Approximately 40% of chronic low back pain is discogenic, and the treatment of discogenic low back pain is controversial, and intervertebral fusion or long-term pain medication is usually used after conservative treatment fails. Intradiscal electrothermal therapy (IDET), as a minimally invasive technique for the treatment of discogenic low back pain, has been developing rapidly in recent years and has been shown to be effective. 1. Development background IDET was first designed and applied to clinical practice by American rehabilitation physicians Jeffrey Saal and Joel Saal in the late 1990s. According to Back Letter, 640 physicians have treated 11,000 patients with this method throughout the United States, but only 2 articles by Saal et al. have been published in journals to date. This method was reported in several articles at the North American Spine Congress (NASS) in 1999 and 2000, all with short-term follow-up of a dozen to a few dozen cases. Tong Guohai, Department of Radiology, Shanghai Ruijin Hospital, was the first to introduce this technique into China in November 2003, and has performed more than 40 cases. 2.Basic principle The main pathological change of discogenic low back pain is internal disc disruption (IDD), that is, nucleus pulposus degeneration with radial fissure extending around the annulus fibrosus to the outer 1/3 layer of the annulus fibrosus, where there are sinus vertebral nerve fiber endings. The principle of IDET in the treatment of low back pain: (1) local heat therapy causes the collagen fibers in the fissures to contract and remodel to heal the tears; (2) heat inactivates inflammatory factors and degradative enzymes in the intervertebral disc, thus eliminating chemical pain-causing factors; and (3) heat causes the collagen fibers in the fissures to contract and remodel to heal the tears. ③Heat inactivates the nociceptive nerve endings distributed in the outer layer of the annulus fibrosus and loses the ability to receive and transmit pain signals; ④Deep heat therapy improves the microcirculation in the spinal canal. 3. Indications and contraindications 3.1. Indications: ① chronic persistent low back pain for more than 6 months; ② ineffective conservative treatment; ③ no abnormal findings on neurological physical examination; ④ negative straight leg raise test; ⑤ no spinal cord compression manifestation on MR examination and suggesting a high signal zone (HIZ) in the intervertebral disc; discography of the diseased segment can induce typical lower back pain, and pain-inducing test of adjacent segments is negative. Liu Weiwei et al. concluded that in addition to the above indications, IDET should be strictly controlled for the treatment of low back pain, and better results will be obtained when the following conditions exist: ① Age.