Objective: To study the CT imaging quality of low dose scanning lumbar intervertebral disc combined with IMR reconstruction and its consistency with MRI diagnosis. Methods: Forty patients suspected of lumbar intervertebral disc diseases were enrolled in the study. All patients underwent lumbar plain CT and MRI examination. Patients were divided into two groups: low-dose group (100 kV and DoseRight index 15) and conventional dose group（100 kV and Dose Right index of 26）. Images were reconstructed along the direction of the intervertebral space with 1 mm thickness. Images in the low-dose group were reconstructed by filtering back-projection (FBP) and IMR (level 1, soft tissue algorithm), while those in the conventional dose group were reconstructed by FBP algorithm. Parameters of each intervertebral disc were measured, including the CT value of intervertebral disc, yellow ligament, vertebral canal, lumbar major or iliopsoas muscle, and subcutaneous fat noise in the back. SNR (signal to noise ratio) and CNR (contrast to noise ratio) were calculated, respectively. Imaging quality was evaluated by 5-scale points. MRI was defined as the reference standard to evaluate the diag-nostic accuracy. Results: Radiation dose indices in the low dose group were significantly lower than those in the conventional dose group [CTDI_vol: （5.49±1.48） mGy vs（1.06±4.42） mGy; DLP: （182.36±51.10） mGy·cm vs （730.05±182.45） mGy·cm; Effective dose: （2.35±0.66） mSv vs （9.42±2.35） mSv, P<0.05]. The SNR and CNR of IMR images of the low-dose IMR group were superior to those of FBP images of low-dose and conventional-dose group(P<0.05). The diagnostic accuracy of low-dose IMR images (95%) was significantly higher than that of FBP images in low-dose group(45%) and was similar to that of FBP images of conventional-dose group (90%). Conclusions: Low-dose CT scan of intervertebral disc combined with IMR reconstruction algorithm can improve imaging quality and diagnostic performance.