Multi-center application of a convolutional neural network for preoperative detection of cavernous sinus invasion in pituitary adenomas.

OBJECTIVE: Cavernous sinus invasion (CSI) plays a pivotal role in determining management in pituitary adenomas. The study aimed to develop a Convolutional Neural Network (CNN) model to diagnose CSI in multiple centers. METHODS: A total of 729 cases were retrospectively obtained in five medical centers with (n = 543) or without CSI (n = 186) from January 2011 to December 2021. The CNN model was trained using T1-enhanced MRI from two pituitary centers of excellence (n = 647). The other three municipal centers (n = 82) as the external testing set were imported to evaluate the model performance. The area-under-the-receiver-operating-characteristic-curve values (AUC-ROC) analyses were employed to evaluate predicted performance. Gradient-weighted class activation mapping (Grad-CAM) was used to determine models' regions of interest. RESULTS: The CNN model achieved high diagnostic accuracy (0.89) in identifying CSI in the external testing set, with an AUC-ROC value of 0.92 (95% CI, 0.88-0.97), better than CSI clinical predictor of diameter (AUC-ROC: 0.75), length (AUC-ROC: 0.80), and the three kinds of dichotomizations of the Knosp grading system (AUC-ROC: 0.70-0.82). In cases with Knosp grade 3A (n = 24, CSI rate, 0.35), the accuracy the model accounted for 0.78, with sensitivity and specificity values of 0.72 and 0.78, respectively. According to the Grad-CAM results, the views of the model were confirmed around the sellar region with CSI. CONCLUSIONS: The deep learning model is capable of accurately identifying CSI and satisfactorily able to localize CSI in multicenters.

Predictive value of cyst/tumor volume ratio of pituitary adenoma for tumor cell proliferation.

BACKGROUND: MRI has been widely used to predict the preoperative proliferative potential of pituitary adenoma (PA). However, the relationship between the cyst/tumor volume ratio (C/T ratio) and the proliferative potential of PA has not been reported. Herein, we determined the predictive value of the C/T ratio of PA for tumor cell proliferation. METHODS: The clinical data of 72 patients with PA and cystic change on MRI were retrospectively analyzed. PA volume, cyst volume, and C/T ratio were calculated. The corresponding intraoperative specimens were collected. Immunohistochemistry and hematoxylin-eosin staining were performed to evaluate the Ki67 index and nuclear atypia. Patients were categorized according to the Ki67 index (< 3% and ≥ 3%) and nuclear atypia (absence and presence). Univariate and multivariate analyses were used to identify the significant predictors of the Ki67 index and nuclear atypia. The receiver operating characteristic curve assessed the prediction ability of the significant predictors. RESULTS: Larger tumor volumes, smaller cyst volumes, and lower C/T ratios were found in patients with higher Ki67 indexes and those with nuclear atypia (P < 0.05). C/T ratio was an independent predictor of the Ki67 index (odds ratio = 0.010, 95% confidence interval = 0.000-0.462) and nuclear atypia (odds ratio = 0.010, 95% confidence interval = 0.000-0.250). The predictive value of the C/T ratio did not differ significantly from that of tumor volume (P > 0.05) but was better than that of cyst volume (P < 0.05). The area under the curve of the C/T ratio for predicting the Ki67 index and nuclear atypia was larger than that for predicting cyst volume and tumor volume. CONCLUSIONS: C/T ratios can be used to predict PA tumor proliferation preoperatively. Our findings may facilitate the selection of surgery timing and the efficacy evaluation of surgery.

Association between Lipid-Lowering Drugs and Traumatic Subdural Hemorrhage: A Mendelian Randomization Study.

BACKGROUND: There are current clinical observations that atorvastatin may promote subdural hematoma resorption. We aimed to assess the causal effects of lipid-lowering agents 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) inhibitors, Proproteinconvertase subtilisin/kexin type 9 (PCSK9) inhibitors and Niemann-Pick C1-like protein 1 (NPC1L1) inhibitors on traumatic subdural hematomas. METHODS: We used genetic instruments to proxy lipid-lowering drug exposure, with genetic instruments being genetic variants within or near low-density lipoprotein (LDL cholesterol)-associated drug target genes. These were analyzed by using a two-sample Mendelian randomization (MR) study. RESULTS: A causal relationship was found between HMGCR inhibitors and traumatic subdural hematoma (Inverse variance weighted (ß = -0.7593341 (Odds Ratio (OR) = 0.4679779), p = 0.008366947 < 0.05)). However, no causal relationship was found between PCSK9 inhibitors and NPC1L1 inhibitors and traumatic subdural hematoma (PCSK9 inhibitors: Inverse variance weighted (ß = 0.23897796 (OR = 1.2699505), p = 0.1126327), NPC1L1 inhibitors: Inverse variance weighted (ß = -0.02118558 (OR = 0.9790373), p = 0.9701686)). Sensitivity analysis of the data revealed good stability of the results. CONCLUSIONS: This two-sample MR study suggests a potential causal relationship between HMGCR inhibition (atorvastatin) and traumatic subdural hemorrhage.

Analysis of MRI features and associated factors of the pituitary neuroendocrine tumor streaky sign.

OBJECTIVES: Observation of pituitary neuroendocrine tumors with streaky sign on MRI, analysis of their features on imaging and further investigation of the relationship between the direction of the streak sign and the direction of optimal tumor expansion. METHODS: The MR images of 237 patients with pituitary neuroendocrine tumors were retrospectively analyzed. The streaky-like high signal with a substantial length of more than 10 mm and obvious enhancement on T1WI was defined as the streaky sign. Finally, 66 patients were included in the study, comprising 33 patients with streaky sign pituitary neuroendocrine tumors and 33 randomly selected patients with non-streaky sign pituitary neuroendocrine tumors. The general condition of these 66 patients, the imaging features of the tumor, and the measurement and analysis of the direction of the streaky sign in relation to the direction of optimal tumor extension were observed and analyzed. RESULTS: On MRI, 85 streaky signs were observed. The average deviation between the direction angle of all the streaky signs and the optimal extension direction angle of the tumor was approximately 11°. The longest streaky sign angle was positively correlated with the optimal extension angle of the tumor, with a correlation coefficient of 0.967. CONCLUSION: The presence of a streaky sign of pituitary neuroendocrine tumors may indicate a dilated sinus or a small blood vessel. Its direction is highly consistent with the optimal extension direction of the tumor, which has a certain supporting effect on the long-distance growth of the tumor.

Pre- and Postoperative Magnetic Resonance Imaging Comparative Studies of Pituitary Tissues Following Transsphenoidal Resection of Pituitary Macroadenomas.

BACKGROUND: Magnetic resonance imaging (MRI) has become the most important radiological procedure for diagnosing and following pituitary tumors. But previous MRI studies on pituitary adenomas are mainly focused on the posterior pituitary. Few research has been done on residual normal pituitary tissue before and after transsphenoidal surgery. This retrospective cohort study investigates the pre- and postoperative magnetic resonance imaging characteristics of normal pituitary tissues regarding transsphenoidal resection of pituitary macroadenomas. METHODS: Pre- and postoperative magnetic resonance imaging scanning of 112 consecutive pituitary macroadenoma patients who underwent tumor resection via transsphenoidal approach was performed, and their medical records were studied. RESULTS: On preoperative MRI, 66 cases of pituitary stalks were identifiable, 9 of them were roughly in the middle, and 57 cases showed left or right deviation, with the angle between pituitary stalks and the sagittal plane was 5.32°-64.05° (average 21.65°). Among the 57 patients with preoperative pituitary stalk deviation, 55 of the pituitary stalk deviations improved in 1 week after surgery, and 30 cases were almost in the middle in 4-6 months after operation, with the other cases get better in varying degrees. The diameter of pituitary stalk was 1.08-3.89 mm (mean 2.36 mm) in pre-operation, and 1.29-3.43 mm (mean 2.30 mm) in 4-6 months after operation. The length of pituitary stalk was 1.41-11.74 mm (mean 6.12 mm) preoperatively, 3.61-11.63 mm (mean 6.93 mm) early postoperatively, and 5.37-17.57 mm (mean 8.83 mm) in 4-6 months after operation. Pituitary stalk was thickened or compressed on preoperative MR images, and gradually recovered to normal during postoperative period. It tended to be in the middle position and its length increased gradually until 4-6 months after operation. On preoperative MRI, 69 out of 112 patients showed residual pituitary tissues (RPT)(+) on enhanced MRI. RPT were likely located above the adenomas in somatotroph adenoma patients. Morphological restitution of postoperative normal pituitary tissues was better in lateral displacement than in superior or superolateral patterns on preoperative magnetic resonance imaging. Postoperative normal pituitary tissues usually subsided directly in superior displacement pattern on preoperative MRI, while were likely to be confined in the lateral side in lateral and superolateral displacement patients. Postoperative morphologic remodeling grade of RPT was positively correlated with the maximum diameter of pituitary adenoma (p = 0.000), but not with age. CONCLUSIONS: The larger the tumor diameter, the worse the pituitary morphological recovery after tumor resection. Relative locations of normal pituitary and adenoma tissues may be related to adenoma type and may affect postoperative reconstruction of residual normal pituitary tissues. These findings enable surgeons to distinguish pituitary tissue from residual or recurring tumor tissue on postoperative magnetic resonance imaging.

A novel rat model for cerebral venous sinus thrombosis: verification of similarity to human disease via clinical analysis and experimental validation.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is a rare neurovascular disorder with highly variable manifestations and clinical courses. Animal models properly matched to the clinical form of CVST are necessary for elucidating the pathophysiology of the disease. In this study, we aimed to establish a rat model that accurately recapitulates the clinical features of CVST in human patients. METHODS: This study consisted of a clinical analysis and animal experiments. Clinical data for two centres obtained between January 2016 and May 2021 were collected and analysed retrospectively. In addition, a Sprague-Dawley rat model of CVST was established by inserting a water-swellable rubber device into the superior sagittal sinus, following which imaging, histological, haematological, and behavioural tests were used to investigate pathophysiological changes. Principal component analysis and hierarchical clustering heatmaps were used to evaluate the similarity between the animal models and human patients. RESULTS: The imaging results revealed the possibility of vasogenic oedema in animal models. Haematological analysis indicated an inflammatory and hypercoagulable state. These findings were mostly matched with the retrospective clinical data. Pathological and serological tests further revealed brain parenchymal damage related to CVST in animal models. CONCLUSIONS: We successfully established a stable and reproducible rat model of CVST. The high similarity between clinical patients and animal models was verified via cluster analysis. This model may be useful for the study of CVST pathophysiology and potential therapies.

Diagnostic value of Knosp grade and modified Knosp grade for cavernous sinus invasion in pituitary adenomas: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to examine the reliability of existing Knosp grade (KG) and modified KG for cavernous sinus invasion (CSI). METHODS: A thorough search of literature from 1993 to 2020 in six databases was performed. Studies that reported the intraoperative confirmation of CSI using KG and/or modified KG were included. The pooled estimates were calculated by meta-analysis with a bivariate mixed-effect model and the assessment of heterogeneity with I2 statistic. RESULTS: The final search yielded 12 eligible studies, which enrolled 3006 patients assessed with KG and 1315 patients assessed with modified KG. The results of the area under the receiver operating characteristic curve showed the good discriminative abilities of grades 2-4 (0.90), 3-4 (0.86) and 3B-4 (0.91) in predicting CSI. Grade 3A showed a remarkably lower CSI rate (44% versus 81%) and incomplete resection rate (26% versus 52%) than grade 3B. Grades 0 and 1 showed a low CSI rate. CSI and incomplete resection rates in grade 2 (30% and 21%, respectively) were close to those in grade 3A. CONCLUSIONS: Modifying the KG improved its prognostic role in CSI and gross total resection. However, these grading systems cannot be used as the group standard for invasive and non-invasive pituitary adenomas (PAs) because of the weak reliability of the scale's middle grades (grades 2 and 3A). Authors of future PA studies should consider reporting KG as high (grades 3B and 4), medium (grades 2 and 3A) and low (grades 0 and 1) to optimise the application of the scale.

Diaphragma sellae sinking can predict the onset of hyponatremia after transsphenoidal surgery for pituitary adenomas.

PURPOSE: Sinking of the diaphragma sellae (DS) may stretch the pituitary stalk, which in turn impairs neurohypophyseal function; thus, it may play a role in the development of postoperative hyponatremia. We aimed to assess the factors influencing the development of hyponatremia after transsphenoidal surgery (TSS) for pituitary adenomas and analyze the effect of DS sinking on hyponatremia. METHODS: After applying the inclusion and exclusion criteria, we retrospectively analyzed the clinical data of patients with pituitary adenoma who underwent TSS. The pituitary gland was scanned using a 3.0-T magnetic resonance imaging, and sagittal and coronal images were acquired. We evaluated the following: preoperative and postoperative hypothalamus‒pituitary‒thyroid axis function, hypothalamus‒pituitary‒adrenal axis function, intra-operative cerebrospinal fluid leaks, diabetes insipidus, hyponatremia, time from the day of surgery to the day of discharge, and time of hyponatremia onset. RESULTS: Of the 460 patients who had microscopic TSS for pituitary adenoma, 83 experienced postoperative hyponatremia. Hyponatremia occurred approximately 5.25 days postoperatively and persisted for 5.54 days. The lowest average blood sodium level was 123.9 mEq/L, which occurred at 7.49 days after surgery. Logistic regression analysis showed that the risk of hyponatremia was greater for patients with a significant DS sinking depth, a large pituitary stalk deviation angle difference, and a longer postoperative "measurable pituitary stalk". The difference in blood sodium levels between pre-TSS and 2 days post-TSS was also an independent predictor of postoperative hyponatremia onset. CONCLUSION: DS sinking plays an important role in predicting hyponatremia onset after TSS for pituitary adenomas.

The Correlative Factors and Probable Mechanism of Epidural Fluid Collection After Cranioplasty.

OBJECTIVE: Epidural fluid collection (EFC) is one of the postoperative complications of cranioplasty and is easily ignored. Not only the predictive factors of EFC formation are unknown, the pathologic mechanisms are also unknown. We determined to analyze the predictive factors and the mechanism of EFC formation. METHODS: A total of 340 patients underwent cranioplasty were retrospectively analyzed in this study. A series of factors were compared in the EFC and none-EFC groups and farther compared in the progress epidural fluid collection (PEFC) and none-PEFC subgroups to determine the predictive factors. The t test, χ test, and logistic regression analysis were used in statistical analysis. RESULTS: The rate of EFC formation was 34.41%, and the size of skull defect, preoperative volume of collapse, intraoperative dura suspending, a pre- or intraoperative ventriculoperitoneal shunt (V-P shunt), and an postoperative air bubble in epidural space were predictive factors for EFC formation. Furthermore, the incidence of PEFC was 10.29%, the size of skull defects and intraoperative dura suspending were predictive factors for PEFC formation. The protein ratio and lactate dehydrogenase (LDH) ratio of effusion to serum were >0.5 and 0.6, respectively. There was no adverse prognosis. CONCLUSIONS: Although EFC can be treated with conservative therapy, we need to emphasize EFC incidence and development. As neurosurgeons, it is necessary to analyze the preoperative predictive factors of EFC, pay attention to the intraoperative details such as dura suspending to prevent PEFC formation, and the early intervention should be performed in the postoperative.

Endothelial cell-specific molecule-1 as an invasiveness marker for pituitary null cell adenoma.

BACKGROUND: Endothelial cell-specific molecule-1 (ESM-1) is a biomarker associated with tumor progression in pituitary adenoma. We specifically focused on one type of pituitary adenoma, namely null cell adenoma (NCA) and evaluated the relationship between invasion and ESM-1 expression in both vascular endothelial and adenoma tissues. METHODS: Tissue samples from 94 patients with pituitary NCA were obtained through microscopic transsphenoidal resection. Tumor size and invasion were determined through preoperative magnetic resonance imaging. Immunohistochemical staining was performed to detect ESM-1 expression. ESM-1 index of ≥3 was defined as high expression. RESULTS: Signs of invasion were observed in 46 (47.9%) of the 94 patients. Significant differences were observed in the invasion state and maximum tumor diameter between high and low expression of ESM-1 in vascular endothelial tissues (both P < 0.05). Significant positive associations were noted between ESM-1 expression in vascular endothelial tissues and tumor invasion (P = 0.002) and tumor size (P = 0.020). However, only tumor size was associated with ESM-1 expression in adenoma tissues (P = 0.016). CONCLUSION: In NCA, a significant positive association between tumor invasion and ESM-1 expression was observed only in vascular endothelial tissues, suggesting that tumor progression occurs mainly through ESM-1-associated mechanism.