Multimodality Imaging in Ischemic Cardiomyopathy

Abstract

Cardiac multimodality (hybrid) imaging can be obtained from a variety of techniques, such as nuclear medicine with single photon emission computed tomography (SPECT) and positron emission tomography (PET), or radiology with multislice computed tomography (CT), magnetic resonance (MR) and echography. They are typically combined in a side-by-side or fusion mode in order to provide functional and morphological data to better characterise coronary artery disease, with more proven efficacy than when used separately. The gained information is then used to guide revascularisation procedures. We present an up-to-date comprehensive overview of multimodality imaging already in clinical use, as well as a combination of techniques with promising or developing applications.

Keywords: Cardiomyopathy; Ischemia; Myocardial perfusion; PET/CT; PET/MR; SPECT/CT.

Fig. 1

Diagnostic added value of SPECT/CTCA (Rispler et al. [20], Sato et al. 2010 [25]) and PET/CTCA (Namdar et al. [42], Groves et al. [43], and Kajander et al. [44]) as compared to invasive coronary angiography on a vessel-based analysis. Abbreviations: PPV = positive predictive likelihood; NPV = negative predictive likelihood

Fig. 2

Example of hybrid SPECT/CTA under adenosine pharmacological stress in a 58-year male patient with two coronary stents (one implanted in the proximal left anterior descending [LAD] and one in the first diagonal branch) (a) A myocardial perfusion imaging was requested for investigating the start of angor similar as described before stent implantation. The CTCA did not show any intra-stent stenosis, but failed to visualize a small branch from the LAD which was recovered by the stent mesh and which was not visible anymore on CTCA, responsible for the symptomatic ischemia with a stress-induced perfusion defect (summed stress score = 10; summed rest score = 4; summed difference score = 6). There was unfortunately no possibility to revascularize this small branch and, consequently, maximal risk factor reduction and physical activity training were recommended. (b) After 9 months, myocardial perfusion imaging was repeated and fused with the same CTCA and regained normal perfusion at stress and rest, without ischemia and scar

Fig. 3

Annualized event rate of major acute coronary event (MACE: cardiac death, myocardial infarct, unstable angina requiring hospitalization and coronary revascularizations) and hard events (myocardial infarct [MI]/cardiac death) according to the outcome of the individual SPECT and CTCA studies stratified according to the yielded results and their agreement (matched vs. unmatched) (data from the study by Pazhenkottil et al. [31])

Fig. 4

(a) Three transaxial slices of cardiac Rb-82 myocardial perfusion imaging in a 55-year women with pulmonary arterial hypertension showing the left ventricle (LV, arrow) and the hypertrophied right ventricle (RV, arrowhead), usually only faintly visible. (b) Corresponding polar map quantification of myocardial flow reserve of the left and right ventricle, with corresponding MFR in each territory and the right ventricle

Fig. 5

Example of PET/ICA hybrid imaging with our user interface allowing live fusion of PET myocardial blood flow information (in colour) onto angiographic projection of rotational X-ray angiograms (in black and white) in the catheterization laboratory

Fig. 6

Example of Ga-68-NODAGA-RGD for imaging neoangiogenesis in a 72-year male patient with history of cardiac infarct 7 years prior to PET/CT imaging. Selected transaxial slice through the heart at 70-min post radiopharmaceutical injection showing no abnormal uptake in the old myocardial infarct indicating that no active angiogenesis is taking place