Quantification of Hepatocellular Carcinoma Vascular Dynamics With Contrast-Enhanced Ultrasound for LI-RADS Implementation

OBJECTIVE

The aim of this study is to describe a comprehensive contrast-enhanced ultrasound (CEUS) imaging protocol and analysis method to implement CEUS LI-RADS (Liver Imaging Reporting and Data System) in a quantifiable manner. The methods that are validated with a prospective single-center study aim to simplify CEUS LI-RADS evaluation, remove observer bias, and potentially improve the sensitivity of CEUS LI-RADS.

MATERIALS AND METHODS

This prospective single-center study enrolled patients with hepatocellular carcinoma (April 2021-June 2022; N = 31; mean age ± SD, 67 ± 6 years; 24 men/7 women). For each patient, at least 2 CEUS loops spanning over 5 minutes were collected for different lesion scan planes using an articulated arm to hold the transducer. Automatic respiratory gating and motion compensation algorithms removed errors due to breathing motion. The long axis of the lesion was measured in the contrast and fundamental images to capture nodule size. Parametric processing of time-intensity curve analysis on linearized data provided quantifiable information of the wash-in and washout dynamics via rise time ( RT ) and degree of washout ( DW ) parameters extracted from the time-intensity curve, respectively. A Welch t test was performed between lesion and parenchyma RT for each lesion to confirm statistically significant differences. P values for bootstrapped 95% confidence intervals of the relative degree of washout ( rDW ), ratio of DW between the lesion and surrounding parenchyma, were computed to quantify lesion washout. Coefficient of variation (COV) of RT , DW , and rDW was calculated for each patient between injections for both the lesion and surrounding parenchyma to gauge reproducibility of these metrics. Spearman rank correlation tests were performed among size, RT , DW , and rDW values to evaluate statistical dependence between the variables.

RESULTS

The mean ± SD lesion diameter was 23 ± 8 mm. The RT for all lesions, capturing arterial phase hyperenhancement, was shorter than that of surrounding liver parenchyma ( P < 0.05). All lesions also demonstrated significant ( P < 0.05) but variable levels of washout at both 2-minute and 5-minute time points, quantified in rDW . The COV of RT for the lesion and surrounding parenchyma were both 11%, and the COV of DW and rDW at 2 and 5 minutes ranged from 22% to 31%. Statistically significant relationships between lesion and parenchyma RT and between lesion RT and lesion DW at the 2- and 5-minute time points were found ( P < 0.05).

CONCLUSIONS

The imaging protocol and analysis method presented provide robust, quantitative metrics that describe the dynamic vascular patterns of LI-RADS 5 lesions classified as hepatocellular carcinomas. The RT of the bolus transit quantifies the arterial phase hyperenhancement, and the DW and rDW parameters quantify the washout from linearized CEUS intensity data. This unique methodology is able to implement the CEUS-LIRADS scheme in a quantifiable manner for the first time and remove its existing issues of currently being qualitative and suffering from subjective evaluations.

Automated motion artifact correction for dynamic contrast-enhanced fluorescence imaging during open orthopedic surgery

Indocyanine green (ICG)-based dynamic contrast-enhanced fluorescence imaging (DCE-FI) can objectively assess bone perfusion intraoperatively. However, it is susceptible to motion artifacts due to patient's involuntary respiration during the 4.5-minute DCE-FI data acquisition. An automated motion correction approach based on mutual information (MI) frameby-frame was developed to overcome this problem. In this approach, MIs were calculated between the reference and the adjacent frame translated and the maximal MI corresponded to the optimal translation. The images obtained from eighteen amputation cases were utilized to validate the approach and the results show that this correction can significantly reduce the motion artifacts and can improve the accuracy of bone perfusion assessment.

Application value of contrast-enhanced ultrasonography in the treatment of uterine fibroids by high-intensity focused ultrasound ablation: A retrospective study

PURPOSE

To determine efficacy and safety of contrast-enhanced ultrasonography (CEUS) in high-intensity focused ultrasound (HIFU) ablation of uterine fibroids (UFs).

METHODS

We retrospectively reviewed women undergoing HIFU ablation for UFs between June 2018 and January 2020. Before and after HIFU, patients underwent CEUS and magnetic resonance imaging (MRI) examinations. The relationship between CEUS features and ablation rate was analyzed. The time-intensity curves on CEUS were measured before and after HIFU ablation, and compared with those obtained using MRI. Adverse reactions were recorded.

RESULTS

A total of 64 patients were included. The immediate HIFU ablation rate significantly differed between low-, iso-, and high-enhancement UFs (87.2% ± 1.6%, 83.3% ± 2.1%, and 72.9% ± 3.1%, respectively; p < 0.05). On CEUS, the peak time of the time-intensity curve was significantly longer after treatment than before treatment (32.2 ± 9.7 and 26.7 ± 9.4 s, respectively; p < 0.05). Peak intensity was significantly lower after treatment than before treatment (13.7 ± 7.5 and 30.9 ± 11.2 dB, respectively; p < 0.05). All measurements were comparable between CEUS and MRI. The most common peri- and post-procedure adverse reaction was pain, which was temporary.

CONCLUSION

CEUS could dynamically and safely evaluate the immediate effects of the HIFU ablation of UFs.

Evaluation of blood-brain barrier integrity by the analysis of dynamic contrast-enhanced MRI - a comparison of quantitative and semi-quantitative methods

Disruption of the blood-brain barrier (BBB) is a key feature of various brain disorders. To assess its integrity a parametrization of dynamic magnetic resonance imaging (DCE MRI) with a contrast agent (CA) is broadly used. Parametrization can be done quantitatively or semi-quantitatively. Quantitative methods directly describe BBB permeability but exhibit several drawbacks such as high computation demands, reproducibility issues, or low robustness. Semi-quantitative methods are fast to compute, simply mathematically described, and robust, however, they do not describe the status of BBB directly but only as a variation of CA concentration in measured tissue. Our goal was to elucidate differences between five semi-quantitative parameters: maximal intensity (Imax), normalized permeability index (NPI), and difference in DCE values between three timepoints: baseline, 5 min, and 15 min (delta5-0, delta15-0, delta15-5) and two quantitative parameters: transfer constant (Ktrans) and an extravascular fraction (Ve). For the purpose of comparison, we analyzed DCE data of four patients 12-15 days after the stroke with visible CA enhancement. Calculated parameters showed abnormalities spatially corresponding with the ischemic lesion, however, findings in individual parameters morphometrically differed. Ktrans and Ve were highly correlated. Delta5-0 and delta15-0 were prominent in regions with rapid CA enhancement and highly correlated with Ktrans. Abnormalities in delta15-5 and NPI were more homogenous with less variable values, smoother borders, and less detail than Ktrans. Moreover, only delta15-5 and NPI were able to distinguish vessels from extravascular space. Our comparison provides important knowledge for understanding and interpreting parameters derived from DCE MRI by both quantitative and semi-quantitative methods.

Dynamic contrast-enhanced fluorescence imaging compared with MR imaging in evaluating bone perfusion during open orthopedic surgery

ICG-based dynamic contrast-enhanced fluorescence imaging (DCE-FI) and intraoperative DCE- magnetic resonance imaging (MRI) have been carried out nearly simultaneously in three lower extremity bone infection cases to investigate the relationship between these two imaging modalities for assessing bone blood perfusion during open orthopedic surgeries. Time-intensity curves in the corresponding regions of interest of two modalities were derived for comparison. The results demonstrated that ICG-based DCE-FI has higher sensitivity to perfusion changes while DCE-MRI provides superior and supplemental depth-related perfusion information. Research applying the depth-related perfusion information derived from MRI to improve the overall analytic modeling of intraoperative DCE-FI is ongoing.

Differentiation of Malignant and Benign Orbital Space-Occupying Lesions Using Contrast-Enhanced Ultrasound: Added Value From a Time-Intensity Curve-Based Quantitative Analysis

OBJECTIVES

To evaluate the value of time-intensity curve (TIC) analysis of contrast-enhanced ultrasound (CEUS) signal to differentiate malignant from benign orbital space-occupying lesions.

METHODS

The CEUS signal of 111 patients with orbital space-occupying lesions was retrospectively analyzed using SonoLiver software. TIC-related parameters such as the arrival time (AT), rise time (RT), time to peak (TTP), maximum intensity (IMAX), mean transit time (mTT), slope of the increase (RS), and slope of the decrease (DS) were compared between the malignant and benign groups. Receiver operating characteristic (ROC) curve analysis was used to acquire the cutoff values of these parameters for differential diagnosis.

RESULTS

TIC patterns were characterized by fast increase and fast decrease in signal intensity in the malignant group, fast increase and a slow decrease in signal intensity in the benign group. The differences in the IMAX, RS, DS, mTT, TTP, and RT between the 2 groups were statistically significant (p <.01), while the difference in the AT were not (p = .672). ROC curve analysis showed that IMAX = 427.20, DS = 34.72, and mTT = 33.55 were the best cutoff values for differential diagnosis of malignant and benign space-occupying lesions. The accuracy rate of CEUS visual evaluation for differential diagnosis was 66.67% (74/111), while TIC quantitative analysis could effectively improve the accuracy to 89.19% (99/111).

CONCLUSIONS

TIC analysis can improve CEUS efficiency to differentiate malignant from benign orbital space-occupying lesions.

Quantitative contrast-enhanced ultrasound for the differentiation of kidney allografts with significant histopathological injury

OBJECTIVE

To identify specific quantitative contrast-enhanced ultrasound (CEUS) parameters that could distinguish kidney transplants with significant histopathological injury.

METHODS

Sixty-four patients were enrolled in this prospective observational study. Biopsies were performed following CEUS and blood examination.

RESULTS

28 biopsy specimens had minimal changes (MC group), while 36 had significant injury (SI group). Of these, 12 had rejection (RI group) and 24 non-rejection injury (NRI group). In RI and NRI groups, temporal difference in time to peak (TTP) between medulla and cortex (ΔTTPm-c) was significantly shorter compared to the MC group (5.77, 5.92, and 7.94 s, P = 0.048 and 0.026, respectively). Additionally, RI group had significantly shorter medullary TTP compared to the MC group (27.75 vs. 32.26 s; P = 0.03). In a subset of 41 patients with protocol biopsy at 1-year post-transplant, ΔTTPm-c was significantly shorter in the SI compared to the MC group (5.67 vs. 7.67 s; P = 0.024). Area under receiver operating characteristic curves (AUROCs) for ΔTTPm-c was 0.69 in all patients and 0.71 in patients with protocol biopsy.

CONCLUSIONS

RI and NRI groups had shorter ΔTTPm-c compared to the MC group. AUROCs for both patient groups were good, making ΔTTPm-c a promising CEUS parameter for distinguishing patients with significant histopathological injury.

Correlation Between Enhancement Patterns on Transabdominal Ultrasound and Survival for Pancreatic Ductal Adenocarcinoma

Objective

Investigate the CEUS enhancement patterns of PDAC and analyse correlations between the CEUS enhancement pattern and both the degree of tumour tissue differentiation and overall survival (OS).

Methods

The study included 56 patients with locally advanced PDAC, performed conventional ultrasound and CEUS, and analysed characteristics of the CEUS enhancement patterns. In addition, clinical data, such as serum level of CA19-9, TNM stage were collected, and patients’ survival times were followed up. TICs of dynamic CEUS images were acquired using image processing software to obtain the peak, TP, sharpness, and AUC. Correlations of the CEUS enhancement patterns of PDAC with the degree of differentiation of tumour tissue and OS were quantitatively analysed, as were the correlations of the TIC parameters and CEUS enhancement patterns with OS.

Results

Enhancement in the arterial phase included iso-enhancement (30.3%) and hypo-enhancement (69.6%), and was not significantly correlated with sex, age at disease onset, or lesion size. Also was not significantly correlated with tumour tissue differentiation. Clear survival times were obtained for 50 patients during follow-up, and the median survival time was significantly longer for the patients with iso-enhancement than hypo-enhancement. Among the TIC parameters, peak_tumour, sharpness_tumour, AEsharpness, and REsharpness differed significantly between the group with iso-enhancement and hypo-enhancement (p < 0.05).

Conclusion

The CEUS enhancement patterns of PDAC in the arterial phase include iso-enhancement and hypo-enhancement. Enhancement pattern was not significantly correlated with the degree of differentiation of tumour tissue, but patient survival time differed significantly between the two enhancement patterns, with longer survival for patients with iso-enhancement.

Computer Simulation of the Effects of Contrast Protocols on Aortic Signal Intensity on Magnetic Resonance Angiograms

BACKGROUND

While iodine-enhanced computed tomography has been studied, detailed information on gadolinium-enhanced magnetic resonance imaging has not been reported.

OBJECTIVE

We evaluated the effects of different gadolinium contrast agent (Gd-CA) factors on the enhancement of aortic magnetic resonance angiography (MRA) using computer simulation.

METHODS

We developed computer-simulation software that combines pharmacokinetic models and tables; it converts the blood concentration of particular Gd-CAs into the signal intensity (SI). We simulated aortic time-intensity curves (TIC) in our MRA study and compared the effect of the Gd-- CA volume, injection rate, and of different Gd-CAs on the TIC.

RESULTS

An increase in the Gd-CA volume from 14.0 to 28.0 ml increased maximal aortic intensity 1.11 times. Changing the injection rate from 1.0 to 2.8 ml/s increased it 1.10 times. The maximal SI of gadoterate-meglumine and gadobutrol was 1.03 and 1.01 times, respectively, that of gadoteridol.

CONCLUSION

In our computer-simulated MRA study, different Gd-CA factors resulted in no significant difference in the maximal aortic SI.

Contrast-Enhanced Ultrasound Assessment of Renal Parenchymal Perfusion in Patients with Atherosclerotic Renal Artery Stenosis to Predict Renal Function Improvement After Revascularization

Background

Identifying patients with atherosclerotic renal artery stenosis (ARAS) who will be improved in renal function after percutaneous transluminal renal artery stenting (PTRAS) is crucial since most patients show no worthwhile benefit of PTRAS. Although the assessment of renal parenchymal perfusion is useful for the identification, few studies predict the renal functional improvement by evaluating the characteristics of renal perfusion.

Objective

The aim of this study was to assess the renal parenchymal perfusion in ARAS patients with contrast-enhanced ultrasonography (CEUS) and predict the benefits of renal function after PTRAS utilizing time-intensity curve (TIC) parameters.

Methods

Thirty-eight kidneys in 30 ARAS patients received PTRAS in this study. They were divided into moderate stenosis group (n=25) and severe stenosis group (n=13) and mild dysfunction group (n=14) and moderate dysfunction group (n=24) according to the degree of renal stenosis and radioisotope glomerular filtration rate (rGFR). The baseline assessment of renal function and renal parenchymal perfusion were performed for all patients. rGFR was repeated to evaluate the renal outcome at 4 months after PTRAS. The outcome of PTRAS was classified as improved, stable, or deteriorated compared to the baseline. Time-intensity curve (TIC) parameters obtained from CEUS were analyzed to evaluate the predictive accuracy.

Results

TIC parameters (AUC and PI) were positively correlated with renal function (r=0.617, 0.663; P<0.05) but weakly and negatively correlated with the stenosis (r=−0.360, −0.435; P<0.05). Baseline rGFR was not accurate in predicting improved renal function after PTRAS (0.670). The accuracy of the combined prediction model of baseline AUC and PI (0.889) was higher than the individual indicators (baseline AUC: 0.855 and PI: 0.782).

Conclusion

CEUS could accurately assess renal parenchymal perfusion and identify ARAS patients with potential benefit after PTRAS. The combination of TIC parameters (AUC and PI) is valuable in the prediction of improved renal function after PTRAS.

Quantitative evaluation of dexamethasone treatment effects in renal ischemia-reperfusion injury using contrast enhanced ultrasonography in rats

BACKGROUND

Renal ischemia-reperfusion (I/R) injury often occurs in various clinical events, and its incidence and mortality have been increasing.

OBJECTIVE

To investigate the value of contrast enhanced ultrasonography (CEUS) in the monitoring of dexamethasone in the improvement of renal I/R injury in rats.

METHODS

Eighteen healthy male Sprague-Dawley rats were randomly divided into sham-operated, I/R, and I/R surgery plus dexamethasone treatment (Dexa) groups. In the I/R group 45-minute renal ischemia with 24 h reperfusion period was monitored. Time-intensity curve (TIC)-derived parameters, which included peak value, time to peak (TP), area under the curve (AUC), and mean transit time (MTT) were compared to the blood creatinine, urea, Caspase-1, and NLRP3 levels.

RESULTS

The I/R group showed an increased peak value, prolonged TP and MTT, and greater AUC (P < 0.05). The Dexa group showed shorter TP and MTT, and smaller AUC (P < 0.05). Results show that the associations between (i) TP, AUC, and MTT and (ii) creatinine, urea, Caspase-1, and NLRP3 levels were significant (P < 0.05).

CONCLUSION

Dexamethasone can alleviate renal I/R injury in rats, which may be related to the inhibition of NLRP3 and caspase-1. CEUS can quantitatively measure this change, in which the changes in TP, AUC and MMT values have considerable reference values.

Clinical value and application of contrast-enhanced ultrasound in the differential diagnosis of malignant and benign breast lesions

The aim of the present study was to assess the performance of contrast-enhanced ultrasound in distinguishing between malignant and benign breast lesions and the diagnostic value of its clinical application. A total of 52 cases with malignant breast tumors and 73 cases with benign breast lesions were included in the study. Time-intensity curves (TICs) for contrast-enhanced ultrasound were recorded, and the perfusion parameters were obtained and analyzed. Typical features of malignant breast tumors included irregular shape and vascular morphology, uneven contrast agent distribution, filling defects and contrast agent retention, ‘fast-out’ wash-out mode, unclear boundaries and uneven internal echo. Benign lesions were characterized by ‘slow-out’ or synchronous wash-out mode. Regarding perfusion, the starting time of the perfusion of the Sone-Vue microbubble contrast (always 20-30 sec) and time to peak (TTP) were significantly earlier for the malignant lesions, while the wash-out time was later. A significantly greater peak intensity, rising slope and area under the TIC were observed for the malignant breast lesions. All of the malignant breast lesions exhibited an enlarged focus scope on ultrasound, while no obvious focus scope enhancement was observed for benign breast lesions. Furthermore, the TICs of 88.4% of malignant breast lesions were of the fast-rising and slow-declining type, while the TICs of 75.3 and 17.8% of the benign breast lesions were of the slow-rising and fast-declining, and fast-rising and fast-declining type, respectively. Receiver operating characteristics analysis indicated that the TTP, wash-out time and rising slope might contribute to the differential diagnosis between malignant and benign breast lesions. In conclusion, TIC parameters of contrast-enhanced ultrasound have promising clinical value in differentiating between malignant and benign breast lesions. The TTP, wash-out time and rising slope may contribute to the diagnosis of patients with breast lesions to facilitate timely treatment and prognostication of breast cancer patients.

Association Between Contrast-Enhanced Ultrasound Indicators and Prostate Cancer Biochemical Recurrence After Treatment

Background

Some patients with prostate cancer (PCa) will experience biochemical recurrence (BCR) after treatment. Current researches have identified the influencing factors of BCR, but these factors are difficult to quantify and hence unable to accurately predict the BCR in PCa patients.

Objective

To explore the value of contrast-enhanced ultrasound (CEUS) indicators in predicting the BCR after treatment by evaluating the association between them.

Patients and Methods

In a retrospective cohort study, 157 PCa patients were recruited and received prostate specific antigen (PSA) measurement, CEUS, pathological classification, and immunohistochemistry after puncture biopsy. PCa patients with BCR were included in the recurrence group, while the remaining patients were included in the non-recurrence group after a 5-year follow-up. The clinical characteristics and CEUS indicators were compared between the two groups, and the multivariable COX regression was used for screening the influencing factors of BCR. Receiver operating characteristic (ROC) curves were used to analyze the value of potential factors in predicting BCR. The effect of the combined prediction model was explored to improve the accuracy of the prediction.

Results

Twelve patients are lost during the follow-up period and the final analysis included 145 patients. The 5-year BCR rate of PCa patients was 27%, with 43 patients in the recurrence group and 102 patients in the non-recurrence group. Multivariate analysis showed that lymph node metastasis (P<0.001), distant metastasis (P<0.001), Gleason score (P<0.001), pretreatment PSA (P<0.001), treatment method (P<0.001), peak intensity (PI) (P=0.001), and time to peak (TTP) (P=0.003) were independent influencing factors for BCR after treatment. ROC analysis showed that the AUCs of all indicators in predicting BCR were not high (all <0.9). The combination of lymph node metastasis, Gleason score, pretreatment PSA, and treatment method can improve the predictive accuracy (AUC = 0.85), but the AUC was still under 0.9. The combined prediction model including CEUS time-intensity curve (TIC) indicators (PI and TTP) could accurately predict the BCR after treatment (AUC=0.953). The sensitivity and specificity were 93.02% and 88.24%, respectively.

Conclusion

The prediction model including TIC indicators and common influencing factors can more accurately predict the BCR in PCa patients.

Evaluation of Femoral Head Perfusion by Contrast-Enhanced Ultrasound in a Rabbit Model of Steroid-Induced Osteonecrosis

OBJECTIVES

To study the technical feasibility of contrast-enhanced ultrasound (CEUS) in evaluating femoral head perfusion in a rabbit model of steroid-induced femoral head osteonecrosis.

METHODS

Twenty rabbits were divided randomly into a control group (n = 8) and an experimental group (n = 12). Rabbits in the experimental group were induced by lipopolysaccharide and methylprednisolone to build a model of steroid-induced femoral head osteonecrosis. Contrast-enhanced ultrasound examinations were performed at 3 and 5 weeks after induction. Then, pathologic examinations and microvessel density (MVD) calculations were performed on the excised rabbit femoral heads.

RESULTS

The MVD of the experimental group decreased significantly 3 and 5 weeks after induction compared with that of the control group. According to the CEUS examination results, significant differences existed in the ascending slope, descending slope, mean transit time, and time to peak between the groups at 5 weeks (P < .05). A correlation analysis showed that the descending slope had a certain correlation with the MVD (correlation coefficient, 0.376). A receiver operating characteristic curve was used to analyze the capacity of the CEUS parameters to predict the occurrence of osteonecrosis. The areas under the curve for the ascending slope and descending slope were 0.758 and 0.760, respectively (P < .05).

CONCLUSIONS

Contrast-enhanced ultrasound can visualize the microcirculation in steroid-induced osteonecrosis of the femoral head in rabbits and may be a useful imaging method for the early monitoring and prediction of femoral head osteonecrosis.

Current status of imaging diagnosis in the transplanted kidney. A review of the literature with a special focus on contrast-enhanced ultrasonography

Objectives

Ultrasonographic scanning is currently the most widespread imaging diagnostic procedure. The method provides real-time morphological, vascular and elastographic information in a non-invasive manner. In recent years, harmonic vascular examination has become accessible using intravenous contrast agents. In urological pathology, this procedure is used in the detection and evaluation of vascular and ischemic complications, in the classification of complex cysts according to the Bosniak system, also in the renal lesions with uncertain etiology and in acute pyelonephritis for the detection of abscesses. The contrast agent (SonoVue) is angiospecific and can be used in patients transplanted immediately after surgery without adverse effects or impaired renal function. Thus, it is desirable to be used in the nephrological pathology of the renal graft and to develop diagnostic models based on the evaluation of renal microvascularization, as well as the quantitative data resulting from the graphical representation of the specific parameters. The purpose of this review is to evaluate the current state of the literature regarding the place and role of contrast substance ultrasound in the early diagnosis of acute renal graft dysfunction and to make a differential diagnosis of this pathological entity.

Method

This review quantifies the role of contrast ultrasound in the diagnosis of acute complications of the renal graft. The research was conducted based on the databases PubMed, MedScape, Cochrane, according to the search criteria such as contrast-enhanced ultrasound + kidney transplant, “time intensity curves” + “kidney transplant”, filtered for the period 2004–2018.

Results

In the nephrological pathology of the renal graft, contrast-enhanced ultrasound is a valuable tool, superior to Doppler ultrasound in predicting the evolution of the renal graft, identifying very small early defects in renal microvascularization. A number of studies succeeded in identifying acute graft dysfunction, some of which establish its etiology - humoral rejection versus acute tubular necrosis. On the other hand, the contrast-enhanced ultrasound parameters do not have the ability to distinguish between cellular and humoral rejection.

Conclusions

If, at present, the histopathological examination is the only one that can differentiate with certainty the cause of acute renal graft dysfunction, we consider that contrast-enhanced ultrasound, as a non-invasive imaging technique, opens a favorable perspective for increasing the survival of the renal graft and decreasing the complications in the renal transplant. The combination of other ultrasound techniques, together with contrast-enhanced ultrasound, could lead to the development of new diagnostic models.

Application of quantitative analysis of contrast-enhanced ultrasonography in the evaluation of acute radiation-induced liver damage

The aim of the present study was to evaluate the microcirculation perfusion in patients with acute radiation-induced liver damage (RILD) and explore the feasibility of non-invasive evaluation of RILD using quantitative analysis of contrast-enhanced ultrasound (CEUS). Patients who successfully underwent three-dimensional conformal intensity-modulated radiotherapy for abdominal tumors were selected. CEUS was performed on the liver prior to and 2, 3 and 4 weeks after exposure, and the time-intensity curve (TIC) was obtained by quantitative analysis of CEUS. The time to peak (TTP), gradient (Grad) and area under the curve (AUC) were analyzed offline. The Grad of the CEUS TIC was decreased and TTP increased with the prolongation of the irradiation duration, with statistically significant differences between the values in the 2-, 3- and 4-week groups vs. those prior to exposure (P<0.05), as well as among the values of the 2-, 3- and 4-week groups (P<0.05). Following irradiation, the AUC decreased gradually in the 2- and 3-week groups and increased in the 4-week group, with statistically significant differences compared with the AUC prior to irradiation (P<0.05). The quantitative analysis parameters of CEUS may be important reference parameters for the early diagnosis of acute RILD.

Quantitative evaluation of renal parenchymal perfusion using contrast-enhanced ultrasonography in renal ischemia-reperfusion injury in dogs

This study evaluated whether renal perfusion changes can be noninvasively estimated by using contrast-enhanced ultrasonography (CEUS) in renal ischemia-reperfusion injury and investigated the correlation between renal perfusion measured by CEUS and necrosis and apoptosis of renal tubular epithelial cells. In six dogs with experimentally induced renal ischemia-reperfusion injury, changes in time to peak intensity, peak intensity, and area under the curve were measured on CEUS. Peak intensity and area under the curve of the renal cortex began to decrease on day 1 (about 20% lower than baseline) and reached the lowest levels (about 50% of baseline) on day 4. They then gradually increased until day 10, at which time peak intensity was about 87% and area under the curve was about 95% of baseline; neither fully recovered. Both parameters were strongly correlated with the necrosis scores on histopathologic examination on day 4 (r = −0.810 of peak intensity and r = −0.886 of area under the curve). CEUS allowed quantitative evaluation of perfusion changes in acute renal ischemia-reperfusion injury, and CEUS results were correlated with renal tubular damage on histopathologic examination. Thus, CEUS could be a noninvasive, quantitative diagnostic method for determining progress of renal ischemia-reperfusion injury.

[Comparison of Time-intensity Curve with Gadobenatedimeglumine and Gadobutrol on Multiphase Contrast-enhanced Breast MRI]

The purpose of this study was to compare the time-intensity curve (TIC) on multiphase contrast-enhanced breast magnetic resonance imaging (MRI) between Gadobenatedimeglumine (Gd-DTPA) and Gadobutrol. We assessed the images of 53 cases obtained from MRI that had malignant findings by pathology from October 2015 to October 2016 in our institute. Gd-DTPA and Gadobutrol were administrated in 16 and 37 cases, respectively. The TIC of the lesion was classified according to the Kuhl's method (type I: persistent pattern, type II: plateau pattern and type III: washout pattern). Type III was the most common TIC pattern in both the groups (Gd-DTPA, 12 cases; Gadobutrol, 18 cases). Type II was the second common TIC pattern in Gadobutrol group (12 cases). As a result, there was no significant difference in TIC analysis between Gd-DTPA and gadobutrol. In conclusion, the contrast between Gd-DTPA and Gadobutrol contrast media did not differ in TIC pattern of multiphasic contrast-enhanced breast MRI.

Analysis of Contrast-Enhanced Ultrasound Perfusion Patterns and Time-Intensity Curves for Metastatic Lymph Nodes From Lung Cancer: Preliminary Results

OBJECTIVES

To retrospectively summarize the similarities and differences in contrast-enhanced ultrasound (US) findings for lymph node metastasis from adenocarcinoma, squamous carcinoma, and small cell lung cancer.

METHODS

Patients who had received contrast-enhanced US examinations and had a histologic diagnosis of supraclavicular lymph node metastasis from lung cancer were included. The perfusion patterns on contrast-enhanced US images and time-intensity curve parameters were analyzed for the different pathologic types. The microvascular density and microvascular diameter were evaluated.

RESULTS

Totally, 61 patients were enrolled in this study, including 26 cases with lung squamous carcinoma, 26 with lung adenocarcinoma, and 9 with small cell lung cancer. Contrast-enhanced US perfusion showed no significant differences in enhancement uniformity during the arterial phase and in the presence of unenhanced areas of metastatic lymph nodes with the 3 different pathologic origins (P > .05), but fewer unenhanced areas could be seen in metastatic lymph nodes from adenocarcinoma. The analysis of the time-intensity curve parameters showed that there were significant differences in the peak intensity between metastatic lymph nodes from lung squamous carcinoma and lung adenocarcinoma (P < .05). The microvascular density of metastatic lymph nodes from adenocarcinoma was significantly higher than that of metastatic lymph nodes from squamous carcinoma and small cell lung cancer (P < .001; P = .0444), whereas the microvascular diameter of metastatic lymph nodes from adenocarcinoma was significantly smaller than that from squamous carcinoma and small cell lung cancer (P = .0277; P < .001).

CONCLUSIONS

Effects of the pathologic diagnosis should be considered when analyzing quantitative parameters of metastatic lymph nodes during contrast-enhanced US examinations, even in the same organ.

Diagnostic Value of Contrast-Enhanced Ultrasonography and Time-Intensity Curve in Differential Diagnosis of Cervical Metastatic and Tuberculous Lymph Nodes

OBJECTIVES

To evaluate the diagnostic value of contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of tuberculous and metastatic lymph nodes.

METHODS

Nineteen cervical tuberculous lymph nodes and 43 cervical metastatic lymph nodes were investigated. The CEUS perfusion patterns and parameters of time-intensity curve (TIC) were analyzed. Diagnostic accuracy and consistency of two physicians were compared before and after CEUS and TIC analysis.

RESULTS

Conventional ultrasonography showed no significant differences between tuberculous and metastatic lymph nodes. Concentric enhancement at the arterial phase of CEUS occurred in 15 of 19 (78.9%) tuberculous lymph nodes and 42 of 43 (97.7%) metastatic lymph nodes (P < .05). For the TIC curve, a steep descending curve with an apparent notch was commonly found in tuberculous lymph nodes (13 of 16). Although a shallow descending curve was common (40 of 43) in metastatic lymph nodes, most did not have a notch on the curve (39 of 43) (P < .01). The k-value and the peak intensity (PI) value of tuberculous lymph nodes were significantly higher and the △PI value was significantly lower than that of metastatic lymph nodes (P < .05, respectively). Kappa values for the diagnosis consistency of the two physicians before and after CEUS and TIC analysis were 0.582 and 0.761, respectively. Diagnostic accuracy before and after CEUS and TIC analysis was 47.4% (28 of 59) and 96.6% (57 of 59), respectively (P < .001).

CONCLUSIONS

Contrast-enhanced ultrasonography with TIC analysis is helpful in differentiating tuberculous from metastatic lymph nodes.

Differentiation between high- and low-grade urothelial carcinomas using contrast enhanced ultrasound

Purpose

To evaluate the value of contrast-enhanced ultrasonography (CEUS) in the differentiation of high and low grade urothelial carcinoma.

Materials and Methods

192 with 192 bladder lesions, including 110 high grade urothelial carcinoma and 82 low grade urothelial carcinoma were examined by CEUS. Among 192 tumors, enhancement patterns of 96 tumors between August 2010 and December 2012 were analyzed retrospectively. Then from January 2013 to April 2015, compared with CEUS was performed on 96 tumors for prospective differential diagnosis. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were assessed.

Results

With the CEUS view, dominant enhancement patterns were revealed as fast wash-in and slow wash-out for high grade urothelial carcinoma, fast wash-in and fast wash-out for low grade urothelial carcinoma, respectively. At CEUS, the prospective differentiation of bladder tumors showed sensitivity 86% , specificity 90%, accuracy 88%, positive predictive value 92%, and negative predictive value 82% for high grade tumors, while sensitivity 85% , specificity 89%, accuracy 88%, positive predictive value 85% and negative predictive value 89% for low grade tumors, respectively.

Conclusions

Our study demonstrates the great potential of CEUS in the differentiation of high and low grade urothelial carcinoma. Since CEUS is an effective, inexpensive, and non-invasive method. It could be a reliable tool in the evaluation of patients with bladder tumors.

Assessment of renal perfusion with contrast-enhanced ultrasound: Preliminary results in early diabetic nephropathies

OBJECTIVE

We performed a prospective study to evaluate the value of contrast-enhanced ultrasound (CEUS) in quantitative evaluation of renal cortex perfusion in patients suspected of early diabetic nephropathies (DN), with the estimated GFR (MDRD equation) as the gold standard.

METHODS

The study protocol was approved by the hospital review board; each patient gave written informed consent. Our study included 46 cases (21 males and 25 females, mean age 55.6 ± 4.14 years) of clinical confirmed early DN patients. After intravenous bolus injection of 1 ml sulfur hexafluoride microbubbles of ultrasound contrast agent, real time CEUS of renal cortex was performed successively using a 2-5 MHz convex probe. Time-intensity curves (TICs) and quantitative indexes were created with Qlab software. Receiver operating characteristic (ROC) curves were used to predict the diagnostic criteria of CEUS quantitative indexes, and their diagnostic efficiencies were compared with resistance index (RI) and peak systolic velocity (PSV) of renal segmental arteries by chi square test. Our control group included forty-five healthy volunteers. Difference was considered statistically significant with P <  0.05.

RESULTS

Changes of area under curve (AUC), derived peak intensity (DPI) were statistically significant (P <  0.05). DPI less than 12 and AUC greater than 1400 had high utility in DN, with 71.7% and 67.3% sensitivity, 77.8% and 80.0% specificity. These results were significantly better than those obtained with RI and PSV which had no significant difference in early stage of DN (P > 0.05).

CONCLUSIONS

CEUS might be helpful to improve early diagnosis of DN by quantitative analyses. AUC and DPI might be valuable quantitative indexes.

Quantitative contrast-enhanced ultrasonography for the differential diagnosis of endometrial hyperplasia and endometrial neoplasms

The present study aimed to investigate the feasibility of applying contrast-enhanced ultrasonography (CEUS) imaging technology for distinguishing between benign and malignant endometrial lesions, and to screen markers that could be correlated with the pathological results. In this study, endometrial diseases were diagnosed by biopsy under hysteroscopy and CEUS examinations. The intensity and time parameters of the time-intensity curve (TIC) were analyzed. The mean arrival time (AT), time-to-peak (TTP), rise time (RT), washout half-time and clearance half-time of malignant lesions were shorter than those of benign lesions (P<0.05), whereas the average peak intensity (PI) and enhancement intensity (EI) of malignant lesions were higher than those of benign lesions (P<0.05). The receiver operating characteristic curve showed the following cut-off values: PI, 29.2 dB; EI, 21.35 dB; AT, 12.75 sec; TTP, 26.75 sec; RT, 13.2 sec; clearance half-time, 89.3 sec; and washout half-time, 75.45 sec. The lesions with PI, an EI higher than that of the cut-off and lesions with an AT, TTP, RT, half clearing time and washout half-time shorter than the cut-off were considered malignant. The TTP, RT and half clearing time were negatively correlated with microvessel density (MVD), i.e., MVD was higher when the TTP, RT and half clearing time were shorter. Overall, changes in the enhancement and clearing of lesions could be quantitatively analyzed by CEUS TIC and further discriminate benign from malignant lesions. In the present study, CEUS appeared to indirectly reflect blood vessel changes inside the lesions and provided a pre-operative non-invasive fast imaging method for the diagnosis of endometrial disease.

Contrast-enhanced sonography of thyroid nodules

PURPOSE

To investigate the value of contrast-enhanced ultrasound (CEUS) in the differentiation of benign and malignant nodules.

METHODS

One hundred eighty-nine patients with 213 thyroid nodules were enrolled in this retrospective study. All patients underwent preoperative CEUS and were subsequently scheduled for surgery. The pathology results were obtained after surgery. The time-intensity curves were plotted with TomTec software. The quantitative parameters of the time-intensity curve, such as the maximum intensity of peak (IMAX), the rise time from 10% to 90% of the IMAX, and the time to peak, were compared between the benign and malignant nodules.

RESULTS

There were no significant differences in the rise time or the time to peak among thyroid papillary carcinoma, nodular goiter, and follicular adenoma. However, a significant difference was identified in the IMAX.

CONCLUSIONS

A quantitative evaluation of CEUS is helpful to differentiate benign and malignant thyroid nodules.

Value of whole body MRI and dynamic contrast enhanced MRI in the diagnosis, follow-up and evaluation of disease activity and extent in multiple myeloma

PURPOSE

To evaluate the significance of dynamic contrast enhanced MRI (DCE-MRI) and whole body MRI (WB-MRI) in the diagnosis, prognosis and assessment of therapy for patients with monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM).

MATERIALS AND METHODS

The retrospective study includes 219 patients providing 463 WB-MRI and DCE-MRI investigations for the subgroups MGUS (n=70), MM active disease (n=126; this includes 70 patients with new diagnosis of MM, according to the International Staging System (ISS): 41.4% ISS stage I, 20.0% ISS stage II, 7.1% ISS stage III, 31.4% insufficient for staging; and 56 patients with '(re-)active disease': 16.07% relapse, 32.14% progressive disease and 51.79% stable disease) and MM remission (n=23; 60.87% complete remission, 17.39% very good partial remission and 21.74% partial remission). Investigations of patients with hereditary multiple exostoses (n=5), neurofibromatosis (n=7) and healthy persons (n=9) were added as control subjects (n=21). WB-MRI evaluation was done by evaluating thirteen skeletal regions, providing a 'skeletal score'. DCE-MRI images of the spine, were analyzed with regions-of-interest and time-intensity-curves (TIC).

RESULTS

All TIC parameters can significantly differentiate between the predefined subgroups (p<0.001). One hundred days after autologous stem cell transplantation a 75% decrease of the slope wash-in value (p<0.001) can be seen. A cubic regression trend between 'skeletal score' and slope wash-in (adj.R(2)=0.412) could demonstrate a significant increase bone marrow perfusion if MM affects more than 10 skeletal regions (p<0.001), associated with a poorer prognosis (p<0.001).

CONCLUSION

DCE-MRI evaluation of the spine is useful for diagnosis of MM, follow-up after stem cell transplantation and evaluation of disease activity. A combined evaluation with WB-MRI and DCE-MRI provides additional micro-vascular information on the morphologic lesions and could help categorize patients with MM in two different groups to offer useful therapeutic and prognostic advise.

Rapid 3-D imaging of contrast flow: application in a perfused kidney phantom

Previous studies indicate imaging of ultrasound contrast in 3-D is potentially superior to 2-D imaging for vascular characterization. A dual-beam, dynamic refill technique, which relies on volumetric contrast clearance and sequential imaging, was used to image a preserved porcine kidney perfused with contrast. A model was developed for the contrast profile across the renal artery to estimate fractional blood volume. This model was used along with refill curve information to measure absolute perfusion within renal cortex for a 100-cm(3) volume. Perfusion measurements from a slice within the volume were also made using a modified interval imaging technique. The measured perfusion using the dual-beam technique was consistent with the perfusion measured using the interval imaging technique (dual-beam values were 1.06 +/- 0.04 x corresponding interval imaging values). These experiments suggest that ultrasound contrast perfusion measurements are independent of the volume of contrast eliminated before refill.