Apparatus and methods for ablating material in a region within a vascular system of a patient are provided. A determination of at least one of a type of material in the region and an indication of a distance to the material in the region is made based on at least one property of the region determined from light reflected from the region. Light from a light source is transmitted in at least one of a plurality of optical fibers based on the determination, and at least some of the transmitted light is received at a first emitter disposed along a length of a laser catheter proximate a distal end thereof. The first emitter radially transmits the at least some of the light from the length of the laser catheter so that the light impinges upon and ablates the material through an opening in the length of the laser catheter.