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1.
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2.
Madeleine Kok Jakub Turek Casper Mihl Sebastian D. Reinartz Robin F. Gohmann Estelle C. Nijssen Suzanne Kats Vincent G. van Ommen Bas L. J. H. Kietselaer Joachim E. Wildberger Marco Das 《European radiology》2016,26(8):2426-2435
Purpose
To evaluate image quality using reduced contrast media (CM) volume in pre-TAVI assessment.Methods
Forty-seven consecutive patients referred for pre-TAVI examination were evaluated. Patients were divided into two groups: group 1 BMI?<?28 kg/m2 (n?=?29); and group 2 BMI?>?28 kg/m2 (n?=?18). Patients received a combined scan protocol: retrospective ECG-gated helical CTA of the aortic root (80kVp) followed by a high-pitch spiral CTA (group 1: 70 kV; group 2: 80 kVp) from aortic arch to femoral arteries. All patients received one bolus of CM (300 mgI/ml): group 1: volume?=?40 ml; flow rate?=?3 ml/s, group 2: volume?=?53 ml; flow rate?=?4 ml/s. Attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the levels of the aortic root (helical) and peripheral arteries (high-pitch). Diagnostic image quality was considered sufficient at attenuation values > 250HU and CNR > 10.Results
Diagnostic image quality for TAVI measurements was obtained in 46 patients. Mean attenuation values and CNR (HU?±?SD) at the aortic root (helical) were: group 1: 381?±?65HU and 13?±?8; group 2: 442?±?68HU and 10?±?5. At the peripheral arteries (high-pitch), mean values were: group 1: 430?±?117HU and 11?±?6; group 2: 389?±?102HU and 13?±?6.Conclusion
CM volume can be substantially reduced using low kVp protocols, while maintaining sufficient image quality for the evaluation of aortic root and peripheral access sites.Key points
? Image quality could be maintained using low kVp scan protocols. ? Low kVp protocols reduce contrast media volume by 34–67 %. ? Less contrast media volume lowers the risk of contrast-induced nephropathy.3.
Selma Uysal Ramadan Pınar Kosar Iclal Sonmez Sevilay Karahan Ugur Kosar 《European radiology》2010,20(9):2100-2107
Objective
To compare the image quality of computed tomography pulmonary angiography (CTPA) obtained with the injection of various low doses of contrast medium (CM) with different injection-related factors.Methods
A total of 90 patients (42 females, 48 males; 54.3?±?18.6 years) undergoing CTPA were included. Three CM protocols, each containing 30 patients, were created. Protocols 1, 2 and 3 consisted of a CM of 60 ml, 55 ml and 50 ml, and a bolus trigger level of 120 HU, 90 HU and 75 HU, respectively. Injection was uniphasic for protocols 1 and 2 (flow rate 5 ml/s), and biphasic for protocol 3 (flow rates 5 and 4 ml/s); with saline flushing afterwards. Enhancement was measured in three central and six peripheral pulmonary arteries.Results
The mean attenuation value for pulmonary arteries was over 250 HU for all protocols. There was no difference between the attenuation levels with the protocols (p?>?0.05). The percentage of pulmonary arteries exceeding optimal attenuation (≥250 HU) showed that protocols 2 and 3 were 90–100% successful (p?<?0.05).Conclusion
The use of proper injection-related factors during CTPA, such as a low trigger level and a high flow rate with saline injection following a decreased CM volume (55 ml or 50 ml), will enable adequate pulmonary artery contrast enhancement. 相似文献4.
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5.
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6.
Anders Svensson Jonas Björk Kerstin Cederlund Peter Aspelin Ulf Nyman Torkel B. Brismar 《European radiology》2014,24(8):1959-1963
Purpose
To compare hepatic parenchymal contrast media (CM) enhancement during multi-detector row computed tomography (MDCT) and its correlation with volume pitch-corrected computed tomography dose index CTDIvol) and body weight (BW).Material and methods
One hundred patients referred for standard three-phase thoraco-abdominal MDCT examination were enrolled. BW was measured in the CT suite. Forty grams of iodine was administered intravenously (iodixanol 320 mg I/ml at 5 ml/s or iomeprol 400 mg I/ml at 4 ml/s) followed by a 50-ml saline flush. CTDIvol presented by the CT equipment during the parenchymal examination was recorded. The CM enhancement of the liver was defined as the attenuation HU of the liver parenchyma during the hepatic parenchymal phase minus the attenuation in the native phase.Results
Liver parenchymal enhancement was negatively correlated to both CTDIvol (r?=??0.60) and BW (r?=??0.64), but the difference in correlation between those two was not significant.Conclusion
CTDIvol may replace BW when adjusting CM doses to body size. This makes it potentially feasible to automatically individualize CM dosage by CT.Key points
? CTDI vol is related to liver CM enhancement in the parenchymal phase. ? CTDI vol provides comparable information to body weight (BW). ? CTDI vol may be used when automatically adjusting CM dose for patient size. 相似文献7.
Maffei E Nieman K Martini C Catalano O Seitun S Arcadi T Malagò R Rossi A Clemente A Mollet NR Cademartiri F 《La Radiologia medica》2012,117(2):230-241
Purpose
The authors assessed the effect of vascular attenuation and density thresholds on the classification of noncalcified plaque by computed tomography coronary angiography (CTCA).Materials and methods
Thirty patients (men 25; age 59±8 years) with stable angina underwent arterial and delayed CTCA. At sites of atherosclerotic plaque, attenuation values (HU) were measured within the coronary lumen, noncalcified and calcified plaque material and the surrounding epicardial fat. Based on the measured CT attenuation values, coronary plaques were classified as lipid rich (attenuation value below the threshold) or fibrous (attenuation value above the threshold) using 30-HU, 50-HU and 70-HU density thresholds.Results
One hundred and sixty-seven plaques (117 mixed and 50 noncalcified) were detected and assessed. The attenuation values of mixed plaques were higher than those of exclusively noncalcified plaques in both the arterial (148.3±73.1 HU vs. 106.2±57.9 HU) and delayed (111.4±50.5 HU vs. 64.4±43.4 HU) phases (p<0.01). Using a 50-HU threshold, 12 (7.2%) plaques would be classified as lipid rich on arterial scan compared with 28 (17%) on the delayed-phase scan. Reclassification of these 16 (9.6%) plaques from fibrous to lipid rich involved 4/30 (13%) patients.Conclusions
Classification of coronary plaques as lipid rich or fibrous based on absolute CT attenuation values is significantly affected by vascular attenuation and density thresholds used for the definition. 相似文献8.
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9.
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
Objectives
The purpose of this study was to determine whether performing the test bolus (TB) of computed tomography coronary angiography (CTCA) and computed tomography pulmonary angiography (CTPA) at 80 kVp reduces dose without compromising diagnostic quality.Methods
An 80 kVp TB protocol for CTCA and CTPA was retrospectively compared to standard TB protocol (non-obese: 100 kVp, obese: 120 kVp). CT angiogram parameters were unchanged between cohorts. Thirty-seven consecutive 80 kVp TB CTCA images were compared to 53 standard CTCA images. Fifty consecutive CTPAs from each protocol were analysed. Diagnostic quality of the CT angiogram was assessed by: mean attenuation, signal-to-noise ratio (SNR) in the ascending aorta (AA) in CTCA and in the main pulmonary artery (MPA) in CTPA, diagnostic rate, and number of repeated monitoring scans. Mean effective dose was estimated using the dose-length product.Results
Mean TB effective doses were significantly lower (P?0.0001) for 80 kVp scans compared to the standard in non-obese CTCA (0.15?±?0.04 mSv Vs 0.33?±?0.09 mSv), obese CTCA (0.17?±?0.06 mSv Vs 0.57?±?0.12 mSv), and CTPA patients (0.07?±?0.03 mSv Vs 0.15?±?0.06 mSv). No difference was demonstrated in mean attenuation, SNR (AA), SNR (MPA), diagnostic rates, or number of repeated monitoring scans between protocols.Conclusions
Routinely performing TB at 80 kVp, regardless of body habitus, in CTCA and CTPA results in a small but significant dose reduction, without compromising CT angiogram diagnostic quality.Key Points
? CT coronary angiography is performed to exclude the presence of significant coronary atherosclerosis. ? CT pulmonary angiography is performed to diagnose pulmonary thromboembolism. ? This retrospective study showed dose reduction by performing test bolus at 80 kVp. ? Diagnosis can be made with reduced exposure to ionising radiation. 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.
Satoshi Goshima Masayuki Kanematsu Yoshifumi Noda Hiroshi Kondo Haruo Watanabe Hiroshi Kawada Nobuyuki Kawai Yukichi Tanahashi Kyongtae T. Bae 《European radiology》2014,24(8):1853-1859
Objectives
To determine the optimal iodine mass (IM) to achieve a 50-HU increase in hepatic attenuation for the detection of liver metastasis based on total body weight (TBW) or body surface area (BSA) at 80-kVp computed tomography (CT) imaging of the liver.Methods
One-hundred and fifty patients who underwent contrast-enhanced CT at 80-kVp were randomised into three groups: 0.5 gI/kg, 0.4 gI/kg and 0.3 gI/kg. Portal venous phase images were evaluated for hepatic parenchymal enhancement (?HU) and visualisation of liver metastasis. Iodine mass per BSA (gI/m2) calculated in individual patients were evaluated.Results
Mean ?HU for the 0.5 gI/kg group (84.2 HU) was higher than in the 0.4 gI/kg (66.1 HU) and 0.3 gI/kg (53.7 HU) groups (P?<?0.001). Linear correlation equations between ?HU and IM per TBW or BSA are ?HU?=?7.0?+?153.0?×?IM/TBW (r?=?0.73, P?<?0.001) and ?HU?=?11.4?+?4.0?×?IM/BSA (r?=?0.75, P?<?0.001), respectively. The three groups were comparable for the visualisation of hepatic metastases.Conclusions
The iodine mass to achieve a 50-HU increase in hepatic attenuation at 80-kVp CT was estimated to be 0.28 gI/kg of body weight or 9.6 gI/m2 of body surface area.Key Points
? Hepatic enhancement is expressed as ?HU?=?7.0?+?153.0?×?IM [g]/TBW [kg]. ? Hepatic enhancement is expressed as ?HU?=?11.4?+?4.0?×?IM [g]/BSA [m 2 ]. ? Essential iodine dose at 80-kVp CT was 0.28 gI/kg or 9.6 gI/m 2 . 相似文献12.
Anoeshka S. Dharampal Stella L. Papadopoulou Alexia Rossi W. Bob Meijboom Annick Weustink Marcel Dijkshoorn Koen Nieman Eric H. Boersma Pim J. de Feijter Gabriel P. Krestin 《European radiology》2013,23(11):2934-2943
Objectives
To determine the diagnostic performance of CT coronary angiography (CTCA) in detecting and excluding left main (LM) and/or three-vessel CAD (“high-risk” CAD) in symptomatic patients and to compare its discriminatory value with the Duke risk score and calcium score.Materials and methods
Between 2004 and 2011, a total of 1,159 symptomatic patients (61?±?11 years, 31 % women) with stable angina, without prior revascularisation underwent both invasive coronary angiography (ICA) and CTCA. All patients gave written informed consent for the additional CTCA. High-risk CAD was defined as LM and/or three-vessel obstructive CAD (≥50 % diameter stenosis).Results
A total of 197 (17 %) patients had high-risk CAD as determined by ICA. The sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratios of CTCA were 95 % (95 % CI 91–97 %), 83 % (80–85 %), 53 % (48–58 %), 99 % (98–99 %), 5.47 and 0.06, respectively. CTCA provided incremental value (AUC 0.90, P?<?0.001) in the discrimination of high-risk CAD compared with the Duke risk score and calcium score.Conclusions
CTCA accurately excludes high-risk CAD in symptomatic patients. The detection of high-risk CAD is suboptimal owing to the high percentage (47 %) of overestimation of high-risk CAD. CTCA provides incremental value in the discrimination of high-risk CAD compared with the Duke risk score and calcium score.Key Points
? Computed tomography coronary angiography (CTCA) accurately excludes high-risk coronary artery disease. ? CTCA overestimates high-risk coronary artery disease in 47?%. ? CTCA discriminates high-risk CAD better than clinical evaluation and coronary calcification. 相似文献13.
Fabian Stenzel Matthias Rief Elke Zimmermann Johannes Greupner Felicitas Richter Marc Dewey 《European radiology》2014,24(6):1229-1238
Objectives
Comparison of bolus tracking with a fixed threshold versus a manual fast start for coronary CT angiography.Methods
We retrospectively analysed 320-row coronary CT angiography of 50 patients with suspected or known coronary artery disease. Twenty-five examinations were initiated by a bolus tracking method (group 1), 25 examinations with a manual fast surestart (group 2).Results
Mean attenuation values in the ascending aorta were 519?±?111 Hounsfield units (HU) in group 1 and 476?±?65 HU in group 2 (p?=?0.10). Assessable vessel lengths were 171?±?44 mm vs 172?±?29 mm for the right coronary artery (p?=?0.91), 11?±?4 mm vs 12?±?4 mm for the left main (p?=?0.9), 163?±?28 mm vs 151?±?26 mm for the left anterior descending coronary artery (p?=?0.11) and 125?±?41 mm vs 110?±?37 mm for the left circumflex coronary artery (p?=?0.18). Image quality for all coronary arteries was not significantly different between the groups (p?>?0.41). The attenuation ratio between the left and right ventricle was 2.8?±?0.7 vs 3.6?±?1.0 (p?=?0.003). Significantly less contrast agent was used in group 2 (64?±?6 ml vs 80?±?0 ml; p?<?0.001).Conclusions
Bolus tracking with a fixed threshold and with a manual fast start are both suitable methods; the fast start allowed a reduction of contrast agent volumes.Key Points
? Fixed threshold bolus tracking is suitable for coronary 320-row CT angiography ? Manual fast start bolus tracking can reduce contrast agent volumes ? Manual fast start and fixed threshold initiation achieve good image quality ? Fixed threshold bolus tracking achieves a more reliable contrast bolus position 相似文献14.
Sebastian Leschka Paul Stolzmann Lotus Desbiolles Stephan Baumueller Robert Goetti Thomas Schertler Hans Scheffel Andre Plass Volkmar Falk Gudrun Feuchtner Borut Marincek Hatem Alkadhi 《European radiology》2009,19(12):2896-2903
Objectives
The objective was to prospectively investigate the diagnostic accuracy of high-pitch (HP) dual-source computed tomography coronary angiography (CTCA) compared with catheter coronary angiography (CCA) for the diagnosis of significant coronary stenoses.Methods
Thirty-five patients (seven women; mean age 62?±?8 years) underwent both CTCA and CCA. CTCA was performed with a second-generation dual-source CT system permitting data acquisition at an HP of 3.4. Patients with heart rates >60 bpm were excluded from study enrolment. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a four-point scale (1: excellent to 4: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). CCA served as the standard of reference. Radiation dose values were calculated using the dose-length product.Results
Diagnostic image quality was found in 99% of all segments (455/459). Non-diagnostic image quality occurred in a single patient with a sudden increase in heart rate immediately before and during CTCA. Taking segments with non-evaluative image quality as positive for disease, the sensitivity, specificity and positive and negative predictive values were 94, 96, 80 and 99% per segment and 100, 91, 88 and 100% per patient. The effective radiation dose was on average 0.9?±?0.1 mSv.Conclusion
In patients with heart rates ≤60 bpm, CTCA using the HP mode of the dual-source CT system is associated with high diagnostic accuracy for the assessment of coronary artery stenoses at sub-milliSievert doses. 相似文献15.
Hiroshi Kondo Masayuki Kanematsu Satoshi Goshima Haruo Watanabe Hiroshi Kawada Noriyuki Moriyama Kyongtae T. Bae 《European radiology》2013,23(7):1855-1861
Objective
To compare total body weight (TBW), lean body weight (LBW) and body surface area (BSA) for the adjustment of the iodine dose required for contrast-enhanced multi-detector computed tomography (MDCT) of the aorta and the liver.Methods
One hundred and three patients undergoing MDCT of the abdomen were randomised into three groups: the TBW group receiving 0.6 g iodine/kg of TBW (n?=?33), the LBW group receiving 0.75 g iodine/kg of LBW (n?=?35) and the BSA group receiving 22 g iodine/m2 (n?=?35). ?HU (increases in CT value) per gram of iodine (?HU/g) and adjusted maximum hepatic enhancement (adjusted MHE; ?HU/[g iodine/kg]) correlated with three groups using linear regressions.Results
Correlation coefficients of ?HU/g were 0.67 (TBW), 0.86 (LBW) and 0.85 (BSA) for the aorta, and 0.74 (TBW), 0.77 (LBW) and 0.84 (BSA) for the liver. Adjusted MHE was constant at 70.2 with LBW and at 2.69 with BSA, but correlated positively with TBW (r?=?0.58, P?<?0.001).Conclusion
Iodine load may need to be tailored by LBW or BSA in contrast enhanced MDCT of the abdomen. BSA is a simple and feasible index for the determination of iodine dose in individual patients.Key Points
? Optimisation of enhancement is very important for high quality MDCT. ? Iodine dose is best adjusted according to LBW or BSA. ? BSA may be adopted because calculation is simple. ? Iodine dose of 0.712 g/kg LBW/18.6 g/m 2 BSA gives 50 HU hepatic enhancement. 相似文献16.
Alejandro N. Mazzadi PhD Julien Pineau MD Nicolas Costes PhD Didier Le Bars PhD Fréderic Bonnefoi BSc Rapha?l Porcher PhD Pierre Croisille MD PhD Philippe Chevalier MD PhD 《Journal of nuclear cardiology》2012,19(5):1017-1025
Background
Vagal innervation modulates the electrical stability of the left ventricle (LV) during ischemia. Thus, abnormal parasympathetic activity in myocardial infarction (MI) patients with primary ventricular fibrillation (FV) can account for their arrhythmic disorders. We evaluated LV muscarinic receptor density (B max) after MI in patients with (FVG, n?=?11) or without (nFVG, n?=?12) primary FV.Methods and Results
The B max was measured by positron emission tomography and the specific antagonist [11C]methylquinuclidinyl benzilate ([11C]MQNB) in 23 patients 39?±?19?days post-MI, and 10 volunteers. Myocardial damage was quantified by delayed contrast-enhanced magnetic resonance imaging. Three short-axis slices per subject were analyzed and six time-activity curves per slice were fitted to a 3-compartment ligand-receptor model. The B max in remote regions of the 23 patients (67?±?36?pmol/mL?·?tissue; n?=?139) was higher than in normal regions of volunteers (33?±?16?pmol/mL?·?tissue; n?=?171; P?=?.01). Receptor density in remote regions was similarly upregulated in nFVG (69?±?31?pmol/mL?·?tissue, n?=?73) and FVG (66?±?40?pmol/mL?·?tissue, n?=?66; P?=?.72). In damaged regions, the B max was reduced in both patient groups (44?pmol/mL?·?tissue).Conclusions
Chronically infarcted patients with or without primary FV share similar patterns of ventricular muscarinic receptor remodeling, characterized by receptor upregulation, in remote non-damaged territories. 相似文献17.
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18.
Masafumi Kidoh Takeshi Nakaura Takaaki Ogata Hiroki Takashima Makoto Yoshikawa Shouzaburou Uemura Kazunori Harada Yasuyuki Yamashita 《European radiology》2013,23(11):3012-3019
Objectives
To evaluate the usefulness of an 80-kVp and compact contrast material protocol for arterial phase subtracted cerebral 3D-CTA using 256-slice multidetector CT.Methods
Thirty-two patients underwent CT with 100 kVp and received a contrast dose of 370 mgI/kg body weight over 15 s (protocol A). Thirty-three patients underwent CT with 100 kVp and received a contrast dose of 296 mgI/kg body weight over 10 s (protocol B). Thirty-three other patients underwent CT with 80 kVp and received a contrast medium dose of 296 mgI/kg body weight over 10 s (protocol C). We compared the arterial attenuation and contrast noise ratio (CNR) of each protocol. Two independent readers assessed overall image quality.Results
Arterial attenuation was significantly higher under protocols A (418.6?±?71.1 HU) and C (442.7?±?79.3 HU) than under protocol B (355.8?±?107.2 HU; P?<?0.05). The CNR of protocol C (26.1?±?6.1) was higher than that of protocol A (20.7?±?8.4; P?<?0.05). The overall image quality of protocol A was higher than that of protocol C (P?<?0.01).Conclusion
The 80-kVp plus compact contrast protocol is well suited to arterial phase subtracted cerebral 3D-CTA without confounding venous enhancement.Key Points
? Subtracted 3D CT angiography is useful in the evaluation of intracranial aneurysms. ? A compact contrast material protocol increased arterial attenuation without venous contamination. ? Low-kVp CT compensated for the decreased amount of contrast medium. ? An 80-kVp CT with a compact enhancement bolus provides good intracranial 3D-CT angiography. 相似文献19.
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20.
Tilo Niemann Simon Henry Jean-Baptiste Faivre Kanna Yasunaga Sofiane Bendaoud Ariana Simeone Jacques Remy Alain Duhamel Thomas Flohr Martine Remy-Jardin 《European radiology》2013,23(10):2643-2651