Differentiation of parotid gland tumors with contrast-enhanced ultrasound.

PURPOSE: Pilot study to evaluate a new ultrasound (US) technique for differentiating parotid cystadenolymphoma (CL) from pleomorphic adenoma (PA). MATERIALS AND METHODS: 27 patients presenting with a palpable lesion of the parotid gland were examined by B-mode US. All patients underwent US examination with administration of 2.4 ml US contrast medium (USCM). The intratumoral time-to-peak was determined. The contrast medium inflow curves from the tumor and parotid parenchyma were compared by using AUC analysis and compared with histology. RESULTS: Histology demonstrated cystadenolymphoma in 9 cases (CL group) and pleomorphic adenoma in 9 (PA group). The intratumoral time-to-peak in the PA group was markedly longer than in the CL group (26.8 +/- 11.1 sec versus 22.6 +/- 5.1 sec, p < 0.05). AUC analysis for the tumor area demonstrated a significant difference between the PA group (30.3 +/- 24.3 dB/area) and the CL group (77.4 +/- 45.6 dB/area, p < 0.05). CONCLUSION: The standardized analysis of USCM inflow curves has the potential to differentiate cystadenolymphoma and pleomorphic adenoma. More patient numbers, perhaps with blinded readers, would allow reliable diagnostic determination for future studies.

Snoring noise pollution--the need for objective quantification of annoyance, regulatory guidelines and mandatory therapy for snoring.

Habitual snoring without episodes of apnea or hypoventilation and without respiratory related arousals is considered to be annoying and without any need for treatment. However, studies seem to suggest an enormous psychosocial impact of annoyance for the bed partner. Apart from subjective questionnaires there still exists no generally accepted mode of measurement that can describe snoring objectively. We therefore adapted methods developed for environmental medicine and established a new snore score using psycho-acoustic parameters. For quantification of snoring noise we conducted nocturnal measurements in 19 habitual snorers. Free-field snore sounds were acquired with two low-cost non-contact microphones and transferred to a PC (sampling frequency 11 kHz). The data were recorded, analysed and stored automatically using a MATLAB script. Following the analysis of sound characteristics and levels, the score was computed from relevant parameters containing the rating level (L(R)), maximum level, two percentile levels for frequent maxima (L(5)S; L(1)) and snoring time. The determined values substantially exceeded the prescribed limits defined by WHO noise guidelines, and mainly affected the equivalent continuous sound exposure level, rating level and the immission standard values of brief noise peaks, whose maximum was exceeded by up to 32 dB(A). The Berlin snore score illustrated the objective acoustic annoyance on a scale from 0 to 100. It allows inter-individual comparison and objectifies the need for therapy. The clinical applicability of evaluating the reduction of snoring after surgical therapy is discussed exemplarily. The presented measuring method was found to be suitable for quantifying snoring noise and can be easily integrated into existing polysomnographic applications. In the case of habitual snoring with objective evidence of psychosocially disturbing acoustic annoyance, health fund providers should assume the costs of mandatory medical therapy.