Practical Guidance for Clinical Microbiology Laboratories: Microbiologic diagnosis of implant-associated infections.

SUMMARYImplant-associated infections (IAIs) pose serious threats to patients and can be associated with significant morbidity and mortality. These infections may be difficult to diagnose due, in part, to biofilm formation on device surfaces, and because even when microbes are found, their clinical significance may be unclear. Despite recent advances in laboratory testing, IAIs remain a diagnostic challenge. From a therapeutic standpoint, many IAIs currently require device removal and prolonged courses of antimicrobial therapy to effect a cure. Therefore, making an accurate diagnosis, defining both the presence of infection and the involved microorganisms, is paramount. The sensitivity of standard microbial culture for IAI diagnosis varies depending on the type of IAI, the specimen analyzed, and the culture technique(s) used. Although IAI-specific culture-based diagnostics have been described, the challenge of culture-negative IAIs remains. Given this, molecular assays, including both nucleic acid amplification tests and next-generation sequencing-based assays, have been used. In this review, an overview of these challenging infections is presented, as well as an approach to their diagnosis from a microbiologic perspective.

Current nanocomposite advances for biomedical and environmental application diversity.

Nanocomposite materials are emerging as key players in addressing critical challenges in healthcare, energy storage, and environmental remediation. These innovative systems hold great promise in engineering effective solutions for complex problems. Nanocomposites have demonstrated various advantages such as simplicity, versatility, lightweight, and potential cost-effectiveness. By reinforcing synthetic and natural polymers with nanomaterials, a range of nanocomposites have exhibited unique physicochemical properties, biocompatibility, and biodegradability. Current research on nanocomposites has demonstrated promising clinical and translational applications. Over the past decade, the production of nanocomposites has emerged as a critical nano-structuring methodology due to their adaptability and controllable surface structure. This comprehensive review article systematically addresses two principal domains. A comprehensive survey of metallic and nonmetallic nanomaterials (nanofillers), elucidating their efficacy as reinforcing agents in polymeric matrices. Emphasis is placed on the methodical design and engineering principles governing the development of functional nanocomposites. Additionally, the review provides an exhaustive examination of recent noteworthy advancements in industrial, environmental, biomedical, and clinical applications within the realms of nanocomposite materials. Finally, the review concludes by highlighting the ongoing challenges facing nanocomposites in a wide range of applications.

Emerging Strategies to Prevent Bacterial Infections on Titanium-Based Implants.

Titanium and titanium alloys remain the gold standard for dental and orthopedic implants. These materials are heavily used because of their bioinert nature, robust mechanical properties, and seamless integration with bone. However, implant-associated infections (IAIs) remain one of the leading causes of implant failure. Eradicating an IAI can be difficult since bacteria can form biofilms on the medical implant, protecting the bacterial cells against systemic antibiotics and the host's immune system. If the infection is not treated promptly and aggressively, device failure is inevitable, leading to costly multi-step revision surgeries. To circumvent this dire situation, scientists and engineers continue to develop novel strategies to protect the surface of medical implants from bacteria. In this review, details on emerging strategies to prevent infection in titanium implants are reported. These strategies include anti-adhesion properties provided by polymers, superhydrophobic, superhydrophilic, and liquid-infused surface coatings, as well as strategies and coatings employed to lyse the bacteria. Additionally, commercially available technologies and those under preclinical trials are examined while discussing current and future trends.

Environmental, Microbiological, and Immunological Features of Bacterial Biofilms Associated with Implanted Medical Devices.

The spread of biofilms on medical implants represents one of the principal triggers of persistent and chronic infections in clinical settings, and it has been the subject of many studies in the past few years, with most of them focused on prosthetic joint infections. We review here recent works on biofilm formation and microbial colonization on a large variety of indwelling devices, ranging from heart valves and pacemakers to urological and breast implants and from biliary stents and endoscopic tubes to contact lenses and neurosurgical implants. We focus on bacterial abundance and distribution across different devices and body sites and on the role of environmental features, such as the presence of fluid flow and properties of the implant surface, as well as on the interplay between bacterial colonization and the response of the human immune system.

TIVAP-related infection due to Gram-negative aerobic bacilli: should TIVAP stay or should it go?

We aimed to describe the outcome of totally implantable venous-access port (TIVAP)-related infections due to Gram-negative aerobic bacilli (Pseudomonas aeruginosa and other Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia), or GNAB, and assess the safety of conservative treatment. We conducted a retrospective study in a French teaching hospital, from January 2016 to December 2020, including adult patients treated for TIVAP-related infection due to GNAB. Success of conservative treatment was defined as a functional TIVAP 3 months after infection with no recurrence. We performed a bivariate analysis and analyzed causes for treatment failure. We included 68 patients (53 TIVAP-related bloodstream infections, 11 TIVAP-related infections, and 4 probable TIVAP-related infections) due to GNAB, mostly P. aeruginosa (50/68, 74%). TIVAP removal was initially decided for 49/68 patients (72%). Among the 19/68 (28%) patients with conservative treatment (all for infections caused by P. aeruginosa), 5/19 (26%) had successful treatment, 7/19 (37%) experienced failure (without sepsis or septic shock), 6/19 (32%) died within 3 months without TIVAP removal and no signs of infection recurrence, and 1 patient had TIVAP removal as it was no longer required. TIVAP-related infections caused by GNAB frequently require TIVAP removal. Conservative treatment can be performed in selected patients with a non-complicated infection caused by P. aeruginosa, who can benefit from the continuation of antineoplastic chemotherapy or palliative care. Treatment failures were not associated with sepsis or septic shock.

A Comprehensive Mechanistic Antibacterial and Antibiofilm Study of Potential Bioactive ((BpA)2bp)Cu/Zn Complexes via Bactericidal Mechanisms against Escherichia coli.

Bacterial resistance to antibiotics and host defense systems is primarily due to bacterial biofilm formation in antibiotic therapy. In the present study, two complexes, bis (biphenyl acetate) bipyridine Cu (II) (1) and bis (biphenyl acetate) bipyridine Zn (II) (2), were tested for their ability to prevent biofilm formation. The minimum inhibitory concentration and minimum bactericidal concentration of complexes 1 and 2 were 46.87 ± 1.822 and 93.75 ± 1.345 and 47.87 ± 1.345 and 94.85 ± 1.466 µg/mL, respectively. The significant activity of both complexes was attributed to the damage caused at the membrane level and was confirmed using an imaging technique. The biofilm inhibitory potential levels of complexes 1 and 2 were 95% and 71%, respectively, while the biofilm eradication potential levels were 95% and 35%, respectively, for both complexes. Both the complexes showed good interactions with the E. coli DNA. Thus, complexes 1 and 2 are good antibiofilm agents that exert their bactericidal actions possibly by disrupting the bacterial membrane and interacting with the bacterial DNA, which can act as a powerful agent to restrain the development of bacterial biofilm on therapeutic implants.

Binding stability of peptides to Co-Cr-Mo alloy affects proliferation and differentiation of osteoblast.

Cobalt-chromium-molybdenum (CCM) alloys possess high corrosion-resistant properties as well as good mechanical properties. Hence, the alloys are employed in medical implants such as artificial knee and hip joints, coronary stents, and removable partial dentures. To improve the biocompatibility of CCM alloys, we reported that CCM-binding peptide (CBP) linked to cell-adhesive motif Arg-Gly-Asp (RGD) improved the attachment of endothelial cells on CCM alloys. However, the stability of CBP adsorption on the alloy and its effect on osteoblast compatibility are still unclear. In this study, we evaluated the stabilization of the adsorption layer of CBP-RGD on CCM alloy surface and investigated the effect of CBP-RGD peptide on the proliferation and differentiation of the osteoblasts. CBP-RGD layer exhibited higher stabilization than the RGD adsorption layer for 7 days. In addition, the proliferation of osteoblast on CBP-RGD adsorbed alloy higher than that on RGD adsorbed alloy. Moreover, the calcification of cells cultured on the CBP-RGD adsorbed alloy was significantly higher than that of the cells on RGD adsorbed alloy. These findings indicate that the CBP binding was stable during the culture of osteoblasts on the CCM alloy.

Transcutaneous Pulsed RF Energy Transfer Mitigates Tissue Heating in High Power Demand Implanted Device Applications: In Vivo and In Silico Models Results.

This article presents the development of a power loss emulation (PLE) system device to study and find ways of mitigating skin tissue heating effects in transcutaneous energy transmission systems (TETS) for existing and next generation left ventricular assist devices (LVADs). Skin thermal profile measurements were made using the PLE system prototype and also separately with a TETS in a porcine model. Subsequent data analysis and separate computer modelling studies permit understanding of the contribution of tissue blood perfusion towards cooling of the subcutaneous tissue around the electromagnetic coupling area. A 2-channel PLE system prototype and a 2-channel TETS prototype were implemented for this study. The heating effects resulting from power transmission inefficiency were investigated under varying conditions of power delivery levels for an implanted device. In the part of the study using the PLE setup, the implanted heating element was placed subcutaneously 6-8 mm below the body surface of in vivo porcine model skin. Two operating modes of transmission coupling power losses were emulated: (a) conventional continuous transmission, and (b) using our proposed pulsed transmission waveform protocols. Experimental skin tissue thermal profiles were studied for various levels of LVAD power. The heating coefficient was estimated from the porcine model measurements (an in vivo living model and a euthanised cadaver model without blood circulation at the end of the experiment). An in silico model to support data interpretation provided reliable experimental and numerical methods for effective wireless transdermal LVAD energization advanced solutions. In the separate second part of the study conducted with a separate set of pigs, a two-channel inductively coupled RF driving system implemented wireless power transfer (WPT) to a resistive LVAD model (50 Ω) to explore continuous versus pulsed RF transmission modes. The RF-transmission pulse duration ranged from 30 ms to 480 ms, and the idle time (no-transmission) from 5 s to 120 s. The results revealed that blood perfusion plays an important cooling role in reducing thermal tissue damage from TETS applications. In addition, the results analysis of the in vivo, cadaver (R1Sp2) model, and in silico studies confirmed that the tissue heating effect was significantly lower in the living model versus the cadaver model due to the presence of blood perfusion cooling effects.

Vertical open-bore MRI scanners generate significantly less radiofrequency heating around implanted leads: A study of deep brain stimulation implants in 1.2T OASIS scanners versus 1.5T horizontal systems.

PURPOSE: Patients with active implants such as deep brain stimulation (DBS) devices are often denied access to MRI due to safety concerns associated with the radiofrequency (RF) heating of their electrodes. The majority of studies on RF heating of conductive implants have been performed in horizontal close-bore MRI scanners. Vertical MRI scanners which have a 90° rotated transmit coil generate fundamentally different electric and magnetic field distributions, yet very little is known about RF heating of implants in this class of scanners. We performed numerical simulations as well as phantom experiments to compare RF heating of DBS implants in a 1.2T vertical scanner (OASIS, Hitachi) compared to a 1.5T horizontal scanner (Aera, Siemens). METHODS: Simulations were performed on 90 lead models created from post-operative CT images of patients with DBS implants. Experiments were performed with wires and commercial DBS devices implanted in an anthropomorphic phantom. RESULTS: We found significant reduction of 0.1 g-averaged specific absorption rate (30-fold, P < 1 × 10-5 ) and RF heating (9-fold, P < .026) in the 1.2T vertical scanner compared to the 1.5T conventional scanner. CONCLUSION: Vertical MRI scanners appear to generate lower RF heating around DBS leads, providing potentially heightened safety or the flexibility to use sequences with higher power levels than on conventional systems.

In silico assessment of collateral eddy current heating in biocompatible implants subjected to magnetic hyperthermia treatments.

Purpose: Bearing partially or fully metallic passive implants represents an exclusion criterion for patients undergoing a magnetic hyperthermia procedure, but there are no specific studies backing this restrictive decision. This work assesses how the secondary magnetic field generated at the surface of two common types of prostheses affects the safety and efficiency of magnetic hyperthermia treatments of localized tumors. The paper also proposes the combination of a multi-criteria decision analysis and a graphical representation of calculated data as an initial screening during the preclinical risk assessment for each patient.Materials and methods: Heating of a hip joint and a dental implant during the treatment of prostate, colorectal and head and neck tumors have been assessed considering different external field conditions and exposure times. The Maxwell equations including the secondary field produced by metallic prostheses have been solved numerically in a discretized computable human model. The heat exchange problem has been solved through a modified version of the Pennes' bioheat equation assuming a temperature dependency of blood perfusion and metabolic heat, i.e. thermorregulation. The degree of risk has been assessed using a risk index with parameters coming from custom graphs plotting the specific absorption rate (SAR) vs temperature increase, and coefficients derived from a multi-criteria decision analysis performed following the MACBETH approach.Results: The comparison of two common biomaterials for passive implants - Ti6Al4V and CoCrMo - shows that both specific absorption rate (SAR) and local temperature increase are found to be higher for the hip prosthesis made by Ti6Al4V despite its lower electrical and thermal conductivity. By tracking the time evolution of temperature upon field application, it has been established that there is a 30 s delay between the time point for which the thermal equilibrium is reached at prostheses and tissues. Likewise, damage may appear in those tissues adjacent to the prostheses at initial stages of treatment, since recommended thermal thresholds are soon surpassed for higher field intensities. However, it has also been found that under some operational conditions the typical safety rule of staying below or attain a maximum temperature increase or SAR value is met.Conclusion: The current exclusion criterion for implant-bearing patients in magnetic hyperthermia should be revised, since it may be too restrictive for a range of the typical field conditions used. Systematic in silico treatment planning using the proposed methodology after a well-focused diagnostic procedure can aid the clinical staff to find the appropriate limits for a safe treatment window.

Encapsulation of Capacitive Micromachined Ultrasonic Transducers (CMUTs) for the Acoustic Communication between Medical Implants.

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.

RF heating of deep brain stimulation implants in open-bore vertical MRI systems: A simulation study with realistic device configurations.

PURPOSE: Patients with deep brain stimulation (DBS) implants benefit highly from MRI, however, access to MRI is restricted for these patients because of safety hazards associated with RF heating of the implant. To date, all MRI studies on RF heating of medical implants have been performed in horizontal closed-bore systems. Vertical MRI scanners have a fundamentally different distribution of electric and magnetic fields and are now available at 1.2T, capable of high-resolution structural and functional MRI. This work presents the first simulation study of RF heating of DBS implants in high-field vertical scanners. METHODS: We performed finite element electromagnetic simulations to calculate specific absorption rate (SAR) at tips of DBS leads during MRI in a commercially available 1.2T vertical coil compared to a 1.5T horizontal scanner. Both isolated leads and fully implanted systems were included. RESULTS: We found 10- to 30-fold reduction in SAR implication at tips of isolated DBS leads, and up to 19-fold SAR reduction at tips of leads in fully implanted systems in vertical coils compared to horizontal birdcage coils. CONCLUSIONS: If confirmed in larger patient cohorts and verified experimentally, this result can open the door to plethora of structural and functional MRI applications to guide, interpret, and advance DBS therapy.

[Is the unlimited use of surgical instruments safe? : Discussion using the example of endoprosthetics]. / Ist der unbegrenzte Gebrauch von chirurgischen Instrumenten unbedenklich? : Diskussion am Beispiel der Endoprothetik.

As medical devices surgical instruments are important components when performing surgery. They can significantly influence the course and outcome of the surgery. Instruments are mechanically stressed in daily use and resterilized multiple times. The majority of manufacturer documentation for endoprostheses lacks specific information regarding tolerable instrument wear and the maximum number of applications for surgical instruments. So far, there are no mandatory algorithms for the necessity of checking and replacing surgical instruments. The risk of mechanical failure, surface damage and ultimately incidents is illustrated using endoprosthesis instruments as examples.

Reconfigurable MRI technology for low-SAR imaging of deep brain stimulation at 3T: Application in bilateral leads, fully-implanted systems, and surgically modified lead trajectories.

Patients with deep brain stimulation devices highly benefit from postoperative MRI exams, however MRI is not readily accessible to these patients due to safety risks associated with RF heating of the implants. Recently we introduced a patient-adjustable reconfigurable coil technology that substantially reduced local SAR at tips of single isolated DBS leads during MRI at 1.5 T in 9 realistic patient models. This contribution extends our work to higher fields by demonstrating the feasibility of scaling the technology to 3T and assessing its performance in patients with bilateral leads as well as fully implanted systems. We developed patient-derived models of bilateral DBS leads and fully implanted DBS systems from postoperative CT images of 13 patients and performed finite element simulations to calculate SAR amplification at electrode contacts during MRI with a reconfigurable rotating coil at 3T. Compared to a conventional quadrature body coil, the reconfigurable coil system reduced the SAR on average by 83% for unilateral leads and by 59% for bilateral leads. A simple surgical modification in trajectory of implanted leads was demonstrated to increase the SAR reduction efficiency of the rotating coil to >90% in a patient with a fully implanted bilateral DBS system. Thermal analysis of temperature-rise around electrode contacts during typical brain exams showed a 15-fold heating reduction using the rotating coil, generating <1°C temperature rise during ∼4-min imaging with high-SAR sequences where a conventional CP coil generated >10°C temperature rise in the tissue for the same flip angle.

RF-induced heating in tissue near bilateral DBS implants during MRI at 1.5 T and 3T: The role of surgical lead management.

Access to MRI is limited for patients with deep brain stimulation (DBS) implants due to safety hazards, including radiofrequency (RF) heating of tissue surrounding the leads. Computational models provide an exquisite tool to explore the multi-variate problem of RF heating and help better understand the interaction of electromagnetic fields and biological tissues. This paper presents a computational approach to assess RF-induced heating, in terms of specific absorption rate (SAR) in the tissue, around the tip of bilateral DBS leads during MRI at 64MHz/1.5 T and 127 MHz/3T. Patient-specific realistic lead models were constructed from post-operative CT images of nine patients operated for sub-thalamic nucleus DBS. Finite element method was applied to calculate the SAR at the tip of left and right DBS contact electrodes. Both transmit head coils and transmit body coils were analyzed. We found a substantial difference between the SAR and temperature rise at the tip of right and left DBS leads, with the lead contralateral to the implanted pulse generator (IPG) exhibiting up to 7 times higher SAR in simulations, and up to 10 times higher temperature rise during measurements. The orientation of incident electric field with respect to lead trajectories was explored and a metric to predict local SAR amplification was introduced. Modification of the lead trajectory was shown to substantially reduce the heating in phantom experiments using both conductive wires and commercially available DBS leads. Finally, the surgical feasibility of implementing the modified trajectories was demonstrated in a patient operated for bilateral DBS.

Inhibition of pathogenic bacterial biofilms on PDMS based implants by L. acidophilus derived biosurfactant.

BACKGROUND: Lactobacillus spp. predominantly shows its presence as a normal mucosal flora of the mouth and intestine. Therefore, the objective of our research is to investigate the in-vitro conditions for the prospective of medically valuable biosurfactants (BSs) derived from Lactobacillus spp. Biosurfactant (BS) obtained from Lactobacillus spp. exhibit antibiofilm and antiadhesive activity against broad range of microbes. In the present study we investigated the production, purification and properties of key components of the cell-associated-biosurfactant (CABS) from Lactobacillus acidophilus NCIM 2903. RESULTS: Extracted, purified, freeze-dried CABS shows reduction in surface tension (SFT) of phosphate buffer saline (PBS @pH 7.0) from 71 to 26 mN/m and had a critical micelle concentration (CMC) of 23.6 mg/mL. The CABS showed reduction in interfacial tension (IFT) against various hydrocarbons and had effective spreading capability as reflected through the decrease in contact angle (CA) on different surfaces (polydimethylsiloxane - PDMS, Teflon tape, glass surface, polystyrene film and OHP sheet). The anionic nature of CABS displayed stability at different pH and temperatures and formed stable emulsions. Thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR) revealed CABS as glycolipoprotein type. The Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) showed presence of multiple bands in a molecular range of 14.4 to 60 kDa, with prominent bands of 45 kDa. The CABS has significant antiadhesion and antibiofilm activity against tested bacterial strains. CONCLUSION: The current challenging situation is to develop methods or search for the molecules that will prevent the formations of biofilm on medical bioimplants of PDMS based materials. These findings are supportive for the use of Lactobacilli derived BS as potential antiadhesive agent on various surfaces of biomedical devices.

Reducing RF-induced Heating near Implanted Leads through High-Dielectric Capacitive Bleeding of Current (CBLOC).

Patients with implanted medical devices such as deep brain stimulation or spinal cord stimulation are often unable to receive magnetic resonance imaging (MRI). This is because once the device is within the radiofrequency (RF) field of the MRI scanner, electrically conductive leads act as antenna, amplifying the RF energy deposition in the tissue and causing possible excessive tissue heating. Here we propose a novel concept in lead design in which 40cm lead wires are coated with a ~1.2mm layer of high dielectric constant material (155 < ε r < 250) embedded in a weakly conductive insulation (σ = 20S/m). The technique called High-Dielectric Capacitive Bleeding of Current, or CBLOC, works by forming a distributed capacitance along the lengths of the lead, efficiently dissipating RF energy before it reaches the exposed tip. Measurements during RF exposure at 64 MHz and 123 MHz demonstrated that CBLOC leads generated 20-fold less heating at 1.5 T, and 40-fold less heating at 3 T compared to control leads. Numerical simulations of RF exposure at 297 MHz (7T) predicted a 15-fold reduction in specific absorption rate (SAR) of RF energy around the tip of CBLOC leads compared to control leads.

Mechanisms of the enhanced antibacterial effect of Ag-TiO2 coatings.

It has been demonstrated that Ag-TiO2 nanocomposite coatings with excellent antimicrobial activity and biocompatibility have the potential to reduce infection problems. However, the mechanism of the synergistic effect of Ag-TiO2 coatings on antibacterial efficiency is still not well understood. In this study, five types of Ag-TiO2 nanocomposited coatings with different TiO2 contents were prepared on a titanium substratum. Leaching tests indicated that the incorporation of TiO2 nanoparticles into an Ag matrix significantly promoted Ag ion release. Surface energy measurements showed that the addition of TiO2 nanoparticles also significantly increased the electron donor surface energy of the coatings. Bacterial adhesion assays with Escherichia coli and Staphylococcus aureus demonstrated that the number of adhered bacteria decreased with increasing electron donor surface energy. The increased Ag ion release rate and the increased electron donor surface energy contributed to an enhanced antibacterial efficiency of the coatings.

Construction and modeling of a reconfigurable MRI coil for lowering SAR in patients with deep brain stimulation implants.

Post-operative MRI of patients with deep brain simulation (DBS) implants is useful to assess complications and diagnose comorbidities, however more than one third of medical centers do not perform MRIs on this patient population due to stringent safety restrictions and liability risks. A new system of reconfigurable magnetic resonance imaging head coil composed of a rotatable linearly-polarized birdcage transmitter and a close-fitting 32-channel receive array is presented for low-SAR imaging of patients with DBS implants. The novel system works by generating a region with low electric field magnitude and steering it to coincide with the DBS lead trajectory. We demonstrate that the new coil system substantially reduces the SAR amplification around DBS electrodes compared to commercially available circularly polarized coils in a cohort of 9 patient-derived realistic DBS lead trajectories. We also show that the optimal coil configuration can be reliably identified from the image artifact on B1+ field maps. Our preliminary results suggest that such a system may provide a viable solution for high-resolution imaging of DBS patients in the future. More data is needed to quantify safety limits and recommend imaging protocols before the novel coil system can be used on patients with DBS implants.

Feasibility of using linearly polarized rotating birdcage transmitters and close-fitting receive arrays in MRI to reduce SAR in the vicinity of deep brain simulation implants.

PURPOSE: MRI of patients with deep brain stimulation (DBS) implants is strictly limited due to safety concerns, including high levels of local specific absorption rate (SAR) of radiofrequency (RF) fields near the implant and related RF-induced heating. This study demonstrates the feasibility of using a rotating linearly polarized birdcage transmitter and a 32-channel close-fit receive array to significantly reduce local SAR in MRI of DBS patients. METHODS: Electromagnetic simulations and phantom experiments were performed with generic DBS lead geometries and implantation paths. The technique was based on mechanically rotating a linear birdcage transmitter to align its zero electric-field region with the implant while using a close-fit receive array to significantly increase signal to noise ratio of the images. RESULTS: It was found that the zero electric-field region of the transmitter is thick enough at 1.5 Tesla to encompass DBS lead trajectories with wire segments that were up to 30 degrees out of plane, as well as leads with looped segments. Moreover, SAR reduction was not sensitive to tissue properties, and insertion of a close-fit 32-channel receive array did not degrade the SAR reduction performance. CONCLUSION: The ensemble of rotating linear birdcage and 32-channel close-fit receive array introduces a promising technology for future improvement of imaging in patients with DBS implants. Magn Reson Med 77:1701-1712, 2017. © 2016 International Society for Magnetic Resonance in Medicine.