Imaging findings are essential for a definitive diagnosis of thoracic spinal stenosis. The most commonly used imaging tests are x-rays, computer-aided tomography (CT), and magnetic resonance imaging (MRI). So the question arises, which of these three tests is better? Is it necessary to do all three? To answer these questions, it is necessary to first briefly introduce the imaging principles of X-ray, CT and MRI. The image obtained reflects the density of each section of the scanned area, the higher the density the brighter (e.g. bone cortex is brighter than bone cancellous) and the lower the density the darker (e.g. muscle tissue is darker than bone tissue), so X-rays and CT are ideal for examining bony structures for abnormalities, with the former being better at grasping the overall situation and the latter focusing more on providing local details. In contrast, the images obtained by MRI reflect the signal strength of the examined area under specific magnetic field conditions, which is related to the number of hydrogen atoms present in each area and has nothing to do with density, and its properties determine that MRI is well suited to show lesions in soft tissues. In summary, the different imaging methods obtain different information, each has its own strengths and can complement the other, so it is not easy to conclude which is better. What clinicians need to do is to make full use of the characteristics of each test according to the clinical diagnostic needs and to “choose as needed. Specifically, when it is necessary to measure whether the thoracic lordosis is too large or too small, or to find out whether there is scoliosis in the spine, X-rays are better; when it is necessary to find out whether the ligaments are ossified, calcified or simply hypertrophic, CT is better; when it is necessary to find out whether the dural sac is compressed, whether the spinal cord is compressed, whether there is edema or necrosis inside the spinal cord, MRI is better …… According to the recommendations of the “Clinical Guidelines for the Treatment of Thoracic Spinal Stenosis”, which was approved by the Spine Surgery Group of the Orthopedic Branch of the Chinese Medical Association earlier this year, two types of examinations, thoracic spine X-ray and thoracic spine MRI scan, should be preferred to confirm the diagnosis of thoracic spinal stenosis. After the diagnosis of thoracic spinal stenosis is confirmed, a CT scan is required to further understand the details of the condition in order to develop the next treatment plan and surgical approach. In other words, patients with thoracic spinal stenosis need all three of these tests before surgery. In addition to the above imaging tests, electromyography is an option when the clinical diagnosis is not clear, especially when the symptoms of thoracic stenosis are atypical and need to be differentiated from motor neuron disease (a neurological diagnosis).