ABSTRACT
Lymphoscintigraphy is an imaging technique to diagnose and characterize the severity of edema in the upper and lower extremities. In lymphoscintigraphy, a scoring system can increase the ability to differentiate between diagnoses, but the use of any scoring system requires sufficient reliability. Our aim was to determine the inter- and intraobserver reliability of a proposed scoring system for visual interpretation of lymphoscintigrams of the lower extremities. Methods: The lymphoscintigrams of 81 persons were randomly selected from our database for retrospective evaluation. Two nuclear medicine physicians scored these scans according to the 8 criteria of a proposed scoring system for visual interpretation of lymphoscintigrams of the lower extremities. Each scan was scored twice 3 mo apart. The total score was the sum of the scores for all criteria, with a potential range of 0 (normal lymphatic drainage) to 58 (severe lymphatic impairment). The intra- and interobserver reliability of the scoring system was determined using the Wilcoxon signed-rank test, percentage of agreement, weighted κ, and intraclass correlation coefficient with 95% confidence interval. In addition, for 7 categories, differences in total scores between and within observers were determined. Results: We found some insignificant differences between observers. Percentage agreement was high or very high, at 82.7%-99.4% between observers and 84.6%-99.4% within observers. For each criterion of the scoring system, the κ-correlations showed moderate to very good inter- or intraobserver reliability. The total scores for all criteria had good inter- and intraobserver reliability. Regarding the interobserver comparison, 66% and 64% of the difference in total scores were within ±1 scale point (-1, +1), and regarding the intraobserver comparison, 68% and 72% of the difference in total scores were within ±1 scale point. Conclusion: The proposed scoring system is a reliable tool for visual qualitative evaluation of lymph transport problems in patients with lymphedema of the lower extremities.
