Early bone scan imaging protocol: a pragmatic approach to maintain patients throughput in a busy Nuclear Medicine Section

ABSTRACT

Radionuclide bone scan are acquired 3-4 hours after Technetium-99m Methylene Diphosphonate [[99m] Tc MDP] injection to ensures a better contrast between bone and soft tissue. However, in a busy department with limited gamma cameras this imaging protocol is the limiting factor for reduced patient throughput. Compare the image quality of early [1.5 hr] and delayed [3 hr] acquired bone scans in same patients for image quality and lesion detection efficiency. This prospective study was conducted at Section of Nuclear Medicine, Department of Radiology, Aga Khan University Hospital, Karachi from 1st August 2011 till 15th September 2011. We recruited 12 patients [age range 18-75 years] with a male female ratio of 48, who were pain free, cooperative and mobile. [99m]Tc MDP was injected intravenously. Patients were asked to have at least 250 cc of water after every 15 minutes] and void urine frequently to minimize bladder dose. At 1.5 hour and 3 hour post-injection, whole body imaging were acquired under a double head, gamma camera [ECAM, Siemens, Germany] with same acquisition parameters for both images. These images were read by an experienced nuclear physician who evaluated the scans for over all image quality [subjective] and lesion detection efficiency [estimation of lesion appreciable on a scan]. The image quality of early [1.5 hr] and delayed scans were labeled as acceptable [fair bone to soft tissue contrast] and good [good bone to soft tissue contrast] respectively by the reader. Twenty three [23] lesions were identified on early scan and all of these lesions were appreciable on delayed studies as well and no discordance was identified. In a busy nuclear medicine section, to maintain patients' throughput, imaging at 1.5 hour may be used safely in those patients who are cooperative and mobile