Firearm Injury, It's Not Just Physical: The Adverse Impact on Patient-Reported Socioeconomic, Mental Health, and Quality-of-Life Outcomes.

Background: The burden of firearm injury (FI) extends beyond hospitalization; however, literature focuses mostly on short-term physical outcomes. This study aimed to assess changes in patient-reported outcomes following firearm-related trauma. We hypothesized long-term patient-reported socioeconomic, mental health, and quality-of-life (QoL) outcomes are worse post-FI compared to pre-FI.Methods: This was a retrospective study where a phone survey was conducted with FI survivors admitted between January 2017 and August 2022 at a level 1 trauma center. Survey questions assessed demographics, socioeconomics, and mental and physical health pre-FI vs ≥ 6 months post-FI; the McNemar test was used for comparisons. The PROMIS-29 + 2v2.1 NIH validated instrument was used to assess long-term QoL. Standardized NIH PROMIS T-scores were calculated using the HealthMeasures Scoring Service.Results: Of 204 eligible FI survivors, 71 were successfully contacted and 38 surveyed. Respondents were male (86.8%), Black (76%), and aged 18-29 (55.3%), and 68.4% had high school level education. Post-FI, patients were more likely to be unemployed (55.2% vs 13.2%, P < .001) and report increased mental health needs (84.2% vs 21%, P < .001) compared to pre-FI. Most (73.7%) also reported lasting physical disability. Similarly, the PROMIS instrument demonstrated largely worse health-related QoL scores post-FI, particularly high anxiety/fear (T-score 60.2, SE 3.1, CI 54.6-66.3, Table 2), pain resulting in life interference (T-score 60.0, SE 2.3, CI 55.7-63.9), and worse physical function (T-score 42.5, SE 3.0, CI 38.2-46.9).Conclusions: Firearm injury survivors had more unemployment and worse mental health post-FI compared to pre-FI. Firearm injury survivors also reported significantly worse health-related QoL metrics including pain, anxiety, and physical function 6 months following their trauma. These long-term patient-reported outcomes are a framework to build future outpatient resources.Level of Evidence: IV.

Utility of computed tomography reconstructed thoracolumbar spinal imaging in blunt trauma.

OBJECTIVES: Fractures of the thoracolumbar (TL) spine are common and may cause neurologic damage, pain, and reduced quality of life. Computed tomography (CT) TL reconstructions from CT chest, abdomen, and pelvis (CAP) are used to identify TL fractures; however, their benefit over CAP imaging is unclear. We hypothesized that reformatted TL images do not identify additional clinically significant injuries or change outcomes. METHODS: Retrospective data were collected 2016 to 2021 from trauma patients at a level 1 trauma center. All patients 18 years or older with TL fractures on CT CAP with/without CT TL reformats were included. Clinically significant TL fractures were defined as requiring operative fixation, brace, or spinal rehabilitation. A binary classification model was created to assess the diagnostic utility of CTCAP compared with CTTL in predicting clinically significant fractures in patients who underwent CT CAP/TL. RESULTS: There were 828 patients with TL fractures, 634 had both CT CAP/CT TL (CAPTL) and 194 CTCAP only (CAP). There were 134 clinically significant TL fractures (16%) (14 [7.2%] CT CAP vs. 120 [18.9%] CT CAPTL, p < 0.001). There were no differences among unstable fractures, fractures on magnetic resonance imaging (MRI) only, mortality, or neurologic deficits on discharge between CAPTL and CAP ( p > 0.05). Among clinically significant fractures, CAPTL was not associated with increased MRI utilization, surgery, spinal brace, or spinal cord rehabilitation ( p > 0.05). Among clinically insignificant fractures, CAPTL was associated with increased MRIs, length of stay (LOS), and intensive care unit LOS ( p < 0.05). CAPTL was also an independent predictor of increased MRIs (odds ratio, 5.79; 95% confidence interval, 2.29-14.65; p < 0.01) and spine consultation (odds ratio, 2.39; 95% confidence interval, 1.64-3.67; p < 0.01). More CT CAP/TL were performed in those with clinically significant fractures; however, CTCAP was equivalent to CTTL for detection of fractures ( p > 0.05). CONCLUSION: CTCAP alone is sufficient to identify clinically significant TL fractures. While the addition of TL reformatted imaging minimizes missed injuries, it is associated with increased hospital LOS and MRI resource utilization. Therefore, careful consideration is needed for appropriate CT TL patient selection. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Monte Carlo fluorescence microtomography.

Fluorescence microscopy allows real-time monitoring of optical molecular probes for disease characterization, drug development, and tissue regeneration. However, when a biological sample is thicker than 1 mm, intense scattering of light would significantly degrade the spatial resolution of fluorescence microscopy. In this paper, we develop a fluorescence microtomography technique that utilizes the Monte Carlo method to image fluorescence reporters in thick biological samples. This approach is based on an l(0)-regularized tomography model and provides an excellent solution. Our studies on biomimetic tissue scaffolds have demonstrated that the proposed approach is capable of localizing and quantifying the distribution of optical molecular probe accurately and reliably.

In situ parameter identification of optimal density-elastic modulus relationships in subject-specific finite element models of the proximal femur.

Quantitative computed tomography based finite element analysis of the femur is currently being investigated as a method for non-invasive stiffness and strength predictions of the proximal femur. The specific objective of this study was to determine better conversion relationships from QCT-derived bone density to elastic modulus, in order to achieve accurate predictions of the overall femoral stiffness in a fall-on-the-hip loading configuration. Twenty-two femurs were scanned, segmented and meshed for finite element analysis. The elastic moduli of the elements were assigned according to the average density in the element. The femurs were then tested to fracture and force-displacement data were collected to calculate femoral stiffness. Using a training set of nine femurs, finite element analyses were performed and the parameters of the density-elastic modulus relationship were iteratively adjusted to obtain optimal stiffness predictions in a least-squares sense. The results were then validated on the remaining 13 femurs. Our novel procedure resulted in parameter identification of both power and sigmoid functions for density-elastic modulus conversion for this specific loading scenario. Our in situ estimated power law achieved improved predictions compared to published power laws, and the sigmoid function yielded even smaller prediction errors. In the future, these results will be used to further improve the femoral strength predictions of our finite element models.

Differential evolution approach for regularized bioluminescence tomography.

Bioluminescence tomography (BLT) is an inverse source problem that localizes and quantifies bioluminescent probe distribution in 3-D. The generic BLT model is ill-posed, leading to nonunique solutions and aberrant reconstruction in the presence of measurement noise and optical parameter mismatches. In this paper, we introduce the knowledge of the number of bioluminescence sources to stabilize the BLT problem. Based on this regularized BLT model, we develop a differential evolution-based reconstruction algorithm to determine the source locations and strengths accurately and reliably. Then, we evaluate this novel approach in numerical, phantom, and mouse studies.

Integral equations of the photon fluence rate and flux based on a generalized Delta-Eddington phase function.

We present a generalized Delta-Eddington phase function to simplify the radiative transfer equation to integral equations with respect to both photon fluence rate and flux vector. The photon fluence rate and flux can be solved from the system of integral equations. By comparing to the Monte Carlo simulation results, the solutions of the system of integral equations accurately model the photon propagation in biological tissue over a wide range of optical parameters.

Improving the accuracy of the diffusion model in highly absorbing media.

The diffusion approximation of the Boltzmann transport equation is most commonly used for describing the photon propagation in turbid media. It produces satisfactory results in weakly absorbing and highly scattering media, but the accuracy lessens with the decreasing albedo. In this paper, we presented a method to improve the accuracy of the diffusion model in strongly absorbing media by adjusting the optical parameters. Genetic algorithm-based optimization tool is used to find the optimal optical parameters. The diffusion model behaves more closely to the physical model with the actual optical parameters substituted by the optimized optical parameters. The effectiveness of the proposed technique was demonstrated by the numerical experiments using the Monte Carlo simulation data as measurements.

Multispectral bioluminescence tomography: methodology and simulation.

Bioluminescent imaging has proven to be a valuable tool for monitoring physiological and pathological activities at cellular and molecular levels in living small animals. Using biological techniques, target cells can be tagged with reporters encoding several kinds of luciferase enzymes, which generate characteristic photons in a wide spectrum covering the infrared range. Part of the diffused light can reach the body surface of the small animal, be separated into several spectral bands using appropriate filters, and collected by a sensitive CCD camera. Here we present a bioluminescence tomography (BLT) method for a bioluminescent source reconstruction from multispectral data measured on the external surface, and demonstrate the advantages of multispectral BLT in a numerical study using a heterogeneous mouse chest phantom. The results show that the multispectral approach significantly improves the accuracy and stability of the BLT reconstruction even if the data are highly noisy.

Practical reconstruction method for bioluminescence tomography.

Bioluminescence tomography (BLT) is used to localize and quantify bioluminescent sources in a small living animal. By advancing bioluminescent imaging to a tomographic framework, it helps to diagnose diseases, monitor therapies and facilitate drug development. In this paper, we establish a direct linear relationship between measured surface photon density and an unknown bioluminescence source distribution by using a finite-element method based on the diffusion approximation to the photon propagation in biological tissue. We develop a novel reconstruction algorithm to recover the source distribution. This algorithm incorporates a priori knowledge to define the permissible source region in order to enhance numerical stability and efficiency. Simulations with a numerical mouse chest phantom demonstrate the feasibility of the proposed BLT algorithm and reveal its performance in terms of source location, density, and robustness against noise. Lastly, BLT experiments are performed to identify the location and power of two light sources in a physical mouse chest phantom.

A finite-element-based reconstruction method for 3D fluorescence tomography.

In this paper, we propose a dual-excitation-mode methodology for three-dimensional (3D) fluorescence molecular tomography (FMT). For this modality, an effective reconstruction algorithm is developed to reconstruct fluorescent yield and lifetime using finite element techniques. In the steady state mode, a direct linear relationship is established between measured optical data on the body surface of a small animal and the unknown fluorescent yield inside the animal, and the reconstruction of fluorescent yield is formulated as a linear least square minimization problem. In the frequency domain mode, based on localization results of the fluorescent probe obtained using the first mode, the reconstruction of fluorescent lifetime is transformed into a relatively simple optimization problem. This algorithm helps overcome the ill-posedness with FMT. The effectiveness of the proposed method is numerically demonstrated using a heterogeneous mouse chest phantom, showing good accuracy, stability, noise characteristics and computational efficiency.