MRI

The use of MRI on an animal with a DSI implant has been and can be done successfully. There are a few considerations to keep in mind regarding MRI.

1. The implants will not work during the MRI and may turn on/off. Therefore, you should not expect to collect physiologic data during the MRI. After MRI is complete, make sure implant is turned off. 
2. We cannot fully predict the impact of the metal in the implant on the MRI results or the physical impact to the animals. DSI implantable devices have been used in MRIs in rats and larger animals such as pigs with no notable physical damage to the animals. The metal content of the implant is likely to obscure the MRI image in a significant area around the implant and produce artifacts (e.g., voids or shadows). 

See publication for more information:

Nölte, I., Gorbey, S., Boll, H., Figueiredo, G., Groden, C., Lemmer, B., & Brockmann, M. A. (2011). Maintained functionality of an implantable radiotelemetric blood pressure and heart rate sensor after magnetic resonance imaging in rats. Physiological Measurement, 32(12), 1941–1951. https://doi.org/10.1088/0967-3334/32/12/005

SPECT

Please see the attached document "Impact of DSI Implants on SPECT Images" pertaining to an investigation of using SPECT with implantable devices.  The results of the investigation is: 

Our investigation revealed that the presence of the two telemetry devices can lead to local brightness distortions in the SPECT images. With the Philips recommended ASTONISH reconstruction, local activity can be overestimated by up to 54%. With the standard 3D-OSEM reconstruction, the overestimation is substantially less (up to 21%). It is not clear why the two algorithms perform so differently. For this reason, it is impossible to predict how other SPECT systems would respond to the presence of the telemetry devices. However, we believe that the root cause for these artifacts is an overcorrection for attenuation.  It seems worthwhile to investigate potential improvements to the attenuation correction process. One such possibility could consist of imposing an upper limit to the numbers in the CT image (or in the attenuation map) that corresponds to bone tissue or a similar value that minimizes the distortion. This “quick-fix” could be fairly easy to implement. Another possibility is to use the dual-energy CT scan technique that allows, in principle, to determine the elemental composition of the object and, thus, allows the construction of more accurate attenuation maps than the ones currently in use. This, however, will require a bigger effort to implement.