Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. ORIGINAL RESEARCH n MUSCULOSKELETAL IMAGING 502 radiology.rsna.org n Radiology: Volume 259: Number 2—May 2011 Sonoelastography of the Plantar Fascia 1 Chueh-Hung Wu, MD Ke-Vin Chang, MD Sun Mio, MD Wen-Shiang Chen, MD, PhD Tyng-Guey Wang, MD Purpose: To compare the stiffness of the plantar fascia by using sonoelastography in healthy subjects of different ages, as well as patients with plantar fasciitis. Materials and Methods: The study protocol was approved by the Research Ethics Committee of the hospital, and all of the subjects gave their informed consent. Bilateral feet of 40 healthy sub- jects and 13 subjects with plantar fasciitis (fasciitis group) were examined by using color-coded sonoelastography. Healthy subjects were divided into younger (18–50 years) and older ( . 50 years) groups. The color scheme was red (hard), green (medium stiffness), and blue (soft). The color histogram was subsequently analyzed. Each pixel of the image was separated into red, green, and blue compo- nents (color intensity range, 0–255). The color histogram then computed the mean intensity of each color compo- nent of the pixels within a standardized area. Mixed model for repeated measurements was used for comparison of the plantar fascia thickness and the intensity of the color components on sonoelastogram. Results: Quantitative analysis of the color histogram revealed a sig- nificantly greater intensity of blue in older healthy subjects than in younger (94.5 6 5.6 [ 6 standard deviation] vs 90.0 6 4.6, P = .002) subjects. The intensity of red and green was the same between younger and older healthy subjects ( P = .68 and 0.12). The intensity of red was sig- nificantly greater in older healthy subjects than in the fas- ciitis group (147.8 6 10.3 vs 133.7 6 13.4, P , .001). The intensity of green and blue was the same between older healthy subjects and those in the fasciitis group ( P = .33 and .71). Conclusion: Sonoelastography revealed that the plantar fascia softens with age and in subjects with plantar fasciitis. q RSNA, 2011 1 From the Department of Physical Medicine & Rehabilita- tion, National Taiwan University Hospital Yun-Lin Branch, Yunlin, Taiwan, ROC (C.H.W.); and Department of Physical Medicine & Rehabilitation, National Taiwan University Hospital, 7 Chan-Shan South Road, 100 Taipei, Taiwan, Republic of China (K.V.C., S.M., W.S.C., T.G.W.). Received August 18, 2010; revision requested September 20; revi- sion received November 7; accepted November 26; final version accepted December 9. Address correspondence to T.G.W. (e-mail: tgw@ntu.edu.tw ). q RSNA, 2011