Up-to-date Doppler techniques for breast tumor vascularity: superb microvascular imaging and contrast-enhanced ultrasound

Role of Superb Microvascular Imaging (SMI) vascularity index values and vascularity patterns in the differential diagnosis of malignant liver lesions

PURPOSE

To evaluate the Superb Microvascular Imaging (SMI) vascular patterns and vascularity index (VI) values of malignant focal liver lesions (FLLs), assess their role in differential diagnosis, and examine interobserver agreement.

MATERIALS AND METHODS

A total of 107 patients (52 males, 55 females; mean age 62 ± 12.8 years, range 25-87) referred to the interventional radiology clinic for FLL biopsy between April 2022 and April 2023 were analyzed. Two radiologists independently assessed the SMI vascular patterns and calculated VI values. Differences among three lesion groups - hepatocellular carcinoma (HCC, n = 16), non-HCC primary liver malignancies (n = 16), and metastases (n = 75) - were evaluated, and interobserver agreement was assessed.

RESULTS

Most metastases (88%) demonstrated hypovascular patterns, while HCCs predominantly exhibited hypervascular patterns (68.7-81.3%). Non-HCC primary malignancies showed no dominant vascular pattern. Significant differences in SMI patterns were observed among lesion types (p = 0.001-0.035). VI values for HCCs (7.53-7.73) were significantly higher than those for non-HCC malignancies (2.73-2.93) and metastases (1.35-1.36) (p = 0.0001). ROC analysis based on VI values yielded AUCs of 0.886-0.887, with a cutoff of 2.92 providing 81.3% sensitivity and 79.1-80.2% specificity for HCC diagnosis. The inter-reader agreement for SMI patterns had a kappa score of 0.634, while the intraclass correlation coefficient (ICC) for VI values was 0.959.

CONCLUSION

HCCs displayed more hypervascular SMI patterns and significantly higher VI values compared to other malignant FLLs, emphasizing the diagnostic potential of VI in distinguishing HCC from non-HCC tumors. Although metastases primarily exhibited hypovascular patterns and low VI values, no dominant vascular pattern was identified in non-HCC primary liver malignancies. Assessing VI values provided higher interobserver agreement compared to SMI patterns, enhancing objectivity and reproducibility.

The Role of Monochromatic Superb Microvascular Index to Predict Malignancy of Solid Focal Lesions: Correlation Between Vascular Index and Histological Bioptic Findings

OBJECTIVES

This study aims to assess the potential role of the ultrasound (US) monochromatic Superb Microvascular Index (mSMI) to predict malignancy of solid focal lesions, correlating the vascular index (VI) with bioptic histological results.

METHODS

In this single-center retrospective analysis, patients undergoing percutaneous US-guided biopsy of solid lesions were considered. Biopsy indication was given by a multidisciplinary team evaluation based on clinical radiological data. Exclusion criteria were: unfeasible SMI evaluations due to poor respiratory compliance, locations not appreciable with the SMI, previous antiangiogenetic chemo/immunotherapies, and inconclusive histological reports. The mSMI examination was conducted in order to visualize extremely low-velocity flows with a high resolution and high frame rate; the VI was semi-automatically calculated. All bioptic procedures were performed under sole US guidance using 16G or 18G needles, immediately after mSMI assessment.

RESULTS

Forty-four patients were included (mean age: 64 years; 27 males, 17 females). Liver (15/43), kidneys (9/43), and lymph nodes (6/43) were the most frequent targets. At histopathological analysis, 7 lesions were benign and 37 malignant, metastasis being the most represented. The VI calculated in malignant lesions was statistically higher compared to benign lesions (35.45% and 11% in malignant and benign, respectively; p-value 0.013). A threshold VI value of 15.4% was identified to differentiate malignant lesions. The overall diagnostic accuracy of the VI with the mSMI was 0.878, demonstrating a high level of diagnostic accuracy.

CONCLUSIONS

In this study, the mSMI analysis of solid focal lesions undergoing percutaneous biopsy significantly correlated with histological findings in terms of malignant/benign predictive value, reflecting histological vascular changes in malignant lesions.

Evaluation of in-stent restenosis after carotid artery stenting with superb microvascular imaging: initial findings

BackgroundCarotid artery stenting (CAS) is an interventional management in preventing ischemic stroke caused by carotid artery stenosis. After the treatment with CAS, in-stent restenosis caused by neointimal hyperplasia may develop.PurposeThis study aims to obtain a better determination of neointimal hyperplasia using superb microvascular imaging (SMI), which provides a high-quality visualization of the endoluminal lesions, and to compare these results with B-mode and Doppler ultrasound (US).Material and MethodsA total of 106 patients who underwent CAS in our interventional radiology unit between 2018 and 2020 were retrospectively analyzed. In total, 44 patients whose procedure images and post-procedural follow-up Doppler US and SMI data could be accessed were included.ResultsThere were nine patients who had in-stent restenosis. One patient had no velocity increase; however, on SMI the measurements showed in-stent restenosis both in area and diameter. The other eight patients had a stenosis degree in the range of 50%-79% on Doppler US. Five patients had in-stent restenosis, both in Doppler US and SMI, by area and diameter measurements. Two patients underwent digital subtraction angiography (DSA).ConclusionWe suggest that using SMI with duplex sonography improves detecting neointimal hyperplasia and in-stent restenosis. With SMI, better visualization of the stent lumen may improve the patient selection for DSA.

Microvascular imaging versus CEUS in the characterization of renal masses: preliminary experience in a tertiary care referral university hospital

Evaluation of the possible role of microvascular imaging (MI) for the detection of vascularization of renal lesions, while comparing it with contrast-enhanced ultrasound (CEUS).137 patients (160 renal lesions, 64 solid and 96 cystic) were enrolled in this single-center, retrospective, observational study. For solid masses, both the intralesional and the peripheral vascularization was analyzed and quantified by MI and then compared to peak enhancement on CEUS. Regarding cystic lesions, we evaluated the presence or absence of vascularization within the cystic wall and/or septa. MI results were compared with CEUS findings using Pearson's Chi square test. An optimal size cut-off for renal lesions was determined with the Youden test.For solid lesions, a statistically significant correlation (p <0.05) was observed between the MI parameters and the peak enhancement on CEUS. The detection rate (DR) for lesional vascularization on MI was 87.5%, while if we consider only lesions larger than the optimal cut-off (14mm), the DR increases to 98%. In cystic lesions, the MI showed a high specificity (93.9%) in predicting CEUS results and a high positive predictive value (84.2%). The concordance was 100% in Bosniak I lesions and 80% in Bosniak IV lesions, while it was lower for the other classes. Furthermore, we found a statistically significant correlation (p <0.05) between Bosniak grade and lesional vascularity on MI.Our preliminary study shows that MI cannot replace CEUS, but could reduce its use, especially in solid lesions larger than 14mm and in cysts classified as Bosniak IV, a goal that is particularly important in an active surveillance setting.

Non-Invasive Assessment of Vascular Damage Through Pulse Wave Velocity and Superb Microvascular Imaging in Pre-Dialysis Patients

Background/Objectives: Cardiovascular disease is the main cause of morbidity and mortality in Chronic Kidney Disease (CKD), so it is of great importance to find simple and non-invasive tools to detect vascular damage in pre-dialysis CKD patients. This study aimed to assess the applicability of non-invasive techniques to evaluate vascular damage in stages CKD-2 to CKD-5 and its progression after an 18-month follow-up using (A) carotid-femoral pulse wave velocity (PWV) to assess aortic stiffness and (B) Superb Microvascular Imaging (SMI) ultrasound to assess adventitial neovascularization compared with other traditional techniques to evaluate vascular damage, such as carotid intima-media thickness and Kauppila index. Methods: The study involved 43 CKD patients in stages CKD-2 to CKD-5 and a group of 38 sex- and age-matched controls, studied at baseline and at an 18-month follow-up. Age, sex, body mass index, arterial pressure, pharmacological treatments, and blood and urinary parameters were collected. Aortic stiffness was determined by carotid-femoral PWV and abdominal aortic calcification was assessed in lateral lumbar X-rays and quantified by the Kauppila index. Carotid intima-media thickness (cIMT), the number of carotid plaques, and adventitial neovascularization were evaluated by SMI. Results: Vascular impairment was mostly detected in CKD-4 and CKD-5 stages, with increased aortic stiffness measured by PWV and increased carotid plaques and adventitial neovascularization measured by SMI ultrasound. Furthermore, CKD-5 patients showed greater abdominal aortic calcification. Interestingly, CKD patients displayed a negative correlation between serum soluble Klotho (sKlotho) and cIMT. Finally, CKD patients showed no progression of vascular impairment after the 18-month follow-up, with the exception of carotid plaques. Conclusions: Performing non-invasive PWV and SMI ultrasound might be useful to evaluate vascular damage in CKD before entering dialysis, possibly helping to prevent cardiovascular events, although future studies should clarify the use of these techniques in clinical practice.

Establishing Reference Values for Thyroid Vascularity Using Ultra-Micro Angiography (UMA) Ultrasound Technology

Background/Objectives: Ultra-Micro Angiography (UMA) is an advanced Doppler technique designed to improve the visualization of slow blood flow in small vessels. The Subtraction UMA (sUMA) setting enhances these features by removing background tissue interference, allowing for more precise assessments of microvascularity. This study aims to establish reference values for thyroid vascularity using sUMA technology, providing a foundation for future research in thyroid pathology. Methods: This prospective, single-center study included 106 healthy participants with no evidence of thyroid disease based on biochemical and ultrasound evaluations. All participants underwent multiparametric ultrasound, followed by sUMA to assess thyroid vascularity. The quantitative sUMA measurements were performed using the color pixel percentage (CPP), and three measurements were taken in each thyroid lobe. The median CPP values were calculated and analyzed. Statistical analysis was conducted to evaluate intraobserver reliability and to examine correlations between CPP values and demographic characteristics. Results: The study cohort had a mean age of 41.2 ± 16.3 years, with a predominance of women (82%). CPP sUMA measurements demonstrated excellent feasibility (100%) and intraobserver reliability, with an intraclass correlation coefficient of 0.905 for the right thyroid lobe and 0.897 for the left lobe. The median CPP for the right and left lobes was 26.5% and 27.1%, respectively, with no significant difference between lobes (p = 0.8799). Conclusions: sUMA technology is a reliable and reproducible method for evaluating thyroid microvascularity in healthy individuals. These reference values provide a foundation for future studies investigating thyroid pathology, potentially enhancing the accuracy of diagnostic assessments in clinical practice.

The Clinical Application of Superb Microvascular Imaging in Evaluating Thyroid Related Diseases: A Systematic Review

This article reviews all published articles on the application of superb microvascular imaging (SMI) technique in thyroid related diseases before December 31, 2023. SMI, a recently developed ultrasound imaging modality, could display microvascular information by eliminating clutter and preserving low flow signals. Most studies used SMI to help diagnose malignant thyroid nodules and concluded that SMI performed better than color Doppler imaging and power Doppler imaging. At present, there is no consensus when depicting the morphology of vascularity of thyroid nodules (TNs). This problem may be solved by quantitative SMI which makes it possible to quantitatively evaluate the vascularity of TNs. SMI is also applied to evaluate cervical lymph node or thyroid inflammatory diseases. Although, SMI has some limitations, such as no standard for the normal perfusion patterns, and it has a broad application prospect in the diagnosis and management of thyroid related diseases.

Integrating traditional biomarkers and emerging predictors to assess neoadjuvant chemotherapy efficacy in breast cancer: a multifactorial analysis of Ki-67, CDK4, EGFR, TILs and ctDNA

OBJECTIVE

This study aimed to analyse the correlation between the expression of cell proliferation-associated antigen (Ki-67), cell cycle protein-dependent kinase 4 (CDK4), epidermal growth factor receptor (EGFR), tumour-infiltrating lymphocytes (TILs) and circulating tumour DNA (ctDNA) with the outcome and prognosis of patients with breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT).

METHODS

We retrospectively analysed the clinicopathological data of 231 patients with BC who underwent preoperative NACT at XX Hospital between 1 January 2018 and 31 December 2021. Logistic regression models were used to analyse factors influencing NACT efficacy. The Cox risk regression model was used to analyse prognostic factors. The TILs were assessed on pre-treatment biopsies, and ctDNA levels were monitored during NACT. Propensity score matching and subgroup analyses were performed.

RESULTS

After 4-6 cycles of chemotherapy, the response rate was 77.92% (180/231), with 58.87% (136/231) achieving pathological complete response (pCR). Multifactorial analysis showed that tumour, node and metastasis (TNM) stage II, EGFR positivity, low Ki-67 expression, CDK4 negativity, non-triple-negative subtypes and effective NACT results were associated with higher pCR rates. Higher TIL levels correlated with increased pCR rates (72.4% for high TILs vs 39.1% for low TILs, p < 0.001). The ctDNA levels decreased significantly in patients with pCR compared with patients without pCR during NACT (p < 0.001). After propensity score matching, the 3-year disease-free survival rate was significantly higher in the pCR group (88.9% vs 71.1%, p = 0.003). Subgroup analysis revealed varying pCR rates and predictive biomarkers across BC subtypes.

CONCLUSION

The TNM classification, EGFR, Ki-67, CDK4 expression, BC subtype and NACT results have predictive value for pCR in patients with BC. Lower TNM classification, lower Ki-67 expression and EGFR positivity are associated with better outcomes. High TIL levels and significant decreases in ctDNA during NACT correlate with improved response and prognosis. These findings highlight the potential for integrating traditional clinicopathological factors with novel biomarkers for personalised treatment strategies in BC.

Evaluation of wound temperature monitoring at various anatomical sites in the management of patients with diabetic foot undergoing microcirculation reconstruction

OBJECTIVE

This study aims to assess the significance of monitoring temperature change trends at various wound sites in the healing process of diabetic foot ulcers after microcirculation reconstruction surgery.

METHODS

A retrospective analysis was conducted on individuals with diabetic foot ulcers who had been admitted to the Department of Orthopedics at the Second Hospital of Shanxi Medical University between July 2020 and February 2022. Temperature changes were regularly monitored at the center of the wound and the distal tibia of the ipsilateral lower leg to assess microcirculatory blood perfusion. Wound, ischemia, and foot infection (WIFi) grading was performed at admission and the final follow-up was to determine the value of temperature monitoring at various sites. Additionally, the formation of collateral microarterial vessels was monitored to determine their consistency with the observed trends in temperature differences. Follow-up assessments included the recurrence of ulcers, development of ulcers at different locations, re-amputation of the toe or limb, and diabetes-related mortality.

RESULTS

A total of 29 patients were included in the follow-up, with an average age of 57.14 ± 14.75 years and a follow-up period of 9.79 ± 4.13 months. Following microcirculation reconstruction surgery, as the microvascular network formed, the temperature difference between the center of the wound and the distal tibia on the same side gradually decreased, with no statistical difference observed at 4 weeks postoperatively. At both admission and the final follow-up, there was a significant reduction in the wound (W) and ischemia (I) grades within the WIFi classification. The temperature at the wound center showed progressive improvement as collateral microarterial vessels developed. During the follow-up period, there were 2 cases of ulcer recurrence, 1 case of an ulcer appearing at a different location, no cases of re-amputation of the toe or limb, and 2 diabetes-related fatalities.

CONCLUSION

Skin temperature monitoring offers a direct and reliable indication of microcirculatory blood perfusion. Its simplicity and cost-effectiveness make it a valuable tool for widespread use in evaluating wound healing following microcirculation reconstruction surgery.

Ultrasound-Based Noncontrast Microvascular Imaging for Evaluation of Breast Lesions: Imaging Techniques and Review of Diagnostic Criteria

Vascularity plays a pivotal role in the progression of breast lesions and may be associated with their aggressiveness and likelihood of being malignant. Contrast-enhanced imaging techniques are necessary to evaluate vascularity due to the limited sensitivity of conventional color Doppler techniques, in which motion artifacts are eliminated using wall filters. However, in this process, low-flow signals from small vessels also get removed unintentionally. Advancements in technology have revolutionized the way ultrasound images are generated, resulting in tremendous improvements in Doppler imaging techniques. The new, ultrasound-based noncontrast microvascular imaging techniques overcome the limitations of conventional Doppler, and are highly sensitive for detecting microvessels and low flow. The resultant high Doppler sensitivity leads to detection of vascularity in more breast lesions. It is important for radiologists to understand the imaging principles and the clinical implications of the new techniques, to optimally utilize them and aid correct diagnosis. Angio-PLUS is one such recent advancement, which uses unfocused or plane waves and three-dimensional wall filtering to analyze tissue motion in time, space, and amplitude domains that effectively distinguish between blood flow and tissue. The information is beneficial for assessing the lesion vascularity without using contrast. This article aims to explain the Doppler imaging techniques, their clinical applications, scanning methods, and review the common Doppler-based diagnostic criteria used in the evaluation of breast lesions.

Comparing qSMI and qCEUS for assessing vascularization in uterine cervical cancer: operable versus non-operable group

Objective

The present study aimed to compare the effectiveness and reliability of quantified superb microvascular imaging (qSMI) and quantified contrast-enhanced ultrasonography (qCEUS) in assessing vascularization in both operable and non-operable uterine cervical cancer.

Methods

A case-control study included 64 patients with pathology-proven and untreated cervical cancer, who underwent transvaginal ultrasonography combined with qSMI and qCEUS between January 2022 and June 2023. SMI results were quantified as the vascular index (VI), which were compared to 12 quantitative parameters of CEUS calculated with time-intensity curves (TIC).

Results

According to FIGO staging and different treatment regimens, 64 patients with cervical cancer were divided into operable group (IA ~ IIA, n = 19) and non-operable group (IIB ~ IV, n = 45). In comparison to the operable group, the non-operable group showed significantly higher values in VI, peak intensity (PI), area under the curve (AUC), wash-in area (iAUC), wash-out area (oAUC), wash-in rate (WiR), mean intensity (Mean Int), and standard deviation (STD) (all P < 0.05). VI demonstrated strong correlations with CEUS parameters, notably PI (r = 0.854, P < 0.001) and AUC (r = 0.635, P < 0.001). Furthermore, VI showed a better predictive performance for treatment-group assignment than qCEUS parameters, with an 80.7% accuracy, 64.4% sensitivity and 89.5% specificity.

Conclusion

Both qSMI and qCEUS exhibit significant and comparable utility in detecting microvascular hyperplasia and predicting treatment-group assignments in cervical cancer. Furthermore, qSMI may offer added convenience in implementation.

Artificial intelligence for ultrasound microflow imaging in breast cancer diagnosis

PURPOSE

To develop and evaluate artificial intelligence (AI) algorithms for ultrasound (US) microflow imaging (MFI) in breast cancer diagnosis.

MATERIALS AND METHODS

We retrospectively collected a dataset consisting of 516 breast lesions (364 benign and 152 malignant) in 471 women who underwent B-mode US and MFI. The internal dataset was split into training (n = 410) and test datasets (n = 106) for developing AI algorithms from deep convolutional neural networks from MFI. AI algorithms were trained to provide malignancy risk (0-100%). The developed AI algorithms were further validated with an independent external dataset of 264 lesions (229 benign and 35 malignant). The diagnostic performance of B-mode US, AI algorithms, or their combinations was evaluated by calculating the area under the receiver operating characteristic curve (AUROC).

RESULTS

The AUROC of the developed three AI algorithms (0.955-0.966) was higher than that of B-mode US (0.842, P < 0.0001). The AUROC of the AI algorithms on the external validation dataset (0.892-0.920) was similar to that of the test dataset. Among the AI algorithms, no significant difference was found in all performance metrics combined with or without B-mode US. Combined B-mode US and AI algorithms had a higher AUROC (0.963-0.972) than that of B-mode US (P < 0.0001). Combining B-mode US and AI algorithms significantly decreased the false-positive rate of BI-RADS category 4A lesions from 87% to 13% (P < 0.0001).

CONCLUSION

AI-based MFI diagnosed breast cancers with better performance than B-mode US, eliminating 74% of false-positive diagnoses in BI-RADS category 4A lesions.

Malignant glomus tumor of the breast: a case report

Malignant glomus tumor (MGT) is a rare mesenchymal neoplasm. It is rarely located in the breast. We present a case of a 57-year-old female patient presenting with complaints of a progressively growing mass found in her left breast. Though multiple imaging examinations have been performed, especially multimodal ultrasound examinations, an accurate diagnosis still cannot be determined. Finally, the lesion was confirmed to be a MGT of the breast by postoperative pathological diagnosis. In conclusion, MGT originating from breast is extremely rare. No such case has ever been described before. This study demonstrates the imaging characteristics of a patient with MGT of the breast in order to provide more extensive insights to consider the differential diagnosis of breast lesions.

Prediction of complete response after neoadjuvant chemotherapy for invasive breast cancers: The utility of shear wave elastography and superb microvascular imaging in pretreatment breast ultrasound

PURPOSE

To investigate whether multiparametric parameters of pretreatment breast ultrasound (US) and clinicopathologic factors are associated with pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) for breast cancer.

METHODS

Between November 2018 and September 2022, 88 patients who underwent NAC and subsequent surgery were included in this study (median age, 55 years; interquartile range [IQR], 45, 59.3). Multiparametric breast US including grayscale, shear wave elastography (SWE) and superb microvascular imaging (SMI) of pathologically proven invasive breast cancers were retrospectively reviewed. Clinicopathological and multiparametric parameters of breast US, including size, SWEmax, SWEratio and vascular index on SMI (SMIVI) were compared between the groups. Univariate and multivariate logistic regression analyses were performed to determine factors predicting pCR after NAC. AUROC curve analysis was performed to determine the predictors' optimal cut-off values and diagnostic performance.

RESULTS

The pCR group (n = 24) showed a significantly smaller tumor size, lower SWEmax, higher Ki-67 index, higher hormone receptor negativity and negative axillary lymph node metastasis compared to the non-pCR group (n = 64). Multivariate regression analysis showed that SWEmax (adjusted odds ratio[aOR] = 0.956, 95 % confidence interval [CI] = 0.919-0.994, P = 0.025) and Ki-67 index (aOR = 1.083, 95 % CI = 1.012-1.159, P = 0.021) were independently associated with pathologically complete response. The optimal cut-off values for predicting pCR were 27.5 % for Ki-67 with an AUC of 0.743 and 134.8 kPa for SWEmax with an AUC of 0.779. A combination model including clinical factors and SWEmax showed the best diagnostic performance with an AUC of 0.876.

CONCLUSION

A higher Ki-67 index and lower SWEmax measured on pretreatment breast US were independently associated with pCR in invasive breast cancer after NAC.

Diagnostic performance of ACR-TIRADS combined with superb microvascular imaging for differential diagnosis of mummified thyroid nodules and papillary thyroid carcinomas

Objective

The aim was to investigate the ability of superb microvascular imaging (SMI) to improve the differential diagnosis of mummified thyroid nodules (MTNs) and papillary thyroid carcinomas (PTCs) using the 2017 American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS).

Materials and methods

We enrolled 110 cases of MTNs and 110 cases of PTCs confirmed by fine needle aspiration (FNA) or surgery. Conventional ultrasound (US) and the quantity of microvessels detected by SMI were analyzed for all nodules. Thyroid nodules were initially categorized by ACR-TIRADS based on US imaging features and then reclassified based on ACR-TIRADS combined with SMI blood-flow grade (SMI-TIRADS). We compared the diagnostic performances of ACR-TIRADS and SMI-TIRADS by receiver operating characteristic curve, sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV).

Results

US-detected margin, shape, and echogenic foci differed between MTNs and PTCs (P < 0.05). The SMI blood-flow grade was significantly greater in PTCs compared with MTNs (Χ2 = 158.78, P < 0.05). There was no significant difference in ACR-TIRADS indicators between MTNs and PTCs (Χ2 = 1.585, P = 0.453); however, reclassification by SMI-TIRADS showed significant differences between the groups (Χ2 = 129.521, P < 0.001). The area under the curve was significantly lower for ACR-TIRADS compared with SMI-TIRADS (0.517 vs 0.887, P < 0.05). SMI-TIRADS had significantly higher diagnostic value for distinguishing MTNs and PTCs than ACR-TIRADS (sensitivity: 91.82% vs 74.55%, P < 0.05; specificity: 84.55% vs 21.82%, P < 0.05; accuracy: 88.18% vs 48.18%, P < 0.05; PPV: 85.59% vs 48.81%, P < 0.05; and NPV: 91.18% vs 46.15%, P < 0.05).

Conclusion

The detection of microvascular flow and large vessels in thyroid nodules by SMI resulted in high diagnostic specificity and sensitivity. ACR-TIRADS combined with SMI could effectively distinguish between MTNs and PTCs, to avoid unnecessary FNA or surgical excision.

Macrophage-derived biomimetic nanoparticles enhanced SDT combined with immunotherapy inhibited tumor growth and metastasis

Combination therapy based on sonodynamic therapy (SDT) combined with immune checkpoint blockers anti-PD-L1 provides effective anti-tumor effects. We designed a combination therapy based on M1/PLGA@IR780/CAT NPs of SDT-enhanced immunity combined with immune checkpoint blockers against PD-L1, which was based on M1 macrophage membrane-encapsulated poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with the acoustic sensitizer IR780 and catalase (CAT) to successfully realize it. SDT based on M1/PLGA@IR780/CAT NPs could induce tumor cell death by promoting dendritic cell (DC) maturation and modulating the tumor immune microenvironment. In particular, the systemic anti-tumor immune response and potent immune memory induced upon combination with anti-PD-L1 checkpoint blockade not only alleviated the progression of mammary cancer in 4T1 mice and effectively blocked distant metastasis, but also prevented tumor recurrence, providing a promising new therapeutic strategy for clinical tumor therapy.

Quantitative evaluation of ocular vascularity and correlation analysis in patients with diabetic retinopathy by SMI and OCTA

AIMS

To find potential relation between retrobulbar vessels and fundus microvessels and to detect sensitive and effective clinical indicators in predicting the progress of diabetic retinopathy (DR), ocular hemodynamics were measured using superb microvascular imaging (SMI) and ultrawide-field optical coherence tomography angiography (UWF-OCTA).

METHODS

Observational, cross-sectional study evaluating ocular hemodynamics in patients with DR by SMI (Aplio i900, Canon Medical) and UWF-OCTA (BM-400 K BMizar, Tupai Medical Technology). The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) of the central retinal artery (CRA), posterior ciliary artery (PCA), and ophthalmic artery (OA) were measured by SMI. UWF-OCTA evaluated the fundus vascular parameters. A correlation analysis was used to determine the correlation between SMI and UWF-OCTA parameters.

RESULTS

One hundred thirty-nine eyes of 139 diabetic patients were included: 29 without DR (NDR), 36 with mild to moderate nonproliferative DR (M-NPDR), 37 with severe NPDR (S-NPDR), and 37 with proliferative DR (PDR). PSV and EDV of retrobulbar vessels decreased from NDR to S-NPDR while increasing PDR. RI of OA showed a decreasing trend in the progression of DR, but other vessels didn't show the same trend. ROC curve analysis showed that CRAPSV, CRAEDV, PCAEDV, OAPSV, and OAEDV had diagnostic value distinguishing M-NPDR and S-NPDR. The correlation analysis observed a significant association between the SMI parameters of CRA and PCA and UWF-OCTA parameters. CRA hemodynamics were more associated with fundus vascular parameters, especially the retina, in the NDR group than in the M-NPDR group. In contrast, PCA consistently correlated with fundus vascular parameters, especially in the choroid, from the NDR to the M-NPDR group. However, OA showed a poor correlation with OCTA parameters.

CONCLUSION

The velocity of retrobulbar vessels, mainly the CRA, may serve as a valuable predictor for assessing the progress of DR. The use of SMI in diabetic patients may help identify patients at risk of developing retinopathy.

Assessment of the carpal tunnel and associated neural structures with superb microvascular imaging: a scoping review

INTRODUCTION

Superb microvascular imaging (SMI) is an advanced ultrasound technique that portrays microcirculation. Its clinical applications have been studied in various diseases, including carpal tunnel syndrome (CTS) i.e. the most common entrapment neuropathy. This scoping review explores the role of SMI in diagnosing CTS or the assessment of relevant neural structures.

METHODS

We conducted a comprehensive search of electronic databases (PubMed, Embase and Web of Science) up to 26 September 2023. Two independent authors conducted the literature search, quality assessment, and data extraction.

RESULTS

This review includes seven studies comprising 385 wrists. SMI consistently revealed increased intraneural vascularity in the median nerves of patients with CTS compared to healthy individuals. While SMI demonstrated higher sensitivity than traditional Doppler methods for detecting CTS, its specificity was somewhat lower. Combining SMI with B-mode ultrasound appears to enhance the diagnostic accuracy for CTS. However, the relationship between SMI findings and CTS severity remains unclear.

CONCLUSIONS

This review highlighted the ability of SMI to provide detailed vascular structures in both healthy wrists and those with CTS. Additional research is crucial to determine the typical SMI findings of the carpal tunnel and within that context, tailor more precise diagnostic/therapeutic applications for the CTS population.

Maximum intensity projection based on high frame rate contrast-enhanced ultrasound for the differentiation of breast tumors

Objective

We explored the role of maximum intensity projection (MIP) based on high frame rate contrast-enhanced ultrasound (H-CEUS) for the differentiation of breast tumors.

Methods

MIP imaging was performed in patients with breast tumors who underwent H-CEUS examinations. The microvasculature morphology of breast tumors was assessed. The receiver operating characteristic curve was plotted to evaluate the diagnostic performance of MIP.

Results

Forty-three breast tumors were finally analyzed, consisting of 19 benign and 24 malignant tumors. For the ≤30-s and >30-s phases, dot-, line-, or branch-like patterns were significantly more common in benign tumors. A tree-like pattern was only present in the benign tumors. A crab claw-like pattern was significantly more common in the malignant tumors. Among the tumors with crab claw-like patterns, three cases of malignant tumors had multiple parallel small spiculated vessels. There were significant differences in the microvasculature morphology for the ≤30-s and >30-s phases between the benign and malignant tumors (all p < 0.001). The area under the curve, sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the ≤30-s phase were all higher than those of the >30-s phase for the classification of breast tumors.

Conclusion

MIP based on H-CEUS can be used for the differentiation of breast tumors, and the ≤30-s phase had a better diagnostic value. Multiple parallel small spiculated vessels were a new finding, which could provide new insight for the subsequent study of breast tumors.

Evaluation of nipple vascularity using superb microvascular imaging in patients with reduction mammoplasty

We aimed to investigate the effect of the chosen pedicle on nipple vascularity by evaluating changes in the microvascular circulation of the nipples in patients undergoing reduction mammoplasty through superb microvascular imaging study (SMI). 70 nipples were included in this retrospective study. There were 15 patients (30 nipples) in Group A using the inferior pedicle and 20 patients (40 nipples) in Group B using the superomedial pedicle. The vascular index (VI) of each nipple were evaluated preoperatively and at the third postoperative month using SMI. The mean VI in Group A was 1.25 (0.5-3.6) preoperatively and 1.3 (0.4-3.2) at the third postoperative month (P > .05). The mean VI in Group B was 1.65 (0.7/2.9) preoperatively and 1.15 (0.2/1.9) at the third postoperative month (P < .05). While the VI increased by 11.3% in Group A, it decreased by 30.6% in Group B (P < .001). The changing of the VI was analyzed between comparable groups, and decreasing microvascular circulation of the nipple with use of the superomedial pedicle was detected by quantitative values, which can be useful in at-risk patient groups, the planning of surgical procedures, and early revisions at postoperative month 3.

Progress of Ultrasound Techniques in the Evaluation of Carotid Vulnerable Plaque Neovascularization

BACKGROUND

The rupture and detachment of unstable plaques in the carotid artery can cause embolism in the cerebral artery, leading to acute cerebrovascular events. Intraplaque neovascularization (IPN) is a very important contributor to carotid plaque instability, and its evolution plays a key role in determining the outcome of vulnerable plaques. Ultrasound techniques, represented by contrast-enhanced ultrasound (CEUS) and superb microvascular imaging (SMI), are reported to be non-invasive, rapid, and effective techniques for the semi-quantitative or quantitative evaluation for IPN. Although ultrasound techniques have been widely applied in the detection of carotid plaque stability, it has been limited owing to the lack of unified IPN quantitative standards.

SUMMARY

This review summarizes the application and semi-quantitative/quantitative diagnostic standards of ultrasound techniques in evaluating IPN and looks forward to the prospects of the future research. With the development of novel techniques like artificial intelligence, ultrasound will offer appropriate selections for achieving more accuracy diagnosis.

KEY MESSAGES

A large number of studies have used CEUS and SMI to detect IPN and perform semi-quantitative grading to predict the occurrence of diseases such as stroke and to accurately assess drug efficacy based on rating changes. These studies have made great progress at this stage, but more accurate and intelligent quantitative imaging methods should become the future development goal.

The Diagnostic Role of Shear Wave Elastography and Superb Microvascular Imaging in the Evaluation of Suspicious Microcalcifications

OBJECTIVES

The aim of this study was to investigate the role of superb microvascular imaging (SMI) and shear wave elastography (SWE) in the prediction of malignancy and invasiveness of isolated microcalcifications (MC) that can be visualized by ultrasonography (US).

MATERIAL AND METHODS

Sixty-seven women with MC, who were considered suspicious on mammography were evaluated. Only those lesions that could be visualized by US and presented as non-mass lesion were included. They were evaluated by B-mode US, SMI, and SWE before US-guided core-needle biopsy. B-mode US, SMI (vascular index (SMIvi)), and SWE (E-mean, E-ratio) findings were compared with histopathologic features.

RESULTS

Pathology confirmed 45 malignant (21 invasive and 24 in situ carcinomas) and 22 benign lesions. There was a statistically significant difference between malignant and benign groups in terms of size (P = .015), distortion (P = .028), cystic component (P < .001), E-mean (P < .001), E-ratio (P < .001), and SMIvi (P = .006). For differentiation of invasiveness E-mean (P = .002), E-ratio (P = .002), and SMIvi (P = .030) were statistically significant. According to ROC analysis E-mean (cut-off point at 38 kPa) was the most sensitive (78%) and the most specific (95%) value among four numeric parameters (size, SMI, E-mean, and E-ratio) with AUC = 0.895, PPV = 97%, and NPV = 68% in detecting malignancy. In the evaluation of invasiveness, the most sensitive (71.4%) method was SMI (cut-off point at 3.4) and the most specific (72%) method was E-mean (cut-off point at 91.5 kPa).

CONCLUSION

Our study shows that adding SWE and SMI to the sonographic evaluation of MC would be an advantage for US-guided biopsy. Including suspicious areas according to SMI and SWE in the sampling area can help target the invasive part of the lesion and avoid underestimation of core biopsy.

Superb Microvascular Imaging at Evaluation of Nonvisible Buried De-epitelized Flap Vascularization in Breast Reconstruction

OBJECTIVE

Superb microvascular imaging is a Doppler technique that increases the visibility of small vessels and gives quantitative information about tissue blood supply by measuring the vascular index. In this study, it is aimed to evaluate the long-term and postradiotherapy changes in blood flow of buried de-epitelized flaps in breast reconstruction by using the quantitative values obtained through superb microvascular imaging.

MATERIALS AND METHODS

Retrospective review of the 14 patients who underwent nipple-sparing breastconserving surgery and immediately breast reconstruction with a de-epitelized extended latissimus dorsi flap was done. In order to demonstrate the effect of radiotherapy on flaps microvascular circulation, patients were evaluated using superb microvascular imaging postoperative first week, first month, and postradiotherapy first week and sixth month. The normal distribution of the data was evaluated with the Shapiro-Wilk test. Paired samples t-test was used for comparisons.

RESULTS

According to the paired samples t-tests, postoperative first week mean vascular index was higher than postoperative first month and postradiotherapy first week (P < .05). Besides, postradiotherapy first week mean vascular index was higher than postoperative first month and also than postradiotherapy sixth month (P < .05).

CONCLUSION

Radiotherapy can affect the results of breast reconstruction by endothelial and fibrotic injury. In this study, the changes in the microvascular circulation of the latissimus dorsi flap were discussed and found to increase at postoperative and postradiotherapy early period related to inflammation and not decreased significantly at long-term follow-up after radiotherapy.

New microvascular ultrasound techniques: abdominal applications

Microvascular ultrasound (MVUS) is a new ultrasound technique that allows the detection of slow-velocity flow, providing the visualization of the blood flow in small vessels without the need of intravenous contrast agent administration. This technology has been integrated in the most recent ultrasound equipment and applied for the assessment of vascularization. Compared to conventional color Doppler and power Doppler imaging, MVUS provides higher capability to detect intralesional flow. A growing number of studies explored the potential applications in hepatobiliary, genitourinary, and vascular pathologies. Different flow patterns can be observed in hepatic and renal focal lesions providing information on tumor vascularity and improving the differential diagnosis. This article aims to provide a detailed review on the current evidences and applications of MVUS in abdominal imaging.

Magnetically assisted soft milli-tools for occluded lumen morphology detection

Methodologies based on intravascular imaging have revolutionized the diagnosis and treatment of endovascular diseases. However, current methods are limited in detecting, i.e., visualizing and crossing, complicated occluded vessels. Therefore, we propose a miniature soft tool comprising a magnet-assisted active deformation segment (ADS) and a fluid drag-driven segment (FDS) to visualize and cross the occlusions with various morphologies. First, via soft-bodied deformation and interaction, the ADS could visualize the structure details of partial occlusions with features as small as 0.5 millimeters. Then, by leveraging the fluidic drag from the pulsatile flow, the FDS could automatically detect an entry point selectively from severe occlusions with complicated microchannels whose diameters are down to 0.2 millimeters. The functions have been validated in both biologically relevant phantoms and organs ex vivo. This soft tool could help enhance the efficacy of minimally invasive medicine for the diagnosis and treatment of occlusions in various circulatory systems.

Superb Microvascular Imaging for the Differentiation of Benign and Malignant Breast Lesions: A System Review and Meta-Analysis

OBJECTIVE

To evaluate the diagnostic performance of SMI in the diagnosis of benign and malignant breast lesions.

METHODS

A systematic search of PubMed, EMBASE, Cochrane, OVID, SCI, and SCOPUS was performed to find relevant studies which applied SMI to differentiate benign and malignant breast lesions. All the studies were published before October 10, 2022. Only studies published in English were collected. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was applied to assess the quality of the included studies. Summary receiver operating characteristic (SROC) modeling was also performed to the diagnostic performance of SMI in the diagnosis of benign and malignant breast lesions. Subgroup analyses and meta-regression were performed to find out the heterogeneity.

RESULTS

Twenty studies which include a total of 2873 lesions (1748 benign and 1125 malignant) in 2740 patients were evaluated in this meta-analysis. The summary sensitivity and specificity were 0.82 (95% confidence interval [CI]: 0.76-0.86), 0.70 (95% CI: 0.64-0.76) for SMI vascular degree, 0.77 (95% CI: 0.67-0.84), 0.79 (95% CI: 0.75-0.83) for SMI vascular distribution, 0.78 (95% CI: 0.70-0.84), 0.75 (95% CI: 0.69-0.80) for SMI vascular morphology, 0.81 (95% CI: 0.72-0.87), 0.80 (95% CI: 0.75-0.85) SMI penetration vessel. For SMI overall vascular features, the summary sensitivity and summary specificity were 0.74 (95% CI: 0.61-0.84) and 0.80 (95% CI: 0.76-0.84). The result of subgroup analysis and meta-analysis showed malignant rate and country might be the cause of heterogeneity of diagnostic accuracy of vascular grade and morphology.

CONCLUSION

SMI vascular features have high sensitivity and specificity in the differentiation of benign and malignant lesions. Future international multicenter studies in various regions with large sample size are required to confirm these findings.

Diagnostic use of superb microvascular imaging in evaluating septic arthritis of the manubriosternal joint: A case report

BACKGROUND

Septic arthritis of the manubriosternal joint is a diagnostic challenge due to its rarity and anatomical characteristic. Conventional ultrasound, plain radiographs, and computed tomography are not able to confirm or even suspect arthritis early. Superb microvascular imaging is a new advanced Doppler technique in evaluating low-flow microvascular patterns. The higher sensitivity for increased peri-synovial vascularity helps to suspect septic arthritis and forms a methodical approach to using magnetic resonance imaging (MRI).

CASE SUMMARY

A 34-year-old immunocompetent woman presented with a fever and a dull ache in the chest radiating to the right arm. Traumatic injury and the most common respiratory and cardiac disorders were ruled out. Blood cultures came back positive for Staphylococcus aureus, and sepsis was confirmed. A small lump was noted on the chest during the first week of hospitalization. Superb microvascular imaging was performed and septic arthritis of the manubriosternal joint was detected. MRI confirmed the diagnosis and showed septic arthritis of the manubriosternal joint with several localized abscesses behind the sternum. The patient was treated for three weeks with intravenous antibiotics and the outcome was favorable: Inflammatory markers became normal, and the lump disappeared. Three months later, the patient was examined for a new episode of mild pain in the sternum and was diagnosed with persistent perichondritis by ultrasound in comparison with MRI.

CONCLUSION

Superb microvascular imaging is a useful tool for the early diagnosis of septic arthritis of the manubriosternal joint and following-up.

Advanced Neuromonitoring Modalities on the Horizon: Detection and Management of Acute Brain Injury in Children

Timely detection and monitoring of acute brain injury in children is essential to mitigate causes of injury and prevent secondary insults. Increasing survival in critically ill children has emphasized the importance of neuroprotective management strategies for long-term quality of life. In emergent and critical care settings, traditional neuroimaging modalities, such as computed tomography and magnetic resonance imaging (MRI), remain frontline diagnostic techniques to detect acute brain injury. Although detection of structural and anatomical abnormalities remains crucial, advanced MRI sequences assessing functional alterations in cerebral physiology provide unique diagnostic utility. Head ultrasound has emerged as a portable neuroimaging modality for point-of-care diagnosis via assessments of anatomical and perfusion abnormalities. Application of electroencephalography and near-infrared spectroscopy provides the opportunity for real-time detection and goal-directed management of neurological abnormalities at the bedside. In this review, we describe recent technological advancements in these neurodiagnostic modalities and elaborate on their current and potential utility in the detection and management of acute brain injury.

Association between vascular ultrasound features and DNA sequencing in breast cancer: a preliminary study

There are few radiogenomic studies to correlate ultrasound features of breast cancer with genomic changes. We investigated whether vascular ultrasound phenotypes are associated with breast cancer gene profiles for predicting angiogenesis and prognosis. We prospectively correlated quantitative and qualitative features of microvascular ultrasound (vascular index, vessel morphology, distribution, and penetrating vessel) and contrast-enhanced ultrasound (time-intensity curve parameters and enhancement pattern) with genomic characteristics in 31 breast cancers. DNA obtained from breast tumors and normal tissues were analyzed using targeted next-generation sequencing of 105 genes. The single-variant association test was used to identify correlations between vascular ultrasound features and genomic profiles. Chi-square analysis was used to detect single nucleotide polymorphisms (SNPs) associated with ultrasound features by estimating p values and odds ratios (ORs). Eight ultrasound features were significantly associated with 9 SNPs (p < 0.05). Among them, four ultrasound features were positively associated with 5 SNPs: high vascular index with rs1136201 in ERBB2 (p = 0.04, OR = 7.75); large area under the curve on contrast-enhanced ultrasound with rs35597368 in PDGFRA (p = 0.04, OR = 4.07); high peak intensity with rs35597368 in PDGFRA (p = 0.049, OR = 4.05) and rs2305948 in KDR (p = 0.04, OR = 5.10); and long mean transit time with rs2275237 in ARNT (p = 0.02, OR = 10.25) and rs755793 in FGFR2 (p = 0.02, OR = 10.25). We identified 198 non-silent SNPs in 71 various cancer-related genes. Vascular ultrasound features can reflect genomic changes associated with angiogenesis and prognosis in breast cancer.

Utility of ultrasound Angio-PLUS imaging for detecting blood flow in breast masses and comparison with color Doppler for differentiating benign from malignant masses

BACKGROUND

Tumor neo-angiogenesis plays an important role in the development and growth of breast cancers, but its detection by imaging is challenging. A novel microvascular imaging (MVI) technique, Angio-PLUS, promises to overcome the limitations of color Doppler (CD) in detecting low-velocity flow and small diameter vessels.

PURPOSE

To determine the utility of the Angio-PLUS technique for detecting blood flow in breast masses and compare it with CD for differentiating benign from malignant masses.

MATERIAL AND METHODS

A total of 79 consecutive women with breast masses were prospectively evaluated using CD and Angio-PLUS techniques, and biopsied as per BI-RADS recommendations. Vascular imaging scores were assigned using three factors (number, morphology, and distribution) and vascular patterns were divided into five groups: internal-dot-spot, external-dot-spot, marginal, radial, and mesh patterns. The independent samples t-test, Mann-Whitney U test, Wilcoxon signed rank test, or Fisher's exact test were used to compare the two groups as appropriate. Area under the receiver operating characteristic (ROC) curve (AUC) methods were used to assess diagnostic accuracy.

RESULTS

Vascular scores were significantly higher on Angio-PLUS than CD (median=11, [IQR=9-13] vs. 5 [IQR=3-9], P < 0.001). Malignant masses had higher vascular scores than benign masses on Angio-PLUS (P < 0.001). AUC was 80% (95% CI=70.3-89.7; P < 0.001) for Angio-PLUS and 51.9% for CD. Using Angio-PLUS at a cutoff value of ≥9.5, sensitivity was 80% and specificity was 66.7%. Vascular pattern descriptors on AP showed good correlation with histopathological results (PPV mesh 95.5%, radial 96.9%, and NPV of marginal orientation 90.5%).

CONCLUSION

Angio-PLUS was more sensitive in detecting vascularity and superior in differentiating benign from malignant masses compared to CD. Vascular pattern descriptors on Angio-PLUS were useful.

Recent Advances in Ultrasound Breast Imaging: From Industry to Clinical Practice

Breast ultrasound (US) has undergone dramatic technological improvement through recent decades, moving from a low spatial resolution, grayscale-limited technique to a highly performing, multiparametric modality. In this review, we first focus on the spectrum of technical tools that have become commercially available, including new microvasculature imaging modalities, high-frequency transducers, extended field-of-view scanning, elastography, contrast-enhanced US, MicroPure, 3D US, automated US, S-Detect, nomograms, images fusion, and virtual navigation. In the subsequent section, we discuss the broadened current application of US in breast clinical scenarios, distinguishing among primary US, complementary US, and second-look US. Finally, we mention the still ongoing limitations and the challenging aspects of breast US.

Fibroepithelial lesions of the breast: improving the accuracy of imaging diagnosis and reducing unnecessary biopsy

Fibroadenomas and phyllodes tumours are fibroepithelial lesions of the breast. Fibroadenomas are common benign breast masses encountered both symptomatically and incidentally. Phyllodes tumours are uncommon and usually present symptomatically. Management of fibroadenomas focuses on reducing biopsies without missing cancers while radiological management of phyllodes tumours should focus on predicting the need for surgical excision with or without margins.

Modern Imaging Techniques in the Study and Disease Diagnosis of the Mammary Glands of Animals

The study of the structure and function of the animals' mammary glands is of key importance, as it reveals pathological processes at their onset, thus contributing to their immediate treatment. The most frequently studied mammary diseases are mastitis in cows and ewes and mammary tumours in dogs and cats. Various imaging techniques such as computed tomography, positron emission tomography, magnetic resonance imaging, and ultrasonographic techniques (Doppler, contrast-enchanced, three-dimensional and elastography) are available and can be applied in research or clinical practice in order to evaluate possible abnormalities in mammary glands, as well as to assist in the differential diagnosis. In this review, the above imaging technologies are described, and the perspectives of each method are highlighted. It is inferred that ultrasonographic modalities are the most frequently used imaging techniques for the diagnosis of clinical or subclinical mastitis and treatment guidance on a farm. In companion animals, a combination of imaging techniques should be applied for a more accurate diagnosis of mammary tumours. In any case, the confirmation of the diagnosis is provided by laboratory techniques.

Quantitative analysis of superb microvascular imaging for monitoring tumor response to chemoradiotherapy in locally advanced cervical cancer

Objectives

As an ultrasound (US) image processing method, superb microvascular imaging (SMI) extracts and visualizes flow signals from vessels through advanced clutter suppression technology. We investigated the feasibility of SMI in monitoring treatment response in patients with locally advanced cervical cancer (LACC) undergoing chemoradiotherapy (CRT).

Methods

Forty-nine patients underwent CRT and received SMI examination at 3 time points: before therapy (baseline), 3 weeks during, and 1 month after CRT. The maximum tumor diameter (Dmax), vascularity index (VI), and their percentage changes (ΔDmax and ΔVI) were calculated. ΔDmax was compared with MRI results as the reference standard.

Results

Based on the MRI findings, 44 were classified as complete response (CR) group and 5 as partial response (PR) group. The Dmax and ΔDmax showed decrease in CR and PR groups at 3 weeks during CRT (P< 0.05), but no significant difference between the two groups (P > 0.05). Compared to the baseline, significant decrease in VI and ΔVI were observed at during and after treatment in the two groups (P< 0.05). Moreover, there were significant differences in VI and ΔVI at 3 weeks during CRT between the CR and PR groups (P< 0.05). ΔVI at 3 weeks during CRT showed a better predictive performance for responder prognosis than VI (AUC = 0.964, AUC = 0.950, respectively, P = 0.001), with a cut-off value of 41.6% yielding 100% sensitivity and 86.4% specificity.

Conclusions

The SMI parameters (VI and ΔVI) have potential for monitoring treatment response in LACC.

Evaluation of tenosynovitis in patients with seronegative rheumatoid arthritis using microvascular flow imaging

OBJECTIVES

The purpose of this research was investigate the potential use of MVFI (microvascular flow imaging) in the assessment of tenosynovitis in cases with SNRA (seronegative rheumatoid arthritis).

METHODS

Fifty-six SNRA cases and 20 HCs (healthy controls) were enrolled, and all of them were subjected to ultrasonographic examination of the compartments I-VI of the extensor tendons of the wrist, flexor carpi radialis and flexor tendons of the five digits. Each tendon synovial sheath was semi-quantitatively scored by GS (gray-scale) ultrasound, PD (power Doppler) ultrasound, and MVFI. The PD and MVFI scores for each tendon synovial sheath were added up for each patient to get the total scores. GS scores, PD scores, and MVFI scores of tendon synovial sheaths were compared between the two groups. The correlations of total PD scores and total MVFI scores with DAS28 (disease activity scores in 28 joints), ESR (erythrocyte sedimentation rate), and CRP (C-reactive protein) were analyzed.

RESULTS

(1) In the HC group (480 tendons), GS revealed abnormalities in 29 (6.04%) tendon synovial sheaths. The GS score was 1.03 ± 0.18 with the predominance of GS grade 1 (96.55%). In the SNRA group (1,344 tendons), GS detected abnormalities in 418 tendon synovial sheaths (31.10%). The GS score was 1.97 ± 0.53 with the predominance of GS grade 2 (71.77%). There were significant differences in the GS examination rate and grade for tenosynovitis between the two groups (P < 0.05). (2) In the SNRA group, involvement of the extensor carpi ulnaris in the 6^th dorsal compartment was the most common among all extensor tendons; the flexor tendon of the third digit was the most commonly affected among all flexor tendons. (3) In the HC group, the MVFI and PD scores were 0 for tendon synovial sheaths upon GS examination. In the SNRA group, the blood flow display rate of abnormal tendon synovial sheaths indicated by GS was 83.49% and 64.59% upon MVFI and PD, respectively. The results of the two imaging techniques were significantly different (P < 0.05). The blood flow grade of abnormal tendon synovial sheaths indicated by GS was significantly different between MVFI and PD (P < 0.05), which was higher upon MVFI than PD. (4) The total MVFI score and the total PD score in the SNRA group were correlated positively with CRP, ESR and DAS28 (P < 0.05).

CONCLUSION

MVFI is a more sensitive way in detection of blood flow in the tendon synovial sheaths of SNRA cases, which may be used in clinic to evaluate disease activity and tenosynovitis in SNRA cases.

Diagnostic Value of Superb Microvascular Imaging in Differentiating Benign and Malignant Breast Tumors: A Systematic Review and Meta-Analysis

PURPOSE

We performed a systematic review and meta-analysis of studies that investigated the diagnostic performance of Superb Microvascular Imaging (SMI) in differentiating between benign and malignant breast tumors.

METHODS

Studies published between January 2010 and March 2022 were retrieved by online literature search conducted in PubMed, Embase, Cochrane Library, Web of Science, China Biology Medicine Disc, China National Knowledge Infrastructure, Wanfang, and Vip databases. Pooled sensitivity, specificity, and diagnostic odd ratios were calculated using Stata software 15.0. Heterogeneity among the included studies was assessed using I2 statistic and Q test. Meta-regression and subgroup analyses were conducted to investigate potential sources of heterogeneity. Influence analysis was conducted to determine the robustness of the pooled conclusions. Deeks' funnel plot asymmetry test was performed to assess publication bias. A summary receiver operating characteristic curve (SROC) was constructed.

RESULTS

Twenty-three studies involving 2749 breast lesions were included in our meta-analysis. The pooled sensitivity and specificity were 0.80 (95% confidence interval [CI], 0.77-0.84, inconsistency index [I2] = 28.32%) and 0.84 (95% CI, 0.79-0.88, I2 = 89.36%), respectively. The pooled diagnostic odds ratio was 19.95 (95% CI, 14.84-26.82). The area under the SROC (AUC) was 0.85 (95% CI, 0.81-0.87).

CONCLUSION

SMI has a relatively high sensitivity, specificity, and accuracy for differentiating between benign and malignant breast lesions. It represents a promising supplementary technique for the diagnosis of breast neoplasms.

Utility of Superb Microvascular Imaging in the Assessment of Foot Perfusion in Patients with Critical Limb Ischemia

(1) Background: Although the ankle-brachial index (ABI) and skin perfusion pressure (SPP) are commonly used to evaluate the peripheral circulation in critical limb ischemia (CLI), they often cannot be performed on sore areas. We investigated the utility of superb microvascular imaging (SMI) for assessing foot perfusion in CLI patients. (2) Methods: We measured the SMI-based vascular index (SMI-VI) at six sites in the foot before and after endovascular treatment (EVT) in 50 patients with CLI who underwent EVT of the superficial femoral artery and compared the results with SPP values and the ABI. (3) Results: SMI visualized foot perfusion in all subjects in accordance with the angiosome, including the toe areas, while the ABI was unmeasurable in three patients on hemodialysis and SPP failed in four patients. SMI-VI values were significantly lower in the CLI group than in controls, and the plantar SMI-VI had the highest diagnostic performance for CLI (sensitivity 88.6%, specificity 95.6%). After EVT, the increase in the SMI-VI was positively correlated with the increase in SPP but not that in the ABI, implying that the SMI-VI reflects foot microcirculation. (4) Conclusions: SMI enables the visualization and quantification of foot microcirculation based on the angiosome. SMI has high utility as a tool for assessing foot perfusion in CLI.

Prospective analysis of breast masses using the combined score for quantitative ultrasonography parameters

To investigate the diagnostic value of combined SWE, SMI, and B-mode US scores for distinguishing between benign and malignant masses. A total of 450 breast masses that underwent US-guided core needle biopsies were prospectively enrolled. The breast masses were assessed based on the BI-RADS and quantitative SWE and SMI parameters. The SWEmax, SWEratio, and SMI_VI cutoff value were determined using Youden’s index by comparison to the pathological results. The BI-RADS categories were scored on a scale from 1 to 5, and SWEmax, SWEratio, and SMI_VI were dichotomized based on each cutoff values (0 or 1). The combined scores (1 to 8) were calculated as the sum of the BI-RADS score and the quantitative scores and compared to the pathologic results using AUROC analysis. The cutoff values were 52.25 kPa for SWEmax, 5.03 for SWEratio, and 2.15% for SMI_VI. In AUROC, the combined scores showed significantly better diagnostic performance compared to BI-RADS alone (p < 0.001). The combined score showed significantly increased than BI-RADS alone in specificity (p < 0.001) and accuracy (p < 0.001), but a sensitivity decreased without significance (p = 0.082). When a combined score cutoff value of 4 was used, the false negative rate was 2.7%. Using the combined score, 76.4% of the C4a lesions were considered benign also pathologically diagnosed as benign. The combined scores showed improved diagnostic performance in differentiating between benign and malignant breast masses, which could be helpful for determining a breast biopsy eligibility.

Power Doppler artifacts in evaluating inflammatory arthritis of small joints: comparison with a superb microvascular imaging technique

Conventional Doppler techniques provide clinical information about tissue vascularisation, but they have limitations in detecting low-velocity blood flow. The innovative Doppler technique called superb microvascular imaging provides visualization of microvascular flow never seen before with the ultrasound. The new tool suppresses the noise caused by motion artifacts with an innovative filter system without removing the weak signal arising from small vessel flow, hence it achieves a greater sensitivity than power Doppler. Explanation of motion artifact genesis reveals SMI imaging principles and helps to distinguish false-positive results. Due to the higher SMI sensitivity to flow, there are nuances in the interpretation of other artifacts as well as motion. The paper presents commonly encountered artifacts of power Doppler compared with a novel microvascular imaging technique focused on a small joints inflammation. The main attention is intent on the practical recommendations for ultrasound machine settings and evaluation of comparable images.

An optoacoustic imaging feature set to characterise blood vessels surrounding benign and malignant breast lesions

Combining optoacoustic (OA) imaging with ultrasound (US) enables visualisation of functional blood vasculature in breast lesions by OA to be overlaid with the morphological information of US. Here, we develop a simple OA feature set to differentiate benign and malignant breast lesions. 94 female patients with benign, indeterminate or suspicious lesions were recruited and underwent OA-US. An OA-US imaging feature set was developed using images from the first 38 patients, which contained 14 malignant and 8 benign solid lesions. Two independent radiologists blindly scored the OA-US images of a further 56 patients, which included 31 malignant and 13 benign solid lesions, with a sensitivity of 96.8% and specificity of 84.6%. Our findings indicate that OA-US can reveal vascular patterns of breast lesions that indicate malignancy using a simple feature set based on single wavelength OA data, which is therefore amenable to application in low resource settings for breast cancer management.

Contrast-Enhanced Ultrasound Parameters and D-Dimer: New Prognostic Parameters for Diffuse Large B-Cell Lymphoma

Objective

To investigate the predictive role of contrast-enhanced ultrasonography (CEUS) plus D-dimer levels in the prognosis of patients with diffuse large B-cell lymphoma (DLBCL).

Methods

CEUS was applied to assess lymph nodes in 186 patients with confirmed DLBCL. The clinical data and laboratory indicators were collected from these patients, and a retrospective analysis was conducted on the relationship between the quantitative parameters of CEUS (TTP, PI, AUC, WOT), D-dimer levels, and clinical features of the DLBCL patients. The Cox regression model was used for univariate and multivariate analyses for the risk factors associated with the prognosis.

Results

There was an increase of D-dimer levels in advanced DLBCL patients, who were combined with a significant reduction in TTP and WOT and a significant increase in PI and AUC. D-dimer levels and quantitative parameters of CEUS were strongly correlated with the Ann Arbor, B symptoms, International Prognostic Index (IPI), LDH and CRP levels. The results of the Cox regression model indicated that D-dimer levels, TTP and PI, the quantitative parameters of CEUS, were important prognostic factors for DLBCL.

Conclusion

CEUS results and D-dimer levels can be used as independent prognostic factors for DLBCL.

The clinical application of ultrasonography with superb microvascular imaging-a review

Superb microvascular imaging (SMI) is among the latest doppler ultrasound methods. It uses an advanced clutter filter to eliminate artifacts caused by breathing, movement and retains the low-speed blood signals in microvessels. The great advantage of SMI is that it can intuitively detect very slow blood signals in microvessels, providing clinicians with more significant information about flow distribution in the target area. Therefore, it is speculated that SMI has important application value. The purpose of this article is to outline the application of SMI in different parts of the body.

Ultrasound imaging of preterm brain injury: fundamentals and updates

Neurosonography has become an essential tool for diagnosis and serial monitoring of preterm brain injury. Preterm infants are at significantly higher risk of hypoxic-ischemic injury, intraventricular hemorrhage, periventricular leukomalacia and post-hemorrhagic hydrocephalus. Neonatologists have become increasingly dependent on neurosonography to initiate medical and surgical interventions because it can be used at the bedside. While brain MRI is regarded as the gold standard for detecting preterm brain injury, neurosonography offers distinct advantages such as its cost-effectiveness, diagnostic utility and convenience. Neurosonographic signatures associated with poor long-term outcomes shape decisions regarding supportive care, medical or behavioral interventions, and family members' expectations. Within the last decade substantial progress has been made in neurosonography techniques, prompting an updated review of the topic. In addition to the up-to-date summary of neurosonography, this review discusses the potential roles of emerging neurosonography techniques that offer new functional insights into the brain, such as superb microvessel imaging, elastography, three-dimensional ventricular volume assessment, and contrast-enhanced US.

Comparison of superb microvascular imaging and shear wave elastography for assessing liver fibrosis in chronic hepatitis B

Purpose

The present study investigated the effectiveness and applicability of superb microvascular imaging (SMI) in determining the degree of liver fibrosis noninvasively in comparison with shear wave elastography (SWE).

Methods

Ninety-eight consecutive patients with chronic hepatitis B who underwent ultrasound (US)-guided needle biopsy were examined using US combined with SMI and SWE. The predictive performance of the two US techniques in staging liver fibrosis and inflammation was compared with reference to the histological findings obtained from liver biopsy. The intraobserver and interobserver reproducibility of SMI in vascularity scores were evaluated.

Results

SWE values and SMI vascular scores were statistically significantly different among fibrosis stages (χ²(3)=76.3, χ²(3)=81.5, P<0.001). The SWE and SMI models significantly predicted fibrosis stages separately, and SMI scores alone predicted fibrosis stages better than SWE values (50.1% for SWE, 63.5% for SMI, P<0.001). A model with both SMI scores and SWE values together explained 73.2% of variance in fibrosis stages. When other clinical and laboratory predictors were added to the model (81.5%, P<0.001), SWE values and SMI scores remained the main predictors of fibrosis stages. SWE and SMI were also applicable in predicting inflammatory grades, explaining 31% and 34% of variance, respectively, and 37.7% when used together (P<0.001).

Conclusion

Both SWE and SMI had good diagnostic performance in determining the degree of liver fibrosis in chronic hepatitis B patients. The efficacy of SMI was better than that of SWE. SMI can improve diagnostic performance for staging liver fibrosis and shows potential for estimating necroinflammation of the liver.

Comparison of superb microvascular imaging (SMI) quantified with ImageJ to quantified contrast-enhanced ultrasound (qCEUS) in liver metastases-a pilot study

BACKGROUND

The aim of the study was to compare methods for the assessment of vascularisation of liver metastases (LM) between superb microvascular imaging (SMI), contrast-enhanced ultrasound, and microvascular density (MVD).

METHODS

SMI results were quantified as the vascularisation quotient (VQ), based on a grey-scale analysis with ImageJ image software. Those results were compared to contrast-enhanced ultrasonography (CEUS) values, calculated with VueBox^®. MVD was measured with an anti-CD34 antibody.

RESULTS

This study included 13 patients with LM. The VQ showed a strong correlation with the quantified parameters of contrast-enhanced ultrasound. The parameters of quantified contrast-enhanced ultrasound compared with quantified SMI showed the following statistical correlations: peak enhancement (PE), in arbitrary unit (a.u.) (r=0.72104, P=0.0054), PE in Decibel (dB) (r=0.65918, P=0.00141), Wash-in- Area Under the Curve (WiAUC) in a.u. (r=0.63604, P=0.00194), Wash-in Perfusion-Index (WiPI) in a.u. (r=0.73337, P=0.0043), Wash-in Perfusion-Index (WiPI) in dB (r=0.65642, P=0.0194), Wash-in-Rate (WiR) in a.u. (r=0.7304, P=0.0036) and Wash-in-Rate (WiR) in dB (r=0.82897, P=0.0005).

CONCLUSIONS

Comparison of the two methods, SMI and contrast-enhanced ultrasound (CEUS), for quantitative assessment of vascularisation of LM showed good correlation. The contrast-independent Doppler technique SMI can qualitatively assess the vascularisation of LM.

A preliminary animal study on the prediction of nerve block success using ultrasonographic parameters

This study aimed to evaluate the diagnostic value of ultrasonographic parameters as an indicator for predicting regional nerve block success. Ultrasound-guided sciatic nerve block was performed in seven dogs using either 2% mepivacaine (nerve-block group) or saline (sham-block group). The cross-sectional area (CSA), nerve blood flow (NBF), and shear wave velocity (SWV) of the sciatic nerve (SWVN), SWV of the biceps femoris muscle (SWVM), and their ratio (SWVNMR) were measured at 0, 30, 60, and 90 min after the nerve block as well as the change rate of each parameter from the baseline. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic value of each parameter in the prediction of nerve block success. No significant changes were observed in the CSA or NBF in association with the nerve block. The SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at 90 min and at 30, 60, and 90 min, respectively (p < 0.05). The change rates of SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at all time points (p < 0.05). The ROC curve analysis showed that SWVN had a moderate diagnostic accuracy (area under the curve [AUC], 0.779), whereas SWVNMR and change rates of SWVN and SWVNMR had a high diagnostic accuracy (AUC, 0.947, 0.998, and 1.000, respectively). Ultrasonographic evaluation of the SWVN and SWVNMR could be used as indicators for predicting nerve block success.

Quantitative analysis of vascularity for thyroid nodules on ultrasound using superb microvascular imaging: Can nodular vascularity differentiate between malignant and benign thyroid nodules?

This study aimed to investigate the utility of adding superb microvascular imaging (SMI) to B-mode ultrasound (US) for distinguishing between benign and malignant thyroid nodules and evaluate the usefulness of SMI quantification of nodular vascularity for diagnosing thyroid cancer.The malignancy likelihood was scored for 3 datasets before versus after additional color Doppler imaging or SMI using 4-scale visual analysis (i.e., B-mode US alone, B-mode US + color Doppler image, and B-mode US + SMI). Further, the SMI pixel count was measured in the region of interest, including the whole nodule, on the longitudinal view. It was compared between benign and malignant nodules and analyzed according to the US patterns of thyroid nodules based on the Korean thyroid imaging reporting and data system. We calculated the area under the receiver operating characteristic curve values, sensitivities, and specificities.There was no significant difference in the area under the receiver operating characteristic curve values among B-mode, B-mode + color Doppler, and B-mode + SMI. However, the SMI pixel count was significantly higher in malignant thyroid nodules than in benign ones. The optimal cut-off value for the SMI pixel count for predicting malignant thyroid nodules obtained using a receiver operating characteristic curve was 17 (40.54% in sensitivity, 91.3% in specificity). Analysis based on the US pattern of thyroid nodules revealed significant differences in the nodules with low-to-intermediate suspicious US features between malignant and benign nodules.Quantification analysis of vascularity using SMI can differentiate malignant thyroid nodules from benign ones.