What Can An MRI Discover After A Car Accident That An X-Ray May Miss?


Disclaimer: The following neither contains medical or legal advice but is for Informational Purposes Only. Consult a medical professional or attorney for your unique situation.

Car accidents are one of most common causes of injuries in adults. It is very important to recognize and diagnose all injuries that occur during car accidents so that they can be treated adequately and on time. Any delay in establishing a correct diagnosis will lead to delay of treatment and possible prolonged symptoms as well as a chance of permanent damage.

Usually medical professionals follow certain protocols when it comes to injury diagnostics and treatment. The diagnostic methods ordered will depend on the type of injury and injured body area. There are some body areas which can be injured in car accidents but don’t benefit from certain diagnostic or radiographic methods.

The examination will start with the history of the injury. In many cases, injury characteristics can lead the examiner to anticipate probable injury and its severity. The symptoms and signs of injury will further lead the investigator to the injury and its severity. For example, it can be expected that the patient with pain in the neck and no radiculopathy symptoms such as pain radiation, numbness, or tingling, will have less severe injury than those patients which have these symptoms.

After the examination, the examiner will order the radiographic studies which will help him/her to detect the injuries.

The most commonly used radiographic study after car accidents are X-rays. X-rays are a great diagnostic method to detect bone and joint injuries which are very common as a result of car accidents. X-rays of the injured area will reveal any bone injury such as fracture or joint dislocation. However, X-rays are not sensitive enough for soft tissue injuries or injuries of the brain, abdomen, etc.1

MRI is a very sensitive diagnostic method which uses the force of a magnetic field to reveal the changes in different body structures and tissues. It is very sensitive for soft tissue changes that X-rays can’t show adequately.

Cervical Spine

Whiplash is one of the most common injuries in car accidents which results in stretching of soft tissues in the neck following an impact. The cervical spine will go through very big motion range, from hyperextension to flexion. During these motions there is a chance that one can suffer fracture of some part of the cervical spine. X-rays will show any major fracture of the spine or spine dislocation. However, it will not show soft tissue injuries.2

Symptoms and signs present after the injury might indicate possible injury of nerve roots of the cervical spine, ligaments, etc.

So, if strong pain in the neck is present, or pain radiation to the back of the head, down the spine, down the arms, together with numbness or tingling in some body part, weakness of arm or hand, these are strong indicators for nerve injury and an MRI might be needed to reveal the full extent of injury.3

Lower Back Injury

Lower back or lumbar spine is another commonly injured area in car accidents. In most cases it is only muscle strain which can cause pain in the lower back. X-rays are a good starting point to confirm possible fractures of the lumbar spine. However, if one has normal X-rays and severe pain or pain that radiates down to buttocks, thighs, legs, or feet, or if there is numbness or tingling in those areas then there is a chance of injury to the spinal cord, spinal nerve roots, disc bulge, etc. If the foot keeps falling and one doesn’t have the ability to perform flexion of the foot, then there is a high chance of nerve compression. Another red flag is inability to control defecation and urination after surgery. These types of injuries can’t be diagnosed with X-rays and an MRI should be ordered to confirm the diagnosis. MRI is able to detect injuries of the spinal nerves and spinal cord. It has a high sensitivity for revealing disc bulges, which can occur after car accidents.4

Knee Injury

Knees can be injured in car collisions when they hit some part of the car. X-rays will detect the fracture but they are not sensitive enough to detect other injuries. The anatomy of the human knee is very complex and there are a number of different structures within the knee joint which can be injured (ACL, PCL, menisci, etc.). MRI is a great option to detect the injury of any intra-articular structures within the knee joint. Some patients will have a constant pain in the knee even if their X-rays are normal. In those situations, there is a chance that they have bone contusions or in some cases parts of cartilage can be detached from the joint surface. MRI will show these changes clearly.5

Brain Injury

Brain injuries are also very common in car accidents. One can suffer brain injury if their head is hit on the steering wheel, dashboard, seat in front, side window, etc. X-rays will show only skull bones and possible fracture. One might need an MRI of the brain in order to detect all the changes in the brain which occurred during the accident, like brain contusions or presence of hematoma, hemorrhage, etc.6

Shoulder Injury

Another commonly injured area in car accidents is the shoulder. It can be injured when the shoulder hits the side of the car during impact or roll over, or when the patient’s hold a firm grip on the steering wheel during the accident, etc. A simple contusion will require a normal X-ray with less severe pain and the injury will heal in a short period of time. However, if the patient has significant pain but the X-rays don’t show any injury, there is a high chance that soft tissues are injured. One commonly injured structure is rotator cuff. The rotator cuff is a name for a number of tendons and muscles which help the shoulder to move in different directions. An injury of the rotator cuff will cause inability of the shoulder to move in a certain direction or pain with movement. MRI will show even smallest tears of rotator cuff and it can direct the examiner to the right treatment method.7

In conclusion, X-rays are a great diagnostic tool to detect bone and joint injuries, such as fractures or dislocations. But in order to detect more subtle injuries of intra-articular structures or injuries of soft tissues, an MRI is the preferred diagnostic method.

  1. “X-Rays.” Nibib.nih.gov. N. p., 2019. Web. 1 Dec. 2019.
  2. MacDonald RL, et al. “Diagnosis Of Cervical Spine Injury In Motor Vehicle Crash Victims: How Many X-Rays Are Enough? – Pubmed – NCBI .” Ncbi.nlm.nih.gov. N. p., 2019. Web. 1 Dec. 2019.
  3. “Whiplash Injuries Can Be Visible By Functional Magnetic Resonance Imaging.” Pain Research and Management 11.3 (2006): 197-199. Web. 1 Dec. 2019.
  4. “MRI And Low Back Pain: Medlineplus Medical Encyclopedia.” Medlineplus.gov. N. p., 2019. Web. 1 Dec. 2019.
  5. “Need A Knee MRI? Here’S What You Can Expect.” WebMD. N. p., 2019. Web. 1 Dec. 2019.
  6. “Neuroimaging In Traumatic Brain Imaging.” NeuroRX 2.2 (2005): 372-383. Web. 1 Dec. 2019.
  7. (ACR), Radiological. “What Is MRI Of The Shoulder?.” Radiologyinfo.org. N. p., 2019. Web. 1 Dec. 2019.