Our research focus is connective tissue diseases, including Sjogren's syndrome, and we will describe a standardized approach to salivary gland ultrasound in diagnosing Sjogren's syndrome. We hope the protocol will be useful for clinicians unfamiliar with doing ultrasound to enhance its application In clinical practice, Ultrasound is a powerful tool in evaluating various rheumatological conditions, including arthritis, Sjogren's syndrome, and interstitial lung disease. It is helpful in diagnosis, monitoring, and prognostication.
It can be applied as an outcome measure in clinical studies, such as detecting subclinical synovitis to assess the risk of rheumatoid arthritis progression. Ultrasound is an operator-dependent procedure, and the result may be unreliable if inexperienced hands perform it. Well-validated and quantitative measurements are often needed to standardize the description and reporting of pathological sonographic findings before they can be applied in clinical practice and research.
In this procedure, we will describe how to conduct a salivary gland ultrasound in patients with sicker symptoms. This approach is easy to perform and can usually be completed within 10 to 15 minutes. We will also demonstrate techniques to perform reliable and reproducible results to ensure the quality of the ultrasound scanning.
Our center will continue to research on applying ultrasound in diagnosis and monitoring in rheumatology. We will research utilizing lung ultrasound for screening of interstitial lung disease associated with connective tissue diseases, hoping to improve the current screening strategy for lung fibrosis in rheumatology patients. To begin, select a high frequency linear transducer of 10 megahertz.
Set the ultrasound to B mode, and use the highest frequency of the probe. Adjust the depth to three centimeters and gain 50%to 60%Position the patient in the supine position with the neck slightly extended. Use a pillow to support the patient's head.
For transverse images, orient the probe with the marker pointing towards the patient's right side. For longitudinal scanning, orient the marker at the cephalic side. Apply gel to the probe's surface.
Place the probe below the thyroid cartilage to scan the thyroid gland. Save the obtained images, the isthmus connects the right and left lobes of the thyroid gland. Consider the echogenicity of a normal thyroid gland as a reference.
For any concomitant thyroid disease, compare the echogenicity to that of the surrounding muscles. To begin, turn the patient's head to the opposite side of the gland being examined. Place the transducer longitudinally along the anterior border of the parotid gland, just anterior to the ear and parallel to the tragus, and move it from the superior to the inferior pole of the gland to obtain the standard view.
Place the probe transversely at the angle of the mandible to obtain the transverse scan. Ideally, the parotid gland is located between the mastoid and mandible ramus in a transverse view. Scan the parotid gland transversely from the superior to the inferior pole.
Slide the probe below the mandible's ramus to visualize the parotid gland's deep part, which the mandible could partially obscure. Place the probe between the mastoid process and the angle of the mandible. Save and label the images in both the longitudinal and transverse views.
Assess the size of the parotid gland. Compare the echogenicity with that of the thyroid gland, which is similar to the normal parotid gland. Turn on the color doppler to differentiate blood vessels from the dilated intraglandular duct.
The retromandibular vein and external carotid artery divide the superficial and deep parotid lobes. Capture the degree of inhomogeneity, the clearness of the gland margin, and the presence of hypo or anechoic areas. Note the presence of focal lesions and document the size, location, shape, and echogenicity.
Turn on the color doppler to look for vascularity. Score the degree of sonographic involvement on a scale of zero to three as defined on the screen. The presence of lymph nodes within the parotid gland could be normal and common, especially when located in the superficial lobe.
Measure the diameter of the lymph nodes. Evaluate the shape, echogenicity, and preservation of fatty hilum. Repeat the scanning at the contralateral parotid gland and compare the size and echo texture between the two parotid glands.
Normal parotid glands appeared homogenous with clear demarcation with overlying tissues and muscles. Position the patient in the supine position with the head maximally tilted to the back. To obtain the transverse view of the submandibular gland, position the transducer just below the angle of the mandible at the submandibular area.
Examine the entire submandibular gland from anterior to posterior. The mandible, mylohyoid muscles, and the anterior belly of the digastric muscles bound it. Obtain the longitudinal view by placing the probe medial to the horizontal body of the mandible.
Visualize the facial artery in this plane. Save and label the images in both transverse and longitudinal views of the submandibular gland. Assess the size of the submandibular gland.
Examine the echogenicity of the submandibular gland, which is usually less echogenic than the parotid gland. Assess the degree of inhomogeneity, the clearness of the gland margin, and the presence of hypo or anechoic areas within the glands. Note the presence of focal lesions.
Grade the degree of inhomogeneity using the OMERACT score. If the evaluation of the gland is not possible due to qualitative parameters, follow the alternate grading parameters. Measure the size of the submandibular lymph nodes.
Evaluate fatty hilum's shape, echogenicity, and preservation. Repeat the scanning at the contralateral submandibular gland and compare the size and echo texture between the two submandibular glands. Normal submandibular glands demonstrated a clear demarcation with the overlying structures.
