Advanced Imaging: Sharing Insights<\/h2>\n\n\n\n
Imaging Technician Rachel Pokora has been with Rossdales Veterinary Surgeons<\/a> for 22 years. With sixteen of those years spent working in the Advanced Imaging Department, Rachel has a wealth of experience in acquiring the best quality images when scanning the proximal limb. Always looking to obtain the best outcome for the patient, client, and those reading the images, Rachel outlines the protocols around how to do that quickly, efficiently, and effectively.<\/p>\n\n\n\n Thorough preparation is essential when preparing for standing MRI and that starts with the patient\u2019s background information:<\/p>\n\n\n\n Understand The Horse\u2019s History – <\/strong>engaging with clinicians to clarify whether the focus is on bone, soft tissue, or both can help direct sequence selection and scanning protocols.<\/p>\n\n\n\n Knowing How The Horse Behaved During<\/strong> Workup<\/strong> \u2013 whether the patient was cooperative or challenging must be considered to ensure team members are not put into unsafe situations. Horses with difficult temperaments may require additional planning, such as adapting image acquisition techniques or ensuring a strong team is available to manage the horse.<\/p>\n\n\n\n The success of imaging a horse doesn\u2019t solely depend on the skill of the MRI operator. While the operator\u2019s expertise in setting up and managing the scan is crucial, the role of the horse handlers is equally as important. They play a critical role in understanding the goals of the scan, managing sedation, and minimizing motion \u2013 all of which are vital to image acquisition. Their knowledge of how the horse\u2019s behavior, posture, and sedation impact the outcome contributes significantly to the success of the procedure. Teamwork between handlers and operators is essential for smooth, effective scans.<\/p>\n\n\n\n Time to Relax<\/strong> – horses arriving for imaging need adequate time to settle after travel. Stall rest ahead of the procedure gives them time to relax, eat, drink, and urinate before the scan begins. A tired horse will not be able to stand still for long periods, so avoid scanning after a full day of diagnostics.<\/p>\n\n\n\n Review Sedation \u2013 <\/strong>if possible, prior sedation should be avoided to ensure the horse is responsive to the tailored sedation protocol administered for the scan procedure. If the horse is in pain, however, appropriate pain relief should be administered before scanning.<\/p>\n\n\n\n Assess Fitness and Stability<\/strong> – a fit, well-muscled horse can maintain its stance longer than one in poorer condition and the individual patient\u2019s ability to stand should be considered.<\/p>\n\n\n\n The preparation process should include cleaning the limbs, removing shoes, and marking the skin if needed, to help correlate MRI with any previous imaging, such as ultrasound.<\/p>\n\n\n\n Before scanning the proximal limb, the horse should be allowed to stand as naturally as possible. Watch and correct for:<\/p>\n\n\n\n These considerations ensure the horse is comfortable, reducing the likelihood of movement during the scan.<\/p>\n\n\n\n The right balance of sedation is critical, particularly when imaging the hindlimbs, where excessive motion can compromise safety and image quality. Handlers are responsible for monitoring the horse\u2019s level of sedation and adjusting or requesting adjustment as needed. <\/p>\n\n\n\n Ideally, sedation adjustments should be made at the end of a sequence rather than mid-sequence to avoid motion artifacts. For especially anxious horses, ACP (acepromazine) may be useful, administered 30 minutes before entering the MRI room to ensure a calmer patient.<\/p>\n<\/div>\n\n\n\n Correct handling throughout the scan can make the difference between diagnostic and non-diagnostic images:<\/p>\n\n\n\n In some cases, creative solutions may be required! Each horse is unique, so adapting to its needs may involve thinking outside the box, but every patient should be able to achieve a diagnostic scan and receive appropriate treatment.<\/p>\n\n\n\n It will pay dividends to follow best practice when putting a horse into the MRI magnet. There\u2019s a lot to consider and time spent in getting this step right will be time well spent.<\/p>\n\n\n\n The first step in imaging the proximal limb of a standing sedated horse is ensuring the horse is comfortable and relaxed. After sedation, it\u2019s important to give the horse time to adjust to the environment and settle. <\/p>\n\n\n\n Moving too quickly can startle the horse, leading to unnecessary stress and movement that could disrupt the scan or require re-sedation. Establishing a calm atmosphere allows for smoother handling and reduces motion, which leads to better imaging results.<\/p>\n<\/div>\n\n\n\n Achieving even weight distribution across all four limbs is crucial to the success of the imaging process. If the horse shifts its weight, it may distort the images or require repositioning. Handlers should monitor the horse\u2019s stance closely, adjusting as needed to ensure the horse maintains a balanced weight distribution. A relaxed and evenly supported horse will be less likely to move unexpectedly during the scan.<\/p>\n\n\n\n Appropriate head carriage is essential to maintain balance. A slight adjustment to the horse\u2019s head can shift its weight and affect its stance. For example, dropping the head down and forward encourages more weight on the front limbs, while raising the head shifts the weight backward. Moving the head and neck to one side shifts the weight onto the ipsilateral forelimb. Careful attention to head positioning helps distribute the horse’s weight as needed for the scan. A skilled handler can make these subtle adjustments, ensuring the horse stays balanced and comfortable throughout the process.<\/p>\n\n\n\n It\u2019s important to monitor the horse\u2019s limb positioning, especially the orientation of the feet. The limb should ideally remain neutral, but some horses may naturally toe out or in. Excessive inward or outward rotation of the toe can place unnecessary strain on the joints and affect the alignment for the scan. Keeping the feet in a neutral or slightly outward position ensures that the limb is properly aligned with the magnet.<\/p>\n\n\n\n The fetlock should remain in a natural, neutral position. Any signs of rotation or angling could interfere with the scan. Ensuring the fetlock is positioned correctly allows for clear imaging of the proximal limb without distortion or artefacts.<\/p>\n\n\n\n Bandaging the limb before positioning helps stabilize the limb and prevent muscle twitches during the scan. However, it is important to bandage after the limb has been properly positioned to avoid the risk of the bandage slipping or altering its height during the scan.<\/p>\n\n\n\n A properly applied bandage also provides a stable surface for the MRI RF coil and can be adjusted easily as needed.<\/p>\n<\/div>\n\n\n\n Correct alignment of the MRI magnet when scanning the proximal limb is key to obtaining high-quality images. Spend time ensuring the magnet is perfectly in line with the limb before beginning the scan \u2013 tilting the magnet in line with the limb if appropriate. Misalignment can lead to poor image quality and artifacts.<\/p>\n<\/div>\n\n\n\n By positioning the magnet before bringing the horse into the magnet, you avoid unnecessary adjustments and minimize disruption to the patient. Generally, horses will tend to move medially as the scan progresses. Initial positioning of the limb to accommodate for this so is important. As the scan progresses you will then be able to easily adjust for limb movement and limit the likelihood of having to take the horse out of the magnet and completely reposition if you reach the limit of the medial-lateral adjustment of the magnet mid scan.<\/p>\n\n\n\n It\u2019s essential not to rush the process. Moving too quickly or startling the horse with sudden movements – like hitting the opposite limb with the magnet for example \u2013 may cause the horse to react, potentially ruining the scan. Take the time to let the horse relax in the environment, communicate with the handler, and make careful adjustments as needed. Keep a hand on the horse so you are in contact with the horse consistently through any adjustments, which gives the horse confidence. Avoid touching the horse unexpectedly. A calm, slow approach will reduce the likelihood of needing to reposition the horse, which can save time in the long run and ensure that high-quality images are obtained.<\/p>\n\n\n\n Proper RF coil positioning is critical to obtaining high-resolution images. The coil should be placed directly over the area of interest, and it must fit snugly around the limb without gaps. The coil can be embedded into the bandage material to stabilize its position if needed. In addition, manual stabilization of the leg or the use of padding materials like towels or sponges can help prevent unwanted movement. However, avoid giving the horse something to lean on, as this may encourage it to lean more heavily on that side, leading to further instability.<\/p>\n\n\n\n At the point when the team is ready to start imaging, clear communication between the operator and other team members is essential. As an operator, it’s important to know precisely how proximal or distal you need to go to fully evaluate the area being imaged (Figs 1. 2. and 3. below). <\/p>\n\n\n\n Sometimes, the initial request may focus on a specific region, such as the proximal suspensory ligament, but it’s crucial to remember that lesions can extend both proximally and distally. This highlights the need for a broader assessment of the entire area, ensuring that you don\u2019t miss any potential issues that could significantly alter the course of treatment.<\/p>\n\n\n\n Understanding anatomy and lesion progression is key to making the right decisions. For instance, if you’re imaging the suspensory ligament and find a lesion at the origin, you may handle the case in one way. However, if the lesion extends to the mid-body, that changes the treatment plan dramatically. This is why the ability to track lesions both proximally and distally is critical, as it provides a clearer picture of the injury\u2019s extent. When planning, it\u2019s important to anticipate such variations and adjust the imaging accordingly to ensure a thorough evaluation.<\/p>\n\n\n\n Collaboration is vital during the imaging process. For example, starting the scan at the right height ensures you capture the necessary structures – such as positioning high enough to scan through the knee, while keeping the center nicely aligned with the suspensory ligament. If the team is aligned in their understanding of the anatomy and scan requirements, this coordination helps achieve better imaging outcomes.<\/p>\n\n\n\n Fine-tuning the magnet\u2019s coil just slightly can make a big difference. Adjusting the coil height by just an inch, for example, makes a significant difference in the signal distribution for both the proximal and distal areas of the scan. This highlights the importance of understanding the technology being used and how it interacts with the anatomy. Often, it\u2019s not just about moving the magnet but recognizing how small adjustments in coil placement can optimize image quality. Clear communication between team members helps to ensure these adjustments are made efficiently.<\/p>\n\n\n\n Choosing the correct protocol for the area you’re scanning is crucial when imaging the proximal limb of a standing horse. It\u2019s important to have a clear understanding of why you’re selecting certain sequences, such as T1 and T2*. Knowing which sequence to use depends on understanding the pathology you’re dealing with.<\/p>\n\n\n\n For chronic injuries, you might need a different protocol than for acute injuries. For example to evaluate acute soft tissue injuries, consider if a fast spin echo is the more suitable option to include. Similarly, knowing when to check for STIR activity is key to making the right decisions for the scan.<\/p>\n\n\n\n A strong understanding of anatomy and pathology helps guide decision-making in real-time, allowing you to adapt your scan based on what you find. For example, you need to ensure that all relevant structures are captured in a single session to avoid having to repeat scans. If the horse becomes unstable or is likely to move, it’s best to avoid sequences that are highly sensitive to motion at this stage of the examination.<\/p>\n\n\n\nOptimizing Image Acquisition<\/h2>\n\n\n\n
Planning Ahead<\/h4>\n\n\n\n
Skilled Staff<\/h4>\n\n\n\n
Preparation of The Patient: Outside The MRI Room<\/h2>\n\n\n\n
Assessing The Patient<\/h4>\n\n\n\n
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Sedation<\/h4>\n\n\n\n
![\"When](\"https:\/\/hallmarq.net\/app\/uploads\/2024\/12\/20241030-HM-PT-6W1A0732Oakhill-1024x683.jpg\")
Handling of The Patient During Scanning<\/h4>\n\n\n\n
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Preparation of The Patient Inside The MRI Room<\/h2>\n\n\n\n
Get The Horse Comfortable<\/h4>\n\n\n\n
![\"The](\"https:\/\/hallmarq.net\/app\/uploads\/2024\/12\/20241029-HM-PT-6W1A0417Oakhill-1024x683.jpg\")
Even Weight Distribution<\/h4>\n\n\n\n
Head Carriage<\/h4>\n\n\n\n
Toe Out or In?<\/h4>\n\n\n\n
Fetlock Position<\/h4>\n\n\n\n
Bandaging<\/h4>\n\n\n\n
![\"Bandaging](\"https:\/\/hallmarq.net\/app\/uploads\/2025\/05\/Image-2-225x300.jpg\")
<\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\nAlignment of The MRI Magnet<\/h4>\n\n\n\n
![\"Stabilising](\"https:\/\/hallmarq.net\/app\/uploads\/2025\/05\/image-4.jpg\")
Take Your Time!<\/h4>\n\n\n\n
Coil Positioning<\/h4>\n\n\n\n
Teamwork: Understanding Anatomy For Better Decision-Making<\/h2>\n\n\n\n
Pilot Positioning<\/h4>\n\n\n\n
![\"\"](\"https:\/\/hallmarq.net\/app\/uploads\/2025\/05\/pilot-1.png\")
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![\"\"](\"https:\/\/hallmarq.net\/app\/uploads\/2025\/05\/Picture3.png\")
Awareness and Case Management<\/h4>\n\n\n\n
Team Coordination<\/h4>\n\n\n\n
Coil Position and Signal Quality<\/h4>\n\n\n\n
![\"When](\"https:\/\/hallmarq.net\/app\/uploads\/2025\/05\/coil-placement--300x300.jpg\")
![\"When](\"https:\/\/hallmarq.net\/app\/uploads\/2025\/05\/coil-re-placement-1-3-300x300.jpg\")
The Importance of Correct Sequence Selection When Scanning The Proximal Limb<\/h2>\n\n\n\n
Sequence Selection<\/h4>\n\n\n\n
Pathology and Decision-Making<\/h4>\n\n\n\n
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