It’s easy to forget all the potential uses of ultrasonography. For this month’s “case” we have elected to use a collection of images from a variety of cases to demonstrate the versatility of ultrasound and highlight areas that are often overlooked. Dr. Eric Lindquist, DMV, DABVP, Cert. IVUSS has presented the following videos and stills to demonstrate the opportunities that exist when you think outside of the abdomen/cardiac “box”.
Uniform normal thyroid measuring 8mm in width as evaluated with linear probe. Normal esophagus in far field. Carotid artery is in near field to the right.
Hypoechoic 4 mm expansive cranial parathyroid adenoma in a Havanese with primary hyperparathyroidism. The esophagus is visible in the far field. Carotid is visible in near field to the right.
Lobar thyroid capsular mass with cystic component and no evidence of capsular escape in a feline. Mass appears resectable. Strongly consistent with thyroid carcinoma. However, cystic hyperplasia with adenoma is possible.
Cystic thyroid mass impinging on carotid. Mass appears expansive, yet encapsulated. Carotid is visible to right of field. The esophagus is visible to the left. Mass appears potentially resectable. FNA can be considered to determine underlying etiology.
Thyroid mass noted on prior sonogram with Color Doppler added to demonstrate significant vascularity consistent with thyroid carcinoma.
Power Doppler assessment of the same cystic expansive thyroid mass consistent with carcinoma. Appears resectable.
Normal eye imaged with microconvex probe demonstrating anterior chamber and lens in near field with anechoic posterior chamber and optic nerve in far field. Retrobulbar tissue appears normal at this time.
Why Do These Matter?
Here we have demonstrated 4 additional areas (thyroid, parathyroid, eye, and retrobulbar region) that with some practice can be imaged using ultrasound. But the uses are confined only by your imagination. Patient has an abscess? What about anal sacculitis and severe cellulitis versus potential tumor? You can even find that recurrent SQ foreign body, such as a stick, for removal. And for those that have an interest in orthopedics or rehabilitation, how about imaging the cranial cruciate ligament, the shoulder or hock.
Importance of Imaging Thyroid/Parathyroid.
Importance of Imaging the Thyroid: Thyroid tumors are more frequent in older dogs (>10 years) with overrepresentation in Golden Retrievers and Beagles. They are frequently found by the owner or DVM during a physical exam. Ultrasound of this area allows differentiation of a mass from surrounding structures (lymph nodes, salivary glands) and allows confirmation that a mass originates from the thyroid itself. In addition, it aids in determination of invasiveness of thyroid tumors.
Importance of Imaging Parathyroid: In animals with signs of primary hyperparathyroidism, clinicians may develop a suspicion upon noting an elevated ionized calcium and decreased phosphorus in the blood work. Tumors of the parathyroid are usually from an adenoma; however, carcinomas and adenomatous hyperplasia are also possible. Lab work abnormalities may lead the clinician to thyroid/parathyroid imaging. Approximately 95% of parathyroid tumors can be identified with ultrasound.
Importance of Imaging the Eye/Retrobulbar region:
Most ocular imaging is done with a linear probe because of its increased frequency range and thus increased resolution in shallow structures. For those that want to specialize in ocular ultrasound a 50mHz probe is available. Scanning of the globe can be used to assess the posterior segment of the eye when corneal disease or anterior chamber disease prohibits normal fundic evaluation. Intraocular masses can be evaluated, retinal detachment can be monitored, and even the retrobulbar area can be interrogated for disease/abscessation.
Looking to enhance the range of your ultrasound diagnostic efficiency?
Here are a few of our recommendations: