Direct Digital Radiology, successfully used in high income countries, is now becoming available to low and medium income countries for more effective TB case detection. Breakthrough innovations in digital Chest X-ray (amongst others in operation in the Netherlands, USA, UAE, China, Brazil, Zambia and South Africa) are evaluated by various National TB programmes, WHO Stop TB and UNION on their suitability for wider use in low resource areas.

Dr. Donald A. Enarson stated during the 39th UNION World Conference: "The way forward in Chest X-ray (CXR) is to use digital images. Digital images can be read immediately without processing, they have a constant high quality, the data can be much more efficiently stored and transmitted –allowing them to be diagnosed even by distant specialists- and settings for the readings can be standardized to support electronic interpretation of images".

Check for TB using Direct digital X-ray will give patients access to fast, accurate and convenient TB screening, reducing their travel cost, waiting time and speeding up diagnosis and treatment. Intensified TB case finding using digital radiology will support the combat against TB in people living with HIV who often present with smear negative sputum. New technology X-ray allows for low dose exposure for patients, making it an appropriate tool also for large scale TB prevalence studies and screening of risk groups. Digital radiology can also be used to support primary health care services, for example through diagnosis of fractures.

Digital images are instantly available on the diagnostic monitor with constant high quality. Software tools to zoom in or to add contrast to the digital image are available and enhance ease and accuracy of TB screening. Issues of poor readability and deterioration or loss of films are prevented.

Low image cost

Films and developer are no longer needed, storage of images is done electronically and superior readability allow for a very low cost per image. Cost savings relative to analogue systems using films in high throughput settings can exceed Euro 100.000 per year per system. Even at a low throughput of 50 images per day, digital images are more economic. The section on "Cost Saving" presents the calculation of savings for different settings. A customised cost calculation can be made on this page in just some seconds.

Digital radiology systems using an integrated Picture Archiving and Communications System (PACS) can efficiently archive and retrieve large numbers of images. This eliminates the high archiving cost of analogue film based images. Using the universal Digital Imaging and Communications in Medicine (DICOM) format, the PACS attaches patient information to the right image, eliminating the risk of “storing a film in the wrong envelope” and, enhancing patient safety.

Digital X-ray is clean technology as chemical waste from film developing, that can cause serious environmental damage, is completely eliminated.

Remote diagnosis

If the X-ray image cannot be interpreted locally because no specific knowledge is available or the image is particularly difficult to interpret, it can be sent over the internet or even over a low bandwidth (mobile phone) connection to a centre where accurate reading can be done. The diagnosis can be sent back immediately and continues to be attached to the right digital Chest image.

Computer Aided Diagnosis

A software protocol is being developed that allows for the recognition of abnormalities consistent with TB in a digital Chest image. The sensitivity of the pattern recognition techniques is expected to reach 90% while its specificity target is set at a challenging 80%. In order to support national TB programme prevalence studies and early case detection in risk groups, this revolutionary protocol will become available in second half of 2010.