title: Intraprocedural diffusion-weighted PROPELLER MRI to guide percutaneous biopsy needle placement within rabbit VX2 liver tumors.
abstract: OBJECTIVE
  To test the hypothesis that diffusion-weighted (DW)-PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) magnetic resonance imaging (MRI) can be used to guide biopsy needle placement during percutaneous interventional procedures to selectively target viable and necrotic tissues within VX2 rabbit liver tumors.
  
  
  METHODS
  Our institutional Animal Care and Use Committee approved all experiments. In six rabbits implanted with 15 VX2 liver tumors, baseline DW-PROPELLER images acquired prior to the interventional procedure were used for apparent diffusion coefficient (ADC) measurements. Next, intraprocedural DW-PROPELLER scans were performed with needle position iteratively adjusted to target viable, necrotic, or intermediate border tissue regions. DW-PROPELLER ADC measurements at the selected needle tip locations were compared with the percentage of tumor necrosis qualitatively assessed at histopathology.
  
  
  RESULTS
  DW-PROPELLER images demonstrated intratumoral tissue heterogeneity and clearly depicted the needle tip position within viable and necrotic tumor tissues. Mean ADC measurements within the region-of-interest encompassing the needle tip were highly correlated with histopathologic tumor necrotic tissue assessments.
  
  
  CONCLUSIONS
  DW-PROPELLER is an effective method to selectively position the biopsy needle tip within viable and necrotic tumor tissues. The DW-PROPELLER method may offer an important complementary tool for functional guidance during MR-guided percutaneous procedures.
authors.affiliation: Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Deng
authors.forename: Sumeet
authors.initials: S
authors.lastname: Virmani
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Yang
authors.forename: Richard
authors.initials: R
authors.lastname: Tang
authors.forename: Gayle
authors.initials: G
authors.lastname: Woloschak
authors.forename: Reed A
authors.initials: RA
authors.lastname: Omary
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Larson
mesh_terms: D000818:Animals; D001707:Biopsy, Needle; D045744:Cell Line, Tumor; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000473:pathology*; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D009336:Necrosis; D011817:Rabbits
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA