title: Two-dimensional spectroscopic imaging for pretreatment evaluation of prostate cancer: comparison with the step-section histology after radical prostatectomy.
abstract: OBJECTIVE
  To minimize user and vendor dependence of the spectrum processing of prostate spectra, to measure the ratio of choline (Cho) plus creatine (Cr) to citrate (Cit) in the prostate tissue of normal volunteers and cancer patients, and to compare the results with pathologic findings after radical prostatectomy.
  
  
  METHODS
  Four healthy volunteers and 13 patients with prostate cancer were measured. Measurements were performed using two-dimensional magnetic resonance spectroscopic imaging (MRSI) and endorectal coil. A standard vendor's spectrum processing approach has been modified. An original feature of this methodology was the combination of vendor-optimized and user-independent spectrum preprocessing in the scanner and user-independent quantitation in the environment of an MRUI software package. (Cho+Cr)/Cit ratio was used for the classification of prostate tissue. Results were compared with histopathology after radical prostatectomy.
  
  
  RESULTS
  Eight of 13 cancer patients were classified as suspicious or very suspicious for cancer at spectroscopy, three were ambiguous for cancer and two patients were evaluated as false negative. A considerable overlap of metabolite ratios at various Gleason score was found.
  
  
  CONCLUSIONS
  The proposed spectrum processing has the potential to improve the accuracy and user independency of the (Cho+Cr)/Cit quantitation. This study confirmed the previous results that a considerable overlap of (Cho+Cr)/Cit ratios exists at various Gleason score levels.
authors.affiliation: Department of Radiology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden. jan.weis@radiol.uu.se
authors.forename: Jan
authors.initials: J
authors.lastname: Weis
authors.forename: Håkan
authors.initials: H
authors.lastname: Ahlström
authors.forename: Peter
authors.initials: P
authors.lastname: Hlavcak
authors.forename: Mikael
authors.initials: M
authors.lastname: Häggman
authors.forename: Francisco
authors.initials: F
authors.lastname: Ortiz-Nieto
authors.forename: Antonina
authors.initials: A
authors.lastname: Bergman
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D016022:Case-Control Studies; D002794:Choline / Q000378:metabolism*; D019343:Citric Acid / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism*; D005188:False Negative Reactions; D005240:Feasibility Studies; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery
chemical_list: D019343:Citric Acid; D003401:Creatine; D002794:Choline