Abbildung 1: 13N-ammonia PET in the evaluation of multivessel CAD. Value of hyperemic MBFs and MFR in an abnormal 13N-ammonia myocardial perfusion
PET/CT study. A 54-year-old man with increasing chest pain during daily activities. He had previous percutaneous coronary intervention (PCI) with stent
employment in the LAD. Cardiovascular risk profile with advanced obesity (body mass index of 41 kg/m2
), dyslipidemia, and hypertension. (A): Regadenoson-stress and rest 13N-ammonia PET/CT images in corresponding short-axis (top), vertical long-axis (middle), and horizontal long-axis (bottom) slices. On
stress-images, there is a large area of severely decrease in myocardial perfusion, involving the inferior and inferolateral walls extending to the antero-lateral, anterior, and apical wall segments but less in severity that becomes reversible on rest images. In addition, a transient ischemic dilation (TID) of 1.3 is noted on the stress-rest 13N-ammonia images indicative of diffuse ischemia-induced myocardial stunning. (B): Regional myocardial blood flow quantification
(MBF) and myocardial flow reserve (MFR) calculation. The summarized quantitative data signify an impairment of hyperemic MBF in the LAD distribution
(1.58 ml/g/min), but also and more pronounced in the LCx and RCA distribution (1.07 and 1.09 ml/g/min, respectively). Correspondingly, the MFR is abnormally reduced in all three major coronary territories, most pronounced in the LCs (1.29), followed by RCA (1.36), and LAD (1.61) distribution, respectively.
Invasive coronary angiography (not shown) in this patient unraveled indeed severe multivessel CAD accounting for the observed diffuse ischemia. The
proximal LAD had previous extensive stenting without significant stenosis, whilst the mid-portion of the LAD demonstrated a ≈ 90–95% in-stent restenosis.
The LCx demonstrated a 70% lesion in the posterolateral marginal brach, while in a dominant RCA, the posterior descending artery (PDA) was occluded.