Ultrasonography is sometimes included under this umbrella term, especially with reference to echocardiography, which produces standardised axial slices through the heart. However most radiologists do not tend to think of ultrasound as a cross-sectional technique since although it generates two-dimensional image "slices" of the body, the angle of the slices are often not perpendicular to the axis of the body.
Examples of imaging techniques that are not cross-sectional include plain radiography, and fluoroscopy. The techniques rely on projection of an x-ray beam through an object to a receptor. Planar nuclear medicine is also not cross-sectional, although the imaging radiation is emitted from the object of interest, rather than passed through it.
History and etymology
Cross-sectional imaging was being used as an imaging term in the mid-1970s in
some of the early CT papers 1.
- 1. Stephens DH, Sheedy PF, Hattery RR, Hartman GW. Initial clinical experience with computerized tomography of the body. Radiologic clinics of North America. 14 (1): 149-58. Pubmed