Radiofrequency Probe Research Articles

Endoscopic Repair of Cerebrospinal Fluid Leak

BACKGROUND AND IMPORTANCE: The evolution of endoscopic techniques in spine has allowed novel approaches to various pathologies. We describe the use of endoscopy for repair of refractory cerebrospinal fluid (CSF) leak after lumbar puncture (LP). CLINICAL PRESENTATION: A 31-year-old female presented with refractory postural headaches after undergoing LP. The patient underwent 4 total epidural blood patches (EBPs) with minimal symptomatic relief. The LP opening pressure was found to be 18 cm of water, inconsistent with underlying pseudotumor cerebri. A myelogram demonstrated persistent CSF leak and contrast accumulation within the dorsal epidural space at L2-3. Endoscopic exploration was ultimately performed, which demonstrated well-placed EBPs; however, continuous CSF egressed from a pinhole site. This was repaired with coagulation using a radiofrequency probe, DuraSeal (Integra LifeSciences) and DuraGen (Integra LifeSciences). Postoperatively, the patient noted resolution of debilitating intracranial hypotension symptoms and was able to return to work. CONCLUSION: Postdural puncture headaches occur in about 1/3 of patients after LP. Symptoms are often debilitating and can include nausea, neck pain, dizziness, tinnitus, visual changes, and hearing loss. Multiple pharmacological and invasive treatments, such as EBP, have been used historically with success, but Postdural puncture headaches refractory to these interventions can put patients at risk for serious complications including seizures and subdural hematomas. We present the first reported case of an endoscopic approach to repair refractory CSF leak in the lumbar spine. Our approach highlights the potential of minimally invasive endoscopic techniques in the repair of refractory CSF leak from the puncture site after LP.

A novel guided approach to radiofrequency ablation of thyroid nodules: the Toronto Sunnybrook experience.

Thyroid nodules are extremely common being detected by ultrasonography in up to 67% of the population, with current surgical tenet maintaining that lobectomy is required for large symptomatic benign nodules or autonomously functionally nodules resulting in a risk of hypothyroidism or recurrent laryngeal nerve injury even in high volume centres. The introduction of radiofrequency ablation (RFA) has allowed thermal ablation of both benign and autonomously functioning thyroid nodules with minimal morbidity. The moving shot technique is the most well-established technique in performing RFA of thyroid nodules, and has proven to be safe, efficacious, accurate and successful amongst experienced clinicians. The purpose of this article to propose the use of a novel guide when performing RFA of thyroid nodules in clinical practice utilizing the moving shot technique. The technique proposed of RFA involves the use of a 10MHz linear ultrasound probe attached to an 18G guide which provides robust in line visualisation of a 7cm or 10cm radiofrequency probe tip (STARmed, Seoul, Korea) utilizing the trans isthmic moving shot technique. A geometric analysis of the guide has been illustrated diagrammatically. The use of an 18G radiofrequency probe guide (CIVCO Infiniti Plus™ Needle Guide) maintains in line visualisation of the radiofrequency probe over a cross-sectional area up to 28cm2, facilitating efficient and complete ablation of conceptual subunits during RFA of thyroid nodules. Radiofrequency ablation of thyroid nodules can be performed safely and effectively using the novel radiofrequency probe guide proposed which we believe potentially improves both accuracy and overall efficiency, along with operator confidence in maintaining visualisation of the probe tip, and hence we believe provides a valuable addition to the armamentarium of clinicians wishing to embark on performing RFA of thyroid nodules.

Short failure localization in advanced package using optoelectronic sampling terahertz time domain reflectometry and deconvolution method

Failure localization in advanced packaging is a challenging task. Optoelectronic sampling Terahertz time-domain reflectometry (OES THz TDR) employs ultrafast lasers to generate high-frequency THz pulse. The THz pulse is coupled into advanced package trace using radio frequency probe. When there is an open or short failure in the circuit, TDR signal could be captured. Deconvolution processing method was introduced to remove noise from multiple reflections of the remaining circuit. A short failure model with remaining circuit was studied. After deconvolution, the TDR localization accuracy improves from 573 μm to 12 μm, and the correlation coefficient improved from 99.612 % to 99.955 %. Advanced package sample including substrate, C4 bump, interposer, and micro bump was analyzed. By comparing the TDR waveform of short failure sample and references, the short failure is localized inside of the die. By destroying the failure sample and measuring the current-voltage curve, the short failure location is verified.

Double Row Rotator Cuff Repair for Massive Reparable Rotator Cuff Tear

Background: Massive rotator cuff tears, defined as those that involved 2 or more tendons or where the length of the greatest diameter is greater than 5 cm, present a unique surgical challenge as there can be significant scarring, retraction, and poor tissue quality. Furthermore, healing of these tears is less reliable. This video presents our technique for anatomic, double row repair of a massive reparable rotator cuff tear. Indications: Indications for operative intervention include acute traumatic tears, as well as patients with pain and weakness who have failed to respond to conservative management, including physical therapy with confirmed large full thickness rotator cuff tear on advanced imaging. Of note, findings such as glenohumeral osteoarthritis, advanced muscle atrophy (Goutalier III/IV), superior migration of the humeral head >7 mm, and tears larger than 40 mm in length and width are concerning for irreparable tears, and may represent contraindications to surgical repair. Technique Description: The patient is placed in the lateral decubitus position. After diagnostic arthroscopy is performed, a subacromial bursectomy is performed. A radiofrequency probe and arthroscopic shaver are used to perform releases in the subacromial space as well as superior to the glenoid. Preparation of the footprint of the humeral head is then performed to create a good healing surface. The rotator cuff is grasped to confirm tension free mobilization. The medial row anchors are then placed. Once placed, the sutures are incorporated into 2 lateral row anchors in sequential fashion. Subacromial decompression is then performed. Results: Reduced pain and improved shoulder function are the goals of treatment, with sling immobilization lasting for roughly 6 weeks postoperatively prior to initiating strengthening and range of motion protocols. Discussion/Conclusion: Arthroscopic double row repair produces an anatomic and stable reduction of reparable massive rotator cuff tears for patients that have failed conservative management. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Uncertainty analysis of the plasma impedance probe

A plasma impedance probe (PIP) is a type of in situ, radio frequency (RF) probe that is traditionally used to measure plasma properties (e.g., density) in low-density environments such as the Earth's ionosphere. We believe that PIPs are underrepresented in laboratory settings, in part because PIP operation and analysis have not been optimized for signal-to-noise ratio (SNR), reducing the probe's accuracy, upper density limit, and acquisition rate. This work presents our efforts in streamlining and simplifying the PIP design, circuit-based-model, calibration, and analysis for unmagnetized laboratory plasmas, in both continuous and pulsed PIP operation. The focus of this work is a Monte Carlo uncertainty analysis, which identifies operational and analysis procedures that improve SNR by multiple orders of magnitude. Additionally, this analysis provides evidence that the sheath resonance (and not the plasma frequency as previously believed) sets the PIP's upper density limit, which likely provides an additional method for extending the PIP's density limit.

Bailout Options for Intra-operative Implant and Instrumentation Related Incidents and Complications During Arthroscopic Knee Surgery-A Retrospective Study.

Arthroscopic knee procedures are one amongst the common surgical interventions for problems in the knee. It is technically more demanding than an open procedure and is associated with several potential complications. During arthroscopy procedures, several technical challenges may arise, and even experienced surgeons may encounter new issues. However, careful attention to the surgical technique can help prevent or resolve them. The study was conducted on all patients who underwent knee arthroscopy procedure during study period. We recorded details of the implants used and any unexpected situations related to them, as well as how they were managed. Instrumentation-related parameters such as screwdriver issues, radiofrequency ablator issues, scope damages, shaver complications, probe complications, and meniscus suture passing devices were also assessed. In total, there were 12 (3.73%) implant and instrument-related incidents and complications, of which 5 (1.55%) were implant-related and 7 (2.17%) were instrument related. Among the instrumentation-related incidents and complications, two (0.62%) were screwdriver breakage incidents, two (0.62%) were radiofrequency ablator-related incidents, one was arthroscopic probe (0.31%) related incident, one (0.31%) was meniscus suture passing device related complication and one (0.31%) was arthroscope related incident. Surgeons must be ready to anticipate and effectively manage any technical difficulties that may arise during the procedure, maintaining composure in the face of unexpected challenges and guiding the team. In most cases, incidents can be addressed intra operatively and may not have long-term effects on patient outcomes. It is crucial to have multiple implant and instrument backup options available for successful surgery.

New unifying metric for NMR/MRI probe evaluation based on optimized solenoid coil geometry

A three-dimensional numerical simulation of the magnetic field distribution and Bloch equations for arbitrary radio frequency (RF) coils is developed and compared against nuclear magnetic resonance (NMR) experimental results to evaluate the NMR signal intensity. Because NMR is inherently insensitive and its signal intensity is dependent on RF coil geometry, the investigation of RF coil geometry to maximize signal intensity for a given sample volume is important for improving the signal-to-noise ratio (SNR) and shortening the accumulation time. The developed simulation can optimize the RF coil geometry, specifically a single-layer solenoid coil with a constant winding pitch, and the result of the solenoid coil simulation serves as a new unifying metric for evaluating NMR/MRI probes. It is found that the most efficient sample aspect ratio (ratio of sample length to sample diameter) and pitch to wire diameter ratio for the highest signal intensity are around 2.2 and 1.65, respectively. Some discrepancies from the solenoid coil geometry ratios for higher signal intensity in previous studies can be explained by the difference in the gap between the inner diameter of the solenoid coil and the sample diameter. These results are confirmed through NMR signal intensity expressed in voltages with three approaches: 3D simulation, experiment, and estimation based on probe parameters. The simulated signal intensity shows a maximum error of approximately 5 % and an average error of 1 % when compared to the experimental results. This result suggests that the developed methods hold the potential for application in quantitative NMR (qNMR) without relying on standard reference materials. Finally, this study introduces a standardized geometry for the optimized solenoid coil for higher signal intensity and uses it to establish an evaluation metric called the signal-to-optimized-solenoid-signal ratio (3SR). The 3SR addresses the volume-dependence problem in conventional metrics like SNR and SNR per sample volume. It provides a standardized approach for the unified evaluation of all RF coils and probe designs, regardless of sample volume and measurement frequency. Therefore, 3SR can be utilized as a useful metric in the search for optimal coil geometry, while metrics such as SNR or SNR per sample volume are currently used for such purpose. This metric is expected to be useful for NMR/magnetic resonance imaging (MRI) users and developers.

Multinuclear MR and MRI study of lithium-ion cells using a variable field magnet and a fixed frequency RF probe

An exploratory multinuclear magnetic resonance (MR) and magnetic resonance imaging (MRI) study was performed on lithium-ion battery cells with 7Li, 19F, and 1H measurements. A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency (RF) probe was employed in the study. The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz. Two cartridge-like lithium-ion cells, with graphite anodes and LiNi0.5Mn0.3Co0.2O2 (NMC) cathodes, were interrogated. One cell was pristine, and one was charged to a cell voltage of 4.2 V. The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries. These methods open the door for developing faster and simpler methods for detecting, quantifying, and interpreting MR and MRI data from lithium-ion and other batteries.

Use of monopolar and bipolar radiofrequency probes for treatment of cutaneous leiomyoma

Abstract Cutaneous leiomyomas are tumors of smooth muscle origin which appear as erythematous papules and nodules that are mostly painful to touch. Although surgical excision is the gold standard treatment, other destructive methods such as electrodessication, cryotherapy or carbon-dioxide laser may also be done for cure. Our patient presented with painful cutaneous leiyomyomas which resolved well with radiofrequency ablation done with two different techniques using monopolar and bipolar radiofrequency probes. There was no recurrence at 8 months follow-up.

Improving capacitance measurements of aqueous solutions with alpha and beta corrections in a parallel-plate capacitor system: Insights into dielectric properties

Radio-frequency (RF) heating relies on a parallel-plate capacitor heating applicator system, necessitates accurate capacitance measurements despite challenges posed by fringing fields. In this paper, we present protocols for improving capacitance measurements of aqueous solutions in a parallel-plate capacitor heating applicator system operating at a frequency of 27.12 MHz. Our method incorporates alpha and beta corrections to optimize the system, ensuring accurate capacitance measurements and enabling RF heating analysis of various samples. A parallel-plate capacitor was designed to be used for dielectric characterization in terms of capacitance and impedance of water and saline under various conditions at different working temperatures. The capacitance and dielectric properties of pure water and saline solutions with varying concentrations were measured at room temperature (25 °C) using a parallel-plate capacitor and RF probe, respectively. The effects of different concentrations of air, pure water, and saline solution on the capacitance of the parallel-plate capacitor heating applicator system were also studied. Alpha and beta values were estimated from simulations to improve the accuracy and precision of the measurements. Furthermore, our RF heating analysis revealed localized overheating at the edges and corners of dry soybeans, while the remaining areas of the sample exhibited improved heating uniformity. Simulations conducted with different heat transfer coefficients highlighted the significance of RF heating in different food products using a 6 kW, 27.12 MHz RF system. Our findings offer implications for designing optimum parallel-plate capacitor heating applicator systems, applicable to fields such as food processing, medical devices, water treatment, and environmental monitoring.

Water-circulating probes significantly modify lesion length and axon damage in cooled radiofrequency ablations when compared with similar-sized standard radiofrequency probes in rats

IntroductionPreclinical research demonstrated water-cooled radiofrequency (CRF) ablations have a significant impact on structural and functional changes compared to standard radiofrequency (SRF) ablations. Clinical procedures utilizing RF to treat chronic pain...

Quantitative Operando 7Li NMR Investigations of Silicon Anode Evolution during Fast Charging and Extended Cycling.

The development and optimization of fast battery charging protocols require detailed information regarding lithium speciation inside a battery. Nuclear magnetic resonance (NMR) spectroscopy has the unique capability of identifying the Li phases formed in an anode during Li-ion cell operation and quantifying their relative amounts. In addition, both Li metal films and dendrites are readily detected and quantified. Here, our recently reported parallel-plate resonator radio frequency (RF) probe and the cartridge-type single-layer full cell were used to track the behavior of Si electrodes during cycling and during fast charging. The LixSi compounds formed during electrochemical cycling exhibit an unexpected intrinsic nonequilibrium behavior at both slow and fast rates, evolving toward increasingly disordered local environments. The evolution with time of lithiated phases is nonlinear during both charging and discharging at constant current, unlike the case for pure graphite, and asymmetric between charge and discharge. During charging at rates of 1C, 2C, and 3C, metallic Li in both films and (to a lesser extent) dendritic forms are deposited on the Si anode. Part of the Li metal film formation is reversible, but a fraction remains on the electrode surface as dead Li, while all of the dendritic Li, even though formed in a considerably smaller amount, is entirely irreversible. Such performance-governing properties are critical to the development of fast-charging protocols for lithium-ion batteries (LIBs) and are exceptionally well evaluated and quantified by 7Li magnetic resonance strategies such as those presented here.

Is Intraoperative Bleeding Control Useful After Tourniquet Release in Arthroscopic Anterior Cruciate Ligament Reconstruction?

Background Arthroscopic anterior cruciate ligament (ACL) reconstruction is a common orthopedic surgery, and rehabilitation is very important to achieve successful postoperative results. Postoperative hemarthrosis causes pain and limitation of movement, which prolongs the rehabilitation period. For these reasons, various strategies are used to reduce hemarthrosis in patients undergoing ACL reconstruction. This study aimed to evaluate the effect of bleeding control after releasing the tourniquet in ACL reconstruction surgery on the amount of hemarthrosis and pain in the postoperative period. Methodology A total of 60 patients who underwent arthroscopic single-bundle ACL reconstruction were enrolled in this prospective randomized control study. Bleeding control with the radiofrequency (RF) probe after releasing the tourniquet was done at the end of the arthroscopic ACL reconstruction in 30 patients (coagulation group) while bleeding control was not done for the other 30 patients (control group). Both groups were compared in terms of the degree of hemarthrosis using the Coupens and Yates classification in the early postoperative period and the degree of pain using the Visual Analog Scale (VAS) score and postoperative complications. Results In both groups, isolated ACL reconstruction was performed in 10 patients, additional partial meniscectomy in three patients, and additional arthroscopic meniscus repair in 17 patients. There was no statistically significant difference between the coagulation and control groups in terms of VAS (p > 0.05) and the degree of hemarthrosis (p > 0.05). Although the duration of tourniquet application was similar in both groups (p = 0.78), the duration of anesthesia was significantly longer in the coagulation group (p = 0.001). There was no significant difference between the groups in terms of postoperative complications. Conclusions Bleeding control with the RF probe after tourniquet release does not yield superior outcomes. More research with larger populations is needed to confirm these findings.

Measurements of variable capacitance using single port radio frequency reflectometry

A radio frequency (RF) reflectometry technique is presented to measure device capacitances using a probe station. This technique is used to characterize micro-electromechanical system (MEMS) variable capacitor devices that can be connected to create pull-up and pull-down networks used in digital gates for reversible computing. Adiabatic reversible computing is a promising approach to energy-efficient computing that can dramatically reduce heat dissipation by switching circuits at speeds below their RC time constants, introducing a trade-off between energy and speed. The variable capacitors in this study will be measured using single port RF reflectometry achieved with a custom-made RF probe. The RF probe consists of a micromanipulator with an on-board matching network and is calibrated by measuring a capacitive bank that shows a clearly visible frequency shift with the increase in capacitance. The RF probe worked well when measuring static capacitors with no parasitic resistance; however, the frequency shift is masked when measuring the MEMS variable capacitors due to their high in-series parasitic resistance (around 80 kΩ). Therefore, RF reflectometry has the potential to measure MEMS variable capacitors in the range of 0–30 fF when not masked by a high in-series parasitic resistance, creating a fast and versatile method for characterizing variable capacitors that can be used in energy-efficient computing.

The parallel-plate resonator: An RF probe for MR and MRI studies over a wide frequency range

We explore the use of the parallel-plate resonator for the study of thin cuboid samples over a wide range of magnetic resonance frequencies. The parallel-plate resonator functions at frequencies from tens to hundreds of MHz. Seven parallel-plate resonators are presented and discussed in a frequency range from 8 to 500 MHz. Magnetic resonance experiments were performed on both horizontal and vertical bore magnet systems with lithium and hydrogen nuclei. Parallel-plate radiofrequency (RF) probes are easy to build and easy to optimize. Experiments and simulations showed good sensitivity of the parallel-plate RF probe geometry with a small decrease in sensitivity at higher frequencies.

Galaxy clusters in high definition: A dark matter search

Recent radio-frequency probes, with the ATCA and ASKAP telescopes, have proven themselves to be at the forefront of placing indirect limits on the properties of dark matter. The latter being able to substantially exceed the constraining power of Fermi-LAT data. However, these observations were based only on dwarf galaxies, where magnetic field uncertainties are large. Here we reexamine the case for galaxy clusters, often ignored due to substantial diffuse radio backgrounds, by considering the extrapolation of known cluster surface brightness profiles down to scales observable with MeerKAT. Despite large baryonic backgrounds, we find that clusters can be competitive with dwarf galaxies. Extrapolated Coma data being able to rule out weakly interacting massive particles of mass $<700\text{ }\text{ }\mathrm{GeV}$ annihilating via $b$-quarks. This is while having lesser uncertainties surrounding the magnetic field and diffusive environment. Such compelling results are possible due to a clash between the inner shape of the dark matter halo and the flat inner profile of radio halos which is most pronounced for Navarro-Frenk-White-like Einasto profiles, the presence of which having some supporting evidence in the literature.

Deep Learning Multi-Class Approach for Human Fall Detection Based on Doppler Signatures.

Falling events are a global health concern with short- and long-term physical and psychological implications, especially for the elderly population. This work aims to monitor human activity in an indoor environment and recognize falling events without requiring users to carry a device or sensor on their bodies. A sensing platform based on the transmission of a continuous wave (CW) radio-frequency (RF) probe signal was developed using general-purpose equipment. The CW probe signal is similar to the pilot subcarriers transmitted by commercial off-the-shelf WiFi devices. As a result, our methodology can easily be integrated into a joint radio sensing and communication scheme. The sensing process is carried out by analyzing the changes in phase, amplitude, and frequency that the probe signal suffers when it is reflected or scattered by static and moving bodies. These features are commonly extracted from the channel state information (CSI) of WiFi signals. However, CSI relies on complex data acquisition and channel estimation processes. Doppler radars have also been used to monitor human activity. While effective, a radar-based fall detection system requires dedicated hardware. In this paper, we follow an alternative method to characterize falling events on the basis of the Doppler signatures imprinted on the CW probe signal by a falling person. A multi-class deep learning framework for classification was conceived to differentiate falling events from other activities that can be performed in indoor environments. Two neural network models were implemented. The first is based on a long-short-term memory network (LSTM) and the second on a convolutional neural network (CNN). A series of experiments comprising 11 subjects were conducted to collect empirical data and test the system's performance. Falls were detected with an accuracy of 92.1% for the LSTM case, while for the CNN, an accuracy rate of 92.1% was obtained. The results demonstrate the viability of human fall detection based on a radio sensing system such as the one described in this paper.

Contactless RF Probe Interconnect Technology Enabling Broadband Testing to the Terahertz Range

Radiofrequency (RF) probes based on 50- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\Omega$</tex-math></inline-formula> planar transmission lines play a key role in almost every stage of RF device development, establishing the physical contact between high-end instrumentation and the device. With the continuous downscaling of semiconductor technologies to reach into the millimeter-wave (30–300 GHz) and Terahertz (300 GHz to 3 THz) bands and devices exhibiting broader frequency response, current RF probe technology is the Achilles heel for precise and repeatable measurements. Here, we propose a novel RF probe technology based on the near-field coupling of single-mode dielectric waveguide structures, which according to our full-wave simulations provide an extremely broad frequency range covering from 0 Hz up to 340 GHz, the largest continuous bandwidth reported to date. A concept demonstrator using this approach shows contactless RF probing on test structures, which shows the path toward continuous measurements across the microwave, millimeter-wave, and Terahertz range.

Multibranched-Based Fluorinated Materials: Tailor-Made Design of 19F-MRI Probes

ConspectusFuture medicine is primarily aiming at the development of novel approaches for an early diagnosis of diseases and a personalized therapy for patients. For achieving these objectives, a key role is played by medical imaging. Among available noninvasive imaging techniques, Fluorine-19 (19F) Magnetic Resonance Imaging (MRI) is emerging as a powerful quantitative detection modality for clinical use both for molecular imaging and for cell tracking.The strength of using 19F-MRI is mainly related to the lack of endogenous organic fluorine in tissues, with no background, enabling the visualization of fluorinated tracers as hot-spot images, adding secondary independent information to the anatomical features provided by the grayscale 1H-MRI. The main challenge for 19F-MRI clinical application is the intrinsic reduced sensitivity of MRI. To improve sensitivity, undoubtedly the use of a high field MRI scanner and cryogenic radiofrequency probes is advantageous, but there is a clear need of developing increasingly effective fluorinated tracers.The ideal tracer should bear as many as possible magnetically equivalent fluorine atoms and show optimal magnetic resonance relaxivity properties (i.e., T1 and T2), which enable reduced acquisition time with the possibility to apply fast imaging methods. Moreover, it should be biocompatible with reduced tendency to bioaccumulate in tissues, which is one of the main drawbacks in using perfluorocarbons (PFCs), together with their difficulty to be chemically modified with functional groups. In fact, PFCs such as perfluorooctyl bromide (PFOB), perfluoro-15-crown-5-ether (PFCE), and linear perfluoropolyethers (PFPE) are currently the most used tracers in 19F-MRI preclinical and clinical studies, with the above-mentioned limitations. In this regard, molecules bearing short branched fluorinated chains gained a lot of attention for their high number of equivalent fluorines and expected capability of reducing bioaccumulation concerns. A valuable building block for branched fluorinated tracers is perfluoro-tert-butanol (PFTB), with nine magnetically equivalent fluorines and easy availability and modification.In this Account we will discuss the main challenges that 19F-MRI has to overcome for increasing its clinical use, highlighting on one hand the need of developing customized fluorinated materials for increasing sensitivity and enabling multimodal properties, and on the other hand, the importance of the ultrastructure of the final formulation for the final biological response (i.e., clearance). In this context, our group has been focusing on the synthesis and development of branched fluorinated tracers, for which the originator is a molecule called PERFECTA (from suPERFluorinatEdContrasT Agent), bearing 36 equiv 19F atoms, which showed not only optimal relaxometry properties but also a very specific and intense Raman signal. Thus, PERFECTA and its derivatives represent a new family of multimodal tracers enabling multiscale analysis, from whole body imaging (19F-MRI) to microscopic detection at the cellular/tissue level (Raman microscopy). We believe that our proposed PFTB strategy can strongly promote the production of increasingly effective 19F-MRI materials with additional functionalities, facilitating the clinical translation of this imaging modality.

Target-oriented Percutaneous Lumbar Annuloplasty in Ambulatory Spine Center: Proctorship Description of Technique

Objective: To describe an alternative technique of annuloplasty for treatment of chronic discogenic back pain in an ambulatory setting.Method: A retrospective review of all patients presenting with chronic discogenic low back pain and managed by target-oriented thermal annuloplasty at our institute from May 2015 to June 2019 was performed. The procedure is carried out under local anaesthesia in prone position. The principle of the technique relies on dividing the posterior annulus into nine equal segments on AP-view of the C-arm. The trajectory is through the Kambin’s triangle in a horizontal trajectory as much as possible to target the posterior part of the disc annulus. Each of the nine segments is treated with radio-frequency probe to produce disc alterations required to relieve the pain.Results: A total of 9 patients were treated by this method with an average follow-up of 28.1±11.4 months. The average VAS improved from 4.1±1.2 to 2.5±0.4 at final follow-up. The ODI improved from 42±6.7 to 19.98±5.6. None of the patients had any complications. The patient satisfaction rate was 82%, the rate of return to daily life was 100% and recommendation rate to others was 100%.Conclusion: Target-oriented lumbar percutaneous nine point annuloplasty may be considered as a viable option for chronic discogenic back pain patients with relatively well-maintained disc heights. A successful outcome depends upon proper patient selection and correct trajectory.