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Purpose:To determine whether quantitative computed tomographic (CT) measurements of emphysema and airway dimensions are associated with lung cancer risk in a screening population. Materials and Methods:Institutional review board approval and informed consent for the use of deidentifi ed images were obtained. In this retrospective study, CT scans were analyzed from 279 participants in the CT screening arm of the National Lung Screening Trial who were diagnosed with lung cancer and 279 participants who were not diagnosed with lung cancer after a median follow-up period of 6.6 years. Quantitative CT measurements of emphysema and right upper lobe apical segmental and subsegmental airway dimensions, and multiple patient history-related variables, were compared between the two groups. Signifi cant variables were tested in multivariate models for association with lung cancer by using multiple logistic regression. Results:The emphysema index of percentage upper lung volume less than 2 950 HU had the strongest association with lung cancer (mean, 10.7% [standard deviation, 13.5] in patients vs 7.2% [standard deviation, 10.4] in control subjects; P , .001 ), but the relationship was weak ( R 2 = 0.015, P , .001, c = 0.57). No CT measures of emphysema had an association with lung cancer independent of the patient medical history variables. Airway dimensions were not associated with lung cancer. Conclusion:Quantitative CT measurements of emphysema but not airway dimensions were only weakly associated with lung cancer, demonstrating no potential practical value for clinical risk stratifi cation.q RSNA, 2011Supplemental material: http://radiology.rsna.org/lookup /suppl

Abdominal pain, nausea, and vomiting are common presenting symptoms among adult patients seeking care in the emergency department, and, with the increased use of computed tomography (CT) to image patients with these complaints, radiologists will more frequently encounter a variety of emergent gastric pathologic conditions on CT studies. Familiarity with the CT appearance of emergent gastric conditions is important, as the clinical presentation is often nonspecific and the radiologist may be the first to recognize gastric disease as the cause of a patient's symptoms. Although endoscopy and barium fluoroscopy remain important tools for evaluating patients with suspected gastric disease in the outpatient setting, compared with CT these modalities enable less comprehensive evaluation of patients with nonspecific complaints and are less readily available in the acute setting. Endoscopy is also more invasive than CT and has greater potential risks. Although the mucosal detail of CT is relatively poor compared with barium fluoroscopy or endoscopy, CT can be used with the appropriate imaging protocols to identify inflammatory conditions of the stomach ranging from gastritis to peptic ulcer disease. In addition, CT can readily demonstrate the various complications of gastric disease, including perforation, obstruction, and hemorrhage, which may direct further clinical, endoscopic, or surgical management. We will review the normal anatomy of the stomach and discuss emergent gastric disease with a focus on the usual clinical presentation, typical imaging appearance, and differentiating features, as well as potential imaging pitfalls.

Background The Liver Imaging Reporting and Data System (LI‐RADS) is being adapted by many clinical practices. To support continuation of its use, LI‐RADS (LR) is in need of multicenter validation studies of recent LI‐RADS iterations. Furthermore, while both gadoxetate and extracellular agents have been incorporated into LI‐RADS, comparison of the diagnostic performance between the two has yet to be determined. Purpose/Hypothesis To evaluate the rate, diagnostic performance, and interreader reliability (IRR) of LI‐RADS 2017 for hepatocellular carcinoma, including LR major and ancillary features, with both gadoxetate and extracellular agent‐enhanced MRI against a reference standard of histopathology or imaging follow‐up. Study Type Retrospective. Population In all, 114 patients with 144 observations were included who met LR 2017 criteria for at risk and had at least one hepatic observation on liver MRI performed with either gadoxetate (n = 52) or an extracellular agent (n = 92) between 2010–2016, with histopathology (n = 103) or follow‐up imaging (n = 41). Field Strength/Sequence 1.5 and 3.0T/T1‐T2WI, diffusion‐weighted imaging. Assessment Three radiologists independently assessed major/ancillary features and assigned overall LI‐RADS category for every observation. Statistical Tests Diagnostic performance of LR5/TIV+LR5 for identifying hepatocellular carcinoma (HCC) was compared between contrast agents with a generalized estimating equation. Weighted kappa was performed for interrater reliability. Results The frequency of HCCs among LR1, LR2, LR3, L4, LR5, LRTIV+LR5, and LRM observations were: 0% (all readers), 0–12.5%, 11.4–26.9%, 50–76%, 83.0–95.1%, 83.3–100.0%, and 45.0–65.0%, respectively. Sensitivity of LR5/LRTIV+LR5 for HCC was 59.7–71.4% and specificity 85.0–96.8%. LI‐RADS specificity and positive predictive value for observations imaged with gadoxetate was higher than extracellular agent for the most inexperienced reader (R3) (P = 0.009–0.034). IRR for LI‐RADS categorization was substantial (k = 0.661). Data Conclusion Increasing numerical LI‐RADS 2017 categories demonstrate a greater percentage of HCCs. LR5/TIV+LR5 demonstrates excellent specificity and fair sensitivity for HCC. MRI with gadoxetate in liver transplant candidates may be beneficial for less experienced readers, although further large‐scale prospective studies are needed. Level of Evidence: 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:e205–e215.

Surgical mesh is used most frequently for tension-free repair of abdominal wall hernias in adults, because the rate of hernia recurrence is lower with mesh than with primary soft-tissue repair. Since the introduction of polypropylene mesh in the middle of the 20th century, many mesh materials and configurations for specific surgical procedures have been developed. In addition to abdominal wall hernia repair, mesh may be used for repair of diaphragmatic hernias, urinary incontinence in women (female slings), genitourinary prolapse (vaginal mesh and sacrocolpopexy), rectal prolapse (rectopexy), and postprostatectomy male urinary incontinence (male slings). General mesh repair complications include chronic pain; fluid collections such as seromas, hematomas, and abscesses; adhesions that may lead to intestinal blockage; erosion into solid or hollow viscera including enterocutaneous fistulizing disease; and mesh failure characterized by mesh shrinkage, detachment, and migration with repair malfunction. Several mesh complications are often diagnosed with imaging, primarily with CT and less frequently with MRI and US, despite variable mesh visibility at imaging. This article reviews the common surgical mesh applications in the abdomen and pelvis, discusses imaging of mesh repair complications, and provides complication treatment highlights. © RSNA, 2020 • radiographics.rsna.org