Mitral regurgitation (MR) is one of the most frequent indications for valve surgery in developed countries, and echocardiographic assessment is an essential tool to evaluate its etiologies, severity, and therapeutic indications. The mitral valve apparatus is a complex structure composed of several parts: apart from the mitral valve leaflets and annulus, it also includes the chordae tendineae, papillary muscles, and left ventricular (LV) wall. MR can be caused not only by organic changes of the mitral valve leaflets or chordae (primary MR) but also by extreme mitral annular enlargement or mitral leaflet tethering due to displacement and malfunction of papillary muscles and LV wall (secondary MR). In secondary MR with LV dysfunction, a milder degree of MR can be associated with adverse outcomes compared with primary MR. Grading the severity is the first step in evaluation of indication for surgical/transcatheter interventions. As such, there are several techniques to assess the severity of MR using echocardiography. However, none of the techniques is reliable enough by itself, and it is always recommended to integrate multiple methods. In cases where echocardiographic assessment of MR severity is inconclusive, magnetic resonance may be helpful. In addition to the severity, anatomical information, such as localization in primary MR due to mitral valve prolapse and LV size in secondary MR due to LV dilatation/dysfunction, is an important concern in presurgical echocardiography. Transesophageal echocardiography and three-dimensional echocardiography are key techniques for anatomical evaluation including mitral valve and LV volumes. In transcatheter intervention for MR, echocardiography plays a pivotal role as a guide for procedures and endpoints. In this review article, the authors provide a comprehensive summary of current standards of echocardiographic assessment of MR.

Aortic stenosis (AS) represents a major healthcare issue because of its ever-increasing prevalence, poor prognosis, and com-plex pathophysiology. Echocardiography plays a central role in providing a comprehensive morphological and hemodynamic evaluation of AS. The diagnosis of severe AS is currently based on three hemodynamic parameters including maximal jet velocity, mean pressure gradient (mPG) across the aortic valve, and aortic valve area (AVA). However, inconsistent grading of AS severity is common when the AVA is ＜ 1.0 cm² but the mPG is ＜ 40 mmHg, also known as low-gradient AS (LGAS). Special attention should be paid to patients with symptomatic LGAS with low stroke volume and/or low ejection fraction because this entity is more difficult to diagnose and has a worse prognosis. Stress echocardiography testing plays an important role in this disease entity. Elderly patients with prohibitive comorbidities for surgical aortic valve replacement (AVR) were without procedural options until the advent of transcatheter AVR (TAVR), which has dramatically changed these circumstances. Along with computed tomography, echocardiography plays a vital role in the periprocedural assessment of the aortic valve and surrounding apparatus. This review describes the evolution of the role of echocardiography in the diagnosis and management of AS, the complexity of the aortic apparatus, and the increased need for expert use of three-dimensional echocardiography.

Stress echocardiography is widely used to assess several cardiovascular diseases, including ischemic heart disease, valvular heart disease (VHD), heart failure, congenital heart disease, and pulmonary hypertension. In valvular heart disease with asymptomatic severe or symptomatic non-severe status, stress echocardiography plays a central role in the management. As of 2017, the updated American College of Cardiology/American Heart Association and European Society of Cardiology/European Association for Cardio-Thoracic Surgery VHD guidelines recommended stress testing to (1) confirm symptoms and (2) evaluate the hemodynamic response to exercise. In patients with undetermined VHD severity in the presence of low-flow status, it can also be helpful to determine whether the VHD is severe based on flow-dependent changes in response to stress. The clinical indications of stress echocardiography in VHD have expanded with growing evidence for prognosis and being an early marker for interventions. As a result, demand has increased in major cardiology societies for the standardization of stress echocardiography in VHD. Echocardiographic centers should be aware of the clinical potential of stress echocardiography to ensure its optimal application and performance in VHD. This article reviews the clinical application of stress echocardi-ography, including dobutamine, semisupine bicycle, treadmill, and leg-positive pressure for VHD patient management, and focuses on the current consensus regarding the use of stress echocardiography in VHD. Stress echocardiography is safe and should be encouraged, especially in heart valve clinics, to understand the complex mechanism in asymptomatic patients.

Purpose: The present study investigated the contamination of ultrasound accessories. The goal of this study was to establish a protocol for disinfecting gel bottles and gel warmers. Subjects and Methods: Bacterial samples were collected from gel bottles, gel warmers, gel containers, and the basket used for drying washed objects, before and after washing the objects, except for the basket, for which the sample was collected only at the beginning of the study. Additionally, samples from gel bottles and gel warmers were collected when the gel in each gel bottle was depleted, as well as 3 weeks after washing. The samples were inoculated onto Tryptic soy agar plates, and the plates were incubated at 35°C and 5% CO₂ for 48 hr. The species of the bacterial colonies on the plates were identified automatically, and the number of bacteria was analyzed semiquantitatively. Results and Discussion: Staphylococcus caprae were detected in the samples collected from one gel bottle and one gel warmer, and Bacillus subtilis from one gel warmer before cleaning, while after cleaning no bacteria were detected. B. subtilis was detected from specimens collected from two gel warmers when the gel in gel bottles was exhausted and 3 weeks after cleaning. Only commensal or environmental bacteria, but no pathogenic bacteria, were detected from the samples in the present study. This finding suggested that ultrasound accessories such as gel bottles or gel warmers were contaminated by clinical procedures during ultrasound examinations. Gel bottles should not be refilled from larger gel containers. As no bacteria were detected after cleaning, gel bottles can be reused after sufficient cleaning and drying. Conclusion: In this report, we presented a cleaning method for reuse of accessories such as gel bottles and gel warmers contaminated with commensal or environmental bacteria. Our results confirmed that this method sufficiently removed the bacterial contamination on the accessories.

Purpose: Liver stiffness (LS) measured using ultrasound shear wave elastography is reported to be influenced not only by liver fibrosis but also by other clinical conditions such as hepatic inflammation, jaundice, and liver congestion. The aim of this study was to investigate the influence of liver fibrosis, hepatic necrosis, and inflammation on LS. Materials and Methods: Of 7,825 chronic liver disease cases, 809 patients who met our study criteria were included. LS measurements obtained using transient elastography (TE) and Virtual Touch Quantification (VTQ) were compared with histologically evaluated liver fibrosis stage and necro-inflammatory activity grade. Results and Discussion: The area under the receiver-operating characteristic curve of TE to predict F2≤, F3≤, and F4 was 0.809, 0.860, and 0.947, respectively, and that of VTQ was 0.793, 0.836, and 0.941, respectively. LS showed significant increase with the progression of fibrosis. In addition, LS showed significant increase with the progression of hepatic necrosis and inflammation. In the analysis based on each fibrosis grade, LS showed an increase along with the severity of inflammation, except in F4 (liver cirrhosis) cases. Conclusions: LS measurement is useful in predicting liver fibrosis stage noninvasively, but it can be influenced by hepatic inflammation. Therefore, LS measurements should be interpreted with caution.

Placental hemangiomas exist only histologically. While many are clinically harmless, they can cause fetal growth restriction and fetal anemia. We report our case and discuss the need for color Doppler during placental examinations with ultrasonography. The patient was referred to our hospital for fetal growth restriction at 31 weeks of gestation. There were no obvious abnormalities in the medical history, foetation, or fetal appendages. Chromosome tests had not been performed, but the diagnosis was fetal growth restriction for which no obvious cause could be identified. Subsequent B-mode ultrasonography revealed that part of the placenta was less bright than the other placental parenchyma, and color Doppler was performed. As a result, an abundant increase in blood flow was observed, and placental hemangioma was diagnosed. As a policy of controlled delivery, labor was induced and the baby was delivered at 37 weeks of gestation. The child weighed 2,162 g, with Apgar scores of 9 and 10 at 1 and 5 minutes, respectively. No complications such as anemia, disseminated intravascular coagulation, or heart failure were observed in the infant. A slightly red mass measuring 4×6 cm was found in the delivered placenta. Histological examination revealed that the mass was a hemangioma, and a small infarct image was also found around the hemangioma. The hemangioma in this case was not small, but the B-mode imaging findings were such that it was difficult to distinguish it from the normal placental parenchyma. Routine use of color Doppler as well as B-mode ultrasonography for placental evaluation and screening during pregnancy may be warranted.