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Purpose: The aim of this study was to estimate the severity of fibrosis without a biopsy., Methods: The 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., Results: The SNR, skewness and kurtosis, expressed as averages of corresponding values from each sub-ROI, correlated closely with the fibrosis index., Conclusion: These 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.

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.

Visceral fat syndrome, which includes visceral fat accumulation, glucose intolerance, hyperlipidemia, and hypertension, refers to a highly atherogenic state with a cluster of risk factors secondary to visceral fat accumulation. Although X-ray computed tomography (CT) is used commonly in diagnosis of visceral fat accumulation, it is expensive and exposes the patient to radiation. Some indices obtained using ultrasonography, which is fast and easy to use, have been reported. The ratio of the maximum thickness of preperitoneal fat (P) to the minimum thickness of subcutaneous fat (S), the abdominal wall fat index (P/S), is widely used in ultrasonographic diagnosis, however, this ratio tends to vary largely according to examiners. To establish a more reliable ultrasonographic index of visceral fat accumulation, we measured the thickness of the mesenterium, and tried to examine the relation between its thickness and maximum thickness of preperitoneal fat, minimum thickness of subcutaneous fat, and abdominal wall fat index, as well as body mass index, systolic and diastolic blood pressure, and levels of serum triglyceride, high-density lipoprotein cholesterol, total cholesterol, and blood sugar. The subjects were 131 individuals, 98 males and 33 females, averaging 47.0±7.9 years, with a mean body mass index of 24.1±2.6. The mesenterium was measured with a 3.5 or 3.75 MHz convex probe by longitudinal scanning on the left side of the umbilicus of the patient in the supine position. The thickness of the mesenterium correlated positively with maximum thickness of the preperitoneal fat, abdominal wall fat index, body mass index, and levels of serum triglyceride, total cholesterol, and blood sugar, and negatively with levels of high-density lipoprotein cholesterol. When the subjects were divided into a high-M group and a normal-M group, body mass index, triglyceride level, and blood sugar levels in the high-M group were significantly higher and level of high-density lipoprotein cholesterol was significantly lower than in the normal-M group. These results suggest that the thickness of mesenteium measured by ultrasonography may be useful in the diagnosis of accumulation of visceral fat.

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.

Purpose: To evaluate a new system for displaying processed images of liver parenchyma based on quantitative estimation of heterogeneity by texture analysis., Methods: We measured the signal to noise ratio, one of the first-order statistics in the histogram of enveloped amplitude of radio-frequency backscattered echoes, using a 3.75-MHz transducer with texture analysis in conjunction with a new method in which the small ROI (region of interest) is segmented into multiple layers to minimize the influence of tissue attenuation and beam diffraction. In our computerized system, gray-display and color-display images, two types of processed images, were produced from the visual intensity of each small ROI, which was based on its signal to noise ratio. We studied 10 cases of normal liver, 10 cases of fatty liver, and 10 cases of cirrhotic liver. The processed images obtained from these livers were reviewed to observe their features and to compare their usefulness in estimating the heterogeneity of the liver parenchyma with that of conventional B-mode images., Results: Gray-display images of cirrhotic livers appeared much blacker than the images produced from other disorders, and color-display images of cirrhotic liver appeared much bluer or greener than the others. Rate of correct diagnosis from B-mode images was 68.3 ±6.8%; from gray-display images, 85.8±7.4%; and from color-display images, 91.7±8.2%. Rate of correct assessment from B-mode images and gray-display images was significantly correlated (p=0.0015), as was rate of correct assessment from the B-mode images and the color-display images (p=0.0060)., Conclusion: The processed images obtained using this computerized system contributed to the correct and objective interpretation of the heterogeneity of the liver parenchyma.

Application of the velocity profile method is recommended for reliable measurement of flow volume in larger vessels, and ultrasonic flowmetry is a useful clinical tool for this purpose. We used the velocity profile in conjunction with a minor modification in the conventional velocity profile method and examined the reproducibility of flowmetry from color Doppler data. Data of three examiners were allowed to analyze intraobserver reproducibility and interobserver agreement in the common carotid artery, and we measured flow volume in the peripheral vessels of healthy individuals. Estimated flow volumes in five healthy examinees were 350 to 550 ml/min and did not vary significantly between examiners. Interobserver correlation was good (r 1=0.63), but intraobserver correlations in two sonographers were excellent (r 1=0.85) in by one who was experienced in this method and poor (r 1=0.32) in the other. Good interobserver agreement and intraobserver reproducibility of experienced examiners suggests that this method is reliable. Values obtained with normal controls averaged 438±78 (mean±SD) ml/min and 449±64 ml/min, respectively, in the right and left carotid arteries (n=12) and 120±31 ml/min and 83±23 ml/min, respectively, in the right and left vertebral arteries (n=10). Normal values were 542±71 ml/min (n=11) in the right renal artery, 1210±211 ml/min in the abdominal artery (n=10), and 799±182 ml/min in the main portal vein (n=17). Arterial blood flow volume can measure reliably by the velocity profile color Doppler method.

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.

A 13-year-old girl was admitted to the hospital because of cardiomegaly found incidentally at regular medical checkup at her school. Although dilated cardiomyopathy was suspected, the girl showed no symptoms. chest x-ray film showed cardiomegaly (cardiothoracic ratio, 67%), and echocardiogram demonstrated a dilatation of the left ventricle without thinning of the wall. While contraction was diffusely decreased, estimated cardiac output was increased to 13l/minute. Abdominal ultrasonography conducted to clarify the cause of this high output showed a multicystic lesion (8×6×4 cm) at the back of the left common iliac artery. Color Doppler ultrasonography revealed abundant blood flow within the lesion, establishing the diagnosis of arteriovenous malformation. Aortography delineated the arteriovenous malformation being supplied from the left internal iliac artery and from the left third and fourth lumbar arteries and drainage into the left common iliac vein and the right internal iliac vein. Although it did not show the precise location of the feeding and draining vessels, color Doppler ultrasonography was useful for the diagnosis of arteriovenous malformation.