To investigate dose reduction and comparability of standard dose CT vs Ultra low dose CT in evaluating pulmonary emphysema

2019 ◽  
Vol 53 ◽  
pp. 115-119 ◽  
Author(s):  
Ciara O'Brien ◽  
Hong Kuan Kok ◽  
Brendan Kelly ◽  
Kanako Kumamaru ◽  
Abhilash Sahadevan ◽  
...  
Keyword(s):  
Dose Reduction ◽  
Pulmonary Emphysema ◽  
Low Dose ◽  
Standard Dose ◽  
Low Dose Ct

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 Abdominal CT radiation dose reduction at Siriraj Hospital (Phase II)

2020 ◽  
Vol 21 (3) ◽  
pp. 5-24
Author(s):  
Piyaporn Apisarnthanarak ◽  
Suchanya Hongpinyo ◽  
Krittya Saysivanon ◽  
Chulaluck Boonma ◽  
Sureerat Janpanich ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Low Dose ◽  
Standard Dose ◽  
Image Noise ◽  
Satisfaction Score ◽  
Abdominal Ct ◽  
Low Dose Ct ◽  
The Mean

Objective: To compare radiation dose, radiologists’ satisfaction, and image noise between the standard dose abdominal CT currently performed at our hospital and the new automatic tube current modulation (ATCM) low dose abdominal CT, using various parameters (0%, 10%, 20%, and 30%) of the Adaptive Statistical Iterative Reconstruction (ASiR). Materials and Methods: We prospectively performed the ATCM low dose abdominal CT in 111 participants who had prior standard dose CT for comparison. The ATCM low dose CT images were post processed with 4 parameters (0%, 10%, 20% and 30%) of ASiR on a CT workstation. The volume CT dose index (CTDIvol) of the ATCM low dose and the standard dose CT were compared. Four experienced abdominal radiologists independently assessed the quality of the ATCM low dose CT with the aforementioned ASiR parameters using a 5-point-scale satisfaction score (1 = unacceptable, 2 = poor, 3 = average, 4 = good, and 5 = excellent image quality) by using the prior standard dose CT as a reference of an excellent image quality (5). Each reader selected the preferred ASiR parameter for each participant. The image noise of the liver and the aorta in all 5 techniques (1 prior standard dose and 4 current ATCM low dose techniques) was measured. The correlation between the image quality vs the participants’ body mass index (BMI) and waist circumferences were analyzed. Results: The mean CTDIvol of the ATCM low dose CT was significantly lower than of the standard dose CT (7.29 ± 0.20 vs 11.28 ± 0.23 mGy, p<0.001). The mean satisfaction score for the ATCM low dose CT with 0%, 10%, 20% and 30% ASiR were 4.14, 4.16, 4.17, and 4.26, respectively with the ranges of 3 to 5 in all techniques. The preferred ASiR parameters of each participant randomly selected by each reader were varied, depending on the readers’ opinions. The mean image noise of the aorta on the standard dose CT and the ATCM low dose CT with 0%, 10%, 20%, and 30% ASiR was 30.69, 36.60, 34.05, 31.43, and 29.09, respectively, while the mean image noise of the liver was 24.96, 29.90, 27.86, 25.66, and 23.68, respectively. There was a correlation between the image quality (satisfaction score and image noise) vs the participants’ BMI and waist circumferences. Conclusion: The ATCM low dose CT received acceptable radiologists’ satisfaction with significant radiation dose reduction. The increment of ASiR was helpful in reducing the image noise and had a tendency to increase the radiologists’ satisfaction score.

Ultra-Low-Dose CT of the Thorax Using Iterative Reconstruction: Evaluation of Image Quality and Radiation Dose Reduction

2015 ◽  
Vol 204 (6) ◽  
pp. 1197-1202 ◽  
Author(s):  
Yookyung Kim ◽  
Yoon Kyung Kim ◽  
Bo Eun Lee ◽  
Seok Jeong Lee ◽  
Yon Ju Ryu ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Radiation Dose Reduction ◽  
Low Dose Ct

A new low-dose CT examination compared with standard-dose CT in the diagnosis of acute sinusitis

2003 ◽  
Vol 13 (5) ◽  
pp. 976-980 ◽  
Author(s):  
T. Hagtvedt ◽  
T. Aaløkken ◽  
J. Nøtthellen ◽  
A. Kolbenstvedt
Keyword(s):  
Low Dose ◽  
Standard Dose ◽  
Acute Sinusitis ◽  
Low Dose Ct ◽  
Ct Examination

Comparison of low dose CT and standard dose Cone-beam CT for periprocedural 3D-planning of TIPSS guidance

2020 ◽  
Author(s):  
A Estler ◽  
K Nikolaou ◽  
R Hoffmann ◽  
J Herrmann ◽  
U Grosse ◽  
...  
Keyword(s):  
Low Dose ◽  
Standard Dose ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Low Dose Ct

scholarly journals Feasibility of Ultra-Low-Dose CT for Bronchoscopy of Peripheral Lung Lesions

Medicina ◽  
2020 ◽  
Vol 56 (9) ◽  
pp. 479 ◽  
Author(s):  
Jung Seop Eom ◽  
Geewon Lee ◽  
Jiyeon Roh ◽  
Hyun Sung Chung ◽  
Yeon Joo Jeong
Keyword(s):  
Thin Section ◽  
Wall Thickness ◽  
Low Dose ◽  
Standard Dose ◽  
Endobronchial Ultrasound ◽  
Lung Lesions ◽  
Low Dose Ct ◽  
Group 4 ◽  
Peripheral Lung ◽  
Group 2

Background and objectives: Thin-section computed tomography (CT) is essential for identifying small bronchi during bronchoscopy using radial endobronchial ultrasound. Some patients should receive an additional CT for a thin-section image. We performed a retrospective study with a prospectively collected database to identify the optimal radiation dose for thin-section CT during peripheral bronchoscopy. Materials and Methods: In total, 91 patients with peripheral lung lesions underwent thin-section CT (both standard CT as a reference and ultra-low-dose CT (ultra-LDCT)). The patients were randomly assigned to one of four groups according to the ultra-LDCT parameters: group 1 = 120 kVp, 25 mAs; group 2 = 100 kVp, 15 mAs; group 3 = 120 kVp, 5 mAs; and group 4 = 100 kVp, 5 mAs. Two radiologists and two physicians analyzed both the standard CT and ultra-LDCT. Results: The effective doses (EDs) of ultra-LDCT significantly differed among the four groups (median EDs were 0.88, 0.34, 0.19, and 0.12 mSv for groups 1–4, respectively; p < 0.001). Median differences in peripheral airway wall thickness were higher in group 4 than in other groups (differences in median wall thickness measured by two radiologists were 0.4–0.5 mm and 0.8–0.9 mm for groups 1–3 and group 4, respectively). Bronchus signs on ultra-LDCT in groups 1 and 2 were well correlated with those of the standard-dose CT (accuracies of two radiologists and two pulmonary physicians were 95–100%). Conclusions: Our results indicate that ultra-LDCT with ED of >0.34 mSv (ED of group 2) is feasible for peripheral bronchoscopy.

Prediction of invasive adenocarcinomas manifesting as pure ground-glass nodules based on radiomic signature of low-dose CT in lung cancer screening

2022 ◽  
Author(s):  
Yong Li ◽  
Jieke Liu ◽  
Xi Yang ◽  
Hao Xu ◽  
Haomiao Qing ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Screening ◽  
Low Dose ◽  
Validation Cohort ◽  
Standard Dose ◽  
Lung Cancer Screening ◽  
Ground Glass ◽  
Semantic Features ◽  
Low Dose Ct ◽  
Ground Glass Nodules

Objectives: To develop a radiomic model based on low-dose CT (LDCT) to distinguish invasive adenocarcinomas (IAs) from adenocarcinoma in situ/minimally invasive adenocarcinomas (AIS/MIAs) manifesting as pure ground-glass nodules (pGGNs) and compare its performance with conventional quantitative and semantic features of LDCT, radiomic model of standard-dose CT, and intraoperative frozen section (FS). Methods: A total of 147 consecutive pathologically confirmed pGGNs were divided into primary cohort (43 IAs and 60 AIS/MIAs) and validation cohort (19 IAs and 25 AIS/MIAs). Logistic regression models were built using conventional quantitative and semantic features, selected radiomic features of LDCT and standard-dose CT, and intraoperative FS diagnosis, respectively. The diagnostic performance was assessed by area under curve (AUC) of receiver operating characteristic curve, sensitivity, and specificity. Results: The AUCs of quantitative-semantic model, radiomic model of LDCT, radiomic model of standard-dose CT, and FS model were 0.879 (95% CI, 0.801–0.935), 0.929 (95% CI, 0.862–0.971), 0.941 (95% CI, 0.876–0.978), and 0.884 (95% CI, 0.805–0.938) in the primary cohort and 0.897 (95% CI, 0.768–0.968), 0.933 (95% CI, 0.815–0.986), 0.901 (95% CI, 0.773–0.970), and 0.828 (95% CI, 0.685–0.925) in the validation cohort. No significant difference of the AUCs was found among these models in both the primary and validation cohorts (all p > 0.05). Conclusions: The LDCT-based quantitative-semantic score and radiomic signature, with good predictive performance, can be preoperative and non-invasive biomarkers for assessing the invasive risk of pGGNs in lung cancer screening. Advances in knowledge: The LDCT-based quantitative-semantic score and radiomic signature, with the equivalent performance to the radiomic model of standard-dose CT, can be preoperative predictors for assessing the invasiveness of pGGNs in lung cancer screening and reducing excess examination and treatment.

Is sub-mSv CT for evaluation of non-specific findings in bone scintigraphy of oncological patients feasible?

2019 ◽  
Vol 61 (5) ◽  
pp. 662-667 ◽  
Author(s):  
Yousuf Zakko ◽  
Daniel Thor ◽  
Irina Savitcheva ◽  
Albert Sundvall ◽  
Cecilia Wassberg ◽  
...  
Keyword(s):  
Bone Scintigraphy ◽  
Low Dose ◽  
Standard Dose ◽  
Observer Agreement ◽  
Ct Scans ◽  
Significant Shift ◽  
Low Dose Ct ◽  
Oncological Patients ◽  
Significant Difference

Background Hybrid SPECT/CT systems allow the shortening of lead time for investigation of cancer patients, since a complementary CT for radiological characterization of focally increased isotope uptake of unclear origin in bone scintigraphy can be performed simultaneously. The use of low-dose CT (sub-mSv CT) reduces radiation dose compared to standard-dose CT and facilitates the application of complementary CT. Purpose To test the feasibility of sub-mSv CT for the characterization of non-specific findings in the bone scintigraphy of oncological patients. Material and Methods Nineteen oncological patients with a total of 50 findings of unclear origin on bone scintigraphy which required further correlation with morphologic data were included in the study. Each patient underwent two CT scan series consecutively: one low-dose CT and one standard-dose CT. The CT studies were randomized and each finding was rated by four blinded experienced radiologists. A shift in ratings between standard-dose and low-dose images were assessed using the Stuart–Maxwell chi-squared test. Inter-observer agreement and intra-observer agreement was assessed using Light’s kappa and Cohen’s kappa, respectively. Results The mean effective dose of low-dose CT scans was 0.8 mSv compared to 4.2 mSv for the standard-dose CT scans. No statistically significant shift in ratings was observed ( P = 0.62). There was no statistically significant difference in the inter-observer agreements: the values for the standard-dose and low-dose groups were 0.68 (95% confidence interval [CI] 0.57–0.79) and 0.60 (95% CI 0.47–0.72), respectively. Conclusion These results indicate that sub-mSv CT for characterization of non-specific findings in bone scintigraphy of oncological patients is feasible.

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