Neck Lymph Nodes Levels - CT Anatomy
Transcrição
Neck Lymph Nodes Levels - CT Anatomy
Neck Lymph Nodes Levels - CT Anatomy Poster No.: C-1664 Congress: ECR 2015 Type: Educational Exhibit Authors: A. E. A. G. Costa , M. S. R. O. Faustino , M. L. D. Fernandes , I. 1 2 1 2 2 2 Távora ; Vila Nova De Gaia/PT, Lisbon/PT Keywords: Head and neck, CT, Diagnostic procedure, Neoplasia DOI: 10.1594/ecr2015/C-1664 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myESR.org Page 1 of 21 Learning objectives To review the most important neck CT landmarks, to help identifying lymph node level in CT scans using a visual and practical approach and to name the most important features to distinguish normal nodes from adenopathy. Background Cervical lymph node staging is very important in oncologic patient management, especially in patients with head and neck cancer. Following the anatomic classification by Rouvière, various classifications have been created grouping lymph nodes together on the basis of clinical and pathophysiologic information, which influence treatment procedures. Consensus groups, such as the American Joint Committee on Cancer and the American Academy of Otolaryngology-Head and Neck Surgery, developed clinically based nodal classifications. However these clinically based classifications are not always accurate, especially in deep tissue lymph nodes. In this poster we will use imaging-based nodal classification developed by Som. et al, which groups lymph nodes in levels and improves lymph node staging accuracy. CT scan offers detailed evaluation of the neck, including lymph nodes, therefore it is an essential tool in tumor staging. To correctly interpret neck CT scans it is very important to have good anatomy knowledge. Findings and procedure details To use the imaging-based nodal classification developed by Som its essential to know the anatomic landmarks of the classification: the skull base at the jugular fossa, the bottom of the body of the hyoid bone, the bottom of the cricoid arch, the top of the manubrium, the back edge of the submandibular gland, the back edge of the sternocleidomastoid muscle, the lateral posterior edge of the anterior scalene muscle, the anterior edge of the trapezius muscle, both the internal carotid and common carotid arteries, the internal jugular vein, the clavicle, the medial margin of the anterior belly of the digastric muscle, and the mylohyoid muscle. Page 2 of 21 Fig. 1 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 3 of 21 Fig. 2 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 4 of 21 Fig. 3 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level I includes all nodes above the hyoid bone, below the mylohyoid muscle, and anterior to the posterior edge of the sub-mandibular gland. Level IA represents the nodes that lie between the medial margins of the anterior bellies of the digastric muscles, Level IB represents the nodes that lie posterior and lateral to the medial edge of the anterior belly of the digastric muscle Page 5 of 21 Fig. 4 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 6 of 21 Fig. 5 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level II is limited cranially by the skull base and extends caudally to the the lower body of the hyoid bone. Level II nodes lie anterior to the posterior edge of the sternocleidomastoid muscle and lie posterior to the posterior edge of the submandibular gland. Level II nodes can be subclassified into levels IIA and IIB. Level IIA nodes are level II nodes that lie posterior to the internal jugular vein and are inseparable from the vein or that lie anterior, lateral, or medial to the vein. Level IIB nodes lie posterior to the internal jugular vein and have a fat plane separating the nodes and the vein Page 7 of 21 Fig. 6 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 8 of 21 Fig. 7 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level III nodes lie between the of the lower body of the hyoid bone and the level of the lower margin of the cricoid cartilage arch, anterior to the posterior edge of the sternocleidomastoid muscle and lateral to the medial margin of either the common carotid artery or the internal carotid artery. Page 9 of 21 Fig. 8 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 10 of 21 Fig. 9 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level IV nodes lie between the level of the lower margin of the cricoid cartilage arch the level of the clavicle, anterior and medial to an oblique line drawn through the posterior edge of the sternocleidomastoid muscle and the posterolateral edge of the anterior scalene muscle. The medial aspect of the common carotid artery is the landmark that separates level IV nodes (lateral to this artery) from level VI nodes (medial to this artery). Page 11 of 21 Fig. 10 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 12 of 21 Fig. 11 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level V nodes extend from the skull base, at the posterior border of the attachment of the stermocleidomastoid muscle, to the level of the clavicle. Level V nodes all lie anterior to the anterior edge of the trapezius muscle. Between the levels of the skull base and the bottom of the cricoid arch, these nodes are situated posterior to the posterior edge of the sternocleidomastoid muscle. Between the axial level of the bottom of the cricoid arch and the level of the clavicle, level V nodes lie posterior and lateral to an oblique line through the posterior edge of the sternocleidomastoid muscle and the posterolateral edge of the anterior scalene muscle. The level V nodes can be subdivided into VA and VB nodes. The lower margin of the cricoid is the landmark that separates level VA (superior to the cartilage) and level VB (inferior to the cartilage) Page 13 of 21 Fig. 12 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 14 of 21 Fig. 13 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 15 of 21 Fig. 14 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level VI nodes lie inferior to the lower body of the hyoid bone, superior to the top of the manubrium, and between the medial margins of the left and right common carotid arteries or the internal carotid arteries. Page 16 of 21 Fig. 15 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 17 of 21 Fig. 16 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Level VII nodes lie caudal to the top of the manubrium in the superior mediastinum, between the medial margins of the left and right common carotid arteries. These superior mediastinal nodes extend caudally to the level of the innominate vein. Page 18 of 21 Fig. 17 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Page 19 of 21 Fig. 18 References: Imagiologia Geral, Centro Hospitalar Lisboa Norte, Hospital de Santa Maria - Vila Nova De Gaia/PT Conclusion The presence and extent of nodal metastases in head and neck cancer has a great impact on treatment and prognosis. CT of the neck is commonly performed to identify nodal metastases. Therefore radiologists should be familiar with neck CT anatomy and lymph node levels to correctly interpret and report the exam. Personal information References Page 20 of 21 -Som, P; Curtin, H; Imaging-Based Nodal Classification for Evaluation of Neck Metastatic Adenophaty; AJR 2000;174:837-744 -Hoang, J;Vanka, J; Ludwig, B; Glastonbury, C; Evaluation of Cervical Lymph Nodes in Head and Neck Cancer With CT and MRI: Tips, Traps, and a Systematic Approach; AJR 2013;200:W17-W25 -Harnsberger, H R. Diagnostic Imaging: Head & Neck (2nd Edition). Amirsys, 2011. Page 21 of 21