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Over the past few years, computed tomography (CT) angiography has emerged as a reliable non-invasive method for the assessment of coronary anatomy and cardiac function [1–17]. Multiple studies involving over several thousands of patients have established that CT angiography is highly accurate for delineation of the presence and severity of coronary atherosclerosis [18–35]. With its high negative predictive value cardiac CT is optimally suited for the evaluation of patients with a low or intermediate risk of coronary disease, allowing the non-invasive exclusion of coronary disease at relatively low cost and risk [36–48]. However, the appropriate radiation dose remains an important issue in cardiac CT. On one hand, a too low radiation dose may result in a high level of image noise and therefore in non-evaluable images. On the other hand, using higher radiation exposure levels may put patients at unnecessary risk of radiation damage [49–57].
The median exposure of CT angiography is approximately equivalent to 600 chest X-rays (12 mSv). Traditional angiography exposes patients to roughly half the dose of CT angiography. However, the radiation exposure of almost 2,000 people having 64-slice cardiac CT images at 50 medical centers in different countries may vary more than six-fold [58]. Effective strategies to reduce radiation dose, such as prospective gating, ECG-correlated modulation of the tube current, and tube voltage below 100 kV, are becoming more and more available.
In the current issue of the International Journal of Cardiovascular Imaging, Blankstein and coworkers [59] investigated the effective radiation dose and image quality of 100 kV versus 120 kV tube voltage among patients referred for cardiac dual source CT imaging. The authors collected prospective data on 294 consecutive patients. For each scan, a physician specializing in cardiac CT chose all parameters including tube current and voltage, axial versus helical acquisition, and use of tube current modulation. Lower tube voltage was selected for thinner patients or when lower radiation was desired for younger patients, particularly in females. For each study, image quality was rated on a subjective imaging quality score and contrast-to-noise and signal-to-noise ratios were assessed. Tube voltage of 100 kV was used for 77 (26%) exams while 120 kV was used for 217 (74%) exams. Use of 100 kV was more common in thinner patients. It was shown that the effective radiation dose for the 100 kV versus the 120 kV scans was significantly lower for the 100 kV scans: 8.5 and 15.4 mSv, respectively. Between the 100 and 120 kV scans, there was no differences in indication, use of beta-blocking agents, heart rate, scan length and use of radiation saving techniques such as prospective ECG triggering and tube current modulation. The imaging quality score was significantly higher for 100 kV scans. While 100 kV scans were found to have higher image noise then those utilizing 120 kV, the contrast-to-noise and signal-to-noise were significantly higher for the 100 kV scans. The authors concluded that in selected non-obese patients, the use of low voltage kV results in a substantial reduction of radiation dose and results in improved image quality. The study by Blankstein et al. [59] therefore suggests that low kV should be used more frequently in non-obese patients.
These findings are very interesting and may have direct implications in clinical practice. At present, there are serious concerns about radiation safety of cardiac CT images [60–64]. In a recent paper by Leschka et al. [62], it was shown that adjustment of the scan length of CT coronary angiography using the images from calcium scoring instead of the scout was associated with a 16% reduction in radiation dose of dual-source CT coronary angiography. In a large multicenter study of coronary CT angiography in patients with excellent heart rate control, Labounty et al. [63] reported that the use of minimal padding (i.e. additional surrounding X-ray beam on time), was associated with a substantial reduction in radiation dose together with preserved image interpretability. Recently, Rogalla et al. [64] recently showed that the anterior-posterior diameter adapted tube current in dynamic volume CT coronary angiography provided a new simple and practical approach to keep image quality constant by accounting for differences in patient size. Maintaining a constant image quality in CT, independent of patient body habitus, significantly contributed to a substantially improved diagnostic image quality together with a reduced radiation dose for the patient. Radiation exposure might be further decreased with 320-row MSTC scanners but further comparative studies are needed [65–67].
Generally, cardiac imaging tests should be used cautiously to minimize patient exposure to ionizing radiation. Cardiac imaging studies should be ordered only after thoughtful consideration of the potential benefits to the patient, thereby keeping in line with the established so-called ‘appropriateness’ criteria. As to CT angiography, Ayyad et al. [68] showed that the number of appropriate CT examinations increased from 69.5 to 78.5% during the period from 2006 to 2007, whereas the number of inappropriate examinations decreased from 11.5 to 4.6%. Interestingly, cardiologists were more likely than non-cardiologists to order CT examinations that were appropriate during the study period. However, a more recent study by Miller et al. [69] suggested that still a significant proportion (46%) of the coronary CT angiography studies are for indications not covered by the published appropriateness criteria. Adherence to the appropriateness criteria is of paramount importance in clinical practice. This policy will have a significant impact on physician decision making and patient care, such as exposure to a minimal radiation dose.
To summarize, in selected non-obese patients, Blankstein et al. [59] have convincingly demonstrated that use of low kV results in a substantial reduction of radiation dose without compromising image quality.
References
Schuijf JD, Pundziute G, Jukema JW et al (2006) Diagnostic accuracy of 64-slice multislice computed tomography in the noninvasive evaluation of significant coronary artery disease. Am J Cardiol 98:145–148
Jongbloed MR, Lamb HJ, Bax JJ et al (2005) Noninvasive visualization of the cardiac venous system using multislice computed tomography. J Am Coll Cardiol 45:749–753
Schuijf JD, Wijns W, Jukema JW et al (2006) Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging. J Am Coll Cardiol 48:2508–2514
Bax JJ, Lamb H, Dibbets P, Pelikan H et al (2000) Comparison of gated single photon emission computed tomography with magnetic resonance imaging for evaluation of left ventricular function in ischemic cardiomyopathy. Am J Cardiol 86:1299–1305
van der Wall EE, Heidendal GA, den Hollander W, Westera G, Roos JP (1980) I-123 labeled hexadecenoic acid in comparison with thallium-201 for myocardial imaging in coronary heart disease. A preliminary study. Eur J Nucl Med 5:401–405
Bavelaar-Croon CD, Pauwels EK, van der Wall EE (2001) Gated single-photon emission computed tomographic myocardial imaging: a new tool in clinical cardiology. Am Heart J 141:383–390
Molhoek SG, Bax JJ, Bleeker GB et al (2004) Comparison of response to cardiac resynchronization therapy in patients with sinus rhythm versus chronic atrial fibrillation. Am J Cardiol 94:1506–1509
Groothuis JG, Beek AM, Meijerink MR, Brinckman SL, Hofman MB, van Rossum AC (2010) Towards a noninvasive anatomical and functional diagnostic work-up of patients with suspected coronary artery disease. Neth Heart J 18:270–273
van Mieghem CA, de Feyter PJ (2009) Combining noninvasive anatomical imaging with invasive functional information: an unconventional but appropriate hybrid approach. Neth Heart J 17:292–294
Knaapen P, de Haan S, Hoekstra OS et al (2010) Cardiac PET-CT: advanced hybrid imaging for the detection of coronary artery disease. Neth Heart J 18:90–98
van der Wall EE, van Dijkman PR, de Roos A et al (1990) Diagnostic significance of gadolinium-DTPA (diethylene- triamine penta-acetic acid) enhanced magnetic resonance imaging in thrombolytic treatment for acute myocardial infarction: its potential in assessing reperfusion. Br Heart J 63:12–17
Wijpkema JS, Dorgelo J, Willems TP et al (2007) Discordance between anatomical and functional coronary stenosis severity. Neth Heart J 15:5–11
van de Wal RM, van Werkum JW, le Cocq d’Armandville MC et al (2007) Giant aneurysm of an aortocoronary venous bypass graft compressing the right ventricle. Neth Heart J 15:252–254
de Leeuw JG, Wardeh A, Sramek A, van der Wall EE (2007) Pseudo-aortic dissection after primary PCI. Neth Heart J 15:265–266
Braun S, van der Wall EE, Emanuelsson S, Kobrin I (1996) Effects of a new calcium antagonist, mibefradil (Ro 40-5967), on silent ischemia in patients with stable chronic angina pectoris: a multicenter placebo-controlled study. The mibefradil international study group. J Am Coll Cardiol 27:317–322
ten Kate GJ, Wuestink AC, de Feyter PJ (2008) Coronary artery anomalies detected by MSCT-angiography in the adult. Neth Heart J 16:369–375
Schuijf JD, Jukema JW, van der Wall EE, Bax JJ (2007) Multi-slice computed tomography in the evaluation of patients with acute chest pain. Acute Card Care 9:214–221
Groen JM, Greuter MJ, Vliegenthart R et al (2008) Calcium scoring using 64-slice MDCT, dual source CT and EBT: a comparative phantom study. Int J Cardiovasc Imaging 24:547–556
van Werkhoven JM, Schuijf JD, Jukema JW et al (2008) Anatomic correlates of a normal perfusion scan using 64-slice computed tomographic coronary angiography. Am J Cardiol 101:40–45
Bakx AL, van der Wall EE, Braun S, Emanuelsson H, Bruschke AV, Kobrin I (1995) Effects of the new calcium antagonist mibefradil (Ro 40-5967) on exercise duration in patients with chronic stable angina pectoris: a multicenter, placebocontrolled study. Ro 40-5967 International Study Group. Am Heart J 130:748–757
Schuijf JD, Bax JJ, van der Wall EE (2007) Anatomical and functional imaging techniques: basically similar or fundamentally different? Neth Heart J 15:43–44
Juwana YB, Wirianta J, Suryapranata H, de Boer MJ (2007) Left main coronary artery stenosis undetected by 64-slice computed tomography: a word of caution. Neth Heart J 15:255–256
van Dijkman PR, van der Wall EE, de Roos A et al (1991) Acute, subacute, and chronic myocardial infarction: quantitative analysis of gadolinium-enhanced MR images. Radiology 180:147–151
Pundziute G, Schuijf JD, Jukema JW et al (2007) Prognostic value of multislice computed tomography coronary angiography in patients with known or suspected coronary artery disease. J Am Coll Cardiol 49:62–70
Henneman MM, Schuijf JD, Pundziute G et al (2008) Noninvasive evaluation with multislice computed tomography in suspected acute coronary syndrome: plaque morphology on multislice computed tomography versus coronary calcium score. J Am Coll Cardiol 52:216–222
de Nooijer R, Verkleij CJ, von der Thüsen JH et al (2006) Lesional overexpression of matrix metalloproteinase-9 promotes intraplaque hemorrhage in advanced lesions but not at earlier stages of atherogenesis. Arterioscler Thromb Vasc Biol 26:340–346
Hoogendoorn LI, Pattynama PM, Buis B, van der Geest RJ, van der Wall EE, de Roos A (1995) Noninvasive evaluation of aortocoronary bypass grafts with magnetic resonance flow mapping. Am J Cardiol 75:845–848
van der Laarse A, Kerkhof PL, Vermeer F et al (1988) Relation between infarct size and left ventricular performance assessed in patients with first acute myocardial infarction randomized to intracoronary thrombolytic therapy or to conventional treatment. Am J Cardiol 61:1–7
van der Wall EE, den Hollander W, Heidendal GA, Westera G, Majid PA, Roos JP (1981) Dynamic myocardial scintigraphy with 123I-labeled free fatty acids in patients with myocardial infarction. Eur J Nucl Med 6:383–389
Vliegen HW, Doornbos J, de Roos A, Jukema JW, Bekedam MA, van der Wall EE (1997) Value of fast gradient echo magnetic resonance angiography as an adjunct to coronary arteriography in detecting and confirming the course of clinically significant coronary artery anomalies. Am J Cardiol 79:773–776
van der Hoeven BL, Pires NM, Warda HM et al (2005) Drug-eluting stents: results, promises and problems. Int J Cardiol 99:9–17
Ertaş G, van Beusekom HM, van der Giessen WJ (2009) Late stent thrombosis, endothelialisation and drug-eluting stents. Neth Heart J 17:177–180
Pluim BM, Lamb HJ, Kayser HW et al (1998) Functional and metabolic evaluation of the athlete’s heart by magnetic resonance imaging and dobutamine stress magnetic resonance spectroscopy. Circulation 97:666–672
Scholte AJ, Schuijf JD, Kharagjitsingh AV et al (2008) Different manifestations of coronary artery disease by stress SPECT myocardial perfusion imaging, coronary calcium scoring, and multislice CT coronary angiography in asymptomatic patients with type 2 diabetes mellitus. J Nucl Cardiol 15:503–509
Scholte AJ, Schuijf JD, Kharagjitsingh AV et al (2008) Prevalence of coronary artery disease and plaque morphology assessed by multi-slice computed tomography coronary angiography and calcium scoring in asymptomatic patients with type 2 diabetes. Heart 94:290–295
Torn M, Bollen WL, van der Meer FJ, van der Wall EE, Rosendaal FR (2005) Risks of oral anticoagulant therapy with increasing age. Arch Intern Med 165:1527–1532
Ypenburg C, Schalij MJ, Bleeker GB et al (2007) Impact of viability and scar tissue on response to cardiac resynchronization therapy in ischaemic heart failure patients. Eur Heart J 28:33–41
Ypenburg C, Roes SD, Bleeker GB et al (2007) Effect of total scar burden on contrast-enhanced magnetic resonance imaging on response to cardiac resynchronization therapy. Am J Cardiol 99:657–660
de Roos A, Matheijssen NA, Doornbos J et al (1990) Myocardial infarct size after reperfusion therapy: assessment with Gd-DTPA-enhanced MR imaging. Radiology 176:517–521
de Roos A, Matheijssen NA, Doornbos J, van Dijkman PR, van Rugge PR, van der Wall EE (1991) Myocardial infarct sizing and assessment of reperfusion by magnetic resonance imaging: a review. Int J Card Imaging 7:133–138
van Rugge FP, van der Wall EE, van Dijkman PR, Louwerenburg HW, de Roos A, Bruschke AV (1992) Usefulness of ultrafast magnetic resonance imaging in healed myocardial infarction. Am J Cardiol 70:1233–1237
Holman ER, van Jonbergen HP, van Dijkman PR, van der Laarse A, de Roos A, van der Wall EE (1993) Comparison of magnetic resonance imaging studies with enzymatic indexes of myocardial necrosis for quantification of myocardial infarct size. Am J Cardiol 71:1036–1040
Schuijf JD, Bax JJ, van der Wall EE (2005) Non-invasive visualization of the coronary arteries with multi-detector row computed tomography; influence of technical advances on clinical applicability. Int J Cardiovasc Imaging 21:343–345
Bleeker GB, Schalij MJ, Boersma E et al (2007) Relative merits of M-mode echocardiography and tissue Doppler imaging for prediction of response to cardiac resynchronization therapy in patients with heart failure secondary to ischemic or idiopathic dilated cardiomyopathy. Am J Cardiol 99:68–74
Ypenburg C, Sieders A, Bleeker GB et al (2007) Myocardial contractile reserve predicts improvement in left ventricular function after cardiac resynchronization therapy. Am Heart J 154:1160–1165
Ypenburg C, van der Wall EE, Schalij MJ, Bax JJ (2008) Imaging in cardiac resynchronisation therapy. Neth Heart J 16:S36–S40
Nemes A, Geleijnse ML, van Geuns RJ et al (2008) Dobutamine stress MRI versus threedimensional contrast echocardiography: it’s all black and white. Neth Heart J 16:217–218
van der Geest RJ, Niezen RA, van der Wall EE, de Roos A, Reiber JH (1998) Automated measurement of volume flow in the ascending aorta using MR velocity maps: evaluation of inter- and intraobserver variability in healthy volunteers. J Comput Assist Tomogr 22:904–911
Tops LF, Schalij MJ, Holman ER, van Erven L, van der Wall EE, Bax JJ (2006) Right ventricular pacing can induce ventricular dyssynchrony in patients with atrial fibrillation after atrioventricular node ablation. J Am Coll Cardiol 48:1642–1648
Bleeker GB, Holman ER, Steendijk P et al (2006) Cardiac resynchronization therapy in patients with a narrow QRS complex. J Am Coll Cardiol 48:2243–2250
Bleeker GB, Bax JJ, Fung JW et al (2006) Clinical versus echocardiographic parameters to assess response to cardiac resynchronization therapy. Am J Cardiol 97:260–263
van Rugge FP, Boreel JJ, van der Wall EE et al (1991) Cardiac first-pass and myocardial perfusion in normal subjects assessed by sub-second Gd-DTPA enhanced MR imaging. J Comput Assist Tomogr 15:959–965
van der Wall, Vliegen HW, de Roos A, Bruschke AV (1995) Magnetic resonance imaging in coronary artery disease. Circulation 92:2723–2739
Oemrawsingh PV, Mintz GS, Schalij MJ, Zwinderman AH, Jukema JW, van der Wall EE (2003) Intravascular ultrasound guidance improves angiographic and clinical outcome of stent implantation for long coronary artery stenoses: final results of a randomized comparison with angiographic guidance (TULIP Study). Circulation 107:62–67
Portegies MC, Schmitt R, Kraaij CJ et al (1991) Lack of negative inotropic effects of the new calcium antagonist Ro 40-5967 in patients with stable angina pectoris. J Cardiovasc Pharmacol 18:746–751
Tops LF, Bax JJ, Zeppenfeld K et al (2005) Fusion of multislice computed tomography imaging with three-dimensional electroanatomic mapping to guide radiofrequency catheter ablation procedures. Heart Rhythm 2:1076–1081
Gerber TC, Kuzo RS, Morin R (2005) Techniques and parameters for estimating radiation exposure and dose in cardiac computed tomography. Int J Cardiovasc Imaging 21:165–176
Hausleiter J, Meyer T, Hermann F et al (2009) Estimated radiation dose associated with cardiac CT angiography. JAMA 301:500–507
Blankstein R, Bolen MA, Pale R et al. (2010) Use of 100 kV versus 120 kV in Cardiac Dual source computed tomography: effect on radiation dose and image quality. Int J Cardiovasc Imaging. [Epub ahead of print]
Blankstein R, Shah A, Pale R et al (2009) Radiation dose and image quality of prospective triggering with dual-source cardiac computed tomography. Am J Cardiol 103:1168–1173
van der Wall EE (2009) CT angiography, underuse, overuse, or appropriate use? Neth Heart J 17:223
Leschka S, Kim CH, Baumueller S et al (2010) Scan length adjustment of CT coronary angiography using the calcium scoring scan: effect on radiation dose. AJR Am J Roentgenol 194:W272–W277
Labounty TM, Leipsic J, Min JK et al (2010) Effect of padding duration on radiation dose and image interpretation in prospectively ECG-triggered coronary CT angiography. AJR Am J Roentgenol 194:933–937
Rogalla P, Blobel J, Kandel S et al. (2010) Radiation dose optimisation in dynamic volume CT of the heart: tube current adaptation based on anterior-posterior chest diameter. Int J Cardiovasc Imaging 2010 Apr 27. [Epub ahead of print]
de Graaf FR, Schuijf JD, van Velzen JE et al (2010) Diagnostic accuracy of 320-row multidetector computed tomography coronary angiography to noninvasively assess in-stent restenosis. Invest Radiol 45:331–340
de Graaf FR, Schuijf JD, van Velzen JE et al (2010) Assessment of global left ventricular function and volumes with 320-row multidetector computed tomography: a comparison with 2D-echocardiography. J Nucl Cardiol 17:225–331
de Graaf FR, Schuijf JD, van Velzen JE et al (2010) Diagnostic accuracy of 320-row multidetector computed tomography coronary angiography in the non-invasive evaluation of significant coronary artery disease. Eur Heart J 31:1908–1915
Ayyad AE, Cole J, Syed A et al (2009) Temporal trends in utilization of cardiac computed tomography. J Cardiovasc Comput Tomogr 3:16–21
Miller JA, Raichlin E, Williamson EE et al (2010) Evaluation of coronary CTA Appropriateness Criteria in an academic medical center. J Am Coll Radiol 7:125–131
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van der Wall, E.E., Jukema, J.W., Schuijf, J.D. et al. 100 kV versus 120 kV: effective reduction in radiation dose?. Int J Cardiovasc Imaging 27, 587–591 (2011). https://doi.org/10.1007/s10554-010-9693-1
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DOI: https://doi.org/10.1007/s10554-010-9693-1