Dignitätsbeurteilung vergrößerter Lymphknoten durch qualitative und semiquantitative Auswertung der Lymphknotenperfusion mit der farbkodierten Duplexsonographie

Abstract

Perfusion of enlarged lymph nodes by colour-coded sonography was studied prospectively in 105 benign and 115 malignant lymph nodes. The diagnosis was confirmed histologically in 158 and clinically in 62. Spectral analysis in the benign lymph nodes provided normal values for pulsatility and resistance indices. A pulsatility index greater than = 1.8, or a resistance greater than = 0.9 indicate lymph node metastases with positive prediction of 93% and specificity of 97%. In addition, subjective, semiquantitative classification of lymph node perfusion in relation to the surrounding fat or connective tissue improves the diagnosis of lymph node metastases and of malignant lymphomas.

Evaluation of vascular patterns of cervical lymph nodes with power Doppler sonography

“…16 For these reasons, reports on the Doppler ultrasound evaluation of lymph nodes has not produced comparable nor standardizable results: increased vascularity or changes in resistive index cannot be proposed as reliable parameters. [4][5][6][7][8][9] Recently, a new method to collect and display data derived from Doppler sonography has been developed: the name ''power Doppler,'' used by the majority of manufacturers, reflects the parameter that the method is focused on. [10][11][12][13] Although conventional color Doppler sonography is based on mean frequency (because this parameter is calcu- lated when assigning color hue to each pixel), with power Doppler sonography the parameter on which the color scale is calculated is the ''power'' or ''intensity'' of the signal, which expresses indirectly the number of red blood cells insonated by the ultrasound beam.…”

“…3 The introduction of color Doppler sonography (CD) has multiplied the amount of information that can be obtained during an ultrasound examination, because since this technique can easily collect interesting data about the vascularity of parenchymatous structures, the application of CD to lymph node analysis, however, has not demonstrated a definite clinical usefulness. [4][5][6][7][8][9] Power Doppler sonography (PD), a interesting evolution of the color Doppler technology, seems even more promising in the detection of low flow in small structures: PD calculates the integrated power of the Doppler signal instead of the mean frequency, so it does not alias, is angle-independent, and is not substantially affected by noise. [10][11][12] To date, no applications of PD in the evaluation of adenopathy have been reported, but the ability of PD to detect low flow could give this technique a substantial advantage over CD.…”

Value of axillary ultrasonography and sonographically guided puncture of axillary nodes: A prospective study in 144 consecutive patients

“…[6][7][8] We suspected that the sensitivity of ultrasound was higher than previously published indications, provided that optimal transducers, updated electronics, and very experienced sonographers were used. We, therefore, decided to conduct a prospective study.…”

Ultrasound in Metastatic Neck Disease

“…The development of color-coded duplex sonography has focused interest in the question of whether lymph node métastasés can be differentiated from unspecific enlarged lymph nodes by their pulsatility and/or resis tance indices [12]. It seems to be too early to determine whether this method can provide reliable information in detecting métastasés.…”