TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Morenz, Katrin A1 - Biller, Heike A1 - Wolfram, Frank A1 - Leonhardt, Steffen A1 - RĂ¼ter, Dirk A1 - Glaab, Thomas A1 - Uhlig, Stefan A1 - Hohlfeld, Jens M. T1 - Detection of air trapping in chronic obstructive pulmonary disease by low frequency ultrasound JF - BMC Pulmonary Medicine N2 - Background: Spirometry is regarded as the gold standard for the diagnosis of COPD, yet the condition is widely underdiagnosed. Therefore, additional screening methods that are easy to perform and to interpret are needed. Recently, we demonstrated that low frequency ultrasound (LFU) may be helpful for monitoring lung diseases. The objective of this study was to evaluate whether LFU can be used to detect air trapping in COPD. In addition, we evaluated the ability of LFU to detect the effects of short-acting bronchodilator medication.Methods: Seventeen patients with COPD and 9 healthy subjects were examined by body plethysmography and LFU. Ultrasound frequencies ranging from 1 to 40 kHz were transmitted to the sternum and received at the back during inspiration and expiration. The high pass frequency was determined from the inspiratory and the expiratory signals and their difference termed F. Measurements were repeated after inhalation of salbutamol.Results: We found signi ficant differences in F between COPD subjects and healthy subjects. These differences were already significant at GOLD stage 1 and increased with the severity of COPD. Sensitivity for detection of GOLD stage 1 was 83% and for GOLD stages worse than 1 it was 91%. Bronchodilator effects could not be detected reliably.Conclusions: We conclude that low frequency ultrasound is cost-effective, easy to perform and suitable for detecting air trapping. It might be useful in screening for COPD Y1 - 2012 UN - https://nbn-resolving.org/urn:nbn:de:hbz:1393-opus4-1705 UR - http://publica.fraunhofer.de/eprints/urn_nbn_de_0011-n-2067978.pdf SN - 1471-2466 SS - 1471-2466 U6 - https://doi.org/10.1186/1471-2466-12-8 DO - https://doi.org/10.1186/1471-2466-12-8 IS - 12 SP - 1 EP - 7 ER -