biostudies-literatureNakajima KKanazawa UniversityJapan Society for the Promotion of Science814-824https://www.ebi.ac.uk/biostudies/studies/S-EPMC11401792biostudies-literatureUnknown38(10)<h4>Objective</h4>We aimed to establish a practical diagnostic index for Lewy body diseases (LBD), such as Parkinson's disease and dementia, with Lewy bodies in outpatient settings and criteria for exempting patients from late imaging.<h4>Methods</h4>We acquired early and late ¹²³I-metaiodobenzylguanidine (MIBG) images from 108 consecutive patients with suspected LBD and standardized heart-to-mediastinum (H/M) ratios for collimator conditions. Exclusions included young-onset Parkinson's disease (age < 50 years) and genetic transthyretin-type amyloidosis. We developed logistic models incorporating H/M ratios with or without age (n = 92). The sympathetic MIBG index for LBD (SMILe index), categorized LBD likelihood from 0 (lowest) to 1 (highest). Diagnostic accuracy was assessed asAnnals of nuclear medicineSympathetic ¹²³I-metaiodobenzylguanidine index for Lewy body disease: probability-based diagnosis and identifying patients exempt from late imaging.PMC1140179223K07203Nakajima KKinuya SWakabayashi HOno KMatsumura TKomatsu JfalseSympathetic ¹²³I-metaiodobenzylguanidine index for Lewy body disease: probability-based diagnosis and identifying patients exempt from late imaging.<h4>Objective</h4>We aimed to establish a practical diagnostic index for Lewy body diseases (LBD), such as Parkinson's disease and dementia, with Lewy bodies in outpatient settings and criteria for exempting patients from late imaging.<h4>Methods</h4>We acquired early and late ¹²³I-metaiodobenzylguanidine (MIBG) images from 108 consecutive patients with suspected LBD and standardized heart-to-mediastinum (H/M) ratios for collimator conditions. Exclusions included young-onset Parkinson's disease (age < 50 years) and genetic transthyretin-type amyloidosis. We developed logistic models incorporating H/M ratios with or without age (n = 92). The sympathetic MIBG index for LBD (SMILe index), categorized LBD likelihood from 0 (lowest) to 1 (highest). Diagnostic accuracy was assessed as2024-01-01T00:00:00Z2024 Oct2025-04-18T13:07:01.988Z2025-04-06T22:40:00.72ZS-EPMC114017923886980910.1007/s12149-024-01950-4