Purpose To investigate the correlation between intervertebral disc degeneration and paraspinal muscle fatty infiltration in chronic low back pain(CLBP)using quantitative MRI techniques.Materials and Methods A total of 63 CLBP patients and 42 volunteers in Zigong Fourth People's Hospital from September 2023 to March 2024 were retrospectively collected.Magnetic resonance scans were performed using multi-echo water-fat separation technique and T2 mapping technique.Intervertebral disc degeneration was assessed using the Pfirrmann grading,while paraspinal muscle fatty infiltration was evaluated using the Goutallier grading.Proton density fat fraction(PDFF)of the multifidus and erector spinae muscles,and T2 values of the nucleus pulposus were quantitatively measured.The relationships between these parameters and their associations with age and gender were analyzed.Results Compared with healthy volunteers,CLBP patients showed significantly reduced T2 values of the nucleus pulposusand significantly increased PDFF of the paraspinal muscles(Z=-5.54-4.65,all P<0.001).The Pfirrmann grading of intervertebral discs and the Goutallier grading of paraspinal muscles were significantly correlated with the T2 value of the nucleus pulposus and the PDFF of the paraspinal muscles(|r|>0.4,P<0.05).Age and Pfirrmann grading were independent predictors of paraspinal muscle fat infiltration(β=0.228-5.682,all P<0.001),and gender was also an independent predictor at the L4/5 intervertebral disc level(β=-2.834,-3.352,both P<0.05).Conclusion Intervertebral disc degeneration and paraspinal muscle fat infiltration are closely related in CLBP,age and gender also have an impact.

Purpose To investigate the correlation between intervertebral disc degeneration and paraspinal muscle fatty infiltration in chronic low back pain(CLBP)using quantitative MRI techniques.Materials and Methods A total of 63 CLBP patients and 42 volunteers in Zigong Fourth People's Hospital from September 2023 to March 2024 were retrospectively collected.Magnetic resonance scans were performed using multi-echo water-fat separation technique and T2 mapping technique.Intervertebral disc degeneration was assessed using the Pfirrmann grading,while paraspinal muscle fatty infiltration was evaluated using the Goutallier grading.Proton density fat fraction(PDFF)of the multifidus and erector spinae muscles,and T2 values of the nucleus pulposus were quantitatively measured.The relationships between these parameters and their associations with age and gender were analyzed.Results Compared with healthy volunteers,CLBP patients showed significantly reduced T2 values of the nucleus pulposusand significantly increased PDFF of the paraspinal muscles(Z=-5.54-4.65,all P<0.001).The Pfirrmann grading of intervertebral discs and the Goutallier grading of paraspinal muscles were significantly correlated with the T2 value of the nucleus pulposus and the PDFF of the paraspinal muscles(|r|>0.4,P<0.05).Age and Pfirrmann grading were independent predictors of paraspinal muscle fat infiltration(β=0.228-5.682,all P<0.001),and gender was also an independent predictor at the L4/5 intervertebral disc level(β=-2.834,-3.352,both P<0.05).Conclusion Intervertebral disc degeneration and paraspinal muscle fat infiltration are closely related in CLBP,age and gender also have an impact.

Objective To explore the relationship between the orbital fat volume and the age,gender,orbital anteroposterior and transverse diameter in healthy person.Methods 210 healthy person (105 males and 105 females)were enrolled and equally divided into 7 groups according to the age.The area of the orbital fat,orbital anteroposterior and transverse diameter in all the above groups were measured in axial CT images.Then the volume of the orbital fat were computed using equation.The relationship between the orbital fat volume and the age,gender,orbital anteroposterior and transverse diameter were analyzed in the different gender and age groups.Results The volume of orbital fat was symmetrical in all age groups,and the mean fat volume of bilateral orbital was(18 957±4 143)mm3,in which adults (age＞20 years old)had the average orbital fat volume (20 340±3 514)mm3.The mean values of the orbital anteroposterior and transverse diameter were (5.16±0.37)mm and (3.74±0.23)mm,respectively.The orbital fat volume in male was greater than that in female in all age group,in addition,it was positively correlated with the age,orbital oranteroposterior and transverse diameter (P＜0.001).Conclusion The orbital fat volumes are associated with the age,gender,orbital anteroposterior and transverse diameter in healthy person.In addition,the orbital fat volume in male is greater than that in female.