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Aims: The aim of this study was to assess the usefulness of somatostatin receptor scintigraphy (SRS) using 99mTc-[HYNIC, Tyr3]-octreotide (TOC) and 123I-metaiodobenzylguanidine (mIBG) in patients with SDHx-related syndromes in which paragangliomas were detected by computed tomography and to establish an optimal imaging diagnostic algorithm in SDHx mutation carriers. Methods: All carriers with clinical and radiological findings suggesting paragangliomas were screened by SRS and 123I-mIBG. Lesions were classified by body regions, i.e. head and neck, chest, abdomen with pelvis and adrenal gland as well as metastasis. Results: We evaluated 46 SDHx gene mutation carriers (32 index cases and 14 relatives; 28 SDHD, 16 SDHB and 2 SDHC). In this group, 102 benign tumors were found in 39 studied patients, and malignant disease was diagnosed in 7 patients. In benign tumors, the sensitivity of SRS was estimated at 77% and of 123I-mIBG at 22.0%. The SRS and mIBG sensitivity was found to be clearly region dependent (p < 0.001). The highest SRS sensitivity was found in head and neck paragangliomas (HNP; 91.4%) and the lowest was found in abdominal paragangliomas and pheochromocytomas (40 and 42.9%, respectively). The highest 123I-mIBG sensitivity was found in pheochromocytomas (sensitivity of 100%) and the lowest in HNP (sensitivity of 3.7%). In metastatic disease, SRS was superior to mIBG (sensitivity of 95.2 vs. 23.8%, respectively). Conclusion: SRS and 123I-mIBG single photon emission computed tomography (SPECT) sensitivity in SDHx patients is highly body region dependent. In malignant tumors, SRS is superior to 123I-mIBG SPECT. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Iodine-123 metaiodobenzylguanidine (123I-MIBG) lung uptake in the early phase has been proposed as a potential marker of endothelial function because MIBG behaves qualitatively similarly to norepinephrine in pulmonary circulation. Objectives: The purpose of the present study was to examine the lung uptake of 123I-MIBG in patients diagnosed with myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA)-associated vasculitis without clinical or radiological abnormalities of the thorax. Methods: Six patients with MPO-ANCA-associated vasculitis were enrolled. They had severe renal damage (mean creatinine: 5.1 mg/dl, mean blood urea nitrogen: 54.6 mg/dl), but no respiratory symptoms clinically or radiographic findings on chest computed tomography. The total lung to upper mediastinum ratio of 123I-MIBG uptake (L/M) 15 min after the injection was measured. The result was compared with those for 6 patients with renal damage due to other diseases (mean creatinine: 6.2 mg/dl, blood urea nitrogen: 51.7 mg/dl) and for 8 healthy subjects. Results: The mean value of L/M in patients with MPO-ANCA-positive vasculitis was 1.21 ± 0.04, which was significantly less than that of other groups (1.41 ± 0.06 for patients with renal failure and 1.45 ± 0.03 for normal volunteers). There were no significant differences in MIBG accumulation in the heart among the groups. Conclusions: The reduction in kinetic behavior of MIBG in the lung reflects the presence of pulmonary endothelial impairment in patients with MPO-ANCA-associated vasculitis, even though there are no clinical manifestations in the lungs. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

To characterize uremic cardiac autonomic neuropathy, we measured plasma catecholamines, analyzed the 24-hour heart rate variability (HRV), and acquired serial images with [sup 123] I-metaiodobenzylguanidine (MIBG) in 44 patients with chronic renal failure on hemodialysis and in 14 controls. Time-domain measures were calculated using the Marquette HRV program. MIBG clearance rates from the heart and lung were evaluated on planar images, and the regional MIBG uptake in the left ventricular myocardium was evaluated with single-photon emission computed tomography. Compared with controls, plasma dopamine and norepinephrine levels were elevated (p < 0.001 and p = 0.03, respectively), and all the time-domain measures of HRV were reduced in the patients (p < 0.001). The MIBG clearance rate from the heart was higher (p < 0.001), that from the lung was lower (p < 0.001), and the myocardial MIBG distribution was more heterogeneous in patients than in controls (total uptake score p ≤ 0.03). These variables were similar between 26 patients without and 18 patients with hypertension. Uremic cardiac autonomic neuropathy may be characterized by high plasma levels of dopamine and norepinephrine, reduced HRV, and abnormal MIBG kinetics in the heart with heterogeneous myocardial MIBG distribution, suggesting cardiac sympathetic overactivity and parasympathetic deterioration. In addition, abnormal MIBG kinetics in the lung may imply pulmonary sympathetic nervous dysfunction and/or endothelial dysfunction in uremic patients.Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]