18F-DGPET/CT Imaging of Ovarian Yolk Sac Tumor in a Woman after Induction of Labor: A Case Report.

Introduction: Ovarian yolk sac tumor (OYST) during pregnancy is rare and usually missed. There are few PET/CT studies on OYST in the literature. We reported a case of OYST detected by 18F-FDG PET/CT in a woman after induction of labor. Case Presentation: A 19-year-old woman after induction of labor because of severe malformation presented with abdominopelvic mass, laboratory tests revealed significantly elevated serum alpha-fetoprotein (AFP) level and elevated carbohydrate antigen 125 level. Abdomino-pelvic CT showed a cysticsolid mass of 82×152×167mm arising from the right ovary with abundant intratumoral vessels and intense enhancement in the solid part. Further evaluation of 18F-FDG PET/CT imaging showed significantly increased 18FDG uptake (SUVmax7.7) by the solid component of the ovarian mass and slight 18FDG-avid perihepatic effusion. The mass was resected and was confirmed to be the right OYST, After four courses of chemotherapy, the patient was followed up by PET/CT and had a complete metabolic response. Discussion: 18F-FDG PET/CT is a useful imaging modality for diagnosis and evaluation of OYST.

[Hydrochemical Characteristics and Genesis Mechanism of Groundwater in the Dry Period in the Zhangjiakou Area].

In order to better support the construction of the capital water conservation functional area and ecological environment support area， research on the chemical characteristics of groundwater and its formation mechanism in the dry period in the Zhangjiakou area can provide a great reference for the rational development and utilization of groundwater resources. A total of 41 groups of groundwater samples were collected， and the hydrochemical types， composition characteristics， and control factors of groundwater in the study area were analyzed by using the combined method of descriptive statistical analysis， Piper triplot， correlation analysis， Gibbs plot， and ion ratio. The results showed that the groundwater in the study area was weakly alkaline， with the total hardness and ρ（TDS） ranging from 105.00 mg·L-1 to 1 433.00 mg·L-1 and 137.00 mg·L-1 to 2 286.00 mg·L-1， respectively. The total hardness and TDS mass concentrations of groundwater in the Bashang area were higher than those in the Baxia area. HCO3- and Na+ were the main dominant anions and cations in the groundwater in the study area. The highest overstandard rate of the main components in groundwater was that of total hardness （36.59%）. The overstandard rate and maximum excess multiple of each component in groundwater in the Bashang area were greater than those in the Baxia area. HCO3-Ca·Mg·Na was the main type of groundwater hydrochemistry in the study area， and there was little difference between the Bashang area and the Baxia area. SO42-， Cl-， HCO3-， Na+， and Mg2+ contributed the most to TDS. The chemical characteristics of groundwater were affected by weathering and filtration of rock minerals such as salt rock， albite， and dolomite； cation exchange； and human activities. Evaporative crystallization and atmospheric precipitation contributed to a small part of the main ion source of groundwater in the area. The effect of human activities on groundwater in the Bashang area was greater than that in the Baxia area， and NO3- mainly originated from agricultural activities.

Pre-procedure 18F-FDG PET/CT imaging improves the performance of CT-guided transthoracic biopsy.

PURPOSE: To compare computed tomography (CT)-guided transthoracic lung biopsies (CTLB) with and without pre-procedure 18F-fluorodeoxgyglucose positron emission tomography (18F-FDG PET)/CT images in the diagnosis of pulmonary nodules/masses. METHODS: This is a case-control study in a single center. The data of patients with a transthoracic lung biopsy guided by CT and pre-procedure 18F-FDG PET/CT (group 2, here called the "PETCTLB" group), including demographics, clinical characteristics, and biopsy-related parameters, were collected. The PET/CT scan was performed within 15 days before the biopsy. The data from patients with CTLB were used as controls (group 1). Biopsies for all patients were performed by the same physician between January 2019 and December 2021. The final diagnosis was based on surgical outcomes, or imaging findings, and the results of at least one 6-month follow-up. The demographics and clinical characteristics of patients, lesions and biopsy-related variables, diagnostic yields, and incidence of complications were compared between the two groups. Two-tailed t-tests were used to compare the mean values in the two independent groups, while categorical variables were compared using the Pearson chi-squared test, and P values < 0.05 were considered to be significant. RESULTS: A total of 84 patients were included, and 84 biopsies of 84 lung nodules/masses were analyzed. The demographics and clinical characteristics of group 2 (n = 39; 21 men; mean age, 63.2 ± 9.29 years) and group 1 (n = 45; 30 men; mean age, 61.2 ± 12.3 years) had no significant difference (P = 0.230 and 0.397, respectively). The procedure duration (11.1 ± 3.0 vs. 12.9 ± 3.3 minutes, P = 0.008), the number of samples (2.6 ± 0.5 vs. 3.1 ± 0.4, P < 0.001), diagnostic accuracy (97.4% vs. 82.2%, P = 0.033), and bleeding complication (25.6% vs. 42.2%, P = 0.034) of group 2 and group 1 were statistically different. CONCLUSION: A biopsy guided by CT plus pre-procedure 18F-FDG PET/CT (PETCTLB) is a safe procedure that can provide a precise diagnosis in the majority of lung nodules/masses. It has better diagnostic performance than CTLB.

The sensitivity and specificity of 18F-FDG PET/CT in spinal leptomeningeal metastases: the synergistic effect of the 18F-FDG PET-CT to gadolinium-enhanced MRI.

Background: Magnetic resonance imaging (MRI) plays an important role in the diagnosis of leptomeningeal metastases (LM); however, some sub-centimeter lesions may be missed. Positron emission tomography/computed tomography (PET/CT) has a high sensitivity and may play a synergistic role with MRI in diagnosing spinal LM (SLM). We aimed to retrospectively evaluate the detection of SLM with 18F-fluorodeoxyglucose PET/CT (18F-FDG PET/CT) compared to that of whole spinal cord MRI in a single center. Methods: Patients with SLM who had undergone 18F-FDG PET/CT and MRI were enrolled. 18F-FDG PET/CT imaging findings were independently reviewed by 2 nuclear medicine physicians. 18F-FDG PET/CT findings of SLMs were described. A consistency test was conducted to assess the patient-based diagnostic results obtained by the 2 physicians. Patient-based sensitivity, accuracy, and specificity in diagnosing SLM between 18F-FDG PET/CT and MRI of the whole spinal cord were compared using the chi-square or Fisher's exact test. A P value of <0.05 was considered statistically significant. The receiver operating characteristic (ROC) curve was obtained to assess the diagnostic performance of maximum standardized uptake value (SUVmax) to diagnose SLM. Results: A total of 16 patients with SLM were included in this study from October 2010 to April 2022. The primary tumor involved the lungs, liver, ovaries, prostate, esophagus, and unknown primary site. The mean age of patients, including 13 males and 3 females, was 57.8±11.2 (range, 34-73) years. Of 16 patients with SLM, 10 had nodular diseases, 2 had linear diseases, and 4 had mixed diseases. The kappa value of the consistency test of the 2 radiologists' diagnostic results was 0.765. The patient-based sensitivity, specificity, and accuracy of 18F-FDG PET/CT in diagnosing SLM were 87.5%, 89.2%, and 88.7%, respectively and those of whole spinal cord MRI were 75.0%, 100.0%, and 92.5%, respectively. There were no significant differences in sensitivity, specificity, and accuracy between the 2 methods, with P values of 0.654, 0.115, and 0.506, respectively. However, more nodular diseases were observed on PET/CT. The area under the ROC curve (AUC) for the prediction of SLM by SUVmax was 0.907 [95% confidence interval (CI): 0.831-0.983]. When SUVmax ≥2.45, the Youden index was the largest, and the sensitivity and specificity were 89.3% and 75.7%, respectively. Conclusions: 18F-FDG PET/CT is a good choice of imaging modality for assessing SLM. In the diagnosis of SLMs, PET/CT and enhanced MRI can play a better synergistic role.

[Evaluation and Source Analysis of Soil Heavy Metal Pollution in a Planting Area in Wanquan District, Zhangjiakou City].

Taking the soil of a vegetable planting area in Wanquan District of Zhangjiakou City as the research object, 132 surface and 80 deep soil samples were collected to test and analyze the contents of eight heavy metals such as As, Cd, Cr, Hg, Cu, Ni, Pb, and Zn and the occurrence forms of Cr and Ni. By applying geostatistical analysis and the PMF receptor model and combining three heavy metal pollution evaluation methods, the spatial distribution characteristics of soil heavy metals in the study area, the degree of heavy metal pollution, and the distribution of Cr and Ni fugitive forms in the vertical layer were clarified, and the sources and contribution rates of soil heavy metal pollution were analyzed. The results showed that the average contents of Cd and Pb in surface soils were higher than the background values of soils in Hebei Province, and the spatial distribution characteristics of Cr, Ni, Cu, Cd, Pb, and Zn in surface soils were similar. The ground accumulation index method showed that the study area was mainly free of pollution, with a small number of lightly polluted sites, and most of them were polluted with Cd. The enrichment factor method showed that the study area was mainly free-weakly polluted, with medium pollution of all elements; the significantly polluted elements in the background area were As, Pb, and Hg, and the significantly polluted element in the key area was Cd. The potential ecological risk index method showed that the study area was mainly lightly polluted, with local distribution. The potential ecological risk index method showed that the study area was mainly lightly polluted, with a local distribution of "medium" and "strong" risk points, with "very strong" risk points for Hg in the background area and "very strong" risk points for Cd in the focus area. These three evaluation results indicated that the background area was dominated by Cd and Hg pollution, whereas the focus area was dominated by Cd pollution. The study on the fugitive morphology of vertical soil showed that Cr was dominated by the residue state (F4) and supplemented by the oxidizable state (F3), and the vertical direction was dominated by the surface aggregation type and supplemented by the weak migration type. Ni was dominated by the residue state (F4) and supplemented by the reducible state (F2), and the vertical direction was dominated by the strong migration type and supplemented by the weak migration type. The sources of heavy metals in the surface soil were divided into three categories; Cr, Cu, and Ni were mainly from natural geological background sources. The contributions of Cr, Cu, and Ni were 66.9%, 66.9%, and 76.1%, respectively. As, Cd, Pb, and Zn were mainly from anthropogenic sources, with contributions of 77.38%, 59.2%, 83.5%, and 59.5%, respectively. Hg was mainly from dry and wet atmospheric deposition, with a contribution of 87.8%.

[Characteristics and Causes of Ge Enrichment in Vegetable Growing Areas of Beixintun Town, Zhangjiakou City].

The vegetable planting base in the Beixintun area of Zhangjiakou City was selected as the study area, divided into the focus area and regional range as well as the upstream area. A total of 132 surface soil samples, 16 vertical soil profiles, 3 groups of surface profiles, and 4 samples each of colored pepper fruit, purple kale fruit, and corn fruit were collected. From the soil, rock, and crop sample Sc, Cr, Mo, Cd, V, Zn, Sr, Pb, Co Ni, Cu, Ge, and REE on the basis of the referenced germanium (Ge) enrichment standards and enrichment factor levels, it was found that the regional Ge enrichment rate was not high (19.7%), whereas the key area had a high Ge enrichment rate (52%). The spatial distribution of Ge and rare earth elements in the soils of the regional scope and the focal area showed a more obvious consistency, and further comparison of the correlation characteristics of Ge and rare earth elements in soil and crops showed that the ranking of rare earth content was purple kale>colored pepper>maize, whereas the ranking of the Ge element uptake intensity was maize (weak uptake)>purple kale (very weak uptake)>colored pepper (very weak uptake), and there was no obvious synergy between the uptake of Ge and rare earth elements by crops. The PMF and RDA analysis of 28 elements and indicators of soil in the study area showed that the source of regional Ge was dominated by natural geological background factors (66.3%), supplemented by anthropogenic activity-influenced factors (27%) and river deposition factors (6.7%). The source of Ge in the focal area was dominated by natural geological background factors (33.8%) and anthropogenic activity-influenced factors (27.2%), with river sedimentation factors (18.5%) and atmospheric dry and wet deposition factors Ge (20.5%) being supplemented. Soil Ge was positively correlated with rare earth elements and trace elements such as Cd, Zn, Mn, Ni, V, Co, and Cr and negatively correlated with the main elements CNa2[KG-*2/5]O, SiO2, and K2[KG-*2/5]O and pH. Finally, by combining the analysis of soil lateral profiles with vertical profiles, it was found that the Ge migrating from the source area to the area was primarily in the main river pathway, supplemented by the secondary river and flood flow pathways.

The role of 18F-FDG PET/CT in patients with synchronous multiple primary malignant neoplasms occurring at the same time.

Background: Synchronous multiple primary malignant neoplasms occurring at the same time (SMPMNS) are not currently uncommon in clinical oncological practice; however, the diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for SMPMNS needs further elucidation. Purpose: This study aimed to evaluate the application of 18F-FDG PET/CT in patients with SMPMNS. Materials and methods: The clinical and imaging data of 37 patients with SMPMNS who had undergone 18F-FDG PET/CT from October 2010 to December 2020 were retrospectively analyzed. The kappa consistency test was applied to evaluate the consistency of the diagnostic performance between PET/CT and conventional imaging (CI). The sensitivity, specificity, and accuracy of PET/CT and CI in the detection of metastatic lesions were compared. Results: This retrospective diagnostic study included 74 lesions identified in 37 patients with SMPMNS, with 94.6% of patients having double primary tumors. Of the incidences of SMPMNS, 18.9% occurred in the same organ system, with respiratory tumors being the most common type of neoplasm (43.2%) and the lung being the most common primary site (40.5%). The overall survival of SMPMNS patients without metastases was longer than that of those with metastases (χ 2 = 12.627, p = 0.000). The maximum standardized uptake value (SUVmax), the SUVmax ratio (larger SUVmax/smaller SUVmax), and the difference index of SUVmax (DISUVmax) [(larger SUVmax - smaller SUVmax)/larger SUVmax] of the primary lesions ranged from 0.9 to 41.7 (average = 12.3 ± 7.9), from 0.3 to 26.7 (average = 4.4 ± 6.9), and from 0.0% to 96.3% (average = 50.3% ± 29.3%), respectively. With regard to diagnostic accuracy, PET/CT and CI showed poor consistency (κ = 0.096, p = 0.173). For the diagnosis of primary lesions (diagnosed and misdiagnosed), PET/CT and CI also showed poor consistency (κ = 0.277, p = 0.000), but the diagnostic performance of PET/CT was better than that of CI. In the diagnosis of metastases, the patient-based sensitivity, specificity, and accuracy of PET/CT were 100.0%, 81.8%, and 89.2%, respectively, while those of CI were 73.3%, 100.0%, 89.2%, respectively. The sensitivity and specificity values were significantly different, with PET/CT having higher sensitivity (p = 0.02) and CI showing higher specificity (p = 0.02). Conclusions: 18F-FDG PET/CT improves the diagnostic performance for SMPMNS and is a good imaging modality for patients with SMPMNS.

Role of 18F-FDG PET/CT in the diagnosis and management of patients with Langerhans cell histiocytosis.

Background: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm that can involve multisystem organs. Positron emission tomography/computed tomography (PET/CT) has been widely used in tumor staging and efficacy evaluation. However, at present, there are few 18F-fluorodeoxyglucose (FDG) PET/CT studies on LCH. This study aimed to explore the possible role of 18F-FDG PET/CT in the diagnosis and management of patients with LCH. Methods: 18F-FDG PET/CT images of 22 Chinese patients diagnosed with LCH on biopsy or surgery histopathology between January 2011 and December 2020 were retrospectively analyzed. The incidence of LCH in each system was assessed by a PET/CT scan. The imaging characteristics were analyzed semiquantitatively and qualitatively. The discrepancies between PET/CT and conventional imaging modalities were recorded. Evaluations of curative effect according to RECIST1.1 and PERCIST1.0 were compared using Fisher's exact chi-squared test, and P values <0.05 were considered significant. Results: Eight (36.4%) of the 22 patients presented with single system involvement (4 isolated site involvement, 4 multiple site involvement), and 14 (63.6%) presented with multiple system involvement. Twenty-one (95.5%) patients had hypermetabolic lesions. Musculoskeletal, lymphatic, respiratory, liver, skin-soft tissue and thyroid involvement were seen in 14 (63.6%), 13 (59.1%), 5 (22.7%), 4 (18.2%), 5 (22.7%) and 1 (4.5%) patient, respectively. Cranial and facial bones were the most common sites of musculoskeletal involvement. Ten patients underwent PET/CT follow-up, and there was no significant difference in curative effect evaluations according to RECIST1.1 and PERCIST1.0. However, among the complete remission cases assessed by RECIST1.1, three were partial metabolic responses assessed by PERCIST1.0, while among the partial response cases assessed by RECIST1.1, one was metabolic progressive disease assessed by PERCIST1.0. Conclusions: 18F-FDG PET/CT is an imaging modality option for the diagnosis and assessment of the curative effect of LCH.

[Distribution of polycyclic aromatic hydrocarbons in soil profiles in southeast suburb of Beijing wastewater irrigation area].

3 borehole profiles samples were collected using Eijkelkamp soil sampler from the wastewater irrigation area of Beijing Southeast suburb. The soil samples were collected from surface to 5.5 m underground every 0.5 m. Physical-chemical properties of the samples such as clay content, total amount of clay minerals, cation exchange capacity (CEC), total organic compounds (TOC), etc. were analyzed. 16 polycyclic aromatic hydrocarbons (PAHs) defined by the U.S. EPA were also analyzed with gas chromatography-mass spectrometry (GC-MS). Results show that 14 PAHs were detected in the surface soil samples. The concentrations of PAHs range from 4 microg/kg to 428 microg/kg. Under the surface,both species and concentrations of PAHs in soil samples drop very fast. Only 2 rings and 3 rings PAHs were detected, which were naphthalene,phenanthrene, fluorene, acenaphthylene, acenaphthene, and fluoranthene. Clay content, total amount of clay minerals, CEC and TOC have significant correlations at 0.05 level between each other. Under the surface, clay contents also have a relationship with low-rings PAHs concentration. Where the layers have higher clay contents,the PAHs have higher concentrations. The contents of PAHs changing along the profiles also show that, low-rings PAHs are easier to migrate than high-rings PAHs. The sequence of the migration capabilities of low-ring PAHs is acenaphthene > fluorene > naphthalene > phenanthrene > acenaphthylene > fluoranthene. However, high-ring PAHs were only detected in surface soil samples. That means low-rings PAHs can reach the deep layers of the vertical profiles under long-term wastewater irrigation. Therefore, the shallow groundwater has the possibility to be contaminated.