Radiation Dose and Image Quality of Low-dose Protocol in Chest CT: Comparison of Standard-dose Protocol

Purpose To analyze possible influencing factors on radiation exposure in pediatric chest CT using different approaches for radiation dose optimization and to determine major indicators for dose development. Materials and Methods In this retrospective study at a clinic with maximum care facilities including pediatric radiology, 1695 chest CT examinations in 768 patients (median age: 10 years; range: 2 days to 17.9 years) were analyzed. Volume CT dose indices, effective dose, size-specific dose estimate, automatic dose modulation (AEC), and high-pitch protocols (pitch ≥ 3.0) were evaluated by univariate analysis. The image quality of low-dose examinations was compared to higher dose protocols by non-inferiority testing. Results Median dose-specific values annually decreased by an average of 12 %. High-pitch mode (n = 414) resulted in lower dose parameters (p < 0.001). In unenhanced CT, AEC delivered higher dose values compared to scans with fixed parameters (p < 0.001). In contrast-enhanced CT, the use of AEC yielded a significantly lower radiation dose only in patients older than 16 years (p = 0.04). In the age group 6 to 15 years, the values were higher (p < 0.001). The diagnostic image quality of low-dose scans was non-inferior to high-dose scans (2.18 vs. 2.14). Conclusion Radiation dose of chest CT was reduced without loss of image quality in the last decade. High-pitch scanning was an independent factor in this context. Dose reduction by AEC was limited and only relevant for patients over 16 years. Key Points Citation Format

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Implementation of ultra-low-dose lung protocols in CT-guided lung biopsies: feasibility and safety in the clinical setting

Journal of International Medical Research ◽

10.1177/0300060517712165 ◽

2017 ◽

Vol 45 (6) ◽

pp. 2101-2109 ◽

Cited By ~ 3

Author(s):

Barbara K Frisch ◽

Karin Slebocki ◽

Kamal Mammadov ◽

Michael Puesken ◽

Ingrid Becker ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Low Dose ◽

Standard Dose ◽

Complication Rates ◽

Dose Length Product ◽

Ct Guided ◽

Total Radiation Dose ◽

Lung Biopsies ◽

Histological Results

Objective To evaluate the use of ultra-low-dose computed tomography (ULDCT) for CT-guided lung biopsy versus standard-dose CT (SDCT). Methods CT-guided lung biopsies from 115 patients (50 ULDCT, 65 SDCT) were analyzed retrospectively. SDCT settings were 120 kVp with automatic mAs modulation. ULDCT settings were 80 kVp with fixed exposure (20 mAs). Two radiologists evaluated image quality (i.e., needle artifacts, lesion contouring, vessel recognition, visibility of interlobar fissures). Complications and histological results were also evaluated. Results ULDCT was considered feasible for all lung interventions, showing the same diagnostic accuracy as SDCT. Its mean total radiation dose (dose–length product) was significantly reduced to 34 mGy-cm (SDCT 426 mGy-cm). Image quality and complication rates ( P = 0.469) were consistent. Conclusions ULDCT for CT-guided lung biopsies appears safe and accurate, with a significantly reduced radiation dose. We therefore recommend routine clinical use of ULDCT for the benefit of patients and interventionalists.

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Radiology examination of increasing importance during pandemic: Low-dose chest CT; Diagnostic efficacy and exposure to ionizing radiation dose compared to standard-dose chest CT in COVID-19 cases

Dokuz Eylül Üniversitesi Tıp Fakültesi Dergisi ◽

10.5505/deutfd.2021.38039 ◽

2021 ◽

Vol 35 (50) ◽

pp. 179-189

Author(s):

Abdullah Taylan ◽

BANU Kucuk Taylan ◽

Ozgur Gunal

Keyword(s):

Radiation Dose ◽

Ionizing Radiation ◽

Low Dose ◽

Standard Dose ◽

Chest Ct ◽

Diagnostic Efficacy

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High-pitch, 120 kVp/30 mAs, low-dose dual-source chest CT with iterative reconstruction: Prospective evaluation of radiation dose reduction and image quality compared with those of standard-pitch low-dose chest CT in healthy adult volunteers

PLoS ONE ◽

10.1371/journal.pone.0211097 ◽

2019 ◽

Vol 14 (1) ◽

pp. e0211097 ◽

Cited By ~ 4

Author(s):

Hyun Kyung Lim ◽

Hong Il Ha ◽

Hye Jeon Hwang ◽

Kwanseop Lee

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Iterative Reconstruction ◽

Low Dose ◽

Healthy Adult ◽

Chest Ct ◽

Prospective Evaluation ◽

High Pitch ◽

Dual Source ◽

Adult Volunteers

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Low Dose Computed Tomography in Diagnosis of Ureteric Calculus in Obese Patients

Journal of Nobel Medical College ◽

10.3126/jonmc.v9i1.29464 ◽

2020 ◽

Vol 9 (1) ◽

pp. 27-31

Author(s):

Mahesh Gautam ◽

Aziz Ullah ◽

Manish Raj Pathak

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Radiation Dose ◽

Iterative Reconstruction ◽

Low Dose ◽

Standard Dose ◽

Reconstruction Technique ◽

Obese Patients ◽

Low Dose Computed Tomography ◽

Effective Radiation

Background: Standard dose computed tomography is standard imaging modality in diagnosis of urolithiasis. The introduction of low dose techniques results in decrease radiation dose without significant change in image quality. However, the image quality of low dose computed tomography is affected by skin fold thickness and subcutaneous abdominal adipose tissue. The aim of this study to evaluate stone location, size, and density using low dose computed tomography compared with standard dose computed tomography in obese population. Material and Methods: This non-randomized non-inferiority trial includes 120 patient having BMI≥25kg/m2 with acute ureteric colic. The low dose and standard dose computed tomography were performed accordingly. Effective radiation doses were calculated from dose-length product obtained from scan report using conversion factor of 0.015. The images were reconstructed using iterative reconstruction algorithm. Effective dose, number and size of stone, Hounsfield Unit value of stone and image quality was assessed. Results: Stones were located in 69 (57.5%) in right and 51 (42.5%) in left ureter. There was no statistical difference in mean diameter, number and density of stones in low dose as compared with standard dose. The radiation dose was significantly lower with low dose. (3.68 mSv) The delineation of the ureter, outline of the stones and image quality in low dose was overall sufficient for diagnosis. No images of low dose scan were subjectively rated as non-diagnostics. Conclusion: Low dose computed tomography with iterative reconstruction technique is as effective as standard dose in diagnosis of ureteric stones in obese patients with lower effective radiation dose.

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Evaluation of an iterative model-based reconstruction of pediatric abdominal CT with regard to image quality and radiation dose

Acta Radiologica ◽

10.1177/0284185117728415 ◽

2017 ◽

Vol 59 (6) ◽

pp. 740-747

Author(s):

Marie-Louise Aurumskjöld ◽

Marcus Söderberg ◽

Fredrik Stålhammar ◽

Kristina Vult von Steyern ◽

Anders Tingberg ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Iterative Reconstruction ◽

Low Dose ◽

Pediatric Patients ◽

Standard Dose ◽

Reconstruction Method ◽

Abdominal Ct ◽

Model Based ◽

Iterative Model

Background In pediatric patients, computed tomography (CT) is important in the medical chain of diagnosing and monitoring various diseases. Because children are more radiosensitive than adults, they require minimal radiation exposure. One way to achieve this goal is to implement new technical solutions, like iterative reconstruction. Purpose To evaluate the potential of a new, iterative, model-based method for reconstructing (IMR) pediatric abdominal CT at a low radiation dose and determine whether it maintains or improves image quality, compared to the current reconstruction method. Material and Methods Forty pediatric patients underwent abdominal CT. Twenty patients were examined with the standard dose settings and 20 patients were examined with a 32% lower radiation dose. Images from the standard examination were reconstructed with a hybrid iterative reconstruction method (iDose4), and images from the low-dose examinations were reconstructed with both iDose4 and IMR. Image quality was evaluated subjectively by three observers, according to modified EU image quality criteria, and evaluated objectively based on the noise observed in liver images. Results Visual grading characteristics analyses showed no difference in image quality between the standard dose examination reconstructed with iDose4 and the low dose examination reconstructed with IMR. IMR showed lower image noise in the liver compared to iDose4 images. Inter- and intra-observer variance was low: the intraclass coefficient was 0.66 (95% confidence interval = 0.60–0.71) for the three observers. Conclusion IMR provided image quality equivalent or superior to the standard iDose4 method for evaluating pediatric abdominal CT, even with a 32% dose reduction.

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Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department

Acta Radiologica ◽

10.1177/0284185121989958 ◽

2021 ◽

pp. 028418512198995

Author(s):

Erdal Tekin ◽

Kutsi Tuncer ◽

Ibrahim Ozlu ◽

Recep Sade ◽

Rustem Berhan Pirimoglu ◽

...

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Radiation Dose ◽

Low Dose ◽

Standard Dose ◽

Control Group ◽

Study Group ◽

Effective Radiation Dose ◽

Wrist Trauma ◽

Effective Radiation

Background The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed. Purpose To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT). Material and Methods This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale. Results The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group ( P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images. Conclusion ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy.

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