Browsing by Subject "imaging"
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Item Open Access A Case of Rare Inherited Restrictive Cardiomyopathy With Severe Biatrial Enlargement.(JACC. Case reports, 2019-12) Nafissi, Navid A; Fudim, Marat; Milano, Carmelo A; Rosenberg, Paul B; DeVore, Adam D; Agarwal, RichaWe describe a case of inherited restrictive cardiomyopathy in a patient presenting with severe biatrial enlargement. We review the evaluation and management of restrictive cardiomyopathy with a focus on genetic etiologies. (Level of Difficulty: Intermediate.).Item Open Access Association of Jump-Landing Biomechanics With Tibiofemoral Articular Cartilage Composition 12 Months After ACL Reconstruction.(Orthopaedic journal of sports medicine, 2021-07) Pfeiffer, Steven J; Spang, Jeffrey T; Nissman, Daniel; Lalush, David; Wallace, Kyle; Harkey, Matthew S; Pietrosimone, Laura S; Padua, Darin; Blackburn, Troy; Pietrosimone, BrianBackground
Excessively high joint loading during dynamic movements may negatively influence articular cartilage health and contribute to the development of posttraumatic osteoarthritis after anterior cruciate ligament reconstruction (ACLR). Little is known regarding the link between aberrant jump-landing biomechanics and articular cartilage health after ACLR.Purpose/hypothesis
The purpose of this study was to determine the associations between jump-landing biomechanics and tibiofemoral articular cartilage composition measured using T1ρ magnetic resonance imaging (MRI) relaxation times 12 months postoperatively. We hypothesized that individuals who demonstrate alterations in jump-landing biomechanics, commonly observed after ACLR, would have longer T1ρ MRI relaxation times (longer T1ρ relaxation times associated with less proteoglycan density).Study design
Cross-sectional study; Level of evidence, 3.Methods
A total of 27 individuals with unilateral ACLR participated in this cross-sectional study. Jump-landing biomechanics (peak vertical ground-reaction force [vGRF], peak internal knee extension moment [KEM], peak internal knee adduction moment [KAM]) and T1ρ MRI were collected 12 months postoperatively. Mean T1ρ relaxation times for the entire weightbearing medial femoral condyle, lateral femoral condyle (global LFC), medial tibial condyle, and lateral tibial condyle (global LTC) were calculated bilaterally. Global regions of interest were further subsectioned into posterior, central, and anterior regions of interest. All T1ρ relaxation times in the ACLR limb were normalized to the uninjured contralateral limb. Linear regressions were used to determine associations between T1ρ relaxation times and biomechanics after accounting for meniscal/chondral injury.Results
Lower ACLR limb KEM was associated with longer T1ρ relaxation times for the global LTC (ΔR 2 = 0.24; P = .02), posterior LTC (ΔR 2 = 0.21; P = .03), and anterior LTC (ΔR 2 = 0.18; P = .04). Greater ACLR limb peak vGRF was associated with longer T1ρ relaxation times for the global LFC (ΔR 2 = 0.20; P = .02) and central LFC (ΔR 2 = 0.15; P = .05). Peak KAM was not associated with T1ρ outcomes.Conclusion
At 12 months postoperatively, lower peak KEM and greater peak vGRF during jump landing were related to longer T1ρ relaxation times, suggesting worse articular cartilage composition.Item Open Access Convolutional neural network to identify symptomatic Alzheimer's disease using multimodal retinal imaging.(The British journal of ophthalmology, 2020-11-26) Wisely, C Ellis; Wang, Dong; Henao, Ricardo; Grewal, Dilraj S; Thompson, Atalie C; Robbins, Cason B; Yoon, Stephen P; Soundararajan, Srinath; Polascik, Bryce W; Burke, James R; Liu, Andy; Carin, Lawrence; Fekrat, SharonBACKGROUND/AIMS:To develop a convolutional neural network (CNN) to detect symptomatic Alzheimer's disease (AD) using a combination of multimodal retinal images and patient data. METHODS:Colour maps of ganglion cell-inner plexiform layer (GC-IPL) thickness, superficial capillary plexus (SCP) optical coherence tomography angiography (OCTA) images, and ultra-widefield (UWF) colour and fundus autofluorescence (FAF) scanning laser ophthalmoscopy images were captured in individuals with AD or healthy cognition. A CNN to predict AD diagnosis was developed using multimodal retinal images, OCT and OCTA quantitative data, and patient data. RESULTS:284 eyes of 159 subjects (222 eyes from 123 cognitively healthy subjects and 62 eyes from 36 subjects with AD) were used to develop the model. Area under the receiving operating characteristic curve (AUC) values for predicted probability of AD for the independent test set varied by input used: UWF colour AUC 0.450 (95% CI 0.282, 0.592), OCTA SCP 0.582 (95% CI 0.440, 0.724), UWF FAF 0.618 (95% CI 0.462, 0.773), GC-IPL maps 0.809 (95% CI 0.700, 0.919). A model incorporating all images, quantitative data and patient data (AUC 0.836 (CI 0.729, 0.943)) performed similarly to models only incorporating all images (AUC 0.829 (95% CI 0.719, 0.939)). GC-IPL maps, quantitative data and patient data AUC 0.841 (95% CI 0.739, 0.943). CONCLUSION:Our CNN used multimodal retinal images to successfully predict diagnosis of symptomatic AD in an independent test set. GC-IPL maps were the most useful single inputs for prediction. Models including only images performed similarly to models also including quantitative data and patient data.Item Open Access Developing Needle-Tracking Techniques with Real-Time Transrectal Ultrasound Guidance in GYN Hybrid HDR Brachytherapy(2024) Bloom, LindseyIntroduction:In interstitial gynecological (GYN) high-dose rate (HDR) brachytherapy, the lack of real-time imaging during procedures is a recognized limitation, often resulting in inaccuracies in needle placement. Traditionally, clinicians rely on a combination of pre-treatment MRI scans and clinical examinations to guide needle placement, but this approach can lead to suboptimal outcomes. To address these challenges and improve the clinical workflow, this research introduces the utilization of a 3D-printed pelvic phantom designed to evaluate the feasibility and efficacy of intraoperative 3D transrectal-ultrasound (TRUS) guidance for needle insertion. Materials and Methods: This research developed needle-tracking techniques utilizing real-time TRUS guidance specifically tailored for GYN malignancies within the context of hybrid HDR brachytherapy. Leveraging the Eigen Health system, originally designed for prostate biopsy, we adapted its real-time imaging capabilities for GYN applications. To facilitate this, anatomical phantoms that replicate female pelvic anatomy were created and optimized. These phantoms served as the cornerstone for a series of feasibility tests that examined the integration of TRUS guidance into brachytherapy workflows. Additionally, comprehensive quality assurance (QA) protocols were established to ensure the reliability of needle tracking and characterization in relation to our ground-truth CT images. The system's MR/TRUS deformable registration algorithm was evaluated through two different experiments. Results: The execution of feasibility tests yielded promising results, demonstrating the Eigen Health system's compatibility with existing brachytherapy workflows and its potential to significantly improve needle placement accuracy. The study also highlighted the system's adaptability to accommodate multiple needle insertions and implement rod-based planning. Through quality assurance evaluations of the reliability and precision of needle characterization, a scaling issue within the needle-tracking system was discovered. Furthermore, the MR-3DUS surface-based elastic registration process was thoroughly examined, with uncertainty variables acknowledged, the preliminary results of this experiment showed that the system can adapt to anatomical variation. Conclusion: The integration of real-time TRUS guidance into GYN HDR brachytherapy significantly improves needle placement accuracy, promising enhanced treatment efficacy and minimized complications. This research contributes valuable insights to medical physics and cancer treatment, paving the way for future clinical trials and potential integration into standard brachytherapy protocols.
Item Open Access Interspecies Correlations between Human and Mouse NR2E3-Associated Recessive Disease.(Journal of clinical medicine, 2021-01-27) Iannaccone, Alessandro; Brabbit, Emily; Lopez-Miro, Christiaan; Love, Zoe; Griffiths, Victoria; Kedrov, Marina; Haider, Neena BNR2E3-associated recessive disease in humans is historically defined by congenital night blinding retinopathy, characterized by an initial increase in short-wavelength (S)-cone sensitivity and progressive loss of rod and cone function. The retinal degeneration 7 (rd7) murine model, harboring a recessive mutation in the mouse ortholog of NR2E3, has been a well-studied disease model and recently evaluated as a therapeutic model for NR2E3-associated retinal degenerations. This study aims to draw parallels between human and mouse NR2E3-related disease through examination of spectral domain optical coherence tomography (SD-OCT) imaging between different stage of human disease and its murine counterpart. We propose that SD-OCT is a useful non-invasive diagnostic tool to compare human clinical dystrophy presentation with that of the rd7 mouse and make inference that may be of therapeutically relevance. Additionally, a longitudinal assessment of rd7 disease progression, utilizing available clinical data from our patients as well as extensive retrospective analysis of visual acuity data from published cases of human NR2E3-related disease, was curated to identify further valuable correlates between human and mouse Nr2e3 disease. Results of this study validate the slow progression of NR2E3-associated disease in humans and the rd7 mice and identify SD-OCT characteristics in patients at or near the vascular arcades that correlate well with the whorls and rosettes that are seen also in the rd7 mouse and point to imaging features that appear to be associated with better preserved S-cone mediated retinal function. The correlation of histological findings between rd7 mice and human imaging provides a solid foundation for diagnostic use of pathophysiological and prognostic information to further define characteristics and a relevant timeline for therapeutic intervention in the field of NR2E3-associated retinopathies.Item Open Access Patellar Tendon Orientation and Strain Are Predictors of ACL Strain In Vivo During a Single-Leg Jump.(Orthopaedic journal of sports medicine, 2021-03) Englander, Zoë A; Lau, Brian C; Wittstein, Jocelyn R; Goode, Adam P; DeFrate, Louis EBackground
There is little in vivo data that describe the relationships between patellar tendon orientation, patellar tendon strain, and anterior cruciate ligament (ACL) strain during dynamic activities. Quantifying how the quadriceps load the ACL via the patellar tendon is important for understanding ACL injury mechanisms.Hypothesis
We hypothesized that flexion angle, patellar tendon orientation, and patellar tendon strain influence ACL strain during a single-leg jump. Specifically, we hypothesized that patellar tendon and ACL strains would increase concurrently when the knee is positioned near extension during the jump.Study design
Descriptive laboratory study.Methods
Models of the femur, tibia, ACL, patellar tendon, and quadriceps tendon attachment sites of 8 male participants were generated from magnetic resonance imaging (MRI). High-speed biplanar radiographs during a single-leg jump were obtained. The bone models were registered to the radiographs, thereby reproducing the in vivo positions of the bones, ligament, and tendon attachment sites. Flexion angle, patellar tendon orientation, patellar tendon strain, and ACL strain were measured from the registered models. ACL and patellar tendon strains were approximated by normalizing their length at each knee position to their length at the time of MRI. Two separate bivariate linear regression models were used to assess relationships between flexion angle and patellar tendon orientation and between ACL strain and patellar tendon strain. A multivariate linear regression model was used to assess whether flexion angle and patellar tendon strain were significant predictors of ACL strain during the inflight and landing portions of the jump.Results
Both flexion angle and patellar tendon strain were significant predictors (P < .05) of ACL strain. These results indicate that elevated ACL and patellar tendon strains were observed concurrently when the knee was positioned near extension.Conclusion
Concurrent increases in patellar tendon and ACL strains indicate that the quadriceps load the ACL via the patellar tendon when the knee is positioned near extension.Clinical relevance
Increased ACL strain when the knee is positioned near extension before landing may be due to quadriceps contraction. Thus, landing with unanticipated timing on an extended knee may increase vulnerability to ACL injury as a taut ligament is more likely to fail.Item Open Access The Unavoidable Intentionality of Affect: The History of Emotions and the Neurosciences of the Present Day(Emotion Review, 2020-07-01) Reddy, WM© The Author(s) 2020. The “problem of emotions,” that is, that many of them are both meaningful and corporeal, has yet to be resolved. Western thinkers, from Augustine to Descartes to Zajonc, have handled this problem by employing various forms of mind–body dualism. Some psychologists and neuroscientists since the 1970s have avoided it by talking about cognitive and emotional “processing,” using a terminology borrowed from computer science that nullifies the meaningful or intentional character of both thought and emotion. Outside the Western-influenced contexts, emotion and thought are not seen as distinct kinds of things. Here a solution of sorts is proposed by thinking of emotional expression as a dynamic activity that declares and stirs emotions at the same time. As such, its dynamism may help historians to understand the dramatic changes and trends they investigate.Item Open Access Time-Resolved Synchronous Fluorescence for Biomedical Diagnosis.(Sensors (Basel), 2015-08-31) Zhang, Xiaofeng; Fales, Andrew; Vo-Dinh, TuanThis article presents our most recent advances in synchronous fluorescence (SF) methodology for biomedical diagnostics. The SF method is characterized by simultaneously scanning both the excitation and emission wavelengths while keeping a constant wavelength interval between them. Compared to conventional fluorescence spectroscopy, the SF method simplifies the emission spectrum while enabling greater selectivity, and has been successfully used to detect subtle differences in the fluorescence emission signatures of biochemical species in cells and tissues. The SF method can be used in imaging to analyze dysplastic cells in vitro and tissue in vivo. Based on the SF method, here we demonstrate the feasibility of a time-resolved synchronous fluorescence (TRSF) method, which incorporates the intrinsic fluorescent decay characteristics of the fluorophores. Our prototype TRSF system has clearly shown its advantage in spectro-temporal separation of the fluorophores that were otherwise difficult to spectrally separate in SF spectroscopy. We envision that our previously-tested SF imaging and the newly-developed TRSF methods will combine their proven diagnostic potentials in cancer diagnosis to further improve the efficacy of SF-based biomedical diagnostics.