What is the meaning of the suffix "-gram" in medical terminology?

The suffix "-gram" in medical terminology signifies a record or a written representation of data. This term is commonly used to denote different types of recorded information that have been gathered through various diagnostic processes. For instance, an electrocardiogram (ECG) is a written record of the electrical activity of the heart, while a mammogram refers to a recorded image of breast tissue obtained during mammography.

In contrast, the meanings associated with the other options do not accurately represent the essence of the suffix "-gram." The implication of a type of disease is more appropriately captured by other terms that refer to specific medical conditions or illnesses. The act of imaging is better described by terms like "imaging" or "graphy," which focus on the process of generating images rather than the resulting record. Lastly, an instrument for measurement is typically indicated by terms that end in "-meter," which relates to tools or devices used for measuring physical quantities rather than the recording of data itself.