The abdominal ultrasonographic findings of neonates with vomiting and abdominal distension are presented. (1) Hypertrophic pyloric stenosis can be diagnosed if the muscular layer thickness is more than 4 mm with a length exceeding 15 mm at the pyloric ring and the passage of the gastric contents is disturbed. Because gastric dilatation causes the pyloric ring to move to the right posterior portion, the position of the probe must be adjusted accordingly. (2) Intestinal malrotation with midgut volvulus is easily diagnosed based on a positive “whirlpool sign.” In the absence of this sign, passage of the contents of the third portion of the duodenum in the normal direction rules out intestinal malrotation without midgut volvulus. (3) Duodenal atresia involving the second portion of the duodenum will causes enlargement of the left side of the gallbladder. In small intestinal atresia, the enlarged small intestine above the atresial site will have a common boundary with the collapsed gastrointestinal tract below this site. (4) Necrotizing enterocolits presents as multiple hyperechoic dots in the edematously thickened wall of the gastrointestinal tract. The dots represent foci of intestinal pneumatosis. Gas in the portal vein adjacent to the liver will also present as hyperechoic dots on B-mode, whereas gas trapped in the liver are visible as a ventral hyperechoic area of the liver parenchyma. Hyperechoic dots and portal vein gas are characteristic of the early stage of necrotizing enterocolitis. These findings can be detected by ultrasonographic examination while it is impossible to do so by X-ray.

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The clinical application of ultrasonography for the respiratory tract started in the latter half of 1970 with B-mode ultrasound. Ultrasonography is useful for diagnosis and evaluation of chest wall lesions, costal lesions, pleural lesions, pleural effusion, lung lesions in contact with the pleura (subpleural lesions), pleural invasion of lung cancer, and mediastinal lesions. Ultrasonography is also useful for ultrasound-guided biopsy and the support during bronchoscopy. Recently, the usefulness of ultrasonography has gained attention in emergency cases requiring anesthesiology and in the emergency room, e.g., pneumothorax and lung edema. The diagnosis of lung lesions in contact with the pleura has limits with use of B-mode alone, but the diagnostic ability improves by adding blood flow information. Diagnosis by means of ultrasound blood flow imaging of the respiratory tract was subsequently introduced. Power Doppler, 3D, B-Flow color, and enhanced ultrasonography with Levovist^® and Sonazoid^® enable the detailed blood flow diagnosis in the respiratory tract. Blood flow diagnosis is also useful for the evaluation of ultrasound-guided biopsy and the response to therapy for lung cancer. Like other areas where it is used, ultrasonography of the respiratory tract is very useful.

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Background: Patients who undergo ultrasound examinations are three-dimensional structures. Although the output is a B-mode image, we do not think of it as a two-dimensional object. Hence, use of the expression “spherical” mass is favorable. On the other hand, the expression “circular” mass is inconsistent. Misuse of the medical ultrasound terminology: A retrospective analysis of papers reported in the Jpn J Med Ultrasonics or JSUM meetings disclosed misuse of the following medical ultrasound terminology: “periphery,” “border,” “contour,” and “adjacent zone,” resulting in confusion among them. In particular, confusion between “periphery” and “contour” is noteworthy. The situation could lead to a confused discussion associated with misunderstanding of the ultrasound findings. Conclusion: It is important that results of medical studies are conveyed through correct medical terms and proper expressions because misunderstandings could be a barrier to progress.

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After the Great East Japan Earthquake on March 11, 2011, the Japan Society of Ultrasonics in Medicine sent portable echo machines to Iwate, Miyagi, and Fukushima prefectures at the request of a member of the society. This manuscript aims to record what the society considered, what the society did, and what kinds of obstacles the society faced for future reference.

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The Great East Japan Earthquake generated on March 11, 2011 caused unprecedented damage. In particular, there was serious destruction in three prefectures in the Tohoku area. After the disaster, the Japan Society of Ultrasonics in Medicine (JSUM) sent portable ultrasound equipment to the stricken area. We who live in the stricken area were active in order to put them to practical use. Thanks to the teamwork of the members of JSUM, the portable ultrasound equipment was utilized for primary care and screening of lower limbs thrombosis in the shelters. On the other hand, on the occasion of this activity, the securing of transportation for the equipment was very difficult due to interruption of the transportation system. It is necessary to examine how to secure transportation means and human resources in the event of a disaster in the future.

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The activities of the Japan Society of Medical Ultrasonics in Miyagi Prefecture after the Great East Japan Earthquake are described.

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In response to the Great East Japan Earthquake, the Japan Society of Ultrasonics in Medicine (JSUM) deployed portable ultrasound machines to the three most seriously devastated prefectures in the northeastern region of Japan: Fukushima, Miyagi, and Iwate. Twenty-five portable ultrasound machines were loaned or donated to Iwate Prefecture.
In Iwate Prefecture, the medically underserved coast area was hit by a record-breaking tsunami; 5,115 people were confirmed dead, 1,132 remain missing, and 211 were injured, indicating a remarkably low injury-to-death ratio (0.04). At first, the impact of the tsunami on the healthcare system was underestimated as a result of the shutdown of the telecommunication networks. There were significant increases in the occurrence of acute decompensated heart failure, sudden cardiac and unexpected death, and cerebral infarction during the initial 30 days after the disaster. Due to disruptions at hospitals and in distribution systems, the rate of percutaneous coronary intervention decreased and in-hospital mortality increased in patients with ST-elevation myocardial infarction.
In the initial phase, deployed machines were used by local physicians at evacuation shelters and temporary hospitals or clinics, and by volunteer medical teams for DVT screening of the refugees. After 30 days, the machines were utilized to replace those damaged at hospitals and clinics in the coastal area.
In order to realize proper operation and consistent management of the machines, we directly communicated with members at JSUM headquarters, Iwate prefecture government officials, Iwate Disaster Medical Support Network officials, ultrasound machine companies and their agencies, and local physicians who requested the machines. E-mail and cellular phones were irreplaceable in these communications.
We need to develop resilient telecommunication and distribution networks to prepare against massive disasters in the near future. It is important that medical societies and industry work together to build logistics for supporting devastated regions.

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In the aftermath of the Great East Japan Earthquake on March 11, 2011, I received a request to serve as a sonographer in charge of lower extremity venous ultrasound screening as part of the “economy-class syndrome medical care group,” popularly referred to as “team Eco,” which was organized by Fukushima Medical University. I visited refugees at various locations in Fukushima Prefecture and carried out lower extremity venous ultrasound checks for one week beginning on April 4. I had various valuable experiences including preparation of a pocket guide and setting up hands on classes about securing lower extremity venous ultrasound check workers, procuring ultrasound units, dispatching information about our activities, and future activities. A natural disaster can happen anywhere at any time. Medical institutions, scientific organizations, the government, and other groups should work together to set up a system that is capable of responding rapidly and smoothly in the event of a natural disaster.

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A landslide disaster unexpectedly happened in Hiroshima on August 20, 2015. We were asked for medical support, and the Japan Society of Ultrasonics in Medicine immediately sent ultrasound machines in response to our request. We joined the medical team for the examination and prophylaxis of deep vein thrombosis in evacuees together with doctors from Hiroshima University, Niigata University, and Fukui University. We found a 9.8% incidence of deep vein thrombosis in 108 evacuees in 2 days, and properly referred them to local medical services. The local organizations and services did not function fully enough to support the evacuees in shelters at that time. We herein report on medical activities during a huge landslide disaster in Hiroshima and advocate that a special team of well-trained experts that can control and act as a bridge between requester and supporter should be established by the government or local administration.

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Purpose: Acoustic lenses have generally been used in probes of ultrasonic diagnostic equipment and are primarily composed of silicone rubber. Manufacturers are now conducting material research on these lenses considering the use of in the air. This study considers the utilization of a phononic crystal structure as a new device for acoustic lenses used as probe, in order to improve the performance of ultrasonic probes for ultrasonic diagnostic equipment. Subjects and Methods: To determine the basic properties of a conventional planar acoustic lens that uses water as a filler and an acoustic lens that uses silicone rubber as a filler, we obtained the acoustic focusing field of the lenses using the two-dimensional elastic finite-difference time-domain method as the numerical analysis method. Furthermore, we obtained the focal distance, beam width, and frequency characteristics in order to clarify various properties of an acoustic lens. Results and Discussion: Analysis of the acoustic focusing field of the planar acoustic lens with silicone rubber clearly showed that the planar acoustic lens focused ultrasound when the radiation frequency of sound was varied from 2.5 MHz to 3.2 MHz. The frequency range of convergence shifted to the low frequency compared with that of the planar acoustic lens with water. The frequency shift results from the low limiting basic frequency between crystalline lattices that is caused by the slow sound velocity of silicone rubber compared with the sound velocity of water. Conclusion: We confirmed the expansion of frequency bands of the planar acoustic lens with a phononic crystal structure constructed with silicone and stainless steel rods considering the use of in the air. In future studies, we plan to analyze the precise sound distribution in three-dimensions using the three-dimensional elastic finite-difference time-domain method.

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Purpose: To investigate the possibility of improving the diagnostic accuracy by identifying the time course of various Ultrasonography (US) findings of acute cholecystitis. Subjects and Methods: The subjects were 69 patients (41 male and 28 female patients, mean age: 54.0 years old) who developed acute cholecystitis between January 2010 and February 2015, in whom the onset date and time could be identified and active treatment was not performed prior to US examination. We investigated the time-course incidences of various US findings (gallbladder enlargement, biliary sludge, wall thickening, intramural hypoechoic layer, fluid retention around the gallbladder, and abscess formation). Results and Discussion: The incidences of swelling, biliary sludge, gallbladder wall thickening, hypoechoic layer, fluid retention around the gallbladder, and abscess formation increased over time in this order. Swelling alone was noted in 70.0% (7/10) of patients who were examined within 10 hours after onset, and all such patients were examined by US within 15 hours after onset, suggesting that acute cholecystitis cannot be ruled out within 15 hours, even though only swelling is observed. In 91.7% (33/36) of patients who were examined by US 24 or more hours after development, at least swelling + biliary sludge + wall thickening were observed, suggesting that when swelling, biliary sludge, and wall thickening are not observed 24 or more hours after development, acute cholecystitis is unlikely. Conclusion: Diagnostic accuracy may be improved by investigating the order of the development of various US findings of acute cholecystitis and the time course of their development.

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Hepatic lymphomas generally appear as diffuse hypoechoic lesions. Here we report an unusual case of a hepatic lymphoma that showed a mixed pattern on contrast-enhanced ultrasonography (CEUS) because of central necrosis or hemorrhage. A woman in her 70s was referred to Hokkaido University Hospital with epigastralgia. Hepatic metastasis from gastroesophageal cancer was initially suspected on the basis of computed tomography (CT) findings. Ultrasonography (US) revealed a 91-mm, solid lesion with a clearly defined border in hepatic segment 4. The peripheral and central zones of the lesion were hypoechoic and hyperechoic, respectively. The arterial phase of CEUS revealed strong homogeneous enhancement in the peripheral zone and no enhancement in the central zone, while the portal phase showed a decrease in the peripheral zone enhancement. The nodule showed an enhancement defect in the postvascular phase. Contrast-enhanced CT also revealed homogeneous hyperenhancement in the peripheral zone and hypoenhancement in the central zone, which was considered to be a result of degeneration or hemorrhage. Both CEUS and CT showed multiple enlarged lymph nodes in the hepatic hilum. CT also showed multiple lymph node metastases in the neck. All these findings suggested that the mass was a secondary lesion. Biopsy confirmed a diagnosis of stage IV diffuse large B-cell lymphoma. The patient was treated with rituximab, cyclophosphamide, pirarubicin, vincristine, and prednisolone and achieved unconfirmed complete remission after 6 cycles of treatment.

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