الفهرس 
Introduction & aim of the workOnly 14 pages are availabe for public view
 |  | from | 138 |  |  |
| | | from | 138 | | |
Abstract
The important role of the radiologist in oncologic imaging is, first, to provide accurate pretreatment staging of the tumor for planning medical, surgical, and radiation interventions and, second, to monitor response to therapy and provide surveillance after curative treatment. Ultrasound is a useful imaging modality in assessment of cervical lymph nodes. Distribution of nodes, grey scale and power Doppler sonographic features are useful to identify the cause of cervical lymphadenopathy. Useful grey scale features include size, shape and status of echogenic hilus, echogenicity, micronodular appearance, intranodal necrosis and calcification. Adjacent soft tissue edema and matting are particularly useful to identify tuberculosis. Useful power Doppler features include vascular pattern and displacement of vascularity. Fused PET/CT is considered to be the most accurate imaging modality for detecting nodal metastases, because it simultaneously provides prompt and accurate co registration of functional and anatomical images. However, it is expensive, lessoften available. Diffusion-weighted MR imaging with ADC map is a new promising technique that can help in differentiation of non-necrotic malignant from benign lymph nodes, delineation of the solid viable part of the lymph node and even allows detecting very small adenopathies. The addition of Diffusion-weighted MR imaging to routine MR imaging provides additional useful physiological and functional information regarding characterization of the cervical lymph nodes. super paramagnetic particles of iron oxide (SPIO)-enhanced MR imaging of the neck provided a sensitivity of 86% and a specificity of 100% and is therefore one of the most promising modalities for the evaluation of the neck in patients with squamous cell carcinoma of the head and neck. Micro infiltration of lymph nodes will remain a problem even with high-spatial-resolution MR sequences.