Sialography

Sialography

Enumerate various specialized radiographic techniques and write in detail about sialography.
Answer. Enumeration of various specialized radiographic techniques

• Scanography
• Nuclear medicine
• Diagnostic ultrasound
• Arthrography
• Arthroscopy
• Xeroradiography
• Sialography
• Radiographic image storage via LASER optical technology.

“Understanding the role of sialography in diagnosing salivary gland disorders: Q&A explained”

Sialography

• Sialography is the specialized radiographic procedure used for detection and monitoring the salivary gland disease.
• This technique is used to examine the ductal and acinar systems of the major salivary glands. The glands are cannulated and filed with a radiopaque-contrast agent to make them visible on the radiographs. The procedure reveals the location and integrity of the salivary glands, and indicates the presence of diseases that change the internal architecture.

Indications of sialography

• For detection of calculus or calculi or foreign bodies, whether these are radiopaque or radiolucent.
• For determination of the extent of destruction of the gland secondary to obstructing calculi or foreign bodies. This will aid in deciding whether a total excision of the gland or a simple lithotomy should be performed.
• For detection and portrayal of fitulae, diverticula or strictures.
• For determination and diagnosis of recurrent swellings and inflammatory processes.
• For demonstration of a tumor and the determination of its location, size and origin, whether the radiograph suggests a benign or a malignant lesion.

“Importance of studying sialography for better diagnostic outcomes: Questions explained”

Sialography procedure

• In selection of a site for biopsy.
• Outline of the plane of the facial nerve as a guide in planning a biopsy or dissection.
• For detection of residual stone or stones, residual tumor, fitula or stenosis, or retention cysts following simple lithotomy or other surgical procedures.
• Sialography has also been recognized as a therapeutic procedure because:
  • The dilatation of the ductal system produced during the study may aid in the drainage of the ductal debris.
  • The therapeutic effct produced by the iodinated contrast media when injected into the ductal system has also been seen.

Contraindications of sialography

• In patient with a known sensitivity to iodine compounds and patients who have experienced severe asthmatic attcks or anaphylaxis following use of iodine compounds in a prior radiologic examination, should not be considered subjects for this technique. A history of nausea and vomiting following the intravenous injection of contrast media is not considered a contraindication.

Salivary gland sialography

• Use of sialography during a period of acute inflmmation of the salivary system is contraindicated. During this period, the ductal epithelium may be disrupted, and escape of the contrast medium from the ductal system into the parenchyma can produce severe foreign body reaction, accompanied by severe pain. This is especially true when the oily contrast medium is used. Foreign body reaction following the use of water soluble media has not been reported.

Submandibular sialography

“Common challenges in performing sialography effectively: FAQs provided”

• Administration and retention of the iodinated contrast material may interfere with subsequent thyroid function tests, such function studies if required, should be done prior the sialography procedure.

Procedure of sialography

Armamentaria required for carrying out sialography:

• Polyethylene tubing with a special blunt end metallic tip with
  • Side hole for parotid gland
  • End terminal hole for submandibular gland
• 5 or l0 cc syringe.
• Lacrimal dilators.
• Contrast media.
• Sialagogue-like 5 lemon slices or lemon extract or chewing gum.
  • Locate the parotid orifice at the base of the papilla in the buccal mucosa adjacent to the fist or second molar.
  • Area over the mucosa where the duct orifice is expected to be located should be dried with a sponge.
  • If gland consists of some degree of function, a drop of saliva can be expressed by applying gentle pressure to the skin over main parotid area, thus identifying the location of the orifie.

Sialography contraindications

“Steps to explain sialography: Contrast injection vs imaging: Q&A guide”

• • Submandibular excretory duct orifice is situated over the summit of the small papilla at the side of the lingual frenum, but care should be taken to diffrentiate it from the sublingual gland orifies in the same region.
  • Explore the duct with lacrimal probe, after the appropriate orifie is identifid.
    • In case of the submandibular gland, the probe should pass through the length of the flor of the mouth to the level of the posterior border of the mylohyoid muscle, a penetration of about 5 cm.
    • Because of the tortuous course of the parotid duct, the cheek has to be turned outward before it is inserted into the duct. The aversion of the cheek will help reduce the possibility of penetrating the duct at one of the sharp angles in its course.
    • In both the parotid and submandibular ducts, the probe should slide easily back and forth and also rotate freely without dragging.
• When the duct orifie has been adequately sized and enlarged, the sialographic cannula is inserted into the duct so that the tissue stop presses fimly into the orifie to prevent dye reflx.
• After inserting the cannula, the radiopaque dye is slowly introduced into the duct. The amount of dye to be injected into the gland for adequate filing varies from patient to patient and depends on the condition of the gland.

Contrast media in sialography

“Role of contrast media in sialography: Questions answered”

• The amount used is best determined by fluoroscopic observation; the patient should be instructed to inform the operator when the gland area feels tight or full.
• Appropriate volumes of dye required vary from 0.76 to 1.00 mL for the parotid glands, and 0.0 to 0.75 mL for the submandibular glands. The cardinal rule is that the injection should be stopped when the gland is full, if the dye is extravasated, or when the patient experiences mild discomfort.

Xeroradiography Radiographic Projections

• Filming procedure should be carried out with the patient in the supine position. Oftn several fims are obtained during the injection in order to monitor the filing phase and degree of filing.
• The lateral oblique projection or mandibular occlusal view is used to delineate the submandibular gland.
• In the lateral oblique view, the duct pattrn is not distorted, while a sialolith is well demarcated on the occlusal view. The AP view of both glands demonstrates the medial and lateral gland structures.

Radiopaque dye in sialography

“Early warning signs of issues addressed by proper sialography: Common questions”

• In case of the parotid gland, the patient should be asked to keep the mouth open. The panoramic projection may also be taken, which is helpful in studying erosion of bone or destruction of the mandible, in case of salivary tumors.
• The evacuation (fat soluble medium) or the parenchymal phase (water-soluble medium)
  • After the fial sialographic views have been made, the cannula should be removed from the duct orifie. The patient is instructed to chew gum or the lemon slice and then asked to rinse. This is done to stimulate the gland and cause excretion of the dye.
  • Lateral jaw, lateral oblique or anteroposterior view radiographs should be made 5 minutes aftr removal of the cannula. They provide the information about the excretory function of the gland.
  • Normal salivary gland will excrete l00% of the contrast dye within 5 minutes aftr removal of the cannula.

Additional Views Required to be taken to study special Features

• Reverse basilar view to demonstrate the deep portion of the parotid.
• Afim made with the cheek in the blow-out position in the anteroposterior view to demonstrate the superfiial portion of the course of the Stensen duct of the parotid gland.
• Occlusal view for demonstration ofthe distal submandibular gland’s Wharton duct.

“Asymptomatic vs symptomatic effects of ignoring sialography protocols: Q&A”

• Filming ofthe filing phase with the mouth open will reduce superimposition of the mandible on the parotid gland.
• Stereoscopic studies are invaluable for the study of the spatial relationships of the gland and the duct.
• Subtraction views are of great value in the delineation of the finer ducts and of the sublingual ductal system.
• Plesioradiography is a technique in which a small X-ray tube is placed in contact with the facial soft tissues contralateral to the gland being examined in an attempt to eliminate the obscuring overlying bony structures.