Nafi Aygun

Purpose Surgical resection is considered standard of care for primary intramedullary astrocytomas, but the infiltrative nature of these lesions often precludes complete resection without causing new post-operative neurologic deficits. Radiotherapy and chemotherapy serve as potential adjuvants, but high-quality data evaluating their efficacy are limited. Here we analyze the experience at a single comprehensive cancer center to identify independent predictors of postoperative overall and progression-free survival. Methods Data was collected on patient demographics, tumor characteristics, pre-operative presentation, resection extent, long-term survival, and tumor progression/recurrence. Kaplan–Meier curves modeled overall and progression-free survival. Univariable and multivariable accelerated failure time regressions were used to compute time ratios (TR) to determine predictors of survival. Results 94 patients were included, of which 58 (62%) were alive at last follow-up. On multivariable analysis, older age (TR = 0.98; p = 0.03), higher tumor grade (TR = 0.12; p < 0.01), preoperative back pain (TR = 0.45; p < 0.01), biopsy [vs GTR] (TR = 0.18; p = 0.02), and chemotherapy (TR = 0.34; p = 0.02) were significantly associated with poorer survival. Higher tumor grade (TR = 0.34; p = 0.02) and preoperative bowel dysfunction (TR = 0.31; p = 0.02) were significant predictors of shorter time to detection of tumor growth. Conclusion Tumor grade and chemotherapy were associated with poorer survival and progression-free survival. Chemotherapy regimens were highly heterogeneous, and randomized trials are needed to determine if any optimal regimens exist. Additionally, GTR was associated with improved survival, and patients should be counseled about the benefits and risks of resection extent.

Purpose: Measurement of global spinal alignment (GSA) is an important aspect of diagnosis and treatment evaluation for spinal deformity but is subject to a high level of inter-reader variability. Approach: Two methods for automatic GSA measurement are proposed to mitigate such variability and reduce the burden of manual measurements. Both approaches use vertebral labels in spine computed tomography (CT) as input: the first (EndSeg) segments vertebral endplates using input labels as seed points; and the second (SpNorm) computes a two-dimensional curvilinear fit to the input labels. Studies were performed to characterize the performance of EndSeg and SpNorm in comparison to manual GSA measurement by five clinicians, including measurements of proximal thoracic kyphosis, main thoracic kyphosis, and lumbar lordosis. Results: For the automatic methods, 93.8% of endplate angle estimates were within the inter-reader 95% confidence interval (CI₉₅). All GSA measurements for the automatic methods were within the inter-reader CI₉₅, and there was no statistically significant difference between automatic and manual methods. The SpNorm method appears particularly robust as it operates without segmentation. Conclusions: Such methods could improve the reproducibility and reliability of GSA measurements and are potentially suitable to applications in large datasets—e.g., for outcome assessment in surgical data science.

BACKGROUND AND PURPOSE: The DESH (disproportionately enlarged subarachnoid-space hydrocephalus) pattern of “tight high-convexity and medial subarachnoid spaces, and enlarged Sylvian fissures with ventriculomegaly” is used to determine which patients undergo an operation for adult hydrocephalus at many centers. Our aim was to review adult hydrocephalus cases when DESH has not been a criterion for an operation to determine the prevalence of DESH among the cohort and compare the surgical outcomes in the presence or absence of DESH. MATERIALS AND METHODS: A retrospective cohort study was conducted at a single institution (Johns Hopkins Hospital) to include patients surgically treated for adult hydrocephalus between 2003 and 2014 drawn from a data base of patients who had undergone standardized hydrocephalus protocol MR imaging. Preoperative imaging was reviewed by 2 blinded neuroradiologists to characterize the presence of DESH. Preoperative and postoperative clinical symptomatology was recorded. Frequencies were compared using the Fisher exact test, and nonparametric means were compared using the Mann-Whitney U Test. RESULTS: One hundred thirty-three subjects were identified and included (96 DESH absent, 37 DESH present). Shunting led to significant improvement in gait and urinary and cognitive symptoms for the overall cohort and for patients with and without DESH (P < .05). The Fisher exact test did not demonstrate any significant differences in either gait or urinary or cognitive symptom improvement between patients with or without DESH (P > .05). CONCLUSIONS: The current study demonstrated symptom improvement in patients with adult hydrocephalus following shunting, with no significant differences between subjects with and without DESH. Thus, shunt insertion for patients with adult hydrocephalus should not rely solely on the presence of preoperative DESH findings.

BACKGROUND AND PURPOSE: Thin-section MR imaging through the posterior fossa is frequently used for trigeminal neuralgia. Typical heavily T2-weighted imaging methods yield high anatomic detail and contrast between CSF and neurovascular structures, but poor contrast between vessels and nerves. We hypothesized that the addition of gadolinium-based contrast material to 3D-constructive interference in steady-state imaging would improve the characterization of trigeminal compression. MATERIALS AND METHODS: Retrospective review of high-resolution MRIs was performed in patients without prior microvascular decompression. 3D-CISS imaging without contrast and with contrast for 81 patients with trigeminal neuralgia and 15 controls was intermixed and independently reviewed in a blinded fashion. Cisternal segments of both trigeminal nerves were assessed for the grade of neurovascular conflict, cross-sectional area, and degree of flattening. Data were correlated with symptom side and pain relief after microvascular decompression using the Fisher exact test, receiver operating curve analysis, and a paired t test. RESULTS: Contrast-enhanced CISS more than doubled the prevalence of the highest grade of neurovascular conflict (14.8% versus 33.3%, P = .001) and yielded significantly lower cross-sectional area (P = 8.6 × 10⁻⁶) and greater degree of flattening (P = .02) for advanced-grade neurovascular conflict on the symptoms side compared with non-contrast-enhanced CISS. Patients with complete pain relief after microvascular decompression had significantly lower cross-sectional area on contrast-enhanced CISS compared with non-contrast-enhanced CISS on preoperative imaging (P = 2.0 × 10⁻⁷). Performance based on receiver operating curve analysis was significantly improved for contrast-enhanced CISS compared with non-contrast-enhanced CISS. CONCLUSIONS: The addition of contrast material to 3D-CISS imaging improves the performance of identifying unilateral neurovascular compression for symptomatic trigeminal neuralgia and predicting outcomes after microvascular decompression.

SUMMARY: SMARCB1 (INI1)-deficient sinonasal carcinomas were first described in 2014, and this series of 17 cases represents the first imaging description. This tumor is part of a larger group of SMARCB1-deficient neoplasms, characterized by aggressive behavior and a rhabdoid cytopathologic appearance, that affect multiple anatomic sites. Clinical and imaging features overlap considerably with other aggressive sinonasal malignancies such as sinonasal undifferentiated carcinoma, which represents a common initial pathologic diagnosis in this entity. SMARCB1 (INI1)-deficient sinonasal tumors occurred most frequently in the nasoethmoidal region with invasion of the adjacent orbit and anterior cranial fossa. Avid contrast enhancement, intermediate to low T2 signal, and FDG avidity were frequent imaging features. Approximately half of the lesions demonstrated calcification, some with an unusual “hair on end” appearance, suggesting aggressive periosteal reaction.

BACKGROUND AND PURPOSE: Patients with trigeminal neuralgia often undergo trigeminal rhizotomy via radiofrequency thermocoagulation or glycerol injection for treatment of symptoms. To date, radiologic changes in patients with trigeminal neuralgia post-rhizotomy have not been described, to our knowledge. The aim of this study was to evaluate patients after trigeminal rhizotomy to characterize post-rhizotomy changes on 3D high-resolution MR imaging. MATERIALS AND METHODS: A retrospective review of trigeminal neuralgia protocol studies was performed in 26 patients after rhizotomy compared with 54 treatment-na|fkve subjects with trigeminal neuralgia. Examinations were reviewed independently by 2 neuroradiologists blinded to the side of symptoms and treatment history. The symmetry of Meckel's cave on constructive interference in steady-state and the presence of contrast enhancement within the trigeminal nerves on volumetric interpolated breath-hold examination images were assessed subjectively. The signal intensity of Meckel's cave was measured on coronal noncontrast constructive interference in steady-state imaging on each side. RESULTS: Post-rhizotomy changes included subjective clumping of nerve roots and/or decreased constructive interference in steady-state signal intensity within Meckel's cave, which was identified in 17/26 (65%) patients after rhizotomy and 3/54 (6%) treatment-na|fkve patients (P < .001). Constructive interference in steady-state signal intensity within Meckel's cave was, on average, 13% lower on the side of the rhizotomy in patients posttreatment compared with a 1% difference in controls (P < .001). Small regions of temporal encephalomalacia were noted in 8/26 (31%) patients after rhizotomy and 0/54 (0%) treatment-na|fkve patients (P < .001). CONCLUSIONS: Post-trigeminal rhizotomy findings frequently include nerve clumping and decreased constructive interference in steady-state signal intensity in Meckel's cave. Small areas of temporal lobe encephalomalacia are encountered less frequently.