Mimics of Neck Lesions in Post Treatment Neck Surveillance

Abstracts and exquisitely displayed by US using a high-frequency linear array transducer. In most of the cases, US can differentiate cystic from solid lesions. For the cystic lesions, the imaging diagnosis is based on location. The midline or paramedian location of cystic neck masses in pediatrics mostly are thyroglossal duct cyst and dermoid/epidermoid when locating between hyoid bone and thyroid gland, ranula or plunging ranula when locating in sublingual or submandibular spaces, and dermoid/epidermoid again when locating at suprasternal notch. Epiglottic cyst can also be detected in its typical location when there is no intervening air. The laterally-located cystic lesions are branchial cleft cyst, venolymphatic malformation, and phlebectasia of the jugular vein. Lymphatic malformation has its typical location in posterior triangle of the neck. Contents within cystic neck masses in many cases are not echo-free and may appear as pseudo-solid lesions on US. For the solid neck masses in pediatrics, US usually can tell whether it is an enlarged lymph node or not. Like in adult, US may depict the suspicious lymph node for biopsy. The imaging diagnosis of the solid neck masses other than enlarged lymph nodes in many cases are nonspecific and need histological diagnosis. However, there are some typical solid lesions that the diagnosis could be provided, e.g., fibromatosis colli, infantile hemangioma, ectopic thymus, and ectopic thyroid. Symposium

T13-14-IN01 The Role of Ultrasound in Imaging Obstructive Salivary Gland Diseases E. Dai, W. K. Tang, A. T. Ahuja Department of Imaging & Interventional Radiology, The Chinese University of Hong Kong, Hong Kong SAR, China Advances in minimally invasive treatment have altered the management of obstructive salivary gland diseases. It requires early detection & cause of the obstruction, it’s anatomical site, & any associated complications. The imaging modalities to evaluate these conditions include Xray/orthopantomogram, ultrasound, conventional/digital subtraction sialography, CT/CBCT, MRI. The superficial location of the major salivary glands render them readily amenable for examination with high resolution ultrasound, particularly the sublingual & submandibular glands. Although the superficial parotid can be evaluated with ultrasound, the deep lobe is obscured by the mandible & cannot be visualized. In addition to identifying the cause of obstruction, imaging, including ultrasound evaluates associated changes in glandular parenchyma, abscess/ mucocele/sialocele, Kuttner tumour formation & glandular atrophy. This presentation will discuss the role of ultrasound as 1st line investigation amongst the gamut of available imaging modalities, it’s advantages & limitations & the appropriate choice of other imaging modalities when ultrasound fails. T13-14-IN02 Pearls and Pitfalls in Ultrasound of Pediatric Head and Neck Panruethai Trinavarat Radiology, Chulalongkorn University, Bangkok, Thailand US is the first imaging method for several diseases of the head and neck in pediatric patients, including developmental and acquired lesions. To get the most benefit out of US examination, good technique in scanning and good knowledge in interpretation are required. Knowledge of developmental disorders (e.g., thyroglossal duct cyst, branchial cleft or pouch anomalies), unique pediatric normal structures (e.g., thymus, palatine tonsil) and the ones in ectopic location (e.g., thyroid, thymus, parotid), unique pediatric diseases (e.g., hemangioma, fibromatosis colli), awareness of a pseudo-solid or pseudo-cystic lesion and adding techniques to

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clarify (e.g., adjust settings, turn on color mode, compressing), knowing the artifacts (e.g., mirror image from skull), and getting the most out of clinical information (e.g., patient’s age, mass appears only in specific position or situation, sign of inflammation) are very important for scanning and interpretation. Many of the pitfalls are from not following the basic ultrasound scanning instructions. The examples of the basic instructions are selecting the appropriate type and frequency of the transducer, covering the appropriate depth, selecting proper window for scanning, scanning in two orthogonal planes, and comparing the echogenicity. T13-14-IN03 High Resolution Ultrasound of Paediatric Neck Prof. P. K. Srivastava, MBBS, MD (Radiology), FICR, FICMU Professor, Deptt. Of Radiodiagnosis, King George’s Medical University, Lucknow High resolution ultrasound is an excellent modality of evaluation of paediatric neck. The excellent tissue details and anatomical landmarks in the neck like thyroid cartilage, trachea, strep muscles and neck vessels have made assessment of the neck masses a practical proposition. The neck masses are divided into two major groups, 1. Thyroid neck masses 2. Non thyroid neck masses. The non thyroid neck masses include cervical masses, lymph node mass, salivary gland masses, nerve tumors, vascular masses, inflammatory masses, parasitic infestations, congenital masses, benign and malignant neck tumors. High resolution ultrasound is multi planner, non invasive, cost effective imaging modality, which is having advantage of CT scan and MRI, since the spatial resolution of ultrasound is much better than CT and MRI. The biggest advantage is that it is dynamic modality, which does not require any sedation or special preparation for evaluation of neck masses. The excellent tissue characterization of various structures in the neck on ultrasound, clearly differentiate different pathologies. The 3D ultrasound with multi planner imaging increases the diagnostic accuracy. The lecture is only restricted to non thyroidal soft tissue masses of the neck. T13-14-IN04 Mimics of Neck Lesions in Post Treatment Neck Surveillance Asif Abalal Momin Chief of Imaging, Prince Aly Khan Hospital, Mumbai, India This talk highlights the possible mimics seen in a busy oncology centre during a follow up imaging, especially ultrasound (US) of the neck. Various innocuous findings may be mistaken for recurrent or residual disease causing confusion due to inexperience or an apparent lack of knowledge. All the findings, which may lead to an erroneous diagnosis, have been divided into the following categories. Thyroid and salivary gland abnormalities, nodal, vascular, neurogenic, cartilaginous, bony and soft tissue abnormalities. These include several conditions which mimic metastatic nodes, extra capsular nodal spread, residual lesions of thyroid bed, parathyroid adenomas and a few specific lesions such as Kutteners tumor of submandibular gland. Post operative or foreign body granulomas may mimic soft tissue recurrences or laryngeal neoplasm. In two cases parasitic pathology was identified causing concern for neoplasm. Calcified, necrotic or non necrotic tuberculous lymph nodes also form an important subset due to its high incidence in some countries. Normal thymic and tonsillar tissue also adds to the confusion. These various normal and abnormal findings in Head and Neck cancer follow-up need to be understood by radiologists of various levels of expertise in busy imaging departments. T13-14-IN05 How Does Ultrasound-Guided Core Biopsy Change the Clinical Practice of Diagnosing Head and Neck Diseases Tsung-Lin Yang, MD, PhD