COMPUTED TOMOGRAPHY FOR TECHNOLOGISTS
Since its inception in the early 1970s, computed tomography (CT) has made an enormous impact in diagnostic imaging. Over the years, improvements in both CT hardware and software have resulted in advances in all its major features including image resolution, temporal resolution, and reconstruction speed. In just over 30 years, technological innovation has taken us from scanners that employed a single x-ray detector and took several minutes to acquire a single cross-sectional slice to scanners that employ multiple rows of detectors, in both x and y directions and can acquire more than 100 cross-sectional slices in less than a second. In 1972, scan time per slice was 300 seconds; by 2005, it had decreased to just 0.005 seconds! This technologic evolution has opened the door to new and varied uses for CT, from assessing coronary disease to colorectal screening. In some cases, new indications for CT exams may replace other, more invasive procedures;