Imaging of ischemia, obstruction and infection in the abdomen

Intestinal ischemia is a serious condition that continues to be associated with mortalities in excess of 70%. Intestinal obstruction and gastrointestinal tract sepsis are common conditions, accounting for a large proportion of patients admitted to emergency departments with acute abdominal symptoms. This article discusses the imaging methods and key findings of these entities in the emergency radiology department. The article includes imaging examples, diagnostic options, protocol selections, diagnostic criteria, and differential diagnoses

CT densitometry as a predictor of pulmonary function in lung cancer patients.

Purpose: Preoperative pulmonary assessment is undertaken in patients with resectable lung cancer to identify those at increased risk of perioperative complications. Guidelines from the American College of Chest Physicians indicate that if the FEV1 and DLCO are ≥60% of predicted, patients are suitable for resection without further evaluation. The aim of our study is to determine if quantitative measures of lung volume and density obtained from pre-operative CT scans correlate with pulmonary function tests. This may allow us to predict pulmonary function in patients with lung cancer and identify patients who would tolerate surgical resection. Materials and Methods: Patients were identified retrospectively from the lung cancer database of a tertiary hospital. Image segmentation software was utilized to estimate total lung volume, normal lung volume (values -500 HU to -910 HU), emphysematous volume (values less than -910 HU), and mean lung density from pre-operative CT studies for each patient and these values were compared to contemporaneous pulmonary function tests. Results: A total of 77 patients were enrolled. FEV1 was found to correlate significantly with the mean lung density (r=.762, p<.001) and the volume of emphysema (r= -.678, p<.001). DLCO correlated significantly with the mean lung density (r =.648, p<.001) and the volume of emphysematous lung (r= -.535, p<.001). Conclusion: The results of this study suggest that both FEV1 and DLCO correlate significantly with volume of emphysema and mean lung density. We now plan to prospectively compare these CT parameters with measures of good and poor outcome postoperatively to identify CT measures that may predict surgical outcome preoperatively

Esophageal intramural pseudodiverticulosis characterized by barium esophagography: a case report

<p>Abstract</p> <p>Introduction</p> <p>Esophageal intramural pseudodiverticulosis is a rare condition characterized by the dilatation of the submucosal glands.</p> <p>Case presentation</p> <p>We present a case of esophageal intramural pseudodiverticulosis in a 72-year-old Caucasian man who presented with dysphagia and with a background history of alcohol abuse. An upper gastrointestinal endoscopy of our patient showed an esophageal stricture with abnormal mucosal appearances, but no malignant cells were seen at biopsy. Appearances on a barium esophagram were pathognomonic for esophageal intramural pseudodiverticulosis.</p> <p>Conclusion</p> <p>We demonstrate the enduring usefulness of barium esophagography in the characterization of abnormal mucosal appearances at endoscopy.</p

Reduction of guide needle streak artifact in CT-guided biopsy

Purpose: Computed tomography (CT)–guided core needle biopsy (CNB) can be affected by streak artifact obscuring the needle tip. This study investigates factors that influence the occurrence and severity of streak artifact during CNB. Materials and Methods: Eight coaxial guide needles of two sizes from two manufacturers with and without stylets were imaged in a CT phantom, with CT reconstructed with adaptive statistical iterative reconstruction and filtered back projection. CNB-related streak artifact was quantified with profile analysis in an image-processing program. Differences between maximum attenuation at the needle tip and minimum attenuation in the streak artifact were compared for each variable. Diagnostic acceptability and streak artifact were subjectively assessed on each phantom image and on 40 clinical CNB procedures by three independent blinded reviewers following training case review. Results: Artifact was significantly less with the central stylet removed versus in situ (median, 1,145 HU vs 3,390 HU; P < .001) for all needles, and less for 19-gauge needles versus 17-gauge needles (median, 1,334 HU vs 2,780 HU, respectively; P = .006). There were no differences based on manufacturer (P = .906) or reconstruction algorithm (P = .524). Independent reviews found that streak artifact was significantly reduced when the central stylet was removed (κ = 0.875–1.0; P < .001), and needle tip position was better in cases in which the stylet was removed (κ = 0.231–0.711; P < .001). Conclusions: Streak artifact can be reduced and needle tip visualization improved by confirming final biopsy needle position with the central stylet removed on CT and using smaller-gauge guide needles

Implementing an electronic sideband offset lock for precision spectroscopy in radium

We demonstrate laser frequency stabilization with at least 6 GHz of offset tunability using an in-phase/quadrature (IQ) modulator to generate electronic sidebands (ESB) on a titanium sapphire laser at 714 nm and we apply this technique to the precision spectroscopy of $^{226}$Ra, and $^{225}$Ra. By locking the laser to a single resonance of a high finesse optical cavity and adjusting the lock offset, we determine the frequency difference between the magneto-optical trap (MOT) transitions in the two isotopes to be $2630.0\pm0.3$ MHz, a factor of 29 more precise than the previously available data. Using the known value of the hyperfine splitting of the $^{3}P_{1}$ level, we calculate the isotope shift for the $^{1}S_{0}$ to $^{3}P_{1}$ transition to be $2267.0\pm2.2$ MHz, which is a factor of 8 more precise than the best available value. Our technique could be applied to countless other atomic systems to provide unprecedented precision in isotope shift spectroscopy and other relative frequency comparisons

Descriptive Analysis of a Baseline Concussion Battery Among U.S. Service Academy Members: Results from the Concussion Assessment, Research, and Education (CARE) Consortium

Introduction The prevalence and possible long-term consequences of concussion remain an increasing concern to the U.S. military, particularly as it pertains to maintaining a medically ready force. Baseline testing is being used both in the civilian and military domains to assess concussion injury and recovery. Accurate interpretation of these baseline assessments requires one to consider other influencing factors not related to concussion. To date, there is limited understanding, especially within the military, of what factors influence normative test performance. Given the significant physical and mental demands placed on service academy members (SAM), and their relatively high risk for concussion, it is important to describe demographics and normative profile of SAMs. Furthermore, the absence of available baseline normative data on female and non-varsity SAMs makes interpretation of post-injury assessments challenging. Understanding how individuals perform at baseline, given their unique individual characteristics (e.g., concussion history, sex, competition level), will inform post-concussion assessment and management. Thus, the primary aim of this manuscript is to characterize the SAM population and determine normative values on a concussion baseline testing battery. Materials and Methods All data were collected as part of the Concussion Assessment, Research and Education (CARE) Consortium. The baseline test battery included a post-concussion symptom checklist (Sport Concussion Assessment Tool (SCAT), psychological health screening inventory (Brief Symptom Inventory (BSI-18) and neurocognitive evaluation (ImPACT), Balance Error Scoring System (BESS), and Standardized Assessment of Concussion (SAC). Linear regression models were used to examine differences across sexes, competition levels, and varsity contact levels while controlling for academy, freshman status, race, and previous concussion. Zero inflated negative binomial models estimated symptom scores due to the high frequency of zero scores. Results Significant, but small, sex effects were observed on the ImPACT visual memory task. While, females performed worse than males (p < 0.0001, pη2 = 0.01), these differences were small and not larger than the effects of the covariates. A similar pattern was observed for competition level on the SAC. There was a small, but significant difference across competition level. SAMs participating in varsity athletics did significantly worse on the SAC compared to SAMs participating in club or intramural athletics (all p’s < 0.001, η2 = 0.01). When examining symptom reporting, males were more than two times as likely to report zero symptoms on the SCAT or BSI-18. Intramural SAMs had the highest number of symptoms and severity compared to varsity SAMs (p < 0.0001, Cohen’s d < 0.2). Contact level was not associated with SCAT or BSI-18 symptoms among varsity SAMs. Notably, the significant differences across competition level on SCAT and BSI-18 were sub-clinical and had small effect sizes. Conclusion The current analyses provide the first baseline concussion battery normative data among SAMs. While statistically significant differences may be observed on baseline tests, the effect sizes for competition and contact levels are very small, indicating that differences are likely not clinically meaningful at baseline. Identifying baseline differences and significant covariates is important for future concussion-related analyses to inform concussion evaluations for all athlete levels

Tumour-specific HMG-CoAR is an independent predictor of recurrence free survival in epithelial ovarian cancer

<p>Abstract</p> <p>Background</p> <p>Our group previously reported that tumour-specific expression of the rate-limiting enzyme in the mevalonate pathway, 3-hydroxy-3-methylglutharyl-coenzyme A reductase (HMG-CoAR) is associated with more favourable tumour parameters and a good prognosis in breast cancer. In the present study, the prognostic value of HMG-CoAR expression was examined in tumours from a cohort of patients with primary epithelial ovarian cancer.</p> <p>Methods</p> <p>HMG-CoAR expression was assessed using immunohistochemistry (IHC) on tissue microarrays (TMA) consisting of 76 ovarian cancer cases, analysed using automated algorithms to develop a quantitative scoring model. Kaplan Meier analysis and Cox proportional hazards modelling were used to estimate the risk of recurrence free survival (RFS).</p> <p>Results</p> <p>Seventy-two tumours were suitable for analysis. Cytoplasmic HMG-CoAR expression was present in 65% (n = 46) of tumours. No relationship was seen between HMG-CoAR and age, histological subtype, grade, disease stage, estrogen receptor or Ki-67 status. Patients with tumours expressing HMG-CoAR had a significantly prolonged RFS (p = 0.012). Multivariate Cox regression analysis revealed that HMG-CoAR expression was an independent predictor of improved RFS (RR = 0.49, 95% CI (0.25-0.93); p = 0.03) when adjusted for established prognostic factors such as residual disease, tumour stage and grade.</p> <p>Conclusion</p> <p>HMG-CoAR expression is an independent predictor of prolonged RFS in primary ovarian cancer. As HMG-CoAR inhibitors, also known as statins, have demonstrated anti-neoplastic effects <it>in vitro</it>, further studies are required to evaluate HMG-CoAR expression as a surrogate marker of response to statin treatment, especially in conjunction with current chemotherapeutic regimens.</p