A system comprising: a) a catheter for scanning a luminal surface of a body lumen to generate electronic signals for generating a digital topographic model of the luminal surface, said catheter comprising: a catheter shaft (12; 112; 212; 312) having a distal end (14; 114; 214; 314) and a proximal end (16; 116; 216; 316); at least one illumination source (20; 120; 220; 320) mounted on a distal portion of the catheter shaft, wherein the illumination source is configured to project an optical pattern with a known geometry on the luminal wall when the distal portion is in the body lumen, wherein the at least one illumination source (20; 120; 220; 320) is mounted to axially translate over the distal portion of the catheter shaft (12; 112; 212; 312); and at least one sensor (22; 122; 222; 322) mounted on the distal portion of the catheter and spaced-apart from the illumination source, wherein said sensor is configured to sense a reflected light pattern resulting from reflection from the luminal wall of the optical pattern with the known geometry projected onto the luminal wall from the illumination source and to produce an electronic signal representative of the reflected light pattern; and b) a processor connected to receive the electronic signal and configured to: determine an angle of the reflected light pattern based on the electronic signal; and generate the digital topographic model by triangulation based on the projected optical pattern, the distance between the illumination source and the sensor and the angle of the reflected light pattern. a) a catheter for scanning a luminal surface of a body lumen to generate electronic signals for generating a digital topographic model of the luminal surface, said catheter comprising: a catheter shaft (12; 112; 212; 312) having a distal end (14; 114; 214; 314) and a proximal end (16; 116; 216; 316); at least one illumination source (20; 120; 220; 320) mounted on a distal portion of the catheter shaft, wherein the illumination source is configured to project an optical pattern with a known geometry on the luminal wall when the distal portion is in the body lumen, wherein the at least one illumination source (20; 120; 220; 320) is mounted to axially translate over the distal portion of the catheter shaft (12; 112; 212; 312); and at least one sensor (22; 122; 222; 322) mounted on the distal portion of the catheter and spaced-apart from the illumination source, wherein said sensor is configured to sense a reflected light pattern resulting from reflection from the luminal wall of the optical pattern with the known geometry projected onto the luminal wall from the illumination source and to produce an electronic signal representative of the reflected light pattern; and a catheter shaft (12; 112; 212; 312) having a distal end (14; 114; 214; 314) and a proximal end (16; 116; 216; 316); at least one illumination source (20; 120; 220; 320) mounted on a distal portion of the catheter shaft, wherein the illumination source is configured to project an optical pattern with a known geometry on the luminal wall when the distal portion is in the body lumen, wherein the at least one illumination source (20; 120; 220; 320) is mounted to axially translate over the distal portion of the catheter shaft (12; 112; 212; 312); and at least one sensor (22; 122; 222; 322) mounted on the distal portion of the catheter and spaced-apart from the illumination source, wherein said sensor is configured to sense a reflected light pattern resulting from reflection from the luminal wall of the optical pattern with the known geometry projected onto the luminal wall from the illumination source and to produce an electronic signal representative of the reflected light pattern; and b) a processor connected to receive the electronic signal and configured to: determine an angle of the reflected light pattern based on the electronic signal; and generate the digital topographic model by triangulation based on the projected optical pattern, the distance between the illumination source and the sensor and the angle of the reflected light pattern. determine an angle of the reflected light pattern based on the electronic signal; and generate the digital topographic model by triangulation based on the projected optical pattern, the distance between the illumination source and the sensor and the angle of the reflected light pattern.