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Objective: We compared the diameter of the jugular foramen (JF) between normal individuals and those with a diagnosis of craniovertebral junction abnormalities, such as Chiari malformation type I (CMI) and/or basilar invagination (BI)., Methods: This cross-sectional analytical study measured the diameter of the right and left JF on magnetic resonance imaging scans of patients divided into 4 groups: 68 with combined CMI and BI (CMI+BI), 42 with isolated BI, 45 with isolated CMI, and 102 control cases. The t test determined sex differences, and univariate analysis of variance with Tukey's post hoc test assessed JF differences between groups., Results: Considering all combinations of laterality and sex, the CMI+BI group had a JF narrower than their respective control groups. The JF was bilaterally narrower in the BI group than in the control group only in the women. Regardless of laterality, the CMI group had a wider JF than did the CMI+BI group in men and did not differ from that of the control group. In the female patients with CMI, the right JF did not differ from that of the controls and was wider than that in the CMI+BI group. Also, the left JF was narrower than that in the control group and did not differ from that in the CMI+BI group., Conclusions: JF narrowing is associated with CMI and BI when combined in the same patient. When CMI or BI are detected separately, they do not imply evident changes in JF morphometry. It is expected that these findings could bring empiric substrate to support theories that claim a possible role of intracranial pressure disturbances as a triggering factor for CMI., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The cerebellar tonsil tip position (TP) is a common parameter used for the radiologic diagnosis of Chiari malformation type 1 (CM1). However, these paramedian structures are usually not properly visualized in the midsagittal section. Such mismatch may be a source of bias in TP measurements based on the McRae line (ML) traced between median craniometric points. This study aims to evaluate the intraoperator and interoperator reliability and agreement of 2 protocols to trace the ML in magnetic resonance imaging (MRI) for the cerebellar tonsil tip localization, adding a 3-dimensional multiplanar reconstruction (MPR) approach to the midsagittal plane., Methods: Sixty-two T1-weighted head MRIs were obtained for 32 CM1 patients and 30 controls. Two operators independently applied 2 TP measurement protocols, one considering only the visualization of the sagittal plane and the other using MPR. The intraclass correlation coefficient was used to assess intraoperator and interoperator reliability, and the Bland-Altman graphical method was used to evaluate the agreement between the measurement protocols., Results: The sagittal method significantly underestimated ML and tonsillar herniation when compared with the MPR method. The MPR method provided better reliability of the ML measurement when compared to the sagittal method, but this did not influence the reliability of the TP. Analysis of the Bland-Altman plot showed that the limits of agreement were close to acceptable for the ML, but not for measures of TP., Conclusions: The standardization of the LM tracing by the MPR method improves the acquisition of data regarding the position of the tonsils., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: We sought to compare the diagnostic accuracy of cephalic indices for type B basilar invagination (BI)., Methods: This retrospective study examined head and neck magnetic resonance imaging sequences of 31 Group B BI cases and 96 controls. Two examiners blinded to diagnostic data evaluated the cephalic indices of each magnetic resonance imaging sequence, described as width/length (WLI) and height/width (HWI). The distance of the odontoid process apex to Chamberlain line and clivus canal angle were measured. The interexaminer and intraexaminer reproducibility of the cephalic indices was calculated using intraclass correlation coefficient. The diagnostic accuracy was discerned by the receiver operating characteristic (ROC) curve. All analyses were scrutinized with a 95% confidence interval., Results: Cephalic indices showed interexaminer and intraexaminer reproducibility ≥94%. The areas under the ROC curve were 0.639 (WLI) and 0.874 (HWI) (95% confidence interval: P < 0.05). The HWI showed a sensitivity of 74.7% and a specificity of 85.5% for the cutoff criterion ≤58. The WLI presented a sensitivity of 53.3% and a specificity of 66.7% for the cutoff criterion ≥86., Conclusions: The HWI showed the largest area under the ROC curve in comparison with the WLI, with robust sensitivity and specificity values, indicating that the proportions between cranial height and width can help clinicians in investigating type B BI., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: To describe the foramen magnum angle (FMA) as a new parameter for basilar invagination (BI) type B., Methods: The FMA was performed on sagittal slice of magnetic resonance imaging (MRI) as a line from the hard palate to the opisthion (angle vertex), and another line from the opisthion to the basion. The MRIs from 31 participants with BI type B and 96 controls were used. Intraclass correlation coefficient, descriptive data, and receiver operating characteristic (ROC) curve were used for statistical analysis at the 95% confidence interval., Results: The interobserver agreement of the FMA was 0.952. Patients with BI type B had a FMA significantly greater (25.9° ± 9.3°) than control participants (11.6° ± 4.9°) (P < 0.001). The area under the ROC curve showed a diagnostic value of 0.947. The FMA showed sensitivity 0.900 and specificity 0.854 for the cutoff criterion 17° (P < 0.001)., Conclusions: The FMA had an optimal diagnostic value that provided complementary evidence to investigate BI type B., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: To determine the optimal number of adult intensive care unit beds to reduce patient's queue waiting time and to propose policy strategies., Methods: Multimethodological approach: (a) quantitative time series and queueing theory were used to predict the demand and estimate intensive care unit beds in different scenarios; (b) qualitative focus group and content analysis were used to explore physicians' attitudes and provide insights into their behaviors and belief-driven healthcare delivery changes., Results: A total of 33,101 requests for 268 regulated intensive care unit beds in one year resulted in 25% admissions, 55% queue abandonment and 20% deaths. Maintaining current intensive care unit arrival and exit rates, there would need 628 beds to ensure a maximum wait time of six hours. A reduction of the current abandonment rates due to clinical improvement or the average intensive care unit length of stay would decrease the number of beds to 471 and 366, respectively. If both were reduced, the number would reach 275 beds. The interviews generated 3 main themes: (1) the doctor's conflict: fair, legal, ethical and shared priorities in the decision-making process; (2) a failure of access: invisible queues and a lack of infrastructure; and (3) societal drama: deterioration of public policies and health care networks., Conclusion: The queue should be treated as a complex societal problem with a multifactorial origin requiring integrated solutions. Improving intensive care unit protocols and reengineering the general wards may decrease the length of stay. It is essential to redefine and consolidate the regulatory centers to organize the queue and provide available resources in a timely manner, by using priority criteria, working with stakeholders to guarantee clinical governance and network organization.

Background: Basilar invagination (BI) is an abnormality characterized by a superior projection at the craniovertebral junction (CVJ). The high prevalence of BI in Northeastern Brazil associated with brachycephaly, which is measured by the cranial index (CI), has been widely reported by several neurosurgeons and radiologists from that region since the 1950s. However, strong evidence for this relationship is still pending. The aim of this study is to investigate whether there is a relationship between BI and CI in a sample with participants from Northeastern Brazil., Methods: The study used magnetic resonance images (MRIs) from 34 patients with BI and 92 controls. These participants had the CI correlated with radiological measurements used in BI diagnosis: Welcker's basal angle (WBA), clivus-canal angle (CCA), apex distance of the odontoid process to Chamberlain's line (DOCL), and Boogaard's angle (BOA). Craniometry was performed using the software Osirix, version 3.9.2 and statistical analysis by SPSS. We used Pearson's test for correlation analysis and the ROC curve was used for depicting CI accuracy related to BI diagnosis. All tests were calculated at the 95% confidence interval., Results: The BI group showed a moderate correlation between CI and CVJ measurements (P < 0.05). The control group had a weak correlation between CI and DOCL, and no statistical significance was verified for other correlations (P > 0.05). The area under the ROC was 0.659 and a CI greater than 86 had a specificity of approximately 80% for BI (P = 0.002)., Conclusions: The results indicated a greater cephalic projection of the CVJ in patients with high CI in the BI group. Moreover, a CI above 86 has a good diagnosis specificity for BI, showing evidence of a relationship between hyperbrachycephaly and CVJ anomalies in Northeastern Brazil., (Copyright © 2018 Elsevier B.V. All rights reserved.)