Clinical compatibility of magnetic resonance imaging with magnetic intramedullary nails: a feasibility study.

INTRODUCTION: The use of magnetic resonance imaging (MRI) with a magnetic intramedullary lengthening nail in place is contraindicated per the manufacturer due to the concern of implant activation and migration. A prior in vitro study did not confirm these complications only noting that a 3.0 T MRI weakened the internal magnet. Therefore, a retrospective analysis of patients who underwent an MRI with a magnetic nail in place was performed to determine if any adverse effects occurred in the clinical setting. MATERIALS AND METHODS: A retrospective review of all patients who underwent an MRI with a magnetic lengthening nail in place was performed. The time spent being imaged in the MRI, number of times the patient entered the MRI suite, and the images obtained were recorded. Radiographs were performed before and after the MRI to determine if any hardware complications occurred. The patients were monitored for any adverse symptoms while they were in the suite. RESULTS: A total of 12 patients with 13 nails were identified. Two patients underwent imaging with a 3.0 T MRI while the remaining 10 underwent imaging with a 1.5 T MRI. Each patient entered the MRI suite 2.1 times and spent an average of 84.7 min being imaged in the MRI (range 21-494). No patients noted any adverse symptoms related to the nail while in the suite and no hardware complications were identified. CONCLUSION: MRI appears to be safe with a magnetic nail in place and did not result in any complications. Given the manufacturer's recommendations, informed consent should be obtained prior to an MRI being performed and a 3.0 T MRI should be avoided when possible if further activation of the nail is required.

Sacral neuromodulation: Rechargeable versus non-rechargeable device. What would the patient preferences be in France?

AIMS: Sacral neuromodulation (SNM) is a minimally invasive technique that provides effective treatment for the management of refractory overactive bladder (OAB), non-obstructive urinary retention (NOUR), and fecal incontinence (FI). This study assessed patient preferences between the currently available non-rechargeable SNM device and a new, full-body magnetic resonance imaging (MRI)-safe, smaller, rechargeable device. METHODS: An online cross-sectional survey was conducted among French OAB, NOUR, FI patients, recruited via a market research vendor. To assess their preferences, patients were asked to indicate their level of agreement with 10 statements regarding the size of the device, its rechargeability, and the role of MRI using a 6-item Likert scale. A descriptive statistical analysis was performed. RESULTS: In all, 95 patients (68% women), mean age 50 years, were included in the study: 51% were treated for OAB; 44% received an oral treatment and 28% had SNM. Overall, 71% of the 95 patients indicated a preference for the new device; 75% considered that recharging the device would not impact their lifestyle; 74% believed that the smaller size of the rechargeable device would facilitate their choice to be treated with SNM; 80% found full-body MRI compatibility important. CONCLUSIONS: Most patients may prefer the new rechargeable SNM device over the current "standard". Compatibility with full-body MRI and the smaller device size seemed the key features of the newer device that would influence their choice of being treated with SNM. Future national and international recommendations should consider a shared decision-making process between the physician and the patient.

[MRI in patients with auditory implants equipped with implanted magnets-an update : Overview and procedural management]. / MRT bei Patienten mit Hörimplantaten mit Magnetausstattung ­ ein Update : Überblick und prozedurales Management.

BACKGROUND: More than 100,000 patients with cochlear implants live in Germany. In addition, numerous patients have auditory bone conducted, middle-ear conducted or brainstem conducted implants equipped with implanted magnets. At the same time, the number of patients being examined by magnetic resonance imaging (MRI) is increasing. Therefore, MRI compatibility of these implants is an essential quality feature. METHODS: This article provides information about technical innovations and new auditory devices since November 2013 that have medical-technical certification in the European Union and the USA. We communicate the restrictions of the manufacturers and a selective literature search in PubMed using the following keywords: MRI compatibility/MRI safety + cochlear implant/auditory brainstem implant/Bonebridge/Sophono alpha/Vibrand Soundbridge/BAHA attract. We included all publications of this search concerning MRI compatibility of hearing implants complemented by papers cited in the primary articles. RESULTS: In rare cases, high electromagnetic field intensities as used in MRI can cause shearing movements up to dislocation of the implant or the magnet of the device. As a result the implant function could fail. Image artifacts in head MRIs can be reduced by using appropriate MRI sequences. Nevertheless, possible artifacts and the hereby reduced validity of the skull MRI results have to be considered when indicating the examination. Meanwhile, all innovations of these auditory devices are licensed to 1.5 T MRI examination, some implants up to 3.0 T MRI magnetic field intensity. For older devices, the necessary safety measures listed in the article published by Nospes, Mann and Keilmann in November 2013 should be used. CONCLUSION: Respecting the manufacturer's instructions, MRI scans without removal of the magnet in patients with these auditory implants is safe. However, due to possible defects/dislocations of the implant that may occur and the reduced quality of the skull MRI images, the indication for MRI in devices with MRI certification should only be performed under close consultation between the investigating physicians, the implanting team supervising the patient and the radiologist. All other possible diagnostic procedures should be exhausted first.

Signal-to-noise ratio evaluation of magnetic resonance images in the presence of an ultrasonic motor.

BACKGROUND: Safe robot-assisted intervention using magnetic resonance imaging (MRI) guidance requires the precise control of assistive devices, and most currently available tools are rarely MRI-compatible. To obtain high precision, it is necessary to characterize and develop existing MRI-safe actuators for use in a high magnetic field (≥3 T). Although an ultrasonic motor (USM) is considered to be an MRI-safe actuator, and can be used in the vicinity of a high field scanner, its presence interferes with MR images. Although an MR image provides valuable information regarding the pathology of a patient's body, noise, generally of a granular type, decreases the quality of the image and jeopardizes the true evaluation of any existing pathological issues. An eddy current induced in the conductor material of the motor structure can be a source of noise when the motor is close to the isocenter of the image. We aimed to assess the effects of a USM on the signal-to-noise ratio (SNR) of MR images in a 3-T scanner. The SNR was compared for four image sequences in transverse directions for three orientations of the motor (x, y, and z) when the motor was in the "off" state. The SNR was evaluated to assess three artifact reduction methods used to minimize the motor-induced artifacts. RESULTS: The SNR had a range of 5-10 dB for slices close to the motor in the x and y orientations, and increased to 15-20 dB for slices far from the motor. Averaging the SNR for slices in all cases gave an SNR loss of about 10 dB. The maximum SNR was measured in the z orientation. In this case, the SNR loss was almost the same as that of other motor orientations, approximately 10 dB, but with a higher range, approximately 20-40 dB. CONCLUSIONS: The selection of certain scanning parameters is necessary for reducing motor-generated artifacts. These parameters include slice selection and bandwidth. In developing any MRI-compatible assisted device actuated by a USM, this study recommends the use of an approximately 3-mm slice thickness with minimum bandwidth to achieve optimized SNR values when a USM is operating close to (within approximately 40 mm) the region being imaged. The SNR can be further enhanced by increasing the number of signal averages, but this is achieved only at the cost of increased scan duration.

Challenges regarding MR compatibility of an MRgFUS robotic system.

Numerous challenges are faced when employing Magnetic Resonance guided Focused Ultrasound (MRgFUS) hardware in the Magnetic Resonance Imaging (MRI) setting. The current study aimed to provide insights on this topic through a series of experiments performed in the framework of evaluating the MRI compatibility of an MRgFUS robotic device. All experiments were performed in a 1.5 T MRI scanner. The main metric for MRI compatibility assessment was the signal to noise ratio (SNR). Measurements were carried out in a tissue mimicking phantom and freshly excised pork tissue under various activation states of the system. In the effort to minimize magnetic interference and image distortion, various set-up parameters were examined. Significant SNR degradation and image distortion occurred when the FUS transducer was activated mainly owing to FUS-induced target and coil vibrations and was getting worse as the output power was increased. Proper design and stable positioning of the imaged phantom play a critical role in reducing these vibrations. Moreover, isolation of the phantom from the imaging coil was proven essential for avoiding FUS-induced vibrations from being transferred to the coil during sonication and resulted in a more than 3-fold increase in SNR. The use of a multi-channel coil increased the SNR by up to 50 % compared to a single-channel coil. Placement of the electronics outside the coil detection area increased the SNR by about 65 %. A similar SNR improvement was observed when the encoders' counting pulses were deactivated. Overall, this study raises awareness about major challenges regarding operation of an MRgFUS system in the MRI environment and proposes simple measures that could mitigate the impact of noise sources so that the monitoring value of MR imaging in FUS applications is not compromised.

Silicon Carbide Technology for Advanced Human Healthcare Applications.

Silicon carbide (SiC) is a highly robust semiconductor material that has the potential to revolutionize implantable medical devices for human healthcare, such as biosensors and neuro-implants, to enable advanced biomedical therapeutic applications for humans. SiC is both bio and hemocompatible, and is already commercially used for long-term human in vivo applications ranging from heart stent coatings and dental implants to short-term diagnostic applications involving neural implants and sensors. One challenge facing the medical community today is the lack of biocompatible materials which are inherently smart or, in other words, capable of electronic functionality. Such devices are currently implemented using silicon technology, which either has to be hermetically sealed so it does not directly interact with biological tissue or has a short lifetime due to instabilities in vivo. Long-term, permanently implanted devices such as glucose sensors, neural interfaces, smart bone and organ implants, etc., require a more robust material that does not degrade over time and is not recognized and rejected as a foreign object by the inflammatory response. SiC has displayed these exceptional material properties, which opens up a whole new host of applications and allows for the development of many advanced biomedical devices never before possible for long-term use in vivo. This paper is a review of the state-of-the art and discusses cutting-edge device applications where SiC medical devices are poised to translate to the commercial marketplace.

MRI-Compatible and Conformal Electrocorticography Grids for Translational Research.

Intraoperative electrocorticography (ECoG) captures neural information from the surface of the cerebral cortex during surgeries such as resections for intractable epilepsy and tumors. Current clinical ECoG grids come in evenly spaced, millimeter-sized electrodes embedded in silicone rubber. Their mechanical rigidity and fixed electrode spatial resolution are common shortcomings reported by the surgical teams. Here, advances in soft neurotechnology are leveraged to manufacture conformable subdural, thin-film ECoG grids, and evaluate their suitability for translational research. Soft grids with 0.2 to 10 mm electrode pitch and diameter are embedded in 150 µm silicone membranes. The soft grids are compatible with surgical handling and can be folded to safely interface hidden cerebral surface such as the Sylvian fold in human cadaveric models. It is found that the thin-film conductor grids do not generate diagnostic-impeding imaging artefacts (<1 mm) nor adverse local heating within a standard 3T clinical magnetic resonance imaging scanner. Next, the ability of the soft grids to record subdural neural activity in minipigs acutely and two weeks postimplantation is validated. Taken together, these results suggest a promising future alternative to current stiff electrodes and may enable the future adoption of soft ECoG grids in translational research and ultimately in clinical settings.

Mythbusters! The Truth about Common Misconceptions in Cochlear Implantation.

Cochlear implantation (CI) is the preferred method of hearing rehabilitation when patients cannot perform well with traditional amplification. Unfortunately, there are still significant misconceptions around this life-changing intervention. The goal of this article is to address some of the most common myths around CI surgery. After reading this article, the learner will be able to explain the utility of CI in patients with residual hearing and recognize that insurance coverage is widespread. The reader will be able to list common risks associated with this well-tolerated procedure including anesthetic risk and the risk of vestibular dysfunction. Additionally, the reader will be able to identify the significant positive impact of CI on patients' quality of life. Finally, the reader will identify that many patients can safely have an MRI scan after implantation, including nearly all contemporary recipients.

Silicon Carbide and MRI: Towards Developing a MRI Safe Neural Interface.

An essential method to investigate neuromodulation effects of an invasive neural interface (INI) is magnetic resonance imaging (MRI). Presently, MRI imaging of patients with neural implants is highly restricted in high field MRI (e.g., 3 T and higher) due to patient safety concerns. This results in lower resolution MRI images and, consequently, degrades the efficacy of MRI imaging for diagnostic purposes in these patients. Cubic silicon carbide (3C-SiC) is a biocompatible wide-band-gap semiconductor with a high thermal conductivity and magnetic susceptibility compatible with brain tissue. It also has modifiable electrical conductivity through doping level control. These properties can improve the MRI compliance of 3C-SiC INIs, specifically in high field MRI scanning. In this work, the MRI compliance of epitaxial SiC films grown on various Si wafers, used to implement a monolithic neural implant (all-SiC), was studied. Via finite element method (FEM) and Fourier-based simulations, the specific absorption rate (SAR), induced heating, and image artifacts caused by the portion of the implant within a brain tissue phantom located in a 7 T small animal MRI machine were estimated and measured. The specific goal was to compare implant materials; thus, the effect of leads outside the tissue was not considered. The results of the simulations were validated via phantom experiments in the same 7 T MRI system. The simulation and experimental results revealed that free-standing 3C-SiC films had little to no image artifacts compared to silicon and platinum reference materials inside the MRI at 7 T. In addition, FEM simulations predicted an ~30% SAR reduction for 3C-SiC compared to Pt. These initial simulations and experiments indicate an all-SiC INI may effectively reduce MRI induced heating and image artifacts in high field MRI. In order to evaluate the MRI safety of a closed-loop, fully functional all-SiC INI as per ISO/TS 10974:2018 standard, additional research and development is being conducted and will be reported at a later date.

Deep Brain Stimulation Initiative: Toward Innovative Technology, New Disease Indications, and Approaches to Current and Future Clinical Challenges in Neuromodulation Therapy.

Deep brain stimulation (DBS) is one of the most important clinical therapies for neurological disorders. DBS also has great potential to become a great tool for clinical neuroscience research. Recently, the National Engineering Laboratory for Neuromodulation at Tsinghua University held an international Deep Brain Stimulation Initiative workshop to discuss the cutting-edge technological achievements and clinical applications of DBS. We specifically addressed new clinical approaches and challenges in DBS for movement disorders (Parkinson's disease and dystonia), clinical application toward neurorehabilitation for stroke, and the progress and challenges toward DBS for neuropsychiatric disorders. This review highlighted key developments in (1) neuroimaging, with advancements in 3-Tesla magnetic resonance imaging DBS compatibility for exploration of brain network mechanisms; (2) novel DBS recording capabilities for uncovering disease pathophysiology; and (3) overcoming global healthcare burdens with online-based DBS programming technology for connecting patient communities. The successful event marks a milestone for global collaborative opportunities in clinical development of neuromodulation to treat major neurological disorders.

Safety and Efficacy of MRI Scans in Patients With Implanted Microvascular Coupling Devices.

OBJECTIVE: To demonstrate the safety and compatibility of microvascular couplers in patients undergoing postoperative magnetic resonance imaging (MRI) scans. STUDY DESIGN: Retrospective case series. METHODS: A consecutive review of 1,252 patients undergoing free tissue transfer for head and neck reconstruction at Oregon Health and Sciences University (OHSU) between 2010 and 2017 who had microvascular coupler Synovis, Baxter Deerfield, IL (Synovis Life Technologies, Saint Paul, MN) implantation were reviewed. One hundred fifteen patients had a subsequent MRI scan, which consisted of a variety of Phillips (Amsterdam, Netherlands) MRI machines ranging from 1.0 to 3.0 Tesla (T) in magnetic strength. RESULTS: These 115 patients underwent 121 free flaps with 131 couplers (including 32 flow couplers) utilized for venous anastomoses. Couplers ranged in size from 1.5 to 4.0 mm (3.0 mm [42%] followed by 3.5 mm [21%], 2.5 mm [19%], 2.0 mm [10%], 4.0 mm [6%], and 1.5 mm [2%]. Three hundred fifty-nine MRI scans (2 days to 91 months postoperatively) were obtained with 233 MRIs for cancer surveillance, and the remaining were obtained for neurologic disease, injury, or evaluation for metastases. No complications occurred related to the MRI and the metallic components of the coupler or other metal implants, such as reconstruction bars, vascular clips, or metallic surgical mesh. Additionally, no radiology report commented on MRI distortion due to the coupler placement, which contrasts the distortion seen with the other metallic implants. CONCLUSION: Microvascular couplers and their constitutive stainless-steel pins have not been found to cause any complications in a large series of consecutive patients undergoing multiple MRIs with magnetic strength up to 3 T. The U.S. Food and Drug Administration advocates medical alert notification for patients with couplers; however, hesitation regarding potential MRI scanning for surveillance or otherwise is unwarranted. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1428-1430, 2020.

Design and control of a MRI-compatible pneumatic needle puncture robot.

Percutaneous needle puncture operation is widely used in the image-guided interventions, including biopsy and ablation. MRI guidance has the advantages of high-resolution soft tissue imaging and thermal monitoring during energy-based ablation. This paper proposes the design of a 5-DOF pneumatic needle puncture robot, with all the cylinders, sensors and structure material MRI-compatible. Also, a hybrid fuzzy-PID controller is designed for the pneumatic driven system to adjust the PID parameters adaptively. The experiment validation result shows that, compared with the traditional fix-parameter PID control, the proposed hybrid fuzzy-PID control has no overshoot, and the settle time/steady state error remains low even with increasing load. This proves that the hybrid fuzzy-PID control strategy can increases the positioning accuracy and robustness of the pneumatic driven needle puncture robot, which is significant for the safety of percutaneous needle puncture operation.

A study on observed ultrasonic motor-induced magnetic resonance imaging (MRI) artifacts.

BACKGROUND: The safe performance of magnetic resonance imaging (MRI)-guided robot-assisted interventions requires full control and high precision of assistive devices. Because many currently available tools are not MRI-compatible, the characterization of existing tools and development of new ones are necessary. The purpose of this research is to identify and minimize the image artifacts generated by a USM in MR images. METHODS: The behavior of an ultrasonic motor (USM), the most common MRI-safe actuator, in a high-field scanner was investigated. The motor was located in three orientations with respect to the bore axis with the power on or off. The induced image artifacts were compared across four sequences. Three artifact reduction methods (employing ultrashort sequences, slice thickness reductions, and bandwidth increments) were tested. RESULTS: Signal voids, pileups, and geometric distortions were observed when the motor was off. The artifact size was minimal when the motor shaft was aligned with the bore axis. In addition to the above artifacts, zipper and motion artifacts were noted when the motor was running, and these artifacts increased with increasing motor speed. Increasing the bandwidth slightly reduced the artifacts. However, decreasing the slice thickness from 5 mm to 3 mm and from 5 mm to 1 mm reduced artifact size from 30% to 40% and from 60% to 75%, respectively. CONCLUSION: The image artifacts were due to the non-homogenous nature of the static and gradient fields caused by the motor structure. The operating motor interferes with the RF field, causing zipper and motion artifacts.

MRI compatibility of several early transition metal based alloys and its influencing factors.

Magnetic resonance imaging (MRI) compatibility of three early transition metal (ETM) based alloys was assessed in vitro with agarose gel as a phantom, including Zr-20Nb, near-equiatomic (TiZrNbTa)90 Mo10 and Nb-60Ta-2Zr, together with pure tantalum and L605 Co-Cr alloy for comparison. The artifact extent in the MR image was quantitatively characterized according to the maximum area of 2D images and the total volume in reconstructed 3D images with a series of slices under acquisition by fast spin echo (FSE) sequence and gradient echo (GRE) sequence. It was indicated that the artifacts extent of L605 Co-Cr alloy with a higher magnetic susceptibility (χv ) was approximately 3-fold greater than that of the ETM-based alloys with χv in the range of 160-250 ppm. In the ETM group, the MRI compatibility of the materials can be ranked in a sequence of Zr-20Nb, pure tantalum, (TiZrNbTa)90 Mo10 and Nb-60Ta-2Zr. In addition, using a rabbit cadaver with the implanted tube specimens as a model for ex vivo assessment, it was confirmed that the artifact severity of Nb-60Ta-2Zr alloy is significantly reduced in comparison with the L605 alloy. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 377-385, 2018.

Ultrasonic motor-induced geometric distortions in magnetic resonance images.

Ultrasonic motors (USMs) are common actuators that can be safely used in the magnetic resonance imaging (MRI) environment. However, lack of MRI compatibility results in issues such as image distortion. This fact led researchers to shift focus from USMs to pneumatic and hydraulic actuators in development of surgical robots. The aim is to quantify and compensate the geometric distortion of MR images as generated by the presence of USMs. An ultrasonic motor was positioned in three orientations with respect to the bore axis. The induced distortions were compared across four image sequences. To reduce the distortions, three artifact reduction methods were employed. Geometric distortion is the only artifact in image slices farther from the motor. The various motor orientations lead to different distortions, with the lowest distortion for the z orientation. The maximum measured distortion of ten pixels occurred. This maximal distortion is equal to a 1-cm displacement of the displayed points relative to their actual locations and it is beyond the acceptable level for medical display standards. Bandwidth reduction reduced the distortion, with a 50% reduction for a doubled bandwidth. In conclusion, USMs can be preferred alternative because accurate targeting of pathologies can occur in free distorted images.

An overview of development and status of fiber-reinforced composites as dental and medical biomaterials.

Fibr-reinforced composites (FRC) have been used successfully for decades in many fields of science and engineering applications. Benefits of FRCs relate to physical properties of FRCs and versatile production methods, which can be utilized. Conventional hand lamination of prefabricated FRC prepregs is utilized still most commonly in fabrication of dental FRC devices but CAD-CAM systems are to be come for use in certain production steps of dental constructions and medical FRC implants. Although metals, ceramics and particulate filler resin composites have successfully been used as dental and medical biomaterials for decades, devices made out of these materials do not meet all clinical requirements. Only little attention has been paid to FRCs as dental materials and majority of the research in dental field has been focusing on particulate filler resin composites and in medical biomaterial research to biodegradable polymers. This is paradoxical because FRCs can potentially resolve many of the problems related to traditional isotropic dental and medical materials. This overview reviews the rationale and status of using biostable glass FRC in applications from restorative and prosthetic dentistry to cranial surgery. The overview highlights also the critical material based factors and clinical requirement for the succesfull use of FRCs in dental reconstructions.

Migration of innumerable chronically retained acupuncture needles.

We present a case of a 50-year-old female with a 2-day history of back and abdominal pain who was discovered to have innumerable chronically retained acupuncture needles, which had migrated throughout her abdomen and pelvis. Although many of these needles were in precarious positions, including the epidural space, renal parenchyma, small bowel, and vasculature, there was no evidence for acute injury. We also briefly discuss evidence for the magnetic resonance imaging compatibility of acupuncture needles. Although a rare complication, given the high frequency of acupuncture therapy in the United States, physicians must be aware of the potential for retained and migrated needles.

Computed tomography and magnetic resonance imaging contrast media injectors: technical feature review - what is really needed?

There has been little technical innovation over the last few years for contrast media (CM) injectors that are used for diagnostic imaging (computed tomography [CT], magnetic resonance imaging [MRI], and hybrid imaging systems, such as positron emission tomography-CT or magnetic resonance-positron emission tomography) examinations. The medical need of CM for the enhancement of diagnostic images has been around for a long time, but the application of the CM into the blood stream comes with potential medical complications for the patient and requires a lot of operator experience and training. Most power injector systems that are currently used can do significantly more than what is typically required; this complexity however, adds error potential and cost. This paper focuses on the main features that CM injector systems should have and highlights the technical developments that are useful to have but which add complexity and cost, increase setup time, and require intensive training for safe use. CM injection protocols are very different between CT and MRI, with CT requiring many more variances, has a need for multiphase protocols, and requires a higher timing accuracy. A CM injector used in the MRI suite, on the other-hand, could only need a relatively time insensitive injection with a standard injection flow rate and a volume that is dependent on the patients' weight. This would make easy and lightweight systems possible, which are able to safely and accurately perform the injection task, while allowing full MRI compatibility with relatively low cost investment and consumable costs.

Development of an MRI-compatible digital SiPM detector stack for simultaneous PET/MRI.

Advances in solid-state photon detectors paved the way to combine positron emission tomography (PET) and magnetic resonance imaging (MRI) into highly integrated, truly simultaneous, hybrid imaging systems. Based on the most recent digital SiPM technology, we developed an MRI-compatible PET detector stack, intended as a building block for next generation simultaneous PET/MRI systems. Our detector stack comprises an array of 8 × 8 digital SiPM channels with 4 mm pitch using Philips Digital Photon Counting DPC 3200-22 devices, an FPGA for data acquisition, a supply voltage control system and a cooling infrastructure. This is the first detector design that allows the operation of digital SiPMs simultaneously inside an MRI system. We tested and optimized the MRI-compatibility of our detector stack on a laboratory test bench as well as in combination with a Philips Achieva 3 T MRI system. Our design clearly reduces distortions of the static magnetic field compared to a conventional design. The MRI static magnetic field causes weak and directional drift effects on voltage regulators, but has no direct impact on detector performance. MRI gradient switching initially degraded energy and timing resolution. Both distortions could be ascribed to voltage variations induced on the bias and the FPGA core voltage supply respectively. Based on these findings, we improved our detector design and our final design shows virtually no energy or timing degradations, even during heavy and continuous MRI gradient switching. In particular, we found no evidence that the performance of the DPC 3200-22 digital SiPM itself is degraded by the MRI system.