Direct MRI-guided biopsy of the prostate: use of post-biopsy needle track imaging to confirm targeting

Abstract

Purpose To report the observation that in-plane post-biopsy T2-weighted MRI often demonstrates the needle track as a transient visible linear tissue distortion during direct MRI-guided biopsy. Materials and methods We retrospectively identified 11 prostatic lesions in 9 men that underwent direct MRI-guided biopsy and in which post-biopsy images were obtained in the plane of the biopsy needle. Results In 9 of 11 targets, a post-biopsy needle track was visible as a linear tissue distortion on in-plane T2-weighted images obtained at a mean interval of 6 min (range 3–15). In these nine cases, the needle track traversed the intended target, and the biopsy was positive for malignancy in six. Biopsy was positive in one of two cases where the needle track was not visible. In five targets, one or more delayed series were obtained after a mean interval of 21 min (range 8–33), showing the track was no longer visible (n = 3) or was of progressively decreased conspicuity (n = 2). Conclusion Accurate targeting during direct MRI-guided biopsy of the prostate can be confirmed by obtaining post-biopsy in-plane images, since the needle track is usually visible as a transient linear tissue distortion.

Endorectal multiparametric MRI of the prostate: incremental effect of perfusion imaging on biopsy target identification

“…In particular, in order to validate the process used to identify biopsy targets, we specifically tracked those patients who proceeded to direct MR-guided biopsy of the prostate following the identification of an actionable target at diagnostic multiparametric MRI study. Direct MR-guided biopsy of the prostate is a clinical service that has been provided at our institution for the past two years, using previously described methodology [5]. The first author correlated biopsy targets identified by MRI during this study with targets that were clinically identified by MRI and underwent MR-guided biopsy to determine if they were the same lesion and to establish the resulting tissue diagnosis.…”

“…Multiparametric prostate MRI is an important and widely used adjunct to standard clinical assessment by digital rectal examination and serum prostatic specific antigen level determination for the approximately one million men who currently undergo prostate biopsy in the United States every year [2, 3]. Imaging can stratify such patients by likelihood of cancer, assist with biopsy target identification and guide biopsy of targets that appear likely to be malignant [4, 5]. This represents a sea-change in our approach to studying prostate MRI, because biopsy target identification is becoming a major research endpoint in addition to the traditional endpoints of tumor localization, tumor characterization, and outcome correlation [6, 7].…”

Direct magnetic resonance imaging-guided biopsy of the prostate: lessons learned in establishing a regional referral center

“…Initially (n=4), we simply assumed that needle deployment was accurate if the pre-deployment alignment was satisfactory and the post-biopsy images showed no movement of the introducer. Later (n=16), we used the visibility of the biopsy track (linear tissue distortion on post-biopsy T2 images obtained in the plane of the needle deployment) to confirm accurate targeting ( 21 ). However, neither of these methods appeared adequately robust, and since then directly image the deployed needle after at least one of the samples using an oblique T2 image obtained in the plane of the needle trajectory.…”