title: Comparison of abdominal MRI with diffusion-weighted imaging to 68Ga-DOTATATE PET/CT in detection of neuroendocrine tumors of the pancreas.
abstract: OBJECTIVE
  The aim of the study was to evaluate contrast-enhanced MRI, diffusion-weighted MRI (DW MRI), and (68)Ga-DOTATATE positron emission tomography (PET)/CT in the detection of intermediate to well-differentiated neuroendocrine tumors (NET) of the pancreas.
  
  
  METHODS
  Eighteen patients with pathologically proven pancreatic NET who underwent MRI including DW MRI and PET/CT within 6 weeks of each other were included in this retrospective study. Two radiologists evaluated T2-weighted (T2w), T2w + DW MRI, T2w + contrast-enhanced T1-weighted (CE T1w) MR images, and PET/CT for NET detection. The sensitivity and level of diagnostic confidence were compared among modalities using McNemar's test and a Wilcoxon signed rank test. Apparent diffusion coefficients (ADC) of pancreatic NETs and normal pancreatic tissue were compared with Student's t test.
  
  
  RESULTS
  Of the NETs, 8/23 (34.8 %) and 9/23 (39.1 %) were detected on T2w images by observers 1 and 2, respectively. Detection rates improved significantly by combining T2w images with DW MRI (observer 1: 14/23 = 61 %; observer 2: 15/23 = 65.2 %; p < 0.05) or CE T1w images (observer 1: 14/23 = 61 %; observer 2: 15/23 = 65.2 %; p < 0.05). Detection rates of pancreatic NET with PET/CT (both observers: 23/23 = 100 %) were statistically significantly higher than with MRI (p < 0.05). The mean ADC value of NET (1.02 ± 0.26 × 10(-3) mm(2)/s) was statistically significantly lower than that of normal pancreatic tissue (1.48 ± 0.39 × 10(-3) mm(2)/s).
  
  
  CONCLUSIONS
  DW MRI is a valuable adjunct to T2w imaging and comparable to CE T1w imaging in pancreatic NET detection, quantitatively differentiating between NET and normal pancreatic tissue with ADC measurements. (68)Ga-DOTATATE PET/CT is more sensitive than MRI in the detection of pancreatic NET.
authors: Institute for Clinical Radiology, Ludwig Maximilians University Hospital Munich, Munich, Germany.
authors: Christine
authors: C
authors: Schmid-Tannwald
authors: Christoph M
authors: CM
authors: Schmid-Tannwald
authors: John N
authors: JN
authors: Morelli
authors: Ralph
authors: R
authors: Neumann
authors: Alexander R
authors: AR
authors: Haug
authors: Nathalie
authors: N
authors: Jansen
authors: Konstantin
authors: K
authors: Nikolaou
authors: Nicolai
authors: N
authors: Schramm
authors: Maximilian F
authors: MF
authors: Reiser
authors: Carsten
authors: C
authors: Rist
mesh_terms: D000005:Abdomen / Q000473:pathology; D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000473:pathology*; D015588:Observer Variation; D009942:Organometallic Compounds / Q000494:pharmacology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D009942:Organometallic Compounds; C513399:gallium Ga 68 dotatate