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Rengier F, Notohamiprodjo M, Weber MA. Thoughts on sustainability in the use of iodinated contrast media in CT: a practice-oriented review based on the example of a hospital and a private practice. ROFO-FORTSCHR RONTG 2024; 196:819-826. [PMID: 38408475 DOI: 10.1055/a-2246-6697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Affiliation(s)
- Fabian Rengier
- Pharmaceuticals Medizin, Radiology, Bayer Vital GmbH, Leverkusen, Germany
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Germany
| | - Mike Notohamiprodjo
- Radiological and Nuclear Medicine Partnership Munich (PR 1432), DIE RADIOLOGIE, Sonnenstraße 17, 80331 München, Germany
| | - Marc-André Weber
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, Rostock University Medical Center, Rostock, Germany
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Fleitmann M, Uzunova H, Pallenberg R, Stroth AM, Gerlach J, Fürschke A, Barkhausen J, Bischof A, Handels H. Artificial Intelligence-Based Prediction of Contrast Medium Doses for Computed Tomography Angiography Using Optimized Clinical Parameter Sets. Methods Inf Med 2024. [PMID: 38262476 DOI: 10.1055/s-0044-1778694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
OBJECTIVES In this paper, an artificial intelligence-based algorithm for predicting the optimal contrast medium dose for computed tomography (CT) angiography of the aorta is presented and evaluated in a clinical study. The prediction of the contrast dose reduction is modelled as a classification problem using the image contrast as the main feature. METHODS This classification is performed by random decision forests (RDF) and k-nearest-neighbor methods (KNN). For the selection of optimal parameter subsets all possible combinations of the 22 clinical parameters (age, blood pressure, etc.) are considered using the classification accuracy and precision of the KNN classifier and RDF as quality criteria. Subsequently, the results of the evaluation were optimized by means of feature transformation using regression neural networks (RNN). These were used for a direct classification based on regressed Hounsfield units as well as preprocessing for a subsequent KNN classification. RESULTS For feature selection, an RDF model achieved the highest accuracy of 84.42% and a KNN model achieved the best precision of 86.21%. The most important parameters include age, height, and hemoglobin. The feature transformation using an RNN considerably exceeded these values with an accuracy of 90.00% and a precision of 97.62% using all 22 parameters as input. However, also the feasibility of the parameter sets in routine clinical practice has to be considered, because some of the 22 parameters are not measured in routine clinical practice and additional measurement time of 15 to 20 minutes per patient is needed. Using the standard feature set available in clinical routine the best accuracy of 86.67% and precision of 93.18% was achieved by the RNN. CONCLUSION We developed a reliable hybrid system that helps radiologists determine the optimal contrast dose for CT angiography based on patient-specific parameters.
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Affiliation(s)
- Marja Fleitmann
- Artificial Intelligence in Medical Imaging, German Research Center for Artificial Intelligence, Kaiserslautern, Germany
| | - Hristina Uzunova
- Artificial Intelligence in Medical Imaging, German Research Center for Artificial Intelligence, Kaiserslautern, Germany
| | - René Pallenberg
- Institute for Signal Processing, University of Lübeck, Schleswig-Holstein, Germany
| | - Andreas M Stroth
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein (UKSH) Lübeck, Lübeck, Germany
| | - Jan Gerlach
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein (UKSH) Lübeck, Lübeck, Germany
| | - Alexander Fürschke
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein (UKSH) Lübeck, Lübeck, Germany
| | - Jörg Barkhausen
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein (UKSH) Lübeck, Lübeck, Germany
| | - Arpad Bischof
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein (UKSH) Lübeck, Lübeck, Germany
- IMAGE Information Systems Europe, Rostock, Germany
| | - Heinz Handels
- Artificial Intelligence in Medical Imaging, German Research Center for Artificial Intelligence, Kaiserslautern, Germany
- Institute of Medical Informatics, University of Lübeck, Schleswig-Holstein, Germany
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van der Star S, de Jong PA, Kok M. Incidental Indeterminate Renal Lesions: Distinguishing Non-Enhancing from Potential Enhancing Renal Lesions Using Iodine Quantification on Portal Venous Dual-Layer Spectral CT. J Pers Med 2023; 13:1546. [PMID: 38003860 PMCID: PMC10672440 DOI: 10.3390/jpm13111546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
The purpose of our study is to determine a threshold for iodine quantification to distinguish definitely non-enhancing benign renal lesions from potential enhancing masses on portal venous dual-layer spectral computed tomography (CT) to reduce the need for additional multiphase CT. In this single-center retrospective study, patients (≥18 years) scanned between April 2021 and January 2023 following the local renal CT protocol were included. Exclusion criteria were patients without renal lesions, lesions smaller than 10 mm, only fat-containing lesions, abscesses or infarction, follow-up after radiofrequent ablation, wrong scan protocol, or artefacts. Scans were performed on a dual layer detector-based spectral CT (CT 7500, Philips Healthcare, Best, The Netherlands). Iodine concentration (mgI/mL) in renal lesions was determined using spectral data. Analyses were performed for all lesions and for lesions of >30 HU on portal venous CT. Enhancement on multiphase CT (≥20 ΔHU from true unenhanced (TUE) to portal venous phase (PVP) CT) was used as reference standard. To determine thresholds for iodine concentration receiver operating characteristic (ROC) curves, area under the curve (AUC) and 95% confidence intervals were calculated. To obtain thresholds for definite (non-)enhancement, 100% sensitivity with maximum specificity and 100% specificity with maximum sensitivity were noted. Data were measured using one reader. To assess interobserver agreement, a second reader performed measurements on the PVP CT scans. A total of 103 patients (62 years ± 14, 68 men) were included. We measured 328 renal lesions, 56 enhancing lesions (17%) in 38 patients and 272 non-enhancing lesions (83%) in 86 patients. The threshold for non-enhancing lesions was 0.76 mgI/mL or lower (100% sensitivity, 76% specificity). The threshold for a definite enhancing mass was 1.69 mgI/mL or higher (100% specificity, 78% sensitivity). A total of 77% of indeterminate lesions (>30 HU on PVP CT) in our study could be definitely characterized. Renal lesions can be definitively classified as non-enhancing or enhancing on PVP spectral CT using thresholds of 0.76 mgI/mL or 1.69 mgI/mL, respectively, eliminating the need for multiphase imaging.
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Affiliation(s)
- Simone van der Star
- Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3584 CX Utrecht, The Netherlands; (P.A.d.J.); (M.K.)
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Macri F, Khasanova E, Niu BT, Parakh A, Patino M, Kambadakone A, Sahani DV. Optimal Abdominal CT Image Quality in Non-Lean Patients: Customization of CM Injection Protocols and Low-Energy Acquisitions. Diagnostics (Basel) 2023; 13:2279. [PMID: 37443673 PMCID: PMC10377374 DOI: 10.3390/diagnostics13132279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/20/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
We compared the image quality of abdominopelvic single-energy CT with 100 kVp (SECT-100 kVp) and dual-energy CT with 65 keV (DECT-65 keV) obtained with customized injection protocols to standard abdominopelvic CT scans (SECT-120 kVp) with fixed volumes of contrast media (CM). We retrospectively included 91 patients (mean age, 60.7 ± 15.8 years) with SECT-100 kVp and 83 (mean age, 60.3 ± 11.7 years) patients with DECT-65 keV in portovenous phase. Total body weight-based customized injection protocols were generated by a software using the following formula: patient weight (kg) × 0.40/contrast concentration (mgI/mL) × 1000. Patients had a prior abdominopelvic SECT-120 kVp with fixed injection. Iopamidol-370 was administered for all examinations. Quantitative and qualitative image quality comparisons were made between customized and fixed injection protocols. Compared to SECT-120 kVp, customized injection yielded a significant reduction in CM volume (mean difference = 9-12 mL; p ≤ 0.001) and injection rate (mean differences = 0.2-0.4 mL/s; p ≤ 0.001) in all weight categories. Improvements in attenuation, noise, signal-to-noise and contrast-to-noise ratios were observed for both SECT-100 kVp and DECT-65 keV compared to SECT-120 kVp in all weight categories (e.g., pancreas DECT-65 keV, 1.2-attenuation-fold increase vs. SECT-120 kVp; p < 0.001). Qualitative scores were ≥4 in 172 cases (98.8.4%) with customized injections and in all cases with fixed injections (100%). These findings suggest that customized CM injection protocols may substantially reduce iodine dose while yielding higher image quality in SECT-100 kVp and DECT-65 keV abdominopelvic scans compared to SECT-120 kVp using fixed CM volumes.
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Affiliation(s)
- Francesco Macri
- Department of Radiology, Geneva University Hospitals, University of Geneva, 1211 Geneva, Switzerland
| | - Elina Khasanova
- Department of Radiology, Geneva University Hospitals, University of Geneva, 1211 Geneva, Switzerland
| | - Bonnie T Niu
- Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Anushri Parakh
- Department of Radiology, Abdominal Division, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Manuel Patino
- Department of Radiology, Abdominal Division, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Avinash Kambadakone
- Department of Radiology, Abdominal Division, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Dushyant V Sahani
- Department of Radiology, University of Washington, Seattle, WA 98195, USA
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Van Gompel G, Delombaerde L, Zanca F, Tanaka K, Belsack D, de Mey J, Buls N. A patient- and acquisition-tailored injection approach for improving consistency of CT enhancement towards a target CT value in coronary CT angiography. J Appl Clin Med Phys 2022; 24:e13867. [PMID: 36537145 PMCID: PMC9860000 DOI: 10.1002/acm2.13867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Unoptimized coronary CT angiography (CTA) exams typically result in a highly variable arterial enhancement (HUa ) across patients. This study aimed at harmonizing arterial enhancement by implementing a patient-, contrast- and kV-tailored injection protocol. METHODS First, the optimal body size metric to predict HUa was identified by retrospectively analysing images of 76 patients, acquired with 70 ml contrast media (G1). Second, using phantom experiments, correction factors for the effect of kV and contrast concentration on HUa were determined. Third, a model was developed, prescribing the optimal contrast dose to be injected to obtain a diagnostically appropriate arterial target enhancement HUtarget . The model was then validated on 278 prospectively collected patients, in two groups with two different HUtarget : 525 HU (207 patients, G2A) and 425 HU (71 patients, G2B). The HUa histograms were compared among groups and to the target enhancement through their mean and standard deviation (SD) at 100 kVp reference level. Also, signal-to-noise ratio was obtained and compared among the groups. RESULTS Fat free mass (FFM) showed the highest correlation with HUa (r = 0.69). KVp correction factors ranged from 0.65 at 70 kVp to 1.22 at 140 kVp. The obtained model reduced the group heterogeneity (SD) from 101HU for reference G1 to 75HU (p < 0.001) for G2A and 68HU (p < 0.001) for G2B. The mean HUa of 506HU in G2A was slightly below HUtarget = 525HU (p = 0.01) whereas in G2B, the mean HUa of 414HU was not significantly different from HUtarget = 425HU (p = 0.54). The total iodine dose was lowered from 19.5 g-I to 17.6 g-I and 14.2 g-I from G1 to G2A and G2B, on average. CONCLUSION A contrast injection model, based on patient's fat free mass and accounting for the contrast agent concentration and the planned CT-scan tube voltage, harmonized arterial enhancement among patients towards a predefined target enhancement in coronary CTA scanning, without affecting the bolus timing.
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Affiliation(s)
- Gert Van Gompel
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Department of RadiologyBrusselsBelgium
| | | | | | - Kaoru Tanaka
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Department of RadiologyBrusselsBelgium
| | - Dries Belsack
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Department of RadiologyBrusselsBelgium
| | - Johan de Mey
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Department of RadiologyBrusselsBelgium
| | - Nico Buls
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Department of RadiologyBrusselsBelgium
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Personalization of CM Injection Protocols in Coronary Computed Tomographic Angiography (People CT Trial). CONTRAST MEDIA & MOLECULAR IMAGING 2020; 2020:5407936. [PMID: 32410922 PMCID: PMC7201621 DOI: 10.1155/2020/5407936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 11/22/2019] [Indexed: 02/04/2023]
Abstract
Aim To evaluate the performance of three contrast media (CM) injection protocols for cardiac computed tomography angiography (CCTA) based on body weight (BW), lean BW (LBW), and cardiac output (CO). Materials and methods. A total of 327 consecutive patients referred for CCTA were randomized into one of the three CM injection protocols, where CM injection was based on either BW (112 patients), LBW (108 patients), or CO (107 patients). LBW and CO were calculated via formulas. All scans were ECG-gated and performed on a third-generation dual-source CT with 70-120 kV (automated tube voltage selection) and 100 kVqual.ref/330 mAsqual.ref. CM injection protocols were also adapted to scan time and tube voltage. The primary outcome was the proportion of patients with optimal intravascular attenuation (325-500 HU). Secondary outcomes were mean and standard deviation of intravascular attenuation values (HU), contrast-to-noise ratio (CNR), and subjective image quality with a 4-point Likert scale (1 = poor/2 = sufficient/3 = good/4 = excellent). The t-test for independent samples was used for pairwise comparisons between groups, and a chi-square test (χ2) was used to compare categorical variables between groups. All p values were 2-sided, and a p < 0.05 was considered statistically significant. Results Mean overall HU and CNR were 423 ± 60HU/14 ± 3 (BW), 404 ± 62HU/14 ± 3 (LBW), and 413 ± 63HU/14 ± 3 (CO) with a significant difference between groups BW and LBW (p=0.024). The proportion of patients with optimal intravascular attenuation (325-500 HU) was 83.9%, 84.3%, and 86.9% for groups BW, LBW, and CO, respectively, and between-group differences were small and nonsignificant. Mean CNR was diagnostic (≥10) in all groups. The proportion of scans with good-excellent image quality was 94.6%, 86.1%, and 90.7% in the BW, LBW, and CO groups, respectively. The difference between proportions was significant between the BW and LBW groups. Conclusion Personalization of CM injection protocols based on BW, LBW, and CO, and scan time and tube voltage in CCTA resulted in low variation between patients in terms of intravascular attenuation and a high proportion of scans with an optimal intravascular attenuation. The results suggest that personalized CM injection protocols based on LBW or CO have no additional benefit when compared with CM injection protocols based on BW.
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Watanabe J, Endo K, Tanaka Y, Goto K, Urushibara S, Osaki T, Tatebe S, Nakamura S, Hirooka Y, Ikeguchi M. Investigation of the Utility and Safety of Dynamic Computed Tomography with Vasodilators. Yonago Acta Med 2020; 63:47-54. [PMID: 32158333 DOI: 10.33160/yam.2020.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/17/2020] [Indexed: 01/10/2023]
Abstract
Background Dynamic computed tomography (CT) angiography is useful for evaluating of hepatic vascularity. Although vasodilators increase hepatic blood flow, the utility of dynamic CT with vasodilators is unclear. Here we investigated the utility and safety of dynamic CT with vasodilators. Methods A prospective case-control radiographic evaluation using abdominal dynamic CT with and without vasodilator was performed at a single center between October 2015 and September 2016. We compared the CT values in Hounsfield units of the aorta; celiac artery; and common, right, and left hepatic arteries in the arterial phase and the main trunk; right and left branches of the portal vein; and right, middle, and left hepatic veins in the portal phase with and without vasodilators. The region of interest was set in each element of the liver vasculature. Four radiological technologists independently and visually compared the scores of the portal vein (P-score) and hepatic vein (V-score) on a 5-point scale with and without vasodilators. Results The CT values of arteries and veins using vasodilators were significantly higher than those without vasodilators. With and without vasodilators, the P-scores were 3.1 ± 1.2 and 4.0 ± 1.1 (P < 0.05) and the V-scores were 3.3 ± 1.4 and 4.3 ± 1.0 (P < 0.05). Only one patient with vasodilator use had transient hypotension and recovered immediately without medication. Conclusion Dynamic CT with vasodilators can provides better visualization of vascular structures.
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Affiliation(s)
- Jun Watanabe
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Kanenori Endo
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Yasutaka Tanaka
- Department of Radiology, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Keisuke Goto
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Shoichi Urushibara
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Tomohiro Osaki
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Shigeru Tatebe
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Seiichi Nakamura
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Yasuaki Hirooka
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
| | - Masahide Ikeguchi
- Department of Surgery, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
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An Optimized Test Bolus Contrast Injection Protocol for Consistent Coronary Artery Luminal Enhancement for Coronary CT Angiography. Acad Radiol 2020; 27:371-380. [PMID: 31155485 DOI: 10.1016/j.acra.2019.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/19/2019] [Accepted: 05/02/2019] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Consistent levels of coronary artery enhancement are essential for quantitative analysis of coronary artery plaque. We studied three contrast injection protocols for coronary CT angiography (CCTA) and compared mean attenuation level and consistency of vascular contrast enhancement. We hypothesized that test bolus adjusted protocols will have a superior consistency of coronary attenuation compared to a weight-based protocol. MATERIALS AND METHODS We prospectively evaluated a standard test bolus injection protocol (protocol 1, 32 subjects) and an optimized test bolus injection protocol (protocol 2, 59 subjects) in comparison to a body weight-based injection protocol (60 subjects). The test bolus was diluted contrast (20%-30% iopamidol 370 mixed with normal saline); peak aortic attenuation was measured and used to calculate a specific water/contrast mixture for the CCTA. The mean attenuation of the coronary lumen was measured on CCTA. Metrics of optimum arterial enhancement included the percentage of patients within a predetermined range for coronary attenuation (325-500 HU) and optimal timing with maximal ascending aortic attenuation. In addition, interpatient variation in coronary enhancement was quantified as percentage standard deviation of the attenuation. RESULTS The mean attenuation of the coronary arteries was similar in all protocols (362, 364, and 375 HU for the weight-based, test bolus 1 and 2 protocols, respectively). The percentage standard deviations of the weight-based, test bolus 1 and 2 protocols for coronary attenuation were 25.3%, 27.1%, and 10.5%, respectively (p < 0.0001). Test optimized bolus protocol 2 yielded the highest percentage of scans within the preferred coronary attenuation range (88%, p = 0.002). In test bolus protocol 2, the contrast timing was optimal in 73% of cases compared to only 22% of cases in the body mass guided injection protocol (protocol 1, p < 0.0001). CONCLUSION An optimized test bolus guided injection protocol resulted in a marked reduction in variation in coronary enhancement for CCTA compared to a body weight-based injection protocol.
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Individually Body Weight-Adapted Contrast Media Application in Computed Tomography Imaging of the Liver at 90 kVp. Invest Radiol 2019; 54:177-182. [PMID: 30721159 DOI: 10.1097/rli.0000000000000525] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES The aim of the present study was to evaluate the attenuation and image quality (IQ) of a body weight-adapted contrast media (CM) protocol compared with a fixed injection protocol in computed tomography (CT) of the liver at 90 kV. MATERIALS AND METHODS One hundred ninety-nine consecutive patients referred for abdominal CT imaging in portal venous phase were included. Group 1 (n = 100) received a fixed CM dose with a total iodine load (TIL) of 33 g I at a flow rate of 3.5 mL/s, resulting in an iodine delivery rate (IDR) of 1.05 g I/s. Group 2 (n = 99) received a body weight-adapted CM protocol with a dosing factor of 0.4 g I/kg with a subsequent TIL adapted to the patients' weight. Injection time of 30 seconds was kept identical for all patients. Therefore, flow rate and IDR changed with different body weight. Patients were divided into 3 weight categories; 70 kg or less, 71 to 85 kg, and 86 kg or greater. Attenuation (HU) in 3 segments of the liver, signal-to-noise ratio, and contrast-to-noise ratio were used to evaluate objective IQ. Subjective IQ was assessed by a 5-point Likert scale. Differences between groups were statistically analyzed (P < 0.05 was considered statistically significant). RESULTS No significant differences in baseline characteristics were found between groups. The CM volume and TIL differed significantly between groups (P < 0.01), with mean values in group 1 of 110 mL and 33 g I, and in group 2 of 104.1 ± 21.2 mL and 31.2 ± 6.3 g I, respectively. Flow rate and IDR were not significantly different between groups (P > 0.05). Body weight-adapted protocoling led to more homogeneous enhancement of the liver parenchyma compared with a fixed protocol with a mean enhancement per weight category in group 2 of 126.5 ± 15.8, 128.2 ± 15.3, and 122.7 ± 21.2 HU compared with that in group 1 of 139.9 ± 21.4, 124.6 ± 24.8, and 116.2 ± 17.8 HU, respectively. CONCLUSIONS Body weight-adapted CM injection protocols result in more homogeneous enhancement of the liver parenchyma at 90 kV in comparison to a fixed CM volume with comparable objective and subjective IQ, whereas overall CM volume can be safely reduced in more than half of patients.
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Tan SK, Ng KH, Yeong CH, Raja Aman RRA, Mohamed Sani F, Abdul Aziz YF, Sun Z. Personalized administration of contrast medium with high delivery rate in low tube voltage coronary computed tomography angiography. Quant Imaging Med Surg 2019; 9:552-564. [PMID: 31143647 DOI: 10.21037/qims.2019.03.13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background High delivery rate is an important factor in optimizing contrast medium administration in coronary computed tomography angiography (CCTA). A personalized contrast volume calculation algorithm incorporating high iodine delivery rate (IDR) can reduce total iodine dose (TID) and produce optimal vessel contrast enhancement (VCE) in low tube voltage CCTA. In this study, we developed and validated an algorithm for calculating the volume of contrast medium delivered at a high rate for patients undergoing retrospectively ECG-gated CCTA with low tube voltage protocol. Methods The algorithm for an IDR of 2.22 gI·s-1 was developed based on the relationship between VCE and contrast volume in 141 patients; test bolus parameters and characteristics in 75 patients; and, tube voltage in a phantom study. The algorithm was retrospectively tested in 45 patients who underwent retrospectively ECG-gated CCTA with a 100 kVp protocol. Image quality, TID and radiation dose exposure were compared with those produced using the 120 kVp and routine contrast protocols. Results Age, sex, body surface area (BSA) and peak contrast enhancement (PCE) were significant predictors for VCE (P<0.05). A strong linear correlation was observed between VCE and contrast volume (r=0.97, P<0.05). The 100-to-120 kVp contrast enhancement conversion factor (Ec) was calculated at 0.81. Optimal VCE (250 to 450 HU) and diagnostic image quality were obtained with significant reductions in TID (32.1%) and radiation dose (38.5%) when using 100 kVp and personalized contrast volume calculation algorithm compared with 120 kVp and routine contrast protocols (P<0.05). Conclusions The proposed algorithm could significantly reduce TID and radiation exposure while maintaining optimal VCE and image quality in CCTA with 100 kVp protocol.
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Affiliation(s)
- Sock Keow Tan
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kwan Hoong Ng
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Chai Hong Yeong
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Raja Rizal Azman Raja Aman
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Fadhli Mohamed Sani
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yang Faridah Abdul Aziz
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, Curtin University, Perth, Australia
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Matsumoto Y, Higaki T, Masuda T, Sato T, Nakamura Y, Tatsugami F, Awai K. Minimizing individual variations in arterial enhancement on coronary CT angiographs using "contrast enhancement optimizer": a prospective randomized single-center study. Eur Radiol 2018; 29:2998-3005. [PMID: 30421021 DOI: 10.1007/s00330-018-5823-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/20/2018] [Accepted: 10/03/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To investigate the clinical utility of our newly developed contrast enhancement optimizer (CEO) software for coronary CT angiography (CCTA). METHODS We randomly assigned 295 patients (168 males, 127 females, median age 71 years) undergoing CCTA to one of two contrast media injection protocols. Group A (n = 150) was injected with a CEO-selected iodine dose based on patient factors. In group B (n = 145), we used our standard protocol (245 mg I/kg). We recorded the CT number in the ascending aorta and determined whether the CT number was equivalent in groups A and B. For the equivalence test, we adopted 75 Hounsfield units (HU) as the equivalence margin. The standard deviation in the CT number and the rate of patients with an acceptable CT number were compared using the F test and the chi-square test, respectively. RESULTS The iodine dose in group A was significantly smaller than that in group B (235.7 vs. 253.6 mg I/kg, p < 0.001). The CT number of the ascending aorta was 428.6 ± 55.5 HU in group A and 436.1 ± 68.7 HU in group B; the 95% confidence interval for the difference between the groups was -4.3 HU to 16.9 HU and within the range of the predetermined equivalence margins. In group A, the variance was significantly smaller than that in group B (p = 0.009). The number of patients with an acceptable CT number was significantly higher in group A than in group B (84.7% vs. 71.7%, p = 0.007). CONCLUSIONS The use of our CEO for CCTA studies yielded optimal aortic contrast enhancement in significantly more patients than the standard protocol based on the body weight. KEY POINTS • With our contrast enhancement optimizer (CEO) software, optimal and stable aortic enhancement can be obtained on coronary CT angiography scans irrespective of patient factors. • Management of contrast media becomes more appropriate by the CEO software. • The CEO software can control contrast enhancement at different tube voltage levels.
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Affiliation(s)
- Yoriaki Matsumoto
- Department of Radiological Technology, Tsuchiya General Hospital, 3-30 Nakajima-cho, Naka-ku, Hiroshima, 730-8655, Japan. .,Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
| | - Toru Higaki
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Takanori Masuda
- Department of Radiological Technology, Tsuchiya General Hospital, 3-30 Nakajima-cho, Naka-ku, Hiroshima, 730-8655, Japan.,Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Tomoyasu Sato
- Department of Radiology, Tsuchiya General Hospital, 3-30 Nakajima-cho, Naka-ku, Hiroshima, 730-8655, Japan
| | - Yuko Nakamura
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Fuminari Tatsugami
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
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12
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Patient Comfort During Contrast Media Injection in Coronary Computed Tomographic Angiography Using Varying Contrast Media Concentrations and Flow Rates: Results From the EICAR Trial. Invest Radiol 2017; 51:810-815. [PMID: 27164459 DOI: 10.1097/rli.0000000000000284] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Pain sensation and extravasation are potential drawbacks of contrast media (CM) injection during computed tomographic angiography. The purpose was to evaluate safety and patient comfort of higher flow rates in different CM protocols during coronary computed tomographic angiography. METHODS Two hundred consecutive patients of a double-blind randomized controlled trial (NCT02462044) were analyzed. Patients were randomized to receive 94 mL of prewarmed iopromide 240 mg I/mL at 8.3 mL/s (group I), 75 mL of 300 mg I/mL at 6.7 mL/s (group II), or 61 mL of 370 mg I/mL at 5.4 mL/s (group III), respectively. Iodine delivery rate (2.0 g I/s) and total iodine load (22.5 g I) were kept identical. Outcome was defined as intravascular enhancement, patient comfort during injection, and injection safety, expressed as the occurrence of extravasation. Patients completed a questionnaire for comfort, pain, and stress during CM injection. Comfort was graded using a 5-point scale, 1 representing "very bad" and 5 "very well." Pain was graded using a 10-point scale, 0 representing "no pain" and 10 "severe pain." Stress was graded using a 5-point scale, 1 representing "no stress" and 5 "unsustainable stress." RESULTS Mean enhancement levels within the coronary arteries were as follows: 437 ± 104 Hounsfield units (HU) (group I), 448 ± 111 HU (group II), and 447 ± 106 HU (group III), with P ≥ 0.18. Extravasation occurred in none of the patients. Median (interquartile range) for comfort, pain, and stress was, respectively, 4 (4-5), 0 (0-0), and 1 (1-2), with P ≥ 0.68. CONCLUSIONS High flow rates of prewarmed CM were safely injected without discomfort, pain, or stress. Therefore, the use of high flow rates should not be considered a drawback for CM administration in clinical practice.
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Svensson A, Cederlund K, Aspelin P, Nyman U, Brismar TB. The effect of arm positioning on timing and enhancement of intravenous contrast media at coronary computed tomography angiography. Acta Radiol 2016; 57:1049-55. [PMID: 26567961 DOI: 10.1177/0284185115615004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 10/09/2015] [Indexed: 12/27/2022]
Abstract
BACKGROUND Adequate intravenous contrast media (CM) enhancement is crucial for evaluation of the coronary arteries. PURPOSE To compare the timing and enhancement of intravenous CM at coronary computed tomography angiography (CCTA) when positioning the arms in the traditional superior direction with that of positioning them in the ventral direction during the CM injection. MATERIAL AND METHODS One hundred patients were randomized into two groups. Group A (n = 50) had their arms positioned in the superior direction, resting on a head and arm support. Group B (n = 50) held their arms resting on the front panel of the computer tomography (CT) scanner. Scanning delay time was defined by test bolus technique. A total of 60 mL iodixanol, 320 mg/mL, was followed by a 50 mL saline flush at 6 mL/s. Cardiac output (CO) and heart rate (HR) were obtained before scanning. The attenuation was calculated by placing regions of interest (ROI) in ascending aorta, left atrium, and inferior vena cava. RESULTS More patients in group A compared with group B (26 versus 14) showed a higher attenuation of the left atrium in comparison to the ascending aorta (P < 0.05). Body weight (BW) and CO were significantly related to the attenuation of ascending aorta (P < 0.01). CONCLUSION By placing the arms in a ventral, instead of superior position the frequency of too early imaging at CCTA can be reduced.
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Affiliation(s)
- Anders Svensson
- Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden
- Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden
| | - Kerstin Cederlund
- Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden
- Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden
| | - Peter Aspelin
- Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden
- Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden
| | - Ulf Nyman
- Department of Radiology, Institution of Clinical Sciences, Malmö, Faculty of Medicine, University of Lund, SE-221 00 Lund, Sweden
| | - Torkel B Brismar
- Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden
- Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden
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14
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Vardhanabhuti V, Nicol E, Morgan-Hughes G, Roobottom CA, Roditi G, Hamilton MCK, Bull RK, Pugliese F, Williams MC, Stirrup J, Padley S, Taylor A, Davies LC, Bury R, Harden S. Recommendations for accurate CT diagnosis of suspected acute aortic syndrome (AAS)--on behalf of the British Society of Cardiovascular Imaging (BSCI)/British Society of Cardiovascular CT (BSCCT). Br J Radiol 2016; 89:20150705. [PMID: 26916280 PMCID: PMC4985448 DOI: 10.1259/bjr.20150705] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Accurate and timely assessment of suspected acute aortic syndrome is crucial in this life-threatening condition. Imaging with CT plays a central role in the diagnosis to allow expedited management. Diagnosis can be made using locally available expertise with optimized scanning parameters, making full use of recent advances in CT technology. Each imaging centre must optimize their protocols to allow accurate diagnosis, to optimize radiation dose and in particular to reduce the risk of false-positive diagnosis that may simulate disease. This document outlines the principles for the acquisition of motion-free imaging of the aorta in this context.
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Affiliation(s)
- Varut Vardhanabhuti
- 1 Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth, UK.,2 Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Edward Nicol
- 3 Radiology Department, Royal Brompton Hospital, London, UK
| | | | - Carl A Roobottom
- 1 Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth, UK.,5 Department of Radiology, Derriford Hospital, Plymouth, UK
| | - Giles Roditi
- 6 Department of Radiology, Glasgow Royal Infirmary, Glasgow, UK
| | | | - Russell K Bull
- 8 Department of Radiology, Royal Bournemouth Hospital, Bournemouth, UK
| | - Franchesca Pugliese
- 9 Centre for Advanced Cardiovascular Imaging, NIHR Cardiovascular Biomedical Research Unit, Barts and The London School of Medicine & Barts Health NHS Trust, London, UK
| | - Michelle C Williams
- 10 University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - James Stirrup
- 3 Radiology Department, Royal Brompton Hospital, London, UK
| | - Simon Padley
- 3 Radiology Department, Royal Brompton Hospital, London, UK
| | - Andrew Taylor
- 11 Cardiothoracic Unit, Great Ormond Street Hospital for Children, London, UK
| | - L Ceri Davies
- 9 Centre for Advanced Cardiovascular Imaging, NIHR Cardiovascular Biomedical Research Unit, Barts and The London School of Medicine & Barts Health NHS Trust, London, UK
| | - Roger Bury
- 12 Radiology Department, Blackpool Teaching Hospitals, Blackpool, UK
| | - Stephen Harden
- 13 Department of Cardiothoracic Radiology, University Hospital Southampton NHS Trust, Southampton, UK
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15
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Hendriks BMF, Kok M, Mihl C, Bekkers SCAM, Wildberger JE, Das M. Individually tailored contrast enhancement in CT pulmonary angiography. Br J Radiol 2016; 89:20150850. [PMID: 26689096 DOI: 10.1259/bjr.20150850] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The purpose was to evaluate individually shaped contrast media (CM) delivery in CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE). METHODS 100 consecutive emergency patients with clinical suspicion of PE were evaluated. High-pitch CTPA was performed on a second-generation dual-source CT using the following parameters: 100 kV, 200-250 mAsref, rotation time 0.28 s, 128 × 0.6 mm col. and image reconstruction 1.0/0.8 mm (B30f). Group 1 (n = 50) then received a fixed CM bolus (300 = mgI ml(-1), volume = 90 ml and flow rate = 6 ml s(-1)); Group 2 (n = 50) received a body weight-adapted CM bolus determined by dedicated contrast injection software. For analysis, groups were further subdivided into low-weight (40-75 kg) and high-weight (76-117 kg) groups. Technical image quality was graded using a four-point Likert scale (1 = non-diagnostic; 2 = diagnostic; 3 = good and 4 = excellent image quality) at the level of the pulmonary trunk and pulmonary arteries. Objective image quality analysis was performed by measuring contrast enhancement in Hounsfield units (HU) at the same levels. Attenuation levels > 180 HU were considered diagnostic. RESULTS All examinations were graded as diagnostic at each level. The individual minimum pulmonary attenuation was 184 and 270 HU for Group 1 and 2, respectively. Mean attenuation was as follows: Group 1: 475 ± 105 HU (40-75 kg) and 402 ± 115 HU (76-117 kg), p < 0.03. Group 2: 424 ± 76 HU (40-75 kg) and 418 ± 100 HU (76-117 kg), p = 0.8. For Group 2, CM volumes were: 55 ± 5 ml (40-75 kg) and 66 ± 5 ml (76-117 kg), leading to 16-51% CM reduction. CONCLUSION Even under emergency conditions, individualized CM protocols can provide diagnostic and robust image quality in CTPA for PE with a substantial reduction of CM volume for lower weight patients, compared with a fixed CM protocol. ADVANCES IN KNOWLEDGE CM volume can substantially be reduced by using individualized CM protocols in CT angiography for PE without compromising the diagnostic image quality.
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Affiliation(s)
- Babs M F Hendriks
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Madeleine Kok
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Casper Mihl
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Sebastiaan C A M Bekkers
- 2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands.,3 Departments of Cardiology, Maastricht University Medical Center, Maastricht, Netherlands
| | - Joachim E Wildberger
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Marco Das
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
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16
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Mihl C, Kok M, Altintas S, Kietselaer BLJH, Turek J, Wildberger JE, Das M. Evaluation of individually body weight adapted contrast media injection in coronary CT-angiography. Eur J Radiol 2016; 85:830-6. [PMID: 26971431 DOI: 10.1016/j.ejrad.2015.12.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 11/14/2015] [Accepted: 12/29/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Contrast media (CM) injection protocols should be customized to the individual patient. Aim of this study was to determine if software tailored CM injections result in diagnostic enhancement of the coronary arteries in computed tomography angiography (CTA) and if attenuation values were comparable between different weight categories. MATERIALS AND METHODS 265 consecutive patients referred for routine coronary CTA were scanned on a 2nd generation dual-source CT. Group 1 (n=141) received an individual CM bolus based on weight categories (39-59 kg; 60-74 kg; 75-94 kg; 95-109 kg) and scan duration ('high-pitch: 1s; "dual-step prospective triggering": 7s), as determined by contrast injection software (Certegra™ P3T, Bayer, Berlin, Germany). Group 2 (n=124) received a standard fixed CM bolus; Iopromide 300 mgI/ml; volume: 75 ml; flow rate: 7.2 ml/s. Contrast enhancement was measured in all proximal and distal coronary segments. Subjective and objective image quality was evaluated. Statistical analysis was performed using SPSS (IBM, version 20.0). RESULTS For group 1, mean attenuation values of all segments were diagnostic (>325 HU) without statistical significant differences between different weight categories (p>0.17), proximal vs. distal: 449 ± 65-373 ± 58 HU (39-59 kg); 443 ± 69-367 ± 81 HU (60-74 kg); 427 ± 59-370 ± 61 HU (75-94 kg); 427 ± 73-347 ± 61 HU (95-109 kg). Mean CM volumes were: 55 ± 6 ml (39-59 kg); 61 ± 7 ml (60-74 kg); 71 ± 8 ml (75-94 kg); 84 ± 9 ml (95-109 kg). For group 2, mean attenuation values were not all diagnostic with differences between weight categories (p<0.01), proximal vs. distal: 611 ± 142-408 ± 69 HU (39-59 kg); 562 ± 135-389 ± 98 HU (60-74 kg); 481 ± 83-329 ± 81 HU (75-94 kg); 420 ± 73-305 ± 35 HU (95-109 kg). Comparable image noise and image quality were found between groups (p ≥ 0.330). CONCLUSIONS Individually tailored CM injection protocols yield diagnostic attenuation and a more homogeneous enhancement pattern between different weight groups. CM volumes could be reduced for the majority of patients utilizing individualized CM bolus application.
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Affiliation(s)
- Casper Mihl
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Madeleine Kok
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Sibel Altintas
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Bas L J H Kietselaer
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Jakub Turek
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
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17
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Application of an Advanced Image-Based Virtual Monoenergetic Reconstruction of Dual Source Dual-Energy CT Data at Low keV Increases Image Quality for Routine Pancreas Imaging. J Comput Assist Tomogr 2015. [PMID: 26196343 DOI: 10.1097/rct.0000000000000276] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To compare image quality on contrast-enhanced dual-energy computed tomography (DECT) during the pancreatic parenchymal phase of pancreatic masses between linearly-blended simulated 120 kVp images (routine) and advanced image-based virtual monoenergetic reconstructions at 55 keV. METHODS This was a retrospective evaluation of 24 nonconsecutive adults found to have a focal pancreatic mass on a multiphasic abdominal dual-source DECT (12 adenocarcinoma, 5 neuroendocrine, 7 cystic tumors). For pancreatic-parenchymal phase images, subjects had routine and 55 keV images reconstructed at the time of clinical evaluation. Quantitative evaluation by contrast-to-noise ratio and qualitative evaluations of image quality by (1) direct comparison of image pairs (preference) and (2) blinded assessment of image quality measures based on Likert scores were performed. RESULTS Mean patient weight was 205.8 ± 26.6 lbs. Mean pancreatic lesion contrast-to-noise ratio was significantly higher at 55 keV (6.8 ± 4.1) compared to the routine image series (5.8 ± 3.8; P = 0.0002). All 3 readers preferred the 55-keV images over routine blended images in 70.1% to 95.8% of cases. No significant differences were observed for subjective sharpness of the mass, visualization of internal mass structures, or image noise. CONCLUSIONS Use of a single advanced image-based virtual monoenergetic reconstruction at 55 keV in pancreatic DECT showed improved objective image quality and reader preference compared to routine images. As this image reconstruction can be incorporated into the scan protocol, this technique should be considered for routine clinical use.
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18
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Kok M, Kietselaer BLJH, Mihl C, Altintas S, Nijssen EC, Wildberger JE, Das M. Contrast Enhancement of the Right Ventricle during Coronary CT Angiography--Is It Necessary? PLoS One 2015; 10:e0128625. [PMID: 26029905 PMCID: PMC4451990 DOI: 10.1371/journal.pone.0128625] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 04/29/2015] [Indexed: 11/19/2022] Open
Abstract
Purpose It is unclear if prolonged contrast media injection, to improve right ventricular visualization during coronary CT angiography, leads to increased detection of right ventricle pathology. The purpose of this study was to evaluate right ventricle enhancement and subsequent detection of right ventricle disease during coronary CT angiography. Materials and Methods 472 consecutive patients referred for screening coronary CT angiography were retrospectively evaluated. Every patient underwent multidetector-row CT of the coronary arteries: 128x 0.6mm coll., 100-120kV, rot. time 0.28s, ref. mAs 350 and received an individualized (P3T) contrast bolus injection of iodinated contrast medium (300 mgI/ml). Patient data were analyzed to assess right ventricle enhancement (HU) and right ventricle pathology. Image quality was defined good when right ventricle enhancement >200HU, moderate when 140-200HU and poor when <140HU. Results Good image quality was found in 372 patients, moderate in 80 patients and poor in 20 patients. Mean enhancement of the right ventricle cavity was 268HU±102. Patients received an average bolus of 108±24 ml at an average peak flow rate of 6.1±2.2 ml/s. In only three out of 472 patients (0.63%) pathology of the right ventricle was found (dilatation) No other right ventricle pathology was detected. Conclusion Right ventricle pathology was detected in three out of 472 patients; the dilatation observed in these three cases may have been picked up even without dedicated enhancement of the right ventricle. Based on our findings, right ventricle enhancement can be omitted during screening coronary CT angiography.
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Affiliation(s)
- Madeleine Kok
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM Cardio Vascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
- * E-mail:
| | - Bas L. J. H. Kietselaer
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM Cardio Vascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Cardiology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Casper Mihl
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM Cardio Vascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Sibel Altintas
- CARIM Cardio Vascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Cardiology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Estelle C. Nijssen
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joachim E. Wildberger
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM Cardio Vascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM Cardio Vascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
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19
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Hardie AD, Perry JD, Bradshaw ML, Picard MM. Increased renal cyst density on abdominal CT at 100-kVp compared with 120-kVp: a preliminary evaluation. Clin Imaging 2015; 39:642-5. [PMID: 25794849 DOI: 10.1016/j.clinimag.2015.02.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/23/2015] [Accepted: 02/27/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the radiographic density of renal cysts on contrast-enhanced computed tomography (CT) scans performed at tube voltages of 100 versus 120 kVp. METHODS Thirty-six renal cysts from contrast-enhanced CT performed on 21 subjects at both 120 kVp and 100 kVp were compared by Kolmogorov-Smirnov statistical testing. RESULTS The radiographic density (mean+/-standard deviation in Hounsfield units) of cysts was greater on 100-kVp than on 120-kVp CT scans for both 5-mm and 2-mm reconstructed slice thicknesses: 16.6+/-5.6 versus 10.9+/-4.9 and 14.1+/-5.6 versus 8.5+/-3.9, respectively. CONCLUSIONS Decrease in tube voltage significantly increases measured radiographic density of renal cysts on CT. Further studies are indicated to assess the clinical impact of lower-tube-voltage CT.
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Affiliation(s)
- Andrew D Hardie
- Medical University of South Carolina, Department of Radiology and Radiological Science, 169 Ashley Avenue, Charleston, SC 29425.
| | - Jonathan D Perry
- Medical University of South Carolina, Department of Radiology and Radiological Science, 169 Ashley Avenue, Charleston, SC 29425
| | - Marques L Bradshaw
- Medical University of South Carolina, Department of Radiology and Radiological Science, 169 Ashley Avenue, Charleston, SC 29425
| | - Melissa M Picard
- Medical University of South Carolina, Department of Radiology and Radiological Science, 169 Ashley Avenue, Charleston, SC 29425
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20
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Entezari P, Collins J, Chalian H, Tore HG, Carr J, Yaghmai V. Impact of beta-blockade premedication on image quality of ECG-gated thoracic aorta CT angiography. Acta Radiol 2014; 55:1180-5. [PMID: 24345768 DOI: 10.1177/0284185113516950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Thoracic aortic aneurysm is one of the most common aorta pathologies worldwide, which is commonly evaluated by computed tomography angiography (CTA). One of the routine methods to improve the image quality of CTA is heart rate reduction prior to study by beta-blockade administration. PURPOSE To assess the effect of beta-blockade on image quality of the ascending aorta in electrocardiography (ECG)-gated dual-source CTA (DSCTA) images. MATERIAL AND METHODS In this retrospective study, ECG-gated thoracic aorta CTA images of 40 patients without beta-blocker administration were compared with ECG-gated images of 40 patients with beta-blockade. Images of the aorta were analyzed objectively and subjectively at three levels: sinus of Valsalva (sinus), sinotubular junction (STJ), and mid ascending aorta (MAA). Quantitative sharpness index (SI) and signal-to-noise ratio (SNR) were calculated and two radiologists evaluated the image quality using a 3-point scale. RESULTS Mean heart rate in beta-blocker and non-beta-blocker groups was 61.7 beats per minute (bpm) (range, 58.1-63.9 bpm) and 72.9 bpm (range, 69.3-84.1 bpm), respectively (P < 0.05). Aorta wall SI, SNR, and subjective grading were comparable between the two groups at all three levels (P > 0.05). CONCLUSION Beta-blocker premedication may not be necessary for imaging of ascending aorta with ECG-gated DSCTA.
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Affiliation(s)
- Pegah Entezari
- Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA
| | - Jeremy Collins
- Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA
| | - Hamid Chalian
- Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA
| | - Huseyin Gurkan Tore
- Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA
| | - James Carr
- Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA
| | - Vahid Yaghmai
- Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, Chicago, IL, USA
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Contrast agent bolus tracking with a fixed threshold or a manual fast start for coronary CT angiography. Eur Radiol 2014; 24:1229-38. [DOI: 10.1007/s00330-014-3148-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 12/27/2022]
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Patient body weight-tailored contrast medium injection protocol for the craniocervical vessels: a prospective computed tomography study. PLoS One 2014; 9:e88867. [PMID: 24558438 PMCID: PMC3928316 DOI: 10.1371/journal.pone.0088867] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/13/2014] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To evaluate body weight-tailored contrast medium (CM) administration for computed tomography angiography (CTA) of the craniocervical vessels. METHODS Institutional review board approval was obtained, and all patients gave written informed consent. Sixty patients were consecutively assigned to one of three dose groups (20 patients per group) with CM doses of Visipaque 270® (iodixanol 270 mg/ml) tailored to body weight at doses of 1.5, 1.0, or 0.5 ml/kg. Region-of-interest (ROI) analysis of maximum enhancement (ME) was conducted, and signal-to-noise-ratios (SNR) and contrast-to-noise-ratios (CNR) were calculated. Retrospective comparison was performed with three matched control groups examined with a standard CM dose (80 ml of Visipaque 270®). Image quality was rated by two neuroradiologists blinded to the CM dose used. Interrater reliability was calculated using kappa statistics. RESULTS Body weight/BMI and ME were inversely correlated in the three control groups receiving the standard dose (r = -0.544/-0.597/-0.542/r = -0.358/r = -0.424/r = -0.280). Compared to standard dose, 1.5 ml/kg produced higher ME, SNR, and CNR in the anterior circulation (p≤0.038), 1.0 ml/kg had higher ME in cervical and medium-sized cerebral arteries (p≤0.034), and 0.5 ml/kg had lower ME, SNR and CNR for medium-sized cerebral arteries (p≤0.049). ME, SNR, and CNR were the same for 1.5 ml/kg and 1.0 ml/kg (p≥0.24), and both had higher values compared to 0.5 ml/kg (p≤0.043/p≤0.028). In patients with BMI>25, 1.5 ml/kg and 1.0 ml/kg produced higher ME than standard dose (p<0.001/p = 0.008), but ME in patients with BMI>25 did not differ between group 1 and group 2 (p = 0.673). In patients with BMI≤25, 1.5 ml/kg and 1.0 ml/kg produced ME comparable to standard dose (p = 0.132/p = 0.403). Regardless of patient weight, 0.5 ml/kg yielded lower ME than standard dose (p = 0.019/0.002). CONCLUSIONS Craniocervical CTA with a body weight-tailored CM dose of 1.0 ml/kg (270 mg iodine/ml) reduces iodine load in patients weighing <80 kg while producing ME similar to standard dose and improves ME in patients with BMI>25.
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Lembcke A, Schwenke C, Hein PA, Knobloch G, Durmus T, Hamm B, Huppertz A. High-pitch dual-source CT coronary angiography with low volumes of contrast medium. Eur Radiol 2013; 24:120-7. [PMID: 23949727 DOI: 10.1007/s00330-013-2988-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 07/13/2013] [Accepted: 07/17/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess the effect of lower volumes of contrast medium (CM) on image quality in high-pitch dual-source computed tomography coronary angiography (CTCA). METHODS One-hundred consecutive patients (body weight 65-85 kg, stable heart rate ≤65 bpm, cardiac index ≥2.5 L/min/m(2)) referred for CTCA were prospectively enrolled. Patients were randomly assigned to one of five groups of different CM volumes (G30, 30 mL; G40, 40 mL; G50, 50 mL; G60, 60 mL; G70, 70 mL; flow rate 5 mL/s each, iodine content 370 mg/mL). Attenuation within the proximal and distal coronary artery segments was analysed. RESULTS Mean attenuation for men and women ranged from 345.0 and 399.1 HU in G30 to 478.2 and 571.8 HU in G70. Mean attenuation values were higher in groups with higher CM volumes (P < 0.0001) and higher in women than in men (P < 0.0001). The proportions of segments with attenuation of at least 300 HU in G30, G40, G50, G60 and G70 were 89 %, 95 %, 98 %, 98 % and 99 %. CM volume of 30 mL in women and 40 mL in men proved to be sufficient to guarantee attenuation of at least 300 HU. CONCLUSIONS In selected patients high-pitch dual-source CTCA can be performed with CM volumes of 40 mL in men or 30 mL in women. KEY POINTS • High-pitch dual-source coronary angiography is feasible with low contrast media volumes. • Traditional injection rules still apply: higher volumes result in higher enhancement. • The patient's gender is a co-factor determining the level of contrast enhancement. • Volumes can be reduced down to 30-40 mL in selected patients.
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Affiliation(s)
- Alexander Lembcke
- Department of Radiology, Charité - University Medicine Berlin, Campus Charité Mitte, Charitéplatz 1, 10117, Berlin, Germany,
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Zhu X, Zhu Y, Xu H, Yang G, Tang L, Xu Y. Dual-source CT coronary angiography involving injection protocol with iodine load tailored to patient body weight and body mass index: estimation of optimal contrast material dose. Acta Radiol 2013; 54:149-55. [PMID: 23171529 DOI: 10.1258/ar.2012.120362] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Body mass index (BMI) has a positive linear influence on arterial attenuation at coronary CT angiography involving injection protocol with dose linearly tailored to body weight (BW). Excessive contrast material may inadvertently be given in heavier patients when the dose is determined by BW only. PURPOSE To investigate the effect of injection protocol with dose of contrast material (CM) tailored to BW and BMI on coronary arterial attenuation, contrast-to-noise ratio, and image noise at dual-source CT coronary angiography (DSCT-CA). MATERIAL AND METHODS A total of 233 consecutive patients (mean age, 60.2 years) undergoing DSCT-CA were included. Image acquisition protocol was standardized (120 kV, 380 mAs, and retrospective electrocardiograph-triggered DSCT-CA). CM dosage calculation was randomly categorized into groups: a BW group and a BW-BMI group. CM flow rate in both groups was calculated as dosage divided by scan time plus 8 s. Correlations between BW, BMI, and attenuations of ascending aorta (AA) above coronary ostia, left main coronary artery (LM), proximal right coronary artery (RCA), left anterior descending (LAD), and left circumflex artery (LCX), contrast to noise ratio of LM (LMCNR) and RCA (RCACNR), and image noise were evaluated with simple linear regression for two groups individually. RESULTS In BW group, attenuations of AA and coronary arteries showed positive linear correlations to BW and BMI. In contrast, no relationships were found in BW-BMI group. LMCNR and RCACNR were inversely determined by BW and BMI in both groups. Image noise increased with BW and BMI increasing in two groups. CONCLUSION BMI has a positive linear influence on arterial attenuation with fixed iodine per BW. The injection protocol with CM dose tailored to BW and BMI is reasonable during DSCT-CA.
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Affiliation(s)
- Xiaomei Zhu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu
| | - Yinsu Zhu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu
| | - Hai Xu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu
| | - Guanyu Yang
- Laboratory of Image Science & Technology, School of Computer Science and Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Lijun Tang
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu
| | - Yi Xu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu
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Zhu X, Zhu Y, Xu H, Tang L, Xu Y. The influence of body mass index and gender on coronary arterial attenuation with fixed iodine load per body weight at dual-source CT coronary angiography. Acta Radiol 2012; 53:637-42. [PMID: 22798383 DOI: 10.1258/ar.2012.110657] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Most of current coronary CT angiography protocols are not adapted to body weight (BW) or cardiac output and no literature about influence of gender on coronary attenuation are reported with administration of a fixed iodine load per BW. PURPOSE To determine the influence of body mass index (BMI) and gender on coronary arterial attenuation if contrast material dose is linearly adjusted to a patient's BW at dual-source CT coronary angiography (DSCT-CA). MATERIAL AND METHODS A total of 207 consecutive patients (mean age 60.6 years) undergoing DSCT-CA were included. Contrast material (370 mg I/mL) dose calculation was randomly categorized into two groups (Group 1: 1.10 mL/kg for men and women; Group 2: men 1.10 mL/kg, women 0.99 mL/kg) and flow rate was calculated as dose was divided by scan time plus 8 s. Mean arterial attenuations between men and women were compared with respect to attenuations of ascending aorta (AA) above coronary ostia, left main coronary artery (LM), proximal segments of right coronary artery (RCA), left anterior descending (LAD), and left circumflex artery (LCX) in two groups, respectively. Attenuations of coronary arteries were correlated with BW and BMI with simple linear regression. RESULTS The mean attenuations of AA, LM, RCA, LAD, and LCX were 407.8 ± 53.6 HU, 412.6 ± 55.4 HU, 411.4 ± 64.3 HU, 399.1 ± 56.7 HU, and 399.1 ± 60.2 HU, respectively, and there were no significant differences between men and women in group 1 (AA, P = 0.571; LM, P = 0.670; RCA, P = 0.737; LAD, P = 0.439, and LCX, P = 0.888). In group 2, the mean attenuations of AA, LM, RCA, LAD, and LCX in men were significantly higher than those in women (AA, P = 0.008; LM, P = 0.025; RCA, P = 0.017; LAD, P = 0.015, and LCX, P = 0.002). Positive linear regression between BW and attenuations of AA (R(2) = 0.047, P = 0.02), LM (R(2) = 0.036, P = 0.04), RCA (R(2) = 0.080, P < 0.01), LAD (R(2) = 0.078, P < 0.01), and LCX (R(2) = 0.033, P = 0.05) was found in group 1, suggesting that attenuations of coronary arteries increased in heavier patients. Similarly, there was positive linear regression between BMI and attenuations of AA (R(2) = 0.117, P < 0.01), LM (R(2) = 0.090, P < 0.01), RCA (R(2) = 0.138, P < 0.01), LAD (R(2) = 0.111, P < 0.01), and LCX (R(2) = 0.078, P < 0.01). CONCLUSION Men and women have similar coronary attenuations with a fixed iodine load per BW. BMI has a positive linear influence on arterial attenuation at DSCT-CA involving injection protocol with dose linearly tailored to BW. Excessive contrast material may inadvertently be given in heavier patients when the dose is determined by BW only. Contrast material dose may need to be tailored individually by BW and BMI.
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Affiliation(s)
- Xiaomei Zhu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yinsu Zhu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hai Xu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Lijun Tang
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yi Xu
- Department of Radiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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Shorter delay time reduces interpatient variability in coronary enhancement in coronary CT angiography using the bolus tracking method with 320-row CT. Int J Cardiovasc Imaging 2012; 29:185-90. [DOI: 10.1007/s10554-012-0045-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/26/2012] [Indexed: 02/05/2023]
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Tomizawa N, Nojo T, Akahane M, Torigoe R, Kiryu S, Ohtomo K. Prediction of the attenuation of the ascending aorta using bolus-tracking parameters and heart rate in coronary computed tomography angiography. Eur J Radiol 2012; 81:3250-3. [PMID: 22370097 DOI: 10.1016/j.ejrad.2012.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 02/02/2012] [Accepted: 02/03/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the correlation between bolus-tracking parameters and heart rate (HR) with attenuation of the ascending aorta and create a linear regression model for predicting coronary attenuation in coronary computed tomography angiography (CCTA). METHODS A total of 50 patients (31 men, 19 women; mean age, 67.2±10.8 y) underwent CCTA using a 320-detector CT scanner. A bolus-tracking scan was performed to optimize the scan timing. The average HR under normal breathing for 10s was recorded just before the bolus-tracking scan started. Attenuation values of the pulmonary artery at 7s (PA7) and 10s (PA10) after the beginning of the injection were recorded during the bolus-tracking scan and the ascending aortic attenuation (CEAAo) was measured during the diagnostic scan. RESULTS A positive correlation was observed between PA7 and CEAAo (r=0.41, P=0.003) and PA10 and CEAAo (r=0.66, P<0.0001), and weak negative correlation was observed between HR and CEAAo (r=-0.46, P=0.15). A multivariable linear regression model for predicting CEAAo was evaluated, and the residual error between the predicted and the measured CEAAo was within approximately ±100 HU. CONCLUSIONS Coronary attenuation could be predicted using HR and pulmonary artery attenuation during the bolus-tracking method.
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Affiliation(s)
- Nobuo Tomizawa
- Department of Radiology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Coronary enhancement for prospective ECG-gated single R-R axial 320-MDCT angiography: comparison of 60- and 80-mL iopamidol 370 injection. AJR Am J Roentgenol 2011; 197:844-50. [PMID: 21940571 DOI: 10.2214/ajr.10.5980] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to evaluate the difference in coronary enhancement provided by 60 versus 80 mL of contrast medium (370 mg I/mL) for prospectively ECG-gated single-heartbeat axial 320-MDCT. MATERIALS AND METHODS We retrospectively evaluated 108 consecutive 320-MDCT angiography studies. Group 1 (n = 36) received 60 mL of an iodinated contrast medium and group 2 (n = 72), 80 mL. All patients were imaged with a standardized protocol: iopamidol 370 followed by 40 mL of saline, both administered at a rate of 6 mL/s. Two imagers subjectively assessed image quality throughout the coronary arteries. Region-of-interest attenuation (HU) measurements were performed in the aorta plus the proximal and distal coronary arteries. RESULTS Subjective analysis of all coronary segments showed slightly better image quality for group 2. Patients in group 1 had significantly (p < 0.05) lower mean attenuation values for the individual coronary vessels. Nevertheless, 96.7% of all coronary segments in the group 1 patients had an attenuation of greater than 300 HU; when analysis was limited to group 1 patients with a body mass index of greater than 30, 92.8% of the segments were more than 300 HU, and all segments measured more than 250 HU. CONCLUSION An injection protocol based on 60 mL of iopamidol (370 mg I/mL) for prospectively ECG-gated wide-area detector single-heartbeat coronary CT angiography (CTA) has less coronary enhancement than a protocol based on 80 mL. However, using 60 mL, more than 96% of coronary segments had sufficient enhancement (i.e., > 300 HU), supporting the general use of 60-mL protocols for clinical wide-area detector coronary CTA.
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Ultrafast imaging of the entire chest without ECG synchronisation or beta-blockade: to what extent can we analyse the coronary arteries? Insights Imaging 2011; 3:73-9. [PMID: 22696000 PMCID: PMC3292649 DOI: 10.1007/s13244-011-0133-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 08/30/2011] [Accepted: 09/26/2011] [Indexed: 12/17/2022] Open
Abstract
Objectives To evaluate the accessibility of coronary arteries from chest CT examinations acquired without ECG gating or beta-blockade. Materials and methods Two hundred forty-two patients (median heart rate: 81.7 bpm) underwent a non-ECG-gated CT examination with high pitch and high temporal resolution. Image analysis was obtained by consensus between two readers. Results The percentage of accessible segments was 88% at the proximal level (i.e. 4 segments), 75% at the proximal and mid-segment level (i.e. 7 segments), and 61% and 48% when considering 10 and 15 segments, respectively. The mean (± SD) number of accessible segments per patient was 3.5 ± 0.78 and 5.2 ± 1.50 when considering four and seven segments per patient, respectively. The percentage of patients with four segments accessible was 67% (126/242), decreasing to 23% (55/242) with seven segments accessible and 3% (7/242) with ten segments accessible, while the entire coronary artery tree was not accessible for any of the patients. No significant difference was found in the patients’ mean hearts with four, seven, or ten accessible segments (P = 0.4897). Conclusion Diagnostic image quality was attainable at the level of proximal segments in 67% of patients, while proximal and mid-coronary segments were accessible in 23% of patients. Main Messages • High-pitch and high-temporal resolution scanning modes make accessible proximal coronary arteries on non ECG-gated chest CT angiograms • It is not necessary to administer beta-blockers to achieve good results. • Tobacco-related cardiovascular disorders could benefit from this scanning mode.
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Effects of iopamidol-370 versus iodixanol-320 on coronary contrast, branch depiction, and heart rate variability in dual-source coronary MDCT angiography. AJR Am J Roentgenol 2011; 197:W445-51. [PMID: 21862771 DOI: 10.2214/ajr.10.6154] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this article is to assess whether iopamidol-370 provides superior vascular contrast of the coronaries and depiction of anatomic detail without affecting heart rate and beat-to-beat variability during coronary dual-source MDCT compared with iodixanol-320. SUBJECTS AND METHODS In this prospective trial, coronary CT angiography was performed on 60 adult patients using either iopamidol-370 or iodixanol-320. Cohorts were matched by age, habitus, sex, and baseline heart rate, with cohort sizes determined by power analysis. All studies were performed on a dual-source MDCT scanner with retrospective ECG-gating utilizing automatic pitch adjustment. Data assessment focused on heart rate variability during contrast administration statistically evaluated as Student t test comparisons within and between cohorts, coronary contrast-to-noise ratio analysis of the main coronary arteries utilizing Student t test comparisons between cohorts, and coronary branch depiction and distribution analysis in dual-reader consensus decisions between cohorts. RESULTS Thirty patients matched for age, habitus, sex, and heart rate were evaluated in each cohort. ECG analyses found a statistically significant (p = 0.013) decrease in heart rate during administration of iodixanol-320. Beat-to-beat variations, expressed as coefficient of variation, within and among cohorts were low (coefficient of variation, < 0.05). Contrast-to-noise ratio was significantly increased for iopamidol-370 versus iodixanol-320 (aortic root, p = 0.021; left main, p = 0.032; left anterior descending, p = 0.033; left circumflex, p = 0.039; and right, p = 0.009). Analysis of coronary branch visualization revealed improved depiction for iopamidol-370 compared with iodixanol-320. CONCLUSION Iopamidol-370, with its higher iodine concentration, provided greater vascular contrast of the arterial coronary tree and improved depiction of anatomic detail without significantly impacting cardiac heart rate during coronary MDCT imaging, as compared with iodixanol-320.
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Keeling AN, Flaherty JD, Davarpanah AH, Ambrosy A, Farrelly CT, Harinstein ME, Flamm SL, Abecassis MI, Skaro AI, Carr JC, Gheorghiade M. Coronary multidetector computed tomographic angiography to evaluate coronary artery disease in liver transplant candidates: methods, feasibility and initial experience. J Cardiovasc Med (Hagerstown) 2011; 12:460-8. [PMID: 21610507 DOI: 10.2459/jcm.0b013e3283483916] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIMS In patients undergoing orthotopic liver transplantation (OLT), coronary artery disease (CAD), obstructive and nonobstructive, is associated with high morbidity and mortality. In OLT candidates, stress testing for detecting ischemia is often inaccurate, and this patient population often has relative contraindications for cardiac catheterization. The objective of this study was to describe the methods, assess the feasibility and determine the extent and severity of CAD in OLT candidates without a prior history of CAD using coronary multidetector computer tomographic angiography (MDCTA). METHODS Sixty-five OLT candidates without known CAD underwent coronary MDCTA with dual source cardiac computed tomography (Siemens Definition). Coronary arteries were divided into 17 segments based on American Heart Association guidelines and evaluated independently by two blinded reviewers. Image quality of coronary MDCTA was assessed on a four-point Likert scale (0 = poor, 1 = fair, 2 = good, and 3 = excellent). Atherosclerotic lesions were evaluated for severity [mild (0-50%), moderate (51-70%), and severe (71-100%)], morphology, extent, location and consistency. RESULTS Image quality was graded as good or excellent in 73.8%. In this cohort of OLT candidates without known CAD, 9% had normal coronary arteries, 58% had mild CAD and 34% had moderate to severe CAD. Plaque severity and burden scores were high. CONCLUSION The prevalence of asymptomatic CAD is high in OLT candidates. Coronary MDCTA is feasible in OLT candidates and appears to be a useful technique to diagnose occult CAD in this patient population.
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Affiliation(s)
- Aoife N Keeling
- Division of Cardiovascular Imaging, Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA
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Indications, imaging technique, and reading of cardiac computed tomography: survey of clinical practice. Eur Radiol 2011; 22:59-72. [PMID: 21845461 DOI: 10.1007/s00330-011-2239-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 06/09/2011] [Accepted: 07/01/2011] [Indexed: 10/17/2022]
Abstract
OBJECTIVES To obtain an overview of the current clinical practice of cardiac computed tomography (CT). METHODS A 32-item questionnaire was mailed to a total of 750 providers of cardiac CT in 57 countries. RESULTS A total of 169 questionnaires from 38 countries were available for analysis (23%). Most CT systems used (94%, 207/221) were of the latest generation (64-row or dual-source CT). The most common indications for cardiac CT was exclusion of coronary artery disease (97%, 164/169). Most centres used beta blockade (91%, 151/166) and sublingual nitroglycerine (80%, 134/168). A median slice thickness of 0.625 mm with a 0.5-mm increment and an 18-cm reconstruction field of view was used. Interpretation was most often done using source images in orthogonal planes (92%, 155/169). Ninety percent of sites routinely evaluate extracardiac structures on a large (70%) or cardiac field of view (20%). Radiology sites were significantly more interested in jointly performing cardiac CT together with cardiology than cardiologists. The mean examination time was 18.6 ± 8.4 min, and reading took on average 28.7 ± 17.8 min. CONCLUSIONS Cardiac CT has rapidly become established in clinical practice, and there is emerging consensus regarding indications, conduct of the acquisition, and reading.
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Cardiothoracic CT angiography: current contrast medium delivery strategies. AJR Am J Roentgenol 2011; 196:W260-72. [PMID: 21343473 DOI: 10.2214/ajr.10.5814] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Over the last decade, rapid technologic evolution in CT has resulted in improved spatial and temporal resolution and acquisition speed, enabling cardiothoracic CT angiography to become a viable and effective noninvasive alternative in the diagnostic algorithm. These new technologic advances have imposed new challenges for the optimization of contrast medium delivery and image acquisition strategies. CONCLUSION Thorough understanding of contrast medium dynamics is essential for the design of effective acquisition and injection protocols. This article provides an overview of the fundamentals affecting contrast enhancement, emphasizing the modifications to contrast material delivery protocols required to optimize cardiothoracic CT angiography.
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Current contrast media delivery strategies for cardiac and pulmonary multidetector-row computed tomography angiography. J Thorac Imaging 2011; 25:270-7. [PMID: 21042065 DOI: 10.1097/rti.0b013e3181efe8b0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Recent advances in multidetector-row computed tomography (MDCT) have led to substantial improvements in coverage area, acquisition speed, and temporal/spatial resolution, which have strengthened the performance of thoracic and cardiac MDCT angiography but have also imposed new challenges for optimization of contrast medium enhancement and scan acquisition strategies. Understanding contrast media dynamics is fundamental for the design of scan acquisition and injection protocols. This article examines the fundamentals of the physiological and contrast delivery factors that determine the quality of contrast enhancement, emphasizing the modifications required in contrast delivery protocols for optimizing cardiothoracic MDCT angiography with modern-era MDCT scanners.
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