PT - JOURNAL ARTICLE AU - Robert W. Foley AU - Stewart L. Redman AU - Isabel J. Laurence AU - Richard N. Graham AU - David Little TI - Interobserver Agreement in the Diagnosis of Parkinson Disease with Cardiac <sup>123</sup>I-Metaiodobenzylguanidine Scintigraphy AID - 10.2967/jnmt.120.258632 DP - 2021 Sep 01 TA - Journal of Nuclear Medicine Technology PG - 262--264 VI - 49 IP - 3 4099 - http://tech.snmjournals.org/content/49/3/262.short 4100 - http://tech.snmjournals.org/content/49/3/262.full SO - J. Nucl. Med. Technol.2021 Sep 01; 49 AB - The aim of this study was to analyze the interobserver agreement of visual and quantitative assessment of cardiac 123I-metaiodobenzylguanidine scintigraphy. Methods: Planar images were acquired using a low-energy collimator. The heart-to-mediastinum (HM) ratio was adjusted for the use of a low-energy collimator, using a published formula. Interpretation was undertaken both visually and after the addition of adjusted HM ratios. Image findings were classified as normal, abnormal, or borderline. Results: The cohort consisted of 10 patients. On visual interpretation only, there was strong agreement on the interpretation of the scan (κ = 0.82, P &lt; 0.01). Adjusted HM ratios led to a significant increase in mean ratios (1.79 vs. 1.36, P = 0.02) and, when utilized in reporting, resulted in perfect agreement (κ = 1.0, P &lt; 0.01). Conclusion: The use of quantified HM ratios adjusted for low-energy collimator use improves on visual assessment alone and allowed for excellent interobserver agreement.