Breast diseases may present an array of histologic features, and no two lesions are the same. Because ultrasound images reflect histologic components, knowledge of the histology of various breast diseases is important. We describe ultrasound images and their pathologic correlation in common breast diseases.

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We now have two important techniques for obtaining contrast enhancement imaging of abdominal organs: the loss-of-correlation technique (LOC) and the phase-inversion harmonic imaging technique. The loss-of-correlation technique involves using pseudo-Doppler signals produced when microbubbles collapse; the phase-inversion harmonic imaging technique uses harmonic signals (nonlinear propagation) by canceling the fundamental and inverted fundamental waves. Both techniques effectively enhance contrast in images of abdominal organs and neoplasms. However, although the loss-of-correlation technique can produce a very strong enhancement effect, it is not suitable for continuous enhancement. On the other hand, the phase-inversion technique may fail to detect faint enhancement, because harmonic signals from the native tissues can not be completely eliminated. Contrast ultrasonography can differentiate hepatic tumors, detect microvascular architecture of abdominal organs and neoplasms, evaluate the effect of treatments of pancreatic cancer and hepatocellular carcinoma, and provide guidance in radiofrequency ablation (RFA) under contrast ultrasonography. Contrast ultrasonography is now an important tool when precise diagnosis of the abdominal disorders is necessary.

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Purpose: The maximum measurable velocity of blood flow in conventional Doppler color flow mapping is limited due to the aliasing phenomenon. This paper describes a novel method, called “wideband Doppler,” for alias-free estimation of high blood velocity. Method: The new method presented here utilizes the wideband echo information obtained by the transmission of a short ultrasound pulse with a wide frequency band. Received echoes are Fourier transformed and converted to the cross spectrum. The phase of the cross spectrum is a function of frequency, and the gradient of the fitted line of the phase corresponds to the average velocity of the targets. When the target velocity is greater than the Nyquist limit, a part of the phase of the cross spectrum is greater than ±π rad, and is wrapped in ±π rad. The wrapped phase is corrected using wideband echo information to avoid aliasing. Then the gradient of the corrected phase is estimated and converted to the target velocity. Result: The results of computer simulation showed that the range of velocity estimation could be expanded to three times that of the conventional method. Furthermore, good robustness against noise and the dispersion of target velocity was also confirmed. Conclusion: The proposed method has the ability to estimate blood velocity beyond the Nyquist limit. An alias-free color flow mapping system might be realized with this method.

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Hepatic hydrothorax is defined as pleural effusion in a patient with cirrhosis of the liver and no cardiopulmonary disease. We reported a case of hepatic hydrothorax diagnosed by color Doppler ultrasonography. A 75-year-old woman with nonBnonC cirrhosis was admitted to our institution with right hydrothorax. Color Doppler ultrasonography revealed movement of fluid from the peritoneal cavity to the pleural space through a small diaphragmatic defect as a jet flow. The size of the diaphragmatic defect and the velocity of the jet flow changed in relation to the clinical course. Color Doppler ultrasonography proved to be useful for diagnosing hepatic hydrothorax.

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