title: Dynamic contrast-enhanced magnetic resonance imaging: a non-invasive method to evaluate significant differences between malignant and normal tissue.
abstract: OBJECTIVE
  An ever recurring challenge in diagnostic radiology is the differentiation between non-malignant and malignant tissue. Based on evidence that microcirculation of normal, non-malignant tissue differs from that of malignant tissue, the goal of this study was to assess the reliability of dynamic contrast-enhanced Magnetic Resonance Imaging (dcMRI) for differentiating these two entities.
  
  
  METHODS
  DcMRI data of rectum carcinoma and gluteus maximus muscles were acquired in 41 patients. Using an fast T1-mapping sequence on a 1.5-T whole body scanner, T1-maps were dynamically retrieved before, during and after constant rate i.v. infusion of a contrast medium (CM). On the basis of the acquired data sets, PI-values were calculated on a pixel-by-pixel basis. The relevance of spatial heterogeneities of microcirculation was investigated by relative frequency histograms of the PI-values.
  
  
  RESULTS
  A statistically significant difference between malignant and normal tissue was found for the mean PI-value (P < 0.001; 8.95 ml/min/100 g +/- 2.45 versus 3.56 ml/min/100 g +/- 1.20). Additionally relative frequency distributions of PI-values with equal class intervals of 2.5 ml/min/100 g revealed significant differences between the histograms of muscles and rectum carcinoma.
  
  
  CONCLUSIONS
  We could show that microcirculation differences between malignant and normal, non-malignant tissue can be reliably assessed by non-invasive dcMRI. Therefore, dcMRI holds great promise in the aid of cancer assessment, especially in patients where biopsy is contraindicated.
authors.affiliation: Department of Radiology, University Hospital of Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria, Europe a.rudisch@uibk.ac.at
authors.forename: Ansgar
authors.initials: A
authors.lastname: Rudisch
authors.forename: Christian
authors.initials: C
authors.lastname: Kremser
authors.forename: Werner
authors.initials: W
authors.lastname: Judmaier
authors.forename: Hildegard
authors.initials: H
authors.lastname: Zunterer
authors.forename: Alexander F
authors.initials: AF
authors.lastname: DeVries
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000473:pathology*; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA