title: Real-time tomographic reflection in facilitating percutaneous access to the renal collecting system.
abstract: OBJECTIVE
  Real-time tomographic reflection is a novel technique that uses a geometrically fixed arrangement of a conventional ultrasound transducer, a transducer-incorporated monitor, and a half-silvered mirror. This device, dubbed the Sonic Flashlight, generates a virtual anatomically scaled image, obviating the need for a separate monitor. It may therefore facilitate invasive procedures, such as percutaneous access to the kidney. This proof-of-concept study assesses the feasibility of this technique for renal imaging and concomitant needle puncture guidance.
  
  
  METHODS
  In a swine model with induced hydronephrosis, the Sonic Flashlight was used to visualize and guide needle access to the renal pelvis. Passage of a 7-inch, 18-gauge spinal needle was performed. Entry into the collecting system was confirmed by the aspiration of urine.
  
  
  RESULTS
  The anechoic renal pelvis and hyperechoic needle tip could be seen with the Sonic Flashlight device. Successful access to the collecting system was obtained twice without dificulty. The sonographic image, appearing to emanate from the tip of the transducer, makes visualization and manipulation more intuitive. Furthermore, by placing the operator's eyes and hands in the same field as the sonogram, image-guided procedures are potentially easier to learn.
  
  
  CONCLUSIONS
  The relatively shallow depth of penetration of the current device limits its clinical usefulness. A new Sonic Flashlight with a greater depth of penetration is in development.
authors.affiliation: Department of Urology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA. chenml@upmc.edu
authors.forename: Mang L
authors.initials: ML
authors.lastname: Chen
authors.forename: Gaurav
authors.initials: G
authors.lastname: Shukla
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Jackman
authors.forename: Alice K
authors.initials: AK
authors.lastname: Tsao
authors.forename: Marc C
authors.initials: MC
authors.lastname: Smaldone
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ost
authors.forename: George D
authors.initials: GD
authors.lastname: Stetten
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Averch
mesh_terms: D000818:Animals; D007682:Kidney Pelvis / Q000601:surgery; D007685:Kidney Tubules, Collecting / Q000601:surgery*; D034421:Sus scrofa / Q000601:surgery; D013997:Time Factors; D014054:Tomography / Q000379:methods*