Kiyoka Omoto

Sonographic detection of diffuse peripheral nerve hypertrophy in Chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy is an autoimmune disease characterized by recurrent demyelination and remyelination with resultant thickening of the peripheral nerves. We report a case in which sonography was instrumental in demonstrating diffuse peripheral nerve hypertrophy. On sonography, both brachial plexuses were found to be diffusely hypertrophic and hypoechoic. Similar findings were noted for the median, sciatic, and femoral nerves. The brachial plexus findings were confirmed by MRI.

SENTINEL NODE DETECTION METHOD USING CONTRAST-ENHANCED ULTRASONOGRAPHY WITH SONAZOID IN BREAST CANCER: PRELIMINARY CLINICAL STUDY

This study aimed to evaluate the usefulness of sentinel lymph node (SLN) detection in breast cancer using contrast-enhanced ultrasonography (CEUS) with subareolar Sonazoid injection. The subjects were 20 breast cancer patients. General anesthesia was induced and 2 mL of Sonazoid was injected subareolarly. After massage of the injection site, the axillary area was observed transdermally using coded phase inversion harmonic ultrasonography with mechanical indices of 0.15 to 0.19. When contrast-enhanced lymph nodes (LNs) were seen, they were defined as CE-SLN. Two other SLN detection methods, the gamma-probe-guided and dye-guided methods, were performed together. We evaluated the SLNs detected by each method to determine if they corresponded with each other and calculated the SLN detection rate. After the SLNs were resected, pathologic examinations were done. The SLN detection rate of the CEUS-guided method, the dye-guided method and the gamma-probe-guided method were 70%, 75% and 100%, respectively. There was no statistically significant difference in these rates between the CEUS-guided and dye-guided methods (p = 0.99) but the CEUS-guided method showed a significantly lower rate than the gamma-probe-guided method (p = 0.020), and dye-guided method also showed a significantly lower rate than the gamma-probe-guided method (p = 0.047). The number of CE-SLNs was 1 or 2 (average 1.1) and each took 2 to 20 (average 5.3) min to detect. The CE-SLNs corresponded grossly with SLNs detected by the gamma-probe-guided and dye-guided methods. The pathologic results indicated no metastasis from the resected SLNs in 15 of 20 cases. However, the CEUS-guided method detected 12 cases of these 15 and CE-SLNs were detected in two of the remaining five metastasis cases. In summary, in breast cancer patients, after subareolar injection of Sonazoid, contrast-enhanced LNs were observed in real time with ultrasonography. In an initial clinical study of 20 cases, the detection rate of the CEUS-guided method was less than that of the gamma-probe-guided method. It is suggested that the CEUS-guided method using Sonazoid may, with some improvements, be a useful new modality for sentinel node identification.

Efficacy of Sonazoid (Perflubutane) for Contrast-Enhanced Ultrasound in the Differentiation of Focal Breast Lesions: Phase 3 Multicenter Clinical Trial

OBJECTIVE The objective of our study was to compare the efficacy of contrast-enhanced ultrasound (CEUS) using the ultrasound contrast agent Sonazoid (perflubutane) with unenhanced ultrasound and supplementary contrast-enhanced MRI in the differential diagnosis (benign vs malignant) of focal breast lesions. The safety of Sonazoid was also assessed in this study. SUBJECTS AND METHODS A total of 127 patients with focal breast lesions were enrolled in this study at five centers in Japan. Three reviewers who were blinded to the patient characteristics independently assessed the ultrasound images and MR images in a randomized sequence. The accuracy, sensitivity, and specificity of CEUS, unenhanced ultrasound, and supplementary contrast-enhanced MRI for the differential diagnosis were compared using generalized estimating equation analyses. Diagnostic confidence was also assessed. RESULTS The accuracy of CEUS was significantly higher than that of unenhanced ultrasound (87.2% vs 65.5%, respectively; p < 0.001). In addition, CEUS showed significantly higher specificity, although the improvement in sensitivity was not statistically significant. The accuracy and specificity were significantly higher with CEUS than with contrast-enhanced MRI, but the improvement in sensitivity was not statistically significant. The area under the curve in a receiver operating characteristic analysis was significantly greater with CEUS than with unenhanced ultrasound. The incidence of adverse events was 11.4% and the incidence of adverse drug reactions was 3.3%. All adverse drug reactions were mild. CONCLUSION CEUS using Sonazoid was confirmed to be superior to unenhanced ultrasound for the differential diagnosis (benign vs malignant) of focal breast lesions in terms of diagnostic accuracy with no serious adverse reactions.

Studies on tissue characterization by texture analysis with co-occurrence matrix method using ultrasonography and CT imaging.

We used texture analysis with the co-occurrence matrix method to analyze ultrasonograms from normal and diseased livers, and X-ray CT images obtained from normal cases and cases of idiopathic interstitial pneumonia. Ten cases of normal, fatty, and cirrhotic livers; 10 cases of normal lungs; and 10 cases of idiopathic interstitial pneumonia, all confirmed by clinical findings, laboratory data, surgery, or biopsy, were the subjects of this study. We compared the results of texture analysis in normal and diseased livers under the same conditions of gain, focus, magnification rate, probe frequency, and depth of the region of interest. Here we discuss the relationship between Fisher ratio of texture analysis and pathological character. Although the normal and diseased liver groups did not differ significantly, the different pathological grades of fibrosis and the different size of nodules in the cirrhotic and normal liver groups did have different Fisher ratios. We compared the results of texture analysis with images obtained from normal cases and cases of idiopathic interstitial pneumonia. Significant differences between normal lungs and those with idiopathic interstitial pneumonia were also found. We thus think that texture analysis can be used to analyze ultrasonograms obtained from lesions of different pathological grades and to classify CT images as well.

Endothelial cell injury and platelet aggregation induced by contrast ultrasonography in the rat hepatic sinusoid

Objective. To determine whether contrast ultrasonography can affect the sinusoidal cells and platelets of the liver by using ultrastructural analysis in vivo. Methods. Fifteen Wistar rats were placed into the following 5 groups of 3 rats each: 3 control groups comprising a sham operation group, a contrast agent injection‐alone group, and an ultrasound exposure‐alone group; and 2 contrast agent injection with ultrasound exposure groups, split according to excision time. After a dose of an echo contrast agent (100 mg/kg of body weight) was administered through the femoral vein, the rats that received injections were subjected to ultrasound for the first minute, no ultrasound for the next 4 minutes, and then ultrasound sweep scanning for 10 seconds. The rats were perfused via the heart with cold physiologic saline containing 2% paraformaldehyde and 2.5% glutaraldehyde solution buffered with 0.1‐mol/L phosphate. The livers of the rats in 4 of the groups were excised immediately. The livers of the rats in 1 of the 2 contrast agent with ultrasound exposure groups were excised by the same procedure 5 hours after they received the injections. All specimens were studied with light and electron microscopy. Results. Platelet aggregation and injury to endothelial cells were more severe in the contrast agent injection and ultrasound exposure groups than in the other groups. Conclusions. Contrast ultrasonography can cause platelet aggregation and endothelial cell damage in the rat hepatic sinusoid.

New method of sentinel node identification with ultrasonography using albumin as contrast agent: a study in pigs

The purpose of our study was to verify in animals the possibility of using albumin-enhanced ultrasonography as a modality for sentinel node detection. The nine pigs were injected subcutaneously in the neck with albumin, five with 5% solution and four with 25% solution, and then the regional lymph nodes were observed over time. It was found that, where the 5% solution had been injected, the lymph nodes showed no change, but where the 25% solution had been used, a high echo 1 to 5 mm in size was seen at the hilus of the nearest lymph node. Examination of the excised pathologic specimens of lymph nodes demonstrated that this echo was due to albumin accumulated in the efferent lymphatics. This finding suggested that this technique of ultrasonography using albumin as a contrast agent was an effective new method of identifying sentinel nodes.

In Vitro Platelet Activation by an Echo Contrast Agent

Objective. We investigated whether an ultrasonic echo contrast agent containing microbubbles (Levovist [SH U 508A]; Schering AG, Berlin, Germany) could in routine use activate platelets. Methods. Levovist and its main component, galactose, were mixed with separate samples of whole blood (1.5–75 mg/mL) from 5 healthy volunteers to form a 1‐mL suspension sample. After in vitro exposure to ultrasound emitted from a commercial ultrasonic scanner at a pulse frequency of 3.5 MHz with a mechanical index of 1.9 and an exposure duration of 5 minutes, 5 μL of the sample was incubated for 20 minutes with the fluorescein isothiocyanate‐labeled CD61 antibody, which is a platelet‐specific antigen, and the phycoerythrin‐labeled CD62P (P‐selectin) antibody, an activation‐specific antigen, both on the platelet surface. After more than 30 minutes of fixing in 1% paraformaldehyde, flow cytometric analysis was performed. Results. The percentage of CD62P‐expressing platelets increased according to the concentrations of Levovist and galactose, which showed almost equal effects. Ultrasound exposure did not enhance the effect except at the highest concentration of Levovist (75 mg/mL). Conclusions. In vitro, a galactose‐based echo contrast agent could not activate the platelets at its routine concentration.

Clinical application of a new method that segments the region of interest into multiple layers for RF amplitude histogram analysis in the cirrhotic liver

PurposeWe used texture analysis in conjunction with an alternative method of analyzing the amplitude histogram using a radiofrequency (RF) signal to differentiate ultrasonograms of normal and cirrhotic livers. This method segments the region of interest (ROI) into multiple layers (sub-ROIs). In each sub-ROI of a homogeneous medium, the histogram of enveloped-amplitude of RF backscattered echoes resembles a Rayleigh distribution. Theoretically, the values of the signal-to-noise ratio (SNR), skewness, and kurtosis for Rayleigh statistics are constant and independent of the mean scattering intensity, which is contributed by such undesirable effects as tissue attenuation, beam diffraction, and incident waveforms. These values, which averaged overall sub-ROI, should provide an unbiased estimator.MethodsWe studied 36 normal livers and 28 cirrhotic livers, all confirmed by clinical findings including laboratory and pathology data; the SNR, skewness, and kurtosis values of the disease groups were compared. At the same time, these values were estimated using the conventional method, which did not segment the ROI into multiple sub-ROIs. The unpaired t-test was used to determine statistical significance.ResultsWith the new method, all values obtained from cirrhotic livers differed significantly from those obtained from normal livers, and the standard deviation of these values was smaller than those obtained using the conventional method.ConclusionsThese results suggest that the new method can be used to diagnose the cirrhotic liver objectively.

The Effects of Levovist and DD-723 in Activating Platelets and Damaging Hepatic Cells of Rats

The purpose of this study was to compare platelet activation and hepatic cell damage produced by 2 ultrasonographic contrast agents with flow cytometric and ultrastructural analysis.

Coexistence of Papillary Thyroid Cancer and Hashimoto Thyroiditis in Children Report of 3 Cases

This report documents 3 pediatric papillary thyroid carcinoma cases with associated Hashimoto thyroiditis. In all 3 cases, hypoechoic nodules accompanied by multiple echogenic spots were noted on sonography of the thyroid. Hashimoto thyroiditis was suspected on the basis of positive thyroid autoantibody test results and pathologic examinations of thyroidectomy specimens, which revealed chronic thyroiditis with lymphocytic infiltration as the background of papillary thyroid carcinoma development. The potential for papillary carcinoma development warrants close follow‐up, and meticulous sonographic examinations must be performed in children with Hashimoto thyroiditis.