A Cystic Clival Chordoma with CT and MRI Unconventional Appearances.

We present the first case of clival cystic chordoma with extradural location, transdural transgression, and moderate bone involvement in a 10-year-old girl. Chordoma showed unconventional appearances on computed tomography (CT) and magnetic resonance imaging (MRI), due to cystic components, extradural space location with extensive intradural extension, moderate superficial bone involvement. Surgery confirmed the extradural location and histopathological examination revealed cystic chordoma. MRI and CT findings were not characteristic for a single lesion; differential diagnoses included cystic lesions such as epidermoid and dermoid cyst, ecchordosis physaliphora, and benign notochordal cell tumors.

Neuro-Oncology Multidisciplinary Tumor Board: The Point of View of the Neuroradiologist.

BACKGROUND: The multi-disciplinary tumor board (MTB) is essential to quality cancer care and currently recommended to offer the best personalized clinical approach, but little has been published regarding MTBs in neuro-oncology (nMTBs). The aim of the present paper is to describe our nMTB, to evaluate its impact on clinical management decisions, and to assess the role of neuroradiologists. METHODS: The retrospective evaluation of the cases discussed at our nMTB from March 2017 to March 2020. From the electronic records, we extracted epidemiological, clinical and other specific data of nMTB. From the radiological records, we calculated data relating to the number, time for revision, and other specifications of MRI re-evaluation. Statistical analysis was performed. RESULTS: a total of 447 discussions were analyzed, representing 342 patients. The requests for case evaluations came from radiation oncologists (58.8%) and neurosurgeons (40.5%), and were mainly addressed to the neuroradiologist (73.8%). The most frequent questions were about the treatment's changes (64.4%). The change in patient treatment was reported in 40.5% of cases, 76.8% of these were based on the neuroradiologic assessment. A total of 1514 MRI examinations were re-evaluated, employing approximately 67 h overall. The median of the MRI exams reviewed per patient was 3 (min-max 1-12). CONCLUSIONS: Our study supported that the multidisciplinary approach to patient care can be particularly effective in managing brain tumors. A review by an expert neuroradiologist impacts patient management in the context of nMTBs, but has costs in terms of the time and effort spent preparing for it.

ColorViz, a New and Rapid Tool for Assessing Collateral Circulation during Stroke.

Prognosis of patients with acute ischemic stroke is strictly related to the patency and prominence of the collateral leptomeningeal pathways distal to the arterial occlusion. The gold standard for assessment of collateral circulation is conventional angiography, but it is invasive and used in selected cases. To date, the most reliable technique is multiphase CTA; currently, the available classifications of collateral circles are often complex, time-consuming, and require a trained observer. The purpose of our work is to establish the effectiveness of a new semi-automatic post-processing software (ColorViz FastStroke, GE Healthcare, Milwaukee, Wisconsin) in evaluation of collateral circulation compared to the six-point classifications of multiphase CTA already validated in literature. We selected 86 patients with anterior ischemic stroke symptoms who underwent multiphasic CTA in our emergency department. Two radiologists separately evaluated the collateral leptomeningeal vessels, analyzing respectively, the multiphase CTA (using the six-point scale and its trichotomized form) and ColorViz (using a three-point scale). Then the results were matched. We found a good correlation between the two different analyses; the main advantage of ColorViz is that, while maintaining fast diagnostic times, it allows a simpler and more immediate evaluation of collateral circulation, especially for less experienced radiologists.

Role of susceptibility-weighted imaging and intratumoral susceptibility signals in grading and differentiating pediatric brain tumors at 1.5 T: a preliminary study.

PURPOSE: Susceptibility-weighted imaging (SWI) is useful for glioma grading and discriminating between brain tumor categories in adults, but its diagnostic value for pediatric brain tumors is unclear. Here we evaluated the usefulness of SWI for pediatric tumor grading and differentiation by assessing intratumoral susceptibility signal intensity (ITSS). METHODS: We retrospectively enrolled 96 children with histopathologically diagnosed brain tumors, who underwent routine brain MRI exam with SWI (1.5 T scanner). Each tumor was assigned an ITSS score by a radiology resident and an experienced neuroradiologist, and subsequently by consensus. Statistical analyses were performed to differentiate between low-grade (LG) and high-grade (HG) tumors, histological categories, and tumor locations. Inter-reader agreement was assessed using Cohen's kappa (κ). RESULTS: The interobserver agreement was 0.844 (0.953 between first reader and consensus, and 0.890 between second reader and consensus). Among all tumors, we found a statistically significant difference between LG and HG for ITSS scores of 0 and 2 (p = 0.002). This correlation was weaker among astrocytomas alone, and became significant when considering only off-midline astrocytomas (p = 0.05). Scores of 0 and 2 were a strong discriminating factor (p = 0.001) for astrocytomas (score 0) and for embryonal, choroid plexus, germ-cell, pineal, and ependymoma tumors (score 2). No medulloblastoma showed a score of 0. CONCLUSIONS: Our preliminary ITTS results in pediatric brain tumors somewhat differed from those obtained in adult populations. These findings highlight the potential valuable role of ITSS for tumor grading and discriminating between some tumor categories in the pediatric population.

Investigating dynamic susceptibility contrast-enhanced perfusion-weighted magnetic resonance imaging in posterior fossa tumors: differences and similarities with supratentorial tumors.

PURPOSE: To assess the accuracy of dynamic susceptibility contrast-enhanced perfusion-weighted magnetic resonance imaging in glioma grading and brain tumor characterization of infratentorial tumors, and to investigate differences from supratentorial tumors. METHODS: This retrospective study, approved by the institutional review board, included 246 patients with brain tumors (184 supratentorial, 62 infratentorial), grouped by tumor type: high-grade gliomas (HGG), low-grade gliomas (LGG), metastases (Met), and primary central nervous system lymphoma (PCNSL). Relative cerebral blood volume (rCBV) and mean percentage of signal recovery (PSR) were calculated. For statistical analyses, lesions were grouped by location and histology. Differences were tested with Mann-Whitney U tests. From ROC curves, we calculated accuracy, sensitivity, specificity, PPV, and NPV, for rCBV and PSR. RESULTS: For infratentorial tumors, rCBV was highly accurate in differentiating HGG from LGG (AUC = 0.938). Mean PSR showed high accuracy in differentiating PCNSL and HGG from Met (AUC = 0.978 and AUC = 0.881, respectively). Infratentorial and supratentorial tumors had similarly high rCBV in HGG, high mean PSR in PCNSL, and low mean PSR in Met. The main differences were the optimum threshold rCBV values (3.04 for supratentorial, 1.77 for infratentorial tumors) and the mean PSR, which was significantly higher in LGG than in HGG in supratentorial (p = 0.035), but not infratentorial gliomas. Using infratentorial rCBV threshold values for supratentorial tumors decreased the sensitivity and specificity. CONCLUSION: rCBV and mean PSR were useful in grading and differentiating infratentorial tumors. Proper cutoff values were important in the accuracy of perfusion-weighted imaging in posterior fossa tumors.