1
|
Park J, Kim HK, Park EA, Park JB, Lee SP, Lee W, Kim YJ, Sohn DW. Coronary Computed Tomography Angiography for the Diagnosis of Vasospastic Angina: Comparison with Invasive Coronary Angiography and Ergonovine Provocation Test. Korean J Radiol 2020; 20:719-728. [PMID: 30993923 PMCID: PMC6470084 DOI: 10.3348/kjr.2018.0847] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 01/11/2019] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVE To investigate the diagnostic validity of coronary computed tomography angiography (cCTA) in vasospastic angina (VA) and factors associated with discrepant results between invasive coronary angiography with the ergonovine provocation test (iCAG-EPT) and cCTA. MATERIALS AND METHODS Of the 1397 patients diagnosed with VA from 2006 to 2016, 33 patients (75 lesions) with available cCTA data from within 6 months before iCAG-EPT were included. The severity of spasm (% diameter stenosis [%DS]) on iCAG-EPT and cCTA was assessed, and the difference in %DS (Δ%DS) was calculated. Δ%DS was compared after classifying the lesions according to pre-cCTA-administered sublingual nitroglycerin (SL-NG) or beta-blockers. The lesions were further categorized with %DS ≥ 50% on iCAG-EPT or cCTA defined as a significant spasm, and the diagnostic performance of cCTA on identifying significant spasm relative to iCAG-EPT was assessed. RESULTS Compared to lesions without SL-NG treatment, those with SL-NG treatment showed a higher Δ%DS (39.2% vs. 22.1%, p = 0.002). However, there was no difference in Δ%DS with or without beta-blocker treatment (35.1% vs. 32.6%, p = 0.643). The significant difference in Δ%DS associated with SL-NG was more prominent in patients who were aged < 60 years, were male, had body mass index < 25 kg/m², and had no history of hypertension, diabetes, or dyslipidemia. Based on iCAG-EPT as the reference, the per-lesion-based sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of cCTA for VA diagnosis were 7.5%, 94.0%, 60.0%, 47.1%, and 48.0%, respectively. CONCLUSION For patients with clinically suspected VA, confirmation with iCAG-EPT needs to be considered without completely excluding the diagnosis of VA simply based on cCTA results, although further prospective studies are required for confirmation.
Collapse
Affiliation(s)
- Jiesuck Park
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Hyung Kwan Kim
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea.
| | - Eun Ah Park
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.
| | - Jun Bean Park
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Seung Pyo Lee
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Whal Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
| | - Yong Jin Kim
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Dae Won Sohn
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| |
Collapse
|
2
|
Di Cesare E, Di Sibio A, Gennarelli A, Di Luzio M, Casazza I, Splendiani A, Di Cesare A, Gravina GL, Barile A, Masciocchi C. Low Dose versus Standard Single Heartbeat Acquisition Coronary Computed Tomography Angiography. J Clin Imaging Sci 2018; 8:52. [PMID: 30546936 PMCID: PMC6251242 DOI: 10.4103/jcis.jcis_51_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 09/18/2018] [Indexed: 11/21/2022] Open
Abstract
Purpose: The aim of this study was to compare image quality and mean radiation dose between two groups of patients undergoing coronary computed tomography angiography (CCTA) using a 640-slice CT scanner with two protocols with different noise level thresholds expressed as standard deviation (SD). Materials and Methods: Two-hundred and sixty-eight patients underwent a CCTA with 640 slice CT scanner. In the experimental group (135 patients), an SD 51 protocol was employed; in the control group (133 patients), an SD 33 protocol was used. Mean effective dose and image quality with both objective and subjective measures were assessed. Image quality was subjectively assessed using a five-point scoring system. Segments scoring 2, 3, and 4 were considered having diagnostic quality, while segments scoring 0 and 1 were considered having nondiagnostic quality. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between the two groups as well as the effective radiation dose (ED) was finally assessed. Results: Comparative analysis considering diagnostic quality (2, 3, and 4 score) and nondiagnostic (score 0 and 1) quality demonstrated that image quality of SD 51 group is not significantly lower than that of S33 group. The noise was significantly higher in the SD 51 group than in the SD 33 group (P < 0.0001). The SNR and CNR were higher in the SD 33 group than in SD 51 group (P < 0.0001). Mean effective dose was 49% lower in the SD 51 group than in SD 33 group; indeed mean effective dose was 1.43 mSv ± 0.67 in the SD 51 group while it was 2.8 mSv ± 0.57 in the SD 33 group. Conclusion: Comparative analysis shows that using a 640-slice CT with a 51 SD protocol, it is possible to reduce the mean radiation dose while maintaining good diagnostic image quality.
Collapse
Affiliation(s)
- Ernesto Di Cesare
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Alessandra Di Sibio
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Antonio Gennarelli
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Margherita Di Luzio
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Ines Casazza
- Department of Radiology, Sant’Andrea Hospital, Sapienza University, Rome, Italy
| | - Alessandra Splendiani
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Annamaria Di Cesare
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Giovanni Luca Gravina
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Antonio Barile
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| | - Carlo Masciocchi
- Department of Biotechnological and Applied Clinical Science, University of L’aquila, L’aquila, Italy
| |
Collapse
|
3
|
Abdullah KA, McEntee MF, Reed W, Kench PL. Development of an organ-specific insert phantom generated using a 3D printer for investigations of cardiac computed tomography protocols. J Med Radiat Sci 2018; 65:175-183. [PMID: 29707915 PMCID: PMC6119733 DOI: 10.1002/jmrs.279] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/28/2018] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION An ideal organ-specific insert phantom should be able to simulate the anatomical features with appropriate appearances in the resultant computed tomography (CT) images. This study investigated a 3D printing technology to develop a novel and cost-effective cardiac insert phantom derived from volumetric CT image datasets of anthropomorphic chest phantom. METHODS Cardiac insert volumes were segmented from CT image datasets, derived from an anthropomorphic chest phantom of Lungman N-01 (Kyoto Kagaku, Japan). These segmented datasets were converted to a virtual 3D-isosurface of heart-shaped shell, while two other removable inserts were included using computer-aided design (CAD) software program. This newly designed cardiac insert phantom was later printed by using a fused deposition modelling (FDM) process via a Creatbot DM Plus 3D printer. Then, several selected filling materials, such as contrast media, oil, water and jelly, were loaded into designated spaces in the 3D-printed phantom. The 3D-printed cardiac insert phantom was positioned within the anthropomorphic chest phantom and 30 repeated CT acquisitions performed using a multi-detector scanner at 120-kVp tube potential. Attenuation (Hounsfield Unit, HU) values were measured and compared to the image datasets of real-patient and Catphan® 500 phantom. RESULTS The output of the 3D-printed cardiac insert phantom was a solid acrylic plastic material, which was strong, light in weight and cost-effective. HU values of the filling materials were comparable to the image datasets of real-patient and Catphan® 500 phantom. CONCLUSIONS A novel and cost-effective cardiac insert phantom for anthropomorphic chest phantom was developed using volumetric CT image datasets with a 3D printer. Hence, this suggested the printing methodology could be applied to generate other phantoms for CT imaging studies.
Collapse
Affiliation(s)
- Kamarul A. Abdullah
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
- Faculty of Health SciencesUniversiti Sultan Zainal AbidinTerengganuMalaysia
| | - Mark F. McEntee
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| | - Warren Reed
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| | - Peter L. Kench
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| |
Collapse
|
4
|
Object shape dependency of in-plane resolution for iterative reconstruction of computed tomography. Phys Med 2017; 33:146-151. [DOI: 10.1016/j.ejmp.2017.01.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 12/11/2016] [Accepted: 01/01/2017] [Indexed: 01/29/2023] Open
|
5
|
Precht H, Kitslaar PH, Broersen A, Dijkstra J, Gerke O, Thygesen J, Egstrup K, Lambrechtsen J. Influence of Adaptive Statistical Iterative Reconstruction on coronary plaque analysis in coronary computed tomography angiography. J Cardiovasc Comput Tomogr 2016; 10:507-516. [DOI: 10.1016/j.jcct.2016.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 09/22/2016] [Accepted: 09/26/2016] [Indexed: 10/20/2022]
|
6
|
Clark TJ, Wilson GJ, Maki JH. Effect of injection rate on contrast-enhanced MR angiography image quality: Modulation transfer function analysis. Magn Reson Med 2016; 78:357-369. [DOI: 10.1002/mrm.26349] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 06/29/2016] [Accepted: 06/29/2016] [Indexed: 12/20/2022]
|
7
|
Abdullah KA, McEntee MF, Reed W, Kench PL. Radiation dose and diagnostic image quality associated with iterative reconstruction in coronary CT angiography: A systematic review. J Med Imaging Radiat Oncol 2016; 60:459-68. [PMID: 27241506 DOI: 10.1111/1754-9485.12473] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 04/16/2016] [Indexed: 11/28/2022]
Abstract
The aim of this systematic review is to evaluate the radiation dose reduction achieved using iterative reconstruction (IR) compared to filtered back projection (FBP) in coronary CT angiography (CCTA) and assess the impact on diagnostic image quality. A systematic search of seven electronic databases was performed to identify all studies using a developed keywords strategy. A total of 14 studies met the criteria and were included in a review analysis. The results showed that there was a significant reduction in radiation dose when using IR compared to FBP (P < 0.05). The mean and standard deviation (SD) difference of CTDIvol and dose-length-product (DLP) were 14.70 ± 6.87 mGy and 186 ± 120 mGy.cm respectively. The mean ± SD difference of effective dose (ED ) was 2.9 ± 1.7 mSv with the range from 1.0 to 5.0 mSv. The assessment of diagnostic image quality showed no significant difference (P > 0.05). The mean ± SD difference of image noise, signal-noise ratio (SNR) and contrast-noise ratio (CNR) were 1.05 ± 1.29 HU, 0.88 ± 0.56 and 0.63 ± 1.83 respectively. The mean ± SD percentages of overall image quality scores were 71.79 ± 12.29% (FBP) and 67.31 ± 22.96% (IR). The mean ± SD percentages of coronary segment analysis were 95.43 ± 2.57% (FBP) and 97.19 ± 2.62% (IR). In conclusion, this review analysis shows that CCTA with the use of IR leads to a significant reduction in radiation dose as compared to the use of FBP. Diagnostic image quality of IR at reduced dose (30-41%) is comparable to FBP at standard dose in the diagnosis of CAD.
Collapse
Affiliation(s)
- Kamarul Amin Abdullah
- Discipline of Medical Radiation Sciences, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia.,Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | - Mark F McEntee
- Discipline of Medical Radiation Sciences, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia
| | - Warren Reed
- Discipline of Medical Radiation Sciences, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia
| | - Peter L Kench
- Discipline of Medical Radiation Sciences, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia
| |
Collapse
|
8
|
Di Cesare E, Gennarelli A, Di Sibio A, Felli V, Perri M, Splendiani A, Gravina GL, Barile A, Masciocchi C. 320-row coronary computed tomography angiography (CCTA) with automatic exposure control (AEC): effect of 100 kV versus 120 kV on image quality and dose exposure. Radiol Med 2016; 121:618-25. [PMID: 27169907 DOI: 10.1007/s11547-016-0643-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 04/18/2016] [Indexed: 01/02/2023]
Abstract
PURPOSE To compare the impact of a 100 kV tube voltage protocol to 120 kV in terms of image quality and radiation dose by a 320 row coronary computed tomography angiography (CCTA) with automatic exposure control (AEC). MATERIALS AND METHODS Using a propensity matched analysis we compared a group of 135 patients scanned using a 100 kV tube voltage protocol with a group of 135 subjects scanned employing a 120 kV tube voltage setting. In all subjects the heart rate (HR) was <65 bpm and all CT scans were acquired using a prospective ECG gating and AEC strategy. Mean effective radiation dose and subjective and objective (Noise or N, signal to noise ratio or SNR, contrast to noise ratio or CNR) image quality, were evaluated. Subjective quality was assessed by two experienced radiologists using a 5-point scale (0: non diagnostic-4: excellent) using the 15-segment American Heart Association (AHA) coronary artery classification. RESULTS Mean effective dose and noise were non significantly different between the two groups: mean effective dose was 2.89 ± 0.7 mSv in the 100 kV group and 2.80 ± 0.57 mSv in the 120 kV group (p = 0.25) while noise was 28.9 ± 3.3 in the 120 kV group and 29.05 ± 3.6 in the 100 kV group (p = 0.72). Both SNR and CNR were significantly higher in the 100 kV group than in the 120 kV group. This data agrees with the evidence that subjective quality was significantly higher in the 100 kV group in the middle and distal segmental classes. CONCLUSION Our study shows that, in using a 320 row CCTA with AEC strategy it is better to employ a 100 kV tube voltage protocol because compared to 120 kV tube voltage setting, it appears to significantly improve both subjective and objective image quality without decreasing the mean effective radiation dose.
Collapse
Affiliation(s)
- Ernesto Di Cesare
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
| | - Antonio Gennarelli
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Alessandra Di Sibio
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Valentina Felli
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Marco Perri
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Alessandra Splendiani
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Giovanni Luca Gravina
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Antonio Barile
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| | - Carlo Masciocchi
- Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy
| |
Collapse
|
9
|
Geyer LL, Schoepf UJ, Meinel FG, Nance JW, Bastarrika G, Leipsic JA, Paul NS, Rengo M, Laghi A, De Cecco CN. State of the Art: Iterative CT Reconstruction Techniques. Radiology 2015. [PMID: 26203706 DOI: 10.1148/radiol.2015132766] [Citation(s) in RCA: 395] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Lucas L Geyer
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - U Joseph Schoepf
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Felix G Meinel
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - John W Nance
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Gorka Bastarrika
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Jonathon A Leipsic
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Narinder S Paul
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Marco Rengo
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Andrea Laghi
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Carlo N De Cecco
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| |
Collapse
|
10
|
Litmanovich DE, Tack DM, Shahrzad M, Bankier AA. Dose reduction in cardiothoracic CT: review of currently available methods. Radiographics 2015; 34:1469-89. [PMID: 25310412 DOI: 10.1148/rg.346140084] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Radiation exposure from computed tomography (CT) has received much attention lately in the medical literature and the media, given the relatively high radiation dose that characterizes a CT examination. Although there are a variety of possible strategies for reducing radiation exposure from CT in an individual patient, optimal CT image acquisition requires that the radiologist understand new scanner technology and how to implement the most effective means of dose reduction while maintaining image quality. The authors describe a practical approach to dose reduction in cardiothoracic radiology, discussing CT radiation dose metrics (eg, CT dose index, dose-length product, effective diameter, and size-specific dose estimate) as well as CT scanner parameters that directly or indirectly influence radiation dose (eg, scan length, x-ray tube output, tube current modulation, pitch, image reconstruction techniques [including iterative reconstruction], and noise reduction). These variables are discussed in terms of their relative importance to image quality and the implications of parametric changes for image quality and diagnostic content, and practical recommendations are made for their immediate implementation in the clinical setting. Taken together, the principles of physics and key parameters involved in reducing radiation dose while maintaining image quality can serve as a "survival guide" for a diagnostic radiology practice.
Collapse
Affiliation(s)
- Diana E Litmanovich
- From the Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, Shapiro 4, Boston, MA 02215 (D.E.L., M.S., A.A.B.); and Department of Radiology, Epicura Hospital, Baudour, Belgium (D.M.T.)
| | | | | | | |
Collapse
|
11
|
Güler E, Vural V, Ünal E, Köse IÇ, Akata D, Karcaaltıncaba M, Hazırolan T. Effect of iterative reconstruction on image quality in evaluating patients with coronary calcifications or stents during coronary computed tomography angiography: a pilot study. Anatol J Cardiol 2015; 16:119-24. [PMID: 26467371 PMCID: PMC5336725 DOI: 10.5152/akd.2015.5920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To determine the effect of "Iterative Reconstruction in Image Space" (IRIS) on image quality by comparing reconstructions of both medium and sharp kernels when evaluating coronary calcifications or stents during coronary computed tomography (CT) angiography. METHODS Thirty one consecutive patients were scanned with an electrocardiogram-gated helical technique on a dual-source CT system. Image reconstruction was performed using standard filtered back projection (FBP) and IRIS algorithm on both medium and sharp kernels (B26f, I26f, B46f, I46f). Each reconstruction was derived from the same raw data. Two blinded readers graded image quality using a five-point scale. Noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) were obtained. Noise was derived from the ascending aorta and left ventricle. SNR was obtained from sinus Valsalva, interventricular septum, and coronary vessels. CNR was obtained from septum, coronary vessels, and left ventricle. Comparisons of paired results between FBP and IRIS images were analyzed using the repeated measures analysis of variance method. Interreader correlation was assessed using weighted Kappa statistic. RESULTS Noise values of the ascending aorta and left ventricle were significantly lower in the images reconstructed with IRIS than those reconstructed with FBP for the evaluation of the same filters. SNR and CNR values were higher in the IRIS images (p<0.05). Interreader agreement for four reconstructions was interpreted as moderate (κ=0.40-0.59). CONCLUSION IRIS significantly reduced image noise and improved imaging of coronary calcifications or stents. When combined with a sharp kernel, IRIS can improve image quality by reducing the negative effects of decreased signal that may result from using a sharp kernel.
Collapse
Affiliation(s)
- Ezgi Güler
- Department of Radiology, Faculty of Medicine, Hacettepe University; Ankara-Turkey.
| | | | | | | | | | | | | |
Collapse
|
12
|
Ramirez-Giraldo JC, Fuld M, Grant K, Primak AN, Flohr T. New Approaches to Reduce Radiation While Maintaining Image Quality in Multi-Detector-Computed Tomography. CURRENT RADIOLOGY REPORTS 2015. [DOI: 10.1007/s40134-014-0084-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Effect of iDose4 iterative reconstruction algorithm on image quality and radiation exposure in prospective and retrospective electrocardiographically gated coronary computed tomographic angiography. J Comput Assist Tomogr 2014; 38:956-62. [PMID: 25119063 DOI: 10.1097/rct.0000000000000137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aims of this study were to compare a commercially available reconstruction algorithm (iDose4) with filtered back projection (FBP) in terms of image quality (IQ) for both retrospective electrocardiographically gated and prospective electrocardiographically triggered cardiac computed tomographic angiography (CCTA) protocols and to evaluate the achievable radiation dose reduction. METHODS A total cohort of 58 patients underwent either prospective CTCA or retrospective CTCA with full or reduced tube current-time product (in milliampere-second) protocol on a 64-slice multidetector computed tomographic scanner. All images were reconstructed with FBP, whereas the reduced milliampere-second images were also reconstructed using 2 levels (levels 4 and 6) of iDose4. Subjective and objective IQ was evaluated. RESULTS Dose reductions of 43% in the retrospective CCTA protocol and 27% in the prospective CCTA protocol were achieved without compromising IQ. In the prospective CCTA protocol, the reduced-dose images were highly scored; thus, additional reduction of exposure settings is feasible. In the retrospective acquisition, dose reduction has led to similar IQ scores between the reduced-dose iDose4 images and the full-dose FBP images. Considering different reconstructions (FBP, iDose-L4 and -L6) of the same acquisition data, increase in iDose4 level resulted in less noisy images. A slight improvement was also noticed in all IQ indices; however, this improvement was not statistically significant for both acquisition protocols. CONCLUSIONS This study demonstrated that the application of iDose at CCTA facilitates significant radiation dose reduction by maintaining diagnostic quality. The combination of iDose4 with prospective acquisition is able to significantly reduce effective dose associated with CTCA at values of approximately 2 mSv and even lower.
Collapse
|
14
|
Berta L, Mascaro L, Feroldi P, Maroldi R. Optimisation of an MDCT abdominal protocol: Image quality assessment of standard vs. iterative reconstructions. Phys Med 2014; 30:271-9. [DOI: 10.1016/j.ejmp.2013.07.126] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 07/04/2013] [Accepted: 07/15/2013] [Indexed: 01/01/2023] Open
|
15
|
Impact of sinogram affirmed iterative reconstruction (SAFIRE) algorithm on image quality with 70 kVp-tube-voltage dual-source CT angiography in children with congenital heart disease. PLoS One 2014; 9:e91123. [PMID: 24614683 PMCID: PMC3948727 DOI: 10.1371/journal.pone.0091123] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 02/07/2014] [Indexed: 12/01/2022] Open
Abstract
Purpose To compare the image quality and diagnostic accuracy between sinogram affirmed iterative reconstruction (SAFIRE) algorithm and filtered back projection (FBP) reconstruction algorithm at 70 kVp-tube-voltage DSCT angiography in children with congenital heart disease (CHD). Materials and Methods Twenty-eight patients (mean age: 13 months; range: 2–48 months; male: 16; female: 12; mean weight: 8 kg) with CHD underwent 70 kVp DSCT angiography. Imaging data were reconstructed with both FBP and SAFIRE algorithms. Subjective image quality was evaluated on a five-point scale. The parameters of image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) on the objective image quality were compared for the two reconstruction algorithms. Surgery was performed in 20 patients, whereas conventional cardiac angiography (CCA) was performed in 8 patients. The diagnostic accuracy was evaluated on the surgical and/or CCA findings. The effective radiation doses were calculated. Results Compared to FBP algorithm, SAFIRE algorithm had significantly higher scores for subjective image quality (P<0.05), and lower image noise (P<0.05) as well as higher SNR &CNR values (P<0.05). There was no significant difference in the diagnostic accuracy between the FBP and SAFIRE algorithm (χ2 = 1.793, P>0.05). The mean effective dose for 70 kVp DSCT angiography was 0.30±0.13 mSv. Conclusions The SAFIRE algorithm can significantly reduce image noise and improve the image quality at 70 kVp DSCT angiography for the assessment of CHD in children.
Collapse
|
16
|
Veldhoen S, Laqmani A, Derlin T, Karul M, Hammerle D, Buhk JH, Sehner S, Nagel HD, Chun F, Adam G, Regier M. 256-MDCT for evaluation of urolithiasis: iterative reconstruction allows for a significant reduction of the applied radiation dose while maintaining high subjective and objective image quality. J Med Imaging Radiat Oncol 2014; 58:283-90. [PMID: 24581030 DOI: 10.1111/1754-9485.12159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 12/17/2013] [Indexed: 11/28/2022]
Abstract
PURPOSE Multidetector CT (MDCT) is the established imaging modality in diagnostics of urolithiasis. The aim of iterative reconstruction (IR) is to allow for a radiation dose reduction while maintaining high image quality. This study evaluates its performance in MDCT for assessment of urolithiasis. MATERIALS AND METHODS Fifty-two patients underwent non-contrast abdominal MDCT. Twenty-six patients were referred to MDCT under suspicion of urolithiasis, and examined using a dose-reduced scan protocol (RDCT). Twenty-six patients, who had undergone standard-dose MDCT, served as reference for radiation dose comparison. RDCT images were reconstructed using an IR system (iDose4™, Philips Healthcare, Cleveland, OH, USA). Objective image noise (OIN) was recorded and five radiologists rated the subjective image quality independently. Radiation parameters were derived from the scan protocols. RESULTS The CTDIvol could be reduced by 50% to 5.8 mGy (P < 0.0001). The same reduction was achieved for DLP and effective dose to 253 ± 27 mGy*cm (P < 0.0001) and 3.9 ± 0.4 mSv (P < 0.0001). IR led to a reduction of the OIN of up to 61% compared with classic filtered back projection (FBP) (P < 0.0001). The OIN declined with increasing IR levels. RDCT with FBP showed the lowest scores of subjective image quality (2.32 ± 0.04). Mean scores improved with increasing IR levels. iDose6 was rated with the best mean score (3.66 ± 0.04). CONCLUSION The evaluated IR-tool and protocol may be applied to achieve a considerable radiation dose reduction in MDCT for diagnostics of urolithiasis while maintaining a confident image quality. Best image quality, suitable for evaluation of the entire abdomen concerning differential diagnoses, was achieved with iDose6.
Collapse
Affiliation(s)
- Simon Veldhoen
- Department of Diagnostic and Interventional Radiology, University Medical Center Würzburg, Würzburg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Spears JR, Schoepf UJ, Henzler T, Joshi G, Moscariello A, Vliegenthart R, Cho YJ, Apfaltrer P, Rowe G, Weininger M, Ebersberger U. Comparison of the effect of iterative reconstruction versus filtered back projection on cardiac CT postprocessing. Acad Radiol 2014; 21:318-24. [PMID: 24360635 DOI: 10.1016/j.acra.2013.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 01/22/2023]
Abstract
RATIONALE AND OBJECTIVES To investigate the impact of iterative reconstruction in image space (IRIS) on image noise, image quality (IQ), and postprocessing at coronary computed tomography angiography (cCTA) compared to traditional filtered back-projection (FBP). MATERIALS AND METHODS The cCTA results of 50 patients (26 men; 58 ± 15 years, body mass index 31.5 ± 6.7 kg/m²) were investigated using a second-generation dual-source computed tomography system. Scan data were reconstructed with the use of IRIS and FBP algorithms. Two radiologists independently evaluated the reconstructions using automated coronary tree analysis software. Image noise was measured and IQ was rated on a 5-point Likert scale. The number of manual corrections after automated vessel segmentation, the time required to complete segmentation, and the number of missed segments were assessed in both IRIS and FBP reconstructions. Results were compared using paired t-test. RESULTS IRIS significantly reduced image noise compared to FBP (23.3 ± 8.8 vs. 33.5 ± 13.5 Hounsfield units, P < .001). Subjective IQ improved with IRIS (IRIS 3.2 ± 1.0 vs. FBP 3.0 ± 1.0, P < .05). IRIS decreased the time needed for coronary segmentation from 111.9 ± 40.5 seconds to 95.2 ± 38.2 seconds with FBP (P < .01) and required fewer manual corrections (5.7 ± 3.0 vs. 6.8 ± 3.6, P < .01). The number of missed vessel segments was not significantly different (3.6 ± 1.8 vs. 3.8 ± 1.9, P > .05) between IRIS and FBP, respectively. CONCLUSIONS During cCTA postprocessing, IRIS significantly decreases the time and the number of manual corrections for a complete coronary segmentation compared to FBP. This effect is likely attributable to suppression of image noise by IRIS, which improves the performance of automated vessel segmentation and positively impacts cCTA analysis.
Collapse
Affiliation(s)
- J Reid Spears
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260
| | - U Joseph Schoepf
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260.
| | - Thomas Henzler
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260; Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Gayatri Joshi
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260
| | - Antonio Moscariello
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260; Department of Bioimaging and Radiological Sciences, Catholic University of the Sacred Heart, "A. Gemelli" Hospital, Rome, Italy
| | - Rozemarijn Vliegenthart
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260; Department of Radiology, Center for Medical Imaging - North East Netherlands, University of Groningen/University Medical Center Groningen, Groningen, The Netherlands
| | - Young Jun Cho
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260; Department of Radiology, Konyang University College of Medicine, Daejeon, Republic of Korea
| | - Paul Apfaltrer
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260; Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Garrett Rowe
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260
| | - Markus Weininger
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260
| | - Ullrich Ebersberger
- Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260; Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich, Germany
| |
Collapse
|
18
|
Assessment of dose exposure and image quality in coronary angiography performed by 640-slice CT: a comparison between adaptive iterative and filtered back-projection algorithm by propensity analysis. Radiol Med 2014; 119:642-9. [DOI: 10.1007/s11547-014-0382-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 10/01/2013] [Indexed: 10/25/2022]
|
19
|
Eck B, Fahmi R, Brown KM, Raihani N, Wilson DL. Comparison of computational to human observer detection for evaluation of CT low dose iterative reconstruction. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2014; 9037:90370P. [PMID: 32362709 PMCID: PMC7194204 DOI: 10.1117/12.2043335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Model observers were created and compared to human observers for the detection of low contrast targets in computed tomography (CT) images reconstructed with an advanced, knowledge-based, iterative image reconstruction method for low x-ray dose imaging. A 5-channel Laguerre-Gauss Hotelling Observer (CHO) was used with internal noise added to the decision variable (DV) and/or channel outputs (CO). Models were defined by parameters: (k1) DV-noise with standard deviation (std) proportional to DV std; (k2) DV-noise with constant std; (k3) CO-noise with constant std across channels; and (k4) CO-noise in each channel with std proportional to CO variance. Four-alternative forced choice (4AFC) human observer studies were performed on sub-images extracted from phantom images with and without a "pin" target. Model parameters were estimated using maximum likelihood comparison to human probability correct (PC) data. PC in human and all model observers increased with dose, contrast, and size, and was much higher for advanced iterative reconstruction (IMR) as compared to filtered back projection (FBP). Detection in IMR was better than FPB at 1/3 dose, suggesting significant dose savings. Model(k1,k2,k3,k4) gave the best overall fit to humans across independent variables (dose, size, contrast, and reconstruction) at fixed display window. However Model(k1) performed better when considering model complexity using the Akaike information criterion. Model(k1) fit the extraordinary detectability difference between IMR and FBP, despite the different noise quality. It is anticipated that the model observer will predict results from iterative reconstruction methods having similar noise characteristics, enabling rapid comparison of methods.
Collapse
Affiliation(s)
- Brendan Eck
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Rachid Fahmi
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
| | | | | | - David L Wilson
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, 44106, USA
| |
Collapse
|
20
|
Renker M, Geyer LL, Krazinski AW, Silverman JR, Ebersberger U, Schoepf UJ. Iterative image reconstruction: a realistic dose-saving method in cardiac CT imaging? Expert Rev Cardiovasc Ther 2014; 11:403-9. [DOI: 10.1586/erc.12.178] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
21
|
Suh YJ, Kim YJ, Hong SR, Hong YJ, Lee HJ, Hur J, Choi BW. Combined Use of Automatic Tube Potential Selection with Tube Current Modulation and Iterative Reconstruction Technique in Coronary CT Angiography. Radiology 2013; 269:722-9. [DOI: 10.1148/radiol.13130408] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
22
|
Nance JW, Schoepf UJ, Ebersberger U. The Role of Iterative Reconstruction Techniques in Cardiovascular CT. CURRENT RADIOLOGY REPORTS 2013. [DOI: 10.1007/s40134-013-0023-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
23
|
Oncel G, Oncel D. The Prevalence and Extent of Coronary Atherosclerosis among Patients with a Zero Calcium Score and the Influence of Patient Characteristics. Heart Surg Forum 2013; 16:E198-204. [DOI: 10.1532/hsf98.20121132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
<p><b>Purpose:</b> Coronary artery calcium (CAC) is a specific indicator of and an independent risk factor for atherosclerosis; however, calcium scoring may miss noncalcified plaques, which may have clinical importance. The aim of this study was both to identify the presence and extent of coronary plaques during computed tomography coronary angiography (CTCA) in patients with a zero CAC score and to evaluate the effect of risk factors and symptom status on the presence of noncalcified plaques.</p><p><b>Materials and Methods:</b> In this retrospective study, we analyzed the cases of 842 consecutive patients between October 2006 and November 2011. Of these patients, we included 357 with a zero calcium score in the study. Information regarding patient age, sex, coronary risk factors, and symptom status were recorded. Coronary calcium-scoring scans were followed by CTCA. The calcium scores were calculated, and the presence of noncalcified plaques and significant stenoses (>50% of vessel diameter) was evaluated.</p><p><b>Results:</b> Of the 357 patients with a zero calcium score, 37 (10.36%) had atherosclerotic plaques; 9 patients (2.52%) had significant coronary stenosis. Among coronary risk factors, only diabetes mellitus was significantly correlated with any risk factors (presence of atherosclerosis and obstructive coronary artery disease; <i>P</i> = .030 and .013, respectively).</p><p><b>Conclusion:</b> Although CAC scoring is a safe and a reliable test to exclude obstructive coronary artery disease, the absence of CAC does not definitively exclude the presence of atherosclerosis. CTCA is a more appropriate method for determining the atheroma burden.</p>
Collapse
|
24
|
Hou Y, Ma Y, Fan W, Wang Y, Yu M, Vembar M, Guo Q. Diagnostic accuracy of low-dose 256-slice multi-detector coronary CT angiography using iterative reconstruction in patients with suspected coronary artery disease. Eur Radiol 2013; 24:3-11. [PMID: 23887663 DOI: 10.1007/s00330-013-2969-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/24/2013] [Accepted: 06/26/2013] [Indexed: 01/10/2023]
Abstract
OBJECTIVES To evaluate the accuracy of low-dose coronary CTA with iterative reconstruction (IR) in the diagnosis of coronary artery disease (CAD) in patients with suspected CAD. METHODS Ninety-six patients with suspected CAD underwent low-dose prospective electrocardiogram-gated coronary CTA, with images reconstructed using IR. Image quality (IQ) of coronary segments were graded on a 4-point scale (4, excellent; 1, non-diagnostic). With invasive coronary angiography (ICA) considered the "gold standard", the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of coronary CTA were calculated on segment-, vessel- and patient-based levels. The patient data were divided into two groups (Agatston scores of ≥ 400 and <400). The differences in diagnostic performance between the two groups were tested. RESULTS Diagnostic image quality was found in 98.1 % (1,232/1,256) of segments. The sensitivity, specificity, PPV, NPV and accuracy were 90.8 %, 95.3 %, 81.8 %, 97.8 % and 94.3 % (segment-based) and 97.2 %, 83.3 %, 94.6 %, 90.9 % and 93.8 % (patient-based). Significant differences between the two groups were seen in specificity, PPV and accuracy (92.1 % vs. 97.9 %, 76.0 % vs. 86.7 %, 91.7 % vs. 96.6 %, P < 0.05; segment-based). The average effective dose was 1.30 ± 0.15 mSv. CONCLUSION Low-dose prospective coronary CTA with IR can acquire satisfactory image quality and show high diagnostic accuracy in patients with suspected CAD; however, blooming continues to pose a challenge in severely calcified segments. KEY POINTS • Coronary artery disease (CAD) is increasingly investigated using coronary CTA. • The iterative reconstruction (IR) algorithm is promising in decreasing radiation doses. • Low-dose prospective coronary CTA with IR can acquire satisfactory image quality. • Low-dose prospective coronary CTA with IR can show high diagnostic accuracy.
Collapse
Affiliation(s)
- Yang Hou
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, 110004, China,
| | | | | | | | | | | | | |
Collapse
|
25
|
Williams MC, Weir NW, Mirsadraee S, Millar F, Baird A, Minns F, Uren NG, McKillop G, Bull RK, van Beek EJR, Reid JH, Newby DE. Iterative reconstruction and individualized automatic tube current selection reduce radiation dose while maintaining image quality in 320-multidetector computed tomography coronary angiography. Clin Radiol 2013; 68:e570-7. [PMID: 23838086 PMCID: PMC3807656 DOI: 10.1016/j.crad.2013.05.098] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 05/13/2013] [Accepted: 05/29/2013] [Indexed: 01/22/2023]
Abstract
AIM To assess the effect of two iterative reconstruction algorithms (AIDR and AIDR3D) and individualized automatic tube current selection on radiation dose and image quality in computed tomography coronary angiography (CTCA). MATERIALS AND METHODS In a single-centre cohort study, 942 patients underwent electrocardiogram-gated CTCA using a 320-multidetector CT system. Images from group 1 (n = 228) were reconstructed with a filtered back projection algorithm (Quantum Denoising Software, QDS+). Iterative reconstruction was used for group 2 (AIDR, n = 379) and group 3 (AIDR3D, n = 335). Tube current was selected based on body mass index (BMI) for groups 1 and 2, and selected automatically based on scout image attenuation for group 3. Subjective image quality was graded on a four-point scale (1 = excellent, 4 = non-diagnostic). RESULTS There were no differences in age (p = 0.975), body mass index (p = 0.435), or heart rate (p = 0.746) between the groups. Image quality improved with iterative reconstruction and automatic tube current selection [1.3 (95% confidence intervals (CI): 1.2-1.4), 1.2 (1.1-1.2) and 1.1 (1-1.2) respectively; p < 0.001] and radiation dose decreased [274 (260-290), 242 (230-253) and 168 (156-180) mGy cm, respectively; p < 0.001]. CONCLUSION The application of the latest iterative reconstruction algorithm and individualized automatic tube current selection can substantially reduce radiation dose whilst improving image quality in CTCA.
Collapse
Affiliation(s)
- M C Williams
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh, UK.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Iterative Reconstruction Techniques: What do they Mean for Cardiac CT? CURRENT CARDIOVASCULAR IMAGING REPORTS 2013. [DOI: 10.1007/s12410-013-9203-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
27
|
Bezerra HG, Costa RA, Reiber JHC, Rybicki FJ, Schoenhagen P, Stillman AA, De Sutter J, Van de Veire NRL, van der Wall EE. Cardiovascular imaging 2012 in the International Journal of Cardiovascular Imaging. Int J Cardiovasc Imaging 2013; 29:725-36. [DOI: 10.1007/s10554-013-0216-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
28
|
Chun HY, Son J, Jung H, Kim MT, Kim TY, Kim KG, Kim JH. Load and speed effects on thyroid ultrasonography. Biomed Eng Lett 2013. [DOI: 10.1007/s13534-013-0089-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
29
|
Hou Y, Zheng J, Wang Y, Yu M, Vembar M, Guo Q. Optimizing radiation dose levels in prospectively electrocardiogram-triggered coronary computed tomography angiography using iterative reconstruction techniques: a phantom and patient study. PLoS One 2013; 8:e56295. [PMID: 23437110 PMCID: PMC3577795 DOI: 10.1371/journal.pone.0056295] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/07/2013] [Indexed: 11/18/2022] Open
Abstract
Aim To investigate the potential of reducing the radiation dose in prospectively electrocardiogram-triggered coronary computed tomography angiography (CCTA) while maintaining diagnostic image quality using an iterative reconstruction technique (IRT). Methods and Materials Prospectively-gated CCTA were first performed on a phantom using 256-slice multi-detector CT scanner at 120 kVp, with the tube output gradually reduced from 210 mAs (Group A) to 125, 105, 84, and 63 mAs (Group B–E). All scans were reconstructed using filtered back projection (FBP) algorithm and five IRT levels (L2-6), image quality (IQ) assessment was performed. Based on the IQ assessment, Group D(120 kVp, 84 mAs) reconstructed with L5 was found to provide IQ comparable to that of Group A with FBP. In the patient study, 21 patients underwent CCTA using 120 kV, 210 mAs with FBP reconstruction (Group 1) followed by 36 patients scanned with 120 kV, 84 mAs with IRT L5 (Group 2). Subjective and objective IQ and effective radiation dose were compared between two groups. Results In the phantom scans, there were no significant differences in image noise, contrast-to-noise ratio (CNR) and modulation transfer function (MTF) curves between Group A and the 84 mAs, 63 mAs groups (Groups D and E). Group D (120 kV, 84 mAs and L5) provided an optimum balance, producing equivalent image quality to Group A, at the lowest possible radiation dose. In the patient study, there were no significant difference in image noise, signal-to-noise ratio (SNR) and CNR between Group 1 and Group 2 (p = 0.71, 0.31, 0.5, respectively). The effective radiation dose in Group 2 was 1.21±0.14 mSv compared to 3.20±0.58 mSv (Group 1), reflecting dose savings of 62.5% (p<0.05). Conclusion iterative reconstruction technique used in prospectively ECG-triggered 256-slice coronary CTA can provide radiation dose reductions of up to 62.5% with acceptable image quality.
Collapse
Affiliation(s)
- Yang Hou
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jiahe Zheng
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yuke Wang
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Mei Yu
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Mani Vembar
- CT Clinical Science Philips Healthcare, Cleveland, Ohio, United States of America
| | - Qiyong Guo
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
- * E-mail:
| |
Collapse
|
30
|
Chen MY, Steigner ML, Leung SW, Kumamaru KK, Schultz K, Mather RT, Arai AE, Rybicki FJ. Simulated 50 % radiation dose reduction in coronary CT angiography using adaptive iterative dose reduction in three-dimensions (AIDR3D). Int J Cardiovasc Imaging 2013; 29:1167-75. [PMID: 23404384 PMCID: PMC3701132 DOI: 10.1007/s10554-013-0190-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 01/28/2013] [Indexed: 11/06/2022]
Abstract
To compare the image quality of coronary CT angiography (CTA) studies between standard filtered back projection (FBP) and adaptive iterative dose reduction in three-dimensions (AIDR3D) reconstruction using CT noise additional software to simulate reduced radiation exposure. Images from 93 consecutive clinical coronary CTA studies were processed utilizing standard FBP, FBP with 50 % simulated dose reduction (FBP50 %), and AIDR3D with simulated 50 % dose reduction (AIDR50 %). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured within 5 regions-of-interest, and image quality for each reconstruction strategy was assessed by two independent readers using a 4-point scale. Compared to FBP, the SNR measured from the AIDR50 % images was similar or higher (airway: 38.3 ± 12.7 vs. 38.5 ± 14.5, p = 0.81, fat: 5.5 ± 1.9 vs. 5.4 ± 2.0, p = 0.20, muscle: 3.2 ± 1.2 vs. 3.1 ± 1.3, p = 0.38, aorta: 22.6 ± 9.4 vs. 20.2 ± 9.7, p < 0.0001, liver: 2.7 ± 1.0 vs. 2.3 ± 1.1, p < 0.0001), while the SNR of the FBP50 % images were all lower (p values < 0.0001). The CNR measured from AIDR50 % images was also higher than that from the FBP images for the aorta relative to muscle (20.5 ± 9.0 vs. 18.3 ± 9.2, p < 0.0001). The interobserver agreement in the image quality score was excellent (κ = 0.82). The quality score was significantly higher for the AIDR50 % images compared to the FBP images (3.6 ± 0.6 vs. 3.3 ± 0.7, p = 0.004). Simulated radiation dose reduction applied to clinical coronary CTA images suggests that a 50 % reduction in radiation dose can be achieved with adaptive iterative dose reduction software with image quality that is at least comparable to images acquired at standard radiation exposure and reconstructed with filtered back projection.
Collapse
Affiliation(s)
- Marcus Y Chen
- Advanced Cardiovascular Imaging Laboratory, Cardiovascular and Pulmonary Branch, Department of Health and Human Services, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Willemink MJ, Leiner T, de Jong PA, de Heer LM, Nievelstein RAJ, Schilham AMR, Budde RPJ. Iterative reconstruction techniques for computed tomography part 2: initial results in dose reduction and image quality. Eur Radiol 2013; 23:1632-42. [PMID: 23322411 DOI: 10.1007/s00330-012-2764-z] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 11/21/2012] [Accepted: 12/05/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To present the results of a systematic literature search aimed at determining to what extent the radiation dose can be reduced with iterative reconstruction (IR) for cardiopulmonary and body imaging with computed tomography (CT) in the clinical setting and what the effects on image quality are with IR versus filtered back-projection (FBP) and to provide recommendations for future research on IR. METHODS We searched Medline and Embase from January 2006 to January 2012 and included original research papers concerning IR for CT. RESULTS The systematic search yielded 380 articles. Forty-nine relevant studies were included. These studies concerned: the chest(n = 26), abdomen(n = 16), both chest and abdomen(n = 1), head(n = 4), spine(n = 1), and no specific area (n = 1). IR reduced noise and artefacts, and it improved subjective and objective image quality compared to FBP at the same dose. Conversely, low-dose IR and normal-dose FBP showed similar noise, artefacts, and subjective and objective image quality. Reported dose reductions ranged from 23 to 76 % compared to locally used default FBP settings. However, IR has not yet been investigated for ultra-low-dose acquisitions with clinical diagnosis and accuracy as endpoints. CONCLUSION Benefits of IR include improved subjective and objective image quality as well as radiation dose reduction while preserving image quality. Future studies need to address the value of IR in ultra-low-dose CT with clinically relevant endpoints. KEY POINTS • Iterative reconstruction improves image quality of CT images at equal acquisition parameters. • IR preserves image quality compared to normal-dose filtered back-projection. • The reduced radiation dose made possible by IR is advantageous for patients. • IR has not yet been investigated with clinical diagnosis and accuracy as endpoints.
Collapse
Affiliation(s)
- Martin J Willemink
- Department of Radiology, Utrecht University Medical Center, PO Box 85500, E01.132, 3508 GA Utrecht, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
32
|
Iterative reconstruction techniques for computed tomography Part 1: technical principles. Eur Radiol 2013; 23:1623-31. [PMID: 23314600 DOI: 10.1007/s00330-012-2765-y] [Citation(s) in RCA: 283] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 12/05/2012] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To explain the technical principles of and differences between commercially available iterative reconstruction (IR) algorithms for computed tomography (CT) in non-mathematical terms for radiologists and clinicians. METHODS Technical details of the different proprietary IR techniques were distilled from available scientific articles and manufacturers' white papers and were verified by the manufacturers. Clinical results were obtained from a literature search spanning January 2006 to January 2012, including only original research papers concerning IR for CT. RESULTS IR for CT iteratively reduces noise and artefacts in either image space or raw data, or both. Reported dose reductions ranged from 23 % to 76 % compared to locally used default filtered back-projection (FBP) settings, with similar noise, artefacts, subjective, and objective image quality. CONCLUSION IR has the potential to allow reducing the radiation dose while preserving image quality. Disadvantages of IR include blotchy image appearance and longer computational time. Future studies need to address differences between IR algorithms for clinical low-dose CT. KEY POINTS • Iterative reconstruction technology for CT is presented in non-mathematical terms. • IR reduces noise and artefacts compared to filtered back-projection. • IR can improve image quality in routine-dose CT and lower the radiation dose. • IR's disadvantages include longer computation and blotchy appearance of some images.
Collapse
|
33
|
|
34
|
Willemink MJ, Habets J, de Jong PA, Schilham AMR, Mali WPTM, Leiner T, Budde RPJ. Iterative reconstruction improves evaluation of native aortic and mitral valves by retrospectively ECG-gated thoracoabdominal CTA. Eur Radiol 2012; 23:968-74. [PMID: 23064676 DOI: 10.1007/s00330-012-2673-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/05/2012] [Accepted: 09/13/2012] [Indexed: 12/17/2022]
Abstract
OBJECTIVES To compare native aortic (AV) and mitral valve (MV) image quality on limited-dose retrospectively ECG-gated CTA of the thoracoabdominal aorta reconstructed with iterative reconstruction (IR) and filtered back projection (FBP). METHODS Fifty patients underwent routine care retrospectively ECG-gated thoracoabdominal limited-dose 256-slice CTA. At 30 % (systole) and 75 % (diastole) of the R-R interval AV and MV were reconstructed using FBP and IR. Objective image quality [density and noise (SD of density measurement)] was measured. Two independent observers scored subjective valve image quality using four-point Likert scales. RESULTS IR significantly decreased image noise, but did not alter the aorta and interventricular septum density. Interobserver variability was moderate to good. Valve image quality was scored at least moderate in most cases. IR scored one or two Likert scale points higher than FBP in 10 (first observer) and 27 (second observer) scores. Conversely, IR scored one Likert scale point lower than FBP in 1 (first observer) and 4 (second observer) scores. CONCLUSIONS Limited-dose retrospectively ECG-gated thoracoabdominal CTA enables moderate to excellent evaluation of AV and MV in most patients, in addition to the primary diagnostic question. Image quality is further improved by IR.
Collapse
Affiliation(s)
- Martin J Willemink
- Department of Radiology, Utrecht University Medical Center, P.O. Box 85500, E01.132, 3508 GA, Utrecht, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
35
|
Current and Future Post-Processing and Reconstruction Methods for Improved Image Quality in Coronary Computed Tomographic Angiography. CURRENT CARDIOVASCULAR IMAGING REPORTS 2012. [DOI: 10.1007/s12410-012-9151-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
36
|
Yoo RE, Park EA, Lee W, Shim H, Kim YK, Chung JW, Park JH. Image quality of adaptive iterative dose reduction 3D of coronary CT angiography of 640-slice CT: comparison with filtered back-projection. Int J Cardiovasc Imaging 2012; 29:669-76. [PMID: 22923280 DOI: 10.1007/s10554-012-0113-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 08/07/2012] [Indexed: 01/25/2023]
Abstract
To assess the image quality of coronary CT angiography (CCTA) of 640-slice CT reconstructed by Adaptive Iterative Dose Reduction (AIDR) three-dimensional (3D) in comparison with the conventional filtered back-projection (FBP). CCTA images of 51 patients were scanned at the lowest tube voltage possible on condition that the built-in automatic exposure control system could suggest the optimal tube current. They were, then, reconstructed with FBP and AIDR 3D (standard). Objective measurements including CT density, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were performed. Subjective assessment was done by two radiologists, using a 5-point scale (0:nondiagnostic-4:excellent) based on the 15-coronary segment model which was grouped into three parts as the proximal, mid, and distal segmental classes. Radiation dose was also measured. AIDR images showed lower noise than FBP images (45.0 ± 9.4 vs. 73.4 ± 14.6 HU, p < 0.001) without any significant difference in CT density (665.5 ± 131.7 vs. 668 ± 136.3 HU, p = 0.8). Both SNR (15.0 ± 2.1 vs. 9.2 ± 1.7) and CNR (16.8 ± 2.3 vs. 10.4 ± 1.8) were significantly higher for AIDR than FBP (p < 0.001). Total subjective image quality score was also significantly improved in AIDR compared with FBP (3.1 ± 0.6 vs. 1.6 ± 0.4, p < 0.001), with better interpretability of the mid and distal segmental classes (100 vs. 95 % for the mid, p < 0.001; 100 vs. 90 % for the distal, p < 0.001). Mean effective radiation dose was 2.0 ± 1.0 mSv. The AIDR 3D reconstruction algorithm reduced image noise by 39 % compared with the FBP without affecting CT density, thus improving SNR and CNR for CCTA. Its advantages in interpretability were also confirmed by subjective evaluation by experts.
Collapse
Affiliation(s)
- Roh-Eul Yoo
- Department of Radiology, Institute of Radiation Medicine, Seoul National University Hospital, 28 Yongon-Dong, Chongno-Gu, Seoul 110-744, Korea
| | | | | | | | | | | | | |
Collapse
|
37
|
Carr JC. Un protocolo integral de tomografía computarizada para evaluar la disfunción sistólica ventricular izquierda. Rev Esp Cardiol (Engl Ed) 2012; 65:501-3. [DOI: 10.1016/j.recesp.2012.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 01/22/2012] [Indexed: 10/28/2022]
|