RT Journal Article SR Electronic T1 Machine Learning in Nuclear Medicine: Part 1—Introduction JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 451 OP 458 DO 10.2967/jnumed.118.223495 VO 60 IS 4 A1 Uribe, Carlos F. A1 Mathotaarachchi, Sulantha A1 Gaudet, Vincent A1 Smith, Kenneth C. A1 Rosa-Neto, Pedro A1 Bénard, François A1 Black, Sandra E. A1 Zukotynski, Katherine YR 2019 UL http://jnm.snmjournals.org/content/60/4/451.abstract AB This article, the first in a 2-part series, provides an introduction to machine learning (ML) in a nuclear medicine context. This part addresses the history of ML and describes common algorithms, with illustrations of when they can be helpful in nuclear medicine. Part 2 focuses on current contributions of ML to our field, addresses future expectations and limitations, and provides a critical appraisal of what ML can and cannot do.