scholarly journals Feasibility study of ultra-low-dose dedicated maxillofacial computed tomography using filter-based spectral shaping in patients with craniofacial trauma: assessment of image quality and radiation dose

2021 ◽  
Vol 11 (4) ◽  
pp. 1292-1302
Author(s):  
Ji Young Ha ◽  
Hye Jin Baek ◽  
Kyeong Hwa Ryu ◽  
Eun Cho
2020 ◽  
pp. 028418512096555
Author(s):  
Yun Seok Choi ◽  
Hye Jung Choo ◽  
Sun Joo Lee ◽  
Dong Wook Kim ◽  
Ji-yeon Han ◽  
...  

Background Tin filter-based spectral shaping has been used for low-dose and ultra-low-dose computed tomography (CT) in several body parts. However, studies of shoulder CT arthrography with spectral shaping are limited. Purpose To investigate image quality and radiation dose of shoulder CT arthrography with tin filter-based spectral shaping at 100 kV (Sn 100 kV) and 140 kV (Sn 140 kV) in comparison with the conventional protocol. Material and Methods Ninety-nine shoulder CT arthrographies with protocols of Sn 100 kV (n = 32), Sn 140 kV (n = 25), and conventional 120 kV (n = 42) were retrospectively evaluated. Qualitative image quality, CT attenuations of intra-articular contrast mixture and tissues, background noise, contrast-to-noise ratios (CNRs), and figures of merit were assessed. Radiation doses were compared. Results CT arthrographies with Sn 100 kV and Sn 140 kV yielded approximately 70% and 60% radiation dose reduction, respectively, compared with the conventional 120 kV ( P < 0.001). Qualitative image noise and quantitative background noise of Sn 100 kV and Sn 140 kV were significantly less than those of the conventional protocol. Qualitative image contrast, CT attenuations of intra-articular contrast mixture and tissues, and CNRs for Sn 100 were similar to those of the conventional 120 kV. However, Sn 140 kV showed significantly lower qualitative contrast and CNRs than 120 kV. Sn 100 kV was the most dose efficient among the three protocols. Conclusion Shoulder CT arthrography with Sn 100 kV substantially reduced radiation dose and image noise and maintained image contrast, compared with the conventional protocol.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Richard G. Kavanagh ◽  
John O’Grady ◽  
Brian W. Carey ◽  
Patrick D. McLaughlin ◽  
Siobhan B. O’Neill ◽  
...  

Magnetic resonance imaging (MRI) is the mainstay method for the radiological imaging of the small bowel in patients with inflammatory bowel disease without the use of ionizing radiation. There are circumstances where imaging using ionizing radiation is required, particularly in the acute setting. This usually takes the form of computed tomography (CT). There has been a significant increase in the utilization of computed tomography (CT) for patients with Crohn’s disease as patients are frequently diagnosed at a relatively young age and require repeated imaging. Between seven and eleven percent of patients with IBD are exposed to high cumulative effective radiation doses (CEDs) (>35–75 mSv), mostly patients with Crohn’s disease (Newnham E 2007, Levi Z 2009, Hou JK 2014, Estay C 2015). This is primarily due to the more widespread and repeated use of CT, which accounts for 77% of radiation dose exposure amongst patients with Crohn’s disease (Desmond et al., 2008). Reports of the projected cancer risks from the increasing CT use (Berrington et al., 2007) have led to increased patient awareness regarding the potential health risks from ionizing radiation (Coakley et al., 2011). Our responsibilities as physicians caring for these patients include education regarding radiation risk and, when an investigation that utilizes ionizing radiation is required, to keep radiation doses as low as reasonably achievable: the “ALARA” principle. Recent advances in CT technology have facilitated substantial radiation dose reductions in many clinical settings, and several studies have demonstrated significantly decreased radiation doses in Crohn’s disease patients while maintaining diagnostic image quality. However, there is a balance to be struck between reducing radiation exposure and maintaining satisfactory image quality; if radiation dose is reduced excessively, the resulting CT images can be of poor quality and may be nondiagnostic. In this paper, we summarize the available evidence related to imaging of Crohn’s disease, radiation exposure, and risk, and we report recent advances in low-dose CT technology that have particular relevance.


2020 ◽  
Vol 9 (1) ◽  
pp. 27-31
Author(s):  
Mahesh Gautam ◽  
Aziz Ullah ◽  
Manish Raj Pathak

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.


Author(s):  
Lifeng Wang ◽  
Xingxing Jin ◽  
Zhenguo Qiao ◽  
Bin Xu ◽  
Jiaqing Shen

Objectives: This study investigated the radiation dose and value of prospective dualenergy computed tomography (DECT) in the diagnosis of gastric cancer. Methods: Sixty patients scheduled for computed tomography (CT) for preoperative staging were divided into two groups. Thirty patients (Group A) underwent a single contrast-enhanced abdominal CT acquisition using a dual-source mode (100 kV/140 kV). Weighted average images of the two-kilovolt acquisitions and iodine maps were created. The remaining 30 patients underwent a standard CT scan (Group B). Two observers performed a blinded read of the images for gastric lesions, evaluating the image quality and recording effective dose. Results: During the blinded read, observers found 90% (27/30) of the cancers in both groups. The mean imaging quality scores were 2.1±0.9 for Group A, and 2.3±1.1 for Group B. The effective mean doses were 6.59±0.59 mSv and 25.86±0.44 mSv for Groups A and B, respectively. Compared with the control group (B), the imaging quality in the low-dose group decreased a little, but the radiation dose substantially decreased by 74.6%. Conclusion: The new DECT technique is valuable for examining gastric cancer patients. The dualkV scan mode can substantially reduce radiation dose while preserving good diagnostic image quality.


2021 ◽  
pp. 028418512198995
Author(s):  
Erdal Tekin ◽  
Kutsi Tuncer ◽  
Ibrahim Ozlu ◽  
Recep Sade ◽  
Rustem Berhan Pirimoglu ◽  
...  

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.


2013 ◽  
Vol 18 (1) ◽  
pp. 301-311 ◽  
Author(s):  
Elisabeth Hofmann ◽  
Matthias Schmid ◽  
Martin Sedlmair ◽  
Rosemarie Banckwitz ◽  
Ursula Hirschfelder ◽  
...  

2020 ◽  
Vol 24 (3) ◽  
pp. 107-113
Author(s):  
A. Yu. Silin ◽  
I. S. Gruzdev ◽  
G. V. Berkovich ◽  
A. E. Nikolaev ◽  
S. P. Morozov

Aim: A literature review of the possibilities of applying model iterative reconstruction (MIR) in computed tomography to improve image quality, including in low-dose scanning protocols.Materials and methods. The analysis of publications devoted to the application of MIR to reduce the radiation dose and improve the quality of images in CT diagnostics of lung pathology with an emphasis on the value of the achieved radiation dose was carried out.Results. The use of MIR eliminates digital noise from medical images, improving their quality. This feature can significantly reduce radiation exposure with low-dose protocols without loss of diagnostic quality. On average, application of MIR allows to reduce the radiation dose by 70% compared to a standard protocol, without increasing the noise level of CT images and maintaining the contrast-to-noise ratio. Previous studies have shown positive experience with the use of MIR in lung cancer screening programs and monitoring of cancer patients.Conclusion. The introduction of MIR in clinical practice can optimize the radiation exposure on the population without reducing the quality of CT images, however, the threshold dose to achieve a satisfactory image quality remains unexplored.


2018 ◽  
Vol 59 (10) ◽  
pp. 1247-1253 ◽  
Author(s):  
Paola Maria Cannaò ◽  
Francesco Secchi ◽  
Marco Alì ◽  
Ida Daniela D'Angelo ◽  
Marco Scarabello ◽  
...  

Background Cardiovascular computed tomography (CCT) technology is rapidly advancing allowing to perform good quality examinations with a radiation dose as low as 1.2 mSv. However, latest generation scanners are not available in all centers. Purpose To estimate radiation dose and image quality in pediatric CCT using a standard 64-slice scanner. Material and Methods A total of 100 patients aged 6.9 ± 5.4 years (mean ± standard deviation) who underwent a 64-slice CCT scan using 80, 100, or 120 kVp, were retrospectively evaluated. Radiation effective dose was calculated on the basis of the dose length product. Two independent readers assessed the image quality through signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and a qualitative score (3 = very good, 2 = good, 1 = poor). Non-parametric tests were used. Results Fifty-five exams were not electrocardiographically (ECG) triggered, 20 had a prospective ECG triggering, and 25 had retrospective ECG triggering. The median effective dose was 1.3 mSv (interquartile range [IQR] = 0.8–2.7 mSv). Median SNR was 30.6 (IQR = 23.4–33.6) at 120 kVp, 29.4 (IQR = 23.7–34.8) at 100 kVp, and 24.7 (IQR = 19.4–34.3) at 80 kVp. Median CNR was 21.0 (IQR = 14.8–24.4), 19.1 (IQR = 15.6–23.9), and 25.3 (IQR = 19.4–33.4), respectively. Image quality was very good, good, and poor in 56, 39, and 5 patients, respectively. No significant differences were found among voltage groups for SNR ( P = 0.486), CNR ( P = 0.336), and subjective image quality ( P = 0.296). The inter-observer reproducibility was almost perfect (κ = 0.880). Conclusion High-quality pediatric CCT can be performed using a 64-slice scanner, with a radiation effective dose close to 2 mSv in about 50% of the cases.


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