Echocardiography is an integral part of characterizing patients with hypertrophic cardiomyopathy and helps procedural guidance for percutaneous transluminal septal myocardial ablation (PTSMA). Preprocedural echocardiography is useful in determining whether surgical septal myocardial resection or PTSMA is preferable for the treatment of septal reduction, based on the presence or absence of mitral valve complex abnormalities or repairable concomitant cardiac disease. Intraprocedural echocardiography provides essential information on the suitability of the targeted coronary septal branch for ablation and expected reduction in the pressure gradient after ablation. After the procedure, the pressure gradient in the middle of the left ventricle and near the apex may become prominent, necessitating evaluation of these stenoses. Appropriate use of echocardiography enables better patient selection for PTSMA and helps achieve the optimal procedure and follow-up strategies.

Ultrasonography (US) has the overwhelming advantages of not entailing radiation exposure and being a noninvasive, real-time, convenient, easy-to-perform, and relatively inexpensive imaging modality. It is used as the first-line imaging modality for screening, detection, and diagnosis of focal liver lesions (FLLs) ［small hepatocellular carcinomas (HCCs), in particular］. However, with the increasing demand for accurate and early diagnosis of small HCCs, newer radiologic methods need to be explored to overcome certain limitations of US. For example, the imaging is easily negatively affected by the presence of gas, rib cage, and subcutaneous fat, and is insensitive for capturing the subtle but vital information on the blood flow. It was in response to this need that new promising technologies such as contrast-enhanced ultrasound and fusion imaging were introduced for the detection of liver lesions. This paper presents an overview of the epidemiology and mechanisms of the development of HCCs, with an emphasis on the application of US in the diagnosis and treatment of FLLs. The aim of this article is to provide the state-of-the-art developments in the imaging diagnosis of FLLs and evaluation of ablation treatment of early HCCs. By keeping abreast of these recent advances, we hope that doctors and researchers working in the field of diagnosis/treatment of liver diseases will be able to discriminate benign FLLs such as regenerative nodules and focal nodular hyperplasia from HCCs, so as to avoid unnecessary repeated tumor biopsies and overtreatment. In particular, we expect that small HCCs or precancerous nodules (such as dysplastic nodules) can be accurately diagnosed and appropriately treated even at an early stage.

Ultrasonography (US) is a major, sustainable hepatocellular carcinoma (HCC) surveillance method as it provides inexpensive, real-time, and noninvasive detection. Since US findings are based on pathological features, knowledge of pathological features is essential for delivering a correct US diagnosis. Recent advances in US equipment have made it possible to provide more information, such as malignancy potential and accurate localization diagnosis of HCC. Evaluation of malignancy potential is important to determine the treatment strategy, especially for small HCC. Diagnosis of blood flow dynamics using color Doppler and contrast-enhanced US is one of the most definitive approaches for evaluating HCC malignancy potential. Recently, a new Doppler microvascular imaging technique, superb microvascular imaging, which can detect Doppler signals generated by low-velocity blood flow, was developed. A fusion imaging system, another innovative US technology, has already become an indispensable technology over the last few years not only for US-guided radiofrequency ablation but also for the detection of small, invisible HCC. This article reviews the evidence on the use of ultrasound and contrast-enhanced ultrasound with Sonazoid for the practical management of HCC.

With advances in imaging technology, images from ultrasound (US) and computed tomography (CT) or magnetic resonance imaging (MRI) can be displayed simultaneously and in real time, according to the angle of the transducer. CT/MR-US fusion imaging improves the visualization of inconspicuous hepatocellular carcinoma (HCC) and helps us to understand the threedimensional relationship between the liver vasculature and HCC. US fusion imaging guidance facilitates improvement in the treatment response for HCC with poor conspicuity, and the rates of technical success of ablation and local tumor progression for inconspicuous HCC range from 94.4 to 100% and 0 to 8.3%, respectively. Moreover, the development of image fusion has made it possible to compare and overlay pre- and post-ablation US images. This US-US fusion imaging allows side-by-side comparison of the ablative margin, while US-US overlay fusion can visualize the ablative margin because the tumor image is projected onto the ablative hyperechoic zone. Thus, US-US overlay fusion guidance is highly effective for safety margin achievement in local ablation therapy for HCC, providing a lower risk of local tumor progression. This manuscript reviews the current status of ultrasound fusion imaging for percutaneous ablation therapy of HCC.

Although microwave ablation (MWA) exhibits a high thermal efficiency, the major limitation of conventional MWA systems is the lack of predictability of the ablation zone size and shape. Therefore, a specific newer generation MWA system, The EmprintTM Ablation System with ThermosphereTM Technology, was designed to create predictable large spherical zones of ablation that are not impacted by varying tissue environments. The time required for ablation with MWA systems is short, and the shape of the necrosis is elliptical with the older systems and spherical with the new system. In addition, because MWA has no heat-sink effect, it can be used to ablate tumors adjacent to major vessels. Although these factors yield a large ablation volume and result in good local control, excessive ablation of liver tissue and unexpected ablation of surrounding organs are possible. Therefore, MWA should be carefully performed. This review highlights the efficacy and complications of MWA performed with conventional systems and the newer generation system in patients with hepatocellular carcinoma (HCC). MWA with the newer generation system seems to be a promising treatment option for large HCCs and secondary hepatic malignancies, with several advantages over other available ablation techniques, including conventional MWA. However, further randomized controlled trials are necessary to fully clarify the benefits and pitfalls of this new system.

Purpose: Endometrial polyps and submucosal myoma of the uterus are common masses occupying the uterine cavity. Strain elastography is an imaging modality that qualitatively determines the hardness of tissue. Since endometrial polyps and subuterine myomas have different tissue hardness, they are likely to be distinguishable on strain elastography and may be a useful test. Subjects and Methods: Patients who underwent hysteroscopic transcervical tumor resection (TCR) for an intrauterine tumor at our hospital between 2016 and 2019 were included in this study. Vaginal strain elastography was performed on the day before surgery. The ultrasonologist and obstetrician-gynecologist independently determined whether the patient had an endometrial polyp or a submucosal myoma. Based on the above test results, we compared the diagnostic accuracy of B-mode ultrasound and strain elastography, investigated the inter-examiner error of strain elastography, and examined how accurate the obstetrician-gynecologist’s judgment was in terms of the pathological diagnosis. Results and Discussion: According to the pathological diagnosis, uterine fibroids were found in five cases, endometrial polyps in 17 cases, and endometrial polyps and uterine fibroids in one case. There was no significant difference in the test accuracy between B-mode ultrasound and strain elastography. The Kappa coefficient between examiners was 0.61. The accuracy rate for pathological diagnosis was 95%. It is possible to distinguish between endometrial polyps and submucosal leiomyoma with strain elastography. Conclusion: Transvaginal elastography seems to be a promising tool that an obstetricians and gynecologists can use to make a differential diagnosis.

Conservative management of retained placenta after full-term delivery is an alternative option when there is a desire to preserve fertility. Changes over time in β-hCG levels and uterine artery pulsatility index (PI) were investigated in three cases under conservative management. In all three cases, the half-life of β-hCG levels was about 5 days. The uterine artery PI tended to be lower on the placental attachment side, and PI increased in a time-dependent manner. After the uterine artery PI on the placental attachment side exceeded 1.5, the residual placenta was expelled. In conservative management, uterine artery PI measurement may be significant as a predictor of spontaneous expulsion of the retained placenta.