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Abstract Individuals with prodromal symptoms of Lewy body disease (LBD), such as rapid eye movement sleep behavior disorder (RBD), often showed imaging defects similar to patients with Parkinson’s disease and dementia with Lewy bodies. We examined dopamine transporter (DaT) single-photon-emission computed tomography (SPECT) and metaiodobenzylguanidine (MIBG) scintigraphy in 69 high-risk subjects with ≥2 prodromal symptoms (dysautonomia, hyposmia, and probable RBD) and 32 low-risk subjects without prodromal symptoms, whom were identified through a questionnaire survey of health checkup examinees. The high-risk subjects had significantly worse scores on Stroop test, line orientation test, and the Odor Stick Identification Test for Japanese than the low-risk subjects. The prevalence of abnormalities on DaT-SPECT was higher in the high-risk group than in the low-risk group (24.6% vs. 6.3%, p = 0.030). A decreased uptake on DaT-SPECT was associated with motor impairment, and MIBG scintigraphy defects were associated with hyposmia. The simultaneous evaluation of DaT-SPECT and MIBG scintigraphy may capture a wide range of individuals with prodromal LBD.

Abstract Background Before radioiodine therapy for Graves’ disease, the estimated thyroid-absorbed dose is calculated based on various clinical parameters. However, the actual accumulation of iodine in the thyroid during radioiodine therapy is not determined. We validated the feasibility of post-therapeutic image-based thyroid dosimetry through quantitative single-photon emission computed tomography (SPECT) imaging and thyroid biokinetics and expanding the Medical Internal Radiation Dose Committee’s (MIRD) voxel dosimetry guidelines. Methods Forty-three patients with Graves’ disease who underwent radioiodine therapy were chosen as subjects for this retrospective analysis. We acquired patients’ SPECT images 24 h after oral administration. SPECT images were quantified using system volume sensitivity to calculate time-integrated activity coefficients on a voxel basis. Absorbed dose was obtained by convolving MIRD guideline voxel S values with time-integrated activity coefficients. To determine accuracy, we compared the results obtained using the post-therapeutic image-based absorbed-dose method (D̅ image,PVC) with absorbed doses calculated using the method described by the European Association of Nuclear Medicine (pre-therapeutic method; D EANM). Results Using image-based dosimetry as post-therapeutic dosimetry, we visualized the local accumulation and absorbed dose distribution of iodine in the thyroid. Furthermore, we determined a strong correlation (Pearson’s correlation coefficient = 0.89) between both dosimetries, using the regression equation: D̅ image,PVC = 0.94 × D EANM + 1.35. Conclusion Post-therapeutic image-based doses absorbed in the thyroid resembled those of pre-therapeutic EANM method-based absorbed doses. Additionally, the post-therapeutic image-based method had the advantage of visualizing thyroid iodine distribution, thus determining local dose distributions at the time of treatment. From these points, we propose that post-therapeutic image-based dosimetry could provide an alternative to standard pre-therapeutic dosimetry to evaluate dose response.

The usefulness of the parameters of biventricular function simultaneously measured using enhanced multi-detector computed tomography (MDCT) pulmonary angiography in patients with chronic thromboembolic pulmonary hypertension (CTEPH) has not been clarified. This study aimed to verify the correlation between left and right ventricular (RV) parameters and pulmonary vascular resistance (PVR). Patients who underwent enhanced MDCT before diagnostic right heart catheterization at Nagoya University Hospital between October 2014 and April 2021 were enrolled. The correlation of biventricular function and volume parameters with PVR was assessed. Eighty patients were retrospectively analyzed. Patients’ mean age was 65 ± 13 years, mean PVR was 9.1 (range, 6.1–11.3) Wood units, and mean end-systolic eccentricity index (esEI) was 1.76 ± 0.50. RV end-systolic volume (ESV) (p = 0.007), RV cardiac output (CO) (p < 0.001), RV ejection fraction (p < 0.001), LV end-diastolic volume (EDV) (p < 0.001), left ventricular (LV) ESV (p = 0.006), LVCO (p < 0.001), end-diastolic EI (p < 0.001), and esEI (p < 0.001) were significantly correlated with PVR. The LVEDV (p = 0.001) and esEI (p < 0.009) were independent predictors of PVR. Systolic pulmonary arterial pressure (PAP) (p < 0.001), diastolic PAP (p < 0.001), mean PAP (p < 0.001), right atrial pressure (p < 0.023), and PVR (p < 0.001) were significantly higher in the high esEI group than in the low esEI group. The esEI was a simple predictor of CTEPH severity.

Background: Imaging studies in Alzheimer’s disease (AD) have yet to answer the underlying questions concerning the relationship among tau retention, neuroinflammation, network disruption and cognitive decline. We compared the spatial retention patterns of 18F-THK5351 and resting state network (RSN) disruption in patients with early AD and healthy controls.Methods: We enrolled 23 11C-Pittsburgh compound B (PiB)-positive patients with early AD and 24 11C-PiB-negative participants as healthy controls. All participants underwent resting state functional MRI and 18F-THK5351 PET scans. We used scaled subprofile modeling/principal component analysis (SSM/PCA) to reduce the complexity of multivariate data and to identify patterns that exhibited the largest statistical effects (variances) in THK5351 concentration in AD and healthy controls.Findings: SSM/PCA identified a significant spatial THK5351 pattern composed by mainly three clusters including precuneus/posterior cingulate cortex (PCC), right and left dorsolateral prefrontal cortex (DLPFC) which accounted for 23.6% of the total subject voxel variance of the data and had 82.6% sensitivity and 79.1% specificity in discriminating AD from healthy controls. There was a significant relationship between the intensity of the 18F-THK5351 covariation pattern and cognitive scores in AD. The spatial patterns of 18F-THK5351 uptake showed significant similarity with intrinsic functional connectivity, especially in the PCC network. Seed-based connectivity analysis from the PCC showed significant decrease in connectivity over widespread brain regions in AD patients. An evaluation of an autopsied AD patient with Braak V showed that 18F-THK5351 retention corresponded to tau deposition, monoamine oxidase-B (MAO-B) and astrogliosis in the precuneus/PCC.Interpretation: We identified an AD-specific spatial pattern of 18F-THK5351 retention in the precuneus/PCC, an important connectivity hub region in the brain. Disruption of the functional connections of this important network hub may play an important role in developing dementia in AD.

We aimed to elucidate the distribution pattern of the positron emission tomography probe [18F]THK 5351, a marker for astrogliosis and tau accumulation, in healthy aging. We also assessed the relationship between THK5351 retention and resting state networks. We enrolled 62 healthy participants in this study. All participants underwent magnetic resonance imaging/positron emission tomography scanning consisting of T1-weighted images, resting state functional magnetic resonance imaging, Pittsburgh Compound-B and THK positron emission tomography. The preprocessed THK images were entered into a scaled subprofile modeling/principal component analysis to extract THK distribution patterns. Using the most significant THK pattern, we generated regions of interest, and performed seed-based functional connectivity analyses. We also evaluated the functional connectivity overlap ratio to identify regions with high between-network connectivity. The most significant THK distributions were observed in the medial prefrontal cortex and bilateral putamen. The seed regions of interest in the medial prefrontal cortex had a functional connectivity map that significantly overlapped with regions of the dorsal default mode network. The seed regions of interest in the putamen showed strong overlap with the basal ganglia and anterior salience networks. The functional connectivity overlap ratio also showed that three peak regions had the characteristics of connector hubs. We have identified an age-related spatial distribution of THK in the medial prefrontal cortex and basal ganglia in normal aging. Interestingly, the distribution’s peaks are located in regions of connector hubs that are strongly connected to large-scale resting state networks associated with higher cognitive function. [ABSTRACT FROM AUTHOR]

We retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation. [ABSTRACT FROM AUTHOR]

Histological chorioamnionitis (CAM) is one form of intrauterine inflammation that is often seen in cases of preterm birth and are usually confirmed based on pathological examination after delivery. Histological CAM is related to significant neonatal morbidity and mortality; however, its etiology is unknown. The objective of this study was to determine the risk factors for histological CAM, using medical background, including fetal heart rate (FHR) patterns in preterm birth cases. The preterm birth cases delivered between 28 and 36 weeks were categorized into two groups according to the presence of histological CAM. Ninety-five preterm infants were included: 48 infants without histological CAM and 47 cases with histological CAM. The odds ratio for histological CAM was adjusted for FHR patterns, gestational age, and delivery mode (vaginal delivery or Caesarean section). Logistic regression analysis showed that vaginal delivery and gestational age were associated with histological CAM (odds Ratio [OR]: 3.1, 95% confidence interval [CI]: 1.0-9.4, p < 0.05, and OR: 0.8, 95% CI: 0.6-0.9, p < 0.05, respectively). However, there were no specific FHR patterns associated with histological CAM. Our study indicates that in preterm birth cases, histological CAM is not related to any specific FHR pattern. However, labor uterine contraction and immature gestational age at the delivery are related to histological CAM. These results may provide better delivery management methods for preterm birth cases. [ABSTRACT FROM AUTHOR]

Objective: We compared the efficacies of 18F-fluoride positron emission tomography (18F-fluoride PET)/CT, 18F-fludeoxyglucose PET (18F-FDG PET)/CT, and 99mTc bone scintigraphy [planar and single photon emission CT (SPECT)] for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC). Methods: We examined 11 patients (8 females and 3 males; mean age ± standard deviation, 61.9 + 8.7 years) with DTC who had been suspected of having bone metastases after total thyroidectomy and were hospitalized to be given 131l therapy. Bone metastases were verified either when positive findings were obtained on both 131l scintigraphy and CT or when MRI findings were positive if MRI was performed. Results: Metastases were confirmed in 24 (13.6%) of 176 bone segments in 9 (81.8%) of the 11 patients. The sensitivities of 18F-fluoride PET/CT and 99mTc bone scintigraphy (SPECT) were significantly higher than those of 18F-FDG PET/CT and 99mTc bone scintigraphy (planar) (p < 0.05). The accuracies of 18F-fluoride PET/CT and 99mTc bone scintigraphy (SPECT) were significantly higher than that of 99mTc bone scintigraphy (planar) (p<0.05). Conclusion: The sensitivity and accuracy of 18F-fluoride PET/CT for the detection of bone metastases of DTC are significantly higher than those of 99mTc bone scintigraphy (planar). However, the sensitivity and accuracy of 99mTc bone scintigraphy (planar) are improved near to those of 18F-fluoride PET/CT when SPECT is added to a planar scan. The sensitivity of 18F-FDG PET/CT is significantly lower than that of 18F-fluoride PET/CT or 99mTc bone scintigraphy (SPECT). Advances in knowledge: This article has demonstrated first the high efficacy of 18F-fluoride PET/CT for the detection of bone metastases of DTC. [ABSTRACT FROM AUTHOR]

After daily treatments with Mt. Fuji ground water containing natural vanadium (approximately 65 μg/l) at doses of 0.53 μg/kg/day for 12 weeks, blood glucose (BG), serum hemoglobin A1C (HbA1C) levels and insulin secretion from the pancreas of Goto-Kakisaki (GK) rats, a genetic model of Type 2 diabetes, were improved. In GK rat liver insulin receptors, the binding properties of [125I] insulin, and the activities of insulin receptor β subunit and primary insulin-like growth factor-1β all recovered to normal levels of those found in Wistar rats. These results suggest that daily treatment with small concentrations of natural vanadium improves hyperglycemia by ameliorating liver insulin receptor activity. (Mol Cell Biochem 267: 203–207, 2004) [ABSTRACT FROM AUTHOR]

Aim: Previously, we devised a method for estimating123I labeled N-isopropyl-p-iodoamphetamine (123I IMP) arterial blood activity at 10 minutes after intravenous injection of 123I IMP (Ca10) without any blood sampling using 123I IMP autoradiography (ARG) acquisition data, and verified its usefulness for quantification of regional cerebral blood flow (rCBF). In this study, we attempted to develop an improved noninvasive method for estimating rCBF., Patients, Methods: 123I IMP studies with 23 patients and 15O-H2O positron emission tomography (PET) ARG studies with 20 patients were evaluated. Multiple regression analysis was used to estimate an integral of the arterial blood counts during the time after injection of 123I (∫Ca) using parameters from the time series of the lung counts and brain counts as the explanatory variables and the fraction [brain single-photon emission computed tomography (SPECT) average count / the mean of rCBFs (mean CBF) measured by 15O-H2O PET ARG method] as the objective variable., Results: The regression equation was as follows: Estimated ∫Ca = (7.09×10⁻³ · Cb12) - (1.57×10⁻⁴ · CbpreSPECT) + (9.48×10⁻⁵ · CbpostSPECT) + (1.35×10⁻⁴ · L15) - (6.95×10⁻⁴ · L33) + (7.61×10⁻⁴ · L81) - (0.417), where Cb12: brain count at 12 minutes, Cbpre-SPECT: brain count before SPECT, Cbpost-SPECT: brain count after SPECT, L15, L33, and L81: lung count at 15, 33, and 81 seconds, respectively. The mean CBF values (ml/min/100g) calculated using the estimated ∫Ca values more closely correlated with those measured by 15O-H2O PET ARG method (r = 0.833, p < 0.01) than those obtained by our previous method (r = 0.590, p < 0.01)., Conclusion: The rCBFs obtained by this method approximated more accurately to the values measured by 15O-H2O PET ARG method than those obtained by our previous method.