Evaluating Deep Learning Techniques for Detecting Aneurysmal Subarachnoid Hemorrhage: A Comparative Analysis of Convolutional Neural Network and Transfer Learning Models.

OBJECTIVE: Machine learning and deep learning techniques offer a promising multidisciplinary solution for subarachnoid hemorrhage (SAH) detection. The novel transfer learning approach mitigates the time constraints associated with the traditional techniques and demonstrates a superior performance. This study aims to evaluate the effectiveness of convolutional neural networks (CNNs) and CNN-based transfer learning models in differentiating between aneurysmal SAH and nonaneurysmal SAH. METHODS: Data from Istanbul Ümraniye Training and Research Hospital, which included 15,600 digital imaging and communications in medicine images from 123 patients with aneurysmal SAH and 7793 images from 80 patients with nonaneurysmal SAH, were used. The study employed 4 models: Inception-V3, EfficientNetB4, single-layer CNN, and three-layer CNN. Transfer learning models were customized by modifying the last 3 layers and using the Adam optimizer. The models were trained on Google Collaboratory and evaluated based on metrics such as F-score, precision, recall, and accuracy. RESULTS: EfficientNetB4 demonstrated the highest accuracy (99.92%), with a better F-score (99.82%), recall (99.92%), and precision (99.90%) than the other methods. The single- and three-layer CNNs and the transfer learning models produced comparable results. No overfitting was observed, and robust models were developed. CONCLUSIONS: CNN-based transfer learning models can accurately diagnose the etiology of SAH from computed tomography images and is a valuable tool for clinicians. This approach could reduce the need for invasive procedures such as digital subtraction angiography, leading to more efficient medical resource utilization and improved patient outcomes.

Maximum Safety Limits of Laminectomy of the C1 Vertebra for Chiari Malformation Surgery: A Finite Element Analysis.

Background: The treatment of Chiari malformations generally consists of posterior fossa decompression. C1 laminectomy is required in selected cases. However, cases of iatrogenic anterior arch fractures at C1 without high-energy trauma have been reported. Developing theoretical models of atlas C1 bones that have undergone a laminectomy can help researchers identify the regions where fractures may occur as a result of sudden loads. Methods: In this study, we created a detailed three-dimensional solid finite element model of the human atlas bone (C1) using geometric data. The loadings of the laminectomy dimension were evaluated on the basis of three groups. Group I comprised atlas bones that had not undergone a laminectomy. For Group II, the lateral border of the laminectomy was determined as the projection of the lateral mass medial border on the lamina. For Group III, the bilateral sulcus arteriosus was determined as the border for the lateral border of the laminectomy. The analysis results, which are in good agreement with those of previous reports, showed high concentrations of localized stress in the anterior and posterior arches of the atlas bone. Results: The analysis results showed that the stress increased in the laminectomy models. The maximum stress observed was consistent with the clinical observations of fracture sites in previous studies. Conclusion: In the treatment of patients with Chiari malformations, C1 laminectomy is often required. The width of this laminectomy can lead to iatrogenic anterior arch fractures. This is the first study to evaluate C1 laminectomy width using finite element modeling.

Increased Neutrophil Lymphocyte Ratio Could be Predictive for Higher Mortality in Preterm Infants with Intraventricular Hemorrhage.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is a simple, cost-effective index of inflammation that can be measured by peripheral blood count. This study aimed to reveal that a high NLR value could be a prognostic marker for mortality risk in preterm babies born with IVH. METHODS: Preterm babies who had been followed up in the neonatal intensive care unit (ICU) between 2018 and 2020 were included in the study. These patients were examined in two groups, those who had had IVH and those who had not. The patients were evaluated by the week of birth, gender, first-minute APGAR score and NLR obtained from the first postnatal peripheral blood sample. RESULTS: A total of 113 babies had been born preterm and had been treated in the newborn intensive care unit (NICU) were included in the study. Intraventricular hemorrhage (IVH) was observed in 26 (23%) of the infants, and a total of 14 (12.4%) died, with the mortality rate being higher among those with IVH than those without (P = 0.026). There was also a statistically significant difference in the NLR between infants with IVH who died and those who did not (P < 0.001). NLR above 1.5 had 33.7 times higher risk of mortality compared to those with an NLR of 1.5 or below. CONCLUSIONS: This was the first study to examine the relationship between the NLR and mortality in preterm babies with IVH. This study showed that a high NLR was strongly associated with mortality in premature infants with low APGAR scores and having IVH.

Spinal Schwannomas: A Proposal for a New Classification to Aid Surgical Planning.

Background The treatment of spinal schwannomas, which is the most common nerve sheath tumor, is total microsurgical resection. The localization, size and relationship with the surrounding structures of these tumors are crucial in terms of preoperative planning. A new classification method is presented in this study for the surgical planning of spinal schwannoma. Methods All patients who underwent surgery for spinal schwannoma between 2008 and 2021 were reviewed retrospectively, along with radiological images, clinical presentation, surgical approach, and postoperative neurological status. Results A total of 114 patients, 57 male, and 57 females were included in the study. Tumor localizations were cervical in 24 patients, cervicothoracic in one patient, thoracic in 15 patients, thoracolumbar in eight patients, lumbar in 56 patients, lumbosacral in two patients, and sacral in eight patients. All tumors were divided into seven types according to the classification method. Type 1 and Type 2 groups were operated on with a posterior midline approach only, Type 3 tumors were operated on with a posterior midline approach and extraforaminal approach, and Type 4 tumors were operated on with only an extraforaminal approach. While the extraforaminal approach was sufficient in type 5 patients, partial facetectomy was required in 2 patients. Combined surgery including hemilaminectomy and extraforaminal approach was performed in the type 6 group. A posterior midline approach with partial sacrectomy/corpectomy was performed in Type 7 group. Conclusion Effective treatment of spinal schwannoma depends on preoperative planning, which includes correctly classifying tumors. In this study, we present a categorization scheme that covers bone erosion and tumor volume for all spinal localizations.

A Simple Cost-Effectiveness Analysis of Bilateral Decompression via Unilateral Approach versus Instrumented Total Laminectomy and Fusion for Lumbar Spinal Stenosis.

AIM: To compare the clinical and economic results of two different surgical approaches (bilateral decompression via unilateral approach and instrumented total laminectomy and fusion) in the treatment of lumbar spinal stenosis. MATERIAL AND METHODS: The clinical, surgical, and economic aspects of 100 surgically treated patients with lumbar spinal stenosis were retrospectively reviewed. RESULTS: Decompression was performed at 158 levels in 100 patients. The most commonly decompressed levels were L4-5 and L3-4. Significant difference was observed between pre- and postoperative visual analog scale scores in both groups (p < 0.05). In Group 1 (instrumented total laminectomy and fusion), the mean surgery cost was 2539.2 USD (mean procedure cost: 1440.1 USD, mean implant cost: 1099.2 USD). In Group 2 (bilateral decompression via unilateral approach) the mean surgery cost was 998.5 USD. The cost difference was significant (p < 0.05). CONCLUSION: Both instrumented total laminectomy and fusion and bilateral decompression via unilateral approach performed with and without stabilization showed similar clinical results in patients with lumbar spinal stenosis. However, the cost of surgery was found to be 2.5-fold higher in the instrumented total laminectomy and fusion group. This study supports the concept that minimally invasive spine surgery is cost-effective.

A novel surgical technique for aggressive vertebral hemangiomas.

Vertebral hemangiomas are relatively common, but those causing spinal cord compression are rare. A 19-year-old male presented with thoracic back pain. The neurologic examination was normal and radiological examinations demonstrated an aggressive vertebral hemangioma centered within the T11 vertebral body. Damaged vertebral bone and soft tissue components of the mass were observed in the epidural space. Surgery was performed using a new technique involving radiofrequency ablation, injection of a hemostatic agent (FLOSEAL, Baxter, USA), and bone autograft placement in the affected vertebral body. There were no complications intra- or postoperatively, and the patient's back pain resolved completely during the postsurgical period. Bleeding is a serious issue in cases of aggressive vertebral hemangioma. This new technique provides improved bleeding control and strengthens the affected vertebra through autograft placement.

Thyroid Carcinoma Presenting as a Dural and Calvarial Metastasis Mimicking a Lipoma With Difficult Diagnosis of the Primary Lesion.

Calvarial and dural metastases of papillary thyroid carcinomas (PTC) are rarely reported in the medical literature. Most frequent calvarial metastases are seen to originate from lung, breast, and prostate cancers. Thyroid cancer metastases are generally well vascularized and cause destruction in the bone tissues. First choice of treatment in distant metastases of PTC is surgery and radioactive iodine treatment for the primary cause. Postsurgical radiotherapy is used in accepted and suitable patients.

Stereologic and ultrastructural comparison of human and rat amniotic membrane wrapping for rat sciatic nerve repair.

In this study we aimed to examine the effects on wound healing and nerve regeneration of human and rat amniotic membrane wraps around primary epineural anastomosis areas after a peripheral nerve transection injury in rats. We randomized 25 male adult rats with induced peripheral transection injuries into 5 groups (control, transection injury, primary epineural anastomosis [PEA] after injury, PEA with a human amniotic membrane [hAM] wrap, and PEA with a rat amniotic membrane [rAM] wrap groups and treated their injuries accordingly. We took tissue samples from the anastomosis regions, 12 weeks after the experiment, and analyzed them stereologically and ultrastructurally. We performed a statistical analysis with the recovered stereological counts and the measurement data. Our results showed that the use of amniotic membranes for allografts (between same species) instead of xenografts (between different species), along with microsurgery, provides a suitable microenvironment during the healing process with less immunological reaction on the injured site and supports axonal regeneration.

Dural prostate metastasis presenting as a subdural hematoma.

The incidence of subdural hematoma is approximately 13.1/100.000 per year. Subdural hematoma due to skull and dura mater metastases is rare. In this study, a 71-year-old patient with prostate adenocarcinoma who presented with chronic subdural hematoma due to skull bone and dura mater metastasis is presented.

The Role of Wrist Magnetic Resonance Imaging in the Differential Diagnosis of the Carpal Tunnel Syndrome.

AIM: The carpal tunnel syndrome (CTS) is the commonest compressive neuropathy. Electromyography (EMG) is accepted as gold standard in diagnosis of CTS. However, pathologies and variations that are associated with a various findings may lead to failure. MATERIAL AND METHODS: Magnetic resonance Imaging (MRI) was applied to 69 wrists of 55 patients, who received a diagnosis of CTS by means of clinical and electrodiagnostic testing (EDT) during the years 2011 and 2013. RESULTS: We detected a total of 71 additional pathologies in MRI analyses: 29 degenerative bone cysts, 28 ganglion cysts, 8 tenosynovitis, and 6 avascular necroses. While the MRI detected 44 (59.5%) additional radiological pathologies in 39 wrists diagnosed with mid-level CTS by means of EMG, the number of detected additional pathologies was 27 (36.5%) in 30 wrists diagnosed with advanced-level CTS. CONCLUSION: Wrist MRI is an effective means to reveal associated pathologies in patients diagnosed with CTS by means of clinical testing and EDT. Additional pathologies may not only change the applicable type of surgery, but also decrease the number of postoperative failures. Wrist MRI is recommended, especially for young cases with unilateral CTS history accompanied by dubious clinical symptoms and lacking any pronounced predisposing factors.