In vivo X-Ray Computed Tomographic Imaging of Soft Tissue with Native, Intravenous, or Oral Contrast

X-ray Computed Tomography (CT) is one of the most commonly utilized anatomical imaging modalities for both research and clinical purposes. CT combines high-resolution, three-dimensional data with relatively fast acquisition to provide a solid platform for non-invasive human or specimen imaging. The primary limitation of CT is its inability to distinguish many soft tissues based on native contrast. While bone has high contrast within a CT image due to its material density from calcium phosphate, soft tissue is less dense and many are homogenous in density. This presents a challenge in distinguishing one type of soft tissue from another. A couple exceptions include the lungs as well as fat, both of which have unique densities owing to the presence of air or bulk hydrocarbons, respectively. In order to facilitate X-ray CT imaging of other structures, a range of contrast agents have been developed to selectively identify and visualize the anatomical properties of individual tissues. Most agents incorporate atoms like iodine, gold, or barium because of their ability to absorb X-rays, and thus impart contrast to a given organ system. Here we review the strategies available to visualize lung, fat, brain, kidney, liver, spleen, vasculature, gastrointestinal tract, and liver tissues of living mice using either innate contrast, or commercial injectable or ingestible agents with selective perfusion. Further, we demonstrate how each of these approaches will facilitate the non-invasive, longitudinal, in vivo imaging of pre-clinical disease models at each anatomical site

Feasibility of Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Essential Tremor in the Setting of Prior Craniotomy

BACKGROUND: Magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy is a rapidly evolving therapy for the treatment of essential tremor. Although the skull is a major determinant of the delivery of acoustic energy to the target, how the presence of a prior craniotomy must be accounted for during lesioning is unclear. OBJECTIVE: To demonstrate novel application of this therapeutic option in a patient with a history of prior craniotomies for unrelated intracranial pathologies. METHODS: A 55-yr-old man with a history of right frontal craniotomy for resection of a colloid cyst underwent a left ventrointermedius nucleus thalamotomy through MRgFUS. The prior craniotomy flap was not excluded in the treatment plan; however, all bony defects and hardware were marked as no-pass regions. Clinical outcomes were collected at the 6-mo follow-up. RESULTS: Transducer elements whose acoustic paths would have been altered by the craniotomy defect were turned off. Sonications reaching lesional temperatures of up to 56°C were successfully delivered. The procedure was well-tolerated, without any persistent intra-ablation or postablation adverse effects. The presence of a lesion was confirmed on MRI, which was associated with a significant reduction in the patient\u27s tremor that was sustained at the 6-mo follow-up. CONCLUSION: This case demonstrates the safety and efficacy of MRgFUS thalamotomy in a patient with prior craniotomies and highlights our strategy for acoustic lesioning in this setting

The Digital Impact of Neurosurgery Awareness Month: Retrospective Infodemiology Study

BackgroundNeurosurgery Awareness Month (August) was initiated by the American Association of Neurological Surgeons with the aim of bringing neurological conditions to the forefront and educating the public about these conditions. Digital media is an important tool for disseminating information and connecting with influencers, general public, and other stakeholders. Hence, it is crucial to understand the impact of awareness campaigns such as Neurosurgery Awareness Month to optimize resource allocation, quantify the efficiency and reach of these initiatives, and identify areas for improvement. ObjectiveThe purpose of our study was to examine the digital impact of Neurosurgery Awareness Month globally and identify areas for further improvement. MethodsWe used 4 social media (Twitter) assessment tools (Sprout Social, SocioViz, Sentiment Viz, and Symplur) and Google Trends to extract data using various search queries. Using regression analysis, trends were studied in the total number of tweets posted in August between 2014 and 2022. Two search queries were used in this analysis: one specifically targeting tweets related to Neurosurgery Awareness Month and the other isolating all neurosurgery-related posts. Total impressions and top influencers for #neurosurgery were calculated using Symplur’s machine learning algorithm. To study the context of the tweets, we used SocioViz to isolate the top 100 popular hashtags, keywords, and collaborations between influencers. Network analysis was performed to illustrate the interactions and connections within the digital media environment using ForceAtlas2 model. Sentiment analysis was done to study the underlying emotion of the tweets. Google Trends was used to study the global search interest by studying relative search volume data. ResultsA total of 10,007 users were identified as tweeting about neurosurgery during Neurosurgery Awareness Month using the “#neurosurgery” hashtag. These tweets generated over 29.14 million impressions globally. Of the top 10 most influential users, 5 were faculty neurosurgeons at US university hospitals. Other influential users included notable organizations and journals in the field of neurosurgery. The network analysis of the top 100 influencers showed a collaboration rate of 81%. However, only 1.6% of the total neurosurgery tweets were advocating about neurosurgery awareness during Neurosurgery Awareness Month, and only 13 tweets were posted by verified users using the #neurosurgeryawarenessmonth hashtag. The sentiment analysis revealed that the majority of the tweets about Neurosurgery Awareness Month were pleasant with subdued emotion. ConclusionsThe global digital impact of Neurosurgery Awareness Month is nascent, and support from other international organizations and neurosurgical influencers is needed to yield a significant digital reach. Increasing collaboration and involvement from underrepresented communities may help to increase the global reach. By better understanding the digital impact of Neurosurgery Awareness Month, future health care awareness campaigns can be optimized to increase global awareness of neurosurgery and the challenges facing the field

In vivo X-Ray Computed Tomographic Imaging of Soft Tissue with Native, Intravenous, or Oral Contrast

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The Differences Between Same-Day and Staged (Circumferential) Fusion Surgery in Adult Spinal Deformity: Protocol for a Systematic Review

BackgroundAdult spinal deformity (ASD) is a deformity in the curvature of the adult spine. ASD includes a range of pathology that leads to decreased quality of life for patients as well as debilitating morbidities. Treatment can range from nonoperative management to long-segment surgical corrections and depends greatly on the deformity and patient profiles. If surgical treatment is indicated, circumferential (a combined anterior and posterior approach) fusion is one of the tools in the spine surgeon’s armamentarium. Depending on the complexity, the procedure is either completed on the same day or staged. Determining whether to perform a circumferential surgery in a staged fashion is based largely on the surgeon’s preference and perception of the individual case complexity; at present, there is no high-quality evidence that can be used to support that decision. ObjectiveThis paper presents the protocol for a systematic review that aims to investigate the differences between same-day versus staged circumferential fusion surgery in ASD both in patient selection and in outcomes. MethodsSearches will be performed on MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. Gray literature and the reference lists of articles included in the full-text screening will also be screened for inclusion. Results will be exported to Covidence. Data will be collected on demographics, type of procedures performed, surgery levels, blood loss, total operation time, length of stay, disposition, readmissions (30 days and 90 days), and perioperative complications. Patient-reported outcomes will also be assessed. Data quality assessment of randomized controlled trials will be performed using the Cochrane Collaboration’s tool for assessing risk of bias in randomized trials, and nonrandomized studies will be assessed with the ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) tool. All screening, quality assessment, and data extraction will be done by 2 independent reviewers. A descriptive synthesis will be performed, and data will be evaluated for further analysis. ResultsThis study is currently in the screening phase. There are no results yet. The search strategy has been developed and documented. Information has been exported to Covidence. Upon conclusion of the critical appraisal stage, screening and extraction, as well as a synthesis of the results, will be performed. ConclusionsThe intended review will summarize the differences in perioperative outcomes and complications between same-day and staged (circumferential) fusion surgery in adult spinal deformity. It will also describe the patients selected for such procedures based on their demographics and pathology. Identified gaps in knowledge will provide insight into current limitations and guide further studies on this topic. Trial RegistrationPROSPERO CRD42022339764; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=339764 International Registered Report Identifier (IRRID)PRR1-10.2196/4233

Antioxidant enzymes mediate survival of breast cancer cells deprived of extracellular matrix.

Metastasis by cancer cells relies upon the acquisition of the ability to evade anoikis, a cell death process elicited by detachment from extracellular matrix (ECM). The molecular mechanisms that ECM-detached cancer cells use to survive are not understood. Striking increases in reactive oxygen species (ROS) occur in ECM-detached mammary epithelial cells, threatening cell viability by inhibiting ATP production, suggesting that ROS must be neutralized if cells are to survive ECM-detachment. Here, we report the discovery of a prominent role for antioxidant enzymes, including catalase and superoxide dismutase, in facilitating the survival of breast cancer cells after ECM-detachment. Enhanced expression of antioxidant enzymes in nonmalignant mammary epithelial cells detached from ECM resulted in ATP elevation and survival in the luminal space of mammary acini. Conversely, silencing antioxidant enzyme expression in multiple breast cancer cell lines caused ATP reduction and compromised anchorage-independent growth. Notably, antioxidant enzyme-deficient cancer cells were compromised in their ability to form tumors in mice. In aggregate, our results reveal a vital role for antioxidant enzyme activity in maintaining metabolic activity and anchorage-independent growth in breast cancer cells. Furthermore, these findings imply that eliminating antioxidant enzyme activity may be an effective strategy to enhance susceptibility to cell death in cancer cells that may otherwise survive ECM-detachment

Determining Differences in Perioperative Functional Mobility Patterns in Lumbar Decompression Versus Fusion Patients Using Smartphone Activity Data

Smartphone activity data recorded through high-fidelity accelerometry can provide accurate postoperative assessments of patient mobility. The "big data" available through smartphones allows for advanced analyses, yielding insight into patient well-being. This study compared rate of change in functional activity data between lumbar fusion (LF) and lumbar decompression (LD) patients to determine preoperative and postoperative course differences. Twenty-three LF and 18 LD patients were retrospectively included. Activity data (steps per day) recorded in Apple Health, encompassing over 70 000 perioperative data points, was classified into 6 temporal epochs representing distinct functional states, including acute preoperative decline, immediate postoperative recovery, and postoperative decline. The daily rate of change of each patient's step counts was calculated for each perioperative epoch. Patients undergoing LF demonstrated steeper preoperative declines than LD patients based on the first derivative of step count data (P = .045). In the surgical recovery phase, LF patients had slower recoveries (P = .041), and LF patients experienced steeper postoperative secondary declines than LD patients did (P = .010). The rate of change of steps per day demonstrated varying perioperative trajectories that were not explained by differences in age, comorbidities, or levels operated. Patients undergoing LF and LD have distinct perioperative activity profiles characterized by the rate of change in the patient daily steps. Daily steps and their rate of change is thus a valuable metric in phenotyping patients and understanding their postsurgical outcomes. Prospective studies are needed to expand upon these data and establish causal links between preoperative patient mobility, patient characteristics, and postoperative functional outcomes

Gamma Knife radiosurgery for trigeminal neuralgia provides greater pain relief at higher dose rates

In Gamma Knife (GK) radiosurgery, dose rate decreases during the life cycle of its radiation source, extending treatment times. Prolonged treatments influence the amount of sublethal radiation injury that is repaired during exposure, and is associated with decreased biologically-equivalent dose (BED). We assessed the impact of treatment times on clinical outcomes following GK of the trigeminal nerve - a rare clinical model to isolate the effects of treatment times. This is a retrospective analysis of 192 patients with facial pain treated across three source exchanges. All patients were treated to 80 Gy with a single isocenter. Treatment time was analyzed in terms of patient anatomy-specific dose rate, as well as BED calculated from individual patient beam-on times. An outcome tool measuring pain in three distinct domains (pain intensity, interference with general and oro-facial activities of daily living), was administered before and after intervention. Multivariate linear regression was performed with dose rate/BED, brainstem dose, sex, age, diagnosis, and prior intervention as predictors. BED was an independent predictor of the degree of improvement in all three dimensions of pain severity. A decrease in dose rate by 1.5 Gy/min corresponded to 31.8% less improvement in the overall severity of pain. Post-radiosurgery incidence of facial numbness was increased for BEDs in the highest quartile. Treatment time is an independent predictor of pain outcomes, suggesting that prescription dose should be customized to ensure iso-effective treatments, while accounting for the possible increase in adverse effects at the highest BEDs