SPUDDS
Research type
Research Study
Full title
Sniff test Protocols: comparing Ultrasound to Dynamic Diaphragm Screening
IRAS ID
301038
Contact name
Thomas FitzMaurice
Contact email
Sponsor organisation
Liverpool Heart and Chest Hospital
Duration of Study in the UK
2 years, 0 months, 0 days
Research summary
Paralysis of the diaphragm can occur due to a range of factors including infection, surgery or trauma, and can lead to significant symptoms, such as breathlessness and reduced exercise tolerance. An abnormal diaphragm may be seen on a plain chest radiograph, but further tests are needed to confirm the presence of this condition. This usually consists of functional imaging, either ultrasound or fluoroscopy, in which a series of rapid ‘sniff’ breaths are taken to assess the movement of the diaphragm. This is usually known as a ‘sniff test’. Diagnosis is made if both a sniff test shows paradoxical (upwards) diaphragm motion during sniffing, and a postural change in lung capacity is seen on spirometry. Both fluoroscopy and ultrasound have their disadvantages; fluoroscopy carries a relatively high radiation dose (upwards of 0.3mSv), and is complex to perform, providing only images of the diaphragm and not the entire thorax. Images are not digitized, limiting their applicability for later analysis. Ultrasound is operator dependent, and requires skill and practice; it is not routinely available in many UK centres. Dynamic chest radiography, or DCR, provides a quick, lower-radiation alternative in the form of a digital, wide field-of-view cineradiographic system, that can quickly and easily acquire images of the entire thorax (including the diaphragm) in motion.
This study aims to compare DCR to ultrasound, and to assess the ability of DCR to calculate lung volume changes with reference to spirometry. The study also aims to assess if DCR images captured at a lower frame rate (number of images taken per unit time) is of a similar diagnostic value to those at the standard frame rate.REC name
North West - Greater Manchester West Research Ethics Committee
REC reference
21/NW/0251
Date of REC Opinion
23 Sep 2021
REC opinion
Further Information Favourable Opinion