Potential diagnostic value of regional myocardial adrenergic imaging using I-MIBG SPECT to identify patients with Lewy body diseases.

Purpose: The aim of this study was to determine the potential diagnostic value of regional myocardial adrenergic I-metaiodobenzylguanidine (MIBG) single photon emission computed tomography (SPECT) imaging to identify patients with Lewy body diseases (LBD+). Methods: Sixty-four consecutive patients who underwent cardiac I-MIBG SPECT to differentiate LBD+, including Parkinson's disease (PD) and dementia with Lewy bodies (DLB), from patients without LBD (LBD−) were retrospectively reviewed. A neurologist expert in memory disorders determined the final clinical diagnosis by using international clinical diagnostic criteria. Planar [heart to mediastinum ratio (HMR)] and I-MIBG SPECT[(innervation defect score (IDS)] using the 17-segment left ventricular model (five-point scale) were obtained 4 h after the injection of I-MIBG on a low-energy high-resolution (LEHR) collimator. Receiver-operating characteristic (ROC) analysis was performed to determine the optimal HMR and IDS cut-off values to discriminate LBD+ from LBD−. Results: Of the 64 patients, 45 (70 %) were diagnosed LBD+ (DLB, n = 27; PD, n = 18) and 19 were diagnosed LBD− (5 other dementias, 14 other parkinsonisms). The HMR and IDS of LBD+ were significantly different from those of LBD− (1.30 ± 0.21 vs 1.65 ± 0.26, p < 0.001; 39 ± 28 vs 8 ± 16, p = 0.001). The optimal HMR and IDS cut-off values to discriminate LBD+ ( n = 45) from LBD− ( n = 19) were 1.47 and 6/68, providing a sensitivity and specificity of 82.2 and 84.2 % and 86.7 and 73.7 %, respectively. Conclusion: Regional myocardial adrenergic I-MIBG imaging SPECT has a potential diagnostic value to identify LBD+. [ABSTRACT FROM AUTHOR]