Implant Heating: Physics

Can gradients cause implant heating like RF-pulses?
As described several prior Q&As ([1], [2]) energy deposited in tissues during MRI produces heating. Changing magnetic fields (from both RF- and imaging gradients) generate electric (eddy) currents in accordance with Faraday's law of induction. When these currents encounter electrical resistance, thermal energy is produced. The degree of energy transfer can be quantified by the specific absorption rate (SAR), measured in units of power per mass of tissue (W/kg). When a metallic implant is present, energy may be deposited both within the implant itself as well as in the immediately adjacent tissues. The latter effect may be intensified by scattered radiation at the surface of the implant. What happens precisely depends on the shape and composition of the implant and whether we are dealing with RF- or switched gradient-sources.
Differences Between RF- and Gradient-Induced Heating
Both RF and gradient fields produce tissue heating, but the effects are different because of the geometry, magnitude, and frequency characteristics of each. In typical MRI applications, RF-fields are designed to be relatively uniform over the entire volume of the transmit coil; they have maximum amplitudes on the order of 10μT and frequencies in the 100 MHz range. Time-varying gradient fields for spatial encoding are designed to have amplitudes near zero at isocenter, increasing to the range of 10mT near the ends of the scanner bore;  their base frequencies lie in the range of 1-2 kHz with harmonics extending to over 10 kHz.
RF-related heating is the dominant cause of peri-implant heating. The currents induced by RF-irradiation do not penetrate to the center of the metallic implant but reside almost entirely along its surface; this phenomenon is known as the skin effect (explained more completely in the Popović reference below). RF-induced currents thus flow through only a tiny fraction of the total implant mass  at its surface and do not cause direct heating of the implant. In the soft tissues immediately adjacent to the implant, however, electric fields and currents become concentrated and very high levels of heating may occur. 
One special example of localized RF-heating around an implant is known as the "antenna effect", seen in elongated implants like wires or electrode leads whose lengths are between ¼ and ½ the RF-wavelength. In this scenario electrical fields can become augmented at the tip of the device, leading to heating and the possibility of internal burns.
Picture
SAR "hot-spot" due to antenna effect at the tip of a deep brain stimulator.
(From Iacono et al under CC BY)
Gradient-related heating is entirely different, depositing energy within the implant itself that only indirectly heats surrounding tissues. Because gradient switching frequencies are 100,000 times lower than RF frequencies, induced electrical currents are not confined to the "skin" of the implant, but circulate throughout it. Heating may occur in implants with large cross sections having low-resistance closed current loops (such as hip prostheses, pulse generators, and infusion pumps). Gradients do not generate appreciable eddy currents in tissues, so any adverse thermal effects are due to heat diffusion from the implant itself.
Gradient vs RF heating anatomy
Numerical simulations of gradient coil (GC) and radiofrequency (RF) heating in adult with a unilateral hip prosthesis. Gradient heating is confined to the immediate vicinity of the implant and greatest in extended cross-sections (here the acetabular cup). RF heating can create hotspots throughout the body. RF heating near the implant is most prominent at pointed elements (tip of femoral stem and screw in the superior acetabulum). (From Winter et al under CC BY)
The major differences between gradient-induced and RF heating are summarized below

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References
     Al-Dayeh L, Rahman M, Venook R. Practical aspects of MR imaging safety test methods for MR conditional active implantable medical devices. Magn Reson Imaging Clinic N Am 2020: 28:559-571.  [DOI Link]
     Arduino A, Zanovello U, Hand J, et al. Heating of hip joint implants in MRI: the combined effect of RF and switched-gradient fields. Magn Reson Med 2021; 85:3447-3462.  [DOI LINK]
     ASTM F2182-19e2, Standard Test Method for Measurement of Radio Frequency Induced Heating On or Near Passive Implants During Magnetic Resonance Imaging, ASTM International, West Conshohocken, PA, 2019, www.astm.org 
     Graf H, Steidle G, Schick F. Heating of metallic implants and instruments induced by gradient switching in a 1.5-Tesla whole-body unit. J Magn Reson Imaging 2007; 26:1328-1333.  [DOI LINK]
     Iacono MI, Makris N, Mainardi L, et al. MRI-based multi scale model for electromagnetic analysis in the human head with implanted DBS. Comput Math Methods Med 2013; 2013:694171. [DOI Link]
     ISO/TS 10974:2018. Assessment of the safety of magnetic resonance imaging for patients with an active implantable medical device (2nd Ed). International Standards Organization, Geneva, 2018.
     Konings MK, Bartels LW, Smits HFM, Bakker CJG. Heating around intravascular guidewires by resonating RF waves. J Magn Reson Imaging 2000; 12:79-85.  (mathematical theory of the antenna effect).
     Winter L, Seifert F, Zilberti L, et al. MRI-related heating of implants and devices: a review. J Magn Reson Imaging 2020;(in press) [DOI Link]
     Popović Z, Popović BD. The Skin Effect. In: Introductory Electromagnetics, Prentice Hall, 2000; Chapter 20: 382-392. (Detailed explanation of the Skin Effect and Skin Depth in conductors). 
Related Questions
     What does it mean when an implant or device is labeled "conditional"?
     How do radiofrequency fields affect biological tissues?
     What is SAR? 
     Can one safely scan patients with total joints and other orthopedic hardware like plates and screws?