共查询到20条相似文献,搜索用时 46 毫秒
1.
Annika Schuhbaeck Stephan Achenbach Christian Layritz Jasmin Eisentopf Franziska Hecker Tobias Pflederer Soeren Gauss Johannes Rixe Willi Kalender Werner G. Daniel Michael Lell Dieter Ropers 《European radiology》2013,23(3):597-606
Objectives
We evaluated the potential of prospectively ECG-triggered high-pitch spiral acquisition with low tube voltage and current in combination with iterative reconstruction to achieve coronary CT angiography with sufficient image quality at an effective dose below 0.1 mSv.Methods
Contrast-enhanced coronary dual source CT angiography (2?×?128?×?0.6 mm, 80 kV, 50 mAs) in prospectively ECG-triggered high-pitch spiral acquisition mode was performed in 21 consecutive individuals (body weight <100 kg, heart rate ≤60/min). Images were reconstructed with raw data-based filtered back projection (FBP) and iterative reconstruction (IR). Image quality was assessed on a 4-point scale (1 = no artefacts, 4 = unevaluable).Results
Mean effective dose was 0.06?±?0.01 mSv. Image noise was significantly reduced in IR (128.9?±?46.6 vs. 158.2?±?44.7 HU). The mean image quality score was lower for IR (1.9?±?1.1 vs. 2.2?±?1.0, P?<?0.0001). Of 292 coronary segments, 55 in FBP and 40 in IR (P?=?0.12) were graded “unevaluable”. In patients with a body weight ≤75 kg, both in FBP and in IR, the rates of fully evaluable segments were significantly higher in comparison to patients >75 kg.Conclusions
Coronary CT angiography with an estimated effective dose <0.1 mSv may provide sufficient image quality in selected patients through the combination of high-pitch spiral acquisition and raw data-based iterative reconstruction.Key Points
? Coronary CT angiography with an estimated effective dose <0.1 mSv is possible. ? Combination of high-pitch spiral acquisition with iterative reconstruction achieves sufficient image quality. ? Diagnostic accuracy remains to be assessed in future trials. 相似文献2.
Long Jiang Zhang Li Qi Jing Wang Chun Xiang Tang Chang Sheng Zhou Xue Man Ji James V. Spearman Carlo Nicola De Cecco Felix G. Meinel U. Joseph Schoepf Guang Ming Lu 《European radiology》2014,24(7):1537-1546
Objectives
To evaluate the feasibility, image quality and radiation dose of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) with 30 mL contrast agent at 70 kVp.Methods
Fifty-eight patients with suspected coronary artery disease, a body mass index (BMI) of less than 25 kg/m2, sinus rhythm and a heart rate (HR) of less than 70 beats per minute (bpm) were prospectively enrolled in this study. Thirty mL of 370 mg I/mL iodinated contrast agent was administrated at a flow rate of 5 mL/s. All patients underwent prospectively ECG-triggered high-pitch CCTA on a second-generation dual-source CT system at 70 kVp using automated tube current modulation.Results
Fifty-six patients (96.6 %) had diagnostic CCTA images and two patients (3.4 %) had one vessel with poor image quality each rated as non-diagnostic. No significant effects of HR, HR variability and BMI on CCTA image quality were observed (all P?>?0.05). Effective dose was 0.17?±?0.02 mSv and the size-specific dose estimate was 1.03?±?0.13 mGy.Conclusion
Prospectively ECG-triggered high-pitch CCTA at 70 kVp with 30 mL of contrast agent can provide diagnostic image quality at a radiation dose of less than 0.2 mSv in patients with a BMI of less than 25 kg/m2 and an HR of less than 70 bpm.Key points
? Prospectively ECG-triggered high-pitch CCTA at 70 kVp/30 mL contrast agent is feasible. ? Diagnostic image quality can be obtained at a radiation dose of less than 0.2 mSv. ? This protocol is suitable for normal-weight patients with slow heart rate. 相似文献3.
Michael Lell Mohamed Marwan Tiziano Schepis Tobias Pflederer Katharina Anders Thomas Flohr Thomas Allmendinger Willi Kalender Dirk Ertel Carsten Thierfelder Axel Kuettner Dieter Ropers Werner G. Daniel Stephan Achenbach 《European radiology》2009,19(11):2576-2583
Objective
We evaluated radiation exposure and image quality of a new coronary CT angiography protocol, high-pitch spiral acquisition, using dual source CT (DSCT).Material and methods
Coronary CTA was performed in 25 consecutive patients with a stable heart rate of 60 bpm or less after premedication, using 2?×?128 0.6-mm sections, 38.4-mm collimation width and 0.28-s rotation time. Tube settings were 100 kV/320 mAs and 120 kV/400 mAs for patients below and above 100-kg weight, respectively. Data acquisition was prospectively ECG-triggered at 60% of the R–R interval using a pitch of 3.2 (3.4 for the last 10 patients). Images were reconstructed with 75-ms temporal resolution, 0.6-mm slice thickness and 0.3-mm increment. Image quality was evaluated using a four-point scale (1 = excellent, 4 = unevaluable).Results
Mean range of data acquisition was 113?±?22 mm, mean duration was 268?±?23 ms. Of 363 coronary artery segments, 327 had an image quality score of 1, and only 2 segments were rated as “unevaluable”. Mean dose–length product (DLP) was 71?±?23 mGy cm, mean effective dose was 1.0?±?0.3 mSv (range 0.78–2.1 mSv). For 21 patients with a body weight below 100 kg, mean DLP was 63?±?5 mGy cm (0.88?±?0.07 mSv; range 0.78–0.97 mSv).Conclusion
Prospectively ECG-triggered high-pitch spiral CT acquisition provides high and stable image quality at very low radiation dose. 相似文献4.
Moscariello A Takx RA Schoepf UJ Renker M Zwerner PL O'Brien TX Allmendinger T Vogt S Schmidt B Savino G Fink C Bonomo L Henzler T 《European radiology》2011,21(10):2130-2138
Objectives
To compare image noise, image quality and diagnostic accuracy of coronary CT angiography (cCTA) using a novel iterative reconstruction algorithm versus traditional filtered back projection (FBP) and to estimate the potential for radiation dose savings.Methods
Sixty five consecutive patients (48 men; 59.3?±?7.7?years) prospectively underwent cCTA and coronary catheter angiography (CCA). Full radiation dose data, using all projections, were reconstructed with FBP. To simulate image acquisition at half the radiation dose, 50% of the projections were discarded from the raw data. The resulting half-dose data were reconstructed with sinogram-affirmed iterative reconstruction (SAFIRE). Full-dose FBP and half-dose iterative reconstructions were compared with regard to image noise and image quality, and their respective accuracy for stenosis detection was compared against CCA.Results
Compared with full-dose FBP, half-dose iterative reconstructions showed significantly (p?=?0.001 ?C p?=?0.025) lower image noise and slightly higher image quality. Iterative reconstruction improved the accuracy of stenosis detection compared with FBP (per-patient: accuracy 96.9% vs. 93.8%, sensitivity 100% vs. 100%, specificity 94.6% vs. 89.2%, NPV 100% vs. 100%, PPV 93.3% vs. 87.5%).Conclusions
Iterative reconstruction significantly reduces image noise without loss of diagnostic information and holds the potential for substantial radiation dose reduction from cCTA. 相似文献5.
Schuhbäck A Marwan M Gauss S Muschiol G Ropers D Schneider C Lell M Rixe J Hamm C Daniel WG Achenbach S 《European radiology》2012,22(7):1529-1536
Background
We compared the interobserver variability concerning the detection of calcified and non-calcified plaque in two different low-dose and standard retrospectively gated protocols for coronary CTA.Methods
150 patients with low heart rates and less than 100?kg body weight were randomised and examined by contrast-enhanced dual-source CT coronary angiography (100?kV, 320?mAs). 50 patients were examined with prospectively ECG-triggered axial acquisition, 50 patients with prospectively ECG-triggered high pitch spiral acquisition, and 50 patients using spiral acquisition with retrospective ECG gating. Two investigators independently analysed the datasets concerning the presence of calcified and non-calcified plaque on a per-segment level.Results
Mean effective dose was 1.4?±?0.2?mSv for axial, 0.8?±?0.07?mSv for high-pitch spiral, and 5.3?±?2.6?mSV for standard spiral acquisition (P?0.0001). In axial acquisition, interobserver agreement concerning the presence of atherosclerotic plaque was achieved in 650/749 coronary segments (86.8%). In high-pitch spiral acquisition, agreement was achieved in 664/748 segments (88.8%, n.s.). In standard spiral acquisition, agreement was achieved in 672/738 segments (91.0%, P?0.0001). Interobserver agreement was significantly higher for calcified than for non-calcified plaque in all data acquisition modes.Conclusion
Low-dose coronary CT angiography permits the detection of coronary atherosclerotic plaque with good interobserver agreement.Key Points
? Low-dose CT protocols permit coronary plaque detection with good interobserver agreement. ? Image noise is a major predictor of interobserver variability. ? Interobserver agreement is significantly higher for calcified than for non-calcified plaque. 相似文献6.
Lisan A. Neefjes Alexia Rossi Tessa S. S. Genders Koen Nieman Stella L. Papadopoulou Anoeshka S. Dharampal Carl J. Schultz Annick C. Weustink Marcel L. Dijkshoorn Gert-Jan R. ten Kate Admir Dedic Marcel van Straten Filippo Cademartiri M. G. Myriam Hunink Gabriël P. Krestin Pim J. de Feyter Nico R. Mollet 《European radiology》2013,23(3):614-622
Objectives
To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction.Methods
We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients.Results
In group A (231 patients, 146 men, mean heart rate 58?±?7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P?=?0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P?>?0.05) but radiation dose was lower (1.16?±?0.60 vs. 3.82?±?1.65 mSv, P?<?0.001). In group B (228 patients, 132 men, mean heart rate 75?±?11 bpm), per-segment sensitivity, specificity, PPV and NPV were comparable (94 %, 95 %, 67 %, 99 % vs. 92 %, 95 %, 66 %, 99 %, P?>?0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12?±?2.58 vs. 8.13?±?4.52 mSv, P?<?0.001). Diagnostic performance was comparable in both groups.Conclusion
Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose.Key Points
? 128-slice dual-source CT coronary angiography offers several different acquisition protocols. ? Randomized comparison of protocols reveals an optimal protocol selection strategy. ? Appropriate CTCA protocol selection lowers radiation dose, while maintaining high quality. ? CTCA protocol selection should be based on individual patient characteristics. ? A prospective sequential protocol is preferred for CTCA. 相似文献7.
Fabian Morsbach Sonja Gordic Lotus Desbiolles Daniela Husarik Thomas Frauenfelder Bernhard Schmidt Thomas Allmendinger Simon Wildermuth Hatem Alkadhi Sebastian Leschka 《European radiology》2014,24(8):1889-1895
Objectives
To evaluate image quality, maximal heart rate allowing for diagnostic imaging, and radiation dose of turbo high-pitch dual-source coronary computed tomographic angiography (CCTA).Methods
First, a cardiac motion phantom simulating heart rates (HRs) from 60-90 bpm in 5-bpm steps was examined on a third-generation dual-source 192-slice CT (prospective ECG-triggering, pitch 3.2; rotation time, 250 ms). Subjective image quality regarding the presence of motion artefacts was interpreted by two readers on a four-point scale (1, excellent; 4, non-diagnostic). Objective image quality was assessed by calculating distortion vectors. Thereafter, 20 consecutive patients (median, 50 years) undergoing clinically indicated CCTA were included.Results
In the phantom study, image quality was rated diagnostic up to the HR75 bpm, with object distortion being 1 mm or less. Distortion increased above 1 mm at HR of 80-90 bpm. Patients had a mean HR of 66 bpm (47-78 bpm). Coronary segments were of diagnostic image quality for all patients with HR up to 73 bpm. Average effective radiation dose in patients was 0.6?±?0.3 mSv.Conclusions
Our combined phantom and patient study indicates that CCTA with turbo high-pitch third-generation dual-source 192-slice CT can be performed at HR up to 75 bpm while maintaining diagnostic image quality, being associated with an average radiation dose of 0.6 mSv.Key points
? CCTA is feasible with the turbo high-pitch mode. ? Turbo high-pitch CCTA provides diagnostic image quality up to 73 bpm. ? The radiation dose of high-pitch CCTA is 0.6 mSv on average. 相似文献8.
Wuest W Anders K Schuhbaeck A May MS Gauss S Marwan M Arnold M Ensminger S Muschiol G Daniel WG Uder M Achenbach S 《European radiology》2012,22(1):51-58
Objectives
Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical valve replacement in high risk patients. Angiography of the aortic root, aorta and iliac arteries is required to select suitable candidates, but contrast agents can be harmful due to impaired renal function. We evaluated ECG-triggered high-pitch spiral dual source Computed Tomography (CT) with minimized volume of contrast agent to assess aortic root anatomy and vascular access.Methods
42 patients (82?±?6?years) scheduled for TAVI underwent dual source (DS) CT angiography (CTA) of the aorta using a prospectively ECG-triggered high-pitch spiral mode (pitch?=?3.4) with 40?mL iodinated contrast agent. We analyzed aortic root/iliac dimensions, attenuation, contrast to noise ratio (CNR), image noise and radiation exposure.Results
Aortic root/iliac dimensions and distance of coronary ostia from the annulus could be determined in all cases. Mean aortic and iliac artery attenuation was 320?±?70 HU and 340?±?77 HU. Aortic/iliac CNR was 21.7?±?6.8 HU and 14.5?±?5.4 HU using 100?kV (18.8?±?4.1 HU and 8.7?±?2.6 HU using 120?kV). Mean effective dose was 4.5?±?1.2?mSv.Conclusions
High-pitch spiral DSCTA can be used to assess the entire aorta and iliac arteries in TAVI candidates with a low volume of contrast agent while preserving diagnostic image quality. Key Points ? Transcatheter Aortic Valve Implantation (TAVI) offers an alternative to surgical valve replacement in high risk patients. ? Such procedures require essential information about aortic root anatomy and vascular access. ? High pitch ECG-triggered dual source Computed Tomography (CT) can provide this information ? Sufficient image quality can be maintained even with low volumes of contrast agent and reduced x-ray exposure. 相似文献9.
J. Matthias Kerl Ralf W. Bauer Tobias B. Maurer Rene Aschenbach Huedayi Korkusuz Thomas Lehnert Simon Deseive Hanns Ackermann Thomas J. Vogl 《European radiology》2011,21(3):530-537
Purpose
To compare the dose estimates and image quality of Dual Energy CT (DECT), Dual Source CT (DSCT) and 16-slice CT for coronary CT angiography (cCTA).Methods
Sixty-eight patients were examined with 16 - slice MDCT (group 1), 68 patients with DSCT (group 2) and 68 patients using DSCT in dual energy mode (DECT group 3). CT dose index volume, dose length product, effective dose, signal-to-noise, and contrast-to-noise ratio were compared. Subjective image quality was rated by two observers, blinded to technique.Results
The mean estimated radiation dose of all patients investigated on a 16 - slice MDCT was 12?±?3.59?mSv, for DSCT in single energy 9.8?±?4.77?mSv and for DECT 4.54?±?1.87?mSv. Dose for CTA was significantly lower in group 3 compared to group 1 and 2. The image noise was significantly lower in Group 2 in comparison to group 1 and group 3. There was no significant difference in diagnostic image quality comparing DECT and DSCT.Conclusion
cCTA shows better dose levels at both DECT and DSCT compared to 16-slice CT. Further, DECT delivers significantly less dose than regular DSCT or single source single energy cCTA while maintaining diagnostic image quality. 相似文献10.
Lei Xu Lin Yang Zhaoqi Zhang Yining Wang Zhengyu Jin Longjiang Zhang Guangming Lu 《European radiology》2013,23(7):1822-1828
Objective
To investigate the feasibility of applying prospectively ECG-triggered sequential coronary CT angiography (CCTA) to patients with atrial fibrillation (AF) and evaluate the image quality and radiation dose compared with a retrospectively ECG-gated helical protocol.Methods
100 patients with persistent AF were enrolled. Fifty patients were randomly assigned to a prospective protocol and the other patients to a retrospective protocol using a second-generation dual-source CT (DS-CT). Image quality was evaluated using a four-point grading scale (1 = excellent, 2 = good, 3 = moderate, 4 = poor) by two reviewers on a per-segment basis. The coronary artery segments were considered non-diagnostic with a quality score of 4. The radiation dose was evaluated.Results
Diagnostic segment rate in the prospective group was 99.4 % (642/646 segments), while that in the retrospective group was 96.5 % (604/626 segments) (P?<?0.001). Effective dose was 4.29?±?1.86 and 11.95?±?5.34 mSv for each of the two protocols (P?<?0.001), which was a 64 % reduction in the radiation dose for prospective sequential imaging compared with retrospective helical imaging.Conclusion
In AF patients, prospectively ECG-triggered sequential CCTA is feasible using second-generation DS-CT and can decrease >60 % radiation exposure compared with retrospectively ECG-gated helical imaging while improving diagnostic image quality.Key Points
? Coronary computed tomographic angiography (CCTA) can be difficult in patients with arrhythmias. ? Prospectively ECG-triggered sequential CCTA is feasible in patients with atrial fibrillation. ? Prospective sequential imaging can improve quality compared with retrospective analysis. ? Prospective sequential imaging decreases radiation exposure by 64 % compared with retrospective mode. 相似文献11.
Siobhan B O’Neill Patrick D Mc Laughlin Lee Crush Owen J O’Connor Sebastian R Mc Williams Orla Craig Anne Marie Mc Garrigle Fiona O’Neill Jackie Bye Max F. Ryan Fergus Shanahan Michael M Maher 《European radiology》2013,23(9):2503-2512
Objective
Iterative reconstruction (IR) allows diagnostic CT imaging with less radiation exposure than filtered back projection (FBP). We studied an IR low-dose CT abdomen/pelvis (LDCTAP) protocol, designed to image at an effective dose (ED) approximating 1 mSv in patients with Crohn’s disease (CD).Methods
Forty patients, mean age 37?±?13.4 years (range 17–69), with CD underwent two synchronous CT protocols (conventional-dose (CDCTAP) and LDCTAP). CDCTAP and LDCTAP images were compared for diagnostic acceptability, yield, image quality and ED (in millisieverts). The optimal level of IR for LDCTAP was also studied.Results
LDCTAP yielded a mean ED of 1.3?±?0.8 mSv compared with 4.7?±?2.9 mSv for CDCTAP, reducing ED by 73.7?±?3.3 % (mean dose reduction, 3.5?±?2.1 mSv; P?<?0.001) and dose length product by 73.6?±?2.6 % (P?<?0.001). Sub-millisievert (0.84 mSv) imaging was performed for patients with a body mass index (BMI) less than 25 (i.e. 63 % of our cohort). LDCTAP resulted in increased image noise and reduced diagnostic acceptability compared with CDCTAP despite use of IR, but detection of extra-luminal complications was comparable.Conclusion
Patients with suspected active CD can be adequately imaged using LDCTAP, yielding comparable information regarding extent, activity and complications of CD compared with CDCTAP, but with 74 % less dose. LDCTAP at doses equivalent to that of two abdominal radiographs represents a feasible alternative to CDCTAP.Key points
? Radiation dose is a concern when imaging patients with Crohn’s disease. ? New techniques allow low-dose abdominopelvic CT with acceptable image quality. ? Using hybrid iterative reconstruction, its diagnostic yield compares well with that of conventional CT. ? Sub-millisievert CT of patients with Crohn’s disease appears technically and clinically feasible. 相似文献12.
Sun ML Lu B Wu RZ Johnson L Han L Liu G Yu FF Hou ZH Gao Y Wang HY Jiang S Yang YJ Qiao SB 《European radiology》2011,21(8):1635-1642
Objective
To evaluate the diagnostic accuracy of dual-source CT (DSCT) prospective ECG-triggering coronary angiography in patients with different heart rate (HR).Methods
103 patients with suspected coronary artery disease underwent DSCT prospective ECG-triggered coronary angiography and invasive coronary angiography (ICA). The patients were grouped by HR during CT scans: low HR (??60?bpm, n?=?34); medium HR (60?n?=?36) and high HR (>70?bpm, n?=?33). The sensitivity and specificity of DSCT in detecting ??50% stenosis were compared among subgroups where ICA was the gold standard. Image quality was scored using a 4-point scale.Results
A total of 1,580 (95.9%) coronary artery segments were evaluable. Sensitivity and specificity were 82.8% and 98.4%, 88.3% and 98.7%, and 80.3% and 98.6% for different subgroups (all p?>?0.05). The overall area under the curve of the receiver-operating characteristic analysis was 0.94. The image quality scores were 3.1?±?0.3, 3.1?±?0.3 and 3.0?±?0.4 for subgroups (p?>?0.05). The overall average effective radiation dose was 3.60?±?1.60?mSv.Conclusion
DSCT coronary angiography with prospective ECG-triggering could be just as accurate in patients with medium to high HR compared to those with low HR. 相似文献13.
Guang Ming Lu Song Luo Felix G. Meinel Andrew D. McQuiston Chang Sheng Zhou Xiang Kong Yan E. Zhao Ling Zheng U. Joseph Schoepf Long Jiang Zhang 《European radiology》2014,24(12):3260-3268
Objectives
To evaluate the image quality, radiation dose and diagnostic accuracy of 80kVp, high-pitch CT pulmonary angiography (CTPA) with iterative reconstruction using 20 ml of contrast agent.Methods
One hundred patients with suspected pulmonary embolism (PE) were randomly divided into two groups (n?=?50 each; group A, 100 kVp, 1.2 pitch, 60 ml of contrast medium and filtered back projection algorithm; group B, 80 kVp, 2.2 pitch, 20 ml of contrast medium and sinogram affirmed iterative reconstruction). Image quality, diagnostic accuracy and radiation dose were evaluated and compared.Results
Mean CT numbers of pulmonary arteries in group B were higher than those in group A (all P?0.001). Contrast-to-noise ratio and signal-to-noise ratio of group B were higher than those of group A (both P?0.001). There was no significant difference in subjective image quality scores between two groups (P?=?0.807). The interobserver agreement was excellent (k?=?0.836). There was no significant difference in diagnostic accuracy between the two groups (P?>?0.05). Compared with group A, radiation dose of group B was reduced by 50.3 % (P?0.001).Conclusions
High-pitch CTPA at 80 kVp can obtain sufficient image quality in normal-weight individuals with 20 ml of contrast agent and half the radiation dose of a conventional CTPA protocol.Key Points
? CTPA is feasible at 80 kVp using only 20 ml of contrast agent. ? High-pitch CTPA at 80 kVp has an effective dose under 1 mSv. ? This CTPA protocol can obtain sufficient image quality in normal-weight individuals. 相似文献14.
Objectives
To evaluate the effect of hybrid iterative reconstruction on qualitative and quantitative parameters at 256-slice cardiac CT.Methods
Prospective cardiac CT images from 20 patients were analysed. Paired image sets were created using 3 reconstructions, i.e. filtered back projection (FBP) and moderate- and high-level iterative reconstructions. Quantitative parameters including CT-attenuation, noise, and contrast-to-noise ratio (CNR) were determined in both proximal- and distal coronary segments. Image quality was graded on a 4-point scale.Results
Coronary CT attenuation values were similar for FBP, moderate- and high-level iterative reconstruction at 293?±?74-, 290?±?75-, and 283?±?78 Hounsfield units (HU), respectively. CNR was significantly higher with moderate- and high-level iterative reconstructions (10.9?±?3.5 and 18.4?±?6.2, respectively) than FBP (8.2?±?2.5) as was the visual grading of proximal vessels. Visualisation of distal vessels was better with high-level iterative reconstruction than FBP. The mean number of assessable segments among 289 segments was 245, 260, and 267 for FBP, moderate- and high-level iterative reconstruction, respectively; the difference between FBP and high-level iterative reconstruction was significant. Interobserver agreement was significantly higher for moderate- and high-level iterative reconstruction than FBP.Conclusions
Cardiac CT using hybrid iterative reconstruction yields higher CNR and better image quality than FBP.Key Points
? Cardiac CT helps clinicians to assess patients with coronary artery disease ? Hybrid iterative reconstruction provides improved cardiac CT image quality ? Hybrid iterative reconstruction improves the number of assessable coronary segments ? Hybrid iterative reconstruction improves interobserver agreement on cardiac CT 相似文献15.
Ullrich Ebersberger Francesco Tricarico U. Joseph Schoepf Philipp Blanke J. Reid Spears Garrett W. Rowe William T. Halligan Thomas Henzler Fabian Bamberg Alexander W. Leber Ellen Hoffmann Paul Apfaltrer 《European radiology》2013,23(1):125-132
Objectives
Comparison of coronary artery stent assessment with cardiac CT angiography (cCTA) using traditional filtered back projection (FBP) and sinogram affirmed iterative reconstruction (SAFIRE), in both full- and half-radiation dose image data.Methods
Dual-source cCTA studies of 37 implanted stents were reconstructed at full- and half-radiation dose with FBP and SAFIRE. Half-dose data were based on projections from one DSCT detector. In-stent noise, signal-to-noise ratio (SNR), and stent-lumen attenuation increase ratio (SAIR) were measured and image quality graded. Stent volumes were measured to gauge severity of beam hardening artefacts.Results
Full-dose SAFIRE reconstructions were superior to full-dose FBP vis-à-vis in-stent noise (21.2?±?6.6 vs. 35.7?±?17.5; P?<?0.05), SNR (22.1?±?8.6 vs. 14.3?±?6.7; P?<?0.05), SAIR (19.6?±?17.6 vs. 33.4?±?20.4%; P?<?0.05), and image quality (4.2?±?0.86 vs. 3.5?±?1.0; P?<?0.05). Stent volumes were lower measured with SAFIRE (119.9?±?53.7 vs. 129.8?±?65.0?mm3; P?>?0.05). Comparing half-dose SAFIRE with full-dose FBP, in-stent noise (26.7?±?13.0 vs. 35.7?±?17.5; P?<?0.05) and SNR (18.2?±?6.9 vs. 14.3?±?6.7; P?<?0.05) improved significantly. SAIR (31.6?±?24.3 vs. 33.4?±?20.4%; P?>?0.05), stent volume (129.6?±?57.3 vs. 129.8?±?65.0?mm3; P?>?0.05), and image quality (3.5?±?1.0 vs. 3.7?±?1.1; P?>?0.05) did not differ. Radiation dose decreased from 8.7?±?5.2 to 4.3?±?2.6?mSv.Conclusions
Iterative reconstruction significantly improves imaging of coronary artery stents by CT compared with FBP, even with half-radiation-dose data.Key Points
? Computed tomography (CT) is becoming an increasingly important investigation for cardiac problems. ? Iterative CT reconstruction techniques significantly improve coronary artery stent evaluation. ? Iterative reconstruction has the potential to reduce radiation dose requirements. ? Improved stent visualisation detects complications better, further reducing the need for catheterisation. 相似文献16.
Francesco Tricarico Anthony M. Hlavacek U. Joseph Schoepf Ullrich Ebersberger John W. Nance Jr. Rozemarijn Vliegenthart Young Jun Cho J. Reid Spears Francesco Secchi Giancarlo Savino Riccardo Marano Stefan O. Schoenberg Lorenzo Bonomo Paul Apfaltrer 《European radiology》2013,23(5):1306-1315
Objectives
To evaluate image quality (IQ) of low-radiation-dose paediatric cardiovascular CT angiography (CTA), comparing iterative reconstruction in image space (IRIS) and sinogram-affirmed iterative reconstruction (SAFIRE) with filtered back-projection (FBP) and estimate the potential for further dose reductions.Methods
Forty neonates and children underwent low radiation CTA with or without ECG synchronisation. Data were reconstructed with FBP, IRIS and SAFIRE. For ECG-synchronised studies, half-dose image acquisitions were simulated. Signal noise was measured and IQ graded. Effective dose (ED) was estimated.Results
Mean absolute and relative image noise with IRIS and full-dose SAFIRE was lower than with FBP (P?<?0.001), while SNR and CNR were higher (P?<?0.001). Image noise was also lower and SNR and CNR higher in half-dose SAFIRE studies compared with full-and half-dose FBP studies (P?<?0.001). IQ scores were higher for IRIS, full-dose SAFIRE and half-dose SAFIRE than for full-dose FBP and higher for half-dose SAFIRE than for half-dose FBP (P?<?0.05). Median weight-specific ED was 0.3 mSv without and 1.36 mSv with ECG synchronisation. The estimated ED of half-dose SAFIRE studies was 0.68 mSv.Conclusions
IR improves image noise, SNR, CNR and subjective IQ compared with FBP in low-radiation-dose paediatric CTA and allows further dose reductions without compromising diagnostic IQ.Key Points
? Iterative reconstruction techniques significantly improve non-invasive cardiovascular CT in children. ? Using half traditional radiation dose image quality is higher with iterative reconstruction. ? Iterative reconstruction techniques may allow further radiation reductions in paediatric cardiovascular CT. 相似文献17.
Christoph Karlo Sebastian Leschka Robert Paul Goetti Gudrun Feuchtner Lotus Desbiolles Paul Stolzmann Andre Plass Volkmar Falk Borut Marincek Hatem Alkadhi Stephan Baumüller 《European radiology》2011,21(1):205-212
Purpose
To compare image quality and radiation dose of high-pitch computed tomography angiography(CTA) of the aortic valve-aortic root complex with and without prospective ECG-gating compared to a retrospectively ECG-gated standard-pitch acquisition.Materials and Methods
120 patients(mean age 68?±?13 years) were examined using a 128-slice dual-source CT system using prospectively ECG-gated high-pitch(group A; n?=?40), non-ECG-gated high-pitch(group B; n?=?40) or retrospectively ECG-gated standard-pitch(C; n?=?40) acquisition techniques. Image quality of the aortic root, valve and ascending aorta including the coronary ostia was assessed by two independent readers. Image noise was measured, radiation dose estimates were calculated.Results
Interobserver agreement was good(κ?=?0.64–0.78). Image quality was diagnostic in 38/40 patients(group A), 37/40(B) and 38/40(C) with no significant difference in number of patients with diagnostic image quality among all groups (p?=?0.56). Significantly more patients showed excellent image quality in group A compared to groups B and C(each, p?<?0.01). Average image noise was significantly different between all groups(p?<?0.05). Mean radiation dose estimates in groups A and B(each; 2.4?±?0.3 mSv) were significantly lower compared to group C(17.5?±?4.4 mSv; p?<?0.01).Conclusion
High-pitch dual-source CTA provides diagnostic image quality of the aortic valve-aortic root complex even without ECG-gating at 86% less radiation dose when compared to a standard-pitch ECG-gated acquisition. 相似文献18.
Objectives
To compare accuracy, image quality and radiation dose between high-pitch spiral and sequential modes on 128-slice dual-source computed tomographic (DSCT) angiography in children with congenital heart disease (CHD).Methods
Forty patients suspected with CHD underwent 128-slice DSCT angiography with high-pitch mode and sequential mode respectively. All the anomalies were confirmed by the surgical and/or the conventional cardiac angiography (CCA) findings. The diagnostic accuracy, the subjective and objective image quality and effective radiation doses were compared.Results
There was no significant difference in diagnostic accuracy (χ 2 ?=?0.963, P?>?0.05), the objective parameters for image quality (P?>?0.05) and the image quality of great vessels (u?=?167.500, P?>?0.05) between the two groups. The image quality of intracardiac structures and coronary arteries was significantly better in the sequential mode group than that in the high-pitch group (u?=?112.500 and 100.000, P?0.05). The mean effective dose in high-pitch group (0.17?±?0.05?mSv) was significantly lower (t?=?5.287, P?0.05) than that in the sequential mode group (0.29?±?0.09?mSv).Conclusions
Both the high-pitch and the sequential modes for 128-slice DSCT angiography provide high accuracy for the assessment of CHD in children, while the high-pitch mode, even with some image quality decrease, further significantly lowers the radiation dose.Key Points
? Modern CT provides excellent anatomical detail of congenital heart disease. ? Dual source CT systems offer high-pitch spiral and sequential modes. ? The high-pitch mode provides high accuracy for the assessment of CHD. ? A few images using the high-pitch mode were occasionally slightly degraded. ? But the high-pitch mode significantly lowers the radiation dose. 相似文献19.
Martin J. Willemink Richard A. P. Takx Pim A. de Jong Ricardo P. J. Budde Ronald L. A. W. Bleys Marco Das Joachim E. Wildberger Mathias Prokop Nico Buls Johan de Mey Arnold M. R. Schilham Tim Leiner 《European radiology》2014,24(9):2201-2212
Objectives
To analyse the effects of radiation dose reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS).Methods
Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four dose levels using unenhanced prospectively ECG-triggered protocols. Tube voltage was 120 kV and tube current differed between protocols. CT data were reconstructed with filtered back projection (FBP) and reduced dose CT data with IR. CCS was quantified with Agatston scores, calcification mass and calcification volume. Differences were analysed with the Friedman test.Results
Fourteen hearts showed coronary calcifications. Dose reduction with FBP did not significantly change Agatston scores, calcification volumes and calcification masses (P?>?0.05). Maximum differences in Agatston scores were 76, 26, 51 and 161 units, in calcification volume 97, 27, 42 and 162 mm3, and in calcification mass 23, 23, 20 and 48 mg, respectively. IR resulted in a trend towards lower Agatston scores and calcification volumes with significant differences for one vendor (P?0.05). Median relative differences between reference FBP and reduced dose IR for Agatston scores remained within 2.0–4.6 %, 1.0–5.3 %, 1.2–7.7 % and 2.6–4.5 %, for calcification volumes within 2.4–3.9 %, 1.0–5.6 %, 1.1–6.4 % and 3.7–4.7 %, for calcification masses within 1.9–4.1 %, 0.9–7.8 %, 2.9–4.7 % and 2.5–3.9 %, respectively. IR resulted in increased, decreased or similar calcification masses.Conclusions
CCS derived from standard FBP acquisitions was not affected by radiation dose reductions up to 80 %. IR resulted in a trend towards lower Agatston scores and calcification volumes.Key points
? In this ex vivo study, radiation dose could be reduced by 80 % for coronary calcium scoring ? Iterative reconstruction resulted in a trend towards lower Agatston scores and calcification volumes ? Caution should be taken for coronary calcium scoring with iterative reconstruction 相似文献20.
J. C. L. Rodrigues D. Joshi S. M. Lyen I. S. Negus N. E. Manghat M. C. K. Hamilton 《European radiology》2014,24(10):2458-2466