Browsing by Subject "dysplasia"
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Item Open Access Assessment of Disability Related to Hip Dysplasia Using Objective Measures of Physical Performance.(Orthopaedic journal of sports medicine, 2020-02) Scott, Elizabeth J; Willey, Michael C; Mercado, Arthur; Davison, John; Wilken, Jason MBackground
Lower extremity physical performance measures (PPMs), which can objectively quantify functional ability, are an attractive adjuvant to patient-reported outcome (PRO) instruments. However, few tests have been validated for use in hip instability.Purpose
To evaluate 4 different PPMs for their ability to differentiate between young adults with hip dysplasia indicated for treatment with periacetabular osteotomy (PAO) and asymptomatic controls and to test inter- and intratest reliability and relationship with popular hip PRO instruments.Study design
Cohort study (diagnosis); Level of evidence, 2.Methods
A total of 24 symptomatic patients aged 15 to 39 years (100% female) with hip dysplasia (lateral center-edge angle <25°) indicated for treatment with PAO completed the visual analog scale (VAS) for pain, Hip disability and Osteoarthritis Outcome (HOOS) Pain subscale, HOOS Short Version (HOOS PS), International Hip Outcome Tool Short Version (iHOT-12), modified Harris Hip Score (mHHS), Patient Reported Outcome Measurement Information System (PROMIS) physical function (PF) and pain interference (PI), and 4 physical function tests: (1) self-selected walking speed (SSWS), sit-to-stand 5 times (STS5), (3) 4-square step test (FSST), and (4) timed stair ascent (TSA). A further 21 young, asymptomatic adults aged 18 to 39 years (91% female) also underwent testing. Between-group comparisons were made with unpaired t test with Bonferroni-Holm correction. Inter- and intrarater reliability was assessed in 38 participants by repeating PPMs at a second visit and using 2 raters. Spearman rank correlation coefficients were used to determine associations between PPMs and PRO instruments.Results
Significant differences between patients with hip dysplasia and controls were observed for all PRO instruments (HOOS Pain, 47.8 vs 99.2; HOOS PS, 61.9 vs 99.2; iHOT-12, 32.2 vs 99.2; mHHS, 54.5 vs 90.6; PROMIS PF, 41.4 vs 65.6; and PROMIS PI, 62.0 vs 39.1 [all P < .001]), and all PPMs (SSWS, 1.21 vs 1.53 m/s; STS5, 10.85 vs 5.95 s; FSST, 6.59 vs 4.03 s [all P < .001]; and TSA, 4.58 vs 3.29 s [P = .002]). All 4 PPMs demonstrated excellent intra- and intertest reliability (intraclass correlation coefficient, 0.83-0.99). STS5, FSST, and TSA were correlated highly (r > 0.5) with physical function PRO instruments, including PROMIS PF, mHHS, and iHOT-12.Conclusion
Patients with symptomatic hip dysplasia demonstrated significant impairment on functional testing compared with asymptomatic controls, and performance measure testing demonstrated excellent test-retest reliability. Timed stair ascent and sit-to-stand testing in particular were correlated strongly with physical function PRO instruments. PPMs may be a viable and well-received adjuvant to PRO instrument administration for patients with nonarthritic hip conditions, and investigation of the ability of PPMs to assess surgical outcomes for hip dysplasia is warranted.Item Open Access Diagnostic Imaging and Assessment Using Angle Resolved Low Coherence Interferometry(2012) Giacomelli, Michael GeneThe redistribution of incident light into scattered fields ultimately limits the ability to image into biological media. However, these scattered fields also contain information about the structure and distribution of protein complexes, organelles, cells and whole tissues that can be used to assess the health of tissue or to enhance imaging contrast by excluding confounding signals. The interpretation of scattered fields depends on a detailed understanding of the scattering process as well as sophisticated measurement systems. In this work, the development of new instruments based on low coherence interferometry (LCI) is presented in order to perform precise, depth-resolved measurements of scattered fields. Combined with LCI, the application of new light scattering models based on both analytic and numerical methods is presented in order to interpret scattered field measurements in terms of scatterer geometry and tissue health.
The first portion of this work discusses the application of a new light scattering model to the measurement recorded with an existing technique, Angle Resolved Low Coherence Interferometry (a/LCI). In the a/LCI technique, biological samples are interrogated with collimated light and the energy per scattering angle at each depth in the volume is recorded interferometrically. A light scattering model is then used to invert the scattering measurements and measure the geometry of cell nuclei. A new light scattering model is presented that can recover information about the size, refractive index, and for the first time, shape of cell nuclei. This model is validated and then applied to the study of cell biology in a series of experiments measuring cell swelling, cell deformation, and finally detecting the onset of apoptosis.
The second portion of this work introduces an improved version of a/LCI based on two dimension angle resolved measurement (2D a/LCI) and Fourier domain low coherence interferometry (FD-LCI). Several systems are presenting for high speed and polarization-resolved measurements of scattered fields. An improved light scattering model based on fully polarization and solid angle resolved measurements is presented, and then efficiently implemented using distributed computing techniques. The combined system is validated with phantoms and is shown to be able to uniquely determine the size and shape of scattering particles using a single measurement.
The third portion of this work develops the use of angle-resolved interferometry for imaging through highly scattering media by exploiting the tendency of scatterers to forward scatter light. A new interferometers is developed that can image through very large numbers of scattering events with acceptable resolution. A computational model capable of reproducing experimental measurements is developed and used to understand the performance of the technique.
The final portion of the work develops a method for processing 2D angle resolved measurements using optical autocorrelation. In this method, measurements over a range of angles are fused into a single depth scan that incorporates the component of scattered light only from certain spatial scales. The utility of the technique is demonstrated using a gene knockout model of retinal degeneration in mice. Optical autocorrelation is shown to be a potentially useful biomarker of tissue disease.
Item Open Access Novel Instrumentation for Optical Screening of Epithelial Dysplasia(2020) Steelman, Zachary AndrewCancer, despite its status as the second leading cause of death worldwide, is often preventable given proper surveillance and timely intervention. In the esophagus, metaplastic changes linked to reflux disease lead to alterations in cellular DNA, abnormal growth, and eventually, metastatic cancer. Fortunately, this process takes place over a period of several years, during which treatment and eradication of the precancerous lesions is possible if discovered at a sufficiently early time.
Current protocols for surveillance of the esophagus are costly and limited. As an alternative, angle-resolved low-coherence interferometry (a/LCI) is an optical technique which enables depth-resolved measurements of nuclear morphology, a biomarker of precancer. a/LCI allows for real-time identification of precancerous lesions, which may be treated using radiofrequency ablation or related techniques.
In this dissertation, several advances in a/LCI technology are presented. Measurements of the nuclear refractive index, an important parameter for a/LCI inverse light scattering analysis, are offered to settle an important debate in the literature regarding the relative density of the cell nucleus. Instrumentational advances in a/LCI are demonstrated to address the need for implementing scanning capability, which is important for screening of larger tissues such as the cervix. The properties of commercially available fiber optic imaging bundles are investigated for their capacity to support coherence-based imaging, and when these are found to be lacking, an a/LCI device based on single-mode optical fibers is designed and validated using an array of pathlength-matched individual fibers, which exhibits significant advantages over previous image bundles. Computational analysis of a previous clinical a/LCI dataset is used to provide design guidance for this methodology. Finally, this new a/LCI device is combined with a rotational endoscopic optical coherence tomography (OCT) probe to create a multimodal imaging system for comprehensive evaluation of the esophageal epithelium. The complete system includes a paddle form factor which allows it to be affixed to the exterior of a commercial endoscope for clinical compatibility, similar to related endoscopic devices. These advances demonstrate the continued applicability of a/LCI for evaluating epithelial health, and present new and attractive options for surveillance and early intervention against cancer.