Chang, H.-C.H.-C.ChangJuan, C.-J.C.-J.JuanChiu, H.-C.H.-C.ChiuCheng, C.-C.C.-C.ChengChiu, S.-C.S.-C.ChiuLiu, Y.-J.Y.-J.LiuChung, H.-W.H.-W.ChungHsu, H.-H.H.-H.HsuHSIAO-WEN CHUNG2018-09-102018-09-102014http://www.scopus.com/inward/record.url?eid=2-s2.0-84905912917&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/387336Objectives: To establish standard apparent diffusion coefficient (ADC) and the fat content as a function of age, gender and body mass index (BMI) in healthy parotid glands, and to address the influences of fat suppression on ADC measurements. Methods: A total of 100 healthy adults (gender and age evenly distributed) were prospectively recruited, with parotid fat content measured from gradient-echo images with fat-water separated using iterative decomposition with echo asymmetry and least squares (IDEAL). The ADCs were estimated using both fat-saturated and non-fat-saturated diffusion-weighted imaging via a periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique. Results: Parotid fat content was larger in men than in women by about 10 percentage points (P<0.005), and positively associated with BMI and age for both genders (mostly with P<0.001). ADCs estimated with non-fat-saturated PROPELLER were significantly lower in men than in women (P<0.005), but showed no gender difference if measured using fat-saturated PROPELLER (P=0.840). The negative association between parotid ADC and age/BMI/fat (P<0.001) showed greater regression slopes in non-fat-saturated PROPELLER than in fat-saturated data. Conclusions: Parotid fat content in healthy adults correlates positively with both age and BMI; the correlation with age is gender-dependent. Parotid ADC measurements are strongly influenced by fat saturation. Key Points: ? Parotid fat content in healthy adults correlates positively with age and BMI. ? The rate of aging-related increase in fat contents is gender-dependent. ? Parotid ADC measurements are strongly influenced by fat saturation. ? 2014 European Society of Radiology.Fat saturation; IDEAL fat-water separation; Parotid ADC measurement; Parotid fat content; PROPELLER[SDGs]SDG3[SDGs]SDG5adipose tissue; adult; age; anatomy and histology; body mass; diffusion weighted imaging; female; human; male; middle aged; parotid gland; procedures; prospective study; reference value; sex difference; three dimensional imaging; very elderly; Adipose Tissue; Adult; Age Factors; Aged, 80 and over; Body Mass Index; Diffusion Magnetic Resonance Imaging; Female; Humans; Imaging, Three-Dimensional; Male; Middle Aged; Parotid Gland; Prospective Studies; Reference Values; Sex Factorsjournal article10.1007/s00330-014-3265-z