title: Evaluation of the Added Value of Diffusion-Weighted Imaging to Conventional Magnetic Resonance Imaging in Pancreatic Neuroendocrine Tumors and Comparison With 68Ga-DOTANOC Positron Emission Tomography/Computed Tomography.
abstract: OBJECTIVE
  The aims of this study were to investigate the added value of diffusion-weighted imaging (DWI) in pancreatic neuroendocrine tumor (pNET) evaluation and to compare magnetic resonance imaging (MRI) to Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) results.
  
  
  METHODS
  Morphological MRI (T2-weighted [T2-w] + contrast-enhanced [CE] T1-w) and DWI (T2-w + DWI) and Ga-DOTANOC PET/CT in 25 patients/30 pNETs were retrospectively evaluated. Per-patient and per-lesion detection rates (pDR and lDR, respectively) were calculated. Apparent diffusion coefficient values were compared among pNET and surrounding and normal pancreas (control group, 18 patients). Apparent diffusion coefficient and standardized uptake value (SUV) values were compared among different grading and staging groups.
  
  
  RESULTS
  No statistically significant differences in PET/CT and MRI session detection rates were found (morphological MRI and DW-MRI, 88% pDR and 87% lDR; combined evaluation, 92% pDR and 90% lDR; Ga-DOTANOC PET/CT, 88% pDR and 80% lDR). Consensus reading (morphological/DW-MRI + PET/CT) improved pDR and lDR (100%). Apparent diffusion coefficient mean value was significantly lower compared with surrounding and normal parenchyma (P < 0.01). The apparent diffusion coefficient and SUV values of pNETs among different grading and staging groups were not statistically different.
  
  
  CONCLUSIONS
  Conventional MRI, DW-MRI + T2-w sequences, and Ga-DOTANOC PET/CT can be alternative tools in pNET detection. Diffusion-weighted MRI could be valuable in patients with clinical suspicion but negative conventional imaging findings. However, the consensus reading of the 3 techniques seems the best approach.
authors.affiliation: From the Institutes of *Radiology and †Nuclear Medicine, Department of Radiological Sciences; ‡Division of Endocrinology; §Digestive Endoscopy Unit; ∥Institute of Pathology; and ¶Institute of Hygiene, Università Cattolica del Sacro Cuore, Rome, Italy; and #Department of Nuclear Medicine and PET/CT Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Farchione
authors.forename: Vittoria
authors.initials: V
authors.lastname: Rufini
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: Brizi
authors.forename: Donato
authors.initials: D
authors.lastname: Iacovazzo
authors.forename: Alberto
authors.initials: A
authors.lastname: Larghi
authors.forename: Roberto Maria
authors.initials: RM
authors.lastname: Massara
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Petrone
authors.forename: Andrea
authors.initials: A
authors.lastname: Poscia
authors.forename: Giorgio
authors.initials: G
authors.lastname: Treglia
authors.forename: Laura
authors.initials: L
authors.lastname: De Marinis
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giordano
authors.forename: Guido
authors.initials: G
authors.lastname: Rindi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bonomo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000473:pathology; D009942:Organometallic Compounds; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: C504894:68Ga-DOTANOC; D009942:Organometallic Compounds