[Cardiac sympathetic innervation imaging with myocardial MIBG scintigraphy]. / Studio dell'innervazione cardiaca mediante scintigrafia miocardica con MIBG.

Metaiodobenzylguanidine (MIBG) was developed initially as a tracer for oncological imaging; when labeled with 123 I or 131 I, it may detect APUDomas, such as pheochromocytomas and paragangliomas. In the last years, MIBG has found an important role also in neurology and cardiology, as cardiac innervation tracer. Actually, MIBG cardiac imaging is a universally accepted method to estimate cardiac sympathetic innervations. This review covers the role of MIBG cardiac imaging in Parkinson disease and parkinsonisms, from the pathophysiological premises for cardiac denervation to new emerging data.

[Whole Body Magnetic Resonance and CT/PET in patients affected by multiple myeloma during staging before treatment]. / TC/PET e WBMRI in pazienti affetti da mieloma multiplo in stadiazione e prima di trattamento.

The diagnostic imaging plays a pivotal role in the staging of multiple myeloma (MM). Traditional imaging techniques allow a precise disease extension before treatment, but some drawbacks have been demonstrated after treatment. WBMRI and CT/PET represent alterative procedures during staging, but few comparative data are available to date. Aim of our study was to estimate the diagnostic accuracy of WB-MRI and CT/PET in 28 consecutive patients affected by MM before therapy. CT/PET was positive in 22/28 patients, whereas WB-MRI correctly identified 100% of patients. In this setting of patients WB MRI have demonstrated to be superior respect to CT/PET in term of diagnostic accuracy, especially when a diffuse disease is detected with a bone marrow aspiration with more than 40% of plasma cells. WBMRI shows a diagnostic accuracy higher than FDG-CT/PET in staging especially when diffuse. However a whole body coverage is crucial to properly manage MM patients irrespective of which technique is used.

Myocardial (123)I-MIBG scintigraphy for differentiation of Lewy bodies disease from FTD.

Clinical distinction between Lewy bodies disease (LBD) and frontotemporal dementia (FTD) is sometimes difficult. Nigrostriatal dopaminergic degeneration occurs in both LBD and FTD, limiting helpfulness of DAT imaging to differentiate these forms of dementia. Several studies have emphasized the usefulness of myocardial scintigraphy with (123)Metaiodobenzylguanidine ((123)I-MIGB) in assessing the sympathetic nerve terminals in LBD demonstrating that cardiac (123)I-MIGB uptake is decreased in patients with this disease. We investigated the role of cardiac (123)I-MIBG scintigraphy in differentiating patients with LBD from those with FTD. Clinical diagnosis of LBD and FTD was determined according to established consensus criteria. Nine patients with LBD (1 possible and 8 probable), 6 patients with FTD, and 16 control subjects were involved in the study. The heart to mediastinum ratio (H/M) of (123)I-MIBG uptake was markedly reduced in all patients with LBD (H/M early: 1.25±0.12; delayed: 1.14±0.13) whereas it was normal in patients with FTD (H/M early: 1.86±0.20; delayed: 1.80±0.23) and in controls (H/M early: 1.91±0.17; delayed: 1.99±0.19), suggesting that cardiac (123)I-MIBG scintigraphy can help distinguish patients with LBD from those with FTD.

Cardiac MIBG scintigraphy in Primary Progressive Freezing Gait.

Freezing of gait (FOG) generally occurs as a late manifestation of Parkinson's Disease (PD). FOG, however, can present in isolation, constituting the so-called "Primary Progressive Freezing Gait"(PPFG). Myocardial (123)Metaiodiobenzylguanidine (MIBG) enables the assessment of postganglionic sympathetic cardiac nerve terminals. MIBG uptake reflects sympathetic system integrity, and reduced myocardial uptake of the tracer has been observed in nearly all patients with PD. We investigated MIBG uptake in 7 patients with PPFG, 14 patients with mild PD, and 6 patients with advanced PD and FOG (PD-FOG), and 18 control subjects. Our study shows that myocardial MIBG uptake was normal in all patients with PPFG (H/M ratio: mean+/-SD, 1.85+/-0.11 early; 1.71+/-0.15 delayed) and in the controls (H/M ratio: mean+/-SD, 1.94+/-0.18 early; 2.02+/-0.19 delayed) whereas it was markedly decreased in the patients with mild and advanced PD (H/M ratio: mean+/-SD, PD: 1.17+/-0.02 early; 1.16+/-0.02 delayed; PD-FOG: 1.22+/-0.10 early; 1.08+/-0.06 delayed). Our findings demonstrate that cardiac sympathetic denervation did not occur in patients with PPFG, confirming that PPFG and PD are distinct diseases.