Percentage fat fraction in magnetic resonance imaging: upgrading the osteoporosis-detecting parameter

Abstract

Background: Osteoporosis (OP) is a systemic metabolic bone disorder identified as an essential health issue worldwide. Orthopedic imaging approaches were commonly used with some limitations. Thus, our study aimed to investigate the diagnostic value of magnetic resonance spectroscopy (1-H MRS) and m-Dixon-Quant in OP.

Methods: A total of 76 subjects were enrolled in the study and bone mineral density (BMD) was measured using quantitative computed tomography (QCT). Then, the subjects were divided into three groups according to BMD: normal control group, osteopenia group and OP group. The following parameters were recorded for each patient: gender, age, height, body weight, waist circumference, and hip circumference. Further, the fat fraction percentage (FF%) values were determined by 1-H MRS and m-Dixon-Quant methods.

Results: In both 1-H MRS and magnetic resonance Imaging (MRI) m-Dixon-Quant, the FF% exhibited a negative correlation with BMD (P < 0.05). The FF% value of the OP group was significantly higher than that of the control group (P < 0.05). In addition, the FF% value in the m-Dixon scans was positively related to age, while BMD showed a negative linear relationship with age (P < 0.0001). Further, females had a significantly higher FF% value compared to males (P < 0.01), and height was correlated with BMD (P < 0.05) but not with FF% (P > 0.05).

Conclusions: MRI investigations especially FF% value in the m-Dixon-Quant imaging system is correlated with OP. Its diagnostic value remains to be demonstrated on a large prospective cohort of patients. Besides, parameters such as age, gender, and height are important factors for predicting and diagnosing OP.

Keywords: Bone mineral density; Fat fraction; MRI m-Dixon-quant; Magnetic resonance spectroscopy; Osteoporosis.

Fig. 1

FF is negatively correlated with BMD. a The FF% for both 1H MRS and m-Dixon-Quant imaging had a significantly negative correlation with the average bone density value. b The patients were divided into three groups: normal control group, osteopenia group, and OP group; the FF% value in the m-Dixon-Quant method was significantly higher in the OP group compared to normal control group. The bar presents the standard deviation; *P < 0.05

Fig. 2

The 1H MRS and m-Dixon-Quant images of two individuals in normal control group and OP group. In the 1H MRS quantitative analysis, the lipid peak of the L2 vertebral body of OP patient (b) was significantly increased compared to the normal control (a). The same trend was observed for the L3 vertebral body in the m-Dixon-Quant analysis of normal control (c) and OP (d) cases

Fig. 3

Age, gender, and height correlated with BMD and FF% values. a Age largely determined BMD and FF levels a. FF% in m-Dixon exhibited a positive correlation with age, while BMD showed a negative linear relationship. b Females had a higher FF% level compared to males. The bar presents the standard deviation; **P < 0.01. c Height was correlated with BMD, but not FF% (P = 0.064)