Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound Treatment at 1.5 T: A Retrospective Study on Treatment- and Patient-Related Parameters Obtained From 52 Procedures

Gagliardo, Cesare; Marrale, Maurizio; D'Angelo, Costanza; Cannella, Roberto; Collura, Giorgio; Iacopino, Domenico Gerardo; D'Amelio, Marco; Napoli, Alessandro; Bartolotta, Tommaso Vincenzo; Catalano, Carlo; Lagalla, Roberto; Midiri, Massimo

doi:10.3389/fphy.2019.00223

Cited by 11 publications

(19 citation statements)

References 32 publications

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“…The skull is the most critical barrier to the ultrasound delivery. Skull density ratio and skull volume are well-known factors affecting the thermal rise 32 , 39 . Prior studies have also reported a correlation between the number of elements on and thermal rise during sonications 39 .…”

Section: Discussionmentioning

confidence: 99%

“…CT was acquired in order to calculate the skull-density ratio (SDR). This score quantifies the discrepancy in Hounsfield Units between the spongious and cortical bone and it is mandatory to apply the phase correction algorithm for the HI-FU beams that allow a precise trans-cranial focusing and energy release on target 31 , 32 . CT is also used to identity frontal sinuses and calcifications that may interfere the HI-FU transmission.…”

Section: Methodsmentioning

confidence: 99%

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Preoperative imaging findings in patients undergoing transcranial magnetic resonance imaging-guided focused ultrasound thalamotomy

Gagliardo

Cannella

Filorizzo

et al. 2021

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The prevalence and impact of imaging findings detected during screening procedures in patients undergoing transcranial MR-guided Focused Ultrasound (tcMRgFUS) thalamotomy for functional neurological disorders has not been assessed yet. This study included 90 patients who fully completed clinical and neuroradiological screenings for tcMRgFUS in a single-center. The presence and location of preoperative imaging findings that could impact the treatment were recorded and classified in three different groups according to their relevance for the eligibility and treatment planning. Furthermore, tcMRgFUS treatments were reviewed to evaluate the number of transducer elements turned off after marking as no pass regions the depicted imaging finding. A total of 146 preoperative imaging findings in 79 (87.8%) patients were detected in the screening population, with a significant correlation with patients’ age (rho = 483, p < 0.001). With regard of the group classification, 119 (81.5%), 26 (17.8%) were classified as group 1 or 2, respectively. One patient had group 3 finding and was considered ineligible. No complications related to the preoperative imaging findings occurred in treated patients. Preoperative neuroradiological findings are frequent in candidates to tcMRgFUS and their identification may require the placement of additional no-pass regions to prevent harmful non-targeted heating.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Preoperative imaging findings in patients undergoing transcranial magnetic resonance imaging-guided focused ultrasound thalamotomy

Gagliardo

Cannella

Filorizzo

et al. 2021

Sci Rep

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“…Further multicentric studies should be performed to compare the image quality and intraoperative neuroimaging findings in treatment performed with 1.5-T or 3.0-T MR scanners. Finally, we did not evaluate the correlations among intraoperative imaging findings, sonications parameters, patients’ characteristics, and clinical outcome at subsequent follow-ups, since other studies [ 9 , 31 , 32 , 33 ] have already assessed these aspects in larger cohorts.…”

Section: Discussion and Future Directionsmentioning

confidence: 99%

Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound with a 1.5 Tesla Scanner: A Prospective Intraindividual Comparison Study of Intraoperative Imaging

et al. 2021

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Background: High-quality intraoperative imaging is needed for optimal monitoring of patients undergoing transcranial MR-guided Focused Ultrasound (tcMRgFUS) thalamotomy. In this paper, we compare the intraoperative imaging obtained with dedicated FUS-Head coil and standard body radiofrequency coil in tcMRgFUS thalamotomy using 1.5-T MR scanner. Methods: This prospective study included adult patients undergoing tcMRgFUS for treatment of essential tremor. Intraoperative T2-weighted FRFSE sequences were acquired after the last high-energy sonication using a dedicated two-channel FUS-Head (2ch-FUS) coil and body radiofrequency (body-RF) coil. Postoperative follow-ups were performed at 48 h using an eight-channel phased-array (8ch-HEAD) coil. Two readers independently assessed the signal-to-noise ratio (SNR) and evaluated the presence of concentric lesional zones (zone I, II and III). Intraindividual differences in SNR and lesional findings were compared using the Wilcoxon signed rank sum test and McNemar test. Results: Eight patients underwent tcMRgFUS thalamotomy. Intraoperative T2-weighted FRFSE images acquired using the 2ch-FUS coil demonstrated significantly higher SNR (R1 median SNR: 10.54; R2: 9.52) compared to the body-RF coil (R1: 2.96, p < 0.001; R2: 2.99, p < 0.001). The SNR was lower compared to the 48-h follow-up (p < 0.001 for both readers). Intraoperative zone I and zone II were more commonly visualized using the 2ch-FUS coil (R1, p = 0.031 and p = 0.008, R2, p = 0.016, p = 0.008), without significant differences with 48-h follow-up (p ≥ 0.063). The inter-reader agreement was almost perfect for both SNR (ICC: 0.85) and lesional findings (k: 0.82–0.91). Conclusions: In the study population, the dedicated 2ch-FUS coil significantly improved the SNR and visualization of lesional zones on intraoperative imaging during tcMRgFUS performed with a 1.5-T MR scanner.

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“…Pre-operative and intra-operative brain MRI allows for a precise calculation of stereotactic coordinates of the target and to evaluate the lesion appearance made by FUS. Initial low-energy sonications are used to assess the thermal map, confirming the absence of areas of unwanted overheating outside the target point, and to ensure the focusing of ultrasound beams into the target area [ 11 , 12 ]. Once the focusing is confirmed, the energy is gradually increased.…”

Section: Introductionmentioning

confidence: 99%

“…During this stage, the patient is continuously monitored and neurologically evaluated after every sonication. Once the target is even clinically confirmed, with the best neurological improvement without adverse events, sonication parameters (temperature (C/F), frequency (Hz), application duration (sec), power (W), energy (J) are adjusted to reach a peak temperature above 52 °C, which makes a permanent necrotic lesion [ 12 , 13 ].…”

Section: Introductionmentioning

confidence: 99%

Focused Ultrasound in Neuroscience. State of the Art and Future Perspectives

et al. 2021

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Transcranial MR-guided Focused ultrasound (tcMRgFUS) is a surgical procedure that adopts focused ultrasounds beam towards a specific therapeutic target through the intact skull. The convergence of focused ultrasound beams onto the target produces tissue effects through released energy. Regarding neurosurgical applications, tcMRgFUS has been successfully adopted as a non-invasive procedure for ablative purposes such as thalamotomy, pallidotomy, and subthalamotomy for movement disorders. Several studies confirmed the effectiveness of tcMRgFUS in the treatment of several neurological conditions, ranging from motor disorders to psychiatric disorders. Moreover, using low-frequencies tcMRgFUS systems temporarily disrupts the blood–brain barrier, making this procedure suitable in neuro-oncology and neurodegenerative disease for controlled drug delivery. Nowadays, tcMRgFUS represents one of the most promising and fascinating technologies in neuroscience. Since it is an emerging technology, tcMRgFUS is still the subject of countless disparate studies, even if its effectiveness has been already proven in many experimental and therapeutic fields. Therefore, although many studies have been carried out, many others are still needed to increase the degree of knowledge of the innumerable potentials of tcMRgFUS and thus expand the future fields of application of this technology.

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Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound Treatment at 1.5 T: A Retrospective Study on Treatment- and Patient-Related Parameters Obtained From 52 Procedures

Cited by 11 publications

References 32 publications

Preoperative imaging findings in patients undergoing transcranial magnetic resonance imaging-guided focused ultrasound thalamotomy

Preoperative imaging findings in patients undergoing transcranial magnetic resonance imaging-guided focused ultrasound thalamotomy

Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound with a 1.5 Tesla Scanner: A Prospective Intraindividual Comparison Study of Intraoperative Imaging

Focused Ultrasound in Neuroscience. State of the Art and Future Perspectives

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