This study will be performed at clinical sites that have administered CardioGen-82® to patients from January to July 2011. The patients enrolled(i.e., "target date patients") will be all those who were dosed at the end of use of the CardioGen-82® generators on the last day of generator use from the generator that was used immediately prior to the recalled generator (i.e., "target date generators"). These are not patients who received drug eluted from the recalled generator. Of these patients, it is planned that 100 patients will be entered in this trial.

This clinical study protocol will use a three tier approach consisting of the following examinations:

1. Patient examination with Survey Meter: Patients who agree to be tested at the clinical sites will be first evaluated using a survey meter. In those patients in whom radiation count is ≥ 2 times above background count using a standard survey meter, the presence of Sr-82 and/or Sr-85 will be assessed through a quantitative reading from a calibrated portable isotope identifier.
2. Patient examination with Portable Isotope Identifier: This examination will be done by use of a portable isotope identifier, which will be supplied by the Sponsor to the study sites. An assessor, independent to the study site, will perform the examination. In those patients whose radiation count is ≥ 2 times above background count using a standard survey meter, the presence of Sr-82 and/or Sr-85 will be assessed through a quantitative reading from a calibrated portable isotope identifier. The reading will be forwarded along with the date of the reading, the date of the patient's CardioGen-82® scan, and the total dose of CardioGen-82® administered to the patient, to an independent medical expert, independent to the study site, who will back-calculate an estimated dose of Sr-82 and/or Sr-85 from these data.
3. Patient examination at Oak Ridge National Laboratory: Any patient whose estimated dose of Sr-82 exceeds the specified limit of 0.02 microcuries per mCi Rb-82 administered, and/or whose estimated dose of Sr-85 exceeds the specified limit of 0.2 microcuries per mCi Rb-82 administered, will be asked to travel to Oak Ridge National Laboratory in Tennessee, for accurate whole body scanning. Scan data from Oak Ridge National Laboratories will be analyzed by one or more independent medical experts to accurately back-calculate exposure to Sr-82 and/or Sr-85, and to estimate health hazard for the patient.

Inclusion Criteria:

Enroll a patient in this study if the patient meets the following inclusion criteria:

• Male or female
• Gave informed consent to participate in the study
• Received CardioGen-82® that had been eluted from the generator on the last usage day the generator was used prior to the generator that was recalled.

Exclusion Criteria:

• Exclude a patient from this study if the patient has previously been enrolled in and completed this study.

The study population would come from sites who administered CardioGen-82® during the time period of January 2011 to July 2011. The patient population is expected to be patients (i.e., target date patients) who were administered Caridogen-82 that had been eluted from the generator on the last usage day the generator was used prior to the generator that was recalled (i.e., target date generator). It is planned to enroll 100 patients in this study. Each site that agrees to participate will be encouraged to enroll at least 1 patient. Depending on the number of sites agreeing to participate, the enrollment time frame may be extended to include the last 3 to 5 days of generator usage.