Computed Tomography Angiography Quantification of Intracranial and Extracranial Vascular Narrowing in Ischemic Stroke: Differences Between Patients With and Without Illicit Drug Use.

OBJECTIVE: Previous studies have linked illicit drug consumption and stroke. The purpose of this study is to identify specific imaging findings depicted on computed tomography angiography on patients with illicit drug-associated stroke. METHODS: This is a retrospective case-control study that included ischemic stroke patients. Subjects who tested positive for cocaine or marijuana were considered as cases, while patients who tested negative were included as controls. Matching of the controls was carried out based on the presence of stroke risk factors. A previously validated scale was used to calculate narrowing scores through computed tomography angiography. Comparison between cases and matched controls was evaluated by paired t test for age and body mass index, and by Wilcoxon signed rank test for intracranial, extracranial, and total scores. RESULTS: One hundred seventy-four patients were included in the study, 87 subjects for each group. Because of matching, baseline status differed only on body mass index, with a greater proportion of obese subjects among controls ( P < 0.016). Subgroup analysis demonstrated that it is more likely to find any intracranial abnormality among cocaine consumers when compared with controls ( P = 0.041). CONCLUSIONS: By using computed tomography angiography, we found that stroke patients with history of cocaine consumption had a higher incidence of intracranial circulation narrowing compared with matched controls.

Traumatic spondylolisthesis of axis: clinical and imaging experience at a level one trauma center.

PURPOSE: Traumatic spondylolisthesis of the axis (TSA) with bilateral pars interarticularis fracture (a pattern also known as Hangman's fractures) accounts for 4-5% of all cervical fractures. Various classification systems have been described to assist therapeutic decision-making. The goal is to reassess the utility of these classifications for treatment strategy and evaluate additional imaging associations. METHODS: This is an IRB approved, retrospective analysis of patients with imaging diagnosis of TSA from 2016 to 2019. Consensus reads were performed classifying TSA into various Levine and Edwards subtypes and typical vs. atypical fractures. Other imaging findings such as additional cervical fractures, traumatic brain injury, spinal cord injury, and vertebral artery injury were recorded. Treatment strategy and outcome were reviewed from clinical charts. Fisher exact test was used for statistical analysis. RESULTS: A total of 58 patients were included, with a mean age of 62.7 ± 25 years, and male to female ratio of 1:1.2. Motor vehicle collision was the most common cause of TSA. Type I and III injuries were the most and the least common injuries, respectively. Patients with type I injuries were found to have good healing rates with conservative management (p < 0.001) while type IIa and III injuries were managed with surgical stabilization (p = 0.04 and p = 0.01, respectively). No statistical difference was observed in the treatment strategy for type II fractures (p = 0.12) and its prediction of the associated injuries. Atypical fractures were not found to have a higher incidence of SCI (p = 0.31). A further analysis revealed significantly higher-grade vertebral artery injuries (grades III and IV according to Biffl grading) in patients with type IIa and III injuries (p = 0.001) and an 11-fold increased risk of TBI compared to type I and type II fractures (p = 0.013). CONCLUSION: TSA fracture types were not associated with any clinical outcome. Levine and Edwards type II classification itself is not enough to guide the treatment plan and does not account for associated injuries. Additional imaging markers may be needed.

Prenatal and Postnatal Imaging Findings After Fetal Repair of Spinal Dysraphisms Using Cryopreserved Human Umbilical Cord Patch: A Case Series of 4 Patients.

We describe a case series of imaging findings of 4 patients who underwent spinal dysraphisms repair in utero with novel patch material, cryopreserved human umbilical cord, in our institution. In our study, the prenatal and postnatal magnetic resonance imaging and ultrasound are reviewed and showed cord tethering and syrinx progression in all cases. Our report is the first description of magnetic resonance imaging and ultrasound findings in the context of using this novel patch in severe cases of spinal dysraphisms.

Deep learning enabled brain shunt valve identification using mobile phones.

BACKGROUND AND OBJECTIVE: Accurate information concerning implanted medical devices prior to a Magnetic resonance imaging (MRI) examination is crucial to assure safety of the patient and to address MRI induced unintended changes in device settings. The identification of these devices still remains a very challenging task. In this paper, with the aim of providing a faster device detection, we propose the adoption of deep learning for medical device detection from X-rays. METHOD: In particular, we propose a pipeline for the identification of implanted programmable cerebrospinal fluid shunt valves using X-ray images of the radiologist workstation screens captured with mobile phone integrated cameras at different angles and illuminations. We compare the proposed convolutional neural network with published methods. RESULTS: Experimental results show that this approach outperforms methods trained on images digitally transferred directly from the scanners and then applied on mobile phones images (mean accuracy 95% vs 77%, Avg. Precision 0.96 vs 0.77, Avg. Recall 0.95 vs 0.77, Avg. F1-score 0.95 vs 0.77) and existing published methods based on transfer learning fine-tuned directly on the mobile phone images (mean accuracy 94% vs 75%, Avg. Precision 0.94 vs 0.75, Avg. Recall 0.94 vs 0.75, Avg. F1-score 0.94 vs 0.75). CONCLUSION: An automated shunt valve identification system is a promising safety tool for radiologists to efficiently coordinate the care of patients with implanted devices. An image-based safety system able to be deployed on a mobile phone would have significant advantages over methods requiring direct input from X-ray scanners or clinical picture archiving and communication system (PACS) in terms of ease of integration in the hospital or clinical ecosystems.

Neuroimaging Features of Intracranial Hypertension in Pediatric Patients With New-Onset Idiopathic Seizures, a Comparison With Patients with Confirmed Diagnosis of Idiopathic Intracranial Hypertension: A Preliminary Study.

CONCLUSION: A cutoff value of 6.0 mm for optic nerve sheath dilation may be used as a screening imaging marker to suspect elevated opening pressure with specificity of 88% in pediatric patients with new-onset idiopathic seizures.

Uncovering the Dorsal Thalamo-hypothalamic Tract of the Human Limbic System.

As a non-limbic structure, the human thalamus is the most important modulator of the limbic system. The hypothalamus plays vital roles in the survival of species by regulating fear, learning, feeding behavior, circadian rhythm, sociosexual and reproductive activities of the limbic system through connections with the thalamus. The detailed anatomy of the pathways responsible for mediating these responses, however, is yet to be determined. The mammillothalamic tract is known as the major direct thalamo-hypothalamic connection in the primates including the human brain connecting the ventral thalamus to the dorsal hypothalamus. Multiple dissection animal studies revealed additional connections specially from the dorsal thalamus to the ventral hypothalamic nuclei. Diffusion weighted imaging may be helpful in better visualizing the surgical anatomy of this additional connectivity noninvasively. This study aimed to investigate the utility of high spatial and high angular resolution diffusion weighted tractography technique for mapping the trajectory of this dorsal thalamic connectivity with the ventral hypothalamus in the human brain. We studied 30 healthy human subjects. Using a high-resolution diffusion weighted tractography technique, for the first time, we were able to delineate and reconstruct the trajectory of the dorsal thalamo-hypothalamic tract (DTH). We further revealed the close relationship of the DTH, fornix and hippocampus in healthy adult human brain.

A direct visuosensory cortical connectivity of the human limbic system. Dissecting the trajectory of the parieto-occipito-hypothalamic tract in the human brain using diffusion weighted tractography.

The human hypothalamus is at the center of the human limbic system anatomically and physiologically. The hypothalamus plays pivotal roles in controlling autonomic responses and instinctive behaviors such as regulating fear, aggression, learning, feeding behavior, circadian rhythm, and reproductive activities. The detailed anatomy of the pathways responsible for mediating these responses, however, is yet to be determined. The inhibitory effect of the cerebral cortex on the hypothalamus in many autonomic responses, suggests the presence of direct connection between the cortex and hypothalamic nuclei. While, there is ample information to support the cortico-hypothalamic association between the prefrontal cortex and hypothalamic nuclei, the information regarding a direct posterior cortico-hypothalamic alliance is scant. The visuosensory information may be crucial for the limbic system to regulate some of the important limbic functions. Multiple dissection animal studies revealed direct posterior cortical connectivity with the hypothalamic nuclei. However, a direct cortico-hypothalamic connectivity from the parieto-occipital cortices has not been revealed in the human brain yet. Diffusion weighted imaging (DWI) may be helpful in better visualizing the anatomy of this direct posterior cortico-limbic connectivity noninvasively in the human brain. We studied 30 healthy human subjects. Using a high-spatial and high angular resolution diffusion weighted tractography technique, for the first time, we were able to delineate and reconstruct the trajectory of the parieto-occipito-hypothalamic tract.