Exhausting of effective energies and materials all results in entropy, and the more the exhausting is, the more the values of entropy gradully tend to. Evidence- based medicine (EBM),as a clinical new concept, can really guide clinical practices from solving problems to finding problems and finally overcoming problems. With EBM, we can put the medical and health resources to more scientific and rational use. It saves up effective energies, prevents exhausting of materials and reduces the values of entropy.

Objective To investigate the application value of slice encoding for metal artifact correction-view angle tilting(SEMAC-VAT)in chronic hip pain after total hip arthroplasty(THA).Methods A total of 22 patients who underwent TH A and required MRI reassessment for chronic hip pain were enrolled.All patients underwent coronal and axial short time inversion recovery(STIR)and SEMAC-VAT sequence scans.The prosthesis and surrounding artifact areas of STIR sequence and SEMAC-VAT sequence images were measured respectively.Likert scores were assigned to evaluate prosthesis clarity and visibility of surrounding anatomical structures.The number of abnormal lesions detected was recorded.Paired t-test and rank-sum test were used for comparisons between groups.Results Among the 22 patients,the mean prosthesis and surrounding artifact areas measured in coronal and axial STIR sequences were(73.08±11.28)cm2 and(34.36±8.47)cm2,respectively.For SEMAC-VAT sequences,the corresponding values were(44.30±8.41)cm2 and(23.08±5.85)cm2,respectively.These differences were statistically significant(t=13.942,8.659,P＜0.05).SEMAC-VAT sequences had higher Likert scores on coronal and axial prosthesis clarity and surrounding anatomical structures visibility than STIR sequences(P＜0.05).Additionally,SEMAC-VAT sequences were more effective in detecting abnormal lesions than STIR sequences(P＜0.05).Conclusion Compared to STIR sequences,SEMAC-VAT sequences significantly reduce metal artifacts and enhance image quality in the assessment of chronic hip pain after THA.This technique is advantageous in detecting more positive signs,facilitating the evaluation of hip images in patients with chronic pain after TH A,and subsequently clarifying the etiology of pain.