Neuroimaging Considerations in Patients with Chronic Kidney Disease

Chronic Kidney Disease is a common medical condition that frequently overlaps with neurologic disease. Neuroimaging can be a useful tool to aid in the diagnoses of neurologic illness, including those that result from renal impairment. Some neuroimaging studies also have the potential to lead to adverse effects on the kidneys necessitating a thoughtful approach to selection of imaging modalities. In particular, multimodal imaging is becoming increasingly common in patients presenting with symptoms of acute stroke, a population that may be at higher risk for renal complications. This article will summarize the neuroimaging manifestations of conditions with shared renal and neurologic involvement and highlight considerations regarding the use of contrast media, nephrogenic systemic fibrosis, and metformin-associated lactic acidosis.

The Functional Field of View of Older Adults is Associated With Contrast Discrimination in the Magnocellular not Parvocellular Pathway

OBJECTIVES

As we age, the functional field of view (FFOV) declines and these declines predict falls and motor vehicle accidents in older adults (Owsley, C. (2013). Visual processing speed. Vision Research, 90, 52-56. doi:10.1016/j.visres.2012.11.014). To increase understanding of possible causes of this decline, the current study explored whether the FFOV in older adults is associated with the sensitivity of the magnocellular and parvocellular sub-cortical pathways.

METHOD

Forty-four younger (M = 27.18, SD = 5.40 years) and 44 older (M = 72.18, SD = 5.82 years) adults completed an FFOV test and the steady- and pulsed-pedestal paradigms of Pokorny and Smith (Pokorny, J., & Smith, V. C. (1997). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain. Journal of the Optical Society of America. A, Optics, Image Science, and Vision, 14, 2477-2486. doi:10.1364/josaa.14.002477) as measures of magnocellular and parvocellular pathways, respectively.

RESULTS

Older adults made more FFOV errors and had higher contrast discrimination thresholds in both the steady- and pulsed-pedestal paradigms, than younger adults. FFOV errors in the younger group were not related to contrast discrimination thresholds. In multiple regression, older group FFOV errors showed a strong unique association with contrast discrimination thresholds mediated via the magnocellular, but not the parvocellular pathway.

DISCUSSION

We infer that reduced magnocellular pathway contrast sensitivity may contribute to reduced functional vision in older adults.

miR-30e-5p regulates autophagy and apoptosis by targeting Beclin1 involved in contrast-induced acute kidney injury

AIMS

This study aims to verify if miR-30e-5p targets Beclin1 (BECN1), a key regulator of autophagy, and investigate the function of miR-30e-5p and Beclin1 through mediating autophagy and apoptosis in contrast-induced acute kidney injury (CI-AKI).

METHODS

Human renal tubular epithelial HK-2 cells were treated with Urografin to construct a cell model of CI-AKI. Real-time reverse transcription-polymerase chain reaction was used to detect gene expression. The dual-luciferase reporting assay and endogenous validation were used to verify targeting and regulating function. The expressions of protein were detected using Western blot. Cell proliferation was detected using methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. Cell apoptosis was detected using terminal-deoxynucleoitidyl transferase mediated nick end labeling assay, and autophagy was detected using transmission electron microscopy.

RESULTS

HK-2 cells exposed to Urografin for 2 h induced a significant increase in miR-30e-5p. miR-30e-5p had a targeting effect on Beclin1. Moreover, Urografin exposure can enhance cell apoptosis by increasing caspase 3 gene expression and inhibiting autophagy, which was induced by decreased Beclin1 expression regulated by miR-30e-5p, thereby resulting in renal cell injury. Downregulation of miR-30e-5p or upregulation of Beclin1 restored cell vitality by promoting autophagy and suppressing apoptosis in Urografin-treated cells.

CONCLUSIONS

Urografin increased the expression of miR-30e-5p in HK-2 cells and thus decreased Beclin1 levels to inhibit autophagy, but induced apoptosis, which may be the mechanism for CI-AKI.

One versus many: Multiple examples in word learning

A large body of research indicates that children can map words to categories and generalize the label to new instances of the category after hearing a single instance of the category labeled. Additional research demonstrates that word learning is enhanced when children are presented with multiple instances of a category through comparison or contrast. In this study, 3-year-old children participated in a novel noun generalization task in which a label was given for either (a) a single instance of a category, (b) multiple instances of a category, or (c) contrasting a category instance with non-category members. Children were asked to extend the label to a new category at test either immediately (Study 1) or after a 10-s delay (Study 2). The results indicate that when tested immediately, children who heard a single instance labeled outperformed children who were presented with multiple instances. However, when tested after a brief delay, there was no difference among the conditions.

Task-dependent contrast gain in anomalous trichromats

Anomalous trichromacy is a form of color vision deficiency characterized by the presence of three cone types, but with shifted spectral sensitivities for L or M cones, causing a red-green color deficiency. However, long-term adaptation to this impoverished opponent input may allow for a more normal color experience at the suprathreshold level ("compensation"). Recent experimental evidence points to the presence of compensation in some tasks. The current study used threshold detection, suprathreshold contrast matching, and a reaction-time task to compare contrast coding in normal and anomalous observers along the cardinal cone-opponent axes. Compared to color normals, anomals required more L-M contrast, but not S contrast, to detect stimuli and to match an achromatic reference stimulus. Reaction times were measured for several contrast levels along the two cone-opponent axes. Anomals had higher overall reaction times, but their reaction-time versus contrast functions could be matched to those of controls simply by scaling contrast by the detection thresholds. Anomalous participants were impaired relative to controls for L-M stimuli in all three tasks. However, the contrast losses were three times greater for thresholds and reaction times than for suprathreshold matches. These data provide evidence for compensation in anomalous trichromats, but highlight the role that the experimental task plays in revealing it.

Acute Stroke Care for Patients with Chronic Kidney Disease

Chronic kidney disease is a common comorbidity in patients presenting to emergency departments with acute ischemic stroke. There are numerous considerations that must be taken into account in the acute diagnosis and management of these patients. CKD patients may have different stroke presentations compared to the general population that may make diagnosis more challenging. With the expanding use of endovascular thrombectomy for acute ischemic stroke, more contrasted studies are being employed as part of the acute evaluation, particularly in the identification of patients with large vessel occlusion and demonstration of salvageable penumbra. For most patients with renal dysfunction, studies such as CT angiography and perfusion may still be performed despite concerns of acute kidney injury. Although patient outcomes with reperfusion therapies such as intravenous alteplase and endovascular thrombectomy are not as robust as those seen within the general population, the available data supports utilization of these therapies among CKD patients. This article provides a review of the factors that must be considered in the acute management of the CKD patient presenting with acute ischemic stroke.

Delayed Echo Enhancement Imaging to Quantify Myocardial Infarct Size

BACKGROUND

Perfluoropropane droplets formulated from commercial microbubbles exhibit different acoustic characteristics than their parent microbubbles, most likely from enhanced endothelial permeability. This enhanced permeability may permit delayed echo-enhancement imaging (DEEI) similar to delayed enhancement magnetic resonance imaging (DE-MRI). We hypothesized this would allow detection and quantification of myocardial scar.

METHODS

In 15 pigs undergoing 90 minutes of left anterior descending ischemia by either balloon (n = 13) or thrombotic occlusion (n = 2), DE-MRI was performed at 2-24 days postocclusion. Delayed echo-enhancement imaging was performed at 2-4 minutes following an intravenous injection of 1 mL of 50% Definity (Lantheus Medical) compressed into 180 nm droplets; DEEI was attempted in all pigs with single-pulse harmonic imaging at 1.7 transmit/3.4 MHz receive. Myocardial defects observed with DEEI were quantified (percentage of infarct area) and compared with DE-MRI as well as postmortem staining. In six pigs, multipulse low-mechanical index (MI) fundamental nonlinear imaging (FNLI) with intermittent high-MI impulses was performed to determine whether droplet activation within the infarct zone was achievable with a longer pulse duration.

RESULTS

The range of infarct size area by DE-MRI ranged from 0% to 46% of total left ventricular area. Single-pulse harmonic imaging detected a contrast defect that correlated closely with infarct area by DE-MRI (r = 0.81, P = .0001). The FNLI high-MI impulses resulted in droplet activation in both the infarct and normal zones. Harmonic subtraction of the FNLI images resulted in infarct zone enhancement that also correlated closely with infarct size (r = 0.83; P = .04). Droplets were observed on postmortem transmission electron microscopy within myocytes of the infarct and remote normal zone.

CONCLUSION

Intravenously Definity nanodroplets can be utilized to detect and quantify infarct zone at the bedside using DEEI techniques.

Quantifying contrast of latent fingerprints developed by fluorescent nanomaterials based on spectral analysis

Fluorescent nanoparticles (NPs) have been used to develop latent fingerprints with enhanced contrast. However, a method for quantifying the contrast is still lacking, making it impossible to achieve quantitative comparison in the contrast enhancement between different fingerprint developing agents. Here we proposed a new method to quantify the developed contrast using two indexes when fluorescent NPs were used to develop the latent fingerprint. One is the intensity index (I) defined as the ratio between the integrated fluorescence intensities of the signal and background in the fluorescence spectra of the developed fingerprint. Another is the chroma index (C) determined from the color difference between developed fingerprints and their substrates in the chromaticity graph. We defined the developed contrast as the product of the chroma index and the common logarithm of the intensity index (C·lg I), and validated this method using both down- and up-conversion fluorescent NPs and on a variety of different substrates (glass, marble, red paper and money). We showed that the developed contrast quantified by our method effectively reflected the true contrast but the intensity or chroma index alone was not always effective. This work opens up a new avenue to quantifying and enhancing the developed contrast.

Biliary cannulation with contrast and guide-wire versus exclusive guide-wire: A prospective, randomized, double-blind trial

BACKGROUND

The use of exclusive guide-wire cannulation (e-GW) instead of contrast injection reduces post-ERCP pancreatitis (PEP) and pre-cutting and increases cannulation rate. Herein, we intend to compare e-GW with the hybrid technique (GW-C and/or contrast injection).

METHODS

Prospective single-center randomized comparative study, which included all patients referred to ERCP to our unit. Patients with non-naïve papilla; previous ERCP; direct infundibulotomy, ampullectomy, Billroth II gastrectomy or pancreatic sphincterotomy and patients lost to follow up were excluded.

RESULTS

727 consecutive patients were assessed. Of these, 588 naïve papilla patients were included and randomized to receive e-GW (n = 299) or GW-C (n = 289) for selective biliary cannulation. The mean age was 60.3 years and 60.5% were women. PEP occurred in 15(5%) cases in e-GW group and 9(3.1%) in the GW-C group (p = 0.29). Time to reach deep cannulation was faster in the latter group (75% < 5 min vs. 50.2% < 5 min, p<0.001). > 10 min until cannulation was observed in 21% vs. 10% of the ERCPs (groups e-GW and GW-C, respectively, p < 0.001). Total ERCP time was also shorter in the GW-C group (12 vs. 10 min; p < 0.001). Pre-cut (23.8 vs.11.8%, p < 0.001) and pancreatic sphincterotomy as a pre-cut technique (15.8 vs. 5.6%, p < 0.001) were used more frequently in the e-GW group.

CONCLUSIONS

Compared to exclusive G-W- assisted biliary cannulation, the hybrid technique did not significantly reduce the PEP rate, however it promoted faster cannulation and, consequently, reduced the total procedure time and the use of pre-cut techniques.

Definity, an affinity for painful crisis: a case series describing vaso-occlusive pain crises in sickle cell patients undergoing echocardiogram with Definity contrast

Background 

Individuals with sickle cell disease (SCD) are at risk for painful crises and long-term cardiopulmonary morbidity. Echocardiogram is recommended if signs or symptoms of cardiopulmonary disease develop in previously asymptomatic patients, or worsen in those with known disease. Second-generation echocardiogram contrast agents (ECAs) improve the diagnostic capacity of echocardiogram; however, these agents have risks in SCD populations that have yet to be investigated.

Case summary 

We report a case series of two patients who experienced vaso-occlusive crises following administration of the ECA, Definity. Both patients were referred for echocardiogram from our institution's sickle cell clinic because of concern for SCD-related cardiopulmonary complications. Both patients were in their usual state of health at the time of their exams. The first patient experienced acute back and hip pain minutes after receiving Definity and was diagnosed with acute vaso-occlusive crisis requiring admission for 6 days for pain management. The second patient developed dyspnoea and chest pain within 90 min of her echocardiogram. She was diagnosed with acute chest syndrome and admitted for further management. Her hospitalization was complicated by hyper-haemolysis and multiple organ failure syndrome. After 13 days, she was discharged home.

Discussion 

The safety profile of ECAs has not been fully evaluated and warrants further study in individuals with SCD. Proposed mechanisms for our observations include the release of pro-inflammatory metabolites from Definity contrast agent's shell and ultrasound-induced haemolysis secondary to ECA administration. Alternative imaging modalities and proper precautions should be considered when evaluating cardiopulmonary function in this patient population.

"What you see may not be what you get": Reverse contingency and perceived loss aversion in pigeons

The reverse-contingency task is a task in which one is given a choice between two rewards, but one receives the larger amount only if one chooses the smaller amount. This task is very difficult for chimpanzees unless the choice is between symbolic representations of the amounts. We found that pigeons can learn this task easily, if the reward amounts are associated with distinctive colors and the choice is delayed by 5 s. The reverse-contingency task involves three components: a loss when choosing one alternative, a gain when choosing the other, and the contrast between what was expected and what occurred. In Experiment 2 we separated the loss from the gain and found that experiencing a loss is sufficient for pigeons to learn to avoid that alternative. Finally, we found evidence for perceived loss aversion. When pigeons were offered a small amount of food and they received that amount, they preferred it over an alternative that offered them a larger amount but gave them only the smaller amount (a perceived loss). The results indicate that loss aversion, based on reference dependence, is likely a general phenomenon, and not only found in humans and other primates. We suggest that it can be attributed to contrast, the difference between what is expected and what is obtained, and it is related to the endowment effect and the mere ownership effect found in humans.

Combination of Lymphatic and Intravenous Contrast-Enhanced Ultrasound for Evaluation of Cervical Lymph Node Metastasis from Papillary Thyroid Carcinoma: A Preliminary Study

The aim of this prospective study was to evaluate the value of the combination of lymphatic contrast-enhanced ultrasound (LCEUS) and intravenous contrast-enhanced ultrasound (IVCEUS) for the identification of cervical lymph node metastasis (CLNM) from papillary thyroid carcinoma (PTC). From November 2018 to March 2019, 24 consecutive patients with PTC were evaluated. All patients underwent routine US, LCEUS and IVCEUS. Pathology was used as the gold standard. After injection of a contrast agent into the thyroid parenchyma, lymphatic vessels and lymph nodes (LNs) could be exclusively displayed as hyper-enhancement on LCEUS. Benign LNs displayed a complete bright ring (100%) and homogeneous perfusion (88.9%) on LCEUS, while displaying centrifugal perfusion (66.7%) and homogenous enhancement (88.9%) on IVCEUS. Perfusion defects (94.9%) and interruption of the bright ring (71.8%) were the two characteristic LCEUS signs for diagnosing CLNM. On IVCEUS, CLNM appeared as centripetal perfusion (59.0%) and heterogeneous enhancement (59.0%). After comparison with pathology, perfusion defect was correlated to the metastatic foci in the medulla and interruption of the bright ring to the tumor seeding in the marginal sinus (all p values <0.05). LCEUS had more value (area under the receiver operating characteristic curve [AUC] = 0.850, 95% confidence interval [CI]: 0.682-1.000) in diagnosing CLNM than IVCEUS (AUC = 0.692, 95% CI: 0.494-0.890) and routine US (AUC = 0.581, 95% CI: 0.367-0.796). The combination of LCEUS and IVCEUS has the highest diagnostic value (AUC = 0.863, 95% CI: 0.696-1.000). LCEUS had higher diagnostic value than IVCEUS and US for CLNM from PTC. The combination of LCEUS and IVCEUS has the highest diagnostic value for CLNM.

Delayed bolus-tracking trigger at CT correlates with cardiac dysfunction and suboptimal portovenous contrast phase

OBJECTIVE

To assess whether delayed trigger during bolus-tracking for CT correlates with reduced heart function and suboptimal portovenous contrast phase.

METHODS AND MATERIALS

Patients who underwent portovenous abdominal CT using bolus-tracking and echocardiography within 2 weeks were included and excluded if there was a non-standard contrast injection. The bolus trigger time (BTT) at 100 Hounsfield units in the abdominal aorta, patient age, congestive heart failure (CHF) history, and ejection fraction were recorded. Two radiologists scored the liver contrast phase (1-5, 5 being an optimal portovenous phase). When applicable, the BTT and contrast score of the most recent comparison examination with equivalent technical parameters were also recorded. Simple linear regression (univariate) was used to test for associations with trigger time.

RESULTS

114 patients with a mean age of 61 ± 15 years fulfilled criteria. The mean trigger time was 18 ± 6 s (range: 6-38 s) and the mean ejection fraction was 52 ± 12% (range: 19-69%). A longer bolus trigger had a significant correlation with reduced ejection fraction (P = 0.0018), lower hepatic contrast score (P < 0.0001), history of CHF (P = 0.0212), and older age (P = 0.0223). Contrast score differences between the study exam and available prior exams revealed score differences of 0 (n = 73), 1 (n = 15) and 2 (n = 5); these were associated, respectively, with a mean bolus trigger time difference between exams of 2 s (range, 0-6 s), 6 s (range, 1-15 s), and 11 s (range, 5-13). The P-value comparing bolus trigger time and contrast score differences was less than 0.0001. A lower ejection fraction also significantly correlated with suboptimal PV contrast phase (P < 0.0001).

CONCLUSION

Delayed time to trigger during bolus-tracking for CT can indicate cardiac dysfunction and may not adequately adjust to provide an optimal portovenous contrast phase.

Diagnosis of a primary pericardial mesothelioma by the combination of conventional echocardiography and contrast echocardiography

Primary malignancies arising from the pericardium are rare, even more unusual for primary pericardial mesothelioma. The diagnosis is difficult and has no standard treatment. We herein present a case of a 65-year-old woman with primary pericardial mesothelioma associated with dyspnoea and palpitations. Transthoracic conventional echocardiography revealed mild pericardial effusion and a hypo-echogenic mass in the pericardium. Contrast echocardiography showed that the mass was hyper-enhanced with a radial enhancement pattern. The patient underwent open chest exploration and was diagnosed by pathological examination. She had no further treatment and died 2 years later. In conclusion, the combination of conventional echocardiography and contrast echocardiography plays a significant role in diagnosing primary pericardial mesothelioma. Comprehensive evaluation and accurately preoperative diagnosis are important to exclude certain tumours that do not require surgery.

Saline as an alternative to radio-contrast for optical coherence tomography guided percutaneous coronary intervention: A prospective comparison

OBJECTIVES

To do a quantitative comparison of saline and contrast Frequency domain optical coherence tomography (FD-OCT) during percutaneous coronary intervention (PCI) optimisation.

METHODS

13 pairs of OCT runs were analysed, wherein each pair consisted of a contrast run and a heparinized saline run taken in the same coronary artery at the same position. Quantitative analysis was done comparing minimal lumen area (MLA), proximal reference diameter (PRD), distal reference diameter (DRD) and percentage area stenosis (AS) at the same anatomical location. Lesion morphologies, rendered stent view and 3D reconstruction were compared for image clarity.

RESULT

The saline OCT runs resulted in comparable MLA (3.88 ± 2.59 mm² with saline run vs 3.88 ± 2.71 mm² with contrast run; p = 0.650), PRD (3.66 ± 0.52 mm with saline vs 3.65 ± 0.52 mm with contrast; p = 0.463), DRD (2.97 ± 0.22 mm with saline vs 2.99 ± 0.88 mm with contrast; p = 0.433), and AS (59.60 ± 18.62% with saline vs 59.18 ± 19.11% with contrast; p = 0.753) with respect to the contrast runs. The Bland Altman plots of the measured parameters indicate good agreement between saline and contrast OCT. Linear regression analysis indicated the absence of proportional bias All lesion morphologies (calcified, fibrotic, thin cap fibroatheroma, macrophages, cholesterol crystals and edge dissection), 3D reconstruction and rendered stent view were clearly demonstrable in the saline OCT runs.

CONCLUSIONS

Using heparinized saline as flushing media in coronary FD-OCT may result in vessel dimensions that are comparable with contrast. Heparinized saline may be used as a contrast saving alternative for FD-OCT during PCI optimization.

Safety and diagnostic efficacy of gadoteridol for magnetic resonance imaging of the brain and spine in children 2 years of age and younger

BACKGROUND

Neonates and young children require efficacious magnetic resonance imaging (MRI) examinations but are potentially more susceptible to the short- and long-term adverse effects of gadolinium-based contrast agents due to the immaturity of their body functions.

OBJECTIVE

To evaluate the acute safety and diagnostic efficacy of gadoteridol (ProHance) for contrast-enhanced MRI of the central nervous system (CNS) in children ≤2 years of age.

MATERIALS AND METHODS

One hundred twenty-five children ≤2 years old (including 57 children <6 months old) who underwent contrast-enhanced MRI of the CNS with gadoteridol at 0.1 mmol/kg body weight were retrospectively enrolled at five imaging centers. Safety data were assessed for acute/subacute adverse events in the 48 h following gadoteridol administration and, when available, vital signs, electrocardiogram (ECG) and clinical laboratory values obtained from blood samples taken from 48 h before until 48 h following the MRI exam. The efficacy of gadoteridol-enhanced MRI compared to unenhanced MRI for disease diagnosis was evaluated prospectively by three blinded, unaffiliated readers.

RESULTS

Thirteen changes of laboratory values (11 mild, 1 moderate, 1 unspecified) were reported as adverse events in 7 (5.6%) patients. A relationship to gadoteridol was deemed possible though doubtful for two of these adverse events in two patients (1.6%). There were no clinical adverse events, no serious adverse events and no clinically meaningful changes in vital signs or ECG recordings. Accurate differentiation of tumor from non-neoplastic disease, and exact matching of specific MRI-determined diagnoses with on-site final diagnoses, was achieved in significantly more patients by each reader following the evaluation of combined pre- and post-contrast images compared to pre-contrast images alone (84.6-88.0% vs. 70.9-76.9%; P≤0.006 and 67.5-79.5% vs. 47.0-66.7%; P≤0.011, respectively).

CONCLUSION

Gadoteridol at 0.1 mmol/kg body weight is safe, well tolerated and effective for contrast-enhanced MRI of the CNS in children ≤2 years of age.

Ultrasound and Photoacoustic Imaging of the Kidney: Basic Concepts and Protocols

Noninvasive, robust, and reproducible methods to image kidneys are provided by different imaging modalities. A combination of modalities (multimodality) can give better insight into structure and function and to understand the physiology of the kidney. Magnetic resonance imaging can be complemented by a multimodal imaging approach to obtain additional information or include interventional procedures. In the clinic, renal ultrasound has been essential for the diagnosis and management of kidney disease and for the guidance of invasive procedures for a long time. Adapting ultrasound to preclinical requirements and for translational research, the combination with photoacoustic imaging expands the capabilities to obtain anatomical, functional, and molecular information from animal models. This chapter describes the basic concepts of how to image kidneys using different and most appropriate modalities.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

Does the Contrast Dispersion Pattern During Fluoroscopically Guided Cervical Transforaminal Epidural Steroid Injection Predict Short-Term Pain and Functional Outcomes? An Exploratory Analysis of Prospective Cohort Data

SUMMARY OF BACKGROUND DATA

No study has evaluated the relationship between contrast dispersion patterns and outcomes after fluoroscopically guided cervical transforaminal epidural steroid injection (CTFESI).

OBJECTIVES

Determine whether contrast dispersion patterns predict pain and functional outcomes after CTFESI.

METHODS

Secondary analysis of data collected during two prospective studies of CTFESI for the treatment of refractory radicular pain. Contrast dispersion patterns visualized by true anteroposterior (AP) projections during CTFESIs were categorized by flow: 1) completely external to the lateral border of the neuroforamen (zone 1); 2) within the neuroforamen but without entry into the lateral epidural space (zone 2); and 3) with extension into the lateral epidural space (zone 3). At baseline and at 1 month post-CTFESI, neck pain, arm pain, and "dominant index pain" (the greater of arm or neck pain) were evaluated using a numeric rating scale (NRS); physical function was assessed using the Five-Item Version of the Neck Disability Index (NDI-5).

RESULTS

One-month post-CTFESI, neck pain, arm pain, and "dominant index pain" reductions of ≥50% were observed in 39.4% (95% confidence interval [CI], 28.2-51.8), 55.6% (95% CI, 43.0-67.5), and 44.1% (95% CI, 32.7-56.2) of participants, respectively. Regarding "dominant index pain," 72.7% (95% CI, 40.8-91.2), 39.4% (95% CI, 24.2-57.0), and 37.5% (95% CI, 20.5-58.2) of participants reported ≥50% pain reduction when zone 1, zone 2, and zone 3 contrast flow patterns were observed. Contrast dispersion zone was not significantly associated with subgroup differences in neck pain, arm pain, or NDI-5 scores (P>0.05).

CONCLUSION

Improvements in pain and function 1 month after treatment with CTFESI did not differ significantly based on the contrast dispersion pattern. Future study is needed to confirm or refute these findings in other procedural settings, in broader patient populations, and with longer-term outcome assessment.

Comparison of powdered and fresh jambu (Acmella oleracea)

Jambu, Acmella oleracea (L.), is a low-growing herb plant, with cylindrical, fleshy, decumbent and branched stem varying from 20 to 30 cm in height. It is an abundantly cultivated and consumed vegetable in the northern region of Brazil and usually consumed in preparations of typical foods of the Amazon region. So, this work aimed to compare the chemical composition and physical chemistry of powdered and jambu leaf mass. Acmella oleracea plants were selected, sanitized and their leaves were crushed (without adding water). The mass was dried in an oven with forced air circulation under different conditions of temperature (60, 70 and 80 °C) and relative humidity (13.09, 8.14 and 5.45%, respectively), in two layer thicknesses (0.5 and 1.0 cm). The physical, chemical, physicochemical parameters moisture content, water activity, ash, protein, lipids, pH, total titratable acidity and color were analyzed in powdered and fresh leaves. Contrast test was used to evaluate the interaction between the layer thicknesses at 5% level of significance. Considering the contrasts, the parameters total soluble solids, ash, protein and lipids do not differ from those in the fresh sample, demonstrating that these parameters are not modified or degraded with the drying conditions. The pH and color parameters differed from those of the fresh material, due to degradation, which can be linked to the rise in temperature sensitivity. The moisture content and water activity also differed and were reduced, contributing to conservation of the material. Contrast analysis made it possible to conclude that the physicochemical composition did not undergo modifications through the use of drying. In addition, a powdered material with reduced water activity was obtained.

Impact of a volume challenge on haemodynamics and prognosis in patients with severe aortic stenosis

Aims

A volume challenge can unmask pulmonary hypertension (PH) and its mechanism. We evaluated the impact of a volume challenge on mean pulmonary artery pressure (mPAP) and mean pulmonary artery wedge pressure (mPAWP) and its prognostic implications in patients with severe aortic stenosis (AS) undergoing aortic valve replacement (AVR).

Methods and results

In 285 patients with severe AS (indexed aortic valve area 0.41 ± 0.13 cm²/m²), mPAP and mPAWP were measured before and after administration of 150 ± 58 mL of low‐osmolal or iso‐osmolal contrast. Following contrast, mPAP and mPAWP rose from 25 ± 10 and 16 ± 8 mmHg by 5 ± 4 and 4 ± 4 mmHg to 30 ± 11 and 20 ± 8 mmHg. There were 112 (39%) patients with pre‐contrast PH and 70 (40% of those without pre‐contrast PH) patients with post‐contrast PH only. Post‐contrast PH patients were intermediate between pre‐contrast PH and no PH in terms of AS severity, cardiac dysfunction, and haemodynamics. After a median follow‐up of 43 months post‐AVR, pre‐contrast PH patients had numerically the highest mortality driven by those with pre‐contrast combined pre‐capillary and post‐capillary PH (n = 35), while post‐contrast changes in mPAP and mPAWP were not related to mortality. Patients with any post‐contrast mPAWP > 18 mmHg had significantly higher mortality than those with post‐contrast mPAWP ≤ 18 mmHg,

Conclusions

In severe AS, a contrast challenge leads to post‐contrast PH in ~40% of patients without pre‐contrast PH. However, post‐contrast haemodynamic changes do not adversely affect outcomes in patients undergoing AVR. Post‐contrast PH represents an intermediate stage of ‘cardiac damage’, which may be attenuated or reversible after AVR.

Prognostic impact of FFR/contrast FFR discordance

BACKGROUND

Contrast fractional flow reserve (cFFR) is a relatively new tool for the assessment of intermediate coronary artery stenosis and represents a reliable surrogate of FFR with the advantage of potentially simplifying functional evaluation. We aimed to compare the incidence of major adverse cardiac events (MACE) in patients undergoing functional evaluation with both FFR and cFFR based on the results of the two indexes.

METHOD AND RESULT

We retrospectively analyzed outcomes in 488 patients who underwent functional evaluation with FFR and cFFR. Patients were divided into four groups using the cutoff values of 0.80 for FFR and 0.85 for cFFR: -/- (n = 298), +/+ (n = 134), -/+(n = 31) and +/- (n = 25). All patients were treated according to FFR value. MACE rate was assessed in each group, including death, myocardial infarction and urgent target vessel revascularization (TVR). Mean follow-up time was 22 ± 15 months. Incidence of MACE at follow-up was 8.3% in FFR-/cFFR-, 14.0% in FFR+/cFFR+, 16.0% in FFR-/cFFR+ and 8.0% in FFR+/cFFR- without a significant difference amongst the 4 groups (p = 0.2). Nevertheless, a significant difference in the rate of TVR comparing FFR-/cFFR- (n = 17) and FFR-/cFFR+ (n = 5) was found at 24 months (5.7% vs 16.0%; p = 0.027).

CONCLUSION

cFFR is accurate in predicting FFR and consequently reliable in guiding coronary revascularization. In the rare case of discordance, while FFR+/cFFR- patients show a prognosis similar to FFR-/cFFR- patients, FFR-/cFFR+ patients show a prognosis similar to FFR+/cFFR+ patients.

An exploratory study to evaluate visual function endpoints in non-advanced age-related macular degeneration

Background

To prevent irreversible vision loss in age-related macular degeneration (AMD), it is critical to detect retinal dysfunction before permanent structural loss occurs. In the current study we evaluated a series of visual function tests to identify potential endpoints to detect visual dysfunction in non-advanced AMD.

Methods

A series of visual function tests were performed on 23 non-advanced AMD subjects (AREDS grade 1–4 on simplified scale) and 34 age-matched normals (AREDS grade 0). Tests included some commonly used endpoints such as ETDRS visual acuity (VA), low luminance (LL) 2.0ND ETDRS VA, MNREAD as well as newly developed tests such as the Ora-VCF™ test, Ora-tablet reading test, color sensitivity etc. Differences between the two groups were compared for each test. Test-retest repeatability and reproducibility was assessed on a subset of subjects and percent agreement was calculated.

Results

There was no difference in standard ETDRS VA between non-advanced AMD (0.06 ± 0.02 logMAR) and normal groups (0.04 ± 0.02 logMAR) (p = 0.57). LL 2.0 ETDRS VA and MNREAD showed no difference between the groups (p > 0.05). Ora-VCF™ test was significantly worse in the non-advanced AMD group compared to normals (0.67 ± 0.07 in AMD; 0.45 ± 0.04 in normals, p = 0.005). Non-advanced AMD subjects also had significantly worse reading performance using the Ora-tablet with LL 2.0ND (114.55 ± 11.22 wpm in AMD; 145.17 ± 9.55 wpm in normals p = 0.049). No significant difference between the groups was noted using other tests. Repeatability was 82% for Ora-VCF™ test and 92% for Ora-tablet LL 2.0ND reading. Reproducibility was 89% for both Ora-VCF™ test and Ora-tablet LL 2.0ND reading.

Conclusion

While there was no significant difference between non-advanced AMD and normal groups using some current common endpoints such as ETDRS VA, LL 2.0 ETDRS VA or MNREAD, Ora-VCF™ test and Ora-tablet LL 2.0ND reading tests were able to identify significant visual dysfunction in non-advanced AMD subjects. These tests show promise as endpoints for AMD studies.

Prevalence and outcome of contrast-induced nephropathy in major trauma patients

Background

Contrast-induced nephropathy (CIN) has been well investigated in patients undergoing coronary angiography, but not in trauma patients. The main aim of this study was to determine the prevalence and to investigate independent risk factors for the development of CIN.

Methods

Between 2008 and 2014, all pre-hospital intubated major trauma patients with documented serum creatinine levels (SCr) undergoing a contrast-enhanced whole-body CT at admission were retrospectively analyzed. CIN was defined as a relative increase in SCr > 25% over the baseline value or an absolute SCr increase of > 44 µmol/l within 72 h. Univariate and multivariable regression analyses were performed to identify significant risk factors. A p value of < 0.01 was considered statistically significant and a p value of 0.01–0.049 suggested evidence.

Results

Of 284 analyzed patients, 41 (14%) met the criteria for CIN. There is suggestive evidence that age and lactate level influenced the development of CIN. Six patients (15%) had hemodialysis in the CIN-group and eight (3.3%) in the group without CIN. Complication and mortality rate was higher in patients with CIN (71% vs. 56% and 32% vs. 23%, respectively). CIN was not an independent risk factor for complications or mortality while controlling for age, gender, injury severity score, and lactate level. The length of stay was not affected by CIN.

Conclusion

CIN occurs frequently in trauma patients, but is not an independent risk factor for complications or mortality. Therefore, contrast enhanced whole-body CT can safely be performed in trauma patients.

Use of saline contrast ultrasonography in the diagnosis of complete jugular vein occlusion in a horse

Background

Thrombophlebitis and thrombosis are the most common causes of jugular vein occlusion in horses. Medical and surgical treatments aim to recanalize the occluded vessel and reduce proximal venous congestion and edema.

Case Description

The present report describes a clinical case of equine jugular vein thrombosis (JVT) with complete vein occlusion diagnosed by saline contrast ultrasonography (SCU) and confirmed by contrast venography.

Conclusion

Our results demonstrated that the SCU test can be easily performed and objectively interpreted using standard ultrasound equipment; it is not expensive and it does not require x-ray exposure. The SCU test is a valid tool to assess vessel patency and presence of collateral circulation in JVT. The test could therefore be used to monitor the progression of the disease and the effectiveness of therapy against JVT in horses.

The role of contrast polarities in binocular luster: Low-level and high-level processes

The binocular fusion of two center-surround configurations, where one center is brighter, the other darker than the common surround, leads to a strong impression of luster in the central patch. Without reversed contrast polarities of the center patches, this impression is much weaker or even absent. However, we observed that in the latter case the perceived luster can be considerably enhanced by enclosing both centers with a thin ring of fixed luminance. Compared to the standard stimulus, this center-ring-surround configuration shows much less binocular rivalry and the luster has also a different, more glass-like material quality. In a psychophysical experiment, we examined how the magnitude of the lustrous response depends on the width of the ring, both in stimuli with reversed and consistent contrast polarities. It has been proposed that binocular luster results from a neuronal conflict between ON and OFF visual pathways. To test this hypothesis with respect to our data, we developed a simple model to estimate the amount of interocular conflict resulting from a given binocular stimulus pair and applied it to all stimuli used in the experiment. We found strong correlations between the interocular conflict measure and the strength of luster observed in the experiment, suggesting that a common low-level mechanism determines the magnitude of the lustrous response. Regarding the differences in the perceived material quality of the lustrous impressions, we discuss evidence indicating that high-level processes are involved that promote the visual system's interpretation of the ring-stimuli as a certain depth-segmented 3D scene.