Cardiology is a medicine sector that covers the clinical study, treatment and imaging of the heart actions and diseases.

See also Ischemia, Calcium Score, Cardiac Phase, Diastole, Adventitia, Defibrillator, ECG Trigger, Arrhythmia Rejection.

(CT or CAT scan) Computed tomography is a diagnostic imaging technique, previously also known as computerized axial tomography (CAT), computer-assisted tomography (CAT), computerized tomographic imaging, and reconstructive tomography (RT).
A CT scan is based on the measurement of the amount of energy that a tissue absorbs as a beam of radiation passes through it from a source to a detector. As the patient table moves through the CT scanner, the CT tube rotates within the circular opening and the set of x-ray detectors rotate in synchrony. The narrow, fan-shaped x-ray beam has widths ranging from 1 to 20 mm. The large number of accurate measurements with precisely controlled geometry is transformed by mathematical procedures to image data. Corresponding to CT slices of a certain thickness, a series of two-dimensional cross-sectional images is created.
A CT is acquired in the axial plane, while coronal and sagittal images can be rendered by computer reconstruction. Although a conventional radiography provides higher resolution for bone x-rays, CT can generate much more detailed images of the soft tissues. Contrast agents are often used for enhanced delineation of anatomy and allow additional 3D reconstructions of arteries and veins.
CT scans use a relatively high amount of ionizing radiation compared to conventional x-ray imaging procedures. Due to widespread use of CT imaging in medicine, the exposure to radiation from CT scans is an important issue. To put this into perspective, the FDA considers the risk of absorbed x-rays from CT scans to be very small. Even so, the FDA recommends avoiding unnecessary exposure to radiation during diagnostic imaging procedures, especially for children.
CT is also used in other than medical fields, such as nondestructive testing of materials including rock, bone, ceramic, metal and soft tissue.

See also Contrast Enhanced Computed Tomography.

A coronary angiogram (or cardiac catheterization) is the radiographic visualization of the coronary arteries after the introduction of a contrast agent. A coronary angiography can be performed for both diagnostic and interventional (treatment) purposes.
A catheter, inserted into a major blood vessel has to be maneuvered up to the coronary arteries to inject a blood compatible iodinated contrast material (dye). The x-ray visible catheter allows injecting a small amount of contrast agent selectively in the coronary arteries or the heart chambers. Continuous images are recorded (movies or cineangiogram) in multiple views from different angles are in order to ascertain the precise location and severity of coronary artery blockages. Digitized images are also saved on computer and replayed onto a video screen as needed.
A coronary angiogram is more invasive and requires more patient recovery time than coronary CT angiography. In the past, the gold standard for detecting atherosclerotic plaque was a coronary angiography and intravascular ultrasound. Today, the American Heart Association considers CT scanning to be one of the most effective, non-invasive methods for the detection of calcification in the coronary arteries.

See also Interventional Radiology.

(CCTA) Coronary computed tomography angiography is a diagnostic imaging procedure to visualize the coronary arteries. CCTA is a non-invasive angiogram that allows the assessment of narrowed and clogged arteries that can cause heart attack and stroke.
Coronary CTA is a non-invasive alternative to traditional angiography that offers detailed images of heart function, resulting in faster, more accurate diagnosis. It helps stratify cardiac risk in patients with low to intermediate likelihood of coronary artery disease. For some patients with chest pain, coronary CTA can rule out the need for cardiac catheterization.
Coronary imaging requires a very fast CT scan, because the coronary arteries and other cardiac structures move rapidly during the cardiac cycle. The current 'state of the art' 64 slice multi-detector row CT systems rotate around the patient in less than 500 ms. The data must be acquired monitored by an electrocardiogram, which allows the computer to reconstruct retrospectively slices at different small segments of the cardiac cycle. This cardiac synchronization reduces motion artifacts in the coronary arteries and provides movies of the beating heart and valve motion.
See also Coronary Angiogram, Calcium Score, Cardiac Phase, Cine Mode and Defibrillator.

The digital mammography is an electronic imaging procedure of the breast. The number of breast imaging facilities equipped with digital mammography (also called computed radiography mammogram (CRM), CR mammogram) is growing due to a number of advantages.
Digital images can be stored directly in a picture archiving and communication system (PACS) and allows the printing, enhancement, magnification, or brightness and contrast manipulation for further evaluation. The sensitivity of digital mammography compared to film mammography is better in women with dense breasts, a population at higher risk for breast cancer, due to these post processing possibilities.
'The American College of Radiology's (ACR) Imaging Network found that digital mammography detected up to 28 percent more cancers than film-screen mammography in women age 50 and younger, premenopausal and perimenopausal women, and women with dense breasts, as reported in October 2005 in the New England Journal of Medicine.'

Advantages of digital mammography:
Existing mammography equipment can be converted to 'digital' operation, which allows cost savings compared to integrated digital mammography systems.

See also Breast MRI.