123I-MIBG Scintigraphy Research Articles

<sup>123</sup>I-MIBG in Latin America

Heart Failure (HF) is a life-threatening disease which incidence is growing over the years, leading to a considerable increase in disability, mortality and healthcare costs. The actual treatment of HF, includes, beside optimal medical treatment, use of resynchronization therapy and implantable cardiac defibrillator. In some developing countries, the cost of these two devices is extremely high, being mandatory the adequate selection of the patients whose will benefit more from these measures. 123I-MIBG scintigraphy is the only technique approved to provide information of the adrenergic function of the heart, being a powerful risk stratification tool in patients with HF. Multiple studies have shown that the evaluation of cardiac sympathetic nerve activity using 123I-MIBG imaging, especially the heart-to-mediastinum ratio, can differentiate high-risk from low-risk patients. Cardiac MIBG imaging has still poor availability in Latin America. It is mostly performed in Brazil, where some studies showed the possible benefits and potential uses for MIBG.

Pheochromocytomas and Hypertension

Pheochromocytomas and paragangliomas (PPGLs) are uncommon catecholamine-producing neuroendocrine neoplasms that usually present with secondary hypertension. This review is to update the current knowledge about these neoplasms, the pathophysiology, genetic aspects and diagnostic and therapeutic algorithms based on scientific literature mostly within the past 3years. Eighty to eighty-five percent of PPGLs arise from the adrenal medulla (pheochromocytomas; PCCs) and the remainder from the autonomic neural ganglia (paragangliomas; PGLs). Catecholamine excess causes chronic or paroxysmal hypertension associated with sweating, headaches and palpitations, the presenting features of PPGLs, and increases the cardiovascular morbidity and mortality. Genetic testing should be considered in all cases as mutations are reported in 35-40% of cases; 10-15% of PCCs and 20-50% of PGLs can be malignant. Measurements of plasma-free metanephrines or 24-h urine-fractionated metanephrines help biochemical diagnosis with high sensitivity and specificity. Initial anatomical localization after biochemical confirmation is usually with computed tomography (CT) or magnetic resonance imaging (MRI). 123Iodine metaiodobenzylguanidine (123I-MIBG) scintigraphy, positron emission tomography (PET) or single-photon emission computed tomography (SPECT) is often performed for functional imaging and prognostication prior to curative or palliative surgery. Clinical and biochemical follow-up is recommended at least annually after complete tumour excision. Children, pregnant women and older people have higher morbidity and mortality risk. De-bulking surgery, chemotherapy, radiotherapy, radionuclide agents and ablation procedures are useful in the palliation of incurable disease. PPGLs are unique neuroendocrine tumours that form an important cause for endocrine hypertension. The diagnostic and therapeutic algorithms are updated in this comprehensive article.

Relationship of left ventricular global longitudinal strain with cardiac autonomic denervation as assessed by 123I-mIBG scintigraphy in patients with heart failure with reduced ejection fraction submitted to cardiac resynchronization therapy: Assessment of cardiac autonomic denervation by GLS in patients with heart failure with reduced ejection fraction submitted to CRT

BackgroundHeart failure (HF) is associated with cardiac autonomic denervation (AD), which can be non-invasively assessed by 123I-metaiodobenzylguanidine (123I-mIBG) scintigraphy and has prognostic implications. We aimed to study the relationship between myocardial contractility assessed by global longitudinal strain (GLS) and AD assessed by 123I-mIBG scintigraphy in advanced HF. Methods/ResultsBETTER-HF is a prospective randomized clinical trial including HF patients (pts) submitted to cardiac resynchronization therapy (CRT) who are submitted to a clinical, echocardiographic, and scintigraphic assessment before and 6 months after CRT. 81 pts were included. An echocardiographic response (absolute increase in left ventricular ejection fraction ≥ 10%) was observed in 73.7% of pts. A higher baseline late heart-to-mediastinum ratio (HMR) was associated with a better echocardiographic response. There was a significant association between late HMR and GLS at baseline and 6 months. At baseline, GLS had an AUC of 0.715 for discrimination for a late HMR < 1.6. A GLS cut-off of − 9% maximized the likelihood of correctly classifying a pt as having severe AD (HMR < 1.6). ConclusionMyocardial contractility as assessed by GLS is moderately correlated with AD as assessed by 123I-mIBG scintigraphy and has a good discrimination for the identification of severe cardiac denervation. GLS may allow for a more readily accessible estimation of the degree of AD in advanced HF pts.

Determinants of decreased cardiac uptake in 123i-mibg scintigraphy in patients with idiopathic REM sleep behavior disorder

Determinants of decreased cardiac uptake in 123i-mibg scintigraphy in patients with idiopathic REM sleep behavior disorder

Investigation into cardiac sympathetic innervation during the commencement of haemodialysis in patients with chronic kidney disease

BackgroundPatients with chronic kidney disease (CKD) who undergo chronic haemodialysis (HD) show altered sympathetic tone, which is related to a higher cardiovascular mortality. The purpose of this study was to investigate the effect of transition from pre-HD to HD on cardiac sympathetic innervation.MethodsEighteen patients aged 58 ± 18 years (mean ± standard deviation [SD]), 13 males and five females, with stage 5 CKD and nine healthy control subjects aged 52 ± 17 (mean ± SD), three males and six females, were included in this prospective study between May 2010 and December 2013. All patients underwent 123I-labelled meta-iodobenzylguanidine (123I-MIBG) scintigraphy for cardiac sympathetic innervation and electrocardiographically gated adenosine stress and rest 99mTc-labelled tetrofosmin single-photon emission computed tomography for myocardial perfusion imaging prior to (pre-HD) and 6 months after the start of HD. Results of 123I-MIBG scans in patients were compared to controls. Impaired cardiac sympathetic innervation was defined as late heart-to-mediastinum ratio (HMR) < 2.0.ResultsMean late HMR was lower in patients during HD (2.3) than in controls (2.9) (p = 0.035); however, in patients it did not differ between pre-HD and after the start of HD. During HD, two patients showed new sympathetic innervation abnormalities, and in three patients innervation abnormalities seemed to coincide with myocardial perfusion abnormalities.ConclusionsCKD patients show cardiac sympathetic innervation abnormalities, which do not seem to progress during the maintenance HD. The relationship between sympathetic innervation abnormalities and myocardial perfusion abnormalities in HD patients needs further exploration.

Potential diagnostic value of 131I-MIBG myocardial scintigraphy in discrimination between Alzheimer disease and dementia with Lewy bodies

ObjectivesClinical difficulty to discriminate between the Alzheimer disease (AD) and dementia with Lewy bodies (DLB) has led researchers to focus on highly sensitive functional imaging modalities. The aim of the present study was to assess 131I-MIBG cardiac imaging to distinguish between AD and DLB. Patients and methodsSeventeen patients who were known cases of dementia underwent 131I-MIBG myocardial scintigraphy to differentiate AD from DLB. Planar and 131I-MIBG SPECT were obtained 2h after the injection of 1mCi 131I-MIBG on a dual head gamma camera. The visual assessment of the heart uptake compared with lungs and the quantification based on the heart to mediastinal ratio (HMR) were done. The cardiac receiver operating characteristic (ROC) curve was designed for the optimal HMR cut-off values to predict the diagnoses of the patients. The diagnoses were clinically confirmed during the follow up of 14±8.2 months. ResultsOut of 17 patients (13 males; 76.5%), 10 patients had AD (7 males; 70%) and 7 patients had DLB (6 males; 85%). The pooled HMR was 1.74±0.33 in the study population; with 1.95±0.22 in the AD group and 1.43±0.20 in the DLB group to demonstrate significantly different HMR scores between patients with AD and DLB (p value=0.001). The visual interpretation was positive in 10 patients (accuracy of 88.2%). The shortest distance on the ROC curve to the optimal value corresponding to HMR=1.57 identified 10 patients with a high HMR (positive cardiac uptake) and 7 patients with a low HMR (negative cardiac uptake), the accuracy calculated at 88.2%. Conclusion131I-MIBG myocardial scintigraphy is a potential alternative diagnostic modality for discrimination between AD and DLB when 123I is not available.

The relationship between 123I-MIBG myocardial scintigraphy and cognitive function in parkinsonism-predominant multiple system atrophy patients

The relationship between 123I-MIBG myocardial scintigraphy and cognitive function in parkinsonism-predominant multiple system atrophy patients

PP.27.14] PHEOCHROMOCYTOMA PRESENTED WITH ACUTE HEART FAILURE AND MULTIPLE ORGAN DAMAGE

Objective: Pheochromocytomas are catecholamine secreting tumors that provoke paroxysmal hypertensive crises. Design and method: We describe an atypical manifestation of pheochromocytoma in a patient presented with acute pulmonary edema and multiple organ dysfunction. Results: Case report: A 61-year-old woman with a medical history of hypothyroidism was admitted due to acute pyelonephritis. On day two, under antibiotic treatment, she developed acute pulmonary edema and severe left vertical (LV) systolic dysfunction (Ejection Fraction: 35%). Coronary angiography showed normal coronary arteries. She rapidly became hemodynamically unstable with multiple organ dysfunction, which was remitted during the next days. However, her blood pressure (BP) fluctuated from 180/105 to 200/115mmHg and she was treated with amlodipine, metoprolol and nitroglycerin. The new echocardiogram showed normal LV systolic function and concentric hypertrophy of LV walls. The BP levels were below 130/70mmHg without antihypertensive medication. Due to the suspicion of a pheochromocytoma an abdominal computed tomography was performed which revealed a right adrenal tumor of 4 × 2.7 cm. This finding was further supported by an abdominal MRI scan. The 24-hour urine collection revealed an elevation of total metanephrines. An I-123 MIBG scintigraphy was carried out showing selective uptake of MIBG by the right adrenal tumor, indicating that the tumor was probably a pheochromocytoma. The patient was started on doxazosin and is about to undergo a right adrenalectomy. Conclusions: Pheochromocytomas should be considered as part of the differential diagnosis in patients with symptoms suggestive of both Acute Heart Failure and multiple organ dysfunction.

Cardiac 123I-mIBG scintigraphy is associated with freedom of appropriate ICD therapy in stable chronic heart failure patients

AimChronic heart failure (CHF) is a life-threatening clinical syndrome, partly due to sudden cardiac death (SCD). Implantable cardioverter defibrillators (ICD) for primary prevention of SCD have improved overall survival of CHF patients. However, a high percentage of patients never receives appropriate ICD therapy. This prospective multicentre study evaluated whether cardiac sympathetic activity assessed by 123I-mIBG scintigraphy could be helpful in selecting patients for ICD implantation. Materials and methods135 stable CHF subjects (age 64.5±9.3years, 79% male, LVEF 25±6%) referred for prophylactic ICD implantation were enrolled in 13 institutions. All subjects underwent planar and SPECT 123I-mIBG scintigraphy. Early and late heart-to-mediastinum (H/M) ratio, 123I-mIBG washout (WO) and late summed scores were calculated. The primary endpoint was appropriate ICD therapy. The secondary endpoint was defined as the combined endpoint of all first cardiac events: appropriate ICD therapy, progression of heart failure (HF) and cardiac death. ResultsDuring a median follow-up of 30months (6–68months), 24 subjects (17.8%) experienced a first cardiac event (appropriate ICD therapy [12], HF progression [6], cardiac death [6]). Late H/M ratio and defect size of 123I-mIBG SPECT were not associated with appropriate ICD therapy. However, late H/M ratio was independently associated with the combined endpoint (HR 0.135 [0.035–0.517], p=0.001). Post-hoc analysis showed that the combination of late H/M ratio (HR 0.461 [0.281–0.757]) and LVEF (HR 1.052 [1.021–1.084]) was significantly associated with freedom of appropriate ICD therapy (p<0.001). Conclusion123I-mIBG scintigraphy seems to be helpful in selecting CHF subjects who might not benefit from ICD implantation.

P5527Additive value of myocardial sympathetic innervation study with I123-mIBG scintigraphy in patients eligible for primary-prevention ICD implantation

P5527Additive value of myocardial sympathetic innervation study with I123-mIBG scintigraphy in patients eligible for primary-prevention ICD implantation

P2976Incidence of recovery and recurrence in patients with idiopathic dilated cardiomyopathy; usefulness of 123I-MIBG scintigraphy in predicting prognosis and effectiveness of beta-blockers

P2976Incidence of recovery and recurrence in patients with idiopathic dilated cardiomyopathy; usefulness of 123I-MIBG scintigraphy in predicting prognosis and effectiveness of beta-blockers

ADRENAL NEUROENDOCRINE CARCINOMA TREATED WITH LAPAROSCOPIC ADRENALECTOMY: A CASE REPORT

We report a case of adrenal neuroendocrine carcinoma that was treated with laparoscopic adrenalectomy. A 70-year-old man was referred to our department for investigation of a 5 cm right adrenal mass detected by abdominal CT. No increased endocrine activity attributable to the adrenals was observed clinically, and there was no obvious uptake in 123I-MIBG scintigraphy. An adrenalectomy was performed laparoscopically. Positive immunohistochemical results for synaptophysin, chromogranin A and CD56 were compatible with neuroendocrine carcinoma.

123I-ioflupane brain SPECT and 123I-MIBG cardiac planar scintigraphy combined use in uncertain parkinsonian disorders.

We evaluated the clinical usefulness of the combined use of 123I-ioflupane brain single photon emission computed tomography (SPECT) and 123I-metaiodobenzylguanidine (MIBG) cardiac scintigraphy in discriminating uncertain parkinsonism with vascular lesions in striatal nuclei at magnetic resonance imaging (MRI). Forty-three consecutive patients with uncertain parkinsonism and vascular lesions at MRI in striatal nuclei were retrospectively evaluated; the uncertain differential diagnosis was between Parkinson's disease and vascular parkinsonism (PD/VP) in 22 patients, between PD and other neurodegenerative parkinsonism (PD/PS) in 11 patients and between Lewy body dementia and Alzheimer disease (LBD/AD) in the remaining 10 cases. All patients underwent 123I-ioflupane SPECT with striatal dopaminergic activity determination as binding potentials (BP; cut-off: 3.3). 123I-MIBG cardiac planar scintigraphy was performed 2 weeks later, in early (15 minutes) and delayed (240 minutes) phases also calculating heart to mediastinum (H/M) ratio (cut-off: 1.56). 123I-Ioflupane uptake was normal in 9 patients with BP values >3.3, while it was reduced in 34/43 cases with BP values <3.3 at least in one of the striatal nuclei. 123I-MIBG uptake was normal in 21/43 patients (5 of whom with normal and 16 with 123I-ioflupane striatal defects) showing the H/M ratio >1.56 in all cases; the uptake was reduced in 22/43 cases, (4 of whom were normal and 18 were with 123I-ioflupane striatal defects) with the H/M ratio <1.56 in all cases. No statistical differences were found when early and delayed H/M ratios were mutually compared. Combining the 2 radioisotopic procedures, a more reliable diagnosis was achieved in 39/43 cases properly classifying 13 PD, 10 VP, 7 PS, 5 LBD, and 4 AD. However, the diagnosis remained uncertain in four patients with normal 123I-ioflupane and reduced 123I-MIBG uptake. The results of the present study confirmed that in uncertain parkinsonian syndromes associated with vascular lesions in striatal nuclei, brain 123I-ioflupane SPECT alone did not prove able to discriminate between the different forms of disease. Only the association with 123I-MIBG cardiac scintigraphy, also with the early acquisition alone, allowed the most appropriate diagnosis in 90.7% of our cases. However, patients with normal 123I-ioflupane and reduced 123I-I-MIBG uptakes need a close clinical and instrumental follow-up as sympathetic damage could precede striatal disorders in the early stage of PD and LBD.

Significant correlation between renal 123I-metaiodobenzylguanidine scintigraphy and muscle sympathetic nerve activity in patients with primary hypertension

BackgroundIodine-123 metaiodobenzylguanidine (123I-MIBG) scintigraphy is used as a noninvasive imaging method for assessing cardiac sympathetic nerve activity. We tested the hypothesis that renal 123I-MIBG imaging is correlated with muscle sympathetic nerve activity (MSNA) in patients with primary hypertension. MethodsThirty-one consecutive patients with primary hypertension were included. Multiunit MSNA was recorded from the peroneal nerve to evaluate direct efferent sympathetic nerve activity. Planar renal and cardiac 123I-MIBG images were acquired. Early and delayed kidney-to-mediastinum ratio (K/M), early and delayed heart-to-mediastinum ratio (H/M), and washout rates (WR) were calculated. ResultsIn 27 of 31 patients, blood pressure was controlled on antihypertensive medication. Mean systolic and diastolic blood pressures were 118 ± 18 and 67 ± 15 mmHg, respectively. Although early and late K/M and H/M were not significantly correlated with MSNA, both cardiac and average renal WR were significantly correlated with MSNA (r = 0.45, P = .0035 and r = 0.68, P < .001, respectively). Right and left renal WR were similarly correlated with MSNA. Renal WR was significantly higher than cardiac WR (43.2% vs 25.8%, P < .001) in these patients with hypertension. ConclusionsRenal 123I-MIBG WR was significantly associated with multiunit MSNA. Renal 123I-MIBG imaging offers a noninvasive clinical methodology for assessing renal sympathetic nerve function.

Assessment of late anthracycline-induced cardiotoxicity by 123I-mIBG cardiac scintigraphy in patients treated during childhood and adolescence

PurposeThe goal of this study was to evaluate late cardiotoxic effects of anthracyclines (ATC) by evaluating cardiac sympathetic activity in a cohort of asymptomatic patients previously treated with ATC for childhood cancers. MethodsWe studied 89 asymptomatic patients previously treated with ATC with a normal echocardiogram (49 men and 40 women) and a control group of 40 healthy individuals (26 men and 14 women). Both groups underwent planar myocardial 123I-meta-iodobenzylguanidine scintigraphy (123I-mIBG). From these images, the early and late heart-to-mediastinum (H/M) ratio and washout rate (WR) were assessed. ResultsThe mean survival at the time of the 123I-mIBG scintigraphy was 5.3 ± 3.4 years. Patients treated with ATC had a lower but clinical normal left ventricular ejection fraction (LVEF) compared to controls (60.44 ± 6.5 vs 64.1 ± 6.0%, P < 0.01). Both the late H/M ratio and WR were not able to discriminate ATC treated patients from controls. The cumulative ATC dose was the only independent predictor of the LVEF, explaining approximately 12% of the variation in LVEF (P = 0.01). ConclusionsAlthough the pathophysiology behind ATC cardiotoxicity is most likely multifactorial, myocardial sympathetic activity is not associated with a reduction in LVEF 5-years after completion of chemotherapy.

Sensitivity of 6-[F-18]fluoro-L-dihydroxyphenylalanine positron emission tomography for localizing tumors causing catecholamine excess

11064 Background: Positron emission tomography (PET) using the catecholamine precursor 6-[F-18]fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) has emerged as promising technique to localize tumors with catecholamine excess. This study investigated the sensitivity of (18)F-DOPA PET, compared to (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy and computer tomography (CT)/ magnetic resonance imaging (MRI) in patients with catecholamine excess. METHODS: In a single center prospective study (18)F-DOPA PET was compared to (123)I-MIBG and CT/MRI in patients with catecholamine excess. The performance of each imaging modality was analyzed for individual patients and individual lesions. (18)F-DOPA PET, (123)I-MIBG, and CT/MRI were compared using a composite reference standard derived from all available imaging, clinical and histological information. Sensitivities were calculated and discordance between imaging techniques was compared. (18)F-DOPA PET uptake was measured to determine whole body metabolic burden. Correlations between (18)F-DOPA PET imaging and biochemical data were evaluated. RESULTS: 48 patients were included. The tumor localization was found in 45 patients, 43 with (18)F-DOPA PET, 31 with (123)I-MIBG and 32 with CT/MRI, resulting with surgery in final diagnosis of pheochromocytoma in 40, adrenal hyperplasia in 2, paraganglioma in 2, ganglioneuroma in 1 and 3 unknown (as yet no lesion detected). Per patient based analysis showed sensitivities for (18)F-DOPA PET, (123)I-MIBG and CT/MRI of 90, 65 and 67% (P<.01 (18)F-DOPA PET vs (123)I-MIBG, P<.01 (18)F-DOPA PET vs CT/MRI, P=1.0 (123)I-MIBG vs CT/MRI). Corresponding sensitivities in the lesion based analysis were 73, 48 and 44%, respectively (P<.001 for both (18)F-DOPA PET vs (123)I-MIBG and vs CT/MRI, P=.51 (123)I-MIBG vs CT/MRI). The (8)F-DOPA PET+CT/MRI combination was superior to (123)I-MIBG+CT/MRI (93 vs 76%, P<.001) Whole body metabolic burden measured with (18)F-DOPA PET correlated with plasma free normetanephrine (r=.82) and 24h urinary total normetanephrine (r=.84) and metanephrine (r=.57). CONCLUSIONS: The sensitivity of (18)F-DOPA PET to localize tumors with catecholamine excess is superior to either (123)I-MIBG scintigraphy or CT/MRI. No significant financial relationships to disclose.

A European myocardial 123I-mIBG cross-calibration phantom study

AimPlanar myocardial 123I-meta-iodobenzylguanidine (123I-mIBG) scintigraphy is a highly reproducible technique. However, differences in collimator use are one of the most important factors that cause variation among institutions and studies in heart-to-mediastinum (H/M) ratio. Therefore, standardization among various gamma camera-collimator combinations is needed. Previously, a phantom has been developed to cross-calibrate different acquisition conditions in Japan. For further cross-calibration of European myocardial 123I-mIBG imaging, the aim of this study was to collect 123I-mIBG data for H/M ratios from common European gamma camera vendors. Methods210 experiments were performed in 27 European institutions. Based on these experiments, conversion coefficients for each gamma camera-collimator combination were calculated. An averaged conversion coefficient of 0.88 was used to calculate a standardized H/M ratio. ResultsOn average, LE-collimator-derived H/M ratios were significantly lower compared to ME-collimator-derived H/M ratios. The mean conversion coefficients ranged from 0.553 to 0.605 for the LE-collimator group and from 0.824 to 0.895 for the ME-collimator group. ConclusionClinically established H/M ratios can be converted into standardized H/M ratios using cross-calibrated conversion coefficients. This standardization is important for identifying appropriate thresholds for adequate risk stratification. In addition, this cross-calibration enables comparison between different national and international data.

Diagnosis of dementia with Lewy bodies: can 123I-IMP and 123I-MIBG scintigraphy yield new core features?

Since the clinical symptoms of different types of dementia frequently overlap, especially in the earlier stages at onset, it is difficult to distinguish dementia with Lewy bodies (DLB) from other neurodegenerative dementias based on their clinical manifestations alone. Nuclear medicine imaging has been reported as a high-value index for the objective evaluation and diagnosis of DLB. The aim of this study was to evaluate whether nuclear medicine imaging findings may yield core features to be added to the diagnosis of DLB. We enrolled 332 patients with suspected DLB. All were evaluated by both 123I-metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy and 123I-labelled N-isopropyl-p-iodoamphetamine (123I-IMP). brain perfusion single-photon emission CT. The final clinical diagnosis indicated probable DLB in 92 patients (40 males, 52 females; mean age ± standard deviation, 77.4 ± 6.4 years; range, 56-89 years); 240 patients (98 males, 142 females; mean age, 75.5 ± 9.0 years; range, 70-87 years) were recorded as being without DLB. The accepted core features used for clinical evaluations were fluctuating cognition, visual hallucinations and Parkinsonism. The nuclear medicine evaluation indices were the severity score of cerebral blood flow on 123I-IMP scintigraphs of the posterior cingulate and praecuneus and a reduction in the blood flow in the occipital lobe. For 123I-MIBG evaluation, we recorded the early and delayed heart-to-mediastinum (H/M) ratios and the washout rate. Univariate and multivariate analyses of fluctuating cognition, visual hallucinations, Parkinsonism and early H/M ratio in patients with probable and without DLB revealed significant differences. Parameters based on 123I-IMP studies did not show any significant differences by multivariate analysis. The area under the curve for the early H/M ratio was 0.918; for fluctuating cognition, visual hallucinations and Parkinsonism, it was 0.693, 0.760 and 0.611, respectively, by receiver-operating characteristic analysis. The early H/M ratio of <2.0 on 123I-MIBG scintigraphs was of the highest diagnostic accuracy. The sensitivity, specificity and accuracy for the diagnosis of probable DLB were 82.4%, 96.3% and 92.5%, respectively. The early H/M ratio obtained by 123I-MIBG myocardial scintigraphy can serve as a reliable diagnostic index for the core clinical features of DLB. It can be used for the early diagnosis and treatment of DLB. Advances in knowledge: 123I-MIBG myocardial scintigraphy performed at the initial clinical examination can facilitate the early identification or exclusion of DLB and the early H/M ratio may be a diagnostic biomarker for DLB.

The use of Cardiac 123I-mIBG Scintigraphy in Clinical Practice: The Necessity to Standardize!

Cardiac adrenergic imaging has a great potential in a wide variety of clinical applications. Cardiac 123I-meta-iodobenzylguanidine (123I-mIBG) scintigraphy has a key role to assess chronic heart failure (CHF) by risk stratifying patients for cardiac events. The mIBG is a norepinephrine (NE) analogue that can evaluate cardiac sympathetic activity by assessing the down expression of β-adrenergic receptor (β-AR) in CHF. Furthermore, 123I-mIBG scintigraphy in combination with other parameters of left ventricular function can be used to identify the best responder for implantable cardiac devices, as well as to assess oncological cardiotoxicity. Despite its usefulness, 123I-mIBG scintigraphy is not widely performed because of the lack of standardization between different institutions. Thus, standardization and validation may contribute to its acceptance in clinical setting.

神経芽腫診断における^(131)I-MIBG シンチグラフィの臨床経験

神経芽腫診断における^(131)I-MIBG シンチグラフィの臨床経験