X-ray, a type of high-energy electromagnetic radiation, is often used for cancer diagnosis, staging and treatment. An X-ray uses electromagnetic radiation to make images. The image is recorded on a film, called a radiograph. The images produced appear light or dark, depending on the absorption rates of the different tissues. For example, dense materials, such as bone, show up as white on a film, while fat and muscle appear as varying shades of gray.

An X-ray exam is fast and painless. In low doses, X-rays can be used to construct images of structures inside the body to detect and stage a tumor. In higher doses X-rays can be used in radiation therapy to help destroy cancerous cells in the body.

The advantages of capturing and storing X-Ray Images digitally rather than on film are overwhelming. Digital x-ray imaging has many advantages:

The images can be stored in a very compact manner without risk of loss or deterioration in quality.

The images can be easily enlarged and "suspicious" areas of an image can be more easily studied. The images can be easily retrieved, and can be transmitted electronically to an expert or to another medical practitioner in the same hospital or to an insurance company for reimbursement purposes.

An electrocardiogram (ECG or EKG, abbreviated from the German Electrocardiogram) is a graphic produced by an electrocardiograph, which records the electrical activity of the heart over time. Its name is made of different parts: electro, because it is related to electrical activity, cardio, Greek for heart, gram, a Greek root meaning "to write". In the US, the abbreviation "EKG" is often preferred over "ECG", while "ECG" is used universally in the UK and many other countries.

Electrical impulses in the heart originate in the sinoatrialnode and travel through the heart muscle where they cause contraction. The electrical waves can be measured at selectively placed electrodes (electrical contacts) on the skin. Electrodes on different sides of the heart measure the activity of different parts of the heart muscle. An ECG displays the voltage between pairs of these electrodes, and the muscle activity that they measure, from different directions, also understood as vectors. This display indicates the overall rhythm of the heart, and weaknesses in different parts of the heart muscle. It is the particularly abnormal rhythms caused by damage to the conductive tissue that carries electrical signals, or abnormal rhythms caused by levels of dissolved salts (electrolytes), such as potassium,

In myocardial infarction (MI), the ECG can identify damaged heart muscle. But it can only identify damage to muscle in certain areas, so it can't rule

The ECG cannot reliably measure the pumping ability of the heart; for which ultrasound-based (echocardiography) or nuclear medicine tests are used.