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.
X-ray attenuation coefficient of mixtures: Inputs for dual-energy CT
Rent:
Rent this article for
USD
10.1118/1.3626572
/content/aapm/journal/medphys/38/10/10.1118/1.3626572
http://aip.metastore.ingenta.com/content/aapm/journal/medphys/38/10/10.1118/1.3626572

Figures

Image of FIG. 1.
FIG. 1.

X-ray spectrum S(E,V) as obtained by the Boone, Seibert (Ref. 11) formula. The X-axis denotes the energy of the photon, expressed in keV, while the Y-axis denotes the number of photons discharged by the x-ray tube.

Image of FIG. 2.
FIG. 2.

A lateral view of the phantom.

Image of FIG. 3.
FIG. 3.

The log[R(E, E 0:Z eff)] versus log(E) plot, where E is in keV and E 0 = 8 keV. The mass attenuation coefficient data from the NIST tables are correct up to 4 significant digits. This gives an error of only 0.1% in the values of log[R(E, E 0:Z eff)], which are plotted in the curve but cannot be seen.

Image of FIG. 4.
FIG. 4.

The Klein–Nishina coefficient fKN (E) versus energy.

Image of FIG. 5.
FIG. 5.

Comparison of the NIST data on the attenuation coefficient of water at different energies with those calculated for y = 3.0669 is the 8–80 keV fit and y = 2.8893 is the 8–150 keV fit.

Image of FIG. 6.
FIG. 6.

Concentration in weight by weight percentage versus density in gm/cm3 for different solutions.

Image of FIG. 7.
FIG. 7.

Top, CT images of distilled water in the test tube of the phantom for scanning at (a) 80 kVp, (b) 120 kVp, and (c) 140 kVp. Middle row, scan of 10% weight/weight aqueous solution of HCl, in the test tube of the phantom for scanning at (d) 80 kVp, (e) 120 kVp, and (f) 140 kVp. Bottom row, scan of 25% weight/weight aqueous solution of HCl, in the test tube of the phantom for scanning at (g) 80 kVp, (h) 120 kVp, and (i) 140 kVp. The first row data for water considered as HU0 and were used to calculate the HU corrected by using HU corrected = HU observedHU 0 where HU observed is the HU values of HCl in the 2nd and 3rd rows.

Image of FIG. 8.
FIG. 8.

The HU corrected ( = HU observed − HU 0) values of HCl solution being compared with the ones calculated by using x fixed at x  =  2.5672, i.e., the x value for water.

Tables

Generic image for table
TABLE I.

Calculated and standard values (Ref. 8) of effective atomic number and electron density (number of electrons per unit mass) of various substances.

Generic image for table
TABLE II.

Calculated values of mass attenuation coefficient (Cal. μ(E)/ρ in cm2/gm), as calculated from Eq. (11) with x = 2.5672 (the average value of x for water) at energy E, for different substances, and comparison with standard mass attenuation coefficient (Stn. μ(E)/ρ in cm2/gm) data from NIST tables. The quantity x match shows the value of x for which the mass attenuation coefficient value, obtained from Eq. (11) matches with the NIST values.

Generic image for table
TABLE III.

Comparison between the observed and the calculated values of mass attenuation coefficient ((/ρ)observed, (/ρ)calculated, respectively) of HNO3 for different concentrations, at 80 kVp.

Generic image for table
TABLE IV.

Values of x match for different concentrations (Conc.) HNO3 solutions, corresponding to observations at 80, 120, and 140 kVp. The parameter x match denotes the value of x for which the calculated HU value matches with the observed value of HU. (ρe and Z eff represent electron density and effective atomic number, respectively).

Generic image for table
TABLE V.

Values of x match for different concentrations (Conc.) KOH solutions, corresponding to observations at 80, 120, and 140 kVp. The parameter x match denotes the value of x for which the calculated HU value matches with the observed value of HU. (ρe and Z eff represent electron density and effective atomic number, respectively).

Generic image for table
TABLE VI.

Values of x match for different concentrations (Conc.) HCl solutions, corresponding to observations at 80, 120, and 140 kVp. The parameter x match denotes the value of x for which the calculated HU value matches with the observed value of HU. (ρe and Z eff represent electron density and effective atomic number, respectively).

Loading

Article metrics loading...

/content/aapm/journal/medphys/38/10/10.1118/1.3626572
2011-09-09
2014-04-19
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: X-ray attenuation coefficient of mixtures: Inputs for dual-energy CT
http://aip.metastore.ingenta.com/content/aapm/journal/medphys/38/10/10.1118/1.3626572
10.1118/1.3626572
SEARCH_EXPAND_ITEM