[Lymphedema as initial manifestation of malignancy]. / Lymphödem als erstes Zeichen eines Malignoms.

Lymphedema may result from various benign or malignant causes. In particular rapidly progressing central or unilateral lymphedema (even in case of only discrete clinical findings) should initiate an extensive diagnostic workup to detect underlying malignancies in order to enable early therapy.

In vivo ultrasonic measurement of tissue vibration at a stenosis: a case study.

It is known that bruits often can be heard downstream from stenoses. They are thought to be produced by disturbed blood flow and vessel wall vibrations. Our understanding of bruits has been limited, though, to analysis of sounds heard at the level of the skin. For direct measurements from the stenosis site, we developed an ultrasonic pulse-echo multigate system using quadrature phase demodulation. The system simultaneously measures tissue displacements and blood velocities at multiple depths. This paper presents a case study of a severe stenosis in a human infrainguinal vein bypass graft. During systole, nearly sinusoidal vessel wall vibrations were detected. Solid tissue vibration amplitudes measured up to 2 microm, with temporal durations of 100 ms and frequencies of roughly 145 Hz and its harmonics. Cross-axial oscillations were also found in the lumen that correlate with the wall vibrations, suggesting coupling between wall vibration and blood velocity oscillation.

Compact adaptive optical system based on blind optimization and a micromachined membrane deformable mirror.

We describe and demonstrate an adaptive optical system based on the combination of a micromachined membrane deformable mirror and the stochastic parallel gradient descent control algorithm. This compact and relatively inexpensive adaptive optical system is used to maximize the coupling of a distorted laser beam into a single-mode optical fiber. The coupling efficiency is improved by 12 dB, and the coupling efficiency after correction is 64% of the diffraction-limited coupling efficiency.

Cross-beam vector Doppler ultrasound for angle-independent velocity measurements.

Combining Doppler measurements taken along multiple intersecting ultrasound (US) beams is one approach to obtaining angle-independent velocity. Over 30 laboratories and companies have developed such cross-beam systems since the 1970s. Early designs focused on multiple single-element probes. In the late 1980s, combining multiple color Doppler images acquired from linear-array transducers became a popular modality. This was further expanded to include beam steering and the use of subapertures. Often, with each change in design, came a new twist to calculating the velocity. This article presents a review of most proposed cross-beam systems published to date. The emphasis is on the basic design, the approach used to determine the angle-independent velocity, the advantages of the design, and the disadvantages of the design. From this, requirements needed to convert the idea of angle-independent vector Doppler into a commercial system are suggested.

Hemostasis of punctured vessels using Doppler-guided high-intensity ultrasound.

The use of Doppler ultrasound was investigated to determine if it would aid in guiding the application of high-intensity focused ultrasound (HIFU) to stop bleeding from punctured vessels. Major vessels (abdominal aorta, illiac, carotid, common femoral and superficial femoral arteries and the jugular vein) were surgically exposed, punctured and treated in anesthetized pigs. Treatment was applied when the Doppler sounds indicated the focus coincided with the bleeding site. In 89 treatment trials, the average time to achieve major hemostasis (a point where bleeding was reduced to a level of only oozing) was 8 s, and for complete hemostasis was 13 s. These times were significantly shorter than those of an identical former study in which only visual guidance was used. In that study, the average times for major and complete hemostasis were 40 and 62 s, respectively. The advantage of Doppler guidance in applying HIFU in treating bleeding vessels was demonstrated.