title: Cancellous bone volume is an indicator for trabecular bone connectivity in dialysis patients.
abstract: OBJECTIVE
  A new assessment system for bone histology, termed the turnover-mineralization-volume system, is advocated for patients with chronic kidney disease-related mineral and bone disorder. The system measures cancellous bone volume (BV/TV) as a third major evaluation axis; however, the physiologic significance of BV/TV remains unclear.
  
  
  METHODS
  Conventional bone histomorphometry was performed in 75 iliac bone samples obtained from dialysis patients. In 47 of the 75 samples, the remaining samples were subjected to direct microfocus x-ray computed tomographic observation. Quantitative morphologic examinations, including micro-bone mineral densitometry, and marrow space star volume, Euler number, and node-strut analyses, were performed in the virtual three-dimensional space reconstructed from the microfocus x-ray computed tomographic images.
  
  
  RESULTS
  The levels of BV/TV were comparable in each of the conventional bone histomorphometric criteria. No significant correlations were found between BV/TV and other parameters. Two- and three-dimensional BV/TVs were significantly correlated with cancellous bone mass but not with cortical bone thickness or cortical bone mass. Two- and three-dimensional BV/TVs were significantly correlated with trabecular bone connectivity as determined by marrow space star volume, Euler number, and node-strut analyses.
  
  
  CONCLUSIONS
  In dialysis patients, BV/TV is not dependent on bone turnover or bone mineralization. BV/TV is unlikely to indicate the balance between bone formation and bone resorption. Instead, it reflects trabecular bone connectivity, and improved trabecular bone connectivity is physiologically beneficial in terms of bone quality. The turnover-mineralization-volume system offers an advantage over the conventional system for the assessment of bone quality.
authors.affiliation: Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan. jjkaz@med.niigata-u.ac.jp
authors.forename: Junichiro James
authors.initials: JJ
authors.lastname: Kazama
authors.forename: Ryo
authors.initials: R
authors.lastname: Koda
authors.forename: Suguru
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Ichiei
authors.initials: I
authors.lastname: Narita
authors.forename: Fumitake
authors.initials: F
authors.lastname: Gejyo
authors.forename: Akihide
authors.initials: A
authors.lastname: Tokumoto
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000473:pathology; D016723:Bone Remodeling; D002113:Calcification, Physiologic; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007085:Ilium / Q000000981:diagnostic imaging / Q000473:pathology*; D021621:Imaging, Three-Dimensional; D007674:Kidney Diseases / Q000150:complications / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011857:Radiographic Image Interpretation, Computer-Assisted; D006435:Renal Dialysis; D055114:X-Ray Microtomography