title: Physiological Background of Differences in Quantitative Diffusion-Weighted Magnetic Resonance Imaging Between Acute Malignant and Benign Vertebral Body Fractures: Correlation of Apparent Diffusion Coefficient With Quantitative Perfusion Magnetic Resonance Imaging Using the 2-Compartment Exchange Model.
abstract: OBJECTIVE
  To test the hypothesis that apparent diffusion coefficient (ADC) in vertebral bone marrow of benign and malignant fractures is related to the volume of the interstitial space, determined with dynamic contrast-enhanced (DCE) magnetic resonance imaging.
  
  
  METHODS
  Patients with acute benign (n = 24) and malignant (n = 19) vertebral body fractures were examined at 1.5 T. A diffusion-weighted single-shot turbo-spin-echo sequence (b = 100 to 600 s/mm) and DCE turbo-FLASH sequence were evaluated. Regions of interest were manually selected for each fracture. Apparent diffusion coefficient was determined with a monoexponential decay model. The DCE magnetic resonance imaging concentration-time curves were analyzed using a 2-compartment tracer-kinetic model.
  
  
  RESULTS
  Apparent diffusion coefficient showed a significant positive correlation with interstitial volume in the whole study population (Pearson r = 0.66, P < 0.001), as well as in the malignant (Pearson r = 0.64, P = 0.004) and benign (Pearson r = 0.52, P = 0.01) subgroup. A significant correlation between ADC and the permeability-surface area product could be observed when analyzing the whole study population (Spearman rs = 0.40, P = 0.008), but not when separately examining the subgroups. Plasma flow showed a significant correlation with ADC in benign fractures (Pearson r = 0.23, P = 0.03). Plasma volume did not show significant correlations with ADC.
  
  
  CONCLUSIONS
  The results support the hypothesis that the ADC of a lesion is inversely correlated to its cellularity. This explains previous observations that ADC is reduced in more malignant lesions.
authors.affiliation: From the *Department of Clinical Radiology, †Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, Ludwig-Maximilians University Munich, Munich, Germany; and ‡Division of Medical Physics, University of Leeds, Leeds, United Kingdom.
authors.forename: Tobias
authors.initials: T
authors.lastname: Geith
authors.forename: Andreas
authors.initials: A
authors.lastname: Biffar
authors.forename: Gerwin
authors.initials: G
authors.lastname: Schmidt
authors.forename: Steven
authors.initials: S
authors.lastname: Sourbron
authors.forename: Olaf
authors.initials: O
authors.lastname: Dietrich
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Andrea
authors.initials: A
authors.lastname: Baur-Melnyk
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000209:etiology / Q000473:pathology*; D013125:Spinal Neoplasms / Q000150:complications / Q000473:pathology*; D013131:Spine / Q000473:pathology; D055815:Young Adult
chemical_list: D003287:Contrast Media