Comparison of Multivendor Single-Voxel MR Spectroscopy Data Acquired in Healthy Brain at 26 Sites.

Background The hardware and software differences between MR vendors and individual sites influence the quantification of MR spectroscopy data. An analysis of a large data set may help to better understand sources of the total variance in quantified metabolite levels. Purpose To compare multisite quantitative brain MR spectroscopy data acquired in healthy participants at 26 sites by using the vendor-supplied single-voxel point-resolved spectroscopy (PRESS) sequence. Materials and Methods An MR spectroscopy protocol to acquire short-echo-time PRESS data from the midparietal region of the brain was disseminated to 26 research sites operating 3.0-T MR scanners from three different vendors. In this prospective study, healthy participants were scanned between July 2016 and December 2017. Data were analyzed by using software with simulated basis sets customized for each vendor implementation. The proportion of total variance attributed to vendor-, site-, and participant-related effects was estimated by using a linear mixed-effects model. P values were derived through parametric bootstrapping of the linear mixed-effects models (denoted Pboot). Results In total, 296 participants (mean age, 26 years ± 4.6; 155 women and 141 men) were scanned. Good-quality data were recorded from all sites, as evidenced by a consistent linewidth of N-acetylaspartate (range, 4.4-5.0 Hz), signal-to-noise ratio (range, 174-289), and low Cramér-Rao lower bounds (≤5%) for all of the major metabolites. Among the major metabolites, no vendor effects were found for levels of myo-inositol (Pboot > .90), N-acetylaspartate and N-acetylaspartylglutamate (Pboot = .13), or glutamate and glutamine (Pboot = .11). Among the smaller resonances, no vendor effects were found for ascorbate (Pboot = .08), aspartate (Pboot > .90), glutathione (Pboot > .90), or lactate (Pboot = .28). Conclusion Multisite multivendor single-voxel MR spectroscopy studies performed at 3.0 T can yield results that are coherent across vendors, provided that vendor differences in pulse sequence implementation are accounted for in data analysis. However, the site-related effects on variability were more profound and suggest the need for further standardization of spectroscopic protocols. © RSNA, 2020 Online supplemental material is available for this article.

Natural History of Acromegaly: Incidences, Re-operations, Cancers, and Mortality Rates in a National Cohort.

BACKGROUND: Acromegaly is so rare that its natural history, including incidence, risk of cancers, and mortality rates, remains elusive. This natural study utilized a nationwide database to provide a better understanding of acromegaly's disease course. METHODS: A cohort of 1,195 acromegaly patients were identified and followed-up from 1997 to 2013. Incidence, operation, and re-operation rates were calculated. Excessive mortality and cancer risk related to acromegaly were estimated by standardized mortality ratio (SMR) and standardized incidence ratio (SIR). RESULTS: The incidence was 2.78 per million-person-years, with little gender predominance (female vs. male, 49.5 vs. 50.5%, respectively). There was female predominance only among 50 and 60 year-olds (incidence rate ratio: 1.37 and 1.43, p < 0.001 and p = 0.002). Among them, 673 (56.3%) had hypophysectomy surgery, and the young-onset (<40 years) patients had more re-operations (15.5%, p = 0.01). The overall mortality rate was 22.3 per 1,000 person-years, with a median survival of 4.67 years (with no gender differences, p = 0.38). The overall SMR of acromegaly patients was 1.41, and the onset-age-specific SMRs of the early- and middle-onset patients were higher than for those with late-onset. There were 87 newly diagnosed cancers in the cohort, with an incidence rate of 10.6 per 1,000 person-years (median 5.4 years). The overall SIR of cancers was 1.91, and there were no differences among gender, onset-age, and disease duration (all SIR >1, approximately 2). CONCLUSION: Acromegaly is associated with an excessive risk of mortality and two-fold higher risk of cancers. Patients with acromegaly should be managed appropriately after the diagnosis.

Altered hypothalamic functional connectivity in cluster headache: a longitudinal resting-state functional MRI study.

BACKGROUND: Neuroimaging studies implicate hypothalamic dysfunction in the pathogenesis of cluster headache (CH). Disruptions in non-traditional pain processing areas, including the cerebellum and visual cortex, have also been reported in CH. It is unknown whether the hypothalamus interacts significantly with these areas, and whether any such interactions vary between the 'in-bout' and 'out-of-bout' periods in CH. This study aimed to investigate the resting-state functional connectivity (FC) of the hypothalamus of patients with CH. METHODS: Using 3-T functional MRI, we conducted a seed-based resting-state intrinsic FC analysis of the hypothalamus in 18 episodic CH patients during in-bout and out-of-bout periods, and in 19 healthy controls. Correlations between hypothalamic FC and clinical variables were also assessed. RESULTS: Compared to controls, CH patients showed hypothalamic FC changes with the medial frontal gyrus and occipital cuneus during in-bout and out-of-bout periods. Compared to out-of-bout scans, in-bout scans revealed decreased hypothalamic FC with the medial frontal gyrus, precuneus, and cerebellar areas (tonsil, declive and culmen). Additionally, the annual bout frequency correlated significantly with the hypothalamic FC in the cerebellar culmen (r=-0.576, p=0.02) and cerebellar declive (r=-0.522, p=0.038). CONCLUSIONS: Our findings suggest that in CH, FC differences between the hypothalamus and its regional distribution extends beyond traditional pain processing areas, primarily to the cerebellar, frontal and occipital areas. These changes may be important and associated with CH pathophysiology.

Association of thalamic serotonin transporter and interleukin-10 in bipolar I disorder: a SPECT study.

OBJECTIVES: The serotonin hypothesis plays a critical role in the etiology of bipolar disorder (BD). Although many studies have demonstrated reciprocal relationships between serotonin metabolism and immune-inflammatory pathways that occur in depression, studies linking serotonergic function and cytokines are still limited concerning BD. The aim of this study was to investigate the interaction of brain serotonin transporter (SERT) and cytokines in BD. METHODS: Twenty patients with euthymic BD and 20 age- and sex-matched healthy controls (HC) were recruited. Single photon emission computed tomography with the radiotracer (123) I-ADAM was used for the SERT imaging. The specific uptake ratio, which represents SERT availability, was the primary measured outcome. Cytokines included the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and the anti-inflammatory cytokine interleukin-10 (IL-10). Cytokine concentration was measured using an enzyme-linked immunosorbent assay. RESULTS: SERT availability was significantly lower in the midbrain and caudate of patients with BD compared with HC, but not in the thalamus and putamen. IL-10 was significantly higher, whereas TNF-α was not different in euthymic patients with BD compared with HC. There was a significant association of SERT availability and IL-10 in the thalamus, but not in the midbrain, caudate, or putamen. CONCLUSIONS: Our results demonstrate the interaction of SERT availability and IL-10 in euthymic BD. This result may further explain the role of SERT and cytokines in the etiology of BD.