Visual and Quantitative Evaluation of Low-Concentration Bismuth in Dual-Contrast Imaging of Iodine and Bismuth Using Clinical Photon-Counting CT.

Simultaneous dual-contrast imaging of iodine and bismuth has shown promise in prior phantom and animal studies utilizing spectral CT. However, it is noted that in previous studies, Pepto-Bismol has frequently been employed as the source of bismuth, exceeding the recommended levels for human subjects. This investigation sought to assess the feasibility of visually differentiating and precisely quantifying low-concentration bismuth using clinical dual-source photon-counting CT (PCCT) in a scenario involving both iodinated and bismuth-based contrast materials. Four bismuth samples (0.6, 1.3, 2.5, and 5.1 mg/mL) were prepared using Pepto-Bismol, alongside three iodine rods (1, 2, and 5 mg/mL), inserted into multi-energy CT phantoms with three different sizes, and scanned on a PCCT system at three tube potentials (120, 140, and Sn140 kV). A generic image-based three-material decomposition method generated iodine and bismuth maps, with mean mass concentrations and noise levels measured. The root-mean-square errors for iodine and bismuth determined the optimal tube potential. The tube potential of 140 kV demonstrated optimal quantification performance when both iodine and bismuth were considered. Distinct differentiation of iodine rods with all three concentrations and bismuth samples with mass concentrations ≥ 1.3 mg/mL was observed across all phantom sizes at the optimal kV setting.

Radiologists' Increasing Role in Population Health Management: AJR Expert Panel Narrative Review.

Population health management (PHM) is the holistic process of improving health outcomes of groups of individuals through the support of appropriate financial and care models. Radiologists' presence at the intersection of many aspects of health care, including screening, diagnostic imaging, and image-guided therapies, provides the opportunity for increased radiologist engagement in PHM. Furthermore, innovations in artificial intelligence and imaging informatics will serve as critical tools to improve value in health care through evidence-based and equitable approaches. Given radiologists' limited engagement in PHM to date, it is imperative to define the PHM priorities of the specialty so that radiologists' full value in improving population health is realized. The purpose of this expert review is to explore programs and future directions for radiologists in PHM.

Know your way around acute unenhanced CT during global iodinated contrast crisis: a refresher to ED radiologists.

Due to a contrast shortage crisis resulting from the decreased supply of iodinated contrast agents, the American College of Radiology (ACR) has issued a guidance statement followed by memoranda from various hospitals to preserve and prioritize the limited supply of contrast. The vast majority of iodinated contrast is used by CT, with a minority used by vascular and intervention radiology, fluoroscopy, and other services. A direct consequence is a paradigm shift to large volume unenhanced CT scans being utilized for acute and post traumatic patients in EDs, an uncharted territory for most radiologists and trainees. This article provides radiological diagnostic guidance and a pictorial example through systematic review of common unenhanced CT findings in the acute setting.

Influences of the Social Media Continuum Model in Radiology: Theory and Reality.

Social media utilization has been growing exponentially worldwide and has created a thriving venue for radiologists and the profession of radiology to engage in on both the academic and social levels. The aim of this article is to conduct updated literature review and address a gap in the literature by introducing a simple classification for social media utilization and a new theoretical model to outline the role and potential value of social media in the realm of radiology. We propose classifying social media through usage-driven and access-driven indices. Furthermore, we discuss the interdependency of radiologists, other physicians and non-physician stakeholders, scientific journals, conferences/meetings and the general public in an integrated social media continuum model. With the ongoing sub-specialization of radiology, social media helps mitigate the physical barriers of making connections with peers and audiences which would have otherwise been unfeasible. The constant evolution and diversification of social media platforms necessitates a novel approach to better understand its role through a radiological lens. With the looming fear of 'ancillary service' labelling, social media could be the golden plate to halt the path towards commoditization of radiology.

Response to COVID-19: Minimizing Risks, Addressing Challenges and Maintaining Operations in a Complex Academic Radiology Department.

The coronavirus disease 2019 (COVID-19) pandemic has necessitated rapid response plans to minimize risks of infection in the workforce while ensuring maintenance of essential functions of radiology departments. Plan adoption is, however, challenged by the need to coordinate with institutional efforts, a rapidly expanding number of patients, and the diversity of clinical and administrative functions in the department. Here, we describe the implementation of a response plan in an academic radiology department, challenges encountered, and tactics used to address these challenges.

Postoperative Imaging after Surgical Repair for Pelvic Floor Dysfunction.

Pelvic floor dysfunction encompasses an extremely common set of conditions, with various surgical and nonsurgical treatment options. Surgical options include injection of urethral bulking agents, native tissue repair with or without bioabsorbable or synthetic graft material, placement of synthetic midurethral slings or use of vaginal mesh kits, and mesh sacrocolpopexy procedures. Numerous different synthetic products with varied imaging appearances exist, and some of these products may be difficult to identify at imaging. Patients often present with recurrent or new symptoms after surgery; and depending on the presenting complaint and the nature of the initial intervention, imaging with ultrasonography (US), magnetic resonance (MR) imaging, voiding cystourethrography, or computed tomography (CT) may be indicated. US and MR imaging can both be used to image urethral bulking agents; US is often used to follow potential changes in bulking agent volume with time. Compared with MR imaging, US depicts midurethral slings better in the urethrovaginal space, and MR imaging is better than US for depiction of the arms in the retropubic space and obturator foramen. Mesh along the vaginal wall may be depicted with both US and MR imaging; however, the distal arms of the mesh traversing the sacrospinous ligaments or within the ischiorectal fossae (ischioanal fossae) are better depicted with MR imaging. Scarring can mimic slings and mesh at both US and MR imaging. MR imaging is superior to US for depiction of sacrocolpopexy mesh and associated complications. Voiding cystourethrography and CT are used less commonly because they rarely allow direct depiction of implanted material. Online supplemental material is available for this article. (©)RSNA, 2016.

Implementation and Uptake of Rural Lung Cancer Screening.

OBJECTIVE: Given the higher rates of tobacco use along with increased mortality specific to lung cancer in rural settings, low-dose CT (LDCT)-based lung cancer screening could be particularly beneficial to such populations. However, limited radiology facilities and increased geographical distance, combined with lower income and education along with reduced patient engagement, present heightened barriers to screening initiation and adherence. METHODS: In collaboration with community leaders and stakeholders, we developed and implemented a community-based lung cancer screening program, including telephone-based navigation and tobacco cessation counseling support, serving 18 North Texas counties. Funding was available to support clinical services costs where needed. We collected data on LDCT referrals, orders, and completion. RESULTS: To raise awareness for lung cancer screening, we leveraged our established collaborative network of more than 700 community partners. In the first year of operation, 107 medical providers referred 570 patients for lung cancer screening, of whom 488 (86%) were eligible for LDCT. The most common reasons for ineligibility were age (43%) and insufficient tobacco history (20%). Of 381 ordered LDCTs, 334 (88%) were completed. Among screened patients, 61% were current smokers and 36% had insurance coverage for the procedure. The program cost per patient was $430. DISCUSSION: Implementation, uptake, and completion of LDCT-based lung cancer screening is feasible in rural settings. Community outreach, health promotion, and algorithm-based navigation may support such efforts. Given low lung cancer screening rates nationally and heightened lung cancer risk in rural populations, similar programs in other regions may be particularly impactful.

CT colonography's role in the COVID-19 pandemic: a safe(r), socially distanced total colon examination.

PURPOSE: To describe the favorable procedural profile of CT colonography (CTC) during the COVID-19 pandemic. CONCLUSION: Postponement of cancer screening due to COVID-19 has resulted in a backlog of individuals needing to undergo structural examination of the colon. The experience during the initial COVID-19 surge with urgent evaluation of the colon for transplant patients prior to transplant suggests that CTC can be done in a lower risk manner as compared to other structural examinations. The procedural profile of CTC is advantageous during this pandemic as maintaining social distancing and preserving healthcare supplies including PPE are of paramount importance. CTC is an important option to utilize in the screening armamentarium to allow effective screening of average risk asymptomatic individuals in the COVID-19 era.

Computed tomographic colonography (virtual colonoscopy): a multicenter comparison with standard colonoscopy for detection of colorectal neoplasia.

CONTEXT: Conventional colonoscopy is the best available method for detection of colorectal cancer; however, it is invasive and not without risk. Computed tomographic colonography (CTC), also known as virtual colonoscopy, has been reported to be reasonably accurate in the diagnosis of colorectal neoplasia in studies performed at expert centers. OBJECTIVE: To assess the accuracy of CTC in a large number of participants across multiple centers. DESIGN, SETTING, AND PARTICIPANTS: A nonrandomized, evaluator-blinded, noninferiority study design of 615 participants aged 50 years or older who were referred for routine, clinically indicated colonoscopy in 9 major hospital centers between April 17, 2000, and October 3, 2001. The CTC was performed by using multislice scanners immediately before standard colonoscopy; findings at colonoscopy were reported before and after segmental unblinding to the CTC results. MAIN OUTCOME MEASURES: The sensitivity and specificity of CTC and conventional colonoscopy in detecting participants with lesions sized at least 6 mm. Secondary outcomes included detection of all lesions, detection of advanced lesions, possible technical confounders, participant preferences, and evidence for increasing accuracy with experience. RESULTS: A total of 827 lesions were detected in 308 of 600 participants who underwent both procedures; 104 participants had lesions sized at least 6 mm. The sensitivity of CTC for detecting participants with 1 or more lesions sized at least 6 mm was 39.0% (95% confidence interval [CI], 29.6%-48.4%) and for lesions sized at least 10 mm, it was 55.0% (95% CI, 39.9%-70.0%). These results were significantly lower than those for conventional colonoscopy, with sensitivities of 99.0% (95% CI, 97.1%->99.9%) and 100%, respectively. A total of 496 participants were without any lesion sized at least 6 mm. The specificity of CTC and conventional colonoscopy for detecting participants without any lesion sized at least 6 mm was 90.5% (95% CI, 87.9%-93.1%) and 100%, respectively, and without lesions sized at least 10 mm, 96.0% (95% CI, 94.3%-97.6%) and 100%, respectively. Computed tomographic colonography missed 2 of 8 cancers. The accuracy of CTC varied considerably between centers and did not improve as the study progressed. Participants expressed no clear preference for either technique. CONCLUSIONS: Computed tomographic colonography by these methods is not yet ready for widespread clinical application. Techniques and training need to be improved.

Subclinical lung disease, macrocytosis, and premature graying in kindreds with telomerase (TERT) mutations.

BACKGROUND: Mutations in the human gene encoding the protein component of telomerase (TERT) are the most common genetic defect in patients with familial idiopathic pulmonary fibrosis (IPF). The subclinical phenotypes of asymptomatic members of these families have not been evaluated with respect to TERT mutation status or telomere length. METHODS: We measured a variety of pulmonary, blood, skin, and bone parameters for 20 subjects with heterozygous TERT mutations (carriers) and 20 family members who had not inherited a TERT mutation (noncarriers) to identify the spectrum of phenotypes associated with mutations in this gene. The two groups were matched for sex, age, and cigarette smoking. Three TERT mutation carriers had IPF (IPF carriers). The rest of the carriers were apparently healthy (asymptomatic carriers) and were compared with the noncarriers. RESULTS: Asymptomatic carriers exhibited significantly lower diffusing capacity of lung for carbon monoxide (Dlco), impaired recruitment of Dlco with exercise, radiographic signs of lung fibrosis, and increased fractional lung tissue volume quantified by high-resolution chest CT scan than noncarriers. RBC and platelet counts were significantly lower, and the mean corpuscular volume and mean corpuscular hemoglobin concentration were significantly higher in carriers than in noncarriers. Carriers reported significantly earlier graying of hair than noncarriers. TERT mutation status is more accurately predicted by short telomere lengths than any of these measured phenotypes. CONCLUSIONS: TERT mutation carriers exhibit early preclinical signs of lung fibrosis, bone marrow dysfunction, and premature graying. These clinical features and short telomere lengths characterize patients with germline TERT mutations.

Three-dimensional sonographic evaluation of the common bile duct.

OBJECTIVE: To assess the accuracy of three-dimensional sonographic measurements of the common bile duct compared with standard two-dimensional anteroposterior measurement of the common duct. METHODS: Fifty-five consecutive patients referred for abdominal sonography underwent standard two-dimensional abdominal sonography followed by three-dimensional sonographic data acquisition of the right upper quadrant. A radiologist blinded to the results of the two-dimensional examination later measured the three-dimensional long axis anteroposterior common duct diameter and three-dimensional short axis anteroposterior and transverse common duct diameters. RESULTS: The mean average common duct diameter as measured by two-dimensional sonography (long axis anteroposterior) was 3.6 mm. The mean average common duct diameter as measured by long axis anteroposterior three-dimensional sonography was 4.1 mm. The mean average common duct diameter as measured by anteroposterior short axis three-dimensional sonography was 4.1 mm, and by transverse short axis three-dimensional sonography, it was 4.4 mm. The two-dimensional common duct measurement correlated with the long axis anteroposterior three-dimensional measurement (P < .001), the short axis anteroposterior three-dimensional measurement (P < .001), and the short axis transverse three-dimensional measurement (P < .005) by the Spearman rank order correlation coefficient test. CONCLUSIONS: Three-dimensional sonographic measurements of the common bile duct correlate highly with two-dimensional measurements, validating the use of three-dimensional sonography as a reliable method for evaluation of common bile duct size.