Persons using assistive technology may not be able to fully access information in this file. For assistance, e-mail niddk-cr@imsweb.com. Include the Web site and filename in your message. 663 Records 5 Variables Variable Type Len DLen Format InFormat Label StudyIdN Num 8 12 12. . StudyIdN MassSize Num 8 12 12. . MassSize Density Num 8 12 12. . Density Kidney Num 8 12 12. . Kidney RecID Num 8 12 12. . RecID