2013 Volume 52 Issue 3 Pages 195-204
In this paper, we review the latest trend of diagnostic imaging modalities, especially X-ray CT, positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI).
Although only less than 40 years have passed since X-ray CT was invented by Dr. Hounsfield in 1972, X-ray CT has largely advanced in the meanwhile. Helical scan was made possible by the adoption of a slip ring, and then the appearance of multi-detector-row CT scanners has brought the rapid progress of high-speed and high-resolution scans. Recently, dual-energy CT and virtual monochromatic images can be obtained, by which the quantitative accuracy of CT values can be improved, and the possibility of new molecular imaging by use of CT is expected.
Regarding the diagnostic imaging modalities for nuclear medicine, we review the recent development of integrated CT/PET and CT/SPECT scanners which allow the fusion of functional and anatomic information. We also review the semiconductor PET and SPECT scanners which allow short data acquisition. In addition, we review newly-developed integrated PET/MR scanners which are expected to integrate the functional images of PET and the functional and/or anatomic images of MRI. These integrated modalities will provide more useful and valuable diagnostic images than either modality can offer alone, leading to the further development of integrated diagnostic imaging.
Finally, as topics of the latest trend of MRI, we will focus on the techniques of non-contrast perfusion and angiography and the tissue elasticity imaging (elastography) using MRI.
