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1.
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2.
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3.
Objectives
Thin-slice helical unenhanced CT can be used for thrombus imaging but increases radiation exposure. Conventional sequential images obtained by multidetector CT can be reconstructed into thin-slice images. The purpose of this study was to evaluate if conventional sequential unenhanced CT images can replace helical unenhanced CT for thrombus imaging.Methods
Fifty consecutive patients with acute ischaemic stroke underwent both 5-mm conventional sequential unenhanced CT and helical unenhanced CT. Each of the sequential and helical unenhanced CT images was subsequently reconstructed into four 1.25-mm images. Thrombus volumes and HU were measured semi-automatically using both types of unenhanced CT. Thrombus HU ratio (rHU) was calculated using the HU of the contralateral segment. The intraclass correlation coefficient (ICC) and Bland–Altman plots were used to assess measurement agreement.Results
The mean rHUs were 1.47?±?0.17 for sequential unenhanced CT and 1.47?±?0.18 helical unenhanced CT (P?=?0.542). The mean thrombus volumes were 124.25?±?125.65?mm3 and 117.84?±?124.32?mm3 on sequential and helical unenhanced CT images, respectively (P?=?0.063). Measurement agreement between thrombus volumes from the two unenhanced CT images was high (ICC?=?0.981).Conclusions
Thin-slice unenhanced CT images reconstructed from 5-mm sequential images can replace helical unenhanced CT for thrombus imaging in acute ischaemic stroke.Key Points
? Unenhanced CT is used to evaluate intra-arterial thrombus. ? Thrombus HU and volume measurements using sequential or helical CT are comparable. ? Conventional sequential images can replace helical CT for thrombus imaging. ? Radiation dose for thrombus imaging can be reduced using sequential CT. 相似文献4.
Wei-Hua Yin Bin Lu Zhi-Hui Hou Nan Li Lei Han Yong-Jian Wu Hong-Xia Niu Justin R. Silverman Carlo Nicola De Cecco U. Joseph Schoepf 《European radiology》2013,23(11):2927-2933
Objectives
To evaluate the diagnostic accuracy of sub-milliSievert (mSv) coronary CT angiography (cCTA) using prospectively ECG-triggered high-pitch spiral CT acquisition combined with iterative image reconstruction.Methods
Forty consecutive patients (52.9?±?8.7 years; 30 men) underwent dual-source cCTA using prospectively ECG-triggered high-pitch spiral acquisition. The tube current-time product was set to 50 % of standard-of-care CT examinations. Images were reconstructed with sinogram-affirmed iterative reconstruction. Image quality was scored and diagnostic performance for detection of ≥50 % stenosis was determined with catheter coronary angiography (CCA) as the reference standard.Results
CT was successfully performed in all 40 patients. Of the 601 assessable coronary segments, 543 (90.3 %) had diagnostic image quality. Per-patient sensitivity for detection of ≥50 % stenosis was 95.7 % [95 % confidence interval (CI), 76.0-99.8 %] and specificity was 94.1 % (95 % CI, 69.2-99.7 %). Per-vessel sensitivity was 89.5 % (95 % CI, 77.8-95.6 %) with 93.2 % specificity (95 % CI, 86.0-97.0 %). The area under the receiver-operating characteristic curve on per-patient and per-vessel levels was 0.949 and 0.913. Mean effective dose was 0.58?±?0.17 mSv. Mean size-specific dose estimate was 3.14?±?1.15 mGy.Conclusions
High-pitch prospectively ECG-triggered cCTA combined with iterative image reconstruction provides high diagnostic accuracy with a radiation dose below 1 mSv for detection of coronary artery stenosis.Key Points
? Cardiac CT with sub-milliSievert radiation dose is feasible in many patients ? High-pitch spiral CT acquisition with iterative reconstruction detects coronary stenosis accurately. ? Iterative reconstruction increases who can benefit from low-radiation cardiac CT. 相似文献5.
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6.
Eun-Ju Kang Jongmin Lee Ki-Nam Lee Heejin Kown Dong-Ho Ha Rock Bum Kim 《European radiology》2013,23(5):1199-1209
Objectives
To evaluate the feasibility of free-breathing coronary computed tomography angiography (CCTA) in adults using with a 320-detector multidetector CT (MDCT).Methods
In 74 patients who underwent CCTA, 37 CCTA examinations were performed during free-breathing, and the remaining 37 CCTA examinations were produced with the standard breath-holding method. The quality scores for 16 segments of all coronary arteries were analysed and defined as: 1 (excellent), 2 (good), and 3 (poor). The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and effective radiation dose of each image were compared between the two methods.Results
No significant differences were observed in the quality scores between the breath-holding and free-breathing methods (1.10?±?0.31 vs. 1.12?±?0.33; P?=?0.443). The SNR and CNR were not significantly different between the two methods. The overall mean effective radiation dose revealed no significant difference between the two methods (P?=?0.585).Conclusions
Free-breathing CCTA using 320-detector MDCT showed no significant difference in image quality compared with standard breath-holding CCTA. For patients with difficulties of breath-holding or non-negligible apnoea-related heart rate variability, free-breathing CCTA can be an alternative solution for coronary artery evaluation.Key Points
? Cardiac CT is becoming widely used and some patients are inevitably breathless. ? Multidetector CT (e.g. 320) offers new opportunities for the breathless patient. ? Free breathing images yielded similar image quality to those obtained using breath-holding. ? However, a possibility of higher radiation dose precludes its routine application. 相似文献7.
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8.
Objectives
To evaluate image quality, coronary evaluability and radiation exposure of coronary CT angiography (CCTA) performed with whole-heart coverage cardiac-CT in patients with atrial fibrillation (AF).Materials and methods
We prospectively enrolled 164 patients with AF who underwent a clinically indicated CCTA with a 16-cm z-axis coverage scanner. In all patients CCTA was performed using prospective ECG-triggering with targeted RR interval. We evaluated image quality, coronary evaluability and effective dose (ED). Patients were divided in two subgroups based on heart rate (HR) during imaging. Group 1: 64 patients with low HR (<75 bpm), group 2: 100 patients with high HR (≥75 bpm). Written informed consent was obtained from all patients and the institutional ethics committee approved the study protocol.Results
In a segment-based analysis, coronary evaluability was 98.4 % (2,577/2,620 segments) in the whole population, without significant differences between groups (1,013/1,024 (98.9 %) and 1,565/1,596 (98.1 %), for groups 1 and 2, respectively, p=0.15). Mean ED was similar in both groups (3.8±1.9 mSv and 3.9±2.1 mSv in groups 1 and 2, respectively, p=0.75)Conclusions
The whole-heart-coverage scanner could evaluate coronary arteries with high image quality and without increase in radiation exposure in AF patients, even in the high HR group.Key points
? Last-generation CT scanner improves coronary artery assessment in AF patients. ? The new CT scanner enables low radiation exposure in AF patients. ? Diagnostic ICA maybe avoided in AF patients with suspected CAD. ? Whole-heart coverage CT scanner enables low radiation exposure in AF patients.9.
Objective
To prospectively investigate the feasibility, image quality and radiation dose estimates for computed tomography angiography (CTA) of the pulmonary veins and left atrium using prospective electrocardiography (ECG)-triggered sequential dual-source (DS) data acquisition at end-systole in patients with paroxysmal atrial fibrillation undergoing radiofrequency ablation.Methods
Thirty-five patients (mean age 66.2?±?12.6 years) with paroxysmal atrial fibrillation underwent prospective ECG-triggered sequential DS-CTA with tube current (250 mAs/rotation) centred 250 ms past the R-peak. Tube voltage was adjusted to the BMI (<25 kg/m2: 100 kV, >25 kg/m2: 120 kV). Presence of motion or stair-step artefacts was assessed. Effective radiation dose was calculated from the dose-length product.Results
All data sets could be integrated into the electroanatomical mapping system. Twenty-two patients (63%) were in sinus rhythm (mean heart rate 69.2?±?11.1 bpm, variability 1.0?±?1.7 bpm) and 13 (37%) showed an ECG pattern of atrial fibrillation (mean heart rate 84.8?±?16.6 bpm, variability 17.9?±?7.5 bpm). Minor step artefacts were observed in three patients (23%) with atrial fibrillation. Mean estimated effective dose was 1.1?±?0.3 and 3.0?±?0.5 mSv for 100 and 120 kV respectively.Conclusion
Imaging of pulmonary vein anatomy is feasible using prospective ECG-triggered sequential data acquisition at end-systole regardless of heart rate or rhythm at the benefit of low radiation dose. 相似文献10.
Devang Odedra Joerg Blobel Saad AlHumayyd Miranda Durand Laura Jimenez-Juan Narinder Paul 《European radiology》2014,24(1):86-94
Objectives
To compare the image quality and radiation dose using image-noise (IN)-based determination of X-ray tube settings compared with a body mass index (BMI)-based protocol during CT coronary angiography (CTCA).Methods
Two hundred consecutive patients referred for CTCA to our institution were divided into two groups: BMI-based, 100 patients had CTCA with the X-ray tube current adjusted to the patient’s BMI while maintaining a fixed tube potential of 120 kV; IN-based, 100 patients underwent imaging with the X-ray tube current and voltage adjusted to the IN measured within the mid-left ventricle on a pre-acquisition trans-axial image. Two independent cardiac radiologists performed blinded image quality assessment with quantification of the IN and signal-to-noise ratio (SNR) from the mid-LV and qualitative assessment using a three-point score. Radiation dose (CTDI and DLP) was recorded from the console.Results
Results showed: IN (HU): BMI-based, 30.1?±?9.9; IN-based, 33.1?±?6.7; 32 % variation reduction (P?=?0.001); SNR: BMI-based, 18.6?±?7.1; IN-based, 15.4?±?3.7; 48 % variation reduction (P?<?0.0001). Visual scores: BMI-based, 2.3?±?0.6; IN-based, 2.2?±?0.5 (P?=?0.54). Radiation dose: CTDI (mGy), BMI-based, 22.68?±?8.9; IN-based, 17.16?±?7.6; 24.3 % reduction (P?<?0.001); DLP (mGy.cm), BMI-based, 309.3?±?127.5; IN-based, 230.6?±?105.5; 25.4 % reduction (P?<?0.001).Conclusions
Image-noise-based stratification of X-ray tube parameters for CTCA results in 32 % improvement in image quality and 25 % reduction in radiation dose compared with a BMI-based protocol.Key Points
? Image quality and radiation dose are closely related in CT coronary angiography. ? So too are the image quality, radiation dose and body mass index (BMI). ? An image-noise-based CTCA protocol reduces the radiation dose by 25 %. ? It improves inter-patient image homogeneity by 32 %. 相似文献11.
Ryo Nakazato MD PhD Damini Dey PhD Erick Alexánderson MD Aloha Meave MD Moisés Jiménez MD Edgar Romero MD Rodrigo Jácome MD Marco Pe?a MD Daniel S. Berman MD Piotr J. Slomka PhD 《Journal of nuclear cardiology》2012,19(3):482-491
Background
Hybrid PET/CT allows for acquisition of cardiac PET and coronary CT angiography (CCTA) in one session. However, PET and CCTA are acquired with differing breathing protocols and require software registration. We aimed to validate automatic correction for breathing misalignment between PET and CCTA acquired on hybrid scanner.Methods
Single-session hybrid PET/CT studies of rest/stress 13N-ammonia PET and CCTA in 32 consecutive patients were considered. Automated registration of PET left ventricular (LV) surfaces with CCTA volumes was evaluated by comparing with expert manual alignment by two observers.Results
The average initial misalignments between the position of LV on PET and CCTA were 27.2?±?11.8, 13.3?±?11.5, and 14.3?±?9.1?mm in x, y, and z axes on rest, and 26.3?±?10.2, 11.1?±?9.5, and 11.7?±?7.1?mm in x, y, and z axes on stress, respectively. The automated PET-CCTA co-registration had 95% agreement as judged visually. Compared with expert manual alignment, the translation errors of the algorithm were 5.3?±?2.8?mm (rest) and 6.0?±?3.5?mm (stress). 3D visualization of combined coronary vessel anatomy and hypoperfusion from PET could be made without further manual adjustments.Conclusion
Software co-registration of CCTA and PET myocardial perfusion imaging on hybrid PET/CT scanners is necessary, but can be performed automatically, facilitating integrated 3D display on PET/CT. 相似文献12.
Stefanie Mangold Julian L. Wichmann U. Joseph Schoepf Sheldon E. Litwin Christian Canstein Akos Varga-Szemes Giuseppe Muscogiuri Stephen R. Fuller Andrew C. Stubenrauch Konstantin Nikolaou Carlo N. De Cecco 《European radiology》2016,26(9):2937-2946
Objectives
To evaluate the image quality of coronary CT angiography (CCTA) in obese patients using a 3rd generation, dual-source CT scanner.Methods
We retrospectively evaluated 102 overweight and obese patients who had undergone CCTA. Studies were performed with 3rd generation dual-source CT, prospectively ECG-triggered acquisition at 120 kV, and automated tube current modulation. Advanced modeled iterative reconstruction was used. Patients were divided into three BMI groups: 1)25–29.9 kg/m2; 2)30–39.9 kg/m2; 3)?≥?40 kg/m2. Vascular attenuation in the coronary arteries was measured. Contrast-to-noise ratio (CNR) was calculated. Image quality was subjectively evaluated using five-point scales.Results
Image quality was considered diagnostic in 97.6 % of examinations. CNR was consistently adequate in all groups but decreased for groups 2 and 3 in comparison to group 1 as well as for group 3 compared to group 2 (p?=?0.001, respectively). Subjective image quality was significantly higher in group 1 compared to group 3 (attenuation proximal: 4.8?±?0.4 vs. 4.4?±?0.6, p?=?0.011; attenuation distal: 4.5?±?0.7 vs. 4.0?±?0.8, p?=?0.019; noise: 4.7?±?0.6 vs. 3.8?±?0.7, p?<?0.001). The mean effective dose was 9.5?±?3.9 mSv for group 1, 11.4?±?4.7 mSv for group 2 and 14.0?±?6.4 mSv for group 3.Conclusion
Diagnostic image quality can be routinely obtained at CCTA in obese patients with 3rd generation DSCT at 120 kV.Key Points
? Diagnostic CCTA can be routinely performed in obese patients with 3 rd generation DSCT.? 120-kV tube voltage allows diagnostic image quality in patients with BMI?>?40 kg/m 2 .? 80-ml contrast medium can be administered without significant decline in vascular attenuation.13.
Linfeng Yang Tao Zhou Ruijie Zhang Lin Xu Zhaohui Peng Juan Ding Sen Wang Min Li Gang Sun 《European radiology》2014,24(10):2345-2352
Objectives
To investigate the diagnostic performance of coronary computed tomographic angiography (CCTA) with prospective electrocardiograph (ECG) gating based on step-and-shoot (SAS), Flash and volume imaging modes.Methods
We searched the electronic databases PubMed for all published studies regarding CCTA. We used an exact binomial rendition of the bivariate mixed-effects regression model developed for synthesis of diagnostic data.Results
A total of 21,852 segments, 4,851 vessels and 1,375 patients were identified using database searches. Patient-level pooled sensitivity was 0.99 (95 % confidence interval [CI], 0.98–1.00); specificity was 0.88 (CI, 0.85–0.91). The results showed that the sensitivity and specificity for detection of significant stenosis did not differ in the three protocols (P?=?0.24). No heterogeneity was found at the patient level for sensitivity (Q?=?26.23; P?=?0.12; I 2?=?27.56 % [CI, 0.00-67.02 %]) and specificity (Q?=?19.54; P?=?0.42; I 2?=?2.78 % [CI, 0.00-66.26 %]).Conclusions
CCTA with prospective ECG gating has similar high diagnostic value to rule out CAD in all three presented modes.Key Points
? The accuracy of CCTA with different prospective ECG gating is similar ? CCTA with prospective ECG gating is effective to exclude coronary artery disease ? The radiation dose of volume mode increases with higher heart rate 相似文献14.
Nam Chull Paik 《European radiology》2014,24(9):2109-2117
Objectives
To test whether radiation dose reduction in CTF-guided LIESI would be achieved by replacing the preliminary planning CT with a spot CTF while still maintaining technical performance.Methods
This retrospective study included a review of 247 consecutive procedures performed on 241 patients before (comparison group: n?=?124) and after (study group: n?=?123) instituting the above-mentioned the protocol modification. The patient (age, sex, body diameter, and level injected) and performance (procedure time, number of CTF acquisitions, and DLP) characteristics were compared between the two groups.Results
The total DLP of the study group (median 4.94 mGy?·?cm) was significantly reduced compared to that of the comparison group (median 31.78 mGy?·?cm, P?0.001). The numbers of CTF acquisitions needed for needle placement and epidurography were very similar for both groups (median 3, P?=?0.685). The mean procedure time was significantly shorter for the study group (5:14?±?1:06 min) compared to the comparison group (5:53?±?1:19 min, P?0.001).Conclusions
When conducting CTF-guided LIESIs, a significant radiation dose reduction (median 84.5 % in DLP, P?0.001) can be achieved by minimizing the preliminary planning examination, without compromising the number of CTF acquisitions and the procedure time.Key Points
? Majority of radiation is delivered during the preliminary planning image acquisition ? Spot CTF scan can replace the preliminary planning helical examination ? Patient dose can be reduced to as low as 0.09 mSv 相似文献15.
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16.
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17.
Yuzo Yamasaki Michinobu Nagao Kenichiro Yamamura Masato Yonezawa Yoshio Matsuo Satoshi Kawanami Takeshi Kamitani Ko Higuchi Ichiro Sakamoto Yuichi Shiokawa Hidetake Yabuuchi Hiroshi Honda 《European radiology》2014,24(12):3289-3299
Objectives
To compare 256-slice cardiac computed tomography (CCT) with cardiac magnetic resonance (CMR) imaging to assess right ventricular (RV) function and pulmonary regurgitant fraction (PRF) in patients with repaired tetralogy of Fallot (TOF).Methods
Thirty-three consecutive patients with repaired TOF underwent retrospective ECG-gated CCT and 3-Tesla CMR. RV and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured using CCT and CMR. PRF-CCT (%) was defined as (RVSV???LVSV)/RVSV. PRF-CMR (%) was measured by the phase-contrast method. Repeated measurements were performed to determine intra- and interobserver variability.Results
CCT measurements, including PRF, correlated highly with the CMR reference (r?=?0.71–0.96). CCT overestimated RVEDV (mean difference, 17.1?±?2.9 ml), RVESV (12.9?±?2.1 ml) and RVSV (4.2?±?2.0 ml), and underestimated RVEF (?2.6?±?1.0 %) and PRF (?9.1?±?2.0 %) compared with CMR. The limits of agreement between CCT and CMR were in a good range for all measurements. The variability in CCT measurements was lower than those in CMR. The estimated effective radiation dose was 7.6?±?2.6 mSv.Conclusions
256-slice CCT can assess RV function and PRF with relatively low dose radiation exposure in patients with repaired TOF, but overestimates RV volume and underestimates PRF.Key points
? 256-slice CT assessment of RV function is highly reproducible in repaired TOF. ? Pulmonary regurgitation can be evaluated by biventricular systolic volume difference. ? CT overestimates RV volume and underestimates pulmonary regurgitation, compared with MRI. 相似文献18.
Rosario Francesco Grasso Roberto Luigi Cazzato Giacomo Luppi Francesco D’Agostino Emiliano Schena Riccardo Del Vescovo Francesco Giurazza Eliodoro Faiella Bruno Beomonte Zobel 《European radiology》2013,23(11):3071-3076
Objectives
To compare patients’ radiation exposure, technical feasibility, imaging quality and complication rate of percutaneous lung biopsies (PLBs) performed with a low-dose (LD) CT protocol under guidance of an optical navigation system.Methods
Fifty-two consecutive patients with suspected malignant lung lesions were enrolled and randomised into group 1 (PLBs under the guidance of the navigation system) and group 2 (PLBs under the guidance navigation system with an LD protocol). Patients’ demographics, lesion features, procedure-related variables and CT image quality for group 2 were recorded and compared.Results
Technical success was 100 % in both groups. The radiation dose to patients’ chest was significantly lower in group 2 than in group 1 (group 1: mean TDLP 206?±?59 mGy·cm, ~ 3.5?±?1.0 mSv; group 2: 54.2?±?46.2 mGy·cm, ~ 0.92?±?0.78 mSv; P?<?0.0001). The PNX rate was 12 % in group 1 and 11.1 % in group 2. The haemoptysis rate was 8.0 % in group 1 and 3.7 % in group 2. CT image quality obtained in group 2 was always rated as adequate and as excellent in 15 cases (56.0 %).Conclusions
An optical navigation system with LD CT protocol is useful for performing lung biopsies with decreased patient radiation exposure.Key Points
? Navigation systems are useful tools in percutaneous imaging-guided procedures. ? For lung biopsies, low-dose (LD) CT protocols may be used. ? Combining LD protocols with optical CT navigation results in significantly reduced radiation exposure. 相似文献19.
Daniella F. Pinho Naveen M. Kulkarni Arun Krishnaraj Sanjeeva P. Kalva Dushyant V. Sahani 《European radiology》2013,23(2):351-359
Objectives
To assess image quality of virtual monochromatic spectral (VMS) images, compared to single-energy (SE) CT, and to evaluate the feasibility of material density imaging in abdominal aortic disease.Methods
In this retrospective study, single-source (ss) dual-energy (DE) CT of the aorto-iliac system in 35 patients (32 male, mean age 76.5 years) was compared to SE-CT. By post-processing the data from ssDECT, VMS images at different energies and material density water (WD) images were generated. The image quality parameters were rated on 5-point scales. The aorto-iliac attenuation and contrast-to-noise ratio (CNR) were recorded. Quality of WD images was compared to true unenhanced (TNE) images. Radiation dose was recorded and statistical analysis was performed.Results
Image quality and noise were better at 70 keV (P?<?0.01). Renal artery branch visualisation was better at 50 keV (P?<?0.005). Attenuation and CNR were higher at 50 and 70 keV (P?<?0.0001). The WD images had diagnostic quality but higher noise than TNE images (P?<?0.0001). Radiation dose was lower using single-phase ssDECT compared to dual-phase SE-CT (P?<?0.0001).Conclusion
70-keV images from ssDECT provide higher contrast enhancement and improved image quality for aorto-iliac CT when compared to SE-CT at 120 kVp. WD images are an effective substitute for TNE images with a potential for dose reduction.Key Points
? Multi-detector computed tomography (MDCT) angiography is now a routine procedure. ? Single-source dual-energy CT (ssDECT) can provide simultaneous data with different kilovoltages. ? 70 keV images showed better image quality than conventional single-energy (SE) CT. ? 70 keV images exhibited less image noise in comparison to SE-CT. 相似文献20.
T. Werncke C. von Falck M. Wittmann T. Elgeti F. K. Wacker B. C. Meyer 《European radiology》2013,23(9):2482-2491