A novel design of MRI visible prostate biopsy needle

Abstract

A reliable diagnosis is vital to apply the proper treatment for prostate cancer. Conventional prostate biopsy methods have limited accuracy for the diagnosis. Magnetic Resonance Imaging (MRI) provides superior anatomical images of the prostate, o ering precise tumor targeting which in turn increases diagnostic yield. For that purpose, we aimed to develop a novel MRI compatible and visible prostate biopsy needle. The visible distal tip of the needle is expected to provide accurate placement while the proposed biopsy mechanism can reduce the bleeding and infection risk. The prostate biopsy needle has been designed using MRI compatible nitinol hypo tubes and fabricated using an Nd: YAG laser cutting system. Furthermore, the distal tip sharpness and force resistance of the three di erent needle designs were tested in vitro (silicon mold). According to results the needle with high walled biopsy groove was preferable. Equally spaced Iron Oxide (Fe2O3) nano-particle coatings were placed over the distal tip of the outer needle surface to enhance its visibility under real time MRI. The coating concentration and marker size were optimized using di erent MR sequences. MRI visibility experiments indicate that spin-echo acquisitions should be preferred over gradient-echo acquisitions and Fe2O3 coatings with moderate concentrations appear to be more suitable for the passive tracking of penetration depth. The biopsy needle handle also has been designed in Solidworks 2015 and generated using a rapid prototyping system. Finally, the in-vitro performance of the biopsy mechanism was carried out on fresh veal meat. Obtained samples indicate that Nd: YAG laser cutting can be successfully utilized in nitinol needle production and the biopsy handle design provided repeatable successful biopsy sample collections through in vitro trials.|Keywords : interventional MRI, prostate biopsy, biopsy needle, passive device visualization.