Thallium Stress Tests and Bank Vaults

To the Editor: A 65-year-old man with atypical chest pain underwent a thallium stress test. The test was negative, and the patient was discharged. The following day he went to examine the contents of his safe-deposit box, and as he entered the bank vault, the alarm sounded. The bank had installed a radiation detector, a device now commonly used as a safety measure since the possibility that clients may leave radioactive material in their safe-deposit boxes has become an important concern. Thallium-201 is a radioactive isotope with a half-life of 73 hours that emits both x-rays and gamma rays. The . . . No extract is available for articles shorter than 400 words.