Proximal femur fat fraction variation in healthy subjects using chemical shift-encoding based MRI

Abstract

The objective of this study was to describe the normal variation of bone marrow fat content in the proximal femur considering the influence of side, age, sex and body mass index using fat fraction MRI. From September 2012 to July 2016, the MRI of 131 patients (258 hips) considered to have a normal MRI appearance were retrospectively evaluated. Patient records were searched to allow calculation of the body mass index (BMI). Water-fat based chemical shift MRI was available for all patients included. Proton density fat fraction maps were calculated, and measurements were performed in the femoral epiphysis, intertrochanteric region, and greater trochanter. The influence of patient age, sex, hip side and BMI on fat fraction values was assessed. Fat fraction was significantly different in the different locations evaluated (P = 0.0001). Patient sex and age significantly influenced fat fraction values in all regions evaluated (P < 0.02) with the exception of the epiphysis for sex (p = 0.07). In all locations, PDFF values were higher in men compared to women (3.3%, 4.4% and 13.1% higher in the epiphysis, greater trochanter and intertrochanteric region respectively). The intertrochanteric region presented the lowest fat fraction values with the highest variation compared to the greater trochanter and the epiphysis. BMI only influenced fat fraction values in the intertrochanteric region of females over 42 years old (P = 0.014). The interobserver variability of the measurements performed was considered to be excellent (ICC = 0.968). In conclusion, patient sex, age, and measurement location significantly influenced fat fraction values indicating that specific standards of reference are needed depending on these factors.

Correlation Analysis between Fat Fraction and Bone Mineral Density Using the DIXON Method for Fat Dominant Tissue in Knee Joint MRI: A Preliminary Study

“…본 연구에는 총 93명의 환자가 포함되었으며, 대퇴골 원위부 골간단의 지방신호분율(FmFF)과 경골 근위부 골간단의 지방신호 분율(TmFF) 평균값은 각각 80.6% ± 1.1%, 79.4% ± 1.3%로 계산되었고, 이는 Gondim Teixeira 등( 24 )과 Martel 등( 25 )의 연구에서 나타난 대퇴골의 FF값과 유사하다.…”