Sustained Performance of Cardiac Arrest Prevention in Pediatric Cardiac Intensive Care Units.

Importance: The Pediatric Cardiac Critical Care Consortium (PC4) cardiac arrest prevention (CAP) quality improvement (QI) project facilitated a decreased in-hospital cardiac arrest (IHCA) incidence rate across multiple hospitals. The sustainability of this outcome has not been determined. Objective: To examine the IHCA incidence rate at participating hospitals after the QI project ended and discern which factors best aligned with sustained improvement. Design, Setting, and Participants: This observational cohort study compared IHCA data from the CAP era (July 1, 2018, to December 31, 2019) with data from the 2-year follow-up era (March 1, 2020, to February 28, 2022). Data were obtained from pediatric cardiac intensive care units (CICUs) from 17 PC4 CAP-participating hospitals. Intervention: The CAP practice bundle was designed to facilitate local practice integration, with the intention to implement, adapt, and continue CAP processes beyond the CAP era. A web-based survey was administered 2 years after the end of the project to estimate CAP-specific QI work. Main Outcomes and Measures: Risk-adjusted IHCA incidence rates across all admissions were compared between study eras. The survey generated a novel hospital-specific QI sustainability score, which is generally reflective of the sum of local CAP work performed. Results: There were no clinically important differences in demographic and admission characteristics between the 13 082 CAP era admissions and 16 284 follow-up admissions (total mean [SD] age, 5.1 [8.4] years; 56.1% male). Risk-adjusted IHCA incidences were not different between the CAP vs follow-up eras (2.8% vs 2.8%; odds ratio, 1.03; 95% CI, 0.89-1.19), suggesting sustained prevention improvement. There was also no difference between eras in risk-adjusted IHCA incidence within medical, surgical, or high-risk subgroups. A lower hospital QI sustainability score was correlated with higher odds for IHCA in the follow-up vs CAP era (correlation coefficient, -0.58; P = .02). Five hospitals had increases of 1% or greater in risk-adjusted IHCA rates in the follow-up era; these hospitals had significantly lower QI sustainability scores and were less likely to have adopted sustainability elements during the CAP era or report persistent engagement for CAP-related QI processes during follow-up. Conclusions and Relevance: In this cohort study of all CICU admissions across 17 hospitals, IHCA prevention was feasible and sustainable; the established reduction in risk-adjusted IHCA rate was maintained for at least 2 years after the end of the CAP project. Both implementation strategies and continued engagement in CAP processes during the follow-up era were associated with sustained improvement.

Fast Non-contrast MR Angiography Using a Zigzag Centric ky - kz k-space Trajectory and Exponential Refocusing Flip Angles with Restoration of Longitudinal Magnetization.

PURPOSE: Fresh blood imaging (FBI) utilizes physiological blood signal differences between diastole and systole, causing a long acquisition time. The purpose of this study is to develop a fast FBI technique using a centric ky - kz k-space trajectory (cFBI) and an exponential refocusing flip angle (eFA) scheme with fast longitudinal restoration. METHODS: This study was performed on 8 healthy subjects and 2 patients (peripheral artery disease and vascular disease) with informed consent, using a clinical 3-Tesla MRI scanner. A numeric simulation using extended phase graph (EPG) and phantom studies of eFA were carried out to investigate the restoration of longitudinal signal by lowering refocusing flip angles in later echoes. cFBI was then acquired on healthy subjects at the popliteal artery station to assess the effect of varying high/low flip ratios on the longitudinal restoration effects. In addition, trigger-delays of cFBI were optimized owing to the long acquisition window in zigzag centric ky - kz k-space trajectory. After optimizations, cFBI images were compared against standard FBI (sFBI) images in terms of scan time, motion artifacts, Nyquist N/2 artifacts, blurring, and overall image quality. We also performed two-way repeated measures analysis of variance. RESULTS: cFBI with eFA achieved nearly a 50% scan time reduction compared to sFBI. The high/low flip angle of 180/2 degrees with lower refocusing pulses shows fast longitudinal restoration with the highest blood signals, yet also more sensitive to the background signals. Overall, 180/30 degrees images show reasonable blood signal recovery while minimizing the background signal artifacts. After the trigger delay optimization, maximum intensity projection image of cFBI after systole-diastole subtraction demonstrates less motion and N/2 artifacts than that of sFBI. CONCLUSION: Together with eFA for fast longitudinal signal restoration, the proposed cFBI technique achieved a 2-fold reduction in scan time and improved image quality without major artifacts.

Analysis of Surgeon and Center Case Volume and Stroke or Death after Transcarotid Artery Revascularization.

BACKGROUND: It has been suggested that the annual hospital volume of cases may affect the number of adverse events following carotid endarterectomy (CEA). We aim to study the associations between hospital as well as surgeon volume and the risk of stroke/death following TCAR. STUDY DESIGN: Retrospective review of the Vascular Quality Initiative data of patients undergoing TCAR from 2016 to 2021. Surgeon and center volume were calculated based on the mean number of cases (MNC) performed yearly by each surgeon and center. The primary outcome was a composite endpoint of in-hospital stroke/death. RESULTS: A total of 22,624 cases were included. Surgeon volume was divided into three quantiles: low (MNC=4), medium (MNC=10), and high (MNC=26). Center volume was also divided into low (MNC=14), medium (MNC=32), and high (MNC=64). After adjusting for potential confounders, and when compared to high volume centers, low and medium center volume was not associated with any increased odds of in-hospital stroke/death, stroke, death, or stroke/TIA. Compared to high volume surgeons, low surgeons' volume was associated with a higher odd of stroke (OR: 1.5, 95%CI (1.1-2.04), P=0.008), and stroke/TIA (OR: 1.5, 95%CI (1.2-1.9), P=.002). However, medium surgeon volume was not associated with higher odds of stroke/death, stroke, and stroke/TIA. Neither low nor medium surgeon volume was associated with a difference in mortality compared to high surgeon volume. CONCLUSIONS: In this retrospective study, center volume was not associated with any differences in outcomes among patients undergoing TCAR. On the other hand, surgeons with low volume were associated with a higher risk of stroke/death/MI and stroke/TIA when compared to high surgeon volume. There was no difference in outcomes between medium and high surgeon volume.

Photon-Counting CT in the Head and Neck: Current Applications and Future Prospects.

Photon-counting detectors (PCDs) represent a major milestone in the evolution of CT imaging. CT scanners using PCD systems have already been shown to generate images with substantially greater spatial resolution, superior iodine contrast-to-noise ratio, and reduced artifact compared with conventional energy-integrating detector-based systems. These benefits can be achieved with considerably decreased radiation dose. Recent studies have focused on the advantages of PCD-CT scanners in numerous anatomic regions, particularly the coronary and cerebral vasculature, pulmonary structures, and musculoskeletal imaging. However, PCD-CT imaging is also anticipated to be a major advantage for head and neck imaging. In this paper, we review current clinical applications of PCD-CT in head and neck imaging, with a focus on the temporal bone, facial bones, and paranasal sinuses; minor arterial vasculature; and the spectral capabilities of PCD systems.

Investigation of the weekend effect on perioperative complications and mortality after carotid revascularization.

OBJECTIVE: Outcomes for weekend surgical interventions are associated with higher rates of mortality and complications than weekday interventions. Although prior investigations have reported the "weekend effect" for carotid endarterectomy (CEA), this association remains unclear for transcarotid artery revascularization (TCAR) and transfemoral carotid artery stenting (TFCAS). We investigated the weekend effect for all three carotid revascularization methods. METHODS: We queried the Vascular Quality Initiative for patients who underwent CEA, TCAR, and TFCAS between 2016 and 2022. χ2 and logistic regression modeling analyzed outcomes including in-hospital stroke, death, myocardial infarction, and 30-day mortality by weekend vs weekday intervention. Backward stepwise regression was used to identify significant confounding variables and was ultimately included in each final logistic regression model. Logistic regression of outcomes was substratified by symptomatic status. Secondary multivariable analysis compared outcomes between the three revascularization methods by weekend vs weekday interventions. RESULTS: A total of 155,962 procedures were analyzed including 103,790 CEA, 31,666 TCAR, and 20,506 TFCAS. Of these, 1988 CEA, 246 TCAR, and 820 TFCAS received weekend interventions. Logistic regression demonstrated no significant differences for TCAR and increased odds of in-hospital stroke/death/myocardial infarction for CEA (odds ratio [OR]: 1.31, 95% confidence interval [CI]: 1.04-1.65) and TFCAS (OR: 1.46, 95% CI: 1.09-1.96) weekend procedures. Asymptomatic TCAR patients had nearly triple the odds of 30-day mortality (OR: 2.85, 95% CI: 1.06-7.68, P = .038). Similarly, odds of in-hospital death were nearly tripled for asymptomatic CEA (OR: 2.89, 95% CI: 1.30-6.43, P = .009) and asymptomatic TFCAS (OR: 2.78, 95% CI: 1.34-5.76, P = .006) patients. Secondary analysis demonstrated that CEA and TCAR had no significant differences for all outcomes. TFCAS was associated with increased odds of stroke and death compared with CEA and TCAR. CONCLUSIONS: In this observational cohort study, we found that weekend carotid revascularization is associated with increased odds of complications and mortality. Furthermore, asymptomatic weekend patients perform worse in the CEA and TFCAS procedural groups. Among the three revascularization methods, TFCAS is associated with the highest odds of perioperative stroke and mortality. As such, our findings suggest that TFCAS procedures should be avoided over the weekend in favor of CEA or TCAR. In patients who are poor candidates for CEA, TCAR offers the lowest morbidity and mortality for weekend procedures.

Stapedotomy Versus Cochlear Implantation for Far Advanced Otosclerosis: Insights From a Patient With Matched Preoperative and Postoperative Function.

OBJECTIVE: To examine patient preference after stapedotomy versus cochlear implantation in a unique case of a patient with symmetrical profound mixed hearing loss and similar postoperative speech perception improvement. PATIENTS: An adult patient with bilateral symmetrical far advanced otosclerosis, with profound mixed hearing loss. INTERVENTION: Stapedotomy in the left ear, cochlear implantation in the right ear. MAIN OUTCOME MEASURE: Performance on behavioral audiometry, and subjective report of hearing and intervention preference. RESULTS: A patient successfully underwent left stapedotomy and subsequent cochlear implantation on the right side, per patient preference. Preoperative audiometric characteristics were similar between ears (pure-tone average [PTA] [R: 114; L: 113 dB]; word recognition score [WRS]: 22%). Postprocedural audiometry demonstrated significant improvement after stapedotomy (PTA: 59 dB, WRS: 75%) and from cochlear implant (PTA: 20 dB, WRS: 60%). The patient subjectively reported a preference for the cochlear implant ear despite having substantial gains from stapedotomy. A nuanced discussion highlighting potentially overlooked benefits of cochlear implants in far advanced otosclerosis is conducted. CONCLUSION: In comparison with stapedotomy and hearing aids, cochlear implantation generally permits greater access to sound among patients with far advanced otosclerosis. Though the cochlear implant literature mainly focuses on speech perception outcomes, an underappreciated benefit of cochlear implantation is the high likelihood of achieving "normal" sound levels across the audiogram.

Cochlear Implantation in Patients With Osteolytic Labyrinthitis: A Case Series.

OBJECTIVE: To describe the rare process of osteolytic labyrinthitis, previously referred to as labyrinthine sequestrum, which involves progressive obliteration of the bony and membranous labyrinth with eventual supplantation with soft tissue and, in some cases, bony sequestrum. PATIENTS: Three patients with diverse presentations of osteolytic labyrinthitis from two tertiary care academic medical centers. INTERVENTIONS: Case series report analyzing the relevant clinical, radiologic, pathologic, and surgical data on our patients with osteolytic labyrinthitis and comparing these index cases to the existing literature. MAIN OUTCOME MEASURES: We describe the varying image findings seen in osteolytic labyrinthitis on computed tomography and magnetic resonance imaging. Also, we report successful surgical intervention and hearing rehabilitation with cochlear implantation in patients with osteolytic labyrinthitis. RESULTS: Our three patients presented with profound sudden sensorineural hearing loss and vertigo consistent with labyrinthitis. None of the three patients had a history of chronic otitis media. Imaging workup revealed varying degrees of erosion to the otic capsule bone demonstrating the spectrum of disease seen in osteolytic labyrinthitis. Although two cases showed osteolytic changes to the semicircular canals and vestibule, the first case revealed frank bony sequestrum within the obliterated labyrinth. The three cases were taken for surgical debridement and cochlear implantation. CONCLUSIONS: We propose the new term, osteolytic labyrinthitis-previously referred to as labyrinthine sequestrum-to describe the rare spectrum of disease characterized by destruction of the osseous and membranous labyrinth and potential supplantation with bony sequestrum. Cochlear implantation is a viable option in selected patients with osteolytic labyrinthitis.

Storylines of family medicine III: core principles-primary care, systems and family.

Storylines of Family Medicine is a 12-part series of thematically linked mini-essays with accompanying illustrations that explore the many dimensions of family medicine, as interpreted by individual family physicians and medical educators in the USA and elsewhere around the world. In 'III: core principles-primary care, systems, and family', authors address the following themes: 'Continuity of care-building therapeutic relationships over time', 'Comprehensiveness-combining breadth and depth of scope', 'Coordination of care-managing multiple realities', 'Access to care-intersectional, systemic, and personal', 'Systems theory-a core value in patient-centered care', 'Family-oriented practice-supporting patients' health and well-being', 'Family physician as family member' and 'Family in the exam room'. May readers develop new understandings from these essays.

Imaging Findings Post-Stereotactic Radiosurgery for Vestibular Schwannoma: A Primer for the Radiologist.

Noninvasive tumor control of vestibular schwannomas through stereotactic radiosurgery allows high rates of long-term tumor control and has been used primarily for small- and medium-sized vestibular schwannomas. The posttreatment imaging appearance of the tumor, temporal patterns of growth and treatment response, as well as extratumoral complications can often be both subtle or confusing and should be appropriately recognized. Herein, the authors present an imaging-based review of expected changes as well as associated complications related to radiosurgery for vestibular schwannomas.

Non-contrast MRI of micro-vascularity of the feet and toes.

PURPOSE: This study aimed to develop novel non-contrast MR perfusion techniques for assessing micro-vascularity of the foot in human subjects. METHODS: All experiments were performed on a clinical 3 T scanner using arterial spin labeling (ASL). Seven healthy subjects (30-72 years old, 5 males and 2 females) were enrolled and bilateral feet were imaged with tag-on and tag-off alternating inversion recovery spin labeling for determining micro-vascularity. We compared an ASL technique with 1-tag against 4-tag pulses. For perfusion, we determined signal increase ratio (SIR) at varying inversion times (TI) from 0.5 to 2 s. SIR versus TI data were fit to determine perfusion metrics of peak height (PH), time to peak (TTP), full width at half maximum (FWHM), area under the curve (AUC), and apparent blood flow (aBF) in the distal foot and individual toes. Using analysis of variance (ANOVA), effects of tag pulse and region of interest (ROI) on the mean perfusion metrics were assessed. In addition, a 4-tag pulse perfusion experiment was performed on patients with peripheral artery disease (PAD) and Raynaud's disease. RESULTS: Using our MR perfusion techniques, SIR versus TI data showed well-defined leading and trailing edges, with a peak near TI of 0.75-1.0 s and subsiding quickly to near zero by TI of 2 s, particularly when 4-tag pulses were used. When imaged with 4-tag pulse, we found significantly greater values in perfusion metrics, as compared to 1-tag pulse. The patients with PAD and Raynaud's disease showed a reduced or scattered perfusion curves compared to the healthy control. CONCLUSION: MR perfusion imaging of the distal foot shows greater SIR and perfusion metrics with the 4-tag pulse compared to the 1-tag pulse technique. This will likely benefit those with low perfusion due to aging, PAD, diabetic foot, and other vascular diseases.

Prevalence of Scarpa's ganglion enhancement on high-resolution MRI imaging.

BACKGROUND AND PURPOSE: The vestibular ganglion, or Scarpa's ganglion, is a cluster of afferent vestibular neurons within the internal auditory canal (IAC). There is minimal literature describing enhancement of this region on magnetic resonance imaging (MRI) and its correlation to clinical symptoms. Here, we sought to find the prevalence of enhancement at Scarpa's ganglion, and determine whether such enhancement correlates with demographics or clinical symptoms. MATERIALS AND METHODS: A retrospective review was performed of consecutive patients with an MRI of the IAC between 3/1/2021 and 5/20/2021. Two neuroradiologists independently reviewed for T1 and FLAIR enhancement of the Scarpa's ganglion on post-contrast fat-saturated T1 and post-contrast FLAIR images. Discrepancies were agreed upon by consensus. Clinical variables (hearing loss, vestibular symptoms, tinnitus, and MRI indication) were gathered from a retrospective chart review. RESULTS: Eighty-nine patients were included (51 female); the mean age was 58 (range 19-85). The most common MRI indication was hearing loss (n = 53). FLAIR enhancement was present on the right in 7 patients, on the left in 7 patients, and bilaterally in 6 patients. No enhancement was seen on post-contrast T1 images. There was no statistically significant correlation between consensus FLAIR on at least one side and age (p = .74), gender (p = .29), hearing loss (p = .32), hearing loss side (p = .39), type of hearing loss (p = .87), vestibular symptoms (p = .71), or tinnitus (p = .81). CONCLUSIONS: Enhancement is present in the minority of patients on post-contrast FLAIR images. If seen, it should be considered an uncommon but not unexpected finding with no clinical significance.

Pathophysiology of Facial Nerve Stimulation and Its Implications for Electrical Stimulation in Cochlear Implants.

OBJECTIVES: A small number of cochlear implant (CI) users experience facial nerve stimulation (FNS), which can manifest as facial twitching. In some patients, this can be resolved by adjusting the electrical stimulation parameters. However, for others, facial stimulation can significantly impair CI outcomes or even prevent its use. The exact mechanisms underlying FNS are unclear and may vary among patients. DESIGN: Transimpedance measurements were used to assess lateral and longitudinal spread of current within 15 cochlea of nucleus CI recipients with FNS (13 unilateral recipients and 1 bilateral recipient). We compared the transimpedance measurements with programming parameters from clinical visits and pre- and postoperative temporal bone computed tomography (CT) scans to identify factors that may contribute to FNS in each CI ear. RESULTS: In nine ears, transimpedance curves showed inflection, which suggests a localized current sink within the cochlea. This indicates a low-impedance pathway through which current exits the cochlea and stimulates the labyrinthine segment of the facial nerve canal. Electrodes near this current sink were disabled or underfit to minimize facial stimulation. In the other seven ears, current flow peaked toward the basal end of the cochlea, suggesting that current exits through the round window or other structures near the basal end of the cochlea, stimulating the tympanic segment of the facial nerve. CONCLUSIONS: Objective transimpedance measurements can be used to elucidate the mechanisms of FNS and to develop strategies for optimizing electrical stimulation parameters and speech coding to minimize or eliminate FNS in a small subset of CI users.

Magnetic Resonance Imaging Artifact Associated With Transcutaneous Bone Conduction Implants: Cholesteatoma and Vestibular Schwannoma Surveillance.

OBJECTIVE: To evaluate the magnetic resonance (MR) image artifact and image distortion associated with the two transcutaneous bone conduction implants currently available in the United States. STUDY DESIGN: Cadaveric study. METHODS: Two cadaveric head specimens (1 male, 1 female) were unilaterally implanted according to manufacturer guidelines and underwent MR imaging (General Electric and Siemens 1.5 T scanners) under the following device conditions: (1) no device, (2) Cochlear Osia with magnet and headwrap, (3) Cochlear Osia without magnet, and (4) MED-EL Bonebridge with magnet. Maximum metal mitigation techniques were employed in all conditions, and identical sequences were obtained. Blinded image scoring (diagnostic vs nondiagnostic image) was performed by experienced neuroradiologists according to anatomical subsites. RESULTS: All device conditions produced artifact and image distortion. The Osia with magnet produced diagnostic T1- and T2-weighted images of the ipsilateral temporal bone, however, non-echo planar imaging diffusion-weighted imaging (DWI) was nondiagnostic. The Osia without magnet scanned on the Siemens MR imaging demonstrated the least amount of artifact and was the only condition that allowed for diagnostic imaging of the ipsilateral temporal bone on DWI. The Bonebridge produced a large area of artifact and distortion with the involvement of the ipsilateral and contralateral temporal bones. CONCLUSION: In summary, of the three device conditions (Osia with magnet, Osia without magnet, and Bonebridge), Osia without magnet offered the least amount of artifact and distortion and was the only condition in which diagnostic DWI was available for the middle ear and mastoid regions on the Siemens MR imaging scanner.

A Single-Institution Case Series of Total Endovascular Relining for Type 3 Endoleaks in Traditional Endovascular Aneurysm Repair (EVAR) Grafts with Raised Bifurcations.

BACKGROUND: The endovascular repair of infrarenal abdominal aortic aneurysms can be performed with a wide variety of devices. Many of these grafts elevate the aortic bifurcation which can limit future repairs if the graft material fails thereby creating a type III endoleak to aorto-uniliac grafts. Many manufacturers have grafts susceptible to this, but we have seen this in the Medtronic AneuRx graft. Our goal is to provide technical details and outcomes regarding a novel technique to reline these grafts while maintaining inline flow to the iliac arteries. METHODS: This was a single-institution review of patients who had endoleaks requiring intervention after a previously placed graft with an elevated aortic bifurcation. Primary outcomes included technical success defined as placement of all planned devices, resolution of type III endoleak, aneurysm size at follow-up, and requirement of reintervention. Secondary outcomes included 30-day complications, aneurysm-related mortality, and all-cause mortality. Technical details of the operation include back-table deployment of an Ovation device, modification of the deployment system tether and pre-emptive placement of an up and over 0.014″ wire. The wire is placed up and over and hung outside the contralateral gate. Once the main body is introduced above the old graft, the 0.014" is snared from the contralateral side and externalized. The main body is then able to be seated at the bifurcation as the limb is not fully deployed and then device deployment is completed per instructions for use. RESULTS: Our study consists of 4 individuals, 3 of which had an abdominal aortic aneurysm initially managed with an AneuRx endovascular aneurysm repair and 1 with a combination of Gore and Cook grafts. All 4 patients were male with an average age of 84.5 years at time of reline. All patients had at least 10 years between initial surgery and reline at our institution. Primary outcomes revealed no type 1 or 3 endoleaks at follow-up, technical success was 100% and 1 patient required reintervention for aneurysm growth and type 2 endoleak. In terms of our secondary outcomes, there was 1 postoperative complication which was cardiac dysfunction secondary to demand ischemia, aneurysm-related mortality was 0% and all-cause mortality was 25% at average follow-up of 2.44 years. CONCLUSIONS: As individuals continue to age, there are more patients who would benefit from less invasive reinterventions following endovascular aneurysm repair. Whether this is due to aortic degeneration, stent migration, or stent material damage is not always known. In this study, we present an endovascular approach to treating type III endoleak patients with a previous graft and elevated aortic bifurcation using Ovation stent grafts and found no evidence of type 1 or 3 endoleaks on follow-up imaging. This approach may allow patients with type III endoleak the option of a minimally invasive, percutaneous approach where they previously would not have had one.

Photon Counting Versus Energy-integrated Detector CT in Detection of Superior Semicircular Canal Dehiscence.

BACKGROUND: Superior semicircular canal dehiscence (SSCD), an osseous defect overlying the SSC, is associated with a constellation of audiovestibular symptoms. This study sought to compare conventional energy-integrated detector (EID) computed tomography (CT) to photon-counting detector (PCD)-CT in the detection of SSCD. MATERIAL AND METHODS: Included patients were prospectively recruited to undergo a temporal bone CT on both EID-CT and PCD-CT scanners. Two blinded neuroradiologists reviewed both sets of images for 1) the presence or absence of SSCD (graded as present, absent, or indeterminate), and 2) the width of the bone overlying the SSC (if present). Any discrepancies in the presence or absence of SSCD were agreed upon by consensus. RESULTS: In the study 31 patients were evaluated, for a total of 60 individual temporal bones (2 were excluded). Regarding SSCD presence or absence, there was substantial agreement between EID-CT and PCD-CT (k = 0.76; 95% confidence interval, CI 0.54-0.97); however, SSCD was present in only 9 (15.0%) temporal bones on PCD-CT, while EID-CT examinations were interpreted as being positive in 14 (23.3%) temporal bones. This yielded a false positive rate of 8.3% on EID-CT. The bone overlying the SSC was thinner on EID-CT images (0.66 mm; SD = 0.64) than on PCD-CT images (0.72 mm; SD = 0.66) (p < 0.001). CONCLUSION: The EID-CT examinations tend to overcall the presence of SSCD compared to PCD-CT and also underestimate the thickness of bone overlying the SSC.

Third window lesions of the inner ear: A pictorial review.

PURPOSE: Radiographic review of pathologies that associate with third window syndrome. METHODS: Case series and literature review. RESULTS: Eight unique third window conditions are described and illustrated, including superior, lateral, and posterior semicircular canal dehiscence; carotid-cochlear, facial-cochlear, and internal auditory canal-cochlear dehiscence, labyrinthine erosion from endolymphatic sac tumor, and enlarged vestibular aqueduct. CONCLUSION: The present study highlights the characteristic imaging features and symptoms to differentiate third window pathologies for expedient diagnosis and management planning.

Electronic properties and optical spectra of donor-acceptor conjugated organic polymers.

Organic semiconductors based on conjugated donor-acceptor (D-A) polymers are a unique platform for electronic, spintronic, and energy-harvesting devices. Understanding the electronic structure of D-A polymers with a small band gap is essential for developing next-generation technologies. Here, we investigate the electronic structure and optical spectra of cyclopentadithiophene-based closed/open-shell D-A polymers using density functional theory and the Bethe-Salpeter equation based on G[Formula: see text]W[Formula: see text] approximation. We explored the role of different acceptor units and chemical substitutions on the structural changes and, more importantly, electronic, optical, and dielectric behavior. We found that the computed first exciton peak of the polymers agreed well with the available experimentally measured optical gap. Furthermore, D-A polymers with open-shell character display higher dielectric constant than the closed-shell polymers. We show that the exceptional performance of polycyclopentadithiophene-thiophenylthiadiazoloquinoxaline (PCPDT-TTQ) as a scalable n-type material for Faradaic supercapacitors can be partly ascribed to its elevated dielectric constant. Consequently, these D-A polymers, characterized by their high dielectric constants, exhibit significant potential for various applications, including energy storage, organic electronics, and the production of dielectric films.

Field evaluation of semi-automated moisture estimation from geophysics using machine learning.

Geophysical methods can provide three-dimensional (3D), spatially continuous estimates of soil moisture. However, point-to-point comparisons of geophysical properties to measure soil moisture data are frequently unsatisfactory, resulting in geophysics being used for qualitative purposes only. This is because (1) geophysics requires models that relate geophysical signals to soil moisture, (2) geophysical methods have potential uncertainties resulting from smoothing and artifacts introduced from processing and inversion, and (3) results from multiple geophysical methods are not easily combined within a single soil moisture estimation framework. To investigate these potential limitations, an irrigation experiment was performed wherein soil moisture was monitored through time, and several surface geophysical datasets indirectly sensitive to soil moisture were collected before and after irrigation: ground penetrating radar, electrical resistivity tomography (ERT), and frequency domain electromagnetics (FDEM). Data were exported in both raw and processed form, and then snapped to a common 3D grid to facilitate moisture prediction by standard calibration techniques, multivariate regression, and machine learning. A combination of inverted ERT data, raw FDEM, and inverted FDEM data was most informative for predicting soil moisture using a random regression forest model (one-thousand 60/40 training/test cross-validation folds produced root mean squared errors ranging from 0.025-0.046 cm3/cm3). This cross-validated model was further supported by a separate evaluation using a test set from a physically separate portion of the study area. Machine learning was conducive to a semi-automated model-selection process that could be used for other sites and datasets to locally improve accuracy.

Peritumoral Signal on Postcontrast FLAIR Images: Description and Proposed Biomechanism in Vestibular Schwannomas.

BACKGROUND AND PURPOSE: Anecdotally, postcontrast FLAIR images of vestibular schwannomas can show peritumoral hyperintense signal, hypothesized to represent gadolinium extravasation. This study assessed the incidence of this phenomenon in a cohort of patients with treatment-naïve sporadic vestibular schwannomas. MATERIALS AND METHODS: A retrospective review of 20 patients with presumed vestibular schwannoma based on characteristic imaging findings and with dedicated internal auditory canal imaging, including postcontrast T1W1 and postcontrast FLAIR, was performed. Tumor size and location were recorded, as was the presence or absence of a fundal fluid cleft. Images were reviewed for the presence of peritumoral hyperintense signal on FLAIR images (a "halo") and for both subjectively and objectively elevated signal in the ipsilateral cochlea and fundus. RESULTS: Patients were randomly selected from an institutional vestibular schwannoma registry. Eleven (55.0%) were women. A peritumoral halo was present in 90% of patients, averaging 1.0 (SD, 0.2) mm in thickness. The maximum mean FLAIR signal in the ipsilateral fundus (205.9 [SD, 110.2]) was significantly greater than on the contralateral side (121.6 [SD, 27.8]) (P = .02). Maximum mean ipsilateral intracochlear signal (167.8 [SD, 104.5]) was also significantly greater than on the contralateral side (113.4 [SD, 40.1]) (P = .04). CONCLUSIONS: A peritumoral halo on postcontrast FLAIR images was present in 90% of our cohort with randomly selected, treatment-naïve sporadic vestibular schwannomas. Although its mechanism is unknown, this signal is hypothesized to represent gadolinium extravasation, given an ipsilateral increased signal in the adjacent internal auditory canal fundus and cochlea.

Exome sequencing findings in children with annular pancreas.

BACKGROUND: Annular pancreas (AP) is a congenital defect of unknown cause in which the pancreas encircles the duodenum. Theories include abnormal migration and rotation of the ventral bud, persistence of ectopic pancreatic tissue, and inappropriate fusion of the ventral and dorsal buds before rotation. The few reported familial cases suggest a genetic contribution. METHODS: We conducted exome sequencing in 115 affected infants from the California birth defects registry. RESULTS: Seven cases had a single heterozygous missense variant in IQGAP1, five of them with CADD scores >20; seven other infants had a single heterozygous missense variant in NRCAM, five of them with CADD scores >20. We also looked at genes previously associated with AP and found two rare heterozygous missense variants, one each in PDX1 and FOXF1. CONCLUSION: IQGAP1 and NRCAM are crucial in cell polarization and migration. Mutations result in decreased motility which could possibly cause the ventral bud to not migrate normally. To our knowledge, this is the first study reporting a possible association for IQGAP1 and NRCAM with AP. Our findings of rare genetic variants involved in cell migration in 15% of our population raise the possibility that AP may be related to abnormal cell migration.