A catheter is disclosed for providing pressure measurements at a vascular lesion. The catheter includes an outer component having a side opening the providing transverse access to a lumen thereof and an inner component slidably disposed within the lumen. The inner component has a guidewire lumen with a proximal side port. When the inner component is longitudinally translated relative to the outer component, the side port of the inner component is accessible through the side opening of the outer component for providing transverse access to a guidewire. A first pressure sensor is disposed proximate of a distal end of the outer component and a second pressure sensor is disposed proximate of a distal end of the inner component, such that relative longitudinal translation between the inner and outer components permits a distance between the first and second pressure sensors to be varied.