Search

This work explores an image-based approach for localizing needles during MRI-guided interventions, for the purpose of tracking and navigation. Susceptibility artifacts for several needles of varying thickness were imaged, in phantoms, using a 3 tesla MRI system, under a variety of conditions. The relationship between the true needle positions and the locations of artifacts within the images, determined both by manual and automatic segmentation methods, have been quantified and are presented here. [ABSTRACT FROM AUTHOR]

This work describes an integrated system for planning and performing percutaneous procedures—such as prostate biopsy—with robotic assistance under MRI-guidance. The physician interacts with a planning interface in order to specify the set of desired needle trajectories, based on anatomical structures and lesions observed in the patient's MR images. All image-space coordinates are automatically computed, and used to position a needle guide by means of an MRI-compatible robotic manipulator, thus avoiding the limitations of the traditional fixed needle template. Direct control of real-time imaging aids visualization of the needle as it is manually inserted through the guide. Results from in-scanner phantom experiments are provided. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To review the results of genetic studies investigating dopamine-related genes in attention-deficit hyperactivity disorder (ADHD). DATA SOURCES: Papers (association/linkage, meta-analyses and animal model studies) were identified through searches of the PubMed database and systematically reviewed. DATA SYNTHESIS: Consistent results from molecular genetic studies are pointing strongly to the possible link between 2 specific genes, the dopamine transporter (SLC3A6) and the dopamine receptor 4 (DRD4), and ADHD. CONCLUSIONS: The implication of SLC6A3 and DRD4 genes in ADHD appears to be one of the most replicated in psychiatric genetics and strongly suggests the involvement of the brain dopamine systems in the pathogenesis of ADHD. However, more work is required to further these findings by genotype-to-phenotype correlations and identify the functional allelic variants/mutations that are responsible for these associations. The role of other dopamine genes, which may have smaller effects than SLC6A3 and DRD4, needs also to be determined. [ABSTRACT FROM AUTHOR]

Importance: While adverse childhood experiences (ACEs) are known to impart significant risk for negative mental health and cognitive outcomes in youth, translation of ACE scores into clinical intervention is limited by poor specificity in predicting negative outcomes. This work expands on the ACE framework using a data-driven approach to identify 8 different forms of traumatic and adverse childhood experiences (TRACEs) and reveal their differential associations with psychiatric risk and cognition across development., Objective: Building upon the traditional ACEs model, this study aimed to characterize unique components of commonly co-occurring TRACEs and to examine moderation of longitudinal change in mental health and cognitive development during adolescence., Design, Setting, and Participants: This work draws from youth and their caregivers who completed up to 4 annual behavioral assessments from 2016 to 2021 as part of the ongoing Adolescent Brain Cognitive Development (ABCD) study. Data collection was performed at 21 regionally-distributed sites across the United States. Analyses for this work were conducted January 2023 through November 2023., Exposures: Youth participants in the ABCD study's exposure to 268 different TRACEs, which were distilled into adversity components using nonlinear principal components analysis., Main Outcomes and Measures: Mixed-effects and latent change score models considered TRACEs components as moderators of longitudinal change in internalizing and externalizing mental health problems, as well as longitudinal change in cognitive ability., Results: Data were distilled from 11 876 youth participants, who were grouped into dyads with a caregiver. ABCD study youth participants were 9 to 10 years old at baseline assessment (year 0) and 12 to 13 years old at ABCD year 3. A total of 5679 participants (47.8%) were female. Analyses revealed that TRACEs organized into 8 thematic adversity components (e.g., family conflict, interpersonal violence). At baseline assessment (year 0), exposure to nearly every adversity component was associated with poorer mental health and diminished cognitive ability. Yet across time, it was observed that different forms of adversity were variably linked to both increases and decreases in internalizing and externalizing problems. For example, while peer aggression (t = 5.31) and family conflict (t = 5.67) were associated with increases in both internalizing and externalizing problems over early adolescence, community threat (t = 2.82) and poverty (t = 2.07) were linked to decreased problems, potentially representing adaptive suppression of symptoms. Finally, adversity types related to resource deprivation (eg, poverty, caregiver maladjustment) were associated with declines in cognitive ability over early adolescence., Conclusions and Relevance: In this cohort study, distinct forms of TRACEs differentially moderated developmental changes in psychiatric risk and cognitive ability in different ways, offering the possibility for precision-based prediction of risk for youth. Such findings could be used in targeted early prevention and intervention strategies for at-risk youth.

As computer vision algorithms increase in capability, their applications in clinical systems will become more pervasive. These applications include: diagnostics, such as colonoscopy and bronchoscopy; guiding biopsies, minimally invasive interventions, and surgery; automating instrument motion; and providing image guidance using pre-operative scans. Many of these applications depend on the specific visual nature of medical scenes and require designing algorithms to perform in this environment. In this review, we provide an update to the field of camera-based tracking and scene mapping in surgery and diagnostics in medical computer vision. We begin with describing our review process, which results in a final list of 515 papers that we cover. We then give a high-level summary of the state of the art and provide relevant background for those who need tracking and mapping for their clinical applications. After which, we review datasets provided in the field and the clinical needs that motivate their design. Then, we delve into the algorithmic side, and summarize recent developments. This summary should be especially useful for algorithm designers and to those looking to understand the capability of off-the-shelf methods. We maintain focus on algorithms for deformable environments while also reviewing the essential building blocks in rigid tracking and mapping since there is a large amount of crossover in methods. With the field summarized, we discuss the current state of the tracking and mapping methods along with needs for future algorithms, needs for quantification, and the viability of clinical applications. We then provide some research directions and questions. We conclude that new methods need to be designed or combined to support clinical applications in deformable environments, and more focus needs to be put into collecting datasets for training and evaluation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Adam Schmidt reports financial support was provided by Intuitive Surgical Inc. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The rise of antimicrobial resistance poses a substantial threat to our health system, and, hence, development of drugs against novel targets is urgently needed. The natural peptide thanatin kills Gram-negative bacteria by targeting proteins of the lipopolysaccharide transport (Lpt) machinery. Using the thanatin scaffold together with phenotypic medicinal chemistry, structural data, and a target-focused approach, we developed antimicrobial peptides with drug-like properties. They exhibit potent activity against Enterobacteriaceae both in vitro and in vivo while eliciting low frequencies of resistance. We show that the peptides bind LptA of both wild-type and thanatin-resistant Escherichia coli and Klebsiella pneumoniae strains with low-nanomolar affinities. Mode of action studies revealed that the antimicrobial activity involves the specific disruption of the Lpt periplasmic protein bridge.

Robotic surgery bedside assistants play an important role in robotic procedures by performing intra-corporeal tasks while accommodating the physical presence of the robot. We hypothesized that an augmented reality headset enabling 3D intra-corporeal vision while facing the surgical field could decrease time and improve accuracy of robotic bedside tasks. Bedside assistants (one physician assistant, one medical student, three surgical trainees, and two attending surgeons) performed validated tasks within a mock abdominal cavity with a surgical robot docked. Tasks were performed with a bedside monitor providing 2D or 3D vision, or an optical see-through head-mounted augmented reality device with 2D or 3D vision. The effect of augmented reality device resolution on performance was also evaluated. For the simplest task of touching a straw, performance was generally high, regardless of mode of visualization. With more complex tasks, including stapling and pulling a ring along a path, 3D augmented reality decreased time and number of errors per task. 3D augmented reality allowed the physician assistant to perform at the level of an attending surgeon using 3D augmented reality (p = 0.08). All participants had improved times for the ring path task with better resolution (lower resolution 23 ± 11 s vs higher resolution 14 ± 4 s, p = 0.002). 3D augmented reality vision with high resolution decreased time and improved accuracy of more complex tasks, enabling a less experienced robotic surgical bedside assistant to function similar to attending surgeons. These data warrant further study with additional complex tasks and bedside assistants at various levels of training., (© 2021. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Robotic systems may help efficiently execute complicated tasks that require a high degree of accuracy, and this, in large part, explains why robotics have garnered widespread use in a variety of neurosurgical applications, including intracranial biopsies, spinal instrumentation, and placement of intracranial leads. The use of robotics in neurosurgery confers many benefits, and inherent limitations, to both surgeons and their patients. In this narrative review, we provide a historical overview of robotics and its implementation across various surgical specialties, and discuss the various robotic systems that have been developed specifically for neurosurgical applications. We also discuss the relative advantages of robotic systems compared to traditional surgical techniques, particularly as it pertains to integration of image guidance with the ability of the robotic arm to reliably execute pre-planned tasks. As more neurosurgeons adopt the use of robotics in their practice, we postulate that further technological advancements will become available that will help achieve improved technical capabilities, user experience, and overall patient clinical outcomes., (© Congress of Neurological Surgeons 2021.)

We examined: (i) neuro-axonal disturbance (as indicated by (1)H-MRSI NA/Cr values) in the cortical grey matter (cGM) of 10 untreated patients with relapsing-remitting (RR) and 10 with secondary-progressive (SP) multiple sclerosis (MS), and (ii) the relationships between cGM-NA/Cr values and the degree of EDSS-measured clinical disability and cerebral white-matter (WM) lesion load (LL) in these patients. Whereas mean and median cGM-NA/Cr values in our RR group were similar to those in 18 age-matched normal controls (NC), large statistically-significant decreases (between 14.3% and 18.5%) were found in our SP group relative to both our RR and NC groups. When data from all patients was combined, we found: (i) a large negative correlation between EDSS scores and cGM-NA/Cr values (r=-0.55); and (ii) a larger negative correlation of cGM-NA/Cr values with cerebral T1-hypointese WM-LL (T1-LL, r=-0.73) than with cerebral T2-hyperintense-LL (T2-LL, r=-0.63). Importantly, (i) correlations of WM-LL with cGM-NA/Cr were larger in the RR group than in the SP group (T1-LL: r=-0.79 vs. -0.54; T2-LL: r=-0.63 vs. -0.51), and (ii) cerebral WM-LL values could not fully account for the extent of the decrease in mean cGM-NA/Cr that was seen in our SP group relative to our NC group. Our observations are consistent with the possibilities that: (i) in patients with RR-MS, (1)H-MRSI-measured cGM neuro-axonal disturbances are strongly related to the effects of axonal transection that are associated with cerebral WM lesions; and (ii) in patients with SP-MS, such cGM neuro-axonal disturbances are more severe and are associated with a more-widespread degenerative process (which probably includes a considerable degree of cortical demyelination).

Purpose: To quantify needle placement accuracy of magnetic resonance image (MRI)-guided core needle biopsy of the prostate., Materials and Methods: A total of 10 biopsies were performed with 18-gauge (G) core biopsy needle via a percutaneous transperineal approach. Needle placement error was assessed by comparing the coordinates of preplanned targets with the needle tip measured from the intraprocedural coherent gradient echo images. The source of these errors was subsequently investigated by measuring displacement caused by needle deflection and needle susceptibility artifact shift in controlled phantom studies. Needle placement error due to misalignment of the needle template guide was also evaluated., Results: The mean and standard deviation (SD) of errors in targeted biopsies was 6.5 +/- 3.5 mm. Phantom experiments showed significant placement error due to needle deflection with a needle with an asymmetrically beveled tip (3.2-8.7 mm depending on tissue type) but significantly smaller error with a symmetrical bevel (0.6-1.1 mm). Needle susceptibility artifacts observed a shift of 1.6 +/- 0.4 mm from the true needle axis. Misalignment of the needle template guide contributed an error of 1.5 +/- 0.3 mm., Conclusion: Needle placement error was clinically significant in MRI-guided biopsy for diagnosis of prostate cancer. Needle placement error due to needle deflection was the most significant cause of error, especially for needles with an asymmetrical bevel., ((c) 2007 Wiley-Liss, Inc.)

The integration of medical devices with software applications is crucial for image-guided medical applications. This work describes a general device interface that has been designed for high-frequency streaming of multi-modal events, thus providing maximum performance and flexibility for such applications. Several sample applications and performance tests are provided to demonstrate the usability of the concept.

In this paper a comprehensive framework for pre-operative planning, procedural skill training, and intraoperative navigation is presented. The goal of this system is to integrate surgical simulation with surgical planning in order to improve the individual treatment of patients. Various surgical approaches and new, more complex procedures can be assessed using a safe and objective platform that will allow the physicians to explore and discuss possible risks and benefits prior to the intervention. A simulation environment extends the pre-operative planning in a natural way, as it allows for direct evaluation of the surgical approach envisioned for each case. In addition, by providing intraoperative navigation based on this simulation, surgeons can carry out the previously optimized plan with higher precision and greater confidence.

System development for image-guided therapy (IGT), or image-guided interventions (IGI), continues to be an area of active interest across academic and industry groups. This is an emerging field that is growing rapidly: major academic institutions and medical device manufacturers have produced IGT technologies that are in routine clinical use, dozens of high-impact publications are published in well regarded journals each year, and several small companies have successfully commercialized sophisticated IGT systems. In meetings between IGT investigators over the last two years, a consensus has emerged that several key areas must be addressed collaboratively by the community to reach the next level of impact and efficiency in IGT research and development to improve patient care. These meetings culminated in a two-day workshop that brought together several academic and industrial leaders in the field today. The goals of the workshop were to identify gaps in the engineering infrastructure available to IGT researchers, develop the role of research funding agencies and the recently established US-based National Center for Image Guided Therapy (NCIGT), and ultimately to facilitate the transfer of technology among research centers that are sponsored by the National Institutes of Health (NIH). Workshop discussions spanned many of the current challenges in the development and deployment of new IGT systems. Key challenges were identified in a number of areas, including: validation standards; workflows, use-cases, and application requirements; component reusability; and device interface standards. This report elaborates on these key points and proposes research challenges that are to be addressed by a joint effort between academic, industry, and NIH participants.

THE FASCICULUS MEDICINA, printed in 1491, is considered the first illustrated medical book. The Latin essays and illustrations in this volume provide insight into the medical knowledge of Western Europe and, in the Italian edition published in 1493, glimpses into the medical culture of the late 15th century. We outline the scientific and social environments into which the Fasciculus Medicinae of 1491 was introduced and the transition that occurred with the publication of the 1493 Italian edition. The artist of the 1493 Fasciculo witnessed a paradigm shift occurring. In four woodcuts, the artist captured four themes: the relevance of knowledge-based medicine, the emergence of laboratory medicine, the Hippocratic lessons of patient observation, and the emerging revolution in anatomy.

We review our experience using an open 0.5-T magnetic resonance (MR) interventional unit to guide procedures in the prostate. This system allows access to the patient and real-time MR imaging simultaneously and has made it possible to perform prostate biopsy and brachytherapy under MR guidance. We review MR imaging of the prostate and its use in targeted therapy, and describe our use of image processing methods such as image registration to further facilitate precise targeting. We describe current developments with a robot assist system being developed to aid radioactive seed placement.

Background: Cysts of the ligamentum flavum are rare and unusual causes of spinal compression., Methods: We report our experience of four cases of ligamentum flavum cysts occurring in the lumbar spine and discuss some of the possible etiologies and pathophysiologic mechanisms according to the available literature., Conclusion: This entity is clearly different from the synovial facet-joints or ganglion cysts.

Background: Among cases of cerebellopontine angle lesions, vascular lesions involving the internal auditory canal are extremely rare. We report a distal fusiform mycotic pseudoaneurysm of the anterior inferior cerebellar artery (AICA) that simulated an acoustic neuroma on presentation., Methods: A 60-year-old woman was investigated for recent onset of acute dizziness. Laboratory and radiographic investigations are presented, as well as the surgical management of the patient and pathological examination of the aneurysm., Conclusions: An exceptionally rare case of distal mycotic intracanalicular pseudoaneurysm of the AICA with intraluminal thrombus and fusiform anatomy is described. In our review of the literature (1966-present), only five other intracanalicular AICA-aneurysms were encountered, none of which were infectious in etiology. The possible pathophysiologic mechanisms of distal AICA-aneurysms are discussed along with the currently available literature.

Among 32 neuroendocrine carcinomas of the skin, 11 were from patients with previous or concomitant squamous carcinoma. The medical records and pathologic material for these 11 cases were reviewed, and the diagnosis of neuroendocrine carcinoma was confirmed in each instance by electron microscopy. In two cases, the squamous and neuroendocrine carcinomas were admixed, but each preserved its identity and transition between the two was not identified. Despite the lack of evidence for origin from a single cell, the observations nevertheless indicate a common carcinogenetic influence for squamous and neuroendocrine carcinomas of the skin.

The term "water intoxication" is used to describe a condition of agitation, delirium, convulsion, and coma brought on by excessive intake of water, resulting in severe hyponatremia. Psychogenic polydipsia (compulsive water drinking) has until recently been considered a relatively benign process. Since 1974, however, three fatal cases of water intoxication, resulting from psychogenic polydipsia, have been reported. All three individuals died while hospitalized, thereby permitting performance of blood electrolyte determinations and documentation of the associated electrolyte imbalance. In the authors' case, there was a well-documented prior episode of water intoxication in which serum electrolytes showed a pattern typical of this entity. Death, however, occurred at home, thus preventing valid serum electrolyte determinations to be performed. Analysis of the vitreous humor revealed a severe hyponatremia, thus substantiating the diagnosis of fatal water intoxication. This case, once again, points out the usefulness of electrolyte analyses on the vitreous humor as an aid to establishing a cause of death.

Lead poisoning from a retained bullet or missile is rare and is usually dependent on the location of the missile in a bone or immediately adjacent to a joint. A review of the literature revealed only 14 cases in which there was adequate laboratory documentation of plumbism caused by a retained bullet or missile. Only one of these previously reported cases resulted in death. We report a second death due to lead poisoning from a retained bullet with elevated blood lead levels documented by toxicologic analysis.

In 10,995 consecutive medicolegal autopsies, there were 19 deaths due to an unsuspected primary intracranial neoplasm. Nine (47.4%) of the tumors were in the astrocytoma-glioblastoma category. The remainder included four cases of oligodendroglioma and one case each of medulloblastoma, microglioma, meningioma, teratoma, colloid cyst and pituitary chromophobe adenoma. In six cases, death occurred following abrupt loss of consciousness, or else the patient was found dead. In five of these six cases, there were no known preceding symptoms. The remaining 13 patients exhibited the characteristic symptoms produced by intracranial neoplasms, including symptoms of increased intracranial pressure, epilepsy, and psychiatric manifestations. Only one patient presented with a focal neurologic deficit which resolved in 24 hours. A comparison of the duration and type of symptomatology exhibited by these patients with a hospital patient population in which death was caused by a previously diagnosed primary intracranial neoplasm and an autopsy was performed underscored 1) the shorter duration of acute symptomatology, 2) the nonlocalizing nature of the symptoms manifested, 3) the lack of progression or change in symptoms in those patients in whom epilepsy was the primary manifestation of their underlying disease, and 4) the lower incidence of focal neurologic deficits as the presenting symptoms in our series.