Technique for a hybrid system of real‐time transrectal ultrasound with preoperative magnetic resonance imaging in the guidance of targeted prostate biopsy

Abstract

Diagnostic magnetic resonance imaging (MRI) for prostate has achieved increasingly higher levels of accuracy. Because real-time MR-guided targeted biopsy is still a complicated and expensive procedure, there is considerable interest in a technique of MR/transrectal ultrasound (TRUS) hybridized image-guided biopsy. However, because the 3-D shapes of the prostate at the time of image-acquisition at preoperative MRI are likely to be different from the intra-operative TRUS images, the precise registration of each 3-D volume data is critical. To reduce the potential errors in registration of TRUS with MRI, we introduce new procedural techniques in a rigid image fusion technique. First, preoperative MR images were obtained with a specifically-made plastic outer-frame, with exactly the same shape as the real TRUS probe, placed in the rectum, in order to simulate the deformation of the prostate caused by the absence or presence of a TRUS probe during the acquisition of MR or TRUS images. Second , instead of using a single plane of longitudinal image, we applied biplane TRUS images to be shown in parallel on a multiplanar display with corresponding reconstructed MRI, in order to register both horizontal and longitudinal images of the prostate simultaneously, thereby achieving improved 3-D anatomical matching.

Image-guided robotic interventions for prostate cancer

“…One of the main barri ers to MRI-TRUS fusion is image difference, which is caused by distortion artefacts resulting from the presence of the TRUS probe. To account for this, Ukimura et al 50 placed a plastic mould that is the same shape as a TRUS probe in the rectum of the patient during the MRI (3T) scan, attempting to replicate the deformation.…”

Future of Prostate Biopsy: Who Will Get It and How?

“…Incidental reports show identification and confirmation of cancer in patients with previously negative ANNA C-TURS biopsy, however, at present there are no studies which would compare any of the mentioned techniques and show individual strengths and indications. Some researchers perform MRI examination with plastic simulator of endorectal probe insitu to simulate deformation expected during trus biopsy setting (Ukimura et al, 2010). Others perform 3D ultrasound imaging and use electromagnetic positioning device to perform biopsies (Turkbey et al, 2011).…”

MRT-navigierte stereotaktische Prostatabiopsie

“…Außerdem werden bei diesen MR-gesteuerten Biopsien neben den gezielten Biopsien meist keine systematischen Biopsien durchgeführt und die Anwendung einer Endorektalspule stellt für den Patienten eine erhebliche zusätzliche Belastung dar. Eine Kombination von MRT und transrektalem Ultraschall (TRUS) erscheint daher als praktikablere Alternative [14,20,23,24,26]. Allerdings benötigen die bis dato hierfür beschriebenen Systeme sehr sensible und störanfällige elektromagnetische Ortungs-und Navigationssysteme …”