Lymph node imaging: multidetector CT (MDCT).

Advances in cross-sectional imaging, including conventional and helical (spiral) CT and multidetector (MDCT) and MR imaging, now allow detailed evaluation of the anatomy and pathology of the neck and thoracic inlet. The major structures are identified by their appearance and that of contrasting fatty tissue planes surrounding the soft tissues. These structures include the larynx, trachea, thyroid, and parathyroid glands as well as the vessels, lymph node chains, nerves, and supporting muscles. A thorough understanding of the normal cross-sectional anatomy is fundamental to properly interpret pathologic processes. Pathologic processes include both solid and cystic masses. Most solid masses are enlarged lymph nodes. In contrast, cystic masses are of variable pathology, and their characteristic appearances and locations with respect to normal neck anatomy allow a confident diagnosis to be made from a brief differential diagnostic spectrum.