Ultrasonic blood flow imaging such as color Doppler imaging or power Doppler imaging is a very useful function in diagnosis of abnormalities of vessels and organ function. Recently, advanced dynamic flow and superb microvascular imaging have made it possible to observe more fine and low-velocity blood flow in detail. In each of these modes, there are several switches for adjusting the conditions, but they are rarely used. In this paper, in order to make better adjustments and obtain correct information from the blood flow imaging mode, I will explain the meaning of those condition adjustments and the key points of the adjustment method. The names of modes and adjustment items refer to the ultrasound systems made by Canon Medical Systems Corporation.

Carpentier’s classification helps us understand the underlying mechanisms of mitral regurgitation (MR). MR due to leaflet deformation is called degenerative MR (DMR, or primary MR), most of which is mitral valve prolapse. It is divided into fibroelastic deficiency (FED), in which chordal rupture is the main factor, and Barlow disease, in which enlargement of the valve leaflet is the main factor. In many patients with MV prolapse, both mechanisms coexist. Because mitral valvuloplasty has been established as a reliable treatment for MV prolapse, evaluation by preoperative 3D transesophageal echocardiography is becoming increasingly important. MR without deformation in the valve leaflet itself is classified as functional MR (FMR, or secondary MR). This is caused by the valve leaflet being tethered towards the apex due to left ventricular (LV) dilation or LV dysfunction. The severity assessment by the proximal isovelocity surface area (PISA) method in FMR patients tends to be underestimated. The effect of annuloplasty alone is insufficient, and treatment with MitraClip may be effective. Atrial MR is usually defined as significant MR appearing in patients with normal LV volume and contractile function, and an enlarged left atrium. Conventionally, valve annuloplasty or valve replacement has been performed for symptomatic atrial MR. Recently, however, valve repair with posterior mitral leaflet (PML) augmentation using pericardial patch or treatment with MitraClip has been attempted. The heart team members need to understand these mechanisms of MR when making treatment plans.

When an intrahepatic nodule was visualized on abdominal ultrasonography, we used our two reporting systems. Although both were widely used in Japan, in recent years LI-RADS was proposed as an international reporting system. Of particular note is US LI-RADS, which is designed for abdominal ultrasound examinations. LI-RADS is used in the diagnostic algorithm of the 2018 Practice Guidance from the American Association for the Study of Liver Diseases, and US LI-RADS plays an important role in surveillance. Verification of the diagnostic capability of these systems will be important going forward.

Acute appendicitis is the most common disease requiring surgery in pediatric patients. It can be classified into two groups: primary appendicitis and secondary appendicitis. Primary appendicitis is usually due to obstruction by fecal pellets and sometimes requires emergency surgery. In contrast, secondary appendicitis is due to spreading enteritis and does not necessarily require surgery. To adhere to the ALARA concept, sonography is the first-line modality to evaluate acute appendicitis in children. The following sonographic findings are useful for evaluating the severity of acute appendicitis: maximum diameter, wall thickness, loss of mural stratification, hyperemia, and peri-appendiceal fluid. While visualization of the normal appendix appears to be more difficult with sonography than CT, we suggest that, unless clinical symptoms warrant immediate surgery, patients with a non-visualized appendix on initial examination should be managed with active clinical observation and repeated sonography, rather than urgent CT scan as these patients are at a significantly lower risk for both perforated and nonperforated appendicitis.

Purpose: The author devised an acoustic lens “narrow aperture method” in order to improve the elevational resolution in the extremely shallow region, and the effectiveness of the acoustic lens was physically verified in a previous study. In this study, visualization of the central slip and the lateral slips of the extensor tendon of the little finger was evaluated using the narrow aperture method of a linear probe with a single layer and high frequency, which is generally prevalent. Subjects and Methods: The extensor tendon of the little finger of 60 healthy volunteers was scanned by normal scanning and the narrow aperture method, and the visualization capabilities of the two scanning methods were compared. In addition, the effect of visualization of anatomical structures and the effect of age and sex on tendon visualization by the narrow aperture method were examined. Results and Discussion: The narrow aperture method was clinically useful because it had higher visual capability than normal scanning. The average thickness of the tendon was 0.50 mm for the median slip and 0.39 mm for the lateral thickness, which corresponded approximately to that of MRI images, although individual differences were observed. Furthermore, the average thickness of one layer in the fibrillar pattern was 0.16 mm for both central and lateral slips, which was considered to be the limit of the probe frequency and elevational resolution. There was no significant difference in tendon visualization by age and sex, but individual differences were observed in terms of the tendon course and subcutaneous tissue structure. Conclusion: The clinical usefulness of the narrow aperture method for visualization of the extensor tendon of the little finger was verified.

Purpose: Evaluation of the usefulness of shear wave elastography for respiratory diseases. Subjects: Thirteen patients including six primary lung cancers, two metastatic lung cancers, four pneumonias, and one atelectasis. Methods: The shear velocity of lung lesions depicted from the body surface by B-mode ultrasonography was measured by shear wave elastography. Results and Discussion: The shear velocity of lung tumors was 3.26∼7.25 m/s (average: 4.86±1.29 m/s). The shear velocity of pneumonia and atelectasis was 1.08∼2.29 m/s (average: 1.57±0.45 m/s). The shear velocity of lung tumors was apparently faster than that of pneumonia and atelectasis, and a significant difference was recognized. Conclusion: These findings suggest that shear wave elastography may be useful for the qualitative diagnosis of subpleural lung lesions from the body surface.

A 61-year-old man underwent resection for tongue cancer and dissection for cervical lymph node metastases. Two months after the surgery, he experienced local recurrence of tongue cancer, which had spread to cervical and mediastinal lymph nodes and multiple bones. Liver dysfunction, i.e., a high level of AST and ALT (CTCAE Grade 4), occurred 7 days after three courses of nivolumab, which had been administered owing to tumor progression that was noted despite first-line chemotherapy using docetaxel, cisplatin, and 5-FU. An abnormality of the blood flow was not observed by contrast-enhanced MRI. Oral prednisolone (PSL) (2 mg/kg/day) therapy was started immediately. Mycophenolate mofetil (1,000 mg/body) was added to the PSL therapy 8 days after detection of the liver dysfunction. In a contrast-enhanced ultrasound imaging study using Sonazoid, irregular high spots were observed in the whole hepatic parenchyma in the post-vascular phase. Drug-induced liver injury was pathologically diagnosed by an ultrasound-guided needle biopsy 10 days after onset of liver dysfunction. Immunohistochemically, the number of CD3- and CD68-positive cells had slightly increased throughout the whole liver parenchyma. The levels of transaminase decreased, but the level of total bilirubin increased gradually. In a contrast-enhanced ultrasound imaging study using Sonazoid, the same image was observed in the whole hepatic parenchyma in the post-vascular phase 42 days after occurrence of liver dysfunction. The patient died of cytomegalovirus pneumonia and tumor progression 66 days after emergence of liver dysfunction. This is the first case report of irregular high spots in the post-vascular phase detected by contrast-enhanced ultrasound using Sonazoid in a case of nivolumab-induced liver dysfunction.