A system (100; 200) comprising: (a) a catheter assembly (102; 240; 300; 370) including an intravascular imaging device (108; 390); (b) an intravascular blood displacement fluid port; (c) a translation device (119; 220) configured to translate the intravascular imaging device (108; 390); and (d) an imaging engine (140; 210) in communication with the intravascular imaging device (108; 390) and the translation device (119; 220), the imaging engine (140; 210) comprising at least one programmable processor, the imaging engine (140; 210) configured to: (i) generate a screening image of a section of the patient's blood vessel, (ii) identify a sub-section of the patient's blood vessel within the section, (iii) determine a required volume of a quantity of blood displacement fluid based on a physical dimension of the sub-section of the patient's blood vessel, wherein the physical dimension of the sub-section of the patient's blood vessel is determined based on a cross-sectional area of the sub-section or a length of the sub-section, (iv) automatically displace blood within the patient's blood vessel by introducing the determined quantity of blood displacement fluid into the patient's blood vessel via the intravascular blood displacement fluid port, (v) automatically translate the intravascular imaging device (108; 390) through the sub-section with the translation device (119; 220), and (vi) automatically generate a blood-displaced image of the sub-section while blood within the sub-section is displaced by the quantity of blood displacement fluid and while the intravascular imaging device (108; 390) is translating through the sub-section. (a) a catheter assembly (102; 240; 300; 370) including an intravascular imaging device (108; 390); (b) an intravascular blood displacement fluid port; (c) a translation device (119; 220) configured to translate the intravascular imaging device (108; 390); and (d) an imaging engine (140; 210) in communication with the intravascular imaging device (108; 390) and the translation device (119; 220), the imaging engine (140; 210) comprising at least one programmable processor, the imaging engine (140; 210) configured to: (i) generate a screening image of a section of the patient's blood vessel, (ii) identify a sub-section of the patient's blood vessel within the section, (iii) determine a required volume of a quantity of blood displacement fluid based on a physical dimension of the sub-section of the patient's blood vessel, wherein the physical dimension of the sub-section of the patient's blood vessel is determined based on a cross-sectional area of the sub-section or a length of the sub-section, (iv) automatically displace blood within the patient's blood vessel by introducing the determined quantity of blood displacement fluid into the patient's blood vessel via the intravascular blood displacement fluid port, (v) automatically translate the intravascular imaging device (108; 390) through the sub-section with the translation device (119; 220), and (vi) automatically generate a blood-displaced image of the sub-section while blood within the sub-section is displaced by the quantity of blood displacement fluid and while the intravascular imaging device (108; 390) is translating through the sub-section. (i) generate a screening image of a section of the patient's blood vessel, (ii) identify a sub-section of the patient's blood vessel within the section, (iii) determine a required volume of a quantity of blood displacement fluid based on a physical dimension of the sub-section of the patient's blood vessel, wherein the physical dimension of the sub-section of the patient's blood vessel is determined based on a cross-sectional area of the sub-section or a length of the sub-section, (iv) automatically displace blood within the patient's blood vessel by introducing the determined quantity of blood displacement fluid into the patient's blood vessel via the intravascular blood displacement fluid port, (v) automatically translate the intravascular imaging device (108; 390) through the sub-section with the translation device (119; 220), and (vi) automatically generate a blood-displaced image of the sub-section while blood within the sub-section is displaced by the quantity of blood displacement fluid and while the intravascular imaging device (108; 390) is translating through the sub-section.