Recent advances in ultrasound medical technology have been remarkable, particularly in the realm of diagnostic and therapeutic support for the abdominal region. New technologies utilizing artificial intelligence (AI) such as improved B-mode imaging, differential diagnosis of liver tumors, and microvascular flow imaging (MVFI) are being used clinically. Noninvasive diagnostic techniques, including liver and spleen stiffness measurements and attenuation coefficient measurements for fatty liver evaluation, are being established. Endoscopic ultrasound (EUS) has enhanced diagnostic capabilities through contrast enhancement and stiffness diagnosis. In therapeutic support technology, fusion imaging has shown notable progress. While image registration between different modalities previously required manual setting of anatomical landmarks, the development of hepatic vascular morphology recognition and AI-based automatic registration now enables more accurate and convenient image integration. The author has devoted research to developing ultrasound diagnostic and therapeutic support technologies, focusing particularly on establishing noninvasive diagnostic methods for spleen stiffness measurement and liver fat quantification, as well as improving therapeutic techniques utilizing fusion imaging technology. This paper presents the author’s research achievements that have evolved alongside technological progress in medical ultrasonics.

The initial means of detecting right ventricular (RV) dilatation is often transthoracic echocardiography (TTE), and once the presence of RV dilatation is suspected, there is the possibility of RV volume overload, RV pressure overload, RV myocardial disease, and even nonpathological RV dilatation. With respect to congenital heart disease with RV volume overload, defects or valvular abnormalities can be easily detected with TTE, with the exception of some diseases. Volumetric assessment using three-dimensional echocardiography may be useful in determining the intervention timing in these diseases. When the disease progresses in patients with pulmonary hypertension as a result of RV pressure overload, RV dilatation becomes more prominent than hypertrophy, and RV function parameters predict the prognosis at this stage of maladaptive remodeling. The differential diagnosis of cardiomyopathy or comparison with nonpathological RV dilatation may be difficult in the setting of RV myocardial disease. The characteristics of RV function parameters such as two-dimensional speckle tracking may help differentiate RV cardiomyopathy from other conditions. We review the diseases presenting with RV dilatation, their characteristics, and echocardiographic findings and parameters that are significant in assessing their status or intervention timing.

Heart failure with preserved ejection fraction (HFpEF) accounts for nearly 70％ of all HF and has become the dominant form of HF. The increased prevalence of HFpEF has contributed to a rise in the number of HF patients, known as the “heart failure pandemic”. In addition to the fact that HF is a progressive disease and a delayed diagnosis may worsen clinical outcomes, the emergence of disease-modifying treatments such as sodium-glucose transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists has made appropriate and timely identification of HFpEF even more important. However, diagnosis of HFpEF remains challenging in patients with a lower degree of congestion. In addition to normal EF, this is related to the fact that left ventricular (LV) filling pressures are often normal at rest but become abnormal during exercise. Exercise stress echocardiography can identify such exercise-induced elevations in LV filling pressures and facilitate the diagnosis of HFpEF. Exercise stress echocardiography may also be useful for risk stratification and assessment of exercise tolerance as well as cardiovascular responses to exercise. Recent attention has focused on dedicated dyspnea clinics to identify early HFpEF among patients with unexplained dyspnea and to investigate the causes of dyspnea. This review discusses the role of exercise stress echocardiography in the diagnosis and evaluation of HFpEF.