Publications

Tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC) are airway abnormalities that share a common feature of expiratory narrowing but are distinct pathophysiologic entities. Both entities are collectively referred to as expiratory central airway collapse (ECAC). The malacia or weakness of cartilage that supports the tracheobronchial tree may occur only in the trachea (ie, tracheomalacia), in both the trachea and bronchi (TBM), or only in the bronchi (bronchomalacia). On the other hand, EDAC refers to excessive anterior bowing of the posterior membrane into the airway lumen with intact cartilage. Clinical diagnosis is often confounded by comorbidities including asthma, chronic obstructive pulmonary disease, obesity, hypoventilation syndrome, and gastroesophageal reflux disease. Additional challenges include the underrecognition of ECAC at imaging; the interchangeable use of the terms TBM and EDAC in the literature, which leads to confusion; and the lack of clear guidelines for diagnosis and treatment. The use of CT is growing for evaluation of the morphology of the airway, tracheobronchial collapsibility, and extrinsic disease processes that can narrow the trachea. MRI is an alternative tool, although it is not as widely available and is not used as frequently for this indication as is CT. Together, these tools not only enable diagnosis, but also provide a road map to clinicians and surgeons for planning treatment. In addition, CT datasets can be used for 3D printing of personalized medical devices such as stents and splints. An invited commentary by Brixey is available online. Online supplemental material is available for this article. ©RSNA, 2022.

Image-guided core needle biopsy of musculoskeletal lesions can be challenging due to a variety of technical, patient-related, and lesion-related factors. Poor preprocedural planning can result in low diagnostic yield, misdiagnosis, delay in care, and the need for additional procedures. Furthermore, suboptimal procedural technique may place the patient at an increased risk of iatrogenic complications. Optimizing pre-procedural planning by considering potential complications is important in ensuring a safe and successful procedure. We provide a review of strategies for troubleshooting challenging image-guided musculoskeletal tumor biopsies.

PURPOSE: To assess whether adherence to a postprocedural closeout (PPC) checklist decreases adverse events during image-guided procedures.

MATERIALS AND METHODS: Based on the analysis of prior adverse events related to image-guided procedures, the Radiology Quality Committee developed a PPC checklist. The rates of serious reportable events related to image-guided procedures performed in the radiology department were recorded annually from 2015 to 2021. The rate of adverse events was normalized to the procedure volume in the corresponding periods. The number of patients requiring repeat procedures was recorded. The severity of impact was classified according to the Society of Interventional Radiology Adverse Event Classification System. The annual rates before (2015 and 2016) and after (2017-2021) the implementation of PPC were compared.

RESULTS: Seventy-seven safety reports were identified in image-guided procedures over the study period, of which 43 cases were not related to the PPC, leaving 34 cases for the analysis. Radiology adverse events decreased from 0.069% (14/20,218, 7/y) before PPC implementation to 0.034% (20/58,793, 4/y) after implementation (P = .05, 43% decrease). Radiology repeat procedures decreased from 0.040% (8/20,218, 4/y) before PPC implementation to 0.007% (4/58,793, 0.8/y) after implementation (P = .0033, 80% decrease). Moreover, severity of adverse events decreased (P = .009).

CONCLUSIONS: Implementation of a PPC checklist improved patient outcomes by decreasing the number of adverse events that occur from inadequate safety processes at the end of image-guided procedures by 43%, need for repeat procedures by 80%, and severity of impact of errors.

This review article provides an overview of the current status of velocity-selective arterial spin labeling (VSASL) perfusion MRI and is part of a wider effort arising from the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group. Since publication of the 2015 consensus paper on arterial spin labeling (ASL) for cerebral perfusion imaging, important advancements have been made in the field. The ASL community has, therefore, decided to provide an extended perspective on various aspects of technical development and application. Because VSASL has the potential to become a principal ASL method because of its unique advantages over traditional approaches, an in-depth discussion was warranted. VSASL labels blood based on its velocity and creates a magnetic bolus immediately proximal to the microvasculature within the imaging volume. VSASL is, therefore, insensitive to transit delay effects, in contrast to spatially selective pulsed and (pseudo-) continuous ASL approaches. Recent technical developments have improved the robustness and the labeling efficiency of VSASL, making it a potentially more favorable ASL approach in a wide range of applications where transit delay effects are of concern. In this review article, we (1) describe the concepts and theoretical basis of VSASL; (2) describe different variants of VSASL and their implementation; (3) provide recommended parameters and practices for clinical adoption; (4) describe challenges in developing and implementing VSASL; and (5) describe its current applications. As VSASL continues to undergo rapid development, the focus of this review is to summarize the fundamental concepts of VSASL, describe existing VSASL techniques and applications, and provide recommendations to help the clinical community adopt VSASL.

Recent technological advancements, including the introduction of disposable endoscopes, have enhanced the role of interventional radiology (IR) in the management of biliary and gallbladder diseases. There are unanswered questions in this growing field. The Society of Interventional Radiology Foundation convened a virtual research consensus panel consisting of a multidisciplinary group of experts to develop a prioritized research agenda regarding percutaneous image- and endoscopy-guided procedures for biliary and gallbladder diseases. The panelists discussed current data, opportunities for IR, and future efforts to maximize IR's ability and scope. A recurring theme throughout the discussions was to find ways to reduce the total duration of percutaneous drains and improve patients' quality of life. After the presentations and discussions, research priorities were ranked on the basis of their clinical relevance and impact. The research ideas ranked top 3 were as follows: (a) percutaneous multimodality management of benign anastomotic biliary strictures (laser vs endobiliary ablation vs cholangioplasty vs drain upsize protocol alone), (b) ablation of intraductal cholangiocarcinoma with and without stent placement, and (c) cholecystoscopy/choledochoscopy and lithotripsy in nonsurgical patients with calculous cholecystitis. Collaborative, retrospective, and prospective research studies are essential to answer these questions and improve the management protocols for patients with biliary and gallbladder diseases.

PURPOSE: To evaluate the utility of pelvic computed tomography (CT) in emergency department (ED) patients undergoing chest CT angiogram (CTA) for chest pain or suspected pulmonary embolism (PE) followed by abdominopelvic CT in the same session for additional multisystem or generalized complaints.

METHODS: This retrospective study included consecutive adult ED patients from January 2017 to December 2019 who underwent CTA for suspected PE followed by portovenous abdominopelvic CT for multisystem or generalized complaints. Patient demographics, vitals, laboratory values, exam indication, malignancy history, and recent surgery/intervention were recorded. CT reports were reviewed for acute chest, abdomen, and/or pelvic pathology.

RESULTS: There were 400 patients with 243 (61%) women and mean age of 59.8 years. Acute pelvic findings were seen in 11% (45/400). In 53% (24/45) of these, pelvic pathology could be diagnosed based on the abdominal portion of the CT. Five percent (21/400) of patients demonstrated isolated acute pelvic findings with 86% of these (18/21) clinically suspected prior to imaging. Acute pelvic pathology was associated with female gender (p = 0.015) and elevated white blood cell count (WBC) (p = 0.03). Specific pelvic CT indications and female gender were significantly associated with (p = 0.02 each) and independent predictors of isolated acute pelvic pathology.

CONCLUSION: In ED patients undergoing chest CTA for chest pain or suspected PE combined with abdominopelvic CT, the presence of acute pelvic-related pathology not visualized on abdominal CT is low. For this ED patient cohort, pelvic CT may not be necessary in men with normal WBC and a low pre-imaging clinical suspicion for acute pelvic pathology.

Background Despite the increasing use of contrast-enhanced mammography (CEM), there are limited data on the evaluation of findings on recombined images and the association with malignancy. Purpose To determine the rates of malignancy of enhancement findings on CEM images in the presence or absence of low-energy findings using the Breast Imaging Reporting and Data System (BI-RADS) lexicon developed for mammography and MRI. Materials and Methods All diagnostic CEM examinations performed at one academic institution between December 2015 and December 2019 had low-energy and recombined images retrospectively. Data were independently reviewed by three breast imaging radiologists with 5-25 years of experience using the BI-RADS mammography and MRI lexicon. Outcome was determined with pathologic analysis or 1-year imaging or clinical follow-up. The χ2 and Fisher exact tests were used for analysis. Results A total of 371 diagnostic CEM studies were performed in 371 women (mean age, 54 years ± 11[SD]). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value of enhancement on CEM images was 95% (104 of 109 [95% CI: 90, 98]), 67% (176 of 262 [95% CI: 61, 73]), 55% (104 of 190 [95% CI: 47, 62]), and 97% (176 of 181 [95% CI: 94, 99]), respectively. Among 190 CEM studies with enhancing findings, enhancing lesions were more likely to be malignant when associated with low-energy findings (26% vs 59%, P < .001). Among enhancement types, mass enhancement composed 71% (99 of 140) of all malignancies with PPV of 63% when associated with low-energy findings. Foci, non-mass enhancement, and mass enhancement without low-energy findings had PPV of 6%, 24%, and 38%, respectively. Neither background parenchymal enhancement nor density was associated with enhancement type (P = .19 and P = .28, respectively). Conclusion Mass enhancement on recombined images using CEM was most commonly associated with malignancy, especially when associated with low-energy findings. Enhancement types were more likely to be benign when not associated with low-energy findings; however, they should still be viewed with suspicion, given the high association with malignancy. © RSNA, 2022 Online supplemental material is available for this article.

Radiofrequency ablation (RFA) of intrahepatic tumors induces distant tumor growth through activation of interleukin 6/signal transducer and activator of transcription 3 (STAT3)/hepatocyte growth factor (HGF)/tyrosine-protein kinase Met (c-MET) pathway. Yet, the predominant cellular source still needs to be identified as specific roles of the many types of periablational infiltrating immune cells requires further clarification. Here we report the key role of activated myofibroblasts in RFA-induced tumorigenesis and successful pharmacologic blockade. Murine models simulating RF tumorigenic effects on a macrometastatic tumor and intrahepatic micrometastatic deposits after liver ablation and a macrometastatic tumor after kidney ablation were used. Immune assays of ablated normal parenchyma demonstrated significantly increased numbers of activated myofibroblasts in the periablational rim, as well as increased HGF levels, recruitment other cellular infiltrates; macrophages, dendritic cells and natural killer cells, HGF dependent growth factors; fibroblast growth factor-19 (FGF-19) and receptor of Vascular Endothelial Growth Factor-1 (VEGFR-1), and proliferative indices; Ki-67 and CD34 for microvascular density. Furthermore, macrometastatic models demonstrated accelerated distant tumor growth at 7d post-RFA while micrometastatic models demonstrated increased intrahepatic deposit size and number at 14 and 21 days post-RFA. Multi-day atorvastatin, a selective fibroblast inhibitor, inhibited RFA-induced HGF and downstream growth factors, cellular markers and proliferative indices. Specifically, atorvastatin treatment reduced cellular and proliferative indices to baseline levels in the micrometastatic models, however only partially in macrometastatic models. Furthermore, adjuvant atorvastatin completely inhibited accelerated growth of macrometastasis and negated increased micrometastatic intrahepatic burden. Thus, activated myofibroblasts drive RF-induced tumorigenesis at a cellular level via induction of the HGF/c-MET/STAT3 axis, and can be successfully pharmacologically suppressed.

RATIONALE AND OBJECTIVES: To ascertain the perceived obstacles that medical students and Interventional Radiology (IR) residents face performing IR research during training and incorporating research into their future careers.

MATERIALS AND METHODS: The study was reviewed and exempt from Institutional Review Board review. Participants' attitudes and perceived barriers toward performing IR research, and experience with mentorship in IR were assessed using a 27-item survey sent to all members of the Society of Interventional Radiology Resident, Fellow and Student (SIR-RFS, n = 445), and Medical Student Council (SIR-MSC, n = 267) sections between July and September 2020. Descriptive statistics were computed for all assessed categorical variables. Fisher's exact tests were performed to measure the significance of association between categorical variables.

RESULTS: Of the 712 students and residents surveyed, 151 (∼21%) responded. Of respondents, 100% reported that conducting research is important to advancing the field of IR. The highest ranked factors and obstacles to performing IR research were increased clinical demands (67.9%), lack of time (46.2%), lack of institutional support (41.5%), and lack of research experience (35.8%). Interestingly, those with a mentor were more likely to report an interest in pursuing a career in IR compared to those without a mentor (98.6% vs 41.0%, p < 0.0001). Furthermore, those with a mentor were more likely to report an interest in pursuing IR research compared to those without a mentor (32.5% vs 14.4%, p < 0.0001).

CONCLUSION: There are many obstacles to performing IR research. Strong mentorship is an avenue to address these deterrents. The deployment of mentorship programs in IR is needed to ensure trainees can overcome the barriers outlined in this study and successfully pursue research careers in IR.

OBJECTIVES: The study authors hypothesized that a combination of previously used (path length, translational motions, and time) and novel (rotational sum) motion metrics could be used to analyze learning curves of anesthesiology interns (postgraduate year 1) practicing central venous catheter placement in the simulation setting. They also explored the feasibility of using segmented motion recordings to inform deliberate practice.

DESIGN: A prospective cohort study.

SETTING: A single academic medical center.

PARTICIPANTS: Anesthesiology interns (postgraduate year 1).

INTERVENTIONS: Anesthesiology interns underwent a 2-day training course in which they performed 9 central venous catheter placements, while attached to motion sensors on the dorsum of their dominant hand and ultrasound probe.

MEASUREMENTS AND MAIN RESULTS: Motion metrics were analyzed using generalized estimating equations for both the overall procedure and predefined segments. Five attending anesthesiologists performed 3 trials each for comparison. Overall, there was a negative trend in path length, translational motions, rotational sum, and time (p < 0.001), with the exception of translational motions of the ultrasound probe. Interns reached within 1 standard deviation of the attending anesthesiologists by trials 7-to-8 for most metrics. Segmentation identified specific components of the procedure that were either significantly improved upon or required deliberate practice. The novel metric of rotational sum exhibited a moderate-to-strong positive correlation with other metrics (p < 0.001).

CONCLUSIONS: A comprehensive series of motion metrics was able to describe the learning curves of novices training to perform central venous catheter placement in the simulation setting. Furthermore, it was determined that segmentation may provide additional insight into skill acquisition and inform deliberate practice.