October 2024 Article Summaries

In this podcast episode, Dr. Vilanilam discusses “Cerebral Proliferative Angiopathy: Imaging Spectrum and Diagnostic Insights,” by first author Rai.Cerebral proliferative angiopathy is a rare cerebrovascular malformation that can mimic an arteriovenous malformation but has a fundamentally different vascular architecture and underlying physiology. This comprehensive review of 75 studies and 153 patients highlights its characteristic multimodal imaging features, including a diffuse vascular network intermingled with normal brain, absence of a compact nidus or dominant arterial feeders, frequent transdural recruitment, relatively limited early venous drainage, and evidence of chronic hypoperfusion.Dr. Vilanilam reviews the key CT, MRI, perfusion, and angiographic findings that help distinguish cerebral proliferative angiopathy from conventional arteriovenous malformations and other vascular mimics. Recognizing this distinction is critical because normal functioning brain is incorporated within the abnormal vascular network, substantially influencing treatment decisions and emphasizing the importance of accurate imaging diagnosis.Featured Article: Cerebral Proliferative Angiopathy: Imaging Spectrum and Diagnostic Insights

In this podcast episode, Dr. Vilanilam discusses "Indeterminate T1-Hypointense Spine Lesions: Prevalence of Malignancy in the Absence of Aggressive Imaging Features," by first author Barkovich. Indeterminate low-T1-signal vertebral lesions are commonly encountered on spine MRI, but deciding which lesions require additional imaging or follow-up can be challenging. This study examines the outcomes of 278 such lesions and finds an overall malignancy rate of only 2%, with all malignant lesions representing metastases in patients with known or concurrently diagnosed extraskeletal metastatic disease and no primary malignant bone tumors identified. Dr. Vilanilam reviews the imaging features of these lesions, the importance of incorporating the patient's oncologic history into risk assessment, and the implications for follow-up recommendations. The findings suggest that short-interval imaging may be appropriate when there is meaningful concern for metastatic disease, while follow-up may not be necessary for low-risk patients without aggressive imaging features or extraskeletal metastatic disease.

In this AJNR Podcast author interview, Dr. Francis Deng speaks with Dr. Caline Azzi about recent studies identifying imaging and clinical predictors of expansion in traumatic subdural, subarachnoid, and intraparenchymal hemorrhage. Hemorrhage size, multicompartment injury, coagulopathy, mass effect, and neurologic status may help determine which patients truly need routine repeat CT. Related Articles: Risk Stratification for Traumatic SAH Enlargement and Surgical Intervention: Guides to Follow-Up Imaging in Patients with Trauma Predictive Factors for Traumatic Intraparenchymal Hemorrhage Expansion and Its Clinical Outcomes Improving the management of acute subdural hematomas; identifying characteristics associated with acute subdural hematoma size and expansion

In this AJNR Article Summary, Dr. George Vilanilam discusses the article, "Sinking Flap Syndrome: Risk Factors, Outcomes, and the Role of Neuroradiology in Cranioplasty Timing." Sinking flap syndrome is a common yet frequently underrecognized complication of decompressive craniectomy, with imaging findings often preceding clinical deterioration. Recognition and reporting of key features - including a markedly sunken flap, ventricular compression, and significant midline shift (8 mm or greater) were associated with a two-fold reduction in time to cranioplasty highlighting the important role neuroradiologists can play in expediting definitive treatment and improving patient care.

In this AJNR Article Summary, Dr. Francis Deng reviews CTA-based Carotid Plaque-RADS and its role beyond stenosis grading. He explains the key imaging features that define plaque vulnerability, then highlights two AJNR studies showing that the system is learnable, reproducible, and clinically meaningful for predicting future stroke risk, especially in patients with only mild or moderate carotid stenosis. Visit the website to read the related articles. Carotid Plaque-RADS: Inter- and Intrareader Agreement and Learning Curve Analysis in CTA CTA-Based Carotid Plaque-RADS Classification Improves Risk Stratification for Ischemic Cerebrovascular Events

In this AJNR Article Summary, Dr. George Vilanilam discusses the article, "Maximizing the Conspicuity of Cerebrospinal Fluid–Venous Fistulas on Computed Tomography Myelography: Assessment of Contrast Density and Timing Effects." Contrast density, not just timing, plays the dominant role in detecting CSF-venous fistulas, with higher subarachnoid contrast significantly improving diagnostic confidence. These findings support prioritizing contrast pooling strategies during CT myelography to enhance fistula detection in patients with spontaneous intracranial hypotension.

In this AJNR Article Summary, Dr. George Vilanilam discusses the article, "Risk Stratification for Traumatic Subarachnoid Hemorrhage Enlargement and Surgical Intervention: Guides to Follow-Up Imaging in Patients with Trauma." Not all traumatic subarachnoid hemorrhages behave the same - risk factors such as coagulopathy, concurrent intracranial hemorrhage, and low Glasgow Coma Scale scores predict hemorrhage progression and need for intervention. A risk-stratified imaging approach may reduce unnecessary repeat CT scans while focusing surveillance on patients most likely to deteriorate.

In this AJNR Author Interview, Dr. Francis Deng speaks with Dr. Cynthia Greene about her article, "Posttreatment Follow-Up MR Imaging Biomarkers of Collateral Status Are Associated with Short-Term Outcomes in Large-Vessel Acute Ischemic Stroke." In a retrospective study of follow-up MRI after anterior-circulation large-vessel occlusion stroke, a greater burden of FLAIR hyperintense vessels was associated with worse short-term neurologic outcomes, even among successfully reperfused patients, suggesting persistent FLAIR hyperintense vessels may mark ongoing perfusion abnormality or possible no-reflow physiology.

In this AJNR Author Interview, Dr. Francis Deng speaks with Dr. Jimmy Moon about his article, "Use of CTA in Strangulation Evaluation". In a retrospective review, the yield of CTA neck for blunt cerebrovascular injury in patients who presented after strangulation was 1 in 138 (0.7%), suggesting the broad use of CTAs in this setting may be of low value.

In this AJNR Podcast Author Interview, Dr. Francis Deng and Dr. Amy Juliano discuss how CT can subtype Menière disease by assessing the vestibular aqueduct and adjacent bone. During normal childhood, the angular trajectory of the vestibular aqueduct progressively narrows; an angle greater than 120 degrees after age 12 indicates adult-persistent hypoplasia and thus the hypoplastic endolymphatic sac endotype rather than normal maturation. A retrolabyrinthine bone thickness of at least 1.2 mm serves as a practical surrogate for a mature vestibular aqueduct orientation, reliably excluding the hypoplastic endotype and identifying ears that do not belong to this high-risk subgroup. In contrast, in the degenerative endotype of Menière disease, retrolabyrinthine bone thickness is more variable and does not follow this simple threshold pattern, so CT features must be interpreted in a broader clinical and imaging context. Read the AJNR articles mentioned in this episode: "Postnatal Development of the Vestibular Aqueduct Trajectory on CT: Establishing Age-Specific Norms to Distinguish Normal from Arrested (Hypoplastic) Development" "Retrolabyrinthine Bone Thickness as a Radiologic Marker for the Hypoplastic Endotype in Menière Disease".