Vognsenandersen8807
Total thyroidectomy and risk-adapted 131-radioiodine therapy (RaIT) are the treatments of choice in differentiated thyroid cancer (DTC) patients. The response to treatments is assessed 6-12months after RaIT. However, thyroglobulin (Tg) values obtained just before RaIT also provide reliable informations on patients'outcome. As available data were mostly obtained in hypothyroid status, we evaluated the predictive role of preablation-Tg in patients underwent RaIT after rhTSH stimulation.
We enrolled 299 low-to-intermediate risk DTC patients underwent rhTSH-stimulated RaIT (standard protocol). Serum Tg levels were measured before rhTSH administration (basal Tg), before RaIT (early-stimulated Tg), and 2days after RaIT (late-stimulated Tg). The early response assessment was done 12months after RaIT according to 2015 American Thyroid Association (2015 ATA) criteria.
Most patients (277/299, 92.6%) had an excellent response (ER) to RaIT, while 15/299 (5.1%) and 7/299 (2.3%) patients showed biochemical incompleteresponse to primary treatment of DTC.
Cardiac resynchronization therapy (CRT) is effective in selective heart failure (HF) patients, but non-response rate remains high. Positron emission tomography (PET) may provide a better insight into the pathophysiology of left ventricular (LV) remodeling; however, its role for evaluating and selecting patients for CRT remains uncertain.
We investigated if regional LV glucose metabolism in combination with myocardial scar could predict response to CRT.
Consecutive CRT-eligible HF patients underwent echocardiography, cardiac magnetic resonance (CMR), and
F-fluorodeoxyglucose (FDG) PET within 1week before CRT implantation. Echocardiography was additionally performed 12months after CRT and end-systolic volume reduction ≥ 15% was defined as CRT response. Septal-to-lateral wall (SLR) FDG uptake ratio was calculated from static FDG images. Late gadolinium enhancement (LGE) CMR was analyzed semi-quantitatively to define scar extent.
We evaluated 88 patients (67 ± 10 years, 72% males).
F-FDG SLR showed a tively be used to optimize patient selection.
FDG SLR can be used as a predictor of CRT response and combined with septal scar extent, CRT responders can be distinguished from non-responders with high diagnostic accuracy. Further studies are needed to verify whether this imaging approach can prospectively be used to optimize patient selection.
While sampled or short-frame realizations have shown the potential power of deep learning to reduce radiation dose for PET images, evidence in true injected ultra-low-dose cases is lacking. Therefore, we evaluated deep learning enhancement using a significantly reduced injected radiotracer protocol for amyloid PET/MRI.
Eighteen participants underwent two separate
F-florbetaben PET/MRI studies in which an ultra-low-dose (6.64 ± 3.57 MBq, 2.2 ± 1.3% of standard) or a standard-dose (300 ± 14 MBq) was injected. The PET counts from the standard-dose list-mode data were also undersampled to approximate an ultra-low-dose session. A pre-trained convolutional neural network was fine-tuned using MR images and either the injected or sampled ultra-low-dose PET as inputs. Image quality of the enhanced images was evaluated using three metrics (peak signal-to-noise ratio, structural similarity, and root mean square error), as well as the coefficient of variation (CV) for regional standard uptake value ratios (SUVRs). potential to reduce dose significantly for amyloid imaging.
Deep learning methods can synthesize diagnostic-quality PET images from ultra-low injected dose simultaneous PET/MRI data, demonstrating the general validity of sampled realizations and the potential to reduce dose significantly for amyloid imaging.
Synaptic abnormalities are associated with many brain disorders. Recently, we developed a novel synaptic vesicle glycoprotein 2A (SV2A) radiotracer [
F]SynVesT-1 and demonstrated its excellent imaging and binding properties in nonhuman primates. The aim of this study was to perform dosimetry calculations in nonhuman primates and to evaluate this tracer in humans and assess its test-retest reliability in comparison with [
C]UCB-J.
Three rhesus monkeys underwent whole body dynamic PET scanning to estimate the absorbed dose. PET scans in six healthy human subjects were acquired. Time-activity curves (TACs) were generated with defined regions of interest (ROI). Reproducibility of distribution volume (V
) values and its sensitivity to scan duration were assessed with the one-tissue compartment (1TC) model. Non-displaceable binding potential (BP
) was calculated using centrum semiovale as the reference region.
The dosimetry study showed high uptake in the urinary bladder and brain. In humans, [
F]SynVesTeproducibility of binding parameters. As such, [18F]SynVesT-1 is proved to be a favorable radiotracer for SV2A imaging and quantification in humans.
The aim of this study is to evaluate the rate of abnormal myocardial perfusion imaging (MPI) studies at a single medical center during the COVID-19 pandemic compared to prior to the pandemic.
We retrospectively studied stress single-photon emission computed tomography (SPECT)-MPI studies performed during the peak of COVID-19 restrictions at the University of Alabama Medical Center in comparison to the same time period in 2019.
SPECT-MPI volume was reduced from 553 per month in 2019 to 105 per month in 2020. The proportion of abnormal SPECT-MPI for the 2020 cohort (61 ± 13years, 48% men, 41% black) was not different from the 2019 cohort (62 ± 12years, 48% men, 42% black) (31% vs. 27%, p = 0.4). Similar proportion of patients in the 2 cohorts had abnormal myocardial perfusion, moderate-large perfusion defects, myocardial ischemia, myocardial scar, and abnormal left ventricular ejection fraction. The proportion of abnormal SPECT-MPIs was not different based on whether patients were evaluated face-to-face or by telemedicine (28% vs. 27%, p > 0.9) but was higher for cardiology providers (40% vs. 20%, p < 0.001).
There was a significant reduction in the number of SPECT-MPI studies performed during the peak restrictions from the pandemic. Despite this restriction, the rate of abnormal studies remained stable. Our study suggests that it remains difficult to predict which patients will have abnormal SPECT-MPI even when providers and stress laboratories are forced to prioritize the performance of studies to high-yield patients.
There was a significant reduction in the number of SPECT-MPI studies performed during the peak restrictions from the pandemic. Despite this restriction, the rate of abnormal studies remained stable. Our study suggests that it remains difficult to predict which patients will have abnormal SPECT-MPI even when providers and stress laboratories are forced to prioritize the performance of studies to high-yield patients.As a reliable preoperative predictor for microvascular invasion (MVI) and disease-free survival (DFS) is lacking, we developed a radiomics nomogram of [18F]FDG PET/CT to predict MVI status and DFS in patients with very-early- and early-stage (BCLC 0, BCLC A) hepatocellular carcinoma (HCC).
Patients (N= 80) with BCLC0-A HCC who underwent [
F]FDG PET/CT before surgery were enrolled in this retrospective study and were randomized to a training cohort and a validation cohort. Texture features from patients obtained using Lifex software in the training cohort were subjected to LASSO regression to select the most useful predictive features of MVI and DFS. Then, the radiomics nomogram was constructed using the radiomics signature and clinical features and further validated.
To predict MVI, the [
F]FDG PET/CT radiomics signature consisted of five texture features from the PET and six texture features from CT. The signature was significantly associated with MVI status in the training cohort (P = 0.001). None of tch might enable a step forward in precise medicine.
The newly developed [18F]FDG PET/CT radiomics signature was an independent biomarker for the estimation of MVI and DFS in patients with very-early- and early-stage HCC. Moreover, PET/CT nomogram, which incorporated the radiomics signature of [18F]FDG PET/CT and clinical risk factors in patients with very-early- and early-stage HCC, performed better for individualized DFS estimation, which might enable a step forward in precise medicine.Although a number of epidemiological studies have examined the effects of non-optimal temperatures on mortality in Europe, evidence about the mortality risks associated with exposures to hot and cold temperatures in Bulgaria is scarce. This study provides evidence about mortality attributable to non-optimal temperatures in adults aged 65 and over in Sofia, Bulgaria, between 2000 and 2017. We quantified the relationship between the daily mean temperature and mortality in the total elderly adult population aged 65 and over, among males and females aged 65 and over, as well as individuals aged 65-84 and 85 years or older. We used a distributed lag non-linear model with a 25-day lag to fully capture the effects of both cold and hot temperatures and calculated the fractions of mortality attributable to mild and extreme hot and cold temperatures. Cold temperatures had a greater impact on mortality than hot temperatures during the studied period. Most of the temperature-attributable mortality was due to moderate cold, followed by moderate heat, extreme cold, and extreme heat. The total mortality attributable to non-optimal temperatures was greater among females compared to males and among individuals aged 85 and over compared to those aged 65 to 84. The findings of this study can serve as a foundation for future research and policy development aimed at characterizing and reducing the risks from temperature exposures among vulnerable populations in the country, climate adaptation planning and improved public health preparedness, and response to non-optimal temperatures.Difficulties in controlling the effects of outdoor thermal environment on the human body are attracting considerable research attention. This study investigated the outdoor thermal comfort of urban pedestrians by assessing their perceptions of the tropical, micrometeorological, and physical conditions via a questionnaire survey. Evaluation of the outdoor thermal comfort involved pedestrians performing various physical activities (sitting, walking, and standing) in outdoor and semi-outdoor spaces where the data collection of air temperature, globe temperature, relative humidity, wind speed, solar radiation, metabolic activity, and clothing insulation data was done simultaneously. A total of 1011 participants were interviewed, and the micrometeorological data were recorded under outdoor and semi-outdoor conditions at two Malaysian university campuses. The neutral temperatures obtained which were 28.1 °C and 30.8 °C were within the biothermal acceptable ranges of 24-34 °C and 26-33 °C of the PET thermal sensation ranges for the outdoor and semi-outdoor conditions, respectively. Additionally, the participants' thermal sensation and preference votes were highly correlated with the PET and strongly related to air and mean radiant temperatures. The findings demonstrated the influence of individuals' thermal adaptation on the outdoor thermal comfort levels. This knowledge could be useful in the planning and designing of outdoor environments in hot and humid regions to create better thermal environments.