CT Evaluation of the Myocardial Blood Supply: Dual-Source Dual-Energy CT
With dual-source CT in dual-energy mode, two X-ray tubes are operated independently at different voltages, acquiring two data sets showing different attenuation levels. An “iodine distribution map” is used for the assessment of myocardial blood pool status by analyzing iodine distribution within the myocardium based on the specific absorption characteristics of iodine for high and low X-ray energy spectra. Contrast-enhanced dual-energy computed tomography (DECT) perfusion with the patient at rest enables the evaluation of changes in the status of the myocardial blood supply. Rest DECT iodine distribution maps make hypoperfused myocardium more conspicuous and assist in the identification of areas exhibiting reversible myocardial ischemia. Rest DECT has thus expanded the clinical application of multidetector CT, as a “one stop shop” imaging modality to identify both coronary artery disease and myocardial blood pool deficits in a single examination. Stress DECT perfusion has the potential to become a robust clinical tool for the detection of myocardial ischemia. The combined approach of coronary CT angiography and stress DECT perfusion allows identification of hemodynamically significant coronary lesions in high-risk patients with a large calcified plaque burden or stents. This chapter provides a protocol setup and the characteristic features of dual-source DECT, and derives its benefits and limitations for DECT myocardial perfusion.
KeywordsMyocardial Perfusion Imaging Perfusion Defect Coronary Compute Tomography Angiography Fractional Flow Reserve Conventional Coronary Angiography
The author sincerely thanks Dr. Meong Gun Song, Department of Thoracic Surgery at Konkuk University Medical Center, Dr. Tae-Hwan Lim, Department of Radiology at Asan Medical Center, Dr. Bernhard Krauss, Jungmin Hwang, and the CT technologists and the Radiology Department nursing staff at Konkuk University Medical Center.
- Meijboom WB, van Mieghem CA, van Pelt N et al (2008) Comprehensive assessment of coronary artery stenoses. Computed tomography coronary angiography versus conventional coronary angiography and correlation with fractional flow reserve in patients with stable angina. J Am Coll Cardiol 52:636–643PubMedCrossRefGoogle Scholar
- Rodriguez-Granillo GA, Rosales MA, Degrossi E, Rodriguez AE (2010) Signal density of left ventricular myocardial segments and impact of beam hardening artifact: implications for myocardial perfusion assessment by multidetector CT coronary angiography. Int J Cardiovasc Imaging 26:345–354PubMedCrossRefGoogle Scholar
- Wang R, Yu W, Wang Y et al (2011) Incremental value of dual-energy CT to coronary CT angiography for the detection of significant coronary stenosis: comparison with quantitative coronary angiography and single photon emission computed tomography. Int J Cardiovasc Imaging 27:647–656PubMedCrossRefGoogle Scholar