title: A real-time electrical impedance sensing biopsy needle.
abstract: Diagnostic confirmation of cancer in solid organs is based on biopsy findings. In a standard 12-core prostate biopsy protocol, conventional biopsy needles sample only 0.95% (∼0.228 cm³) of a typical 24-cm³ prostate gland. The primary objective of this study was to enhance the sensitivity of standard biopsy protocol by gauging electrical properties of tissue simultaneously with tissue extraction for histopathology analysis. A conventional biopsy (Bx) needle was instrumented with an electrical impedance spectroscopy (EIS) sensor to interrogate the tissue volume surrounding the needle tip. The EIS-Bx device was evaluated in a series of saline bath and ex vivo porcine experiments. It was found to sense a volume of 0.286 cm³ of tissue around the needle tip. EIS measurements were recorded from three ex vivo human prostates using the device, and the extracted biopsy cores were histologically assessed. Prostate conductivity σ ranged from 0.179 to 0.3310 S/m for benign tissues and 0.0746 to 0.0837 S/m for malignant tissues at frequencies ranging from 1 to 100 kHz. Relative permittivity ϵ(r) ranged from 2.10×10⁶ to 2.9 × 10⁴ for benign and 6.63×10⁵ to 5.3 × 10³ for cancer tissues over the same frequency range. Both are found to be significantly higher in normal prostate tissues than in malignant tissue (p < 0.00001).
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA. vmishra@dartmouth.edu
authors.forename: V
authors.initials: V
authors.lastname: Mishra
authors.forename: H
authors.initials: H
authors.lastname: Bouayad
authors.forename: A
authors.initials: A
authors.lastname: Schned
authors.forename: A
authors.initials: A
authors.lastname: Hartov
authors.forename: J
authors.initials: J
authors.lastname: Heaney
authors.forename: R J
authors.initials: RJ
authors.lastname: Halter
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry / Q000473:pathology; D000818:Animals; D001707:Biopsy, Needle / Q000295:instrumentation* / Q000379:methods*; D004553:Electric Conductivity; D017097:Electric Impedance; D004867:Equipment Design; D006801:Humans; D008297:Male; D011467:Prostate / Q000737:chemistry / Q000473:pathology; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000473:pathology; D059629:Signal-To-Noise Ratio; D013552:Swine