title: Dynamic contrast-enhanced MR imaging measurement of vertebral bone marrow perfusion may be indicator of outcome of acute myeloid leukemia patients in remission.
abstract: OBJECTIVE
  To examine whether dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging measurement of bone marrow perfusion in acute myeloid leukemia (AML) patients in complete remission (CR) is associated with outcome and survival.
  
  
  METHODS
  After institutional review board approval and informed consent were obtained, from September 2004 to October 2007, 51 patients (29 women, 22 men; mean age, 43.5 years; range, 17-66 years) agreed to undergo DCE MR imaging to assess bone marrow perfusion, among 96 patients with newly diagnosed de novo AML who had received induction chemotherapy and achieved CR. Two semiquantitative parameters (peak and slope) and another three quantitative parameters (amplitude, K(ep) [efflux rate constant], and K(el) [elimination rate constant]) were calculated. Overall survival (OS) and relapse-free survival (RFS) were assessed with the Kaplan-Meier model, while differences between patient groups with high and low DCE MR imaging parameter values were assessed by using the two-sided log-rank test.
  
  
  RESULTS
  The median follow-up was 25.9 months. Univariate analysis results showed that high values of peak (≥0.42), slope (≥0.0235), amplitude (≥0.03), and K(ep) (≥0.0082) were associated with shorter OS (P = .004, 0.01, 0.034, and 0.026, respectively). Besides, a high value of K(ep) was also associated with shorter RFS (P = .008). When age, sex, and initial karyotype at diagnosis were included in multivariate Cox proportional hazards analysis, the results showed that only K(ep), but not other DCE MR imaging parameters, was an independent factor for OS (relative risk [RR], 30.305; P = .021) and RFS (RR, 6.477; P = .009).
  
  
  CONCLUSIONS
  Bone marrow perfusion measured with DCE MR imaging in AML patients in CR can be an indicator of outcome and survival. K(ep) measured with kinetic modeling was useful and significantly associated with RFS, while heuristic parameters (peak and slope) were not.
authors.affiliation: Department of Medical Imaging and Radiology, Internal Medicine, National Taiwan University Hospital and College of Medicine, No. 7 Chung-Shan S. Rd, Taipei, Taiwan 100.
authors.forename: Bang-Bin
authors.initials: BB
authors.lastname: Chen
authors.forename: Chao-Yu
authors.initials: CY
authors.lastname: Hsu
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Yu
authors.forename: Hsin-An
authors.initials: HA
authors.lastname: Hou
authors.forename: Chieh-Yu
authors.initials: CY
authors.lastname: Liu
authors.forename: Shwu-Yuan
authors.initials: SY
authors.lastname: Wei
authors.forename: Wen-Chien
authors.initials: WC
authors.lastname: Chou
authors.forename: Hwei-Fang
authors.initials: HF
authors.lastname: Tien
authors.forename: Tiffany Ting-Fang
authors.initials: TT
authors.lastname: Shih
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology*; D016009:Chi-Square Distribution; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012074:Remission Induction; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA