Ultrasound-Induced Thermal Elevation in Clotted Blood and Cranial Bone

Nahirnyak, Volodymyr M.; Mast, T. Douglas; Holland, Christy K.

doi:10.1016/j.ultrasmedbio.2007.02.005

Cited by 22 publications

(16 citation statements)

References 46 publications

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“…However, several studies have shown negligible thermal effects in bench-top (Francis et al 1992; Shaw et al 2006; Damianou et al 2014) or clinical studies (Barlinn and Alexandrov 2013). Numerical computations confirm a negligible temperature rise in clots due to 0.12–3.5 MHz insonations during thrombolysis (Nahirnyak et al 2007; Bouchoux et al 2014). In contrast, Sakharov et al (2000) attributed increased thrombolytic efficacy from 1-MHz insonation in-vitro due to the combined effect of heating and acoustic streaming.…”

Section: 2 Mechanisms Of Thrombolytic Enhancementmentioning

confidence: 78%

Sonothrombolysis

Bader¹,

Bouchoux²,

Holland³

2016

Advances in Experimental Medicine and Biology

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Thrombo-occlusive disease is a leading cause of morbidity and mortality. In this chapter, the use of ultrasound to accelerate clot breakdown alone or in combination with thrombolytic drugs will be reported. Primary thrombus formation during cardiovascular disease and standard treatment methods will be discussed. Mechanisms for ultrasound enhancement of thrombolysis, including thermal heating, radiation force, and cavitation, will be reviewed. Finally, in-vitro, in-vivo and clinical evidence of enhanced thrombolytic efficacy with ultrasound will be presented and discussed.

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Section: 2 Mechanisms Of Thrombolytic Enhancementmentioning

confidence: 78%

Sonothrombolysis

Bader¹,

Bouchoux²,

Holland³

2016

Advances in Experimental Medicine and Biology

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“…The largest temperature increase in brain tissue was located next to the insonified bone and was slightly lower than the temperature increase in periosteal tissue. Correspondingly, a slight difference of temperature between the two opposite interfaces of the insonified bone was measured in vitro by Nahirnyak et al (2007).…”

Section: Discussionmentioning

confidence: 93%

“…Nahirnyak et al (2007) measured in vitro a temperature increase of 0.6°C on the surface of temporal bone exposed to 120-kHz ultrasound with a 0.25 MPa peak-to-peak pressure in the free field and an 80% duty cycle. To compare their in vitro measurement with the values of Δ T max obtained by simulation in patient heads (Table 3), the equivalent temporal-average acoustic intensity in the M1 segment must be assessed.…”

Section: Discussionmentioning

confidence: 99%

In silico Study of Low-Frequency Transcranial Ultrasound Fields in Acute Ischemic Stroke Patients

Bouchoux

Shivashankar

Abruzzo

et al. 2014

Ultrasound in Medicine & Biology

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Ultrasound in the sub-megahertz range enhances thrombolysis and may be applied transcranially to ischemic stroke patients. The consistency of transcranial insonification needs to be evaluated. Acoustic and thermal simulations based on computed-tomography (CT) scans of 20 patients were performed. An unfocused 120-kHz transducer allowed homogeneous insonification of the thrombus, and positioning based on external landmarks performed similarly to an optimized placement based on CT data. With a weakly focused 500-kHz transducer, the landmark-based positioning underperformed. The predicted inter-patient variation of in situ acoustic pressure was similar with both transducers for the optimized placement (18.0–26.4% relative standard deviation). The simulated maximum acoustic pressure in intervening tissues was 2.6±0.6 and 2.0±0.7 times the pressure in the thrombus for the 120-kHz and 500-kHz transducers, respectively. A 1 W/cm2 insonification of the thrombus caused a 3.8±2.2°C temperature increase in the bone for the 120-kHz transducer, and a 13.4±3.3°C increase for the 500-kHz transducer. Contralateral local maxima up to 1.1 times the pressure amplitude in the targeted zone were predicted for the 120-kHz transducer. We established two transducer placement approaches, one based on analysis of a head CT and the other using simple external, visible landmarks. Both approaches allowed consistent insonification of the thrombus.

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“…18,19 In contrast to high-intensity continuous ultrasound, LIPUS (<100 mW/cm 2 ) has much lower intensities, which are regarded as nonthermogenic and nondestructive. 20 Mechanical strains received by cells may result in biochemical events and increase membrane permeability.…”

Section: Discussionmentioning

confidence: 99%

Effect of low‐intensity pulsed ultrasound on the expression of neurotrophin‐3 and brain‐derived neurotrophic factor in cultured Schwann cells

et al. 2009

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It is generally known that low-intensity pulsed ultrasound (LIPUS) accelerates peripheral nerve tissue regeneration. However, the precise cellular mechanism involved is still unclear. The purpose of this study was to determine how the Schwann cells respond directly to LIPUS stimuli. Thus, we investigated the effect of LIPUS on cell proliferation, neurotrophin-3 (NT-3), and brain-derived neurotrophic factor (BDNF) mRNA expression in rat Schwann cells. Schwann cells were enzymatically isolated from postnatal 1-3 day rat sciatic nerve tissue and cultured in the six-well plate. The ultrasound was applied at a frequency of 1 MHz and an intensity of 100 mW/cm(2) spatial average temporal average for 5 minutes/day. The control group was cultured in the same way but without the administration of ultrasound. Immunohistochemistry demonstrated that more than 98% of the experimental and control cells were positive for S-100, NT-3, and BDNF. With 5-bromo-2'-deoxyuridine (BrdU) assay, the stimulated cells also exhibited an increase in the rate of cell proliferation on days 4, 7, 10, and 14. Further investigation found that mRNA expression of NT-3 was significantly upregulated in experimental groups compared with the control 14 days after the LIPUS stimulation (the ratio of NT-3/beta-actin was 0.56 +/- 0.13 vs. 0.41 +/- 0.09, P < 0.01), whereas the mRNA expression of BDNF was significantly downregulated in experimental groups compared with the control (the ratio of BDNF/beta-actin was 0.51 +/- 0.05 vs. 0.60 +/- 0.08, P < 0.05). These results demonstrated that the application of LIPUS promotes cell proliferation and NT-3 gene expression in Schwann cells, and involved in the alteration of BDNF gene expression.

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Ultrasound-Induced Thermal Elevation in Clotted Blood and Cranial Bone

Cited by 22 publications

References 46 publications

Sonothrombolysis

Sonothrombolysis

In silico Study of Low-Frequency Transcranial Ultrasound Fields in Acute Ischemic Stroke Patients

Effect of low‐intensity pulsed ultrasound on the expression of neurotrophin‐3 and brain‐derived neurotrophic factor in cultured Schwann cells

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