Salivary Glands PDF

DSX 3120 Salivary Glands Imaging DR. MD. MAHMUD UZ ZAMAN BDS, PhD Asst. Prof. Oral and Maxillofacial Surgery and Diagnostic Sciences Department  Ch 32 Salivary Gland Diseases Oral Radiology, Principles and Interpretation By Mallya & Lam. (8th Ed.) ...

DSX 3120 Salivary Glands Imaging DR. MD. MAHMUD UZ ZAMAN BDS, PhD Asst. Prof. Oral and Maxillofacial Surgery and Diagnostic Sciences Department  Ch 32 Salivary Gland Diseases Oral Radiology, Principles and Interpretation By Mallya & Lam. (8th Ed.) Major Salivary Glands Minor Salivary Glands  The Parotid Salivary Glands The largest major gland. Purely serous. Main part: wedge-like Small deep part Parotid (Stensen) duct. Produce 30% of total saliva.  The Parotid Salivary Glands Lymphatic Drainage Lymph Nodes inside the parotid gland. Drains into preauricular or parotid lymph nodes which ultimately drain to the deep cervical chain  The Parotid Salivary Glands Cross-Section Below the Llingula Ramus of the mandible Parotid Duct Superficial lobe ECA Deep lobe Sternocledomastoid m The Parotid Salivary Glands Adjacent Structures  The Parotid Salivary Glands Facial Nerve Trunk of VII The Parotid Salivary Glands Orifice of the Parotid (Stensen) Duct  The Submandibular Salivary Glands Mixed (mostly serous). Lies between the mandible, mylohyoid m. and hyoid bone as a wedge occupying the submandibular fossa. Drains into the mouth by Wharton's duct. The duct travels forward upward. Constitute 60% of saliva.  The Submandibular Salivary Glands Coronal Section Behind the 1st Molar  The Submandibular Salivary Glands Orifice of the Submandibular (Wharton) Duct  The Sublingual Salivary Glands Lies under the tongue below the floor. Constitute 5% of total saliva. It has 10-20 small ducts open in the submandibular duct or directly in the floor.  Minor Salivary Glands Numerous and present in buccal mucosa, labial, palatal mucosa, tongue and floor of mouth Mucous and secret continuously. Ductal Structure  Imaging of Salivary Glands Plain (intra-or extra oral): Show stones and bone lesions. Sialography: Only ductal structure, gland function & obstruction CT: Bony and soft tissue lesions MRI: Excellent for soft tissue masses Scintigraphy (radioisotope imaging): Function US (Ultra-Sonography): Soft tissue and vascular lesions  Plain radiography Illustrate sialoliths (stone). Shows bone involvement to exclude salivary gland diseases. Show bony changes that cause peri-auricular swelling. Under exposed Lat. Skull  Sialography A radiographic technique in which a contrast agent is infused into the ductal system of the major SG prior to imaging. Technique: 1- Scout view: PA or Lat. Oblique – To determine exposure parameters. – To demonstrate radiopaque calculi. – To detect extra-glandular or bone diseases. Sialography Sialography Technique Sialography Technique Parotid Sialography 2- Dilation of the orifice Parotid Sialography 3- Canulation Parotid Sialography 4- Media injection and imaging  Parotid Sialography Lateral Oblique view of the mandibular ramus  Hilum Intercalated ducts Parotid gland duct (Stensen’s) Collecting ducts Alveoli Parotid Salivary gland Sialogram Parotid Sialography Under exposed PA views Submandibular Sialography Lateral Oblique views of the mandibular body Submandibular Sialography Lateral views of the mandible Submandibular Sialography Lateral view with subtraction C spine Hilum Hyoid bone Submandibular Chin gland duct (Wharton’s) Collecting ducts Inferior border of mandible Submandibular Salivary gland Sialogram Sialography Technique 5- Post-Evacuation radiographs: Unstimulated Stimulated  Contraindications of Sialography Sensitivity to contrast agents Acute Sialadenitis Obstruction in the distal 1/3 of the duct.  Sialographic Interpretation Detailed knowledge of the radiographic appearance of normal salivary gland. Duct: Course and diameter. Ducts within gland: Branching gradually, taper toward the periphery and overall shape. Glandular filling and emptying. Pathologic conditions that affecting the salivary gland.  Normal sialographic appearance Parotid Main duct: 1-2mm Even Filled uniformly Branching gradually inside the gland Tree in winter appearance Parotid Sialography Tree in winter appearance  Normal sialographic appearance Submandibular Main duct: 3-4mm Even Filled uniformly Branching gradually but smaller than parotid Bush in winter appearance  Pathological Sialographic Appearance Definitions Sialolithiasis: Salivary calculus or stone obstruction within the duct or gland. Bacterial sialadenitis: Acute or chronic bacterial infection of the terminal acini of sg. Sialodochitis: Inflammation of the ductal system of sg. Sialectasia: Dilation of salivary ducts. Sialosis (sialadenosis): Non-neoplastic, non-inflammatory enlargement of sg usually related to metabolic and secretory disorders (hormonal, malnutrition, alcoholics, and neurological disorders).  Sialographic Evidence of Salivary Gland Disease Sialolithiasis Sialodochtitis Sialadenitis Tumor Radiopaque or Segmental Dilation of Large Filling Filling Defect Constriction of Ducts Terminal Ducts Defect Retained Contrast Agent Retained Contrast Compression Agent (in Acini) Incomplete Filling Slow Filling Normal Filling Displacement  Pathological sialographic appearance Calculi (sialolithiasis) Filling defect Ductal dilatation Retained contrast on emptying The submand. duct (Wharton) is by far the most frequently affected Submandibular Sialography Calculi (Sialolithiasis) Parotid Calculi (Sialolithiasis) Seen on a lateral skull scout view  Calculi (Sialolithiasis) Same pt in the previous slide: PA view Calculi (Sialolithiasis) Calculi (Sialolithiasis) Tori? Fused to bone? Calculi (Sialolithiasis) In Wharton duct Calculi (Sialolithiasis) In Wharton duct Calculi (Sialolithiasis) Underexposed Panoramic film  Calculi (Sialolithiasis) Submandibular Salivary gland Sialogram Obstructed Wharton’s duct Contrast flowing around the stone  Pathological sialographic appearance Sialaduchitis: Inflammation of the ductal system of SG. Segmented sacculations and strictures of the main duct, SAUSAGE appearance Associated calculi or ductal stenosis.  Sialaduchitis Submandibular Salivary gland Sialogram SAUSAGE appearance: Dilations & constrictions in the ducts Sialectasia: Dilation of salivary ducts. Submandibular Salivary gland Sialogram  Autoimmune Diseases Mikulicz’s disease: Chronic bilat. hypertrophy of the lacrimal and parotid SG with no other symptoms. 1º Sjögren's Syndrome: Xerophthalmia (keratoconjunctivitis sicca) and xerostomia (also called sicca syndrome). » , When associated with other systemic CT disease (Rhum. Arth., SLE…etc) it is called 2º Sjögren's Syndrome. When the SG enlarge and simulate a tumor the lesion is called benign lymphoepithelial lesions (BLEL).  Sjögren's Syndrome A 45 yo female with extensive primary and recurrent caries Filling stage Lat. Skull of parotid sialogram PA of parotid sialogram  Sjögren's Syndrome Same pt. As in previous slide 30 post Evacuation 3 h. post Evacuation Lat. Skull views Sjögren's Syndrome Same pt. As in previous slide PA Skull 25 h post Evacuation Retention of contrast media inside the gland indicating non-functioning gland Autoimmune Sialadenitis Stage Silaographic Changes % 0 Normal 20% I Punctate 40% II Globular 27% III Cavitary 6% IV Destructive 7% Findings in 82 sialographic examinations of glands of Sjögren's Syndrome pt  Autoimmune Sialadenitis punctate and spherical collections of contrast agent within the gland that remain after sialogogue (sialectasia), later larger pools of contrast accumulation (cavitary sialectases)  Mass effect (Ball in Hand Appearance) Duct is smoothly displaced around the mass. Indicating the presence of a mass inside the parotid gland. Sialography is of little value in the diagnosis of intragladular masses. PA of parotid sialogram MRI  MRI Strong magnetic fields (usually 1.5 Tesla) 1 Tesla = 10,000 gauss (the magnetic field of the earth= 0.5 gauss) Normal MRI Appearance- Parotid gland T1-weighted T2-weighted Intermediate-high Low-intermediate Normal MRI Appearance- Submandibular gland T1-weighted T2-weighted Slightly lower signal Slightly higher signal intensity intensity  Coronal MRI NP Nasopharynx OP Oropharynx T Tongue M Masseter m LP MP Medial Pterygoid m NP LP Lateral Pterygoid m M MP P MR Mandibular Ramus OP P Parotid SG SM Submandibular SG T SM  Coronal MRI C P C Head of Mandibular Condyle P Parotid SG  Sag. MRI C Mandibular Condyle MS Maxillary Sinus EAC External Auditory canal PG Parotid Gland. ECA External Carotid a. MS C EAC PG  MRI Axial Sagital Stensen’s Duct Parotid SG This 12 yo boy has a soft, painless swelling over Rt. parotid. He first noticed it 3 years ago. Intraoral examination was unremarkable.  Axial MRI Axial MR T1 Axial MR T2 Pleomorphic Adenoma Axial MRI Cyst Normal Parotid Gland CT Axial CT Parotid SG Submand. SG Axial CT with contrast ma Mandible sl Sublingual gland gg Genioglossus m. mh Mylohyoid m. lt lingual tonsils sm submandibular gland d Posterior Belly of Digastric pg Parotid gland c Carotid a. j Internal Jugular v. s Sternocleidomastoid m. v Vertebral a. Parotid hemangioma  Warthin’s Tumor Axial section Coronal section  Pnumo Parotid Air in the parotid duct and gland Scintigraphy (radioisotope imaging)  Scintigraphy (radioisotope imaging) Saliva excreated in Parotid the mouth Subman. Thyroid 0-5 min 6-15 min * 16-20 min 21-25 min *=Acid stimulation at 15 min. Parotid Subman. * * Scintigraphy (radioisotope imaging) Single-Photon Emission CT (SPECT) CT CT Ultrasound (US) Ultrasound (US) Ultrasound (US) Cyst Ultrasound (US) Fine internal echo Tumor (Pleomorphic Adenoma)  Salivary Gland Diseases Inflammatory: – Acute: e.g. Mumps – Chronic: e.g. Sjögren's syndrome – 2nd : Sialolith, trauma, infection, space-occupying lesions. Non-inflammatory: – Metabolic & secretory abnormalities. – Malnutrition. – Neurological disorders. Space-occupying masses: – Cysts. – Neoplastic: » Benign. » Malignant.  DDx Mass superficial to the gland suggests lymphadenitis, an infected preauricular cyst, an infected sebaceous cyst, benign lymphoid hyperplasia, or an extraparotid tumor. A mass intrinsic to the gland suggests a neoplasm (benign or malignant), intraglandular lymph nodes, or hamaratoma. Rapid growth, facial paralysis, rock-hard texture, pain, ulceration, and older age of occurrence are clinically suggestive of malignant neoplasims. Neoplasms of the submand. gland have a greater chance of being malignant than do those of the parotid.  DDx of SG tumor 80% of SG tumors arise in the parotid. 70-80% in superficial lobe of parotid. Most are benign or low-grade malignancies. Incidence of benign SG tumors increase with the size of the gland. Pleomorphic Adenoma accounts for 75% of SG tumors. 80% of Pleomorphic Adenoma are found in the parotid gland, 4% in the submand., 1% in the sublingual, and 10% in minor SG. Hemangioma is the most common SG tumor during infancy and childhood. Pleomorphic Adenoma Axial T1 MRI demonstrate a sharp circumscribed, homogeneous low-signal oval mass (arrow) in the posterior medial parotid gland. Pleomorphic Adenoma Coronal T1 MRI  DDx of Enlargements in the Parotid Area Unilateral: – Bacterial sialadenitis No mass, just diffused swelling – Sialodochitis. – Cysts. – Benign neoplasm. – Malignant neoplasm. mass intrinsic to the gland – Intraglandular lymph node. – Masseter muscle hypertrophy. – Lesions in adjacent osseous structures.  DDx of Enlargements in the Parotid Area Bilateral: – Bacterial sialadenitis. – Viral sialadenitis (mumps). – Autoimmune Diseases (Sjögren’s Syndrome, Mikulicz disease, BLEL). – Warthin’s tumor. – Alcoholic hypertrophy. – Medication induced (iodine, heavy metals). – HIV-associated multicentric cysts. – Masseter muscle hyperplasia. – Accessory salivary gland. – TMJ-related lesions. – Radiation therapy. DDx of Enlargements in the Submand. Area Unilateral: – Bacterial sialadenitis. Enlargement, pain, tender lymph nodes, decreased – Sialodochitis. salivary flow. – Fibrosis. – Cyst. – Benign neoplasms. No tender lymph nodes – Malignant neoplasms. – AV malformation.  DDx of Enlargements in the Submand. Area Bilateral: – Bacterial sialadenitis. – Autoimmune sialadenitis. – Lymphadenitis. – Brachial cleft cysts. – Submandibular space infection.  Mumps Commonest cause of acute painful swelling of the parotid gland in children Due to paromyxovirus infection Flu-like illness is followed by acute bilateral painful parotid swelling Resolves spontaneously over 5 -10 days Occasionally parotid swelling may be unilateral Occasionally may affect submandibular glands. The End