PedCAT for 3D-imaging in standing position allows for more accurate bone position (angle) measurement than radiographs or CT

2014 ◽  
Vol 20 (3) ◽  
pp. 201-207 ◽  
Author(s):  
Martinus Richter ◽  
Bernd Seidl ◽  
Stefan Zech ◽  
Sarah Hahn
Keyword(s):  
3D Imaging ◽  
Position Angle ◽  
Standing Position ◽  
Angle Measurement

scholarly journals Semi-automatic Software-based 3D-Angular Measurement For Weight-Bearing CT (WBCT) is 97% Faster than Measurement by Hand and Provides Similar Angles

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0040
Author(s):  
Martinus Richter ◽  
Stefan Zech ◽  
Stefan A. Meissner ◽  
Issam Naef
Keyword(s):  
Weight Bearing ◽  
Position Angle ◽  
3D Models ◽  
Standing Position ◽  
Angle Measurement ◽  
Angular Measurement ◽  
Total Process ◽  
Automatic Software ◽  
Haglund Deformity ◽  
Conventional Ct

Category: Basic Sciences/Biologics Introduction/Purpose: Weight-bearing CT (WBCT) has been proven to allow for more precise and valid measurement of bone position (angles) than conventional weight-bearing radiographs (R) and conventional CT without weight-bearing (CT)1. The measurement by hand (MBH) has demonstrated adequate inter- and intraobserver reliability but high time consumption1. Recently, a semi-automatic software-based angular measurement (SAM) has been developed (Disior Ltd, Helsinki, Finland). The purpose of this study was to compare SAM with MBH regarding angles values and time spent for the investigator. Methods: Fifteen bilateral WBCT scans (PedCAT, Curvebeam, Warrington, PA, USA) were randomly extracted from a local institutional database with more than 13,000 scans. Nineteen angles as shown in table 1 were measured with MBH as previously described and with SAM1. SAM includes software generated 3D models with semi-automatic bone specification of tibia, fibula, talus, calcaneus, navicular, cuboid, cuneiforms and metatarsals. The software automatically defines the longitudinal axes of these bones and automatically measures the angles between these axes. The time spent of the investigator for the measurements was recorded (total process MBH and specification of bones for SAM). The software calculation time for SAM was not measured or considered as investigator time spent. The angles and time spent of MBH and SAM were compared (t-test, homoscedatic). Results: Mean age of the subject was 58 years (range, 7-81), 12 (40%) were male. The pathologies were bilateral in 8 (54%), right in 4 (27%) and left in 3 (20%) subjects (23 feet in total) and were specified as follows, ankle osteoarthritis/instability in 6 (26%), Haglund deformity/Achillodynia in 4 (17%), Forefoot deformity in 7 (30%), Charcot arthropathy in 2 (9%), flatfoot in 4 (17%) feet. The angles did not differ between MBH and SAM (Table 1, each p>.05). The time spent for MBH / SAM was 780+-171s / 20+-8 s on average in total for 19 angles and 41+-9s / 1+-0.4 s per angle (p<.01). Conclusion: This is the first study comparing MBH with SAM. SAM shows similar angles as MBH and can be also considered as reliable measurement option. The investigator time spent is 97% lower for SAM (1 s per angle) than for MBH (41 s per angle). SAM is an important step forward for 3D-angle measurement of WBCT. The next desired is fully automatic software-based measurement. References1. Richter M, Seidl B, Zech S, Hahn S. PedCAT for 3D-Imaging in Standing Position Allows for More Accurate Bone Position (Angle) Measurement than Radiographs or CT. Foot Ankle Surg 2014;20:201-7. [Table: see text]

scholarly journals PedCAT for Radiographic 3D-Imaging in standing position

2015 ◽  
Vol 13 (2) ◽  
pp. 85-102 ◽  
Author(s):  
Martinus Richter ◽  
Stefan Zech ◽  
Sarah Hahn
Keyword(s):  
3D Imaging ◽  
Standing Position

Frontomaxillary Facial Angle Measurement at 11-14 Weeks: Assessment of Interobserver and Intraobserver Agreement in 2D and 3D Imaging

2013 ◽  
Vol 34 (2) ◽  
pp. 90-95 ◽  
Author(s):  
Jennifer Alphonse ◽  
Jenny Cox ◽  
Jillian L. Clarke ◽  
Catherine L. Robinson ◽  
Philip J. Schluter ◽  
...  
Keyword(s):  
3D Imaging ◽  
Angle Measurement ◽  
Intraobserver Agreement ◽  
2D And 3D

scholarly journals Absolute Quadrant Determinations from Speckle Observations of Binary Stars

1992 ◽  
Vol 135 ◽  
pp. 536-536
Author(s):  
W.G. Bagnuolo ◽  
B.D. Mason ◽  
D.J. Barry ◽  
W.I. Hartkopf ◽  
H.A. McAlister
Keyword(s):  
Power Spectrum ◽  
Real Time ◽  
Binary Stars ◽  
Position Angle ◽  
Angle Measurement

AbstractReduction of speckle data obtained for binary stars is typically carried out using power spectrum or, equivalently, autocorrelation methods. An especially powerful algorithm from which accuate differential astronomy can be obtained is the vector autocorrelation technique. While such methods are highly suited to extracting astrometric information from very large volumes of speckle data in near real–time, they inherently introduce a 180° ambiguity in position angle measurement. We briefly summarize results with a new algorithm which maintains most of the simplicity of vector autocorrelation while removing the quadrant ambiguity.

scholarly journals Supine fulcrum bending test and in-cast correction of Scheuermann juvenile kyphosis

2019 ◽  
Vol 5 (2) ◽  
pp. 206
Author(s):  
Piotr Janusz ◽  
Wioleta Ostiak-Tomaszewska ◽  
Mateusz Kozinoga ◽  
Tomasz Kotwicki
Keyword(s):  
Cobb Angle ◽  
Lumbar Lordosis ◽  
Standing Position ◽  
Angle Measurement ◽  
Bending Test ◽  
Lateral Radiograph ◽  
Kyphosis Angle ◽  
Scheuermann Disease ◽  
Cobb Angle Measurement ◽  
The Mean

<p class="abstract"><strong>Background:</strong> Patients with Scheuermann disease often require conservative management with a series of corrective casts, followed by anti-kyphotic brace. Flexibility of the kyphosis can be assessed during a supine fulcrum bending test. The aim of the study was to analyze the radiological flexibility of kyphosis and immediate in-cast correction in a series of patients conservatively treated.</p><p class="abstract"><strong>Methods:</strong> Eighty-six adolescents were conservatively treated for Scheuermann disease of thoracic location. Charts of 55 patients, 39 boys and 16 girls, were accessible. The mean age was 14.6±1.6 years. On the lateral full-cassette standing radiograph, the angle of thoracic and lumbar lordosis were measured. The flexibility of kyphosis was assessed on a supine fulcrum bending lateral radiograph. The in-cast kyphosis angle was measured on a standing lateral radiograph.<strong></strong></p><p class="abstract"><strong>Results:</strong> In 18 patients, a mild non-progressive scoliotic curvature was present; it did not exceed a Cobb angle measurement of 25°. The initial kyphosis angle was 59.2°±9.3°. The lordosis angle was 76.3°±9.3°. The kyphosis angle on supine fulcrum bending test was 30.4°±9.7°. The kyphosis angle in the reclining cast was 44.3°±12.5°. There was no correlation between age and the supine bending correction. There was a correlation between the correction obtained with the supine bending test and the immediate correction in the cast (r=0.64, p=0.0012).</p><p class="abstract"><strong>Conclusions:</strong> The reduction of the kyphosis Cobb angle by supine fulcrum bending was 50% on average, while in the cast in standing position, only half of this correction was maintained.</p>

scholarly journals Effect of Body Positions on Quadriceps Angle Measurement

2019 ◽  
Vol 1 (1) ◽  
pp. 20-24
Author(s):  
Swati Paranjape ◽  
Nikita Singhania
Keyword(s):  
Supine Position ◽  
Body Position ◽  
Weight Bearing ◽  
Muscle Mechanics ◽  
Sports Participation ◽  
Standing Position ◽  
Angle Measurement ◽  
Cross Sectional ◽  
Q Angle ◽  
Important Measurement

Background: Quadriceps angle or Q angle is an index of the vector for the combined pull of extensor mechanisms and patellar tendon. It is a clinical measurement for knee and patella alignment. It is not a static but rather a dynamic consequence to the muscle mechanics, leg loading, and foot and leg position. Therefore in present study we assessed whether change of body position i.e. standing and supine position affects the Q angle measurement. Aims and Objectives: Present study aimed at finding whether there are any variations in Q angle in standing and supine position. Objectives of the study were to measure Q angle in supine position and standing position. We intended to assess the variations in the Q angle with change of body position. Methods: In this cross sectional analytical study, we assessed female participants between age group of 18-25 years, in supine and standing position, Q angle was measured in both the positions. Sample size was 100. Results: The results showed statistically significant increase in Q angle in standing position as compared with the supine position (p <0.0001) (C.I.  1.720 to 3.140). Conclusion: There was statistically significant increase in the Q angle measurement in standing as compared with the measurements in supine. Measuring the Q angle is concerned with assessing the knee functions during daily activities and sports participation, therefore assessing this important measurement not only in supine but also in a weight-bearing functional position in clinical setups would be helpful.

Design and calibration of an IVEM for general 3-dimensional imaging of non-diffracting materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1040-1041
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  
Keyword(s):  
3D Imaging ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3 Dimensional ◽  
3D Microstructure ◽  
Image Translation ◽  
Digital Correlation ◽  
On Line ◽  
Mechanical Stage ◽  
Projection Angle

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).

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