Sialography | |
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MeSH | D012796 |
MedlinePlus | 003812 |
Sialography (also termed radiosialography) is the radiographic examination of the salivary glands. It usually involves the injection of a small amount of contrast medium into the salivary duct of a single gland, followed by routine X-ray projections. [1]
The resulting image is called a sialogram.
Sialography has largely been replaced by sialoendoscopy [2] and cross-sectional imaging, such as CT, MRI and ultrasonography. [3]
This procedure is indicated when there is recurrent swelling and pain on the face but ultrasound has not revealed any problems. If Sjögren syndrome (also known as Sicca syndrome, an autoimmune disease that affects the lacrimal and salivary glands, causing reduced tears and saliva production) is suspected, this procedure is useful. Besides, when interventional proecudre is planned such as stone removal from salivary ducts or dilatation of the strictures in the salivary gland, this procedure is also indicated. [4] However, for those who are pregnant, with allergy to iodinated contrast, and ongoing infection or inflammation of the face, the procedure is contraindicated. [4]
Contrast agents are classified into two groups: fat-soluble contrast agents and water-soluble contrast agents. Water-soluble contrast agents can fill the finer elements of the ductal system. Fat-soluble contrast agents are viscous and can cause allergic reactions. These can also cause discomfort to the patients. Fat-soluble contrast agents do not fill finer elements of the duct.[ citation needed ]
A baseline radiograph (scout film) of the required salivary gland would be taken, the duct is dilated using graded lacrimal probes, a cannula then is inserted in this salivary gland duct's opening in the mouth, then a radio-opaque fluid (contrast medium) is injected in the duct through a small tube.[ citation needed ]
A series of radiographs would then be taken to determine the flow of the fluid, identify any obstructions and its location, the rate of fluid excretion from the gland.[ citation needed ]
Usually the radiographs taken are lateral oblique views of the face [5] as orthopantomograms are not useful for the purpose of locating the area due to superimpositions and the way they are taken to put the teeth in the main field.
This study is interpreted by evaluating the morphology of the salivary ducts for obstructions and chronic inflammation. Sialodochitis is a term describing dilation of the ducts caused by repeated inflammatory or infective processes. There is also irregular salivary duct stricture (narrowing) of the duct, which creates an appearance known as "sausage link" pattern on a sialogram. Suggestions of abscesses and autoimmune diseases such as Sjögren syndrome can also be elicited. Sialadenitis is inflammation of the salivary glands, which may cause acinar atrophy and create an appearance known as "pruning of the tree" on a sialogram, where there are less branches visible from the duct system. A space occupying lesion that occurs within or adjacent to a salivary gland can displace the normal anatomy of the gland. This may create an appearance known as "ball in hand" on an sialogram, where the ducts are curved around the mass of the lesion. [6]
Like any medical imaging utilizing ionizing radiation, there will be a degree of direct ionizing damage and indirect damage from free radicals created during the ionization of water molecules within cells. The risk of causing the development of a malignant tumor is incredibly small, and is weighed against the benefits of the investigation on a case-by-case basis.
Possible complications include:
Sjögren syndrome or Sjögren's syndrome is a long-term autoimmune disease that affects the body's moisture-producing glands, and often seriously affects other organ systems, such as the lungs, kidneys, and nervous system. Primary symptoms are dryness, pain and fatigue. Other symptoms can include dry skin, vaginal dryness, a chronic cough, numbness in the arms and legs, feeling tired, muscle and joint pains, and thyroid problems. Those affected are also at an increased risk (15%) of lymphoma.
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands, as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous, or seromucous (mixed).
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands. Sometimes accessory parotid glands are found close to the main parotid glands.
A lower gastrointestinal series is a medical procedure used to examine and diagnose problems with the human colon of the large intestine. Radiographs are taken while barium sulfate, a radiocontrast agent, fills the colon via an enema through the rectum.
Endoscopic retrograde cholangiopancreatography (ERCP) is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat certain problems of the biliary or pancreatic ductal systems. It is primarily performed by highly skilled and specialty trained gastroenterologists. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject a contrast medium into the ducts in the biliary tree and pancreas so they can be seen on radiographs.
Radiocontrast agents are substances used to enhance the visibility of internal structures in X-ray-based imaging techniques such as computed tomography, projectional radiography, and fluoroscopy. Radiocontrast agents are typically iodine, or more rarely barium sulfate. The contrast agents absorb external X-rays, resulting in decreased exposure on the X-ray detector. This is different from radiopharmaceuticals used in nuclear medicine which emit radiation.
Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause.
The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. Inflammation of the lacrimal glands is called dacryoadenitis. The lacrimal gland produces tears which are secreted by the lacrimal ducts, and flow over the ocular surface, and then into canals that connect to the lacrimal sac. From that sac, the tears drain through the lacrimal duct into the nose.
Parotitis is an inflammation of one or both parotid glands, the major salivary glands located on either side of the face, in humans. The parotid gland is the salivary gland most commonly affected by inflammation.
A pericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. The pericardium is a two-part membrane surrounding the heart: the outer fibrous connective membrane and an inner two-layered serous membrane. The two layers of the serous membrane enclose the pericardial cavity between them. This pericardial space contains a small amount of pericardial fluid. The fluid is normally 15-50 mL in volume. The pericardium, specifically the pericardial fluid provides lubrication, maintains the anatomic position of the heart in the chest, and also serves as a barrier to protect the heart from infection and inflammation in adjacent tissues and organs.
Myelography is a type of radiographic examination that uses a contrast medium to detect pathology of the spinal cord, including the location of a spinal cord injury, cysts, and tumors. Historically the procedure involved the injection of a radiocontrast agent into the cervical or lumbar spine, followed by several X-ray projections. Today, myelography has largely been replaced by the use of MRI scans, although the technique is still sometimes used under certain circumstances – though now usually in conjunction with CT rather than X-ray projections.
Sialadenitis (sialoadenitis) is inflammation of salivary glands, usually the major ones, the most common being the parotid gland, followed by submandibular and sublingual glands. It should not be confused with sialadenosis (sialosis) which is a non-inflammatory enlargement of the major salivary glands.
Sialolithiasis is a crystallopathy where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland. Less commonly the parotid gland or rarely the sublingual gland or a minor salivary gland may develop salivary stones.
Autoimmune Pancreatitis (AIP) is an increasingly recognized type of chronic pancreatitis that can be difficult to distinguish from pancreatic carcinoma but which responds to treatment with corticosteroids, particularly prednisone. Although autoimmune pancreatitis is quite rare, it constitutes an important clinical problem for both patients and their clinicians: the disease commonly presents itself as a tumorous mass which is diagnostically indistinguishable from pancreatic cancer, a disease that is much more common in addition to being very dangerous. Hence, some patients undergo pancreatic surgery, which is associated to substantial mortality and morbidity, out of the fear by patients and clinicians to undertreat a malignancy. However, surgery is not a good treatment for this condition as AIP responds well to immunosuppressive treatment. There are two categories of AIP: Type 1 and Type 2, each with distinct clinical profiles.
Percutaneous transhepatic cholangiography, percutaneous hepatic cholangiogram (PTHC) is a radiological technique used to visualize the anatomy of the biliary tract. A contrast medium is injected into a bile duct in the liver, after which X-rays are taken. It allows access to the biliary tree in cases where endoscopic retrograde cholangiopancreatography has been unsuccessful. Initially reported in 1937, the procedure became popular in 1952.
Oral and maxillofacial pathology refers to the diseases of the mouth, jaws and related structures such as salivary glands, temporomandibular joints, facial muscles and perioral skin. The mouth is an important organ with many different functions. It is also prone to a variety of medical and dental disorders.
Sialoendoscopy is a minimally invasive technique that allows for salivary gland surgery for the safe and effective treatment of obstructive salivary gland disorders and other conditions of the salivary glands. During sialoendoscopy a small endoscope is placed into the salivary glands through the salivary ducts that empty into the mouth. Sialoendoscopy is an efficient yet simple mode of treatment for major salivary gland obstructions, strictures and sialoliths. Depending on the obstruction, sialoendoscopy can be conducted under local anesthesia in an outpatient office or in the operating room under general anesthesia.
Salivary gland diseases (SGDs) are multiple and varied in cause. There are three paired major salivary glands in humans – the parotid glands, the submandibular glands, and the sublingual glands. In addition there are about 800-1000 minor salivary glands in the mucosa of the mouth. The parotid gland is located in front of each ear, and secretes mostly serous saliva via the parotid duct into the mouth, usually opening roughly opposite the maxillary second molar. The submandibular gland is located medial to the angle of the mandible, and it drains its mixture of serous and mucous saliva via the submandibular duct into the mouth, usually opening in a punctum located in the floor of mouth. The sublingual gland is located below the tongue, on the floor of the mouth. It drains its mostly mucous saliva into the mouth via about 8-20 ducts which open along the plica sublingualis.
Salivary duct stricture is narrowing of the duct of a major salivary gland.
Sialodochitis, is inflammation of the duct system of a salivary gland. This is compared to sialadenitis, which is inflammation of the gland parenchyma.