I have a bad spine, what kind of check-up should I do?

This is the 4255th article of Da Yi Xiao Hu

My friend Xiao Li is a financial manager of a listed company. The beginning and end of the year are the busiest times for financial people. Xiao Li worked "996" and "007" for several weeks, and finally the "busy season" came to an end, but his physical condition was getting worse and worse. The most difficult thing was the discomfort in the cervical and lumbar vertebrae, so he thought of going to the hospital for a CT scan. He went to the orthopedic department of the hospital to explain his purpose, but the orthopedic doctor suggested that he do an MRI scan. MRI cannot be done on the same day, and an appointment is required in about a week. Seeing the MRI examination order, which costs more than twice as much as CT, he called Dr. Yu to ask if this is over-medicalization.

"No, this is a reasonable examination." Dr. Yu answered very straightforwardly. Many friends know that if you have discomfort in your cervical and lumbar spine, you should go to the hospital to "take an X-ray", but they are not very clear about what kind of X-ray to take. Here I will explain what the three common imaging examinations in clinical practice - X-ray, CT and magnetic resonance imaging (MRI) can see, and how they should be used in spinal examinations.

X-ray and CT

X-rays have been used in clinical practice for more than 100 years. When X-rays penetrate the human body, the density of each tissue is different, so the amount of X-rays that penetrate the tissue is different, and the grayscale displayed on the image is also different. Since X-rays can only display two-dimensional images, they are also called "plain films". The principle of CT is to use X-rays to scan the layers of a certain part of the human body, and then perform a series of transformations through a computer, and finally reconstruct it into a CT image. CT can provide complete three-dimensional information of the examined part of the human body, so that the organs and structures can be clearly visualized. In short, it is a 3D version of an X-ray. In the diagnosis of orthopedic diseases, X-rays and CT are the most suitable for looking at bones, including fractures, displacements, etc. When X-rays cannot confirm whether there is a fracture, CT is required for three-dimensional observation.

Magnetic resonance imaging (MRI)

The fact that there is no problem with the bones does not mean that there is really no problem. In many cases, an MRI examination is required to clearly see the muscles, ligaments and other soft tissues around the joints or to determine whether the fracture is fresh or old. The two most important applications of MRI in the diagnosis of orthopedic diseases are the spine and the knee joint. MRI can well display structures such as vertebral bodies, intervertebral discs, dura mater sacs, nerves, etc. in the spine. It can also show pathological changes such as intervertebral disc degeneration, dura mater sac compression, cauda equina disorder, etc. MRI can display structures such as the meniscus, cruciate ligaments, and intra-articular fluid in the knee joint.

How to choose the inspection

In outpatient examinations of the cervical and lumbar spine, MRI can reflect more information, and some MRI examination results cannot be replaced by X-rays and CT scans. However, MRI requires an appointment and waiting time, and the price is significantly higher than X-rays and CT scans. If the patient is in severe pain, or is inconvenient to wait for economic reasons, CT scans can be selected. X-rays can reflect less information in spinal diagnosis and are usually only used for trauma screening.

If you want to perform preoperative examination for spinal surgery, you usually need a full set of X-rays, CT, and MRI examinations. In addition to the conventional anteroposterior and lateral views, the X-rays also need hyperextension and hyperflexion views to reflect the stability of the spine. Of course, if you come to this step, you still have to listen to the doctor.

Author: Department of Orthopedics, Shanghai Putuo District Central Hospital

Yu Luchao