Sialogram is a technique of radiopaque examination of the parotid, submandibular and sublingual salivary glands and their ducts. The procedure detects inflammatory and tumor diseases of the salivary glands. Before contrast is introduced, native survey images are taken in two perpendicular projections. The contrast solution enters the opening of the excretory glandular duct through a catheter, less often through a special needle or cannula. Sialogram is carried out in different positions, with sighting images.
Like any other type of X-ray, salivary gland sialogram is prescribed in the presence of certain indications.
- The presence of stones in the excretory ducts (salivary stone disease). Salivary stone disease is the most common among all existing pathologies of the salivary gland. The submandibular salivary gland and the warton duct are most often affected. The causes of this pathology have not been definitively clarified, there are only a few theories. Localization of a stone in salivary stone disease is most often in the gland itself or in the duct of the submandibular gland. Also, stones can form in the parotid, sublingual salivary glands without clinical manifestations and inflammatory processes or with their presence (often in a chronic form). A similar pathology can be suspected if there is a slight increase in the size of the gland during examination. With palpation, slight pressure, scanty purulent discharge may be noted. Sialogram is an X-ray image on which dense formations of various sizes (concretions, or simply stones) will be viewed.
- Sialolithiasis. Sialolithiasis is called the same salivary stone disease, which has already acquired a chronic appearance. It is most likely that a violation of mineral metabolism, or rather calcium and vitamin A, leads to such a pathology.
- The presence of mumps (persistent inflammatory diseases of the salivary glands). Mumps is called inflammation of the parotid salivary glands. This pathology is often seen already at the first examination: the patient has swelling in the parotid salivary glands. Sialogram will show numerous rounded cavities of various sizes – foci of mumps. It is important to find out their size, quantity, localization.
- The presence of tumors of the salivary glands. Sialogram of salivary glands with tumor neoplasms is evaluated by the nature of the filling of the ducts, as well as by the pattern of shadows of the parenchyma of the gland. According to the image, the degree of filling of the ducts with contrast is revealed, the ratio of the ducts to bone and soft tissues is established. First of all, the position, shape, length, width of the ducts, the degree of their filling are analyzed. Next, the intragastric ducts are studied. If the tumor is benign, the structure of the ducts does not change. Their displacement by the tumor to the sides is noted. Neoplasms in the images are revealed in the form of defects in the filling of ducts and gland tissue. With a malignant tumor, defects in the filling of the ducts formed as a result of the destruction of the salivary gland tissue are most often determined.
- Determination of cysts of varying degrees of complexity. Cysts are also neoplasms that constrain the ducts of the salivary glands and disrupt their normal operation. Based on the darkening on X-ray images, it is possible to determine the localization of cysts, their density, structure, size and other important parameters.
- Determination of duct obstruction. With the help of sialogram, it is possible to identify such pathology as obstruction of the ducts of the salivary glands. In other words, it is possible to find out which of the ducts is closed and for what reason.
Method of conducting
It is worth paying attention to how the sialogram procedure is performed. The sequence of actions is as follows:
- The contrast medium is heated to a temperature of 40 °. This is necessary to avoid the appearance of convulsions of the ducts.
- The ducts of the patient’s glands are washed with isotonic essence of sodium chloride and boosted with a subtle booge.
- A contrast catheter moves deep into the ducts (about 3 cm) and is fixed on the patient’s cheek.
- Survey images are taken: straight, profile, tangential, axial.
Contraindications to diagnosis
Let’s consider the main contraindications to this type of diagnosis.
- The presence of acute inflammation of the oral mucosa. Since sialogram is an X-ray method that requires the introduction of a contrast agent, it is prohibited to carry out it with identified acute inflammatory diseases of the oral cavity. The introduction of a contrast agent may worsen the patient’s condition, and the picture may turn out to be uninformative.
- Inflammation of the papilla of the excretory duct of the salivary gland (relative contraindication). As in the previous case, the contraindication is due to the fact that the X-ray requires the introduction of contrast through the excretory ducts. This can cause the patient discomfort, pain and provoke an increase in inflammation of the salivary glands. The decision on the appointment or cancellation of sialogram is made by the attending physician, weighing the possible harm and potential diagnostic benefits of the procedure.
- High susceptibility of the body to iodine. Radiography of the salivary glands is performed using a contrast agent, which includes iodine. Accordingly, if the patient has an allergy to iodine, such a diagnostic procedure is contraindicated for him.
- The period of pregnancy (except in life-threatening cases). If the potential benefit of X-ray examination is much lower than the likely harm to the unborn child or mother, a pregnant woman is not prescribed sialogram. Exceptions can only be those cases when it comes to a fatal risk for a woman or for a fetus. For example, when salivary stone disease passes with complications, a woman may feel constant nausea, malaise, and an increase in body temperature. Pus accumulated in the salivary gland can pass to other soft tissues. All these factors in the early stages can lead to miscarriage, in the late stages – to premature birth.
Decoding the results of the sialogram, experts take into account the following criteria:
- duct size;
- duct conductivity;
- location of salivary glands;
- the structure of the glands, their contours;
- the state of the lymph nodes.
If the patient is healthy, then a homogeneous tissue structure will be visualized on the X-ray, the glands will have clear contours, and their sizes will be proportional and coincide with the normative ones. For example, the parotid glands should be 32-42 mm wide and 40-50 mm long. The sublingual glands should be 19-22 mm long, 10-16 mm wide and thick. If the X-ray showed a deviation from the norm, this indicates the presence of inflammation.