Lower-extremity vascular disease has a high morbidity rate and often leads to disability and death in its advanced stages. Although angiography-guided endovascular intervention is the primary treatment for peripheral vascular disease, it frequently fails to detect subtle lumen features and falls short of meeting the increasing clinical need for precise management. Intravascular ultrasound (IVUS) merges noninvasive ultrasound imaging with invasive catheterization techniques, providing 360° imaging of the vascular cross-section and delivering accurate information about lesion morphology. IVUS has been crucial in supporting decisionmaking for preoperative assessment, intraoperative monitoring, and postoperative optimization during vascular interventions. This review aims to summarize the latest applications of IVUS in lower-extremity vascular disease, discuss its strengths and limitations, and explore future directions for its use.

Lower-extremity vascular disease has a high morbidity rate and often leads to disability and death in its advanced stages. Although angiography-guided endovascular intervention is the primary treatment for peripheral vascular disease, it frequently fails to detect subtle lumen features and falls short of meeting the increasing clinical need for precise management. Intravascular ultrasound (IVUS) merges noninvasive ultrasound imaging with invasive catheterization techniques, providing 360° imaging of the vascular cross-section and delivering accurate information about lesion morphology. IVUS has been crucial in supporting decisionmaking for preoperative assessment, intraoperative monitoring, and postoperative optimization during vascular interventions. This review aims to summarize the latest applications of IVUS in lower-extremity vascular disease, discuss its strengths and limitations, and explore future directions for its use.

Lower-extremity vascular disease has a high morbidity rate and often leads to disability and death in its advanced stages. Although angiography-guided endovascular intervention is the primary treatment for peripheral vascular disease, it frequently fails to detect subtle lumen features and falls short of meeting the increasing clinical need for precise management. Intravascular ultrasound (IVUS) merges noninvasive ultrasound imaging with invasive catheterization techniques, providing 360° imaging of the vascular cross-section and delivering accurate information about lesion morphology. IVUS has been crucial in supporting decisionmaking for preoperative assessment, intraoperative monitoring, and postoperative optimization during vascular interventions. This review aims to summarize the latest applications of IVUS in lower-extremity vascular disease, discuss its strengths and limitations, and explore future directions for its use.

Contrast-enhanced ultrasound（CEUS），as a non-invasive imaging technique，has been widely applied in the characterization of focal liver lesions（FLLs）. By intravenously injecting contrast agents and using specific low mechanical index imaging techniques，CEUS not only provides high spatial and temporal resolution，but also enables dynamic assessment of blood flow perfusion in both large vessels and microvessels，including capillaries in the liver. However，CEUS is highly operator-dependent. The quantitative analysis of time-intensity curves in dynamic contrast-enhanced ultrasound（DCE-US）can provide further information，overcome the subjectivity limitations of traditional CEUS and improve the accuracy of diagnosis and treatment in FLLs. This review discusses the theoretical basis of DCE-US and its quantitative analysis methods，their applications in the diagnosis and treatment of FLLs，limitations，and future directions.

Lower-extremity vascular disease has a high morbidity rate and often leads to disability and death in its advanced stages. Although angiography-guided endovascular intervention is the primary treatment for peripheral vascular disease, it frequently fails to detect subtle lumen features and falls short of meeting the increasing clinical need for precise management. Intravascular ultrasound (IVUS) merges noninvasive ultrasound imaging with invasive catheterization techniques, providing 360° imaging of the vascular cross-section and delivering accurate information about lesion morphology. IVUS has been crucial in supporting decisionmaking for preoperative assessment, intraoperative monitoring, and postoperative optimization during vascular interventions. This review aims to summarize the latest applications of IVUS in lower-extremity vascular disease, discuss its strengths and limitations, and explore future directions for its use.

Lower-extremity vascular disease has a high morbidity rate and often leads to disability and death in its advanced stages. Although angiography-guided endovascular intervention is the primary treatment for peripheral vascular disease, it frequently fails to detect subtle lumen features and falls short of meeting the increasing clinical need for precise management. Intravascular ultrasound (IVUS) merges noninvasive ultrasound imaging with invasive catheterization techniques, providing 360° imaging of the vascular cross-section and delivering accurate information about lesion morphology. IVUS has been crucial in supporting decisionmaking for preoperative assessment, intraoperative monitoring, and postoperative optimization during vascular interventions. This review aims to summarize the latest applications of IVUS in lower-extremity vascular disease, discuss its strengths and limitations, and explore future directions for its use.

Contrast-enhanced ultrasound（CEUS），as a non-invasive imaging technique，has been widely applied in the characterization of focal liver lesions（FLLs）. By intravenously injecting contrast agents and using specific low mechanical index imaging techniques，CEUS not only provides high spatial and temporal resolution，but also enables dynamic assessment of blood flow perfusion in both large vessels and microvessels，including capillaries in the liver. However，CEUS is highly operator-dependent. The quantitative analysis of time-intensity curves in dynamic contrast-enhanced ultrasound（DCE-US）can provide further information，overcome the subjectivity limitations of traditional CEUS and improve the accuracy of diagnosis and treatment in FLLs. This review discusses the theoretical basis of DCE-US and its quantitative analysis methods，their applications in the diagnosis and treatment of FLLs，limitations，and future directions.

Purpose: This study examined the diagnostic value of high-frequency ultrasound (HFUS) features in differentiating between benign and malignant skin lesions. Methods: A total of 1,392 patients with 1,422 skin lesions who underwent HFUS examinations were included in an initial dataset (cohort 1) to identify features indicative of malignancy. Qualitative clinical and HFUS characteristics were recorded for all lesions. To determine which HFUS and clinical features were suggestive of malignancy, univariable and multivariable logistic regression analyses were employed. The diagnostic performance of HFUS features combined with clinical information was evaluated. This assessment was validated using internal data (cohort 2) and multicenter external data (cohort 3). Results: Features significantly associated with malignancy included age above 60 years; lesion location in the head, face, and neck or genital regions; changes in macroscopic appearance; crawling or irregular growth pattern; convex or irregular base; punctate hyperechogenicity; blood flow signals; and feeding arteries. The area under the receiver operating characteristic curve, sensitivity, and specificity of HFUS features combined with clinical information were 0.946, 92.5%, and 86.9% in cohort 1; 0.870, 93.1%, and 80.8% in cohort 2 (610 lesions); and 0.864, 86.2%, and 86.6% in cohort 3 (170 lesions), respectively. However, HFUS is not suitable for evaluating lesions less than 0.1 mm in thickness or lesions exhibiting surface hyperkeratosis. Conclusion In a clinical setting, the integration of HFUS with clinical information exhibited good diagnostic performance in differentiating malignant and benign skin lesions. However, its utility was limited in evaluating extremely thin lesions and those exhibiting hyperkeratosis.

Purpose: This study examined the diagnostic value of high-frequency ultrasound (HFUS) features in differentiating between benign and malignant skin lesions. Methods: A total of 1,392 patients with 1,422 skin lesions who underwent HFUS examinations were included in an initial dataset (cohort 1) to identify features indicative of malignancy. Qualitative clinical and HFUS characteristics were recorded for all lesions. To determine which HFUS and clinical features were suggestive of malignancy, univariable and multivariable logistic regression analyses were employed. The diagnostic performance of HFUS features combined with clinical information was evaluated. This assessment was validated using internal data (cohort 2) and multicenter external data (cohort 3). Results: Features significantly associated with malignancy included age above 60 years; lesion location in the head, face, and neck or genital regions; changes in macroscopic appearance; crawling or irregular growth pattern; convex or irregular base; punctate hyperechogenicity; blood flow signals; and feeding arteries. The area under the receiver operating characteristic curve, sensitivity, and specificity of HFUS features combined with clinical information were 0.946, 92.5%, and 86.9% in cohort 1; 0.870, 93.1%, and 80.8% in cohort 2 (610 lesions); and 0.864, 86.2%, and 86.6% in cohort 3 (170 lesions), respectively. However, HFUS is not suitable for evaluating lesions less than 0.1 mm in thickness or lesions exhibiting surface hyperkeratosis. Conclusion In a clinical setting, the integration of HFUS with clinical information exhibited good diagnostic performance in differentiating malignant and benign skin lesions. However, its utility was limited in evaluating extremely thin lesions and those exhibiting hyperkeratosis.

Purpose: This study examined the diagnostic value of high-frequency ultrasound (HFUS) features in differentiating between benign and malignant skin lesions. Methods: A total of 1,392 patients with 1,422 skin lesions who underwent HFUS examinations were included in an initial dataset (cohort 1) to identify features indicative of malignancy. Qualitative clinical and HFUS characteristics were recorded for all lesions. To determine which HFUS and clinical features were suggestive of malignancy, univariable and multivariable logistic regression analyses were employed. The diagnostic performance of HFUS features combined with clinical information was evaluated. This assessment was validated using internal data (cohort 2) and multicenter external data (cohort 3). Results: Features significantly associated with malignancy included age above 60 years; lesion location in the head, face, and neck or genital regions; changes in macroscopic appearance; crawling or irregular growth pattern; convex or irregular base; punctate hyperechogenicity; blood flow signals; and feeding arteries. The area under the receiver operating characteristic curve, sensitivity, and specificity of HFUS features combined with clinical information were 0.946, 92.5%, and 86.9% in cohort 1; 0.870, 93.1%, and 80.8% in cohort 2 (610 lesions); and 0.864, 86.2%, and 86.6% in cohort 3 (170 lesions), respectively. However, HFUS is not suitable for evaluating lesions less than 0.1 mm in thickness or lesions exhibiting surface hyperkeratosis. Conclusion In a clinical setting, the integration of HFUS with clinical information exhibited good diagnostic performance in differentiating malignant and benign skin lesions. However, its utility was limited in evaluating extremely thin lesions and those exhibiting hyperkeratosis.