Cardiac computed tomography (CT), the most highly developed application of x-ray imaging, is currently experiencing more advancement per year than ever in its history— probably more than any other imaging modality in the history of x-ray–based medical imaging.
THE ROAD TO THE PRESENT
Wilhelm Conrad Roentgen was awarded the first Nobel Prize in Physics in 1901 for the first intentional generation and use of x-rays, in 1895. He was a firm academic traditionalist, and, intending to preserve his scientific integrity, he signed away all commercial rights to his invention. His name lives on as one of many units of (medical) radiation. His descriptions of the physics of his novel form of “rays” were so definitive that they still constitute a large proportion of the theory of x-ray radiation.
Angiography and Catheterization
The first cardiac catheterization performed may be the one done by Claude Bernard in 1844 on a horse.1,2 The first human cardiac catheterization was performed in 1929 by a surgery resident, Werner Forssmann, on himself. Using his right hand, Forssmann blindly passed a urethral catheter up the basilar vein in his left arm. He then walked down to the floor below and used, by himself, an x-ray fluoroscopy unit, which enabled him to determine that the catheter was not within the heart. He then advanced the catheter further until he confirmed that it was indeed within the right
ventricle, thereby affirming Law Number Six from Samuel Shem’s The House of God that “there is no body cavity that cannot be reached with a #14G needle and a good strong arm.” Forssmann then documented the position of the tip of the catheter using radiographs. He was rewarded for his feat by being fired from the training program, but he ultimately was awarded a Nobel Prize in Medicine, nearly three decades later, in 1956.3,4
The first human angiogram probably was performed on the excised hand of a cadaver, with injection of an empiric contrast-enhancing formula of heavy metals and petroleum jelly into the hand vessels.
The first coronary angiogram was inadvertent. In 1958, Mason Sones, the great pioneer of coronary angiography, was performing a cardiac catheterization on a 26-year-old man with rheumatic aortic and mitral valve disease. The aortic root catheter inadvertently fell into the right coronary ostium, resulting in a powered injection of 50 mL of contrast dye, intended for the aortic root, into the right coronary artery. The patient was asystolic for 5 seconds, but recovered with bradycardia. Purely by chance, angiography was shown to be feasible and tolerable and to yield clinically useful images (Fig. 1-1).5
Sones, Seldinger, Judkins, and others pioneered many developments to enable peripheral arterial access, selective angiography, adequate image intensifiers, and development of rotating gantries that allowed first left-right rotation and later craniocaudal rotation.
In 2012, approximately 600,000 angiograms were performed in Germany, approximately 150,000 in Canada, and nearly 2 million in the United States, with an overall complication rate of 3.6% and a mortality rate of 0.1%. The average annual cost of coronary angiography in the United States exceeds $9 billion.6 The yearly worldwide number of coronary angiograms performed is unknown. Angiography remains the current standard for imaging of coronary artery stenosis, delivery of percutaneous coronary intervention, and determination of surgical bypass amenability. Cardiac CT is vying to offer accurate noninvasive angiography; it is a bold prerogative.