title: Calcification in calcium pyrophosphate dihydrate (CPPD) crystalline deposits in the knee: anatomic, radiographic, MR imaging, and histologic study in cadavers.
abstract: OBJECTIVE
  To demonstrate and determine the frequency and location of calcification within cadaveric knees with or without calcification typical of calcium pyrophosphate dihydrate (CPPD), utilizing histologic, radiographic and MR imaging techniques.
  
  
  METHODS
  Ten cadaveric knees of elderly individuals that demonstrated no radiographic evidence of prior surgery or trauma were studied with MR imaging and subsequently sectioned in planes corresponding to those obtained with MR imaging. The slices were imaged with high-resolution radiography. Two musculoskeletal radiologists correlated the anatomic, MR and radiographic findings. Three of the knees, which did not demonstrate calcifications, were utilized as controls. Histologic sections were obtained from four knees that contained calcifications and from the three controls, and analyzed with special histologic stains that demonstrate phosphorus and calcium.
  
  
  RESULTS
  Radiographic imaging and histologic analysis demonstrated widespread CPPD crystal deposition in four of the 10 knee specimens (40%). MR imaging demonstrated some calcifications only within the articular cartilage of the femoral condyles in three of the four (75%) specimens that had CPPD deposits. In all four specimens radiographs and histologic analysis were more sensitive than MR imaging. Histologic analysis demonstrated no evidence of CPPD crystals in the control specimens.
  
  
  CONCLUSIONS
  MR imaging is insensitive to the presence of CPPD deposits in the knee, even when such deposits are widespread. Our study suggests that the sensitivity of MR imaging was significantly better in detecting CPPD deposits in the hyaline cartilage of the femoral condyles when compared with other internal structures, even when such structures contained a higher amount of calcification.
authors.affiliation: Department of Musculoskeletal Radiology, University of California, San Diego, VA San Diego Healthcare System, 3350 La Jolla Village Drive, CA 92162, San Diego, USA.
authors.forename: M
authors.initials: M
authors.lastname: Abreu
authors.forename: K
authors.initials: K
authors.lastname: Johnson
authors.forename: C B
authors.initials: CB
authors.lastname: Chung
authors.forename: J E
authors.initials: JE
authors.lastname: De Lima
authors.forename: D
authors.initials: D
authors.lastname: Trudell
authors.forename: R
authors.initials: R
authors.lastname: Terkeltaub
authors.forename: S
authors.initials: S
authors.lastname: Pe
authors.forename: D
authors.initials: D
authors.lastname: Resnick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D002131:Calcium Pyrophosphate / Q000378:metabolism*; D002805:Chondrocalcinosis / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D011859:Radiography
chemical_list: D002131:Calcium Pyrophosphate