RESUMEN
Aims: A strong association between fatty liver disease (FLD) and coronary artery disease is consistently reported. Our aim was to evaluate whether FLD diagnosed using low-dose non-contrast computed tomography (LDCT), as a by-product of myocardial perfusion imaging (MPI), is associated with myocardial ischaemia or left ventricular function parameters. Methods and results: We analysed 742 patients who had undergone MPI using single photon emission computed tomography (SPECT) and LDCT. A liver-to-spleen ratio (in Hounsfield units) of <1 was defined as FLD. Myocardial ischaemia was defined as a summed difference score (SDS) ≥3. Left ventricular size and systolic function were assessed from the electrocardiogram-gated SPECT. FLD patients were younger (63 vs. 68 years) and had a higher body mass index (34.6 vs. 29.0â kg/m2) and a higher SDS (2.65 vs. 1.63), P < 0.001 for all. Independently of several possible confounding factors including traditional risk factors, patients with FLD had a 1.70-fold risk of ischaemia (95% confidence interval 1.11-2.58, P = 0.014). Left ventricular end-diastolic volume (109 vs. 109â mL) and ejection fraction (61 vs. 61%) were comparable in those with and without FLD (non-significant for both). Conclusions: With the help of LDCT, it is possible to identify FLD, which is associated with an increased risk of myocardial ischaemia. Therefore, evaluation of FLD from LDCT is recommended along with MPI.
Fatty liver disease is the most common liver disease, affecting a quarter of the population worldwide. It is connected to diabetes and high blood pressure as well as to overweight and obesity. Computed tomography is a common diagnostic method. Its downside is that it exposes patients to radiation. Images can be taken with lower doses of radiation, but these images are less clear and often cannot be used for diagnosis. Low-dose computed tomography is often used with other methods of medical imaging, especially for the heart and lungs. This study shows that fatty liver disease can be diagnosed as a free by-product of low-dose computed tomography images gathered as part of other diagnostic imaging. We also show that fatty liver disease diagnosed from these images is connected to reduced blood flow of heart muscle. Based on the findings, we recommend that these images be scanned for fatty liver disease to identify patients who are at higher risk of heart disease.
RESUMEN
Our objective was to develop a method for studying the biomechanics of the common carotid artery (CCA) by evaluating both radial and less known axial distension of the arterial wall. We developed software capable of tracking the movements of different arterial wall layers from ultrasound recordings of CCA, and we then calculated several indices of arterial stiffness. The wide spectrum of arterial stiffness indices defined from one measurement is a unique feature of our method. The motion-tracking algorithm is based on 2-D cross-correlation enhanced with luminance optimizations. The repeatability and reproducibility of the motion tracking were evaluated by performing 10-s ultrasound recordings of left CCA twice to 19 healthy volunteers (11 women, 8 men, age 41.3 ± 14.3 y). The method revealed a biphasic axial movement of the CCA and demonstrated that the indices of arterial stiffness defined from radial movement of carotid artery are reproducible (Cronbach's α, 0.59-0.97) as well as the indices from axial movement are reproducible (Cronbach's α, -0.68 to 0.93). The good reproducibility of the motion tracking is evidence that this method of studying arterial elastic properties is adequate for in vivo studies.