scholarly journals Correlation Between Lung Density Changes Under Different Dose Gradients and Radiation Pneumonitis—Based on an Analysis of Computed Tomography Scans During Esophageal Cancer Radiotherapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Feng Du ◽  
Hong Liu ◽  
Wei Wang ◽  
Yingjie Zhang ◽  
Jianbin Li
Keyword(s):  
Computed Tomography ◽  
Esophageal Cancer ◽  
Radiation Dose ◽  
Correlation Coefficient ◽  
Radiation Pneumonitis ◽  
Regression Coefficient ◽  
Lung Density ◽  
Occurrence Time ◽  
Planning Ct ◽  
Different Doses

PurposeTo assess the relationship between different doses of radiation and lung density changes and to determine the ability of this correlation to identify esophageal cancer (EC) patients who develop radiation pneumonitis (RP) and the occurrence time of RP.MethodsA planning computed tomography (CT) scan and a re-planning CT scan were retrospectively collected under institutional review board approval for each of 103 thoracic segment EC patients who underwent radiotherapy (RT). The isodose curve was established on the planning CT with an interval of 5 Gy, which was used as the standard for dividing different gradient doses. Planning CT and re-planning CT scans were matched and the mean lung CT value (HU) between different doses gradients was automatically obtained by the software system. The density change value (ΔHU) was the difference of CT value between each dose gradient before and after treatment. The correlation between ΔHU and the corresponding dose was calculated, as well as the regression coefficients. Additionally the correlation between ΔHU and the occurrence and time of RP (< 4 weeks, 4–12 weeks, > 12 weeks) was calculated.ResultsThe radiation dose and ΔHU was positively correlated, but the correlation coefficient and regression coefficient were lower, 0.261 (P <0.001) and 0.127 (P <0.001), respectively. With the increase of radiation dose gradient, ΔHU in RP≥2 group was higher than that in RP<2 group, and there was significant difference between two groups in ΔHU20-25, ΔHU25-30, ΔHU30-35, ΔHU35-40, ΔHU40-45, ΔHU45-50 (p<0.05). The occurrence time of RP was negatively correlated with the degree of ΔHU (P<0.05), with a high correlation coefficient (Y = week actual value −0.521, P < 0.001) (Y = week grade value −0.381, P = 0.004) and regression coefficient (Y = week actual value −0.503, P<0.001) (Y = week rating value −0.401, P=0.002).ConclusionsA relationship between radiation dose and lung density changes was observed. For most dose intervals, there was an increase of ΔHU with an increased radiation dose, although low correlation coefficient. ΔHU were obvious after irradiation with dose ≥20 Gy which was closely related to the occurrence of RP. For patients with RP, the more obvious ΔHU, the earlier the occurrence of RP, there was a significant negative correlation between them.

scholarly journals Intra- and inter-rater reliability in a comparative study of cross-sectional and spiral computed tomography pelvimetry methods

2019 ◽  
Vol 8 (6) ◽  
pp. 205846011985518 ◽  
Author(s):  
Erika Phexell ◽  
Anna Åkesson ◽  
Marcus Söderberg ◽  
Anetta Bolejko
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Confidence Interval ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Measurement Reliability ◽  
Cross Sectional ◽  
Rater Reliability ◽  
Short Spiral

Background Different low-dose computed tomography (CT) pelvimetry methods can be used to evaluate the size of birth canal before delivery. CT pelvimetry might generate an acceptable low fetal radiation dose but its measurement accuracy is unknown. Purpose To investigate intra- and inter-rater measurement reliability of cross-sectional and two spiral CT pelvimetry methods: standard spiral and short spiral. Material and Methods Ten individuals (age ≥60 years, body mass index ≥30 kg/m2) having a CT scan of the abdomen also had CT pelvimetry scans. Three radiologists made independent measurements of each pelvimetry method on two occasions and also in consensus for a reference pelvimetry computed from the standard-dose CT scan of the abdomen. Inter- and intra-rater reliability was analyzed by intraclass correlation coefficient. Results Measurements in the short spiral pelvimetry demonstrated excellent intra- and inter-rater reliability, intraclass correlation coefficient ≥0.93, and good to excellent 95% confidence interval 0.87–0.99. Corresponding results of the standard spiral and cross-sectional pelvimetry showed good to excellent intraclass correlation coefficient ≥0.85 and ≥0.76, and 95% confidence interval was least good and moderate 0.73–0.98 and 0.59–0.97, respectively. Intraclass correlation coefficient between reference pelvimetry and other CT methods showed analogous results. Conclusion The short spiral pelvimetry demonstrated high and best reliability in comparison to other methods. Standard spiral method showed also good measurement reliability but the short spiral pelvimetry generates lower fetal radiation dose. This method might be suitable for measurements at narrow pelvis. Patient acceptance and attitude to CT pelvimetry should be investigated.

Acute Pulmonary Oxygen Toxicity in Rats: Findings and Lung Density Changes in High Resolution Computed Tomography

2000 ◽  
Vol 42 (3) ◽  
pp. 473
Author(s):  
Dae Sik Ryu ◽  
Kun Sang Kim ◽  
Kil Hyen Kang ◽  
Haing Sup Chung ◽  
Bung Wok Lee ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Oxygen Toxicity ◽  
High Resolution Computed Tomography ◽  
Lung Density

Measurement of Lung Density by Computed Tomography

1978 ◽  
Vol 2 (3) ◽  
pp. 263-273 ◽  
Author(s):  
O. H. Wegener ◽  
P. Koeppe ◽  
H. Oeser
Keyword(s):  
Computed Tomography ◽  
Lung Density

scholarly journals Radiation dose estimation for pencil beam X-ray luminescence computed tomography imaging

2021 ◽  
pp. 1-12
Author(s):  
Ignacio O. Romero ◽  
Changqing Li
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Small Animal ◽  
Pencil Beam ◽  
Computed Tomography Imaging ◽  
Step Size ◽  
Imaging Protocol ◽  
X Ray ◽  
Beam Geometry ◽  
Muscle Tissues

BACKGROUND: Pencil beam X-ray luminescence computed tomography (XLCT) imaging provides superior spatial resolution than other imaging geometries like sheet beam and cone beam geometries. However, the pencil beam geometry suffers from long scan times, resulting in concerns overdose which discourages the use of pencil beam XLCT. OBJECTIVE: The dose deposited in pencil beam XLCT imaging was investigated to estimate the dose from one angular projection scan with three different X-ray sources. The dose deposited in a typical small animal XLCT imaging was investigated. METHODS: A Monte Carlo simulation platform, GATE (Geant4 Application for Tomographic Emission) was used to estimate the dose from one angular projection scan of a mouse leg model with three different X-ray sources. Dose estimations from a six angular projection scan by three different X-ray source energies were performed in GATE on a mouse trunk model composed of muscle, spine bone, and a tumor. RESULTS: With the Sigray source, the bone marrow of mouse leg was estimated to have a radiation dose of 44 mGy for a typical XLCT imaging with six angular projections, a scan step size of 100 micrometers, and 106 X-ray photons per linear scan. With the Sigray X-ray source and the typical XLCT scanning parameters, we estimated the dose of spine bone, muscle tissues, and tumor structures of the mouse trunk were 38.49 mGy, 15.07 mGy, and 16.87 mGy, respectively. CONCLUSION: Our results indicate that an X-ray benchtop source (like the X-ray source from Sigray Inc.) with high brilliance and quasi-monochromatic properties can reduce dose concerns with the pencil beam geometry. Findings of this work can be applicable to other imaging modalities like X-ray fluorescence computed tomography if the imaging protocol consists of the pencil beam geometry.

scholarly journals Interrelationships of body weight and bone weight with densitometric properties of tibiotarsal bone in geese during post-hatching development

2017 ◽  
Vol 60 (No. 12) ◽  
pp. 682-690
Author(s):  
A. Charuta ◽  
MR Tatara ◽  
M. Dzierzecka ◽  
E. Polawska ◽  
I. Ptaszynska-Sarosiek
Keyword(s):  
Computed Tomography ◽  
Body Weight ◽  
Correlation Coefficient ◽  
Quantitative Computed Tomography ◽  
Peripheral Quantitative Computed Tomography ◽  
Dual Energy ◽  
X Ray ◽  
Males And Females ◽  
Different Parts

The aim of this study was to evaluate interrelationships of body weight and bone weight and densitometric properties of the tibiotarsus in White Koluda Geese (W31) in the post-hatching period. The study was performed using dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT) at two different parts of tibia: proximal metaphysis and mid-diaphysis. The investigation was performed on 100 bones obtained from males and females at the age of 1, 14, 28, 42 and 56 days of life. All the calculations were performed using the Statistica 9.0 software (StatSoft, Inc. Tulsa, USA). Pearson’s correlation coefficient of body weight and bone weight with all the investigated variables of bone was determined. Depending on the method used for densitometric measurements – DEXA or pQCT, the current study has revealed significant differences in the number of correlations of bone weight and body weight with the evaluated densitometric parameters. Sex-related differences in the investigated interrelationships were also found. In the case of proximal epiphysis, negative correlations of vBMD, tBMC, CTR_DEN and CRT_CNT with body weight and bone weight dominated in one-day-old males. Based on the current observations and the negative correlations of body weight and vBMD, CRT_DEN and TRAB_DEN obtained in the mid-diaphysis of tibiotarsus at the age of 14 days of life, it was concluded that this bone is much more prone to deformations and fractures in males than in females.

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