Most work assessing lymph nodes on the basis of their size refers to the short-axis diameter. Rotating the probe by 90° “over the finding” allows an identification to be quickly made. The pinnate structure of the muscle can mimic a lymph node hilus. There is a danger of confusing lymph nodes in level II, which are commonly found at the posterior border of the submandibular gland, with the posterior belly of the digastric muscle sliced obliquely or in cross-section. Owing to the typical physiological configuration of cervical lymph nodes (oval/ellipsoid), the node should always be measured in all three orthogonal planes: the diameter is measured in one long axis and two short axes ( Figs. Within the node, there is generally a hypoechoic marginal zone, which can be distinguished from the central hyperechoic hilar region (the medullary sinuses with blood vessels and efferent lymph vessels).Ĭlassification of the Cervical Lymph NodesĪlthough the size of a lymph node in the neck may be used as a classification criterion, this is not without problems. Lymph nodes in the neck are oval or ellipsoid in shape. The sonographic appearance of cervical lymph nodes on high-resolution ultrasound reflects their structure and has some distinctive characteristics. The patient is usually examined with the neck hyperextended (see Chapters 3 and 4).įigure 6.1 shows the histological appearance of a typical cervical lymph node. Given the optimal exposure of the cervical soft tissues and the high spatial resolution, diagnostic ultrasonography is the first choice of method, as lymph nodes exceeding 3 mm are easy to identify. The use of ultrasound has been validated in examination of the superficial structures of the head and neck as considerably more sensitive than clinical assessment through palpation in the identification and interpretation of the 200–300 lymph nodes of the neck and soft tissues changes in this region.
0 kommentar(er)
