[Measurement of myocardial blood flow increase rate at exercise with 99mTc-tetrofosmin radionuclide angiography].
We developed new method to calculate myocardial blood flow increase rate at exercise (MBF-IR) with 99mTc-tetrofosmin (TF) radionuclide (RN) angiography and myocardial perfusion SPECT and assessed its feasibility using clinical data.


METHODS
Fifteen patients who were suspected to have coronary artery disease underwent TF RN angiography and SPECT at exercise and at rest. Seven patients had coronary stenosis and eight patients had no significant coronary stenosis in coronary angiography. MBF-IRs were calculated by the following equation: [formula: see text] where Cr = regional myocardial count at rest, Ce = regional myocardial count at exercise [formula: see text] = the area under ventricular time activity curve at rest and [formula: see text] = the area under ventricular time activity curve at exercise.


RESULTS
Rate pressure product (RPP) was similar in patients with and without coronary stenosis (24,509 +/- 6701.9 vs. 27,196 +/- 4862.4, p = 0.39). MBF-IR was 1.88 +/- 0.73 in the area covered by stenosed coronary artery, 2.53 +/- 0.75 in unstenosed coronary artery in patients who have significant coronary stenosis and 2.97 +/- 0.77 in normal coronary patients. MBF-IRs in the area covered by stenosed coronary arteries were significantly smaller than that of normal coronary artery patient (p = 0.037). Interobserver and intraobserber reproducibility were good (r = 0.96, 0.95 respectively). There was strong positive correlation between MBF-IR and RPP in normal patients (r = 0.69, p = 0.0018), suggesting MBF increase depends on the cardiac workload.


CONCLUSIONS
MBF-IR can be estimated by the combination of TF RN angiography and SPECT at exercise and at rest.
Higuchi
T
T
Department of Nuclear Medicine, Kanazawa University School of Medicine.
Taki
J
J
Nakajima
K
K
Muramori
A
A
Miyazaki
Y
Y
Kinuya
S
S
Shimizu
S
S
Tonami
N
N
D000368:Aged; D017023:Coronary Angiography; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D015444:Exercise / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006334:Heart Function Tests / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011875:Radionuclide Angiography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin