Methods of Counting Ribs on Chest CT: The Modified Sternomanubrial Approach

method for detecting lesions in the ribs, sternum and vertebrae. However, it is difficult to count the ribs as the ribs are arranged obliquely in the axial plane. With the introduction of multidetector-row CT (MDCT), the bones of thorax can be clearly examined in three-dimensional images, although the axial images are most commonly used in clinical practice. There are three known methods for counting ribs on axial images. One is the method of counting from the first rib seen below the proximal end of the clavicle (Bhalla et al. 1990) (1). Another is the method of counting, from the seventh costal cartilages, those ribs that J Korean Radiol Soc 2007;57:145-150