Glial Fibrillary Acidic Protein Astrocytopathy: Review of Pathogenesis, Imaging Features, and Radiographic Mimics.

Glial fibrillary acidic protein (GFAP) astrocytopathy is a recently described autoimmune inflammatory disorder of the CNS characterized by the presence of specific antibodies targeting the intracellular filament protein in mature astrocytes. The pathogenesis is heterogeneous and poorly understood, with around 20%-34% of cases occurring as a paraneoplastic syndrome, most frequently associated with ovarian teratomas. It presents clinically as acute or subacute encephalomyelitis, and the diagnosis relies on imaging and detection of GFAP-Immunoglobulin (GFAP-IgG) in the CSF. Characteristic imaging findings include linear perivascular enhancement in the white matter extending in a radial pattern. Other imaging findings include periependymal enhancement, longitudinally extensive cord signal changes, intramedullary enhancement, optic neuritis, and papillitis. There is significant imaging overlap with other neuroinflammatory diseases like neuromyelitis optica spectrum disorder and lymphoproliferative conditions. GFAP astrocytopathy is characteristically responsive to steroids with, however, a significant rate of relapse. Currently, literature on this novel entity is limited with no established diagnostic criteria or standard treatment regimen. This comprehensive review explores the clinical, radiographic, and histopathologic aspects of GFAP astrocytopathy, shedding light on its complex nature and potential diagnostic challenges. The paper highlights the neuroimaging findings with a focus on differentiating GFAP astrocytopathy from other neuroinflammatory disorders.

Contrast-enhanced ultrasound of renal masses in the pre-transplant setting: literature review with case highlights.

With the rising incidence of chronic kidney disease worldwide, an increasing number of patients are expected to require renal transplantation, which remains the definitive treatment of end stage renal disease. Medical imaging, primarily ultrasonography and contrast-enhanced CT and/or MRI, plays a large role in pre-transplantation assessment, especially in the characterization of lesions within the native kidneys. However, patients with CKD/ESRD often have relative contraindications to CT- and MR-contrast agents, limiting their utilization within this patient population. Contrast-enhanced ultrasound (CEUS), which combines the high temporal and spatial resolution of ultrasonography with intravascular microbubble contrast agents, provides a promising alternative. This review aims to familiarize the reader with the literature regarding the use of CEUS in the evaluation of cystic and solid renal lesions and provide case examples of its use at our institution in the pre-transplant setting.

Imaging of the Posttreatment Head and Neck: Expected Findings and Potential Complications.

Interpretation of posttreatment imaging findings in patients with head and neck cancer can pose a substantial challenge. Malignancies in this region are often managed through surgery, radiation therapy, chemotherapy, and newer approaches like immunotherapy. After treatment, patients may experience various expected changes, including mucositis, soft-tissue inflammation, laryngeal edema, and salivary gland inflammation. Imaging techniques such as CT, MRI, and PET scans help differentiate these changes from tumor recurrence. Complications such as osteoradionecrosis, chondroradionecrosis, and radiation-induced vasculopathy can arise because of radiation effects. Radiation-induced malignancies may occur in the delayed setting. This review article emphasizes the importance of posttreatment surveillance imaging to ensure proper care of patients with head and neck cancer and highlights the complexities in distinguishing between expected treatment effects and potential complications. Keywords: CT, MR Imaging, Radiation Therapy, Ear/Nose/Throat, Head/Neck, Nervous-Peripheral, Bone Marrow, Calvarium, Carotid Arteries, Jaw, Face, Larynx © RSNA, 2024.

Recurrent hepatic artery pseudoaneurysm repair with overlapping tapered stent-graft technique.

Hepatic artery pseudoaneurysms (HAPs) are rare but life-threatening complications associated with hepatic artery infusion pump (HAIP) therapy for unresectable liver metastases. Traditional management options include open surgery or stent placement, but these approaches have drawbacks. We present a unique case of a dislodged stent embedded in a HAP, resulting in delayed type-I endoleak. To address this, we employed a novel technique using multiple overlapping tapered stents to reconstruct the hepatic artery. This approach successfully excluded the pseudoaneurysm without endoleak. Stent-graft placement emerges as a safer and more effective option for managing HAP, preserving hepatic arterial flow, and reducing morbidity compared to other methods. However, further research is needed to evaluate this technique's long-term outcomes and potential complications.

Transjugular intrahepatic portosystemic shunt for pediatric portal hypertension: A meta-analysis.

To evaluate the feasibility of transjugular intrahepatic portosystemic shunt (TIPS) in children with portal hypertensive complications, PubMed and Cochrane Library were queried to identify clinical studies evaluating TIPS in patients <18 years old. Baseline clinical characteristics, laboratory values, and clinical outcomes were extracted. Eleven observational studies totaling 198 subjects were included in the study. The pooled technical success rate and hemodynamic success rate were 94% (95% confidence interval [CI]: 86-99%) and 91% (95% CI: 82-97%), respectively; ongoing variceal bleeding resolved in 99.5% (95% CI: 97-100%); refractory ascites was improved in 96% (95% CI: 69-100%); post-TIPS bleeding rate was 14% (95% CI: 1-33%); 88% of patients were alive or successfully received liver transplant (95% CI: 79-96%); and shunt dysfunction rate was 27% (95% CI: 17-38%). Hepatic encephalopathy occurred in 10.6% (21/198), though 85.7% (18/21) resolved with medical management only. In conclusion, based on moderate levels of evidence, TIPS is a safe and effective intervention that should be considered in pediatric patients with portal hypertensive complications. Future comparative studies are warranted.