123I-MIBG Myocardial Scintigraphy Research Articles

Insulin resistance is associated with impaired cardiac sympathetic innervation in patients with heart failure.

Insulin resistance (IR) represents, at the same time, cause and consequence of heart failure (HF) and affects prognosis in HF patients, but pathophysiological mechanisms remain unclear. Hyperinsulinemia, which characterizes IR, enhances sympathetic drive, and it can be hypothesized that IR is associated with impaired cardiac sympathetic innervation in HF. Yet, this hypothesis has never been investigated. Aim of the present observational study was to assess the relationship between IR and cardiac sympathetic innervation in non-diabetic HF patients. One hundred and fifteen patients (87% males; 65 ± 11.3 years) with severe-to-moderate HF (ejection fraction 32.5 ± 9.1%) underwent iodine-123 meta-iodobenzylguanidine ((123)I-MIBG) myocardial scintigraphy to assess sympathetic innervation and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) evaluation to determine the presence of IR. From (123)I-MIBG imaging, early and late heart to mediastinum (H/M) ratios and washout rate were calculated. Seventy-two (63%) patients showed IR and 43 (37%) were non-IR. Early [1.68 (IQR 1.53-1.85) vs. 1.79 (IQR 1.66-1.95); P = 0.05] and late H/M ratio [1.50 (IQR 1.35-1.69) vs. 1.65 (IQR 1.40-1.85); P = 0.020] were significantly reduced in IR compared with non-IR patients. Early and late H/M ratio showed significant inverse correlation with fasting insulinemia and HOMA-IR. Cardiac sympathetic innervation is more impaired in patients with IR and HF compared with matched non-IR patients. These findings shed light on the relationship among IR, HF, and cardiac sympathetic nervous system. Additional studies are needed to clarify the pathogenetic relationship between IR and HF.

Diagnostic accuracy of 123I-meta-iodobenzylguanidine myocardial scintigraphy in dementia with Lewy bodies: a multicenter study.

Background and PurposeDementia with Lewy bodies (DLB) needs to be distinguished from Alzheimer’s disease (AD) because of important differences in patient management and outcome. Severe cardiac sympathetic degeneration occurs in DLB, but not in AD, offering a potential system for a biological diagnostic marker. The primary aim of this study was to investigate the diagnostic accuracy, in the ante-mortem differentiation of probable DLB from probable AD, of cardiac imaging with the ligand 123I-meta-iodobenzylguanidine (MIBG) which binds to the noradrenaline reuptake site, in the first multicenter study.MethodsWe performed a multicenter study in which we used 123I-MIBG scans to assess 133 patients with clinical diagnoses of probable (n = 61) or possible (n = 26) DLB or probable AD (n = 46) established by a consensus panel. Three readers, unaware of the clinical diagnosis, classified the images as either normal or abnormal by visual inspection. The heart-to-mediastinum ratios of 123I-MIBG uptake were also calculated using an automated region-of-interest based system.ResultsUsing the heart-to-mediastinum ratio calculated with the automated system, the sensitivity was 68.9% and the specificity was 89.1% to differentiate probable DLB from probable AD in both early and delayed images. By visual assessment, the sensitivity and specificity were 68.9% and 87.0%, respectively. In a subpopulation of patients with mild dementia (MMSE ≥ 22, n = 47), the sensitivity and specificity were 77.4% and 93.8%, respectively, with the delayed heart-to-mediastinum ratio.ConclusionsOur first multicenter study confirmed the high correlation between abnormal cardiac sympathetic activity evaluated with 123I-MIBG myocardial scintigraphy and a clinical diagnosis of probable DLB. The diagnostic accuracy is sufficiently high for this technique to be clinically useful in distinguishing DLB from AD, especially in patients with mild dementia.

Efficacy of diflunisal on autonomic dysfunction of late-onset familial amyloid polyneuropathy (TTR Val30Met) in a Japanese endemic area

ObjectiveTo evaluate the long-term efficacy and safety of diflunisal in late-onset familial amyloid polyneuropathy (FAP) in a Japanese endemic area. MethodsConsecutive six FAP patients (mean age: 65.8±7.3years) with a transthyretin (TTR) Val30Met mutation from an endemic area of late-onset FAP were prospectively recruited to an open label study with oral diflunisal (250mg twice a day). We evaluated clinical symptoms, Kumamoto FAP score, modified body mass index (mBMI), Medical Research Council sum score, nerve conduction studies (NCS), electrocardiogram (ECG), ECG Holter monitor test, echocardiography, and 123iodine-metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy. ResultsOne patient ceased to take diflunisal because of hematuria which was reversible. The other five patients were treated with diflunisal for 3–5 (4.4±0.9years) years. Autonomic symptoms (orthostatic hypotension and gastrointestinal symptoms) disappeared after treatment in two of the four patients with the symptoms. Delayed heart to mediastinum ratio on 123I-MIBG imaging, a marker of cardiac postganglionic sympathetic nerve function, increased during the three-year treatment. mBMI was maintained through observation period. While, motor and sensory symptoms, Kumamoto FAP scores, and data on NCS gradually deteriorated. ConclusionDiflunisal might be effective especially for autonomic dysfunction in late-onset FAP with a TTR Val30Met mutation.

For what endpoint does myocardial 123I-MIBG scintigraphy have the greatest prognostic value in patients with chronic heart failure? Results of a pooled individual patient data meta-analysis

The purpose of this study was to determine the most appropriate prognostic endpoint for myocardial (123)I-metaiodobenzylguanidine (MIBG) scintigraphy in patients with chronic heart failure (CHF) based on aggregate results from multiple studies published in the past decade. Original individual late (3-5 h) heart/mediastinum (H/M) ratio data of 636 CHF patients were retrieved from six studies from Europe and the USA. All-cause mortality, cardiac mortality, arrhythmic events, and heart transplantation were investigated to determine which provided the strongest prognostic significance for the MIBG imaging data. The majority of patients was male (78%), had a decreased left ventricular ejection fraction (31.1 ± 12.5%), and a mean late H/M of 1.67 ± 0.47. During follow-up (mean 36.9 ± 20.1 months), there were 83 deaths, 67 cardiac deaths, 33 arrhythmic events, and 56 heart transplants. In univariate regression analysis, late H/M was a significant predictor of all event categories, but lowest hazard ratios (HRs) were for the composite endpoint of any event (HR = 0.30, 95% CI 0.19-0.46), all-cause (HR = 0.29, 95% CI 0.16-0.53), and cardiac mortality (HR = 0.28, 95% CI 0.14-0.55). In multivariate analysis, late H/M was an independent predictor for all event categories, except for arrhythmias. This pooled individual patient data meta-analysis showed that, in CHF patients, the late H/M ratio is not only useful as a dichotomous predictor of events (high vs. low risk), but also has prognostic implication over the full range of the outcome value for all event categories except arrhythmias.

多角的自律神経機能検査法をもちいた小径線維ニューロパチーの診断

It is well known that transthyretin-related familial amyloidotic polyneuropathy (TTR-FAP) and diabetic peripheral neuropathy are characterized by early selective involvement of small nerve fibers. However, early diagnosis of these diseases is not easy because prominent early diagnostic markers for small fiber neuropathies have not established. Thus, we adopted several methods to evaluate autonomic function accurately for detecting the onset of small-fiber neuropathy, such as laser-Doppler flowmetry, sweating tests using capsule type sweating ratemeter, morphological check of sweat gland, electrogastrography, density check of small-fiber and gastrointestinal interstitial cells of Cajal, R-R interval study, (123)I-MIBG myocardial scintigraphy, and head-up tilt test to check the overshoot phenomenon. These tests may indicate very early stage of small-fiber neuropathies in asymptomatic mutated TTR carriers or impaired glucose tolerance patients. Moreover, assessment of the pain thresholds by preferential stimulation of C and Aδ fibers are particularly useful tools for diagnosing the onset of small-fiber neuropathies in addition to the autonomic testing.

Validation of an optimal analysis method and reproducibility to calculate the heart-to-mediastinum ratio and washout rate in the iodine-123-labeled metaiodobenzylguanidine myocardial scintigraphy

The aim of this study was to investigate an appropriate analysis method and multicenter reproducibility of heart-to-mediastinum ratio (H/M) and washout rate (WR) in iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy with a phantom. We evaluated the optimal region of interest (ROI) setting method about the mediastinum and heart by varying the position and shape of the ROI. The mathematical method was changed to a combination of decay time correction (DTC) and background correction (BC). We evaluated the reproducibility of the H/M and WR between institutions. H/M decreased to 23.49% and WR increased to 20.68% by changing the mediastinum ROI position from upper to lower. H/M increased to 26.03% by changing the heart ROI position from base to apex. H/M decreased to 38.36% with BC, and WR was reduced up to 48.51% with DTC. Reproducibility of the H/M and WR between institutions was improved by performing optimization of the ROI setting and unification of the mathematical method. The position of the mediastinum ROI should be set on the upper mediastinum. The position of the heart ROI should be set on the apex of the heart. WR should be calculated with DTC and BC. Our results suggest that the reproducibility of the H/M and WR between institutions was improved by performing optimization of the ROI setting and unification of the mathematical method.

Association of Iodine-123 BMIPP and MIBG Cardiac Uptakes with Left Ventricular Functional Parameters Assessed by Gated Myocardial Perfusion SPECT

We investigated how the degree of cardiac uptakes of radioactive fatty acid (FA) analog ( 123 I-BMIPP) or norepinephrine (NE) analog ( 123 I-MIBG) was related to left ventricular (LV) functional parameters in patients with heart disease, which might be a predictor of cardiac events. Patients with ejection fraction (EF) of 16.2%-82.2% underwent 123 I-BMIPP or 123 I-MIBG myocardial scintigraphy, and were followed up over 1177±486 days. LV systolic functional parameter EF, diastolic parameters 1/3FR (first third filling rate), PFR (peak filling rate), and TPF (time to PFR) were calculated using quantitative gated SPECT. 123 I-BMIPP uptake (n=30) was significantly correlated with EF, 1/3FR, and PFR but not TPF. 123 I-MIBG uptake (n=37) was also correlated with EF, 1/3FR, and PFR but not TPF. In contrast, TPF was positively correlated with age, and was significantly longer in women than in men. Such findings were also observed in normal EF patients (≥50%, n=100). Kaplan–Meier analysis showed the occurrence of earlier cardiac events in the case of patients with decreased 123 I-BMIPP and 123 I-MIBG uptake, decreased PFR, and prolonged TPF. The degree of decreased cardiac uptakes of FA and NE may be associated with the grade of systolic and diastolic dysfunctions assessed by EF, PFR, and 1/3FR. In contrast, prolonged TPF, another diastolic parameter, may rather be caused by aging and female gender, independent of EF. Despite these differences, myocardial FA metabolism impairment, cardiac sympathetic nerve inactivity, decreased PFR, and prolonged TPF may all indicate poor cardiac prognosis in patients with heart disease. Keywords123 I-BMIPP; 123 I-MIBG; Cardiac Function; Heart Failure

Diagnosis of dementia with Lewy bodies: diagnostic performance of combined 123I-IMP brain perfusion SPECT and 123I-MIBG myocardial scintigraphy

Objective We assessed the value of combining 123I-IMP brain perfusion SPECT and 123I-MIBG myocardial scintigraphy for the discrimination of dementia with Lewy bodies (DLB) from other types of dementia. MethodsWe subjected 252 consecutive patients with clinically suspected DLB to both 123I-IMP brain perfusion SPECT and 123I-MIBG myocardial scintigraphy. Patients with Parkinson’s disease were included. The 252 patients were randomly assigned to an estimation (n = 152) or a validation group (n = 100). Using univariate analysis, we first analyzed the relationship between various variables and the presence or absence of DLB in estimation group and then proceeded to multivariate analysis to obtain a combined index that predicted the likelihood of DLB. The diagnostic value of the index was assessed by calculating the area under the receiver operating characteristic (ROC) curve (AUC) with the cutoff value selected from the ROC curve. We then tested the predictive accuracy of the index in validation group. ResultsThe combined index was an arithmetic expression that combined the age, early 123I-MIBG heart-to-mediastinum uptake (E-H/M) ratio, and the parietal lobe hypoperfusion score. Values for the AUC of the combined index, the E-H/M ratio, the parietal lobe hypoperfusion score, and the patient age in validation group were 0.95, 0.90, 0.72, and 0.73, respectively. There was a significant difference in the AUC of the combined index among other indices (p < 0.05). The sensitivity, specificity, and accuracy of the combined index for a diagnosis of probable DLB in validation group were 88, 87, and 87 %, respectively.ConclusionsThe combinational diagnosis based on 123I-IMP brain perfusion SPECT, 123I-MIBG myocardial scintigraphy, and the patient age is a simple and reliable means for predicting probable DLB.

How do neurological and psychiatric signs and symptoms which are indicative of lewy body disease appear in apparent idiopathic rem sleep behavior disorder? – A descriptive study in the clinical setting

Introduction There has been accumulating evidence that idiopathic RBD (iRBD) could be pre-motor or pre-dementing state of Levy body disease (LBD) (Parkinson’s disease (PD) and dementia with Lewy bodies). Since the transition from apparent iRBD to full-blown LBD is considered gradual development, various symptoms and signs could appear in this process. This observational study outlines when and how neurological and psychiatric signs and symptoms appeared in our patients with apparent iRBD. Materials and methods We retrospectively reviewed the sleep clinic records of consecutive 19 polysomnographically confirmed iRBD patients who made the first consultation from December 2005 to December 2009 with successful continual follow-up period (once per 1–3 months) up to June 2013. One patient who had end-stage renal disease under hemodialysis was excluded. 18 patients (15 men and 3 women, 66.4 ± 6.5 years of age at the first clinic visit, 71.7 ± 6.6 at the last clinic visit) were analyzed. 16 out of the18 patients underwent myocardial 123I-MIBG scintigraphy within two months from the first clinic visit, the result of which was taken into consideration whether it helps to predict the later development into LBD. Results The follow-up duration was 5.2 ± 1.2 years (range 3.5–7.5). The onset age of iRBD was 59.8 ± 6.9 years old and the duration from the onset to the first clinic visit was 6.6 ± 4.7 years (range 2–19), therefore, our patients have been suffering from RBD for 11.8 ± 5.3 years (range 6.5–26). Seven out of 18 patients (38.9%) showed muscle rigidity at the 7.8 ± 4.6 years from the onset of iRBD, and 2 of them fulfilled the British Brain Bank Criteria of PD at 4.2 years and 1 year respectively after the appearance of rigidity. About the remaining 5 patients with muscle rigidity, 4 of them also showed other symptoms (temporary depressive episodes in 2, mild cognitive impairment in 1, and episodic decreased activity [bedridden all day] continuing a few weeks in 1. All of the 7 patients with rigidity had showed decreased 123I-MIBG uptake. One patient is overall anxious with the past depressive episode (after the onset of RBD), and one started to experience visual hallucination at night which was clearly differentiated from RBD behaviors. Eight out of 18 patients (44.4%) still remained as apparent iRBD at 12.0 ± 4.0 years after the onset of iRBD, however, 7 patients of this group had 123I-MIBG scintigraphy and all but one had showed decreased uptake. The last one patient revealed to be possible multiple system atrophy, of whom 123I-MIBG uptake was within normal limits. In this woman, mild cerebellar signs appeared at the 3.6 years from the onset of iRBD and it took another 2.3 years to have this diagnosis. Conclusion Our results strongly support that iRBD is a predictor of LBD, but neurological and psychiatric signs and symptoms in iRBD which are indicative of LBD seem to appear in a long time span with various severities and combinations. It is still difficult to expect when and what will be overt in the daily clinical settings. Acknowledgement We thank Keiichi Marumoto and Youko Uozumi for their technical support for performing PSG.

Spotlight on the November 12 Issue

The authors examined 94 patients with possible dementia with Lewy bodies based on established consensus criteria. 123I-MIBG myocardial scintigraphy was a good predictor of the future conversion of possible to probable dementia with Lewy bodies. See p. 1741 From editorialists Ballard & Grimmer: “Independent validation, including blinding of diagnosing clinicians with regards to the 123 I-MIBG results, is needed for a potential diagnostic test; optimal cutoffs may overestimate the magnitude of diagnostic discrimination.” See p. 1730 The authors investigated blood glucose markers, memory, and …

Myocardial scintigraphy may predict the conversion to probable dementia with Lewy bodies

To compare the usefulness of brain perfusion SPECT and (123)I-metaiodobenzylguanidine ((123)I-MIBG) in predicting the conversion of possible dementia with Lewy bodies (DLB) to probable DLB. We examined 94 patients with possible DLB based on the Consensus Criteria for the Clinical Diagnosis of DLB by N-Isopropyl-p-(123)I-iodoamphetamine ((123)I-IMP) brain perfusion SPECT and (123)I-MIBG myocardial scintigraphy. After 1 year of follow-up, 33 of 94 patients met the criteria for probable DLB. (123)I-IMP brain perfusion SPECT and (123)I-MIBG myocardial scintigraphy were tested as predictors of the conversion from possible DLB to probable DLB. A receiver operating characteristic (ROC) analysis was performed. The areas under the ROC curves for SPECT for predicting the conversion to probable DLB from possible DLB based on the occipital/cerebellum and occipital/striatum cortex ratios of blood flow counts were 0.591 and 0.585, respectively. The areas under the ROC curves for (123)I-MIBG based on the early heart to mediastinum (H/M) ratio, delayed H/M ratio, and washout rate were 0.935, 0.936, and 0.884, respectively. (123)I-MIBG myocardial scintigraphy is a good predictor of the future conversion of possible DLB to probable DLB.

Reduced cardiac 123I-metaiodobenzylguanidine uptake in patients with spinocerebellar ataxia type 2: a comparative study with Parkinson’s disease

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disorder characterized by cerebellar ataxia, supranuclear ophthalmoplegia, and peripheral neuropathy. Autonomic nervous system dysfunction is often present. This study evaluated the cardiac sympathetic function in patients with SCA2 using (123)I-metaiodobenzylguanidine (MIBG) in comparison with patients with Parkinson's disease (PD) and control subjects. Nine patients with SCA2, nine patients with PD, and nine control subjects underwent (123)I-MIBG imaging studies from which early and late heart-to-mediastinum (H/M) ratios and myocardial washout rates were calculated. Early (F = 12.3, p < 0.0001) and late (F = 16.8, p < 0.0001) H/M ratios were significantly different among groups. In controls, early and late H/M ratios (2.2 ± 0.12 and 2.1 ± 0.20) were significantly higher than in patients with SCA2 (1.9 ± 0.23 and 1.8 ± 0.20, both p < 0.05) and with patients with PD (1.7 ± 0.29 and 1.4 ± 0.35, both p < 0.001). There was also a significant difference in washout rates among groups (F = 11.7, p < 0.0001). In controls the washout rate (19.9 ± 9.6%) was significantly lower (p < 0.005) than in patients with PD (51.0 ± 23.7%), but not different from that in SCA2 patients (19.5 ± 9.4%). In SCA2 patients, in a multivariable linear regression analysis only the Scale for the Assessment and Rating of Ataxia score was independently associated with early H/M ratio (β = -0.12, p < 0.05). (123)I-MIBG myocardial scintigraphy demonstrated an impairment of cardiac sympathetic function in patients with SCA2, which was less marked than in PD patients. These results suggest that (123)I-MIBG cardiac imaging could become a useful tool for analysing the pathophysiology of SCA2.

症例 123I-MIBG心筋シンチグラフィにて遷延する欠損を認めた激症型心筋炎の1例

症例 123I-MIBG心筋シンチグラフィにて遷延する欠損を認めた激症型心筋炎の1例

症例 123I-MIBGシンチグラフィーで心筋への著明な集積低下を認めた特発性起立性低血圧症の1例

症例 123I-MIBGシンチグラフィーで心筋への著明な集積低下を認めた特発性起立性低血圧症の1例

Myocardial 123I-MIBG scintigraphy predicts an impairment in myocardial functional reserve during dobutamine stress in patients with idiopathic dilated cardiomyopathy

We investigated whether myocardial (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy predicts impairment of myocardial functional reserve in response to dobutamine stress in patients with idiopathic dilated cardiomyopathy (DCM). Forty DCM patients (LVEF 39 ± 12 %) underwent myocardial (123)I-MIBG scintigraphy, echocardiography, and cardiac catheterization. Myocardial (123)I-MIBG uptake was quantified as the delayed heart to mediastinum (H/M) ratio and washout rate (WR). Local denervation was evaluated on polar map images. LV dP/dt (max) and T(1/2) were determined from left ventricular pressure curves at baseline and during dobutamine infusion (15 μg/kg /min). Patients were classified into two groups as follows: group A comprised 21 patients showing a delayed H/M ratio of <1.9 (median value); group B comprised 19 patients showing a delayed H/M ratio of ≥ 1.9. The percentage change in heart rate (%HR), LV dP/dt (max) (%LV dP/dt (max)), and T (1/2) (%T (1/2)) from baseline to dobutamine stress were significantly more reduced in group A than in group B (39.3 ± 20.2 %, 55.2 ± 24.1 %, p < 0.01; 102.3 ± 46.3 %, 152.0 ± 72.3 %, p < 0.05; 38.7 ± 15.3 %, 46.9 ± 15.4 %, p < 0.05, respectively). No significant differences between the two groups were observed in the echocardiographic parameters or baseline cardiac catheterization parameters. Significant correlations were found between delayed H/M ratio and %HR (r = 0.35, p < 0.05), %LV dP/dt (max) (r = 0.45, p < 0.05) and %T (1/2) (r = 0.34, p < 0.05). Significant inverse correlations were also found between WR and %HR (r = -0.37, p < 0.05), %LV dP/dt (max) (r = -0.60, p < 0.0001), and %T (1/2) (r = -0.34, p < 0.05). SPECT images revealed enhanced denervation from the inferoposterior to anterior wall in accordance with the advancement of global denervation. Reduced (123)I-MIBG uptake and increased washout were related to impairment in adrenergic myocardial functional reserve in idiopathic DCM.

Iodine-123 metaiodobenzylguanidine imaging can predict future cardiac events in Japanese patients with Parkinson’s disease

Iodine-123 metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy provides useful diagnostic information in differentiating Parkinson's disease (PD) from other neurological diseases. Moreover, a number of studies have reported that 123I-MIBG imaging provides powerful diagnostic and prognostic information in congestive heart failure (HF) patients. The aim of the present study was to investigate the cardiovascular predictive value of cardiac 123I-MIBG imaging in patients with PD. Seventy-eight patients with PD were retrospectively studied. All patients underwent 123I-MIBG imaging at 30 min (early) and 240 min (delayed) after the tracer injection, and clinical parameters were also investigated. During a mean follow-up of 27 ± 12 months, 5 patients required hospitalization for HF. There were no occurrences of myocardial infarction, fatal arrhythmia or sudden death. There was no significant coronary artery stenosis, significant valvular heart disease, or cardiomyopathy in the HF patients. The left ventricular ejection fraction (LVEF) was normal in the HF patients. (123)I-MIBG delayed heart to mediastinal ratio (delayed H/M) was lower and washout rate (WR) was higher in HF patients than non-HF patients (1.62 ± 0.21 vs. 1.34 ± 0.08, p = 0.019; 31.9 ± 5.5 vs. 38.2 ± 3.3, p = 0.005, respectively). Both WR and delayed H/M did not correlate with Hoehn and Yahr stage. The WR showed a weak negative correlation with delayed H/M (R = -0.357, p < 0.001) upon simple linear regression analysis. A multivariate Cox regression analysis revealed that WR and delayed H/M were independently associated with HF (p = 0.014, p = 0.029, respectively). Kaplan-Meier analysis revealed that patients with abnormal WR (> 37%) and delayed H/M (< 1.48) had a higher incidence of HF than those with normal WR and delayed H/M (p = 0.014, p = 0.04, respectively). WR showed stronger predictive power than delayed H/M in Kaplan-Meier analysis. WR has more useful cardiovascular predictive value than delayed H/M in Japanese patients with PD. Further studies are needed to clarify the significance of abnormal MIBG uptake in PD patients.

Reproducibility of planar 123I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy in patients with heart failure

PurposeDespite its high prognostic value, widespread clinical implementation of 123I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is hampered by a lack of validation and standardization. The purpose of this study was to assess the reliability of planar 123I-MIBG myocardial scintigraphy in patients with heart failure (HF).MethodsPlanar myocardial MIBG images of 70 HF patients were analysed by two experienced and one inexperienced observer. The reproducibility of early and delayed heart-to-mediastinum (H/M) ratios, as well as washout rate (WR) calculated by two different methods, was assessed using the intraclass correlation coefficient (ICC) and the Bland-Altman analysis. In addition, a subanalysis in patients with a very low H/M ratio (delayed H/M ratio <1.4) was performed. The delayed H/M ratio was also assessed using fixed-size oval and circular cardiac regions of interest (ROI).ResultsIntra- and interobserver analyses and experienced versus inexperienced observer analysis showed excellent agreement for the measured early and delayed H/M ratios and WR on planar 123I-MIBG images (the ICCs for the delayed H/M ratios were 0.98, 0.96 and 0.90, respectively). In addition, the WR without background correction resulted in higher reliability than the WR with background correction (the interobserver Bland-Altman 95 % limits of agreement were −2.50 to 2.16 and −10.10 to 10.14, respectively). Furthermore, the delayed H/M ratio measurements remained reliable in a subgroup of patients with a very low delayed H/M ratio (ICC 0.93 for the inter-observer analysis). Moreover, a fixed-size cardiac ROI could be used for the assessment of delayed H/M ratios, with good reliability of the measurement.ConclusionThe present study showed a high reliability of planar 123I-MIBG myocardial scintigraphy in HF patients, confirming that MIBG myocardial scintigraphy can be implemented easily for clinical risk stratification in HF.

P1‐153: Clinical features of Pittsburgh compound‐B–negative dementia

Background/Aims: We previously found that some cases of clinically diagnosed Alzheimer’s disease (AD) were rated as Pittsburgh compound B (PiB) negative by amyloid imaging (i.e. cases of PiB-negative dementia). The present study was designed to analyze the clinical features of PiB-negative dementia patients in detail. Methods: Of the 64 cases of clinically diagnosed AD, 14 were rated PiB negative. Eleven of these were further analyzed using CSF biomarker levels and findings from MRI, FDG-PET, 123I-MIBG myocardial scintigraphy and voxel-based morphometry (VBM). Results: When examined by 123I-MIBG myocardial scintigraphy, the heart/mediastinum ratio was significantly higher in the PiB-negative dementia group than in the dementia with Lewy bodies (DLB) group. Analyses of CSF biomarkers and MRI and FDG-PET findings suggested argyrophilic grain disease (AGD) in 3 cases, frontotemporal lobar degeneration (FTLD) in 3 cases, neurofibrillary tangle-predominant dementia (NFTD) in 1 case, and AD in 2 cases. In the VBM data analysis, the PiB-positive AD group showed significant atrophy of both hippocampi compared with the healthy control group, while the PiB-negative dementia group presented with significant atrophy of the left precuneus. Conclusion: PiB-negative dementia is unlikely to include DLB, while it most likely includes diseases of tauopathy, such as FTLD, AGD and NFTD. A better understanding of PiB-negative dementia is expected to further improve the accuracy of the clinical AD diagnosis.

REPRODUCIBILITY OF HEART TO MEDIASTINUM RATIO ON 123IODINE-META-IODOBENZYLGUANIDINE (123I-MIBG) MYOCARDIAL SCINTIGRAPHY IN PATIENTS WITH HEART FAILURE

Although 123Iodine- meta-iodobenzylguanidine (123I-MIBG) myocardial scintigraphy provides important prognostic information in heart failure (HF) patients, widespread clinical implementation is hampered due to lack of validation and standardization. Therefore, the purpose of this study was to assess

123I-MIBG myocardial scintigraphy for differentiating Parkinson’s disease from other neurodegenerative parkinsonism: A systematic review and meta-analysis

ObjectivesDifferential diagnosis of Parkinson’s disease (PD) and other neurodegenerative parkinsonism by clinical consensus criteria and diagnostic imaging is often difficult. 123I-meta-iodobenzylguanidine (123I-MIBG) myocardial scintigraphy is a useful imaging tool for differentiating PD from other parkinsonism. The purpose of the present study is to systematically review and perform a meta-analysis of studies on the diagnostic performance of 123I-MIBG myocardial scintigraphy for the differential diagnosis of PD and other neurodegenerative parkinsonism, specifically multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration. MethodsA computer literature search of the PubMED/MEDLINE database was conducted to find relevant published articles on 123I-MIBG myocardial scintigraphy for the differential diagnosis of PD and other neurodegenerative parkinsonism. We used the bivariate random-effects model to obtain the pooled estimates of the sensitivity and specificity and the corresponding 95% confidence intervals. ResultsThirteen studies comprising 845 patients including 625 PD and 220 other neurodegenerative parkinsonism were analyzed. The pooled sensitivity and specificity to differentiate PD from other neurodegenerative parkinsonism by the early heart-to-mediastinum (H/M) ratio were 82.6% and 89.2%, respectively, and those by the delayed H/M ratio were 89.7% and 82.6%, respectively. When PD was limited to early stage (Hoehn-Yahr stage 1 or 2), the pooled sensitivity and specificity by the delayed H/M ratio were 94.1% and 80.2%, respectively. ConclusionsThe present meta-analysis confirmed high sensitivity and specificity of 123I-MIBG myocardial scintigraphy for differentiating PD from other neurodegenerative parkinsonism in both early and delayed imaging phases. Furthermore, 123I-MIBG myocardial scintigraphy was highly effective for distinguishing early PD.