scholarly journals Optimisation of tube voltage range (kVp) for AP abdomen, pelvis and spine imaging of average patients with a digital radiography (DR) imaging system using a computer simulator

2020 ◽  
Vol 93 (1114) ◽  
pp. 20200565
Author(s):  
Craig Steven Moore ◽  
Tim Wood ◽  
Stephen Balcam ◽  
Liam Needler ◽  
Tim Guest ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Digital Radiography ◽  
Imaging System ◽  
Statistical Significance ◽  
Clinical Image ◽  
Specific Reference ◽  
Tube Voltage ◽  
Voltage Range ◽  
Optimum Range ◽  
Spine Imaging

Objectives: To investigate via computer simulation, an optimised tube voltage (kVp) range for caesium iodide (CsI)-based digital radiography (DR) of the abdomen, pelvis and lumbar spine. Methods: Software capable of simulating abdomen, pelvis and spine radiographs was used. Five evaluators graded clinical image criteria in images of 20 patients at tube voltages ranging from 60 to 120 kVp in 10 kVp increments. These criteria were scored blindly against the same patient reconstructed at a specific reference kVp. Linear mixed effects analysis was used to evaluate image scores for each criterion and test for statistical significance. Results: Score was dependent on tube voltage and image criteria; both were statistically significant. All criteria for all anatomies scored very poorly at 60 kVp. Scores for abdomen, pelvis and spine imaging peaked at 70, 70 and 100 kVp, respectively, but other kVp values were not significantly poorer. Conclusions: Results indicate optimum tube voltages of 70 kVp for abdomen and pelvis (with an optimum range 70–120 kVp), and 100 kVp (optimum range 80–120 kVp) for lumbar spine. Advances in knowledge: There are no recommendations for optimised tube voltage parameters for DR abdomen, pelvis or lumbar spine imaging. This study has investigated and recommended an optimal tube voltage range.

scholarly journals Use of a computer simulator to investigate optimized tube voltage for chest imaging of average patients with a digital radiography (DR) imaging system

2019 ◽  
Vol 92 (1104) ◽  
pp. 20190470 ◽  
Author(s):  
Craig Steven Moore ◽  
Tim Wood ◽  
Ged Avery ◽  
Steve Balcam ◽  
Liam Needler ◽  
...  
Keyword(s):  
Digital Radiography ◽  
Imaging System ◽  
Lung Nodule ◽  
Clinical Image ◽  
Reference Image ◽  
Specific Reference ◽  
Chest Imaging ◽  
Tube Voltage ◽  
Voltage Range ◽  
Low Kvp

Objective: The aim of this study was to investigate via computer simulation a proposed improvement to clinical practice by deriving an optimized tube voltage (kVp) range for digital radiography (DR) chest imaging. Methods: A digitally reconstructed radiograph algorithm was used which was capable of simulating DR chest radiographs containing clinically relevant anatomy. Five experienced image evaluators graded clinical image criteria, i.e. overall quality, rib, lung, hilar, spine, diaphragm and lung nodule in images of 20 patients at tube voltages across the diagnostic energy range. These criteria were scored against corresponding images of the same patient reconstructed at a specific reference kVp. Evaluators were blinded to kVp. Evaluator score for each criterion was modelled with a linear mixed effects algorithm and compared with the score for the reference image. Results: Score was dependent on tube voltage and image criteria in a statistically significant manner for both. Overall quality, hilar, diaphragm and spine criteria performed poorly at low and high tube voltages, peaking at 80–100 kVp. Lung and lung nodule demonstrated little variation. Rib demonstrated superiority at low kVp. Conclusion: A virtual clinical trial has been performed with simulated chest DR images. Results indicate mid-range tube voltages of 80–100 kVp are optimum for average adults. Advances in knowledge: There are currently no specific recommendations for optimized tube voltage parameters for DR chest imaging. This study, validated with images containing realistic anatomical noise, has investigated and recommended an optimal tube voltage range.

Comparison of a Fluoroscopic 3-Dimensional Imaging System and Conventional CT in Detection of Pars Fractures in the Cadaveric Lumbar Spine

2012 ◽  
Vol 25 (8) ◽  
pp. 429-432 ◽  
Author(s):  
Christopher K. Kepler ◽  
Helene Pavlov ◽  
Richard J. Herzog ◽  
Bernard A. Rawlins ◽  
Yoshimi Endo ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Imaging System ◽  
3 Dimensional ◽  
Conventional Ct

Testing of primary stability of the Activ® L intervertebral disc prosthesis in cadaver bone and comparison of the two different anchoring concepts – keel and spike anchoring

2020 ◽  
Author(s):  
Christoph von Schulze Pellengahr ◽  
Wolfram Teske ◽  
Saurabh Kapoor ◽  
Alexander Klein ◽  
Bernd Wegener ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Statistical Significance ◽  
Primary Stability ◽  
Longitudinal Axis ◽  
Disc Prosthesis ◽  
Mean Values ◽  
Intervertebral Disc Prosthesis ◽  
Flexion Extension ◽  
Micro Motion

Abstract Background: High primary stability is the fundamental prerequisite for safe osseointegration of cementless intervertebral disc prosthesis. The aim of our study was to determine the primary stability of intervertebral disc prosthesis with two different anchoring concepts – keel and spike anchoring. Methods: 10 human cadaveric lumbar spine specimens with an ActivL intervertebral disc prosthesis (5 x keel anchoring, 5 x spike anchoring) were tested on a spine simulator. Under axial load, moments of flexion, extension, left and right bending and axial rotation were applied on the lumbar spine specimens through a defined three-dimensional movement program as per ISO 2631 and ISO/CD 18192-1.3 standards. Micro-motion of the implant was measured in every axis for both anchor types and compared using statistical test for significance after calculating 95% confidence intervals. Results: In the transverse axis, the keel anchoring concept showed lower mean values of micro-motion , which was statistically significant (p<0.05) compared to spike anchoring concept. In the sagittal axis, the results were again in favour of the keel anchoring, but did not reach statistical significance (p>0.05). The highest micro-motion values were observed in the longitudinal axis. Both concepts showed values around the threshold of primary stability (150 μm) with the spike concept showing lower mean values, but without a statistically significant difference.Conclusions: Both types of anchors met the criteria of primary stability. The keel anchoring shows a slight advantage compared to anchoring with spikes. Direct postoperative active mobilization doesn’t seem to compromise the primary stability of the prosthesis.

scholarly journals Lumbar Spine Imaging: Myelography

Pain Medicine ◽  
2017 ◽  
pp. 123-125
Author(s):  
Glenn C. Gaviola ◽  
Nehal A. Shah
Keyword(s):  
Lumbar Spine ◽  
Spine Imaging

scholarly journals 4511 Bio-Compatible Implantable Oxygen Sensor Technology with Real-Time Monitoring of Surgical Flaps and Reimplantation

2020 ◽  
Vol 4 (s1) ◽  
pp. 93-93
Author(s):  
Preet Patel ◽  
Mohamed Ibrahim ◽  
Bruce Klitzman
Keyword(s):  
Oxygen Tension ◽  
Optical Sensors ◽  
Oxygen Sensor ◽  
Imaging System ◽  
Statistical Significance ◽  
Surgical Flaps ◽  
Tissue Oxygen Tension ◽  
Sensor Technology ◽  
Tissue Oxygen ◽  
Flap Viability

OBJECTIVES/GOALS: Current surgical flap and replantation monitoring techniques have limitations in detecting the pathologic state, calibration and cost-to-patient issues. Our hypothesis is that novel implantable oxygen sensors can provide a more efficient, accurate, and reliable monitoring of tissue oxygenation. METHODS/STUDY POPULATION: Experimental sensors were used with an exogenous remote used as a reader once implanted (Fig. 1) A rat tissue perfusion model with three regions of an SIEA flap as well as into adjacent control sites was made (Tip, Middle, and Base) Blood flow was greatest at the base, diminishing towards the Tip, thus creating a perfusion gradient. Changes in tissue oxygen tension PO2 were estimated by the steady-state fluorescence of the optical sensors using an IVIS imaging system. The sensors were used to collect data from days 0, 3, and 7 as a reading of Tissue Oxygen Tension (TOT) with ANOVA used to assess for statistical significance in blood oxygen data with respect to relative perfusion status. RESULTS/ANTICIPATED RESULTS: Inspired FiO2 was decreased from 100% to 12% with a corresponding change in the TOT readings from all sensors. (Fig. 2) The tip portion of the flap demonstrated the most profound detection of tissue necrosis, with the middle demonstrating the second most necrosis and the base demonstrating the least with correlating TOT sensor readings. (Fig. 3) Acute vascular compromise of the feeding blood vessels in the pedicle was immediately detected within 70 seconds (*p<0.05). (Fig. 4) DISCUSSION/SIGNIFICANCE OF IMPACT: This study introduces and validates a recent technique to monitor acute vascular occlusion, flap viability, and necrosis in the immediate postoperative period in a validated rodent model. Future directions of this novel technology will aim to reproduce these findings in clinical feasibility studies.

scholarly journals Blood pressure and calcium intake are related tobone density in adult males

1999 ◽  
Vol 81 (5) ◽  
pp. 383-388 ◽  
Author(s):  
Jill A. Metz ◽  
Cynthia D. Morris ◽  
Leslie A. Roberts ◽  
Michael R. McClung ◽  
David A. McCarron
Keyword(s):  
Blood Pressure ◽  
Lumbar Spine ◽  
Bone Mass ◽  
Statistical Significance ◽  
Linear Regression Analysis ◽  
Elevated Blood Pressure ◽  
Dual Photon Absorptiometry ◽  
Elevated Blood ◽  
Low Bone Mass ◽  
Total Body

Based on the premise that elevated blood pressure and low bone mass have both been associated with poor Ca nutriture and disturbances in Ca metabolism, a cross-sectional study was employed to determine if blood pressure and dietary Ca intake were significantly related to bone mass. Forty-seven men between 24–77 years of age with blood pressure values ranging from normal to mildly elevated comprised the study group. Blood pressure was measured with a random-zero sphygmomanometer. Bone mineral content (BMC) and density (BMD) of the hip, spine and total body were measured with dual-photon absorptiometry. Dietary intake and physical activity were also assessed. Multiple linear regression analysis was used for statistical analysis. After adjusting for known confounding variables (age, BMI, Ca intake, and others) diastolic blood pressure was negatively related to BMC (P ≤ 0·05) and BMD (P ≤ 0·01) of the total body, trochanteric region (P < 0·01) and Ward's triangle (P < 0·05), and to BMC of the femoral neck (P < 0·05) and lumbar spine, although the latter was just shy of statistical significance (P = 0·058). Systolic blood pressure was negatively related to trochanteric BMD (P = 0·04) and BMC (P = 0·06). Ca intake was positively related to total body BMD (P = 0·005), and BMC of the lumbar spine (P = 0·05). In this population of men, Ca intake was a positive predictor, and blood pressure was a negative predictor of regional measures of bone mass. These findings support the concept that independent of age, BMI and Ca intake, elevated blood pressure varies indirectly with bone mass and density, known predictors of osteoporotic fractures. Future studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass, and what role dietary Ca plays in that pathway.

Synthetic MRI of the lumbar spine at 3.0 T: feasibility and image quality comparison with conventional MRI

2019 ◽  
Vol 61 (4) ◽  
pp. 461-470
Author(s):  
Weilan Zhang ◽  
Jingyi Zhu ◽  
Xiaohan Xu ◽  
Guoguang Fan
Keyword(s):  
Lumbar Spine ◽  
Image Quality ◽  
Acquisition Time ◽  
Conventional Mri ◽  
Spinal Lesions ◽  
Spine Imaging ◽  
3.0 T ◽  
Magnetic Resonance Imaging Mri ◽  
Quality Assessments ◽  
Synthetic Mri

Background Synthetic magnetic resonance imaging (MRI), which can generate multiple morphologic MR images as well as quantitative maps from a single sequence, is not widely used in the spine at 3.0 T. Purpose To investigate the feasibility of synthetic MRI of the lumbar spine in clinical practice at 3.0 T. Material and Methods Eighty-four patients with lumbar diseases underwent conventional T1-weighted images, T2-weighted images, short-tau inversion recovery (STIR) images, and synthetic MRI of the lumbar spine at 3.0 T. The quantitative and qualitative image quality and agreement for detection of spinal lesions between conventional and synthetic MRI were compared by two radiologists. Results The signal-to-noise ratios of synthetic MRI showed an inferior image quality in the vertebrae and disc, whereas were higher for spinal canal and fat on the synthetic T1-weighted, T2-weighted, and STIR images. The contrast-to-noise ratios of the synthetic MRI was superior to conventional sequences, except for the vertebrae–disc contrast-to-noise ratio on T1-weighted imaging ( P =  0.005). Image quality assessments showed that synthetic MRI had greater STIR fat suppression ( P <  0.001) and fluid brightness ( P =  0.014), as well as higher degree of artifacts ( P <  0.001) and worse spatial resolution ( P =  0.002). The inter-method agreements for detection of spinal lesions were substantial to perfect (kappa, 0.614–0.925). Conclusion Synthetic MRI is a feasible method for lumbar spine imaging in a clinical setting at 3.0-T MR. It provides morphologic sequences with acceptable image quality, good agreement with conventional MRI for detection of spinal lesions and quantitative image maps with a slightly shorter acquisition time compared with conventional MRI.

Portable and Rapid In Vivo Imaging of Tissue Oxygenation Changes Induced by Skin Perfusion Pressure

2019 ◽  
Vol 42 ◽  
pp. 59-66 ◽  
Author(s):  
Audrey Huong ◽  
Xavier Ngu
Keyword(s):  
Vascular Reactivity ◽  
Imaging System ◽  
Statistical Significance ◽  
Systolic Pressure ◽  
Improve Patient Care ◽  
Healthcare Management ◽  
Oxygen Saturation Level ◽  
Healthy Humans ◽  
Time Required

Current imaging systems available in the study of tissue hemodynamics and vascular reactivity are typically complex and bulky, hence limiting their applications to laboratory use. The aim of this study is to present the dynamics of skin oxygen level with changes in the microcirculatory perfusion monitored using a developed field portable, handheld tri-wavelength imaging system. The skin oxygen saturation level (StO2) was measured in-vivo in a span of 12 minutes in the ventral forearm of seven healthy humans at rest, before and after supra-diastolic and supra-systolic pressure inflations. The findings of this work showed statistical significance in the difference between the mean StO2 values in baseline and that following ischemic episodes with ρ ≤ 0.03. The values returned to baseline, although of different magnitude for each individual, within 2 min (ρ =0.217) during reperfusion could suggest the time required for the resume of normal autoregulation mechanisms and vasomotion reactivities in the recruits. This study concluded that the developed imaging system could find potential application in self-healthcare management and may help to improve patient care in remote or rural locations.

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