1. Imaging the unilateral effusion CXR and CT
Dr Anthony Edey

2. North Bristol NHS Trust
X-rays = 650 patients per day
CTs = 160 patients per day

3. Scope Explore respective roles of CXR and CT
Outline potential and limitations

7. Multiple techniques on plain film – tomograms, laterals, obliques, decubitus, fluoroscopy

8. N=32
CT vs CXR against a gold standard of post-mortem
CT equal to CXR for detection of tumour of the lateral chest wall, mediastinum and lung
CT no advantage over CXR
Diaphraghragm more false negative on CT than CXR

9. Benefits of CXR CXR low radiation Portable Accessible
Quick to read by a wide range of staff

10. Role of CXR Initial triage Gross disease monitoring
Evaluating effect of intervention
CXR low radiation
Portable
Accessible
Quick to read by a wide range of staff

11. Intercostal stripe seen between the ribs
1mm soft tissue strip
Mostly intercostal muscle – but also sandwiched visceral pleura, fluid, parietal pleura, and endothoracic fascia

12. 150mls iv contrast at 2.5mls/s
Raj BJR 2011;84(1005):
Hooper Respiration 2014;87:26-31

13. Downsides of CT
Expense and limited resource
Radiation
Expertise

14. Role of CT
Principle diagnostic tool
Detailed disease monitoring

15. Imaging malignant effusions

16. 3 month interval

19. Mediastinal thickening 88% 56%
CT Feature
Specificity
Sensitivity
Circumferential
100%
41%
Nodular pleura
94%
51%
Thickening >1cm
36%
Mediastinal thickening
88%
56%
Positive predictive value is high but abseence of these features does not exclude malignancy
Leung AJR 1990;154:

23. Real life CT….. 2008-2013 scans for Ix of effusion N=370
Positive predictive value 85%
Negative predictive value 65%
1 in 3 patients with “negative” CT had pleural malignancy
“raising the possibility of malignancy”
Inherant bias ‘cos all for biopsy
Need for MDTs
Hallifax et al. Thorax 2015;70:

25. Talc

26. Imaging benign Effusions