scholarly journals Utilization of sinogram affirmed iterative reconstruction on 128 multi slice computed tomography scan to reduce radiation dose and improve image quality on thorax multi slice computed tomography scan: chest phantom study

Author(s):  
Halinda Fatmayanti ◽  
Kusworo Adi ◽  
Yeti Kartikasari

Background: Thorax MSCT examination is a diagnostic imaging that is capable of displaying both normal and pathological lung and respiratory organs. MSCT examination also has a better level of sensitivity and specificity compared to other modalities, but the radiation exposure given is very high, so the radiation dose given to patients is high. The reduction in radiation dose is very important because of the direct exposure to sensitive tissue. One method of reducing radiation dose is by reducing the tube voltage. However, the decrease in tube voltage causes a decrease in image quality as indicated by increased noise and decreased CNR. To maintain the quality of the image at low tube voltage setting, an IR reconstruction of SAFIRE was used. The purpose of this research is to know the impact of using SAFIRE on dose radiation and image quality of thorax MSCT.Methods: This study was an experimental study with a quasi-experimental study design. The object used was the N-1 Lungman chest phantom in which an artificial tumor was attached. Radiation dose assessment used CTDI value, while image quality assessment used noise and CNR. Data processing was conducted using linear regression test.Results: There was an effect of tube voltage setting and SAFIRE setting on radiation dose and image quality.Conclusions: Tube voltage ssetting and SAFIRE setting had an effect on radiation dose and image quality. Tube voltage setting and SAFIRE strength level setting that were able to provide optimal radiation dose and image quality were tube voltage of 80 kVp and SAFIRE strength levels 3 and 4 (S3 and S4). 

Author(s):  
Abdulwahid S. AlQahtani ◽  
Ramzi M. Dagriri ◽  
Radeif E. Shamakhi ◽  
Ahmad M. Alrasheed ◽  
Ahmed A. Etwadi ◽  
...  

<p class="abstract"><strong>Background:</strong> Deviated nasal septum (DNS) is one of the most frequent causes of nasal obstruction in adults. An anterior rhinoscopy (AR), which is usually the first diagnostic procedure in the evaluation of obstructive nasal pathologies, is often inadequate in the assessment of the posterior nasal cavity and the gold standard method for the evaluation of paranasal anatomy and inflammatory paranasal sinus pathologies is paranasal sinus computed tomography (PNS CT). Aim was to validate the recommendation of pre-operative computed tomography scan in minimizing post-septoplasty complications.</p><p class="abstract"><strong>Methods:</strong> A retrospective record based study was conducted including all patients with clinically diagnosed DNS and undergone surgical intervention at Khamis Mushayet General Hospital. Data extracted included patients demographic data, and post-operative recorded complications and history of preoperative CT scan for evaluating and grading DNS.  </p><p class="abstract"><strong>Results:</strong> A total sample of 60 patients’ undergone septoplasty for DNS. Patients who undergone preoperative CT were 30. The remaining 30 patients didn’t undergone pre-operative CT for evaluation of DNS. The most diagnosed complication was nasal obstruction (28.3%) followed by external nose deformity (20%). Exact of 47% of patients had postoperative nasal obstruction didn’t undergone pre-operative CT. About 42% of those who had postoperative nasal deformity didn’t undergone CT while 33% of patient who had post-operative bleeding and septal perforation didn’t undergone CT.</p><p class="abstract"><strong>Conclusions:</strong> In conclusion, the study revealed that preoperative CT showed insignificant efficacy in relieving nasal obstruction or minimizing postoperative complications.</p>


2008 ◽  
Vol 109 (5) ◽  
pp. 864-871 ◽  
Author(s):  
Marc Leone ◽  
Fabienne Brégeon ◽  
François Antonini ◽  
Kathia Chaumoître ◽  
Aude Charvet ◽  
...  

Background Currently, there are limited data available describing the long-term outcomes of chest trauma survivors. Here, the authors sought to describe chest trauma survivor outcomes 6 months and 1 yr after discharge from the intensive care unit, paying special attention to pulmonary outcomes. Methods A cohort of 105 multiple trauma patients with blunt chest trauma admitted to the intensive care unit was longitudinally evaluated. After 6 months, a chest computed tomography scan, pulmonary function testing (PFT), and quality of life were collected in 55 of these patients. A subgroup of 38 patients was followed up for 1 yr. Results At least one abnormal PFT result was found in 39 patients (71%). Compared with normalized data of the age- and sex-matched population, physical function was decreased in 38 patients (70%). The 6-min walk distance was reduced for 29 patients (72%). Although pathologic images were observed on the chest computed tomography scan from 33 patients (60%), no relation was found between PFT and computed tomography. A ratio of arterial oxygen pressure to inspired oxygen fraction less than 200 at admission to the intensive care unit predicted an abnormal PFT result at 6 months. One year after discharge from the intensive care unit, paired comparisons showed a significant increase in forced vital capacity (P = 0.02) and Karnofsky Performance Status (P &lt; 0.001). Conclusions Survivors of multiple traumas including chest trauma demonstrate a persistent decrease in the 6-min walk distance, impairment on PFT, and reduced pulmonary-specific quality of life.


2014 ◽  
Vol 56 (9) ◽  
pp. 797-803 ◽  
Author(s):  
Matthias S. May ◽  
Manuel R. Kramer ◽  
Achim Eller ◽  
Wolfgang Wuest ◽  
Michael Scharf ◽  
...  

Author(s):  
Yang-Ting Hsu ◽  
Jo-Chi Jao

Radiologic technologists face various types of patients during multi-detector computed tomography (CT) examinations. In emergency departments, it is common to have patients who cannot follow instructions for the examinations. The asymmetric axial view of the head CT might affect the correctness of the clinician’s diagnosis. This study aimed to assess the impact of head positioning on the image quality of head CT using two phantoms. All scans were performed on a 16-slice CT scanner. In the control group, the tilted angle of the phantoms was 0[Formula: see text], and no multiplanar reconstruction (MPR) was performed. In the experimental groups, the tilted angles of the phantoms were 5[Formula: see text], 10[Formula: see text] and 15[Formula: see text], respectively, and MPR was performed afterwards. The results showed that if the head was tilted during the head CT examinations, image asymmetry and artifacts appeared without MPR. After MPR, one phantom showed that there were significant differences and the other phantom showed no significant differences quantitatively in image symmetry and artifacts between experimental groups and the control group, while both phantoms showed no significant differences qualitatively in image symmetry and artifacts between experimental groups and the control group. Although MPR can correct the image asymmetry and artifacts caused by tilted head positioning to some extent, it consumes time. Therefore, technologists should position the head as exactly as possible when performing head CT examinations.


2018 ◽  
Vol 60 (2) ◽  
pp. 177-185
Author(s):  
Xiangying Du ◽  
Bin Lu ◽  
Daoyu Hu ◽  
Bin Song ◽  
Kuncheng Li

Background Concern about radiation exposure is leading to an increasing interest in low-concentration contrast medium administration. Purpose To evaluate the image quality and safety profile after administration of iodixanol 270 mg I/mL at 100-kVp tube voltage with iterative reconstruction in subjects undergoing computed tomography angiography (CTA). Material and Methods Patients who completed CTA examination using iodixanol 270 mg I/mL and 100-kVp tube voltage along with iterative reconstruction for coronary, aortic, head and neck, renal, or pulmonary arteries were included. Image quality was qualitatively and quantitatively evaluated. Incidence of adverse events (AEs) and adverse drug reactions (ADRs) within seven days and radiation dose were also analyzed. Results A total of 4513 individuals in 42 centers in China were enrolled, among which 4367 were included in efficacy analysis. The mean image quality score was 4.8 ± 0.45 across all arteries (all above 4.6) and 99.7% of the individuals’ images were classified as evaluable. The CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the regions of interest (ROIs) were 431.79 ± 99.018, 18.29 ± 11.947, and 28.21 ± 19.535 HU, respectively. Of all the participants, 68 (1.5%) and 65 (1.4%) experienced AEs and ADRs, respectively. No serious AEs or AEs leading to discontinuation occurred. The average effective radiation dose was 3.13 ± 2.550 mSv. Conclusion Iodixanol 270 mg I/mL in combination with 100-kVp tube voltage and iterative reconstruction could be safely applied in CTA and yield high-quality and evaluable images with reduced radiation dose.


2017 ◽  
Vol 47 (6) ◽  
pp. 710-717 ◽  
Author(s):  
Ji Eun Park ◽  
Young Hun Choi ◽  
Jung-Eun Cheon ◽  
Woo Sun Kim ◽  
In-One Kim ◽  
...  

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