When is a staging scan required for newly diagnosed brain lesions on CT? A multivariate logistic regression analysis.

PURPOSE: For patients with a new lesion on CT head (CTH) suspected to be a brain tumor, a staging chest, abdomen, and pelvis CT (CTCAP) is only warranted if a metastatic lesion is suspected. Unnecessary CTCAPs are often performed too early in a patient's journey due to poor patient selection. We sought to create a protocol to guide the selection of patients for CTCAPs based on their CTH findings. METHODS: Patients with suspected new brain tumors discussed at the neuro-oncology MDT at a tertiary neurosurgical center were reviewed. Patient demographics and CTH features were collected. For protocol creation, data was collected from July to December 2020, and predictor variables were identified using multivariate logistic regression. Candidate protocols were assessed in a protocol testing stage using similar data collected from January to June 2021. Sensitivity, specificity, and area under the curve (AUC) were computed for each protocol. RESULTS: Variables from the protocol creation stage (222 patients) were assessed in the protocol testing stage (216 patients). The most sensitive variables predicting metastatic disease were a previous history of cancer, multiple lesions, lesion < 4 cm, and infratentorial location. A protocol recommending a CTCAP based on the presence of one of these features has a sensitivity of 99.1% (AUC 0.704). CONCLUSIONS: Unnecessary CTCAPs are reduced if performed only if a patient has one of the four identified predictor variables.

Dynamic imaging of the craniovertebral junction is mandatory in patients with posterior circulation strokes.

INTRODUCTION: The course of the vertebral artery after exiting from the C1 foramen transversarium and prior to entering the dura lends itself to compression in C1-2 instability. However, atlantoaxial dislocation presenting with vertebrobasilar insufficiency and posterior circulation stroke (PCS) is rare. METHODS: In this retrospective study, we identified 96 patients with PCS who had complete radiological data. Ten (10.4%) patients had craniovertebral junction (CVJ) anomalies, of which six underwent surgery and four were managed conservatively. The clinical and functional outcomes were measured in the two groups. RESULTS: Left-sided strokes were seen in 7/10 patients, the majority of whom had left dominant vertebral arteries. The mean age at presentation in those with CVJ anomalies was 27.2 ± 12.8 years that was significantly lower than those without CVJ anomalies, 52.2 ± 14.5 years (p ≤ 0.001). The etiologies of PCS in those < 50 years were CVJ anomalies (30%), atherosclerosis (30%) and vasculitis (27%); however, the overwhelming majority of strokes in the > 50 year age group was atherosclerosis (91%). Postoperatively, there were no recurrent strokes in the operated patients, who also obtained significant clinical improvement on the modified Rankin Scale, Nurick Scale and modified McCormick Scale as compared to those who did not undergo surgery. CONCLUSION: Early diagnosis and surgical treatment of CVJ instability prevent recurrent strokes and improve outcomes in patients with PCS. Physicians and spine surgeons need to be sensitized regarding CVJ anomalies as a cause of PCS enabling early diagnosis with dynamic imaging particularly in the younger age group. These slides can be retrieved under Electronic Supplementary Material.