![]() Color power Doppler should be applied to assess the vascularity. These dimensions may have no relationship to the traditional parasagittal or transverse planes on the body. The probe is then rotated 90 degrees to measure the “width” and “depth” of the node. To be consistent amongst physicians and between follow up exams, the probe should be rotated to find the greatest dimension of the node, which is considered the “length”. The view of each node should be optimized with depth and focus position so details of shape and texture can be observed. All the peripheral node regions are best examined with the patient in the supine position. Lymph nodes are best evaluated with the linear probe and an exam type optimized for good detail and low Nyquist limits. The following diagram shows the inguinal and femoral node groups. The femoral nodes drain the leg and occasionally the genitals. Groin nodes can be inguinal, which are located near the inguinal ligament and drain the lower retro-peritoneum, pelvis, and genitals, or they can be femoral, which are located anterior and medial to the common femoral and great saphenous veins. Notice the close proximity of the node group to the basilic vein near the medial epicondyle. The following image shows the location of potential epitrochlear (supratrochlear) nodes in the groove just medial to the biceps muscle. However, an enlarged node indicates either generalized lymphadenopathy or an inflammatory condition in the lower arm, which should be obvious. The epitrochlear region is small and many normal patients have only very small nodes in this location. A systematic survey of axillary nodes would rarely be done with IMBUS, but when a patient has noticed a lump in this general area, it is important to know where to look for additional nodes in the region. The axillary region has nodes on the lateral chest, high in the axilla, and on the upper, inner arm, as in the following image. For a neck survey, the probe is moved in a transverse orientation up and down the neck from medial to lateral just like a systematic palpation exam would be performed. Some nodes are near the carotid artery and internal jugular vein. There are nodes superficial and deep to the sternocleidomastoid. The next image shows the location of lymph node groups in the neck. The small Subclavian triangle shown in the image is the location of supraclavicular nodes. The neck region is divided into Anterior and Posterior triangles, based on the sternocleidomastoid muscle, as shown in the next diagram. In the primary care setting, initially unexplained lymphadenopathy has only about a 1% chance of malignancy, but failure of node regression over 4 weeks increases the chance of malignancy. Yet, malignancy is the fear, which is why the size and character of nodes is evaluated carefully. ![]() The most frequent enlarged node in clinic is a neck node, the great majority of which are a reaction to head or neck infection. The differential diagnosis for generalized lymphadenopathy is different from that of localized lymphadenopathy. If a lump is an abnormal node, a more general node survey might be done to determine if the lymphadenopathy is generalized. Most patients who need an IMBUS lymph node exam come to clinic after noticing a lump in the neck, armpit, or groin. A physician needs good technique and knowledge of lymph node anatomy to perform such a survey. A general lymph node survey, whether traditional or IMBUS, has not been shown beneficial as part of a periodic physical, but has anecdotally been useful in systemically ill patients who could have an infectious, inflammatory, or neoplastic disease because an abnormal node might be biopsied to make a diagnosis. Ultrasound is usually better than CT at finding and sizing lymph nodes in the neck, axilla, epitrochlear area, and groin. An IMBUS lymph node exam needs to be carefully performed and interpreted to avoid over- or under-reacting to these lumps.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |