EOS X-ray Imaging System

What is EOS?

The EOS Imaging System is a low-dose, 3-D imaging system that provides scans of patients in natural standing positions. The technology produces high-quality, detailed images while using a significantly lower radiation dose than a general radiography X-ray, enabling clinicians to make a more informed diagnosis and create individualized treatment plans for children with musculoskeletal disorders.

By scanning patients in a weight-bearing standing position, EOS is able to capture natural posture and the interaction between joints and the rest of the musculoskeletal system, particularly the spine, hips and legs.

What are the benefits of EOS imaging?

EOS imaging uses an ultra-low dose of radiation to provide extremely detailed, high-quality images that enable accurate diagnosis and more informed treatment decisions.

Reduced radiation dose:

  • EOS delivers a radiation dose that is two to three times less than a general computed radiography X-ray and 20 times less than basic computed tomography (CT) scans.
  • Reducing radiation dose is particularly beneficial for pediatric patients that need to be imaged frequently, such as patients with spinal deformities like scoliosis.

Better diagnostics and image accuracy:

  • 3-D weight-bearing images of patients in an upright, standing position provide the most accurate view of the spine and lower limbs, enabling physicians to evaluate balance and posture and analyze the bones, joints and ligaments from multiple angles.
  • This type of imaging enables us to view all areas of the body with one image, rather than stitching together multiple images, providing an accurate view of the musculoskeletal system that is essential to diagnosis and treatment planning.

What is EOS imaging used for?

EOS image of patient spine
EOS imaging
3-D weight-bearing images enable physicians to get the most accurate view of your child's spine and lower limbs in a natural standing position.

The EOS imaging machine is primarily used for orthopedic imaging in the assessment of patients with spine, hip, and leg disorders.

Because of the low radiation dose, EOS imaging is particularly beneficial to children with progressive conditions such as scoliosis and other spinal deformities that require frequent imaging to monitor disease progression. Learn more about CHOP’s treatment of pediatric spinal deformities »

The detailed images captured by low-dose EOS technology are also useful in the diagnosis and treatment of hip, knee and other lower limb deformities. The ability to get a complete view of musculoskeletal alignment in a weight-bearing position provides the best understanding of these conditions. Learn more about how we care for children with leg and foot disorders as well as pediatric hip disorders.

EOS is not typically used for injuries or conditions that can be evaluated with general radiography, such as broken bones in the arms, legs, hands or feet. Traditional X-rays are still the standard of care for diagnosing these injuries.

The Children’s Hospital of Philadelphia takes every safety precaution and we have set the standards for reducing patients’ exposure to radiation across all imaging tests and procedures. The EOS technology is yet another tool that enables us to provide the best imaging services while reinforcing our commitment to safety and low-dose imaging options for our patients.

Making an appointment

In most cases, EOS exams will be scheduled by your child’s physician in the Division of Orthopedic Surgery at CHOP. If your child’s orthopedic physician determines that EOS imaging is appropriate for your child’s condition, the physician will give you a prescription and/or referral in order to proceed with the EOS exam.

If you feel your child would benefit from EOS imaging but are not a current patient, please contact the Department of Radiology at 215-590-7000 for more information.

All EOS imaging will take place at the Main Hospital on the 2nd floor of the Wood Center. Wood Center 2nd Floor Map (PDF)

What should you do prior to the exam?

Prior to your child’s appointment, you should collect any necessary documents and paperwork, including insurance information and a referral from your child’s physician or orthopedic specialist.

Check with your insurance provider to make sure you are covered and to find out if they require a referral for EOS exams.

Read more information about preparing for your appointment with the Department of Radiology, or call 215-590-7000 if you have any additional questions.

If you’re planning on seeing other specialists while you’re at the Hospital (such as the Division of Orthopedic Surgery or the Musculoskeletal Center), make sure you speak with your physician or call that office ahead of time to make sure you have everything else you need for your appointments.

What should you do when you arrive?

You must check in to Outpatient Registration, located on the third floor of the Main Hospital, 45 minutes prior to your scheduled appointment. This is where your registration process occurs. If your insurance requires a referral, it must be presented at the time of registration. Proof of insurance will also need to be provided at this time.

Once the registration process is completed, a technologist or nurse will come out to the central registration waiting area and bring you and your child to a room to get changed and prepare for the exam.

If you’re coming from the Division of Orthopedic Surgery or another appointment within the hospital, someone will let you know when it is time for you to visit Radiology.

What should you expect during the exam?

Patient in EOS machine
EOS booth at CHOP
Your child will stand in the EOS booth for up to 20 seconds whil the X-ray is taken.

The patient will stand inside the EOS booth, where he/she will need to stand still for up to 20 seconds while the X-ray is taken. Because of the extremely low radiation dose, no protective lead apron is needed like in traditional X-rays.

The exam is performed using two very fine X-ray beams that are capable of simultaneously capturing both frontal and lateral images of the patient’s body. EOS can image the entire spine in less than 20 seconds and can reduce procedure time to less than 4 minutes, as compared to multiple view spine exams that can take up to 15-20 minutes.

What should you do after the exam?

After the EOS exam is complete, you should return to the Division of Orthopedic Surgery where your child’s orthopedic physician will review the results and complete your child’s exam.

There are no special instructions for your child to follow upon completion of this procedure.

Test results

The images from your child’s EOS imaging exam are available immediately. Because EOS creates 3-D images, there is no need to piece together multiple images. A radiologist and your child’s orthopedic physician will review the results. Your physician will then discuss the results with your family and determine next steps.

A report will be sent to your physician's office. If your physician has any questions regarding the report, he/she may call 215-590-2584.


Reviewed by: Diego Jaramillo, MD, MPH
Date: July 2013

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