Evaluation of a new three-dimensional magnetic imaging system for use during colonoscopy

A prototype magnetic imaging system (Scope Guide, Olympus Optical Co., Ltd.) provides a new facility for continuous viewing on a monitor of the position of the colonoscope during examination, without exposing patients or medical staff to radiation. The aim of this prospective study was to compare this magnetic imaging system with routine colonoscopy, including fluoroscopy. The study parameters were the detection of loops, the location of the endoscope tip at defined positions, the insertion time, and the premedication rate.

In the first part of the study, 133 consecutive patients were examined - 64 using an integrated three-dimensional colonoscope and 69 with the three-dimensional probe inserted into the biopsy channel of a routine video colonoscope. Fluoroscopy was used in all investigations for comparison at defined anatomical points and loops, and pathological findings and defined anatomic structures were documented using a laser printer both for three-dimensional colonoscopy and fluoroscopy. In the second part of the study, 25 further patients underwent colonoscopy with a modified prototype, now exclusively using the integrated three-dimensional colonoscope.

The total time for insertion and the premedication rate did not differ from those of routine colonoscopies with fluoroscopy available. Precise detection of loops was observed in the first study in 79 - 100 % of cases in comparison with fluoroscopy. Precise localization of the endoscopic tip improved from 30 % in the first part of the study to 80 % in part 2.

Using magnetic three-dimensional imaging systems, the position of the colonoscope, the detection and observation of loops during straightening, and localization of pathological findings can be accurately achieved. Modification of the prototype led to satisfactory improvement in all parameters tested.