Faculty Bibliography

Sarcoidosis is a complex multisystem inflammatory disease characterized by noncaseating granulomas and variable clinical manifestations, most commonly affecting the lungs, skin, heart, and nervous system. Imaging is central in its diagnosis, staging, and management, providing essential insights into organ involvement and disease activity. Pulmonary manifestations remain the hallmark, with modalities such as high-resolution chest computed tomography (CT) and chest radiography offering critical diagnostic clues. Imaging techniques, including Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and cardiac magnetic resonance imaging, are invaluable for identifying cardiac and systemic involvement, including cutaneous and musculoskeletal, while abdominal MRI and ultrasound help delineate hepatic and splenic manifestations. Neurosarcoidosis requires MRI for precise evaluation, supplemented by FDG-PET to guide biopsy and monitor treatment response. This chapter synthesizes the imaging features of sarcoidosis across organ systems, emphasizing practical approaches to diagnosis and management while identifying key areas for future research.

Cerebrospinal fluid (CSF) is an essential component of the central nervous system, and disruption of normal CSF flow from the lateral ventricles to the subarachnoid spaces around the brain and spinal canal can have serious consequences. Nuclear imaging may be useful to help diagnose abnormalities in CSF flow; cisternograms can be used to assess for CSF leaks or normal-pressure hydrocephalus, and shuntograms can be used to evaluate for CSF shunt malfunction. The authors review normal and pathologic findings and pitfalls of cisternography and shuntogram examinations. ^©RSNA, 2025.

The modified barium swallow study (MBSS) is a diagnostic examination that visualizes the functional anatomy and physiology of the oral pharyngeal swallowing mechanism in real time. The MBSS, a videofluoroscopic imaging method, is indicated for patients with known or suspected oropharyngeal dysphagia and ideally involves the combined expertise of a radiologist and speech pathologist. The MBSS provides critical diagnostic insights that help in identifying and assessing the type and severity of physiological swallowing impairments, evaluating the safety of oral intake, testing the effectiveness of evidence-based interventions, and developing treatment plans. This manuscript aims to present an overview of MBSS standards from an interdisciplinary perspective, emphasizes key areas of best practices, and reviews the common morphologic abnormalities seen on MBSS exams.

The implementation of deep neural networks has spurred the creation of deep learning reconstruction (DLR) CT algorithms. DLR CT techniques encompass a spectrum of deep learning-based methodologies that operate during the different steps of the image creation, prior to or after the traditional image formation process (eg, filtered backprojection [FBP] or iterative reconstruction [IR]), or alternatively by fully replacing FBP or IR techniques. DLR algorithms effectively facilitate the reduction of image noise associated with low photon counts from reduced radiation dose protocols. DLR methods have emerged as an effective solution to ameliorate limitations observed with prior CT image reconstruction algorithms, including FBP and IR algorithms, which are not able to preserve image texture and diagnostic performance at low radiation dose levels. An additional advantage of DLR algorithms is their high reconstruction speed, hence targeting the ideal triad of features for a CT image reconstruction (ie, the ability to consistently provide diagnostic-quality images and achieve radiation dose imaging levels as low as reasonably possible, with high reconstruction speed). An accumulated body of evidence supports the clinical use of DLR algorithms in abdominal imaging across multiple CT imaging tasks. The authors explore the technical aspects of DLR CT algorithms and examine various approaches to image synthesis in DLR creation. The clinical applications of DLR algorithms are highlighted across various abdominal CT imaging domains, with emphasis on the supporting evidence for diverse clinical tasks. An overview of the current limitations of and outlook for DLR algorithms for CT is provided. ^©RSNA, 2024.

T1-weighted (T1W) pulse sequences are an indispensable component of clinical protocols in abdominal MRI but usually require multiple breath holds (BHs) during the examination, which not all patients can sustain. Patient motion can affect the quality of T1W imaging so that key diagnostic information, such as intrinsic signal intensity and contrast enhancement image patterns, cannot be determined. Patient motion also has a negative impact on examination efficiency, as multiple acquisition attempts prolong the duration of the examination and often remain noncontributory. Techniques for mitigation of motion-related artifacts at T1W imaging include multiple arterial acquisitions within one BH; free breathing with respiratory gating or respiratory triggering; and radial imaging acquisition techniques, such as golden-angle radial k-space acquisition (stack-of-stars). While each of these techniques has inherent strengths and limitations, the selection of a specific motion-mitigation technique is based on several factors, including the clinical task under investigation, downstream technical ramifications, patient condition, and user preference. The authors review the technical principles of free-breathing motion mitigation techniques in abdominal MRI with T1W sequences, offer an overview of the established clinical applications, and outline the existing limitations of these techniques. In addition, practical guidance for abdominal MRI protocol strategies commonly encountered in clinical scenarios involving patients with limited BH abilities is rendered. Future prospects of free-breathing T1W imaging in abdominal MRI are also discussed. ^©RSNA, 2024 See the invited commentary by Fraum and An in this issue.

Various radiologic examinations and other diagnostic tools exist for evaluating gastrointestinal diseases. When symptoms of gastrointestinal disease persist and no underlying anatomic or structural abnormality is identified, the diagnosis of functional gastrointestinal disorder is frequently applied. Given its physiologic and quantitative nature, scintigraphy often plays a central role in the diagnosis and treatment of patients with suspected functional gastrointestinal disorder. Most frequently, after functional gallbladder disease is excluded, gastric emptying scintigraphy (GES) is considered the next step in evaluating patients with suspected gastric motility disorder who present with upper gastrointestinal symptoms such as dyspepsia or bloating. GES is the standard modality for detecting delayed gastric emptying (gastroparesis) and the less commonly encountered clinical entity, gastric dumping syndrome. Additionally, GES can be used to assess abnormalities of intragastric distribution, suggesting specific disorders such as impaired fundal accommodation or antral dysfunction, as well as to evaluate gastric emptying of liquid. More recently, scintigraphic examinations for evaluating small bowel and large bowel transit have been developed and validated for routine diagnostic use. These can be performed individually or as part of a comprehensive whole-gut transit evaluation. Such scintigraphic examinations are of particular importance because clinical assessment of suspected functional gastrointestinal disorder frequently fails to accurately localize the site of disease, and those patients may have motility disorders involving multiple portions of the gastrointestinal tract. The authors comprehensively review the current practice of gastrointestinal transit scintigraphy, with diseases and best imaging practices illustrated by means of case review. ^©RSNA, 2024 See the invited commentary by Maurer and Parkman in this issue.

Viral pneumonia is usually community acquired and caused by influenza, parainfluenza, respiratory syncytial virus, human metapneumovirus, and adenovirus. Many of these infections are airway centric and chest imaging demonstrates bronchiolitis and bronchopneumonia, With the exception of adenovirus infections, the presence of lobar consolidation usually suggests bacterial coinfection. Community-acquired viral pathogens can cause more severe pneumonia in immunocompromised hosts, who are also susceptible to CMV and varicella infection. These latter 2 pathogens are less likely to manifest the striking airway-centric pattern. Airway-centric pattern is distinctly uncommon in Hantavirus pulmonary syndrome, a rare environmentally acquired infection with high mortality.