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Previous studies show inconsistent results on the role of innervation imaging (with 123I-mIBG) in predicting late atrial fibrillation (AF) recurrence after catheter ablation (CA). These studies included patients with paroxysmal AF and studied prognostic value of post-CA I-123-mIBG parameters. Current study investigated the ability of pre CA 123-I-mIBG imaging to predict late AF recurrence in patients with persistent AF. 123I-mIBG cardiac imaging was performed before CA in 82 patients with persistent AF. Patient was followed for 12 months. Multivariable analysis demonstrated that late heart-to-mediastinum ratio (H/Mlate) and washout rate (WR) were independent predictors of AF recurrence. ROC-curve analysis data showed that H/Mlate 25.11 (sensitivity 70.6%, specificity 70.8.3%, AUC 0.712, P

Previous single-center or meta-analysis studies analyzed myocardial I-metaiodobenzylguanidine (I-MIBG) scintigraphy in a single image session and demonstrated low sensitivity and high specificity for discriminating Parkinson disease (PD) from atypical Parkinsonian syndromes (APS). This study aimed to assess diagnostic ability of myocardial I-MIBG scintigraphy at 2 phases to discriminate PD from APS.This hospital-based prospective study enrolled 162 PD and 26 APS patients who underwent 2 sequential I-MIBG scintigraphy evaluations. Patients were stratified into normal and decreased I-MIBG groups according to early and delayed heart-to-mediastinum (H/M) ratios. Patients with PD and normal I-MIBG uptake (initial delayed H/M ratio, ≥1.78) were considered scans without evidence of cardiac norepinephrine deficit (SWEND). Early and delayed H/M ratios on the initial and 2-year follow-up scintigraphs were studied. The diagnostic sensitivity and specificity were calculated from these confusion matrices and were analyzed according to receiver-operating characteristic curve analysis. A repeated-measures general linear model was used to investigate differences among groups over time in H/M ratio changes and washout rates.Follow-up I-MIBG scintigraphy analysis had a higher diagnostic sensitivity (89.5%) than the initial imaging (72.2%). The improved sensitivity was associated with a steeper decrease in H/M ratio in the SWEND group than in the APS group.Follow-up I-MIBG scintigraphy can identify cardiac sympathetic denervation and its progression in patients with PD and may be effective in discriminating PD from APS. A later decrease in myocardial I-MIBG uptake in the group with SWEND meets the Braak staging threshold hypothesis for synucleinopathy.

Purpose: To assess agreement between 123I-metaiodobenzylguanidine (MIBG) and Whole Body Magnetic Resonance Imaging with diffusion-weighted whole-body imaging with background body signal suppression (WB MRI-DWIBS) in High and Low, Intermediate risk neuroblastoma, a retrospective review was performed on MIBG and DWIBS paired scans acquired at diagnosis, response-to-therapy steps, after-surgery, off therapy.Methods: 80 paired MIBG and DWIBS scans were acquired for 31 patients between June 2009 and June 2019 within 30 days, without intercurrent therapy. SIOPEN Semi-quantitative scoring systems for NB with 12 body sections was applied at whole body MIBG and WB MRI-DWIBS acquired to evaluate the disease extent. We evaluated specificity, sensitivity, overall accuracy, positive predictive value (PPV) and negative predictive value (NPV) of WB MRI-DWIBS respect MIBG scintigraphy considered as gold standard, and vice versa.Results: DWIBS and MIBG images were concordant in 890 out of the 960 analyzed segments, with high agreement between the two techniques (kendal =0.85 PConclusions: DWIBS and MIBG images showed very high concordance. WB MRI may represent an alternative in weak-avid MIBG tumors and for follow up assessment. An integrated imaging model is proposed for HR, Low and Intermediate Risk protocols.

AIM: Chronic 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 METHODS: 135 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. RESULTS: During 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

OBJECTIVES: Cardiac I-MIBG imaging is an established technique for the diagnosis of dementia with Lewy bodies but various analysis methods are reported in the literature. We assessed different methods in the same cohort of patients to inform best practice. PATIENTS AND METHODS: Seventeen patients with dementia with Lewy bodies, 15 with Alzheimer's disease and 16 controls were included. Planar images were acquired 20 min and 4 h after injection. Nine operators produced heart-to-mediastinum ratios (HMRs) using freehand and 6, 7 and 8 cm diameter circular cardiac regions. Interoperator variation was measured using the coefficient of variation. HMR differences between methods were assessed using analysis of variance. Seven raters assessed the images visually. Accuracy was compared using receiver operating characteristic analysis. RESULTS: There were significant differences in HMR between region methods (P=0.006). However, with optimised cut-offs there was no significant difference in accuracy (P=0.2-1.0). The sensitivity was 65-71% and specificity 100% for all HMR methods. Variation was lower with fixed regions than freehand (P

Purpose: A robust method is required to standardise objective reporting of diagnostic 123I-mIBG images in neuroblastoma. Prerequisites for an appropriate system are low inter- and intra-observer error and reproducibility across a broad disease spectrum. We present a new reporting method, developed and tested for SIOPEN by an international expert panel. Method: Patterns of abnormal skeletal 123I-mIBG uptake were defined and assigned numerical scores [0–6] based on disease extent within 12 body segments. Uptake intensity was excluded from the analysis. Data sets from 82 patients were scored independently by six experienced specialists as unblinded pairs (pre- and post-induction chemotherapy) and in random order as a blinded study. Response was defined as ≥50 % reduction in post induction score compared with baseline. Results: In total, 1968 image sets were reviewed individually. Response rates of 88 % and 82 % were recorded for patients with baseline skeletal scores ≤23 and 24-48 respectively, compared with 44 % response in patients with skeletal scores >48 (p = 0.02). Reducing the number of segments or extension scale had a small but statistically negative impact upon the number of responses detected. Intraclass correlation coefficients [ICCs] calculated for the unblinded and blinded study were 0.95 at diagnosis and 0.98 and 0.99 post-induction chemotherapy, respectively. Conclusions: The SIOPEN mIBG score method is reproducible across the full spectrum of disease in high risk neuroblastoma. Numerical assessment of skeletal disease extent avoids subjective evaluation of uptake intensity. This robust approach provides a reliable means with which to examine the role of 123I mIBG scintigraphy as a prognostic indicator in neuroblastoma.

Introduction The purpose of this study was to investigate the diagnostic accuracy of cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy for the diagnosis of Parkinson's disease (PD), especially in the early stages. Methods We investigated 600 patients who underwent cardiac 123I-MIBG scintigraphy to diagnose their parkinsonism and/or cognitive impairment. Of 600 research subjects, 272 patients were clinically diagnosed with PD. MIBG uptake was compared between patients with PD and other diseases. Furthermore, the sensitivity and specificity of cardiac 123I-MIBG scintigraphy to diagnose PD was estimated by disease duration ( Results MIBG uptakes of PD patients were significantly decreased compared with those of other diseases except dementia with Lewy bodies and pure autonomic failure (p Conclusion Our findings demonstrated that cardiac 123I-MIBG scintigraphy had sufficient diagnostic accuracy to detect the early phase of PD. Indeed, this study of a large number of patients provides further external validation that MIBG has diagnostic ability to distinguish PD from atypical parkinsonism.

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. Resumo A avaliação da atividade adrenérgica cardíaca através de exames de imagem apresenta grande potencial em uma ampla variedade de aplicações clínicas. A cintilografia miocárdica com 123I-mIBG desempenha papel importante na avaliação de insuficiência cardíaca crônica (ICC) ao estratificar o risco de pacientes para eventos cardíacos. A mIBG, um análogo da norepinefrina (NE), pode ser utilizada para avaliar a atividade simpática cardíaca ao se analisar a diminuição da expressão do adrenorreceptor (AR) β na ICC. Além disso, a cintilografia miocárdica com 123I-mIBG em combinação com outros parâmetros de função ventricular esquerda pode ser usada para identificar o melhor respondedor a dispositivos cardíacos implantáveis, assim como avaliar cardiotoxicidade oncológica. Ainda que útil, a cintilografia miocárdica com 123I-mIBG não é amplamente realizada devido à falta de padronização entre as diferentes instituições. Portanto, sua padronização e validação podem contribuir para sua aceitação na prática clínica.

Neuroblastoma is the most common extracranial solid tumor in children and accounts for 8% to 10% of all childhood cancers. The spread of metastases is both lymphatic and hematogenous. Hematogenous route occurs most commonly in bone marrow and cortical bone; pancreatic metastases are very rare, and there are few reports about this topic in medical literature. We report the case of a 14-year-old boy who suffers a third relapse of neuroblastoma: in this patient I-MIBG confirms that lesions detected by CT were due to a relapse in pancreatic tissue and influenced subsequent therapeutic management.

I read with attention the article by Christensen et al. [(1)][1] titled “123I-MIBG scintigraphy in the subacute state of Takotsubo cardiomyopathy.” In this article, the authors studied 32 patients with Takotsubo cardiomyopathy (TTC), using iodine-123-labeled metaiodobenzylguanidine (123I-MIBG

Background: Falls are associated with poor prognosis in patients with Parkinson's disease (PD). Although several factors related to falls were reported in patients with PD, objective predictors of falls are not identified. We aimed to determine whether 123I-meta-iodobenzylguanidine (MIBG) cardiac scintigraphy could be a useful biomarker to predict falls. Methods: Forty-five patients with PD were enrolled in this study. These subjects were followed up more than 5 years after MIBG scintigraphy and were divided into two groups: one with decreased uptake of MIBG and the other without decreased uptake of MIBG. The cut-off value for the delayed heart-to-mediastinum ratio was 1.8. Kaplan-Meier analysis and a log-rank test were performed to test the predictive power of MIBG cardiac scintigraphy for falls. Univariate analysis was selected because we did not have appropriate data for adjustment, such as motor and cognitive assessment. Results: The group with decreased uptake of MIBG had a significantly higher incidence of falls than that without decreased uptake of MIBG (P = 0.022, log-rank test). Conclusions: Although the limitations of this study were lack of several key factors including motor and cognitive assessment, MIBG cardiac scintigraphy may be used to predict falls in patients with PD.

Purpose Scintigraphy using 123I-metaiodobenzylguanidine (123I-MIBG) is widely used for the detection of neuroblastic tumours. The aim of this study was to identify a possible correlation between the uptake intensity on 123I-MIBG SPECT and histopathology of neuroblastic tumours.

A 51-year-old woman with recurrent paragangliomas and catecholamine hypersecretion underwent F-FDG PET/CT for localization and evaluation of extent of disease. This revealed multiple F-FDG avid tumors with localization pattern suggesting multiple primary neoplasms of different origin rather than disseminated paraganglioma. Three additional nuclear medicine investigations were performed (F-DOPA PET/CT, Ga-DOTATOC PET/CT and I-MIBG scintigraphy) to further characterize tumor biology, guide diagnostic workup, and decide treatment strategy. Biopsies showed benign paraganglioma, mucinous adenocarcinoma of the cecum, renal cell carcinoma, and thyroid colloid nodule. Treatment strategy was based on tumor biology determined by the various PET and SPECT tracers used.

Whole-body 123I-Metaiodobenzylguanidine (mIBG) scintigraphy is used as primary image modality to visualize neuroblastoma tumours and metastases because it is the most sensitive and specific radioactive tracer in staging the disease and evaluating the response to treatment. However, especially in paediatric neuroblastoma, information from mIBG scans is difficult to extract because of acquisition difficulties that produce low definition images, with poor contours, resolution and contrast. These problems limit physician assessment. Current oncological guidelines are based on qualitative observer-dependant analysis. This makes comparing results taken at different moments of therapy, or in different institutions, difficult. In this paper, we present a computerized method that processes an image and calculates a quantitative measurement considered as its entropy, suitable for the identification of abnormal uptake regions, for which there is enough suspicion that they may be a tumour or metastatic site. This measurement can also be compared with future scintigraphies of the same patient. Over 46 scintigraphies of 22 anonymous patients were tested; the procedure identified 96.7% of regions of abnormal uptake and it showed a low overall false negative rate of 3.3%. This method provides assistance to physicians in diagnosing tumours and also allows the monitoring of patients’ evolution.

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PURPOSE: (18)F-Dopa positron emission tomography (PET)/CT has proved a valuable tool for the assessment of neuroendocrine tumours. So far no data are available on (18)F-dopa utilization in neuroblastoma (NB). Our aim was to evaluate the role of (18)F-dopa PET/CT in NB and compare its diagnostic value with that of (123)I-metaiodobenzylguanidine (MIBG) scintigraphy in patients affected by stage 3-4 NB. METHODS: We prospectively evaluated 28 paired (123)I-MIBG and (18)F-dopa PET/CT scans in 19 patients: 4 at the time of the NB diagnosis and 15 when NB relapse was suspected. For both imaging modalities we performed a scan-based and a lesion-based analysis and calculated sensitivity, specificity and accuracy. The standard of reference was based on clinical, imaging and histological data. RESULTS: NB localizations were confirmed in 17 of 19 patients. (18)F-Dopa PET/CT and (123)I-MIBG scintigraphy properly detected disease in 16 (94%) and 11 (65%), respectively. On scan-based analysis, (18)F-dopa PET/CT showed a sensitivity and accuracy of 95 and 96%, respectively, while (123)I-MIBG scanning showed a sensitivity and accuracy of 68 and 64%, respectively (p < 0.05). No significant difference in terms of specificity was found. In 9 of 28 paired scans (32%) PET/CT results influenced the patient management. We identified 156 NB localizations, 141 of which were correctly detected by (18)F-dopa PET/CT and 88 by MIBG. On lesion-based analysis, (18)F-dopa PET/CT showed a sensitivity and accuracy of 90% whereas (123)I-MIBG scintigraphy showed a sensitivity and accuracy of 56 and 57%, respectively (p < 0.001). No significant difference in terms of specificity was found. CONCLUSION: In our NB population (18)F-dopa PET/CT displayed higher overall accuracy than (123)I-MIBG scintigraphy. Consequently, we suggest (18)F-dopa PET/CT as a new opportunity for NB assessment.

Aim: The aim of the study was to evaluate the current role of 123I-MIBG scintigraphy in the detection and follow-up of patients with paragangliomas. Materials and Methods: 117 patients were referred for diagnostic 123I-MIBG scintigraphy based on a strong clinical suspicion, positive familial history and genetic testing, or for follow-up of paragangliomas.123I-MIBG images were analyzed and correlated with 111In-octreotide scintigraphy, CT or MRI results. Accuracy of the imaging method was calculated per patient and per tumor per site. Results: A total of 117 patients were referred for 123I-MIBG diagnostic imaging; 80 patients were diagnosed with paraganglioma; 66 patients had a single neuroendocrine tumor and 14 patients multiple tumors. The total number of all lesions in these patients was 172. 123I-MIBG scintigraphy demonstrated 65 lesions in 56 patients (overall sensitivity: 56.3%, specificity: 84%). Lesion-per-site analysis revealed that sensitivity and specificity significantly varied per tumor site (lowest sensitivity for the head and neck: 17.5% and lowest specificity for the abdomen: 87.5%). Hormones were elevated in 85 patients: 55 123I-MIBG tumors were positive and 35 tumors were negative. In 16 patients (13.7%) with a genetic burden and a single neuroendocrine tumor, 123I-MIBG whole-body imaging was successful at detecting a second tumor. In 2 patients (1.7%) with paragangliomas, 123I-MIBG unexpectedly detected metastases, so the restaging was properly done. Conclusion:123I-MIBG scintigraphy remains important in pheochromocytoma and functioning neuroendocrine tumors. The value of 123I-MIBG scintigraphy is high in familial syndromes with multiple neuroendocrine tumors at different sites, multifocal tumors, and relapsing and metastatic disease.

We highlight the dual role of I-MIBG scintigraphy in inverted-Takotsubo pattern cardiomyopathy, the diagnosis of which is sometimes challenging: Firstly, I-MIBG scintigraphy can show myocardial sympathetic dysfunction (low I-MIBG uptake) in the hypokinetic basal segments, sparing the left ventricle apex. It is helpful in the imaging diagnosis of inverted-Takotsubo pattern cardiomyopathy and confirms that acute dysfunction of myocardial sympathetic nerve endings occurs with this cardiomyopathy. Secondly, I-MIBG scintigraphy is an accurate imaging examination to detect and localize pheochromocytoma; it can help in the search for an endogenous cause of this adrenergic stress-related cardiomyopathy.

In patients with heart failure, increased sympathetic activity and cardiac sympathetic dysfunction are present and are related to an unfavorable outcome. In recent years, large-scale clinical trials have documented the benefits of pharmacological therapies aimed at limiting left ventricular remodeling and even reversing this process. These beneficial effects were associated with an increase in myocardial uptake of [123I]-metaiodobenzylguanidine (MIBG), a radiolabeled norepinephrine analog. However, despite the large number of published studies on cardiac [123I]-MIBG imaging, methodological and analytical limitations have interfered with the unequivocal interpretation of the imaging data. In this chapter, the assessment of myocardial sympathetic innervation with [123I]-MIBG is discussed with emphasis on patient preparation, image acquisition, and analysis. Special attention is given to overcoming the aforementioned possible methodological and analytical limitations. In conclusion, improving the standardization and validation of [123I]-MIBG myocardial scintigraphy and thus reducing variations in obtained results will lead to much more accepted application of the findings to clinical patient management.

Ziel: Wir untersuchten die klinische Aussagekraft der kombinierten Rontgen-CT (XCT)/SPECT-Technologie bei der 123I-MIBG-Szintigraphie von Patienten mit biochemischem (n = 25; 81%) und/oder klinischem (n=6; 19%) Verdacht auf Phaochromozytom. Methoden: 31 Patienten (19 Manner, 12 Frauen; mittleres Alter: 55 Jahre, Bereich: 31-79 Jahre) mit fokaler Anreicherung in der planaren 123I-MIBG-Szintigraphie wurden im Anschluss daran mittels einer Doppelkopf-Gammakamera mit integriertem Rontgentomographen (GE Medical Systems, Millenium VG mit Hawkeye, Milwaukee, USA) zur anatomischen Lokalisierung der 123I-MIBGHerde szintigraphiert. Ergebnisse: Bei 23 der 31 Patienten (74%) zeigten die Fusionsbilder eine physiologische MIBG-Anreicherung (z. B. intestinal, renal). Bei 2 Patienten (6%) war die mutmaslich intraadrenale MIBG-Anreicherung durch eine inhomogene Leberspeicherung verursacht. Bei weiteren 2 Patienten (6%) wurden die verdachtigen Herde eindeutig in den Nebennieren lokalisiert. Des Weiteren konnte bei 2 Patienten (6%) eindeutig zwischen Knochenmetastase und Lokalrezidiv differenziert werden. Bei den ubrigen 2 Patienten (6%) erwiesen sich Lasionen, die ursprunglich als Leberherde interpretiert worden waren, in der XCT/SPECT-Fusion als intraadrenal. Schlussfolgerung: Unsere Studie demonstriert die klinische Wertigkeit der kombinierten XCT/SPECT-Technik bei Patienten mit fokalen 123I-MIBG-Speicherungen in der Planarszintigraphie. Diese Kombination bietet eine hohere diagnostische Genauigkeit.

We report a 64-year-old man with diabetic chorea whom we investigated with dopamine transporter SPECT, 18F FDG PET, 99mTc ethylcysteinate dimer (ECD) SPECT, and 123I metaiodobenzylguanidine (MIBG) scintigraphy. Dopamine transporter SPECT revealed reduced 123I ioflupane binding in the bilateral striatum. 18F FDG PET showed metabolic dysfunction in the bilateral striatum, as shown in earlier studies. 99mTc ECD SPECT revealed reduced brain perfusion in the bilateral caudate nucleus and putamen. 123I MIBG scintigraphy revealed no cardiac sympathetic nerve dysfunction. Our case suggests a possible nigrostriatal presynaptic dopaminergic involvement in diabetic chorea.

Background Iodine 123 meta-iodobenzylguanidine (MIBG) scintigraphy has been used in patients with clinical suspicion of pheochromocytoma to confirm the nature of an adrenal or extraadrenal mass or to identify occult disease. Additionally, it may be used to identify unsuspected bilaterality or metastases in the setting of a known unilateral adrenal mass before operation. We sought to determine the role of 123I MIBG scintigraphy in this apparently routine preoperative setting. Our hypothesis was that 123I MIBG would provide additional preoperative information that could modify operative intervention. Methods All patients undergoing 123I MIBG scintigraphy at our institution between 1992 and 2002 were identified. MIBG results, operative procedures and findings, and pathologic findings were retrospectively reviewed and compared. Results The 123I MIBG scintigraphy was performed in a total of 315 patients. Of these, 48 were patients with an initial biochemical diagnosis of pheochromocytoma and a unilateral adrenal mass. 47 of the 48 (98%) primary scans were positive for a single focus of activity concordant with anatomic imaging data from computed tomography or magnetic resonance imaging and operative findings. The 123I MIBG did not reveal unsuspected metastatic or bilateral disease in any patient. Conclusion In this large series of patients undergoing 123I MIBG scintigraphy, the test served only to confirm diagnostic impressions and corroborate anatomic imaging. The 123I MIBG did not alter the operative management of any patient with a solitary adrenal lesion in the clinical context of biochemically-proven catecholamine excess.

Objective: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.Methods: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, 70–8...

After kidney transplantation, sympathetic renal nerves may reinnervate the allograft, but its functional significance is unknown.123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy determines org...

123I-metaiodobenzylguanidine (MIBG) scintigraph y has been used to predict prognosis of patients with dilated cardiomyopathy (DCM), although it is unknown which parameter of MIBG is the most useful clinically. We studied MIBG in 59 patients with DCM, and followed them up to evaluate the prognosis of DCM. Single photon emission tomography (SPET) and planar imaging were performed, both early (e) and 4 h (delayed, d) post-injection. 201 T (TL) SPET and radionuclide-ventriculograph y were also investigated. The total defect score of early and delayed MIBG and 201 Tl (MIBG D DS, MIBG d DS, TLDS) was analysed visually for each SPET image. The heart to mediastinum ratio (H/M) for both the early and delayed MIBG planar images and mvocardial washout rate at 4 h were analysed quantitatively. Sixteen patients died during follow-up. Cox Hazards univariate analysis selected washout rate (P

Summary Chemodectomas, or glomus tumours, are unusual head and neck paragangliomas. A non-invasive imaging technique, 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy, has long been used for the diagnosis of all types of paraganglioma. The aim of this study was to evaluate and compare classic 123I-MIBG scintigraphy with the more recent 111In-pentetreotide scintigraphy in the diagnosis and location of chemodectomas. We performed 121I-MIBG and 111In-pentetreotide scintigraphy in eight patients (7 females, 1 male) with histologically or radiologically confirmed chemodectomas (five carotid body and three jugulotympanie chemodectomas). 123I-MIBG uptake was visualized in four patients on planar views and SPET images (sensitivity 50%); uptake was low in three patients. Using 111In-pentetreotide scintigraphy, all chemodectomas in the eight patients were visualized (sensitivity 100%) and 111In-pentetreotide uptake was high in all cases. In conclusion, our results indicate that 111In-pentetreotide scintigraphy is superior to 123I-MIBG scintigraphy in the diagnosis and location of chemodectomas. 111In-pentetreotide or 123I-MIBG uptake suggests a neuroendocrine origin, providing important functional information in the diagnosis of chemodectomas. Moreover, 111In-pentetreotide scintigraphy permits a good classification of patients with or without somatostatin receptors in the chemodectoma in the application of pharmacological therapy with somatostatin analogues to inoperable tumours. The main therapeutic action of cold somatostatin analogues is to inhibit hormonal hypersecretion in different neuroendocrine tumours. In chemodectomas, however, the most important effect of somatostatin analogues is to reduce tumour volume or inhibit growth progression. (© 1998 Lippincott Williams & Wilkins)

The effect of exercise on the cardiac kinetics of 123I-MIBG was investigated in the present study. 123I-MIBG was administered intravenously at rest in 6 healthy male volunteers, and anterior planar and SPECT images were obtained 15 minutes, and 2 and 4 hours after administration (protocol A). After 4 weeks, 123I-MIBG was again administered intravenously at rest, and images were obtained 15 minutes later. After imaging, the subjects ran 10 km in approximately 1 hour, and anterior planar and SPECT images were obtained 2 and 4 hours after administration of 123I-MIBG (protocol B). The heart-to-mediastinum uptake ratio (H/M) was calculated from each anterior planar image, and the mean 123I-MIBG clearance from 15 minutes to 2 hours, and from 2 hours to 4 hours was calculated with a bull's eye display. The H/M was much lower after exercise. The mean clearance rate between 15 minutes and 2 hours in protocol B was significantly higher than that between 2 hours and 4 hours, and that between 15 minutes and 2 hours in protocol A. It was concluded that the clearance rate of 123I-MIBG may be a useful index of cardiac sympathetic nerve activity.

123I-MIBG myocardial scintigrams obtained in 2 cases with pure progressive autonomic failure are presented. In the less advanced case, 123I-MIBG myocardial SPECT disclosed uptake

123I-MIBG accumulation in focal nodular hyperplasia was demonstrated. A 16-year-old girl who received radiotherapy for neuroblastoma at the age of 5 presented for abdominal pain. Three MIBG-avid tumors within the liver were proven to be focal nodular hyperplasias through biopsy. Previous neuroblastoma was transformed to non-MIBG-avid ganglioneuroma. MIBG accumulation does not necessarily indicate the presence of neuroendocrine tumor.

Recent studies reported that lung 123I-MIBG uptake was impaired in many lung diseases and low uptake of lung 123I-MIBG is suggested to indicate the pulmonary endothelial dysfunction of pulmonary artery (PA). However, the clinical validation of 123I-MIBG scintigraphy for patients with pulmonary

The purpose of this study is to evaluate a new semi-quantitative estimation method using (123)I-MIBG retention ratio to assess response to chemotherapy for advanced neuroblastoma.Thirteen children with advanced neuroblastoma (International Neuroblastoma Risk Group Staging System: stage M) were examined for a total of 51 studies with (123)I-MIBG scintigraphy (before and during chemotherapy). We proposed a new semi-quantitative method using MIBG retention ratio (count obtained with delayed image/count obtained with early image with decay correction) to estimate MIBG accumulation. We analyzed total (123)I-MIBG retention ratio (TMRR: total body count obtained with delayed image/total body count obtained with early image with decay correction) and compared with a scoring method in terms of correlation with tumor markers.TMRR showed significantly higher correlations with urinary catecholamine metabolites before chemotherapy (VMA: r(2) = 0.45, P0.05, HVA: r(2) = 0.627, P0.01) than MIBG score (VMA: r(2) = 0.19, P = 0.082, HVA: r(2) = 0.25, P = 0.137). There were relatively good correlations between serial change of TMRR and those of urinary catecholamine metabolites (VMA: r(2) = 0.274, P0.001, HVA: r(2) = 0.448, P0.0001) compared with serial change of MIBG score and those of tumor markers (VMA: r(2) = 0.01, P = 0.537, HVA: 0.084, P = 0.697) during chemotherapy for advanced neuroblastoma.TMRR could be a useful semi-quantitative method for estimating early response to chemotherapy of advanced neuroblastoma because of its high correlation with urine catecholamine metabolites.

Cardiac sympathetic neuronal function and activity can be assessed noninvasively by the use of I-metaiodobenzylguanidine (I-MIBG), an analogue of norepinephrine [1]. In the past two decades, a large number of investigators have demonstrated decreased myocardial I-MIBG uptake in patients with chronic heart failure (CHF) and have shown that those with the lowest uptake tend to have the poorest prognosis [2–12]. There have also been findings suggesting that abnormalities of myocardial I-MIBG uptake may be predictive of increased risk of ventricular arrhythmia and sudden cardiac death [13, 14]. One factor that has constrained acceptance of cardiac I-MIBG imaging as a clinical management tool in heart failure has been the variability of the technical aspects of the procedure. Although most reports include the heart-to-mediastinum (H/M) ratio as the measure of myocardial uptake, the methods used to obtain this parameter have shown considerable variation. However, the influence of procedural and acquisition parameters on the reproducibility of this measurement technique have only occasionally been considered.

Cardiac support device implantation is a new and promising therapy for refractory heart failure. If functional and echocardiographic modifications have largely been reported following this procedure, there is a paucity of information in the clinical setting about cellular abnormalities modifications during the 'reverse remodeling' process. We report for the first time a clinical measurement of cardiac sympathetic function using 123I-MIBG scintigraphy following cardiac support device implantation.

Objective:Over recent years moderation of renal sympathetic nerve activity by catheter-based renal sympathetic denervation (RDN) has received a considerable amount of attention as a treatment potential for therapy-resistant hypertension. However, incomplete nerve disruption is a possible factor that

This Practice Point commentary discusses the findings and limitations of a retrospective study by Bhatia et al. that compared the performance of 123I-labeled metaiodobenzylguanide (123I-MIBG) scintigraphy with that of cross-sectional CT and MRI for the detection of pheochromocytomas. The sensitivity of 123I-MIBG scintigraphy for detection of adrenal pheochromocytomas was higher than that for extra-adrenal pheochromocytomas (85% versus 58%). Adrenal pheochromocytomas ≥5 cm in diameter were more likely to be detected by 123I-MIBG scintigraphy than those