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Simple Summary: Finding solitary pulmonary nodules (SPNs) during thoracic surgery, especially during minimally invasive procedures, remains a major challenge. Moreover, in cases of unclear focal findings, the frozen section result must be waited for, which influences the surgical procedure. Therefore, we are investigating for the first time the use of intraoperative contrast-enhanced ultrasound (Io-CEUS) in minimally invasive thoracic surgery to, on the one hand, visualize unclear SPNs, and on the other hand, to characterize the SPNs directly before surgical resection. In the future, Io-CEUS could make "live histology" possible in thoracic surgery, which may influence the surgeon's intraoperative decisions and the extent of lung resection. Background: The intraoperative detection of solitary pulmonary nodules (SPNs) continues to be a major challenge, especially in minimally invasive video-assisted thoracic surgery (VATS). The location, size, and intraoperative frozen section result of SPNs are decisive regarding the extent of lung resection. This feasibility study investigates the technical applicability of intraoperative contrast-enhanced ultrasonography (Io-CEUS) in minimally invasive thoracic surgery. Methods: In this prospective, monocentric clinical feasibility study, n = 30 patients who underwent Io-CEUS during elective minimally invasive lung resection for SPNs between October 2021 and February 2023. The primary endpoint was the technical feasibility of Io-CEUS during VATS. Secondary endpoints were defined as the detection and characterization of SPNs. Results: In all patients (female, n = 13; mean age, 63 ± 8.6 years) Io-CEUS could be performed without problems during VATS. All SPNs were detected by Io-CEUS (100%). SPNs had a mean size of 2.2 cm (0.5–4.5 cm) and a mean distance to the lung surface of 2.0 cm (0–6.4 cm). B-mode, colour-coded Doppler sonography, and contrast-enhanced ultrasound were used to characterize all tumours intraoperatively. Significant differences were found, especially in vascularization as well as in contrast agent behaviour, depending on the tumour entity. After successful lung resection, a pathologic examination confirmed the presence of lung carcinomas (n = 17), lung metastases (n = 10), and benign lung tumours (n = 3). Conclusions: The technical feasibility of Io-CEUS was confirmed in VATS before resection regarding the detection of suspicious SPNs. In particular, the use of Doppler sonography and contrast agent kinetics revealed intraoperative specific aspects depending on the tumour entity. Further studies on Io-CEUS and the application of an endoscopic probe for VATS will follow. [ABSTRACT FROM AUTHOR]

Metastatic cervical lymph nodes are a frequent finding in head and neck squamous cell carcinoma (HNSCC). If a non-surgical approach is primarily chosen, a therapy response evaluation of the primary tumor and the affected lymph nodes is necessary in the follow-up. Supplementary contrast-enhanced ultrasound (CEUS) can be used to precisely visualize the microcirculation of the target lesion in the neck, whereby malignant and benign findings differ in their uptake behavior. The same applies to many other solid tumors. For various tumor entities, it has already been shown that therapy monitoring is possible through regular contrast-enhanced sonography of the primary tumor or the affected lymph nodes. Thus, in some cases, maybe in the future, a change in therapy strategy can be achieved at an early stage in the case of non-response or, in the case of therapy success, a de-escalation of subsequent (surgical) measures can be achieved. In this paper, a systematic review of the available studies and a discussion of the potential of therapy monitoring by means of CEUS in HNSCC are presented. [ABSTRACT FROM AUTHOR]

Background: We aimed to evaluate multiparametric ultrasound, to achieve a better understanding of the baseline characteristics of suspected cervical lymph node metastases in head and neck cancer before induction chemotherapy or chemoradiation. Methods: From February 2020 to April 2021, our complete ultrasound examination protocol was carried out on clinically evident malignant lymph nodes of histologically proven HNSCC in the pre-therapeutic setting. Results: A total of 13 patients were eligible for analysis. Using elastography, irregular clear hardening in areas in the center of the lymph node could be detected in all cases. Elastographic Q-analysis showed a significantly softer cortex compared to the center and surrounding tissue. The time–intensity curve analysis showed high values for the area under the curve and a short time-to-peak (fast wash-in) in all cases compared to the surrounding tissue. A parametric evaluation of contrast enhanced the ultrasound in the early arterial phase and showed an irregular enhancement from the margin in almost all investigated lymph nodes. These results show that the implementation of comprehensive, multiparametric ultrasound is suitable for classifying suspected lymph node metastasis more precisely than conventional ultrasound alone in the pre-therapeutic setting of HNSCC. Thus, these parameters may be used for improvements in the re-staging after chemoradiation or neoadjuvant therapy monitoring, respectively. [ABSTRACT FROM AUTHOR]

Aim: Evaluation of an external color coded perfusion quantification software with CEUS for the post-interventional success control following TACE in patients with HCC. Material and methods: 31 patients (5 females, 26 males, age range 34–82 years, mean 66.8 years) with 59 HCC lesions underwent superselective TACE using DSM Beads between 01/2015 and 06/2018. All patients underwent CEUS by an experienced examiner using a convex multifrequency probe (1–6 MHz) within 24 hours following TACE to detect residual tumor tissue. Retrospective evaluation using a perfusion quantification software regarding pE, TTP, mTT, Ri and WiAUC in the center of the lesion, the margin and surrounding liver. Results: In all lesions, a post-interventional visual reduction of the tumor microvascularization was observed. Significant differences between center of the lesion vs. margin and surrounding liver were found regarding peak enhancement (867.8 ± 2416 center vs 2028 ± 3954 margin p<0.005) and center 867.8 ± 2416 vs 2824 ± 4290 surrounding liver, p<0.0001)). However, no significant differences were found concerning Ri, WiAuC, mTT and TTP. Conclusion: CEUS with color- coded perfusion imaging is a valuable supporting tool for post-interventional success control following TACE of liver lesions. Peak enhancement seems to be the most valuable parameter. [ABSTRACT FROM AUTHOR]

Background: Hereditary hemorrhagic telangiectasia (HHT) is marked by arteriovenous fusion comprising hepatic vascular malformations (HVaMs) with the chance of bleeding. Aims: We investigated HVaMs in HHT patients by combination of contrast-enhanced ultrasound (CEUS) with perfusion imaging quantification to be able to sub-classify a high risk cohort of asymptomatic HHT patients. Methods: The imaging characteristics on CEUS in 34 patients (aged 21–84 years; mean 58.9) with HHT were retrospectively evaluated. Real-time contrast harmonic imaging, sulfur hexafluoride-filled microbubbles and motion adjustment were utilized. Cine loops of the liver were digital stored, perfusion was quantified using a software reading DICOM data`s. Results: HVaMs were diagnosed in 31 out of 34 patients. Significant uppermost peak enhancement (PE), wash-in area under the curve (WiAUC) and wash-in perfusion index (WiPI) were identified in the shunt region (100%), next in the hilar region (PE 32.6%; WiAUC 33.9%; WiPI 34.1%), and the lowest in the hepatic parenchyma (PE 10.2%; WiAUC 12.0%; WiPI 9.5%). The perfusion parameters in the shunt region compared to the other regions were significantly increased in one subgroup of patients. Consistent with this, the intrahepatic portal vein diameter and Buscarini grading was significantly higher, while portal vein peak velocity was significantly lower in this patient subset. By statistical analysis, we could correlate PE and WiPI to these clinical parameters, while WiAUC showed no clinical association. Conclusions: For the first time we combined CEUS findings with motion adjustment software to quantitative determine perfusion parameters of a cohort of HHT patients. Hereby, we could identify a subset of HHT patients with two markedly increased parameter values in the shunt region compared to the hilus/hepatic parenchyma. This could contribute to sub-classify a high-risk group of HHT patients with therapeutic indication. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the diagnostic accuracy of IO-SE in comparison to IO-CEUS for the differentiation between malignant and benign liver lesions. Material and Methods: In a retrospective diagnostic study IO-CEUS and SE examinations of 49 liver lesions were evaluated and compared to histopathological examinations. Ultrasound was performed using a multifrequency linear probe (6–9 MHz). The loops of CEUS were evaluated up to 5 min. The qualitative characterization of IO-SE was based on a color coding system (blue = hard, red = soft). Stiffness of all lesions was quantified by a specific scaling of 0–6 (0 = low, 6 = high) using 7 ROIs (2 central, 5 peripheral). Results: All malignant lesions displayed a characteristic portal venous washout and could be diagnosed correctly by IO-CEUS. 3/5 benign lesions could not be characterized properly either by IO-CEUS or IO-SE prior to resection. Thus for IO-CEUS sensitivity, specificity, positive and negative predictive value and accuracy were 100%, 40%, 94%, 100% and 94%. Lesion sizes were between 8 and 59 mm in diameter. Regarding the IO-SE, malignant lesions showed a marked variability. In qualitative analysis, 31 of the malignant lesions were blue colored denoting overall induration. Thirteen malignant lesions showed an inhomogenous color pattern with partial indurations. Two of the benign lesions also displayed overall induration. The other benign lesions showed an inhomogenous color mapping. Calculated sensitivity of the SE was 70.5%, specificity 60%, PPV 94%, NPV 18.75%, and accuracy 69%. Conclusion: IO-CEUS is useful for localization and characterization of liver lesions prior to surgical resection whereas IO-SE provided correct characterization only for a limited number of lesions. [ABSTRACT FROM AUTHOR]

In recent years contrast-enhanced ultrasound (CEUS) has been an emerging diagnostic modality for the detection of acute gastrointestinal (GI) graft-versus-host disease (GvHD) in patients after allogeneic stem cell transplantation. However, broad clinical usage has been partially limited by its high dependence on the expertise of an experienced examiner. Thus, the aim of this study was to facilitate detection of acute GI GvHD by implementing false color-coded parametric imaging of CEUS. As such, two inexperienced examiners with basic knowledge in abdominal and vascular ultrasound analyzed parametric images obtained from patients with clinical suspicion for acute GvHD in a blinded fashion. As diagnostic gold standard, histopathological GvHD severity score on intestinal biopsies obtained from lower GI tract endoscopy was performed. The evaluation of parametric images by the two inexperienced ultrasound examiners in patients with histological confirmation of acute GI GvHD was successful in 17 out of 19 patients (89%) as opposed to analysis of combined B-mode ultrasound, strain elastography, and CEUS by an experienced examiner, which was successful in 18 out of 19 of the patients (95%). Therefore, CEUS with parametric imaging of the intestine was technically feasible and has the potential to become a valuable diagnostic tool for rapid and widely accessible detection of acute GvHD in clinical practice. [ABSTRACT FROM AUTHOR]

Aim: Evaluation of the post-interventional success following irreversible electroporation (IRE) using a new color coded perfusion quantification software with contrast-enhanced ultrasound (CEUS) in patients with malignant lesions of the liver. Methods: Thirty-eight patients with 68 malignant liver lesions underwent IRE. All malignant lesions were investigated with CEUS before and within 24 hours following IRE to detect residual tumor tissue. The parameters analyzed by color coded perfusion quantification software were: the peak enhancement (pE), time to peak (TTP), mean transit time (mTT), rise (Ri) and wash-in area under the curve (WiAUC). Perfusion in the center, the margins of the lesions and in the surrounding liver were evaluated using these parameters. Results: Hepatocellular carcinoma (HCC) with complete ablation showed significantly different changes between the center and the margin of the lesions for WiAUC (p<0.05) and pE (p<0.01). Also significant differences were noted between the center of the lesions and the surrounded tissue for the same parameters (p<0.01). In the completely ablated metastatic lesions, significant differences were found between the center of the lesion and the margins (p < 0.01) and between the center of the lesion and the surrounding liver (p < 0.05) for WiAUC. mTT, TTP and Ri showed no significant changes between the center of the lesions, margin of the lesions or surrounding tissue. Also, no significant differences were found for these parameters in the different regions of interest for HCC or the metastatic lesions with partial ablation success. Conclusion: CEUS with perfusion imaging is a valuable supporting tool for the post-interventional evaluation of liver lesions following IRE. Focus should be placed on the peak enhancement (pE) and the wash-in area under the curve (WiAUC). [ABSTRACT FROM AUTHOR]

To evaluate the diagnostic value of quantification of liver tumor microvascularization using contrast-enhanced ultrasound (CEUS) measured continuously from the arterial phase to the late phase (3 minutes). Material and Methods. We present a retrospective analysis of 20 patients with malignant (n = 13) or benign (n = 7) liver tumors. The tumors had histopathologically been proven or clearly identified using contrast-enhanced reference imaging with either 1.5 T MRI (liver specific contrast medium) or triphase CT and follow-up. CEUS was performed using a multifrequency transducer (1-5MHz) and a bolus injection of 2.4mL sulphur hexafluoride microbubbles. A retrospective perfusion analysis was performed to determine TTP (time-to-peak), RBV (regional blood volume), RBF (regional blood flow), and Peak. Results. Statistics revealed a significant difference (p < 0.05) between benign and malignant tumors in the RBV, RBF, and Peak but not in TTP (p = 0.07). Receiver operating curves (ROC) were generated for RBV, RBF, Peak, and TTP with estimated ROC areas of 0.97, 0.96, 0.98, and 0.76, respectively. Conclusion. RBV, RBF, and Peak continuously measured over a determined time period of 3 minutes could be of valuable support in differentiating malignant from benign liver tumors. [ABSTRACT FROM AUTHOR]