123I-MIBG Scintigraphy Research Articles

Severe polyuria after the resection of adrenal pheochromocytoma

A 73-year-old male patient with hypertension and hyperglycemia was referred to our hospital because of a diagnosis regarding his left adrenal tumor. Because the levels of urinary metanephrine and normetanephrine were elevated, and (131) I-MIBG scintigraphy showed intense uptake in the adrenal tumor, the tumor was diagnosed as a pheochromocytoma. An adrenalectomy was carried out. Severe polyuria, which was accompanied by a rapid decrease in central venous pressure, started 1 hour after the operation. Urine output of more than 8000 mL/day continued until the 16th postoperative day. Plasma antidiuretic hormone (ADH) levels were within the normal range. Plasma human atrial natriuretic peptide (hANP) and brain natriuretic peptide (BNP) were elevated postoperatively, and the elevation of these peptides was one possible cause for the severe polyuria. Because ADH levels in the tumor fluid were not elevated, the tumor was not an ADH-secreting tumor. Urinary β2-microglobulin was significantly elevated after the operation, thus suggesting that renal tubule dysfunction might also have been involved in the polyuria. However, the mechanism of polyuria after the resection of adrenal pheochromocytoma is not fully understood. Polyuria after the resection of adrenal pheochromocytoma is extremely rare, and the present subject is the second case to date.

123I-MIBG imaging detects cardiac involvement and predicts cardiac events in Churg-Strauss syndrome

In Churg-Strauss syndrome (CSS) it is important to detect cardiac involvement, which predicts poor prognosis. This study evaluated whether (123)I-metaiodobenzylguanidine (MIBG) scintigraphy could detect cardiac damage and predict cardiac events in CSS. (123)I-MIBG scintigraphy was performed in 28 patients with CSS, 12 of whom had cardiac involvement. The early and delayed heart to mediastinum ratio (early H/M and delayed H/M) and washout rate were calculated by using (123)I-MIBG scintigraphy and compared with those in control subjects. Early H/M and delayed H/M were significantly lower and the washout rate was significantly higher in patients with cardiac involvement than in those without and in controls (early H/M, p = 0.0024, p = 0.0001; delayed H/M, p = 0.0002, p = 0.0001; washout rate, p = 0.0012, p = 0.0052 vs those without and vs controls, respectively). Accuracy for detecting cardiac involvement was 86% for delayed H/M and washout rate and 79% for early H/M and B-type natriuretic peptide (BNP). Kaplan-Meier analysis showed significantly lower cardiac event-free rates in patients with early H/M ≤ 2.18 and BNP > 21.8 pg/ml than those with early H/M > 2.18 and BNP ≤ 21.8 pg/ml (log-rank test p = 0.006). Cardiac sympathetic nerve function was damaged in CSS patients with cardiac involvement. (123)I-MIBG scintigraphy was useful in detecting cardiac involvement and in predicting cardiac events.

Sequential imaging analysis using MIBG scintigraphy revealed progressive degeneration of cardiac sympathetic nerve in Parkinson’s disease

Metaiodobenzylguanidine (MIBG) cardiac scintigraphy was used to differentiate Parkinson's disease (PD) with Lewy body pathology from other degenerative parkinsonisms. MIBG cardiac scintigraphy demonstrates the extent of degeneration of myocardial post-ganglionic sympathetic nerves in patients with PD. Because of its specificity for Lewy body (LB) pathology, MIBG scan might also be useful biomarker for the neurodegeneration attributed to PD. To estimate the utility of the imaging technique as a biomarker, we conducted sequential imaging analysis and power analysis. Sixty-three patients who met the UK PD Society Brain Bank criteria were enrolled in this study. (123) I-MIBG myocardial scintigraphy was performed on all subjects, and the heart to mediastinum (H/M) ratio was calculated. A second imaging session was carried out after a mean interval of 268 days. Sequential imaging revealed a 2.9% decline of the H/M ratio from the baseline to the follow-up image, which reached statistical significance, but the power analysis showed that a relatively large number of patients would be required to demonstrate the neuroprotective effects of any therapy. Sequential imaging using (123) I-MIBG myocardial scintigraphy revealed progressive degeneration of the cardiac sympathetic nerve in 63 patients with PD. Although careful elimination of other disease conditions that damage the cardiac sympathetic nerve system is necessary, (123) I-MIBG myocardial scintigraphy may be a useful addition to clinical trials that intend to prove neuroprotection among patients with PD.

Iodine-123-metaiodobenzylguanidine imaging can predict future cardiac events in heart failure patients with preserved ejection fraction

Iodine-123-metaiodobenzylguanidine ((123)I-MIBG) has been used to assess the function of the cardiac sympathetic nervous system in patients with chronic heart failure (HF). The usefulness of (123)I-MIBG imaging for evaluating patients with heart failure with preserved ejection fraction (HFPEF) has not been established. We performed (123)I-MIBG scintigraphy and echocardiography and measured the plasma brain natriuretic peptide (BNP) levels of 117 consecutive HF patients (64 men, mean age 66±14years) with a left ventricular ejection fraction (LVEF) of ≥50% who were admitted to our hospital. Patients were divided into 2 groups according to the New York Heart Association (NYHA) functional class. The (123)I-MIBG delayed heart-to-mediastinum (H/M) ratio was significantly lower, and the washout rate (WR) was higher in patients with HFPEF with advanced NYHA functional class (NYHA functional class I and II vs. III: 1.90±0.34 vs. 1.49±0.32, p<0.0001; 25.9±13.4 vs. 46.9±16.3%, p<0.0001, respectively). On the other hand, the (123)I-MIBG WR was not correlated with LVEF and had a weak correlation with plasma BNP levels (R=0.207, p=0.0346). Moreover, patients with a high (123)I-MIBG WR showed a poor clinical outcome (p=0.0033). (123)I-MIBG imaging provides independent prognostic information in patients with HFPEF.

Serial cardiac 123I-metaiodobenzylguanidine scintigraphic studies are more useful for predicting cardiac death than one-time scan in patients with chronic heart failure: sub-analysis of our previous report

Many studies have shown a one-time ¹²³I-metaiodobenzylguanidine (MIBG) scan during a stable period to be useful for determining the prognosis of patients with chronic heart failure (CHF). However, we recently reported that the delta washout rate (WR) determined from serial ¹²³I-MIBG scintigraphic studies is the best prognostic value in patients with CHF. A total of 208 patients with CHF (left ventricular ejection fraction <45%), but no cardiac events for at least 5 months, were identified on the basis of a history of decompensated acute heart failure requiring hospitalization. The patients underwent ¹²³I-MIBG scintigraphy and echocardiography just before leaving the hospital and after 6 months of treatment. We evaluated two models for predicting cardiac death using the Cox proportional hazards regression analysis. In addition to clinical characteristics, New York Heart Association functional class and pharmacotherapy, one model included variables of baseline scintigraphic and echocardiographic parameters (model A), and the other model included those of delta (i.e. follow-up minus baseline) scintigraphic and echocardiographic parameters (model B). Of the 208 patients, 56 experienced fatal cardiac events during the study. In model A, a Cox proportional hazards analysis showed baseline WR ≥50% to be the only independent predictor of cardiac death (hazard ratio=2.335, 95% confidence interval=1.142-4.774, P=0.020). In model B, delta-WR≥-5% was the only incremental predictor of cardiac death (hazard ratio=4.444, 95% confidence interval=1.511-13.069, P=0.009). The survival rates of patients with a delta-WR of less than -5% were significantly higher for those with a baseline WR of less than 50% (P=0.036). Moreover, high delta-WR was the best predictor compared with single scan, single echocardiography, and their combination evaluated by the global χ² analysis. Baseline WR and delta-WR obtained from ¹²³I-MIBG scintigraphy can be used as independent predictors of cardiac death, and two ¹²³I-MIBG scintigraphic studies are more useful than a one-time scan in stabilized patients with CHF.

False-positive radio-iodinated metaiodobenzylguanidine (123I-MIBG) accumulation in a mast cell-infiltrated infantile haemangioma

Radio-iodinated metaiodobenzylguanidine ((123)I-MIBG) is used for the detection and staging of neuroblastoma, pheochromcytoma and other neuroendocrine tumours in diagnostic nuclear medicine. A specific uptake and storage mechanism provides the basis for imaging with (123)I-MIBG. Nevertheless, cases of false-positive (123)I-MIBG scintigraphy with accumulation in non-chromaffin tumours have been described. Here, we present a case of a false-positive (123)I-MIBG scan in a case of a mast-cell infiltrated infantile haemangioma and discuss the possible uptake mechanism.

A novel mutation of the Succinate Dehydrogenase B Gene in a Korean Family with Pheochromocytoma

Pheochromocytoma is a tumor that originates from the adrenal cortex and sympathetic chains. Most pheochromocytomas are sporadic, whereas others occur as hereditary syndromes. Familial pheochromocytoma has been frequently found in association with various mutations in genes of the succinate dehydrogenase family. A 21-year-old Korean male presented with recurrent chest tightness, severe headache, and hypertension. He was diagnosed as pheochromocytoma based on a 24-hour urine test, abdominal computed tomography, and (131)I-MIBG scintigraphy. Genomic DNA was extracted from the patient's whole blood. Primers covering all the coding regions and flanking introns of succinate dehydrogenase (SDH) B, C and D genes were designed and synthesized, and a DNA sequence analysis was performed using the polymerase chain reaction. Direct sequencing of the SDHB gene revealed a deletion of nucleotide 757 (thymidine) in exon 7. This thymidine deletion caused a shift in the reading frame that created a downstream stop codon and a truncated product (p.Cys253ValfsX5). Although the patient had no family history of pheochromocytoma, his father had the same mutation. We report a novel SDHB gene mutation from a Korean family with pheochromocytoma. This is the first report of pheochromocytoma with a confirmed SDHB germline mutation in Korea.

Washout Rate of Cardiac Iodine-123 Metaiodobenzylguanidine is High in Chronic Heart Failure Patients With Central Sleep Apnea

Background The association between sleep-disordered breathing (SDB) assessed by polysomnography and cardiac sympathetic nerve activity (SNA) assessed by cardiac iodine-123 metaiodobenzylguanidine (123I-MIBG) imaging has not been investigated in patients with chronic heart failure (CHF). Methods and Results We performed cardiac 123I-MIBG scintigraphy and overnight polysomnography in 59 patients with stable CHF. The patients were classified into the 3 groups: 19 with no or mild SDB (NM-SDB, apnea-hypopnea index <15); 21 with central sleep apnea (CSA), and 19 with obstructive sleep apnea (OSA). The cardiac washout rate (WR) of 123I-MIBG was obtained from initial and delayed planar 123I-MIBG images. The WR was higher in patients with CSA (54.2 ± 11.6%) than in those with OSA (37.9 ± 8.6%, P < .05) or NM-SDB (40.8 ± 8.8%, P < .05). The WR correlated positively with central apnea index (ρ = 0.40, P = .002). A stepwise multiple regression analysis selected CSA and plasma brain natriuretic peptide levels as independent variables associated with the WR. Conclusions The WR was higher in CHF patients with CSA than in those with OSA or NM-SDB, and CSA was independently associated with the WR, suggesting a link of CSA to increased cardiac SNA in CHF.

Cardiac sympathetic denervation precedes nigrostriatal loss in the E46K mutation of the α-synuclein gene (SNCA)

Here we report the case of an asymptomatic carrier of the E46K substitution in alpha-synuclein gene where we have documented that cardiac sympathetic denervation precedes nigrostriatal dopaminergic loss. She has been followed up regularly with standard neurological examination, UPDRS, neuropsychological formal testing, parkinson disease sleep scale-PDSS, Epworth scale, Hamilton-D scale, SCOPA Aut, orthostatic hypotension test, brief smell identification test, polysomnography, cerebral 123-I-FP-CIT SPECT, and, 123I-MIBG cardiac scintigraphy. She shows no presence of orthostatic hypotension. Olfactory test results demonstrate normal limits. In the PSG the nocturnal sleep shows mild abnormalities although the sleep efficiency and stage proportion remain under normal limits. The 123-I-FP-CIT SPECT is normal; in contrast, the 123I-MIBG cardiac scintigraphy shows a complete lack of isotopic uptake compatible with a severe sympathetic myocardial denervation. This example of monogenic autosomal dominant parkinsonism due to an alpha-synuclein mutation favours the hypothesis that peripheral autonomous nervous system involvement occurs earlier than the CNS degeneration.

Cardiac autonomic neuropathy in patients with diabetes and no symptoms of coronary artery disease: comparison of 123I-metaiodobenzylguanidine myocardial scintigraphy and heart rate variability

PurposeThe purpose of this study was to evaluate the prevalence of cardiac autonomic neuropathy (CAN) in a cohort of patients with type 2 diabetes, truly asymptomatic for coronary artery disease (CAD), using heart rate variability (HRV) and 123I-metaiodobenzylguanidine (123I-mIBG) myocardial scintigraphy.MethodsThe study group comprised 88 patients with type 2 diabetes prospectively recruited from an outpatient diabetes clinic. In all patients myocardial perfusion scintigraphy, CAN by HRV and 123I-mIBG myocardial scintigraphy were performed. Two or more abnormal tests were defined as CAN-positive (ECG-based CAN) and one or fewer as CAN-negative. CAN assessed by 123I-mIBG scintigraphy was defined as abnormal if the heart-to-mediastinum ratio was <1.8, the washout rate was >25%, or the total defect score was >13.ResultsThe prevalence of CAN in patients asymptomatic for CAD with type 2 diabetes and normal myocardial perfusion assessed by HRV and 123I-mIBG scintigraphy was respectively, 27% and 58%. Furthermore, in almost half of patients with normal HRV, 123I-mIBG scintigraphy showed CAN.ConclusionThe current study revealed a high prevalence of CAN in patients with type 2 diabetes. Secondly, disagreement between HRV and 123I-mIBG scintigraphy for the assessment of CAN was observed.

Functional Imaging of Neuroendocrine Tumors: A Head-to-Head Comparison of Somatostatin Receptor Scintigraphy, 123I-MIBG Scintigraphy, and 18F-FDG PET

Functional techniques are playing a pivotal role in the imaging of cancer today. Our aim was to compare, on a head-to-head basis, 3 functional imaging techniques in patients with histologically verified neuroendocrine tumors: somatostatin receptor scintigraphy (SRS) with (111)In-diethylenetriaminepentaacetic acid-octreotide, scintigraphy with (123)I-metaiodobenzylguanidine (MIBG), and (18)F-FDG PET. Ninety-six prospectively enrolled patients with neuroendocrine tumors underwent SRS, (123)I-MIBG scintigraphy, and (18)F-FDG PET on average within 40 d. The functional images were fused with low-dose CT scans for anatomic localization, and the imaging results were compared with the proliferation index as determined by Ki67. The overall sensitivity of SRS, (123)I-MIBG scintigraphy, and (18)F-FDG PET was 89%, 52%, and 58%, respectively. Of the 11 SRS-negative patients, 7 were (18)F-FDG PET-positive, of which 3 were also (123)I-MIBG scintigraphy-positive, giving a combined overall sensitivity of 96%. SRS also exceeded (123)I-MIBG scintigraphy and (18)F-FDG PET based on the number of lesions detected (393, 185, and 225, respectively) and tumor subtypes. (123)I-MIBG scintigraphy was superior to (18)F-FDG PET for ileal neuroendocrine tumors, and (18)F-FDG PET was superior to (123)I-MIBG scintigraphy for pancreaticoduodenal neuroendocrine tumors. The sensitivity of (18)F-FDG PET (92%) exceeded that of both SRS (69%) and (123)I-MIBG scintigraphy (46%) for tumors with a proliferation index above 15%. The overall sensitivity of (123)I-MIBG scintigraphy and (18)F-FDG PET was low compared with SRS. However, for tumors with a high proliferation rate, (18)F-FDG PET had the highest sensitivity. The results indicate that, although SRS should still be the routine method, (18)F-FDG PET provides complementary diagnostic information and is of value for neuroendocrine tumor patients with negative SRS findings or a high proliferation index.

123I-Meta-Iodobenzylguanidine Scintigraphy for the Detection of Neuroblastoma and Pheochromocytoma: Results of a Meta-Analysis

(123)I-mIBG scintigraphy has been in clinical use for more than 20 yr for diagnostic assessment of patients with neural crest and neuroendocrine tumors. Prospective validation of the performance characteristics of this method has recently been published. A meta-analysis was performed to obtain best estimates of performance characteristics of (123)I-mIBG imaging for the two most common applications, evaluation of patients with neuroblastoma and pheochromocytoma. Articles published between 1980 and 2007 were identified from searches of multiple computer databases, including MEDLINE, BIOSIS, EMBASE, and SciSearch. Primary inclusion criteria were: acceptable reference standard(s) for confirming subjects with disease (histopathology and/or a combination of imaging and catecholamine results); reference standards applied to all subjects who received (123)I-mIBG; and data on a minimum of 16 patients confirmed to have or not have the disease(s) under consideration. Two physician reviewers independently evaluated all articles against the inclusion/exclusion criteria. Twenty-two of 100 articles reviewed were included in the final analysis. The two reviewers extracted the data from eligible articles using a standardized form, capturing both study quality and efficacy information. Disagreements were resolved by consensus. Sensitivity of (123)I-mIBG scans for detection of neuroblastoma was 97% [95% confidence interval (CI), 95 to 99%]; data were insufficient to estimate specificity. For pheochromocytoma, with application of the random-effects model, sensitivity and specificity were 94% (95% CI, 91-97%) and 92% (95% CI, 87-98%), respectively. Based upon the literature, (123)I-mIBG scintigraphy has sensitivity and specificity greater than 90% for detection of neuroblastoma and pheochromocytoma.

Recent developments in innervation imaging using iodine-123-metaiodobenzylguanidine scintigraphy in Lewy body diseases

Radiolabeled metaiodobenzylguanidine (MIBG) is an analog of guanethidine and is taken up by the postganglionic presynaptic nerve endings. MIBG uptake in the heart correlates with adrenergic function, which can be reduced in Lewy body diseases. We described the recent developments in innervation imaging using (123)I-MIBG scintigraphy in Lewy body diseases including Parkinson's disease and dementia with Lewy bodies. Particularly, we underlined the role of MIBG scintigraphy in differential diagnosis of movement disorders. As described by recent studies, MIBG scintigraphy is a valuable diagnostic tool for differentiation between Lewy body diseases and parkinsonian syndromes or other movement disorders with parkinsonism. Furthermore, this method may provide a powerful differential diagnostic tool between dementia with Lewy bodies and Alzheimer's disease. We also reported the results of clinical investigations about the correlation between characteristics of Parkinson's disease and myocardial MIBG uptake.

Efeito do carvedilol a curto prazo na atividade simpática cardíaca pela cintilografia com 123I-MIBG

Autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine (123I-MIBG) scintigraphy imaging of the heart. to evaluate the cardiac sympathetic activity through 123I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF) < 45%. Sixteen patients, aged 56.3 +/- 12.6 years (11 males), with a mean LVEF of 28% +/- 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with 123I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine) were measured; the radioisotope ventriculography (RIV) was performed before and after a three-month therapy with carvedilol. Patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8%) and 9 were FC II (56.2%), (p = 0.0001). The mean LVEF assessed by RIV increased from 29% to 33% (p = 0.017). There was no significant variation in cardiac adrenergic activity assessed by 123I-MIBG (early and late resting images and washout rate). No significant variation was observed regarding the measurement of catecholamines. The short-term treatment with carvedilol promoted the clinical and LVEF improvement. However, this was not associated to an improvement in the cardiac adrenergic activity, assessed by 123I-MIBG scintigraphy, as well as the measurement of circulating catecholamines.

Myocardial Iodine-123 Meta-Iodobenzylguanidine Imaging and Cardiac Events in Heart Failure: Results of the Prospective ADMIRE-HF (AdreView Myocardial Imaging for Risk Evaluation in Heart Failure) Study

The ADMIRE-HF (AdreView Myocardial Imaging for Risk Evaluation in Heart Failure) study prospectively evaluated iodine-123 meta-iodobenzylguanidine ((123)I-mIBG) imaging for identifying symptomatic heart failure (HF) patients most likely to experience cardiac events. Single-center studies have demonstrated the poorer prognosis of HF patients with reduced (123)I-mIBG myocardial uptake, but these observations have not been validated in large multicenter trials. A total of 961 subjects with New York Heart Association (NYHA) functional class II/III HF and left ventricular ejection fraction (LVEF) < or =35% were studied. Subjects underwent (123)I-mIBG myocardial imaging (sympathetic neuronal integrity quantified as the heart/mediastinum uptake ratio [H/M] on 4-h delayed planar images) and myocardial perfusion imaging and were then followed up for up to 2 years. Time to first occurrence of NYHA functional class progression, potentially life-threatening arrhythmic event, or cardiac death was compared with H/M (either in relation to estimated lower limit of normal [1.60] or as a continuous variable) using Cox proportional hazards regression. Multivariable analyses using clinical, laboratory, and imaging data were also performed. A total of 237 subjects (25%) experienced events (median follow-up 17 months). The hazard ratio for H/M > or =1.60 was 0.40 (p < 0.001); the hazard ratio for continuous H/M was 0.22 (p < 0.001). Two-year event rate was 15% for H/M > or =1.60 and 37% for H/M <1.60; hazard ratios for individual event categories were as follows: HF progression, 0.49 (p = 0.002); arrhythmic events, 0.37 (p = 0.02); and cardiac death, 0.14 (p = 0.006). Significant contributors to the multivariable model were H/M, LVEF, B-type natriuretic peptide, and NYHA functional class. (123)I-mIBG imaging also provided additional discrimination in analyses of interactions between B-type natriuretic peptide, LVEF, and H/M. ADMIRE-HF provides prospective validation of the independent prognostic value of (123)I-mIBG scintigraphy in assessment of patients with HF. (Meta-Iodobenzylguanidine Scintigraphy Imaging in Patients With Heart Failure and Control Subjects Without Cardiovascular Disease, NCT00126425; Meta-Iodobenzylguanidine [123I-mIBG] Scintigraphy Imaging in Patients With Heart Failure and Control Subjects Without Cardiovascular Disease, NCT00126438).

The Use of Functional Imaging in a Patient with Head and Neck Paragangliomas

A 21-yr-old male presented to the National Institutes of Health with five head and neck paragangliomas, found after treatment for chronic ear infections. Symptoms experienced by the patient included constant right ear pain, mild yellowish discharge from the right ear, decreased hearing, and a constant vibration sound on the right side but no symptoms related to catecholamine excess. On evaluation five paragangliomas were found on anatomical imaging (computed tomography and magnetic resonance imaging) as follows: 2.7- × 1.6-cm right carotid body tumor; 3.1- × 2.6-cm left carotid body tumor; 3.6- × 2.4-cm left glomus vagale tumor; 1.0- × 1.0-cm tumor in the left jugular fossa; and a 2.1- × 1.8-cm tumor in the right jugular fossa, which had caused extensive bone destruction involving the bony walls of the jugular fossa, the external auditory canal, the condylar fossa of the temporal mandibular joint, and the hypotympanic cavity of the right middle ear. Biochemistry (plasma fractionated catecholamines and metanephrines; 24 h fractionated urinary catecholamines and metanephrines) was unremarkable except for elevation of plasma dopamine to 437 pg/ml (reference range 3–46 pg/ml) and urinary dopamine to 431 μg per 24 h (reference range 65–400 μg per 24 h). Genetic testing revealed a mutation (p.Pro81Leu) in the succinate dehydrogenase subunit D gene. Head and neck paragangliomas are often biochemically silent (normal catecholamine and metanephrine values), making imaging a very important diagnostic tool (1,2). Here we present a patient whose head and neck paragangliomas were localized on computed tomography (CT) (Fig. 1​1)) and show avid uptake with four functional imaging techniques: 18F-fluorodihydroxyphenylalanine (18F-FDOPA) positron emission tomography (PET) (Fig. 2A​2A);); 18F-fluorodopamine (18F-FDA) PET/CT (Fig. 2B​2B);); 18F-fluoro-2-deoxy-d-glucose (18F-FDG) PET/CT (Fig. 2C​2C);); and 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy (Fig. 2D​2D).). Two of these modalities, 18F-FDA PET/CT and 123I-MIBG scintigraphy, are paraganglioma specific, targeting the norepinephrine transporters expressed in these tumors (3,4). Although 18F-FDG and 18F-FDOPA PET are not paraganglioma-specific imaging modalities, their efficacy for the localization of these tumors is represented here. 18F-FDOPA PET, in particular, showed avid uptake in all five tumors and should be considered a good imaging technique for head and neck paragangliomas, as previously reported (5). As demonstrated here, multiple imaging modalities, both anatomical and functional, can be used for the accurate localization of head and neck paragangliomas. However, because CT imaging is nonspecific for paragangliomas, functional imaging modalities are a good tool for confirming in the diagnosis of head and neck paragangliomas. Figure 1 Coronal reconstructed CT of the neck. There are five tumors identified: right (1) and left (2) glomus jugulare tumors; a left glomus vagale tumor (3); and left (4) and right (5) carotid body tumors. All five tumors demonstrate homogeneous enhancement. ... Figure 2 A, 18F-FDOPA PET. B, 18F-FDA PET/CT. C, 18F-FDG PET/CT. D, 123I-MIBG scintigraphy. Four functional imaging modalities were used to localize five head and neck paragangliomas: right (1) and left (2) glomus jugulare tumors; a left glomus vagale tumor ( ...

Olfactory dysfunction and cardiovascular dysautonomia in Parkinson’s disease

Several studies have reported that olfactory dysfunction is an early neuropathological manifestation of Parkinson's disease (PD). Reduced cardiac meta-iodobenzylguanidine ((123)I-MIBG) uptake may be one of the earliest signs of PD. We studied the relation of olfactory dysfunction to cardiovascular dysautonomia in patients with PD. The study group comprised 66 patients with PD (70.5 years) and 26 controls (70.3 years) for olfactory assessment, 21 controls (72.1 years) for cardiac (123)I-MIBG scintigraphy and heart rate variability (HRV), assessed using the coefficient of variation for RR intervals (HRV), and 23 controls (69.2 years) for orthostatic blood pressure response. Olfactory function was assessed by the odor stick identification test Japan (OSIT-J), and cardiovascular autonomic function was evaluated by (123)I-MIBG scintigraphy of the heart, the fall in orthostatic blood pressure, and HRV. Patients with PD had a significantly lower OSIT-J score than did the controls (4.1 +/- 3.0 vs. 9.9 +/- 1.7, p = 0.001). The OSIT-J score was unrelated to variables other than gender, including age, disease duration, motor score on the unified Parkinson's disease rating scale, score on the mini-mental state examination, motor phenotype, visual hallucinations, and dopaminergic medication on multiple regression and logistic regression analyses. The OSIT-J score was related to the heart/mediastinum ratio of cardiac (123)I-MIBG uptake, the fall in orthostatic blood pressure, and HRV, after adjustment for other clinical variables. Olfactory dysfunction in PD was, thus, significantly related to both cardiac sympathetic and parasympathetic dysfunction, as well as vascular sympathetic dysfunction. As non-motor symptoms of PD, olfactory dysfunction and autonomic network failure appear to be closely related in PD.

Cardiac 123I-MIBG uptake is reduced more markedly in patients with REM sleep behavior disorder than in those with early stage Parkinson's disease

We investigated cardiac uptake of 123I-metaiodobenzylguanidine (MIBG) in patients with REM sleep behavior disorder (RBD) and compared the findings with those of idiopathic Parkinson's disease (IPD). Thirteen RBD, 222 IPD and 50 controls underwent cardiac 123I-MIBG scintigraphy. Resulting heart-to-mediastinum (H/M) ratios were significantly lower in patients with RBD and IPD as compared to the control ratios. H/M ratios were lower for delayed than for early images in patients with RBD and IPD; whereas, the controls had higher ratios for delayed images. H/M ratios were significantly lower for patients with RBD than for those with IPD at Hoehn and Yahr stages 1 and 2. Disease duration did not differ between the two groups. Our study revealed that cardiac 123I-MIBG uptake was more markedly reduced in patients with RBD than in those with early stage IPD. RBD may not necessarily be a prodromal condition of IPD with respect to cardiac 123I-MIBG uptake results.

Reply: 123I-MIBG Scintigraphy and 18F-FDG PET in Neuroblastoma

Reply: ¹²³I-MIBG Scintigraphy and ¹⁸F-FDG PET in Neuroblastoma

123I-MIBG Scintigraphy and 18F-FDG PET in Neuroblastoma

TO THE EDITOR: We read with great interest a recent article by Sharp et al. ( [1][1] ) in which the authors compared the diagnostic utility of 123I-metaiodobenzylguanidine (MIBG) scintigraphy and 18F-FDG PET in neuroblastoma. In this retrospective study, a total of 113 paired 123I-MIBG and 18F-FDG