A New Way of Looking at Your Lungs

"The CT scan will be performed on a 16 slice GE Discovery 670 SPECT CT scanner. A slice thickness of 0.625mm will be used. Images are acquired during an inspiratory breath hold of up to 20 seconds to minimise movement artefact. The patient will be lying supine and the scan will be a non-contrast study. Using a low dose CT chest protocol (1.7 mSv) will minimise the exposure to ionising radiation of study participants.~Participants in the haemodialysis arm of the study will have a CT done before and after haemodialysis. Participants in all other arms will have a single CT scan done during their study visit."

The ultrasound will be performed by a single operator. The patient's position will ideally be with the patient sitting up at 45°. Ultrasound images and clips will be recorded at 10 points over each hemithorax - the 2nd, 4th and 6th intercostal spaces (ICS) in the mid-clavicular line; the 2nd, 4th and 6th ICS in the mid-axillary line; and the 2nd, 5th, 7th and 9th ICS posteriorly. Ultrasound estimation of the height of the right internal jugular vein will be undertaken. Central venous pressure will be calculated by adding 5cm. Inferior vena cava diameter will also be measured at end-inspiration and expiration. The time taken to perform each ultrasound will be recorded. Control, COPD and ILD groups will be scanned on a single occasion. Haemodialysis group will have 4 scans.

All participants in the study will undergo basic spirometry as specified in the study assessments. This is considered a low-risk intervention and no harm is expected as a consequence of participation in the study.

All participants in the study will undergo blood tests as specified in the study assessments. This is considered a low-risk intervention and no harm is expected as a consequence of participation in the study.