scholarly journals Radiation Dose Reduction in CT Torsion Measurement of the Lower Limb: Introduction of a New Ultra-Low Dose Protocol

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1209
Author(s):  
Gabriel Keller ◽  
Simon Götz ◽  
Mareen Sarah Kraus ◽  
Leonard Grünwald ◽  
Fabian Springer ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Lower Limb ◽  
Low Dose ◽  
Body Volume ◽  
Reconstruction Algorithms ◽  
Pelvic Radiograph ◽  
Lower Radiation Dose ◽  
Median Total Dose ◽  
Image Reconstruction Algorithms

This study analyzed the radiation exposure of a new ultra-low dose (ULD) protocol compared to a high-quality (HQ) protocol for CT-torsion measurement of the lower limb. The analyzed patients (n = 60) were examined in the period March to October 2019. In total, 30 consecutive patients were examined with the HQ and 30 consecutive patients with the new ULD protocol comprising automatic tube voltage selection, automatic exposure control, and iterative image reconstruction algorithms. Radiation dose parameters as well as the contrast-to-noise ratio (CNR) and diagnostic confidence (DC; rated by two radiologists) were analyzed and potential predictor variables, such as body mass index and body volume, were assessed. The new ULD protocol resulted in significantly lower radiation dose parameters, with a reduction of the median total dose equivalent to 0.17 mSv in the ULD protocol compared to 4.37 mSv in the HQ protocol (p < 0.001). Both groups showed no significant differences in regard to other parameters (p = 0.344–0.923). CNR was 12.2% lower using the new ULD protocol (p = 0.033). DC was rated best by both readers in every HQ CT and in every ULD CT. The new ULD protocol for CT-torsion measurement of the lower limb resulted in a 96% decrease of radiation exposure down to the level of a single pelvic radiograph while maintaining good image quality.

scholarly journals Value of whole-body low-dose computed tomography in patients with ventriculoperitoneal shunts: a retrospective study

2018 ◽  
Vol 129 (6) ◽  
pp. 1598-1603 ◽  
Author(s):  
Andrej Pala ◽  
Fadi Awad ◽  
Michael Braun ◽  
Michal Hlavac ◽  
Arthur Wunderlich ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Low Dose ◽  
Whole Body ◽  
Consecutive Series ◽  
Dose Length Product ◽  
Shunt System ◽  
Distal Catheter ◽  
Vp Shunt

OBJECTIVEThe gold standard for evaluation of ventriculoperitoneal (VP) shunt position, dislocation, or disconnection is conventional radiography. Yet, assessment with this modality can be challenging because of low image quality and can result in repetitive radiation exposure with high fluctuation in the radiation dose. Recently, CT-based radiation doses have been significantly reduced by using low-dose protocols. Thus, whole-body low-dose CT (LDCT) has become applicable for routine use in VP shunt evaluation. The authors here compared image quality and approximate radiation dose between radiography and LDCT in patients with implanted VP shunt systems.METHODSVentriculoperitoneal shunt systems have been investigated with LDCT scanning at the authors’ department since 2015. A consecutive series of 57 patients (70 investigations) treated between 2015 and 2016 was retrospectively assessed. A historical patient cohort that had been evaluated with radiography was compared with the LDCT patients in terms of radiation dose and image quality. Three independent observers evaluated projection of the valve pressure level and correct intraperitoneal position, as well as complete shunt projection, using a Likert-type scale of 1–5, where 1 indicated “not assessable” and 5 meant “assessable with high accuracy.” Descriptive statistics and the Mann-Whitney U-test were used for analysis.RESULTSTwenty-seven radiographs (38.6%) and 43 LDCT scans (61.4%) were analyzed. The median dose-length product (DLP) of the LDCT scans was 100 mGy·cm (range 59.9–183 mGy·cm). The median total dose-area product (DAP) of the radiographic images was 3177 mGy·cm2 (range 641–13,833 mGy·cm2). The estimated effective dose (EED) was significantly lower with the LDCT scan (p < 0.001). The median EED was 4.93 and 1.90 mSv for radiographs and LDCT, respectively. Significantly better identification of the abdominal position of the distal shunt catheter was achieved with LDCT (p < 0.001). Simultaneously, significantly improved visualization of the entire shunt system was realized with this technique (p < 0.001). On the contrary, identification of the valve settings was significantly worse with LDCT (p < 0.001).CONCLUSIONSWhole-body LDCT scanning allows good visualization of the distal catheter after VP shunt placement. Despite the fact that only a rough estimation of effective doses is possible in a direct comparison of LDCT and radiography, the data showed that shunt assessment via LDCT does not lead to greater radiation exposure. Thus, especially in difficult anatomical conditions, as in patients who have undergone multiple intraabdominal surgeries, have a high BMI, or are immobile, the use of LDCT shunt evaluation has high clinical value. Further data are needed to determine the value of LDCT for the evaluation of complications or radiation dose in pediatric patients.

scholarly journals Low-Dose Hepatopancreatic MDCT: Practical Experience of Applicability

2017 ◽  
pp. 28-35
Author(s):  
V. G. Aznaurov ◽  
E. V. Kondratiev ◽  
N. K. Oganesyan ◽  
G. G. Karmazanovsky
Keyword(s):  
Radiation Exposure ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Abdominal Cavity ◽  
Practical Experience ◽  
Qualitative Assessment ◽  
Pancreatic Tumors ◽  
Reconstruction Algorithms ◽  
Liver And Pancreas ◽  
Noise Data

Aims: to evaluate the possibilities of low-dose MDCT protocols in visualization of liver and pancreatic tumors.Materials and methods. 40 patients were enrolled in study and divided into 2 groups. Two scanning protocols were used, differing by the voltage on the X-ray tube-standard 120 kV, and the modified 100 kV. All studies were performed with intravenous administration of a contrast agent. The data – noise, a circumference of abdominal cavity, a relation “contrast-noise”, data of contrast strengthening of organs were evaluated. The tomograms were reconstructed using standard and iterative reconstruction algorithms. A qualitative assessment of the images was carried out according to 2 parameters – the evaluation of the whole image and the visualization of tumor on a 3-point scale.Results. Radiation exposure decreased by 31.5% using the modified protocol. The noise level did not differ with the use of standard reconstruction, but it decreased markedly using iterative reconstruction. The contrast-to-noise ratio turned out to be higher in the “100 kV” group and consistently increased with increasing levels of iterative reconstruction. Evaluations of the visualization of tumors were significantly higher in the “100 kV” group.Conclusion. The use of low-dose protocols is justified, it allows to seriously reduce the radiation exposure, improving visualization of the liver and pancreas tumors (primarily hypervascular). Application of iterative reconstruction algorithms allows achieving significant improvement in image quality and noise reduction.

Evaluation of an iterative model-based CT reconstruction algorithm by intra-patient comparison of standard and ultra-low-dose examinations

2018 ◽  
Vol 59 (10) ◽  
pp. 1225-1231 ◽  
Author(s):  
Peter B Noël ◽  
Stephan Engels ◽  
Thomas Köhler ◽  
Daniela Muenzel ◽  
Daniela Franz ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
Low Dose ◽  
Standard Dose ◽  
Health Concern ◽  
Generation Model ◽  
Reconstruction Algorithms ◽  
Low Dose Ct ◽  
Model Based

Background The explosive growth of computer tomography (CT) has led to a growing public health concern about patient and population radiation dose. A recently introduced technique for dose reduction, which can be combined with tube-current modulation, over-beam reduction, and organ-specific dose reduction, is iterative reconstruction (IR). Purpose To evaluate the quality, at different radiation dose levels, of three reconstruction algorithms for diagnostics of patients with proven liver metastases under tumor follow-up. Material and Methods A total of 40 thorax–abdomen–pelvis CT examinations acquired from 20 patients in a tumor follow-up were included. All patients were imaged using the standard-dose and a specific low-dose CT protocol. Reconstructed slices were generated by using three different reconstruction algorithms: a classical filtered back projection (FBP); a first-generation iterative noise-reduction algorithm (iDose4); and a next generation model-based IR algorithm (IMR). Results The overall detection of liver lesions tended to be higher with the IMR algorithm than with FBP or iDose4. The IMR dataset at standard dose yielded the highest overall detectability, while the low-dose FBP dataset showed the lowest detectability. For the low-dose protocols, a significantly improved detectability of the liver lesion can be reported compared to FBP or iDose4 ( P = 0.01). The radiation dose decreased by an approximate factor of 5 between the standard-dose and the low-dose protocol. Conclusion The latest generation of IR algorithms significantly improved the diagnostic image quality and provided virtually noise-free images for ultra-low-dose CT imaging.

scholarly journals Radiation Exposure during Percutaneous Endoscopic Lumbar Discectomy: Interlaminar versus Transforaminal

2019 ◽  
Vol 38 (01) ◽  
pp. 031-035
Author(s):  
Marcelo Amato ◽  
Bruno Aprile ◽  
Cezar de Oliveira
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Lumbar Discectomy ◽  
P Value ◽  
Retrospective Evaluation ◽  
Percutaneous Endoscopic Lumbar Discectomy ◽  
Lower Radiation Dose ◽  
Minimally Invasive Spine ◽  
Endoscopic Lumbar Discectomy ◽  
Fluoroscopy Guidance

Objective Percutaneous endoscopic lumbar discectomy (PELD) relies heavily on fluoroscopy guidance; therefore, medical staff exposure to radiation has become an important issue. The purpose of this study was to determine the radiation dose and the amount of time to which the surgeons are exposed during PELD and to compare both parameters in the transforaminal (TF) and interlaminar (IL) approaches. Although they are considerably different, they may be wrongly considered together. Methods A retrospective evaluation of the last 20 PELD performed by the authors is presented. Patients were distributed in 2 groups. Six (1F, 5M) patients were submitted to IL-PELD and 14 (6F, 8M) to TF-PELD. Fluoroscopy reports were obtained from patients' records, all performed with the same C-Arm device and software mode. Groups were compared using unpaired t-test. Results The IL group showed an average radiation exposure of 8.37 ± 4.21 mGy and duration of 11.1 ± 5.45 seconds, while the TF group showed an average radiation exposure of 28.92 ± 7.56 mGy and duration of 42 ± 16.64 seconds. The p-value for radiation was 0.0000036, and for time it was 0.00027. Conclusions Interlaminar PELD requires a lower radiation dose and a shorter amount of exposure than TF-PELD. Studies that concern radiation required for minimally-invasive spine surgeries should consider the PELD approaches separately.

Ct of the sacroiliac joints

1997 ◽  
Vol 38 (5) ◽  
pp. 870-875 ◽  
Author(s):  
J. Damilakis ◽  
P. Prassopoulos ◽  
K. Perisinakis ◽  
C. Faflia ◽  
N. Gourtsoyiannis
Keyword(s):  
Low Dose ◽  
High Spatial Frequency ◽  
Reconstruction Algorithm ◽  
Conventional Radiography ◽  
Reconstruction Algorithms ◽  
Sacroiliac Joints ◽  
Thin Sections ◽  
Lower Radiation Dose ◽  
Ct Protocol ◽  
Dose Measurements

Purpose: The aim was to select an optimal technique for low-dose high-resolution CT of the sacroiliac joints (SJ). Material and Methods: Dose measurements were performed on a Rando anthropomorphic phantom using thermoluminescence dosimeters for 4 CT protocols and 2 conventional radiography protocols used for SJ evaluation. Six available reconstruction algorithms were tested on CT protocols using 285–665 mAs and 120 or 130 kVp settings and noncontiguous 1.5-mm-thin sections with 3.5-mm intervals. Settings with optimum performance on phantom tests were also applied in a series of 10 patients with SJ arthropathies. Results: A CT protocol using 120 kVp/175 mA2.9 s/1.5-mm slice thicknessb-mm table increment implied the lower radiation dose among all examination protocols tested and provided high image quality of the SJ. A reconstruction algorithm yielding images of improved spatial resolution with acceptable noise was selected. Conclusion: A high spatial frequency reconstruction algorithm, and 120 kVp and 508 mAs were considered optimal for a low-dose CT examination of the SJ that employed narrow (1.5 mm) slice images with interspacing.

scholarly journals Possibilities of applying model-based iterative reconstructions in computed tomography of the lungs

2020 ◽  
Vol 24 (3) ◽  
pp. 107-113
Author(s):  
A. Yu. Silin ◽  
I. S. Gruzdev ◽  
G. V. Berkovich ◽  
A. E. Nikolaev ◽  
S. P. Morozov
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Low Dose ◽  
Ct Images ◽  
Lung Pathology ◽  
Diagnostic Quality ◽  
Screening Programs

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.

scholarly journals Ulltra-low-dose computed tomography in the diagnosis of diseases of the paranasal sinuses in pediatric population: literature review

2021 ◽  
Vol 25 (3) ◽  
pp. 109-118
Author(s):  
A. Sh. Laipan ◽  
S. P. Morozov ◽  
L. A. Nizovtsova ◽  
I. A. Blokhin ◽  
V. A. Gombolevsky
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Paranasal Sinuses ◽  
Low Dose ◽  
Pediatric Population ◽  
Professional Community ◽  
Low Dose Computed Tomography ◽  
Risk Of Cancer ◽  
Radiological Studies

Background. Sinonasal diseases are widespread in childhood. Radiological studies, including computer tomography, are an optimal and effective method of diagnosis. The child's body is more sensitive to radiation exposure than adults. The threshold of exposure, which may induce internal organs injury in children, requires a precise selection of the radiological method with minimal radiation dose. There is currently no unified position in the professional community on the appropriateness of the use of ultra-low-dose computed tomography in pediatrics.We reviewed the data on the appropriateness and effectiveness of paranasal low-dose computed tomography in pediatrics.Materials. 57 domestic and foreign publications, for the period from January 2001 to November 2019. In order to achieve the objective, we analyzed relevant domestic and foreign publications in scientific libraries e-LIBRARY, PubMed, Google Scholar per the keywords: “low-dose CT”, “children”, “paranasal sinus”, “pediatric”, “diagnosis”, “children”, “low-dose computed tomography”, “sinusitis”, “paranasal sinuses”.Results. The analysis of the available literature allowed summarizing the current data on pediatric paranasal disease diagnostics and the use of computed tomography, as well as to identify possible options for reducing radiation dose.Conclusions. Conducting many radiological examinations in a child leads to the risk of cancer. However, these examinations are an effective way to diagnose paranasal diseases, and a CT scan is the “gold standard”. The actual task is to develop a CT technique with reduced radiation exposure without compromising image quality. The need to review and optimize the standard protocols of radiological studies to determine the efficacy and feasibility of studies with minimal radiation exposure to children is justified.

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