MRI Devices Research Articles

How Much Do We Remove the Effects of the Site in Multisite MRI-Based Machine Learning?

Multisite MRI-based machine-learning benefits from larger sample sizes, but the use of different MRI devices introduces effects of the site (EoS). Several methods (e.g., ComBat) remove EoS, increasing accuracy. However, these methods may leave residual EoS that biasedly inflate the accuracy. Thus, we cannot know if EoS-removal methods associated with increased accuracy truly remove more EoS or, conversely, fail to remove EoS that inflate the accuracy. We present a strategy to measure the true efficacy of EoS-removal methods.

Computational Intelligence and Metaheuristic Techniques for Brain Tumor Detection through IoMT-Enabled MRI Devices

The brain tumor is the 22nd most common cancer worldwide, with 1.8% of new cancers. It is likely the most severe ailment that necessitates early discovery and treatment, and it requires the competence of neurosubject-matter experts and radiologists. Because of their enormous increases in data search and extraction speed and accuracy, as well as individualized treatment suggestions, machine and deep learning techniques are being increasingly commonly applied throughout healthcare industries. The current study depicts the methodologies and procedures used to detect a tumor inside the brain utilizing machine and deep learning techniques. Initially, data were preprocessed using contrast limited adaptive histogram equalization. Then, features were extracted using principal component analysis and independent component analysis (ICA). Next, the image was smoothed using multiple optimization techniques such as firefly and cuckoo search, lion, and bat optimization. Finally, Naïve Bayes and recurrent neural networks were utilized to classify the improved results. According to the findings, the ICA with cuckoo search and Naïve Bayes has the best mean square error rate of 1.02. With 64.81% peak signal-to-noise and 98.61% accuracy, ICA with hybrid optimization and a recurrent neural network (RNN) proved to better than the other algorithms. Furthermore, a Smartphone application is designed to perform quick and decisive actions. It helps neurologists and patients identify the tumor from a brain image in the early stages.

Dual k-space and image-space post-processing for field-cycling MRI under low magnetic field stability and homogeneity conditions

We present a method to correct artifacts typically present in images acquired in field-cycled MRI experiments under poor magnetic field spatial-homogeneity and time-stability conditions. The proposed method was tested in both simulated and experimental data. The experiments were performed using a fast field-cycling MRI relaxometer of own design, based on a current-driven variable-geometry electromagnet. Current instability-induced artifacts in the images were mitigated through a phase correction array resulted from entropy and background minimization. Image distortions due to magnetic field inhomogeneity were compensated through two different approaches, involving a previous determination of the magnetic field homogeneity-map, or an experimental protocol where two images are acquired with inverted readout gradient polarity. Results show that images acquired at extreme conditions can be successfully improved, thus strengthening the possibilities for both low-cost MRI devices and faster field-switched MRI systems.

A systematic review of next-generation point-of-care stroke diagnostic technologies

Stroke is a leading cause of morbidity and mortality. Current diagnostic modalities include CT and MRI. Over the last decade, novel technologies to facilitate stroke diagnosis, with the hope of shortening time to treatment and reducing rates of morbidity and mortality, have been developed. The authors conducted a systematic review to identify studies reporting on next-generation point-of-care stroke diagnostic technologies described within the last decade. A systematic review was performed according to PRISMA guidelines to identify studies reporting noninvasive stroke diagnostics. The QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) tool was utilized to assess risk of bias. PubMed, Web of Science, and Scopus databases were utilized. Primary outcomes assessed included accuracy and timing compared with standard imaging, potential risks or complications, potential limitations, cost of the technology, size/portability, and range/size of detection. Of the 2646 reviewed articles, 19 studies met the inclusion criteria and included the following modalities of noninvasive stoke detection: microwave technology (6 studies, 31.6%), electroencephalography (EEG; 4 studies, 21.1%), ultrasonography (3 studies, 15.8%), near-infrared spectroscopy (NIRS; 2 studies, 10.5%), portable MRI devices (2 studies, 10.5%), volumetric impedance phase-shift spectroscopy (VIPS; 1 study, 5.3%), and eddy current damping (1 study, 5.3%). Notable medical devices that accurately predicted stroke in this review were EEG-based diagnosis, with a maximum sensitivity of 91.7% for predicting a stroke, microwave-based diagnosis, with an area under the receiver operating characteristic curve (AUC) of 0.88 for differentiating ischemic stroke and intracerebral hemorrhage (ICH), ultrasound with an AUC of 0.92, VIPS with an AUC of 0.93, and portable MRI with a diagnostic accuracy similar to that of traditional MRI. NIRS offers significant potential for more superficially located hemorrhage but is limited in detecting deep-seated ICH (2.5-cm scanning depth). As technology and computational resources have advanced, several novel point-of-care medical devices show promise in facilitating rapid stroke diagnosis, with the potential for improving time to treatment and informing prehospital stroke triage.

RETRACTED ARTICLE: Current status, utilization, and geographic distribution of MRI devices in Jordan

RETRACTED ARTICLE: Current status, utilization, and geographic distribution of MRI devices in Jordan

A 20-gauge active needle design with thin-film printed circuitry for interventional MRI at 0.55T.

This work aims to fabricate RF antenna components on metallic needle surfaces using biocompatible polyester tubing and conductive ink to develop an active interventional MRI needle for clinical use at 0.55 Tesla. A custom computer numeric control-based conductive ink printing method was developed. Based on electromagnetic simulation results, thin-film RF antennas were printed with conductive ink and used to fabricate a medical grade, 20-gauge (0.87 mm outer diameter), 90-mm long active interventional MRI needle. The MRI visibility performance of the active needle prototype was tested in vitro in 1 gel phantom and in vivo in 1 swine. A nearly identical active needle constructed using a 44 American Wire Gauge insulated copper wire-wound RF receiver antenna was a comparator. The RF-induced heating risk was evaluated in a gel phantom per American Society for Testing and Materials (ASTM) 2182-19. The active needle prototype with printed RF antenna was clearly visible both in vitro and in vivo under MRI. The maximum RF-induced temperature rise of prototypes with printed RF antenna and insulated copper wire antenna after a 3.96 W/kg, 15 min. long scan were 1.64°C and 8.21°C, respectively. The increase in needle diameter was 98 µm and 264 µm for prototypes with printed RF antenna and copper wire-wound antenna, respectively. The active needle prototype with conductive ink printed antenna provides distinct device visibility under MRI. Variations on the needle surface are mitigated compared to use of a 44 American Wire Gauge copper wire. RF-induced heating tests support device RF safety under MRI. The proposed method enables fabrication of small diameter active interventional MRI devices having complex geometries, something previously difficult using conventional methods.

Reduced spatial resolution MRI suffices to image and quantify drought induced embolism formation in trees

BackgroundMagnetic resonance imaging (MRI) is uniquely suited to non-invasively and continuously monitor embolism formation in trees. Depending on the MRI method used, quantitative parameter maps of water content and MRI signal relaxation behavior can be generated. The ability to measure dynamic differences in water content and relaxation behavior can be used to detect xylem embolism formation, even if xylem conduits are too small to be spatially resolved. This is especially advantageous when using affordable small-scale low-field MRI scanners. The amount of signal that can be obtained from an object strongly depends on the strength of the magnetic field of the imager’s magnet. Imaging at lower resolutions thus would allow to reduce the cost, size and weight of the MRI scanner and to shorten image acquisition times.ResultsWe investigated how much spatial resolution can be sacrificed without losing the ability to monitor embolism formation in coniferous softwood (spruce, Picea abies) and diffuse porous beech (Fagus sylvatica). Saplings of both species were bench dehydrated, while they were continuously imaged at stepwise decreasing spatial resolutions. Imaging was done by means of a small-scale MRI device, utilizing image matrix sizes of 128 × 128, 64 × 64 and 32 × 32 pixels at a constant FOV of 19 and 23 mm, respectively. While images at the lowest resolutions (pixel sizes 0.59 × 0.59 mm and 0.72 × 0.72 mm) were no longer sufficient to resolve finer details of the stem anatomy, they did permit an approximate localization of embolism formation and the generation of accurate vulnerability curves.ConclusionsWhen using MRI, spatial resolution can be sacrificed without losing the ability to visualize and quantify embolism formation. Imaging at lower spatial resolution to monitor embolism formation has two advantages. Firstly, the acquisition time per image can be reduced dramatically. This enables continuous imaging at high time resolution, which may be beneficial to monitor rapid dynamics of embolism formation. Secondly, if the requirements for spatial resolution are relaxed, much simpler MRI devices can be used. This has the potential to make non-invasive MR imaging of embolism formation much more affordable and more widely available.

Applying Cross-Modality Data Processing for Infarction Learning in Medical Internet of Things

Cross-modality data processing is critical for the Internet-of-Things (IoT) deployment in healthcare. It can convert the innumerable raw day-to-day medical big data from massive IoT-based medical devices to diagnostic valuable data so that they can be feed to clinical routine. In this article, we propose a novel spatiotemporal two-streams generative adversarial network (SpGAN) as a cross-modality data processing approach to deploy the medical IoT in infarction learning. Our SpGAN remotely converts diagnostic valuable contrast-enhanced images (the “gold standard” for infarction learning, but it requires the injection of contrast agents) directly from raw nonenhanced cine MR images. This converting allows physicians to remotely perform infarction observation and analysis to break through the limitations of time and space by building a cloud computing platform of IoT-based MRI devices. Importantly, this converting offers a low-risk IoT-based manner to eliminate the potential fatal risk caused by contrast agent injection in the current infarction learning workflow. Specifically, SpGAN consists of: 1) a spatiotemporal two-stream framework as an encoding–decoding model to achieve data converting and 2) a spatiotemporal pyramid network enhances those features that are responsible to the infarction learning during encoding to improve decoding performance. Real IoT-based remote diagnosis experiments performed on 230 patients demonstrate that SpGAN provides high-quality converted images for infarction learning and promotes the in-depth application and deployment of IoT in the medical field.

Incidental Finding Prevalences in 3-Tesla Brain and Spine MRI of Military Pilot Applicants.

INTRODUCTION: Incidental findings in brain and spine MRI are common. In aerospace medicine, pilot selection may be affected by improved sensitivity of modern MRI devices. We investigated the occurrence of medically unfit rates caused by incidental findings in military pilot applicants using a 3-Tesla scanner as compared to the outcomes of a lower field strength 1-Tesla device based on similar screening protocols.METHODS: A total of 3315 military pilot applicants were assessed by a standardized German Air Force Imaging Screening Protocol and retrospectively subdivided into two cohorts, one of which was assessed by 1-Tesla MRI (2012-2015; N 1782), while in the second cohort (2016-2019; N 1808), a 3-Tesla MRI was used. Cohorts were statistically analyzed relating to three entities of incidental findings: 1) intervertebral disc displacements, 2) intracerebral vessel malformations, and 3) other abnormal findings in the brain.RESULTS: Pooled prevalences of incidental findings in medically unfit applicants significantly increased by use of 3-Tesla MRI as compared to lower resolution 1-Tesla MRI. Regarding the spine, prevalences more than doubled (1.46 vs. 4.99%; P < 0.05) for intervertebral disc displacements. Similarly, prevalences of cerebral vessel malformations as well as other abnormal CNS incidental findings considerably increased by use of 3-Tesla MRI (0.28 vs. 1.67%; P < 0.05, and 5.12 vs. 9.80%; P < 0.05). Effect sizes and correlations were substantial in all conditions analyzed (Cohens d > 0.8; Pearsons r > 0.75).CONCLUSIONS: Our data suggest a strong dependency of incidental cerebrospinal findings on image resolution and sensitivity of MRI devices used for screening, which is enhanced by refined imaging protocols and followed by increased medical unfit rates in prospective aviators. Adjusted strategies in the assessment of such lesions are needed to redefine their natural history and physiological impact, and to optimize screening protocols for future pilot selection.Snksen S-E, Khn SR, Nobl H-J, Knopf H, Ehling J, Jakobs FM, Frischmuth J, Weber F. Incidental finding prevalences in 3-Tesla brain and spine MRI of military pilot applicants. Aerosp Med Hum Perform. 2021; 92(3):146152.

Organization of postmortem radiological examination in the structure of pathological departments and forensic bureaus

The purpose of this work is to develop an optimal scheme for organizing and conducting postmortem radiation studies in the Russian Federation based on literature data and our own results. One of the primary points in organizing virtopsiy is to determine the place where radiation examinations of deceased patients will be performed. The absence or presence of the equipment and capabilities available in the institution, i.e., the department of radiation diagnostics with functioning CT and MRI devices and software, determines the volume of economic costs. The analysis of the results of radiation research methods should be carried out by a highly qualified radiologist who has both general knowledge of radiation diagnostics and information about the radiation pattern of nonspecific postmortem changes. Based on our own experience in organizing postmortem radiation examinations, we consider it optimal to conduct postmortem CT and/or MRI scans by an X-ray technician in the radiation diagnostics department and to introduce a separate radiologist in the staffing of the pathology department or forensic medical examination bureau. In our opinion, an examination of the corpse by a radiologist in conjunction with a forensic expert is required to determine the most important areas of interest, tactics and methodology of radiation research. The final conclusion of the radiologist should be formed after consultation and agreement of the identified changes with a pathologist or forensic expert. Virtopsy is a highly effective objective method for examining a corpse. This dictates the need for its widespread introduction into the practice of the forensic medical examination bureaus and pathological and anatomical departments.

Technology takeover.

A recent editorial on artificial intelligence1 referred to many tasks now based on digital technology. It led me to find a page, reproduced below, which I wrote 25 years ago, in 1995, as the Royal Alexandra Hospital for Children moved from Camperdown to Westmead. I was pleased to see the predicted reliance on evidence, even if some other predictions are unlikely to materialise any time soon. The New Children's Hospital was at the forefront of electronic advances in 1995. But the pace of change over the next 7 years was anticipated by very few people. By 2002, the Departments of Fund Raising, Public Affairs, Information Technology, Cochrane Studies and Multimedia accounted for 85% of budget expenditure. Clinicians have been almost entirely phased out (Fig. 1). Some previous clinicians with computer and survival skills have become protocol writers. All management is by protocol and all protocols are based on outcome studies. All investigations are electronically ordered. For instance, to investigate for short stature, verified age and anthropometric data allow a predetermined set of tests to be done upon the striking of a single key by a certified person (not a medical graduate) after entering correct passwords and family ability-to-pay information. lnpatient beds have been reduced to 95; ward rounds are done not by medical staff (who now sit at computers in a purpose-built institute) but by physical signs clinical nurse specialists equipped with portable ultrasound, CT, MRI, EEG, cardiac echo and other sophisticated devices. Bronchoscopies are done with minimal invasion and airway dynamics alteration by using specially trained ladybirds with xylocaine-padded feet, homing devices, miniature video and transmitting devices (another victory for feminism). All examination and investigation is by protocol. The clinical nurse specialists are cheaper and more accurate than physicians. Much of the surgery is now carried out by robots or by technicians who have been found to be cheaper and often quicker than surgeons. However, surgeons remain in charge of every case, and direct proceedings from their computer and video stations. Robotic surgeons have even been made more life-like, in that they can be programmed to occasionally throw an instrument or shout. Every medical procedure is captured on video with archival storage for subsequent medicolegal proceedings. Outpatient clinics are done exclusively ‘at a distance’. Physicians sit at computer/video terminals where they first assess computer-validated questionnaires. Where examination is considered necessary it is done via the BIOPAW – a remote controlled palpation device with inbuilt ultrasound. Once again continuous video recording and archiving is carried out for medicolegal and other purposes. Such recordings have already been used to defend an allegation of assault by BIOPAW. Patient education is of course by video; pre-recorded automated opinions are generated for any imaginable circumstance and for some unimaginable ones as well. To increase productivity of protocol writers, Cochrane clerks, terminal physicians and surgeons, administration (a most sophisticated computer) has provided incentives such as banking, stock-broking, virtual food and virtual sex without leaving the workplace. Academics no longer have to interact with students, as computers do it better, so they are free to roam the world as long as they log in from time to time. Unfortunately there has been a downside. Virtual food has become so real that some physicians have starved to death. Virtual sex has led to some nasty electrical burns and one death from a heart attack. Too many choices of networks have driven some mad and others to states of useless confusion.

Association between cognition and gait in elderly people: The putamen as a shared substrate

AbstractBackgroundCognitive impairment and gait disturbance are both prevalent in elderly people. However, few studies have focused on the underlying mechanisms in the relationship between cognition and gait. The aim of our study is to contrast the strength of correlations between each cognitive domain and gait parameters in a community‐dwelling population, as well as giving a new insight into the shared neuroimaging signature of cognitive impairment and gait disturbance.MethodIn the cross‐sectional population‐based Taizhou Imaging Study, 733 older adults with a mean (SD) age of 63.9 (3.1) years accepted brain MRI, neuropsychological tests and wearable gait tracking devices for quantitative gait analysis. Global cognitive function and individual cognitive domains (memory, executive function, language, visuospatial skill) were assessed using the Mini‐Mental State Examination, auditory verbal learning test (with&gt;6 years of education), modified Fuld Object Memory Evaluation (with≤6 years of education), conflicting instructions task, clock drawing test and animal fluency test. Dementia and mild cognitive impairment (MCI) were diagnosed according to DSM‐5 criteria and the Petersen criteria. The volume of brain regions was analyzed by Freesurfer.ResultOf the 733 participants, 500 (68.2%) were cognitive normal, 182 (24.8%) were diagnosed as MCI, 51 (7.0%) were diagnosed as dementia. Gait parameters, including gait velocity, stride length and cadence, were significantly different among three cognition groups (P&lt;0.001). In fully adjusted linear regression models, global cognitive function and each cognitive domain were significantly associated with gait parameters. Executive function demonstrated the strongest association with gait (β: 0.149‐0.206, P&lt;0.001), which remained significant when adjusted for memory, language and visuospatial skill. The volume of putamen was the only region that was related to both executive function (β=0.103, P=0.007) and gait velocity (β=0.107, P=0.007). Mediation analysis confirmed a mediating role of putaminal atrophy in the association between executive function and gait velocity.ConclusionCognitive function is associated with gait performance in community‐dwelling elderly individuals. Executive function had the strongest association with gait among cognitive domains, which is supported by a shared substrate including putaminal atrophy. Future longitudinal studies with neuroimaging techniques are needed to further confirm our findings.

The Role of Fetal Magnetic Resonance Imaging in Prenatal Diagnosis

ÖZET Amaç Üçüncü basamak merkezimizde klinisyenler tarafından tercih edilen fetal MRG endikasyonlarının incelenmesi ve MRG’nin ultrason bulgularına olan ek tanısal katkısının ortaya konmasıdır. Gereç ve Yöntem 2016-2018 yılları arasında fetal MRG yapılan 322 olgu retrospektif olarak incelendi. Fetal lezyonlar organ sistemlerine göre sınıflandırıldı ve klinisyenlerin endikasyonları belirlendi. Prenatal dönemde yapılan fetal ultrason ve MRG sonuçları değerlendirildi. Bulgular MRG çekilen 322 fetüsün endikasyonlarının dağılımı; 138’inde (%42.8) santral sinir sistemi anomalileri, 99’unda (%30.7) plasental anomaliler, 36’sında (%11.2) genitoüriner sistem anomalileri, 18’inde (%5.6) solunum sistemi anomalileri, 17’sinde (%5.3) maternal faktör, 13’ünde (%4) baş, boyun, yüz anomalileri ve 1’inde (%0.4) fetal faktör olarak belirlendi.Tüm endikasyonlar incelendiğinde MRG ile ek bulgu saptanan olgu sayısı 13’tür (%4.03). Santral sinir sistemi anomalileri 7 olgu ile en sık ek bulgu saptanan gruptur, bu grup içerisinde fetal MRG %5.07 oranında ek katkı sunmuştur. Sırasıyla genitoüriner sistem anomalileri olan grupta 3 ek bulgu (%8.33 oranında ek katkı), maternal endikasyonlar grubunda 2 ek bulgu (%11.7 oranında ek katkı) ve solunum sistemi anomalileri olan grupta 1 ek bulgu (%5.55 oranında ek katkı) olduğu görüldü. Sonuç Ultrasonografinin yetersiz kaldığı hallerde uygun perinatal yönetim ve danışmanlık için fetal MRG giderek artan sıklıkta kullanılmaktadır. MR cihazlarının daha ulaşılabilir olması, bu alandaki uzmanlığın artması ve MRG teknolojisindeki ileri gelişmeler, bu modalitenin perinatoloji alanında daha yaygın kullanımı ile sonuçlanacaktır.

Author response: MRI predicts intracranial hemorrhage in patients who receive long-term oral anticoagulation.

We thank Vilanilam et al. for their interest in our study. As reflected in our study,1 the heterogeneity of the images obtained, both in relation to the MRI field strength and in the MRI sequences used, is an important limitation of our study. We are therefore in complete agreement on the need for future studies to consider the technical characteristics of obtaining and evaluating images. However, our study reflects the reality of care—at least in Spain—where each institution updates its MRI devices and uses the sequences used for each clinical reality according to local protocols.

Impact on gadolinium anomaly in river waters in Tokyo related to the increased number of MRI devices in use

The Gd-based contrast agents utilized in magnetic resonance imaging are difficult to remove by usual sewage treatment technology, and they enter rivers in the discharges from waste water treatment plants. Gd anomaly in rivers has been considered depends on used amount of Gd-based contrast agents. In this study, variation of Gd anomaly in rivers of Tokyo was determined by comparisons to previously reported values. The range of anthropogenic Gd was 0.1–138.8 ppt with an average value of 35.5 ppt (n = 40); in particular, the anthropogenic Gd was significantly changed depending on the location of the waste water treatment plants, and the measurement revealed significant increases in the Gd anomaly in the range of 5.0–6.6 times compared to data obtained 22 years ago. This study highlights the necessary of continuous research in setting new public policies for medical practices.

A bridged loop gap resonator (BLGR) for small animal imaging by 1.5 T MRI systems.

A bridged loop gap resonator (BLGR) was developed as a transmit and receive coil for a mobile insert to be used for small animal proton imaging by 1.5 T MRI devices. The insert system has its own gradient system, radio frequency (RF) transmit and receive coil, and control and signal processing unit. The reflection S11 and transmission S21 parameters, quality factor (Q), sensitivity, signal to noise ratio (SNR), and maps of the static (B0) and RF (B1) magnetic flux densities were measured. The RF coil was developed starting from a loop gap resonator (LGR) for a balanced LGR and a shielded balanced LGR for a shielded bridged balanced LGR. The purpose of developing this device is to minimize the influence of the sample and surroundings on the RF coil parameters. The final design of the BLGR does not require retuning after a sample change. A 3D image of a mouse in formalin was acquired with a fast low angle shot (FLASH) MRI sequence. The SNR was calculated from one FLASH image. The signal for SNR calculation was acquired from a gadolinium-doped water sample and the noise from the air outside of the sample. This article verifies that the BLGR is viable for small animal nuclear magnetic resonance imaging at 1.5 T and is independent of sample size and material.

Dimensions of artefacts caused by cochlear and auditory brainstem implants in magnetic resonance imaging

Background: The aim of the study was to investigate the extent of MRI artefacts due to the magnet of selected auditory implants.Study design: Artefacts of the Synchrony cochlear implant at 1.5 T as well as at 3 T MRI devices were examined in cadavers and compared to the artefacts in MRI scans at 1.5 T of 17 patients implanted with CI (n = 12) and auditory brainstem implants (ABI) (n = 5).Results: None of the scanned implants showed any failure after MRI. After removal of the magnet, only a portion of the images in the direct neighbourhood of the implant, especially in the temporal and parietal lobe, contained artefacts. More anatomical substructures were visible without artefacts using the MedEl Synchrony device.Conclusion: Artefacts can be markedly reduced by rotating, self-aligning magnet. Removal of the magnet also results in reduction of artefacts.

A medical transportation robot for carrying and positioning patients between different devices

Purpose This paper aims to present a prototype of medical transportation robot whose positioning accuracy can reach millimeter-level in terms of patient transportation. By using this kind of mobile robot, a fully automatic image diagnosis process among independent CT/PET devices and the image fusion can be achieved. Design/methodology/approach Following a short introduction, a large-load 4WD-4WS (four-wheel driving and four-wheel steering) mobile robot for carrying patient among multiple medical imaging equipments is developed. At the same time, a specially designed bedplate with self-locking function is also introduced. For further improving the positioning accuracy, the authors proposed a calibration method based on Gaussian process regression (GPR) to process the measuring data of the sensors. The performance of this robot is verified by the calibration experiment and Image fusion experiment. Finally, concluding comments are drawn. Findings By calibrating the robot’s positioning system through the proposed GPR method, one can obtain the accuracy of the robot’s offset distance and deflection angle, which are 0.50 mm and +0.21°, respectively. Independent repeated trials were then set up to verify this result. Subsequent phantom experiment shows the accuracy of image fusion can be accurate within 0.57 mm in the front-rear direction and 0.83 in the left-right direction, respectively, while the clinical experiment shows that the proposed robot can practically realize the transportation of patient and image fusion between multiple imaging diagnosis devices. Practical implications The proposed robot offers an economical image fusion solution for medical institutions whose imaging diagnosis system basically comprises independent MRI, CT and PET devices. Also, a fully automatic diagnosis process can be achieved so that the patient’s suffering of getting in and out of the bed and the doctor’s radiation dose can be obviated. Social implications The general bedplate presented in Section 2 that can be mounted on the CT and PET devices and the self-locking mechanism has realized the catching and releasing motion of the patient on different medical devices. They also provide a detailed method regarding patient handling and orientation maintenance, which was hardly mentioned in previous research. By establishing the positioning system between the robot and different medical equipment, a fully automatic diagnosis process can be achieved so that the patient’s suffering of getting in and out of the bed and the doctor’s radiation dose can be obviated. Originality/value The GPR-based method proposed in this paper offers a novel method for enhancing the positioning accuracy of the industrial AGV while the transportation robot proposed in this paper also offers a solution for modern imaging fusion diagnosis, which are basically predicated on the conjoint analysis between different kinds of medical devices.

Particularities in differential diagnostics of epileptogenic brain malformations on the low-field MRI-device

Background.It has been suggested that the part of the cryptogenic epilepsies is a consequence of minor-foci disorders of cortical architectonics, the diagnosis of which is not always possible due to the unavailability of MR-scanners with high magnetic induction.Objective:determination of the best options of the low-field MRI-device for visualization of epileptogenic brain malformations in children with symptomatic focal forms of epilepsy.Materials and methods.Were analyzed MRI data of 24 children undergoing investigations regarding for difficult-to-treat or pharmacoresistant forms of focal epilepsy in the Department of Magnetic-Resonance Tomography, Central Children Clinical Hospital of FMB Agency of Russia at 2015–2017. All the patients underwent brain MRI according to standard routine protocol. Simultaneously we review conclusions of epileptologist and the preliminary video-electroencefalographic monitoring data for determination of the optimal imaging protocol for every specific form of epilepsy. For imaging of the epileptogenic brain lesion the MRI study was conducted on open-ended device “Aperto” (Hitachi Ltd., Japan) of static magnetic field with the tension characteristics of 0.4 T. The thickness of the slices and the scan step was performed at 3.0 and 3.5 mm (the maximum value of slice thickness and step due to the technical conditions of the used scanner without losing in signalto-noise ratio) with the use of special positioning of slices in the coronal and axial projections, T2, T1, STIR, FLAIR weighted images perpendicular and parallel to the long axis of the hippocampus.Results and conclusion.In 24 patients were revealed structural brain changes that have neuroradiological signs of brain malformations. In all the patients this changes were associated with difficult to treat and drug-resistant forms of focal epilepsy. The newly identified malformations were observed in 10 patients, and in 3 cases the changes detected after previous MRI (including high-field MRI-devices) whose results were false-negative. In 11 patients diffuse brain abnormalities had been revealed, including the combinations of several hypogenesis and dysplastic pathologies. In 13 patients were marked different types of hemispheric and regional disorders of cortical development including focal cortical dysplasia. Extensive unilateral and bilateral changes were clearly distinguishable on the routine MRI. The low-tension technique approximated to the epileptic scanning protocol in some cases allowed to assess the affected area and revealed the combination of different variants of pathological cortical organization. In 7 cases the preliminary diagnosis based on the results of previous MRI studies including high-field MRI-devices. In 2 of these patients this changes were minor-focal, not visualized according to the routine MRI protocol, and had the differentiation characteristics between focal cortical dysplasia IIb/dysembryoplastic neuroepithelial tumor/ganglioglioma types. Disappointing results of visualization of mesial-basal temporal lobe regions aimed to detect small-caliber intracortical formations were observed. These patients contained a separate group of 12 children for whom extensive investigation which includes high-field MRI scan protocol on epileptic program was recommended.

Human adipose-derived stem cells loaded with drug-coated magnetic nanoparticles for in-vitro tumor cells targeting

Magnetic nanoparticles (MNPs) functionalized with different therapeutics delivered by mesenchymal stem cells represent a promising approach to improve the typical drug delivery methods. This innovative method, based on the “Trojan horse” principle, faces however important challenges related to the viability of the MNPs-loaded cells and drug stability.In the present study we report about an in vitro model of adipose-derived stem cells (ADSCs) loaded with palmitate-coated MNPs (MNPsPA) as antitumor drug carriers targeting a 3D tissue-like osteosarcoma cells. Cell viability, MNPsPA-drug loading capacity, cell speed, drug release rate, magnetization and zeta potential were determined and analysed. The results revealed that ADSCs loaded with MNPsPA-drug complexes retained their viability at relatively high drug concentrations (up to 1.22 pg antitumor drug/cell for 100% cell viability) and displayed higher speed compared to the targeted tumor cells in vitro. The magnetization of the sterilized MNPsPA complexes was 67 emu/g within a magnetic field corresponding to induction values of clinical MRI devices. ADSCs payload was around 9 pg magnetic material/cell, with an uptake rate of 6.25 fg magnetic material/min/cell. The presented model is a proof-of-concept platform for stem cells-mediated MNPs-drug delivery to solid tumors that could be further correlated with MRI tracking and magnetic hyperthermia for theranostic applications.