Automatic temperature control for MR-guided interstitial ultrasound ablation in liver using a percutaneous applicator: Ex vivo and in vivo initial studies

Delabrousse, Éric; Salomir, Rarès; Birer, Alain; Paquet, Christian; Mithieux, François; Chapelon, Jean‐Yves; Cotton, François; Lafon, Cyril

doi:10.1002/mrm.22328

Cited by 23 publications

(14 citation statements)

References 39 publications

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“…Moreover, such an implantable US device must only minimally interfere with MRI in patients who require repeated MRI to monitor their treatment. Other authors have shown that implantable US devices could be safely used with MRI, 4 and in our case, preliminary tests have shown that our device is also MRI compatible.…”

Section: Discussionsupporting

confidence: 65%

Opening of the blood-brain barrier with an unfocused ultrasound device in rabbits

Beccaria¹,

Canney

Goldwirt

et al. 2013

JNS

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Object The blood-brain barrier (BBB) is a major impediment to the intracerebral diffusion of drugs used in the treatment of gliomas. Previous studies have demonstrated that pulsed focused ultrasound (US) in conjunction with a microbubble contrast agent can be used to open the BBB. To apply the US-induced opening of the BBB in clinical practice, the authors designed an innovative unfocused US device that can be implanted in the skull and used to transiently and repeatedly open the BBB during a standard chemotherapy protocol. The goal of this preliminary work was to study the opening of the BBB induced by the authors' small unfocused US transducer and to evaluate the effects of the sonications on brain parenchyma. Methods Craniectomy was performed in 16 healthy New Zealand White rabbits; epidural application of a single-element planar ultrasonic transducer operating at 1 MHz was then used with a pulse-repetition frequency of 1 Hz, pulse lengths of 10–35 msec, in situ acoustic pressure levels of 0.3–0.8 MPa, and sonication for 60–120 seconds. SonoVue was intravenously injected during the US applications, and opening of the BBB was determined by detecting extravasation of Evans blue dye (EBD) in brain tissues, quantitative measurement of EBD with UV-visible spectrophotometry, and contrast enhancement after Gd injection in 4.7-T MRI. A histological study was performed to determine adverse effects. Results An opening of the BBB was observed over a large extent of the US beam in the brain corresponding to in situ pressures of greater than 0.2 MPa. The BBB opening observed was highly significant for both EBD (p < 0.01) and MRI Gd enhancement (p < 0.0001). The BBB opening was associated with minor adverse effects that included perivascular red blood cell extravasations that were less than 150 μm in size and not visible on MR images. Moderate edema was visible on FLAIR sequences and limited to the extent of the sonication field. Conclusions The results demonstrate that the BBB can be opened in large areas of the brain in rabbits with lowpower, pulsed, and unfocused US with limited damage to healthy tissue.

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Section: Discussionsupporting

confidence: 65%

Opening of the blood-brain barrier with an unfocused ultrasound device in rabbits

Beccaria¹,

Canney

Goldwirt

et al. 2013

JNS

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“…Proton resonance frequency shift (PRFS)-based MR thermometry (Delabrousse et al, 2010) was used on a 3-T clinical scanner (Siemens Magnetom Trio 3T TIM System, Erlangen, Germany) in order to determine the heat transfer time constant in cartilage. We performed MRI acquisitions on the right knee of four male subjects (age¼30.373.8 yr) using a CP Transmit/receive head coil with integrated preamplifier and 16 rungs (Siemens AG, Erlangen, Germany).…”

Section: Time Constant Of Cartilage Heat Transfer Obtained By Magnetimentioning

confidence: 99%

Intrinsic viscoelasticity increases temperature in knee cartilage under physiological loading

Abdel-Sayed

Moghadam

Salomir

et al. 2014

Journal of the Mechanical Behavior of Biomedical Materials

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Temperature Magnetic resonance imagingDifferential scanning calorimetry a b s t r a c t Metabolism of proteoglycans and hyaluronic acid has been shown to be temperaturedependent in cartilage explants, with optimal anabolic effects between 36 1C and 38 1C. At rest, the temperature of human knee has a value of around 33 1C. We aim to show in this study that viscoelastic properties of healthy human cartilage allow its temperature to reach those optimal temperatures during physiological mechanical loadings. We developed a model allowing to determine the temperature increase in cartilage due to viscous dissipation. The model had three parameters, which were determined experimentally. The first parameter was the energy dissipated by cartilage samples submitted to cyclic stimulation. It was obtained with standard in vitro mechanical testing. The second parameter was the cartilage heat capacity and was measured in vitro with differential scanning calorimetry. Finally, the third parameter was the time constant of cartilage heat transfer and was obtained with in vivo magnetic resonance thermometry performed on four volunteers. With these experimentally determined parameters, the model predicted that cartilage dissipation is sufficient to raise the temperature in healthy knee cartilage from 33 1C to 36.7 1C after a 1 h walking. These results showed that intrinsic viscoelastic properties of the cartilage could induce a temperature increase optimal for the production of proteoglycans and hyaluronic acid. Interestingly, degenerated cartilage did not present high enough viscoelastic properties to significantly induce a temperature increase. Taken together, these data suggest an association between cartilage dissipation and its homeostasis.

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“…These devices have diameters ranging from 3 to 10 mm and operate at frequencies of 3-10 MHz. Interstitial therapeutic ultrasound applicators in particular have been built and tested using a variety of designs by several different groups and include single-element 19,20 and multi-element designs with planar 21-24 and cylindrical 18,25 elements.…”

Section: Introductionmentioning

confidence: 99%

A multi-element interstitial ultrasound applicator for the thermal therapy of brain tumors

Canney

Chavrier

Tsysar

et al. 2013

The Journal of the Acoustical Society of America

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Interstitial thermal therapy is a minimally invasive treatment modality that has been used clinically for ablating both primary and secondary brain tumors. Here a multi-element interstitial ultrasound applicator is described that allows for increased spatial control during thermal ablation of tumors as compared to existing clinical devices. The device consists of an array of 56 ultrasound elements operating at 6 MHz, oriented on the seven faces of a 3.2 mm flexible catheter. The device was first characterized using the acoustic holography method to examine the functioning of the array. Then experiments were performed to measure heating in tissue-mimicking gel phantoms and ex vivo tissue samples using magnetic resonance imaging-based thermometry. Experimental measurements were compared with results obtained using numerical simulations. Last, simulations were performed to study the feasibility of using the device for thermal ablation in the brain. Experimental results show that the device can be used to induce a temperature rise of greater than 20 °C in ex vivo tissue samples and numerical simulations further demonstrate that tumors with diameters of greater than 30-mm could potentially be treated.

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Automatic temperature control for MR-guided interstitial ultrasound ablation in liver using a percutaneous applicator: Ex vivo and in vivo initial studies

Cited by 23 publications

References 39 publications

Opening of the blood-brain barrier with an unfocused ultrasound device in rabbits

Opening of the blood-brain barrier with an unfocused ultrasound device in rabbits

Intrinsic viscoelasticity increases temperature in knee cartilage under physiological loading

A multi-element interstitial ultrasound applicator for the thermal therapy of brain tumors

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