Clinical diagnostic reference levels in neuroradiology based on clinical indication.

This study focuses on patient radiation exposure in interventional neuroradiology (INR) procedures, a field that has advanced significantly since its inception in the 1980s. INR employs minimally invasive techniques to treat complex cerebrovascular diseases in the head, neck, and spine. The study establishes diagnostic reference levels (DRLs) for three clinical indications (CIs): stroke (S), brain aneurysms (ANs), and brain arteriovenous malformation (AVM). Data from 209 adult patients were analyzed, and DRLs were determined in terms of various dosimetric and technical quantities. For stroke, the established DRLs median values were found to be 78 Gy cm2, 378 mGy, 118 mGy, 12 min, 442 images, and 15 runs. Similarly, DRLs for brain AN are 85 Gy cm2, 611 mGy, 95.5 mGy, 19.5, 717 images, and 26 runs. For brain AVM, the DRL's are 180 Gy cm2, 1144 mGy, 537 mGy, 36 min, 1375 images, and 31 runs. Notably, this study is unique in reporting DRLs for specific CIs within INR procedures, providing valuable insights for optimizing patient safety and radiation exposure management.

Challenges and Potential of Artificial Intelligence in Neuroradiology.

PURPOSE: Artificial intelligence (AI) has emerged as a transformative force in medical research and is garnering increased attention in the public consciousness. This represents a critical time period in which medical researchers, healthcare providers, insurers, regulatory agencies, and patients are all developing and shaping their beliefs and policies regarding the use of AI in the healthcare sector. The successful deployment of AI will require support from all these groups. This commentary proposes that widespread support for medical AI must be driven by clear and transparent scientific reporting, beginning at the earliest stages of scientific research. METHODS: A review of relevant guidelines and literature describing how scientific reporting plays a central role at key stages in the life cycle of an AI software product was conducted. To contextualize this principle within a specific medical domain, we discuss the current state of predictive tissue outcome modeling in acute ischemic stroke and the unique challenges presented therein. RESULTS AND CONCLUSION: Translating AI methods from the research to the clinical domain is complicated by challenges related to model design and validation studies, medical product regulations, and healthcare providers' reservations regarding AI's efficacy and affordability. However, each of these limitations is also an opportunity for high-impact research that will help to accelerate the clinical adoption of state-of-the-art medical AI. In all cases, establishing and adhering to appropriate reporting standards is an important responsibility that is shared by all of the parties involved in the life cycle of a prospective AI software product.

Emergency Intraoperative Ultrasound for the Neurosurgical Trainee.

The use of intraoperative ultrasound in emergency cranial neurosurgical procedures is not well described. It may improve surgical outcomes and is useful when other neuro-navigation systems are not readily available. We provide a practical guide for neurosurgical trainees to utilize ultrasound for various emergency cranial neurosurgical procedures, including lesion localization, insertion of an external ventricular drain, and shunt revision surgery. Intraoperative ultrasound is a useful modality for urgent neurosurgical procedures.

Artificial Intelligence and Deep Learning in Neuroradiology: Exploring the New Frontier.

There have been many recently published studies exploring machine learning (ML) and deep learning applications within neuroradiology. The improvement in performance of these techniques has resulted in an ever-increasing number of commercially available tools for the neuroradiologist. In this narrative review, recent publications exploring ML in neuroradiology are assessed with a focus on several key clinical domains. In particular, major advances are reviewed in the context of: (1) intracranial hemorrhage detection, (2) stroke imaging, (3) intracranial aneurysm screening, (4) multiple sclerosis imaging, (5) neuro-oncology, (6) head and tumor imaging, and (7) spine imaging.

Early intracranial haemorrhages in acute promyelocytic leukaemia: analysis of neuroradiological and clinico-biological parameters.

Acute promyelocytic leukaemia (APL) represents a modern success of precision medicine. However, fatalities occurring within the first 30 days of induction treatment, in particular intracranial haemorrhage (ICH), remain the main causes of death. We studied the clinico-biological characteristics of 13 patients with APL who experienced ICH. Compared to 85 patients without this complication, patients with ICH were older and more frequently had high-risk APL. Moreover, positivity for the 'swirl' sign at neuroradiological imaging and hydrocephalus were predictors of a fatal outcome, together with lower fibrinogen, prolonged international normalized ratio (INR) and higher lactate dehydrogenase levels.

Transition to virtual appointments for interventional neuroradiology due to the COVID-19 pandemic: a survey of satisfaction.

BACKGROUND: The COVID-19 pandemic has changed the way medicine is practiced, including the implementation of virtual care in many specialties. In the field of interventional neuroradiology (INR), virtual clinics are an uncommon practice with minimal literature to support its use. Our objective was to report prospective, single-centre data regarding patient and physician experience with virtual INR clinics for routine follow-up appointments. METHODS: We surveyed all patients that participated in a virtual INR clinic follow-up appointment at our hospital over a 3 month period. Information gathered included length of appointment delays (ie, wait times), length of appointment times, overall satisfaction, and perceived safety metrics. A survey was also sent out to all physicians who participated in virtual clinics with similar questions. RESULTS: 118/122 patients and 6/6 physicians completed the survey. Wait times before previous in-person appointments were perceived to be much longer than virtual appointments, whereas in-person appointment times were longer. 112/118 (94.9%) patients and 4/6 (67%) physicians reported general satisfaction with their virtual clinic experience. There were 8/118 patients who felt their conditions could not be safely assessed virtually, compared with 1/6 (17%) physicians. Lastly, 72.2% of patients reported that they would prefer virtual or telephone visits in the future for non-urgent follow-up, and 5/6 (83%) of physicians reported the same. CONCLUSION: Virtual INR clinics are more efficient and are preferred among patients and physicians for non-urgent follow-up appointments. Our study demonstrates the feasibility of a virtual platform for INR care, which could be sustainable for future practice.

Presurgical differentiation between malignant haemangiopericytoma and angiomatous meningioma by a radiomics approach based on texture analysis.

PURPOSE: To assess whether a machine-learning model based on texture analysis (TA) could yield a more accurate diagnosis in differentiating malignant haemangiopericytoma (HPC) from angiomatous meningioma (AM). MATERIALS AND METHODS: Sixty-seven pathologically confirmed cases, including 24 malignant HPCs and 43 AMs between May 2013 and September 2017 were retrospectively reviewed. In each case, 498 radiomic features, including 12 clinical features and 486 texture features from MRI sequences (T2-FLAIR, DWI and enhanced T1WI), were extracted. Three neuroradiologists independently made diagnoses by vision. Four Support Vector Machine (SVM) classifiers were built, one based on clinical features and three based on texture features from three MRI sequences after feature selection. The diagnostic abilities of these classifiers and three neuroradiologists were evaluated by receiver operating characteristic (ROC) analysis. RESULTS: Malignant HPCs were found to have larger sizes, slighter degrees of peritumoural oedema compared with AMs (P<0.05), and more serpentine-like vessels. The AUC of the enhanced T1WI-based classifier was 0.90, significantly higher than that of T2-FLAIR-based or DWI-based classifiers (0.77 and 0.73). The AUC of the SVM classifier based on clinical features was 0.66, slightly but not significantly lower than the performances of 3 neuroradiologists (AUC=0.69, 0.70 and 0.73). CONCLUSION: Machine-learning models based on clinical features alone could not provide a better diagnostic performance than that of radiologists. The SVM classifier built by texture features extracted from enhanced T1WI is a promising tool to differentiate malignant HPC from AM before surgery.

Laryngeal mask airway for general anesthesia in interventional neuroradiology procedures.

OBJECTIVES:   To evaluate whether using laryngeal mask airway (LMA) made a difference in terms of airway security, hemodynamic changes, complications, and recovery times compared to tracheal intubation during the procedure in patients undergoing general anesthesia for endovascular treatments  of unruptured cerebrovascular aneurysms. METHODS: The electronic medical records database, patient files, and anesthesia charts were examined between May 2008 and September 2016 to identify patients with the following inclusion criteria: 1) aged 18-70 years; 2) American Society of Anesthesiologists (ASA) classification I-III; 3) diagnosis of unruptured CVA; 4) Glasgow coma scale of 15 without neurological deficit; and 5) underwent elective EVT under general anesthesia. RESULTS:   Tracheal tube (TT) was used in 46 patients (group TT, n=46) and LMA in 42 patients (group LMA, n=42). Mean arterial pressure (MAP) levels were increased to greater than 20% of baseline in 14 patients (30.4%) after intubation and in 6 (13%) after extubation in group TT. All LMA patients remained within normal MAP limits (p less than 0.05). Six patients (13%) displayed coughing or straining at extubation in group TT whereas none in group LMA (p less than 0.05). Recovery and discharge times were similar (p greater than 0.05). Conclusion:  Laryngeal mask airway  and TT provided comparable airway security during procedure. Laryngeal mask airway attenuated stress response in hemodynamic parameters at intubation and extubation and smoother emergence compared to TT without delay in recovery.

A Cross Sectional Study of Tumors Using Bio-Medical Imaging Modalities.

BACKGROUND: Digital Signal Processing (D.S.P) is an evolutionary field. It has a vast variety of applications in all fields. Bio medical engineering has various applications of digital signal processing. Digital Image Processing is one of the branches of signal processing. Medical image modalities proved to be helpful for disease diagnosis. Higher expertise is required in image analysis by medical professional, either doctors or radiologists. METHODS: Extensive research is being done and has produced remarkable results. The study is divided into three main parts. The first deals with introduction of mostly used imaging modalities such as, magnetic resonance imaging, x-rays, ultrasound, positron emission tomography and computed tomography. The next section includes explanation of the basic steps of digital image processing are also explained in the paper. Magnetic Resonance imaging modalities is selected for this research paper. Different methods are tested on MRI images. DISCUSSION: Brain images are selected with and without tumor. Solid cum Cystic tumor is opted for the r esearch. Results are discussed and shown. The software used for digital image processing is MATLAB. It has in built functions which are used throughout the study. The study represents the importance of DIP for tumor segmentation and detection. CONCLUSION: This study provides an initial guideline for researchers from both fields, that is, medicine and engineering. The analyses are shown and discussed in detail through images. This paper shows the significance of image processing platform for tumor detection automation.

Micro-imaging of Brain Cancer Radiation Therapy Using Phase-contrast Computed Tomography.

PURPOSE: Experimental neuroimaging provides a wide range of methods for the visualization of brain anatomic morphology down to subcellular detail. Still, each technique-specific detection mechanism presents compromises among the achievable field-of-view size, spatial resolution, and nervous tissue sensitivity, leading to partial sample coverage, unresolved morphologic structures, or sparse labeling of neuronal populations and often also to obligatory sample dissection or other sample invasive manipulations. X-ray phase-contrast imaging computed tomography (PCI-CT) is an experimental imaging method that simultaneously provides micrometric spatial resolution, high soft-tissue sensitivity, and ex vivo full organ rodent brain coverage without any need for sample dissection, staining or labeling, or contrast agent injection. In the present study, we explored the benefits and limitations of PCI-CT use for in vitro imaging of normal and cancerous brain neuromorphology after in vivo treatment with synchrotron-generated x-ray microbeam radiation therapy (MRT), a spatially fractionated experimental high-dose radiosurgery. The goals were visualization of the MRT effects on nervous tissue and a qualitative comparison of the results to the histologic and high-field magnetic resonance imaging findings. METHODS AND MATERIALS: MRT was administered in vivo to the brain of both healthy and cancer-bearing rats. At 45 days after treatment, the brain was dissected out and imaged ex vivo using propagation-based PCI-CT. RESULTS: PCI-CT visualizes the brain anatomy and microvasculature in 3 dimensions and distinguishes cancerous tissue morphology, necrosis, and intratumor accumulation of iron and calcium deposits. Moreover, PCI-CT detects the effects of MRT throughout the treatment target areas (eg, the formation of micrometer-thick radiation-induced tissue ablation). The observed neurostructures were confirmed by histologic and immunohistochemistry examination and related to the micro-magnetic resonance imaging data. CONCLUSIONS: PCI-CT enabled a unique 3D neuroimaging approach for ex vivo studies on small animal models in that it concurrently delivers high-resolution insight of local brain tissue morphology in both normal and cancerous micro-milieu, localizes radiosurgical damage, and highlights the deep microvasculature. This method could assist experimental small animal neurology studies in the postmortem evaluation of neuropathology or treatment effects.

Introduction of a Dedicated Emergency Department MR Imaging Scanner at the Barrow Neurological Institute.

Use of advanced imaging in the emergency department has been increasing in the United States during the past 2 decades. This trend has been most notable in CT, which has increased concern over the effects of increasing levels of medical ionizing radiation. MR imaging offers a safe, nonionizing alternative to CT and is diagnostically superior in many neurologic conditions encountered in the emergency department. Herein, we describe the process of developing and installing a dedicated MR imaging scanner in the Neuroscience Emergency Department at the Barrow Neurological Institute and its effects on neuroradiology and the emergency department in general.

Importance of a dedicated neuroradiologist in reporting high-resolution computed tomography for otosclerosis: a retrospective comparison study of 40 patients.

OBJECTIVES: This study aimed to compare the reporting of high-resolution computed tomography of temporal bones for otosclerosis by general radiologists and a neuroradiologist within a local National Health Service Trust. METHODS: A retrospective case review of 36 high-resolution temporal bone computed tomography images obtained between 2008 and 2015 from 40 otosclerosis patients (surgically confirmed) was performed in a district general hospital setting. The main outcome measures were correct identification of otosclerosis by high-resolution computed tomography and adherence to the petrous temporal bone imaging protocol. RESULTS: Correct diagnosis rates were significantly different when made by general radiologists vs a neuroradiologist (p < 0.0001; two-tailed Fisher's exact test). None of the high-resolution computed tomography scans adhered to the temporal bone imaging protocol. CONCLUSION: The use of high-resolution computed tomography for suspected otosclerosis is helpful for diagnosis, disease staging, obtaining informed consent, surgical planning and prognosis. This study suggests that radiological detection of otosclerotic changes by high-resolution computed tomography of the temporal bone is significantly better when performed by a dedicated neuroradiologist than by a general radiologist. Use of a standardised temporal bone computed tomography protocol is recommended to provide consistently high-quality images for maximising disease detection.

Neuroradiology of human prion diseases, diagnosis and differential diagnosis.

Human transmissible spongiform encephalopathies (TSEs), or prion diseases, are invariably fatal conditions associated with a range of clinical presentations. TSEs are classified as sporadic [e.g. sporadic Creutzfeldt-Jakob disease (sCJD), which is the most frequent form], genetic (e.g. Gerstmann-Straussler-Scheinker disease, fatal familial insomnia, and inherited CJD), and acquired or infectious (e.g. Kuru, iatrogenic CJD, and variant CJD). In the past, brain imaging played a supporting role in the diagnosis of TSEs, whereas nowadays magnetic resonance imaging (MRI) plays such a prominent role that MRI findings have been included in the diagnostic criteria for sCJD. Currently, MRI is required for all patients with a clinical suspicion of TSEs. Thus, MRI semeiotics of TSEs should become part of the cultural baggage of any radiologist. The purposes of this update on the neuroradiology of CJD are to (i) review the pathophysiology and clinical presentation of TSEs, (ii) describe both typical and atypical MRI findings of CJD, and (iii) illustrate diseases mimicking CJD, underlining the MRI key findings useful in the differential diagnosis.

MR Neurography of Brachial Plexus at 3.0 T with Robust Fat and Blood Suppression.

Purpose To develop and evaluate magnetic resonance (MR) neurography of the brachial plexus with robust fat and blood suppression for increased conspicuity of nerves at 3.0 T in clinically feasible acquisition times. Materials and Methods This prospective study was HIPAA compliant, with institutional review board approval and written informed consent. A low-refocusing-flip-angle three-dimensional (3D) turbo spin-echo (TSE) sequence was modified to acquire both in-phase and out-of-phase echoes, required for chemical shift (Dixon) reconstruction, in the same repetition by using partial echoes combined with modified homodyne reconstruction with phase preservation. This multiecho TSE modified Dixon (mDixon) sequence was optimized by using simulations and phantom studies and in three healthy volunteers. The sequence was tested in five healthy volunteers and was evaluated in 10 patients who had been referred for brachial plexopathy at 3.0 T. The images were evaluated against the current standard of care, images acquired with a 3D TSE short inversion time inversion recovery (STIR) sequence, qualitatively by using the Wilcoxon signed-rank test and quantitatively by using the Friedman two-way analysis of variance, with P < .05 considered to indicate a statistically significant difference. Results Multiecho TSE-mDixon involving partial-echo and homodyne reconstruction with phase preservation achieved uniform fat suppression in half the imaging time compared with multiacquisition TSE-mDixon. Compared with 3D TSE STIR, fat suppression, venous suppression, and nerve visualization were significantly improved (P < .05), while arterial suppression was better but not significantly so (P = .06), with increased apparent signal-to-noise ratio in the dorsal nerve root ganglion and C6 nerve (P < .001) with the multiecho TSE-mDixon sequence. Conclusion The multiecho 3D TSE-mDixon sequence provides robust fat and blood suppression, resulting in increased conspicuity of the nerves, in clinically feasible imaging times and can be used for MR neurography of the brachial plexus at 3.0 T. © RSNA, 2016 Online supplemental material is available for this article.

Quadrigeminal cisterna lipoma: report of two cases and literature review / Lipoma da cisterna quadrigeminal: relato de dois casos e revisão da literatura

Intracranial lipomas are congenital, benign and slow-growing tumors. The incidence were 0.1 to 0.5 percent of all primary brain tumors and are often diagnosed in incidental findings of neuroradiological investigation. Lipoma in quadrigeminal region occurs in 25 percent of intracranial lipomas and has been reported as lipomas in quadrigeminal cistern (perimesencephalic cistern), quadrigeminal plate, ambiens cistern or superior medullary velum. MRI is the most major exam. The treatment is conservative in most cases, surgical removal is hampered by their deep location and contiguous with adjacent neurovascular structures. The authors report two cases of lipoma in the quadrigeminal region, incidental findings and discuss the clinical findings, neuroimaging and treatment.

Lipomas intracranianos são tumores congênito, benigno e de crescimento lento. Sua incidência é de 0.1 a 0.5 por cento de todos os tumores cerebrais primários e são frequentemente diagnosticados em achados incidental de investigação neuroradiológica. Lipoma na região quadrigeminal ocorre em 25 por cento dos lipomas intracranianos e tem sido relatados como lipomas na cisterna quadrigeminal (cisterna perimesencefálica), placa quadrigeminal, cisterna ambiens ou véu medular superior. O exame de eleição é ressonância magnética. O tratamento é conservador na maioria dos casos, a remoção cirúrgica é dificultada pela sua localização profunda e da contiguidade com estruturas neurovasculares adjacentes. Os autores relatam dois casos de lipoma na região quadrigeminal achados incidentalmente e discutem os achados clínicos, imagem e tratamento.