A system for providing blood flow information for a patient, the system comprising: at least a computer system and a tablet computer, the tablet computer being configured to receive, from the computer system: • a three-dimensional model representing at least a portion of an anatomical structure of the patient generated by the computer system based on patient-specific data, and • a reduced-order model of the portion of the anatomical structure; wherein the tablet computer comprises: a touchscreen; a display device, on the touchscreen, for displaying the received three-dimensional model; and a processor configured to, in a first mode, receive a first input relating to a first location on the touchscreen indicated by at least one pointing object controlled by a user, the first location on the touchscreen indicating a first location on the displayed three-dimensional model, and generate a display of first information on the touchscreen, the first information indicating a blood flow characteristic at the first location; and to operate in a second mode to receive a second input on the touchscreen, the second input causing a modification of the three-dimensional model to model placement of a stent in the patient's anatomy, and to generate a display of second information regarding the blood flow characteristic in the anatomical structure based on the modification of the three-dimensional model; characterised in that the processor of the tablet computer is configured to determine said second information by performing computational analysis using the received reduced order model, and the tablet computer is configured to recommend characteristics of the stent, or characteristics of a model of said stent, automatically based on fractional flow reserve values of vessels in the patient's anatomy. at least a computer system and a tablet computer, the tablet computer being configured to receive, from the computer system: • a three-dimensional model representing at least a portion of an anatomical structure of the patient generated by the computer system based on patient-specific data, and • a reduced-order model of the portion of the anatomical structure; • a three-dimensional model representing at least a portion of an anatomical structure of the patient generated by the computer system based on patient-specific data, and • a reduced-order model of the portion of the anatomical structure; wherein the tablet computer comprises: a touchscreen; a display device, on the touchscreen, for displaying the received three-dimensional model; and a processor configured to, in a first mode, receive a first input relating to a first location on the touchscreen indicated by at least one pointing object controlled by a user, the first location on the touchscreen indicating a first location on the displayed three-dimensional model, and generate a display of first information on the touchscreen, the first information indicating a blood flow characteristic at the first location; and to operate in a second mode to receive a second input on the touchscreen, the second input causing a modification of the three-dimensional model to model placement of a stent in the patient's anatomy, and to generate a display of second information regarding the blood flow characteristic in the anatomical structure based on the modification of the three-dimensional model; characterised in that the processor of the tablet computer is configured to determine said second information by performing computational analysis using the received reduced order model, and the tablet computer is configured to recommend characteristics of the stent, or characteristics of a model of said stent, automatically based on fractional flow reserve values of vessels in the patient's anatomy. a touchscreen; a display device, on the touchscreen, for displaying the received three-dimensional model; and a processor configured to, in a first mode, receive a first input relating to a first location on the touchscreen indicated by at least one pointing object controlled by a user, the first location on the touchscreen indicating a first location on the displayed three-dimensional model, and generate a display of first information on the touchscreen, the first information indicating a blood flow characteristic at the first location; and to operate in a second mode to receive a second input on the touchscreen, the second input causing a modification of the three-dimensional model to model placement of a stent in the patient's anatomy, and to generate a display of second information regarding the blood flow characteristic in the anatomical structure based on the modification of the three-dimensional model; characterised in that the processor of the tablet computer is configured to determine said second information by performing computational analysis using the received reduced order model, and the tablet computer is configured to recommend characteristics of the stent, or characteristics of a model of said stent, automatically based on fractional flow reserve values of vessels in the patient's anatomy.