Simulation of Image-Guided Microwave Ablation Therapy Using a Digital Twin Computational Model.

Emerging computational tools such as healthcare digital twin modeling are enabling the creation of patient-specific surgical planning, including microwave ablation to treat primary and secondary liver cancers. Healthcare digital twins (DTs) are anatomically one-to-one biophysical models constructed from structural, functional, and biomarker-based imaging data to simulate patient-specific therapies and guide clinical decision-making. In microwave ablation (MWA), tissue-specific factors including tissue perfusion, hepatic steatosis, and fibrosis affect therapeutic extent, but current thermal dosing guidelines do not account for these parameters. This study establishes an MR imaging framework to construct three-dimensional biophysical digital twins to predict ablation delivery in livers with 5 levels of fat content in the presence of a tumor. Four microwave antenna placement strategies were considered, and simulated microwave ablations were then performed using 915 MHz and 2450 MHz antennae in Tumor Naïve DTs (control), and Tumor Informed DTs at five grades of steatosis. Across the range of fatty liver steatosis grades, fat content was found to significantly increase ablation volumes by approximately 29-l42% in the Tumor Naïve and 55-60% in the Tumor Informed DTs in 915 MHz and 2450 MHz antenna simulations. The presence of tumor did not significantly affect ablation volumes within the same steatosis grade in 915 MHz simulations, but did significantly increase ablation volumes within mild-, moderate-, and high-fat steatosis grades in 2450 MHz simulations. An analysis of signed distance to agreement for placement strategies suggests that accounting for patient-specific tumor tissue properties significantly impacts ablation forecasting for the preoperative evaluation of ablation zone coverage.

Creativity, Connection, and Community: Reimagining the Radiology Society Meeting.

RATIONALE AND OBJECTIVES: With the shifting needs of radiologists due to escalating healthcare demands, the impetus for an increased focus on wellness and the benefits of the humanities in medicine inspired a novel approach to curricular planning of the 2023 Association of University Radiologists (AUR) annual meeting. In this manuscript, we describe the creative process behind planning and executing this innovative meeting format. MATERIALS AND METHODS: Reimagining the annual meeting was a collaborative effort centered around the development of an innovative Arts and Wellness Program, with the goal of integrating opportunities for artistic expression and experiential wellness throughout the meeting. RESULTS: Of the 1313 meeting attendees, 423 (32.2%) completed the annual meeting evaluation, of which 244 were in-person and 61 attended virtually. 178 of 423 respondents (42.1%) participated in the arts and wellness programming. 160 of 203 respondents (78.9%) reported that the arts and wellness programming enhanced the overall meeting experience. 164 of 197 respondents (83.2%) gained greater appreciation for the talents of radiology colleagues. 97 of 195 respondents (49.7%) stated that the programming gave them ideas as to how to cope effectively with stress. CONCLUSION: The incorporation of art, music, and other wellness activities into a national radiology meeting was well-received by meeting attendees. For many radiologists who participated in the various musical and artistic offerings at the AUR 2023 meeting, sharing artistic talents with the radiology community and colleagues represented the most fundamental way to be fully seen, express authenticity, and connect with others.

A CT Scan of Our Earth: The Radiology Department's How-To Guide for Addressing Planetary Health.

The planet has a fever, and it is getting worse. Climate change manifests through mechanisms such as extreme weather, shifting disease burden, wildfires, and drought, which all have negative implications on human health. Simultaneously, the health care sector is responsible for 4.6% of global greenhouse gas emissions. As users of some of the hospital's most energy-intensive equipment, radiology departments are key stakeholders in the transition to clean energy. The authors propose a framework to guide radiology departments to advance health care sustainability. The approach outlines how a radiology department can reduce its environmental footprint through appointing a sustainability officer, forming a dedicated green team, incorporating sustainability into the departmental strategic plan, quantifying total greenhouse gas emissions, committing to education, and advocating for systemic change. By delineating a structured path, the authors hope to encourage the transition toward environmentally friendly practices in all radiology practice settings.

Reducing the Environmental and Economic Costs of Single-Department Infectious Waste Disposal.

PURPOSE: The aim of this study was to demonstrate the efficacy of zero-cost interventions on the reduction of infectious waste (IW) stream production in interventional radiology (IR). METHODS: This quality improvement initiative was developed using needs identification through department-wide meetings with IR stakeholders (physicians, nurses, and radiologic technologists). Department leadership identified and implemented two interventions to reduce disposal of noninfectious waste (NIW) in the IW stream. First, hospital waste management provided focused education for sorting IW versus NIW to IR staff members. Next, the number of IW bins was reduced, and the IW bins were strategically placed on the perimeter of the room. Radiologic technologists tracked IW and NIW bags per case for 25 case days before the intervention and 175 case days after the intervention. A run chart was created to visualize change over time. Wilcoxon rank sum and signed rank tests were performed to evaluate the difference in IW and NIW bags per case before and after the intervention. A goal of significant reduction in NIW stream production was set. RESULTS: Before the intervention, the production of IW and NIW bags per case was similar (median, 1.0 [interquartile range (IQR), 0.86-1.31] vs 1.1 [IQR, 0.86-1.40]; P = .20). After the intervention, IW bags per case decreased (median, 1.0 [IQR, 0.86-1.31] vs 0.05 [IQR, 0.00-0.13]; P < .001). Fewer IW bags than NIW bags were produced per case after the intervention (median, 0.05 [IQR, 0.00-0.13] vs 1.53 [IQR, 1.30-1.76]; P < .001). CONCLUSIONS: Zero-cost interventions, including focused education, stakeholder engagement, and strategic placement of waste bins, can significantly reduce the environmental and economic impact of waste produced in IR.

Navigational Bronchoscopy versus Computed Tomography-guided Transthoracic Needle Biopsy for the Diagnosis of Indeterminate Lung Nodules: protocol and rationale for the VERITAS multicenter randomized trial.

Background: Lung nodule incidence is increasing. Many nodules require biopsy to discriminate between benign and malignant etiologies. The gold-standard for minimally invasive biopsy, computed tomography-guided transthoracic needle biopsy (CT-TTNB), has never been directly compared to navigational bronchoscopy, a modality which has recently seen rapid technological innovation and is associated with improving diagnostic yield and lower complication rate. Current estimates of the diagnostic utility of both modalities are based largely on non-comparative data with significant risk for selection, referral, and publication biases. Methods: The VERITAS trial (na V igation E ndoscopy to R each Indeterminate lung nodules versus T ransthoracic needle A spiration, a randomized controlled S tudy) is a multicenter, 1:1 randomized, parallel-group trial designed to ascertain whether electromagnetic navigational bronchoscopy with integrated digital tomosynthesis is noninferior to CT-TTNB for the diagnosis of peripheral lung nodules 10-30 mm in diameter with pre-test probability of malignancy of at least 10%. The primary endpoint is diagnostic accuracy through 12 months follow-up. Secondary endpoints include diagnostic yield, complication rate, procedure duration, need for additional invasive diagnostic procedures, and radiation exposure. Discussion: The results of this rigorously designed trial will provide high-quality data regarding the management of lung nodules, a common clinical entity which often represents the earliest and most treatable stage of lung cancer. Several design challenges are described. Notably, all nodules are centrally reviewed by an independent interventional pulmonology and radiology adjudication panel relying on pre-specified exclusions to ensure enrolled nodules are amenable to sampling by both modalities while simultaneously protecting against selection bias favoring either modality. Conservative diagnostic yield and accuracy definitions with pre-specified criteria for what non-malignant findings may be considered diagnostic were chosen to avoid inflation of estimates of diagnostic utility. Trial registration: ClinicalTrials.gov NCT04250194.

Modeling the Environmental and Financial Impact of Multi-dose vs. Single-dose Iodinated Contrast Media Packaging and Delivery Systems.

RATIONALE AND OBJECTIVES: Iodinated contrast media (ICM) is used in computed tomography (CT) imaging to better visualize pathophysiology. ICM is commonly sold in "single-dose" bottles that require any unused volume to be discarded. Multi-dose bottles have been developed as an alternative packaging method. The objective of this study was to compare ICM waste, plastic waste, and the associated financial costs for both the single-dose and multi-dose ICM delivery systems. METHODS: Institutional data was used to estimate the average ICM administered per CT scan, average ICM wasted per CT scan, and the total ICM volume wasted annually. Waste estimates for the multi-dose bottles were generated by applying the average ICM administered per CT scan to the larger, multi-dose bottle volumes. Single-dose bottles, multi-dose bottles and injection syringes were weighed and used to calculate plastic waste generated by both packaging methods. Financial analysis was performed to compare the cost of supplies for single-dose and multi-dose ICM delivery systems. RESULTS: We found that 100 mL single-dose ICM bottles waste an average of 19.7 mL per CT scan, representing over 964 L of ICM wasted per year. The multi-dose ICM delivery system was projected to decrease pharmaceutical waste by at least 73% and reduce plastic waste by approximately 93%. We also estimate $494,000 in annual savings using the multi-dose ICM delivery method at our institution. CONCLUSION: Multi-dose ICM packaging can help conserve ICM, an important pharmaceutical that was only recently severely affected supply chain disruptions. The multi-dose delivery system can also reduce plastic waste and generate substantial financial savings to offset capital investment.

Medicolegal considerations associated with cancer during pregnancy.

The management of pregnant patients with cancer is complex and requires a multidisciplinary team to effectively diagnose, stage, and manage the cancer while also being cognizant of the potential harm that diagnosis and treatment may have on the maternal and fetal well-being. Beyond the complex clinical management of these patients is additional medicolegal consideration. Radiologists play a crucial role in the management of these patients as their knowledge of diagnostic and interventional radiology techniques allows for appropriate and safe imaging for both the mother and fetus. In addition, radiologist are able to educate patient on the different imaging modalities and techniques, thus allowing patients to make informed decisions and maintain autonomy over there care. This article will review safety considerations associated with different imaging modalities, contrast agents, interventional radiology procedures and moderate sedation related to the imaging of pregnant patient with cancer with specific attention paid to the medicolegal aspects.

Repeated reversals of concurrent olfactory discriminations in rats: A search for functional equivalence.

Equivalence class formation has been difficult to demonstrate in nonhumans, but one method that has been successful is a simple discrimination procedure in which contingencies associated with two sets of arbitrary discriminative stimuli are repeatedly reversed. Pigeons and sea lions shift responding after encountering the newly-reversed contingency with only a few set members, showing evidence of functional equivalence. We used this strategy to determine whether similar findings would occur in rats using olfactory stimuli. Rats were trained to nose-poke in the presence of six stimuli arbitrarily designated as members of the positive set; responses to the six members of the negative set were not reinforced. When discriminative performance was established, contingencies associated with each set were reversed and re-reversed each time subjects met a performance criterion. All subjects successfully acquired the concurrent simple discriminations and were exposed to between 12 and 60 reversals, but none showed clear evidence of functional class formation until a final procedure in which the stimulus sets that had been in place were arbitrarily rearranged. Acquisition with these new stimulus sets was impaired, showing that class membership generated by the original stimulus sets interfered with learning the new ones, thus providing evidence of functional equivalence.

Fat Quantification Imaging and Biophysical Modeling for Patient-Specific Forecasting of Microwave Ablation Therapy.

Computational tools are beginning to enable patient-specific surgical planning to localize and prescribe thermal dosing for liver cancer ablation therapy. Tissue-specific factors (e.g., tissue perfusion, material properties, disease state, etc.) have been found to affect ablative therapies, but current thermal dosing guidance practices do not account for these differences. Computational modeling of ablation procedures can integrate these sources of patient specificity to guide therapy planning and delivery. This paper establishes an imaging-data-driven framework for patient-specific biophysical modeling to predict ablation extents in livers with varying fat content in the context of microwave ablation (MWA) therapy. Patient anatomic scans were segmented to develop customized three-dimensional computational biophysical models and mDIXON fat-quantification images were acquired and analyzed to establish fat content and determine biophysical properties. Simulated patient-specific microwave ablations of tumor and healthy tissue were performed at four levels of fatty liver disease. Ablation models with greater fat content demonstrated significantly larger treatment volumes compared to livers with less severe disease states. More specifically, the results indicated an eightfold larger difference in necrotic volumes with fatty livers vs. the effects from the presence of more conductive tumor tissue. Additionally, the evolution of necrotic volume formation as a function of the thermal dose was influenced by the presence of a tumor. Fat quantification imaging showed multi-valued spatially heterogeneous distributions of fat deposition, even within their respective disease classifications (e.g., low, mild, moderate, high-fat). Altogether, the results suggest that clinical fatty liver disease levels can affect MWA, and that fat-quantitative imaging data may improve patient specificity for this treatment modality.

Adolescent exposure to fluoxetine impairs serial pattern learning in the serial multiple choice (SMC) task in adult rats.

The effects of chronic adolescent fluoxetine (FLX, Prozac®) exposure on adult cognition are largely unknown. We used a serial multiple choice (SMC) task to characterize the effects of adolescent FLX exposure on rat serial pattern learning in adulthood. Male rats were exposed to either 1.0, 2.0, or 4.0 mg/kg/day FLX for five consecutive days each week for five weeks during adolescence, followed by a 35-day drug-free period. As adults, the rats were trained in a task that required them to learn a highly structured sequential pattern of responses in an octagonal chamber for water reinforcement. In a transfer phase, the terminal element of the pattern was replaced by a violation element that was inconsistent with previously learned pattern structure. Results indicated that adolescent FLX exposure caused differential learning deficits for different types of elements in the serial pattern. Adolescent exposure to 1.0 or 4.0 mg/kg/day FLX, but not 2.0 mg/kg/day FLX, impaired chunk-boundary element learning, which is known to be mediated by stimulus-response (S-R) learning. All three doses of FLX impaired violation element learning, which is known to be mediated by multiple-cue learning. FLX did not impair within-chunk element learning, which is known to be mediated by rule-learning mechanisms. The results indicate that adolescent FLX exposure produced multiple cognitive impairments that were detectable in adulthood long after drug exposure ended.

Successive odor matching- and non-matching-to-sample in rats: A reversal design.

There is a growing body of research on matching- and non-matching-to-sample (MTS, NMTS) relations with rats using olfactory stimuli; however, the specific characteristics of this relational control are unclear. In the current study we examine MTS and NMTS in rats with an automated olfactometer using a successive (go, no-go) procedure. Ten rats were trained to either match- or non-match-to-sample with common scents (apple, cinnamon, etc.) as olfactory stimuli. After matching or non-matching training with four odorants, rats were tested for transfer twice with four new odorants on each test. Most rats trained on MTS showed immediate transfer to new stimuli, and most rats trained on NMTS showed full transfer by the second set of new odors. After meeting criterion on the second transfer test, the contingencies were reversed with four new odor stimuli such that subjects trained on matching were shifted to non-matching and vice versa. Following these reversed contingencies, the effects of the original training persisted for many trials with new odorants. These data extend previous studies on same-different concept formation in rats, showing strong generalization requiring few exemplars. The critical role of olfactory stimuli is discussed.

Difficult biopsy and drainage: just say yes.

Abdominal radiologists are often asked to perform difficult percutaneous chest, abdomen, and pelvis biopsies and drainages with imaging guidance. Many of these procedures involve small target lesions far from the skin surface, in close proximity to critical structures. Organ location is changeable due to respiration, peristalsis, and pulsation, further complicating the planning process. High-level three-dimensional spatial awareness is critical to mastery of complex image-guided procedures. A comprehensive grasp of anatomy and expected changes can be exploited in certain cases to target lesions within a solid organ or to avoid injury to sensitive structures during biopsy, drain placement, or thermal ablation. In this article, we will use illustrative cases to explore the use of anatomic knowledge and the ability to synthesize this three-dimensional data dynamically during planning and execution of difficult CT- and ultrasound-guided procedures. We will discuss unusual biopsy requests-such as bowel biopsies-and the benefits of using ultrasound guidance for certain procedures in the chest. Additionally, we will describe multiple special techniques, including out of standard plane angulation and endocavitary techniques, in order to maximize chances of success.

Online training on the safe use of fluoroscopy can result in a significant decrease in patient dose.

RATIONALE AND OBJECTIVES: Concerns over medical radiation exposure have received national press in recent years, and training in the appropriate use of radiation has become an essential component of every radiology residency program. Appropriate training is particularly important in fluoroscopy because it is commonly used by inexperienced radiology residents and has the potential to impart relatively high patient radiation doses. In an effort to minimize the radiation doses received by patients, our institution has recently initiated an online training program in the safe use of fluoroscopy. This course is required and must be completed by new radiology residents before their first fluoroscopy rotation. The goal of this study was to determine if the use of an online course in the safe use of fluoroscopy could result in decreased patient dose without affecting diagnostic quality. MATERIALS AND METHODS: Four years of retrospective procedural data for residents performing gastrointestinal and genitourinary fluoroscopic procedures without specialized training were reviewed. Incoming residents took an American Medical Association-accredited online training program in the safe use of fluoroscopy the week before their first fluoroscopy rotation. Patient dose and diagnostic quality data, inferred from the frequency of attending physician intervention necessary to complete the procedure, were collected for all exams performed by the new group of residents after completion of the training course. This was then compared to data from prior classes and stratified by procedure type. RESULTS: Statistically significant reductions in both average fluoroscopy time (FT) or dose-area-product (DAP) were found for many of the fluoroscopic procedures performed by residents who participated in the online fluoroscopy training program. Specifically, statistically significant reductions in FT for barium enema, cystogram, defecogram, and esophagram procedures (P < .001) were found. Esophagram and upper gastrointestinal studies were completed with a significantly lower DAP (P < .001). The average reduction in DAP across all procedures performed by first-year residents was 38%, whereas the average reduction in FT was 25%. Based on a review of data from all procedures performed, there was no statistically significant loss in diagnostic quality. CONCLUSION: An online training program can be effectively used to provide radiation safety instruction immediately before the start of a resident's fluoroscopy rotation, decreasing patient dose without affecting diagnostic quality.