title: Fine Needle Elastography (FNE) device for biomechanically determining local variations of tissue mechanical properties.
abstract: Diseased tissues exhibit changes in mechanical properties and thus possess clinical diagnostic significance. We report the design and development of a Fine Needle Elastography (FNE) prototype device integrated with Fine Needle Aspiration Cytology (FNAC) needle that allows for quantitative and sensitive assessment of tissues and materials based on local variations in elastic, friction, and cutting forces on needle insertion. A piezoelectric force-sensor at the base of FNA needle measures the forces opposing needle penetration with micrometer scale resolution. Measurement precision (±5 μm) and axial resolution (~20 μm) of FNE device was tested using control mm size gelatin matrices and unripe pear in assessing needle penetration resistance, force heterogeneity and optimization of needle penetration velocity. Further, we demonstrated the usefulness of FNE in quantitative, biomechanical differentiation of simulated thyroid tumor nodules in an ultrasound neck phantom. Fluid or solid nodules were probed in the phantom study coupled with ultrasound guidance. Our data shows significantly higher force variations (1-D force heterogeneity; HF,a=6.5 mN, HF,q=8.25 mN and stiffness heterogeneity; HS,a=0.0274 kN/m, HS,q=0.0395 kN/m) in solid nodules compared either to fluid nodules or to regions corresponding to healthy thyroid tissue within the ultrasound phantom. The results suggest future applications of in vivo FNE biopsies based on force heterogeneity to diagnose thyroid tumors in areas where ultrasound instrumentation or access to a qualified pathologist for FNAC are unavailable, as well as an ancillary diagnostic tool in thyroid cancer management.
authors.affiliation: Department of Bioengineering, University of California, Los Angeles, CA, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA.
authors.forename: Dayan
authors.initials: D
authors.lastname: Wickramaratne
authors.affiliation: California NanoSystems Institute, University of California, Los Angeles, CA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Wilkinson
authors.affiliation: Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California, Los Angeles, USA.
authors.forename: JianYu
authors.initials: J
authors.lastname: Rao
authors.affiliation: Department of Radiology, University of California, Los Angeles, California, USA.
authors.forename: Nagesh
authors.initials: N
authors.lastname: Ragavendra
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA; California NanoSystems Institute, University of California, Los Angeles, CA, USA. Electronic address: sharmas@ucla.edu.
authors.forename: Shivani
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Bioengineering, University of California, Los Angeles, CA, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA; California NanoSystems Institute, University of California, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California, Los Angeles, USA; International Center for Materials Nanoarchitectonics Satellite (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan. Electronic address: gim@chem.ucla.edu.
authors.forename: James K
authors.initials: JK
authors.lastname: Gimzewski
mesh_terms: D001696:Biomechanical Phenomena; D001703:Biophysics; D044963:Biopsy, Fine-Needle / Q000295:instrumentation; D054459:Elasticity Imaging Techniques / Q000295:instrumentation*; D006801:Humans; D009339:Needles; D019047:Phantoms, Imaging; D016606:Thyroid Nodule / Q000175:diagnosis
keywords: Diagnostic device; Fine Needle Elastography; Needle penetration; Piezoelectric sensor; Thyroid cancer; Tissue biomechanics