Superb Microvascular Imaging Research Articles

Translating new breast ultrasound techniques into clinical practice: evaluating their intended uses and describing other unexpected uses for them.

Several new ultrasound tools have been developed to further evaluate breast lesions detected on B-mode ultrasound. Strain elastography (SRE) was developed to assess the likelihood of malignancy of lesions based on their stiffness. This has been incorporated into the latest edition of the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) lexicon and atlas. However, no agreed cut-off stiffness values have been established to distinguish benign from malignant lesions making the translation into routine clinical practice difficult. Superb microvascular imaging (SMI) was developed to better evaluate the vascularity within sonographic lesions and assess their likelihood of malignancy. However, there is also no agreed cut-off value for vascular index (VI) to distinguish between benign and malignant lesions. MicroPure was developed to better visualize and evaluate calcifications seen on ultrasound. Its effective use in breast screening and evaluating the calcifications detected for likelihood of malignancy have not been established. This article describes the original intended uses of these applications and reviews the studies evaluating them, showing the varying success of the translation of these tools into routine clinical practice. Also described are some other uses of these tools for which they were not originally intended. This illustrates the importance of being perceptive to alternative uses of imaging tools in their translation from bench to bedside.

The value of conventional ultrasound combined with superb microvascular imaging and color Doppler flow imaging in the diagnosis of thyroid malignant nodules: a systematic review and meta-analysis.

To evaluate and compare the value of conventional ultrasound-based superb microvascular imaging (SMI) and color Doppler flow imaging (CDFI) in the diagnosis of malignant thyroid nodule by meta-analysis. The literature included in the Cochrane Library, PubMed, and Embase were searched by using " superb microvascular imaging (SMI), color Doppler flow imaging (CDFI), ultrasound, thyroid nodules" as the keywords from inception through February 1, 2023. According to the inclusion and exclusion criteria, the clinical studies using SMI and CDFI to diagnose thyroid nodules were selected, and histopathology of thyroid nodules was used as reference standard. The diagnostic accuracy research quality assessment tool (QUADAS-2) was used to evaluate the quality of included literature, and the Review Manager 5.4 was used to make the quality evaluation chart. The heterogeneity test was performed on the literature that met the requirements, the combined sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were pooled, and a comprehensive ROC curve analysis was performed. Meta-DiSc version 1.4, StataSE 12, and Review Manager 5.4 software were used. Finally, 13 studies were included in this meta-analysis. A total of 815 thyroid malignant nodules were assessed. All thyroid nodules were histologically confirmed after SMI or CDFI. The combined sensitivity, specificity, PLR, NLR, DOR, and area under the SROC curve of SMI for the diagnosis of malignant thyroid nodules were 0.80(95%CI: 0.77-0.83), 0.79(95%CI: 0.77-0.82), 4.37(95%CI: 3.0-6.36), 0.23(95%CI: 0.15-0.35), 22.29(95%CI: 12.18-40.78), and 0.8944, respectively; the corresponding values of CDFI were 0.62(95%CI: 0.57-0.67), 0.81(95%CI: 0.78-0.85), 3.33(95%CI: 2.18-5.07), 0.41(95%CI: 0.27-0.64), 8.93(95%CI: 3.96-20.16), and 0.8498. Deek funnel pattern showed no significant publication bias. The diagnostic efficiency of SMI for malignant thyroid nodules is better than CDFI, and SMI technology can provide significantly more information on vascularity, make up for the deficiency of CDFI, and has better clinical application value. https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023402064.

Diagnostic Performance of Superb Microvascular Imaging in Differentiating Benign and Malignant Axillary Lymph Nodes.

The aim was to evaluate the effectiveness of superb microvascular imaging (SMI) in axillary lymph nodes (LNs).Benign and malignant LNs diagnosed via histopathological examination constituted the study subgroups. In addition to grayscale findings for morphological evaluation, vascular patterns and appearance of internal vessels were analyzed by both power Doppler ultrasound (PDUS) and SMI. The number of vascular branches was counted, and a vascularity index (VI) was calculated by SMI.Fifty-two LNs with suspicious findings in terms of metastasis (33 malignant and 19 benign) were evaluated. Diagnostic accuracy according to vascular patterns was 82% for PDUS and 92% for SMI. In the presence of asymmetric cortical thickening, there was a significant difference between benign and malignant LNs in the number of vascular branches of both thin and thick cortical sides ( P < 0.01). Mean VI was significantly higher in the malignant group ( P < 0.05). In differentiating malignancy, when a cutoff VI value was set to 9%, sensitivity was 69.7%, and specificity was 63.2%.Evaluating the vascularity of axillary LNs by SMI is a useful tool in determining the potential of axillary metastasis, especially in the absence of typical sonographic findings. Superb microvascular imaging can beneficially be used to select the most suspicious LN and suspicious area of the LN to sample.

Novel application to evaluate endometrial blood flow using transvaginal superb microvascular imaging: A preliminary study describing physiological changes from ovulation to mid-luteal phase.

We aimed to describe physiological changes in endometrial blood flow (minute arterioles running through the endometrium) from ovulation to the mid-luteal phase using superb microvascular imaging. The study involved 17 women (median age, 32.5 years; first to third interquartile range, 29.8-40.0 years) with regular menstrual cycles who were managed in our institute from 2020 to 2021. The uterus was delineated at the sagittal section using transvaginal ultrasonography incorporated with superb microvascular imaging. For each participant, a total of 28 cycles were observed; 17 cycles observed within one day of ovulation and the implantation period, 5-7 days (D5-7) after ovulation in the same cycle, and nine cycles in which only ovulation was observed, and two cycles in which only D5-7 was observed. Therefore, 26 and 19 images at ovulation and D5-7, respectively, were acquired. Endometrial blood flow was evaluated by depth of the vascular signal in the endometrium and categorized as follows: signals only in the basal layer of the endometrium (grade 1), reaching up to half the endometrium (grade 2), and covering the whole endometrium (grade 3). Changes in the grade of endometrial blood flow from ovulation to D5-7 after ovulation, and the relationship between the grade of endometrial blood flow and the endometrial thickness on ovulation and D5-7 after ovulation, were analyzed. Statistical significance was set at p < 0.05. The endometrial blood flow from ovulation to D5-7 after ovulation during the same menstrual period showed a downgrade in 14 of 17 cycles (82.3%) and no change in the remaining three cycles (17.6%), indicating a decrease in the endometrial blood flow from ovulation to D5-7 after ovulation (p = 0.001). There were differences between the grade of endometrial blood flow and median endometrial thickness on ovulation (grade 1: 5.9 mm, grade 2: 9.1 mm, and grade 3: 11.2 mm); however, no differences in the endometrial thickness were found between the grades on D5-7 after ovulation. In the normal menstrual cycle, endometrial blood flow decreased from ovulation to the mid-luteal phase, and the endometrial thickness in the ovulatory phase was related to the endometrial perfusion.

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

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). 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. 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). 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.

Qualitative and quantitative superb vascular imaging in the diagnosis of thyroid nodules ≤10 mm based on the Chinese Thyroid Imaging Reporting and Data System 4 (C-TIRADS 4).

To compare qualitative and quantitative superb microvascular imaging (SMI) and determine the value of SMI in the diagnosis of thyroid nodules (TNs) ≤10 mm based on the Chinese Thyroid Imaging Reporting and Data System 4 (C-TIRADS 4). From October 2020 to June 2022, 106 patients with 109 C-TIRADS 4 (C-TR4) TNs (81 malignant, 28 benign) at the Peking Union Medical College Hospital were included. Qualitative SMI reflected the vascular pattern of the TNs and quantitative SMI was recorded by the vascular index (VI) of the nodules. The VI was significantly higher in malignant nodules versus benign nodules both in the longitudinal (19.9±11.4 vs. 13.8±10.6, P=0.01) and transverse (20.2±12.1 vs. 11.3±8.7, P=0.001) sections. The area under the curve (AUC) of qualitative and quantitative SMI did not show a statistical difference in the longitudinal {0.657 [95% confidence interval (CI): 0.560-0.745] vs. 0.646 (95% CI: 0.549-0.735), P=0.79} and transverse [0.696 (95% CI: 0.600-0.780) vs. 0.725 (95% CI: 0.632-0.806), P=0.51] sections. Next, we combined qualitative and quantitative SMI to upgrade and downgrade the C-TIRADS classification. If a C-TR4B nodule had VIsum >12.2 or intra-nodular vascularity, the original C-TIRADS was upgraded to C-TR4C. If a C-TR4C or C-TR4B nodule manifested VIsum ≤12.2 and no intra-nodular vascularity, the original C-TIRADS was downgraded to C-TR4A. As a result, 18 C-TR4C nodules were downgraded to C-TR4A and 14 C-TR4B nodules were upgraded to C-TR4C. The new model of SMI + C-TIRADS showed high sensitivity (93.8%) and accuracy (79.8%). There is no statistical difference between qualitative and quantitative SMI in the diagnosis of C-TR4 TNs. The combination of qualitative and quantitative SMI may have the potential to manage diagnosis of C-TR4 nodules.

Comparison of conventional Doppler imaging techniques and superb microvascular imaging in determination of vascularization in undescended testes.

Our aim was to gain an idea about testicular injury by comparing the reduced volume, which is one of the indirect indicators of testicular damage in undescended testes, and by evaluating the reduced microvascular blood flow by superb microvascular imaging, and also to determine whether superb microvascular imaging modes could detect microvascular blood flow in more detail in the decreased volume of undescended testes. We compared testicular blood flow in undescended testes via conventional Doppler imaging, color superb microvascular imaging, and monochrome superb microvascular imaging techniques with contralateral normally located testis and normal control group. Each sample of testicular tissue was evaluated using a qualitative method. Spot color encoding and linear flow color encoding counts determined in testicular parenchyma were counted separately and expressed as numerical data. The localization of the examined testes in the grayscale was noted (proximal inguinal canal, medial inguinal canal, distal inguinal canal, and scrotal). The volume of undescended testes was calculated automatically via a formula for volume. Monochrome superb microvascular imaging is significantly superior in visualizing the vascularity of undescended testes compared with color Doppler, power Doppler and color superb microvascular imaging (p = 0.001). Also, undescended testes have a significantly lower blood flow compared with contralateral normal testes (p = 0.001). The volume of undescended testes was significantly lower than the contralateral normal testes. The volume, structure and blood flow are indirect signs of testicular damage in undescended testes. Monochrome superb microvascular imaging can detect vascularity in undescended testes better than the conventional Doppler imaging technique and color superb microvascular imaging. Based on our findings, we can report that monochrome superb microvascular imaging can be used to evaluate testicular injury and vascularity of undescended testes.

Application of decision tree algorithms to predict central lymph node metastasis in well-differentiated papillary thyroid carcinoma based on multimodal ultrasound parameters: a retrospective study.

Prophylactic central neck dissection (pCND) in patients with well-differentiated primary papillary thyroid carcinoma (PTC) has become controversial. Several attempts have been made to predict central compartment lymph node metastasis (CLNM) based on clinical and conventional ultrasonic parameters. This study aimed to develop a decision tree (DT) model for predicting the risk of CLNM in patients with PTC based on clinical and preoperative multimodal ultrasound (US) characteristics. A total of 148 PTC nodules confirmed by surgical pathology at Beijing Tiantan Hospital were retrospectively analyzed. All nodules underwent multimodal US examinations preoperatively from January 2020 to September 2021. Correlation analysis of CLNM with clinical characteristics as well as multimodal US parameters of PTC lesions based on gray-scale US, color Doppler flow imaging (CDFI), superb microvascular imaging (SMI), contrast-enhanced ultrasound (CEUS), and shear wave elastography (SWE) technology was carried out. Finally, the chi-squared automatic interaction detector (CHAID) with a 10-fold cross-validation was used to establish DTs for CLNM prediction. The area under the curve was calculated to compare the predictive performance. Univariate analysis indicated that CLNM was positively correlated with thyroglobulin level, maximum size, taller-than-wide, the number of microcalcifications greater than or equal to 5, contact capsule, abnormal cervical lymph node on conventional US, noncentripetal perfusion, delayed clearance, the average shear wave velocity (SWV mean), and the SWV ratio (P<0.05). The multimodal US DT based on taller-than-wide, contact capsule, abnormal cervical lymph node on conventional US, and centripetal enhancement as independent variables showed good discrimination: the sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve were 80.0%, 76.7%, 78.4%, and 0.837 [95% confidence interval (CI): 0.771-0.902]. There was a significant difference between the multimodal and conventional US DTs (P=0.009). Our results indicated that the DT based on the preoperative multimodal US characteristics of PTCs has a reasonable predictive ability for CLNM and can be conveniently used for clinical decision-making of individualized treatment in patients with well-differentiated PTC.

668 Intraoperative Ultrasound Elastography is a Promising Technology to Quantify Reduced Spinal Cord Tension During Posterior Vertebral Column Subtraction Osteotomy for Recurrent Tethered Cord Syndrome

INTRODUCTION: Tethered cord syndrome (TCS) has been traditionally treated with detethering surgery.1,2 Posterior vertebral column subtraction osteotomy (PVCSO) is a novel surgery that can treat TCS while avoiding complications of detethering surgery, such as retethering or cerebrospinal fluid leaks.2-6 The pathophysiology of PVCSO is not completely understood. However, the hypothesis is that shortening the vertebral column decreases the spinal cord (SC) tension thereby improving neurological function. Intraoperative ultrasound elastography (USE) is well suited to elucidate the changes that can occur in SC parenchyma secondary to PVCSO.7,8 Through different modalities, such as superb microvascular imaging (SMI) and elastography (USE), US can analyze changes in blood flow and tissue tension.9 METHODS: Three patients with recurrent TCS underwent PVCSO and intraoperative USE to analyze the tension of the SC at 3 timepoints: pre-, mid- and post-shortening. RESULTS: All three patients (two female, one male) had undergone multiple detethering surgeries. Prior to shortening, the median SC elasticity of all patients was 9.8 kPa (IQR 9.7-12.4 kPa). After complete compression of the rods, the SC elasticity decreased by 17.4% to 7.7 kPa (6.5-9.7 kPa). All patients had significant improvement in sensation and reduction in pain at their 2 month follow up appointment. CONCLUSIONS: Here we report the first use of USE to demonstrate decreased SC tension after PVCSO for TCS. All patients reported improved symptoms and USE demonstrated decreased SC tension after shortening. USE is a promising tool for evaluating tissue elasticity and blood flow in spinal pathologies, including TCS. This technology serves as an intraoperative confirmation that SC tension decreases after PVCSO. Patients and neurosurgeons both benefit from an intraoperative objective tool to demonstrate reduced SC tension.

Multiparametric ultrasound images of three different cases of schwannoma of the peripheral nervous system

This case image illustrates the importance of new sonographic applications such as superb microvascular imaging and shear wave elastography; as showed, they improve the diagnostic recognition of peripheral nerve lesion thanks to a better definition of vascularity and measure of stiffness.

The feasibility of early response evaluation using superb microvascular imaging one day after transcatheter arterial chemoembolization for hepatocellular carcinoma.

The purpose of this study was to determine the feasibility of early Superb microvascular imaging (SMI) for prediction of the effect of HCC treatment after transcatheter arterial chemoembolization (TACE). A total of 96 HCCs (70 patients) treated with TACE between September 2021 and May 2022 were included in this study. SMI, Color Doppler imaging (CDI), and Power Doppler imaging (PDI) were performed the day after TACE for evaluation of intratumoral vascularity of the lesion using an Aplio500 ultrasound scanner (Toshiba Medical Systems, Corporation, Tochigi, Japan). Grading of the vascular presence was performed using a five-point scale. A dynamic CT image taken after 29-42 days was used for comparison of sensitivity, specificity, and accuracy for detection of tumor vascularity between SMI, CDI, and PDI. Univariate and multivariate analysis were performed for assessment of factors affecting intratumoral vascularity. Fifty-eight lesions (60%) showed complete remission (CR) and 38 lesions (40%) showed partial response (PR) or no response at 29-42 days on Multi-detector Computed Tomography (MDCT) after TACE. SMI showed sensitivity of 86.84% for detection of intratumoral flow, which was significantly higher compared with that of CDI (10.53%, p< 0.001) and PDI (36.84%, p< 0.001). The results of multivariate analysis indicated that tumor size was a significant factor in detection of blood flow using the SMI technique. Early SMI may be utilized as an adjunctive diagnostic test for evaluation of treated lesions after TACE, particularly when the location of the tumor is in an area of the liver where a suitable sonic window can be identified.

Clinical study of carotid superb microvascular imaging in evaluating the activity of Takayasu's arteritis.

The goal of this study is to use superb microvascular imaging (SMI) to observe neovascularization in the carotid vessel wall to identify potential Takayasu's arteritis (TAK) inflammation markers. Bilateral carotid arteries from 96 patients with TAK were imaged by a Doppler ultrasound and SMI. The one-way analysis of variance (ANOVA) was used to document significant differences between the activity and inactivity stages of TAK and the factors closely related to its activity in the binary logistics regression equation. Clinical and laboratory data included age, gender, duration of disease, treatment history, NIH score, erythrocyte sedimentation rate (ESR), and high-sensitivity C-reactive protein. Imaging data included the arterial wall thickness, degree of lesion, SMI grade, and arterial aneurysm formation. There were 45 patients in the active TAK stage and 51 in the inactive stage. The one-way ANOVA showed significant differences in SMI (p = 0.001) and ESR (p = 0.022) between the active and inactive groups. The binary logistics regression analysis showed that SMI was an independent risk factor for TAK activity (B = -1.505, S.E = 0.340, Wald = 19.528, OR = 0.222 95%, CI = 0.114-0.433, p < 0.01). Using SMI G1 or G2 as the cutoff values for the diagnosis of active TAK, the positive predictive value, sensitivity, and specificity were 60 and 86%, 84% and 56%, and 54% and 92%, respectively. The SMI grade is a potential marker of disease activity in patients with TAK.

Intraoperative shear-wave elastography and superb microvascular imaging contribute to the glioma grading

BackgroundTo explore the diagnostic value and feasibility of shear wave elastography and superb microvascular imaging in the grading diagnosis of glioma intraoperatively. Materials and methodsForty-nine patients with glioma were included in this study. B-mode ultrasonography, Young's modulus in shear-wave elastography (SWE) and vascular architecture in superb microvascular imaging(SMI) of tumor tissue and peritumoral tissue were analyzed. Receiver operating characteristic(ROC) curve analysis was used to evaluate the diagnostic effect of SWE. Logistic regression model was used to calculate the prediction probability of HGG diagnosis. ResultsCompared with LGG, HGG was often characterized by peritumoral edema in B mode (P < 0.05). There was a significant difference in Young's modulus between HGG and LGG; the diagnostic threshold of HGG and LGG was 13.05 kPa, the sensitivity was 78.3%, and the specificity was 76.9%. The vascular architectures of the tumor tissue and peritumoral tissues of HGG and LGG were significantly different (P < 0.05). The vascular architectures of peritumoral tissue in HGG often characterized by distorted blood flow signals surrounding the tumor (14/26,53.8%); in the tumor tissue, HGG often presents as dilated and bent vessels(19/26,73.1%). The elasticity value of SWE and the tumor vascular architectures of SMI were correlated with the diagnosis of HGG. ConclusionIntraoperative ultrasound (ioUS), especially SWE, and SMI are beneficial for the differentiation of HGG and LGG and may help optimize clinical surgical procedures.

Ultrasound localization microscopy of the human kidney allograft on a clinical ultrasound scanner

Chronic kidney disease is a major medical problem, causing more than a million deaths each year worldwide. Peripheral kidney microvascular damage characterizes most chronic kidney diseases, yet noninvasive and quantitative diagnostic tools to measure this are lacking. Ultrasound Localization Microscopy (ULM) can assess tissue microvasculature with unprecedented resolution. Here, we optimized methods on 35 kidney transplants and studied the feasibility of ULM in seven human kidney allografts with a standard low frame rate ultrasound scanner to access microvascular damage. Interlobar, arcuate, cortical radial vessels, and part of the medullary organization were visible on ULM density maps. The medullary vasa recta can be seen but are not as clear as the cortical vessels. Acquisition parameters were derived from Contrast-Enhanced Ultrasound examinations by increasing the duration of the recorded clip at the same plane. ULM images were compared with Color Doppler, Advanced Dynamic Flow, and Superb Microvascular Imaging with a contrast agent. Despite some additional limitations due to movement and saturation artifacts, ULM identified vessels two to four times thinner compared with Doppler modes. The mean ULM smallest analyzable vessel cross section was 0.3 ± 0.2 mm in the seven patients. Additionally, ULM was able to provide quantitative information on blood velocities in the cortical area. Thus, this proof-of-concept study has shown ULM to be a promising imaging technique for qualitative and quantitative microvascular assessment. Imaging native kidneys in patients with kidney diseases will be needed to identify their ULM biomarkers.

Intraneural vascularity of the median, ulnar and common peroneal nerve: Microvascular ultrasound and pathophysiological implications.

Changes in the microvascular environment are considered crucial in the pathogenesis of compression neuropathies. Several studies have demonstrated elevated intraneural vascularity in severe neuropathy compared with healthy subjects, where intraneural vascularity is considered predominantly undetectable. The aim of this study was to assess and quantify intraneural vasculature by superb microvascular imaging (SMI) in healthy volunteers in the median, ulnar and common peroneal nerve. Intraneural vascularity was quantified in 26 healthy volunteers (312 segments overall) by SMI sonography using a 22-MHz linear transducer. Individual nerve segment vascularity was compared with the mean vascularity using one-way ANOVA and Kruskal-Wallis tests, respectively. Vendor-provided quantification and manual vessel count were compared by linear regression analysis. Intraneural vascularity was detectable in all nerve segments (100.0%). Vessel density was highest in the median nerve at the wrist (1.54 ± 0.44/mm2, P < 0.0001) and lowest in the sulcal ulnar nerve (0.90 ± 0.34/mm2, P < 0.0001). Vendor-provided automated quantification severely overestimated vascular content compared with manual quantification. Superb microvascular imaging can facilitate the visualisation of nerve vascularity and even detect local variations in vessel density. The pathophysiological implications for peripheral neuropathies, especially compression neuropathies, warrant further investigation, but the absence of visible intraneural vasculature as a negative finding in the diagnostic of compression neuropathies should be interpretedwith caution, as the intraneural vascularity may lie beyond the 18 MHz resolution power of a transducer.

Differential diagnosis of gallbladder neoplastic polyps and cholesterol polyps with radiomics of dual modal ultrasound: a pilot study

PurposeTo verify whether radiomics techniques based on dual-modality ultrasound consisting of B-mode and superb microvascular imaging (SMI) can improve the accuracy of the differentiation between gallbladder neoplastic polyps and cholesterol polyps.MethodsA total of 100 patients with 100 pathologically proven gallbladder polypoid lesions were enrolled in this retrospective study. Radiomics features on B-mode ultrasound and SMI of each lesion were extracted. Support vector machine was used to classify adenomas and cholesterol polyps of gallbladder for B-mode, SMI and dual-modality ultrasound, respectively, and the classification results were compared among the three groups.ResultsSix, eight and nine features were extracted for each lesion at B-mode ultrasound, SMI and dual-modality ultrasound, respectively. In dual-modality ultrasound model, the area under the receiver operating characteristic curve (AUC), classification accuracy, sensitivity, specificity, and Youden’s index were 0.850 ± 0.090, 0.828 ± 0.097, 0.892 ± 0.144, 0.803 ± 0.149 and 0.695 ± 0.157, respectively. The AUC and Youden’s index of the dual-modality model were higher than those of the B-mode model (p < 0.05). The AUC, accuracy, specificity and Youden’s index of the dual-modality model were higher than those of the SMI model (p < 0.05).ConclusionsRadiomics analysis of the dual-modality ultrasound composed of B-mode and SMI can improve the accuracy of classification between gallbladder neoplastic polyps and cholesterol polyps.

A comparison between the superb microvascular imaging technique and conventional Doppler ultrasound in evaluating chronic allograft damage in renal transplant recipients

The present study comparatively evaluates the performance of conventional Doppler ultrasound and superb microvascular imaging (SMI) in delineating the cortical microvessels of the transplanted kidney and compares the chronic allograft damage index (CADI) based on the examination of biopsy specimens with Doppler ultrasound and SMI findings. Sixty-eight renal transplant recipients underwent kidney biopsy with the pre-diagnosis of rejection before undergoing renal Doppler ultrasound examination between January 2020 and October 2020. The distance between the kidney capsule and the vascular structure closest to the kidney capsule was measured at the level of the lower pole in the transplanted kidney using color Doppler ultrasound (CDUS), power Doppler ultrasound (PDUS), and the SMI technique. The kidney size, resistive index at the level of the arcuate artery in the lower pole of the kidney, and renal artery flow rates were also measured. The mean distance between the kidney capsule and the vessel was 2.44 ± 2.0 mm on CDUS, 1.34 ± 1.2 mm on PDUS, 0.99 ± 1.8 mm using the color SMI (cSMI) technique, and 0.86 ± 1.8 mm using the monochrome SMI (mSMI) technique. The study found that the SMI technique was superior to CDUS and PDUS in delineating the cortical microvasculature of the kidney. Both Doppler ultrasound examinations and the SMI technique proved effective in predicting the CADI (P = 0.006 for CDUS, P = 0.002 for PDUS, P = 0.018 for cSMI, and P = 0.027 for mSMI). Among conventional Doppler ultrasound examinations and the SMI technique, PDUS had the highest sensitivity, and cSMI had the highest specificity in differentiating high and low CADI values. Both the cSMI and mSMI techniques had similar sensitivity values, whereas only cSMI exhibited high specificity. CDUS had the lowest specificity value (P = 0.003 for CDUS, P = 0.002 for PDUS, P = 0.005 for cSMI, and P = 0.004 for mSMI). The present study is the first in the literature to demonstrate the utility of the distance between the kidney capsule and the vessels in predicting the CADI score and to compare the Doppler ultrasound examinations and SMI technique in doing so.

Multimodal ultrasound-based carotid plaque risk biomarkers predict poor functional outcome in patients with ischemic stroke or TIA

BackgroundCarotid vulnerable plaque is an important risk factor for stroke occurrence and recurrence. However, the relationship between risk parameters related to carotid vulnerable plaque (plaque size, echogenicity, intraplaque neovascularization, and plaque stiffness) and neurological outcome after ischemic stroke or TIA is unclear. This study investigates the value of multimodal ultrasound-based carotid plaque risk biomarkers to predict poor short-term functional outcome after ischemic stroke or TIA.MethodsThis study was a single-center, prospective, continuous, cohort study to observe the occurrence of adverse functional outcomes (mRS 2–6/3–6) 90 days after ischemic stroke or TIA in patients, where the exposure factors in this study were carotid plaque ultrasound risk biomarkers and the risk factors were sex, age, disease history, and medication history. Patients with ischemic stroke or TIA (mRS ≤3) whose ipsilateral internal carotid artery stenosis was ≥50% within 30 days were included. All patients underwent multimodal ultrasound at baseline, including conventional ultrasound, superb microvascular imaging (SMI), and shear wave elastography (SWE). Continuous variables were divided into four groups at interquartile spacing for inclusion in univariate and multifactorial analyses. After completion of a baseline ultrasound, all patients were followed up at 90 days after ultrasound, and patient modified neurological function scores (mRSs) were recorded. Multivariate Cox regression and ROC curves were used to assess the risk factors and predictive power for predicting poor neurological function.ResultsSMI revealed that 20 (30.8%) patients showed extensive neovascularization in the carotid plaque, and 45 (69.2%) patients showed limited neovascularization in the carotid plaque. SWE imaging showed that the mean carotid plaque stiffness was 51.49 ± 18.34 kPa (23.19–111.39 kPa). After a mean follow-up of 90 ± 14 days, a total of 21 (32.3%) patients had a mRS of 2–6, and a total of 10 (15.4%) patients had a mRS of 3–6. Cox regression analysis showed that the level of intraplaque neovascularization and plaque stiffness were independent risk factors for a mRS of 2–6, and the level of intraplaque neovascularization was an independent risk factor for a mRS of 3–6. After correcting for confounders, the HR of intraplaque neovascularization level and plaque stiffness predicting a mRS 2–6 was 3.06 (95% CI 1.05–12.59, P = 0.041) and 0.51 (95% CI 0.31–0.83, P = 0.007), respectively; the HR of intraplaque neovascularization level predicting a mRS 3–6 was 6.11 (95% CI 1.19–31.45, P = 0.031). For ROC curve analysis, the mRSs for intraplaque neovascularization level, plaque stiffness, and combined application to predict 90-day neurological outcome ranged from 2 to 6, with AUCs of 0.73 (95% CI 0.59–0.87), 0.76 (95% CI 0.64–0.89) and 0.85 (95% CI 0.76–0.95), respectively. The mRSs for the intraplaque neovascularization level to predict 90-day neurological outcome ranged from 3 to 6, with AUCs of 0.79 (95% CI 0.63–0.95).ConclusionIntraplaque neovascularization level and plaque stiffness may be associated with an increased risk of poor short-term functional outcome after stroke in patients with recent anterior circulation ischemic stroke due to carotid atherosclerosis. The combined application of multiple parameters has efficacy in predicting poor short-term functional outcome after stroke.

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

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

TELARŞLI PUBERTE PREKOKS HASTALARINDA VASKÜLARİTENİN DOPPLER ULTRASONOGRAFI YÖNTEMLERİ İLE DEĞERLENDİRİLMESİ

OBJECTIVE: The aim of this study is to investigate the correlation between breast vascularity level and Tanner staging in the evaluation of thelarche, and to compare Doppler methods for demonstrating vascularity.MATERIAL AND METHODS: Girls aged 6–10 who were referred to the radiology clinic with a complaint of breast swelling and prediagnosed with precocious puberty between October and December 2017 were included in the study. Breast ultrasonography (US) and color doppler ultrasonography (CDUS) examinations were performed on all participants. Age, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Estradiol (E2), thelarche stage, both breast volumes were recorded for all participants. Vascular scores were measured for both breasts using imaging modalities such as color doppler (CD), Power US (PD), and superb microvascular imaging (SMI).RESULTS: We included 116 girls and 213 thelarche breasts in the study. A significant correlation was found between the depth and transverse and longitudinal diameter for each breast and breast volume and Tanner stages (rs = 0.762, rs = 0.830, rs = 0.774 rs = 0.824, respectively; p &amp;lt; 0.001). Although the highest correlation between Doppler methods was found in PD (PD rs =0.68, CD rs =: 0.61, SMI rs =:0.61, p&amp;lt;0.001), the methods did not have any superiority over each other (p&amp;gt;0.05). Vascularization with SMI was demonstrated in 30 of 65 breasts for which vascularization could not be demonstrated with power Doppler. Among these 30 cases, 90% (n = 27) were Tanner stage I and II.CONCLUSIONS: In conclusion, although SMI is as successful as conventional Doppler methods in the evaluation of thelarche vascularity, it can provide more data in some cases.