Dense middle cerebral artery computed tomography sign: confirmation by magnetic resonance (MR) imaging and MR angiography

Prediction model of early biomarkers of massive cerebral infarction caused by anterior circulation occlusion: Establishment and evaluation

Objective

The purpose of this study is to establish and evaluate an early biomarker prediction model of massive cerebral infarction caused by anterior circulation occlusion.

Methods

One hundred thirty-four patients with acute cerebral infarction from January 2018 to October 2020 were selected to establish the development cohort for the internal test of the nomogram. Ninety-one patients with acute cerebral infarction hospitalized in our hospital from December 2020 to December 2021 were constituted the validation cohort for the external validation. All patients underwent baseline computed tomography (CT) scans within 12 h of onset and early imaging signs (hyperdense middle cerebral artery sign, obscuration of the lentiform nucleus, insular ribbon sign) of acute cerebral infarction were identified on CT by two neurologists. Based on follow-up CT images, patients were then divided into a massive cerebral infarction group and a non-massive cerebral infarction group. The nomogram model was constructed based on logistic regression analysis with R language. The nomogram was subsequently validated in an independent external validation cohort. Accuracy and discrimination of the prediction model were evaluated by a calibration chart, receiver operating characteristic (ROC) curve, and decision curve.

Results

The indicators, including insular ribbon sign, reperfusion therapy, National Institutes of Health Stroke Scale (NHISS) score, previous cerebral infarction, and atrial fibrillation, were entered into the prediction model through binary logistic regression analysis. The prediction model showed good predictive ability. The area under the ROC curve of the prediction model was 0.848. The specificity, sensitivity, and Youden index were 0.864, 0.733, and 0.597, respectively. This nomogram to the validation cohort also showed good discrimination (AUC = 0.940, 95% CI 0.894–0.985) and calibration.

Conclusion

Demonstrating favorable predictive efficacy and reproducibility, this study successfully established a prediction model of CT imaging signs and clinical data as early biomarkers of massive cerebral infarction caused by anterior circulation occlusion.

A review of problems following insertion of biliary stents illustrated by an unusual complication

INTRODUCTION

The management of obstructive jaundice resulting from both benign and malignant causes relies heavily on minimally invasive techniques and particularly with the insertion of biliary endoprostheses. Migration of these biliary stents is a well-documented problem and can result in a variety of complications including perforation, intra-abdominal sepsis, fistulae formation, obstruction and appendicitis.

METHODS

A literature search was performed using PubMed examining case reports, published abstracts and reviews to date (2009). In addition, we report a left groin abscess as a previously unreported complication following migration of a biliary endoprosthesis.

FINDINGS

Stent migration can lead to serious complications and produce significant morbidity and mortality. Symptomatic patients especially those with other co-morbid abdominal pathologies such as colonic diverticulae, parastomal hernia or abdominal hernias may be at an increased risk of perforation especially when straight plastic stents are used.

The Hyperdense Cerebral Artery Sign on Head CT Scan

The hyperdense artery sign on noncontrast head CT is thought to be one of the earliest and most useful signs of intra-arterial clot and probable (clinical) stroke. It should be evaluated in the context of the clinical scenario. Rigorous criteria should be applied in order to reduce potential false positives. The hyperdense middle cerebral artery sign is the most studied version and correlates with patient outcome. Our data suggest that the density on noncontrast head CT is not likely to universally represent in situ clot.

Fracture of Memotherm metallic stents in the biliary tract

In a series of 66 patients who had palliation of malignant obstructive jaundice by percutaneous placement of Memotherm expanding metal stents, we report four cases of stent fracture. This has not been reported previously.