Time-intensity Curves Research Articles

EFSUMB Technical Review - Update 2023: Dynamic Contrast-Enhanced Ultrasound (DCE-CEUS) for the Quantification of Tumor Perfusion.

Dynamic contrast-enhanced ultrasound (DCE-US) is a technique to quantify tissue perfusion based on phase-specific enhancement after the injection of microbubble contrast agents for diagnostic ultrasound. The guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) published in 2004 and updated in 2008, 2011, and 2020 focused on the use of contrast-enhanced ultrasound (CEUS), including essential technical requirements, training, investigational procedures and steps, guidance regarding image interpretation, established and recommended clinical indications, and safety considerations. However, the quantification of phase-specific enhancement patterns acquired with ultrasound contrast agents (UCAs) is not discussed here. The purpose of this EFSUMB Technical Review is to further establish a basis for the standardization of DCE-US focusing on treatment monitoring in oncology. It provides some recommendations and descriptions as to how to quantify dynamic ultrasound contrast enhancement, and technical explanations for the analysis of time-intensity curves (TICs). This update of the 2012 EFSUMB introduction to DCE-US includes clinical aspects for data collection, analysis, and interpretation that have emerged from recent studies. The current study not only aims to support future work in this research field but also to facilitate a transition to clinical routine use of DCE-US.

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

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. 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. 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). 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.

Contrast-enhanced ultrasonography for identifying acute kidney injury in brain-dead donors.

Acute kidney injury (AKI) is frequently found in deceased donors; however, few studies have reported the use of imaging to detect and identify this phenomenon. The purpose of this study was to detect renal microcirculatory perfusion in brain-dead donors using contrast-enhanced ultrasonography (CEUS), investigate the value of CEUS in identifying AKI, and analyze the correlation between CEUS and preimplantation biopsy results and early post-transplant renal function of grafts. This prospective study recruited 94 kidneys from brain-dead donors (AKI =44, non-AKI =50) from August 2020 to November 2022. The inclusion criteria were age ≥18 years and brain death. The exclusion criteria encompassed donors maintained with extracorporeal membrane oxygenation (ECMO) and the presence of irregular kidney anatomy. The mean age of the donors was 45.1±10.4 [standard deviation (SD)] years, and the majority were male (86.2%). CEUS was performed prior to organ procurement, and time-intensity curves (TICs) were constructed. The time to peak (TTP) and peak intensity (PI) of kidney segmental artery (KA), kidney cortex (KC), and kidney medulla (KM) were calculated using TIC analysis. Arrival time (AT) of KA (P<0.001) and TTP of kidney cortex (TTPKC) (P<0.001) of the non-AKI group were significantly shorter than those of the AKI group. The PI of the KA (P=0.003), KM (P=0.005), and kidney cortex (PIKC; P<0.001) of the non-AKI group were significantly higher than those of the AKI group. Multivariable logistic regression analysis showed that serum creatinine [odds ratio (OR) =1.06; 95% CI: 1.03-1.1; P<0.001], TTPKC (OR =1.38; 95% CI: 1.03-1.84; P=0.03), and PIKC (OR =0.95; 95% CI: 0.91-1; P=0.046) were the independent factors of AKI. The area under the receiver operating characteristic curve (AUC) for identifying AKI for TTPKC and PIKC was 0.73 and 0.71, respectively. TTPKC showed a weak correlation with interstitial fibrosis (r=0.23; P=0.03), PIKC showed a weak correlation with arterial intimal fibrosis ((r=-0.29; P=0.004) and arteriolar hyalinosis (r=-0.27; P=0.008), and PIKC showed the strongest correlation with eGFR on postoperative day 7 (r=-0.46; P=0.046) in the donor kidneys with AKI. CEUS can be used to identify AKI in brain-dead donors. Furthermore, there is a correlation between CEUS-derived parameters and pretransplant biopsy results and early preimplantation renal function of grafts.

Contrast-Enhanced Ultrasonography as a Diagnostic Strategy for Severe Endometrial Injury.

Endometrial injury is associated with poorer pregnancy outcomes. The purpose of this study was to evaluate the diagnostic efficacy of contrast-enhanced ultrasonography (CEUS) in the detection of endometrial injury. This study included women who underwent CEUS of the uterus at the author's hospital between April 2020 and January 2021. The diagnostic performances of the CEUS-derived parameters in the detection of severe endometrial injury were evaluated by receiver operating characteristic curve analyses. The study included 67 participants (healthy control, n = 14; mild endometrial injury, n = 24; severe endometrial injury, n = 29). Enhancement intensity (EI) and area under the time-intensity curve (AUC TIC ) were significantly lower in the severe endometrial injury patients than healthy and mild endometrial injury subjects for both endometrial and subendometrial regions ( P < 0.05). Correlations analysis showed that EI and AUC TIC were positively correlated with endometrial thickness ( r = 0.460, P = 0.01, and r = 0.555, P < 0.01, respectively) and subendometrial thickness ( r = 0.501, P < 0.01, and r = 0.438, P = 0.01, respectively). The area under the receiver operating characteristic curve, sensitivity, and specificity were 0.720 ( P = 0.002), 79.31%, and 66.67% for endometrial EI; 0.818 ( P < 0.001), 75.86%, and 79.17% for subendometrial EI; 0.917 ( P < 0.001), 72.41%, and 95.83% for endometrial AUC TIC ; and 0.810 ( P < 0.001), 89.66%, and 70.83% for subendometrial AUC TIC , respectively. Contrast-enhanced ultrasonography may have clinical utility in the prediction of endometrial injury in women of childbearing age.

Role of combined clinical-radiomics model based on contrast-enhanced MRI in predicting the malignancy of breast non-mass enhancements without an additional diffusion-weighted imaging sequence.

In our previous study, we developed a combined diagnostic model based on time-intensity curve (TIC) types and radiomics signature on contrast-enhanced magnetic resonance imaging (CE-MRI) for non-mass enhancement (NME). The model had a high diagnostic ability for differentiation without the additional diffusion-weighted imaging (DWI) sequence. In this study, we aimed to compare the diagnostic performance of the combined clinical-radiomics model based on CE-MRI and DWI in discriminating Breast Imaging-Reporting and Data System (BI-RADS) 4 NME breast lesions, ductal carcinoma in situ (DCIS), and invasive carcinoma. This retrospective study enrolled 364 NME lesions (343 patients). Of these, 183 malignant and 84 benign breast lesions classified as BI-RADS 4 NMEs by the initial diagnosis were reclassified based on the combined clinical-radiomics model and DWI, respectively. The nomogram score (NS) values for malignancy risk derived from the combined clinical-radiomics model and the minimal apparent diffusion coefficient (ADC) values from DWI were calculated and compared. The percentage of false positives were estimated in comparison with the original classification. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic value of the NS and minimal ADC values in distinguishing benign and malignant lesions, DCIS, and invasive breast carcinoma. An ablation experiment was used to test the value of the additional DWI sequence. The diagnostic value of the NS values [area under curve (AUC) =0.843; 95% CI: 0.789-0.896] for discriminating the 267 NME breast lesions categorized as BI-RADS 4 was significantly higher than the minimal ADC values (AUC =0.662; 95% CI: 0.590-0.735). The NS values showed higher sensitivity, specificity, and accuracy compared with the minimal ADC values (sensitivity: 80.3% vs. 65.6%; specificity: 79.8% vs. 65.5%; accuracy: 80.1% vs. 65.5%). The NS values and minimal ADC values did not achieve high diagnostic accuracy in discriminating between DCIS and invasive cancer. However, the diagnostic performance of the combined NS-ADC model (AUC =0.731; 95% CI: 0.655-0.806) was higher than that of the NS values alone (P=0.008) and comparable to that of the minimal ADC values (P=0.440). The combined clinical-radiomics model based on CE-MRI could improve the diagnostic performance in discriminating the BI-RADS 4 NME lesions without an additional DWI sequence. However, DWI may improve the diagnostic performance in discriminating DCIS from invasive cancer.

Characterization of denosumab treatment response in giant cell tumors of bone with dynamic contrast-enhanced MRI

Rationale and objectivesDenosumab is a monoclonal antibody used neo-adjuvantly in giant cell tumor of bone (GCTB) to facilitate surgery, or long term for axial tumors where surgery comes with high morbidity. Time intervals for treatment effects to occur are unclear and monitoring tools are limited, complicating optimal drug dose titration. We assessed changes in time intensity curve (TIC) - derived perfusion features on DCE-MRI in GCTB during denosumab treatment and evaluated the duration of treatment effects on tumor perfusion. Materials and methodsPatients with GCTB who underwent dynamic contrast enhanced (DCE) MRI before (t = 0) and after 3 (t = 3), 6 (t = 6) or 12 (t = 12) months of denosumab treatment were retrospectively included in a single center. Regions of interest were placed on tumor compartments with visually most intense enhancement and TICs were created. Time-to-enhancement (TTE), wash-in rate (WIR), maximal relative enhancement (MRE), and area-under-the-curve (AUC) were calculated. Differences in perfusion features were calculated with the Wilcoxon signed-rank test. ResultsIn all 24 patients decreased perfusion on DCE-MRI after start of denosumab treatment was seen. TTE increased between t = 0 and t = 3 (p < 0.001). WIR, MRE and AUC decreased between t = 0 and t = 3 (p < 0.001, p = 0.01 and p = 0.02, respectively). No significant differences in features were found between t = 3 and t = 6 or t = 6 and t = 12. No significant perfusion differences in primary versus recurrent, or axial versus appendicular tumors, were found. ConclusionMRI perfusion significantly changed in GCTB within 3 months of denosumab treatment compared to baseline. No further significant change occurred between 3 and 6, and 6 and 12 months of treatment. These findings suggest that evaluation of treatment response and subsequent consideration of maintenance with lower doses of denosumab, may already be indicated after 3 months. In cases where long term denosumab is the preferred therapy, monitoring change in tumor characteristics on DCE-MRI may aid optimal drug dose titration, minimizing side effects.

Voxel-wise mapping of DCE-MRI time-intensity-curve profiles enables visualizing and quantifying hemodynamic heterogeneity in breast lesions.

To propose a novel model-free data-driven approach based on the voxel-wise mapping of DCE-MRI time-intensity-curve (TIC) profiles for quantifying and visualizing hemodynamic heterogeneity and to validate its potential clinical applications. From December 2018 to July 2022, 259 patients with 325 pathologically confirmed breast lesions who underwent breast DCE-MRI were retrospectively enrolled. Based on the manually segmented breast lesions, the TIC of each voxel within the 3D whole lesion was classified into 19 subtypes based on wash-in rate (nonenhanced, slow, medium, and fast), wash-out enhancement (persistent, plateau, and decline), and wash-out stability (steady and unsteady), and the composition ratio of these 19 subtypes for each lesion was calculated as a new feature set (type-19). The three-type TIC classification, semiquantitative parameters, and type-19 features were used to build machine learning models for identifying lesion malignancy and classifying histologic grades, proliferation status, and molecular subtypes. The type-19 feature-based model significantly outperformed models based on the three-type TIC method and semiquantitative parameters both in distinguishing lesion malignancy (respectively; AUC = 0.875 vs. 0.831, p = 0.01 and 0.875vs. 0.804, p = 0.03), predicting tumor proliferation status (AUC = 0.890 vs. 0.548, p = 0.006 and 0.890 vs. 0.596, p = 0.020), but not in predicting histologic grades (p = 0.820 and 0.970). In addition to conventional methods, the proposed computational approach provides a novel, model-free, data-driven approach to quantify and visualize hemodynamic heterogeneity. Voxel-wise intra-lesion mapping of TIC profiles allows for visualization of hemodynamic heterogeneity and its composition ratio for differentiation of malignant and benign breast lesions. • Voxel-wise TIC profiles were mapped, and their composition ratio was compared between various breast lesions. • The model based on the composition ratio of voxel-wise TIC profiles significantly outperformed the three-type TIC classification model and the semiquantitative parameters model in lesion malignancy differentiation and tumor proliferation status prediction in breast lesions. • This novel, data-driven approach allows the intuitive visualization and quantification of the hemodynamic heterogeneity of breast lesions.

Contrast-enhanced endoscopic ultrasound for swollen lymph nodes.

Endoscopic ultrasound (EUS) is an important tool for the evaluation of lymphadenopathy, especially in intra-thoracic or intra-abdominal regions. EUS also provides tissue diagnosis via EUS fine-needle aspiration or biopsy. To select the target for biopsy or aspiration, conventional B-mode images are used for the evaluation, but this approach still lacks diagnostic accuracy. Contrast-enhanced EUS has been used to evaluate the vascularity of lesions. Most malignant lymphadenopathy shows heterogenous enhancement or defect of enhancement, while quantitative studies using time-intensity curves in contrast-enhanced harmonic EUS show a rapid decline in enhancement pattern. These findings are useful as an auxiliary method for tissue diagnosis or in cases in which tissue diagnosis is contraindicated.

Applications of Dynamic Contrast-Enhanced Ultrasound in Differential Diagnosis of Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma in Non-cirrhotic Liver.

The aim of the work described here was to investigate the value of dynamic contrast enhanced ultrasound (DCE-US) and quantitative analysis in pre-operative differential diagnosis of intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) in non-cirrhotic liver. In this retrospective study, patients with histopathologically proven ICC and HCC lesions in non-cirrhotic liver were included. All patients underwent contrast-enhanced ultrasound (CEUS) examinations with an Acuson Sequoia unit (Siemens Healthineers, Mountain View, CA, USA) unit or LOGIQ E20 (GE Healthcare, Milwaukee, WI, USA) within 1 wk before surgery. SonoVue (Bracco, Milan, Italy) was used as the contrast agent. B-mode ultrasound (BMUS) features and CEUS enhancement patterns were analyzed. DCE-US analysis was performed by VueBox software (Bracco). Two regions of interest (ROIs) were set in the center of the focal liver lesions and their surrounding liver parenchyma. Time-intensity curves (TICs) were generated, and quantitative perfusion parameters were obtained and compared between the ICC and HCC groups using the Student t-test or Mann-Whitney U-test. From November 2020 to February 2022, patients with histopathologically confirmed ICC (n=30) and HCC (n=24) lesions in non-cirrhotic liver were included. During the arterial phase (AP) of CEUS, ICC lesions exhibited heterogeneous hyperenhancement (13/30, 43.3%), heterogeneous hypo-enhancement (2/30, 6.7 %) and rim-like hyperenhancement (15/30, 50.0%), whereas all HCC lesions exhibited heterogeneous hyperenhancement (24/24, 100.0%) (p < 0.05). Subsequently, most of the ICC lesions exhibited AP wash-out (83.3%, 25/30), whereas a few cases exhibited wash-out in the portal venous phase (PVP) (15.7%, 5/30). In contrast, HCC lesions exhibited AP wash-out (41.7%, 10/24), PVP wash-out (41.7%, 10/24) and a small part of late phase wash-out (16.7%, 4/24) (p < 0.05). Compared with those of HCC lesions, TICs of ICCs revealed earlier and lower enhancement during the AP, faster decline during the PVP and reduced area under the curve. The combined area under the receiver operating characteristic curve (AUROC) of all significant parameters was 0.946, with 86.7% sensitivity, 95.8% specificity and 90.7% accuracy in differential diagnosis between ICC and HCC lesions in non-cirrhotic liver, which improved the diagnostic efficacy of CEUS (58.3% sensitivity, 90.0% specificity and 75.9% accuracy). ICC and HCC lesions in non-cirrhotic liver might exhibit some overlap of CEUS features in diagnosis. DCE-US with quantitative analysis would be helpful in pre-operative differential diagnosis.

Diagnosis and monitoring denosumab therapy of giant cell tumors of bone: radiologic-pathologic correlation.

To determine the value of CT and dynamic contrast-enhanced (DCE-)MRI for monitoring denosumab therapy of giant cell tumors of bone (GCTB) by correlating it to histopathology. Patients with GCTB under denosumab treatment and monitored with CT and (DCE-)MRI (2012-2021) were retrospectively included. Imaging and (semi-)quantitative measurements were used to assess response/relapse. Tissue samples were analyzed using computerized segmentation for vascularization and number of neoplastic and giant cells. Pearson's correlation/Spearman's rank coefficient and Kruskal-Wallis tests were used to assess correlations between histopathology and radiology. Six patients (28 ± 8years; five men) were evaluated. On CT, good responders showed progressive re-ossification (+7.8HU/month) and cortical remodeling (woven bone). MRI showed an SI decrease relative to muscle on T1-weighted (-0.01 A.U./month) and on fat-saturated T2-weighted sequences (-0.03 A.U./month). Time-intensity-curves evolved from a type IV with high first pass, high amplitude, and steep wash-out to a slow type II. An increase in time-to-peak (+100%) and a decrease in Ktrans (-71%) were observed. This is consistent with microscopic examination, showing a decrease of giant cells (-76%), neoplastic cells (-63%), and blood vessels (-28%). There was a strong statistical significant inverse correlation between time-to-peak and microvessel density (ρ = -0.9, p = 0.01). Significantly less neoplastic (p = 0.03) and giant cells (p = 0.04) were found with a time-intensity curve type II, compared to a type IV. Two patients showed relapse after initial good response when stopping denosumab. Inverse imaging and pathological findings were observed. CT and (DCE-)MRI show a good correlation with pathology and allow adequate evaluation of response to denosumab and detection of therapy failure.

A contrast-enhanced ultrasound-based nomogram for the prediction of therapeutic efficiency of anti-PD-1 plus anti-VEGF agents in advanced hepatocellular carcinoma patients.

There is no study focusing on noninvasive predictors for the efficacy of sintilimab (anti-PD-1) plus IBI305 (a bevacizumab biosimilar) treatment in advanced hepatocellular carcinoma (HCC). A total of 33 patients with advanced HCC were prospectively enrolled and received sintilimab plus IBI305 treatment from November 2018 to October 2019. Baseline characteristics including clinical data, laboratory data, and tumor features based on pretreatment CT/MR were collected. Meanwhile, pretreatment contrast-enhanced ultrasound (CEUS) for target tumor was performed and quantitative parameters were derived from time-intensity curves (TICs). A nomogram was developed based on the variables identified by the univariable and multivariable logistic regression analysis. The discrimination, calibration, and clinical utility of the nomogram were evaluated. Tumor embolus and grad ratio were significant variables related to the efficacy of sintilimab plus IBI305 strategy. The nomogram based on these two variables achieved an excellent predictive performance with an area under curve (AUC) of 0.909 (95% CI, 0.813-1). A bootstrapping for 500 repetitions was performed to validate this model and the AUC of the bootstrap model was 0.91 (95% CI, 0.8-0.98). The calibration curve and decision curve analysis (DCA) showed that the nomogram had a good consistency and clinical utility. This study has established and validated a nomogram by incorporating the quantitative parameters of pretreatment CEUS and baseline clinical characteristics to predict the anti-PD-1 plus anti-VEGF treatment efficacy in advanced HCC patients.

Quantitative analysis using intraoperative contrast-enhanced ultrasound in adult-type diffuse gliomas with isocitrate dehydrogenase mutations: association between hemodynamics and molecular features.

The relationship between contrast-enhanced ultrasound (CEUS) hemodynamics and the molecular biomarkers of adult-type diffuse gliomas, particularly isocitrate dehydrogenase (IDH), remains unclear. This study was conducted to provide a comprehensive description of the vascularization of adult-type diffuse gliomas using quantitative indicators. Additionally, it was designed to identify any variables with the potential to intraoperatively predict IDH mutation status. This prospective study enrolled patients with adult-type diffuse gliomas between November 2021 and September 2022. Intraoperative CEUS was performed, and CEUS videos were recorded for 90-second periods. Hemodynamic parameters, including the peak enhancement (PE) difference, were calculated based on the time-intensity curve of the region of interest. A differential analysis was performed on the CEUS parameters with respect to molecular biomarkers and grades. Receiver operating characteristic curves for various parameters were analyzed to evaluate the ability of those parameters to predict IDH mutation status. Sixty patients with adult-type diffuse gliomas were evaluated. All hemodynamic parameters, apart from rising time, demonstrated significant differences between IDH-mutant and IDH-wildtype adult-type diffuse gliomas. The PE difference emerged as the optimal indicator for differentiating between IDH-wildtype and IDH-mutant gliomas, with an area under the curve of 0.958 (95% confidence interval, 0.406 to 0.785). Additionally, the hemodynamic parameters revealed significant differences across both grades and types of adult-type diffuse gliomas. Hemodynamic parameters can be used intraoperatively to effectively distinguish between IDHwildtype and IDH-mutant adult-type diffuse gliomas. Additionally, quantitative CEUS equips neurosurgeons with dynamic perfusion information for various types and grades of adult-type diffuse gliomas.

MR dynamic-susceptibility-contrast perfusion metrics in the presurgical discrimination of adult solitary intra-axial cerebellar tumors.

Adult solitary intra-axial cerebellar tumors are uncommon. Their presurgical differentiation based on neuroimaging is crucial, since management differs substantially. Comprehensive full assessment of MR dynamic-susceptibility-contrast perfusion-weighted imaging (DSC-PWI) may reveal key differences between entities. This study aims to provide new insights on perfusion patterns of these tumors and to explore the potential of DSC-PWI in their presurgical discrimination. Adult patients with a solitary cerebellar tumor on presurgical MR and confirmed histological diagnosis of metastasis, medulloblastoma, hemangioblastoma, or pilocytic astrocytoma were retrospectively retrieved (2008-2023). Volumetric segmentation of tumors and normal-appearing white matter (for normalization) was semi-automatically performed on CE-T1WI and coregistered with DSC-PWI. Mean normalized values per patient tumor-mask of relative cerebral blood volume (rCBV), percentage of signal recovery (PSR), peak height (PH), and normalized time-intensity curves (nTIC) were extracted. Statistical comparisons were done. Then, the dataset was split into training (75%) and test (25%) cohorts and a classifier was created considering nTIC, rCBV, PSR, and PH in the model. Sixty-eight patients (31 metastases, 13 medulloblastomas, 13 hemangioblastomas, and 11 pilocytic astrocytomas) were included. Relevant differences between tumor types' nTICs were demonstrated. Hemangioblastoma showed the highest rCBV and PH, pilocytic astrocytoma the highest PSR. All parameters showed significant differences on the Kruskal-Wallis tests (p < 0.001). The classifier yielded an accuracy of 98% (47/48) in the training and 85% (17/20) in the test sets. Intra-axial cerebellar tumors in adults have singular and significantly different DSC-PWI signatures. The combination of perfusion metrics through data-analysis rendered excellent accuracies in discriminating these entities. In this study, the authors constructed a classifier for the non-invasive imaging presurgical diagnosis of adult intra-axial cerebellar tumors. The resultant tool can be a support for decision-making in the clinical practice and enables optimal personalized patient management. • Adult intra-axial cerebellar tumors exhibit specific, singular, and statistically significant different MR dynamic-susceptibility-contrast perfusion-weighted imaging (DSC-PWI) signatures. • Data-analysis, applied to MR DSC-PWI, could provide added value in the presurgical diagnosis of solitary cerebellar metastasis, medulloblastoma, hemangioblastoma, and pilocytic astrocytoma. • A classifier based on DSC-PWI metrics yields excellent accuracy rates and could be used as a support tool for radiologic diagnosis with clinician-friendly displays.

Domain knowledge-guided adversarial adaptive fusion of hybrid breast ultrasound data

Contrast-enhanced ultrasound (CEUS), which provides more detailed microvascular information about the tumor, is always taken by radiologists in clinic diagnosis along with B-mode ultrasound (B-mode US). However, automatically analyzing breast CEUS is challenging due to the difference between the CEUS video and the natural video, e.g., sports or action videos, where the CEUS video has no positional displacements. Additionally, most existing methods rarely use the Time Intensity Curve (TIC) information of CEUS and non-imaging clinical (NIC) data. To address these issues, we propose a novel breast cancer diagnosis framework that learns the complementarity and correlation across hybrid modal data, including CEUS, B-mode US, and NIC data, by an adversarial adaptive fusion method. Furthermore, to fully exploit the CEUS information, the proposed method, inspired by the clinical processing of radiologists, first extracts the TIC parameters of CEUS. Then, we select a clip from CEUS using a frame screening strategy and finally get spatio-temporal features from these clips through a critical frame attention network. To our knowledge, this is the first AI system to use TIC parameters, NIC data, and ultrasound imaging in diagnoses. We have validated our method on a dataset collected from 554 patients. The experimental results demonstrate the excellent performance of the proposed method. The result shows that our method can achieve an accuracy of 87.73%, which is higher than that of uni-modal approaches by nearly 5%.

Optimal time for early therapeutic response prediction in nasopharyngeal carcinoma with functional magnetic resonance imaging.

Physiological changes in tumour occur much earlier than morphological changes. They can potentially be used as biomarkers for therapeutic response prediction. This study aimed to investigate the optimal time for early therapeutic response prediction with multi-parametric magnetic resonance imaging (MRI) in patients with nasopharyngeal carcinoma (NPC) receiving concurrent chemo-radiotherapy (CCRT). Twenty-seven NPC patients were divided into the responder (N=23) and the poor-responder (N=4) groups by their primary tumour post-treatment shrinkages. Single-voxel proton MR spectroscopy (1H-MRS), diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI were scanned at baseline, weekly during CCRT and post-CCRT. The median choline peak in 1H-MRS, the median apparent diffusion coefficient (ADC) in DW-MRI, the median influx rate constant (Ktrans), reflux rate constant (Kep), volume of extravascular-extracellular space per unit volume (Ve), and initial area under the time-intensity curve for the first 60s (iAUC60) in DCE-MRI were compared between the two groups with the Mann-Whitney tests for any significant difference at different time points. In DW-MRI, the percentage increase in ADC from baseline to week-1 for the responders (median=11.39%, IQR=18.13%) was higher than the poor-responders (median=4.91%, IQR=7.86%) (p=0.027). In DCE-MRI, the iAUC60 on week-2 was found significantly higher in the poor-responders (median=0.398, IQR=0.051) than the responders (median=0.192, IQR=0.111) (p=0.012). No significant difference was found in median choline peaks in 1H-MRS at all time points. Early perfusion and diffusion changes occurred in primary tumours of NPC patients treated with CCRT. The DW-MRI on week-1 and the DCE-MRI on week-2 were the optimal time points for early therapeutic response prediction.

Practical Tips for Reporting Adnexal Lesions Using O-RADS MRI.

The Ovarian-Adnexal Reporting and Data System (O-RADS) MRI risk stratification system provides a standardized lexicon and evidence-based risk score for evaluation of adnexal lesions. The goals of the lexicon and risk score are to improve report quality and communication between radiologists and clinicians, reduce variability in the reporting language, and optimize management of adnexal lesions. The O-RADS MRI risk score is based on the presence or absence of specific imaging features, including the lipid content, enhancing solid tissue, number of loculi, and fluid type. The probability of malignancy ranges from less than 0.5% when there are benign features to approximately 90% when there is solid tissue with a high-risk time-intensity curve. This information can aid in optimizing management of patients with adnexal lesions. The authors present an algorithmic approach to the O-RADS MRI risk stratification system and highlight key teaching points and common pitfalls. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Near-Infrared Fluorescence Imaging With Indocyanine Green to Predict Clinical Outcome After Revascularization in Lower Extremity Arterial Disease.

Contemporary quality control methods are often insufficient in predicting clinical outcomes after revascularization in lower extremity arterial disease (LEAD) patients. This study evaluates the potential of near-infrared fluorescence imaging with indocyanine green to predict the clinical outcome following revascularization. Near-infrared fluorescence imaging was performed before and within 5days following the revascularization procedure. Clinical improvement was defined as substantial improvement of pain free walking distance, reduction of rest- and/or nocturnal pain, or tendency toward wound healing. Time-intensity curves and 8 perfusion parameters were extracted from the dorsum of the treated foot. The quantified postinterventional perfusion improvement was compared within the clinical outcome groups. Successful near-infrared fluorescence imaging was performed in 72 patients (76 limbs, 52.6% claudication, 47.4% chronic limb-threatening ischemia) including 40 endovascular- and 36 surgical/hybrid revascularizations. Clinical improvement was observed in 61 patients. All perfusion parameters showed a significant postinterventional difference in the clinical improvement group (P-values <.001), while no significant differences were seen in the group without clinical improvement (P-values .168-.929). Four parameters demonstrated significant differences in percentage improvement comparing the outcome groups (P-values within .002-.006). Near-infrared fluorescence imaging has promising additional value besides clinical parameters for predicting the clinical outcome of revascularized LEAD patients.

Handheld photoacoustic imaging of indocyanine green clearance for real-time quantitative evaluation of liver reserve function.

Preoperative assessment of liver function reserve (LFR) is essential for determining the extent of liver resection and predicting the prognosis of patients with liver disease. In this paper, we present a real-time, handheld photoacoustic imaging (PAI) system-based noninvasive approach for rapid LFR assessment. A linear-array ultrasound transducer was sealed in a housing filled with water; its front end was covered with a plastic wrap. This PAI system was first implemented on phantoms to confirm that the photoacoustic (PA) intensity of indocyanine green (ICG) in blood reflects the concentration of ICG in blood. In vivo studies on normal rabbits and rabbits with liver fibrosis were carried out by recording the dynamic PA signal of ICG in their jugular veins. By analyzing the PA intensity-time curve, a clear difference was identified in the pharmacokinetic behavior of ICG between the two groups. In normal rabbits, the mean ICG clearance rate obtained by PAI at 15 min after administration (PAI-R15) was below 21.6%, whereas in rabbits with liver fibrosis, PAI-R15 exceeded 62.0% because of poor liver metabolism. The effectiveness of the proposed method was further validated by the conventional ICG clearance test and pathological examination. Our findings suggest that PAI is a rapid, noninvasive, and convenient method for LFR assessment and has immense potential for assisting clinicians in diagnosing and managing patients with liver disease.

#6323 RENAL CONTRAST-ENHANCED ULTRASOUND AND GLOMERULONEPHRITIS: A GOOD MARKER OF DISEASE ACTIVITY

Abstract Background Contrast-enhanced ultrasound (CEUS) could provide a lot of information of renal blood flow. Renal blood flow is an excellent marker of inflammatory and fibrotic processes in the kidney such as glomerulonephritis. Therefore, in patients with these diseases, renal CEUS can be both a prognostic marker and an index of response to therapy. Currently in the literature there are preliminary studies showing the role of CEUS in terms of histology and outcome in the evaluation of patients with glomerulonephritis. In this pilot study we used perfusion CEUS parameters (WiR and WoR; WiAUC and WoAUC) as possible markers of renal microvascular damage. We compared the perfusion parameters with the clinical and histological findings of our patients. Method Eighteen patients with clinical and laboratory signs of glomerulonephritis were enrolled. All patients underwent ultrasound-assisted renal biopsy and B-mode ultrasound examination, color Doppler ultrasound and contrast-enhanced ultrasound. Time Intensity (TI) curves were obtained from renal CEUS. TI curves and several quantitative perfusion parameters were defined using VueBox® Quantitation Software. Results From April to October 2022, 18 patients (12 men and 6 women) with clinical and laboratory suspicion of glomerular disease were enrolled. Median age was 48.05 years, all patients underwent renal biopsy and contrast-enhanced ultrasound at basal condition. Table 1 shows patients characteristics. CKD patients were stratified into two groups according to their eGFR: group I (eGFR &amp;lt; 60 ml/min/1.73 m2, n. = 4) and group II (eGFR ≥ 60 ml/min/1.73 m2, n. = 3). Moreover, we divided patients into two groups based on the presence of nephrotic-range proteinuria (≥ 3.5 g/24h). At this time, seven patient data are suitable for analysis. The small sample size at present does not allow for statistical significance. However, in our study, the persistence of contrast agent signal during the wash-out phase was differed markedly in correlation with the degree of CKD. In particular, we observed a slower wash-in phase in the presence of vascular hyalinosis (Fig. 1). Conclusion Our experience seems to confirm that CEUS parameters can be excellent indicators both in terms of patient disease outcomes and histological data. CEUS can effectively and quantitatively demonstrate renal microvascular perfusion in patients with glomerulonephritis. Future goal is that CEUS could also be a prognostic and follow-up marker after renal biopsy in patients with glomerulonephritis.

Quantification of indocyanine green near-infrared fluorescence bowel perfusion assessment in colorectal surgery

BackgroundIndocyanine green near-infrared fluorescence bowel perfusion assessment has shown its potential benefit in preventing anastomotic leakage. However, the surgeon's subjective visual interpretation of the fluorescence signal limits the validity and reproducibility of the technique. Therefore, this study aimed to identify objective quantified bowel perfusion patterns in patients undergoing colorectal surgery using a standardized imaging protocol.MethodA standardized fluorescence video was recorded. Postoperatively, the fluorescence videos were quantified by drawing contiguous region of interests (ROIs) on the bowel. For each ROI, a time-intensity curve was plotted from which perfusion parameters (n = 10) were derived and analyzed. Furthermore, the inter-observer agreement of the surgeon’s subjective interpretation of the fluorescence signal was assessed.ResultsTwenty patients who underwent colorectal surgery were included in the study. Based on the quantified time-intensity curves, three different perfusion patterns were identified. Similar for both the ileum and colon, perfusion pattern 1 had a steep inflow that reached its peak fluorescence intensity rapidly, followed by a steep outflow. Perfusion pattern 2 had a relatively flat outflow slope immediately followed by its plateau phase. Perfusion pattern 3 only reached its peak fluorescence intensity after 3 min with a slow inflow gradient preceding it. The inter-observer agreement was poor-moderate (Intraclass Correlation Coefficient (ICC): 0.378, 95% CI 0.210–0.579).ConclusionThis study showed that quantification of bowel perfusion is a feasible method to differentiate between different perfusion patterns. In addition, the poor-moderate inter-observer agreement of the subjective interpretation of the fluorescence signal between surgeons emphasizes the need for objective quantification.