A novel cardiac hybrid imaging using real time transthoracic echocardiography and contrast enhanced multi detector computed tomography: Chain of the technological and scholarly developments.
Medical practice in patients with adult congenital heart disease (ACHD) does not begin without understanding the complex cardiac anatomy and physiology [1,2] Transthoracic echocardiography (TTE) is the most common tool to assess cardiac anatomy and physiology, and is a flexible imaging test performed with sonographers' discretion. For example, cross sections are displayed according to the directions, angles, and force controlled by each sonographer. Therefore, sonographers need to fully know the cardiac anatomy, physiology, and pathology to appropriately perform echocardiography to examine ACHD. The diagnostic process will stop if they just depict the cross sections without solid understanding of cardiac anatomy and physiology. In addition, the poor image quality in echocardiography sometimes leaves sonographers from accurate understanding of a crosssection or the structures, especially in ACHD patients with complex malformations. On the other hand, contrast enhanced multidetector computed tomography (MDCT) has high spatial resolution, and allows us to comprehensively analyze cardiac anatomy. However, MDCT cannot provide real time flexible rendering of cross section, assessment of structures' motion, and measurement of blood flow velocity [3] It can be said echocardiography and MDCT have reciprocal strengths and limitations. In this issue of the Journal of Cardiology, Oe et al. describe potential benefit of simultaneous side by side two screen display of contrast MDCT and real time echocardiogram (STDME) for assessment of ACHD [4] In brief, it is the real time echocardiographic system guided by contrast MDCT images previously recorded in the same patient, developed by Canon Medical Systems Corporation, Otawara, Japan. In this proto type system, a real time echocardiographic image is displayed on the right side of the screen, and a contrast MDCT image corresponding to the echocardiographic image is displayed on the left side of the screen. Then, the cross section of contrast MDCT image automatically changes according to the direction and angle of an echocardiographic cross section changed by sonographer's discretion. This
Journal of cardiology