Salivary Gland Imaging PDF

SALIVARY GLAND IMAGING DR RESHMA V J CONTENTS  Introduction  Clinical features  DIAGNOSTIC IMAGING OF THE SALIVARY GLAND  Plain film radiography  Sialography  MRI  CT  Ultrasound  Scintigraphy INTRODUCTION  Salivary gland disease processes may be divided into the following clin...

SALIVARY GLAND IMAGING DR RESHMA V J CONTENTS  Introduction  Clinical features  DIAGNOSTIC IMAGING OF THE SALIVARY GLAND  Plain film radiography  Sialography  MRI  CT  Ultrasound  Scintigraphy INTRODUCTION  Salivary gland disease processes may be divided into the following clinical categories:  Inflammatory disorders,  Noninflammatory disorders, and  space-occupying masses  Inflammatory disorders – ◦ acute or chronic ◦ sialoliths, trauma, infection, or space-occupying lesions such as neoplasia.  Noninflammatory disorders- metabolic and secretory abnormalities, malnutrition, and neurologic disorders.  Space-occupying masses◦ cystic or ◦ Neoplastic- (benign or malignant.) Clinical signs and symptoms Unilateral or bilateral swellings  Pain  Altered salivary flow  APPLIED DIAGNOSTIC IMAGING OF THE SALIVARY GLAND  Diagnostic Imaging of salivary gland disease –  to differentiate inflammatory processes from neoplastic disease  distinguish diffuse disease from focal suppurative disease  identify and localize sialoliths  demonstrate ductal morphology  determine the anatomic location of a tumor  differentiate benign from malignant disease  demonstrate the relationship between a mass and adjacent anatomic structures  aid in the selection of biopsy sites. Algorithm for diagnostic imaging  Plain film radiography  Sialography  MRI  CT  Ultrasound  Scintigraphy Plain film radiography IOPA  OCCLUSAL RADIOGRAPH  PANORAMIC RADIOGRAPH  LATERAL OBLIQUE  ANTEROPOSTERIOR PROJECTIONS  B A A, Underexposed mandibular occlusal radiograph demonstrating radiopaque sialolith in Wharton duct B, Periapical radiographs of the same case. C sialoloith is not always radiopaque, it going to stages Anterior posterior radiograph CONVENTIONAL SIALOGRAPHY  First performed in 1902, Search in google how to search Performed to nd the ductal morphology  radiographic technique wherein a radiopaque contrast agent (Iodine) is infused into the ductal system of a salivary gland before imaging with plain films, fluoroscopy, panoramic radiography, CT etc.  most detailed way to image the ductal We inject unit the patient feel his check is full system Procedure  First pre-procedure: We take anterior posterior radiograph Post- procedure The procedure is divided into three phases  The preoperative phase  Filling phase  Emptying phase  A surveyor "scout" film  a lacrimal or periodontal probe is used to dilate the sphincter at the ductal orifice  Lipid-soluble or non lipid-soluble contrast solution slowly infused until the patient feels discomfort (usually between 0.2 and 1.5ml).  These iodine containing agents render the ductal system radiopaque.  The intent is to opacify the ductal system all the way to the acini. Q: What is the normal appearance for sialogram? A: Tree limbs  The image of the ductal system appears as "tree limbs," with no area of the gland devoid of ducts.  With acinar filling, the "tree" comes into "bloom," which is the typical appearance of the parenchymal opacification phase  The gland is allowed to empty for 5 minutes without stimulation.  If post evacuation images - contrast retention- a sialogogue such as lemon juice or 2% citric acid may be administered A B A, Lateral projection of the parotid demonstrating opacification all the way to the terminal ducts and acini. B, Anteroposterior projection of the same gland demonstrating “ parenchymal blushing ” from acinar opacification Sialogram of Normal Submandibular Gland. This lateral view demonstrates parenchymal blushing. Normal fine branching is visible. Lack of parenchymal blushing at the anteroinferior margin is caused by radiographic burnout. Very important slide  Indication ◦ for the evaluation of chronic inflammatory diseases ◦ ductal pathoses.  Contraindications ◦ acute infection ◦ known sensitivity to iodine-containing compounds ◦ Immediately anticipated thyroid function tests Functional analysis  SCINTIGRAPHY One technique to detect all glands provides a functional study of the salivary glands KNOW THE FULL NAME WITH CORRECT SPELLING  99m Technetium (Tc)-pertechnetate is injected intravenously  The radionuclide appears in the ducts of the salivary glands within minutes and reaches maximal concentration within 30 to 45 minutes  All major salivary glands can be studied at once. Q: what is the only technique for functional analysis salivary glands? A: scitntography A B Scintigraphy. A, 99m Tc-pertechnetate scan of the salivary glands (right and left anterior oblique views) demonstrates increased uptake of radioisotope in the right parotid gland (black arrowhead). B, Scintigram taken after administration of a sialogoge (lemon juice) demonstrates retention of isotope in right parotid gland (white arrowheads). This is a typical presentation of salivary stasis, Warthin tumor, or oncocytoma. CT  useful in evaluating structures in and adjacent to salivary glands;  it displays both soft and hard tissues, as well as minute differences in soft tissue densities.  Useful in assessing acute inflammatory processes and abscesses, as well as cysts, mucoceles and neoplasms.  Calcifications, such as sialoliths are also well depicted with CT MRI :  Provides better images of soft tissue structures than does CT.  It demonstrates the margins of salivary gland masses, internal structures and regional extension of lesions into adjacent tissues / spaces.  Ultrasonography: Helps in differentiating solid masses from cystic ones. Image Interpretation of Salivary Gland Disorders OBSTRUCTIVE AND INFLAMMATORY DISORDERS  Sialolithiasis(Calculus and salivary stones)  formation of a calcified obstruction within the salivary duct  Radiographic Features  Depending on their degree of calcification, sialoliths may appear either radiopaque or radiolucent on radiographic examinations  vary in shape from long cigar shapes to oval or round shapes.  homogeneous radiopaque internal structure.  Sialography is helpful in locating obstructions that are undetectable with plain radiography  Radiolucent sialoliths appear as ductal filling defects obstruction This partial image of a standard mandibular occlusal film reveals the presence of a sialolith (arrow). B, Sialograph of the same patient demonstrating flow of contrast past the stone (short arrows) and a negative filling defect (long arrow) from a smaller radiolucent sialolith. Sialodochitis(Ductal sialadenitis)  inflammation of the ductal system of the salivary glands.  Radiographic appearnace  Sialography- Doctor favorite question for exam  sausage-string appearance of the main duct Lateral view of a sialogram of a parotid gland demonstrating a negative fill defect (arrow) representing a noncalcified sialolith and prominent intermittent stricture and dilation of the main and secondary ducts, which is typical of advanced sialodochitis. Bacterial Sialadenitis  acute or chronic bacterial infection of the terminal acini or parenchyma of the salivary glands. It’s contraindicated because its acute in ammation  Radiographic Features  Sialography is contraindicated in acute infections because disrupted ductal epithelium may allow extravasation of contrast agent, resulting in a foreign body reaction and severe pain.  This technique is appropriate for use in cases of suspected chronic infections.  Epithelial flattening may lead to mildly dilated terminal ducts and saclike acini, which is demonstrable with sialography. r d about it Autoimmune Sialadenitis  main 3 Stages represents a group of disorders that affect the salivary glands (Sjögren n syndrome, benign lymphoepithelial lesion, Mikulicz disease, and autoimmune sialosis) very important Radiographic Features  Sialography is helpful in the diagnosis and staging of autoimmune disorders.  The early stages of disease - punctate (less than 1 mm) and globular (1 to 2 mm) spheric collections of contrast agent evenly distributed throughout the glands. These collections are referred to as sialectases 3 Stages  As the disease progresses, the collections of contrast agent increase in size (greater than 2 mm in diameter) and are irregular in shape.  These pools of contrast agent are termed cavitary sialectases . These larger sialectases are fewer in number and less uniformly distributed D  O At the end point of this disorder- complete destruction of the gland occurs. Focal collection of dye We can’t see the gland Conventional Sialography of Left Parotid. A, Lateral projection demonstrates punctate sialectases distributed throughout the gland, which is suggestive of autoimmune sialadenitis. . Clinical/histopathologic diagnosis was Sjögren syndrome It’s larger than the previous one Sialography of the Left Parotid. Punctate (small spheric), globular (larger spheric), and cavitary (larger, irregular) sialectases with some dilation of the main duct are suggestive of advanced autoimmune disease with parenchymal destruction with retrograde infection in lateral (A) and anteroposterior (B) projections. Clinical/histopathologic diagnosis was Sjögren syndrome NONINFLAMMATORY DISORDERS Sialadenosis (sialosis)  Sialadenosis is a nonneoplastic, noninflammatory enlargement of primarily the parotid salivary glands. NON IFNLAMMATORY NON NEOPLASTIC DIABETICS ALCHOLOICS   Clinical Features Affected glands are typically enlarged.   Radiographic Features Sialography may demonstrate enlargement of the affected glands or a normal appearance. In enlarged glands, the ducts will be splayed. Cystic Lesions  Rare  most commonly occur unilaterally in the parotid gland  They may be congenital (branchial), lymphoepithelial, dermoid, or acquired, including mucous retention cysts Radiographic Features   On sialographic examination, cystic masses may be indirectly visualized only by the displacement of the ducts arching around them. When imaged with US, cysts are sharply marginated and echo free (represented as a dark area) Ultrasonography Image of the Parotid Gland. Echo-free mass with well-defi ned margins presents a typical cystic appearance (arrows). Here represent as hypo echo sound based Here we don’t use radiolucent and radio opaque because its sound based Hypo echo and hyper echo Hyper echo = radiopqaue and hypo echo = radiolucent BENIGN TUMORS  Radiographic Features  MRI is a preferential modality for salivary gland neoplasia, especially for the submandibular gland, because of its superior soft tissue contrast resolution.  On US examination, benign masses are typically less echogenic than parenchyma, sharply defined, homogeneous.  Sialography may suggest a space occupying mass when the ducts are compressed or smoothly displaced around the lesion (the “ ball-in-hand ” appearance) Q: cherry blossom appearance or fruit branchless appearance SEEN IN SJORGEN SYNDROME WEILL CAME IN EXAAAAAAAAAM A EXIF Sialogram of Left Parotid (Anteroposterior View). A mass within the gland is inferred by the appearance of the ducts displaced around the lesion. This is referred to as the “ ball-in hand ” appearance, which is suggestive of a space-occupying mass. Hemangioma Classi cation of the blood vessels = pheliobolith  benign neoplasm of proliferating endothelial cells  most common salivary gland tumor during infancy and childhood Radiographic Features No details to MRI  Phleboliths -appear as discrete soft tissue calcifications with a radiolucent center  Displaced ducts curving about the mass may also be apparent on sialography.  CT presentation -soft tissue mass that is well distinguished from surrounding tissue, especially when intravenous contrast enhancement is used.  MRI- tumor has a signal similar to that of adjacent muscle onT1weighted images and a very high signal on T2-weighted images.  US -well-defined margins in the hemangioma. Phleboliths image as multiple hyperechoic areas within the body of the gland itself. MALIGNANT TUMORS  About 20% of tumors in the parotid are malignant compared with 50% to 60% of submandibular tumors, 90% of sublingual tumors, and 60% to 75% of minor salivary gland tumors   Radiographic Features The radiographic presentation of malignant tumors is variable and is related to the grade, aggressiveness, location, and type of tumor.  In many cases it is not possible to determine whether a tumor is malignant or benign  features such as ill-defined margins, invasion of adjacent soft tissues (such as fat spaces), and destruction of adjacent osseous structures are considered to be typical indicators of malignancy. This axial soft tissue algorithm CT image reveals an adenocarcinoma of the left parotid gland. Almost all the gland has been replaced by this ill-defined tumor Ultrasonography. The mass in the submandibular gland (arrows) demonstrates a heterogeneous hypoechoic pattern compared with the adjacent tissue. The histopathologic diagnosis was adenoid cystic carcinoma. Reference  Oral radiology-Principles and Interpretation -White &Pharoah 7th edition THANK YOU