Measurement of lower-leg volume change by quantitative computed tomography

Background: Lower-leg edema is a common symptom in many diseases. A precise method with low variability for measurement of edema is warranted in order to obtain optimal conditions for investigation of treatment effects. Purpose: To evaluate computed tomography for precise measurement of lower-leg muscle and adipose tissue volumes using a very low level of effective radiation dose. Material and Methods: Eleven volunteers were examined three times during 1 day, either as two consecutive examinations in the morning and one single examination in the afternoon, or as one examination in the morning and two in the afternoon. Eleven scans with computed tomography were made at each examination, and lower-leg volumes were calculated from automatically measured scan areas and interscan distances. Volumes for muscle, adipose tissue, and bone were calculated separately. Minimal radiation dose was used. Results: Mean difference between the repeated examinations was −0.1 ml for total volume, −1.4 ml for muscle, and 1.6 ml for adipose tissue volume. The corresponding 95% confidence intervals were −6.5 to 6.0 ml, −3.5 to 6.5 ml, and −7.0 to 4.0 ml, respectively. The resulting effective dose was 0.5 µSv to one leg. Conclusion: Computed tomography can be used as a precise quantitative method to measure small volume changes of the lower leg as a whole, and separately for muscle and adipose tissue. The results were obtained with a negligible effective dose, lower than that delivered by modern fan-beam dual-energy X-ray absorptiometry whole-body examinations and equal to a few hours of background radiation.

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EFFECTS OF THE SCAN RANGE ON RADIATION DOSE IN THE COMPUTED TOMOGRAPHY COMPONENT OF ONCOLOGY POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY

Radiation Protection Dosimetry ◽

10.1093/rpd/ncy210 ◽

2018 ◽

Vol 185 (1) ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Yusuke Inoue ◽

Kazunori Nagahara ◽

Hiroko Kudo ◽

Hiroyasu Itoh

Keyword(s):

Computed Tomography ◽

Positron Emission Tomography ◽

Radiation Dose ◽

Effective Dose ◽

The Body ◽

Emission Tomography ◽

Whole Body ◽

Computed Tomography Images ◽

Positron Emission ◽

Proximal Thigh

Abstract We performed phantom experiments to investigate radiation dose in the computed tomography component of oncology positron emission tomography/computed tomography in relation to the scan range. Computed tomography images of an anthropomorphic whole-body phantom were obtained from the head top to the feet, from the head top to the proximal thigh or from the skull base to the proximal thigh. Automatic exposure control using the posteroanterior and lateral scout images offered reasonable tube current modulation corresponding to the body thickness. However, when the posteroanterior scout alone was used, unexpectedly high current was applied in the head and upper chest. When effective dose was calculated on a region-by-region basis, it did not differ greatly irrespective of the scan range. In contrary, when effective dose was estimated simply by multiplying the scanner-derived dose-length product by a single conversion factor, estimates increased definitely with the scan range, indicating severe overestimation in whole-body imaging.

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Radiation doses in diagnostic imaging for suspected physical abuse

Archives of Disease in Childhood ◽

10.1136/archdischild-2018-316286 ◽

2019 ◽

Vol 104 (9) ◽

pp. 863-868 ◽

Cited By ~ 5

Author(s):

Raylene Rao ◽

Diana Browne ◽

Brian Lunt ◽

David Perry ◽

Peter Reed ◽

...

Keyword(s):

Radiation Dose ◽

Effective Dose ◽

Physical Abuse ◽

Background Radiation ◽

Imaging Techniques ◽

Bone Imaging ◽

Effective Radiation Dose ◽

Ct Head ◽

Contrast Ct ◽

Effective Radiation

ObjectiveTo measure the actual radiation dose delivered by imaging techniques commonly used in the radiography of suspected physical abuse and to make this information available to health professionals and families.MethodsData were collected retrospectively on children under 3 years referred for skeletal surveys for suspected physical abuse, non-contrast CT head scan or radionuclide imaging of the bones in Starship Children’s Hospital, Auckland, New Zealand from January to December 2015. Patient size-specific conversion coefficients were derived from International Commission on Radiologic Protection tissue weighting factors and used to calculate effective dose.ResultsSeventy-one patients underwent an initial skeletal survey, receiving a mean effective dose of 0.20 mSv (95% CI 0.18 to 0.22). Sixteen patients had a follow-up survey with a mean effective dose of 0.10 mSv (95% CI 0.08 to 0.11). Eighty patients underwent CT head which delivered a mean effective dose of 2.49 mSv (95% CI 2.37 to 2.60). Thirty-nine patients underwent radionuclide bone imaging which delivered a mean effective dose of 2.27 mSv (95% CI 2.11 to 2.43).ConclusionsIn a paediatric centre, skeletal surveys deliver a relatively low effective radiation dose, equivalent to approximately 1 month of background radiation. Non-contrast CT head scan and radionuclide bone imaging deliver similar doses, equivalent to approximately 1 year of background radiation. This information should be considered when gaining informed consent and incorporated in patient education handouts.

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Biological effective dose, cumulative radiation dose, risk of malignancy and mortality rate estimation in adult patients who have a history of cancer and exposed to recurrent computed tomography

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v10i2.585 ◽

2019 ◽

Vol 10 (2) ◽

pp. 1405-1409 ◽

Cited By ~ 1

Author(s):

Amjaad Majeed Hameed ◽

Dergham Majeed Hameed

Keyword(s):

Computed Tomography ◽

Mortality Rate ◽

Radiation Dose ◽

Effective Dose ◽

Cumulative Dose ◽

Primary Tumour ◽

Effective Radiation Dose ◽

Risk Of Malignancy ◽

Cumulative Radiation Dose ◽

Effective Radiation

Computed tomography is commonly used for the initial diagnosis of a tumour to provide information about the stage of cancer & to assess whether the disease is responding to treatment. Leukemia & solid tumour may have developed as a result of exposure to a low dose of diagnostic ionizing radiation so another primary tumour may develop as a result of radiation exposure. We used information in the patient sheet to measure patient effective radiation dose(E) in millisievert (mSv) & calculate cumulative dose by summation of dose over three years, estimated life attributed risk & mortality rate. The results of the current study revealed that from 50 patients 37 (74%) of them were female & 13 (26%) of them were male, age range 23- 80yr, breast cancer was the commonest cause of malignancy follow by lung cancer. Cumulative dose in mSv/yr rang 12-80 mSv, about 43(86%) of our patients exposed to more than 20mSv /yr & 7(14%) of them expose to 20 & less than 20 per year. Collective dose in three years’ range was 35-250 mSv mean 97 ± 37 Estimated radiological effective dose was more than 100 mSv in 22 (44%) per three years & 28(56%) of them had less than 100mSv. Life attributed risk for incidence of cancers was 1:285 -1:40 & mortality rate 0.21%-1.5%. A high percentage of patient 86% with cancer receive high radiation dose annually from CT scan more than considerable safe radiation dose for a worker in this field and 44% of our patient expose to cumulative dose more than 100 mSv per three which is also excess allowed dose for the radiological worker.

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Simulated Radiation Dose Reduction in Whole-Body CT on a 3rd Generation Dual-Source Scanner: An Intraindividual Comparison

Diagnostics ◽

10.3390/diagnostics11010118 ◽

2021 ◽

Vol 11 (1) ◽

pp. 118

Author(s):

Andreas S. Brendlin ◽

Moritz T. Winkelmann ◽

Phuong Linh Do ◽

Vincent Schwarze ◽

Felix Peisen ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Dose Reduction ◽

Whole Body ◽

Reference Standard ◽

Diagnostic Confidence ◽

Effective Radiation Dose ◽

Intraindividual Comparison ◽

Dual Source ◽

Effective Radiation

To evaluate the effect of radiation dose reduction on image quality and diagnostic confidence in contrast-enhanced whole-body computed tomography (WBCT) staging. We randomly selected March 2016 for retrospective inclusion of 18 consecutive patients (14 female, 60 ± 15 years) with clinically indicated WBCT staging on the same 3rd generation dual-source CT. Using low-dose simulations, we created data sets with 100, 80, 60, 40, and 20% of the original radiation dose. Each set was reconstructed using filtered back projection (FBP) and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 1–5, resulting in 540 datasets total. ADMIRE 2 was the reference standard for intraindividual comparison. The effective radiation dose was calculated using commercially available software. For comparison of objective image quality, noise assessments of subcutaneous adipose tissue regions were performed automatically using the software. Three radiologists blinded to the study evaluated image quality and diagnostic confidence independently on an equidistant 5-point Likert scale (1 = poor to 5 = excellent). At 100%, the effective radiation dose in our population was 13.3 ± 9.1 mSv. At 20% radiation dose, it was possible to obtain comparably low noise levels when using ADMIRE 5 (p = 1.000, r = 0.29). We identified ADMIRE 3 at 40% radiation dose (5.3 ± 3.6 mSv) as the lowest achievable radiation dose with image quality and diagnostic confidence equal to our reference standard (p = 1.000, r > 0.4). The inter-rater agreement for this result was almost perfect (ICC ≥ 0.958, 95% CI 0.909–0.983). On a 3rd generation scanner, it is feasible to maintain good subjective image quality, diagnostic confidence, and image noise in single-energy WBCT staging at dose levels as low as 40% of the original dose (5.3 ± 3.6 mSv), when using ADMIRE 3.

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Using 100- instead of 120-kVp computed tomography to diagnose pulmonary embolism almost halves the radiation dose with preserved diagnostic quality

Acta Radiologica ◽

10.3109/02841850903505222 ◽

2010 ◽

Vol 51 (3) ◽

pp. 260-270 ◽

Cited By ~ 24

Author(s):

Peter Björkdahl ◽

Ulf Nyman

Keyword(s):

Computed Tomography ◽

Pulmonary Embolism ◽

Image Quality ◽

Radiation Dose ◽

Effective Dose ◽

Ct Number ◽

Subjective Image Quality ◽

Diagnostic Quality ◽

X Ray ◽

Tube Potential

Background: Concern has been raised regarding the mounting collective radiation doses from computed tomography (CT), increasing the risk of radiation-induced cancers in exposed populations. Purpose: To compare radiation dose and image quality in a chest phantom and in patients for the diagnosis of pulmonary embolism (PE) at 100 and 120 peak kilovoltage (kVp) using 16-multichannel detector computed tomography (MDCT). Material and Methods: A 20-ml syringe containing 12 mg I/ml was scanned in a chest phantom at 100/120 kVp and 25 milliampere seconds (mAs). Consecutive patients underwent 100 kVp ( n = 50) and 120 kVp ( n = 50) 16-MDCT using a “quality reference” effective mAs of 100, 300 mg I/kg, and a 12-s injection duration. Attenuation (CT number), image noise (1 standard deviation), and contrast-to-noise ratio (CNR; fresh clot = 70 HU) of the contrast medium syringe and pulmonary arteries were evaluated on 3-mm-thick slices. Subjective image quality was assessed. Computed tomography dose index (CTDIvol) and dose–length product (DLP) were presented by the CT software, and effective dose was estimated. Results: Mean values in the chest phantom and patients changed as follows when X-ray tube potential decreased from 120 to 100 kVp: attenuation +23% and +40%, noise +38% and +48%, CNR −6% and 0%, and CTDIvol −38% and −40%, respectively. Mean DLP and effective dose in the patients decreased by 42% and 45%, respectively. Subjective image quality was excellent or adequate in 49/48 patients at 100/120 kVp. No patient with a negative CT had any thromboembolism diagnosed during 3-month follow-up. Conclusion: By reducing X-ray tube potential from 120 to 100 kVp, while keeping all other scanning parameters unchanged, the radiation dose to the patient may be almost halved without deterioration of diagnostic quality, which may be of particular benefit in young individuals.

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Radiation exposure during the treatment of spinal deformities

The Bone & Joint Journal ◽

10.1302/0301-620x.103b.bjj-2020-1416.r3 ◽

2021 ◽

pp. 1-7

Author(s):

Jwalant S. Mehta ◽

Kirsten Hodgson ◽

Lu Yiping ◽

James Swee Beng Kho ◽

Ravindra Thimmaiah ◽

...

Keyword(s):

Radiation Dose ◽

Ionizing Radiation ◽

Effective Dose ◽

Spinal Deformity ◽

Background Radiation ◽

Ct Scans ◽

Intraoperative Fluoroscopy ◽

The Difference ◽

Risk Of Cancer ◽

Surgical Group

Aims To benchmark the radiation dose to patients during the course of treatment for a spinal deformity. Methods Our radiation dose database identified 25,745 exposures of 6,017 children (under 18 years of age) and adults treated for a spinal deformity between 1 January 2008 and 31 December 2016. Patients were divided into surgical (974 patients) and non-surgical (5,043 patients) cohorts. We documented the number and doses of ionizing radiation imaging events (radiographs, CT scans, or intraoperative fluoroscopy) for each patient. All the doses for plain radiographs, CT scans, and intraoperative fluoroscopy were combined into a single effective dose by a medical physicist (milliSivert (mSv)). Results There were more ionizing radiation-based imaging events and higher radiation dose exposures in the surgical group than in the non-surgical group (p < 0.001). The difference in effective dose for children between the surgical and non-surgical groups was statistically significant, the surgical group being significantly higher (p < 0.001). This led to a higher estimated risk of cancer induction for the surgical group (1:222 surgical vs 1:1,418 non-surgical). However, the dose difference for adults was not statistically different between the surgical and non-surgical groups. In all cases the effective dose received by all cohorts was significantly higher than that from exposure to natural background radiation. Conclusion The treatment of spinal deformity is radiation-heavy. The dose exposure is several times higher when surgical treatment is undertaken. Clinicians should be aware of this and review their practices in order to reduce the radiation dose where possible.

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Sex differences in the association of abdominal adipose tissue measurements by using quantitative computed tomography (QCT) with untreated hypertension in a Chinese population

10.21203/rs.3.rs-20237/v1 ◽

2020 ◽

Author(s):

Youzhou Chen ◽

Zhuoli Zhang ◽

Jihong Wang ◽

Huayi Sun ◽

Xingshan Zhao ◽

...

Keyword(s):

Computed Tomography ◽

Blood Pressure ◽

Adipose Tissue ◽

Chinese Population ◽

Quantitative Computed Tomography ◽

Hip Circumference ◽

Hypertension Status ◽

Increased Risk ◽

Visceral Adipose ◽

Subcutaneous Adipose

Abstract Background: There are inconsistent results regarding the relationships of adiposity anthropometric indices and blood pressure (BP) and hypertension, and whether these relationships differ by sex is unclear. We aimed to elucidate the associations of adiposity indices measured using quantitative computed tomography (QCT) with BP and hypertension and to determine the effect of sex on the relationships in a Chinese population. Methods: Abdominal adipose fat, including visceral adipose tissue (VAT) area and subcutaneous adipose tissue (SAT) area, was measured by QCT in 1488 participants. Body mass index (BMI), waist circumference (WC), hip circumference (HC) and systolic (SBP) and diastolic BP (DBP) were measured. Results: Compared to women, men had significantly greater VAT but less SAT regardless of hypertension status. VAT, SAT and WC correlated more with SBP in men than in women. After controlling for body weight, height and age, VAT area and WC in women and VAT area in men were positively associated with SBP and DBP level. VAT area correlated more with the increased risk of hypertension in men than in women [men: odds ratio (OR) = 1.013, women: OR = 1.011]. WC had a significant correlation with an increased risk of hypertension in women but a borderline association in men (P = 0.059) when adjusted for VAT area and SAT area. Conclusions: The association of abdominal adiposity with blood pressure components and hypertension differs qualitatively by sex. WC may be an important determinant of hypertension and may be used for risk stratification for hypertension among Chinese individuals.

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Quantitative Computed Tomography (QCT) of the Distal Forearm in Men Using a Spiral Whole-Body CT Scanner – Description of a Method and Reliability Assessment of the QCT Pro Software

Journal of Clinical Densitometry ◽

10.1016/j.jocd.2019.05.005 ◽

2020 ◽

Vol 23 (3) ◽

pp. 418-425

Author(s):

Birgit C. Hanusch ◽

Stephen P. Tuck ◽

Babitha Mekkayil ◽

Mohamed Shawgi ◽

Richard J.Q. McNally ◽

...

Keyword(s):

Computed Tomography ◽

Quantitative Computed Tomography ◽

Reliability Assessment ◽

Whole Body ◽

Distal Forearm ◽

Ct Scanner ◽

Whole Body Ct ◽

Body Ct

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Reducing cranial computed tomography effective radiation dose by 30% using adaptive iterative dose reduction

Proceedings of Singapore Healthcare ◽

10.1177/2010105816651655 ◽

2016 ◽

Vol 25 (4) ◽

pp. 230-234

Author(s):

Wai-Yung Yu ◽

Thye Sin Ho ◽

Henry Ko ◽

Wai-Yee Chan ◽

Serene Ong ◽

...

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Radiation Dose ◽

Dose Reduction ◽

Diagnostic Image Quality ◽

Radiation Doses ◽

Effective Radiation Dose ◽

Diagnostic Image ◽

Ct Head ◽

Effective Radiation

Introduction: The use of computed tomography (CT) imaging as a diagnostic modality is increasing rapidly and CT is the dominant contributor to diagnostic medical radiation exposure. The aim of this project was to reduce the effective radiation dose to patients undergoing cranial CT examination, while maintaining diagnostic image quality. Methods: Data from a total of 1003, 132 and 27 patients were examined for three protocols: CT head, CT angiography (CTA), and CT perfusion (CTP), respectively. Following installation of adaptive iterative dose reduction (AIDR) 3D software, tube current was lowered in consecutive cycles, in a stepwise manner and effective radiation doses measured at each step. Results: Baseline effective radiation doses for CT head, CTA and CTP were 1.80, 3.60 and 3.96 mSv, at currents of 300, 280 and 130–150 mA, respectively. Using AIDR 3D and final reduced currents of 160, 190 and 70–100 mA for CT head, CTA and CTP gave effective doses of 1.29, 3.18 and 2.76 mSv, respectively. Conclusion: We demonstrated that satisfactory reductions in the effective radiation dose for CT head (28.3%), CTA (11.6%) and CTP (30.1%) can be achieved without sacrificing diagnostic image quality. We have also shown that iterative reconstruction techniques such as AIDR 3D can be effectively used to help reduce effective radiation dose. The dose reductions were performed within a short period and can be easily achievable, even in busy departments.

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