The Present and Future of Cardiac CT in Research and Clinical Practice: Moderated Discussion and Scientific Debate with Representatives from the Four Main Vendors

Zusammenfassung

Die nicht invasive Diagnostik des Herzens mit der Computertomografie (CT) ist eine bei Patienten mit dem Verdacht auf eine oder einer bekannten koronaren Herzkrankheit stetig an Bedeutung gewinnende Methode. Zuvorderst hat die CT-Koronarangiografie aufgrund ihrer bisher nicht erreichten räumlichen und zeitlichen Auflösung bei der Darstellung der Koronararterien und von koronararteriellen Plaques Aufmerksamkeit erregt. In dieser moderierten wissenschaftlichen Debatte diskutieren wir die Vor- und Nachteile unterschiedlicher technischer Ansätze bei der CT des Herzens. Im Detail werden hierbei Entwicklungen zur Erhöhung der Abdeckung entlang der Z-Achse (320-Zeilen Volumen-CT, schnelle Spiralakquisition mit hohem Pitch), der Verbesserung der zeitlichen Auflösung (Dual-source CT, Multisegmentrekonstruktion, und kürzere Gantryrotationszeiten), der Verbesserung der räumlichen Auflösung (verbesserte Inschichtauflösung) und der Weiterentwicklung der Rekonstruktionsalgorithmen (iterative Rekonstruktion, Kegelstrahlrekonstruktion) diskutiert. Des Weiteren gehen wir auf die Notwendigkeit weiterer technischer Entwicklungen mit besonderer Berücksichtigung der Strahlenexposition ein, die notwendig sein dürften, um die Akzeptanz und klinische Verbreitung der Methode zu steigern. Zum Abschluss geben die Vertreter der vier Hersteller einen Einblick in ihre Planungen zu Forschungsprojekten zur CT des Herzens.

Abstract

Noninvasive imaging of the heart using computed tomography (CT) is an increasingly important diagnostic approach for patients with known or suspected coronary artery disease. Coronary CT angiography has recently received great attention because it provides imaging of the coronary arteries and quantification of the coronary plaque burden with a spatial and temporal resolution not available with any other noninvasive imaging test. In this moderated scientific debate we discuss the advantages and disadvantages of different technical solutions to CT imaging of the fast moving heart including its small and tortuous coronary arteries. Our discussion goes into the details of developments regarding larger Z-axis coverage (320-row volume CT, high pitch spiral acquisition), improved temporal resolution (dual-source CT, adaptive multi-segment reconstruction, and shorter gantry rotation times with air-bearing gantries), improved spatial resolution (high-definition detectors), and improved reconstruction algorithms (iterative reconstruction, cone beam reconstruction). The discussion also touches on the future technological developments that will be necessary to further improve the acceptance and widespread clinical use of cardiac CT, focusing on radiation exposure reduction and independence from heart rate. Finally, the representatives of the four main vendors explain the most important research projects regarding cardiac CT that they plan to pursue in the near future.

Key words

cardiac - heart - CT

References

• 1 Anders K, Baum U, Gauss S. et al . Initial experience with prospectively triggered, sequential CT coronary angiography on a 128-slice scanner.  Fortschr Röntgenstr. 2009;  181 332-338
• 2 Artmann A, Enayati S, Ratzenbock M. et al . Image Quality of CT Angiography of Coronary Arteries Dependig on the Degree of Coronary Calcification Using a Dual Source CT Scanner.  Fortschr Röntgenstr. 2009;  181 863-869
• 3 Dewey M, Hamm B. Recent trends in cardiovascular imaging as reflected in Fortschr Röntgenstr.  Fortschr Röntgenstr. 2006;  178 953-956
• 4 Dewey M, Hamm B. CT coronary angiography: examination technique, clinical results, and outlook on future developments.  Fortschr Röntgenstr. 2007;  179 246-260
• 5 Fischbach R, Miller S, Beer M. et al . Recommendations of the Heart Diagnosis Working Group of the German Roentgen Society for use of computerized tomography and magnetic resonance tomography in heart diagnosis. 1-Computerized tomography.  Fortschr Röntgenstr. 2009;  181 700-706
• 6 Koster R, Stevendaal van U, Grass M. et al . Multi-detector computed tomography to analyze in-stent restenoses at different heart rates.  Fortschr Röntgenstr. 2008;  180 821-831
• 7 Wust W, Zunker C, May M. et al . Septal delineation using a 20 % diluted contrast chaser bolus in coronary CT angiography: a comparison of 64-slice and dual source CT.  Fortschr Röntgenstr. 2009;  181 324-331
• 8 Hahn D. Moderne Schnittbilddiagnostik des Herzens, MRT oder MSCT?.  Fortschr Röntgenstr. 2004;  176 1215-1218
• 9 Heyer C M, Peters S, Lemburg S. Structure of the meeting of the german radiological society and scientific discourse pertaining to radiation dose and dose reduction: an analysis of 1998 – 2008.  Fortschr Röntgenstr. 2009;  181 1065-1072
• 10 Maurer M H, Hamm B, Dewey M. Survey regarding the clinical practice of cardiac CT in Germany: indications, scanning technique and reporting.  Fortschr Röntgenstr. 2009;  181 1135-1143
• 11 Dewey M, Hamm B. CT Coronary Angiography: Examination Technique, Clinical Results, and Outlook on Future Developments.  Fortschr Röntgenstr. 2007;  179 246-260
• 12 Bansmann P M, Senegas J, Muellerleile K. et al . Assessment of left ventricular function parameters with a new three-dimensional shape model.  Fortschr Röntgenstr. 2009;  181 161-168
• 13 Begemann P G, Stahmer F, Stork A. et al . Evaluation of two ”fast” software tools for the measurement of left ventricular volumes in retrospectively ECG-gated multidetector CT of the heart: biplane area-length method and ”shape tracking” method.  Fortschr Röntgenstr. 2007;  179 572-580
• 14 Luders F, Fischbach R, Seifarth H. et al . Dual-Source Computed Tomography: Effect on Regional and Global Left Ventricular Function Assessment Compared to Magnetic Resonance Imaging.  Fortschr Röntgenstr. 2009;  181 962-969
• 15 Krug K B, Bovenschulte H, Geissler H J. et al . In-vivo measurements of coronary blood flow using 16-slice multidetector spiral computed tomography (MDCT) in a porcine model.  Fortschr Röntgenstr. 2009;  181 220-229
• 16 Weininger M, Ritter C O, Beer M. et al . Evaluation of coronary calcifications with 64-slice CT – variability of the scores and the influence of the reconstruction interval.  Fortschr Röntgenstr. 2007;  179 938-944
• 17 Weber T F, Klemm H, Koops A. et al . Integration of cardiac computed tomography into pulmonary vein isolation in patients with paroxysmal atrial fibrillation.  Fortschr Röntgenstr. 2007;  179 1264-1271
• 18 Hollander J E, Litt H I, Chase M. et al . Computed tomography coronary angiography for rapid disposition of low-risk emergency department patients with chest pain syndromes.  Acad Emerg Med. 2007;  14 112-116
• 19 Schwarz F, Ruzsics B, Schoepf U J. et al . Dual-energy CT of the heart – principles and protocols.  Eur J Radiol. 2008;  68 423-433
• 20 Blankstein R, Shturman L D, Rogers I S. et al . Adenosine-induced stress myocardial perfusion imaging using dual-source cardiac computed tomography.  J Am Coll Cardiol. 2009;  54 1072-1084
• 21 George R T, Arbab-Zadeh A, Miller J M. et al . Adenosine stress 64- and 256-row detector computed tomography angiography and perfusion imaging: a pilot study evaluating the transmural extent of perfusion abnormalities to predict atherosclerosis causing myocardial ischemia.  Circ Cardiovasc Imaging. 2009;  2 174-182
• 22 Weigold W G, Olszewski M E, Walker M J. Low-dose prospectively gated 256-slice coronary computed tomographic angiography.  Int J Card Imaging. 2009;  25 217-230
• 23 Klass O, Walker M, Siebach A. et al . Prospectively gated axial CT coronary angiography: comparison of image quality and effective radiation dose between 64- and 256-slice CT.  Eur Radiol. 2010;  epub
• 24 Schuetz G M, Zacharopoulou N M, Schlattmann P. et al . Meta-analysis: Noninvasive Coronary Angiography Using Computed Tomography versus Magnetic Resonance Imaging.  Ann Intern Med. 2010;  152 167-177
• 25 Kovacs A, Probst C, Sommer T. et al . CT coronary angiography in patients with atrial fibrillation.  Fortschr Röntgenstr. 2005;  177 1655-1662
• 26 Oncel D, Oncel G, Tastan A. Effectiveness of dual-source CT coronary angiography for the evaluation of coronary artery disease in patients with atrial fibrillation: initial experience.  Radiology. 2007;  245 703-711
• 27 Wolak A, Gutstein A, Cheng V Y. et al . Dual-source coronary computed tomography angiography in patients with atrial fibrillation: initial experience.  J Cardiovasc Comput Tomogr. 2008;  2 172-180
• 28 Yang L, Zhang Z, Fan Z. et al . 64-MDCT coronary angiography of patients with atrial fibrillation: influence of heart rate on image quality and efficacy in evaluation of coronary artery disease.  Am J Roentgenol. 2009;  193 795-801
• 29 Chow B J, Larose E, Bilodeau S. et al . The ”what, when, where, who and how?” of cardiac computed tomography in 2009: guidelines for the clinician.  Can J Cardiol. 2009;  25 135-139
• 30 Bluemke D A, Achenbach S, Budoff M. et al . Noninvasive coronary artery imaging: magnetic resonance angiography and multidetector computed tomography angiography: a scientific statement from the american heart association committee on cardiovascular imaging and intervention of the council on cardiovascular radiology and intervention, and the councils on clinical cardiology and cardiovascular disease in the young.  Circulation. 2008;  118 586-606
• 31 Schroeder S, Achenbach S, Bengel F. et al . 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.  Eur Heart J. 2008;  29 531-556
• 32 Rybicki F J, Otero H J, Steigner M L. et al . Initial evaluation of coronary images from 320-detector row computed tomography.  Int J Cardiovasc Imaging. 2008;  24 535-546
• 33 Dewey M, Zimmermann E, Deissenrieder F. et al . Noninvasive Coronary Angiography by 320-Row CT with Lower Radiation Exposure and Maintained Diagnostic Accuracy: Comparison of Results with Cardiac Catheterization in a Head-To-Head Pilot Investigation.  Circulation. 2009;  120 867-875
• 34 Achenbach S, Marwan M, Ropers D. et al . Coronary computed tomography angiography with a consistent dose below 1 mSv using prospectively electrocardiogram-triggered high-pitch spiral acquisition.  Eur Heart J. 2010;  31 340-346
• 35 Steigner M L, Mitsouras D, Whimore A G. et al . Iodinated Contrast Opacification Gradients in Normal Coronary Arteries Imaged with Prospectively ECG-Gated Single Heart Beat 320-Detector Row Computed Tomography.  Circ Cardiovasc Imaging. 2010;  in press
• 36 Dewey M, Laule M, Krug L. et al . Multisegment and halfscan reconstruction of 16-slice computed tomography for detection of coronary artery stenoses.  Invest Radiol. 2004;  39 223-229
• 37 Dewey M, Teige F, Laule M. et al . Influence of heart rate on diagnostic accuracy and image quality of 16-slice CT coronary angiography: comparison of multisegment and halfscan reconstruction approaches.  Eur Radiol. 2007;  17 2829-2837
• 38 Flohr T, Stierstorfer K, Raupach R. et al . Performance evaluation of a 64-slice CT system with z-flying focal spot.  Fortschr Röntgenstr. 2004;  176 1803-1810
• 39 Flohr T G, McCollough C H, Bruder H. et al . First performance evaluation of a dual-source CT (DSCT) system.  Eur Radiol. 2006;  16 256-268
• 40 Halliburton S S, Stillman A E, Flohr T. et al . Do segmented reconstruction algorithms for cardiac multi-slice computed tomography improve image quality?.  Herz. 2003;  28 20-31
• 41 Engelken F, Lembcke A, Hamm B. et al . Determining optimal acquisition parameters for computed tomography coronary angiography: evaluation of a software-assisted, breathhold exam simulation.  Acad Radiol. 2008;  16 239-243
• 42 Min J K, Swaminathan R V, Vass M. et al . High-definition multidetector computed tomography for evaluation of coronary artery stents: comparison to standard-definition 64-detector row computed tomography.  J Cardiovasc Comput Tomogr. 2009;  3 246-251
• 43 Imai Y, Nukui M, Ishihara Y. et al . Development and performance evaluation of an experimental fine pitch detector multislice CT scanner.  Med Phys. 2009;  36 1120-1127
• 44 Flohr T G, Raupach R, Bruder H. Cardiac CT: how much can temporal resolution, spatial resolution, and volume coverage be improved?.  J Cardiovasc Comput Tomogr. 2009;  3 143-152
• 45 Zimmermann E, Germershausen C, Greupner J. et al . Improvement of Skills and Knowledge by a Hands-on Cardiac CT Course: Before and After Evaluation with a Validated Questionnaire and Self-Assessment.  Fortschr Röntgenstr. 2010;  DOI: 10.1055/s-0028-1109950
• 46 Dewey M. Technical and Personnel Requirements. Chapter 2. Dewey M Coronary CT Angiography Heidelberg; Springer 2008
• 47 Hausleiter J, Meyer T, Hermann F. et al . Estimated radiation dose associated with cardiac CT angiography.  JAMA. 2009;  301 500-507
• 48 Budoff M J, Dowe D, Jollis J G. et al . Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial.  J Am Coll Cardiol. 2008;  52 1724-1732
• 49 Gopal A, Budoff M J. A new method to reduce radiation exposure during multi-row detector cardiac computed tomographic angiography.  Int J Cardiol. 2009;  132 435-436
• 50 Dewey M, Hoffmann H, Hamm B. Multislice CT coronary angiography: effect of sublingual nitroglycerine on the diameter of coronary arteries.  Fortschr Röntgenstr. 2006;  178 600-604
• 51 Klass O, Mutlu S, Hohl K. et al . Multidetector computed tomography coronary angiography: sublingual nitroglycerine improves image quality significantly because of peripheral coronary vasodilatation.  J Comput Assist Tomogr. 2009;  33 199-203
• 52 Chun E J, Lee W, Choi Y H. et al . Effects of nitroglycerin on the diagnostic accuracy of electrocardiogram-gated coronary computed tomography angiography.  J Comput Assist Tomogr. 2008;  32 86-92
• 53 Lehmkuhl L. General Electric Light Speed VCT. Chapter 8 d. Dewey M Coronary CT Angiography Heidelberg; Springer 2008
• 54 Dewey M. Preparation. Chapter 6. Dewey M Coronary CT Angiography Heidelberg; Springer 2008
• 55 Cademartiri F, Nieman K, Lugt van der A. et al . Intravenous contrast material administration at 16-detector row helical CT coronary angiography: test bolus versus bolus-tracking technique.  Radiology. 2004;  233 817-823
• 56 Koonce J, Schoepf J U, Nguyen S A. et al . Extra-cardiac findings at cardiac CT: experience with 1,764 patients.  Eur Radiol. 2009;  19 570-576
• 57 Zimmermann E. Toshiba Aquilion 64. Chapter 8a. Dewey M Coronary CT Angiography Heidelberg; Springer 2008
• 58 Klessen C. Siemens Somatom Sensation and Definition. Chapter 8b. Dewey M Coronary CT Angiography Heidelberg; Springer 2008
• 59 Dewey M. Examination and Reconstruction. Chapter 7. Dewey M Coronary CT Angiography Heidelberg; Springer 2008
• 60 Klink T, Hoffmann M H, Stevendaal van U. et al . Automatic phase point determination of minimal motion reconstruction intervals with motion maps in ECG-gated CT diagnostics of coronary sclerosis.  Fortschr Röntgenstr. 2009;  181 675-682
• 61 Hoffmann M H, Lessick J, Manzke R. et al . Automatic determination of minimal cardiac motion phases for computed tomography imaging: initial experience.  Eur Radiol. 2006;  16 365-373
• 62 Ruzsics B, Gebregziabher M, Lee H. et al . Coronary CT angiography: automatic cardiac-phase selection for image reconstruction.  Eur Radiol. 2009;  19 1906-1913