Imaging pediatric acute head trauma using 100-kVp low dose CT with adaptive statistical iterative reconstruction (ASIR-V) in single rotation on a 16 cm wide-detector CT

2021 ◽  
pp. 1-11
Author(s):  
Yanan Zhu ◽  
Zhian Pi ◽  
Heping Zhou ◽  
Zhengjun Li ◽  
Faqing Lei ◽  
...  
Keyword(s):  
Image Quality ◽  
Head Trauma ◽  
Standard Dose ◽  
Motion Artifacts ◽  
Adaptive Statistical Iterative Reconstruction ◽  
Ct Dose ◽  
Statistical Iterative Reconstruction ◽  
Ct Dose Index ◽  
Group 2 ◽  
Group 1

OBJECTIVE: To demonstrate the ability of achieving low dose and high-quality head CT images for children with acute head trauma using 100 kVp and adaptive statistical iterative reconstruction (ASIR-V) algorithm in single rotation on a 16 cm wide-detector system. MATERIALS AND METHODS: We retrospectively analyzed the CT dose index (CTDI) and image quality of 104 children aged 0–6 years with acute head trauma (1 hour –3 days) in two groups: Group 1(n = 50) on a 256-row CT with single rotation at a reduced-dose of 100 kVp/240 mA and reconstructed using ASIR-V at 70%level; Group 2(n = 54) on a 64-row CT with multiple rotations at a standard dose of 120 kVp/ 180mA and reconstructed using a conventional filtered back-projection (FBP). Both groups used the 0.5 s/r axial scan mode. CT dose index (CTDI) and quantitative image quality measurements were compared using the Student t test; qualitative image quality comparison was carried out using Mann-Whitney rank test and the inter-reviewer agreement was evaluated using Kappa test. RESULTS: The exposure time was 0.5 s for Group 1 and 3.27±0.29 s for Group 2. The CTDI in Group 1 was 9.74±0.86mGy, 36.38%lower than the 15.31mGy in Group 2 (p <  0.001). Group 1 and Group 2 had similar artifact index (2.06±1.06 vs. 2.37±1.18) in the cerebellar hemispheres, and similar contrast-to-noise ratio (2.32±0.83 vs. 1.69±0.68), (1.47±0.72 vs. 1.10±0.43) respectively for cerebellum and thalamus (p >  0.05). Image quality was acceptable for diagnosis, and motion artifacts were reduced in Group 1 (p <  0.001). CONCLUSION: Single rotation CT with 100 kVp and 70%ASIR-V on 16 cm wide-detector CT reduces radiation dose and motion artifacts for children with acute head trauma without compromising diagnostic quality as compared with standard dose protocol. Thus, it provides a novel imaging method in management of pediatric acute head trauma.

scholarly journals Integrated slice-specific dynamic shimming diffusion weighted imaging (DWI) for rectal Cancer detection and characterization

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jianxing Qiu ◽  
Jing Liu ◽  
Zhongxu Bi ◽  
Xiaowei Sun ◽  
Xin Wang ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Image Quality ◽  
Diffusion Weighted Imaging ◽  
Rectal Tumor ◽  
B Values ◽  
Primary Rectal Cancer ◽  
Diffusion Weighted ◽  
Adc Values ◽  
Group 2 ◽  
Group 1

Abstract Purpose To compare integrated slice-specific dynamic shimming (iShim) diffusion weighted imaging (DWI) and single-shot echo-planar imaging (SS-EPI) DWI in image quality and pathological characterization of rectal cancer. Materials and methods A total of 193 consecutive rectal tumor patients were enrolled for retrospective analysis. Among them, 101 patients underwent iShim-DWI (b = 0, 800, and 1600 s/mm2) and 92 patients underwent SS-EPI-DWI (b = 0, and 1000 s/mm2). Qualitative analyses of both DWI techniques was performed by two independent readers; including adequate fat suppression, the presence of artifacts and image quality. Quantitative analysis was performed by calculating standard deviation (SD) of the gluteus maximus, signal intensity (SI) of lesion and residual normal rectal wall, apparent diffusion coefficient (ADC) values (generated by b values of 0, 800 and 1600 s/mm2 for iShim-DWI, and by b values of 0 and 1000 s/mm2 for SS-EPI-DWI) and image quality parameters, such as signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of primary rectal tumor. For the primary rectal cancer, two pathological groups were divided according to pathological results: Group 1 (well-differentiated) and Group 2 (poorly differentiated). Statistical analyses were performed with p < 0.05 as significant difference. Results Compared with SS-EPI-DWI, significantly higher scores of image quality were obtained in iShim-DWI cases (P < 0.001). The SDbackground was significantly reduced on b = 1600 s/mm2 images and ADC maps of iShim-DWI. Both SNR and CNR of b = 800 s/mm2 and b = 1600 s/mm2 images in iShim-DWI were higher than those of b = 1000 s/mm2 images in SS-EPI-DWI. In primary rectal cancer of iShim-DWI cohort, SIlesion was significantly higher than SIrectum in both b = 800 and 1600 s/mm2 images. ADC values were significantly lower in Group 2 (0.732 ± 0.08) × 10− 3 mm2/s) than those in Group 1 ((0.912 ± 0.21) × 10− 3 mm2/s). ROC analyses showed significance of ADC values and SIlesion between the two groups. Conclusion iShim-DWI with b values of 0, 800 and 1600 s/mm2 is a promising technique of high image quality in rectal tumor imaging, and has potential ability to differentiate rectal cancer from normal wall and predicting pathological characterization.

scholarly journals Clinical Utilization of Point-of-care Ultrasound After Training: A Prospective Study

2021 ◽  
Author(s):  
Wan-Ching Lien ◽  
Chih-Heng Chang ◽  
Kah-Meng Chong ◽  
Meng-Che Wu ◽  
Cheng-Yi Wu ◽  
...  
Keyword(s):  
Image Quality ◽  
Positive Impact ◽  
University Hospital ◽  
Point Of Care Ultrasound ◽  
Global Rating ◽  
Clinical Trial Registration ◽  
Clinical Utilization ◽  
Global Ratings ◽  
Group 2 ◽  
Group 1

Abstract Background: This study aimed to investigate the clinical utilization of PoCUS of the first post-graduate year residents after a PoCUS curriculum. Methods: It was conducted at the emergency department of the National Taiwan University Hospital between July 2015 and October 2017. Every resident had one-month ED training and a curriculum was implemented during the first week. The post-training objective structured clinical examination (OSCE) global ratings were obtained, as well as the sonographic examinations by the residents. The participants were categorized into 4 groups: group 1 performed PoCUS before and after the curriculum; group 2 performed only after the curriculum; group 3 performed only before the curriculum; the last did not perform any examinations. Results: Two hundred and thirty-nine residents participated. The median global rating was 4 (interquartile ranges, 4-5). A significantly increasing number of residents integrated PoCUS into patient care (64 vs. 170, p=0.037) with acceptable image quality after the curriculum. Nearly 30% of residents did not use PoCUS although no differences existed in the OSCE global ratings. Group 1 performed more cases with better image quality and using ≥2 ultrasound applications (8/100 vs. 82/359, p=0.0009) after the curriculum. Group 1 performed more cases with better image quality than group 2 after the curriculum. In groups 3 and 4, “no suitable cases” (25/69), and “choosing other imaging priorities” (43/69) were the main feedbacks for not performing PoCUS. Conclusions: A focused training had a substantial positive impact on the utilization of PoCUS of the residents. The global ratings could not predict whether to integrate PoCUS into clinical practice. Further studies would be needed for the sustained effects of the curriculum and how to encourage these residents in groups 3 and 4 to use PoCUS.Clinical trial registration: NCT03738033.

scholarly journals Opportunities to reduce the radiation exposure during computed tomography to assess the changes in the lungs in patients with COVID-19: use of adaptive statistical iterative reconstruction

2021 ◽  
Vol 2 (2) ◽  
pp. 94-104
Author(s):  
Daria A. Filatova ◽  
Valentin E. Sinitsin ◽  
Elena A. Mershina
Keyword(s):  
Image Quality ◽  
Low Dose ◽  
Diagnostic Value ◽  
University Hospital ◽  
State University ◽  
Radiation Load ◽  
Adaptive Statistical Iterative Reconstruction ◽  
Tube Voltage ◽  
Statistical Iterative Reconstruction ◽  
Moscow State University

BACKGROUND: Several COVID-19 patients are subjected to multiple imaging examinations during hospitalization, the cumulative effect of which can significantly increase the total dose of radiation received. The effective radiation dose can be reduced by lowering the current and voltage of the X-ray tube, but this reduces image quality. One possible solution is to use adaptive statistical iterative reconstruction technology on the raw CT data. Recently, data on the efficacy of low-dose CT (LDCT) in the diagnosis of COVID-19 have appeared in the literature. AIM: To analyze the quality and diagnostic value of LDCT images of the lungs after applying an iterative processing algorithm and to assess the possibility of reducing the radiation load on the patient when diagnosing COVID-19. MATERIALS AND METHODS: Patients from the Infectious Diseases Department of the Moscow State University Hospital participated in the prospective study. CT examinations were performed at the time of patient admission and discharge and were repeated as needed during hospitalization. In the first study, a standard CT protocol with a tube voltage of 120 kV and automatic current modulation in the range of 200400 mA was used; in repeated CT scans, the LDKT protocol was used with reduced tube voltage parameters (100 or 110 kV) and automatic current modulation in the range of 40120 mA. To assess the diagnostic value of LDCT in comparison with standard CT, a survey was conducted among doctors from the Department of Radiation Diagnostics at Moscow State University Hospital. The questionnaire included a comparison of the two methods for identifying the following pathological processes: ground-glass opacities, compaction of the lung tissue with reticular changes, areas of lung tissue consolidation, and lymphadenopathy. RESULTS: The study included 151 patients. The average age was 5814.2 years, with men accounting for 53.6% of the population. During LDCT the radiation load was reduced by 2.96 times on average, CTDI by 2.6 times, DLP by 3.1 times, the current on the tube by 1.83 times, and the voltage on the tube by 1.2 times. The results indicate that the effectiveness of detecting the main signs of viral pneumonia and assessing the dynamics of the patients condition does not differ significantly from CT performed according to the standard protocol. CONCLUSIONS: The results of a comparison of standard and low-dose CT show that there is no significant loss of diagnostic information and image quality as the radiation load is reduced. Thus, chest LDCT can be used to successfully diagnose COVID-19 in routine practice.

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