29
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Optimal phase for coronary interpretations and correlation of ejection fraction using late-diastole and end-diastole imaging in cardiac computed tomography angiography: implications for prospective triggering

      research-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          A typical acquisition protocol for multi-row detector computed tomography (MDCT) angiography is to obtain all phases of the cardiac cycle, allowing calculation of ejection fraction (EF) simultaneously with plaque burden. New MDCT protocols scanner, designed to reduce radiation, use prospectively acquired ECG gated image acquisition to obtain images at certain specific phases of the cardiac cycle with least coronary artery motion. These protocols do not we allow acquisition of functional data which involves measurement of ejection fraction requiring end-systolic and end-diastolic phases. We aimed to quantitatively identify the cardiac cycle phase that produced the optimal images as well as aimed to evaluate, if obtaining only 35% (end-systole) and 75% (as a surrogate for end-diastole) would be similar to obtaining the full cardiac cycle and calculating end diastolic volumes (EDV) and EF from the 35th and 95th percentile images. 1,085 patients with no history of coronary artery disease were included; 10 images separated by 10% of R–R interval were retrospectively constructed. Images with motion in the mid portion of RCA were graded from 1 to 3; with ‘1’ being no motion, ‘2’ if 0 to <1 mm motion, and ‘3’ if there is >1 mm motion and/or non-interpretable study. In a subgroup of 216 patients with EF > 50%, we measured left ventricular (LV) volumes in the 10 phases, and used those obtained during 25, 35, 75 and 95% phase to calculate the EF for each patient. The average heart rate (HR) for our patient group was 56.5 ± 8.4 (range 33–140). The distribution of image quality at all heart rates was 958 (88.3%) in Grade 1, 113 (10.42%) in Grade 2 and 14 (1.29%) in Grade 3 images. The area under the curve for optimum image quality (Grade 1 or 2) in patients with HR > 60 bpm for phase 75% was 0.77 ± 0.04 [95% CI: 0.61–0.87], while for similar heart rates the area under the curve for phases 75 + 65 + 55 + 45% combined was 0.92 ± 0.02. LV volume at 75% phase was strongly correlated with EDV (LV volume at 95% phase) ( r = 0.970, P < 0.001). There was also a strong correlation between LVEF (75_35) and LVEF (95_35) ( r = 0.93, P < 0.001). Subsequently, we developed a formula to correct for the decrement in LVEF using 35–75% phase: LVEF (95_35) = 0.783 × LVEF (75_35) + 20.68; adjusted R 2 = 0.874, P < 0.001. Using 64 MDCT scanners, in order to acquire >90% interpretable studies, if HR < 60 bpm 75% phase of RR interval provides optimal images; while for HR > 60 analysis of images in 4 phases (75, 35, 45 and 55%) is needed. Our data demonstrates that LVEF can be predicted with reasonable accuracy by using data acquired in phases 35 and 75% of the R–R interval. Future prospective acquisition that obtains two phases (35 and 75%) will allow for motion free images of the coronary arteries and EF estimates in over 90% of patients.

          Related collections

          Most cited references27

          • Record: found
          • Abstract: found
          • Article: not found

          Cardiac computed tomography: indications, applications, limitations, and training requirements: report of a Writing Group deployed by the Working Group Nuclear Cardiology and Cardiac CT of the European Society of Cardiology and the European Council of Nuclear Cardiology.

          As a consequence of improved technology, there is growing clinical interest in the use of multi-detector row computed tomography (MDCT) for non-invasive coronary angiography. Indeed, the accuracy of MDCT to detect or exclude coronary artery stenoses has been high in many published studies. This report of a Writing Group deployed by the Working Group Nuclear Cardiology and Cardiac CT (WG 5) of the European Society of Cardiology and the European Council of Nuclear Cardiology summarizes the present state of cardiac CT technology, as well as the currently available data concerning its accuracy and applicability in certain clinical situations. Besides coronary CT angiography, the use of CT for the assessment of cardiac morphology and function, evaluation of perfusion and viability, and analysis of heart valves is discussed. In addition, recommendations for clinical applications of cardiac CT imaging are given and limitations of the technique are described.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose.

            To retrospectively compare image quality, radiation dose, and blood vessel assessability for coronary artery computed tomographic (CT) angiograms obtained with a prospectively gated transverse (PGT) CT technique and a retrospectively gated helical (RGH) CT technique. This HIPAA-compliant study received a waiver for approval from the institutional review board, including one for informed consent. Coronary CT angiograms obtained with 64-detector row CT were retrospectively evaluated in 203 clinical patients. A routine RGH technique was evaluated in 82 consecutive patients (44 males, 38 females; mean age, 55.6 years). The PGT technique was then evaluated in 121 additional patients (71 males, 50 females; mean age, 56.7 years). All images were evaluated for image quality, estimated radiation dose, and coronary artery segment assessability. Differences in image quality score were evaluated by using a proportional odds logistic regression model, with main effects for three readers, two techniques, and four arteries. The mean effective dose for the group with the PGT technique was 2.8 mSv; this represents an 83% reduction as compared with that for the group with the RGH technique (mean, 18.4 mSv; P < .001). The image quality score for each of the arteries, as well as the overall combined score, was significantly greater for images obtained with PGT technique than for images obtained with RGH technique. The combined mean image quality score was 4.791 for images obtained with PGT technique versus 4.514 for images obtained with RGH technique (proportional odds model odds ratio, 2.8; 95% confidence interval: 1.7, 4.8). The percentage of assessable coronary artery segments was 98.6% (1196 of 1213) for images obtained with PGT technique versus 97.9% (1741 of 1778) for images obtained with RGH technique (P = .83). PGT coronary CT angiography offers improved image quality and substantially reduced effective radiation dose compared with traditional RGH coronary CT angiography. (c) RSNA, 2008.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Coronary artery motion and cardiac phases: dependency on heart rate -- implications for CT image reconstruction.

              This study had institutional review board approval; written informed consent was obtained. The purpose was to prospectively determine the heart rate (HR) dependency of three-dimensional (3D) coronary artery motion by incorporating into analysis the durations of systole and diastole. Thirty patients (seven women, 23 men; mean age, 56.6 years +/- 12.7 [standard deviation]; HR: 45-100 beats per minute) underwent electrocardiographically gated 64-section computed tomographic (CT) coronary angiography to determine coronary motion velocities at bifurcation points. Significance of velocity differences (P < .05) was determined by using analysis of variance for repeated measures and Bonferroni post hoc tests. HR dependency was determined by using linear regression analysis. HR significantly affected 3D coronary motion (r = 0.47, P < .009) through nonproportional shortening of systole and diastole (r = -0.82, P < .001), leading to percentage reconstruction interval shifts of coronary velocity troughs and peaks (P < .01). Results suggest that image reconstruction algorithms at CT coronary angiography be adapted to the individual patient's HR.
                Bookmark

                Author and article information

                Contributors
                yasminshamshuddin@yahoo.com
                Journal
                Int J Cardiovasc Imaging
                The International Journal of Cardiovascular Imaging
                Springer Netherlands (Dordrecht )
                1569-5794
                1875-8312
                25 July 2009
                October 2009
                : 25
                : 7
                : 739-749
                Affiliations
                [1 ]Beirut Cardiac Institute, Founding Faculty Lebanese American University, Beirut, Lebanon
                [2 ]Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA USA
                [3 ]Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA USA
                Article
                9481
                10.1007/s10554-009-9481-y
                2729417
                19633922
                aa0f362a-c0db-4c36-9c8e-de6ba7b4643d
                © The Author(s) 2009
                History
                : 2 February 2009
                : 9 July 2009
                Categories
                Original Paper
                Custom metadata
                © Springer Science+Business Media, B.V. 2009

                Cardiovascular Medicine
                ejection fraction,optimal phase,end diastoic volume,computed tomography angiography,prospective rigerring,coronary artery motion,radiation reduction

                Comments

                Comment on this article