Table 2.
Identification of vulnerable plaques via imaging method.
| Imaging Method | Imaging Features of Vulnerable Plaques | Identified Features with High Accuracy | Advantages | Disadvantages | References |
|---|---|---|---|---|---|
| US | lower GSM values; Large plaque area (>95 mm2); DWA; Large JBA (>6 mm2) |
- | Fast; Cheap; Available; Noninvasive; No radiation; |
Confusion between lipid and IPH | [17,107,108] |
| 3D US | Low GSM values | - | Quantification; Visualization; Monitor therapeutic effects |
- | [112,113,114] |
| UUI | SWE range of 3–5 m/s | - | - | - | [115] |
| CEUS | Contrast enhancement with high grade and intensity; Grade 2 IPN; |
IPN; Ulceration |
Fast; Cheap; Available; High compatibility with implants; |
Unreliable severe calcification identification; Confusion between IPH and neovascularization; Contrast agents-induced danger |
[101,117,120,126] |
| MRI | Hyperintense on T1-W and TOF sequences; CMBs on T2-W; Significantly discrepant T1 values |
IPH | High accuracy | Long scan time; Low slice resolution; Limited spatial coverage; Possible misregistration between different images |
[126,129,130,134,135] |
| CE-MRA | Accumulation of iron oxide with signal absence; Gadolinium enhancement |
Ulcerations; IPN |
Better vascular imaging; | Expensive; Gadolinium toxicity |
[128,129,141,142,143] |
| BB-MRI | T1-W high signal | - | Better evaluation of lumen area; total vascular area; wall thickness of vessels; Better contrast between blood and tissue; |
Dependence on stable comparison with the tissues | [144,145,146] |
| MATCH | - | Calcification | Reliable calcification identification | Lower slice resolution; Unreliable thin fibrous caps identification |
[135,147] |
| SNAP | - | Ulceration or stenosis colocalizing with IPH | Reliable identification of ulceration or stenosis colocalizing with IPH; | Unreliable chronic or old hemorrhage identification; Confusion between IPH and lipid pools or loose matrix |
[148,149] |
| PET | High 18F-FDG uptake | Lipid-rich plaques; IPN; |
Noninvasive; Reliable identification of glucose metabolism; intraplaque inflammation; |
Expensive; Ionizing radiation |
[17,26,126,150,151] |
| CTA | Significant enhancement low densities (<25 HU) |
Ulcerations; IPN |
Better evaluation of plaque volume; plaque thickness; lumen morphology; Vascular remodeling |
Radiation; Confusion between IPH and LRNC; Contrast material-induced side effects |
[26,129,155,156,157] |
| DSA | - | - | Gold standard of diagnosing atherosclerosis | Expensive; Radiation; Invasiveness; Late diagnosis |
[2,26,52] |
| OCT | - | Plaque rupture; Plaque erosion; |
High-resolution images; Better evaluation of plaque thickness; lipid accumulation |
Invasiveness; | [26,158] |
Abbreviations: US, ultrasound; GSM: grayscale median; DWA: discrete white area; JBA: juxtaluminal black (hypoechoic) area; IPH, intraplaque hemorrhage; CEUS, contrast-enhanced ultrasound; 3D US: three-dimensional ultrasound; UUI: ultrafast ultrasound imaging; SWE: shear wave elastography; IPN: intraplaque neovascularization; MRI, magnetic resonance imaging; T1-W: T1-weighted; T2-W: T2-weighted; TOF: Time-Of-Flight; CMBs: cerebral microbleeds; CE-MRA, contrast-enhanced magnetic resonance angiography; BB-MRI, black-blood MRI; MATCH, multi-contrast atherosclerosis characterization; SNAP, simultaneous noncontrast angiography and intraplaque hemorrhage; PET, positron emission tomography; 18F-FDG: 18F-Fluorodeoxyglucose; CTA, computed tomography angiography; HU: hounsfield units; LRNC, lipid-rich necrotic core; DSA, digital subtraction angiography; OCT, optical coherency tomography.