Patients diagnosed with pancreatic cancer have a 5-year survival rate of only 3%. Endoscopic imaging of the pancreas is limited by the small size of the pancreatic duct, which has an average size of 3 mm. To improve imaging capabilities for the pancreatic duct, two small catheter-based imaging systems have been developed that will fit through the therapeutic channel of a clinical endoscope and into the pancreatic duct. One is a miniature endoscope designed to provide macro-imaging of tissue with both white light reflectance and fluorescence imaging modes. The 1.75 mm diameter catheter consists of separate illumination and imaging channels. At a nominal focal distance of 10 mm, the field of view of the system is ~ 10 mm, and the corresponding in-plane resolution is 60 microns. To complement the broadfield view of the tissue, a confocal microendoscope with 2 micron lateral resolution over a field of view of 450 microns and 25 micron axial resolution has been developed. With an outer diameter of 3 mm, the catheter in this system will also fit through the therapeutic channel and into the pancreatic duct. Images of tissue with both the miniature endoscope and confocal microendoscope are presented.
A fluorescence confocal microendoscope has been developed to provide high resolution, in-vivo imaging of cellular pathology. The microendoscope employs a fiber-optic imaging bundle, a miniature objective, and a miniature focusing mechanism to allow imaging in remote locations of the body. The system uses a 2mm diameter flexible catheter that is capped by a rigid opto-mechanical system measuring 3mm in diameter and 12mm in length. The small size of the confocal microendoscope was chosen so that it may be routed through the therapeutic channel of a clinical endoscope, adding microscopic functionality to conventional endoscopy procedures. The confocal nature of the microendoscope provides optical sectioning with 2 micron lateral resolution and 25 micron axial resolution. The pneumatic focusing mechanism located in the distal opto-mechanical assembly allows for imaging to a maximum depth of 200 micron in the tissue. The system is capable of providing conventional grayscale fluorescence images at 10 frames-per-second as well as spatially resolved multi-spectral fluorescence images at several seconds a frame. Preliminary in-vivo results are be presented.