title: In vivo proton MR spectroscopy of the breast using the total choline peak integral as a marker of malignancy.
abstract: OBJECTIVE
  The purpose of our study was to use the total choline-containing compound (tCho) peak integral as a marker of malignancy in breast MR spectroscopy (MRS).
  
  
  METHODS
  Forty-eight single-voxel water- and fat-suppressed 1.5-T MRS measurements were performed in 42 patients, obtaining both absolute tCho peak integral and tCho peak integral normalized for the volume of interest (VOI). Our reference standard was histology for lesions with BI-RADS category 4 and 5 and histology or at least a 2-year follow-up for findings with BI-RADS 2 and 3 and normal glands. Receiver operating characteristic (ROC) analysis, Mann-Whitney U test, and Spearman's rank correlation were used.
  
  
  RESULTS
  Three of 48 measurements (6%) failed. Of the remaining 45 spectra, 18 nonmalignant tissues showed no tCho peak, eight nonmalignant tissues showed a tCho peak integral from 0.99 to 9.03 arbitrary units (AU), and 19 malignant lesions showed a tCho peak integral from 1.26 to 19.80 AU. The diameter of nonmalignant tissues was 16.9 +/- 7.4 mm; that of malignant lesions was 15.3 +/- 6.9 mm (p = 0.308). At ROC analysis, the optimal threshold was 1.90 AU for absolute tCho peak, with 0.895 (17/19) sensitivity, 0.923 (24/26) specificity, and an AUC (area under the curve) of 0.917 (95% CI, 0.822-1.000); the optimal threshold was 0.85 AU/mL for the normalized tCho peak integral with 0.842 (16/19) sensitivity, 0.885 (23/26) specificity, and an AUC of 0.941 (0.879-1.000) (p = 0.470). A negative correlation (p = 0.011) was found between the VOI and the normalized tCho peak integral of malignant tissues.
  
  
  CONCLUSIONS
  Breast MRS using tCho peak integral reaches a high level of diagnostic performance.
authors.affiliation: University of Milan School of Medicine, Department of Medical and Surgical Sciences, IRCCS Policlinico San Donato, Milan, Italy. francesco.sardanelli@unimi.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Sardanelli
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fausto
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Leo
authors.forename: Robin
authors.initials: R
authors.lastname: de Nijs
authors.forename: Marianne
authors.initials: M
authors.lastname: Vorbuchner
authors.forename: Franca
authors.initials: F
authors.lastname: Podo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D002794:Choline / Q000032:analysis*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008875:Middle Aged; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D011522:Protons; D002794:Choline