Optimal imaging positions for 3-phase bone scanning of patients with bony pathology of the feet.

UNLABELLED: The aim of the study was to optimize imaging positions of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) 3-phase bone scanning for the accurate localization of foot pathology in patients with trauma and diabetes-related complications. METHODS: (99m)Tc-MDP 3-phase bone scanning was performed for 26 controls and 27 patients with foot pathology. Flow was acquired in 1 of the following projections: anterior-posterior, medial-lateral, or plantar. Blood-pool and delayed images were acquired in a set of 5 projections (anterior, posterior, medial, lateral, and plantar). Images from the control group were checked for the views that best visualized individual bones or regions of the foot. These views were cross-correlated with images from the patient group to see whether they localized the exact site of the foot lesion. RESULTS: In the controls, the plantar view was the best view for visualization of the forefoot region. The mid foot was best assessed on the anterior view. Medial-lateral views were best suited for imaging the hind foot, and the posterior view was the best for the ankle joint. In the subjects with foot pathology, lesions were accurately assigned to the affected bone using the imaging criteria derived from the controls. In a few cases, however, additional views were needed because of overlap or shine-through of activity, particularly in mid-foot lesions. CONCLUSION: Optimal imaging positioning of the foot by bone scanning can be achieved using 5 views, which can yield accurate localization of a particular structure or bone, thereby improving the diagnostic accuracy of the procedure.

Post-test probability for pulmonary embolism after ventilation-perfusion scan assessed by nuclear medicine physicians.

OBJECTIVE: The objective of this prospective study was to compare assessments of pre- and post-ventilation-perfusion (V/Q) scan probabilities for pulmonary embolism (PE) by the nuclear medicine physician and the referring physician. MATERIALS AND METHODS: Seventy-nine patients (41 females, 38 males, mean age 49 years) referred for V/Q scans over a period of 6 months and suspected of PE were included in the study. The pre-test likelihood was determined independently by a consultant nuclear physician and a referring physician prior to the V/Q scan. The scan was performed according to a standard protocol using 8 view technetium-99m diethylenetriamine pentaacetic acid aerosol ventilation study followed by a technetium-99m macroaggregated albumin perfusion study. The scan was interpreted according to prospective investigation of pulmonary embolism diagnosis criteria. The post-scan probability was calculated. The probability of PE was quoted as low, intermediate and high. Agreement or disagreement in assessing the pre- and post-scan probability was classified according to the degree of difference (no difference: 0; minor difference: 1, and major difference: 2 grades). RESULTS: The agreement between the nuclear medicine and referring physicians on clinical probability of PE was moderate (63%) before the scan and good (90%) after the scan. The disagreement in assessing the clinical probability between the referring physician and the nuclear medicine physician was predominantly minor. Only 5 and 1% of the disagreement was major in pre-scan and post-scan probabilities, respectively. CONCLUSION: The data show that nuclear medicine physicians can use the assessment of pre-scan clinical likelihood to determine the post-scan probability of PE.