title: Neovascularization of bone marrow in patients with diffuse multiple myeloma: a correlative study of magnetic resonance imaging and histopathologic findings.
abstract: BACKGROUND
  The goal of the current study was to assess the correlation between bone marrow histology and contrast enhancement in infiltrative diffuse myeloma.
  
  
  METHODS
  Forty-four patients with homogeneous diffuse infiltration of bone marrow by multiple myeloma were examined using magnetic resonance imaging of the spine. The sequence protocol included T1-weighted spin-echo (pre- and post-gadolinium dimeglumine administration) and short-inversion time inversion recovery sequences. The percent increase in signal after intravenous gadolinium administration was calculated in bone marrow from patients with myeloma and from a control group of 86 patients who did not have bone marrow disease. Grade of infiltration with plasma cells, fat cell content, and hematopoietic marrow content were evaluated via histologic assessment of bone marrow, and microvessel density was evaluated via anti-CD34-positive immunostaining.
  
  
  RESULTS
  Increased microvessel density was observed in association with increasing plasma cell content (Kruskall-Wallis test: P < 0.0001). Contrast enhancement increased in a stepwise manner according to grade of microvessel density (Mann-Whitney U test: P < 0.05 and P < 0.001 for increases from low to intermediate and intermediate to high grade) and was significantly higher in patients with myeloma compared with control patients (Mann-Whitney U test: P < 0.001). A significant correlation also was found between histologic extent of tumor infiltration and contrast enhancement (Mann-Whitney U test: P < 0.0001). The mean level of contrast enhancement was 18% in the control group, 26% in patients with low-grade infiltration, 49% in patients with intermediate-grade infiltration, and 90% in patients with high-grade infiltration. In addition, fat cell content was found to be inversely correlated with contrast enhancement (chi-square test: P < 0.01).
  
  
  CONCLUSIONS
  As a consequence of increased microvessel density, decreased fat cell content, and increased cellularity, the presence of diffuse bone marrow infiltration in patients with multiple myeloma can be verified using gadolinium-enhanced magnetic resonance imaging.
authors.affiliation: Department of Clinical Radiology, University of Munich-Grosshadern, Munich, Germany. Andrea.Baur@ikra.med.uni-muenchen.de
authors.forename: Andrea
authors.initials: A
authors.lastname: Baur
authors.forename: Reiner
authors.initials: R
authors.lastname: Bartl
authors.forename: Christoph
authors.initials: C
authors.lastname: Pellengahr
authors.forename: Vivian
authors.initials: V
authors.lastname: Baltin
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
mesh_terms: D017667:Adipocytes; D000328:Adult; D000368:Aged; D019046:Bone Marrow Neoplasms / Q000098:blood supply* / Q000473:pathology*; D005260:Female; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009101:Multiple Myeloma / Q000098:blood supply* / Q000473:pathology*; D009389:Neovascularization, Pathologic; D012680:Sensitivity and Specificity; D013131:Spine / Q000098:blood supply / Q000473:pathology*
chemical_list: D005682:Gadolinium