CRISPS: A Pictorial Essay of an Acronym to Interpreting Metastatic Head and Neck Lymphadenopathy  Adam A. Dmytriw, MSc, Ahmed El Beltagi, MD, Eric Bartlett, MD, MPH, Arjun Sahgal, MD, Colin S. Poon, MD, PhD, Reza Forghani, MD, PhD, Girish Fatterpekar, MD, Eugene Yu, MD  Canadian Association of Radiologists Journal  Volume 65, Issue 3, Pages 232-241 (August 2014) DOI: 10.1016/j.carj.2013.07.004 Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 1 (A-D) Computed tomography examples of pathologically proven malignant neck adenopathy. The images show the presence of subcentimetre-sized clustered nodes in the neck (arrows). Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 2 (A) A computed tomography (CT) image, showing a cluster of 3 left periparotid nodes (arrow) related to pathologically proven prostate carcinoma. (B) A coronal CT image, showing several enlarged but vertically elongated nodes, which were reactive in a patient with a tonsillar abscess. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 3 Contrast computed tomography, showing the difference between a normal elongated node with prominent central fatty hila (short arrow) and a node with ill-defined central vague low attenuation secondary to early necrosis (long arrow). The normal node maintains a normal reniform shape and the central hila shows very-low fatty attenuation. The metastatic node shows a more-rounded shape, and the internal low attenuation is low but does not reach the degree of attenuation of fat. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 4 (A, B) Contrast computed tomography images in 2 patents that both show marked nodal heterogeneity secondary to nodal necrosis (arrows). The presence of small gas lucencies (A) is secondary to tissue biopsy. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 5 Axial fat saturation T2 image (A) and coronal T2 image (B) in 2 different patients with head and neck carcinoma, showing areas of internal heterogeneity within neck nodes. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 6 (A-C) Axial contrast computed tomography images, showing the presence of subcentimetre-sized left level IB and IIA nodes (arrows in A, B) in a patient with an unknown primary carcinoma. (C) A patient with a carcinoma that involves the right mandibular alveolus (long arrow); note the small right level IIA node (short arrow). Although not considered enlarged by imaging size criteria, this node was noted to be pathologic after neck dissection. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 7 Axial T2 fat saturation image, showing bilateral retropharyngeal nodes that are suspicious based on their enlarged size as well as their rounded shape. This patient had nasopharyngeal carcinoma (not shown). Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 8 An axial computed tomography image of a patient with pharyngitis and associated reactive bilateral level II adenopathy (arrows). Note the mild degree of enhancement and enlargement. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 9 Two examples of enhancing nodal disease that reflect the presence of vascular metastases. (A) A sagittal image of a patient with metastatic papillary thyroid carcinoma, showing markedly enhancing and heterogeneous adenopathy along the right jugular chain. (B) Axial image, showing an enhancing right level II node (arrow) secondary to metastatic neuroendocrine carcinoma. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 10 (A-C) Contrast computed tomography images in 3 different patients with metastatic adenopathy. In each case, there is an indistinct peripheral margin to the nodes (arrows), which represents extracapsular extension of tumour into the surrounding tissues. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 11 (A-C) Three different patients with examples of left (A, C) and right (B) sided carotid encasement. (A) The tumour has encircled more than three-fourths of the vessel circumference. (B) and (C) show complete circumferential tumour that is also narrowing the calibre of the carotid (arrows). Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 12 An example of a sentinel node. Axial T2 image, showing a large left tongue base carcinoma. These lesions have a high rate of nodal involvement and typically drain into the ipsilateral level II region of the neck (arrow). Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 13 (A, B) Axial contrast computed tomography, showing a right-sided buccal carcinoma (long arrow). Nodes at risk of metastatic involvement include the ipsilateral level IB nodes (short arrow). The second image shows the presence of 2 right level IB nodes, which are otherwise normal appearing in the context of the various radiographic criteria. Their radiographic suspicion is raised only by the context that they are mildly prominent and are in the primary drainage pathway of the known buccal carcinoma. These nodes were positive after neck dissection. Canadian Association of Radiologists Journal 2014 65, 232-241DOI: (10.1016/j.carj.2013.07.004) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions