 Good morning, everyone. Thank you for giving me this opportunity. I am Dr. Vyjayanthi Kadambi, post-graduate resident. And my guide is Dr. Sonia Sandeep, Associate Professor from the Department of Radio Diagnosis, ABVIMS, and Dr. RML Hospital, New Delhi. And my topic is MDCT imaging of vocal cord palsy. Vocal cord paralysis brought on by recurrent laryngeal nerve dysfunction may signal the presence of midiastinal illness, including a variety of neuroplastic, inflammatory, and vascular disorders. Patients with vocal cord paralysis usually present with hoarseness of voice. Utilizing routine CT of the neck, the radiologist can confidently suggest the existence of vocal cord paralysis even in the absence of history of hoarseness. Slow-growing tumors that infiltrate or surround the recurrent laryngeal nerve can produce CT abnormalities even before clinical paralysis is recognized. The larynx, hyperfarings, entire recurrent laryngeal nerve should be carefully examined once vocal cord palsy is discovered, clinically, or on a CT scan. In the recurrent laryngeal nerve, a branch of the vagus nerve supplies the intrinsic muscles of the larynx, except the cricothyroid, which is supplied by the superior laryngeal nerve. These intrinsic muscles control vocal cord motion and palsy can be caused by a lesion anywhere from the vagus nerve's brainstem nuclei to the point where the recurrent laryngeal nerve enters the larynx. The vocal cords are situated in the glottis and the glottis includes true vocal cords, anterior and posterior commissure. Peripheral vocal cord paralysis is more common than central with only 10% of them being central. The vocal cords are in a relaxed, abducted position during silent respiration, whereas breath holding causes the cords to come in a midline, abducted position. Vagal nuclei are situated within the medulla and any lesion in this region can cause vocal cord palsy. Bilateral vocal cord palsy in children is a strong indicator of central disease. When we come to the imaging, it can be divided into intracranial and extracranial parts. Intracranial includes the brainstem and the skull base. Here, bilateral vocal cord palsy is common and usually the onset of symptoms is acute. The area of the medullary nuclei of the vagal nerve can be best evaluated with MRI using T2, DWA and T1, contrast and non-contrast enhanced imaging. Demylinations, infarctions, tumors can involve the medulla and at the cisternal portion, the vagal nerve can be affected by external compression, by various extra-axial masses, vascular structures or by nerve pathologies like schwannoma, paraganglioma or neuritis. If multiple cranial nerves are involved, we should think of any pathology in the jugular foramen. And when we come to the extra-cranial vagal and recurrent laryngeal nerve palsy, this is best evaluated by multi-detector CT with contrast enhancement. Extracranial vagal or RLN palsy are seen usually in lung cancer with midiastinal lymph node metastasis and squamous cell carcinoma of the neck with or without local nodes metastasis. Other pathologies like infections, benign masses or malignancies can also cause vocal cord palsy. Aim of our study was to detect and characterize vocal cord paralysis with multi-detector computed tomography. Materials and methods, when you have the study, was Department of Radio Diagnosis at AB, BIMS and Dr. RML Hospital Delhi. It was a cross-sectional observational study done from July 2021 to September 2022. The sample size was 12 and it was done using a Siemens somatome definition flash, 128 slice dual-source CT scanners and it was performed in supine position at the end of full inspiration. Thin axial sections were taken from the base of skull to upper abdomen in plane and post-contrast phases. It was done in all patients suspected to have vocal cord paralysis on basis of clinical complaints of hoarseness of voice and laryngoscopy reports and the scans were analyzed to identify vocal cord paralysis and to look for the exact cause and localize the site of involvement. When VCP was suspected or confirmed clinically, quiet respiration was used for CT assessment of the larynx since it brings the vocal cords to an intermediate position. And our results and discussion of the 12 total patients, no patient had bilateral vocal cord paralysis, five of them had a right cord paralysis and seven patients had a left vocal cord paralysis. The clinical side of the paralysis was correctly diagnosed on imaging in all the 12 patients with unilateral disease. Among the 12 patients, six patients had palsy due to a neoplasm, five patients due to infective causes and one patient was due to trauma. Of the neoplasms, three patients had lung malignancy, two patients had esophageal malignancy and one had hypopharyngeal malignancy and among infective causes, four of them had left sided palsy and due to involvement of the EP window nodes while one patient had right vocal cord palsy. One patient also had a post-traumatic left hemiparosis with a resultant right vocal cord palsy. Among the three patients with lung malignancy, one patient had a perihylar mass with midiastinal involvement and left vocal cord palsy and two patients had a right upper lung mass with right vocal cord palsy. Among two patients with esophageal malignancy, one patient had a left palsy and other patient had a right palsy. Brief anatomy of the vagal and the recurrent laryngeal nerves. So the vagal nuclei are present in the medulla which travel to the pre-medullary systems, reach the jugular foramine and exit into the carotid sheath. The right recurrent laryngeal nerve leaves the vagus nerve anteriorly to the subclavian artery and runs posteriorly under the artery at the brachiosephylic bifurcation. It has a short mediastinal course running obliquely over the surface of the apical parietal pleura towards the right tracheosophageal groove while the left vagus nerve descends into the mediastinum in the carotid artery sheath on the left side before descending enterolaterally to the thoracic aorta. The left laryngeal nerve emerges from the vagus nerve at the level of the aortic arch and runs posterior medially beneath it passing through the ap window posterior to the ligamentum arteriosum. To reach the tracheosophageal groove it then ascends vertically through the superior mediastinum. Since the left recurrent laryngeal nerve is longer than the right, left palsy is more commonly encountered. Signs of vocal cord palsy can be divided into three. In direct signs, the paralysed cord and supporting features. In direct signs like enlarged laryngeal ventricle, aryepiglottic fold, medial deviation and thickening, dilatation of the piliform sinus, medial deviation of the arytenoid cartilage, wide vallicular and the cord itself is like pointing of the atrophied cord, subglottic fullness, paramedium position of the true cord. And supporting features can be posterior cricoarytenoid muscle atrophy, paralytic curve of the subglottic arch. Some representative images of our cases, there is a coronal reformatted CT image which shows loss of the subglottic arch, ipsilateral laryngeal ventricle and pyreform sinus enlargement and pointing and an atrophied ipsilateral vocal cord. The image on the right side shows a left RLN palsy where there is distention of the ipsilateral pyreform fossa and immediately rotated thickened ipsilateral aryepiglottic fold. Another axial CT where there is enlargement of the ipsilateral pyreform sinus and on the right there is the mushroom-like appearance of the airway due to combination of ipsilateral laryngeal ventricle dilatation and posterior cord medialization. The axial contrast and ansity shows ill-defined heterogeneously enhancing soft tissue mass with its epi-center in the left hyalur region extending to involve the AP window leading to a left recurrent laryngeal nerve palsy in this patient. Axial contrast enhanced CT shows a heterogeneously enhancing soft tissue thickening of the thoracic esophagus to involve the tracheoesophageal groove leading to a right recurrent laryngeal palsy. My conclusion is vocal cord paralysis can be caused by a variety of common and uncommon midiastinal disease entities and it can also be the only presenting symptom of a clinically occult disease or malignancy. Fast-speed high spatial resolution and volumetric imaging with MPR makes CT the technique of choice for non-invasive conformation and localization of the cause of vocal cord paralysis. These are my references.