[1] Mater Misericordiae Univ Hosp, Dept Radiol, Eccles St, Dublin D07 R2WY, Ireland
[2] Yale Sch Med, Dept Radiol & Biomed Imaging, New Haven, CT USA
[3] Wright State Univ, Dept Educ, Boonshoft Sch Med, Dayton, OH USA
[4] Johns Hopkins Med Inst, Russell H Morgan Dept Radiol & Radiol Sci, Baltimore, MD USA