Objective <p>This study aimed to evaluate the accuracy and validity of patient explanations about nuclear medicine examinations generated in Japanese using ChatGPT- 3.5 and ChatGPT- 4.</p> Methods <p>ChatGPT was used to generate Japanese language explanations for seven single-photon emission computed tomography examinations (bone scintigraphy, brain perfusion imaging, myocardial perfusion imaging, dopamine transporter scintigraphy [DAT scintigraphy], sentinel lymph node scintigraphy, lung perfusion scintigraphy, and renal function scintigraphy) and ¹⁸F-fluorodeoxyglucose positron emission tomography. Nineteen board-certified nuclear medicine technologists evaluated the accuracy and validity of the responses using a 5-point scale.</p> Results <p>ChatGPT- 4 demonstrated significantly higher accuracy and validity than ChatGPT- 3.5, with 77.9% of responses rated as above average or excellent for accuracy, in comparison to 36.3% for ChatGPT- 3.5. For validity, 73.1% of ChatGPT- 4’s responses were rated as above average or excellent, in comparison to 19.6% for ChatGPT- 3.5. ChatGPT- 4 outperformed ChatGPT- 3.5 in all examinations, with notable improvements in bone scintigraphy, lung perfusion scintigraphy, and DAT scintigraphy.</p> Conclusion <p>These findings suggest that ChatGPT- 4 can be a valuable tool for providing patient explanations of nuclear medicine examinations. However, its application still requires expert supervision, and further research is needed to address potential risks and security concerns.</p>