scholarly journals Clinical utility of postprocessed low-dose radiographs in skeletal imaging

2021 ◽  
Author(s):  
Johannes Kolck ◽  
Katharina Ziegeler ◽  
Thula Walter-Rittel ◽  
Kay-Geert Kay G Hermann ◽  
Bernd Hamm ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Image Quality ◽  
Clinical Utility ◽  
Radiation Dosage ◽  
Low Dose ◽  
Reference Value ◽  
Diagnostic Value ◽  
X Rays ◽  
Image Postprocessing ◽  
Image Detail

Objectives: Radiography remains the mainstay of diagnostic and follow-up imaging. In view of the risks and the increasing use of ionizing radiation, dose reduction is a key issue for research and development. The introduction of digital radiography and the associated access to image postprocessing have opened up new opportunities to minimize the radiation dosage. These advances are contingent upon quality controls to ensure adequate image detail and maintenance of diagnostic confidence. The purpose of this study was to investigate the clinical applicability of postprocessed low-dose images in skeletal radiography. Methods: In our study setting, the median radiation dose for full dose x-rays was 9.61 dGy*cm2 for pelvis, 1.20 dGy*cm2 for shoulder and 18.64 dGy*cm2 for lumbar spine exams. Based on these values, we obtained 200 radiographs for each anatomic region in four consecutive steps, gradually reducing the dose to 84%, 71%, 60 and 50% of the baseline using an automatic exposure control (AEC). 549 patients were enrolled for a total of 600 images. All x-rays were postprocessed with a spatial noise reduction algorithm. Two radiologists assessed the diagnostic value of the radiographs by rating the visualization of anatomical landmarks and image elements on a five-point Likert scale. A mean-sum score was calculated by averaging the two reader’s total scores. Given the non-parametric distribution, we used the Mann-Whitney U test to evaluate the scores. Results: Median dosage at full dose accounted for 38.4%, 48 and 53.2% of the German reference dose area product for shoulder, pelvis and lumbar spine, respectively. The applied radiation was incrementally reduced to 21.5%, 18.4% and 18.7% of the respective reference value for shoulder, pelvis and lumbar spine. Throughout the study, we observed an estimable tendency of superior quality at higher dosage in overall image quality. Statistically significant differences in image quality were restricted to the 50% dose groups in shoulder and lumbar spine images. Regardless of the applied dosage, 598 out of 600 images were of sufficient diagnostic value. Conclusion: In digital radiography image postprocessing allows for extensive reduction of radiation dosage. Despite a trend of superior image detail at higher dose levels, overall quality and, more importantly, diagnostic utility of low-dose images was not significantly affected. Therefore, our results not only confirm the clinical utility of postprocessed low-dose radiographs, but also suggest a widespread deployment of this advanced technology to ensure further dose limitations in clinical practice. Advances in knowledge: The diagnostic image quality of postprocessed skeletal radiographs is not significantly impaired even after extensive dose reduction by up to 20% of the reference value.

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.

Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine

2016 ◽  
Vol 58 (6) ◽  
pp. 702-709 ◽  
Author(s):  
Muhammed Alshamari ◽  
Mats Geijer ◽  
Eva Norrman ◽  
Mats Lidén ◽  
Wolfgang Krauss ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Image Quality ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Low Dose Ct

Low dose CT of the lumbar spine compared with radiography: a study on image quality with implications for clinical practice

2015 ◽  
Vol 57 (5) ◽  
pp. 602-611 ◽  
Author(s):  
Muhammed Alshamari ◽  
Mats Geijer ◽  
Eva Norrman ◽  
Mats Lidén ◽  
Wolfgang Krauss ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Lumbar Spine ◽  
Image Quality ◽  
Low Dose ◽  
Low Dose Ct

scholarly journals Low-dose computed tomography of the lumbar spine: a phantom study on imaging parameters and image quality

2014 ◽  
Vol 55 (7) ◽  
pp. 824-832 ◽  
Author(s):  
Muhammed Alshamari ◽  
Mats Geijer ◽  
Eva Norrman ◽  
Håkan Geijer
Keyword(s):  
Computed Tomography ◽  
Lumbar Spine ◽  
Image Quality ◽  
Low Dose ◽  
Phantom Study ◽  
Imaging Parameters ◽  
Low Dose Computed Tomography

A study on diagnostic value of oblique lumbar spine radiographs

1982 ◽  
Vol 18 (2) ◽  
pp. 367
Author(s):  
S J Joe ◽  
Y J Suh ◽  
K W Chun ◽  
B C Min ◽  
J S Yoon
Keyword(s):  
Lumbar Spine ◽  
Diagnostic Value ◽  
Spine Radiographs

A Systematic Review of Double Low-dose CT Pulmonary Angiography in Pulmonary Embolism

2019 ◽  
Vol 15 (5) ◽  
pp. 453-460 ◽  
Author(s):  
Sultan Aldosari ◽  
Zhonghua Sun
Keyword(s):  
Systematic Review ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Contrast Medium ◽  
Low Dose ◽  
Pulmonary Angiography ◽  
Ct Pulmonary Angiography ◽  
Low Contrast ◽  
Low Contrast Medium

Background: The aim of this study is to perform a systematic review of the feasibility and clinical application of double low-dose CT pulmonary angiography (CTPA) in the diagnosis of patients with suspected pulmonary embolism. Discussion: A total of 13 studies were found to meet selection criteria reporting both low radiation dose (70 or 80 kVp versus 100 or 120 kVp) and low contrast medium dose CTPA protocols. Lowdose CTPA resulted in radiation dose reduction from 29.6% to 87.5% in 12 studies (range: 0.4 to 23.5 mSv), while in one study, radiation dose was increased in the dual-energy CT group when compared to the standard 120 kVp group. CTPA with use of low contrast medium volume (range: 20 to 75 ml) was compared to standard CTPA (range: 50 to 101 ml) in 12 studies with reduction between 25 and 67%, while in the remaining study, low iodine concentration was used with 23% dose reduction achieved. Quantitative assessment of image quality (in terms of signal-to-noise ratio and contrast-to-noise ratio) showed that low-dose CTPA was associated with higher, lower and no change in image quality in 3, 3 and 6 studies, respectively when compared to the standard CTPA protocol. The subjective assessment indicated similar image quality in 11 studies between low-dose and standard CTPA groups, and improved image quality in 1 study with low-dose CTPA. Conclusion: This review shows that double low-dose CTPA is feasible in the diagnosis of pulmonary embolism with significant reductions in both radiation and contrast medium doses, without compromising diagnostic image quality.

scholarly journals Do Orthopedic Surgeons or Neurosurgeons Detect More Hip Disorders in Patients with Hip-Spine Syndrome? A Nationwide Database Study

2021 ◽  
Vol 11 (4) ◽  
pp. 485
Author(s):  
Tsung-Cheng Yin ◽  
Adam M. Wegner ◽  
Meng-Ling Lu ◽  
Yao-Hsu Yang ◽  
Yao-Chin Wang ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Spine Surgery ◽  
Hip Surgery ◽  
Lumbar Spine Surgery ◽  
Research Database ◽  
X Rays ◽  
Replacement Surgery ◽  
Orthopedic Surgeons ◽  
Spine Pathology ◽  
Sh Group

Background: Disorders of the hip and lumbar spine can create similar patterns of pain and dysfunction. It is unknown whether all surgeons, regardless of orthopedic or neurosurgery training, investigate and diagnose concurrent hip and spine pathology at the same rate. Methods: Data were retrieved from Taiwan’s National Health Insurance Research Database (NHIRD). Enrolled patients were stratified into hip and spine surgery at the same admission (Both), hip surgery before spine surgery (HS), or spine surgery before hip surgery (SH). The SH group was further subdivided based on whether spine surgery was performed by an orthopedic surgeon (OS) or neurosurgeon (NS), and differences in preoperative radiographic examinations and diagnoses were collected and analyzed. Results: In total, 1824 patients received lumbar spine surgery within 1 year before or after hip replacement surgery. Of these, 103 patients had spine and hip surgery in the same admission (Both), 1290 patients had spine surgery before hip surgery (SH), and 431 patients had hip surgery before spine surgery (HS). In the SH group, patients were categorized into spine surgery by orthopedic surgeons (OS) (n = 679) or neurosurgeons (NS) (n = 522). In the SH group, orthopedic surgeons investigated hip pathology with X-rays more often (52.6% vs. 38.1%, p < 0.001) and diagnosed more cases of hip disease (43.6% vs. 28.9%, p < 0.001) than neurosurgeons. Conclusions: Of patients in Taiwan’s NHIRD who had concurrent surgical degenerative hip and lumbar spine disorders who had spine surgery before hip surgery, orthopedic surgeons obtained hip images and made hip-related diagnoses more frequently than did neurosurgeons.

Reactive oxygen species in cell responses to toxic agents

2002 ◽  
Vol 21 (2) ◽  
pp. 85-90 ◽  
Author(s):  
L E Feinendegen
Keyword(s):  
Radiation Exposure ◽  
Mammalian Cells ◽  
Low Dose ◽  
X Rays ◽  
Low Dose Radiation ◽  
Cell Responses ◽  
Toxic Agents ◽  
Particle Tracks ◽  
Dose Radiation

This review first summarizes experimental data on biological effects of different concentrations of ROS in mammalian cells and on their potential role in modifying cell responses to toxic agents. It then attempts to link the role of steadily produced metabolic ROS at various concentrations in mammalian cells to that of environmentally derived ROS bursts from exposure to ionizing radiation. The ROS from both sources are known to both cause biological damage and change cellular signaling, depending on their concentration at a given time. At low concentrations signaling effects of ROS appear to protect cellular survival and dominate over damage, and the reverse occurs at high ROS concentrations. Background radiation generates suprabasal ROS bursts along charged particle tracks several times a year in each nanogram of tissue, i.e., average mass of a mammalian cell. For instance, a burst of about 200 ROS occurs within less than a microsecond from low-LET irradiation such as X-rays along the track of a Compton electron (about 6 keV, ranging about 1 μm). One such track per nanogram tissue gives about 1 mGy to this mass. The number of instantaneous ROS per burst along the track of a 4-meV ¬-particle in 1 ng tissue reaches some 70000. The sizes, types and sites of these bursts, and the time intervals between them directly in and around cells appear essential for understanding low-dose and low dose-rate effects on top of effects from endogenous ROS. At background and low-dose radiation exposure, a major role of ROS bursts along particle tracks focuses on ROS-induced apoptosis of damage-carrying cells, and also on prevention and removal of DNA damage from endogenous sources by way of temporarily protective, i.e., adaptive, cellular responses. A conclusion is to consider low-dose radiation exposure as a provider of physiological mechanisms for tissue homoeostasis.

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