Erbium filtration: a cost-effective, dose-reducing filter which maintains abdominal image quality

1999 ◽  
Vol 9 (9) ◽  
pp. 1923-1925 ◽  
Author(s):  
C. A. Doyle ◽  
P. C. Brennan
2010 ◽  
Vol 51 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Peter Björkdahl ◽  
Ulf Nyman

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.


Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581880583 ◽  
Author(s):  
Ernesto Forte ◽  
Serena Monti ◽  
Chiara Anna Parente ◽  
Lukas Beyer ◽  
Roberto De Rosa ◽  
...  

Purpose: To compare image quality and radiation dose among different protocols in patients who underwent a 128-slice dual source computed tomography coronary angiography (DSCT-CTCA). Methods: Ninety patients were retrospectively grouped according to heart rate (HR): 26 patients (group A) with stable HR ≤60 bpm were acquired using high pitch spiral mode (FLASH); 48 patients (group B) with irregular HR ≤60 bpm or stable HR between 60 and 70 bpm using step and shoot mode; and 16 patients (group C) with irregular HR >60 bpm or stable HR ≥70 bpm by retrospective electrocardiogram pulsing acquisition. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured for the main vascular structures. Moreover, the dose-length product and the effective dose were assessed. Results: Both SNR and CNR were higher in group A compared to group C (18.27 ± 0.32 vs 11.22 ± 0.50 and 16.75 ± 0.32 vs 10.17 ± 0.50; P = .001). The effective dose was lower in groups A and B (2.09 ± 1.27 mSv and 4.60 ± 2.78 mSv, respectively) compared to group C (9.61 ± 5.95 mSv) P < .0001. Conclusion: The correct selection of a low-dose, HR-matched CTCA scan protocol with a DSCT scanner provides substantial reduction of radiation exposure and better SNR and CNR.


Author(s):  
Faisal Rehman ◽  
◽  
Syed Sheeraz Ali ◽  
Hamadullah Panhwar ◽  
Dr. Akhtar Hussain Phul ◽  
...  

In the medical era the Brain tumor is one of the most important research areas in the field of medical sciences. Researcher are trying to find the reliable and cost effective medical equipment’s for the cancer and its type for the diagnosed, especially tumor has deferent kinds but the major two type are discussed in this research paper. Which are the benign and Pre-Malignant, this research work is proposed for these factors such as the accuracy of the MRI image for the tumor identification and actual placing were taken into consideration. In this study, an algorithm is proposed to detect the brain tumor from magnetic resonance image (MRI) data simple. As enhance the image quality for the easiness the tumor treatments and diagnosed for the patients. The proposed algorithm enhances the MR image quality and detects the Brain tumor which helps the Physician to diagnose the tumor easily. As well this algorithm automatically calculates the area of tumor, size and location of the tumor where it is present for diagnostic the Patient.


2018 ◽  
Vol 148 ◽  
pp. 112-120
Author(s):  
Donghoon Lee ◽  
Sunghoon Choi ◽  
Haenghwa Lee ◽  
Dohyeon Kim ◽  
Seungyeon Choi ◽  
...  

2001 ◽  
Vol 11 (5) ◽  
pp. 870-875 ◽  
Author(s):  
J. H. Launders ◽  
A. R. Cowen ◽  
R. F. Bury ◽  
P. Hawkridge

2017 ◽  
Vol 3 (2) ◽  
pp. 591-594 ◽  
Author(s):  
Anja Stüssi ◽  
Marta Bogowicz ◽  
Verena Weichselbaumer ◽  
Patrick Veit-Haibach ◽  
Oliver Riesterer ◽  
...  

AbstractPerfusion computed tomography (CTP) images tumor angiogenesis and can assess tumor aggressiveness. However, the CTP examinations are dose intensive. This study aimed to optimize a routinely used CTP protocol for the head and neck region in oncology in order to reduce the effective dose to the patient and simultaneously achieve the same image quality.The Alderson phantom was scanned on a GE Revolution CT scanner. A scan with our standard protocol for head and neck cancer patients was used (100kV, 80mAs, 5mm slice thickness and backprojection algorithm) and in seven predefined regions (ROI) the signal to noise ratio (SNR) was measured. For the dose optimized protocol, the tube voltage was lowered and the mAs adaptation protocol was used. To improve image quality different percentage of an adaptive statistical iterative reconstruction (ASiR) was applied. For a better resolution we set the slice thickness to 2.5 mm. The mAs adaption range and the percentage of the ASiR reconstruction were varied until we found a combination with the same median SNR in the seven defined ROIs as for our old protocol. For the old and the optimized protocol dose measurements were performed using 25 LiF-TLDs. Organ doses were calculated and the effective dose was determined based on the weighting factors of ICRP103.The optimized scanning protocol used a voltage of 80kV, a mAs range between 15 and 80, a noise level of 10%, and 50% ASiR reconstruction. The median SNR ratio was slightly better (14% better SNR) with the new protocol. An effective dose of 8 mSv was measured with the original protocol and 4 mSv with the optimized scanning protocol. For organs in the scanning field the dose was reduced by a factor of 2 and outside the field by a factor of 2.2.Advanced reconstruction algorithms allow a significant dose reduction and an improvement of image resolution, while maintaining the image quality.


2014 ◽  
Vol 162 (4) ◽  
pp. 597-604 ◽  
Author(s):  
A. G. Davies ◽  
A. J. Gislason-Lee ◽  
A. R. Cowen ◽  
S. M. Kengyelics ◽  
M. Lupton ◽  
...  

2017 ◽  
Vol 17 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Misbah Ahmad ◽  
Habib Ahmad ◽  
Muhammad Rauf Khattak ◽  
Kamran Ali Shah ◽  
Nabila Javed ◽  
...  

AbstractBackground and purposeIn developing countries like Pakistan the cost effectiveness and patient convenience in any treatment modality is a question of major concern. The purpose of this study was two-fold; first to report our experience with a high-dose rate Iridium-192 surface mould brachytherapy of keloid scars after surgical excision, using different radiation treatment regimen and second to establish the most convenient and cost effective treatment protocol having no compromise on the treatment outcomes.Materials and methodsFrom January 2012 to April 2015 a total 51 patients with 65 keloid lesions underwent postoperative Iridium-192 high-dose rate surface mould brachytherapy. The dose regimen used was: 8 Gy in a single fraction, 10 Gy in a single fraction, 15 Gy in three fractions and 18 Gy in three fractions. The median follow-up period was 33 months (range 15–53 months).ResultsThe success rates were 57·2, 89·5, 85 and 89·5% for the treatment regimen of 8 Gy/F×1, 10 Gy/F×1, 5 Gy/F×3 and 6 Gy/F×3, respectively. Grade 2 or above radiation induced toxicity was not observed.FindingsThe results of this study show that a dose regimen of 10 Gy (biological effective dose=20 Gy) in a single fraction have comparable results with a dose regimen of 15 Gy in three fractions or 18 Gy in three fractions. 10 Gy in a single fraction is therefore the most convenient and cost effective dose regimen for the management of keloid scars in developing countries like Pakistan, while 8 Gy in a single fraction is considered suboptimal and discouraged in practice.


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