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Diabetes research and clinical practice 05/2013; · 2.16 Impact Factor
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ABSTRACT: We attempt to determine the possibility of classifying normal and cirrhotic livers by their internal echo texture alone, without
using such basic ultrasonographic information as shape and surface character of the liver. We also assessed intraobserver
reproducibility and interobserver agreement obtained using this classification to ascertain the diagnostic usefulness of the
method. In this evaluation, we used both regional magnified B-mode images and binary black-and-white images, both derived
from conventional B-mode images obtained from 10 patients with normal livers and 10 with cirrhotic livers. These 20 echograms
were randomly divided into two groups and evaluated independently on two occasions by 12 observers who used the unaided eye
and took only internal echo texture into consideration. Accuracy in distinguishing between normal and cirrhotic livers ranged
from 41.7 percent to 100 percent. The intraobserver correlation coefficient r1 between evaluations of the regional magnified
B-mode images was 0.63, while that for the binary black-and-white images was 0.80. Agreement between the decisions of the
12 observers in the first and second evaluations of the binary black-and-white images showedk values between 0 and 1.0 for binary black-and-white images and between −0.32 and 0.29 for regional magnified B-mode images.
Subjective evaluation of normal and cirrhotic livers based on internal echo texture alone was possible: intraobserver correlation
was good; and unexpectedly, agreement with black-and-white images was greater than that with the regional magnified B-mode
images.
Journal of Medical Ultrasonics 04/2012; 30(1):21-29. · 0.33 Impact Factor
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ABSTRACT: PurposeTo determine whether a combination of contrast-enhanced ultrasound-guided methods and dye-guided methods can identify sentinel
lymph nodes in animals.
MethodsSeven pigs were put under general anesthesia and injected subcutaneously in the neck: three with 2 ml saline and four with
2 ml fluid comprising 0.4 ml 5% patent blue violet solution and 1.6 ml of hydroxyethylated starch (Salinhes) solution (PB
+ HS). The regional lymph nodes were observed by ultrasound; blue-stained regional lymph nodes found after the skin was cut
were situated as ultrasound had shown they would be.
ResultsThe regional lymph nodes of the pigs given saline were unchanged, but in the pigs receiving PB + HS, the echo level in the
lymph nodes nearest the injection site was altered, producing a clear contrast with the surrounding tissues. The area of the
relevant regional lymph node in each PB + HS-injected pig increased significantly (t-test, P < 0.01; from 25.7, 39.6, 9.36, 70.2 mm2, and mean, 36.2 mm2; to 50.7, 65.5, 21.1, 98.3 mm2, and mean, 58.9 mm2, respectively). These enlarged regional lymph nodes were easily found by contrast-enhanced ultrasonography. When excised
under ultrasound guidance, all were stained blue, indicating that they were sentinel lymph nodes.
ConclusionThese results suggest that this combination of contrast-enhanced ultrasound-guided and dye-guided methods warrants use as
a quick, simple procedure for detecting sentinel lymph nodes.
Journal of Medical Ultrasonics 04/2012; 33(3):153-158. · 0.33 Impact Factor
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ABSTRACT: A 7-year-old female infant presented with an asymptomatic soft tissue mass in the right neck. The tumor was considered to
be a benign one because it had a smooth margin and no change in its size was observed. Ultrasonography showed a 4.5-cm-diameter
solid tumor with a smooth, well-defined border. Inside the tumor, flow signals were observed on color Doppler and there were
numerous echogenic spots. Magnetic resonance imaging (MRI) examination showed findings consistent with an ectopic thymus,
i.e., T1- and T2-weighted images showed thymus-like signals. The course of the case is being continuously followed.
Journal of Medical Ultrasonics 04/2012; 36(3):145-148. · 0.33 Impact Factor
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ABSTRACT: 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.
Journal of Medical Ultrasonics 04/2012; 29(4):211-223. · 0.33 Impact Factor
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ABSTRACT: 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.
Rinsho byori. The Japanese journal of clinical pathology 08/2011; 59(8):776-80.
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Kiyoka Omoto,
Hiroaki Matsunaga,
Natsuki Take,
Yasuo Hozumi,
Megumi Takehara,
Yawara Omoto,
Mikio Shiozawa,
Hirobumi Mizunuma,
Hiroki Harashima,
Nobuyuki Taniguchi,
Mikihiko Kawano
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ABSTRACT: 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.
Ultrasound in medicine & biology 07/2009; 35(8):1249-56. · 2.02 Impact Factor
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ABSTRACT: In the neurosurgical field, the evoked potential is employed for the monitoring of intraoperative nerve function. During evoked potential monitoring, surgical manipulation-related nerve dysfunction is detected, and functional localization/nerves in the cerebral cortex are identified to prevent postoperative neurological complications. It is important to reduce the contact resistance to 2 kOmega or less on the application of plate electrodes used for recording and prevent noise by bundling electrode leads, to ensure a stable evoked potential during surgery. In our laboratory, intraoperative monitoring, such as ABR to prevent auditory disturbance, SEP to detect cerebral ischemia, cortical SEP and MEP to prevent motor paralysis, and evoked electromyography to identify/maintain the cranial nerves including the facial, trigeminal, oculomotor, and abducens nerves, is performed based on requests from the Department of Neurosurgery.
Rinsho byori. The Japanese journal of clinical pathology 06/2008; 56(6):475-85.
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ABSTRACT: To determine the clinical usefulness of a sentinel lymph node (SLN) identification technique using contrast-enhanced sonography (CEUS) with 25% albumin.
The subjects were 23 women with breast cancer. Each was injected subcutaneously with 5 ml of 25% albumin solution as a negative contrast agent directly superficial to the breast tumor. The area was massaged, and the inferior axillary hairline was examined continuously using gray-scale sonography with a 7.5- or 10-MHz transducer. Any contrast-enhanced lymph node was considered a CEUS-detected SLN, was differentiated from other level I and II nodes, and was resected and pathologically assessed.
In all 23 patients, 1 or 2 CEUS-detected SLNs (mean, 1.3 SLNs) were identified. Their sizes ranged from 5 mm to 25 mm (mean, 11.3 mm), and their depths (from the skin surface) ranged from 5mm to 20 mm (mean, 12.6 mm). Pathologic examination revealed a metastasis in 5 of the 23 patients, all in CEUS-detected SLNs.
In a clinical study using CEUS with 25% albumin, contrast-enhanced nodes were identified in all subjects. The pathologic findings suggested that any metastatic nodes observed were SLNs, indicating that this technique may represent a new modality for SLN identification.
Journal of Clinical Ultrasound 10/2006; 34(7):317-26. · 0.81 Impact Factor
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ABSTRACT: 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.
Suspension samples were made by mixing Levovist (SH U508A; Schering AG, Berlin, Germany) or DD-723 (Nycomed; Amersham Health, Princeton, NJ) with whole blood. The final concentrations of Levovist in citrated whole blood were 0, 15, and 75 mg/mL, and those of DD-723 were 0, 5, and 50 microL/mL. After exposure to ultrasound in vitro, flow cytometric analysis was performed to determine the concentration of the CD62P activation-specific antigen. To compare the hepatic cell damage associated with these 2 agents, we divided 15 rats into 5 groups as follows: group 1, sham operation; group 2, Levovist injection only; group 3, DD-723 injection only; group 4, Levovist injection (contrast agent) and ultrasound exposure; and group 5, DD-723 injection and ultrasound exposure. The ultrasonographic contrast agents Levovist and DD-723 were administered through the femoral vein and sonicated continuously for the first minute; this was followed by sweeping for 5 minutes 10 seconds after the contrast agent was injected. The rats were perfused via the heart with a fixative solution immediately after the sweeping, and then the liver was excised; the specimens were studied with electron and light microscopy.
The percentage of CD62P-expressing platelets increased in both contrast agent-ultrasound exposure groups, and the percentage of CD62P-expressing platelets was greater in the Levovist group. We observed vacuolation and round deposits in the hepatocytes in both contrast agent-ultrasound exposure groups. Microbubbles were observed in the rat Kupffer cells, and a few hepatocytes were seen unexpectedly in the DD-723 group but were found in neither the Kupffer cells nor the hepatocytes in the Levovist group.
Both contrast agents, Levovist and DD-723, produced platelet activation and structural change in the rat hepatic cells, but only the microbubbles of DD-723 were taken up by the Kupffer cells and a few hepatocytes.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 08/2005; 24(7):967-74. · 1.25 Impact Factor
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ABSTRACT: We describe the sonographic findings in a case of Lennert's lymphoma, a rare type of peripheral T-cell lymphoma, involving the subcutaneous tissues of the arm. The sonographic appearance was thought to be more helpful than MRI to establish the diagnosis.
Journal of Clinical Ultrasound 10/2004; 32(7):361-4. · 0.81 Impact Factor
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ABSTRACT: The aim of this study was to estimate the severity of fibrosis without a biopsy.MethodsThe signal-to-noise ratio (SNR), skewness, and kurtosis were measured using a 10-MHz transducer with the texture analysis in conjunction with an alternative method for evaluating fibrous rat 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 radiofrequency (RF) backscattered echoes resembles a Rayleigh distribution. In theory, SNR, skewness, and kurtosis for Rayleigh statistics are constant and independent of the mean scattering intensity, which is enhanced by such undesirable effects as tissue attenuation, beam diffraction, and incident waveforms. Thus, these values, which are averages of the corresponding sub-ROI values, constitute an unbiased estimator. All fibrous liver specimens were induced using the dimethylnitrosamine method. Fiber content was estimated quantitatively as the fibrosis index by computer processing of pathological images obtained by light microscopy.ResultsThe SNR, skewness and kurtosis, expressed as averages of corresponding values from each sub-ROI, correlated closely with the fibrosis index.ConclusionThese results make it possible to predict the severity of liver fibrosis from data obtained without resorting to biopsy. The data, obtained from our earlier study on rats, may be used to evaluate human hepatitis quantitatively by measuring these three values. The method may make it possible to estimate the degree of severity of chronic liver disease noninvasively.
Journal of Medical Ultrasonics 02/2004; 31(1):13-20. · 0.33 Impact Factor
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ABSTRACT: To determine whether contrast ultrasonography can affect the sinusoidal cells and platelets of the liver by using ultrastructural analysis in vivo.
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.
Platelet aggregation and injury to endothelial cells were more severe in the contrast agent injection and ultrasound exposure groups than in the other groups.
Contrast ultrasonography can cause platelet aggregation and endothelial cell damage in the rat hepatic sinusoid.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 02/2004; 23(1):29-36. · 1.25 Impact Factor
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ABSTRACT: We 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.
Journal of Medical Ultrasonics 01/2004; 31(2):91-98. · 0.33 Impact Factor
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ABSTRACT: Bodymarkers are used to label the location and orientation of the transducer during ultrasound examination. We attempt to
evaluate the usefulness of a new system that indicates transducer location over that of the conventional bodymarker. The proposed
system uses an electromagnetic tracking device to track the three-dimensional (3-D) position and orientation of a small electromagnetic
receiver attached to the ultrasound transducer relative to a transmitter placed under the bed. The new bodymarker is displayed
as a 3-D graphic model. The physique of the examinee is calibrated by representing five locations on the body on the original
bodymarker. To evaluate the accuracy of the system visually, we compared the transducer position indicated in the new bodymarker
and the actual transducer position in four abdominal sections. Actual and displayed position and orientation closely agreed
in all cases, and the transducer position indicator in the bodymarker display moved smoothly. Automatic transducer locator
on the virtual 3-D bodymarker accurately indicated its position and orientation. This system is useful and convenient in clinical
examinations.
Journal of Medical Ultrasonics 11/2003; 30(4):211-216. · 0.33 Impact Factor
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ABSTRACT: To assess the feasibility of a novel method of measuring the attenuation coefficient in the thyroid, which offers less variability of results than the conventional method.
In our new method, the attenuation coefficient was evaluated on the basis of the following equation with sound field correction: alpha = -1/4[Fc(z)-epsilon(z)] x d/dz[log(M0(z))-tau(z)]. In our system, the attenuation coefficient was also evaluated by the spectral shift central frequency method at the same time. In this study, we used 32 cases of normal thyroid, 26 cases of Graves disease, and 11 cases of Hashimoto thyroiditis in the system.
With this novel method, attenuation coefficient values of the thyroid (mean +/- SD) were 1.50 +/- 0.26 dB x cm(-1) x MHz(-1) in the normal group, 0.91 +/- 0.23 dB x cm(-1) x MHz(-1) in the Graves disease group, and 1.10 +/- 0.27 dB x cm(-1) x MHz(-1) in the Hashimoto thyroiditis group. The novel method recorded a statistically significant difference between normal and diseased thyroids (P < .0001) and between Graves disease and Hashimoto thyroiditis groups (P = .0035). Statistical variation of the attenuation coefficient values obtained using the novel method was much smaller than that of those obtained by the spectral shift central frequency method in every group.
This new method is considered usable for evaluating the attenuation coefficient of the thyroid in vivo.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 10/2003; 22(10):1067-73. · 1.25 Impact Factor
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ABSTRACT: We ultrasonographically measured renal length in the major axis in children. Here we discuss the differences in measured lengths
in the supine and prone positions. In study 1, which included 214 children, more than 60 percent of the kidneys measured longer
in the supine than in the prone position. The difference (S-P: length in the supine position minus length in the prone position)
was substantially greater in the left kidney. In study 2, we observed the relation between the kidney and the liver or spleen
in 60 children prospectively to determine if artifacts had contributed to the observed differences. When the location of the
liver or spleen was above the ki dney, which may induce velocity displacement and renal duplication artifacts, the kidney
tended to measure longer. We conclude that kidneys tend to measure longer in the supine than in the prone position. Difference
in renal length in different positions was greater in the left kidney than in the right kidney. Sonographic artifacts are
presumed to contribute to differences in measured length.
Journal of Medical Ultrasonics 08/2003; 30(3):187-192. · 0.33 Impact Factor
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ABSTRACT: We applied quantitative parameters in three-dimensional ultrasonic images to distinguish benign from malignant breast tumors
in 29 benign cases including 8 cysts and 21 fibroadenomas, and 32 malignant cases including 23 ductal carcinomas, 2 special
types of carcinoma, 1 malignant lymphoma and 6 others. This procedure involved simultaneously acquiring video data from real-time
ultrasonic images and recording the original position and orientation of the probe. Both sets of data were fed directly into
a desktop computer. Fuzzy reasoning and relaxation techniques were use to automatedly extract the shape of the tumor and render
it in three dimensions. We then evaluated three parameters: 2D-D/W, the so-called depth-width ratio measured in B-mode images:
3D-D/W; and the S/V index ([surface area]3/36π [volume]2) calculated from the three-dimensional volume extracted with this system. All three parameters were significantly higher
in the malignant group (averages: 0.81, 0.64, and 11.3, respectively) than in the benign group (averages: 0.62, 0.47, and
3.78, respectively). All three parameters were thus found to be useful in differentiating the two groups.
Journal of Medical Ultrasonics 05/2003; 30(2):103-110. · 0.33 Impact Factor
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Mikihiko Kawano,
Nobuhiko Kubo,
Nobuyuki Taniguchi,
Tomoko Oohara,
Michiru Nakamura,
Yasuhiro Shibuya, Kiyoka Omoto,
Ko-ichirou Shigeta,
Tomoko Ono,
Harumi Koibuchi,
Ko-ichi Itoh
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ABSTRACT: Graduates from Jichi Medical School are obligated to work at rural clinics or hospitals, where most of them are the only medical doctor in the house. To understand how these graduates actually use laboratory examinations, what examinations they found most important in their practice, and when they were confident of their laboratory techniques, we designed a questionnaire to address these questions. Many respondents reported that their institutions had electrocardiographs, abdominal and/or cardiac ultrasonographs, urinalysis test paper, and portable blood glucose meters, and more than half of them reported having used these instruments without assistance in emergency situations. Moreover, a majority of the respondents said that they considered it important that a physician is able to use these instruments without the help of other staff members. Proficiency in many laboratory techniques was obtained and physicians were confident during their first postgraduate clinical practice. These responses clearly show the importance and usefulness of covering examination techniques and the principles of laboratory medicine in medical education and the first postgraduate clinical practice.
Rinsho byori. The Japanese journal of clinical pathology 05/2003; 51(4):375-9.
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ABSTRACT: We investigated whether an ultrasonic echo contrast agent containing microbubbles (Levovist [SH U 508A]; Schering AG, Berlin, Germany) could in routine use activate platelets.
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 microL 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.
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).
In vitro, a galactose-based echo contrast agent could not activate the platelets at its routine concentration.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 05/2003; 22(4):365-73. · 1.25 Impact Factor
