Modalities and data acquisition

Acquisition modalities are the image engines in a picture archiving and communications system (PACS). Of the modality mix, radiography comprises approximately 60-70% of all studies performed in a diagnostic radiology department. Since analog screen-film recording technology is still being used in many hospitals and clinics, the implementation of a PACS for electronic image acquisition, display, and archiving is associated with the conversion of analog to digital radiography technology. But the imaging modalities are much more than radiography. Real-time digital fluoroscopy, interventional angiography, and cardiology studies are producing hundreds to thousands of images per examination. Cross-sectional imaging acquisition systems such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), single-photon emission computed tomography (SPECT), and positron-emission computed tomography (PET) are expanding rapidly and are in many cases becoming the examinations of choice over projection imaging.