There are several kinds of tests generally done for lumbar spine related diseases: X-ray, CT, MR (magnetic resonance imaging), spinal canal imaging, discography, etc. These tests focus on each other and complement each other, but they cannot replace each other, and we cannot say what is the most expensive to do, nor can we say what is the best to do. X-rays mainly look at the sequence of the entire lumbar spine, stability, whether there is narrowing of the intervertebral space, osteophytes, etc., if abnormalities are found to see more specific may need to supplement the CT or MRI. CT mainly observes the microstructure of the bone, whether there is protrusion of the intervertebral disc, whether there is narrowing of the spinal canal, especially in the observation of the lateral saphenous fossa is more superior, but its disadvantage is that the observation site is more limited, the parts that cannot be scanned can not be observed, in the observation of the whole is not as good as X-ray and MRI. MR mainly observes the nerve compression, disc degeneration and protrusion, and other soft tissue conditions. The advantage of MR is that the scope of examination is wide, and multiple vertebrae and discs and the corresponding spinal cord can be observed in one examination. CT is not useful when the disc is not yet herniated, and it cannot see the changes inside the disc. Spinal canal imaging is an invasive test in which a contrast agent is injected into the spinal canal and then radiographs are performed. This test is being used less and less, but it has a unique role in showing the nerve roots, especially in patients with lumbar scoliosis where other tests are irreplaceable to find out the compression of the nerve roots. Discography is the gold standard test to understand the internal changes of the disc, and the time contrast is injected into the disc and then Most of them need to be combined with CT to further understand the microstructural changes inside the disc, and MRI of the lumbar spine needs to be performed before doing discography for initial screening of discs that may cause disease. In short, what tests are needed for lumbar spine disease depends on the specific circumstances of the patient, depending on the need for diagnosis and treatment, and also related to the level of knowledge of the doctor.