Calcium pyrophosphate dihydrate crystal deposition in and around the atlantoaxial joint: association with type 2 odontoid fractures in nine patients. - Kakitsubata Y; Boutin RD; Theodorou DJ; Kerr RM; Steinbach LS; Chan KK; Pathria MN; Haghighi P; Resnick D (Radiology, 2000)