Understanding Parotid Sialography: A Quick Overview

Understanding Parotid Sialography: A Quick Overview

Write short note on sialography of parotid gland.
Answer. Following is the sialography procedure of salivary gland:

Armamentaria required for carrying out sialography in

Parotid gland:

• Polyethylene tubing with a special blunt end metallic tip with
  • Side hole for parotid gland
  • End terminal hole for submandibular gland
• 5 or 10cc syringe.
• Lacrimal dilators.
• Contrast media.
• Sialagogue-like: 5 lemon slices or lemon extract or chewing gum.

Sialography

Sialography of the parotid gland Procedure

• Parotid is the largest of all salivary glands and lie just below zygomatic arch in front and below the ear and on masseter muscle over the ramus of mandible. Duct from parotid gland i.e. Stensen’s duct run along outer surface of masseter to buccal mucous membrane opposite to upper second molar tooth.
• Locate the parotid orifie at the base of the papilla in the buccal mucosa adjacent to the fist or second molar.
• Area over the mucosa where the duct orifie is expected to be located should be dried with a sponge.

Parotid gland imaging

• 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.
• Explore the duct with lacrimal probe, aftr the appropriate orifie is identifid. 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 parotid 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.

Sialography procedure

• Aftr 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.
• 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.
• Each of the gland is examined turnwise and small amount of the contrasting medium should be injected.
• Appropriate volumes of dye required vary from 0.76 to 1.00 mL for the parotid 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.

Sialography of parotid gland 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. 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.

Radiology of salivary glands

• In the later positioning, head is in exactly lateral position with angle ofmandible over shadowing each other. Central rays of X-rays are passed over the angle of mandible.
• In lateral oblique view, head is straight similar to lateral view. Only diffrence is that the central ray is projected below and behind the angle of jaw away from the fim, 250 towards the head.
• In frontal position i.e. AP view, median plane is kept at right angle to the fim. Head should be slightly raised and chin is lowered towards the chest. In such cases, view of main duct is clear as it crosses the mandible, but gland region is overexposed with intraglandular ducts which are largely obliterated.

Imaging of parotid duct

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 ofthe 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.