title: Assessment of colorectal hepatic metastases by quantitative T2 relaxation time.
abstract: OBJECTIVE
  To determine the T(2) relaxation time of colorectal hepatic metastases and changes in T(2) relaxation times following chemotherapy.
  
  
  METHODS
  42 patients with 96 hepatic colorectal metastases underwent baseline MRI. Axial T(1), T(2) and multi-echo GRASE sequences were acquired. ROIs were drawn on T(2) relaxation maps, obtained from GRASE images, encompassing metastasis and normal liver to record T(2) relaxation time values. In 11 patients with 28 metastases, MRI was repeated using same protocol at 6 weeks following chemotherapy. The median pre-treatment T(2) values of metastases and normal liver were compared using the Mann-Whitney test. The pre- and post-treatment median T(2) values of metastases were compared using the Wilcoxon-Rank test for responding (n=16) and non-responding (n=12) lesions defined by RECIST criteria. The change in T(2) values (ΔT(2)) were compared and correlated with percentage change in lesion size.
  
  
  RESULTS
  There was no difference in the pre-treatment median T(2) of metastases between responding (67.3±8.6) and non-responding metastases (71.4±16.5). At the end of chemotherapy, there was a decrease in the median T(2) of responding lesions (61.6±12.6) p=0.83, and increase in non-responding lesions (76.2±18.4) p=0.03, but these were not significantly different from the pre-treatment values. There was no significant difference in ΔT(2) of responding and non-responding lesions (p=0.18) and no correlation was seen between size change and ΔT(2) (coefficient=0.3).
  
  
  CONCLUSIONS
  T(2) relaxation time does not appear to predict response of colorectal liver metastasis to chemotherapy.
authors: Department of Academic Radiology, Royal Marsden Hospital, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom. arsalanraza@gmail.com
authors: S Arsalan
authors: SA
authors: Raza
authors: L
authors: L
authors: Funicelli
authors: S A
authors: SA
authors: Sohaib
authors: D J
authors: DJ
authors: Collins
authors: E
authors: E
authors: Scurr
authors: M O
authors: MO
authors: Leach
authors: D-M
authors: DM
authors: Koh
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000473:pathology* / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity