In the cardiac resynchronization therapy (CRT) era, it has been widely known that electrical conduction disturbance, particularly left bundle branch block (LBBB), contributes to the deterioration of cardiac function. So far, evidence of the effectiveness of CRT has been established in LBBB, but it is controversial with non-LBBB-type electrical conduction disorders such as right bundle branch block. However, dyssynchrony of left ventricular wall motion differs even in LBBB, and some patients with LBBB may not respond to CRT. Therefore, while it is important to respect the recommended level of guidelines in determining the indication for CRT, the perspective of personalized medicine is even more important. Unfortunately, the current guidelines do not include echocardiographic parameters, but echocardiography is useful in assessing cardiac dyssynchrony based on mechanical properties. Many indices have been reported to predict CRT response and to determine adaptation. Various techniques have been proposed for CRT studies, including M-mode, tissue Doppler, speckle tracking, and 3D echocardiography. CRT devices are also constantly evolving and are now equipped with a more complex sequence of cardiac pacing. Therefore, the adaptation of advanced image technique, such as 3D speckle tracking methods, may be necessary to determine the indications for CRT from the viewpoint of personalized medicine.

Ultrasound flow imagining is a technique used to display blood flow information as images. Nowadays, it is possible to obtain detailed information on the direction, velocity, and characteristics of blood flow by displaying the presence or absence of blood flow and its direction in color in real time. However, blood flow imaging is characterized by use of the Doppler effect in contrast to B-mode, which uses amplitude information. In addition, various ultrasound flow imaging technologies using the Doppler effect have now been developed, and it is important to understand the characteristics of these technologies and use them appropriately.

Left ventricular (LV) diastolic dysfunction is associated with worse outcomes in many cardiovascular diseases. Echocardiography is the primary imaging modality used for the assessment of LV diastolic function. Noninvasive estimation of LV filling pressure is an important role of echocardiography. However, echocardiographic parameters have fundamental limitations in the diagnosis of LV diastolic dysfunction as they are significantly influenced by various hemodynamic factors. In this article, we demonstrate the diagnostic approach of LV diastolic dysfunction and pitfalls in echocardiographic diagnosis for beginners.

In April 2014, three medical societies-the Japanese Society of Ultrasonics in Medicine, the Japanese Society of Gastrointestinal Cancer Screening, and the Japanese Society of Ningen Dock-jointly published the Manual for Abdominal Ultrasound in Cancer Screening and Health Checkups. Based on the results of a questionnaire survey on revision of this manual and the annual report of Gastrointestinal Cancer Screening in Japan, this manual was revised and published on the website in June 2021. Here, we explain the revisions in the revised version of the Manual for Abdominal Ultrasound in Cancer Screening and Health Checkups (2021).

In recent years, fetal echocardiography for congenital heart disease (CHD) has become a part of routine medical care. Fetal echocardiography for CHD is divided into screening and scrutiny. Although the two differ in terms of the observation range, they both check the left and right sides and visualize the abdominal cross section, the four-chamber view, the left and right outflow tracts, the three-vessel view, the three-vessel trachea view, the aortic arch, and the basic cross section, respectively performing screening and scrutiny (definitive diagnosis). While basic techniques are required for visualization of the basic cross section, advanced techniques are required for that of the aortic arch. Moreover, there are no clear criteria to distinguish normal and abnormal from the basic cross section. In particular, screening requires some judgment criteria. CHD can be complicated by chromosomal abnormalities and exocardiac disorders. The diagnostic accuracy can be improved by evaluating exocardiac disorders. Last, the scrutiny of basic cross sections has some pitfalls into which we may fall. For this reason, ventricular septal defects and so on tend to give false positives. This paper clarifies the range to be checked by the current diagnostic method and provides some tips to improve the detection rate by making additions to the established methodology.

Ultrasonography is an imaging test that is often performed as an initial assessment of pediatric renal and urinary tract disease, and sometimes ultrasonography has the accuracy of a detailed test. In many cases, however, newborns and infants must be tested in situations where cooperation is not available. Even in such a situation, in order to obtain useful information for differential diagnosis, it is important that the examiner has a good understanding of child-specific disease concepts such as renal malposition, renal dysplasia, fused kidney, renal cystic lesions, renal tumors, congenital anomalies of the kidney and urinary tract, hydronephrosis, and urinary tract infections. In addition, children often have less time to rest than adults, so it is desirable to finish the test in the shortest possible time. For that purpose, it is important to observe promptly from the point with the highest priority and record highly objective images.

Purpose: Medical ultrasound is often used to specify the puncture position during epidural anesthesia. However, visualization of the thoracic spine is difficult because of the complex structure, i.e., it is difficult to determine whether the thoracic spine or muscle is depicted. Therefore, this study aims to distinguish bone from muscle tissue using the differences in reflection and scattering characteristics of ultrasound. Methods: We experimentally investigated the difference in signals received from bone and muscle. We proposed a new parameter utilizing the ratio of the amplitude of the received signals averaged in a wide range around the ideal delay line and that only along the ideal delay line, to emphasize the bone. Results: First, we confirmed the difference in signals received from bone and muscle tissue by basic experiments. We also investigated the difference by in vitro experiments using chicken thigh and in vivo experiments in humans. In both experiments, the proposed method succeeded to clearly depict bone, suppressing the depiction of muscle, compared with conventional B-mode imaging. Conclusion: Using the difference in the characteristics of reflection from bone and scattering from muscle tissue, we could distinguish bone from muscle tissue with the proposed method.

Purpose: Male breast cancer (MBC) is a relatively rare disease. It is important to distinguish it from gynecomastia, which is close in terms of the predominant age and symptoms. The aim of this study was to investigate ultrasound findings with color Doppler imaging and elastography of MBC and gynecomastia. Subjects and Methods: Of male patients with breast symptoms who had undergone ultrasound evaluation between January 2000 and October 2019, the subjects of the study were 92 patients who were diagnosed with MBC or gynecomastia. The morphology was classified into nodular, dendritic, and diffuse glandular; the vascularity on color Doppler imaging was visually classified into four grades; and the elasticity evaluation was divided into five grades using the Tsukuba elasticity score. We compared whether there was a significant difference in color Doppler imaging and elastography between MBC and gynecomastia for each morphology. Results and Discussion: There were six MBCs and 86 gynecomastias. All MBCs appeared as nodular. Gynecomastia was nodular in 28 cases (32.6%), dendritic in 17 cases (19.8%), and diffuse glandular in 41 cases (47.7%). On color Doppler imaging, the evaluation was hypervascular or vascular in 5/6 cases (83.3%) of MBC and 21/34 cases (61.8%) of gynecomastia. There was no significant difference between the two groups (P＝0.399). As for elastography evaluation, MBC scored 5 in 3/5 cases (60%). For gynecomastia, 46/49 patients (93.9%) scored 1 and 2, showing a significant difference between the two groups (P<0.005). Nodular and dendritic gynecomastia was found in 10/15 cases (66.7%), and 8/11 cases (72.7%) had high blood flow, but 35/41 diffuse glandular cases (85.4%) were diagnosed without using vascularity and elastography. The hardness evaluation was not related to morphological characteristics. Conclusion: Combining B-mode ultrasound with elastography is useful for distinguishing MBC from gynecomastia.

Ultrasonography is a clinically essential diagnostic method for evaluating scrotal and intrascrotal structures such as the testis and epididymis. Since segmental testicular infarction is rare and clinically nonspecific, the role of radiological diagnosis is important. However, it is often difficult to distinguish segmental testicular infarction from testicular tumors. In this report, we describe a case of segmental testicular infarction in which low-flow vascularity was depicted using microvascular imaging (MVI). The patient was a male in his 60s. He presented with transient scrotal pain and left scrotal swelling. Ultrasonography showed a wedge-shaped hypoechoic area without color representation and a marginal hyperechoic area with slight blood flow only on MVI in the left testis. The left testis showed easy rotation of about 180 degrees and a small amount of fluid accumulation in the left scrotum. Magnetic resonance imaging showed a wedge-shaped low-signal area on T2-weighted imaging. The lack of blood flow and the flat/wedge-shaped morphology were atypical for testicular tumors, and segmental testicular infarction was suspected. The possibility of testicular infarction due to intermittent testicular torsion was considered based on the easily rotated background of the left testis, and a mild elevation of tumor marker (alpha-fetoprotein) was observed, which led to high-level testicular resection. The patient was diagnosed with segmental testicular infarction histopathologically.

We were able to observe a case of invasive breast cancer diagnosed based on internal echo changes without an obvious increase in tumor size for 2 years and 3 months. Generally, breast cancer doubling time is considered to be 4 months on average. In this case, the tumor itself had not grown, but the internal echoes revealed some changes during the time period. A medical checkup revealed a left breast mass in a woman in her 40s. On ultrasonography (US), it had a lobulated shape, a well-defined border, a hyperechoic pattern with posterior echo enhancement, and a large depth-width ratio. Color Doppler US showed a blood flow signal at the edge of the mass, and elastography showed decreased strain. US indicated a mucinous carcinoma or intraductal papillary lesion. US-guided fine-needle aspiration cytology (FNAC) showed no mucus aspiration, suggesting intraductal papilloma(IDP) or fibroadenoma (mastopathic type). There was no discrepancy between the US and cytology findings, and the patient was placed on follow-up observation for suspected IDP. Thirteen months after FNAC, the tumor had not increased in volume, but the hypoechoic rim of the tumor became slightly clearer. Twenty-seven months after FNAC, the tumor had not grown, but the internal echo level had decreased. Breast cancer was suspected, and the diagnosis was confirmed by core-needle biopsy. The histopathological specimen was compared with the part showing the change on the US image. There were parts where the small mammary ducts were rich with cancer cells and the collagen fiber had increased. It was speculated that these changes were the factors that decreased the internal echoes. Generally, follow-up evaluation of images focuses on tumor growth, but there are also breast cancers with long tumor doubling times. We would like to emphasize the great importance that should be placed upon the internal echo changes of tumors.

A 99-year-old woman visited our hospital with a complaint of left nipple discharge, and a tumor was found in the inner-upper quadrant of the left breast. The tumor was 1 cm in diameter and painful, located just below the skin. Ultrasonic examination showed an intra-cystic tumor with an interruption of the interface between adipose tissue and gland, and a blood flow signal at the solid part of the tumor was detected. No findings were found on mammography. As a result of fine-needle aspiration cytology from the left intra-cystic tumor, ductal carcinoma was suspected. Therefore, left partial mastectomy was performed under local anesthesia, and the tumor was pathologically diagnosed as pleomorphic adenoma. Although noninvasive ductal carcinoma was found in the right breast, it was considered that the disease of the right breast was unrelated to her prognosis. Pleomorphic adenoma of the breast is a very rare benign tumor, and only 20 cases including this case have been reported in Japan. Among them, this is the only case that exhibited the morphology of an intra-cystic tumor, which is an extremely rare finding in ultrasonic examination of pleomorphic adenoma of the breast. Here, we review the clinicopathological features of 20 cases of pleomorphic adenoma of the breast.