Relationship between specific organ doses and volumetric CT dose indices in multidetector CT studies

2011 ◽  
Vol 55 (5) ◽  
pp. 493-497 ◽  
Author(s):  
Kosuke Matsubara ◽  
Kichiro Koshida ◽  
Kimiya Noto ◽  
Tetsunori Shimono ◽  
Tomoyuki Yamamoto ◽  
...  
Keyword(s):  
Multidetector Ct ◽  
Organ Doses ◽  
Ct Dose ◽  
Specific Organ ◽  
Volumetric Ct ◽  
Ct Studies

ORGAN ABSORBED DOSE ESTIMATION REFLECTING SPECIFIC ORGAN MASSES WITH SIMPLE SCALING OF REFERENCE DOSES USING THE ORGAN MASSES

2020 ◽  
Vol 189 (4) ◽  
pp. 489-496
Author(s):  
Kentaro Manabe ◽  
Shuji Koyama
Keyword(s):  
Absorbed Dose ◽  
Organ Dose ◽  
Wide Distribution ◽  
Organ Doses ◽  
Organ Mass ◽  
Red Marrow ◽  
Straightforward Method ◽  
Simple Scaling ◽  
Specific Organ ◽  
Reference Doses

Abstract Estimating organ absorbed doses in consideration of person-specific parameters is important for radiation protection in diagnostic nuclear medicine. This study proposes a straightforward method for estimating the organ dose that reflects a specific organ mass by scaling the reference organ dose using the inverse ratio of the specific organ mass to the reference organ mass. For the administration of radiopharmaceuticals labelled by 99mTc or 123I, the organ doses for the liver, spleen, red marrow and thyroid obtained by the method were compared with those generated by a Monte Carlo simulation. The discrepancies were less than 14% for the liver, spleen and thyroid. Conversely, in some cases, the red marrow discrepancies were greater than 30% due to the wide distribution of red marrow in the trunk and head regions. This study confirms that the method of scaling organ doses can be effective for estimating mass-specific doses for solid organs.

CT dosimetry at the Australian Synchrotron for 25–100 keV photons and 35–160 mm-diameter biological specimens

2019 ◽  
Vol 26 (2) ◽  
pp. 517-527
Author(s):  
Stewart Midgley ◽  
Nanette Schleich ◽  
Alex Merchant ◽  
Andrew Stevenson
Keyword(s):  
Effective Dose ◽  
Beam Quality ◽  
Absorbed Dose ◽  
Body Region ◽  
Average Dose ◽  
Dose Length Product ◽  
Organ Doses ◽  
Ct Dose ◽  
Radiation Output ◽  
Ct Dosimetry

The dose length product (DLP) method for medical computed tomography (CT) dosimetry is applied on the Australian Synchrotron Imaging and Medical Beamline (IMBL). Beam quality is assessed from copper transmission measurements using image receptors, finding near 100% (20 keV), 3.3% (25 keV) and 0.5% (30–40 keV) relative contributions from third-harmonic radiation. The flat-panel-array medical image receptor is found to have a non-linear dose response curve. The amount of radiation delivered during an axial CT scan is measured as the dose in air alone, and inside cylindrical PMMA phantoms with diameters 35–160 mm for mono-energetic radiation 25–100 keV. The radiation output rate for the IMBL is comparable with that used for medical CT. Results are presented as the ratios of CT dose indices (CTDI) inside phantoms to in air with no phantom. Ratios are compared for the IMBL against medical CT where bow-tie filters shape the beam profile to reduce the absorbed dose to surface organs. CTDI ratios scale measurements in air to estimate the volumetric CTDI representing the average dose per unit length, and the dose length product representing the absorbed dose to the scanned volume. Medical CT dose calculators use the DLP, beam quality, axial collimation and helical pitch to estimate organ doses and the effective dose. The effective dose per unit DLP for medical CT is presented as a function of body region, beam energy and sample sizes from neonate to adult.

SU-FF-I-25: Feasibility of Estimating Multidetector CT Dose Using BEAMnrc Code

2007 ◽  
Vol 34 (6Part3) ◽  
pp. 2343-2343
Author(s):  
C C Chiang-Hsieh ◽  
Hui-Yu Tsai ◽  
C J Tung
Keyword(s):  
Multidetector Ct ◽  
Ct Dose ◽  
Beamnrc Code

The three sisters:multidetector computed tomography and 3D reconstructions of three sister mummies from the Egyptian Museum of Turin

2005 ◽  
Vol 80 (1) ◽  
Author(s):  
Federico Cesarani ◽  
Maria Cristina Martina ◽  
Rosa Boano ◽  
Anna Maria Donadoni Roveri ◽  
Andrea Ferraris ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Multidetector Ct ◽  
Whole Body ◽  
3D Reconstructions ◽  
Whole Body Ct ◽  
Foreign Objects ◽  
Thin Slices ◽  
Similarities And Differences ◽  
Three Sisters ◽  
Ct Studies

The “three sisters” is a particular group of mummies from the Drovetti collection of the Egyptian Museum in Turin. They were purchased in 1824 by King Carlo Felice of Savoy for the new Museum. The mummies come from the area of Tebe in Upper Egypt. Their names are Tapeni (CGT 13002–Cat. 2215), Tamiu (CGT 13003–Cat. 2218), and Renpetnefert (CGT 13007–Cat.2231). They were evaluated the same day with multidetector CT (GE Light Speed Qx/I). In all three cases whole body CT helical acquisition with thin slices (2.5 mm thickness, 1.25 mm reconstruction interval) followed by multiplanar and 3D reconstructions were performed. Stature, anthropometric measurements, sex, and approximate age, were estimated. Also embalming techniques, condition of the skeleton and of the soft tissues, and the presence of foreign objects were analyzed. The similarities and differences of embalming methods were also evaluated. To our knowledge, there are no other reports of CT studies on mummies belonging to the same family. We believe these results are of particular interest for archaeology and computed imaging technology.

Radiation dose from multidetector CT studies in children: results from the first Italian nationwide survey

2014 ◽  
Vol 45 (5) ◽  
pp. 695-705 ◽  
Author(s):  
Claudio Granata ◽  
Daniela Origgi ◽  
Federica Palorini ◽  
Domenica Matranga ◽  
Sergio Salerno
Keyword(s):  
Radiation Dose ◽  
Multidetector Ct ◽  
Nationwide Survey ◽  
Ct Studies

Cone beam CT paranasal sinuses versus standard multidetector and low dose multidetector CT studies

2016 ◽  
Vol 37 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Janan Al Abduwani ◽  
Laura ZilinSkiene ◽  
Steve Colley ◽  
Shahzada Ahmed
Keyword(s):  
Paranasal Sinuses ◽  
Low Dose ◽  
Multidetector Ct ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Ct Studies

Organ doses can be estimated from the computed tomography (CT) dose index for cone-beam CT on radiotherapy equipment

2016 ◽  
Vol 36 (2) ◽  
pp. 215-229 ◽  
Author(s):  
Colin J Martin ◽  
Abdullah Abuhaimed ◽  
Marimuthu Sankaralingam ◽  
Mohamed Metwaly ◽  
David J Gentle
Keyword(s):  
Computed Tomography ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Organ Doses ◽  
Ct Dose ◽  
Ct Dose Index ◽  
Dose Index

scholarly journals Organ doses of the fetus from external environmental exposures

2021 ◽  
Vol 60 (1) ◽  
pp. 93-113
Author(s):  
Nina Petoussi-Henss ◽  
Daiki Satoh ◽  
Helmut Schlattl ◽  
Maria Zankl ◽  
Vladimir Spielmann
Keyword(s):  
Monte Carlo ◽  
Dose Rate ◽  
Organ Dose ◽  
Pregnant Female ◽  
Rate Coefficients ◽  
Monte Carlo Code ◽  
Organ Doses ◽  
Organ Equivalent Dose ◽  
Specific Organ ◽  
External Exposures

AbstractThis article presents nuclide-specific organ dose rate coefficients for environmental external exposures due to soil contamination assumed as a planar source at a depth of 0.5 g cm−2 in the soil and submersion to contaminated air, for a pregnant female and its fetus at the 24th week of gestation. Furthermore, air kerma free-in-air coefficient rates are listed. The coefficients relate the organ equivalent dose rates (Sv s−1) to the activity concentration of environmental sources, in Bq m−2 or Bq m−3, allowing to time-integrate over a particular exposure period. The environmental radiation fields were simulated with the Monte Carlo radiation transport codes PHITS and YURI. Monoenergetic organ dose rate coefficients were calculated employing the Monte Carlo code EGSnrc simulating the photon transport in the voxel phantom of a pregnant female and fetus. Photons of initial energies of 0.015–10 MeV were considered including bremsstrahlung. By folding the monoenergetic dose coefficients with the nuclide decay data, nuclide-specific organ doses were obtained. The results of this work can be employed for estimating the doses from external exposures to pregnant women and their fetus, until more precise data are available which include coefficients obtained for phantoms at different stages of pregnancy.

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