1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Physical characteristics of a low-dose gas microstrip detector for orthopedic x-ray imaging
Rent:
Rent this article for
USD
10.1118/1.1876592
/content/aapm/journal/medphys/32/4/10.1118/1.1876592
http://aip.metastore.ingenta.com/content/aapm/journal/medphys/32/4/10.1118/1.1876592

Figures

Image of FIG. 1.
FIG. 1.

Detection geometry of the EOS system. The strips’ projections point to the x-ray tube focal spot. Photons enter through a collimation slit and a window (not shown).

Image of FIG. 2.
FIG. 2.

Fraction of total energy converted by each electromagnetic process for different absorbers, for spectra of 50 (RQA 3), 70 (RQA 5), 90 (RQA 7), and (RQA 9). , , and gases are thick at , and are 0.5 and thick, respectively. The attenuation data come from XCOM (Ref. 22).

Image of FIG. 3.
FIG. 3.

Diagram of the EOS device with a virtual patient (Ref. 23). The x-ray tubes and detectors move together. The images are acquired from top to bottom (dashed arrows).

Image of FIG. 4.
FIG. 4.

Human subject images taken simultaneously at with tubes set at (face) and (profile). Subject is wearing a geometric calibration vest. The denser and thicker pelvic region is noisier but the images are nevertheless valid for orthopedic planning or follow-up measurements.

Image of FIG. 5.
FIG. 5.

Computed center of mass coordinates of a circular radio-opaque object for 16 consecutive images.

Image of FIG. 6.
FIG. 6.

Detector response curve for . The linear fit was done with air kerma values less or equal to the limit indicated by the arrow.

Image of FIG. 7.
FIG. 7.

(a) LSF and (b) MTF in the horizontal direction for the 50, 80, and beams.

Image of FIG. 8.
FIG. 8.

(a) LSF and (b) MTF in the vertical direction for the 50, 80, and beams.

Image of FIG. 9.
FIG. 9.

Typical NPS for the EOS system showing anisotropy and ripple artifacts in the vertical directions, computed from a flat-field image taken at , , and . Nonlinear display windowing was applied to magnified low frequency components.

Image of FIG. 10.
FIG. 10.

NPS in the (a) vertical and (b) horizontal direction for . A polynomial was fitted to the highest exposure and scaled according to Eq. (8) to produce (dotted lines).

Image of FIG. 11.
FIG. 11.

Noisy channels can produce vertical line artifacts in images, as shown by arrows here.

Image of FIG. 12.
FIG. 12.

Noise level in function of exposure at . The linear fit zero intercept is 0.06.

Image of FIG. 13.
FIG. 13.

DQE in the (a) vertical and (b) horizontal directions for the beam.

Image of FIG. 14.
FIG. 14.

DQE behavior in function of beam energy in the (a) vertical and (b) horizontal directions, with corrections accounting for the detector’s window absorption.

Tables

Generic image for table
TABLE I.

If Characteristics of the beams used in this work. is the input fluence per air kerma and is the fraction of the exposure that goes through the detector’s entrance window.

Generic image for table
TABLE II.

MTF values for different beam qualities at the IEC mandatory frequencies.

Generic image for table
TABLE III.

The measured and corrected DQE values at the IEC mandatory frequencies.

Loading

Article metrics loading...

/content/aapm/journal/medphys/32/4/10.1118/1.1876592
2005-03-30
2014-04-17
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Physical characteristics of a low-dose gas microstrip detector for orthopedic x-ray imaging
http://aip.metastore.ingenta.com/content/aapm/journal/medphys/32/4/10.1118/1.1876592
10.1118/1.1876592
SEARCH_EXPAND_ITEM