Vet360 Vet360 Vol 05 Issue 03 - Page 21

DIAGNOSTIC IMAGING diagnostic imaging techniques help our patients? As a result, radiologists' understanding of what diseases look like is vast and helpful, but only if we’re provided high-quality images and high-quality supporting information. That’s why taking time to support better understanding of effective radiology practices is imperative, and improves the diagnostic quality of every imaging study performed in the future. In doing so, we ensure greater accuracy in diagnoses and further support the well- being of our patients. Below are seven techniques veterinarians and technicians can use to take better images today. 1. No mystery in history One challenge of working as a teleradiologist is that I never see my patients in person. Without physically examining them, being familiar with their history and talking to the owner, quite a bit of background can be lost. It’s critical for whomever is taking and sending the radiographs, whether veterinarian or technician, to provide context that can help my assessment. One practice we’ve implemented in our hospital is for the veterinarian to fill out the physical exam and history sections, thus providing more detail and nuance that can be quickly relayed to a technician or read from the presenting complaint in the chart. Our doctors also copy and paste pertinent parts of the electronic medical record into the radiology consult, relaying additional information to the radiologist. Succinct but thorough information, coupled with our understanding of breed- and-age-related diseases, can help tailor a thought process in order to arrive at a more accurate diagnosis. Otherwise, I won’t know the "coughing," 20-lb, mixed breed is actually an obese, 12-year-old Yorkie that lives in a house with a chain smoker, reeks of smoke and never goes outside. That kind of information changes how helpful a teleradiologist is to you. 2. Collimate and compare It seems obvious, but before taking a radiograph it’s important to know what you’re looking at and where you’re looking. For instance, when evaluating a patient with lameness, an examination should further direct you to a localized area like the hip, stifle joint or foot. Radiographs should then be focused only on this area, with the remaining areas collimated out of the primary radiographic beam. The benefit to collimating—focusing in on a single region of the patient’s body is to improve the image quality of that region (Figures 1 and 2). There are only so many pixels on a digital radiograph plate. If the majority of the radiograph isn't really part of the area that you're interested in (for instance, taking a whole- body radiograph for a stifle lameness), then as a result, the majority of the pixels are useless. The actual area Figure 1. This lateral radiograph was taken without sedation and without collimation, significantly limiting interpretation of the spine. (Photos courtesy of Dr. Michelle Fabiani) Figure 2. This radiograph was obtained after sedation. Adequate centering of the radiograph beam and collimation were utilized allowing for excellent interpretation of the lumbar spine. of interest doesn't have enough resolution to evaluate adequately. How can you tell if this is happening on your images? Magnify to the region of interest and see if you notice a pixelated appearance. Collimating provides better image resolution and greater ability to accurately diagnose, resulting in better patient outcomes. Additionally, most of our patients have a conveniently accessible normal leg that we can use for comparison. If the left elbow is where the pain is localised, you should also take an image of the right elbow so we have an idea of what this patient's normal looks like. And remember you should always take images in orthogonal pairs—both a lateral and a cranial to caudal—of the affected and the normal leg. For most diagnostic images, you should be taking separate radiographs of each leg—that is, don't take both elbows in one lateral view nor both elbows in one cranial to caudal view. 3. Wanna be sedated? At some point, we’ve all dealt with an angry cat whose claws create havoc in the clinic. Or a dog whose long limbs flailed on an imaging table. Their fear- based response to an exam or procedure can harm Issue 03 | JULY 2018 | 21