title: Correlation of measurements from diffusion weighted MR imaging and FDG PET/CT in GIST patients: ADC versus SUV.
abstract: OBJECTIVE
  We investigated the correlation relationship between ADCs measured by MRI and SUVs measured by PET/CT of lesions on GIST (gastrointestinal stromal tumor) patients to verify if MR is able to replace or serve as an alternative to PET/CT in GIST staging and treatment monitoring.
  
  
  METHODS
  Between September 2010 and January 2011, five patients with histologically proven metastatic GIST in Queen Mary Hospital, Hong Kong were enrolled into our study. All patients underwent both MRI and PET/CT scans at prognosis. Pearson's correlations of twenty-nine lesions were conducted between 5 pairs of ADCs and SUVs values.
  
  
  RESULTS
  Lesions in the liver, peritoneum or bowel loops were found by PET/CT and no extra-abdominal lesion was identified. All twenty-nine lesions are identifiable by MRI with sensitivity of 100%. Significant inverse correlation were found between ADC(mean) and SUV(mean) (P=0.006), ADC(mean) and SUV(max) (P=0.010), ADC(min) and SUV(max) (P=0.014), ADC(min) and SUV(mean) (P=0.026), rADC(min) and rSUV(max) (P=0.047).
  
  
  CONCLUSIONS
  DWI is comparable to PET/CT in visually detecting the GIST lesions' location. Significant inverse correlations were found between ADCs from DWIBS and SUVs from PET/CT on data of GIST patients. This finding demonstrates that DWI is potentially capable of offering similar information for diagnosis and treatment response evaluating in GIST's patients as PET/CT does. Furthermore, ADC(min), which is determined by single pixel, is not as reliable as ADC(mean), which is weighted average value of the whole lesion volume.
authors.affiliation: Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. drcswong@gmail.com
authors.forename: Chun Sing
authors.initials: CS
authors.lastname: Wong
authors.forename: Nanjie
authors.initials: N
authors.lastname: Gong
authors.forename: Yiu-Ching
authors.initials: YC
authors.lastname: Chu
authors.forename: Marina-Portia
authors.initials: MP
authors.lastname: Anthony
authors.forename: Queenie
authors.initials: Q
authors.lastname: Chan
authors.forename: Ho Fun
authors.initials: HF
authors.lastname: Lee
authors.forename: Kent Man
authors.initials: KM
authors.lastname: Chu
authors.forename: Pek-Lan
authors.initials: PL
authors.lastname: Khong
mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis*; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18