Yasutomo Fujii

A New Method for Attenuation Coefficient Measurement in the Liver Comparison With the Spectral Shift Central Frequency Method

Objective. To assess the feasibility of a new method of measuring the attenuation coefficient in the liver, which offers less variability of results than the conventional method. Methods. The attenuation coefficient was evaluated on the basis of the following equation with sound field correction:

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.

Ultrasonography improves diagnostic accuracy of acute appendicitis and provides cost savings to hospitals in Japan.

A cost analysis based on changes in patient care was used to evaluate the utility of abdominal ultrasonography in both the clinical management of patients clinically suspected of having acute appendicitis and in reducing expenditure of hospital resources. Among the 200 patients suspected of having acute appendicitis, 57 actually had acute appendicitis. Interpretation of appendiceal ultrasonographic results was 98.5% accurate. The ultrasonographic result led to changes in the treatment of 103 patients. Moreover, ultrasonography led to the prevention of unnecessary appendectomy in 25 patients, providing a savings to the hospital of about Yen 8,013,450 (

Gastric Schwannoma Sonographic Findings

65,150), and prevented unnecessary hospital admission for 78 patient‐days, thus saving the hospital approximately Yen 1,199,250 (

Degradation of ultrasound probes caused by disinfection with alcohol.

9750). The cost of performing the 200 ultrasonographic examinations was about Yen 1,096,176 (

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

8912), and thus the overall savings to the hospital was approximately Yen 40,590 (

An unusual case of a glomus tumor developing in a subcutaneous vein of the wrist

330) per patient. Ultrasonography performed in patients with suspected acute appendicitis improves patient diagnostic accuracy, thus leading to more appropriate selection of patient treatment and reduced hospital expenditure.

Attenuation coefficient measurement in the thyroid

Schwannomas, known as neurinomas and neurilemmomas, are benign, slow-growing neoplasms originating in any nerve that has a Schwann cell sheath. They rarely occur in the digestive tract, but when they do, the most common site is the stomach, 1 , 2 and they represent 0.2% of all gastric tumors. 1 Among 150 gastric submucosal tumors (G-SMTs), only 6 gastric schwannomas (4%) have been found. 3 Because gastric schwannomas are usually covered by intact mucosa and principally involve the submucosa and muscularis propria, 1 - 3 they are categorized as G-SMTs. Although conventional procedures, such as a barium meal and an endoscopic study, are important in the initial evaluation of a G-SMT, they cannot provide enough information in the differential diagnosis of a G-SMT. Cross-sectional imaging findings, such as magnetic resonance imaging4 and transabdominal sonography, may be useful in the detection and characterization of a G-SMT and its relationship with surrounding organs. We describe here the sonographic findings of gastric schwannoma in a 65-year-old patient. To our knowledge, no previous case reported included sonographic documentation.

Comparison of methods for evaluating bacterial contamination of ultrasound probes

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.

New method of sentinel node detection using a combination of contrast-enhanced ultrasound and dye guidance: an animal study

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.