Recommended Resting-State fMRI Acquisition and Preprocessing Steps for Preoperative Mapping of Language and Motor and Visual Areas in Adult and Pediatric Patients with Brain Tumors and Epilepsy

Resting-state (rs) fMRI has been shown to be useful for preoperative mapping of functional areas in patients with brain tumors and epilepsy. However, its lack of standardization limits its widespread use and hinders multicenter collaboration. The American Society of Functional Neuroradiology, American Society of Pediatric Neuroradiology, and the American Society of Neuroradiology Functional and Diffusion MR Imaging Study Group recommend specific rs-fMRI acquisition approaches and preprocessing steps that will further support rs-fMRI for future clinical use. A task force with expertise in fMRI from multiple institutions provided recommendations on the rs-fMRI steps needed for mapping of language, motor, and visual areas in adult and pediatric patients with brain tumor and epilepsy. These were based on an extensive literature review and expert consensus.Following rs-fMRI acquisition parameters are recommended: minimum 6-minute acquisition time; scan with eyes open with fixation; obtain rs-fMRI before both task-based fMRI and contrast administration; temporal resolution of ≤2 seconds; scanner field strength of 3T or higher. The following rs-fMRI preprocessing steps and parameters are recommended: motion correction (seed-based correlation analysis [SBC], independent component analysis [ICA]); despiking (SBC); volume censoring (SBC, ICA); nuisance regression of CSF and white matter signals (SBC); head motion regression (SBC, ICA); bandpass filtering (SBC, ICA); and spatial smoothing with a kernel size that is twice the effective voxel size (SBC, ICA).The consensus recommendations put forth for rs-fMRI acquisition and preprocessing steps will aid in standardization of practice and guide rs-fMRI program development across institutions. Standardized rs-fMRI protocols and processing pipelines are essential for multicenter trials and to implement rs-fMRI as part of standard clinical practice.

Peer Learning Program Metrics: A Pediatric Neuroradiology Example

BACKGROUND AND PURPOSE

The American College of Radiology is now offering an accreditation pathway for programs that use peer learning. Here, we share feasibility and outcome data from a pilot peer learning program in a pediatric neuroradiology section that, in its design, follows the American College of Radiology peer learning accreditation pathway criteria.

MATERIALS AND METHODS

We retrospectively reviewed metrics from a peer learning program with 5 participating full-time pediatric neuroradiologists during 1 year: 1) number of cases submitted, 2) percentage of radiologists meeting targets, 3) monthly attendance, 4) number of cases reviewed, 5) learning points, and 6) improvement actions. In addition, a faculty survey was conducted and is reported here.

RESULTS

Three hundred twenty-four cases were submitted (mean, 7 cases/faculty/month). The faculty never met the monthly submission target. Peer learning meeting attendance was 100%. One hundred seventy-nine cases were reviewed during the peer learning meetings. There were 22 learning points throughout the year and 30 documented improvement actions. The faculty survey yielded the highest ratings (4.8 of 5) for ease of meeting the 100% attendance requirement and for the learning value of the peer learning sessions. The lowest rating (4.2 of 5) was given for the effectiveness of improvements as a result of peer learning discussions.

CONCLUSIONS

Implementing a peer learning program that follows the American College of Radiology peer learning accreditation pathway criteria is feasible. Program metric documentation can be time-consuming. Participant feedback led to meaningful program improvement, such as improving trust, expanding case submission categories, and delegating tasks to administrative staff. Effort to make peer learning operations more efficient and more effective is underway.

Altered Processing of Complex Visual Stimuli in Patients with Postconcussive Visual Motion Sensitivity

BACKGROUND AND PURPOSE

Vestibular symptoms are common after concussion. Vestibular Ocular Motor Screening identifies vestibular impairment, including postconcussive visual motion sensitivity, though the underlying functional brain alterations are not defined. We hypothesized that alterations in multisensory processing are responsible for postconcussive visual motion sensitivity, are detectable on fMRI, and correlate with symptom severity.

MATERIALS AND METHODS

Twelve patients with subacute postconcussive visual motion sensitivity and 10 healthy control subjects underwent vestibular testing and a novel fMRI visual-vestibular paradigm including 30-second "neutral" or "provocative" videos. The presence of symptoms/intensity was rated immediately after each video. fMRI group-level analysis was performed for a "provocative-neutral" condition. Z-statistic images were nonparametrically thresholded using clusters determined by Z > 2.3 and a corrected cluster significance threshold of P = .05. Symptoms assessed on Vestibular Ocular Motor Screening were correlated with fMRI mean parameter estimates using Pearson correlation coefficients.

RESULTS

Subjects with postconcussive visual motion sensitivity had significantly more Vestibular Ocular Motor Screening abnormalities and increased symptoms while viewing provocative videos. While robust mean activation in the primary and secondary visual areas, the parietal lobe, parietoinsular vestibular cortex, and cingulate gyrus was seen in both groups, selective increased activation was seen in subjects with postconcussive visual motion sensitivity in the primary vestibular/adjacent cortex and inferior frontal gyrus, which are putative multisensory visual-vestibular processing centers. Moderate-to-strong correlations were found between Vestibular Ocular Motor Screening scores and fMRI activation in the left frontal eye field, left middle temporal visual area, and right posterior hippocampus.

CONCLUSIONS

Increased fMRI brain activation in visual-vestibular multisensory processing regions is selectively seen in patients with postconcussive visual motion sensitivity and is correlated with Vestibular Ocular Motor Screening symptom severity, suggesting that increased visual input weighting into the vestibular network may underlie postconcussive visual motion sensitivity.

An automated approach to determine antibody endpoint titers for COVID-19 by an enzyme-linked immunosorbent assay

While a variety of therapeutic options continue to emerge for COVID-19 treatment, convalescent plasma (CP) has been used as a possible treatment option early in the pandemic. One of the most significant challenges with CP therapy, however, both when defining its efficacy and implementing its approach clinically, is accurately and efficiently characterizing an otherwise heterogenous therapeutic treatment. Given current limitations, our goal is to leverage a SARS antibody testing platform with a newly developed automated endpoint titer analysis program to rapidly define SARS-CoV-2 antibody levels in CP donors and hospitalized patients. A newly developed antibody detection platform was used to perform a serial dilution enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G, IgM, and IgA SARS-CoV-2 antibodies. Data were then analyzed using commercially available software, GraphPad Prism, or a newly developed program developed in Python called TiterScape, to analyze endpoint titers. Endpoint titer calculations and analysis times were then compared between the two analysis approaches. Serial dilution analysis of SARS-CoV-2 antibody levels revealed a high level of heterogeneity between individuals. Commercial platform analysis required significant time for manual data input and extrapolated endpoint titer values when the last serial dilution was above the endpoint cutoff, occasionally producing erroneously high results. By contrast, TiterScape processed 1008 samples for endpoint titer results in roughly 14 minutes compared with the 8 hours required for the commercial software program analysis. Equally important, results generated by TiterScape and Prism were highly similar, with differences averaging 1.26 ± 0.2 percent (mean ± SD). The pandemic has created unprecedented challenges when seeking to accurately test large numbers of individuals for SARS-CoV-2 antibody levels with a rapid turnaround time. ELISA platforms capable of serial dilution analysis coupled with a highly flexible software interface may provide a useful tool when seeking to define endpoint titers in a high-throughput manner. Immunohematology 2021;37:33-43. While a variety of therapeutic options continue to emerge for COVID-19 treatment, convalescent plasma (CP) has been used as a possible treatment option early in the pandemic. One of the most significant challenges with CP therapy, however, both when defining its efficacy and implementing its approach clinically, is accurately and efficiently characterizing an otherwise heterogenous therapeutic treatment. Given current limitations, our goal is to leverage a SARS antibody testing platform with a newly developed automated endpoint titer analysis program to rapidly define SARS-CoV-2 antibody levels in CP donors and hospitalized patients. A newly developed antibody detection platform was used to perform a serial dilution enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G, IgM, and IgA SARS-CoV-2 antibodies. Data were then analyzed using commercially available software, GraphPad Prism, or a newly developed program developed in Python called TiterScape, to analyze endpoint titers. Endpoint titer calculations and analysis times were then compared between the two analysis approaches. Serial dilution analysis of SARS-CoV-2 antibody levels revealed a high level of heterogeneity between individuals. Commercial platform analysis required significant time for manual data input and extrapolated endpoint titer values when the last serial dilution was above the endpoint cutoff, occasionally producing erroneously high results. By contrast, TiterScape processed 1008 samples for endpoint titer results in roughly 14 minutes compared with the 8 hours required for the commercial software program analysis. Equally important, results generated by TiterScape and Prism were highly similar, with differences averaging 1.26 ± 0.2 percent (mean ± SD). The pandemic has created unprecedented challenges when seeking to accurately test large numbers of individuals for SARS-CoV-2 antibody levels with a rapid turnaround time. ELISA platforms capable of serial dilution analysis coupled with a highly flexible software interface may provide a useful tool when seeking to define endpoint titers in a high-throughput manner. Immunohematology 2021;37:33–43.

Evolving Use of fMRI in Medicare Beneficiaries

Using the Medicare Physician-Supplier Procedure Summary Master File, we evaluated the evolving use of fMRI in Medicare fee-for-service beneficiaries from 2007 through 2017. Annual use rates (per 1,000,000 enrollees) increased from 17.7 to 32.8 through 2014 and have remained static since. Radiologists have remained the dominant specialty group from 2007 to 2017 (86.4% and 88.6% of all services, respectively), and the outpatient setting has remained the dominant place of service (65.4% and 65.4%, respectively).

Divalent EuRh2Si2 as a reference for the Luttinger theorem and antiferromagnetism in trivalent heavy-fermion YbRh2Si2

Application of the Luttinger theorem to the Kondo lattice YbRh2Si2 suggests that its large 4f-derived Fermi surface (FS) in the paramagnetic (PM) regime should be similar in shape and volume to that of the divalent local-moment antiferromagnet (AFM) EuRh2Si2 in its PM regime. Here we show by angle-resolved photoemission spectroscopy that paramagnetic EuRh2Si2 has a large FS essentially similar to the one seen in YbRh2Si2 down to 1 K. In EuRh2Si2 the onset of AFM order below 24.5 K induces an extensive fragmentation of the FS due to Brillouin zone folding, intersection and resulting hybridization of the Fermi-surface sheets. Our results on EuRh2Si2 indicate that the formation of the AFM state in YbRh2Si2 is very likely also connected with similar changes in the FS, which have to be taken into account in the controversial analysis and discussion of anomalies observed at the quantum critical point in this system.

Diagnostic Quality of 3D T2-SPACE Compared with T2-FSE in the Evaluation of Cervical Spine MRI Anatomy

BACKGROUND AND PURPOSE

Spinal anatomy has been variably investigated using 3D MRI. We aimed to compare the diagnostic quality of T2 sampling perfection with application-optimized contrasts by using flip angle evolution (SPACE) with T2-FSE sequences for visualization of cervical spine anatomy. We predicted that T2-SPACE will be equivalent or superior to T2-FSE for visibility of anatomic structures.

MATERIALS AND METHODS

Adult patients undergoing cervical spine MR imaging with both T2-SPACE and T2-FSE sequences for radiculopathy or myelopathy between September 2014 and February 2015 were included. Two blinded subspecialty-trained radiologists independently assessed the visibility of 12 anatomic structures by using a 5-point scale and assessed CSF pulsation artifact by using a 4-point scale. Sagittal images and 6 axial levels from C2-T1 on T2-FSE were reviewed; 2 weeks later and after randomization, T2-SPACE was evaluated. Diagnostic quality for each structure and CSF pulsation artifact visibility on both sequences were compared by using a paired t test. Interobserver agreement was calculated (κ).

RESULTS

Forty-five patients were included (mean age, 57 years; 40% male). The average visibility scores for intervertebral disc signal, neural foramina, ligamentum flavum, ventral rootlets, and dorsal rootlets were higher for T2-SPACE compared with T2-FSE for both reviewers (P < .001). Average scores for remaining structures were either not statistically different or the superiority of one sequence was discordant between reviewers. T2-SPACE showed less degree of CSF flow artifact (P < .001). Interobserver variability ranged between -0.02-0.20 for T2-SPACE and -0.02-0.30 for T2-FSE (slight to fair agreement).

CONCLUSIONS

T2-SPACE may be equivalent or superior to T2-FSE for the evaluation of cervical spine anatomic structures, and T2-SPACE shows a lower degree of CSF pulsation artifact.

Enhanced responsivity resonant RF photodetectors

The responsivity of room-temperature, semiconductor-based photodetectors consisting of resonant RF circuits coupled to microstrip buslines is investigated. The dependence of the photodetector response on the semiconductor material and RF circuit geometry is presented, as is the detector response as a function of the spatial position of the incident light. We demonstrate significant improvement in detector response by choice of photoconductive material, and for a given material, by positioning our optical signal to overlap with positions of RF field enhancement. Design of RF circuits with strong field enhancement are demonstrated to further improve detector response. The improved detector response demonstrated offers opportunities for applications in RF photonics, materials metrology, or single read-out multiplexed detector arrays.

Fermi Surface of Metallic V_{2}O_{3} from Angle-Resolved Photoemission: Mid-level Filling of e_{g}^{π} Bands

Using angle resolved photoemission spectroscopy, we report the first band dispersions and distinct features of the bulk Fermi surface (FS) in the paramagnetic metallic phase of the prototypical metal-insulator transition material V_{2}O_{3}. Along the c axis we observe both an electron pocket and a triangular holelike FS topology, showing that both V 3d a_{1g} and e_{g}^{π} states contribute to the FS. These results challenge the existing correlation-enhanced crystal field splitting theoretical explanation for the transition mechanism and pave the way for the solution of this mystery.

Electronic Structure of YbB_{6}: Is it a Topological Insulator or Not?

To finally resolve the controversial issue of whether or not the electronic structure of YbB_{6} is nontrivially topological, we have made a combined study using angle-resolved photoemission spectroscopy (ARPES) of the nonpolar (110) surface and density functional theory (DFT). The flat-band conditions of the (110) ARPES avoid the strong band bending effects of the polar (001) surface and definitively show that YbB_{6} has a topologically trivial B 2p-Yb 5d semiconductor band gap of ∼0.3  eV. Accurate determination of the low energy band topology in DFT requires the use of a modified Becke-Johnson exchange potential incorporating spin-orbit coupling and an on-site Yb 4f Coulomb interaction U as large as 7 eV. The DFT result, confirmed by a more precise GW band calculation, is similar to that of a small gap non-Kondo nontopological semiconductor. Additionally, the pressure-dependent electronic structure of YbB_{6} is investigated theoretically and found to transform into a p-d overlap semimetal with small Yb mixed valency.

Performance of CT ASPECTS and Collateral Score in Risk Stratification: Can Target Perfusion Profiles Be Predicted without Perfusion Imaging?

BACKGROUND AND PURPOSE

Endovascular trials suggest that revascularization benefits a subset of acute ischemic stroke patients with large-artery occlusion and small-core infarct volumes. The objective of our study was to identify thresholds of noncontrast CT-ASPECTS and collateral scores on CT angiography that best predict ischemic core volume thresholds quantified by CT perfusion among patients with acute ischemic stroke.

MATERIALS AND METHODS

Fifty-four patients with acute ischemic stroke (<12 hours) and MCA/intracranial ICA occlusion underwent NCCT/CTP during their initial evaluation. CTP analysis was performed on a user-independent platform (RApid processing of PerfusIon and Diffusion), computing core infarct (defined as CBF of <30% normal). A target mismatch profile consisting of infarction core of ≤50 mL was selected to define candidates with acute ischemic stroke likely to benefit from revascularization.

RESULTS

NCCT-ASPECTS of ≥9 with a CTA collateral score of 3 had 100% specificity for identifying patients with a CBF core volume of ≤50 mL. NCCT-ASPECTS of ≤6 had 100% specificity for identifying patients with a CBF core volume of >50 mL. In our cohort, 44 (81%) patients had an NCCT-ASPECTS of ≥9, a CTA collateral score of 3, or an NCCT-ASPECTS of ≤6.

CONCLUSIONS

Using an NCCT-ASPECTS of ≥9 or a CTA collateral score of 3 best predicts CBF core volume infarct of ≤50 mL, while an NCCT-ASPECTS of ≤6 best predicts a CBF core volume infarct of >50 mL. Together these thresholds suggest that a specific population of patients with acute ischemic stroke not meeting such profiles may benefit most from CTP imaging to determine candidacy for revascularization.

Performance and Predictive Value of a User-Independent Platform for CT Perfusion Analysis: Threshold-Derived Automated Systems Outperform Examiner-Driven Approaches in Outcome Prediction of Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Treatment strategies in acute ischemic stroke aim to curtail ischemic progression. Emerging paradigms propose patient subselection using imaging biomarkers derived from CT, CTA, and CT perfusion. We evaluated the performance of a fully-automated computational tool, hypothesizing enhancements compared with qualitative approaches. The correlation between imaging variables and clinical outcomes in a cohort of patients with acute ischemic stroke is reported.

MATERIALS AND METHODS

Sixty-two patients with acute ischemic stroke and MCA or ICA occlusion undergoing multidetector CT, CTA, and CTP were retrospectively evaluated. CTP was processed on a fully operator-independent platform (RApid processing of PerfusIon and Diffusion [RAPID]) computing automated core estimates based on relative cerebral blood flow and relative cerebral blood volume and hypoperfused tissue volumes at varying thresholds of time-to-maximum. Qualitative analysis was assigned by 2 independent reviewers for each variable, including CT-ASPECTS, CBV-ASPECTS, CBF-ASPECTS, CTA collateral score, and CTA clot burden score. Performance as predictors of favorable clinical outcome and final infarct volume was established for each variable.

RESULTS

Both RAPID core estimates, CT-ASPECTS, CBV-ASPECTS, and clot burden score correlated with favorable clinical outcome (P < .05); CBF-ASPECTS and collateral score were not significantly associated with favorable outcome, while hypoperfusion estimates were variably associated, depending on the selected time-to-maximum thresholds. Receiver operating characteristic analysis demonstrated disparities among tested variables, with RAPID core and hypoperfusion estimates outperforming all qualitative approaches (area under the curve, relative CBV = 0.86, relative CBF = 0.81; P < .001).

CONCLUSIONS

Qualitative approaches to acute ischemic stroke imaging are subject to limitations due to their subjective nature and lack of physiologic information. These findings support the benefits of high-speed automated analysis, outperforming conventional methodologies while limiting delays in clinical management.

Two-dimensional Fermi surfaces in Kondo insulator SmB6

In the Kondo insulator samarium hexaboride (SmB6), strong correlation and band hybridization lead to an insulating gap and a diverging resistance at low temperature. The resistance divergence ends at about 3 kelvin, a behavior that may arise from surface conductance. We used torque magnetometry to resolve the Fermi surface topology in this material. The observed oscillation patterns reveal two Fermi surfaces on the (100) surface plane and one Fermi surface on the (101) surface plane. The measured Fermi surface cross sections scale as the inverse cosine function of the magnetic field tilt angles, which demonstrates the two-dimensional nature of the conducting electronic states of SmB6.

Persistent non-metallic behavior in Sr2IrO4 and Sr3Ir2O7 at high pressures

Iridium-based 5d transition-metal oxides are attractive candidates for the study of correlated electronic states due to the interplay of enhanced crystal-field, Coulomb and spin-orbit interaction energies. At ambient pressure, these conditions promote a novel Jeff = 1/2 Mott-insulating state, characterized by a gap of the order of ~0.1 eV. We present high-pressure electrical resistivity measurements of single crystals of Sr2IrO4 and Sr3Ir2O7. While no indications of a pressure-induced metallic state up to 55 GPa were found in Sr2IrO4, a strong decrease of the gap energy and of the resistance of Sr3Ir2O7 between ambient pressure and 104 GPa confirm that this compound is in the proximity of a metal-insulator transition.

Superconductivity. Fermi arcs in a doped pseudospin-1/2 Heisenberg antiferromagnet

High-temperature superconductivity in cuprates arises from an electronic state that remains poorly understood. We report the observation of a related electronic state in a noncuprate material, strontium iridate (Sr2IrO4), in which the distinct cuprate fermiology is largely reproduced. Upon surface electron doping through in situ deposition of alkali-metal atoms, angle-resolved photoemission spectra of Sr2IrO4 display disconnected segments of zero-energy states, known as Fermi arcs, and a gap as large as 80 millielectron volts. Its evolution toward a normal metal phase with a closed Fermi surface as a function of doping and temperature parallels that in the cuprates. Our result suggests that Sr2IrO4 is a useful model system for comparison to the cuprates.

Guided-mode resonant coherent light absorbers

We present a new class of coherent perfect absorbers based on guided-mode resonance in thin semiconductor films. Using particle-swarm optimization methods, we design a thin-film amorphous silicon grating that maximizes coherent modulation of the absorbance. The optimized device exhibits a maximum scattering power of ∼94% and a power absorption limit approaching 100% at the 1550-nm wavelength.

Photoemission spectroscopy and the unusually robust one-dimensional physics of lithium purple bronze

Temperature-dependent photoemission spectroscopy in Li(0.9)Mo(6)O(17) contributes to evidence for one-dimensional (1D) physics that is unusually robust. Three generic characteristics of the Luttinger liquid are observed: power law behavior of the k-integrated spectral function down to temperatures just above the superconducting transition, k-resolved lineshapes that show holon and spinon features, and quantum critical (QC) scaling in the lineshapes. Departures of the lineshapes and the scaling from expectations in the Tomonaga-Luttinger model can be partially described by a phenomenological momentum broadening that is presented and discussed. The possibility that some form of 1D physics obtains even down to the superconducting transition temperature is assessed.

Abstract P3-13-07: Clinicopathologic and Biologic Recurrence Risk in African-American Versus Caucasian Women with Early-Stage Hormone Receptor Positive Breast Cancer, a Single Institution Experience

Background: African-American women with hormone receptor positive breast cancer have an inferior survival compared to Caucasians (Sparano, et al (SABCS, 2009, Abstract #37) and Albain, et al (ASCO, 2010, Abstract #511)). It is not clear whether this difference is a result of disparities in access to care and stage at presentation or biological factors. We sought to examine whether African-American women with early-stage hormonereceptor positive breast cancer had a higher risk of recurrence than similarly staged Caucasians using a standard clinicopathologic risk prediction algorithm (AdjuvantOnline!) and a biologic risk prediction algorithm (Oncotype DX).

Materials and Methods: Women with early stage, hormone receptor positive, Her2 normal, lymph node negative breast cancer seen at the University of Tennessee Cancer Institute between 2007-2009 were retrospectively reviewed. All patients had an AdjuvantOnline! recurrence risk calculated. For patients in whom an Oncotype DX was available, differences in risk of recurrence between clinicopathologic and biologic algorithms were evaluated with respect to race (African-American versus Caucasian).

Results: 96 women were identified, 38 of whom were African-American and 58 of whom were Caucasian. 50 women had an Oncotype DX available. Clinicopathologic factors were well-balanced between the groups (see Table 1). Using AdjuvantOnline!, there was no significant difference between African-American and Caucasian patients in their average risk of recurrence (25% versus 23%, P=0.15). Using Oncotype DX, there was similarly no significant difference in the average risk of recurrence by race (18.6% for African-American versus 18.9% for Caucasian, P=0.55).

Patient Characteristics

Grade was not available for 1 Caucasian patient.

Discussion: When matched for stage and general clinicopathologic factors (hormone receptor positivity, Her2 normal, lymph node negative), African-American and Caucasian patients have similar risk of recurrence using AdjuvantOnline! and Oncotype DX, though the expected risk was somewhat lower with Oncotype DX in both groups. This would suggest that there may be little biologic difference between African-American and Caucasian women with early stage hormone receptor positive breast cancer and that any difference in survival is likely related to non-biological factors.

Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

Quantum critical scaling in the single-particle spectrum of a novel anisotropic metal

We report an angle resolved photoemission spectroscopy study of quantum critical scaling in the single-particle spectral function of a novel anisotropic metal Li_{0.9}Mo_{6}O_{17}. We find a temperature (T) scaling exponent value and also low-T angle resolved photoemission spectroscopy line shapes that are very challenging for current one-dimensional theory frameworks. These results add a new spectroscopic component to a growing collection of puzzling low-T transport behaviors of this material.

The impact of telemedicine in cancer care

e20508

Background: The Technology Exchange for Cancer Health Network is a collaborative, multi-state effort using Telemedicine and integrated electronic health records to provide rural cancer care management. Methods: The purpose of the study was to compare quality, safety, and cost outcomes for patients receiving rural Telehealth care versus “routine” urban care. Patients with a cancer diagnosis requiring treatment for at least 1 year were eligible for the study. Telehealth patients saw their oncologist in person at rural sites for initial care and via telemedicine for about half of subsequent visits, allowing clinicians in-person clinical assessments while still taking advantage of time savings associated with telemedicine. Results: 217 patients (134 rural, 83 urban) were enrolled from 05/25/05 to 09/30/08. Patient satisfaction was high; 95 % of patients indicated their telemedicine visit was as good as or better than an in-person visit. Telemedicine patients also reported significant time and travel cost savings. Cost analysis comparing cost savings (physician travel time) with telemedicine costs (equipment, high speed lines) indicated that cost-benefit is driven by distance to rural facility and number of physician trips avoided. Telemedicine must save at least 5 hours of physician travel time per month to break even. Telemedicine was also associated with improvements in access to care. Using patient self-reported health care visit data (verified with local providers), we identified a significant decline in disparities between urban and rural patients (see Table ). Conclusions: Telemedicine offers a promising method for increasing access to oncology care that is convenient for and well-accepted by patients at reasonable costs. Our results also suggest that telemedicine facilitates access to more than just oncology care. The regular follow-up care provided through telemedicine visits may identify unmet need that might otherwise go untreated, yielding improvements in patient outcomes.

[Table: see text]

No significant financial relationships to disclose.

Outcome of surgical resection for pathologic Nx and N0 non-small cell lung cancer (NSCLC)

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Background: Metastasis to lymph nodes (LN) connotes poor prognosis in NSCLC. Sufficient LN must be examined to accurately determine LN negativity. Patients with no LN examined (pNx) may be incompletely staged and erroneously assigned to a low risk group. To evaluate this possibility, we compared the survival of patients with node negative disease and at least 1 LN examined (pN0) to those with pNx. Methods: Retrospective analysis of all resections for NSCLC from January 1, 2004 to December 31, 2007 identified through a search of pathology databases at hospitals in the Memphis Metropolitan Area. Benign and metastatic disease, pre-operative chemo/radio therapy, bronchoalveolar cell, small cell lung, carcinoid tumors and repeat lung resection were excluded. Date of death was obtained from a National Death Index search. Variables were compared by chi-squared test, survival estimates calculated by Kaplan Meier analysis, survival estimates compared by log-rank test. Results: 746 of 809 resections met inclusion criteria. 86 (11.5%) were pNx and 510 (68.4%) pN0. Demographic and histologic characteristics were similar ( Table 1 ). 55.8% of the pNx group had sublobar resection, compared to 5.7% of pN0 (p<0.0001). 179 pN0 patients (35.1%) had only hilar-intrapulmonary LN (stations 10–14), median 3 (range 1–18) examined. 46 patients (9.02%) had only mediastinal LN (stations 1–9), median 2 (1–13); 281 patients (55.1%) had both stations 10–14 and 1–9, median 7 (2–45). 85% of pN0 patients had <10 LNs examined. 3-year survival estimate for the T1NxM0 vs T1N0M0 patients was 69% vs 70% (p= 0.14); for T2NxM0 vs T2N0M0 it was 25% vs 65% (p <0.01). Conclusions: A high percentage of patients (11.5%) undergoing surgical resection for NSCLC had pNx. These patients were more likely to have sublobar resections. Most (85%) patients with pN0 had <10 nodes examined and a large proportion (35.1%) had no mediastinal LNs, raising the possibility of understaging. Patients with pT2NxM0 did significantly worse than those with pT2N0M0.

[Table: see text]

[Table: see text]

Quality of surgical resection for non-small cell lung cancer (NSCLC) in a U.S. metropolitan area

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Background: Curative treatment of early stage NSCLC requires good quality oncologic resection (GQR). For GQR, the National Comprehensive Cancer Network (NCCN) requires a minimum of segmentectomy, negative margins, lymph node (LN) sampling from stations 10–14 (level-1) and >2 mediastinal (level-2) stations. We reviewed details of consecutive resections for NSCLC to determine the proportion that met NCCN GQR criteria and the proportion who would have met eligibility for the RADIANT trial which requires >1 level-2 stations. Methods: Retrospective review of medical records of all patients who underwent curative- intent resection for NSCLC in the Memphis Metropolitan Area from 1/1/2004 to 12/31/2007. Resections for benign and metastatic disease were excluded. Death information was obtained from a national death index search. Categorical variables were compared by chi-square test or Fisher's exact test, survival curves by log-rank test. Results: 746 patients were eligible (Table). Median age was 67.7 (range, 36.5 - 89.4). 61/746 (8.2%) met NCCN GQR criteria. Black patients were more likely than whites to have GQR (P=0.022). No other patient demographic factor was associated with GQR. Three year survival was 72% in those with GQR versus 63% in those without GQR (P=0.50). There was a difference in achievement of GQR between the 3 major institutions where surgery was done (P=0.001) although it was low across the board. 77.9% of patients would have been disqualified from the RADIANT trial. Conclusions: Majority of surgical resections for NSCLC did not achieve GQR standards per RADIANT and NCCN. The greatest deficit is in surgical sampling of level-2 LNs, but evaluation of level-1 LNs is also frequently sub-optimal. Intervention is needed to improve current surgical and pathology practices in collection and examination of surgical specimens in order to achieve minimum standards for accurate staging, prognostication, determination of candidacy for post-operative adjuvant therapy, and eligibility for clinical trials.

[Table: see text]

[Table: see text]

Accuracy and comprehensiveness of pathology reportage after lung cancer resection

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Background: Decisions about prognosis, adjuvant chemo/radiation therapy and clinical trial eligibility require careful examination of the surgical resection specimen. In January 2004, the College of American Pathologists (CAP) and the American College of Surgeons Committee on Cancer mandated reportage of specific items after resection of lung cancer. The extent of compliance is unknown. Methods: We examined final pathology reports for all lung cancer resections in the Memphis Metropolitan Area from January 2004 to December 2007. End-points were the percentage of reports with each CAP item and the 6 most vital determinants of post-operative management and accuracy of TNM staging. Chi-square test was used for year to year comparisons. Results: Table 1 shows frequency of reportage of CAP items. Of those with reported pT stage, it was accurate in 242 of 263 (92.02%) identified as T1; 193 of 208 (92.79%) T2; 21 of 24 (87.5%) T3; 11 of 11 (100%) T4. The most common T-staging error, understaging of satellite nodules (T4), occurred in 12 of 21 (57%) mis-staged as T1, 11 of 15 (73%) T2, 3 of 3 (100%) T3. Overall, 62.6% of reports accurately identified pT-stage. Of those with reported pN-stage, 351 of 352 (99.7%) accurately identified N0; 69 of 81 (85.2%) accurately identified N1, 12 of 81 (14.81%) N1 designations were actually N2; 27 of 27 (100%) N2 designations were accurate; 31 of 34 (91.2%) identified as Nx (no lymph nodes in the specimen) were accurate, 3 (8.8%) were truly N0. Overall, 64.08% of reports accurately identified pN-stage. 4 of 503 identified as pMx (0.8%) had pM1. There was no change in proportion of incomplete and/or inaccurate pathology reports over the 4 years of analysis. Conclusions: Pathology evaluation of lung cancer resection specimens is frequently incomplete or inaccurate, potentially impairing clinical decision-making. Satellite nodules are often understaged. Simple corrective interventions such as enforcement of mandatory institutional utilization of the CAP checklist and AJCC staging manual need to be investigated.

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Feasibility study of capecitabine (cap) and cisplatin (cis) with radiation therapy (RT) in the management of patients with locally advanced unresectable squamous cell carcinoma of the head and neck (HNSCC)

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Background: Concurrent chemoradiation has become the standard of care for locally advanced unresectable HNSCC. The most commonly used chemotherapy is cis and 5-fluorouracil (5-FU). We evaluated the feasibility of using cap and cis during RT in this population. Cap is an oral pro-drug of 5-FU that can be given daily with RT in order to enhance the activity of RT. Methods: Between Oct, 2003 and Sept, 2005, 12 male patients aged 46–83 were treated at the VA Medical Center. Patients received cis 100 mg/m2 on days 1 and 29 and cap 450 mg/m2 bid (2 hours prior to RT and 12 hours later) for 5 days of each week concurrent with RT to a total dose of 70 Gy in 35 fractions over 7 weeks. Primary endpoint of the study was toxicity. Results: All 12 patients were able to complete therapy. Treatment delays and/or dose modifications were needed in 7 patients. Treatment related toxicities included 6 patients with grade 3 mucositis and 5 patients with grade 3 dysphagia. Other grade 3 toxicities included 3 patients with dehydration and 1 patient each with leucopenia, constipation, nausea and vomiting, and odynophagia. Percutaneous gastrostomy (PEG) tubes were required in 5 patients. Complete response to chemoradiation was seen in 9 patients, 2 patients obtained partial response, and 1 patient progressed. Median progression free and overall survivals have not been reached with a median follow-up of 21 months. Conclusions: Cis and cap administered concurrently with RT has manageable toxicities and is active in patients with locally advanced unresectable HNSCC.

No significant financial relationships to disclose.

Orbitally driven spin-singlet dimerization in S=1 La4Ru2O10

Using x-ray absorption spectroscopy at the Ru-L2,3 edge we reveal that the Ru4+ ions remain in the S=1 spin state across the rare 4d-orbital ordering transition and spin-gap formation. We find using local spin density approximation + Hubbard U band structure calculations that the crystal fields in the low-temperature phase are not strong enough to stabilize the S=0 state. Instead, we identify a distinct orbital ordering with a significant anisotropy of the antiferromagnetic exchange couplings. We conclude that La4Ru2O10 appears to be a novel material in which the orbital physics drives the formation of spin-singlet dimers in a quasi-two-dimensional S=1 system.

New Luttinger-liquid physics from photoemission on Li0.9M06O17

Temperature dependent high resolution photoemission spectra of quasi-one-dimensional Li(0.9)Mo(6)O(17)evince a strong renormalization of its Luttinger-liquid density-of-states anomalous exponent. We trace this new effect to interacting charge neutral critical modes that emerge naturally from the two-band nature of the material. Li(0.9)Mo(6)O(17) is shown thereby to be a paradigm material that is capable of revealing new Luttinger physics.

Ambulatory photodynamic therapy: a new concept in delivering photodynamic therapy

BACKGROUND

Photodynamic therapy (PDT) has been shown to be effective in treating Bowen's disease, superficial basal cell carcinoma and actinic keratosis.

OBJECTIVES

To investigate the feasibility of delivering PDT using a portable light-emitting diode device.

METHODS

A prototype diode array, comprising 37 AlGaInP diodes cast in epoxy with a diffuser, and driven by a battery pack, was designed and constructed. A pilot study was carried out in five patients with histologically proven Bowen's disease who were referred for PDT with 5-aminolaevulinic acid. They were all treated in the hospital-based dermatology PDT suite such that each received the same level of supervision as patients receiving PDT with nonambulatory light sources. Patients recorded pain levels. In accordance with our usual practice, patients received two treatments at a 4-week interval.

RESULTS

Four of five patients were clear at follow-up (range 6-13 months, median 9). Pain was classified as none or mild in 80% of treatments and moderate in the remainder.

CONCLUSIONS

There are many potential benefits of ambulatory PDT, including the possibility of a much higher patient throughput, and allowing effective treatment at home. This pilot study provides early promising data of the safety and efficacy of this approach.

Filling of the mott-hubbard gap in the high temperature photoemission spectrum of (V0.972Cr0.028)2O3

Photoemission spectra of the paramagnetic insulating phase of (V0.972Cr0.028)2O3, taken in ultrahigh vacuum up to the unusually high temperature (T) of 800 K, reveal a property unique to the Mott-Hubbard (MH) insulator that has not been observed previously. With increasing T the MH gap is filled by spectral weight transfer, in qualitative agreement with high-T theoretical calculations combining dynamical mean field theory and band theory in the local density approximation.

Favorable early results of gastric banding for morbid obesity: the American experience

BACKGROUND

In 2001 a new device for surgical weight loss was approved by the Food and Drug Administration (Lap-Band, Inamed Health). We describe initial results of laparoscopic gastric banding for morbid obesity in two American academic centers.

METHODS

Prospective data was collected on consecutive morbidly obese patients undergoing laparoscopic adjustable gastric banding, and evaluated retrospectively.

RESULTS

Four hundred forty-five consecutive patients underwent Lap-Band from May 2001 through December 2002. The 103 men and 341 women had an average age of 42.1 years (range 17-72 years) and an average body mass index (BMI) of 49.6 kg/m2 (range 35.2-92.2 kg/m2). One operation required conversion to laparotomy due to bleeding; the rest were completed laparoscopically. Mean length of stay was 1.1 days (range 1-10 days). There was one death. Additional complications included band slippage in 14 patients (3.1%), gastric obstruction without slip in 12 (2.7%), port migration in 2 (0.4%), tubing disconnections in 3 (0.7%), and port infection in 5 (1.1%). Two bands (0.4%) were removed due to intraabdominal abscess 2 months after placement. There was one band erosion (0.2%) and no clinically significant esophageal dilation. Ninety-nine patients have 1-year follow-up and have lost an average of 44.3% excess body weight.

CONCLUSION

Laparoscopic gastric banding has much to offer the morbidly obese. We present data showing weight loss rivaling gastric bypass and acceptably low complications. These results parallel success with this device outside America.

Prominent quasiparticle peak in the photoemission spectrum of the metallic phase of V2O3

We present the first observation of a prominent quasiparticle peak in the photoemission spectrum of the metallic phase of V2O3 and report new spectral calculations that combine the local-density approximation with the dynamical mean-field theory (using quantum Monte Carlo simulations) to show the development of such a distinct peak with decreasing temperature. The experimental peak width and weight are significantly larger than in the theory.

Laparoscopic management of Meckel's diverticulum in adults

BACKGROUND

Meckel's diverticulum is an uncommon entity. A high index of suspicion is necessary for opportune diagnosis and prompt treatment. Technetium (TC) 99m pertechnetate scintigraphy is a sensitive and specific test for Meckel's diverticulum. In adults, the scan contributes little to clinical decision making and often will not change the need for surgical intervention. We describe our experience with four patients.

METHODS

Between August 2000 and August 2001, four patients were seen with Meckel's diverticula. Three were male and one was female. The mean age was 39 years (range, 18-64). Three patients presented with anemia and one with an acute abdomen. A 99mTc pertechnetate scan was performed at a cost of 900 dollars in the three anemic patients after other endoscopic and radiographic tests were nondiagnostic. Only one patient had a positive scan. All four patients underwent exploratory laparoscopy and small bowel resection. In one patient, a minilaparatomy had to be performed.

RESULTS

All patients had a satisfactory outcome without complications. Three patients were discharged within 3 days of surgery. The remaining patient had a prolonged hospital stay because of ongoing chemotherapy for small cell lung cancer. In the three anemic patients who underwent enterectomy, ulcerated small bowel outside the diverticulum was found by the pathologist.

CONCLUSION

Laparoscopy is safe, cost-effective, and efficient for the diagnosis and definitive management of Meckel's diverticulum. Technetium 99m pertechnetate scintigraphy scanning adds considerable time and expense to the care of the patient without significant benefits in adults. The practice of exploratory laparoscopy rather than scintigraphy is recommended.

Totally laparoscopic management of gallstone ileus

Gallstone ileus is an uncommon disease of elderly patients who present with bowel obstruction. Mortality and severe complications are common, even in modern series, due to the comorbidities in the affected patient population. A number of less invasive ways to treat this disease are described. We report on a case where enterolithotomy was performed laparoscopically. The patient is a 60-year-old diabetic woman who presented with a bowel obstruction and pneumobilia on abdominal radiographs. She underwent exploratory laparoscopy using three reusable ports, an enterolithotomy, and her remaining bowel was examined. The benefits to a minimal access approach to this rare disorder are discussed. The ability to suture laparoscopically is emphasized.

Laparoscopic choledochojejunostomy and gastrojejunostomy in a porcine model

BACKGROUND

Surgical extirpation remains the only known curative treatment for cancer of the pancreas. Because of locally advanced or metastatic tumor, up to 80% of patients are unresectable at the time of initial diagnosis [13]. Other investigators previously have suggested that laparoscopy before laparotomy aids in the diagnosis of unresectable pancreatic cancer in a fair number of patients even after negative computed tomography scans [3, 17]. Many surgeons are reluctant to incorporate laparoscopy into the workup of patients with cancer of the pancreas because of the frequent need for surgical bypass in the management of either biliary tract obstruction or gastric outlet obstruction [9, 13]. Previous studies have demonstrated the feasibility of laparoscopic cholecystojejunostomy combined with gastrojejunostomy in a porcine model, as well as the individual accomplishment of laparoscopic choledochojejunostomy. The purpose of this study was to document the feasibility of performing laparoscopic choledochojejunostomy with gastrojejunostomy.

METHODS

Under general anesthesia, seven pigs underwent laparoscopic choledochojejunostomy and gastrojejunostomy using an intracorporeal hand-sutured technique.

RESULTS

The mean operating time ranged from 150 to 450 min. All the animals recovered completely from the operation and had patent anastomoses at the time of necropsy. One pig died of gastric bleeding on postoperative day 13, and two animals had intraabdominal fluid collections discovered at the time of necropsy.

CONCLUSIONS

These results suggest that synchronous laparoscopic bypass of biliary and gastric outlet obstruction is feasible, and can be performed in a manner similar to that used in open operations. We believe this lends support to the argument promoting laparoscopy in the evaluation of pancreatic cancer.

Totally laparoscopic feeding jejunostomy

BACKGROUND

A feeding jejunostomy should be used for nutritional support in a small subset of patients. Minimal-access approaches for the placement of jejunal tubes have been described, but they often require special equipment not common to all operating theaters. We describe a technique of totally laparoscopic jejunostomy tube (LJT) placement using equipment found in most operating theaters.

METHODS

Thirty-five patients underwent LJT over a 12-month period. Indications included gastroparesis, anorexia nervosa, oral cancer, cerebral palsy, and Huntington's chorea. The technique involved three incisions for trocars (one for a 10-mm camera and two for 5-mm working ports) and one small incision for the tube. A 16-Fr T-tube was passed transabdominally under direct vision, and a jejunotomy was made approximately 20 cm distal to the ligament of Trietz. Each limb of the T-tube was passed into the lumen of the bowel, and a purse-string suture was placed around the enterotomy and tied intracorporeally. After insertion, the serosa surrounding the insertion site is tacked to the anterior abdominal wall in four places with a reusable stainless steel suture passer. To test whether the tube was watertight, we injected methylene blue solution into the tube.

RESULTS

All of the patients tolerated the procedure well. There were no operative deaths. Five LJTs were electively removed in the office. One patient was reoperated on 10 days postoperatively because of intractable pain, but the source of pain was not found and the LJT was intact.

CONCLUSIONS

LJT may be placed safely using the described technique. No significant morbidity or mortality occurred in our series. The results of this study have prompted us to consider LJT for any patient requiring access to the jejunum for feeding.

Bulk band gaps in divalent hexaborides

Complementary angle-resolved photoemission and bulk-sensitive k-resolved resonant inelastic x-ray scattering of divalent hexaborides reveal a >1 eV X-point gap between the valence and conduction bands, in contradiction to the band overlap assumed in several models of their novel ferromagnetism. This semiconducting gap implies that carriers detected in transport measurements arise from defects, and the measured location of the bulk Fermi level at the bottom of the conduction band implicates boron vacancies as the origin of the excess electrons. The measured band structure and X-point gap in CaB6 additionally provide a stringent test case for many-body quasiparticle band calculations.