Learn how to interpret and use intracranial EEG findings

Epilepsy surgery is the therapy of choice for many patients with drug-resistant focal epilepsy. Recognizing and describing ictal and interictal patterns with intracranial electroencephalography (EEG) recordings is important in order to most efficiently leverage advantages of this technique to accurately delineate the seizure-onset zone before undergoing surgery. In this seminar in epileptology, we address learning objective "1.4.11 Recognize and describe ictal and interictal patterns with intracranial recordings" of the International League against Epilepsy curriculum for epileptologists. We will review principal considerations of the implantation planning, summarize the literature for the most relevant ictal and interictal EEG patterns within and beyond the Berger frequency spectrum, review invasive stimulation for seizure and functional mapping, discuss caveats in the interpretation of intracranial EEG findings, provide an overview on special considerations in children and in subdural grids/strips, and review available quantitative/signal analysis approaches. To be as practically oriented as possible, we will provide a mini atlas of the most frequent EEG patterns, highlight pearls for its not infrequently challenging interpretation, and conclude with two illustrative case examples. This article shall serve as a useful learning resource for trainees in clinical neurophysiology/epileptology by providing a basic understanding on the concepts of invasive intracranial EEG.

Lightfield hyperspectral imaging in neuro-oncology surgery: an IDEAL 0 and 1 study

Introduction

Hyperspectral imaging (HSI) has shown promise in the field of intra-operative imaging and tissue differentiation as it carries the capability to provide real-time information invisible to the naked eye whilst remaining label free. Previous iterations of intra-operative HSI systems have shown limitations, either due to carrying a large footprint limiting ease of use within the confines of a neurosurgical theater environment, having a slow image acquisition time, or by compromising spatial/spectral resolution in favor of improvements to the surgical workflow. Lightfield hyperspectral imaging is a novel technique that has the potential to facilitate video rate image acquisition whilst maintaining a high spectral resolution. Our pre-clinical and first-in-human studies (IDEAL 0 and 1, respectively) demonstrate the necessary steps leading to the first in-vivo use of a real-time lightfield hyperspectral system in neuro-oncology surgery.

Methods

A lightfield hyperspectral camera (Cubert Ultris ×50) was integrated in a bespoke imaging system setup so that it could be safely adopted into the open neurosurgical workflow whilst maintaining sterility. Our system allowed the surgeon to capture in-vivo hyperspectral data (155 bands, 350-1,000 nm) at 1.5 Hz. Following successful implementation in a pre-clinical setup (IDEAL 0), our system was evaluated during brain tumor surgery in a single patient to remove a posterior fossa meningioma (IDEAL 1). Feedback from the theater team was analyzed and incorporated in a follow-up design aimed at implementing an IDEAL 2a study.

Results

Focusing on our IDEAL 1 study results, hyperspectral information was acquired from the cerebellum and associated meningioma with minimal disruption to the neurosurgical workflow. To the best of our knowledge, this is the first demonstration of HSI acquisition with 100+ spectral bands at a frame rate over 1Hz in surgery.

Discussion

This work demonstrated that a lightfield hyperspectral imaging system not only meets the design criteria and specifications outlined in an IDEAL-0 (pre-clinical) study, but also that it can translate into clinical practice as illustrated by a successful first in human study (IDEAL 1). This opens doors for further development and optimisation, given the increasing evidence that hyperspectral imaging can provide live, wide-field, and label-free intra-operative imaging and tissue differentiation.

Kinematic differences between left- and right-handed cricket fast bowlers during the bowling action

Background

Despite differences between left- and right-handed athletes in other sports, minimal evidence exists regarding biomechanical similarities and differences between left- and right-handed cricket fast bowlers performing an equivalent task.

Objectives

This study aimed to compare the kinematics between left and right-handed fast bowlers performing an equivalent task (i.e. bowling 'over the wicket' to a batter of the same handedness as the bowler).

Methods

Full body, three-dimensional kinematic data for six left-handed and 20 right-handed adolescent, male, fast bowlers were collected using the Xsens inertial measurement system. Time-normalised joint and segment angle time histories from back foot contact to follow-through ground contacts were compared between groups via statistical parametric mapping. Whole movement and subphase durations were also compared.

Results

Left-handed players displayed significantly more trunk flexion from 49%-56% of the total movement (ball release occurred at 54%; p = 0.037) and had shorter back foot contact durations on average (0.153 vs 0.177 s; p = 0.036) compared to right-handed players.

Conclusion

Left- and right-handed bowlers displayed similar sagittal plane kinematics but appeared to use non-sagittal plane movements differently around the time of ball release. The kinematic differences identified in this study can inform future research investigating the effect of hand dominance on bowling performance and injury risk.

Neurophysiology, Neuropsychology, and Epilepsy, in 2022: Hills We Have Climbed and Hills Ahead. Neurophysiology in epilepsy

Since the discovery of the human electroencephalogram (EEG), neurophysiology techniques have become indispensable tools in our armamentarium to localize epileptic seizures. New signal analysis techniques and the prospects of artificial intelligence and big data will offer unprecedented opportunities to further advance the field in the near future, ultimately resulting in improved quality of life for many patients with drug-resistant epilepsy. This article summarizes selected presentations from Day 1 of the two-day symposium "Neurophysiology, Neuropsychology, Epilepsy, 2022: Hills We Have Climbed and the Hills Ahead". Day 1 was dedicated to highlighting and honoring the work of Dr. Jean Gotman, a pioneer in EEG, intracranial EEG, simultaneous EEG/ functional magnetic resonance imaging, and signal analysis of epilepsy. The program focused on two main research directions of Dr. Gotman, and was dedicated to "High-frequency oscillations, a new biomarker of epilepsy" and "Probing the epileptic focus from inside and outside". All talks were presented by colleagues and former trainees of Dr. Gotman. The extended summaries provide an overview of historical and current work in the neurophysiology of epilepsy with emphasis on novel EEG biomarkers of epilepsy and source imaging and concluded with an outlook on the future of epilepsy research, and what is needed to bring the field to the next level.

Hippo signaling instructs ectopic but not normal organ growth

The Hippo signaling pathway is widely considered a master regulator of organ growth because of the prominent overgrowth phenotypes caused by experimental manipulation of its activity. Contrary to this model, we show here that removing Hippo transcriptional output did not impair the ability of the mouse liver and Drosophila eyes to grow to their normal size. Moreover, the transcriptional activity of the Hippo pathway effectors Yap/Taz/Yki did not correlate with cell proliferation, and hyperactivation of these effectors induced gene expression programs that did not recapitulate normal development. Concordantly, a functional screen in Drosophila identified several Hippo pathway target genes that were required for ectopic overgrowth but not normal growth. Thus, Hippo signaling does not instruct normal growth, and the Hippo-induced overgrowth phenotypes are caused by the activation of abnormal genetic programs.

Mortality and major adverse cardiac events in women with breast cancer receiving radiotherapy: a 10-year cohort study of patients and population controls

Background

Treatment for breast cancer (BC) frequently involves radiotherapy. Guidelines recommend screening for cardiac adverse events starting 10 years after radiotherapy. The rationale for recommending this interval is unclear and informed the objective of this study.

Objectives

Study cardiovascular event rates in the first decade following curative radiotherapy for breast cancer, the time frame before guidelines recommend screening.

Methods

We performed a monocentric, retrospective study enrolling all women with unilateral BC in 2007–2008, who received radiotherapy as part of their curative treatment. We compared event rates during 10 years follow-up with an age and risk factor-matched control population (FLEMENGHO population).

Results

We included 1095 BC patients (median age 55y, IQR: 47–66y). Two hundred and eighteen (19.9%) women died. Cancer and cardiovascular mortality accounted for 107 (49.1%) and 22 (10.1%) deaths, respectively. The incidence of coronary artery disease was similar compared to age and risk-matched women [risk ratio 0.75 (95% CI 0.48–1.18)], yet heart failure (HF) [risk ratio 1.97 (95% CI 1.19–3.25)] and atrial fibrillation or flutter (AF) (risk ratio 1.82 (95% CI 1.07–3.08) occurred more often. Age [HR 1.040 (95% CI 1.012–1.069)], tumor grade [HR 1.646 (95% CI 1.103–2.458)], and neo-adjuvant treatment setting [HR 3.079 (95% CI 1.432–6.620)] were risk factors for mortality; hormonal therapy [HR 0.007 (95% CI 0.001–0.042)] proved protective. Risk factors for MACE were mean heart dose [HR 1.079 (95% CI 1.012–1.151], hormonal therapy, history of cardiovascular disease [HR 2.771 (95% CI 1.253–6.126)], and Mayo Clinic Cardiotoxicity Risk Score [HR 2.547 (95% CI 1.538–4.217)]. While mean heart dose [HR 1.141 (95% CI 1.017–1.282)] and cardiovascular history [HR 3.374 (95% CI 1.259–9.043] clearly associated with new onset HF, only a trend towards higher AF burden with increasing mean heart dose could be observed.

Conclusions

Ten-year mortality following curative treatment for unilateral BC was mainly cancer-related. HF and AF constituted significantly increased risks in the first decade following irradiation. Mean heart dose, pre-existing cardiovascular diseases, and Mayo Clinic Cardiotoxicity Risk Score were risk factors for early cardiac mortality and adverse events and should guide early dedicated cardio-oncological follow-up.

Funding Acknowledgement

Type of funding sources: None.

Incidence of cardiovascular events in patients treated with immune checkpoint inhibitors

Background

In rare cases, immune checkpoint inhibitors (ICIs) cause immune-mediated myocarditis. However, the true incidence of other major adverse cardiovascular events (MACE) following ICI treatment remains unknown, mainly because late occurring side effects are rarely reported in prospective clinical trials.

Purpose

To identify the incidence and risk factors of MACE in a real-life ICI-treated cancer cohort and to compare the incidence with non-ICI-treated cancer patients and population controls.

Methods

In total, 672 ICI-treated patients were included. The primary endpoint was MACE, a composite of acute coronary syndrome, heart failure, stroke and transient ischemic attack. Secondary outcomes were acute coronary syndrome and heart failure separately. Incidence rates were compared between groups after matching according to age, sex, cardiovascular history and cancer type.

Results

Incidence of MACE was 10.3% during a median time of follow-up of 13 months (IQR 6 to 22). In multivariable analysis, a history of heart failure (hazard ratio (HR): 2.27; 95% confidence interval (CI): 1.03 to 5.04; p=0.043) and valvular heart disease (HR 3.01; 95% CI: 1.05 to 8.66; p=0.041) remained significantly associated with MACE.

Cumulative incidence rates were significantly higher in the matched ICI group (rate at full range of follow-up (rate): 8.51; 95% CI: 6.18 to 11.4) compared with the cancer cohort not exposed to ICI (rate: 5.20; 95% CI: 3.56 to 7.35; p=0.032) and the population controls (rate: 2.55; 95% CI: 2.16 to 2.99; p<0.001) mainly driven by a higher risk of heart failure events (Figure 1).

Conclusions

Cardiovascular events during and after ICI treatment are more common than currently appreciated. Patients at risk are those with a history of cardiovascular disease. Compared with matched cancer and population controls, MACE incidence rates are significantly higher, suggesting a potential harmful effect of ICI treatment besides the underlying risk.

Funding Acknowledgement

Type of funding sources: None.

Long-term prevention of hereditary angioedema attacks with lanadelumab: The HELP OLE Study

Background

The aim was to evaluate long‐term effectiveness and safety of lanadelumab in patients ≥12 y old with hereditary angioedema (HAE) 1/2 (NCT02741596).

Methods

Rollover patients completing the HELP Study and continuing into HELP OLE received one lanadelumab 300 mg dose until first attack (dose‐and‐wait period), then 300 mg q2wks (regular dosing stage). Nonrollovers (newly enrolled) received lanadelumab 300 mg q2wks from day 0. Baseline attack rate for rollovers: ≥1 attack/4 weeks (based on run‐in period attack rate during HELP Study); for nonrollovers: historical attack rate ≥1 attack/12 weeks. The planned treatment period was 33 months.

Results

212 patients participated (109 rollovers, 103 nonrollovers); 81.6% completed ≥30 months on study (mean [SD], 29.6 [8.2] months). Lanadelumab markedly reduced mean HAE attack rate (reduction vs baseline: 87.4% overall). Patients were attack free for a mean of 97.7% of days during treatment; 81.8% and 68.9% of patients were attack free for ≥6 and ≥12 months, respectively. Angioedema Quality‐of‐Life total and domain scores improved from day 0 to end of study. Treatment‐emergent adverse events (TEAEs) (excluding HAE attacks) were reported by 97.2% of patients; most commonly injection site pain (47.2%) and viral upper respiratory tract infection (42.0%). Treatment‐related TEAEs were reported by 54.7% of patients. Most injection site reactions resolved within 1 hour (70.2%) or 1 day (92.6%). Six (2.8%) patients discontinued due to TEAEs. No treatment‐related serious TEAEs or deaths were reported. Eleven treatment‐related TEAEs of special interest were reported by seven (3.3%) patients.

Conclusion

Lanadelumab demonstrated sustained efficacy and acceptable tolerability with long‐term use in HAE patients.

Predictability of cardiotoxicity at a Belgian cardio-oncology clinic without mandatory physician referral

Background and purpose

Increased morbidity and mortality caused by side-effects of cancer treatment on cardiovascular function mandates careful monitoring and shared decision-making in cardio-oncology clinics. We report the experience of the cardio-oncology clinic at a large Belgian tertiary care center, without mandatory physician referral, and investigated the predictability of cardiotoxicity based on pre-existing cardiovascular risk factors, specific cancer treatment and existing risk scores of the American Society of Clinical Oncology (ASCO) and Mayo Clinic.

Methods

We included all patients seen at the outpatient cardio-oncology clinic between May 2018 and September 2020. We defined cardiotoxicity as a decline in ejection fraction (EF) of 10% in asymptomatic patients and 5% in symptomatic patients. Approval of the ethical committee was obtained (S65084).

Results

The majority were women (68%), with almost half (44%) having metastatic disease. Mean age was 63.4±16.0 years. The most frequent oncological diagnoses were breast cancer (33%) and haematological diseases (24%). Patients most frequently received radiation therapy (42%), anthracyclines (39%) and antimetabolites (35%). Mean follow-up was 443±245 days.

Receiver operating characteristic (ROC) analysis of predictors of cardiotoxicity showed an area under the curve (AUC) of 0.580 (CI 95% bootstrap: 0.525–0.642) for cardiovascular risk factors alone, and an AUC of 0.613 (CI 95% bootstrap: 0.550–0.676) when treatment was added to the model. The ASCO risk score poorly predicted cardiotoxicity (sensitivity 64%, specificity 52%). The Mayo Clinic cardiotoxicity risk score was the best predictor of cardiotoxicity with an AUC of 0.685 (CI 95% bootstrap: 0.625–0.743).

Discussion

Classic cardiovascular risk factors alone, or in combination with the proposed cancer treatment cannot adequately predict cardiotoxicity risk. The Mayo Clinic Cardiotoxicity Risk score outperformed the ASCO risk score but requires further refinement to enhance adequate cardiovascular risk prediction. For future model building, we hypothesize that an all-comer population of oncological patients should be used as a derivation cohort, regardless of previous or current cardiac issues, risk factors or type of therapy. Admittedly, individual susceptibility due to genetic, epigenetic and environmental predisposition cannot be adequately incorporated into a risk score and emphasizes the need for individual cardiotoxicity risk evaluation using bed to bench tools such as the use of induced pluripotent stem cell derived cardiac or vascular cells to assess the susceptibility of individual patients to cancer drug-induced cardiovascular toxicities. In the absence of adequate risk prediction tools, we advocate standardized screening of all patients before oncological treatment starts.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Cardiotoxicity

A methodology to estimate the patient diameter and thickness from thoracic and abdominal projection radiographs of adult patients

Patient dose management systems can be part of a department's quality management tools to estimate items such as the radiation burden in specific groups or list dose outliers for further follow up. Patient size information could improve both aspects, but is not generally available. A new metric is proposed to estimate patient size for thorax and abdominal projection radiography from parameters available in thedicomheader and therefore accessible by dose management software. The tested hypothesis was that an attenuation metric, related to the ratio of detector air-kerma to incident air-kerma, inversely correlates with patient size. Such a metric was defined and then worked out for thorax and abdomen projection radiography. Input material consisted of the thorax or abdominal radiographs of 137 cases, completed with a recent CT scan as ground truth size. From the CT, the water equivalent diameter (WED) and water equivalent thickness (WET) were calculated. The correlation between the attenuation metric and the patient size was established separately for thorax and abdomen. Validation of the attenuation metric predicting the patient size was performed using extra sets of examinations on three more radiographic x-ray devices, with available CT scan. The attenuation metric had a good correlation (R²) of 0.91 and 0.84 with the WED for thorax and abdomen respectively. The corresponding values for the WET were 0.89 and 0.78. Validation of the methodology on the devices with standardized exposure index in thedicomheaders showed that the WED could be estimated within ±15% and the WET within ±30% for thorax and abdomen examinations. The ground truth and estimated size were found statistically equivalent. An attenuation metric based ondicomtags allows to estimate the patient size in projection radiography. This could now be implemented in patient dose management systems.

Impact of lanadelumab on health-related quality of life in patients with hereditary angioedema in the HELP study

Background

An objective of the phase 3 HELP Study was to investigate the effect of lanadelumab on health‐related quality of life (HRQoL) in patients with hereditary angioedema (HAE).

Methods

Patients with HAE‐1/2 received either lanadelumab 150 mg every 4 weeks (q4wks; n = 28), 300 mg q4wks (n = 29), 300 mg every 2 weeks (q2wks; n = 27), or placebo (n = 41) for 26 weeks (days 0–182). The Angioedema Quality of Life Questionnaire (AE‐QoL) was administered monthly, consisting of four domain (functioning, fatigue/mood, fears/shame, nutrition) and total scores. The generic EQ‐5D‐5L questionnaire was administered on days 0, 98, and 182. Comparisons were made between placebo and (a) all lanadelumab‐treated patients and (b) individual lanadelumab groups for changes in scores (day 0–182) and proportions achieving the minimal clinically important difference (MCID, −6) in AE‐QoL total score.

Results

Compared with the placebo group, the lanadelumab total group demonstrated significantly greater improvements in AE‐QoL total and domain scores (mean change, −13.0 to −29.3; p < 0.05 for all); the largest improvement was in functioning. A significantly greater proportion of the lanadelumab total group achieved the MCID (70% vs 37%; p = 0.001). The lanadelumab 300 mg q2wks group had the highest proportion (81%; p = 0.001) and was 7.2 times more likely to achieve the MCID than the placebo group. Mean EQ‐5D‐5L scores at day 0 were high in all groups, indicating low impairment, with no significant changes at day 182.

Conclusion

Patients with HAE‐1/2 experienced significant and clinically meaningful improvements in HRQoL measured by AE‐QoL following lanadelumab treatment in the HELP Study.

Effect of breathing motion on robustness of proton therapy plans for left-sided breast cancer patients with indication for locoregional irradiation

PURPOSE

To investigate the dosimetric impact of breathing motion on robustly optimized proton therapy treatment plans for left-sided breast cancer patients with an indication for locoregional irradiation.

MATERIALS AND METHODS

Clinical Target Volumes (CTVs) (left-sided breast, level 1 to 4 axillary lymph nodes, interpectoral and internal mammary lymph node regions) and organs at risk were delineated on 4 D-CTs of ten female patients. After treatment planning to a prescribed dose of 40.05 Gy(RBE) in 15 fractions on the time-averaged CT, the dose was calculated on all ten phases of the breathing cycle. Robustness to setup (5 mm) and range errors (3%) was evaluated for those ten phases. Correlations were evaluated between the phases of the breathing cycle and the D98% of the CTV and the D_mean of the heart.

RESULTS

Correlations coefficients were between -0.12 and 0.29. At the most extreme values of the 28 robustness scenarios, the clinical goals were met for all but two patients. The mean heart dose was 0.41 Gy(RBE) with a standard deviation of 0.31 Gy(RBE) of proton therapy plans.

CONCLUSION

The effect of breathing motion on the robustness of proton therapy treatment plans for this patient group is minor and not of clinical significance. Based on this patient group, a deep-inspiration breath hold seems to be unnecessary to improve robustness for these patients.

Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks

Background

Lanadelumab demonstrated efficacy in preventing hereditary angioedema (HAE) attacks in the phase 3 HELP Study.

Objective

To assess time to onset of effect and long‐term efficacy of lanadelumab, based on exploratory findings from the HELP Study.

Methods

Eligible patients with HAE type I/II received lanadelumab 150 mg every 4 weeks (q4wks), 300 mg q4wks, 300 mg q2wks, or placebo. Ad hoc analyses evaluated day 0‐69 findings using a Poisson regression model accounting for overdispersion. Least‐squares mean monthly HAE attack rate for lanadelumab was compared with placebo. Intrapatient comparisons for days 0‐69 versus steady state (days 70‐182) used a paired t test for continuous endpoints or Kappa statistics for categorical endpoints.

Results

One hundred twenty‐five patients were randomized and treated. During days 0‐69, mean monthly attack rate was significantly lower with lanadelumab (0.41‐0.76) vs placebo (2.04), including attacks requiring acute treatment (0.33‐0.61 vs 1.66) and moderate/severe attacks (0.31‐0.48 vs 1.33, all P ≤ .001). More patients receiving lanadelumab vs placebo were attack free (37.9%‐48.1% vs 7.3%) and responders (85.7%‐100% vs 26.8%). During steady state, the efficacy of lanadelumab vs placebo was similar or improved vs days 0‐69. Intrapatient differences were significant with lanadelumab 300 mg q4wks for select outcomes. Lanadelumab efficacy was durable—HAE attack rate was consistently lower vs placebo, from the first 2 weeks of treatment through study end. Treatment emergent adverse events were comparable during days 0‐69 and 70‐182.

Conclusion

Protection with lanadelumab started from the first dose and continued throughout the entire study period.

Diagnostic Accuracy & Pathology Revised Reports: Evidence-Based Guideline Development

Introduction/Objective

Diagnostic errors in pathology may have adverse impact on patient outcomes and are often rectified through revised reports (RR). Improving patient outcomes with accurate RR is a tangible yet challenging benefit to assuring continuous quality improvement (CQI). Assessment and elevation of RR optimization requires counterbalance of workflow complexity in the diagnostic reporting domain. Implications inform best-practice guidelines for pathology RR and exemplify improved patient outcomes by driving down negative impacts from diagnostic errors.

Methods

A “Survey for RR in Pathology: Reality & Best Practices” was sent via email to relevant stakeholders. The 8-item survey was designed by the National Pathology Quality Registry team & ASCP’s Institute for Science, Technology & Policy. The model included quantitative and qualitative feedback to probe current experiences with RR. The survey was open April 1-30, 2019, via Key Survey and used snowball sampling.

Results

Key results illuminate necessity for RR standardization. Survey findings represent 172 respondents. Ninety- two percent of respondents indicated report accuracy as a major indication for optimizing RR practices & positively impacting patient care. Pathology practices assure appropriate RR by notifying a care provider when a change in diagnosis necessitates RR (89%) & 86% of respondents indicate delineation of RR types (e.g. addenda, amendment). Still 54% of respondents see inappropriate RR use with lack of notification to care providers and 48% indicate no delineation of RR types. This balance-counterbalance highlights deviations from optimized RR and a need for guidelines. Effects on patient care or impact to a patient’s treatment plan was indicated by 43% who affirmed stratification of diagnostic discrepancies as major vs. minor. Solely focusing on changes in diagnosis (benign vs. malignant) was heralded by 19% of respondents as a reason to categorize diagnostic discrepancies. Forty-two percent of respondents indicate data-driven CQI in the RR domain.

Conclusion

Identified RR practice gaps decrease diagnostic accuracy, confirming the need for optimal RR guidelines. RR guidelines should focus on standardized nomenclature; active dialogue between laboratory team & clinical care partners; streamlined workflows to assure accuracy; & valuing transparency to derive improved patient outcomes based on high-quality diagnostic pathology RR.

Microbiologic Proof-Of-Concept: A Novel Device Combining UV Light And Ozone For Human Skin Antisepsis

Introduction/Objective

Hand hygiene (HH) decreases healthcare-associated infections (HAI). Available products include alcohol-based gels, foams, wipes, and “gold-standard” hand-washing with soap and water. We tested an investigational device (HyLuxO3; GMI, LLC, patent pending) for antimicrobial effect (AME). HyLuxO3 was engineered to deliver UV-C light energy and high velocity O3 airflow to safely achieve human skin antisepsis within OSHA and EPA regulatory limits. Combined UV and O3 has yet to be evaluated for HH and may demonstrate synergistic AME.

Methods

HyLuxO3 was tested on LB agar to titrate device variables to ascertain intensities for optimal AME; later testing was performed on VITRO-SKIN (Florida Suncare Testing, Bunnell, FL), a human skin surrogate. ATCC strains of MRSA, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans were used to test AME vs. vegetative microbes; Bacillus atrophaeus spores were used as a surrogate for C. difficile. Tested variables included time under device, [O3], airflow velocity, 222 and/or 254 nm UV light, sample distance from UV lamp, and UV beam width. Positive controls were used to calculate log-kill curves for AME.

Results

Similar results were seen on LB agar and VITRO-SKIN. &gt;7 log-kill and &gt;5 log-kill were acheived vs. vegetative microbes (&lt;30 sec) and spores (60 sec), respectively, under optimized variables. Presence of UV light and sample distance from and time under the device were the most important variables. 254 nm UV had a significantly better AME than 222 nm; combining both UV lamps had a significant synergistic AME. The narrowest UV beam (2 mm) yielded the greatest AME (total energy input kept constant). Adding O3 to UV had a modest but significant synergistic effect; optimal [O3] was 0.3-0.8 ppm. Changing airflow velocity had no significant effect on AME.

Conclusion

HyLuxO3 is a novel device that achieves &gt;7 log-kill vs. common pathogenic vegetative microbes and &gt;5 log-kill vs. spores using combined UV light and [O3] safe for human skin antisepsis (and surface/fomite decontamination)- and- yields such impressive AME on faster timescales than those required by bleach/other chemical products unsuitable for human skin. Future studies on human hands (using many other microbes) will determine if HyLuxO3 meets regulatory and efficacy requirements for use in and beyond healthcare settings, especially with the specter of emerging respiratory viruses.

Quantitative MRCP Imaging: Accuracy, Repeatability, Reproducibility, and Cohort-Derived Normative Ranges

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is an important tool for noninvasive imaging of biliary disease, however, its assessment is currently subjective, resulting in the need for objective biomarkers.

PURPOSE

To investigate the accuracy, scan/rescan repeatability, and cross-scanner reproducibility of a novel quantitative MRCP tool on phantoms and in vivo. Additionally, to report normative ranges derived from the healthy cohort for duct measurements and tree-level summary metrics.

STUDY TYPE

Prospective.

PHANTOMS/SUBJECTS

Phantoms: two bespoke designs, one with varying tube-width, curvature, and orientation, and one exhibiting a complex structure based on a real biliary tree. Subjects Twenty healthy volunteers, 10 patients with biliary disease, and 10 with nonbiliary liver disease.

SEQUENCE/FIELD STRENGTH

MRCP data were acquired using heavily T2 -weighted 3D multishot fast/turbo spin echo acquisitions at 1.5T and 3T.

ASSESSMENT

Digital instances of the phantoms were synthesized with varying resolution and signal-to-noise ratio. Physical 3D-printed phantoms were scanned across six scanners (two field strengths for each of three manufacturers). Human subjects were imaged on four scanners (two fieldstrengths for each of two manufacturers).

STATISTICAL TESTS

Bland-Altman analysis and repeatability coefficient (RC).

RESULTS

Accuracy of the diameter measurement approximated the scanning resolution, with 95% limits of agreement (LoA) from -1.1 to 1.0 mm. Excellent phantom repeatability was observed, with LoA from -0.4 to 0.4 mm. Good reproducibility was observed across the six scanners for both phantoms, with a range of LoA from -1.1 to 0.5 mm. Inter- and intraobserver agreement was high. Quantitative MRCP detected strictures and dilatations in the phantom with 76.6% and 85.9% sensitivity and 100% specificity in both. Patients and healthy volunteers exhibited significant differences in metrics including common bile duct (CBD) maximum diameter (7.6 mm vs. 5.2 mm P = 0.002), and overall biliary tree volume 12.36 mL vs. 4.61 mL, P = 0.0026).

DATA CONCLUSION

The results indicate that quantitative MRCP provides accurate, repeatable, and reproducible measurements capable of objectively assessing cholangiopathic change. Evidence Level: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:807-820.