Assessment of image quality and dose in contrast-enhanced head and neck CT angiography of New Zealand rabbit.

BACKGROUND: Although computed tomography (CT) is a powerful diagnostic imaging modality for diagnosing vascular diseases, it is some what risky to human health due to the high radiation dosage. Thus, CT vendors have developed low dose computed tomography (LDCT) aiming to solve this problem. Nowadays, LDCT has gradually become a main stream of CT examination. OBJECTIVE: This study aimed to assess the feasibility of LDCTAin an animal model and compare the imaging features and doses in two clinical scanners. METHODS: Twenty-two New Zealand rabbit head and neck CTA images pre- and post-contrast agent injection were performed using256-sliceand 64-slice CT scanners. The tube voltages used in the 256-slice and the 64-slice CTA were 70 kVp and 80 kVp, respectively. Quantitative images indices and radiation doses obtained from CTA in these two scanners were compared. RESULTS: More neck arterial vessels could be visualized in multi-planar reconstruction (MPR) CTA on the 256-slice CT scanner than on the 64-slice CT scanner. After contrast agent injection, all observed neck arterial vessels had higher CT numbers in 256-slice CTA than in 64-slice CTA. There was no significant difference in contrast-to-noise (CNR) of CTA images between these two scanners. CT dose index (CTDI) and dose length product (DLP) for the 256-slice CTA were lower than those for the 64-slice CTA. CONCLUSIONS: Low dose CTA of rabbits with 70 or 80 kVp is feasible in a 256-slice or a 64-slice CT scanner. The radiation dose from the 256-slice CTA was much lower than that from the 64-slice CTA with comparable SNR and CNR. The technique can be further applied in longitudinal monitoring of an animal stroke model in the future.

Assessment of the Effectiveness of the Vaginal Contrast Media in Magnetic Resonance Imaging for Detection of Pelvic Pathologies: A Meta-analysis.

OBJECTIVE: Magnetic resonance imaging (MRI) is an excellent modality for pelvic imaging. The anatomy of uterine cavity and vagina is optimally evaluated when the walls, which may spontaneously be collapsed, are distended. Distension of these cavities during pelvic MRI for evaluation of gynecologic diseases has been conducted with vagina, filled with ultrasound gel or saline solution. In this meta-analysis, we aim to assess the effectiveness of vaginal contrast media in MRI for improving the detection of pelvic pathologies. METHODS: The PubMed, MEDLINE, EMBASE, Web of Science, Google Scholar, Science Citation Index, and Cochrane Library databases were systematically searched through March 2019 for studies of the accuracy of MRI using vaginal contrast media in the diagnosis and staging of pelvic pathologies. Four eligible studies of a total of 120 patients were included in the meta-analysis. The sensitivity rates and relative risk for MRI, before and after vaginal contrast medium administration, were pooled, and their 95% confidence intervals (CIs) were determined. RESULTS: The pooled sensitivity rate for MRI before administering intravaginal contrast medium in detecting pelvic pathologies was 63% (95% CI, 54%-72%), and that after was 89% (95% CI, 83%-93%). The interstudy heterogeneity rate (assessed using the I statistic) was relatively low: 13% (P = 0.33) and 0% (P = 0.45) before and after vaginal contrast medium use, respectively. The average relative risk was 1.54 (SD, 0.22; 95% CI, 1.18-1.89; median, 1.50; range, 1.34-1.80). This demonstrated that, on average, the sensitivity rate for MRI in detecting pelvic disorders increased by 54% after the use of a vaginal contrast medium. CONCLUSIONS: Use of vaginal contrast media improved the diagnostic ability of MRI in identifying pelvic pathologies.

Contrast-Enhanced Ultrasound for Assessment of Local Hemodynamic Changes Following a Rodent Contusion Spinal Cord Injury.

INTRODUCTION: Severe trauma to the spinal cord leads to a near complete loss of blood flow at the injury site along with significant hypoperfusion of adjacent tissues. Characterization and monitoring of local tissue hypoperfusion is currently not possible in clinical practice because available imaging techniques do not allow for assessment of blood flow with sufficient spatial and temporal resolutions. The objective of the current study was to determine whether ultrafast contrast-enhanced ultrasound (CEUS) imaging could be used to visualize and quantify acute hemodynamic changes in a rat traumatic spinal cord injury (SCI) model. MATERIALS AND METHODS: We used novel ultrasound acquisition and processing methods that allowed for measurements of local tissue perfusion as well as for assessment of structural and functional integrity of spinal vasculature. RESULTS: CEUS imaging showed that traumatic SCI results in (1) an area with significant loss of perfusion, which increased during the first hour after injury, (2) structural alterations of the spinal cord vasculature, and (3) significant slowing of arterial blood flow velocities around the injury epicenter. CONCLUSION: We conclude that CEUS has the spatial and temporal sensitivity and resolution to visualize local tissue perfusion and vessel architecture, which maybe useful clinically to determine injury extent and severity in patients with SCI.

Intraprocedural contrast-enhanced ultrasound-CT/MR fusion imaging assessment in HCC thermal ablation to reduce local tumor progression: compared with routine contrast-enhanced ultrasound.

Purpose: To evaluate whether local tumor progression (LTP) would be further reduced when contrast-enhanced ultrasound (CEUS)-CT/MR fusion imaging was used as intraprocedural assessment method in hepatocellular carcinoma (HCC) thermal ablation compared with routine CEUS. Materials and methods: This prospective non-randomized study was conducted from December 2010 to July 2012. CEUS-CT/MR fusion imaging and routine CEUS were used for treatment response assessment in the ablation procedure of 146 HCCs and 122 HCCs, respectively. Supplementary ablations were performed immediately if necessary. The primary technique efficacy rate, LTP rate and overall survival (OS) rate were calculated. Results: For CEUS-CT/MR fusion imaging and routine CEUS, the technical success rate, technique efficacy rate and supplementary ablation rate were 86.3% (126/146) and 98.4% (120/122) (p = .000), 99.2% (125/126) and 94.2% (113/120) (p = .032), and 14.3% (18/126) and 4.2% (5/120) (p = .006), respectively. The cumulative LTP rate and OS rate were not significantly different between fusion imaging group and routine CEUS group. However, for lesions that were larger than 3 cm or close to major vessels (41 lesions in fusion imaging group and 44 lesions in routine CEUS group, who received transcatheter arterial chemoembolization before ablation), the cumulative LTP rate was significantly lower in fusion imaging group than in routine CEUS group (p = .032). Conclusion: Although intraprocedural CEUS-CT/MR fusion imaging has certain limitations in application, it might provide a potential more efficient method compared with routine CEUS in reducing LTP in HCC thermal ablation, especially for difficult ablation lesions.

Feasibility of myocardial perfusion assessment with contrast echocardiography: can it improve recognition of significant coronary artery disease in the ICU?

BACKGROUND: Diagnosis of significant coronary artery disease (CAD) and acute coronary artery occlusion in ICU can be difficult, and an inappropriate intervention is potentially harmful. Myocardial contrast perfusion echo (MCPE) examines ultrasound contrast intensity replenishment curves in individual myocardial segments measuring peak contrast intensity and slope of return as an index of myocardial blood flow (units = intensity of ultrasound per second [dB/s]). MCPE could possibly serve as a triage tool to invasive angiography by estimating blood flow in the myocardium. We sought to assess feasibility in the critically ill and if MCPE could add incremental value to the clinical acumen in predicting significant CAD. METHODS: This is a single-centre, prospective, observational study. Inclusion criteria were as follows: adult ICU patients with troponin I > 50 ng/L and cardiology referral being made for consideration of inpatient angiography. Exclusion criteria were as follows: poor echo windows (2 patients), known ischaemic heart disease, and contrast contraindications. Seven cardiologists and 6 intensivists blinded to outcome assessed medical history, ECG, troponin, and 2D echo images to estimate likelihood of significant CAD needing intervention (clinical acumen). Clinical acumen, quantitative MCPE, and subjective (visual) MCPE were assessed to predict significant CAD. RESULTS: Forty patients underwent MCPE analysis, 6 (15%) had significant CAD, and median 11 of 16 segments (IQR 8-13) could be imaged (68.8% [IQR 50-81]). No adverse events occurred. A significant difference was found in overall MCPE blood flow estimation between those diagnosed with significant CAD and those without (3.3 vs 2.4 dB/s, p = 0.050). A MCPE value of 2.8 dB/s had 67% sensitivity and 88% specificity in detecting significant CAD. Clinical acumen showed no association in prediction of CAD (OR 0.6, p = 0.09); however, if quantitative or visual MCPE analysis was included, a significant association occurred (OR 17.1, p = 0.01; OR 23.0, p = 0.01 respectively). CONCLUSIONS: MCPE is feasible in the critically ill and shows better association with predicting significant CAD vs clinical acumen alone. MCPE adds incremental value to initial assessment of the presence of significant CAD which may help guide those who require urgent angiography.

Assessment of blood flow in the hepatic tumors using non-contrast micro flow imaging: Initial experience.

PURPOSE: To evaluate micro-flow imaging (MFI) in depicting the vascular architecture of hepatocellular carcinoma (HCC) and other focal liver lesions. MATERIALS AND METHODS: A total of 81 hepatic lesions were enrolled in this study. Each patient underwent CDFI, MFI, and CEUS examinations. The blood flow was first graded into three types (grade 1, 2 and 3) based on its richness with Adeler classification method. The differences in the grade of blood flow in liver tumors were compared between CDFI and MFI. With respect to the presented morphology, the blood flow was further classified into five types (Type I, II, III, IV and V). The morphological differences in blood flow shown by MFI between malignant and benign hepatic tumors were then analyzed. RESULTS: For the total 81 lesions, MFI detected 61 lesion cases (75.31%) with blood flow grade 2 and 3, which obviously outperformed CDFI which detected 28 cases (34.57%) of grade 2 and 3 (χ2 = 35.27, P = 0.000). The MFI also showed that the most common blood flow morphology of HCC is Type-III (21/48, 43.75%) while the hepatic hemangioma (HEM) is mostly presented as Type V (5/10, 50%). Moreover, the grade of blood flow in MFI varied with different pathological subtypes of HCC (χ2 = 5.610, P = 0.018). CONCLUSIONS: Compared with traditional CDFI, MFI reveals more blood vessels in liver lesions with clearer view of blood flow distribution. Besides, MFI technology can demonstrate grade of blood flow for various differentiation stages of malignant liver tumors.

The Role of Intravenous Contrast Agent in the Sonographic Assessment of Crohn's Disease Activity: Is Contrast Agent Injection Necessary?

BACKGROUND AND AIMS: Contrast-enhanced ultrasound [CEUS] is reported to be superior to wall thickness or colour Doppler imaging [CDI] in predicting disease activity using endoscopy as the reference standard. Our aims were to determine in patients with Crohn's disease [CD] whether the evaluation of wall thickness or CDI before CEUS examination could help to decide when the injection of contrast agent is justified as a means for detecting disease activity as determined at endoscopy, without reducing the accuracy of ultrasound. METHODS: In total, 180 patients with CD underwent both colonoscopy and ultrasound, including mural thickness, CDI and CEUS evaluation, prospectively as part of clinical care. A receiver operating characteristic curve was constructed to determine the area under the curve and the best cutoff of wall thickness and ultrasound enhancement value to discriminate between endoscopically active and inactive disease. Several analyses were carried out to determine which parameter or combination of parameters best detected endoscopic activity. RESULTS: Comparative evaluation of the different analysis showed that wall thickness alone classified 76.6% of patients correctly, CDI alone 72.7%, and thickness plus CDI 72.2%. The use of CEUS significantly improved the diagnosis of active disease: CEUS alone correctly classified 164 of 180 patients [91.1%], combined analysis of CDI and CEUS 165 of 180 [91.7%], and combined analysis of thickness, CDI and CEUS 164 of 180 [91.1%], without significant differences. Patients with CDI grade 2 or 3 showed a predictive positive value of 97% to detect disease activity, similar to CEUS [100%]. CONCLUSION: CEUS is the most reliable ultrasound criterion for endoscopic disease activity. However, the use of a contrast agent is probably not justified to assess disease activity for patients with CDI grade 2/3.

Evaluation of a water-soluble contrast protocol for nonoperative management of pediatric adhesive small bowel obstruction.

BACKGROUND/PURPOSE: We examined outcomes before and after implementing an enteral water-soluble contrast protocol for management of pediatric adhesive small bowel obstruction (ASBO). METHODS: Medical records were reviewed retrospectively for all children admitted with ASBO between November 2010 and June 2017. Those admitted between November 2010 and October 2013 received nasogastric decompression with decision for surgery determined by surgeon judgment (preprotocol). Patients admitted after October 2013 (postprotocol) received water-soluble contrast early after admission, were monitored with serial examinations and radiographs, and underwent surgery if contrast was not visualized in the cecum by 24 h. Group outcomes were compared. RESULTS: Twenty-six patients experienced 29 admissions preprotocol, and 11 patients experienced 12 admissions postprotocol. Thirteen (45%) patients admitted preprotocol underwent surgery, versus 2 (17%) postprotocol patients (p = 0.04). Contrast study diagnostic sensitivity as a predictor for ASBO resolution was 100%, with 90% specificity. Median overall hospital LOS trended shorter in the postprotocol group, though was not statistically significant (6.2 days (preprotocol) vs 3.6 days (postprotocol) p = 0.12). Pre- vs. postprotocol net operating cost per admission yielded a savings of $8885.42. CONCLUSIONS: Administration of water-soluble contrast after hospitalization for pediatric ASBO may play a dual diagnostic and therapeutic role in management with decreases in surgical intervention, LOS, and cost. TYPE OF STUDY: Retrospective comparative study. LEVEL OF EVIDENCE: Level III.

Contrast-Enhanced Ultrasound Examination for the Assessment of Renal Perfusion in Cats with Chronic Kidney Disease.

BACKGROUND: Contrast-enhanced ultrasound examination (CEUS) is a functional imaging technique allowing noninvasive assessment of tissue perfusion. Studies in humans show that the technique holds great potential to be used in the diagnosis of chronic kidney disease (CKD). However, data in veterinary medicine are currently lacking. OBJECTIVES: To evaluate renal perfusion using CEUS in cats with CKD. ANIMALS: Fourteen client-owned cats with CKD and 43 healthy control cats. METHODS: Prospective case-controlled clinical trial using CEUS to evaluate renal perfusion in cats with CKD compared to healthy control cats. Time-intensity curves were created, and perfusion parameters were calculated using off-line software. A linear mixed model was used to examine differences between perfusion parameters of cats with CKD and healthy cats. RESULTS: In cats with CKD, longer time to peak and shorter mean transit times were observed for the renal cortex. In contrast, a shorter time to peak and rise time were seen for the renal medulla. The findings for the renal cortex indicate decreased blood velocity and shorter total duration of enhancement, likely caused by increased vascular resistance in CKD. Increased blood velocity in the renal medulla has not been described before and may be because of a different response to regulatory factors in cortex and medulla. CONCLUSIONS AND CLINICAL IMPORTANCE: Contrast-enhanced ultrasound examination was capable of detecting perfusion changes in cats with CKD. Further research is warranted to assess the diagnostic capabilities of CEUS in early stage of the disease process.

Quantitative parameters of contrast-enhanced ultrasonography for assessment of renal pathology: A preliminary study in chronic kidney disease.

OBJECTIVE: To assess the severity of renal pathology in patients with chronic kidney disease (CKD) using contrast-enhanced ultrasonography (US). METHODS: 275 patients with CKD who were proven by renal biopsy and 30 healthy adults were examined using conventional US and contrast-enhanced US. Ultrasonic parameters included renal length, cortical thickness, rise time (RT), peak intensity (PI), area under the time-intensity curve (AUC), wash-in slope (WIS) and time to peak (TTP). Based on pathological scores, CKD patients were classified into mild, and moderate to severe CKD groups. The logistic regression analysis and receiver operating characteristic (ROC) curves were used. RESULTS: PI and AUC differed significantly among the controls, mild and moderate to severe CKD groups (P < 0.05). There was significant difference in PI among the different pathology types (P < 0.05). The multivariate logistic regression analysis showed that PI was associated independently with the severity of renal pathology in patients with CKD (P < 0.05). PI less than 13.87 dB had a certain diagnostic ability, and the sensitivity and specificity were 72.5% and 64.0%, respectively. CONCLUSIONS: Contrast-enhanced US may be useful for noninvasive assessment of the severity of renal pathology. PI may be potentially valuable for guiding therapy and follow-up in patients with CKD.

Direct Assessment of Wall Shear Stress by Signal Intensity Gradient from Time-of-Flight Magnetic Resonance Angiography.

The aim of the study was to calculate the arterial wall signal intensity gradient (SIG) from time-of-flight MR angiography (TOF-MRA) and represent arterial wall shear stress. We developed a new algorithm that uses signal intensity (SI) of a TOF-MRA to directly calculate the signal intensity gradient (SIG). The results from our phantom study showed that the TOF-MRA SIG could be used to distinguish the magnitude of blood flow rate as high (mean SIG ± SD, 2.2 ± 0.4 SI/mm for 12.5 ± 2.3 L/min) and low (0.9 ± 0.3 SI/mm for 8.5 ± 2.6 L/min) in vessels (p < 0.001). Additionally, we found that the TOF-MRA SIG values were highly correlated with various flow rates (ß = 0.96, p < 0.001). Remarkably, the correlation coefficient between the WSS obtained from the computational fluid dynamics (CFD) analysis and the TOF-MRA SIG was greater than 0.8 in each section at the carotid artery (p < 0.001 for all ß values). This new technique using TOF-MRA could enable the rapid calculation of the TOF-MRA SIG and thereby the WSS. Thus, the TOF-MRA SIG can provide clinicians with an accurate and efficient screening method for making rapid decisions on the risk of vascular disease for a patient in clinical practice.

Efficiency of contrast enhanced ultrasound for immediate assessment of ablation status after intraoperative radiofrequency ablation of hepatic malignancies.

AIM: To evaluate the efficiency of intraoperative contrast enhanced ultrasound (Io-CEUS) for assessment of radiofrequency ablation (RFA) during liver tumor surgery. MATERIAL AND METHODS: Retrospective analysis was performed on a total number of 18 patients out of over 500 patients who underwent combined liver tumor surgery and RFA of 27 hepatic tumors between 02/2011 and 12/2016. Io-CEUS was performed by bolus injections of up to 10 ml sulphur hexaflourid microbubbles for diagnostic purposes. To guide the RFA up to 20 ml microbubbles were applied to monitor the procedure and assess the ablation status finally. A fully avascular area or absence of any residual vascularization intratumorally was considered technical success. These findings were correlated to findings of follow-up imaging results (CEUS, MRI, CT) at least 1 up to 40 months (mean 11 months) after surgery. RESULTS: 13 male and 5 female patients aged between 45-77 years (mean 59.2±17.1 years) with 26 malignant and one most probable benign hepatic lesion were treated with intraoperative RFA. Io-CEUS detected 23 preoperatively unknown liver lesions leading to a change in therapy in 13/18 cases (72,2%). All 27 treated lesions showed an avascular area immediately after RFA. According to follow-up imaging results (1 month - 3 years after surgery, mean follow-up time 11 months), 2/18 patients had local recurrences, 8 patients had distant intrahepatic recurrences or extrahepatic recurrence, 8 patients remained tumor-free. Thereby, a success rate of CEUS guided RFA of 89% could be obtained concerning the targeted liver lesions. CONCLUSION: Modern intraoperative ultrasound using B-mode and Io-CEUS is a valuable tool for optimization of diagnostic and therapeutic intraoperative liver procedures and ablative therapies.

Contrast-enhanced ultrasound (CEUS) in an interdisciplinary intensive care unit (ICU): Diagnostic efficacy in the assessment of post-operative complications compared to contrast-enhanced computed tomography (CECT): First results.

To evaluate the effectiveness of high-resolution contrast-enhanced ultrasound (CEUS) to diagnose early post-operative complications in an interdisciplinary intensive care unit.In 50 patients (male 32; female 18) 64 CEUS examinations were performed in an intensive care unit (ICU) setting to detect post-operative complications. Multi-frequency transducer (1-5 and/or 6-9 MHz) were used. All 64 examinations were performed by one experienced examiner. CEUS findings were compared with contrast-enhanced computed tomography (CECT) findings. CECT images were acquired within 1-24 hours after CEUS examination in arterial and portal-venous phases of the abdomen using either a 16-slice computed tomography scanner or a 128-dual slice computed tomography scanner.In 56 out of 64 cases (88%) the CEUS-based diagnosis corresponded with the CECT diagnosis. Vascular stenosis in hepatic arteries and portal veins were recognised in both imaging modalities but were evaluated differently [5 cases]. In 3 cases (5%) small peripheral splenic infarction, retroperitoneal hematoma and fluid collection around the liver were not diagnosed by CEUS. CONCLUSION: CEUS in an ICU setting enables a reliable detection of postoperative abdominal complications as compared to CECT.

Comparison between semiquantitative and quantitative methods for the assessment of knee synovitis in osteoarthritis using non-enhanced and gadolinium-enhanced MRI.

OBJECTIVE: To compare different semiquantitative and quantitative methods using both non-enhanced and gadolinium-enhanced MRI techniques for the assessment of synovitis in knee osteoarthritis (OA). METHODS: Knees with end-stage clinical OA in patients undergoing total knee replacement surgery were included in this cross-sectional study. MRI was performed on all knees. Standard non-enhanced and gadolinium-enhanced sequences were acquired. Using non-enhanced MRI, we semiquantitatively assessed two features widely used as surrogates for synovitis: effusion-synovitis and Hoffa-synovitis. Using gadolinium-enhanced sequences, we semiquantitatively assessed synovial thickness. We quantitatively evaluated the total synovial volume on the gadolinium-enhanced sequences as well. We assessed the correlations of effusion-synovitis and Hoffa-synovitis with synovial thickness and volume, applying Spearman correlation analysis. The diagnostic performance of both synovitis features on non-enhanced MRI was assessed using synovial thickness on gadolinium-enhanced MRI as the reference. RESULTS: A total of 104 subjects (one knee per subject) were included. Correlations of effusion-synovitis with synovial thickness and volume were r = 0.41 and r = 0.43 (P < .001) r = 0.32 and r = 0.39 (P < .0001). CONCLUSION: Using synovial thickness assessed on gadolinium-enhanced sequences as the reference, effusion-synovitis showed superior correlations and sensitivity. Effusion-synovitis should be preferred over Hoffa-synovitis as a surrogate marker for synovial thickening, in studies of knee OA for which gadolinium-enhanced sequences are not available.

Assessment of Correlation between Intravoxel Incoherent Motion Diffusion Weighted MR Imaging and Dynamic Contrast-Enhanced MR Imaging of Sacroiliitis with Ankylosing Spondylitis.

The relationships between IVIM and DCE-MRI parameters in AS are not clear. We explore the correlation between intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI) and dynamic contrast-enhanced (DCE) parameters obtained on MR images in patients with ankylosing spondylitis (AS). Forty-four patients with AS were prospectively examined using a 1.5-T MR system. IVIM DWI was performed with 11 b values (range, 0-800 s/mm2) for all patients. The correlation coefficients between IVIM and DCE-MRI parameters were analyzed using Spearman's method. Our results showed that intra- and interobserver reproducibility were excellent to relatively good (ICC = 0.804-0.981; narrow width of 95% limits of agreement). Moderate positive correlations were observed between pure molecular diffusion (Ds) and maximum enhancement (ME) and relative enhancement (RE) (r = 0.700, P < 0.001; r = 0.607, P < 0.001, resp.). Perfusion-related diffusion (Df) showed negative moderate correlation with ME (r = -0.608, P < 0.001). However, no correlation was observed between perfusion fraction (f) and any parameters of ME, RE, TTP, and BE (r = -0.093-0.213; P > 0.165). In conclusion, the IVIM parameters, especially f, might play a critical role in detecting the progression of AS, because it can provide more perfusion information compared with DCE-MRI; besides the IVIM MRI is a noninvasive method.

Intrasurgical dignity assessment of hepatic tumors using semi-quantitative strain elastography and contrast-enhanced ultrasound for optimisation of liver tumor surgery.

OBJECTIVE: To evaluate the efficacy of strain elastography (SE) using semi-quantitative measurement methods compared to constrast enhanced ultrasound during liver tumor surgery (Io-CEUS) for dignity assessment of focal liver lesions(FLL). MATERIAL AND METHODS: Prospective data acquisition and retrospective analysis of US data of 100 patients (116 lesions) who underwent liver tumor surgery between 10/2010 and 03/2016. Retrospective reading of SE color patterns was performed establishing groups depending on dominant color (>50% blue = stiff, inhomogenous, >50% yellow/red/green = soft tissue). Semi-quantitative analysis was performed by Q-analysis based on a scale from 0 (soft) to 6 (stiff). 2 ROIs were placed centrally, 5 ROIs in the lesion's surrounding tissue. Io-CEUS was performed by bolus injection of 5-10 ml sulphurhexaflourid microbubbles evaluating wash-in- and -out- kinetics in arterial, portal venous and late phase. Histopathology after surgical resection served as goldstandard. RESULTS: 100 patients (m: 65, f: 35, mean age 60.5 years) with 116 liver lesions were included. Lesion's size ranged from 0.5 to 8.4 cm (mean 2.42 cm SD±1.44 cm). Postoperative histology showed 105 malignant and 11 benign lesions. Semi-quantitative analysis showed central indurations of >2.5 in 76/105 cases suggesting malignancy. 7 benign lesions displayed no central indurations correctly characterized benign by SE. ROC-analysis and Youden index showed a sensitivity of 72.4% and specificity of 63.6% assuming a cut-off of 2.5. Io-CEUS correctly characterized 103/105 as malignant. Sensitivity was 98%, specificity 72.7%. CONCLUSION: Strain elastography is a valuable tool for non-invasive characterization of FLLs. Semi-quantitative intratumoral stiffness values of >2.5 suggested malignancy. However, sensitivity of Io-CEUS in detecting malignant lesions was higher compared to SE. In conclusion SE should be considered for routine use during intraoperative US in addition to Io-CEUS for optimization of curative liver surgery.

Iron overload by Superparamagnetic Iron Oxide Nanoparticles is a High Risk Factor in Cirrhosis by a Systems Toxicology Assessment.

Superparamagnetic iron oxide nanoparticles (SPIONs) as a contrast agent have been widely used in magnetic resonance imaging for tumor diagnosis and theranostics. However, there has been safety concern of SPIONs with cirrhosis related to excess iron-induced oxidative stress. In this study, the impact of iron overload by SPIONs was assessed on a mouse cirrhosis model. A single dose of SPION injection at 0.5 or 5 mg Fe/kg in the cirrhosis group induced a septic shock response at 24 h with elevated serum levels of liver and kidney function markers and extended impacts over 14 days including high levels of serum cholesterols and persistent low serum iron level. In contrast, full restoration of liver functions was found in the normal group with the same dosages over time. Analysis with PCR array of the toxicity pathways revealed the high dose of SPIONs induced significant expression changes of a distinct subset of genes in the cirrhosis liver. All these results suggested that excess iron of the high dose of SPIONs might be a risk factor for cirrhosis because of the marked impacts of elevated lipid metabolism, disruption of iron homeostasis and possibly, aggravated loss of liver functions.

Advantages and Limitations of Focal Liver Lesion Assessment with Ultrasound Contrast Agents: Comments on the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines.

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in sonography. Due to US contrast agents (UCAs) and contrast-specific techniques, sonography offers the potential to show enhancement of liver lesions in a similar way as contrast-enhanced cross-sectional imaging techniques. The real-time assessment of liver perfusion throughout the vascular phases, without any risk of nephrotoxicity, represents one of the major advantages that this technique offers. CEUS has led to a dramatic improvement in the diagnostic accuracy of US and subsequently has been included in current guidelines as an important step in the diagnostic workup of focal liver lesions (FLLs), resulting in a better patient management and cost-effective therapy. The purpose of this review was to provide a detailed description of contrast agents used in different cross-sectional imaging procedures for the study of FLLs, focusing on characteristics, indications and advantages of UCAs in clinical practice.

Diagnostic significance of arterial spin labeling in the assessment of tumor grade in brain.

BACKGROUND: The objective of the current meta.analysis was to assess the arterial spin labeling. (ASL) perfusion imaging measurement of cerebral blood flow. (CBF) in patients with brain tumors, and assessing preoperative tumor grade in brain. MATERIALS AND METHODS: PubMed, Web of Science, Embase, China BioMedicine (CBM), CINAHL, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases were chosen to evaluate the associations between ASL and brain cancer. Two reviewers separately evaluated the quality of the included trials. Standardized mean difference (SMD) at 95% confidence interval (95% CI) was also calculated. RESULTS: Finally, 475 patients were enrolled into this meta-analysis from 12 eligible studies and were selected for statistical analysis. Results showed that relative tumor blood flow (rTBF) and relative cerebral blood flow (rCBF) in high-grade brain cancer patients were faster than those in low-grade brain cancer patients. Subgroup analysis stratified by country implied that ASL may be the main prediction of increased rTBF in high-grade brain cancer patients among USA, Korea and China; and rCBF was faster in high-grade brain cancer using ASL in USA and China. Further reference by tissue-stratified analysis revealed a positive association of rTBF with high-grade brain cancer by utilization of ASL in all the experimental subgroups, while rCBF was only correlated in white subgroups. CONCLUSION: These results showed that rTBF and rCBF were faster in high-grade brain cancer patients, suggesting that ASL may provide suitable measurement for the differential diagnosis of tumor grade in brain.