The diagnosis of pressure ulcer (PU) has been based on a physical examination consisting of inspection and palpation. Recently, a new type of etiology of PU has been emerging, referred to as a deep tissue injury (DTI). A DTI is difficult to evaluate by the usual inspection because invisible deep tissue damage is already present despite an intact or shallow skin appearance, rapidly deteriorating into an advanced stage. Ultrasonography (US) is a noninvasive, easy-to-use, and real-time technology that will be helpful for early detection of DTI and accurate diagnosis or evaluation of PU status and healing. The efficacy of US for PU assessment has been reported in previous reports. This review briefly introduces the basic diagnostic techniques and procedures of US for PU assessment. It is expected that US will be widely disseminated in the clinical field of PU management.

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The guidelines for breast ultrasound diagnosis 1st edition were published by the Japan Association of Breast and Thyroid Sonology (JABTS) in 2004. The Guidelines promoted standardization of the breast ultrasound terms or concepts of breast ultrasound diagnosis for breast diseases in Japan. Since the publishing of the Guidelines, a breast ultrasound training course has been held by the educational committee of JABTS.The Guidelines introduce fundamentals of breast ultrasound such as ultrasound equipment suitable for breast imaging, the pathology of breast diseases, ultrasonic tissue characterization, breast ultrasoundterminology, diagnostic concepts, flow imaging, elastography, the concept and typical images of each lesion, and screening ultrasound.The most unique concept in these Guidelines is non-mass abnormalities.Advances in imaging technology enabled the recognition of breast cancer lesions difficult to recognize as a mass. The JABTS defined such lesions as non-mass abnormalities. Most of these cancers are ductal carcinoma in situ, and these lesions show abnormality of the ducts or a hypoechoic area in the mammary gland or architectural distortion on ultrasound. A recall criteria in screening ultrasound for breast masses explained in the Guidelines is useful for understanding the basic concept of diagnosis of breast masses. The Guidelines were primarily written based on the consensus of experts. It is important to gradually change these Guidelines so that they are based on sufficient evidence in the future.

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Although the scrotum falls within the area of urology, since the target tissue is located at a shallow range, it is important for equipment settingsto be compatible with superficial areas. New imaging methods including harmonic imaging and compound scanning with color Doppler imaging should be actively employed. In addition, scrotalultrasound applies to urgent cases, and it is necessary that the operator understands various specific sonographic finding. In this review, I provide an overview of the typical diseases frequently encountered in a clinical setting,categorizing them as acute scrotum (both traumatic and non-traumatic), painless scrotal swelling, testicular cystic lesions, and testicular tumors.

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Although ultrasonic energy is relatively thin at the molecular level, it can cause irreversible change to biological tissue after it is accumulated as heat. Thermal treatment using high-intensity focused ultrasound (HIFU) is such an application. Biological tissue converts ultrasonic energy to heat due to its shear viscosity. Because its conversion ratio, i.e., absorption, is approximately proportional to the ultrasonic frequency, the frequency has to be chosen according to the propagation distance in tissue to the target tissue to be treated. By choosing a HIFU exposure duration within the time in which the heat conduction has not taken place significantly, e.g., within a few seconds for focused ultrasound at a few MHz with an f-number of 1, the spatial selectivity of focused ultrasound can be utilized for the treatment. To suppress overheating outside the target tissue, a long cooling time between each consecutive HIFU exposure, in the order of the time constant of blood perfusion ranging from 1 to several minutes, is necessary. This significantly lowers the throughput of HIFU treatment. These are explained in this paper based on the principles of ultrasound and heat transfer. The imaging methods for aiming HIFU and monitoring the treatment as well as research to enhance the treatment throughput are also explained. They are explained without relying too much on equations, which are only used as a supplement.

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Hysterectomy has been the traditional treatment for uterine leiomyoma; nowadays, however, many women opt for less invasive, uterus-preserving therapy. A new currently used technique, MR-guided focused ultrasound surgery (MRgFUS), is a less invasive procedure comprising real-time MR anatomic guidance, MR thermometry, and high-intensity focused ultrasound (HIFU). ExAbalte 2000 (InSightec, Israel) fully integrated with a 1.5T-MRI system (Signa, GE Healthcare, USA) was used in this study. Patients laid prone on the ExAblate table equipped with 208 beams from a phased-array transducer. The procedure, “scalpel-less surgery,” was carried out on an outpatient basis under conscious sedation, which required a short recovery time. About 75% of patients who underwent MRgFUS treatment in our hospital expressed satisfaction. Shrinkage of the leiomyoma and amelioration of symptoms were achieved 6 months after treatment, and pregnancies were achieved in several cases (despite current advice of contraindication). The system, ExAblate 2000, which was approved in 2009 in Japan for the treatment of uterine leiomyoma, entails very few and minor adverse events. Particular attention should be paid, however, to three major adverse events: skin burn, severe neuralgia, and intestine injury. The potential for improvements to MRgFUS includes shortening the duration of treatment, achieving a larger ablated volume, and placing the patient supine (a position requiring further studies on compression of vessels) on the ExAblate table. Another obstacle is extrusion of the bowel from the anterior of the uterus into the path of the ultrasound beam. In some cases, attempts at moving the bowel away from the ultrasound beam took 2 hours or even failed, resulting in the discontinuation of treatment. Our inquiries showed that 6 months after the treatment, about 2% of patients expressed regret at having undergone MRgFUS. Thus, patient selection before treatment with MRgFUS is important. It is expected after further study and worldwide trials that this technique may be applicable to those desiring fertility.

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High-intensity focused ultrasound (HIFU) is a noninvasive method that can cause complete coagulation necrosis without requiring the insertion of any instruments. The purpose of this study was to evaluate the safety and efficacy of HIFU treatment for small liver cancers without performing transcatheter arterial chemoembolization (TACE) or rib resection. HIFU ablation was performed without rib resection or the aid of TACE or percutaneous ethanol injection (PEI) in 25 patients with hepatocellular carcinoma. The HIFU system (Chongqing Haifu Tech, Chongqing, China) was used under ultrasound guidance. All 25 patients completed the treatment without experiencing any adverse events. Complete coagulation was achieved by applying the sonications from the intercostal space when the tumor was located in the right lobe. After treatment, serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) levels were significantly higher than the baseline values; these levels recovered within 1 week. An epidural anesthetic provided sufficient pain suppression during the procedure. None of the patients developed acute hepatic failure, liver abscess or renal dysfunction. In conclusion, HIFU is effective for the treatment of patients with small liver cancer.

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Cancer is not a so-called disease but is another living thing that can propagate itself in human beings. The life expectancy of breast cancer patients depends on the systemic metastasis, not on the existence of cancer in the breast. Accordingly, the aim of local treatment of breast cancer is to completely eradicate the viable cancer cells in the breast. The best approach for the patient is to find and treat the smaller invasive cancer. It can protect the life and the breast of the patient without physical damage and mental suffering. Moreover, it can reduce the mortality rate of breast cancer. The aim of MR-guided focused ultrasound surgery for breast cancer is to achieve treatment results similar to those for conventional breast-conserving surgery. The efficacy and safety of MR-guided focused ultrasound surgery for breast cancer have already been investigated in our excision study. We have been conducting an ongoing non-excision study with radiotherapy since 2005. The major inclusion criteria are no neoadjuvant drug therapy, target tumor less than 15 mm in diameter, well-demarcated mass on MRI, and no lymph node involvement. Sixty-seven evaluated cases of 80 enrolled ones have been followed up for 67 months (median). There has been no local recurrence, no distant recurrence, and no severe adverse events. Cosmetically, this series is superior to conventional breast-conserving surgery. Ultrasound will continue to contribute to detection and treatment of smaller invasive breast cancer.

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With the spread of prostate-specific antigen (PSA) screening and the increasing life expectancy, especially in developed countries, the number of patients with localized prostate cancer has increased dramatically. High-intensity focused ultrasound (HIFU) is an extracorporeal ablative technology. Over the past 15 years, more than 30,000 treatments of whole gland therapy and salvage therapy after recurrence with radiation therapy for localized prostate cancer using HIFU have been performed worldwide with encouraging oncological results and excellent postoperative functional outcomes. HIFU has the advantages of repeatability, applicability in patients after radiation therapy, radical prostatectomy possible after HIFU in patients with prostate cancer, can be used on outpatient basis, low rate of complications, easy to perform, and low cost. These advantages of HIFU are superior to radical prostatectomy or radiation therapy for localized prostate cancer. In addition, its minimal thermal damage to the tissue outside the focal region make HIFU an attractive therapeutic modality for focal therapy of the prostate that aims to cure the cancer whilst preserving continence and erectile function. However, further studies are needed to confirm the effectiveness of focal HIFU in patients with localized prostate cancer.

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Pancreatic cancer is associated with a poor prognosis, with unresectable pancreatic cancer accounting for about 60% of cases. Chemotherapy and chemo-radiotherapy have been the standard therapies for unresectable pancreatic cancer. However, the outcomes of these therapies have not been satisfactory. Therefore, new advances in therapy are expected. High-intensity focused ultrasound (HIFU) therapy is being promoted as a method to ablate the tumor and achieve relief of pain in unresectable pancreatic cancer. The focused tissue temperature reaches 80-100°C and coagulative necrosis within a few seconds. A clinical trial has been conducted to evaluate the safety and clinical application of HIFU therapy for unresectable cancer using the FEP-BY02 HIFU SYSTEM (Yuande Bio-Medical Engineering, Beijing, China) from December 2008. HIFU therapy may serve as a palliative therapy for unresectable pancreatic cancer.

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Bone metastasis from cancer causes various skeletal-related events and decreases the quality of life (QOL). Pain associated with bone metastasis, in particular, is among the most commonly encountered and serious symptoms. Even in the absence of pathological fractures or nerve paralysis, mental and physical pain can decrease the QOL. Even with the existing standard treatments for pain from bone metastasis, there are still some cancer patients in whom sufficient pain relief cannot be achieved. At the turn of this century, pain relief treatment with high-intensity focused ultrasound (HIFU) therapy was introduced for painful bone metastasis, and improvement of refractory cancer pain associated with bone metastasis has been shown soon after the treatment. For the ExAblate system used for this treatment, European CE mark approval was obtained in 2007, and Food and Drug Administration approval was obtained at the end of 2012. Since then, instances of clinical application of HIFU therapy has been seen worldwide for painful bone metastasis, benign bone tumors, non-cancerous chronic low back pain, and knee joint pain. In this report, we provide an explanation of cancer pain as a problem in cases of bone metastasis from cancer, the mechanism underlying its development, and the standard treatments, and describe the possibilities of magnetic resonance-guided HIFU therapy for painful bone metastases with reference to previous reports and therapeutic experience at our hospital.

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Purpose: Hepatic hemangiomas are often detected on abdominal ultrasonography. In many reports, these lesions have been asymptomatic and have shown no change in size; however, changes have occasionally been noted. We therefore examined changes in the size of hepatic hemangiomas during long-term observation. Subjects and Methods: A total of 16,244 subjects were examined by abdominal ultrasonography in our health management center in 2011. Of the 1,600 subjects (9.8%) with diagnosed or suspected hepatic hemangioma, 76 subjects (80 lesions) with long-term observation for ≥10 years were retrospectively enrolled. The mean observation period was 197 months (range, 120-303 months). Change in size was classified as follows: 1) significant increase, change ≥+50%; 2) slight increase, change ≥+25% to ⟨+50%; 3) no change, change ≥-25% to ⟨+25%; or 4) decrease, change ⟨-25%. Results and Discussion: Mean change in size was +39.8% (95% confidence interval, +28.5% to +51.1%; range: -42.6% to +200.0%). Changes in size were as follows: significant increase, 29 lesions (36.3%); slight increase, 16 lesions (20.0%); no change, 32 lesions (40.0%); and decrease, 3 lesions (3.8%). Mean change in size per 10 years was +24.9% (95%CI, +18.1% to +31.7%; range, -19.0% to +112.9%). The change in size per 10 years was as follows: significant increase, 13 lesions (16.3%); slight increase, 22 lesions (27.5%); no change, 45 lesions (56.3%); and decrease, 0 lesions (0%). Conclusion: Our results suggest that about half of hepatic hemangiomas show a tendency to increase slowly in size during long-term observation ≥10 years.

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Introduction: It has been shown that killing of suspended cells by low-intensity ultrasound (0.08-0.11 W/cm²) can be enhanced by a mild non-lethal hypotonic (146 mOsm) medium. Purpose: In this study we wished to determine whether hypotonia-induced cell swelling of suspension cells was directly related to enhancement of ultrasound-mediated cell killing, and to verify whether similar effects could be observed on circulating and attached cells. Methods: U937 cells under mild hypotonia were exposed to ultrasound for different times with real-time monitoring of cell size using a particle-size-distribution analyzer. To study the effect on attached cells, HeLa cells were exposed to ultrasound while under hypotonia in an in vivo-simulated set-up. Results: The result showed that the enhanced cell killing (up to more than twice) was directly proportional to hypotonia-induced cell swelling. Similar membrane damage based on PI staining could be observed on HeLa cell streated with hypotonia. An in vivo-simulated circulating system also showed similar findings for hypotonia enhanced ultrasound cell killing. Conclusion: These findings showed that mild hypotonia can be used to augment the effect of ultrasound in the treatment of cancers, particularly leukemia. The results showing that such enhancement is related to cell swelling could guide us toward proper timing of sonication while under hypotonic treatment.

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