Neuroimaging for Early Diagnosis of Alzheimer's Disease: a Review.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disease that primarily affects people above the age of 60 all around the world. As of now, the cause is unknown and there is no effective cure. The pathological changes of AD have occurred many years before the onset of the disease, and current treatment techniques can only delay the progression of the disease. Because disease-modifying therapies may be most beneficial in the early stages of AD, the clinical significance of an early diagnosis is emphasized. So far, a variety of imaging technologies and related biomarkers have been used to identify and monitor AD, but there are many imaging technologies; finding the most effective imaging technology can assist medical personnel in interpreting the early stages of AD and can also improve patient treatment opportunities. This is, therefore, the main purpose and back-ground of this study. METHODS: PubMed and other repositories were used in this study to conduct a literature search with various keywords, and relevant articles were reviewed. In this review, different neuroimaging techniques are reviewed which are considered advanced tools to help establish the diagnosis, and in addition, the diagnostic utility, advantages, and limitations of contemporary AD imaging techniques are discussed. RESULTS: The results of the literature review and synthesis show that the prevalence of several in vivo biomarkers helps distinguish affected individuals from healthy controls in the early stages of the disease. Additionally, each current imaging method has its advantages and disadvantages, so no single imaging method is the best diagnostic modality. CONCLUSIONS: This article also reviews and draws conclusions on better ways to use the imaging techniques to improve the likelihood of an early diagnosis of AD. It is suggested that future research could focus on expanding the use of imaging technologies and on identifying novel biomarkers manifesting the earliest stages of AD pathology.

A deep learning-based method for the diagnosis of vertebral fractures on spine MRI: retrospective training and validation of ResNet.

PURPOSE: To improve the performance of less experienced clinicians in the diagnosis of benign and malignant spinal fracture on MRI, we applied the ResNet50 algorithm to develop a decision support system. METHODS: A total of 190 patients, 50 with malignant and 140 with benign fractures, were studied. The visual diagnosis was made by one senior MSK radiologist, one fourth-year resident, and one first-year resident. The MSK radiologist also gave the binary score for 15 qualitative imaging features. Deep learning was implemented using ResNet50, using one abnormal spinal segment selected from each patient as input. The T1W and T2W images of the lesion slice and its two neighboring slices were considered. The diagnostic performance was evaluated using tenfold cross-validation. RESULTS: The overall reading accuracy was 98, 96, and 66% for the senior MSK radiologist, fourth-year resident, and first-year resident, respectively. Of the 15 imaging features, 10 showed a significant difference between benign and malignant groups with p < = 0.001. The accuracy achieved by using the ResNet50 deep learning model for the identified abnormal vertebral segment was 92%. Compared to the first-year resident's reading, the model improved the sensitivity from 78 to 94% (p < 0.001) and the specificity from 61 to 91% (p < 0.001). CONCLUSION: Our deep learning-based model may provide information to assist less experienced clinicians in the diagnosis of spinal fractures on MRI. Other findings away from the vertebral body need to be considered to improve the model, and further investigation is required to generalize our findings to real-world settings.

Grey matter alterations in generalized anxiety disorder: A voxel-wise meta-analysis of voxel-based morphometry studies.

OBJECTIVE: Grey matter, a crucial component of the brain, has been found altered in generalized anxiety disorder (GAD) of several voxel-based morphometry studies. The conclusive and consistent grey matter alterations in GAD have not been confirmed. METHOD: Eleven voxel-based morphometry studies of GAD patients were included in the current systematic review and meta-analysis. The linear model of anxiety severity scores was applied to explore the relationship of grey matter alterations and anxiety severity. The subgroup analysis of adult GAD and adolescent GAD was also performed. RESULTS: Significantly modest grey matter alterations in the left superior temporal gyrus of patients with GAD were found. The anxiety severity score was significantly correlated with grey matter alterations in the right insula, lenticular nucleus, putamen and striatum. The subgroup analysis of adult GAD and adolescent GAD all failed to show significant grey matter alterations. However, in the adult GAD subgroup, anxiety severity score was significantly correlated with grey matter alterations in the right insula. CONCLUSION: GAD might have the modest grey matter alterations in the left superior temporal gyrus. Anxiety severity might be related to the grey matter alterations in the limbic regions, such as the right insula, lenticular nucleus, putamen and striatum. This kind of correlation might be related to the effects of adult GAD. Future studies with adequate sample sizes and sophisticated GAD categories will be needed.

Monorail snare technique for retrieval of stretched coil.

Coil stretching is a recognized complication during cerebral aneurysm embolization.1, 3- 5 For over a decade, the microsnare has proven effective in retrieving migrated coils.1- 5 Fiorella et al. unveiled the "Monorail Snare Technique" in 2005, offering a specialized approach to stretched coil recovery.1 However, to gain a complete understanding of this technique, more than just textual descriptions are necessary; a thorough, practical demonstration is essential. In our technical video (video 1), we illustrated an episode of coil stretching during aneurysm embolization, where the "Monorail Snare Technique" was successfully employed to retrieve a stretched coil. Our video emphasizes the meticulous preparation and modification of the microsnare, showcasing enhanced steps to mitigate the potential blood backflow triggered by the exclusive use of one-arm hemostasis valve during the "Monorail Snare Technique."1, 5 This pivotal adjustment substantially lowers the threat of thromboembolic events. We highlighted essential precautions to ensure the procedure's safety and efficacy.4, 5.

Coil embolization of distal vascular lesion using a 1.5 Fr Marathon microcatheter and 'free-running' technique.

In distal vascular lesions, such as the distal anterior inferior cerebellar artery or posterior inferior cerebellar artery (PICA) dissecting aneurysm, and dural arteriovenous fistula (dAVF) and arteriovenous malformation (AVM), super-selective catheterization and embolization using liquid agents, such as NBCA or Onyx liquid embolic system, is the preferred treatment.1 2 We used a flow-directed 1.5 Fr Marathon microcatheter (Medtronic, Minneapolis, MN, USA) for embolization because commonly used detachable coil-compatible microcatheters can be too short or rigid for superselection.3-6 We designed an in vitro coil compatibility test for the Marathon microcatheter and developed a 'free-running' technique (video 1). Using this technique, we trapped the distal PICA dissecting aneurysm and embolized the fistula points of dAVF precisely and safely without affecting adjacent normal structures, which can occur when applying liquid embolizing agents.1-3 After reviewing the case, we determined that this technique can also potentially be applied for implementing the pressure cooker technique7 and combining the management of AVM.4neurintsurg;jnis-2023-020893v1/V1F1V1Video 1Free-running technique via 1.5 Fr Marathon microcatheter.

Lhermitte-Duclos disease: A case report with radiologic-pathologic correlation.

Background: Lhermitte-Duclos disease (LDD) stems from the development of a rare benign lesion of uncertain pathogenesis that distorts the normal cerebellar laminar cytoarchitecture. We explored the lesion's appearance on conventional magnetic resonance imaging (MRI) combined with susceptibility-weighted imaging, diffusion-weighted imaging, perfusion imaging, or arterial spin labeling. Although many cases of LDD have been previously reported in the literature, the radiologic-pathologic correlation has been described in only a few of these cases. To the best of our knowledge, this is the first case report to provide detailed information about the radiologic-pathologic correlation of LDD. Case Report: A 48-year-old woman presented with left facial tics, occipital headache, and dizziness for 1 month. MRI revealed a left cerebellar lesion with hypointensity on T1-weighted images. On T2-weighted images, the mass was hyperintense with tigroid appearance due to alternating high and normal signal intensities. High signal intensity was noted on fluid-attenuated inversion recovery images. Magnetic resonance spectroscopy indicated decreased level of choline (Cho), N-acetyl aspartate, and myoinositol with elevated level of lactate on the affected side. The lesion showed a bright signal on diffusion-weighted images, whereas apparent diffusion coefficient mapping revealed no disturbance of diffusion. The pathology of the excised lesion was consistent with LDD. Conclusion: MRI with advanced techniques can provide not only preoperative diagnosis but also better pathologic correlation.