Table 2 Research utility of IVUS imaging. Advantages and disadvantages.

Assessment of the effect of pharmacological treatment

• Able to quantify changes in plaque volume

• IVUS-RF allows identification and quantification of changes in plaque's composition

• IVUS-RF identifies with moderate sensitivity/specificity a change from lipid to a fibrous plaque

Remodelling assessment

• Complete arterial wall visualisation

• Unable to identify accurately the outer vessel wall border in segments with calcified plaques.

Plaque characterisation

• Complete vessel wall visualisation

• IVUS-RF allows identification of the type of the plaque with good overall sensitivity and specificity

• IVUS-RF identifies with moderate sensitivity/specificity lipid and fibrous plaques

Detection of vulnerable plaque

• Accurate measurement of luminal dimensions, plaque area and remodelling

• IVUS-RF allows identification of the type of the plaque with good overall sensitivity and specificity

• Limited axial resolution - unable to measure the fibrous cap

• Moderate sensitivity in detecting thrombus and plaque disruption/erosion

• Unable to detect macrophages or intraplaque haemorrhage

Assessment of invasive treatments

• Reliable assessment of luminal, stent area and intima hyperplasia

• Precise evaluation of stent expansion

• Reliable evaluation of bioabsorbable stent recoil

• Limited capability in identifying vessel wall trauma (e.g. erosion, dissection) and thrombus

• Incapable of assessing stent struts coverage

Role of heamodynamics in atherosclerosis

• Complete vessel visualisation - plaque characterisation

• Multitude of automated methodologies that allows IVUS segmentation and fusion of IVUS and angiography

• Limited capability in detecting vulnerable plaque characteristics