Real-time Thermographic Vein Visualization and Extravasation Monitoring During Radiopharmaceutical Injection for Bone Scintigraphy

Prevention of extravasation is important in nuclear medicine, given the growth of radioligand therapy and molecular-targeted radiopharmaceutical therapy. We used very-high-sensitivity infrared thermography to observe the puncture site in real time during radiopharmaceutical injection for bone scintigraphy and evaluated superficial vein visualization and the potential for extravasation monitoring.

A total of 23 patients undergoing bone scintigraphy (19 men, four women; mean age of 74.2±7.7 years) were studied. Using very-high-sensitivity infrared thermography (Optris PI 450; thermal resolution 0.04°C), skin-temperature changes around the puncture site were monitored continuously during a saline flush and radiopharmaceutical injection. The minimum skin temperature within 5 mm of the puncture site was compared before and during injection, and its relationship with body mass index and injection site was examined.

No extravasation occurred, and bone scintigraphy was completed normally in all 23 patients. Superficial veins were clearly visualized in 19 out of 23 patients (83%): visualization succeeded in all forearm injections (4/4, 100%) but was poor in 4 out of 19 antecubital-fossa injections (21%). Among the 19 patients with venous visualization ≥5 mm, median minimum skin temperature within 5 mm of the puncture site decreased from 33.62°C before injection to 28.79°C during injection, with no temperature change suggestive of subcutaneous extravasation.

Real-time skin-temperature monitoring with very-high-sensitivity infrared thermography may aid superficial vein visualization and early detection of extravasation. Because visualization is affected by the site of injection, careful site selection and observation are warranted.