الفهرس 
Cervical lymph nodeOnly 14 pages are availabe for public view
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Abstract
A lymph node or lymph gland, is an ovoid or kidney-shaped organ of the lymphatic system, and of the adaptive immune system, that is widely present throughout the body. They are linked by the lymphatic vessels as a part of the circulatory system. Lymph nodes are major sites of B and T lymphocytes, and other white blood cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles and cancer cells.
Lymphadenopathy or adenopathy is disease of the lymph nodes , in which they are abnormal in size, number, or consistency, lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes, infectious lymphadenitides affecting lymph nodes in the neck are often called scrofula
Detection of neck lymph nodes and their differentiation into benign or malignant are important especially in patients with head and neck cancer for staging, treatment planning and follow-up of cancer. Conventional imaging depends upon the morphologic criteria of the lymph node including the maximum short axial diameter, presence of necrosis, loss of LN hilum, heterogeneous enhancement, and perinodal infiltration.
Ultrasound (US), computed tomography (CT) and magnetic resonance (MR) can be used in the detection of enlarged cervical nodes; however, they cannot accurately differentiate benign from malignant lymph nodes. Metabolic imaging using single photon emission-CT (SPECT) and positron emission tomography (PET) can help in this differentiation but they are limited by low spatial resolution and variable physiological fluro-deoxyglucose (FDG) uptake in anatomical structures and inflammatory lymph nodes.
Ultrasound guided fine needle aspiration cytology (FNAC) is invasive with false negative results due to operator-dependency.
DWI can provide excellent tissue contrast and may be able to demonstrate malignant lymph node. ADC values may be valuable in distinguishing between malignant and benign lymph nodes.
Additional advantage of DWI include its completely non-invasive nature and its cost effectiveness. DWI does not involve a radiation exposure, oral and intravenous administration of contrast material and does not elicit patient discomfort. DWI can be easily added to MR study protocols and loses no time to the injection of contrast material. DWI play an important role in the diagnosis and fallow up of patient with enlarged lymph node.