The present invention relates to a sensor guide wire (24) for intravascular measurements of at least one physiological, or other, variable in a living body. The sensor guide wire (24) comprises, a sensor element (18) arranged in a jacket (20) in a sensor region of said sensor guide wire (24), a core wire (26) extending at least partly along the length of said sensor guide wire (24), and at least one electrical lead connected to said sensor element (18). The jacket (20) is tubular and provided with a jacket wall (21), and further comprises a first opening (22) arranged in the jacket wall (21), said jacket (20) is further provided with proximal and distal end openings (29, 30), and wherein a core wire (26) is adapted to extend through said jacket (20) via said proximal and distal end openings (29, 30), and wherein the sensor guide wire (24) has an outer diameter of approximately 0,35 mm The jacket (20) further comprises at least a second opening (23) arranged in said jacket wall (21).
