Conventional vs  invert-grayscale X-ray for diagnosis of pneumothorax in the emergency setting.
BACKGROUND
Pneumothorax is a pathologic condition in which air is accumulated between the visceral and parietal pleura. After clinical suspicion, in order to diagnose the severity of the condition, imaging is necessary. By using the help of Picture Archiving and Communication Systems (PACS) direct conventional X-rays are converted to gray-scale and this has become a preferred method among many physicians.


METHODS
Our study design was a case-control study with cross-over design study. Posterior-anterior chest X-rays of patients were evaluated for pneumothorax by 10 expert physicians with at least 3years of experience and who have used inverted gray-scale posterior anterior chest X-ray for diagnosing pneumothorax.


RESULTS
The study included posterior anterior chest X-ray images of 268 patients of which 106 were diagnosed with spontaneous pneumothorax and 162 patients used as a control group. The sensitivity of Digital-conventional X-rays was found to be higher than that of inverted gray-scale images (95% CI (2,08-5,04), p<0,01). There was no statistically significant difference between the gold standard and digital-conventional images (95% CI (0,45-2,17), p=0,20), while the evaluations of the gray-scale images were found to be less sensitive for diagnosis (95% CI (3,16-5,67) p<0,01).


CONCLUSIONS
Inverted gray-scale imaging is not a superior imaging modality over digital-conventional X-ray for the diagnosis of pneumothorax. Prospective studies should be performed where diagnostic potency of inverted gray-scale radiograms is tested against gold standard chest CT. Further research should compare inverted grayscale to lung ultrasound to assess them as alternatives prior to CT.
Koç University Hospital, Emergency Department, Davutpaşa Caddesi No:4 34010 Topkapı, İstanbul, Turkey. Electronic address: emusalar@kuh.ku.edu.tr.
Ekrem
E
Musalar
Koç University Hospital, Emergency Department, Davutpaşa Caddesi No:4 34010 Topkapı, İstanbul, Turkey. Electronic address: salihekinci@hotmail.com.
Salih
S
Ekinci
Izmir Tepecik Education and Research Hospital, Emergency Department, Güney Mahallesi 1140/1 Sokak No: 1 Yenişehir, Konak, Izmir, Turkey. Electronic address: drorkununek.on@gmail.com.
Orkun
O
Ünek
Koç University Hospital, Emergency Department, Davutpaşa Caddesi No:4 34010 Topkapı, İstanbul, Turkey. Electronic address: ears@kuh.ku.edu.tr.
Eda
E
Arş
Gaziantep University School of Medicine, Emergency Department, Şahinbey Education and Research Hospital, Üniversite Bulvar P.K. 27310, Şehitkamil/Gaziantep, Turkey. Electronic address: eren@gantep.edu.tr.
Hakan Şevki
HŞ
Eren
Koç University Hospital, Radiology Department, Davutpaşa Caddesi No:4 34010 Topkapı, İstanbul, Turkey. Electronic address: bgurses@kuh.ku.edu.tr.
Bengi
B
Gürses
Koç University Hospital, Emergency Department, Davutpaşa Caddesi No:4 34010 Topkapı, İstanbul, Turkey. Electronic address: canaktas@gmail.com.
Can
C
Aktaş
D000328:Adult; D016022:Case-Control Studies; D018592:Cross-Over Studies; D004630:Emergencies; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014421:Turkey
Chest X-ray; Conventional X-ray; Invert-grayscale; Pneumothorax