[Comparison of relative 18FDG uptake with metabolic rate (MRGlucose) in the myocardium in CAD, classified by 99m-Tc-MIBI].
OBJECTIVE
Are i) typical patterns of perfusion/metabolism (match, mismatch), gained from relative 99mTc-MIBI vs relative 18FDG uptake (normalized to the perfusion maximum) obtainable also vs absolute MRGlu and is ii) rMRGlu in the segment of maximum perfusion (MIBI = 100%) within the normal range for all degrees of coronary artery disease (CAD)?


METHODS
In 55 non-diabetic patients with CAD, relative myocardial perfusion (99mTc MIBI SPECT at rest) and relative 18FDG uptake (PET after glucose load) were used to separate for various flow/metabolism constellations. In addition, regional glucose metabolic rate (rMRGlu in mumol/100 g/min; dynamic-graphic analysis from Gambhir/Patlak) was determined in 13 segments of the left ventricle each (i.e., in a total of 715 segments).


RESULTS
rMRGlu revealed wide standard deviations (up to 51%). It decreased from normal (52.7 +/- 27.3 mumol/100 g/min), mismatch (45.3 +/- 17.3) and intermediate (35.2 +/- 12.4) to match ("non viable"; 26.7 +/- 13.3) significantly (p < 0.01). In 26% of the perfusion maxima, MRGlu was < 40 mumol/100 g/min. Out of these, only in five patients (of 28) with 3-vessel disease, it was even smaller (< 30 mumol). In three out of the latter, glucose blood levels were below euglycemia.


CONCLUSIONS
rMRGlu in CAD revealed an identical perfusion/metabolism pattern as relative 18FDG uptake. Thus, the higher efforts employed to compute rMRGlu do not yield diagnostic advantage. The segmental perfusion maximum, used for normalization of relative 18FDG uptake (100% MIBI uptake = 100% FDG uptake) was reliable in euglycemic patients even with 3-vessel disease.
Büll
U
U
Klinik für Nuklearmedizin, Klinikum Aachen, Deutschland.
Foroutan
Y
Y
Hellwig
D
D
Kaiser
H J
HJ
Schulz
G
G
Sabri
O
O
Schreckenberger
M
M
vom Dahl
J
J
D001692:Biological Transport; D003287:Contrast Media; D003327:Coronary Disease / Q000145:classification / Q000000981:diagnostic imaging / Q000378:metabolism*; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D012016:Reference Values; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D003287:Contrast Media; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D017256:Technetium Tc 99m Sestamibi; D003847:Deoxyglucose; D005947:Glucose