What Is an Overexposed X-Ray—and How Can Veterinary Clinics Prevent It?
What Is an Overexposed X-Ray—and How Can Veterinary Clinics Prevent It?
An overexposed veterinary radiograph receives more X-ray exposure than is needed to produce a diagnostic image. With traditional film, the result is usually an image that appears excessively dark. With digital radiography, however, the problem can be much harder to recognize.
Digital imaging software can automatically adjust brightness and contrast, making an overexposed image appear acceptable on the monitor. The image may look good even though the patient received more radiation than necessary.
That is why veterinary teams should not judge exposure by image brightness alone. Proper technique charts, patient measurements, positioning, collimation, exposure indicators, equipment maintenance, and staff training all play important roles in producing consistently diagnostic radiographs.
Important distinction: A radiograph that looks too dark is not necessarily overexposed, and an overexposed digital radiograph may not look too dark. In digital radiography, displayed brightness is heavily influenced by computer processing.
What Does “Overexposed” Mean?
During a radiographic exposure, X-ray photons pass through the patient and reach the image receptor. That receptor may be conventional film, a computed radiography plate, or a digital detector.
The goal is not to send as much radiation as possible through the patient. The goal is to use the lowest exposure that still produces an image with enough detail and an acceptable level of noise for diagnosis.
An exposure that is too low may create a noisy or grainy digital image, sometimes called quantum mottle. An exposure that is unnecessarily high may reduce visible noise, but it also increases radiation exposure and can eventually cause important image information to be lost.
Film and Digital Radiographs Behave Differently
Overexposure With Traditional Film
With screen-film radiography, there is a direct relationship between exposure and the darkness of the processed film. Too much exposure generally produces a film that is too dark. If the overexposure is severe, anatomical details may be obscured and the radiograph may be nondiagnostic.
A bright viewing light may occasionally help reveal information on a mildly overexposed film, but it cannot restore detail that was never properly recorded or that has been lost in a severely overexposed area.
Overexposure With Digital Radiography
Digital radiography has a much wider exposure range than film. After an image is acquired, the computer processes the data and adjusts how the image is displayed. This can make an image obtained with too much radiation appear properly exposed.
Changing the monitor brightness, window level, or window width changes how the image is displayed. It does not change the amount of radiation that was used to create it.
Severe digital overexposure can still cause detector saturation or clipping. When that happens, areas of the image may lose useful information and appear uniformly black or otherwise lack visible detail. Post-processing cannot recreate information that the detector failed to preserve.
Why Overexposure Matters
Overexposure is not simply a cosmetic image problem. It can affect patient care, radiation safety, workflow, and equipment use.
- Unnecessary patient exposure: The patient may receive more ionizing radiation than was required for the examination.
- Loss of diagnostic information: Severe exposure can saturate portions of a digital detector or obscure detail on film.
- Unnecessary retakes: A nondiagnostic image may have to be repeated, increasing radiation exposure and consuming staff time.
- More stress for the patient: Retakes prolong positioning or restraint and may require additional sedation.
- Radiation exposure to personnel: Additional exposures increase the potential occupational exposure of team members, particularly when hands-free positioning practices are not used.
- Premature equipment wear: Habitually excessive techniques create unnecessary heat loading and use of the X-ray tube.
The appropriate principle is ALARA: radiation exposure should be kept “as low as reasonably achievable” while still producing an image that answers the clinical question.
What Is Exposure Creep?
Exposure creep is a gradual increase in the techniques used for digital radiographs. It can occur because a slightly higher exposure often reduces visible image noise, while the computer prevents the image from looking obviously too dark.
Over time, staff members may begin using progressively higher settings because the images appear smoother or because higher techniques seem to reduce the risk of an underexposed image. The clinic may not recognize the increase unless it routinely reviews exposure indicators and technique-chart performance.
A cleaner-looking digital image is not automatically a better image. Once sufficient diagnostic quality has been achieved, additional exposure may provide little or no clinical benefit.
Understand kVp and mAs
The two primary exposure controls are kilovoltage peak, or kVp, and milliampere-seconds, or mAs. They affect the X-ray beam differently.
kVp
kVp primarily controls the energy and penetrating ability of the X-ray beam. Increasing kVp allows more X-rays to penetrate the patient and reach the receptor. It also affects radiographic contrast and scatter production.
Small changes in kVp can produce substantial changes in receptor exposure, so kVp should not be adjusted casually.
mAs
mAs controls the quantity of X-ray photons produced. Increasing mAs generally increases the exposure reaching the receptor. Decreasing mAs reduces the number of photons and may increase image noise if it is lowered too far.
Technique corrections should be based on the appearance of the original image, the exposure indicator, the selected examination, patient thickness, positioning, collimation, and the clinic’s validated technique chart—not on a blanket instruction to lower one setting every time an image looks dark.
How to Recognize Overexposure on a Digital System
Because displayed brightness is unreliable, veterinary teams should review the exposure feedback provided by their system.
Exposure Index
The exposure index, often abbreviated as EI, is a numerical indicator associated with the amount of radiation reaching the detector. It is not a direct measurement of the patient’s radiation dose, but it provides useful feedback about detector exposure.
Veterinary clinics should learn exactly how the index works on their equipment. Older systems and different manufacturers may use different names and scales. On some systems, a higher number means higher detector exposure. On others, especially certain manufacturer-specific scales, the relationship may be reversed.
Target Exposure Index
The target exposure index is the expected detector exposure for a particular examination when the image has acceptable diagnostic quality. Targets may differ according to the body part, projection, patient size, detector, grid use, and clinical purpose.
Deviation Index
Some systems display a deviation index, or DI, showing how far the actual detector exposure differs from the target exposure. A DI near zero generally indicates that the exposure was close to the established target.
The exposure index or deviation index should not be used as the only reason to repeat an image. The veterinary professional should first determine whether the radiograph includes the required anatomy and is diagnostic. An image should not be repeated merely to obtain a perfect number.
Common Causes of Overexposed Veterinary Radiographs
1. Incorrect Patient Measurement
Guessing the patient’s thickness is one of the fastest ways to select the wrong technique. Measurements should be taken at the thickest part of the anatomy being examined and in the position that will be used for the exposure.
For example, a thorax or abdomen may measure differently when the patient is in lateral recumbency than when the patient is standing. Measure the patient after positioning whenever practical.
2. Wrong Examination or Anatomy Selected
Many digital systems use examination-specific processing and technique presets. Selecting “abdomen” when performing a thoracic study—or choosing the wrong patient-size category—may apply inappropriate exposure factors or image-processing algorithms.
Confirm the patient, anatomical region, projection, detector, grid status, and size category before every exposure.
3. Technique Chart Errors
A technique chart may be incorrect, outdated, or based on a different generator, detector, grid, focal distance, or processing system. Technique charts should be developed and validated for the clinic’s actual equipment.
Replacing a detector or generator without reassessing the chart can create consistent exposure errors even when team members follow the chart correctly.
4. Poor Collimation
The X-ray field should be restricted to the anatomy of interest. Excessively open collimation exposes more tissue and creates additional scatter radiation, which reduces image contrast and unnecessarily increases the irradiated area.
Poor collimation can also interfere with some computed radiography systems’ ability to recognize the exposure field correctly, potentially affecting image processing and the reported exposure indicator.
5. Grid-Related Errors
Grids absorb scatter radiation but also absorb some of the primary beam. A technique intended for use with a grid will usually be higher than a nongrid technique. Accidentally using a grid technique without a grid may cause excessive detector exposure.
The team should also verify correct grid alignment, centering, orientation, and focal distance to avoid grid cutoff and inconsistent image quality.
6. Incorrect Source-to-Image Distance
Technique charts are designed around a specific source-to-image distance. Moving the tube or detector closer together without making an appropriate technique adjustment can increase the exposure reaching the receptor.
7. Detector or Plate Differences
Different detectors and computed radiography plates may respond differently to the same technique. Clinics should avoid assuming that every receptor is interchangeable without testing and calibration.
8. Equipment or Calibration Problems
Generator output, timer accuracy, detector calibration, plate-reader performance, and software configuration can all affect exposure and image quality.
An equipment problem becomes more likely when multiple team members experience the same unexplained issue across many patients, body parts, or projections.
A Practical Troubleshooting Process
When a radiograph appears abnormal or the exposure indicator is outside the clinic’s expected range, use a systematic process rather than immediately changing the technique.
| Check | What to Confirm |
|---|---|
| Diagnostic quality | Is the required anatomy included, properly positioned, sharply recorded, and visible? |
| Exposure feedback | What are the exposure index, target index, and deviation index for this examination? |
| Patient measurement | Was the correct anatomical region measured in the actual exposure position? |
| Technique selection | Was the correct chart, body part, projection, patient size, detector, and grid status selected? |
| Collimation | Was the beam restricted to the necessary anatomy without clipping the area of interest? |
| Distance and centering | Were the source-to-image distance, tube alignment, and central ray correct? |
| Pattern | Is this an isolated operator error, or is the same problem occurring repeatedly across the clinic? |
Should an Overexposed Image Always Be Repeated?
No. Repeating every image with an imperfect exposure number can create more radiation exposure without improving patient care.
Before repeating an image, ask:
- Is all required anatomy included?
- Is positioning acceptable?
- Is motion controlled?
- Can the relevant structures be evaluated confidently?
- Is there evidence of detector saturation or lost information?
- Will repeating the study reasonably change the diagnosis or treatment decision?
If the image is diagnostic, it may not need to be repeated. The exposure problem should still be documented and used to improve future technique.
How Veterinary Clinics Can Prevent Overexposure
Create Equipment-Specific Technique Charts
Develop separate techniques when necessary for different anatomical regions, patient thicknesses, projections, grids, detectors, and source-to-image distances. Do not rely exclusively on a generic chart supplied for unrelated equipment.
Measure Every Patient Consistently
Keep calipers near the X-ray table and make measurement part of the standard workflow. Guessing should be the exception, not the normal procedure.
Review Exposure Indicators
Teach every operator how the clinic’s exposure indicator works. Establish expected ranges for common examinations and review trends instead of reacting to a single image.
Track Rejected and Repeated Images
A repeat-analysis program can identify recurring problems with positioning, anatomy selection, motion, collimation, technique, or equipment. The purpose is process improvement—not punishment.
Use Appropriate Positioning and Restraint
Proper positioning reduces motion and prevents avoidable retakes. When medically appropriate, sedation and positioning aids can improve consistency while reducing the need for staff members to manually hold patients.
Collimate Carefully
Include the anatomy required for diagnosis while avoiding an unnecessarily large exposure field. Good collimation improves image quality, reduces scatter, and limits the area exposed to radiation.
Maintain and Calibrate the Equipment
Follow the manufacturer’s recommended preventive-maintenance schedule. Detector calibration, plate care, generator testing, monitor quality, and software configuration should all be part of the clinic’s quality-assurance program.
Train the Entire Team
Every person who performs radiography should understand basic exposure principles, the clinic’s technique chart, the equipment’s exposure-index scale, positioning standards, collimation, repeat criteria, and radiation-safety procedures.
When to Request Equipment Service
Contact a qualified service provider when:
- Exposure problems occur across multiple patients and examinations.
- Identical techniques produce inconsistent results.
- Exposure indicators shift unexpectedly.
- One detector or computed radiography plate behaves differently from the others.
- Images show recurring lines, dead pixels, uneven density, artifacts, or unusual processing.
- The generator, detector, plate reader, workstation, or software was recently repaired or replaced.
- The technique chart no longer produces consistent diagnostic results.
A persistent problem should not be “fixed” by continuing to lower or raise exposure settings without determining the underlying cause. Doing so may hide an equipment fault and create new image-quality problems.
A Simple Pre-Exposure Checklist
Before making the exposure, confirm:
☐ Correct patient and examination
☐ Correct anatomical region and projection
☐ Patient measured in the exposure position
☐ Correct technique-chart setting selected
☐ Grid or nongrid technique confirmed
☐ Detector and source-to-image distance confirmed
☐ Patient positioned and immobilized
☐ Beam centered and collimated
☐ Personnel protected and positioned according to clinic policy
Frequently Asked Questions
Is an Overexposed X-Ray Always Black?
No. An overexposed film radiograph normally appears too dark. An overexposed digital radiograph may appear normal because the computer adjusts its displayed brightness and contrast.
Can Image-Processing Software Correct Overexposure?
Software can change how digital image data are displayed, but it cannot reduce the radiation already delivered to the patient. It also cannot recover data lost through detector saturation or clipping.
Should We Lower kVp or mAs When an Image Is Overexposed?
Not automatically. First confirm that the measurement, examination selection, grid status, distance, collimation, detector, processing, and exposure indicator are correct. Then adjust the appropriate factor according to the clinic’s validated technique chart and equipment instructions.
Does the Exposure Index Equal Patient Dose?
No. The exposure index primarily reflects exposure at the detector. Patient dose is also affected by patient size, beam quality, filtration, collimation, projection, distance, and other technical factors.
Why Do Exposure-Index Values Vary Between Machines?
Different manufacturers and older systems may use different calculations, names, and numerical scales. Veterinary teams should use the documentation and target ranges supplied for their specific equipment.
The Bottom Line
Preventing overexposed radiographs requires more than looking for an image that appears too dark. That approach may work with traditional film, but it is unreliable with modern digital systems.
Veterinary teams should evaluate diagnostic quality, exposure indicators, patient measurements, technique-chart accuracy, positioning, collimation, grid use, equipment performance, and repeat trends together.
A consistent quality-assurance program helps clinics obtain diagnostic images the first time, reduce unnecessary retakes, protect patients and staff, and make better use of their imaging equipment.
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Call 877-545-1202 Is It Time to Upgrade Your X-Ray? Click HereThis article provides general educational information and is not a substitute for the instructions supplied by your equipment manufacturer, applicable radiation-safety regulations, or advice from a qualified veterinary radiologist, medical physicist, radiation-safety professional, or service engineer.
Stop the Blur: Using Gemini AI to Master Large-Dog Radiographs
You position beautifully. You center carefully. You collimate appropriately. You hit expose…
And the image comes up blurry. Not just “a little soft,” but diagnostically questionable.
Full-body radiographs on 100lb Labs or obese cats can humble even the most experienced teams. When you’re up against thickness, motion, scatter, and time pressure, things get tricky fast. This is where Gemini, Google’s AI collaborator, becomes an essential tool for your radiology suite.
Sometimes you don’t need more CE; you need a fast, clear answer while the patient is still on the table.
Step 1: Moving Beyond Generic Search
If your team types: “Why are my x-rays blurry?” they’ll get a generic article. To get "Level 2" results, teach your staff to use Power Prompts that include specific constraints and a requested format.
The Power Prompt: "Act as a senior veterinary radiographer. Give me a 4-point checklist to fix motion blur for a 95lb dog on a DR system. Focus only on kVp/mA adjustments and physical restraint. Keep it under 50 words."
Step 2: Troubleshooting with "Physics-to-Practice"
Most of us don't need a physics lecture mid-shift. We need reminders that translate to immediate action. Instead of asking "why" something works, ask Gemini how to apply it to your specific machine.
The Power Prompt: "I’m shooting a 100lb dog, and the image is blurry from respiratory motion. My current settings are [Insert Your Settings]. What specific mA increase and exposure time decrease do you recommend to stop motion while maintaining density?"
Step 3: Create Instant Clinical "Cheat Sheets"
If your team struggles with consistency, use Gemini to build a reference tool that can be printed and taped to the wall near the generator.
The Power Prompt: "Create a simplified technique chart table for 'Large/Obese Patients' on a DR system. Include columns for: Body Thickness (cm), Grid Use (Yes/No), and kVp adjustment factors. Format it as a clean, scannable table."
Step 4: Mastering Motion Control
Blurry images aren’t always about the settings; they’re about the patient. Gemini can help your team refine their physical approach in seconds.
The Power Prompt: "List the 3 best sedation protocols and 2 positioning aids specifically for reducing respiratory motion in obese cats during thoracic films. Bullet points only."
Why This Matters for Your Workflow
A blurry radiograph is more than just a bad image; it’s a drain on your practice's health. Retakes lead to:
Increased Radiation: Unnecessary exposure for staff and patients.
Bottlenecks: A 10-minute study turning into a 30-minute ordeal.
Staff Burnout: Frustration from "guessing" at settings.
3 Tips for "Talking" to Gemini in the Clinic
Assign a Persona: Start your prompt with "Act as a senior veterinary radiographer" to ensure a professional tone and clinically grounded advice.
Use Specific Constraints: Tell the AI to "Keep it under 50 words" or "Use bullet points." This prevents you from having to read a long article while a patient is on the table.
Give It Your "Inputs": If you want a better setting, tell Gemini what you are currently using. AI is best at suggesting the "next step" when it knows where you are starting.
The "Why" Behind the Prompt
Using Gemini proactively reduces retakes, minimizes staff frustration, and ensures diagnostic-quality images the first time—improving both patient care and clinic efficiency.
The Bottom Line: AI as a Clinical Confidence Tool
We tend to talk about AI as if it’s only for "robotic" diagnostics. But in a busy clinic, Gemini’s best use is helping a technician stand in front of a DR monitor, think clearly, and get the shot right the second time—or better yet, the first.
Why AI Works:
AI answers improve dramatically when it knows:
What equipment
What happened
What you observed
What help do you want?
Think of it like calling tech support — details matter.
How to Identify and Correct Underexposed Veterinary X-Rays
In veterinary diagnostics, every image tells a story—but only if that image is clear, properly exposed, and reveals the details you need to see.
Underexposed radiographs are a common and frustrating issue, especially in busy clinics or those with less experienced staff. They don’t just create workflow delays—they can obscure critical findings and compromise patient care.
The good news? Identifying and correcting underexposed veterinary X-rays is entirely within your team’s reach!
Whether you're using a full-body digital x-ray system or a dental x-ray system, here’s what you need to know to spot underexposure and fix it fast.
What Does an Underexposed X-Ray Look Like?
Underexposed radiographs typically appear too light or “washed out.”
Anatomical structures, especially soft tissue or overlapping organs, may lack contrast and definition. This can make assessing for subtle fractures, pulmonary patterns, or abdominal masses difficult.
Let’s look at an example…
Jasper, a middle-aged Labrador, comes in for coughing and mild lethargy. The initial thoracic X-ray appears extremely pale—lung fields look nearly indistinguishable from the soft tissue.
On retake, using corrected exposure settings, the radiograph reveals a suspicious nodule.
That second image could distinguish between catching early pathology and sending the patient home undiagnosed.
What Causes Underexposure in Veterinary Radiographs?
Several factors can contribute to underexposure:
Incorrect technique settings (kVp and mAs) are often the most common culprits. Too low = too little penetration.
Improper patient positioning or size estimation: Thicker body parts may require adjustments to the technique.
Equipment calibration issues: Older or poorly maintained units may not output consistent exposure levels.
Sensor or plate problems: In digital systems, underexposure may also stem from a malfunctioning DR sensor or image plate.
Best Practices to Correct and Prevent Underexposed X-Rays
You can adjust technique settings thoughtfully.
If you’re routinely seeing underexposed images, review your technique chart. Increasing mAs improves image density, while adjusting kVp affects penetration and contrast.
Use a controlled approach—changing one variable at a time—to determine what works best for your unit and patient size.
Use a standardized positioning protocol
Precise radiographic technique starts with consistent positioning. Ensure your team utilizes positioning aids, is familiar with your machine’s baseline settings, and selects the appropriate view for the clinical question. Consider creating quick-reference guides near your X-ray suite.
Train your team to recognize exposure errors.
Empower your technicians to identify underexposure on the spot and retake images if necessary. Time spent training now saves retakes, delays, and diagnostic errors later.
Upgrade to high-quality digital systems.
Modern digital radiography systems often include automatic exposure detection and produce images in seconds, providing more consistency and reducing the likelihood of human error.
If you're using an older system or film-based radiography, consider upgrading to improve efficiency and accuracy.
Why It Matters
Correct exposure is more than a technical detail—it impacts patient care. A radiograph that misses a mass, hides a fracture, or blurs a lung pattern can delay treatment and put your patient at risk.
By optimizing your imaging protocols and investing in equipment that supports high-quality diagnostics, you help ensure that each patient receives the care they deserve. Each Veterinarian has the information they need to make confident decisions.
Would you be interested in upgrading your Imaging Suite?
Explore our catalog to find the right fit for your hospital. Whether you're opening a new practice or modernizing your existing setup, explore our selection of imaging equipment and don’t hesitate to reach out with any questions.
How to Avoid Under-Exposed X-Rays in Your Animal Hospital
Mastering X-ray Imaging: Essential Techniques for Crystal Clear Animal Radiographs
As veterinarians, we’re sure that you use X-rays commonly as a part of a diagnostic process. In order to achieve an accurate diagnosis, however, these radiographs must be correctly positioned and of high quality. If X-rays are taken poorly, lesions may be both under and over-diagnosed, due to problems with interpretation.
What is an under-exposed X-ray and how do I avoid that in my animal hospital X-ray room?
Having to repeat X-rays is far from ideal, both in terms of increased radiographic exposure for our patients, but also in terms of cost, time, and frustration for the veterinary professional.
We all want our X-rays to be the perfect first time – so how do we achieve that? Exposure problems are a common X-ray fault in animal hospitals, so in this blog, we will go through under-exposure, and how to avoid it. The opposite, over-exposure, is also a common issue – read more about that here.
What is exposure?
Exposure refers to the concentration of X-ray photons in the air at a specific point. If an X-ray is under-exposed, it means there was less penetration of the beam through the target tissue.
X-ray exposure is affected by four factors:
Kilovoltage (kV) – controls the energy of the X-rays, and therefore the penetrating power
Milliampere (mA) – the current applied to the tube to generate X-rays, and therefore the number of photons produced
Exposure time
Focus-film distance (FFD - the distance from the X-ray source to the patient) – as distance increases, the intensity of the beam decreases
It is a combination of these factors which determines the overall exposure of each X-ray.
Why does an under-exposed X-ray matter?
In conventional radiography, an under-exposed X-ray will look ‘lighter’ or ‘whiter’ than a properly exposed X-ray. This whitening effect can make it very difficult to spot subtle abnormalities and lesions. Under-exposure can also lead to increased mottling or cloudiness of an image, which can obscure parts of the radiograph, or lead to artifacts.
Most veterinary staff were taught the “Rule of Toast” to describe this – underdone toast is too white.
However, in a modern digital radiograph, the computer will automatically add additional filters. It is very, very rare for an underexposed digital radiograph to appear pale or white.
This can “trick” the inexperienced radiographer into thinking that the exposure is correct when, in reality, the computer is enhancing and filtering the image.
This enhancement adds an additional layer of complexity when diagnosing from the radiograph because there may be insufficient raw data to obtain a reliable image, despite excellent-appearing radiographs.
Mildly under-exposed images are unlikely to be diagnostically catastrophic, as the signal: noise ratio of a modern DDR plate is high enough that it is likely that sufficient data has been captured. However, the more underexposed the image is, the more serious the potential for errors.
In more severely under-exposed images, the most common sign is pixelation of the image. It may appear subtly grainy, or even blurred (like an image zoomed in too far). This can significantly obscure subtle or fine pathology, especially when viewing lung fields, or fine structures like small animal phalanges or dentitions.
Under-exposure is therefore a real problem when it comes to the interpretation of X-rays in an animal hospital. Poor X-ray quality can lead to both over and under-diagnosis of disease in our patients.
Why is my X-ray under-exposed?
Having problems with under-exposed X-rays in your veterinary clinic? Here’s where you might be going wrong!
A common error when it comes to exposure is changes in the distance between the X-ray machine and the patient. Even a relatively small increase in distance can have a large effect on exposure, and therefore X-ray quality, as exposure is controlled by the inverse square law of radiation dispersal.
A small increase in the FFD requires a corresponding significant increase in the mAs to avoid an underexposed X-ray. Common causes for a variable FFD include adjustable X-ray tables in small animal hospitals, or large animal veterinarians standing too far from the patient with a portable machine.
The kV and mA settings play a large role in the exposure. Low kV levels affect X-ray penetration and therefore result in lower exposure. If an image is under-exposed, this usually means that the kV or mAs need to be increased.
However, adjusting the kV will lead to contrast changes, so in most cases, unless the contrast is too high, the mAs is the adjustment of choice to correct exposure errors.
Exposure can also be low due to various common technical errors, such as using a grid unnecessarily or underestimating the weight or body size of a patient.
Tips for avoiding an under-exposed X-ray
Achieving the right exposure is vital for X-rays of good diagnostic quality. In basic terms, if radiographs are often being under-exposed at your veterinary hospital, then increases to the kV or mAs settings will be needed.
However, for an X-ray of true diagnostic quality, it should be remembered that an image needs to be of high quality, rather than just exposed correctly.
For example, different approaches may be used when imaging the thorax as compared to the abdomen. Thoracic radiographs require a high kV: there is high natural contrast between bone, soft tissue, and gas, and using a high kV value enhances detail in the soft tissue areas of the lung fields.
Conversely, the abdomen has low natural contrast due to the vast majority of content being soft tissue, and therefore abdominal X-rays require a lower kV to maximize contrast.
The mAs setting will therefore need to be adjusted appropriately to accommodate the change in kV whilst retaining good exposure.
Exposure charts can be a really useful way to give a good starting point for determining the best settings. By including appropriate settings for multiple species, breeds, and sizes of animals, as well as different areas of anatomy, quick reference charts can be invaluable for maximizing X-ray quality and exposure.
The other two exposure factors of distance and time should be standardized as much as possible. Using correct restraint of patients should minimize motion blur. It is also important to ensure your X-ray machine is regularly maintained and serviced, to minimize the likelihood of equipment error.
Most modern DR systems have embedded Exposure Indicators, and with “exposure creep” a significant issue in digital radiography, we strongly recommend you use this under-utilized tool to ensure that your exposures are optimal. https://newvetequipment.com/dr-digital
Summing up
Under-exposed X-rays lead to interpretation errors, especially as they can be difficult to detect on a digital radiograph. Under-exposure can be caused by changes to the exposure factors: kV, mAs, distance, and time.
Standardizing exposure factors, using correct calculations for kV and mAs, and using accurate Exposure Indicators will lead to correct exposure and X-rays of true diagnostic quality in your animal hospital.
Many instances of under or overexposure can be attributed to doctors failing to measure animals or consult the technique chart.
References
Mattoon, J. (2006) ‘Digital Radiography’ Vet Comp Orthop Traumatol 19(03) pp.123-132
Kirberger, R. (2005) ‘Radiograph quality evaluation for exposure variables – a review’ Veterinary Radiology and Ultrasound 40(3) pp.220-226