ASNR Statement on Gadolinium-Based Contrast Agent Use in Patients with Chronic Kidney Disease.

BACKGROUND: Beginning in 2006, neuroradiologists became increasingly aware of the risk of nephrogenic system fibrosis (NSF) when patients suffering from chronic kidney disease (CKD) received gadolinium-based contrast agents (GBCAs) in conjunction with MRI scans. Radiology practices began withholding GBCAs from MRI patients with substantial CKD and instated a variety of safety measures to ensure that these individuals did not inadvertently receive GBCAs. As a result, the worldwide incidence of NSF was dramatically reduced. Since that time, a wealth of research on NSF and its etiology has found few unconfounded cases associated with those GBCAs categorized as Group II agents by the American College of Radiology. METHODS: In 2023 and 2024, members of the American Society of Neuroradiology (ASNR) Standards and Guidelines Committee reviewed new research evidence on GBCA safety and its relevance to current MRI contrast administration guidelines for patients with CKD. This focused on systematic reviews and meta-analyses conducted during the past five years. Upon consideration of this literature, recommendations for administration of GBCAs to patients with CKD were formulated. KEY MESSAGE: For neuroimaging applications, the ASNR recommends that Group II GBCAs no longer be withheld in patients with CKD when these agents are medically indicated for diagnosis. Moreover, if Group II GBCAs are exclusively used in an MRI practice, other safety measures such as checking renal function or querying patients about chronic kidney disease can be discontinued. ABBREVIATIONS: ACR = American College of Radiology; ASNR = American Society of Neuroradiology; CKD = chronic kidney disease; GBCA = gadolinium-based contrast agent; NSF = nephrogenic systemic fibrosis.

The ASNR International Collaborations Committee: Cultivating a Global Learning Community.

The American Society of Neuroradiology has expanded its global presence, driven by the efforts of the International Collaborations Committee. This committee is actively involved in training radiologists and fostering collaborations worldwide in the fields of education, research, and community service. This article explores key initiatives of the committee, such as the Anne G. Osborn ASNR International Outreach Professor Program, the International Imaging Series, and Virtual Reading Rooms. Additionally, we provide insight into recent developments related to the pandemic and outline future opportunities.

The Current State of Functional MR Imaging for Trauma Prognostication.

In this review, we discuss the basics of functional MRI (fMRI) techniques including task-based and resting state fMRI, and overview the major findings in patients with traumatic brain injury. We summarize the studies that have longitudinally evaluated the changes in brain connectivity and task-related activation in trauma patients during different phases of trauma. We discuss how these data may potentially be used for prognostication, treatment planning, or monitoring and management of trauma patients.

Equity, diversity & inclusion in academic radiology: An elusive dream.

BACKGROUND: Disparities in sex and race/ethnicity continue to persist in the academic radiology. This study addresses the sex/racial underrepresentation and evolution in the academic radiology. PURPOSE: To evaluate academic radiology temporal trends disparities by analyzing sex and race/ethnicity diversity in academic degree and tenure status. MATERIALS AND METHODS: A retrospective cross-sectional analysis conducted using American Association of Medical College database between 2007 and 2018. Trends in academic degree, tenure status, race/ethnicity, and sex assessed with linear regression analysis and Poisson regression model for annual percent change with statistical significance of p < 0.05. RESULTS: Out of 107,213 radiologists 72%, n = 76,893 males and 64%, n = 68,738 white faculty with 1277 males and 872 females. White MD-degree radiologists constitute 67.2%, Asian (20.9%), Black (2.5%), Hispanic (3.2%), multiple (3.4%), unknown (1.8%) and "other" (1%) races with a similar PhD/other doctoral and dual-degree. White faculty recruitment trend (n2007 = 955, n2018 = 703) and representation (-0.82% per year; 95% CI, -1.00 to -0.63; p < 0.0001) decreased, while Asian URM decreased respectively (n2007 = 152, n2018 = 205) (0.68% per year; 95% CI, 0.58 to 0.77; p < 0.0001). Females were underrepresented in all categories. CONCLUSION: URM and females are underrepresented in academic radiology. Academic degree types and tenure track may contribute to White and male academic radiologists overrepresentation.

Demographic Reporting in Publicly Available Chest Radiograph Data Sets: Opportunities for Mitigating Sex and Racial Disparities in Deep Learning Models.

OBJECTIVE: Data sets with demographic imbalances can introduce bias in deep learning models and potentially amplify existing health disparities. We evaluated the reporting of demographics and potential biases in publicly available chest radiograph (CXR) data sets. METHODS: We reviewed publicly available CXR data sets available on February 1, 2021, with >100 CXRs and performed a thorough search of various repositories, including Radiopaedia and Kaggle. For each data set, we recorded the total number of images and whether the data set reported demographic variables (age, race or ethnicity, sex, insurance status) in aggregate and on an image-level basis. RESULTS: Twenty-three CXR data sets were included (range, 105-371,858 images). Most data sets reported demographics in some form (19 of 23; 82.6%) and on an image level (17 of 23; 73.9%). The majority reported age (19 of 23; 82.6%) and sex (18 of 23; 78.2%), but a minority reported race or ethnicity (2 of 23; 8.7%) and insurance status (1 of 23; 4.3%). Of the 13 data sets with sex distribution readily available, the average breakdown was 55.2% male subjects, ranging from 47.8% to 69.7% male representation. Of these, 8 (61.5%) overrepresented male subjects and 5 (38.5%) overrepresented female subjects. DISCUSSION: Although most publicly available CXR data sets report age and sex on an image-basis level, few report race or ethnicity and insurance status. Furthermore, these data sets frequently underrepresent one of the sexes, more frequently the female sex. We recommend that data sets report standard demographic variables, and when possible, balance demographic representation to mitigate bias. Furthermore, for researchers using these data sets, we recommend that attention be paid to balancing demographic labels in addition to disease labels, as well as developing training methods that can account for these imbalances.

Cerebral venous sinus thrombosis associated with vaccine-induced thrombotic thrombocytopenia.

Thrombosis-thrombocytopenia syndrome and cerebral venous sinus thrombosis have been rarely reported in patients who have received severe acute respiratory syndrome coronavirus 2 adenoviral vector vaccines. Awareness of this potential adverse effect, recognizing early clinical symptoms and subtle signs of cerebral venous sinus thrombosis on head computed tomography and brain magnetic resonance imaging, appropriate vascular imaging, and unique treatment for this condition is critical. This is a report of a case of vaccine-induced thrombotic thrombocytopenia and associated cerebral venous sinus thrombosis with emphasis on imaging and clinical course.

Cerebrovascular Events After Continuous-Flow Left Ventricular Assist Devices.

BACKGROUND: Cerebrovascular events (CVE) are among the most common and serious complications after implantation of continuous-flow left ventricular assist devices (CF-LVAD). We studied the incidence, subtypes, anatomical distribution, and pre- and post-implantation risk factors of CVEs as well as the effect of CVEs on outcomes after CF-LVAD implantation at our institution. METHODS: Retrospective analysis of clinical and neuroimaging data of 372 patients with CF-LVAD between May 2005 and December 2013 using standard statistical methods. RESULTS: CVEs occurred in 71 patients (19%), consisting of 35 ischemic (49%), 26 hemorrhagic (37%), and 10 ischemic+hemorrhagic (14%) events. History of coronary artery disease and female gender was associated with higher odds of ischemic CVE (OR 2.84 and 2.5, respectively), and diabetes mellitus was associated with higher odds of hemorrhagic CVE (OR 3.12). While we found a higher rate of ischemic CVEs in patients not taking any antithrombotic medications, no difference was found between patients with ischemic and hemorrhagic CVEs. Occurrence of CVEs was associated with increased mortality (HR 1.62). Heart transplantation was associated with improved survival (HR 0.02). In patients without heart transplantation, occurrence of CVE was associated with decreased survival. CONCLUSIONS: LVADs are associated with high rates of CVE, increased mortality, and lower rates of heart transplantation. Further investigations to identify the optimal primary and secondary stroke prevention measures in post-LVAD patients are warranted.

Case 236: Middle Interhemispheric Variant of Holoprosencephaly.

History A 13-year-old girl presented for evaluation and further management of spastic diplegia cerebral palsy. Absence of the corpus callosum was noted at screening prenatal head ultrasonography. She was born at full term via spontaneous vaginal delivery. Physical examination revealed decreased axial muscle tone and increased muscle tone in her extremities; the latter was more severe. She was nonambulatory. No midline craniofacial anomaly was seen. She had dysarthria but was able to speak in full sentences. She was in sixth grade with an individualized education program. She had mild behavioral problems, such as "acting out" in school. Brain magnetic resonance (MR) imaging, including three-dimensional T1- and T2-weighted sequences, was performed without intravenous administration of contrast material to evaluate the brain.

Reporting of Resting-State Functional Magnetic Resonance Imaging Preprocessing Methodologies.

There has been a rapid increase in resting-state functional magnetic resonance imaging (rs-fMRI) literature in the past few years. We aim to highlight the variability in the current reporting practices of rs-fMRI acquisition and preprocessing parameters. The PubMed database was searched for the selection of appropriate articles in the rs-fMRI literature and the most recent 100 articles were selected based on our criteria. These articles were evaluated based on a checklist for reporting of certain preprocessing steps. All of the studies reported the temporal resolution for the scan and the software used for the analysis. Less than half of the studies reported physiologic monitoring, despiking, global signal regression, framewise displacement, and volume censoring. A majority of the studies mentioned the scanning duration, eye status, and smoothing kernel. Overall, we demonstrate the wide variability in reporting of preprocessing methods in rs-fMRI studies. Although there might be potential variability in reporting across studies due to individual requirements for a study, we suggest the need for standardizing reporting guidelines to ensure reproducibility.

Neurovascular uncoupling in resting state fMRI demonstrated in patients with primary brain gliomas.

BACKGROUND: To demonstrate that the problem of brain tumor-related neurovascular uncoupling (NVU) is a significant issue with respect to resting state blood oxygen level dependent (BOLD) functional MRI (rsfMRI) similar to task-based BOLD fMRI, in which signal detectability can be compromised by breakdown of normal neurovascular coupling. METHODS: We evaluated seven de novo brain tumor patients who underwent resting state fMRI as part of comprehensive clinical fMRI exams at 3 Tesla. For each of the seven patients who demonstrated evidence of NVU on task-based motor fMRI, we performed both an independent component analysis (ICA) and an atlas-based parcellation-based seed correlation analysis (SCA) of the resting state fMRI data. For each patient, ipsilesional (IL) and contralesional (CL) regions of interest (ROIs) comprising primary motor and somatosensory cortices were used to evaluate BOLD signal changes on Z score maps derived from both ICA and SCA analysis for evidence of NVU. A subsequent two-tailed t-test was performed to determine whether statistically significant differences between the two sides were present that were consistent with NVU. RESULTS: In seven patients, overall decreased BOLD signal (based on suprathreshold voxels in ICA and SCA-derived Z-score maps) was noted in IL compared with CL ROIs (P < 0.01), consistent with NVU. CONCLUSION: We have demonstrated that NVU can result in false negative BOLD signal changes on rsfMRI comparable to previously published findings on standard motor task-based fMRI.

Presurgical brain mapping of the language network in patients with brain tumors using resting-state fMRI: Comparison with task fMRI.

PURPOSE: To compare language networks derived from resting-state fMRI (rs-fMRI) with task-fMRI in patients with brain tumors and investigate variables that affect rs-fMRI vs task-fMRI concordance. MATERIALS AND METHODS: Independent component analysis (ICA) of rs-fMRI was performed with 20, 30, 40, and 50 target components (ICA20 to ICA50) and language networks identified for patients presenting for presurgical fMRI mapping between 1/1/2009 and 7/1/2015. 49 patients were analyzed fulfilling criteria for presence of brain tumors, no prior brain surgery, and adequate task-fMRI performance. Rs-vs-task-fMRI concordance was measured using Dice coefficients across varying fMRI thresholds before and after noise removal. Multi-thresholded Dice coefficient volume under the surface (DiceVUS) and maximum Dice coefficient (MaxDice) were calculated. One-way Analysis of Variance (ANOVA) was performed to determine significance of DiceVUS and MaxDice between the four ICA order groups. Age, Sex, Handedness, Tumor Side, Tumor Size, WHO Grade, number of scrubbed volumes, image intensity root mean square (iRMS), and mean framewise displacement (FD) were used as predictors for VUS in a linear regression. RESULTS: Artificial elevation of rs-fMRI vs task-fMRI concordance is seen at low thresholds due to noise. Noise-removed group-mean DiceVUS and MaxDice improved as ICA order increased, however ANOVA demonstrated no statistically significant difference between the four groups. Linear regression demonstrated an association between iRMS and DiceVUS for ICA30-50, and iRMS and MaxDice for ICA50. CONCLUSION: Overall there is moderate group level rs-vs-task fMRI language network concordance, however substantial subject-level variability exists; iRMS may be used to determine reliability of rs-fMRI derived language networks.

Percutaneous radiofrequency-targeted vertebral augmentation of unstable metastatic C2 and C3 lesions using a CT-guided posterolateral approach and ultra-high-viscosity cement.

STUDY DESIGN: Case report. OBJECTIVE: To report the first technical note describing radio frequency-targeted C2 and C3 vertebral augmentation using a posterolateral approach and high-viscosity cement. SUMMARY OF BACKGROUND DATA: Percutaneous vertebral augmentation is a minimally invasive procedure used for stabilization and pain control in vertebral compression fractures. Its use in the cervical spine, especially the upper cervical spine, is very limited mainly due to technical challenges. METHODS: We report the first use of an ultra-high-viscosity cement and posterolateral approach with computed tomography (CT) guidance and computed tomographic fluoroscopy in a patient with lytic lesions in C2 and C3 and a pathologic fracture of C2 for the purpose of stabilization and pain palliation. RESULTS: Technically successful vertebral augmentation of the C2 and C3 vertebral bodies was achieved. There were no complications. The patient reported pain relief and improved range of motion after treatment and the hard cervical collar was removed. CONCLUSION: Computed tomography-guided radiofrequency-targeted vertebral augmentation of the cervical spine using a posterolateral approach and ultra-high-viscosity cement is a technically feasible procedure that may be used in patients with advanced osteolytic cervical spine metastases who are not surgical candidates for the purpose of pain palliation and fracture stabilization. LEVEL OF EVIDENCE: N/A.

Imaging of cosmetic plastic procedures and implants in the body and their potential complications.

OBJECTIVE: Cosmetic plastic surgery procedures, as well as implants, are increasingly being performed. These implants are often encountered on routine imaging examinations, and radiologists are often asked to evaluate for complications or evidence of failure. Pectoral augmentation, gluteal augmentation, body lift and abdominoplasty, and penile and testicular prostheses are reviewed in this article. CONCLUSION: The typical appearance of common cosmetic implants and cosmetic techniques used in the human body is presented, along with the imaging spectrum of their potential complications.

Pediatric cardiac tumors: clinical and imaging features.

Cardiac tumors in children are rare, are more commonly benign, and differ in types when compared with those in adults. Rhabdomyoma, teratoma, and fibroma are the most common cardiac tumors in fetuses and neonates. In infants and children, the most common cardiac tumors are rhabdomyoma and fibroma, which are benign primary cardiac tumors, whereas in adults, thrombus is the most common cardiac mass and myxoma is the most common primary cardiac tumor. Sarcomas are the most common primary malignant cardiac tumors in both children and adults. Metastatic cardiac tumors are less common in children than in adults and include sarcoma, lymphoma, testicular cancer, and Wilms tumor. Patients with cardiac tumors can be asymptomatic or may present with murmur, arrhythmia, heart failure, or sudden death. Echocardiography is the primary modality for initial evaluation of symptomatic patients. Cardiac magnetic resonance imaging provides further characterization of cardiac masses and tumors for diagnostic purposes and can be used to assess cardiac and extracardiac involvement for treatment planning. Treatment varies from conservative management or surgical resection to transplantation, depending on the diagnosis and the patient's symptoms. Rhabdomyoma typically regresses spontaneously during early childhood and does not require surgical intervention if asymptomatic. However, fibroma is generally resected because it does not regress. An understanding of the types of cardiac tumors that occur in infants and children, their clinical implications and associations, and their imaging appearances will facilitate patient management.