Addition Of Contrast-enhanced Ultrasound Research Articles

The value of multimodal ultrasound in diagnosis of cervical lymphadenopathy: can real-time elastography help identify benign and malignant lymph nodes?

AimTo investigate the multimodal ultrasound(MMUS) features of cervical lymphadenopathy and to assess its value in the differential diagnosis of benign and malignant cervical lymph nodes.MethodsA retrospective analysis of 169 patients with cervical lymph node enlargement who attended Hangzhou Red Cross Hospital from March 2020 to October 2022. All patients underwent conventional ultrasound (CUS), contrast-enhanced ultrasound (CEUS), and real-time elastography (RTE), and were divided into training set and validation set. Univariate analysis was applied to screen out statistically significant parameters, and CUS model and MMUS model were constructed by multifactorial logistic regression analysis. The receiver operator characteristic (ROC) curve was established, and the area under the curve (AUC) was used to compare CUS model with MMUS model to assess the value of MMUS.ResultsOf the cervical 169 lymph nodes in 169 patients included in the study. The 169 enrolled patients were divided into a training set (132 patients) and a validation set (37 patients). In the training set, univariate analysis showed statistically significant differences in long diameter/short diameter(L/S), border, margin, hilus, dermal medulla boundary, blood flow type, enhancement mode, enhancement type, and RTE score (all p< 0.05). Multifactor logistic analysis showed that L/S, blood flow type, enhancement mode and enhancement type were correlates of malignant lymph nodes (all p< 0.05). The comparison of AUC demonstrated that the discriminative ability of the MMUS model was superior to using the CUS model, both in the training set(p = 0.004) and validation set (p<0.001).ConclusionIn this study, MMUS shows higher diagnostic efficiency than CUS. Ultrasound features such as L/S, blood flow type, mode of enhancement, type of enhancement are helpful in distinguishing benign and malignant lymphadenopathy. The addition of CEUS can greatly improve the sensitivity and specificity of ultrasonic diagnosis of malignant cervical lymph nodes. RTE score is of limited value in the diagnosis of malignant cervical lymph nodes.

Contrast enhanced ultrasound for characterization of suspected soft tissue vascular anomalies

BackgroundEvaluation of perfusion characteristics is the key to characterize vascular anomalies. Contrast-enhanced ultrasound (CEUS) is a radiation-free modality to evaluate this in real-time and can be coupled along with Doppler-ultrasound (US). ObjectiveTo evaluate the utility of CEUS in characterization of suspected soft-tissue vascular anomalies and compare its diagnostic accuracy with Doppler-US. Materials and methodsThis was an ethically-approved cross-sectional study, done from November 2017- November 2019, involving 93 patients (55 M/38F; mean age 23.6 ± 11.9 years) in development cohort and 128 (66 M/62F; mean age 21.4 ± 11.1 years) in validation cohort. Patients suspected to have soft-tissue vascular anomalies on clinical evaluation and US were included. Clinical features, US, Doppler, subjective and quantitative CEUS features (from time-intensity curves) were evaluated. Composite gold standard employing MRI, phlebogram, DSA or biopsy was used to make the final diagnosis. The CEUS features found to be significantly different in the development cohort were prospectively validated in the validation cohort. P-value < 0.05 was considered significant, ROC curves were drawn and threshold values obtained for the various quantitative parameters. A prospective diagnosis was suggested in the validation group along with a degree of diagnostic confidence and accuracy was calculated. ResultsThe spectrum of lesions included 77 venous malformations, 46 fibro-adipose vascular anomalies, 32 vascular tumors, 20 arteriovenous malformations and 20 lymphatic malformations. All lesions were found to have distinctive temporal and morphological subjective enhancement patterns. Quantitative parameters like rise-time, mean-transit-time, time-to-peak, peak-enhancement showed significant differences between the various groups (P value < 0.05). Addition of CEUS not only increased the diagnostic accuracy of Doppler-US from 76.5% (91/119) to 88.2% (105/119), but also the degree of diagnostic confidence in characterization of soft-tissue vascular anomalies. None of the patients showed any contrast-related adverse effects. ConclusionContrast-enhanced ultrasound is useful to characterize different types of soft-tissue vascular anomalies and increases the diagnostic accuracy and confidence over Doppler-ultrasound.

Vascularity of Intra-testicular Lesions: Inter-observer Variation in the Assessment of Non-neoplastic Versus Neoplastic Abnormalities After Vascular Enhancement With Contrast-Enhanced Ultrasound

The aim of this study is to assess the additional benefit of contrast-enhanced ultrasound (CEUS) over conventional ultrasonography (US) in identifying intra-testicular abnormalities among observers of different experiences. In this study, 91 focal testicular lesions (46 neoplastic, 45 non-neoplastic) imaged with gray-scale US/Doppler US and CEUS were classified using a 5-point scale. Three experienced and four inexperienced observers rated each lesion using gray-scale/color Doppler US alone and then with the addition of CEUS. Improved diagnostic specificity and accuracy with the addition of CEUS was observed for both experienced (specificity: 71.1% vs. 59.3%, p = 0.005; accuracy: 83.5% vs. 76.9%, p = 0.003) and inexperienced observers (specificity: 75.6% vs. 51.7%, p = 0.005; accuracy: 80.2% vs. 72.0%, p < 0.001). Significant inter-observer variability between the experienced and inexperienced observers when assessing conventional US alone was eliminated with the addition of CEUS. CEUS improves diagnostic accuracy of focal intra-testicular lesions for both experienced and inexperienced observers and reduces inter-observer variability in inexperienced operators.

Feasibility of Contrast-Enhanced Intraoperative Ultrasound for Detection and Characterization of Renal Mass Undergoing Open Partial Nephrectomy.

To determine the feasibility of obtaining intraoperative contrast-enhanced ultrasound (CEUS) imaging in patients undergoing open partial nephrectomy for renal cancer. We hypothesize that the study was feasible and the addition of CEUS would improve lesion identification and characterization. The study population consisted of 10 patients with known renal mass scheduled for intraoperative ultrasound-guided open partial nephrectomy. After dissection and exposure of the kidney by the surgeon, an intraoperative pre- and post-CEUS was performed by the radiologist. Feasibility was defined as successful imaging in 8 of 10 patients with intraoperative CEUS. Image quality, lesion conspicuity/contrast, lesion vascularity, morphology, and size were assessed and graded with pre- and post-contrast images. Intraoperative ultrasound was successfully acquired in 10 of 11 patients for renal mass detection and characterization. One study was canceled intraoperatively as a result of clinical complications related to a difficult surgery. Tumor size ranged from 1.3 to 4.2 cm. All lesions were solid. No additional lesions were found on CEUS compared with baseline imaging. Image quality post-contrast ranged from acceptable to excellent. There were no adverse events recorded for all 10 patients. In our feasibility study consisting of 10 patients, CEUS for detection and characterization of renal mass undergoing open partial nephrectomy was feasible and safe. Because intraoperative ultrasound during open partial nephrectomy can affect the extent of surgery, CEUS can be used to help detect and characterize renal mass for surgical planning/resection intraoperatively.

Prospective evaluation of CT indeterminate renal masses using US and contrast-enhanced ultrasound.

The aim of this study was to assess the accuracy of Ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the characterization of renal nodules indeterminate on CT by identifying benign cystic lesions not requiring further examination. 72 patients with 83 indeterminate renal nodules on CT underwent baseline US and CEUS that classified lesions as benign (Bosniak I, II or IIF cysts) or potentially malignant (Bosniak III or IV cysts, solid nodules). The accuracy of US and CEUS in the differentiation between benign cysts and potentially malignant nodules was analyzed and compared with the final diagnosis obtained by histology or follow-up of at least 23 months with CEUS ± a conclusive CT/MR study. Final diagnoses comprised 50 benign complex cysts, 1 focal nephritis, 1 multilocular cystic nephroma, 3 oncocytomas, 1 transitional cell carcinoma and 27 renal cell carcinomas. Unenhanced US correctly classified 18/50 (36%) benign cysts and 17/33 (51.5%) of the potentially malignant lesions obtaining a sensitivity of 36%, specificity of 51.5%, and overall accuracy of 42.2%. The addition of CEUS allowed a correct diagnosis of 48 /50 (96%) benign cysts and of 31/33 (93.9%) nodules as potentially malignant, with a sensitivity of 96%, specificity of 93.9%, and overall accuracy of 95.2%. CEUS is very useful in the differentiation between benign complex cysts and other lesions that require further investigation in non-conclusive renal nodules detected on CT, improving the accuracy of baseline US from 42.2 to 95.2%.

Therapeutic application of contrast-enhanced ultrasound and low-dose urokinase for thrombolysis in a porcine model of acute peripheral arterial occlusion

The addition of local ultrasound (US) with a contrast agent to standard intra-arterial thrombolysis can accelerate the thrombolytic treatment of stroke and myocardial infarction. The contrast agent consists of microsized gas-filled bubbles that collapse when exposed to US, causing destabilization of the clot and making the clot surface more susceptible to fibrinolytics. In this study, we investigated the effect of additional US and microbubbles on standard low-dose intra-arterial thrombolysis in a porcine model of extensive peripheral arterial occlusion. Extensive arterial thrombosis was induced in 10 pigs in the 4-cm external iliac artery by clamping and injection of 100 IU of bovine thrombin. A transcutaneous laser Doppler flow probe and an ultrasonic perivascular flow probe assessed microcirculation and arterial flow respectively. The urokinase-only (UK) group (n = 4) received standard thrombolytic therapy: intra-arterial bolus injection of 500,000 IU, followed by a continuous low-dose urokinase (50,000 IU/h) infusion through an intra-arterial catheter and local intermittent application of US, 1 second on, 5 seconds off, to visualize vascular patency during the first hour of therapy and to ensure microbubbles replenished the proximal portion of the occluded artery. The urokinase plus microbubbles (UK+) group (n = 6) received the same urokinase therapy with a concomitant intravenous infusion of microbubbles and local intermittent application of US. The contrast infusion protocol consisted of a bolus of two vials of 5 mL in the first 15 minutes and then three times 5 mL slowly hand-injected continuously during the next 45 min. After 3 hours of therapy, the animals were euthanized, and thrombi were harvested and weighed. All organs were cut in thin slices and macroscopically inspected for potential (hemorrhagic) adverse events, and tissue samples were taken. Median thrombus weights were 1.1 g (range, 0.8-1.3 g) in the UK+ group vs 1.6 g (range, 1.3-1.9 g) in the UK group (P = .01). Arterial blood flow increased in four of six pigs in the UK+ group by a mean 61% vs in one of four in the UK group, with 1%. Microcirculation and lower limb arterial pressure levels improved after the start of therapy in the UK+ group, contrary to a trend of decline in the UK group. No signs of bleeding complications were observed in either group. In this experimental pilot study, the addition of contrast-enhanced US accelerated the thrombolytic effect of low-dose intra-arterial thrombolysis in peripheral arterial occlusions. Further clinical studies are warranted.

Contrast-enhanced ultrasound detects perfusion defects in an ex vivo porcine liver model: a useful tool for the study of hepatic reperfusion

Following transplantation, areas of hypoperfusion can be associated with metabolic changes and poor organ recovery. Our study evaluated contrast-enhanced ultrasound (CEUS) agents for the detection of such areas. Livers were collected from ten pigs, connected to extracorporeal circuits and perfused using autologous blood. After 1 and 4h livers were scanned with an ultrasound machine following the administration of CEUS agents. Biopsies from perfused and non-perfused areas were collected. The entire parenchyma enhanced strongly on non-contrast ultrasound at 1h with no perfusion defects. Four hours later multiple perfusion defects manifested not evident with non-contrast ultrasound. Histology confirmed non-perfused areas corresponded to ischemic zones. In our model the addition of CEUS revealed perfusion defects after 4h. This might facilitate detection and characterization of perfusion defects in transplanted livers.

The Use of CEUS in the Diagnosis of Retinal/Choroidal Detachment and Associated Intraocular Masses – Preliminary Investigation in Patients with Equivocal Findings at Conventional Ultrasound

To investigate whether contrast-enhanced ultrasound (CEUS) may help to diagnose retinal/choroidal detachment and may help to differentiate intraocular lumps in cases with equivocal features on conventional grayscale and Doppler modes. The institutional review board approved this retrospective study. The need for informed consent was waived. A computerized data search was performed in the database of our institution for patients with vitreous hemorrhage who underwent CEUS of the eye to assess retinal/choroidal detachment and/or associated masses. This process yielded a total of 31 patients (18 men, 13 women, age range: 39 - 88 years) in whom CEUS was performed because the findings on conventional grayscale and Doppler modes were equivocal. CEUS was performed using low acoustic power contrast-specific modes. A 2.4 - 4.8 mL bolus of SonoVue was injected, followed by a saline flush. All examinations were digitally recorded for retrospective analysis. Confirmation of CEUS findings was obtained at surgery (n = 20) or with binocular indirect fundoscopy performed after clearance of the ocular media (n = 11). Two readers with different levels of ultrasound experience independently reviewed the imaging features. A five-degree scale ranging from definitely absent (score 1) to definitely present (score 5) was used to assess the presence or absence of retinal/choroidal detachment on conventional ultrasound modes alone and with the addition of CEUS. ROC curve analysis was performed to assess the diagnostic accuracy of both methods. The inter-reader agreement was also evaluated. In patients with associated intraocular lumps, conventional Doppler modes and CEUS were used to differentiate non-tumor masses from tumor masses. According to the reference standard, 13 patients had retinal detachment, 4 had choroidal detachment, and 3 had both retinal and choroidal detachment. There were 8 associated intraocular lumps (4 subretinal hemorrhages, 3 malignant melanomas, 1 metastasis). The inter-reader agreement was good (K = 0.644) and very good (K = 0.833) for conventional modes and CEUS, respectively. The diagnostic performance of CEUS was high for both readers (area ± standard error under the ROC curve: 0.966 ± 0.031 and 0.900 ± 0.055 for readers 1 and 2, respectively). There were 2 false-positive results and 1 false-negative result in patients with proliferative diabetic retinopathy. CEUS was effective in differentiating subretinal hemorrhage from hypovascular tumors. CEUS can be used as a problem-solving technique when conventional ultrasound modes are not diagnostic for retinal/choroidal detachment and when intraocular lumps cannot be characterized as tumor or non-tumor masses on conventional modes. The evaluation of patients with proliferative diabetic retinopathy, however, may be problematic.

Characterization of focal liver lesions with SonoVue®-enhanced sonography: International multicenter-study in comparison to CT and MRI

To evaluate in a multicenter study whether the sonographic characterization of focal liver lesions can be improved using SonoVue-enhancement; and to compare this method with computed tomography (CT) and magnetic resonance imaging (MRI). One hundred and thirty four patients with one focal liver lesion detected in baseline ultrasound (US) were examined with conventional US, contrast-enhanced US (n = 134), contrast-enhanced CT (n = 115) and/or dynamic contrast-enhanced MRI (n = 70). The lesions were classified as malignant, benign or indeterminate and the type of lesion was determined. The final diagnosis based on the combined information of all imaging examinations, clinical information and histology (n = 32) was used. Comparisons were made to see whether the addition of contrast-enhanced US led to the improvement of the characterization of doubtful focal liver lesions. In comparison with unenhanced US, SonoVue markedly improves sensitivity and specificity for the characterization (malignant/benign) of focal liver lesions. In comparison with CT and/or dynamic MRI, SonoVue-enhanced sonography applied for characterization of focal liver lesions was 30.2% more sensitive in the recognition of malignancy and 16.1% more specific in the exclusion of malignancy and overall 22.9% more accurate. In the subgroup with confirmative histology available (n = 30), sensitivity was 95.5% (CEUS), 72.2% (CT) and 81.8% (MRI), and specificity was 75.0% (CEUS), 37.5% (CT) and 42.9% (MRI). The sensitivity and specificity of CEUS for the identification of focal nodular hyperplasia (FNH) and hemangiomas was 100% and 87%, resulting in an accuracy of 94.5%. SonoVue-enhanced sonography emerges as the most sensitive, most specific and thus most accurate imaging modality for the characterization of focal liver lesions.