Background: Various imaging modalities are used to identify and characterize cardiac masses. While echocardiography remains the preferred imaging modality to evaluate cardiac masses, computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT are being increasingly employed to assess cardiac mass lesions. However, the clinical value of non-invasive cardiac imaging for differentiating between primary cardiac mass and metastatic lesions has not yet been examined in detail. The purpose of the present study was to evaluate the diagnostic utility of non-invasive cardiac imaging for differentiating primary cardiac tumors from metastatic lesions, and non-tumorous lesions. Methods: A retrospective review was conducted on 22 cardiac mass lesions in 20 patients assessed by cardiac imaging (at least one of CT, MRI, or 18F-FDG PET/CT) between December 2005 and March 2017. CT findings included the tumor size, location, existence of calcification, and morphology of the base portion of the lesion. MRI parameters included signals with T1-weighted imaging (T1WI), T2WI, mobility with cine imaging, and contrast enhancement. Tracer uptake by each cardiac lesion using 18F-FDG PET/CT was also evaluated. Results: Among 17 cardiac mass lesions assessed by contrast-enhanced CT, all cardiac myxomas and papillary fibroelastomas had a pedunculated base portion. All metastases located in the cavity had a sessile base portion (P=0.0035). Malignant tumors (metastases and malignant lymphoma) had no mobility, while cardiac myxomas had a slightly higher frequency of mobility with cine MRI (0% vs. 100%, P=0.0667). Among the four lesions for which 18F-FDG PET/CT was performed, the three malignant lesions had strong 18F-FDG uptake, while the benign lesion showed insignificant accumulation. Conclusions: The characteristics of the base portion of cardiac mass were useful for differentiating primary cardiac tumors from metastatic cardiac tumors. Cine MRI also exhibited diagnostic utility for differentiating between primary cardiac tumors and metastases. Therefore, non-invasive cardiac imaging may be employed to differentiate cardiac mass lesions. The accurate diagnosis of cardiac mass lesions may require the assessment of multiple characteristics on images.
Optical coherence tomography (OCT) has emerged as a high-resolution (10-20μm), light-based, intravascular imaging technique capable of investigating detailed coronary plaque morphology. OCT is highly sensitive and specific for characterizing fibrous, fibrocalcific, and lipid-rich plaque. OCT is capable of discriminating 3 types of unstable plaque morphologies underlying coronary thrombosis such as plaque rupture, erosion, and calcified nodules. The high resolution of OCT has a potential to identify important features of vulnerable plaques such as thin-cap (<65μm thick) fibroatheroma, macrophages, vasa vasorums, cholesterol crystals, and micro-calcifications. As compared with conventional intravascular ultrasound, OCT provides more accurate measurements of coronary lumen diameter and lesion length, which is useful in determining stent size. OCT is much more sensitive in detecting inadequate stent findings such as intrastent tissue protrusion, incomplete stent apposition, stent edge dissection, and intrastent thrombus, which is helpful in optimizing stent implantation. Recently developed new stent optimization software such as OCT/angiography co-registration and 3-dimentional view enhances ease of use, simplifies interpretation and allows us to literally visualize a better outcome of percutaneous coronary intervention (PCI). In conclusion, OCT is a promising technology to assess coronary atherosclerosis and to guide PCI.
Coronary computed tomography angiography (CCTA) is the most commonly used modality for noninvasive plaque imaging in clinical settings. Characteristics of rupture-prone vulnerable plaques include positive remodeling, low attenuation, and napkin-ring sign in CCTA. About 60% of all vulnerable plaques have these characteristics, and these coronary lesions often result in plaque rupture. Identification of such groupings of coronary artery characteristics has been used to predict cardiovascular events.
Purpose: “Heart Function View (HFV)” is a software that performs phase analysis as well as functional assessment of the left ventricle (LV) using myocardial perfusion single photon emission computed tomography (SPECT) (MPS). Phase analysis-derived phase standard deviation (PhSD) and histogram bandwidth (PhHB) are good indices for detecting LV dyssyncrony. We aimed to examine whether PhHB and/or PhSD (PhHB/PhSD) are useful clinical indicators that reflect the severity of heart failure (HF) in comparison with the LV ejection fraction (EF). Methods: Patients underwent 99mTc-tetrofosmin quantitative gated MPS including treadmill exercise. In HFV analyses, patients with induced ischemia were excluded. Phase and time-volume curve analyses were performed using HFV (n=66). Results: PhHB/PhSD correlated with LV end-diastolic volume (EDV), end-systolic volume (ESV), the first-third filling fraction (1/3FF), and peak filling rate (PFR) as well as echocardiography tissue Doppler-derived E/e’ as hemodynamic parameters of HF severity. LVEF also correlated with these hemodynamic parameters, except for 1/3FF. PhHB/PhSD positively correlated with log BNP as a neurohumoral marker of HF severity. LVEF negatively correlated with log BNP. PhHB/PhSD negatively correlated with exercise capacity as physiological indicators of HF severity, whereas LVEF did not. PhHB/PhSD were significantly greater in patients receiving cardiac resynchronization therapy (CRT, n=6) than in non-CRT patients (n=66), whereas LVEF were lower. Conclusion: PhHB/PhSD, similar to LVEF, are useful clinical indicators for evaluating HF severity. However, the clinical significance of LVEF and PhHB/PhSD differ. Thus, a phase analysis may additively offer useful information for the management of HF.