Significance of dipyridamole loading in ultrafast x-ray computed tomography for detection of myocardial ischemia. A study in patients with Kawasaki disease.
OBJECTIVE
To examine the significance of dipyridamole loading as a stress in ultrafast computed tomography (CT) to improve the detection of left ventricular myocardial ischemia.


METHODS
Thirty-eight patients with coronary arterial involvement of Kawasaki disease and 18 control subjects received cardiac ultrafast CT with intravenous long-bolus iodinated contrast injection; dipyridamole was loaded in 40 examinations. Early (first-pass) and late (4 minutes) M/Ls (ratio of postcontrast incremental increases in the left ventricular myocardial [M] and luminal [L] CT number) were analyzed.


RESULTS
Dipyridamole induced a prominent increase in early M/L of the normal myocardium in control subjects (no loading: 26.8%, dipyridamole: 39.2%; P < 0.001) with small influence on late M/Ls. In ischemic or infarcted myocardium in Kawasaki disease, dipyridamole early M/Ls (20.4%, 16.0%) and late M/Ls showed no difference from corresponding values without loading. Using early M/L with dipyridamole, sensitivity and specificity for detection of ischemic abnormalities were 89% and 100%, respectively.


CONCLUSIONS
Dipyridamole-loaded first-pass contrast ultrafast CT was proven to have excellent detectability for myocardial ischemia comparable with stress thallium scintigraphy.
Naito
H
H
Department of Analytical Radiology, Osaka University Medical School, Japan.
Hamada
S
S
Takamiya
M
M
Yoshibayashi
M
M
Kamiya
T
T
Tamura
S
S
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D004176:Dipyridamole; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D007262:Infusions, Intravenous; D007455:Iodine; D008297:Male; D009080:Mucocutaneous Lymph Node Syndrome / Q000000981:diagnostic imaging*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013312:Stress, Physiological / Q000503:physiopathology; D013794:Thallium Radioisotopes; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014665:Vasodilator Agents
D003287:Contrast Media; D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; D004176:Dipyridamole; D007455:Iodine