Canine mitral valvular thickening
What is ultrasound?
Ultrasound imaging is a common diagnostic medical procedure that uses high-frequency sound waves to produce dynamic images of organs, tissues, or blood flow inside the body. Any sound which has a frequency of 20,000 Hz or higher is called “ultrasound”. Frequencies used for diagnostic ultrasound applications are typically between 2.5-12 million Hz (MHz).
What can be seen with diagnostic ultrasound?
Ultrasound is the best modality to evaluate fluid filled and soft tissue organs. Abdominal Ultrasound is used to diagnose a variety of both benign and malignant diseases such as the presence of stones within the urinary bladder, kidneys or gall bladder, infection of the gall bladder, urinary bladder, prostate or kidneys, the presence of enlarged lymph nodes, abnormal blood vessels, or free fluid within the abdomen. It is especially good in diagnosing disease of the pancreas (pancreatitis), adrenal abnormalities, urinary bladder wall tumors, and uterine infections (pyometra). With ultrasound guided sample acquisition, ultrasound can often differentiate benign organ changes and cancer. In animals with a history of vomiting, ultrasound can be used to evaluate if the problem is within the liver, gall bladder or pancreas. It can often diagnose problems that are associated with the stomach or small intestinal wall, or see an intestinal foreign body, thus preventing a labor intensive and costly upper GI barium study. The diagnosis of pregnancy and fetal viability (heartbeats) are commonly seen by 21 days post-conception with ultrasound, which is much earlier than can be done with x-rays (42 days). In the heart, ultrasound is at it’s best, as the heart is fluid filled organ. Abnormalities such as a diseased heart muscle (hypertrophic and dilatory cardiomyopathy), fluid around the heart (pericardial effusion), and congenital abnormalities can be diagnosed and the severity can be assessed. Heartbase tumors, which are rarely seen on radiographs, are easily visualized with ultrasonography. Ultrasound can easily differentiate fluid within the cranial mediastinum from a mass. However, although an ultrasound evaluation is an excellent diagnostic tool for many conditions, there is never any guarantee that every pet’s problem will be diagnosed by means of ultrasound. It is best to think of it as a piece of the puzzle when your veterinarian is trying to diagnose a complex condition.
Intestinal obstruction by a stuffed toy in a dog
Does my pet need to have food withheld?
Yes, food (water is ok) needs to be withheld from midnight the evening prior to the scheduled exam. This is because of the possibility of the need for sedation or anesthesia and also because food in the stomach can block the ability to image organs around the stomach. The exception to fasting is for some cases of diabetes and for hypoglycemia problems.
Will my pet be sedated?
Most pets do not require any sedation or anesthesia for an ultrasound study. If a pet is highly stressed by the procedure, or if a biopsy is being performed, a sedative may be necessary in order to perform a thorough exam.
Why do you need to shave and use gel ?
Clipping the area to be scanned and applying a coupling agent like gel or alcohol will minimize air interposition between the transducer and the skin.
Is it dangerous?
Diagnostic ultrasound has been in use since the late 1950s. Given its known benefits and recognized efficacy for medical diagnosis, including use during human pregnancy, the American Institute of Ultrasound in Medicine has issued the following statement concerning clinical safety:
“There are no confirmed biological effects on patients or instrument operators caused by exposures from present diagnostic ultrasound instruments. Although the possibility exists that such biological effects may be identified in the future, current data indicate that the benefits to patients of the prudent use of diagnostic ultrasound outweigh the risks, if any, that may be present.”
Normal Kidney
Who’s performing my exam?
As the use of ultrasound has grown in the veterinary field, so has the number of human trained sonographers who have cross-trained in this modality. Human sonographers, also referred to as RDMS, are highly skilled professionals that perform the majority of ultrasound studies in human medicine. In fact most insurance companies will not pay for an ultrasound examination unless it has been performed by an RDMS. RDMS stands for “Registered Diagnostic Medical Sonographer” . This is the credential that human sonographers receive after they complete training in an accredited program and pass a series of national certifying exams. Sonography training programs typically range between 2-4 years of ultrasound specific study . Study consists of both didactic and clinical training. Eligibility for program entry varies, schools may require a bachelor’s degree, associate of science, or prior allied health program completion and prerequisite course work. Utilizing a RDMS who has cross-trained in veterinary medicine has many advantages including cost savings and access to different specialists for interpretation. It also means getting a comprehensive advanced study by the same highly skilled professionals trusted in human medicine.