Many of my friends may ask, “Why do I need a CT or MRI of my lumbar disc when I already had an X-ray before my appointment? Today we will solve the problem and answer your questions. Lumbar spine X-ray film Lumbar spine X-ray film: generally includes frontal, double oblique position, hyperextension and hyperflexion position 1, frontal and lateral position film is mainly to observe the general situation of the lumbar spine bones, such as whether the vertebral body has hyperplasia, intervertebral foramen, whether the intervertebral space is narrow, whether there is slippage and so on; 2, double oblique position film is mainly to observe whether there is an isthmus cleft; 3, hyperextension and hyperflexion position film is mainly to observe the dynamic stability of the lumbar spine. Lumbar disc CT is mainly to observe the cross-section of the lumbar spine to see whether the disc is herniated, whether the ligamentum flavum is hypertrophic, whether the intervertebral joint is hyperplastic and a series of factors that cause spinal stenosis. Lumbar MRI not only allows cross-sectional observation, but also sagittal observation, which is more detailed than lumbar CT. At the same time, lumbar MRI has a higher indexing rate for soft tissues and can find information that cannot be observed by lumbar CT, such as free prolapsed discs in the sagittal position. In summary, doctors will prescribe different tests to clarify the diagnosis based on the patient’s clinical symptoms and their experience. Each test has a different focus and there is no duplication or over-examination. For example, if we want to buy a house, an X-ray is similar to looking at the overall structure and general condition of the house from the outside. A lumbar spine CT is equivalent to going into the house and looking at the internal structure. In addition to looking at the internal structure, the lumbar spine MRI also looks at the internal decoration, so that we can have an all-round understanding of the house and finally decide whether to buy it. When we perform clinical diagnosis or lumbar disc surgery, lumbar spine X-ray, CT and MRI all need to be taken, and the doctor will make the most reasonable judgment by checking the body and combining the imaging data to improve the success rate of the surgery.