[1] NIAMSD, Muscle Dis Unit, NIH, Bethesda, MD 20892 USA
[2] Johns Hopkins Univ, Sch Med, Rheumatol, Baltimore, MD USA
[3] Johns Hopkins Univ, Sch Med, Dept Radiol, Baltimore, MD 21205 USA
[4] Univ Western Ontario, Rheumatol, London, ON, Canada
[5] Johns Hopkins Univ, Sch Med, Radiol, Baltimore, MD USA
[6] Johns Hopkins Univ, Sch Med, Med, Baltimore, MD USA
[7] Johns Hopkins, Neurol, Baltimore, MD USA
[8] NIAMSD, NIH, Bethesda, MD 20892 USA