ارزش تشخيصي راديوگرافي قفسه صدري در مقايسه با سي تي اسكن در پنوموكونيوزيز

DIAGNOSTIC VALUE OF CHEST X-RAY COMPARED TO CT SCAN IN PNEUMOCONIOSIS

Pneumoconiosis is a chronic and irreversible lung disease Inhalation of inorganic dust particles over a long period of time is the cause of this disease. Dust particles < 5 Micron enter the alveolar sac and are removed from the sac by macrophages . Irritation of the interestitial lung tissue leads to fibrosis. In this study , 735 workers (all male) employed at Siman Sepahan were asked to fill out a questionnaire and underwent chest X-Rays (Antero - posterior & lateral views) of which 110 of them were additionally C.T scanned . 70% of the X-rays were normal , while 30% had abnormal findings. Abnormal chest X-ray and spirometry findings had a direct relationship with age , and therefore about half of the workers in the 45-54 age group had symptoms of the disease , and 41.6% had an abnormal chest X-ray. On comparison of chest X - Ray findings and CT scan findings, in patients with abnormal spirometry findings, it was realized that the positive predictive value of chest X- Rays in relation to CT Scan was 100% while the negative predictive value was 7.4% . Therefore, a positive chest X-ray finding has a more diagnostic value than a negative one. In other terms, a negative chest X-Ray finding does not rule out Pneumoconiosis . It is therefore suggested that suspected cases of pnuemoconiosis should undergo a CT scan irrespective of the chest X-Ray findings .