DISTAL SECTION FOR MONORAIL CATHETER

1 . In a catheter, a distal section comprising:

a distal tip section, the distal tip section having a distal tip and the distal tip having a longitudinal axis; and

a distal shaft, the distal shaft having a longitudinal axis,

wherein the distal tip longitudinal axis is substantially parallel to and offset from the distal shaft longitudinal axis.

2 . The catheter of claim 1 , wherein the distal shaft is formed from at least one layer of material.

3 . The catheter of claim 1 , wherein the distal shaft includes a lumen for containing a working element.

4 . The catheter of claim 3 wherein the working element comprises a mechanically rotatable ultrasound imaging core.

5 . The catheter of claim 3 wherein the working element comprises a mechanically rotatable optical imaging core.

6 . The catheter of claim 3 wherein the working element comprises a mechanically rotatable combined ultrasound and optical imaging core.

7 . The catheter of claim 1 , wherein the distal tip section includes a guide wire lumen for receiving a guide wire.

8 . The catheter of claim 7 , wherein the longitudinal axis of the distal tip is also the longitudinal axis of the guide wire lumen.

9 . The catheter of claim 7 , wherein the distal shaft includes at least one flushing vent hole arranged to be adjacent the guide wire to enable the guide wire to prevent a flushing stream from the flushing vent hole from impinging a sidewall of a vessel in which the catheter is used.

10 . The catheter of claim 7 , wherein the distal shaft includes at least one forward flushing vent hole to prevent a flushing stream from the flushing vent hole from impinging a sidewall of a vessel in which the catheter is used.

11 . The catheter of claim 1 , wherein the distal tip section has a length of 15 mm or less.