23 research outputs found
Noninvasive Vascular Images for Face Transplant Surgical Planning
Objective: Face transplantation replaces substantial defects with anatomically identical donor tissues; preoperative vascular assessment relies on noninvasive imaging to separate and characterize the external carotid vessels and branches. The objective is to describe and illustrate vascular considerations for face transplantation candidates. Methods: Novel noninvasive imaging using computed tomography and magnetic resonance imaging over 3 spatial dimensions plus time was developed and tested in 4 face transplant candidates. Precontrast images assessed bones and underlying metal. Contrast media was used to delineate and separate arteries from veins. For computed tomography, acquisition over multiple time points enabled the computation of tissue perfusion metrics. Time-resolved magnetic resonance angiography was performed to separate arterial and venous phases. Results: The range of circulation times for the external carotid system was 6 to 14 seconds from arterial blush to loss of venous enhancement. Precontrast imaging provided a roadmap of bones and metal. Among the 4 patients, 3 had surgical clips, metal implants, or both within 1 cm of major vessels considered for surgery. Contrast-enhanced wide area detector computed tomographic data acquired in the axial mode separated these structures and provided arterial and venous images for planning the surgical anastomoses. Magnetic resonance imaging was able to distinguish between the large vessels from the external carotid systems. Conclusions: Vascular imaging maps are challenging in face transplantation because of the rapid circulation times and artifact from the initial injury, prior reconstructive attempts, or both. Nevertheless, face transplant candidates require high spatial and temporal resolution vascular imaging to determine those vessels appropriate for surgical anastomoses
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Research Data supporting REPORT ON THE EXCAVATIONS AT ALDBOROUGH (ISURIUM BRIGANTUM), 2018: BUILDING 2.17 – A ROMAN WAREHOUSE
Research data associated with excavations carried out to investigate a large building in the north-east of Isurium Brigantum. The structure was first excavated in 1924 during investigations of the defences, but the full extent of the building was revealed in the geophysical survey. The re-excavation of the 1924 trench set out to investigate the chronology and use of the building and its immediate context. The building is thought to be a warehouse (horreum) constructed around AD250-270. Its destruction came in the mid-fourth century or later. This huge warehouse sheds new light on the role of Isurium Brigantum as a centre for trade, taxation, and storage. See 'Aldborough 2018 ARCHIVE.xlxs' for detailed descriptions of the data
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Aldborough Roman Town Project: 2017 Excavations
This record primarily consists of a spreadsheet with links to the files that constitute the data and other supporting information that detail the excavations in 2017.
The main record for the Aldborough project is here: https://www.repository.cam.ac.uk/handle/1810/275723
The collection relating to this particular dataset may be found at this URL: https://www.repository.cam.ac.uk/handle/1810/335104; in addition, permanent links (DOIs) to the individual records (context sheets, find listings etc) are available in the attached spreadsheet.
The Aldborough Roman Town Project was set up in 2009 by Dr Rose Ferraby and Prof. Martin Millett, Faculty of Classics, University of Cambridge. The project was designed to carry out archaeological research on the town of Isurium Brigantum, now the village of Aldborough in North Yorkshire, with an aim to better understanding its origins, development and its role in the social, political and economic scene of Roman Britain. This built upon a huge body of work already carried out by Colin Dobinson and volunteers from the Yorkshire Archaeological Society. Fieldwalking took place over large areas in and around the Roman town, as well as some small areas of geophysical survey. This data is all being brought together as part of the project.
To begin with, the project will use geophysical survey to establish a landscape scale view of the sub-surface archaeological remains of the town, its defenses, road system and extra-mural areas. Already after only 3 years, this has revealed that Isurium Brigantium is far less straight forward than has previously presumed; rather the evidence collected so far suggests a much more complex picture of development, use and evolution into the Anglo-Saxon period. Once the survey is complete, excavation may take place to start to investigate some of the more complex areas of the town.
A number of different geophysical techniques are being employed at the site, in order to better understand the various aspects of the archaeological record. Magnetometer and topographic surveys have been used across large areas of the town, whereas Ground Penetrating Radar has been used in limited areas with more complicated stratigraphy
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Reduced exposure using asymmetric cone beam processing for wide area detector cardiac CT
The purpose of this study was to estimate dose reduction after implementation of asymmetrical cone beam processing using exposure differences measured in a water phantom and a small cohort of clinical coronary CTA patients. Two separate 320 × 0.5 mm detector row scans of a water phantom used identical cardiac acquisition parameters before and after software modifications from symmetric to asymmetric cone beam acquisition and processing. Exposure was measured at the phantom surface with Optically Stimulated Luminescence (OSL) dosimeters at 12 equally spaced angular locations. Mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at the center plus four peripheral locations in the water phantom. To assess image quality, mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at five points within the water phantom. Retrospective evaluation of 64 patients (37 symmetric; 27 asymmetric acquisition) included clinical data, scanning parameters, quantitative plus qualitative image assessment, and estimated radiation dose. In the water phantom, the asymmetric cone beam processing reduces exposure by approximately 20% with no change in image quality. The clinical coronary CTA patient groups had comparable demographics. The estimated dose reduction after implementation of the asymmetric approach was roughly 24% with no significant difference between the symmetric and asymmetric approach with respect to objective measures of image quality or subjective assessment using a four point scale. When compared to a symmetric approach, the decreased exposure, subsequent lower patient radiation dose, and similar image quality from asymmetric cone beam processing supports its routine clinical use
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Noninvasive Vascular Images for Face Transplant Surgical Planning
Objective: Face transplantation replaces substantial defects with anatomically identical donor tissues; preoperative vascular assessment relies on noninvasive imaging to separate and characterize the external carotid vessels and branches. The objective is to describe and illustrate vascular considerations for face transplantation candidates. Methods: Novel noninvasive imaging using computed tomography and magnetic resonance imaging over 3 spatial dimensions plus time was developed and tested in 4 face transplant candidates. Precontrast images assessed bones and underlying metal. Contrast media was used to delineate and separate arteries from veins. For computed tomography, acquisition over multiple time points enabled the computation of tissue perfusion metrics. Time-resolved magnetic resonance angiography was performed to separate arterial and venous phases. Results: The range of circulation times for the external carotid system was 6 to 14 seconds from arterial blush to loss of venous enhancement. Precontrast imaging provided a roadmap of bones and metal. Among the 4 patients, 3 had surgical clips, metal implants, or both within 1 cm of major vessels considered for surgery. Contrast-enhanced wide area detector computed tomographic data acquired in the axial mode separated these structures and provided arterial and venous images for planning the surgical anastomoses. Magnetic resonance imaging was able to distinguish between the large vessels from the external carotid systems. Conclusions: Vascular imaging maps are challenging in face transplantation because of the rapid circulation times and artifact from the initial injury, prior reconstructive attempts, or both. Nevertheless, face transplant candidates require high spatial and temporal resolution vascular imaging to determine those vessels appropriate for surgical anastomoses
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Noninvasive vascular images for face transplant surgical planning.
ObjectiveFace transplantation replaces substantial defects with anatomically identical donor tissues; preoperative vascular assessment relies on noninvasive imaging to separate and characterize the external carotid vessels and branches. The objective is to describe and illustrate vascular considerations for face transplantation candidates.MethodsNovel noninvasive imaging using computed tomography and magnetic resonance imaging over 3 spatial dimensions plus time was developed and tested in 4 face transplant candidates. Precontrast images assessed bones and underlying metal. Contrast media was used to delineate and separate arteries from veins. For computed tomography, acquisition over multiple time points enabled the computation of tissue perfusion metrics. Time-resolved magnetic resonance angiography was performed to separate arterial and venous phases.ResultsThe range of circulation times for the external carotid system was 6 to 14 seconds from arterial blush to loss of venous enhancement. Precontrast imaging provided a roadmap of bones and metal. Among the 4 patients, 3 had surgical clips, metal implants, or both within 1 cm of major vessels considered for surgery. Contrast-enhanced wide area detector computed tomographic data acquired in the axial mode separated these structures and provided arterial and venous images for planning the surgical anastomoses. Magnetic resonance imaging was able to distinguish between the large vessels from the external carotid systems.ConclusionsVascular imaging maps are challenging in face transplantation because of the rapid circulation times and artifact from the initial injury, prior reconstructive attempts, or both. Nevertheless, face transplant candidates require high spatial and temporal resolution vascular imaging to determine those vessels appropriate for surgical anastomoses
Associations Among Antiphospholipid Antibody Types, Isotypes, and Titers: An AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) Study
Several antiphospholipid antibody (aPL) profiles ("triple" and lupus anticoagulant [LA] positivity) are associated with a higher risk for clinical manifestations of antiphospholipid syndrome (APS). Further risk is correlated with higher levels of anticardiolipin antibody (aCL) and anti -b2 glycoprotein-I antibody (ab2GPI), and with aPL persistence. Given that the 3 aPL tests detect partially overlapping sets of antibodies, the primary goal of this study was to characterize the associations among aPL tests using AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) core laboratory data. The APS ACTION Registry includes annually followed adult patients with positive aPL based on the Revised Sapporo Classification Criteria. We analyzed baseline and prospective core laboratory data of the registry for associations among aPL tests using the Spearman rank correlation with Bonferroni-adjusted significance level for multiple comparisons. An aPL Load was calculated based on 6 tests (aCL IgG/IgM/IgA and ab2GPI IgG/IgM/IgA); a receiver operating characteristic curve was used to evaluate the diagnostic performance of the aPL Load in predicting LA positivity. In 351 patients simultaneously tested for LA, aCL, and ab2GPI, the frequency of moderate-to-high (>= 40 U) titers of aCL and ab2GPI IgG/IgM/ IgA was higher in patients who were positive for LA vs those who were negative. An aPL Load was calculated for each patient to assess the overall aPL burden. For every 1-point increase in the aPL Load, the possibility of a positive LA test increased by 32% (odds ratio, 1.32; 95% CI, 1.2-1.5; P
Associations Among Antiphospholipid Antibody Types, Isotypes, and Titers: An AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) Study
Several antiphospholipid antibody (aPL) profiles ("triple" and lupus anticoagulant [LA] positivity) are associated with a higher risk for clinical manifestations of antiphospholipid syndrome (APS). Further risk is correlated with higher levels of anticardiolipin (aCL) and anti-β2 glycoprotein-I antibodies (aβ2GPI), and with aPL persistence. Given that the three aPL tests detect partially overlapping sets of antibodies, the primary goal of this study was to characterize the associations among aPL tests using APS ACTION Core Laboratory data. The APS ACTION Registry includes annually followed adult patients with positive aPL based on the Revised Sapporo Classification Criteria. We analyzed baseline and prospective Core Laboratory data of the Registry for associations among aPL tests, using Spearman's rank correlation with Bonferroni adjusted significance level for multiple comparisons. An aPL Load was calculated based on six tests (aCL IgG/M/A and aβ2GPI IgG/M/A); a receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of the aPL Load in predicting LA positivity. In 351 patients simultaneously tested for LA, aCL, and aβ2GPI, the frequency of moderate-to-high (≥40 units) titers of aCL and aβ2GPI IgG/M/A was higher in patients who were positive for LA versus negative. An aPL Load was calculated for each patient to assess their overall aPL burden. For every one-point increase in aPL Load, the possibility of a positive LA test increased by 32% (OR 1.32, 95% CI 1.2, 1.5, p<.001). Based on Core Laboratory data from a large international registry, most aPL ELISA ≥40U and a high calculated aPL Load combining six aPL ELISAs were predictive of a positive LA. These data suggest that the combined quantitative burden of aPL may provide a mechanistic explanation of a positive LA
Validation of quantitative measures of rotatory knee laxity
Background: Prior attempts to quantify the pivot-shift examination have been too invasive or impractical for clinical use. A noninvasive method for quantifying rotatory knee laxity is needed. Hypothesis: Greater quantitative measurements of rotatory knee laxity (both of the involved knee as well as compared with the contralateral healthy knee) are associated with an increasing clinical pivot-shift grade. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 103 patients undergoing anatomic single-bundle anterior cruciate ligament (ACL) reconstruction at 4 international centers underwent a standardized pivot-shift test preoperatively on both knees while anesthetized. Clinical grading of the pivot shift was performed according to the International Knee Documentation Committee (IKDC) knee ligament rating system. Two different quantitative technologies were used to measure rotatory knee laxity: an inertial sensor and an image analysis were independently used to measure tibial acceleration and lateral compartment translation, respectively, during the pivot-shift test. Patients were dichotomized to "high-grade" (abnormal and severely abnormal) or "low-grade" (normal and nearly normal) rotatory knee laxity groups based on the clinical pivot-shift test result of the involved side. Tibial acceleration and lateral compartment translation of the involved knee and the side-to-side difference between the involved and contralateral knees were separately compared between the high- and low-grade rotatory knee laxity groups utilizing t tests; significance was set at P <.05. Results: Forty-three patients were in the low-grade rotatory knee laxity group, and 60 patients were in the high-grade rotatory knee laxity group. Patients in the high-grade knee laxity group had significantly higher lateral compartment translation as measured with the image analysis (involved knee: 3.8 ± 2.3 mm; side-to-side difference: 2.5 ± 2.4 mm) compared with patients in the low-grade group (involved knee: 2.0 ± 1.4 mm; side-to-side difference: 1.4 ± 1.5 mm) (both P <.01). As measured with the inertial sensor, tibial acceleration for patients in the high-grade group was significantly higher (involved knee: 7.2 ± 5.3 m/s2; side-to-side difference: 4.2 ± 5.4 m/s2) compared with patients in the low-grade group (involved knee: 4.2 ± 1.6 m/s2; side-to-side difference: 1.2 ± 1.2 m/s2) (both P <.01). Conclusion: The inertial sensor and image analysis techniques were able to detect differences between low- and high-grade pivot-shift test results. A quantitative assessment of the pivot-shift test could augment the diagnosis of an ACL injury and improve the ability to detect changes in rotatory knee laxity over time