Fluoride is a naturally occurring element in groundwater that supports bone and dental health at low concentrations but can cause health problems at elevated concentrations in drinking water. This ...study investigates spatial and temporal trends for fluoride concentrations in untreated groundwater from over 20,000 public supply wells in California. The presence of a significant temporal trend in fluoride concentrations in a well was assessed using the Mann-Kendall test and a spatial-weighting approach was used to identify the areal extent of the groundwater resources with significant trends. Less than 2% of the groundwater resources used for public supply in the state have concentrations above the California maximum contaminant level of 2 mg/L. Approximately 14% of the groundwater resource used for public supply show a significant recent trend (2000–2019), with decreasing trends occurring in 10% of the resource. Potential drivers for trends were evaluated in two of the areas in southern California with the greatest prevalence of trends but distinct climate and hydrogeological characteristics. Aquifers in the Mojave and Whitewater River watersheds, located in the desert region, and the Los Angeles Basin, located on the coast, have been replenished with imported and treated water over the last half century to maintain sustainable groundwater levels. The recharge of imported water with different chemistries has altered the geochemical conditions in the aquifers, driving changes in fluoride concentrations.
Display omitted
•Trends in fluoride concentrations in public supply wells occur across the state of California.•High fluoride concentrations are related to geology, groundwater age and aquifer geochemistry.•Elevated concentrations and trends occur in higher proportions in the southern California.•Managed recharge in the desert and Los Angeles Basin are driving fluoride trends in groundwater.
Groundwater‐resource quality is assumed to be less responsive to drought compared to that of surface water due to relatively long transit times of recharge to drinking‐supply wells. Here, we evidence ...dynamic perturbations in aquifer pressure dynamics during drought and subsequent recovery periods cause dramatic shifts in groundwater quality on a basin scale. We used a novel application of time‐series clustering on annual nitrate anomalies at >450 public‐supply wells (PSWs) across California's San Joaquin Valley during 2000–22 to group sub‐populations of wells with similar water‐quality responses to drought. Additionally, we statistically evaluated the direction and magnitude of multi‐constituent water‐quality changes across the San Joaquin Valley using a broader dataset of >3000 PSWs with data during two select hydrologic stress periods representing an extreme drought (2012–16) and subsequent recovery (2016–19). Results of time‐series clustering and stress‐period change analyses corroborate a predominant regional response to pumping stress characterized by increased concentrations of anthropogenic constituents (nitrate, total dissolved solids) and decreased concentrations of geogenic constituents (arsenic, fluoride), which largely reversed during recovery. Cluster analysis also identified a secondary, less commonly occurring group of PSWs where nitrate decreased during drought, but explanatory factor analysis was not able to discern hydrogeologic drivers for these two divergent response patterns. Long‐term tracer data support the hypothesis that the predominant regional signal of nitrate increase during drought is caused by enhanced capture of modern‐aged groundwater by PSWs during periods of pumping stress, which can drive rapid changes in water quality on seasonal and multiannual timescales. Pumping‐induced migration of modern, oxic groundwater to depth during drought may affect geochemical conditions in deeper portions of regional aquifers controlling the mobility of geogenic contaminants over the long term.
We observed basin‐scale increases of anthropogenic constituents at drinking‐supply wells during drought, which largely decreased during recovery. Geogenic constituents had an inverse response pattern. Results suggest enhanced capture of modern‐aged groundwater at long‐screened wells as a predominant regional response to intensive pumping during drought.
Traumatic brain injury (TBI) affects an estimated 1.7 million people in the United States and is a contributing factor to one third of all injury related deaths annually. According to the CDC, ...approximately 75% of all reported TBIs are concussions or considered mild in form, although the number of unreported mild TBIs (mTBI) and patients not seeking medical attention is unknown. Currently, classification of mTBI or concussion is a clinical assessment since diagnostic imaging is typically inconclusive due to subtle, obscure, or absent changes in anatomical or physiological parameters measured using standard magnetic resonance (MR) or computed tomography (CT) imaging protocols. Molecular imaging techniques that examine functional processes within the brain, such as measurement of glucose uptake and metabolism using (18)Ffluorodeoxyglucose and positron emission tomography (FDG-PET), have the ability to detect changes after mTBI. Recent technological improvements in the resolution of PET systems, the integration of PET with magnetic resonance imaging (MRI), and the availability of normal healthy human databases and commercial image analysis software contribute to the growing use of molecular imaging in basic science research and advances in clinical imaging. This review will discuss the technological considerations and limitations of FDG-PET, including differentiation between glucose uptake and glucose metabolism and the significance of these measurements. In addition, the current state of FDG-PET imaging in assessing mTBI in clinical and preclinical research will be considered. Finally, this review will provide insight into potential critical data elements and recommended standardization to improve the application of FDG-PET to mTBI research and clinical practice.
ACR Appropriateness Criteria Headache Douglas, Annette C; Wippold, 2nd, Franz J; Broderick, Daniel F ...
Journal of the American College of Radiology,
07/2014, Letnik:
11, Številka:
7
Journal Article
Recenzirano
Most patients presenting with uncomplicated, nontraumatic, primary headache do not require imaging. When history, physical, or neurologic examination elicits "red flags" or critical features of the ...headache, then further investigation with imaging may be warranted to exclude a secondary cause. Imaging procedures may be diagnostically useful for patients with headaches that are: associated with trauma; new, worse, or abrupt onset; thunderclap; radiating to the neck; due to trigeminal autonomic cephalgia; persistent and positional; and temporal in older individuals. Pregnant patients, immunocompromised individuals, cancer patients, and patients with papilledema or systemic illnesses, including hypercoagulable disorders may benefit from imaging. Unlike most headaches, those associated with cough, exertion, or sexual activity usually require neuroimaging with MRI of the brain with and without contrast to exclude potentially underlying pathology before a primary headache syndrome is diagnosed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.
Summary Background Sentinel-lymph-node (SLN) mapping and biopsy maintains staging accuracy in early breast cancer and identifies patients for selective lymphadenectomy. SLN mapping requires injection ...of technetium-99m-sulfur colloid—an effective but sometimes painful method, for which better pain-management strategies are needed. In this randomised, double-blind trial, we compared degree of pain between standard radiocolloid injection and pH-adjusted and lidocaine-supplemented formulations for patients undergoing SLN mapping for breast cancer. Methods Between Jan 13, 2006, and April 30, 2009, 140 patients with early breast cancer were randomly assigned in a 1:1:1:1 fashion to receive the standard topical 4% lidocaine cream and injection of 99m TcTc-sulfur colloid (n=35), or to one of three other study groups: topical placebo cream and injection of Tc-sulfur colloid containing either sodium bicarbonate (n=35), 1% lidocaine (n=35), or sodium bicarbonate and 1% lidocaine (n=35). The randomisation sequence was computer generated, and all patients and investigators were masked to treatment allocation. The primary endpoint was patient-reported breast pain immediately after radioisotope injection, using the Wong-Baker FACES pain rating scale and McGill pain questionnaire, analysed in the per-protocol population. This study is registered with ClinicalTrials.gov , number NCT00940199. Findings 19 of the 140 patients enrolled were excluded from analysis: nine declined study participation or sought care elsewhere, nine did not undergo SLN mapping because of disease extent or a technical problem, and one had unreliable data. There were no adverse events. Mean pain scores on the Wong-Baker scale (0–10) were: 6·0 (SD 2·6) for those who received standard of practice, 4·7 (3·0) for those who received radiocolloid plus bicarbonate, 1·6 (1·4) for those who received radiocolloid plus 1% lidocaine, and 1·6 (1·3) for those who received radiocolloid plus bicarbonate and 1% lidocaine (p<0·0001). Mean pain rating, according to the McGill questionnaire (0–78), was 17·5 (SD 11·8) for the standard-of-care group, 15·4 (14·4) for the sodium bicarbonate group, 4·6 (4·5) for the 1% lidocaine group, and 3·4 (5·1) for the sodium bicarbonate plus 1% lidocaine group (p<0·0001). SLN identification rates for each group were: 96% for the standard of care, 97% for sodium bicarbonate, 90% for 1% lidocaine, and 90% for sodium bicarbonate plus 1% lidocaine group (p=0·56). Interpretation For centres that use radiocolloid injections for SLN mapping in patients with early breast cancer, the addition of 1% lidocaine to the radioisotope solution can improve patient comfort, without compromising SLN identification. Funding US Military Cancer Institute, the Clinical Breast Care Project, and the Army Regional Anesthesia and Pain Management Initiative.
Neurodegenerative disease, including dementia, extrapyramidal degeneration, and motor system degeneration, is a growing public health concern and is quickly becoming one of the top health care ...priorities of developed nations. The primary function of anatomic neuroimaging studies in evaluating patients with dementia or movement disorders is to rule out structural causes that may be reversible. Lack of sensitivity and specificity of many neuroimaging techniques applied to a variety of neurodegenerative disorders has limited the role of neuroimaging in differentiating types of neurodegenerative disorders encountered in everyday practice. Nevertheless, neuroimaging is a valuable research tool and has provided insight into the structure and function of the brain in patients with neurodegenerative disorders. Advanced imaging techniques, such as functional neuroimaging with MRI and MR spectroscopy, hold exciting investigative potential for better understanding of neurodegenerative disorders, but they are not considered routine clinical practice at this time. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.
PDF
