Image-guided therapy in urology

Imaging in percutaneous nephrolithotomy

Image guidance is a critical factor for the performance of urologic interventions. Percutaneous minimally invasive procedures have been developed and are being used with constantly increasing frequency. Procedures such as percutaneous nephrolithotomy (PCNL) are not performed without any image guidance. Recent developments in medical imaging, such as three-dimensional radiographic fluoroscopy, CT, and magnetic resonance (MR) fluoroscopy, four-dimensional ultrasonography, and image fusion techniques, propose a new generation of image-guidance tools that promise to improve patient care. These developments have been used or have the potential to be used in PCNL and other urologic interventional procedures. Moreover, advanced needles and needle guidance systems provide a new perspective for the nephrolithotomy suite of the future. The current review presents existing imaging technology in PCNL and interventional urology as well as advanced imaging techniques that are being or are expected to be evaluated in PCNL practice.

Advances in imaging for urologic procedures

Improvements in imaging and device engineering have led to the rapid development of advanced, minimally invasive techniques in urologic care. While imaging advances have had a major effect in the areas of diagnosis, surgical planning and therapeutic assessment, the focus of this Review is on developments in intraoperative imaging that are currently making an impact in urology and are likely to provide additional opportunities to urologists in the years to come. While previous image-guided urologic procedures have mostly utilized two-dimensional X-ray images, it is expected that new technologies will involve the use of three- and four-dimensional multi-modality imaging, molecular imaging, and robot-assisted image-guidance techniques. Application of these procedures will bring together the complementary disciplines of endourology and interventional radiology in the development of multidisciplinary, cooperative approaches to providing optimal treatments and outcomes for urologic disease.

Biomedical imaging research opportunities workshop IV: a white paper

The Fourth Biomedical Imaging Research Opportunities Workshop (BIROW IV) was held on February 24-25, 2006, in North Bethesda, MD. The workshop focused on opportunities for research and development in four areas of imaging: imaging of rodent models; imaging in drug development; imaging of chronic metabolic disease: diabetes; and image guided intervention in the fourth dimension-time. These topics were examined by four keynote speakers in plenary sessions and then discussed in breakout sessions devoted to identifying research opportunities and challenges in the individual topics. This paper synthesizes these discussions into a strategy for future research directions in biomedical imaging.

Intraoperative magnetic resonance: the future of surgery

Intraoperative magnetic resonance imaging (iMRI) is a new development in medicine that bridges the specialties of surgery and radiology. Deficiencies in the visualization of anatomical architecture and the perception of tumour boundaries in conventional open surgery have led to the integration of imaging within surgery. The superior soft tissue and multiplanar imaging features of magnetic resonance (MR) make this imaging modality superior to that of alternatives. The unique properties of MR to detect heat change and perfusion, and diffusion characteristics of tissue enhance the usefulness of this medium. Concurrent developments in computer aided image guidance and thermoablative technology, herald the era of minimally invasive tumour ablation. Applications have been developed for areas such as neurosurgery, general surgery, gynaecology and urology.

Functional reconstruction and minimally invasive techniques

Recent years have seen notable advances in imaging technologies. Three-dimensional computer-rendered techniques with rapid image acquisition have led to the development of virtual reality imaging. Virtual reality imaging allows interactive intraluminal navigation through any hollow viscus, simulating conventional endoscopy. This technique of virtual endoscopy has been applied to many organs, including the urinary tract. Virtual reality endoscopy is beginning to challenge the gold standard of conventional endoscopic evaluation. Recent advances in laparoscopic surgery are largely attributable to technological improvements in imaging equipment. Laparoscopic ultrasound has become a common adjunct in laparoscopic surgery. In particular, advances in video cameras and digital imaging technology have decreased the steep learning curve associated with laparoscopic procedures. Telerobotic systems offer several advantages to laparoscopic surgery, such as all six degrees of freedom, dexterity enhancement, tremor filtering, and stereovision. In addition, technological breakthroughs allow many procedures to evolve from open operations involving lengthy hospital stays to imaging-guided minimally invasive procedures performed on an outpatient basis. Finally, Internet-based imaging is changing the way in which urology services are delivered, by allowing rapid communication between remote locations.