紺野 啓

This report presents a case of malignant melanoma in a 40-year-old male who underwent resection of the tumor in his right ankle. Eleven months after the resection, a subcutaneous mass was observed on his right femur. Ultrasound examination revealed a hypoechoic tubular structure in the right thigh, with a small amount of blood flow in the lesion. Using ultrasound and fine-needle aspiration, the patient was diagnosed with metastasis and lymphovascular invasion of malignant melanoma. Treatment with an immune checkpoint inhibitor was originally scheduled, but the lesion disappeared spontaneously after the fine-needle aspiration.

PURPOSE: Fine-needle aspiration cytology (FNAC) under ultrasound guidance is clinically useful, but there is a risk of spreading infection by generating droplets of contaminated fluids during the procedure. Risk assessment to better control infection remains to be established. The aim of this study was to estimate infection risks during FNAC by visualization of droplet production and deposition using a simulation model. METHODS: The simulation comprised a puncture needle, a device for holding the needle, and a fluid specimen containing fluorescent particles as a model. Simulating each step of FNAC (removal of the inner and outer cylinder and transferring the specimen onto a glass slide), the generation and deposition of droplets were visualized using a laser. RESULTS: After removal of the inner cylinder, an aerosol of droplets in the air surrounding the needle was observed. After removal of the outer cylinder, several large droplets precipitating onto the circumjacent surface were observed. From the beginning of transferring the specimen, a large amount of sizeable droplets first moving away and then precipitating was observed, followed by the production of a cluster of fine droplets drifting and spreading through the air. CONCLUSIONS: Here, the generation of droplets at each step of FNAC, precipitation of large droplets onto the circumjacent surface, and drifting and spreading through the air of fine droplets was visualized. These results emphasize the need for precautions to prevent the transmission of infectious agents during FNAC.

PURPOSE: This study aimed to assess the feasibility and efficiency of self-learning with or without self-training (subjects performed scans on themselves) and telepresence instruction in focused cardiac ultrasound (FOCUS) education for medical students. METHODS: This study included 24 medical students. The participants initially completed a written pre-test and were randomized into a video lecture (participants watched a video lecture) or self-training (participants watched a video lecture and self-performed FOCUS) group. After finishing self-learning, they completed a written post-test. Then they undertook a skill pre-test and a first perception survey. Telepresence instruction was then provided. Finally, they undertook a skill post-test and a second perception survey. RESULTS: The written post-test total scores were significantly higher than the pre-test total scores (P < 0.001). In the skill pre-test, the scores for the video lecture and self-training groups were not significantly different (P = 0.542). The skill post-test total scores were significantly higher than the skill pre-test total scores (P = 0.008). Forty-two percent of the video lecture group participants agreed that the video lecture was effective preparation for the skill pre-test, while all participants in the same group agreed that the combination of the video lecture and telepresence instruction was effective preparation for the skill post-test. CONCLUSION: This study demonstrated the feasibility and efficiency of self-learning followed by telepresence instruction on FOCUS for medical students.

The concept of point-of-care ultrasound has been widely accepted owing to the development of portable ultrasound systems and growing body of evidence concerning its extensive utility. Thus, it is reasonable to suggest that training to use this modality be included in undergraduate medical education. Training in ultrasonography helps medical students learn basic subjects such as anatomy and physiology, improve their physical examination skills, and acquire diagnostic and procedural skills. Technological advances such as simulators, affordable handheld devices, and tele-ultrasound systems can facilitate undergraduate ultrasound education. Several reports have indicated that some medical schools have integrated ultrasound training into their undergraduate medical curricula. Jichi Medical University in Japan has been providing medical students with ultrasound education to fulfill part of its mission to provide medical care to rural areas. Vertical integration of ultrasound education into a curriculum seems reasonable to ensure skill retention and improvement. However, several issues have hampered the integration of ultrasound into medical education, including a lack of trained faculty, the need to recruit human models, requisition of ultrasound machines for training, and limited curricular space; proposed solutions include peer teaching, students as trained simulated patients, the development of more affordable handheld devices, and a flipped classroom approach with access to an e-learning platform, respectively. A curriculum should be developed through multidisciplinary and bottom-up student-initiated approaches. Formulating national and international consensuses concerning the milestones and curricula can promote the incorporation of ultrasound training into undergraduate medical education at the national level.

Kawasaki Disease (KD) is a febrile disorder seen in infants and young children. One of the most serious complications of the disease is coronary aneurysm. Endothelial dysfunction is considered to underlie the etiopathology of coronary aneurysm. Flow-mediated dilation (FMD), as assessed ultrasonically, is used to observe the endothelial function. The current paper summarizes, by providing a systematic review, the clinical studies that have examined endothelial dysfunction by determining the FMD ultrasonically in patients with KD. A PubMed-based search found eight articles published until 2013. Six studies reported the FMD level to be significantly lower in the patients with KD compared to controls, while two studies reported no significant difference in the FMD level between those with and without KD. Although patients with KD appeared to have endothelial dysfunction in the current summary, most reports have been associated with limitations, such as a small size and no prospective design for vascular outcomes. Further studies are therefore needed to draw definite conclusions regarding whether patients with KD suffer from endothelial dysfunction as determined by the FMD and/or whether this determination can be useful for understanding and managing vascular complications in these patients.

The clinical significance of the diameter of the common carotid artery (CCA) measured ultrasonographically in diabetic practice has not been sufficiently established. The objective of this study was to investigate the relationship of the ultrasonic CCA diameter with atherosclerotic measures and diabetic retinopathy as a microvascular complication in patients with type 2 diabetes mellitus (T2DM). This hospital-based cross-sectional study included 102 patients with T2DM (men: 65%, mean age: 57 years) who had no apparent carotid arterial stenosis and no history of cardiovascular or severe renal disease. The current smoking status, body mass index, blood pressure, hemoglobin A1c, serum low-density lipoprotein cholesterol, and ultrasonic measures of carotid arteries (CCA diameter, intima-media thickness (IMT), plaque score) were measured. The cardio-ankle vascular index (CAVI) and the presence of diabetic retinopathy were also assessed. The CCA diameter showed a significant positive correlation with the mean IMT or plaque score. The CAVI had a significant positive correlation with the mean IMT, plaque score, and CCA diameter, while diabetic retinopathy had a significant positive correlation with the CCA diameter, but not the mean IMT or plaque score. These results were unaltered after adjusting for multiple confounders. The CCA diameter may serve as a useful marker for atherosclerosis and diabetic retinopathy, and in particular, may be a marker associated with diabetic retinopathy more clearly than the carotid IMT and plaque score, in patients with T2DM.

Sister Mary Joseph's nodule (SMJN), which is known as a malignant tumor metastasized to the umbilicus, is a rare condition. We report ultrasonic findings of SMJN secondary to ovarian cancer in a 66-year-old woman. The umbilical tumor was observed as a hypoechoic mass with punctate hyperechoic foci. A pathological specimen obtained by needle biopsy confirmed adenocarcinoma with psammoma bodies. A comparison of the ultrasonographic findings with the pathological findings of the resected specimen suggested that the hyperechoic foci corresponded to psammoma bodies. When hyperechoic foci are observed inside SMJN by ultrasonography, adenocarcinoma from ovarian cancer should be included in the differential diagnosis.

To foster work-ready general physicians, Jichi Medical University has developed various clinical teaching practices since its foundation. The educational courses for clinical laboratory medicine, being one of them, adopt practical trainings in ultrasonography, which is essential in practical medicine today. The aims and the specifics of the trainings adopted in the seminar of ultrasound and the required or the optional subjects of Bedside Learning (BSL) at Jichi Medical University are reported.

The aim of this study was to clarify the degree of degradation of ultrasonic probes that results from their disinfection with alcohol. No defect in the ultrasound beams was found in any of the probes, but a significant decrease of the brightness was found after a certain period of use of the linear-type probe. Disinfection with alcohol may degrade ultrasound probes despite its high degree of effectiveness in preventing iatrogenic bacterial transmission.

We examined the relationship between the coefficient of variation in the R-R intervals (CVR-R) using electrocardiograms and the ultrasonic intima-media thickness (IMT) of the carotid artery, an atherosclerotic parameter, in type 2 diabetes mellitus (DM) patients with diabetic neuropathy (n=47, males/females: 29/18; mean age: 62 years). In this study, the CVR-R-related indexes, including CVR-R at rest (CVR-R(rest)), CVR-R with deep breaths (CVR-R(breath)) and their difference (CVR-R(breath) minus CVR-R(rest): CVR-R(dif)), were defined. Data such as body mass index, smoking habits, hemoglobin A1c, blood pressure, and serum low-density lipoprotein were collected. A significant inverse correlation was observed between max-IMT and CVR-R(dif) (beta=-0.34, p=0.042), but not CVR-R(rest) or CVR-R(breath), in multivariate analyses adjusted for all the data. Therefore, the CVR-R(dif) may serve as a clinical index for the diabetic autonomic neuropathy-atherosclerosis relation in type 2 DM patients.

PURPOSE: To determine suitable methods for evaluating bacterial contamination of ultrasound probes. METHODS: We compared probe imprinting, swab streaking, and swab suspension methods for evaluating bacterial contamination of ultrasound probes. RESULTS: Experimental and clinical investigations showed that the sensitivity for detecting bacterial contamination of ultrasound probes was higher with probe imprinting than with swab methods. Probe imprinting was very simple and required only agar plates. CONCLUSION: Probe imprinting was the most suitable method for evaluating bacterial contamination of ultrasound probes.