A system for planning the treatment of a vessel of a patient, comprising: a first instrument sized and shaped for introduction into the vessel of the patient, and a second instrument sized and shaped for introduction into the vessel of the patient; a processing system in communication with the first and second instruments (108,110), the processing system configured to: obtain pressure measurements from first and second instruments (108,110) positioned within the vessel of the patient during a diagnostic procedure; display on a first visualization device an image of the vessel with treatment diagnostic visualizations based on the obtained pressure measurements; and display on a second visualization device (102,202) a portion of the image of the vessel with diagnostic visualizations based on the obtained pressure measurements, wherein the portion of the image of the vessel displayed on the second visualization device (102,202) is a close up of a region of interest of the vessel; characterised in that the processing system is further configured to simulate a first treatment option, wherein simulating the first treatment option includes modifying the diagnostic visualizations based on an expected result of the first treatment option. a first instrument sized and shaped for introduction into the vessel of the patient, and a second instrument sized and shaped for introduction into the vessel of the patient; a processing system in communication with the first and second instruments (108,110), the processing system configured to: obtain pressure measurements from first and second instruments (108,110) positioned within the vessel of the patient during a diagnostic procedure; display on a first visualization device an image of the vessel with treatment diagnostic visualizations based on the obtained pressure measurements; and display on a second visualization device (102,202) a portion of the image of the vessel with diagnostic visualizations based on the obtained pressure measurements, wherein the portion of the image of the vessel displayed on the second visualization device (102,202) is a close up of a region of interest of the vessel; characterised in that the processing system is further configured to simulate a first treatment option, wherein simulating the first treatment option includes modifying the diagnostic visualizations based on an expected result of the first treatment option. obtain pressure measurements from first and second instruments (108,110) positioned within the vessel of the patient during a diagnostic procedure; display on a first visualization device an image of the vessel with treatment diagnostic visualizations based on the obtained pressure measurements; and display on a second visualization device (102,202) a portion of the image of the vessel with diagnostic visualizations based on the obtained pressure measurements, wherein the portion of the image of the vessel displayed on the second visualization device (102,202) is a close up of a region of interest of the vessel; characterised in that the processing system is further configured to simulate a first treatment option, wherein simulating the first treatment option includes modifying the diagnostic visualizations based on an expected result of the first treatment option.