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Background Virtual unenhanced (VUE) images obtained by using a dual-energy CT (DECT) multimaterial decomposition algorithm hold promise for diagnostic use in the abdomen in lieu of true unenhanced (TUE) images. Purpose To assess VUE images obtained from a DECT multimaterial decomposition algorithm in patients undergoing renal mass and urinary stone evaluation. Materials and Methods In this retrospective Health Insurance Portability and Accountability Act-compliant study, DECT was performed in patients undergoing evaluation for renal mass or urinary stone. VUE images were compared quantitatively to TUE images and qualitatively assessed by four independent radiologists. Differences in attenuation between VUE and TUE images were summarized by using 95% limits of agreement. Diagnostic performance in urinary stone detection was summarized by using area under the receiver operating characteristic curve, sensitivity, and specificity. Results A total of 221 patients (mean age ± standard deviation, 61 years ± 14; 129 men) with 273 renal masses were evaluated. Differences in renal mass attenuation between VUE and TUE images were within 3 HU for both enhancing masses (95% limits of agreement, -3.1 HU to 2.7 HU) and nonenhancing cysts (95% limits of agreement, -2.9 HU to 2.5 HU). Renal mass classification as enhancing mass versus nonenhancing cyst did not change (reclassification rate of enhancing masses, 0% [0 of 78]; 95% CI: 0, 5; reclassification rate of nonenhancing cysts, 0% [0 of 193]; 95% CI: 0, 2) with use of VUE in lieu of TUE images. Among 166 urinary stones evaluated, diagnostic performance of VUE images for stone detection was lower compared with that of TUE images (area under the receiver operating characteristic curve, 0.79 [95% CI: 0.73, 0.84] vs 0.93 [95% CI: 0.91, 0.95]; P < .001) due to reduced sensitivity of VUE for detection of stones 3 mm in diameter or less compared with those greater than 3 mm (sensitivity, 23% [25 of 108; 95% CI: 12, 40] vs 88% [126 of 144; 95% CI: 77, 94]; P < .001). Conclusion Compared with true unenhanced images, virtual unenhanced (VUE) images were unlikely to change renal mass classification as enhancing mass versus nonenhancing cyst. Diagnostic performance of VUE images remained suboptimal for urinary stone detection due to subtraction of stones 3 mm or less in diameter. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Sosna in this issue.

To evaluate the feasibility of CT perfusion performed during routine multiphase contrast-enhanced CT on a 160 mm wide-coverage 256-slice scanner in patients with pancreatic ductal adenocarcinoma (PDAC). Fifty-seven patients had a CT perfusion acquisition during their routine multiphase CT. Perfusion was performed 5 to 42.5 s (15 passes at 2.5 s intervals) after intravenous contrast administration (4.2–5 ml/s), followed by pancreatic parenchymal and portal venous phases for clinical interpretation. Perfusion maps were generated and blood flow (BF), blood volume (BV), and permeability surface area product (PS) for tumor and uninvolved pancreas were calculated using deconvolution algorithms and compared to existing similar publications. Radiation dose information was recorded and size-specific dose estimate (SSDE) was calculated using body dimensions. Diagnostic quality of standard images was unaffected by performing the perfusion acquisition. Average tumor center BF was 20.8 ± 12.1 ml/100 g/min, BV 2.5 ± 2.1 ml/100 g and PS 15.5 ± 39.4 ml/100 g/min. Average pancreas BF was 90.8 ± 50.2 ml/100 g/min, BV 11.9 ± 4.3 ml/100 g and PS 33.6 ± 27.7 ml/100 g/min. For the perfusion acquisition, mean SSDE was 57 ± 11 mGy, CTDIvol 43 ± 6 mGy and DLP 685 ± 100 mGy-cm. Adding a perfusion CT acquisition to standard pancreatic CT protocol is feasible using a wide-detector 256-slice CT scanner and adds quantitative information while maintaining diagnostic quality of the standard of care examination. This novel protocol adds no time or cost to the examination and yields perfusion parameters that are comparable to existing literature using a separate dedicated perfusion protocol.

Rationale and Objectives We hypothesized that providing visual-spatial information to radiologists on where radiation has been delivered in an easily accessible way may improve the accuracy of image interpretation and thereby improve quality of patient care. We present a national representation of radiologists’ opinions regarding the usefulness and optimal approach for implementing a system to promote access to radiotherapy (RT) plans. Methods An anonymous survey was sent to the members of the Association of University Radiologists. Descriptive statistics were performed. Results Questionnaires were returned by 95 of 1383 members. Demographics comprised of 76% attendings with 94% practicing within an academic setting. Only 40% of radiologists reported that they knew most of the time whether a patient has received RT in the field scanned. A large majority of respondents (88%) felt that a history of prior radiation in a cancer patient was at least an occasional barrier that affected the ability to interpret imaging findings in a clinically useful way. The following types of information was considered helpful when interpreting a scan: screenshots of the radiation plan (85%), scrollable DICOM data on planning CT showing delivered RT dose lines (54%), and written text RT treatment summary (47%). Nearly all (89%) desired DICOM data within the clinical radiology Picture Archiving and Communication System system. Radiologists expected the ease of accessibility to RT plans to result in increased efficiency (76%) and accuracy (88%). Conclusion Diagnostic radiologists desire improved access and integration of radiotherapy plans into the diagnostic radiology clinical workup in the form of visual-spatial data.

We present a case-based review of abdominal postoperative complications, organized by organ system affected, including wound/superficial, hepatobiliary, pancreatic, gastrointestinal, genitourinary, and vascular complications. Both general complications and specific considerations for certain types of operations are described, as well as potential pitfalls that can be confused with complications. Representative cases are shown using all relevant imaging modalities, including CT, fluoroscopy, ultrasound, MRI, and nuclear medicine. Management options are also described, highlighting those that require radiologist input or intervention.

Effective induction of antitumor T cells is a pivotal goal of cancer immunotherapy. To this end, lentiviral vectors (LV) are uniquely poised to directly prime CD8 T-cell responses via transduction of dendritic cells in vivo and have shown promise as active cancer therapeutics in preclinical tumor models. However, until now, significant barriers related to production and regulation have prevented their widespread use in the clinic. We developed LV305, a dendritic cell-targeting, integration-deficient, replication incompetent LV from the ZVex platform, encoding the full-length cancer-testis antigen NY-ESO-1. LV305 is currently being evaluated in phase 1 and 2 trials in metastatic recurrent cancer patients with NY-ESO-1 positive solid tumors as a single agent and in combination with anti-PD-L1. Here we report on the first patient treated with LV305, a young woman with metastatic, recurrent, therapy-refractive NY-ESO-1 synovial sarcoma. The patient developed a robust NY-ESO-1-specific CD4 and CD8 T-cell response after 3 intradermal injections with LV305, and subsequently over 85% disease regression that is continuing for >2.5 years posttherapy. No adverse events >grade 2 occurred. This case demonstrates that LV305 can be safely administered and has the potential to induce a significant clinical benefit and immunologic response in a patient with advanced stage cancer.

Purpose Computed tomography (CT) is a fast and ubiquitous tool to evaluate intra-abdominal organs and diagnose appendicitis. However, traditional CT reporting does not necessarily capture the degree of uncertainty and indeterminate findings are still common. The purpose of this study was to evaluate the reproducibility of a standardized CT reporting system for appendicitis across a large population and the system's impact on radiologists' certainty in diagnosing appendicitis. Methods Using a previously described standardized reporting system, eight radiologists retrospectively evaluated CT scans, blinded to all clinical information, in a stratified random sample of 237 patients from a larger cohort of patients imaged for possible appendicitis (2010-2014). Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to evaluate the diagnostic performance of readers for identifying appendicitis. Two-thirds of these scans were randomly selected to be independently read by a second reader, using the original CT reports to balance the number of positive, negative and indeterminate exams across all readers. Inter-reader agreement was evaluated. Results There were 113 patients with appendicitis (mean age 38, 67% male). Using the standardized report, radiologists were highly accurate at identifying appendicitis (AUC=0.968, 95%CI confidence interval: 0.95, 0.99. Inter-reader agreement was >80% for most objective findings, and certainty in diagnosing appendicitis was high and reproducible (AUC=0.955 and AUC=0.936 for the first and second readers, respectively). Conclusions Using a standardized reporting system resulted in high reproducibility of objective CT findings for appendicitis and achieved high diagnostic accuracy in an at-risk population. Predictive tools based on this reporting system may further improve communication about certainty in diagnosis and guide patient management, especially when CT findings are indeterminate.

Gastrointestinal stromal tumor (GIST) is a devastating disease, especially in the setting of metastasis. The natural progression of GIST has been significantly altered by the development of small molecule tyrosine kinase inhibitors (TKIs), including imatinib, sunitinib, and regorafenib, all of which are FDA approved. However, TKIs are not always well-tolerated, and the refractory disease continues to be a problem. For these reasons, alternative treatments are needed. In this report, we discuss a patient with metastatic wild-type (WT) GIST refractory to multiple TKIs, but with a durable clinical response to the anti-programmed cell death protein 1 (PD-1) antibody, nivolumab. This report suggests that continued research evaluating checkpoint inhibitors in GIST is warranted.

Approximately one‐third of Merkel cell carcinoma (MCC) patients eventually develop distant metastatic disease. Little is known about whether the location of the primary lesion is predictive of initial distant metastatic site, or if survival likelihood differs depending on the metastatic site. Such data could inform imaging/surveillance practices and improve prognostic accuracy. Multivariate and competing‐risk analyses were performed on a cohort of 215 MCC patients with distant metastases, 31% of whom had two or more initial sites of distant metastasis. At time of initial distant metastasis in the 215 patients, metastatic sites (n = 305) included non‐regional lymph nodes (present in 41% of patients), skin/body wall (25%), liver (23%), bone (21%), pancreas (8%), lung (7%), and brain (5%). Among the 194 patients who presented with MCC limited to local or regional sites (stage I‐III) but who ultimately developed distant metastases, distant progression occurred in 49% by 1 year and in 80% by 2 years following initial diagnosis. Primary MCC locations differed in how likely they were to metastasize to specific organs/sites (P

MRI can delineate finer details of penile anatomy and pathology due to inherent higher soft-tissue contrast and spatial resolution. It can characterize inflammation and identify abscesses, localize penile fractures, guide surgical planning in penile fibrosis and Peyronie's disease, and depict components of the penile prosthesis and its complications. MRI is a great investigative tool for penile neoplasms, including locally infiltrative neoplasms where clinical examination is limited, and local staging is crucial for surgical planning.

OBJECTIVE. Soft-tissue sarcomas are a diverse group of malignancies, and our rapidly improving understanding of their molecular pathogenesis and treatment is leading to better clinical outcomes. The revised 2013 World Health Organization (WHO) classification of soft-tissue sarcomas introduced several important changes. We provide a comprehensive overview of the relevant changes for radiologists. CONCLUSION. Rapid advances in the understanding of the pathogenesis and molecular biology of soft-tissue sarcomas led to major revisions in the 2013 WHO classification. To provide optimal multidisciplinary patient care, radiologists must remain up-to-date with the latest developments in the field of soft-tissue sarcomas to best correlate the histologic and imaging features of the various types of tumors and understand the unique patterns of treatment response and disease recurrence.

e17016 Background: While sarcopenia is associated with increased mortality in bladder cancer, there is limited data in patients treated with neoadjuvant chemotherapy (NAC) that associates skeletal muscle index (SMI) and adverse treatment-associated outcomes. Herein, we evaluate associations between baseline SMI and severe adverse events (SAEs) during NAC and post-radical cystectomy (RC) 90-day Clavien ≥3 complications. Methods: SMI (cross sectional area of skeletal muscle, cm2 / height2, m2) was measured on an axial computed tomography (CT) image at the level of the third lumbar vertebral body, within 60 days prior to NAC and RC. Patients were classified as being sarcopenic, according to sex-specific consensus definitions: Male: SMI < 55, Female: SMI < 39. Associations with SAEs during NAC and 90-day Clavien grade 3-5 complications were assessed with multivariable logistic regression. Results: CT scans of sufficient quality (2005-18) were available for 143 patients. There were no significant differences in clinicopathologic characteristics between the study cohort and patients without available imaging (N = 261). Median SMI for men and women was 52.1 and 40.9 cm2/m2; 86 (60%) were sarcopenic. SAEs were observed in 92 patients (64%), resulting in hospitalization during NAC in 27 (19%), while 20 (14%) patients did not complete planned NAC due to SAEs. After adjusting for age, performance status, and clinical stage, SMI was not independently associated with NAC-associated SAEs. Postoperative complications occurred in 82 (57%) patients, including infectious complications (39; 27%), wound dehiscence (8; 6%), 90-day readmission (27; 19%). Wound healing complications including dehiscence, clinically significant hernia, urine leaks, or fistulae occurred in 33 (23%). While SMI was not independently associated with risk of complications overall (OR: 1.00, 95% CI: 0.96 - 1.03), it was associated with infectious complications (OR: 0.96, 95% CI: 0.92 - 0.99, p = 0.02), and wound dehiscence (OR: 0.93, 95% CI: 0.86 - 0.99, p = 0.02) with a trend towards significance for associations with any wound-healing complications (OR: 0.96, 95% CI: 0.91 - 1.00, p = 0.08). Conclusions: In the largest reported series of post-NAC patients with RC and detailed follow-up, pretreatment SMI was not associated with SAEs during NAC but was associated with serious infectious complications and wound dehiscence after RC. This data highlights the potential value in measuring SMI to identify patients at risk for select SAEs. Future studies should assess the benefit of prehabilitation before and during NAC.

e17015 Background: Sarcopenia is a modifiable risk factor independently associated with cancer-specific mortality (CSM) in bladder cancer (BC). Sarcopenic obesity, where obesity is measured by fat mass index [FMI, total body fat (kg)/height(m)2], has been proposed as an additive insult. To date, studies have overwhelmingly been performed in patients treated without neoadjuvant chemotherapy (NAC). Herein, we evaluate associations between baseline skeletal muscle index (SMI), FMI, and CSM in patients treated with NAC and radical cystectomy (RC). Methods: Lumbar SMI (cross sectional area of skeletal muscle/height2, cm2/m2) was measured on a computed tomography (CT) image at the level of the third lumbar vertebral body, within 60 days prior to NAC. Total body FMI was calculated from visceral and subcutaneous fat cross-sectional areas. Patients were classified as being sarcopenic, according to sex-specific consensus definitions: Male: SMI < 55, Female: SMI < 39, and as obese if Male: FMI > 9, Female: > 13. Cancer-specific survival (CSS) was estimated using the Kaplan Meier method. Associations with CSM were summarized with multivariable Cox proportional hazards models. Results: 143 patients had CT scans of sufficient quality (2005-18). There were no significant differences in clinicopathologic characteristics between the study cohort and patients without available imaging (N = 261). Cisplatin-based NAC was given to 125 patients (87%), and 18 (13%) received other regimens. In total, 86 (60%) patients were sarcopenic, 52 (36%) obese, and 25 (17%) both sarcopenic and obese, while 48 (34%) were sarcopenic with normal FMI. Median follow-up was 2.7 years (IQR 1.2-6.2), and 43 patients died from BC. Three-year CSS was 61% (sarcopenic) vs. 77% (p < 0.05). Sarcopenic patients with normal FMI had the worst 3-year CSS (55%) compared to those with sarcopenia and FMI-obesity (79%), normal SMI with FMI-obesity (69%), and normal body composition (88%, p = 0.03). On multivariable analysis, neither FMI (HR: 0.77, 95% CI: 0.47-1.3, p = 0.3) nor SMI was independently associated with CSM (HR: 0.98, 95% CI: 0.96-1, p = 0.07) after adjustment for ASA score, pathologic tumor, and nodal stage. Conclusions: In patients treated with NAC+RC, pretreatment SMI trended towards independently predicting risk of CSM. Patients with sarcopenia and normal fat demonstrated the worst CSS. Further study is warranted on the impact of NAC on body composition and the role of the latter in risk stratification of this high-risk patient population.

Purpose To investigate performance in detectability of small (≤1 cm) low-contrast hypoattenuating focal lesions by using filtered back projection (FBP) and iterative reconstruction (IR) algorithms from two major CT vendors across a range of 11 radiation exposures. Materials and Methods A low-contrast detectability phantom consisting of 21 low-contrast hypoattenuating focal objects (seven sizes between 2.4 and 10.0 mm, three contrast levels) embedded into a liver-equivalent background was scanned at 11 radiation exposures (volume CT dose index range, 0.5-18.0 mGy; size-specific dose estimate [SSDE] range, 0.8-30.6 mGy) with four high-end CT platforms. Data sets were reconstructed by using FBP and varied strengths of image-based, model-based, and hybrid IRs. Sixteen observers evaluated all data sets for lesion detectability by using a two-alternative-forced-choice (2AFC) paradigm. Diagnostic performances were evaluated by calculating area under the receiver operating characteristic curve (AUC) and by performing noninferiority analyses. Results At benchmark exposure, FBP yielded a mean AUC of 0.79 ± 0.09 (standard deviation) across all platforms which, on average, was approximately 2% lower than that observed with the different IR algorithms, which showed an average AUC of 0.81 ± 0.09 (P = .12). Radiation decreases of 30%, 50%, and 80% resulted in similar declines of observer detectability with FBP (mean AUC decrease, -0.02 ± 0.05, -0.03 ± 0.05, and -0.05 ± 0.05, respectively) and all IR methods investigated (mean AUC decrease, -0.00 ± 0.05, -0.04 ± 0.05, and -0.04 ± 0.05, respectively). For each radiation level and CT platform, variance in performance across observers was greater than that across reconstruction algorithms (P = .03). Conclusion Iterative reconstruction algorithms have limited radiation optimization potential in detectability of small low-contrast hypoattenuating focal lesions. This task may be further complicated by a high degree of variation in radiologists' performances, seemingly exceeding real performance differences among reconstruction algorithms. © RSNA, 2018 Online supplemental material is available for this article.

To assess whether CT morphology of adnexal lesions in postmenopausal women with history of non-ovarian cancer could be used to discriminate benign and malignant lesions, particularly focusing on applicability of the ACR criteria.This was an IRB-approved HIPAA-compliant retrospective review of contrast-enhanced CTs of 199 women, 55 years and older. Lesions were classified as simple cystic, complex cystic, solid-cystic, or solid based on CT morphology, and were diagnosed as benign, indeterminate, or malignant on follow-up imaging or pathology. Associated metastatic disease was noted, if present. Findings were analyzed to correlate CT morphology, primary tumor pathology, and metastatic disease pattern with eventual lesion diagnosis.There were 223 adnexal lesions, including 123 (55%) simple cystic, 48 (22%) complex cystic, 40 (18%) solid-cystic, and 12 (5%) solid lesions. 186/223 (83%) lesions were benign, and 37/223 (17%) were malignant. Primary colorectal cancer was significantly associated with an increased likelihood of malignant adnexal lesions (OR 10.2, p 0.001) compared to patients with other cancers. Adnexal malignancy was significantly associated with the presence of non-ovarian peritoneal metastases (p 0.001). None of the simple cysts (including 85 cysts between 1-3 cm and 38 cysts 3 cm) were found to be malignant (malignancy rate: 0.0%, 95% CI 0.0-3.0%). Complex cysts were more likely to be malignant than simple cysts (p = 0.002) and solid-cystic lesions were more likely to be malignant than complex cysts (p 0.001).Simple adnexal lesions on CT in this cohort were unlikely to be malignant, supporting the ACR guidelines. A higher size threshold of 3 cm (vs. 1 cm) may be preferred in all cases of simple cysts for recommending further follow-up. However, more complex-appearing cysts need further evaluation as the risk of malignancy is increased. Peritoneal metastases have a significant correlation with malignant adnexal involvement.

The purpose of this article is to assess the performance of a contrast reaction management checklist for optimal management of a contrast reaction scenario created using a high-fidelity hands-on simulation.A safety checklist was designed that presented the five adverse events that most commonly occur after administration of IV contrast medium as well as their step-by-step management. Forty-three radiology residents were randomized into two groups, a checklist group (n = 22) and a control group (n = 21), as stratified by postgraduate year. Participants took written tests involving multiple-choice questions 2 months before and immediately after participating in the high-fidelity simulation scenario, which was videotaped and independently evaluated by three graders.Both groups had similar scores on the multiple-choice question tests taken before and after participation in the simulation (p = 0.35 and p = 0.62, respectively). In the simulation, the checklist group scored significantly higher than the control group with regard to their overall management of a severe contrast reaction (85.1% vs 64.8%; p = 0.001), including individual scores for first-line treatment of bronchospasm (97.0% vs 91.3%; p = 0.035) and use of the correct route of administration and dose of epinephrine (77.3% vs 45.2%; p = 0.021).A standardized contrast reaction management checklist can reduce the number of treatment errors that occur during a simulated severe contrast reaction, particularly with regard to proper administration of epinephrine and treatment of bronchospasm. Such a checklist could be used by radiologists, technologists, and nurses to improve patient safety as a result of improved contrast reaction management and teamwork skills.

Mastectomy rates have increased, coinciding with more advanced reconstruction options. Deep inferior epigastric perforator (DIEP) flaps decrease abdominal donor site morbidity, but require considerable technical expertise. Preoperative computed tomography angiography (CTA) can accurately demonstrate DIEA anatomy and perforator courses, facilitating preoperative planning and flap design, allowing for more targeted intraoperative microdissection. Patients who undergo CTA before DIEP flap have better clinical outcomes with shorter operative times and hospital length of stay, which can decrease overall associated health care costs. Future directions include selected imaging of the thoracic anatomy and recipient vasculature, allowing for additional preoperative planning and customization.

"Acute abdomen" includes spectrum of medical and surgical conditions ranging from a less severe to life-threatening conditions in a patient presenting with severe abdominal pain that develops over a period of hours. Accurate and rapid diagnosis of these conditions helps in reducing related complications. Clinical assessment is often difficult due to availability of over-the-counter analgesics, leading to less specific physical findings. The key clinical decision is to determine whether surgical intervention is required. Laboratory and conventional radiographic findings are often non-specific. Thus, cross-sectional imaging plays a pivotal role for helping direct management of acute abdomen. Computed tomography is the primary imaging modality used for these cases due to fast image acquisition, although US is more specific for conditions such as acute cholecystitis. Magnetic resonance imaging or ultrasound is very helpful in patients who are particularly sensitive to radiation exposure, such as pregnant women and pediatric patients. In addition, MRI is an excellent problem-solving modality in certain conditions such as assessment for choledocholithiasis in patients with right upper quadrant pain. In this review, we discuss a multimodality approach for the usual causes of non-traumatic acute abdomen including acute appendicitis, diverticulitis, cholecystitis, and small bowel obstruction. A brief review of other relatively less frequent but important causes of acute abdomen, such as perforated viscus and bowel ischemia, is also included.

Accurate diagnosis of a wide spectrum of urethral/periurethral pathologies in women remains challenging due to its anatomical location and nonspecific clinical presentations. Magnetic resonance imaging (MRI) has emerged as the modality of choice for diagnosing female urethral and periurethral pathologies due to its multiplanar scanning capability, superior soft tissue differentiation, noninvasive nature, and overall excellent contrast resolution. In this narrative review, we describe the use of MRI to visualize the female urethra and periurethral pathologies. MRI can confidently characterize lesions into cystic or solid, provide a more succinct differential diagnosis, and in some cases provide a specific and accurate diagnosis, enabling surgeons to prepare a roadmap before operative procedure. Moreover, functional MRI can be useful to assess dynamic disorders such as urethral hypermobility. We provide a comprehensive review of normal MR anatomy of the female urethra, as well as the MR features of practically important urethral and periurethral lesions.

Apreviously healthy 37-year-old woman complained of episodic right upper abdominal pain. An extensive clinical workup had been negative, including physical examination, upper endoscopy, complete blood count, comprehensive metabolic panel, and coagulation studies. Contrast-enhanced computed tomography (CT) of the abdomen and pelvis demonstrated a solitary mass adjacent to the gastric antrum (Fig. 1). The mass had a lobulated contour with interdigitation of its parenchyma with the surrounding mesenteric fat along the inferior border. The mass did not appear to obstruct the gastric outlet, and there were no adjacent inflammatory changes. An ultrasound-guided percutaneous core needle biopsy was subsequently performed (not shown). The patient initially tolerated the procedure well and was discharged home. However, during the week following the biopsy, she developed acute right upper quadrant abdominal pain and presented to the emergency department. In the emergency department, she was found to be febrile (101.61F), with elevated white blood cell count (16,000 mm

Optimal treatment of thyroid cancer is highly dependent on accurate staging of the extent of disease at presentation. Preoperative ultrasonography (US) is the most sensitive method for detecting metastatic lymph nodes and is recommended as part of the standard preoperative workup. Missed findings on preoperative scans may lead to understaging and inadequate surgical management, which subsequently predispose these patients to residual disease postoperatively and a higher risk for recurrence, possibly requiring repeat surgery. Traditionally, thyroid US for pre- and postoperative staging has been performed by radiologists. However, there is a growing trend away from radiologist-performed US in favor of surgeon-performed US. Recent surgical and endocrinology literature has shown that, when compared with surgeon-performed US, radiologist-performed preoperative staging US is less accurate and is inadequate for presurgical planning, with higher local recurrence rates. This review highlights the importance of accurate preoperative US for patients with differentiated thyroid cancer, with specific attention to deficiencies that exist in general radiology department thyroid US reports. We present a standardized approach to neck US reporting that incorporates the newly updated 2015 recommendations from the American Thyroid Association and also addresses the pertinent questions for thyroid surgeons. By ensuring comprehensive preoperative assessment and improving thyroid US reporting, we seek to improve patient access to optimized care. ©RSNA, 2016.

This article serves to review the role of MR Enterography (MRE) in current clinical practice. Optimal technique is described based on recent consensus guidelines, as well as the potential role of optional and emerging sequences. The value of MRE for assessing patients with inflammatory bowel disease (IBD) is highlighted, including diagnosis, disease subtyping, detecting extraintestinal findings, and identifying complications, including particular attention to how these findings may be used for treatment decision-making. We specifically address the advantages and disadvantages of MRE compared to CT Enterography, including recently updated American College of Radiology Appropriateness Criteria for Crohn disease. Although less well established, we also discuss the utility of MRE in evaluating noninflammatory small bowel pathologies. Beyond initial diagnosis and disease phenotype characterization, MRE is increasingly incorporated into clinical indices used for treatment decision-making and assessing bowel damage longitudinally. Detecting and quantifying fibrosis remains a challenge in imaging for IBD, but some MRE sequences, such as magnetization transfer (MT) imaging, or fusion modalities, such as PET/MRE, have shown promise in providing functional information and offering meaningful biomarkers. MRE is also increasingly utilized for applications outside of IBD, such as screening for or assessing small bowel neoplasms. MRE is a valuable noninvasive technique for imaging the entire gastrointestinal tract and extraintestinal organs in a single examination without ionizing radiation. In IBD, MRE allows for accurate initial diagnosis and subtyping by assessing the bowel lumen, bowel wall, and surrounding structures simultaneously. Reliably predicting and quantifying fibrosis remains a challenge, but novel techniques, including fusion PET/MRE and MT imaging, offer promise. Quantitative MRE indices have also been developed and validated for assessing treatment response in patients with IBD, which can help guide treatment toward mucosal healing.

Purpose The aim of this study was to assess Society of Uroradiology member use of premedication before the intravenous administration of low-osmolality iodinated contrast materials (LOCM) and gadolinium-based contrast materials (GBCM). Methods Society of Uroradiology members were invited to complete a Web-based survey concerning the use of premedication. The survey included scenarios concerning intravenous LOCM or GBCM injection in which respondents were asked whether they would recommend premedication or withhold contrast material injection. Results for LOCM questions were compared with those for GBCM questions. Question responses for LOCM were also compared with those from a similar Society of Uroradiology survey published in 1995. Results Sixty-two of 72 respondents (86%) used standardized premedication regimens. Fifty-nine of 61 described regimens (97%) included oral corticosteroids and 48 (79%) antihistamines. Twenty of 69 respondents (29%) had separate urgent premedication regimens. There was general agreement concerning premedication use; however, responses were inconsistent in patients with severe food or medication allergies, severe symptomatic asthma, or prior mild urticarial reactions. More respondents recommended premedication before LOCM than GBCM administration. More respondents recommended premedication or avoidance of contrast material injection in patients with prior contrast reactions in the current study compared with the 1995 study. Conclusions There is frequent agreement among uroradiologists concerning the use of corticosteroid prophylaxis, but there is inconsistency in some clinical situations. The threshold for premedication is often lower for LOCM than GBCM. Since 1995, recommendations for use of premedication have become more widespread.

71 Background: Soft tissue sarcomas (STS) are heterogeneous tumors which are morbid and lethal. G100 is under investigation in multiple clinical trials and contains a potent TLR4 agonist (oil-in-water emulsion of glucopyranosyl lipid A) that has been tested as vaccine adjuvant. We hypothesized IT G100 would induce robust local and potentially systemic anti-tumor immune response, leading to improved outcomes. Methods: 15 metastatic STS patients with superficial lesions were treated with weekly IT G100 for 8-12 wks; 12 patients received radiation (RT) for 2 wks to start, while 3 received IT G100 for 6 wks prior to RT. Biopsies and PBMC were collected pre and post treatment, and flow cytometry was performed on biopsies. TIL and PBMC were analyzed with TCR deep sequencing. PBMC were analyzed by single cell multiplex cytokine profiling. Results: No grade ≥ 3 toxicity was observed, and local tumor control was achieved in all evaluable tumors (14/14). Treated tumors tracked post-trial (mean 156 days) had persistent local control with 1 CR (7%), 1 PR (7%), and 11 SD (79%). In 3 patients with long term follow up, treated lesions remained controlled vs index lesions (-53% vs +31% at mean 235 days, p = 0.002). In all tumors after G100 alone, T cell infiltration increased. In P14, CD3 live cells in tumor rose from < 1% to 62%. PBMC clonality increased in 8/14 tested including P06, who had 4× increase in clonality and CR in the injected lesion; PBMC and TIL TCR overlap increased from 13.4% to 21.5%. P13 had a 2.3× rise in TIL clonality; the top clone (a CD4 T cell) expanded from 0.1% to 38% and expressed more TNFα than the rest (p < 0.0001). Single cell cytokine analysis of PBMC showed 7/13 (54%) increased in polyfunctionality (producing > 2 cytokines) in CD4 T cells; no consistent increase was seen in CD8 T cells. TNFα levels in pre-treatment monocytes correlated with PFS (R2= 0.5, p = 0.02). Conclusions: IT G100 is a viable agent for local control of metastatic STS lesions. With or without RT, G100 appears to cause CD4 T cell mediated local and systemic response. Combination of G100 with other immunomodulators could induce clinically significant systemic responses, as seen in follicular NHL treated with G100. Clinical trial information: NCT02180698.

To retrospectively determine the benchmark incidence of nephrogenic systemic fibrosis (NSF) related to the confirmed use of different gadolinium chelate contrast agents at four U.S. university tertiary care centers.Institutional review board approval was obtained for this HIPAA-compliant multi-institutional study; the requirement for informed patient consent was waived. Patients who had a diagnosis of NSF between January 2000 and December 2006 were identified at four tertiary care centers with renal transplant and dialysis services. A standard checklist was used to acquire reliable data from the four centers. The diagnosis of NSF was confirmed histopathologically in all patients. The association of NSF development with gadolinium chelate contrast agent administration in each patient was assessed. The type and cumulative dose of contrast agent administered to each patient with NSF were determined at each center by using the standard checklist. The benchmark incidence of NSF was determined and expressed as the ratio of the number of patients with NSF who had undergone gadolinium chelate-enhanced magnetic resonance (MR) imaging, relative to the total number of patients who underwent gadolinium chelate-enhanced MR imaging at each tertiary care center. Benchmark incidences of NSF were compared among the four centers by using Fisher exact tests.Gadodiamide was used at University of North Carolina at Chapel Hill (center A) and Emory University (center B), and gadopentetate dimeglumine was used at Wake Forest University (center C) and Thomas Jefferson University (center D) during the study period. Twenty-three patients at center A, nine patients at center B, three patients at center C, and one patient at center D had NSF and had undergone gadolinium chelate-enhanced MR imaging. The incidence of NSF was one in 2913 patients who underwent gadodiamide-enhanced MR examinations and one in 44,224 patients who underwent gadopentetate dimeglumine-enhanced MR examinations.The benchmark incidence of NSF was much greater at the two centers where gadodiamide was used than at the two centers where gadopentetate dimeglumine was used.

Although subjective and objective benefits of high-fidelity simulation have been reported in medicine, there has been slow adoption in radiology. The purpose of our study was to identify the perceived barriers in the use of high-fidelity hands-on simulation for contrast reaction management training. An IRB exempt 32 questions online web survey was sent to 179 non-military radiology residency program directors listed in the Fellowship and Residency Electronic Interactive Database Access system (FREIDA). Survey questions included the type of contrast reaction management training, cost, time commitment of residents and faculty, and the reasons for not using simulation training. Responses from the survey were summarized as count (percentage), mean ± standard deviation (SD), or median (range). 84 (47%) of 179 programs responded, of which 88% offered CRM training. Most (72%) conducted the CRM training annually while only 4% conducted it more frequently. Didactic lecture was the most frequently used training modality (97%), followed by HFS (30%) and computer-based simulation (CBS) (19%); 5.5% used both HFS and CBS. Of the 51 programs that offer CRM training but do not use HFS, the most common reason reported was insufficient availability (41%). Other reported reasons included cost (33%), no access to simulation centers (33%), lack of trained faculty (27%) and time constraints (27%). Although high-fidelity hands-on simulation training is the best way to reproduce real-life contrast reaction scenarios, many institutions do not provide this training due to constraints such as cost, lack of access or insufficient availability of simulation labs, and lack of trained faculty. As a specialty, radiology needs to better address these barriers at both an institutional and national level.

Diagnosis of Crohn’s disease (CD) relies on a combination of endoscopy, imaging, and pathologic examination. Imaging is used to suggest the diagnosis of CD, document the distribution of disease, assess activity, and detect complications. Imaging is also useful to suggest alternate diagnoses in patients suspected of having CD.

Introduction: Soft tissue sarcomas (STS) are heterogeneous mesenchymal tumors which are both morbid and lethal. G100 is a stable oil-in-water emulsion of glucopyranosyl lipid adjuvant, a highly potent toll-like receptor 4 (TLR4) agonist, which has been utilized for intratumoral (IT) injections and as vaccine adjuvants without significant toxicity. We hypothesized that IT G100 would induce a robust local and potentially systemic anti-tumor immune response in the STS microenvironment, leading to improved outcomes. Methods: 15 metastatic STS patients who had a superficial injectable lesion were treated with weekly IT G100 for 8-12 weeks; 12 patients received concurrent radiation for 2 weeks at the start, while 3 got IT G100 alone for 6 weeks prior to radiation. Biopsies and blood were collected pre and post treatment, and flow cytometry was performed on fresh tumor samples. T-cell receptor (TCR) deep sequencing of tumor-infiltrating lymphocytes (TIL) and peripheral blood mononuclear cells (PBMC) was performed on 7 patients. RECIST v1.1 and the Common Terminology Criteria for Adverse Events were used to monitor clinical outcomes. Results: Patients had a median of 3 (0~5) prior lines of therapy and mean tumor size of 5.6cm (1~20cm). No grade 3 or higher treatment-related toxicity was observed, and local tumor control was achieved in 93% (14/15). 6 (40%) had stable disease after treatment, and 1 (P06) had complete regression of injected tumor. This tumor had a high percentage of infiltrating pre-treatment immune cells (12% CD45+ on flow cytometry versus 2.7% for all other tumors). TCR sequencing showed that the increase in clonality of PBMC after treatment was greater in P06 (389%) compared to 6 other patients (mean 34%). There was also higher overlap in TCR sequence between TIL versus PBMC after treatment (13% versus 22%), suggesting systemic expansion of tumor-specific T-cells. In 7 patients evaluable for tumor-associated macrophages (tumors with >1000 CD45+CD11b+ cells), 71% had a shift from an M2 to M1 phenotype. In all patients who received G100 alone, there was an increase in T-cell infiltration into tumor after treatment. In one patient (P14), the proportion of CD3+ live cells in tumor went from Conclusion: IT G100 provides a potentially viable agent for local control of metastatic STS. With or without radiation, G100 appears to shift the tumor microenvironment into a more inflammatory state with significant infiltration of T cells. The increase in clonality in PBMC and TIL, as well as increased overlap of tumor-associated versus peripheral TCR sequences, suggest induction of a tumor-specific response. Combination of G100 with other immunomodulators may further enhance the adaptive anti-tumor response. Citation Format: Yongwoo D. Seo, Edward Y. Kim, Ernest U. Conrad, Ryan B. O'Malley, Sara Cooper, Bailey Donahue, Lee D. Cranmer, Hailing Lu, Frank Hsu, Elizabeth T. Loggers, Taylor Hain, Darin J. Davidson, Lynn Bonham, Venu G. Pillarisetty, Gabrielle M. Kane, Stanley R. Riddell, Robin L. Jones, Seth M. Pollack. Intratumoral injection of the toll-like receptor 4 agonist G100 induces a T-cell response in the soft tissue sarcoma microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2947. doi:10.1158/1538-7445.AM2017-2947

Purpose To assess the performance of interprofessional teams of radiologists, technologists, and nurses trained with high-fidelity hands-on (HO) simulation and computer-based (CB) simulation training for contrast reaction management (CR) and teamwork skills (TS). Methods Nurses, technologists, and radiology residents were randomized into 11 teams of three (one of each). Six teams underwent HO training and five underwent CB training for CR and TS. Participants took written tests before and after training and were further tested using a high-fidelity simulation scenario. Results HO and CB groups scored similarly on all written tests and each showed improvement after training ( P = .002 and P = .018, respectively). During the final scenario test, HO teams tended to receive higher grades than CB teams on CR (95% versus 81%, P = .17) and made fewer errors in epinephrine administration (0/6 versus 2/5, P = .18). HO and CB teams scored similarly on TS (51% versus 52%, P = .66), but overall scores were lower for TS than for CR skills in both the HO ( P = .03) and CB teams ( P = .06). HO training was more highly rated than CB as an effective educational tool ( P = .01) and for effectiveness at teaching CR and team communication skills ( P = .02). Conclusions High-fidelity simulation can be used to both train and test interprofessional teams of radiologists, technologists, and nurses for both CR and TS and is more highly rated as an effective educational tool by participants than similar CB training. However, a single session of either type of training may be inadequate for mastering TS.

11017Background: Tumor associated macrophages (TAM) are critical for immune evasion in many tumors. We hypothesized that combining G100, a TLR4 agonist that stimulates innate immunity and increases...

OBJECTIVE. The purpose of this article is to provide an overview of pelvic MRI for the evaluation of perianal fistulas, with a description of the technique, illustration of relevant normal anatomy, and examples of various fistula types. CONCLUSION. MRI evaluation of perianal fistulas can be challenging, and knowledge of relevant pelvic anatomy and fistula classification remains crucial in the diagnosis. MRI is highly accurate for fistula depiction and, by providing an accurate assessment of disease status and extension, can help surgical planning to minimize recurrence and detect clinically unapparent disease.