Evaluation of right heart function and right heart failure had not been emphasized in the past. Recently, it has been reported that right ventricular function and right heart failure are predictors of survival in patients with left heart failure. It has also been reported that the severity of tricuspid regurgitation is a predictor of the long-term prognosis among the general population. Therefore, the significance of right heart function has been increasing . However, the conventional evaluation of cardiac function is mostly limited to the left side, especially the left ventricle. There are many different characteristics between the left and right ventricles. The left and right ventricles influence each other, i.e., interventricular interaction. The left and the right ventricles are connected through pulmonary vasculature as well as through the interventricular septum. In addition, the left and right ventricles exist in the same space surrounded by the pericardium. It is important to accumulate echocardiographic data on right heart function and to compare them to the clinical data in order to establish the evaluation of right heart function.

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As ultrasound (US) is a simple and less invasive modality, it is widely used for mass screening. Both pancreatic cysts and dilated pancreatic ducts are common findings. As the diagnostic accuracy of US depends on the operator's skill and knowledge, sonographers should master the standard scanning method and learn characteristic US findings for the differential diagnosis. Pancreatic neoplasms are generally classified as solid or cystic. The solid neoplasms include pancreatic ductal carcinoma, neuroendocrine tumor, solid-pseudopapillary neoplasm (SPN), and tumor-forming pancreatitis. The cystic neoplasms include serous cystic neoplasm (SCN), mucinous cystic neoplasm (MCN), and intraductal papillary mucinous neoplasm (IPMN). First, we explain the basic scanning method and pitfalls of US imaging of the pancreas. Second, we highlight the high-risk group including dilatation of pancreatic ducts, cystic lesions, and so on. Third, we illustrate the differential diagnosis between ductal carcinomas and other solid lesions.

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Purpose: This paper describes an investigation into direct observation of microscopic images of tissue using a thin acoustic wave guide. Methods: First, the characteristics of the ultrasonic wave propagated in a fused quartz fiber were measured using the reflection method in order to study the insertion loss and the frequency shift of the ultrasonic wave transmitted from the transducer. Next, a receiving transducer was placed close to the end of the fiber, and the characteristics of the ultrasonic waves propagated through the acoustic coupling medium were measured using the penetration method in order to study the insertion loss and the frequency-dependent attenuation of the penetrated waves. Finally, a C-mode image was obtained by optimizing the measuring conditions using the results of the above measurements and scanning the ultrasonic beams on a target (coin) in water. Results: A reflected wave with a peak frequency of approximately 220 MHz was obtained from the end of the fiber. The transmitted ultrasonic waves propagated through the acoustic coupling medium were detected with a frequency range of approximately 125-170 MHz, and the maximum detectable distance of the waves was approximately 1.2 mm within the 100-MHz frequency range. Finally, a high-frequency C-mode image of a coin in water was obtained using a tapered fused quartz fiber. Conclusion: The results suggest that it is necessary to improve the signal-to-noise ratio and reduce the insertion loss in the experimental system in order to make it possible to obtain microscopic images of tissue.

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Introduction: Acoustic radiation force (ARF) elastography is potentially useful for imaging the elasticity of human tissue. Because a “push wave” that is used to generate ARF is a long burst wave comparable to that used in regular clinical imaging, detailed investigation of its safety is required. Materials and methods: We focus on the transient temperature rise in the far field, where the beam paths are overlapped. Soft tissue mimicking a phantom and bone samples were exposed to a 2-MHz plane wave for 20 s. The temperature rises in the far field were measured using a thermocouple. The temperature rises at 1 ms, the time required for the displacement measurement, were estimated by fitting the experimental results. The results showed that the thermosensitivity of the bone was 36 times higher than that of the phantom, and the use of a repeated push wave may have exceeded the allowable maximum temperature rise, 1°C, on the bone surface. Conclusion: In conclusion, the imaging area, including the path of the push wave, should be carefully checked and the time interval for consecutive use should be adjusted to prevent thermal risk on the surface of the bone.

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The combination of congenital cystic adenomatoid malformation of the lung (CCAM) and hydrops fetalis entails compromised birth outcomes, and fetuses with a CCAM volume ratio (CVR)>1.6 are considered at high risk for the development of hydrops. A 33-year-old gravida 3, para 1, mother was admitted at 20+6 weeks of gestation owing to a large fetal lung multilocular mass (macrocystic CCAM) originating in the right lower lobe and hydropic change indicated by skin edema and ascites. The overall size of the mass lesion corresponded to a CCAM volume ratio of 2.0. The mother underwent thoracoamniotic shunting at 22+1 weeks of gestation, with successful drainage of the largest, second cyst. After the procedure, the hydrops resolved completely. The shunt continued to be functional throughout the remainder of the pregnancy; however, the CVR persisted at 0.6-0.8 because of residual multilocular cysts. The mother underwent cesarean delivery at 37+0 weeks of gestation. On the day of birth, the infant underwent right thoracotomy and CCAM resection. The infant survived; however, respiratory demise due to lung hypoplasia and the subsequent pulmonary hypertension was severe and refractory. Our experience suggests the curative effect of thoracoamniotic shunting for hydropic state in a fetus with macrocystic CCAM. However, the criteria for the treatment of multilocular macrocystic CCAM requires further discussion.

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