Comparison of MRI appendix biometrics in children with and without acute appendicitis.

OBJECTIVES: The goal of this study is to improve MRI-specific diagnostic criteria for pediatric appendicitis through comparison of normal and abnormal appendix-related imaging features. METHODS: A retrospective multireader-multicase design was used, including non-contrast MRI performed for suspected pediatric appendicitis following non-diagnostic US from January 2014 to December 2017. Positive diagnosis was defined by surgical pathology or symptom resolution after antibiotics. Four pediatric radiologists independently graded study biometrics while blinded to clinical data. Balanced complete block design was used to determine performance characteristics. RESULTS: Global diagnosis of appendicitis (208 studies) had sensitivity 90.6% and specificity 97.7%. Median appendix diameter was 10.4 mm among positive cases and 5.8 mm among negative cases (p < 0.001) with an optimal diagnostic cutoff of 7.5 mm (sensitivity 89.4%, specificity 86.5%). Median appendix wall thickness was 2.6 mm among positive cases and 1.7 mm among negative cases (p < 0.001) with an optimal diagnostic cutoff of 2.3 mm (sensitivity 63.1%, specificity 82.9%). Performance characteristics for qualitative appendix features included distinguishable appendix luminal signal (sensitivity 89.6%, specificity 83.7%), intraluminal fluid-signal intensity (sensitivity 63.6%; specificity 52.3%), intraluminal signal intermediate between fluid and bowel wall (sensitivity 91.0%; specificity 37.1%), appendicolith (sensitivity 34.9%; specificity 100.0%), intraluminal layering (sensitivity 25.9%; specificity 100.0%), hyperintense appendix wall signal (sensitivity 31.7%; specificity 100.0%), periappendiceal fluid (sensitivity 66.8%; specificity 72.5%), periappendiceal fatty edema (sensitivity 91.3%; specificity 94.5%), and free pelvic fluid (sensitivity 88.5%; specificity 26.0). CONCLUSIONS: This study provides MRI-specific performance of pediatric appendicitis quantitative and qualitative biometrics with peri-appendiceal fatty edema, appendix diameter > 7.5 mm, and distinguishable appendix luminal signal demonstrating the highest overall accuracy. KEY POINTS: • This retrospective multireader-multicase study characterized magnetic resonance imaging-specific diagnostic accuracy of quantitative and qualitative biometrics for pediatric appendicitis. • The optimal quantitative diagnostic thresholds for an abnormal pediatric appendix at MRI included diameter and wall thickness of 7.5 mm and 2.3 mm, respectively. • Qualitative imaging biometrics with high specificity for pediatric appendicitis on MRI included the presence of distinguishable appendix lumen signal from wall signal, appendicolith, intraluminal fluid-fluid layer, appendix wall hyperintensity, and peri-appendiceal fatty edema.

Screening of cancer predisposition syndromes.

Pediatric patients with cancer predisposition syndromes are at increased risk of developing malignancies compared with their age-matched peers, necessitating regular surveillance. Screening protocols differ among syndromes and are composed of a number of elements, imaging being one. Surveillance can be initiated in infants, children and adolescents with a tumor known or suspected of being related to a cancer predisposition syndrome or where genetic testing identifies a germline pathogenic gene variant in an asymptomatic child. Pre-symptomatic detection of malignant neoplasms offers potential to improve treatment options and survival outcomes, but the benefits and risks of screening need to be weighed, particularly with variable penetrance in many cancer predisposition syndromes. In this review we discuss the benefits and risks of surveillance imaging and the importance of integrating imaging and non-imaging screening elements. We explore the principles of surveillance imaging with particular reference to whole-body MRI, considering the strategies to minimize false-negative and manage false-positive whole-body MRI results, the value of standardized nomenclature when reporting risk stratification to better guide patient management, and the need for timely communication of results to allay anxiety. Cancer predisposition syndrome screening is a multimodality, multidisciplinary and longitudinal process, so developing formalized frameworks for surveillance imaging programs should enhance diagnostic performance while improving the patient experience.

Survey of radiologists and emergency department providers after implementation of a global radiology report categorization system.

PURPOSE: Breakdown in communication of important imaging results threatens patient safety and risks malpractice claims. To facilitate closed-loop communication, our institution developed a unique radiology report categorization (RADCAT) system employing automated alert notification systems. This study aimed to understand users' initial experiences with the RADCAT system and obtain feedback. METHODS: Web-based surveys were distributed to radiologists and emergency department (ED) providers at our hospital system within 1 year of institution-wide RADCAT implementation. Survey designs differed based on clinical setting. Most prompts utilized declarative statements with 5-point agreement Likert scales. Closed-response data was analyzed with descriptive statistics. RESULTS: Response rates among radiologists and ED providers were 59.4% (63/106) and 38.4% (69/211), respectively. 78.0% (46/59) of radiologists and 60.9% (42/69) of ED providers agreed that RADCAT improves patient care. Of radiologists, 84.1% (53/63) agreed that RADCAT design is intuitive, and 57.6% (34/59) agreed that RADCAT improves efficiency. Of ED providers, 69.6% (48/69) agreed that RADCAT appropriately differentiates urgent and non-urgent findings, and 65.2% (45/69) agreed that auto-population of discharge documents with imaging results containing follow-up recommendations protects them from liability. Only 35.6% (21/59) of radiologists and 21.7% (15/69) of ED providers agreed that RADCAT implementation decreased reading room visits by ordering providers. Open-response feedback showed that some ED providers find RADCAT too complex while some radiologists desire improved transparency regarding imaging study communication status. CONCLUSION: Since its implementation, RADCAT has been well received among radiologists and ED providers with agreement that it improves patient care and effectively distinguishes and communicates important imaging findings.

Rethinking Thrombolysis in Cerebral Infarction 2b: Which Thrombolysis in Cerebral Infarction Scales Best Define Near Complete Recanalization in the Modern Thrombectomy Era?

BACKGROUND AND PURPOSE: Within the thrombolysis in cerebral infarction (TICI) classification, TICI 2b has been historically considered successful recanalization. Recent studies have suggested that TICI 3 and a proposed TICI 2c should be separately reported from TICI 2b, in both the original (>66% reperfusion) and modified (>50% reperfusion) definitions, because of differences in clinical outcomes with greater reperfusion. The purpose of this study was to evaluate differences in early neurological improvement and independence at 90 days using the original TICI, modified TICI, and modified TICI with 2c scales. METHODS: A retrospective review of 129 consecutive patients with middle cerebral artery, M1 segment or intracranial internal carotid artery occlusions. Patient angiograms were graded by 2 experienced readers by percentage recanalization. This was then categorized into original TICI, modified TICI (mTICI), and mTICI with TICI 2c (mTICI 2c) grading scales. Comparison of baseline demographics, early neurological improvement, and independence at 90 days was performed. RESULTS: A significant difference in early neurological improvement was observed between 2b and 3 (P=0.032), as well as between 2b and 2c (P=0.028) under the mTICI 2c grading scale. Similarly, a significant difference in functional independence was observed between 2b and 3 (P=0.037), as well as between 2b and 2c (P=0.047) under the mTICI 2c scale. The difference in early neurological improvement or functional independence between 2b and 3 for the original TICI and mTICI scales was not significant. When combining the 2c and 3 groups under the mTICI 2c scale, there were significant differences between 2b and 2c/3 in regards to both early neurological improvement (P=0.011) and independence (P=0.018). CONCLUSIONS: Using a TICI grading system that includes an additional category beyond TICI 2b allows for refined prediction of early neurological improvement and functional independence.

Developing a Learning Objective-Based Pediatric Radiology Curriculum to Supplement Resident Education.

Learning objectives are invaluable components of medical curricula. They are required by the ACGME for all educational experiences offered by radiology residencies, but their number and quality varies significantly from program to program. In this article, we describe the development of a new pediatric radiology curriculum featuring outcome-based learning objectives with accompanying recommended resources to achieve these objectives and evaluate its initial reception by first-year radiology residents at our institution.

Study Smarter: Applying the Science of Learning to Radiology.

Lifelong learning is critical to a successful career in radiology, but many learners use inefficient or ineffective studying strategies developed from personal experience. Decades of cognitive psychology research have identified several techniques that consistently improve knowledge consolidation and retrieval. To improve their knowledge and ultimately patient care, radiologists should strive to understand and adopt these learning techniques. The first part of this article reviews several evidence-based learning principles, including active retrieval and the testing effect, spaced repetition, interleaving, deliberate practice, and growth mind-set. The second part provides practical suggestions on how to incorporate these principles into radiology learning, both during training and beyond.

Implementation and Impact of a Comprehensive Radiology Report Categorization System on Communication of Important Results.

PURPOSE: Effective communication of important imaging results is critical to patient care but difficult to accomplish efficiently. To improve communication at their institution, the authors introduced a radiology report categorization system (RADCAT) that organizes diagnostic imaging reports and uses automated communication systems. The study objectives were to (1) describe RADCAT's design, (2) evaluate its implementation for appropriate imaging, and (3) evaluate the communication of important, nonurgent results with recommended follow-up. METHODS: This retrospective study was performed in a multihospital adult and pediatric tertiary referral academic health system. The intervention, a radiology report categorization system with five levels of acuity and IT-supported communication workflows, was globally implemented in November 2017. The primary outcomes were the successful implementation of RADCAT to appropriate diagnostic imaging reports and the successful communication of important, nonurgent results with recommended follow-up to ordering providers and patients by the radiology quality assurance team. RESULTS: Over 18 months after implementation, 740,625 radiology reports were categorized under the RADCAT system, with 42%, 28%, and 30% from the emergency department, inpatient, and outpatient settings, respectively. A random selection of 100 studies from the 23,718 total reports without RADCAT categorization identified 4 diagnostic radiology reports that erroneously lacked RADCAT grading. In 2019, of the 38,701 studies with nonurgent imaging follow-up recommendations, 38,692 (nearly 100.0%) were successfully communicated to providers or patients on the basis of quality assurance data. CONCLUSIONS: A comprehensive radiology report categorization system was successfully implemented across a multihospital adult and pediatric health system, demonstrating reliable communication of imaging results with recommendations for nonacute imaging follow-up.

Association between age and outcomes following thrombectomy for anterior circulation emergent large vessel occlusion is determined by degree of recanalisation.

BACKGROUND: Older patients undergoing thrombectomy for emergent large vessel occlusion have worse outcomes. However, complete or near-complete reperfusion (modified Thrombolysis in Cerebral Ischemia (mTICI) score of 2 c/3) is associated with improved outcomes compared with partial recanalisation (mTICI 2b). OBJECTIVE: To examine the relationship between outcomes and age separately for the mTICI 2c/3, 2b and 0-2a groups in patients undergoing thrombectomy for anterior circulation emergent large vessel occlusion. METHODS: Retrospective review of 157 consecutive patients undergoing thrombectomy at a single centre with an occlusion of the internal carotid artery (ICA), M1 or proximal M2 segments of the middle cerebral artery (MCA). Angiograms were graded in a blinded fashion. Patients were divided into three groups: mTICI 0-2a, mTICI 2b, and mTICI 2c/3. Demographics and workflow parameters were compared. Outcomes at 90 days were compared as a function of age, using both the conventional modified Rankin scale (mRs) and utility weighted mRs (UWmRs). RESULTS: There were 72, 61 and 24 patients in the mTICI 2c/3, 2b and 0-2a groups, respectively. Outcomes were significantly worse with increasing age for the mTICI 2b group, but not for the mTICI 0-2a and 2c/3 groups (P=0.0002). With increasing age, outcomes of the mTICI 2b group approached those of the mTICI 0-2a group. However, outcomes of the mTICI 2c/3 groups were similar for all ages. This association was present for both the original mRs and UWmRs. CONCLUSION: Increasing age was associated with worse outcomes for those with partial (mTICI 2b) recanalisation, not in patients with complete (mTICI 2c/3) recanalisation.

Accuracy of smartphone-based evaluation of Emergent Large Vessel Occlusion on CTA.

OBJECTIVES: Mechanical thrombectomy is the standard of care for stroke caused by an emergent large vessel occlusion in the anterior circulation, and the ability to rapidly review CTA is one hurdle in minimizing the time from diagnosis to intervention. We evaluated the diagnostic accuracy and confidence in review of stroke CTA for ELVO via a smartphone-based application as compared to PACS workstation. PATIENTS AND METHODS: Seventy-six head and neck CTA studies performed for stroke from one comprehensive and seven primary stroke centers were independently reviewed remotely on smartphone by two blinded interventional neuroradiologists in actual-use circumstances. The presence and location of large vessel occlusion(s), diagnostic quality, and confidence in interpretation were recorded. Comparison was made to blinded PACS workstation review performed at a delayed interval. Weighted Kappa and Kendall's Tau statistics were calculated to evaluate intra- and inter-observer reliability. RESULTS: Of the 76 studies, 20 (26%) had a large vessel occlusion. 14 M1 segment occlusions (18%); 2 ICA terminus (3%); 2 tandem carotid and M1 (3%); and 2 basilar artery (3%). There was 100% diagnostic accuracy by both PACS workstation and smartphone review (p = .9999) with high inter- and intra-rater reliability for assessments of both image quality and diagnostic confidence. CONCLUSION: In actual-use circumstances, experienced neuroradiologists can diagnose ELVOs on CTA using a smartphone application as accurately as on PACS workstation without degradation of confidence. These findings support the use of mobile electronic devices by stroke centers to rapidly triage patients for mechanical thrombectomy.

Continuous aspiration prior to intracranial vascular embolectomy (CAPTIVE): a technique which improves outcomes.

BACKGROUND: Modern stent retriever-based embolectomy for patients with emergent large vessel occlusion improves outcomes. Techniques aimed at achieving higher rates of complete recanalization would benefit patients. OBJECTIVE: To evaluate the clinical impact of an embolectomy technique focused on continuous aspiration prior to intracranial vascular embolectomy (CAPTIVE). METHODS: A retrospective review was performed of 95 consecutive patients with intracranial internal carotid artery or M1 segment middle cerebral artery occlusion treated with stent retriever-based thrombectomy over an 11-month period. Patients were divided into a conventional local aspiration group (traditional group) and those treated with a novel continuous aspiration technique (CAPTIVE group). We compared both early neurologic recovery (based on changes in National Institute of Health Stroke Scale (NIHSS) score), independence at 90 days (modified Rankin score 0-2), and angiographic results using the modified Thrombolysis in Cerebral Ischemia (TICI) scale including the TICI 2c category. RESULTS: There were 56 patients in the traditional group and 39 in the CAPTIVE group. Median age and admission NIHSS scores were 78 years and 19 in the traditional group and 77 years and 19 in the CAPTIVE group. Median times from groin puncture to recanalization in the traditional and CAPTIVE groups were 31 min and 14 min, respectively (p<0.0001). While rates of TICI 2b/2c/3 recanalization were similar (81% traditional vs 100% CAPTIVE), CAPTIVE offered higher rates of TICI 2c/3 recanalization (79.5% vs 40%, p<0.001). Median discharge NIHSS score was 10 in the traditional group and 3 in the CAPTIVE group; this difference was significant. There was also an increased independence at 90 days (25% traditional vs 49% CAPTIVE). CONCLUSIONS: The CAPTIVE embolectomy technique may result in higher recanalization rates and better clinical outcomes.