Takeji
T
Saotome
Masao
M
Urushida
Tsuyoshi
T
Katoh
Hideki
H
Takehara
Yasuo
Y
Sakahara
Harumi
H
Hayashi
Hideharu
H
D000368:Aged; D000369:Aged, 80 and over; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000473:pathology
D017256:Technetium Tc 99m Sestamibi