DIAGNOSTIC MODALITIES Medical Assignment Help

DIAGNOSTIC MODALITIES

History and Clinical Examination

The most important component of diagnosis in. salivary gland disorders, as with most other disease processes, is the patient history and the clinical examination. In most cases the patient will guide the doctor to the diagnosis
merely by relating the events that have occurred in association with the presenting complaint. The astute clinician must perform a thorough evaiuation, and, in many – instances, the diagnosis Gin be determined without the necessity of further diagnostic evaluation. At the very least, the clinician may be able to categorize the problem as reactive, obstructive, inflammatory, infectious, metabolic, neoplastic, developmental, or traumatic in origin  and guide further diagnostic testing. Occasionally, the clinician may find it riecessary to use any of several diagnostic  dalities.

Salivary Gland Radiology
Plain film ‘raaiogmphs. The primary purpose of plain films in the assessment of salivary gland disease is to identify salivary stones (calculi), although only 80% to 8S% of all stones are radiopaque and therefore visible
radiographically. The incidence of radiopaque stones varies, depending on the specific gland involved (Box 20-2). A mandibular occlusal film is most useful for detecting sublingual and submandibular gland calculi in
the anterior floor of the mouth (fig. 20-4, A). A “puffed cheek view,” in which the patient forcibly blows the cheek laterally to distend the soft tissues overlying the lateral ramus, can demonstrate parotid stones. Panoramlc radiographs can reveal stones in the parotid gland and
posteriorly located submandibular stones (Fig. 20-S).

FIG. 20-5 Panoramic radiograph demonstrates a right submandibular sialolith (arrows).

FIG. 20-5 Panoramic radiograph demonstrates a right submandibular sialolith (arrows).

Periapical radiographs can show calculiin each salivary gland or duct, including minor salivary glands, depending on film placement. In most instances, the radiographic image corresponds in size and shape to the actual stone’ (see Fig. 20-4, B).

Sialography is a technique in which the salivary duct is. cannulated with a plastic or metal catheter (Fig. 20-6), a radiographic contrast medium is injected into the due- # tal system and the substance of the gland, and a series of radiographs are obtained during this process. Approximately
O.S to 1 nil of contrast material can be injected into the duct and gland before the patient begins to experience pain. The two types of contrast media available for ‘ sialographic studies are water-soluble and oil-based. Both types of contrast material contain relatively high concentrations
(25% to 40%) of iodine. Most clinidans prefer to use water-soluble media, which are more miscible with salivary secretions, more easily injected into the finer portions of the ductal system, and more readily eliminated
from the gland after the study is completed, either by drainage through the duct or systemic absorption from ,the gland and excretion through the’ kidneys. The oilbased media are more viscous and’ require. a higher injection pressure to visualize the finer ductules than do the
water-sol ble media. As a result, they usually produce more 5iiscomfort to the patient during injection. Oilbased media are poorly eliminated from the ductal system  and may cause iatrogenic ductal obstruction.

A complete sialogram consists of three distinct phases depending on the time at which the’ radiograph is obtained after injection of.the contrast materia

l 1. Ductal phase (Fig. 20-7), which occurs almost
immediately after injection of contrast material and allows visualization of the major ducts .

2. Acinar phase (Fig. 20-8), which begins after the
, ductal system has become fully opacified with contrast and the gland parenchyma becomes filled .I , subsequently

3. Evacuation phase, which assesses normal secretary
clearance function of the gland to determine
“whether any evidence, of retention of contrast
remains in the gland or ductal system after the,
sialogram

FIG. 20-6 Cannulation of Sterisen's duct with a plastic catheter

FIG. 20-6 Cannulation of Sterisen’s duct with a plastic catheter

FIG. 20-7 Ductal phase of a submandibular sialogram. Contrast rs contained only within the main salivary ducts (arrows).

FIG. 20-7 Ductal phase of a submandibular sialogram. Contrast rs
contained only within the main salivary ducts (arrows).

FiG, 20-8 Acinar phase of a submandibular sialogram. 'Of. a arborization of the entire ductal system of the gland (arrow) IS , demonstrated.

FiG, 20-8 Acinar phase of a submandibular sialogram. ‘Of. a
arborization of the entire ductal system of the gland (arrow) IS
, demonstrated.

FIG. 20-9 Sialogram of right submandibular gland. Obstruction of duct by- a radiolucent sialolith (arrows) has caused dilation of the duct and loss of normal parenchyma of the gland.

FIG. 20-9 Sialogram of right submandibular gland. Obstruction of duct by- a radiolucent
sialolith (arrows) has caused dilation of the duct and loss of normal parenchyma of the gland.

FIG 20-10 Sialogram of right parotid giand: The characteristic: "sausage link;' appearance of the duct is demonstrated, which indicates ductal damage from obstructive disease with irregular narrowing of duct caused by reparative fibrosis.

FIG 20-10 Sialogram of right parotid giand: The characteristic: “sausage link;’ appearance of
the duct is demonstrated, which indicates ductal damage from obstructive disease with irregular
narrowing of duct caused by reparative fibrosis.

The retention of contrast in the gland or ductal system beyond 5 minutes is considered abnormal normal sialogram shows a Iargeprimary duct branching gradually and smoothly into secondary and terminal ductules.
Evenly distributed contrast will result in opacification of the  cinoparenchyma that will outline the gland and its lobules, When a stone obstructs a salivary duct. continu cretion by the gland .produces  istension of the ductal system proximal to the obstruction and finallyleads to pressure atrophy of the parenchyma of the gland (Fig. 20-9).

Sialodochitis is a dilation of the salivary duct secondary to epithelial atrophy as a result of repeated inflammatory or infectious processes, with irregular narrowing caused by reparative fj.brosis (sausage link paftern)
(Fig. 20-10). Sialaden,i.tis represents inflammation mainly involving the aclnoparenchyma of the gland. Patients with sialadenitis experience sacculardilation

FIG. 20-11 Sialogram of right parotid gland illustrates "ball-in-hand" phenomenon (arrows). The lil,ling defect in this sialogram .locetes a tumor of the gland with displacement of normal surrounding ductal anatorny..,

FIG. 20-11 Sialogram of right parotid gland illustrates “ball-in-hand” phenomenon (arrows).
The lil,ling defect in this sialogram .locetes a tumor of the gland with displacement of normal
surrounding ductal anatorny

of the gland secondary to acinar atrophy and infection, which results in.”pruning” of the normal arborization of the small-ductal system of the gland. Centrally located lesions or tumors that occupy a part of the gland or
impinge on its surface displace the normal ductal anatomy. On sialography, ducts adjacent to the lesion are curvilinearly draped and stretched around the mass, producing a characteristic ball in hand appearance (Fig.·
20-11).

Computed Tomography  magnetic requirement and ultrasound. The use of computed tomography (CT) has been generally reserved for the assessment of mass lesions of  the salivary glands. Although CT scanning results in radiation exposure to patients, it is less . .vasive than sialography and does not require the use of  contrast material. Additionally, CT scanning can demonstrate salivary’ gland calculi, especially submandibular

fiG. 20-12 computerized tomographic scan of the mandible and floor of mouth shows a posterior submandibular sialolith (arrow).

fiG. 20-12 computerized tomographic scan of the mandible and
floor of mouth shows a posterior submandibular sialolith (arrow).

stones that are located posteriorly in the duct, at the . hilum of the gland, or in the substance of the gland itself (Fig. 20-12).

Salivary Gland Endoscopy (Slaloendoscopy)
Minimally invasive modalities of diagnosis and treatment have recently been applied to. the major salivary glands, ‘ Salivary gland endoscopy (sialoendoscopy) is a specialized procedure that uses a small video camera (errdoscope) with a light at the end of ~ flexible cannula, which is introduced into. the ductal orifice. The endoscope can he used diagnostically and therapeutically. Salivary gland endoscopy hasdemonstrated strictures and kinks in the ductal system, as well as mucous plugs and calcifications.  The endoscope 111ay be used to. dilate small strictures and .flush clear small mucous plugs in the salivary gland
ducts. Specialized devices such as small balloon catheters (similar, to those used for coronary angioplasty procedures) may’ be used to. dilate sites of ductal constriction, and small metal baskets may be used to. retrieve stones in the ductal system

Fine-Needle- Aspiration Biopsy
The use of fine-needle aspiration biopsy in the diagnosis of salivary gland tumors has been well documented. This procedure has a high accuracy rate for distinguishinglbenign and malignant lesion Fine-needle aspiration biopsy performed  syringe with a 20-gauge or smaller needle
anesthesia the needle is advanced into the the plunger is activated to. create a vacuum in till’ svringe, and the needle is moved back ‘and forth throughout the mass, with pressure maintained an the plunger ..The pressure is then released, the needle is withdrawn, and the
cellular material and fluid is expelled onto a slide and fixed for histalagic examination. This allows an immediate determination of benign versus malignant disease; it also. offers the passibility of providing a tissue diagnosis, especially if tile oral surgeon and oral pathologist are ,
experienced in performing and interpreting this exarnination and its results.

Salivary Gland Biopsy
A salivary gland biopsy, either incisianal or exclsional can be used to. diagnose a tumor of one of the major salivary glands, but it is usually performed as an aid in the diagnosis of SS. The lower lip labial salivary gland biopsy has been shown to demonstrate certain characteristic
histopathologic changes that pre seen in the major glands in SS. The procedure is performed using local anesthesia, and approximately 10 minor salivary ‘glands are removed far histologic examination (Fig. 20-13).

 

 

 

 

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