Accepted for Publication: July 7, 2011.
Author Contributions: Study concept and design: Kondo and Adachi. Acquisition of data: Adachi. Analysis and interpretation of data: Adachi. Drafting of the manuscript: Kondo and Adachi. Critical revision of the manuscript for important intellectual content: Adachi. Administrative, technical, and material support: Adachi. Study supervision: Adachi.
Financial Disclosure: None reported.
Additional Contributions: Takeshi Koshiishi, MD, PhD (Department of Radiology, Tama Medical Center) provided expertise in the radiographic diagnosis and interpretation.