Thin-film micro-coil detectors: Application in MR-thermometry

MRI for Noninvasive Thermometry

“…Disposable internal coils, easily adaptable to existing applicators [169], are suitable for use in minimally invasive thermal therapies and could offer higher SNR, improve calibration accuracy and lead to a better understanding of the impact of biophysical tissue changes on temperature-sensitive MR-parameters.…”

“…This can be attributed partly to incompatibility with non-invasive thermal therapies and partly to the lack of cost-effective, scalable and reproducible receivers. Recently a micro-coil receiver with these characteristics was shown to provide an excellent solution to improved MRthermometry during minimally invasive LITT ablations and its clinical utility was confirmed on studies at 3T on liver-mimicking gel and ex-vivo porcine liver specimens [169].…”

“…However, little attention has been paid to their use in MR-thermometry [28,30,169,170]. This can be attributed partly to incompatibility with non-invasive thermal therapies and partly to the lack of cost-effective, scalable and reproducible receivers.…”

“…Figure 5 shows the thermal delivery system (a Somatex Laser Applicator) integrated with an MR-imaging device based on the thin-film micro-coil (OD of the modified applicator is 4.8 mm). Figure 6 shows the arrangement used to assess its performance for PRF MR-thermometry based on phase-mapping, and compare it with that of the cardiac array coil used at St. Mary's Hospital [169]. Although non-heated ROIs were used to correct for field drifts, slight deviations from the fluoro-optic temperatures remain.…”

“…the maximum temperature error of the two coils during respiratory-gated MR-thermometry of an unheated liver-mimicking phantom, using a motion simulator to simulate movement due to breathing[169]. The data shows the errors due to local susceptibility variations.…”