Faculty Bibliography

Urologic oncologic emergencies represent a relatively narrow yet diverse group of critical conditions that require prompt recognition and intervention to prevent potentially life-threatening complications. These oncologic emergencies may arise as direct consequences of a malignancy, including local invasion, or as sequelae of surgical or therapeutic interventions. Common urologic emergencies include malignant obstructive uropathy or ureteral obstruction, which may lead to urosepsis or acute kidney injury; large volume hematuria and hemorrhagic cystitis, which both can result in substantial blood loss; renal hemorrhage, which can lead to hemodynamic instability; fistula formation; and postsurgical urinary leaks. Radiologists play a key role in promptly detecting and evaluating such emergencies and can help differentiate expected post-treatment findings from urgent or potentially life-threatening complications. Imaging not only helps to diagnose these emergencies but can also guide subsequent management strategies and thus is essential for optimizing patient outcomes. This review article aims to highlight the clinical and multi-modality imaging manifestations of urologic oncologic emergencies and their potential management strategies.

While many parasitic and vector-borne infections have traditionally been considered to have geographically limited distribution, factors including climate change, the immigration and world travel of individuals, and the importing and exporting of goods continue to shift ecosystems and expand the geographic distributions of parasites and insect vectors and the infections they transmit. Because they may be unexpected, cases emerging in regions of nonendemicity can result in a medical mystery, and because appropriate management relies on an accurate diagnosis, identification of these diseases is vital. Radiologists should be aware of these infections and their potential sequelae to help limit the delays in diagnoses and potentially lifesaving treatment that can occur if the diagnosis is not promptly suggested and investigated. Although some imaging findings are nonspecific, a knowledgeable radiologist can play a crucial role in correlating imaging features or patterns of features with laboratory findings and available clinical information to reveal the diagnosis and/or develop a differential diagnosis. The authors describe a variety of parasitic and vector-borne infections that affect humans, with a specific focus on those that manifest in the head, neck, and spine. A brief introduction to these infections is provided and includes relevant epidemiologic factors, clinical presentations, and potential complications, with the sequelae associated with head, neck, and nervous system infections more thoroughly described. Case examples are included to demonstrate the imaging features associated with acute and chronic and common and uncommon sequelae of these infections across multiple imaging modalities. ^©RSNA, 2026 Supplemental material is available for this article.

Fibromuscular dysplasia (FMD) is a rare idiopathic, noninflammatory, nonatherosclerotic arteriopathy that leads to wall abnormalities in medium- and small-caliber arteries, typically resulting in alternating areas of stenosis and dilatation, or "beading" at angiography. Stenosis, dissection, and aneurysm can also be seen, and clinical manifestations depend on the vascular territory affected by FMD, with the renal and carotid arteries being most frequently involved. The diagnosis of FMD is made based on imaging features of FMD classified according to the angiographic appearance as focal FMD or multifocal FMD. Early diagnosis is often challenging, as mimics of FMD must first be excluded. The presence of aneurysm, dissection, or tortuosity alone is inadequate to establish the diagnosis, as these are variant manifestations; however, if a patient has focal or multifocal manifestations such as stenosis or stenosis and dilatation in one vascular bed, establishing the diagnosis of FMD, the presence of aneurysm, dissection, or tortuosity in additional vascular beds is considered multivessel involvement of all affected vascular beds. The cerebrovascular system, coronary arteries, renal and mesenteric arteries, and extremities should be evaluated for FMD involvement. The most serious potential complications of FMD are hypoperfusion secondary to aneurysm, dissection, or arterial occlusion, which can lead to hypertension, stroke, or myocardial infarction, as well as subarachnoid hemorrhage. Prompt intervention, blood pressure management, and revascularization are necessary to avoid devastating complications. Radiologists play an important role in timely identification of diverse FMD-associated morbidities and thus may contribute to early diagnosis and treatment of FMD. ^©RSNA, 2026 Supplemental material is available for this article.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts (RHIs), characterized by tau tangles around small blood vessels at the depths of the sulci. Currently, CTE can be diagnosed only postmortem, but can present with an array of cognitive, behavioral, mood, and motor symptoms. However, traumatic brain injury is also associated with increased risk of Alzheimer's disease (AD) and may lead to comorbid neuropathology. Characterization of the in vivo biomarkers of CTE is a necessary next step to facilitate accurate diagnoses. We examined the profile of cerebrospinal fluid (CSF) biomarkers of amyloid-β, total tau (tTau), and phospho-tau (pTau) in a cohort of former professional (PRO, n = 100) and college (COL, n = 40) football players at high risk of CTE compared to asymptomatic unexposed controls (UE, n = 43). CSF was collected under controlled conditions using collection, processing, and cryostorage kits provided by the DIAGNOSE CTE Research Project Biomarker Core, and concentrations of Aβ₄₀, Aβ₄₂, tTau, and pTau (pTau₁₈₁, pTau₂₁₇, pTau₂₃₁) were measured at the University of Gothenburg, Sweden, using immunoassays. Associations between CSF biomarker levels with football history, and diagnosis of traumatic encephalopathy syndrome (TES) were examined using linear regression, and corrected for age, education, APOE-ε4 allele status, race, and body mass index. Our analysis revealed that football exposure affected both CSF Aβ₄₀ (p = 0.039) and Aβ₄₂ (p = 0.038), particularly among those under 60 years of age in the PRO compared to the UE exposure group. Among former football players, estimates of RHI exposure were not generally associated with CSF Aβ, tTau, and pTau biomarker levels. CSF Aβ₄₀ (p = 0.0041) and Aβ₄₂ (p = 0.011) were lower in former football players with TES diagnosis compared to unexposed participants, although CSF Aβ, tTau, and pTau biomarker levels did not differ between former players with and without a TES diagnosis. Among former football players, reduced CSF Aβ₄₀ (p = 0.011) and Aβ₄₂ (p = 6e-04) were observed in those with cognitive impairment compared to those with neurobehavioral dysregulation. The findings of significant associations of reduced CSF Aβ levels with RHI in elite football players are in line with recent postmortem studies; however, the lack of relationship with CSF tTau and pTau species observed to be altered in the setting of AD suggests that the pathological features of CTE reflected in fluid biomarkers are complex and require further study. The overlapping comorbid age-dependent features of neurodegeneration that occur in those at risk for CTE suggest that tau pathology in CTE is not reliably reflected by currently available fluid biomarkers and that the use of multiple biomarkers related to the compound characteristics of CTE may be required for early detection.

Trauma during pregnancy presents a clinical challenge because the health and survival of both the mother and fetus are key clinical concerns. Given the prevalence of trauma in pregnancy, affecting an estimated 5%-7% of pregnancies, knowledge of the appropriate treatment of such patients is crucial for emergency and general radiologists. Although US is the default imaging modality during pregnancy, urgent and accurate diagnosis frequently requires the use of CT, despite the potential risk of exposure to ionizing radiation and contrast media. As such, the radiologist must be familiar with both obstetric-specific injuries and how pregnancy may complicate otherwise familiar traumatic presentations. The authors discuss the general treatment of the pregnant trauma patient, with an emphasis on radiologic evaluation. They provide an overview of various imaging modalities available for evaluation of pregnant patients with traumatic injuries, emphasizing their potential risks, benefits, and limitations. The relative role of imaging assessment versus electronic fetal monitoring in a patient with suspected placental abruption is discussed. Proposed grading methods and management pathways for placental abruption, with respect to fetal age and maternal stability, are reviewed. Relevant cases are presented, demonstrating key obstetric abnormalities that may be seen in patients with pregnancy-related trauma. ^©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Mellnick and Raptis in this issue.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Disturbances in brain catecholamine activity may be associated with symptoms after exposure to repetitive head impacts (RHIs) or related chronic traumatic encephalopathy (CTE). In this article, we studied CSF catecholamines in former professional and college American football players and examined the relationship with football proxies of RHI exposure, CTE probability, cognitive performance, neuropsychiatric symptoms, and parkinsonism. METHODS:In this observational cross-sectional study, we examined male former American football players, professional ("PRO") or college ("COL") level, and asymptomatic unexposed male ("UE") individuals from the DIAGNOSE CTE Research Project. Catecholamines-norepinephrine (NE) and its metabolite, 3,4-dihydroxyphenylglycol (DHPG), and dopamine (DA) and its precursor, 3,4-dihydroxyphenylalanine (l-DOPA), and metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC)-were measured in CSF with high-performance liquid chromatography and compared across groups with analysis of covariance. Multivariable linear regression models tested the relationship between CSF catecholamines and proxies of RHI exposure (e.g., total years of playing American football), factor scores for cognition, and neurobehavioral dysregulation (explosivity, emotional dyscontrol, impulsivity, affective lability), as well as depressive/anxiety symptoms, measured with the Beck Depression/Anxiety Inventories. CTE probability and parkinsonism were assessed using the National Institute of Neurological Disorders and Stroke consensus diagnostic criteria for traumatic encephalopathy syndrome (TES), and biomarkers were compared among different diagnostic groups. RESULTS:The cohort consisted of 120 former American football players (85 PRO players, 35 COL players) and 35 UE participants (age 45-75). Former players had significantly lower levels of NE (mean difference = -0.114, 95% CI -0.190 to -0.038), l-DOPA (-0.121, 95% CI -0.109 to -0.027), and DOPAC (-0.116, 95% CI -0.177 to -0.054) than UE participants. For NE and DOPAC, these overall group differences were primarily due to differences between the PRO and UE cohorts. No significant differences were found across TES-CTE probability subgroups or TES-parkinsonism diagnostic groups. Within the COL cohort, tested as post hoc analyses, higher CSF NE and l-DOPA were associated with higher neurobehavioral dysregulation factor scores, BAI total score, and worse executive functioning and processing speed. CSF DHPG and DOPAC were associated with impulsivity only in this subgroup. DISCUSSION/CONCLUSIONS:We observed reduced CSF catecholamine concentrations in former elite American football players, although the relationship with degree of RHI exposure and the clinical impact needs further study.

In patients with cancer, spontaneous renal bleeding can stem from a range of underlying factors, necessitating precise diagnostic tools for effective patient management. Benign and malignant renal tumors are among the primary culprits, with angiomyolipomas and renal cell carcinomas being the most common among them. Vascular anomalies, infections, ureteral obstructions, and coagulation disorders can also contribute to renal-related bleeding. Cross-sectional imaging techniques, particularly ultrasound and computed tomography (CT), play pivotal roles in the initial detection of renal bleeding. Magnetic resonance imaging and CT are preferred for follow-up evaluations and aid in detecting underlying enhancing masses. IV contrast-enhanced ultrasound can provide additional information for active bleeding detection and differentiation. This review article explores specific disorders associated with or resembling spontaneous acute renal bleeding in patients with renal tumors; it focuses on the significance of advanced imaging techniques in accurately identifying and characterizing renal bleeding in these individuals. It also provides insights into the clinical presentations, imaging findings, and treatment options for various causes of renal bleeding, aiming to enhance the understanding, diagnosis, and management of the issue.

Hyperattenuating contents detected in the gastrointestinal (GI) tract on CT scans are commonly seen and are almost always due to the purposeful ingestion of an oral contrast agent, usually barium- or iodine-based, used for evaluating the GI tract. Occasionally, other ingested material such as antacids or other medications, foreign objects, and medical devices can also be hyperattenuating. While these are usually correctly identified, these materials can potentially be misdiagnosed as a pathologic condition. Lokelma (sodium zirconium cyclosilicate (SZC)) is an increasingly used agent to treat hyperkalemia and has a hyperattenuating appearance on CT due to the presence of zirconium. However, this is not well known to the radiologic community. Here, we describe a case where SZC was seen in the GI tract on CT and misinterpreted as an acute GI bleed. A 72-year-old woman underwent single (portal venous) phase intravenous contrast-enhanced abdominal and pelvic CT after presenting to the ED with a lower GI bleed. The CT showed intraluminal hyperattenuation within the cecum, which was diagnosed prospectively as an active GI bleed. A CT angiogram of the abdomen and pelvis performed the following day for follow-up showed the hyperattenuating contents to be present on the non-IV contrast-enhanced series of the study, thereby proving that it was not due to active bleeding. Further investigation of the patient's medical record showed that the patient was being treated with SZC for hyperkalemia, accounting for the hyperattenuating cecal contents. Awareness of the hyperattenuating appearance of SZC on CT by radiologists and clinical staff can help avoid confusion and misdiagnosis.