Journal of Vascular Medicine & Surgery

Advances in Vascular Imaging: Moving Beyond Anatomy to Functional Assessment and Treatment Planning

Guillaume Goudot^* Department of Vascular Surgery, Rennes University Hospital, Rennes, France
^*Correspondence: Guillaume Goudot, Department of Vascular Surgery, Rennes University Hospital, Rennes, France, Email:

Received: 01-Jan-2025, Manuscript No. JVMS-25-28750; Editor assigned: 03-Jan-2025, Pre QC No. JVMS-25-28750 (PQ); Reviewed: 17-Jan-2025, QC No. JVMS-25-28750; Revised: 24-Jan-2025, Manuscript No. JVMS-25-28750 (R); Published: 31-Jan-2025, DOI: 10.35248/2329-6925.25.13.577

Description

The evolution of vascular imaging over the past two decades has transformed our approach to vascular pathology, progressing from purely anatomic delineation to sophisticated functional assessment and precise procedural planning. This paradigm shift reflects both technological innovations and deeper understanding of vascular disease mechanisms. As imaging capabilities continue to expand, thoughtful integration of multiple modalities offers the potential for truly personalized vascular care. This commentary examines key advances in vascular imaging and their clinical implications across different vascular territories.

Duplex ultrasonography remains the cornerstone of vascular assessment, offering real-time anatomic and physiologic information without radiation or contrast exposure. Recent advances have substantially expanded its capabilities beyond traditional applications. Contrast-enhanced ultrasound utilizing gas-filled microbubbles improves vessel wall and lumen delineation, particularly valuable for detecting subtle endoleaks following endovascular aneurysm repair. Superb Microvascular Imaging (SMI) and microflow imaging technologies visualize low-velocity flow within vasa vasorum and neovascularization, potentially identifying vulnerable carotid plaques before symptomatic presentation. Three-dimensional reconstruction protocols allow volumetric assessment and improved visualization of complex anatomy, particularly valuable for dialysis access planning.

The most significant ultrasonographic advance may be the development of elastography techniques that characterize tissue mechanical properties based on deformation under compression. Vascular elastography shows promise for distinguishing stable from vulnerable atherosclerotic plaques based on mechanical heterogeneity, potentially enabling targeted intervention before cerebrovascular events occur. Similarly, elastography may help identify venous segments with favorable compliance for arteriovenous access creation, potentially reducing primary failure rates.

Computed Tomography Angiography (CTA) has undergone remarkable refinement with the development of multi-detector technology, now capable of submillimeter isotropic resolution throughout large coverage volumes. Dual-energy acquisition allows material decomposition and selective visualization, particularly valuable for distinguishing calcification from contrast-enhanced lumen in heavily calcified vessels. Advanced reconstruction algorithms including iterative reconstruction and artificial intelligence-based processing allow substantial radiation dose reduction while maintaining or improving image quality. The integration of CT perfusion imaging provides functional assessment alongside anatomic detail, particularly valuable in cerebrovascular disease for distinguishing hypoperfused but salvageable tissue from infarcted regions.

Perhaps the most transformative CTA advance is dynamic imaging with temporal resolution sufficient to capture arterial, parenchymal, and venous phases from a single contrast bolus. This "4D-CT" technique provides hemodynamic information previously available only with invasive angiography, allowing assessment of collateral pathways, competitive flow, and time-resolved filling patterns. For arteriovenous malformations and fistulas, dynamic acquisition facilitates precise understanding of feeding arteries and draining veins critical for intervention planning.

The development of CT-derived Fractional Flow Reserve (FFRCT) represents another significant functional advance, allowing non-invasive assessment of hemodynamic significance in coronary stenosis through computational fluid dynamics. Similar approaches are under investigation for carotid and peripheral arterial disease, potentially allowing more precise selection of patients likely to benefit from revascularization without requiring invasive pressure measurements or provocative testing.

Magnetic resonance imaging offers complementary capabilities without ionizing radiation, particularly valuable for younger patients requiring serial examinations. Beyond conventional Magnetic Resonance Angiography (MRA), several advanced techniques provide unique insights into vascular pathophysiology. 4D flow MRI quantifies three-dimensional flow patterns and wall shear stress, with applications in thoracic aortic disease where abnormal flow dynamics may contribute to aneurysm formation and dissection propagation. This technique has demonstrated altered helical flow patterns in bicuspid aortic valve patients before overt aortopathy develops, potentially identifying those at highest risk for future complications.

Vessel wall imaging represents another important MRI application, differentiating various arteriopathies based on wall enhancement patterns and morphological features. In intracranial arterial stenosis, concentric enhancement suggests atherosclerotic plaque while eccentric enhancement may indicate vasculitis, with important therapeutic implications. For carotid disease, high-resolution MRI can identify intraplaque hemorrhage, lipid-rich necrotic core, and fibrous cap status—features more predictive of stroke risk than degree of stenosis alone.

Positron Emission Tomography (PET) provides metabolic and molecular information when combined with CT or MRI, offering insights into disease activity beyond structural abnormalities. 18F-Fluorodeoxyglucose (FDG) localizes to metabolically active inflammatory cells, allowing assessment of plaque inflammation in atherosclerosis and disease activity in large vessel vasculitis. Several studies have demonstrated associations between FDG uptake and subsequent stroke risk in carotid disease, independent of stenosis severity. Newer radiotracers targeting specific molecular processes—including 18F-sodium fluoride for microcalcification, 68Ga-DOTATATE for macrophage activity, and various matrix metalloproteinase markers—offer increasingly specific molecular characterization of vascular pathology.

Intravascular imaging modalities provide detailed assessment of vessel wall and lumen from within, complementing external imaging techniques. Intravascular Ultrasound (IVUS) offers cross-sectional visualization of lumen, plaque, and surrounding structures with superior tissue penetration compared to angiography alone. Virtual histology IVUS adds radiofrequency backscatter analysis to differentiate plaque components, including fibrous tissue, lipid core, calcification, and necrotic regions. This capability allows identification of thin-cap fibroatheromas associated with higher rupture risk, potentially guiding selective intervention.

Optical Coherence Tomography (OCT) provides near-microscopic resolution (10-20 μm) exceeding all other intravascular modalities, though with limited tissue penetration. Its exceptional resolution enables detailed assessment of lumen contours, dissection planes, thrombus characteristics, and tissue coverage following stent placement. In carotid intervention, OCT can identify plaque prolapse through stent struts and guide optimal stent expansion. For peripheral intervention, OCT allows precise assessment of vessel preparation and stent apposition, particularly valuable in heavily calcified vessels.

Near-Infrared Spectroscopy (NIRS) specifically identifies lipid content within vessel walls, providing a "chemogram" of lipid distribution. The PROSPECT study demonstrated that lipid-rich plaques identified by NIRS were significantly more likely to cause future events than lipid-poor segments, suggesting potential for preventive intervention. Combined NIRS-IVUS systems provide simultaneous structural and compositional assessment, potentially offering comprehensive plaque characterization in a single evaluation.

The integration of these various imaging modalities into clinical practice requires thoughtful consideration of their relative strengths and limitations. For accurate diagnosis, radiation exposure, contrast requirements, availability, and cost all influence modality selection alongside diagnostic accuracy. Standardized protocols, structured reporting, and quantitative analysis tools help maximize clinical value while minimizing variability between interpreters.

Procedural planning represents another critical imaging application, with dedicated workstations allowing detailed measurement and device selection before intervention. For endovascular aneurysm repair, centerline analysis with multiplanar reformats enables precise sizing and positioning of endografts, substantially reducing procedural time and contrast use. Computational flow dynamics and virtual intervention planning allow prediction of hemodynamic consequences before physical intervention, potentially optimizing device selection and deployment strategies.