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1.
bioRxiv ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39282453

RESUMEN

Intratumoral injections often lack visibility, leading to unpredictable outcomes such as incomplete tumor coverage, off-target drug delivery and systemic toxicities. This study investigated an ultrasound (US) and x-ray imageable thermosensitive hydrogel based on poloxamer 407 (POL) percutaneously delivered in a healthy swine model. The primary objective was to assess the 2D and 3D distribution of the hydrogel within tissue across three different needle devices and injection sites: liver, kidney, and intercostal muscle region. Secondly, pharmacokinetics of POL loaded with doxorubicin (POLDOX) were evaluated and compared to free doxorubicin injection (DOXSoln) with a Single End Hole Needle. Utilizing 2D and 3D morphometrics from US and x-ray imaging techniques such as Computed Tomography (CT) and Cone Beam CT (CBCT), we monitored the localization and leakage of POLDOX over time. Relative iodine concentrations measured with CBCT following incorporation of an iodinated contrast agent in POL indicated potential drug diffusion and advection transport. Furthermore, US imaging revealed temporal changes, suggesting variations in acoustic intensity, heterogeneity, and echotextures. Notably, 3D reconstruction of the distribution of POL and POLDOX from 2D ultrasound frames was achieved and morphometric data obtained. Pharmacokinetic analysis revealed lower systemic exposure of the drug in various organs with POLDOX formulation compared to DOXSoln formulation. This was demonstrated by a lower area under the curve (852.1 ± 409.1 ng/mL·h vs 2283.4 ± 377.2 ng/mL·h) in the plasma profile, suggesting a potential reduction in systemic toxicity. Overall, the use of POL formulation offers a promising strategy for precise and localized drug delivery, that may minimize adverse effects. Dual modality POL imaging enabled analysis of patterns of gel distribution and morphology, alongside of pharmacokinetics of local delivery. Incorporating hydrogels into drug delivery systems holds significant promise for improving the predictability of the delivered drug and enhancing spatial conformability. These advancements can potentially enhance the safety and precision of anticancer therapy.

2.
Sci Rep ; 14(1): 20455, 2024 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-39227382

RESUMEN

Intratumoral injections have the potential for enhanced cancer treatment efficacy while reducing costs and systemic exposure. However, intratumoral drug injections can result in substantial off-target leakage and are invisible under standard imaging modalities like ultrasound (US) and x-ray. A thermosensitive poloxamer-based gel for drug delivery was developed that is visible using x-ray imaging (computed tomography (CT), cone beam CT, fluoroscopy), as well as using US by means of integrating perfluorobutane-filled microbubbles (MBs). MBs content was optimized using tissue mimicking phantoms and ex vivo bovine livers. Gel formulations less than 1% MBs provided gel depositions that were clearly identifiable on US and distinguishable from tissue background and with minimal acoustic artifacts. The cross-sectional areas of gel depositions obtained with US and CT imaging were similar in studies using ex vivo bovine liver and postmortem in situ swine liver. The gel formulation enhanced multimodal image-guided navigation, enabling fusion of ultrasound and x-ray/CT imaging, which may enhance targeting, definition of spatial delivery, and overlap of tumor and gel. Although speculative, such a paradigm for intratumoral drug delivery might streamline clinical workflows, reduce radiation exposure by reliance on US, and boost the precision and accuracy of drug delivery targeting during procedures. Imageable gels may also provide enhanced temporal and spatial control of intratumoral conformal drug delivery.


Asunto(s)
Sistemas de Liberación de Medicamentos , Hidrogeles , Hígado , Poloxámero , Ultrasonografía , Poloxámero/química , Animales , Hidrogeles/química , Hígado/diagnóstico por imagen , Hígado/metabolismo , Bovinos , Ultrasonografía/métodos , Sistemas de Liberación de Medicamentos/métodos , Microburbujas , Porcinos , Fantasmas de Imagen , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada de Haz Cónico/métodos
3.
Sci Rep ; 14(1): 20929, 2024 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-39251665

RESUMEN

Transarterial chemoembolization (TACE) is an image-guided minimally invasive treatment for liver cancer which involves delivery of chemotherapy and embolic material into tumor-supplying arteries to block blood flow to a liver tumor and to deliver chemotherapy directly to the tumor. However, the released drug diffuses only less than a millimeter away from the beads. To enhance the efficacy of TACE, the development of microbubbles electrostatically bound to the surface of drug-eluting beads loaded with different amounts of doxorubicin (0-37.5 mg of Dox/mL of beads) is reported. Up to 400 microbubbles were bound to Dox-loaded beads (70-150 microns). This facilitated ultrasound imaging of the beads and increased the release rate of Dox upon exposure to high intensity focused ultrasound (HIFU). Furthermore, ultrasound exposure (1 MPa peak negative pressure) increased the distance at which Dox could be detected from beads embedded in a tissue-mimicking phantom, compared with a no ultrasound control.


Asunto(s)
Quimioembolización Terapéutica , Doxorrubicina , Sistemas de Liberación de Medicamentos , Microburbujas , Ultrasonografía , Doxorrubicina/administración & dosificación , Doxorrubicina/química , Sistemas de Liberación de Medicamentos/métodos , Quimioembolización Terapéutica/métodos , Ultrasonografía/métodos , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/terapia , Fantasmas de Imagen , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/química , Microesferas
4.
Abdom Radiol (NY) ; 49(8): 2891-2901, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38958754

RESUMEN

OBJECTIVE: To assess impact of image quality on prostate cancer extraprostatic extension (EPE) detection on MRI using a deep learning-based AI algorithm. MATERIALS AND METHODS: This retrospective, single institution study included patients who were imaged with mpMRI and subsequently underwent radical prostatectomy from June 2007 to August 2022. One genitourinary radiologist prospectively evaluated each patient using the NCI EPE grading system. Each T2WI was classified as low- or high-quality by a previously developed AI algorithm. Fisher's exact tests were performed to compare EPE detection metrics between low- and high-quality images. Univariable and multivariable analyses were conducted to assess the predictive value of image quality for pathological EPE. RESULTS: A total of 773 consecutive patients (median age 61 [IQR 56-67] years) were evaluated. At radical prostatectomy, 23% (180/773) of patients had EPE at pathology, and 41% (131/318) of positive EPE calls on mpMRI were confirmed to have EPE. The AI algorithm classified 36% (280/773) of T2WIs as low-quality and 64% (493/773) as high-quality. For EPE grade ≥ 1, high-quality T2WI significantly improved specificity for EPE detection (72% [95% CI 67-76%] vs. 63% [95% CI 56-69%], P = 0.03), but did not significantly affect sensitivity (72% [95% CI 62-80%] vs. 75% [95% CI 63-85%]), positive predictive value (44% [95% CI 39-49%] vs. 38% [95% CI 32-43%]), or negative predictive value (89% [95% CI 86-92%] vs. 89% [95% CI 85-93%]). Sensitivity, specificity, PPV, and NPV for EPE grades ≥ 2 and ≥ 3 did not show significant differences attributable to imaging quality. For NCI EPE grade 1, high-quality images (OR 3.05, 95% CI 1.54-5.86; P < 0.001) demonstrated a stronger association with pathologic EPE than low-quality images (OR 1.76, 95% CI 0.63-4.24; P = 0.24). CONCLUSION: Our study successfully employed a deep learning-based AI algorithm to classify image quality of prostate MRI and demonstrated that better quality T2WI was associated with more accurate prediction of EPE at final pathology.


Asunto(s)
Aprendizaje Profundo , Imagen por Resonancia Magnética , Prostatectomía , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugía , Persona de Mediana Edad , Estudios Retrospectivos , Anciano , Imagen por Resonancia Magnética/métodos , Algoritmos , Interpretación de Imagen Asistida por Computador/métodos , Clasificación del Tumor
5.
Res Sq ; 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38978563

RESUMEN

Intratumoral injections have the potential for enhanced cancer treatment efficacy while reducing costs and systemic exposure. However, intratumoral drug injections can result in substantial off-target leakage and are invisible under standard imaging modalities like ultrasound (US) and x-ray. A thermosensitive poloxamer-based gel for drug delivery was developed that is visible using x-ray imaging (computed tomography (CT), cone beam CT, fluoroscopy), as well as using US by means of integrating perfluorobutane-filled microbubbles (MBs). MBs content was optimized using tissue mimicking phantoms and ex vivo bovine livers. Gel formulations less than 1% MBs provided gel depositions that were clearly identifiable on US and distinguishable from tissue background and with minimal acoustic artifacts. The cross-sectional areas of gel depositions obtained with US and CT imaging were similar in studies using ex vivo bovine liver and postmortem in situ swine liver. The gel formulation enhanced multimodal image-guided navigation, enabling fusion of ultrasound and x-ray/CT imaging, which may enhance targeting, definition of spatial delivery, and overlap of tumor and gel. Although speculative, such a paradigm for intratumoral drug delivery might streamline clinical workflows, reduce radiation exposure by reliance on US, and boost the precision and accuracy of drug delivery targeting during procedures. Imageable gels may also provide enhanced temporal and spatial control of intratumoral conformal drug delivery.

6.
Artículo en Inglés | MEDLINE | ID: mdl-39055486

RESUMEN

Several lung diseases lead to alterations in regional lung mechanics, including ventilator- and radiation-induced lung injuries. Such alterations can lead to localized underventilation of the affected areas, resulting in the overdistension of the surrounding healthy regions. Thus, there has been growing interest in quantifying the dynamics of the lung parenchyma using regional biomechanical markers. Image registration through dynamic imaging has emerged as a powerful tool to assess lung parenchyma's kinematic and deformation behaviors during respiration. However, the difficulty in validating the image registration estimation of lung deformation, primarily due to the lack of ground-truth deformation data, has limited its use in clinical settings. To address this barrier, we developed a method to convert a finite-element (FE) mesh of the lung into a phantom computed tomography (CT) image, advantageously possessing ground-truth information included in the FE model. The phantom CT images generated from the FE mesh replicated the geometry of the lung and large airways that were included in the FE model. Using spatial frequency response, we investigated the effect of " imaging parameters" such as voxel size (resolution) and proximity threshold values on image quality. A series of high-quality phantom images generated from the FE model simulating the respiratory cycle will allow for the validation and evaluation of image registration-based estimations of lung deformation. In addition, the present method could be used to generate synthetic data needed to train machine-learning models to estimate kinematic biomarkers from medical images that could serve as important diagnostic tools to assess heterogeneous lung injuries.

7.
Semin Intervent Radiol ; 41(2): 113-120, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38993597

RESUMEN

Interventional oncology is routinely tasked with the feat of tumor characterization or destruction, via image-guided biopsy and tumor ablation, which may pose difficulties due to challenging-to-reach structures, target complexity, and proximity to critical structures. Such procedures carry a risk-to-benefit ratio along with measurable radiation exposure. To streamline the complexity and inherent variability of these interventions, various systems, including table-, floor-, gantry-, and patient-mounted (semi-) automatic robotic aiming devices, have been developed to decrease human error and interoperator and intraoperator outcome variability. Their implementation in clinical practice holds promise for enhancing lesion targeting, increasing accuracy and technical success rates, reducing procedure duration and radiation exposure, enhancing standardization of the field, and ultimately improving patient outcomes. This narrative review collates evidence regarding robotic tools and their implementation in interventional oncology, focusing on clinical efficacy and safety for nonhepatic malignancies.

8.
Artículo en Inglés | MEDLINE | ID: mdl-38963738

RESUMEN

Walking with an exoskeleton represents a sophisticated interplay between human physiology and mechanical augmentation, yet understanding of cortical responses in this context remains limited. To address this gap, this study aimed to explore cortical responses during walking with an ankle exoskeleton, examining how these responses evolve with familiarity to the augmentation. Healthy participants without prior exoskeleton experience underwent EEG, EMG, and motion capture analysis while walking with exoskeleton assistance at 1.2m/s. Initially, exoskeleton-assisted walking induced significant biomechanical changes accompanied by corresponding cortical alterations, leading to increased cortical involvement. In addition, after a brief familiarization period, significant increases in alpha band cortical power were observed, indicating decreased cortical engagement. These findings hold significance for elucidating the cortical mechanisms involved in exoskeleton-assisted walking and may contribute to the development of more seamlessly integrated augmentation devices.


Asunto(s)
Tobillo , Electroencefalografía , Electromiografía , Dispositivo Exoesqueleto , Voluntarios Sanos , Caminata , Humanos , Caminata/fisiología , Fenómenos Biomecánicos , Masculino , Adulto , Femenino , Adulto Joven , Tobillo/fisiología , Encéfalo/fisiología , Ritmo alfa/fisiología
10.
Sci Rep ; 14(1): 13352, 2024 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-38858467

RESUMEN

Liver cancer ranks as the fifth leading cause of cancer-related death globally. Direct intratumoral injections of anti-cancer therapeutics may improve therapeutic efficacy and mitigate adverse effects compared to intravenous injections. Some challenges of intratumoral injections are that the liquid drug formulation may not remain localized and have unpredictable volumetric distribution. Thus, drug delivery varies widely, highly-dependent upon technique. An X-ray imageable poloxamer 407 (POL)-based drug delivery gel was developed and characterized, enabling real-time feedback. Utilizing three needle devices, POL or a control iodinated contrast solution were injected into an ex vivo bovine liver. The 3D distribution was assessed with cone beam computed tomography (CBCT). The 3D distribution of POL gels demonstrated localized spherical morphologies regardless of the injection rate. In addition, the gel 3D conformal distribution could be intentionally altered, depending on the injection technique. When doxorubicin (DOX) was loaded into the POL and injected, DOX distribution on optical imaging matched iodine distribution on CBCT suggesting spatial alignment of DOX and iodine localization in tissue. The controllability and localized deposition of this formulation may ultimately reduce the dependence on operator technique, reduce systemic side effects, and facilitate reproducibility across treatments, through more predictable standardized delivery.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Doxorrubicina , Sistemas de Liberación de Medicamentos , Hidrogeles , Agujas , Poloxámero , Hidrogeles/química , Animales , Doxorrubicina/administración & dosificación , Doxorrubicina/química , Doxorrubicina/farmacología , Sistemas de Liberación de Medicamentos/métodos , Poloxámero/química , Bovinos , Tomografía Computarizada de Haz Cónico/métodos , Hígado/diagnóstico por imagen , Hígado/metabolismo
11.
Integr Comp Biol ; 64(2): 480-495, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-38849296

RESUMEN

The scales and skin mucus of bony fishes are both proposed to have a role in beneficially modifying the hydrodynamics of water flow over the body surface. However, it has been challenging to provide direct experimental evidence that tests how mucus and fish scales change the boundary layer in part due to the difficulties in working with live animal tissue and difficulty directly imaging the boundary layer. In this manuscript, we use direct imaging and flow tracking within the boundary layer to compare boundary layer dynamics over surfaces of fish skin with mucus, without mucus, and a flat control surface. Our direct measurements of boundary layer flows for these three different conditions are repeated for two different species, bluegill sunfish (Lepomis macrochirus) and blue tilapia (Oreochromis aureus). Our goals are to understand if mucus and scales reduce drag, shed light on mechanisms underlying drag reduction, compare these results between species, and evaluate the relative contributions to hydrodynamic function for both mucus and scales. We use our measurements of boundary layer flow to calculate shear stress (proportional to friction drag), and we find that mucus reduces drag overall by reducing the velocity gradient near the skin surface. Both bluegill and tilapia showed similar patterns of surface velocity reduction. We also note that scales alone do not appear to reduce drag, but that mucus may reduce friction drag up to 50% compared to scaled surfaces without mucus or flat controls.


Asunto(s)
Escamas de Animales , Hidrodinámica , Moco , Perciformes , Animales , Escamas de Animales/fisiología , Perciformes/fisiología , Moco/fisiología , Tilapia/fisiología , Fenómenos Biomecánicos , Fenómenos Fisiológicos de la Piel , Peces/fisiología
12.
Radiology ; 311(2): e230750, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38713024

RESUMEN

Background Multiparametric MRI (mpMRI) improves prostate cancer (PCa) detection compared with systematic biopsy, but its interpretation is prone to interreader variation, which results in performance inconsistency. Artificial intelligence (AI) models can assist in mpMRI interpretation, but large training data sets and extensive model testing are required. Purpose To evaluate a biparametric MRI AI algorithm for intraprostatic lesion detection and segmentation and to compare its performance with radiologist readings and biopsy results. Materials and Methods This secondary analysis of a prospective registry included consecutive patients with suspected or known PCa who underwent mpMRI, US-guided systematic biopsy, or combined systematic and MRI/US fusion-guided biopsy between April 2019 and September 2022. All lesions were prospectively evaluated using Prostate Imaging Reporting and Data System version 2.1. The lesion- and participant-level performance of a previously developed cascaded deep learning algorithm was compared with histopathologic outcomes and radiologist readings using sensitivity, positive predictive value (PPV), and Dice similarity coefficient (DSC). Results A total of 658 male participants (median age, 67 years [IQR, 61-71 years]) with 1029 MRI-visible lesions were included. At histopathologic analysis, 45% (294 of 658) of participants had lesions of International Society of Urological Pathology (ISUP) grade group (GG) 2 or higher. The algorithm identified 96% (282 of 294; 95% CI: 94%, 98%) of all participants with clinically significant PCa, whereas the radiologist identified 98% (287 of 294; 95% CI: 96%, 99%; P = .23). The algorithm identified 84% (103 of 122), 96% (152 of 159), 96% (47 of 49), 95% (38 of 40), and 98% (45 of 46) of participants with ISUP GG 1, 2, 3, 4, and 5 lesions, respectively. In the lesion-level analysis using radiologist ground truth, the detection sensitivity was 55% (569 of 1029; 95% CI: 52%, 58%), and the PPV was 57% (535 of 934; 95% CI: 54%, 61%). The mean number of false-positive lesions per participant was 0.61 (range, 0-3). The lesion segmentation DSC was 0.29. Conclusion The AI algorithm detected cancer-suspicious lesions on biparametric MRI scans with a performance comparable to that of an experienced radiologist. Moreover, the algorithm reliably predicted clinically significant lesions at histopathologic examination. ClinicalTrials.gov Identifier: NCT03354416 © RSNA, 2024 Supplemental material is available for this article.


Asunto(s)
Aprendizaje Profundo , Imágenes de Resonancia Magnética Multiparamétrica , Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Anciano , Estudios Prospectivos , Imágenes de Resonancia Magnética Multiparamétrica/métodos , Persona de Mediana Edad , Algoritmos , Próstata/diagnóstico por imagen , Próstata/patología , Biopsia Guiada por Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos
13.
Am J Physiol Lung Cell Mol Physiol ; 327(1): L19-L39, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38712429

RESUMEN

Mechanical ventilation can cause ventilation-induced lung injury (VILI). The concept of stress concentrations suggests that surfactant dysfunction-induced microatelectases might impose injurious stresses on adjacent, open alveoli and function as germinal centers for injury propagation. The aim of the present study was to quantify the histopathological pattern of VILI progression and to test the hypothesis that injury progresses at the interface between microatelectases and ventilated lung parenchyma during low-positive end-expiratory pressure (PEEP) ventilation. Bleomycin was used to induce lung injury with microatelectases in rats. Lungs were then mechanically ventilated for up to 6 h at PEEP = 1 cmH2O and compared with bleomycin-treated group ventilated protectively with PEEP = 5 cmH2O to minimize microatelectases. Lung mechanics were measured during ventilation. Afterward, lungs were fixed at end-inspiration or end-expiration for design-based stereology. Before VILI, bleomycin challenge reduced the number of open alveoli [N(alvair,par)] by 29%. No differences between end-inspiration and end-expiration were observed. Collapsed alveoli clustered in areas with a radius of up to 56 µm. After PEEP = 5 cmH2O ventilation for 6 h, N(alvair,par) remained stable while PEEP = 1 cmH2O ventilation led to an additional loss of aerated alveoli by 26%, mainly due to collapse, with a small fraction partly edema filled. Alveolar loss strongly correlated to worsening of tissue elastance, quasistatic compliance, and inspiratory capacity. The radius of areas of collapsed alveoli increased to 94 µm, suggesting growth of the microatelectases. These data provide evidence that alveoli become unstable in neighborhood of microatelectases, which most likely occurs due to stress concentration-induced local vascular leak and surfactant dysfunction.NEW & NOTEWORTHY Low-volume mechanical ventilation in the presence of high surface tension-induced microatelectases leads to the degradation of lung mechanical function via the progressive loss of alveoli. Microatelectases grow at the interfaces of collapsed and open alveoli. Here, stress concentrations might cause injury and alveolar instability. Accumulation of small amounts of alveolar edema can be found in a fraction of partly collapsed alveoli but, in this model, alveolar flooding is not a major driver for degradation of lung mechanics.


Asunto(s)
Respiración con Presión Positiva , Alveolos Pulmonares , Lesión Pulmonar Inducida por Ventilación Mecánica , Animales , Alveolos Pulmonares/patología , Alveolos Pulmonares/fisiopatología , Ratas , Masculino , Respiración con Presión Positiva/métodos , Respiración con Presión Positiva/efectos adversos , Lesión Pulmonar Inducida por Ventilación Mecánica/patología , Lesión Pulmonar Inducida por Ventilación Mecánica/fisiopatología , Bleomicina/toxicidad , Bleomicina/efectos adversos , Ratas Sprague-Dawley , Pulmón/patología , Pulmón/fisiopatología , Respiración Artificial/efectos adversos , Respiración Artificial/métodos , Mecánica Respiratoria , Atelectasia Pulmonar/patología , Atelectasia Pulmonar/fisiopatología
14.
Ann Plast Surg ; 92(6): 667-676, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38725110

RESUMEN

INTRODUCTION: A common consideration for replantation success is the ischemia time following injury and the preservation temperature. A classic principle within the hand surgery community describes 12 hours of warm ischemia and 24 hours of cold ischemia as the upper limits for digit replantation; however, these limits are largely anecdotal and based on older studies. We aimed to compare survival data from the large body of literature to aid surgeons and all those involved in the replantation process in hopes of optimizing success rates. METHODS: The PubMed database was queried on April 4th, 2023, for articles that included data on digit replantation survival in terms of temperature of preservation and ischemia time. All primary outcomes were analyzed with the Mantel-Haenszel method within a random effects model. Secondary outcomes were pooled and analyzed using the chi-square statistic. Statistical analysis and forest plot generation were completed with RevMan 5.4 software with odds ratios calculated within a 95% confidence interval. RESULTS: Our meta-analysis identified that digits preserved in cold ischemia for over 12 hours had significantly higher odds of replantation success than the amputated digits replanted with 0-12 hours of warm ischemia time ( P ≤ 0.05). The odds of survival in the early (0-6 hours) replantation group were around 40% greater than the later (6-12 hours) replantation group ( P ≤ 0.05). Secondary outcomes that were associated with higher survival rates included a clean-cut amputation, increased venous and arterial anastomosis, a repair that did not require a vein graft, and replants performed in nonsmokers ( P ≤ 0.05). DISCUSSION: Overall, these findings suggest that when predicting digit replantation success, time is of the essence when the digit has yet to be preserved in a cold environment. This benefit, however, is almost completely diminished when the amputated digit is appropriately maintained in a cold environment soon after injury. In conclusion, our results suggest that there is potential for broadening the ischemia time limits for digit replant survival outlined in the literature, particularly for digits that have been stored correctly in cold ischemia.


Asunto(s)
Amputación Traumática , Traumatismos de los Dedos , Reimplantación , Humanos , Reimplantación/métodos , Amputación Traumática/cirugía , Traumatismos de los Dedos/cirugía , Factores de Tiempo , Dedos/irrigación sanguínea , Dedos/cirugía , Isquemia Tibia , Isquemia Fría , Isquemia/cirugía , Temperatura
15.
Front Netw Physiol ; 4: 1392701, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38757066

RESUMEN

Introduction: Acute respiratory distress syndrome (ARDS) presents a significant clinical challenge, with ventilator-induced lung injury (VILI) being a critical complication arising from life-saving mechanical ventilation. Understanding the spatial and temporal dynamics of VILI can inform therapeutic strategies to mitigate lung damage and improve outcomes. Methods: Histological sections from initially healthy mice and pulmonary lavage-injured mice subjected to a second hit of VILI were segmented with Ilastik to define regions of lung injury. A scale-free network approach was applied to assess the correlation between injury regions, with regions of injury represented as 'nodes' in the network and 'edges' quantifying the degree of correlation between nodes. A simulated time series analysis was conducted to emulate the temporal sequence of injury events. Results: Automated segmentation identified different lung regions in good agreement with manual scoring, achieving a sensitivity of 78% and a specificity of 85% across 'injury' pixels. Overall accuracy across 'injury', 'air', and 'other' pixels was 81%. The size of injured regions followed a power-law distribution, suggesting a 'rich-get-richer' phenomenon in the distribution of lung injury. Network analysis revealed a scale-free distribution of injury correlations, highlighting hubs of injury that could serve as focal points for therapeutic intervention. Simulated time series analysis further supported the concept of secondary injury events following an initial insult, with patterns resembling those observed in seismological studies of aftershocks. Conclusion: The size distribution of injured regions underscores the spatially heterogeneous nature of acute and ventilator-induced lung injury. The application of network theory demonstrates the emergence of injury 'hubs' that are consistent with a 'rich-get-richer' dynamic. Simulated time series analysis demonstrates that the progression of injury events in the lung could follow spatiotemporal patterns similar to the progression of aftershocks in seismology, providing new insights into the mechanisms of injury distribution and propagation. Both phenomena suggest a potential for interventions targeting these injury 'hubs' to reduce the impact of VILI in ARDS management.

16.
J Neuroeng Rehabil ; 21(1): 80, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755606

RESUMEN

BACKGROUND: Individuals with a moderate-to-severe traumatic brain injury (m/sTBI), despite experiencing good locomotor recovery six months post-injury, face challenges in adapting their locomotion to the environment. They also present with altered cognitive functions, which may impact dual-task walking abilities. Whether they present collision avoidance strategies with moving pedestrians that are altered under dual-task conditions, however, remains unclear. This study aimed to compare between individuals with m/sTBI and age-matched control individuals: (1), the locomotor and cognitive costs associated with the concurrent performance of circumventing approaching virtual pedestrians (VRPs) while attending to an auditory-based cognitive task and; (2) gaze behaviour associated with the VRP circumvention task in single and dual-task conditions. METHODOLOGY: Twelve individuals with m/sTBI (age = 43.3 ± 9.5 yrs; >6 mo. post injury) and 12 healthy controls (CTLs) (age = 41.8 ± 8.3 yrs) were assessed while walking in a virtual subway station viewed in a head-mounted display. They performed a collision avoidance task with VRPs, as well as auditory-based cognitive tasks (pitch discrimination and auditory Stroop), both under single and dual-task conditions. Dual-task cost (DTC) for onset distance of trajectory deviation, minimum distance from the VRP, maximum lateral deviation, walking speed, gaze fixations and cognitive task accuracy were contrasted between groups using generalized estimating equations. RESULTS: In contrast to CTLs who showed locomotor DTCs only, individuals with m/sTBI displayed both locomotor and cognitive DTCs. While both groups walked slower under dual-task conditions, only individuals with m/sTBI failed to modify their onset distance of trajectory deviation and maintained smaller minimum distances and smaller maximum lateral deviation compared to single-task walking. Both groups showed shorter gaze fixations on the approaching VRP under dual-task conditions, but this reduction was less pronounced in the individuals with m/sTBI. A reduction in cognitive task accuracy under dual-task conditions was found in the m/sTBI group only. CONCLUSION: Individuals with m/sTBI present altered locomotor and gaze behaviours, as well as altered cognitive performances, when executing a collision avoidance task involving moving pedestrians in dual-task conditions. Potential mechanisms explaining those alterations are discussed. Present findings highlight the compromised complex walking abilities in individuals with m/sTBI who otherwise present a good locomotor recovery.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Peatones , Realidad Virtual , Humanos , Masculino , Adulto , Femenino , Lesiones Traumáticas del Encéfalo/rehabilitación , Lesiones Traumáticas del Encéfalo/psicología , Lesiones Traumáticas del Encéfalo/fisiopatología , Persona de Mediana Edad , Desempeño Psicomotor/fisiología , Caminata/fisiología , Cognición/fisiología , Reacción de Prevención , Atención/fisiología
17.
Artículo en Inglés | MEDLINE | ID: mdl-38814530

RESUMEN

PURPOSE: Targeting accuracy determines outcomes for percutaneous needle interventions. Augmented reality (AR) in IR may improve procedural guidance and facilitate access to complex locations. This study aimed to evaluate percutaneous needle placement accuracy using a goggle-based AR system compared to an ultrasound (US)-based fusion navigation system. METHODS: Six interventional radiologists performed 24 independent needle placements in an anthropomorphic phantom (CIRS 057A) in four needle guidance cohorts (n = 6 each): (1) US-based fusion, (2) goggle-based AR with stereoscopically projected anatomy (AR-overlay), (3) goggle AR without the projection (AR-plain), and (4) CT-guided freehand. US-based fusion included US/CT registration with electromagnetic (EM) needle, transducer, and patient tracking. For AR-overlay, US, EM-tracked needle, stereoscopic anatomical structures and targets were superimposed over the phantom. Needle placement accuracy (distance from needle tip to target center), placement time (from skin puncture to final position), and procedure time (time to completion) were measured. RESULTS: Mean needle placement accuracy using US-based fusion, AR-overlay, AR-plain, and freehand was 4.5 ± 1.7 mm, 7.0 ± 4.7 mm, 4.7 ± 1.7 mm, and 9.2 ± 5.8 mm, respectively. AR-plain demonstrated comparable accuracy to US-based fusion (p = 0.7) and AR-overlay (p = 0.06). Excluding two outliers, AR-overlay accuracy became 5.9 ± 2.6 mm. US-based fusion had the highest mean placement time (44.3 ± 27.7 s) compared to all navigation cohorts (p < 0.001). Longest procedure times were recorded with AR-overlay (34 ± 10.2 min) compared to AR-plain (22.7 ± 8.6 min, p = 0.09), US-based fusion (19.5 ± 5.6 min, p = 0.02), and freehand (14.8 ± 1.6 min, p = 0.002). CONCLUSION: Goggle-based AR showed no difference in needle placement accuracy compared to the commercially available US-based fusion navigation platform. Differences in accuracy and procedure times were apparent with different display modes (with/without stereoscopic projections). The AR-based projection of the US and needle trajectory over the body may be a helpful tool to enhance visuospatial orientation. Thus, this study refines the potential role of AR for needle placements, which may serve as a catalyst for informed implementation of AR techniques in IR.

18.
Oncotarget ; 15: 288-300, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38712741

RESUMEN

PURPOSE: Sequential PET/CT studies oncology patients can undergo during their treatment follow-up course is limited by radiation dosage. We propose an artificial intelligence (AI) tool to produce attenuation-corrected PET (AC-PET) images from non-attenuation-corrected PET (NAC-PET) images to reduce need for low-dose CT scans. METHODS: A deep learning algorithm based on 2D Pix-2-Pix generative adversarial network (GAN) architecture was developed from paired AC-PET and NAC-PET images. 18F-DCFPyL PSMA PET-CT studies from 302 prostate cancer patients, split into training, validation, and testing cohorts (n = 183, 60, 59, respectively). Models were trained with two normalization strategies: Standard Uptake Value (SUV)-based and SUV-Nyul-based. Scan-level performance was evaluated by normalized mean square error (NMSE), mean absolute error (MAE), structural similarity index (SSIM), and peak signal-to-noise ratio (PSNR). Lesion-level analysis was performed in regions-of-interest prospectively from nuclear medicine physicians. SUV metrics were evaluated using intraclass correlation coefficient (ICC), repeatability coefficient (RC), and linear mixed-effects modeling. RESULTS: Median NMSE, MAE, SSIM, and PSNR were 13.26%, 3.59%, 0.891, and 26.82, respectively, in the independent test cohort. ICC for SUVmax and SUVmean were 0.88 and 0.89, which indicated a high correlation between original and AI-generated quantitative imaging markers. Lesion location, density (Hounsfield units), and lesion uptake were all shown to impact relative error in generated SUV metrics (all p < 0.05). CONCLUSION: The Pix-2-Pix GAN model for generating AC-PET demonstrates SUV metrics that highly correlate with original images. AI-generated PET images show clinical potential for reducing the need for CT scans for attenuation correction while preserving quantitative markers and image quality.


Asunto(s)
Aprendizaje Profundo , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Anciano , Persona de Mediana Edad , Glutamato Carboxipeptidasa II/metabolismo , Antígenos de Superficie/metabolismo , Procesamiento de Imagen Asistido por Computador/métodos , Algoritmos , Radiofármacos , Reproducibilidad de los Resultados
19.
Am J Physiol Lung Cell Mol Physiol ; 327(2): L218-L231, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38712433

RESUMEN

Quantitative characterization of lung structures by morphometrical or stereological analysis of histological sections is a powerful means of elucidating pulmonary structure-function relations. The overwhelming majority of studies, however, fix lungs for histology at pressures outside the physiological/pathophysiological respiratory volume range. Thus, valuable information is being lost. In this perspective article, we argue that investigators performing pulmonary histological studies should consider whether the aims of their studies would benefit from fixation at functional transpulmonary pressures, particularly those of end-inspiration and end-expiration. We survey the pressures at which lungs are typically fixed in preclinical structure-function studies, provide examples of conditions that would benefit from histological evaluation at functional lung volumes, summarize available fixation methods, discuss alternative imaging modalities, and discuss challenges to implementing the suggested approach and means of addressing those challenges. We aim to persuade investigators that modifying or complementing the traditional histological approach by fixing lungs at minimal and maximal functional volumes could enable new understanding of pulmonary structure-function relations.


Asunto(s)
Pulmón , Pulmón/fisiología , Animales , Humanos , Fijación del Tejido/métodos
20.
Neurosci Biobehav Rev ; 162: 105718, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38744350

RESUMEN

Our understanding of the neural control of human walking has changed significantly over the last twenty years and mobile brain imaging methods have contributed substantially to current knowledge. High-density electroencephalography (EEG) has the advantages of being lightweight and mobile while providing temporal resolution of brain changes within a gait cycle. Advances in EEG hardware and processing methods have led to a proliferation of research on the neural control of locomotion in neurologically intact adults. We provide a narrative review of the advantages and disadvantages of different mobile brain imaging methods, then summarize findings from mobile EEG studies quantifying electrocortical activity during human walking. Contrary to historical views on the neural control of locomotion, recent studies highlight the widespread involvement of many areas, such as the anterior cingulate, posterior parietal, prefrontal, premotor, sensorimotor, supplementary motor, and occipital cortices, that show active fluctuations in electrical power during walking. The electrocortical activity changes with speed, stability, perturbations, and gait adaptation. We end with a discussion on the next steps in mobile EEG research.


Asunto(s)
Electroencefalografía , Caminata , Humanos , Caminata/fisiología , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Neuroimagen/métodos , Marcha/fisiología
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