Dr. Josef Machac received his undergraduate degree of Bachelor in Science, Magna Cum Laude, in 1975 from Brown University, where he received an M.D. in 1978. He did his internship and residency in internal medicine at The Mount Sinai Hospital between 1978 and 1981, and between 1981 and 1983, a residency in nuclear medicine. This was followed be a fellowship in nuclear cardiology from 1983 to 1984, and a fellowship in clinical cardiology from 1985 to 1986. Dr. Machac is board certified in internal medicine, nuclear medicine, and cardiology.

Dr. Machac has been an attending in nuclear cardiology from 1984 to the present time. He became Director of Nuclear Cardiology in 1988 and held that position until 1996. In 1993, he became Director of Nuclear Medicine. In 1985, he because Assistant Professor in Medicine, and in 1993, Associate Professor in Radiology. In 2003, he became Professor in Radiology.

Throughout his career in nuclear cardiology, Dr. Machac has been responsible for many innovations in diagnostic cardiology at Mount Sinai. This includes the introduction of SPECT (single photon emission tomography) cardiac imaging, pharmacological stress imaging, imaging with Tc-99m labeled perfusion agents, myocardial viability imaging, and more recently, cardiac PET imaging.

Dr. Machac has delivered many invited lectures at Mount Sinai, at regional, national, and international meetings and symposia, has organized numerous educational symposia at regional and national meetings, and recently was president of the Cardiovascular Council of the Society of Nuclear Medicine. He has authored or coauthored many papers and numerous chapters.

At the present time, Dr. Machac is director of the Clinical PET Center and Nuclear Medicine at Mount Sinai, which offer high quality state-of-the art cardiac imaging for diagnosis and evaluation of coronary artery disease, and myocardial viability in patients with poor cardiac function. He also sees patients in the cardiac clinic and Faculty Practice Associates' suite.