Effect of Temperature on Ultrasonic Properties of the Calcaneus In Situ

Nicholson, Patrick; Bouxsein, Mary L.

doi:10.1007/s001980200122

Cited by 33 publications

(13 citation statements)

References 12 publications

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“…Of note, the presence of edema around the focal area might also affect the treatment efficiency in a way yet to be determined. Moreover, the skull's acoustic properties (energy absorption and propagation velocity) are sensitive to temperature . Local changes in the skull temperature due to ultrasound absorption may thus lead to the expansion of the focal size due to acoustic aberrations .…”

Section: Discussionmentioning

confidence: 99%

Zero TE MRI applications to transcranial MR‐guided focused ultrasound: Patient screening and treatment efficiency estimation

Caballero‐Insaurriaga

Rodríguez‐Rojas

Martínez‐Fernández

et al. 2019

Magnetic Resonance Imaging

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Background The high acoustic impedance of the skull limits the performance of transcranial magnetic resonance‐guided focused ultrasound (tcMRgFUS) therapy. Subject suitability screening is based on skull parameters estimated from computed tomography (CT) scans. Purpose To assess the feasibility of screening for tcMRgFUS based on zero echo time (ZTE) MRI, and to explore the influence of measurable skull parameters in treatment performance. Study Type Retrospective. Population Sixteen patients treated with tcMRgFUS thalamotomy for tremor. Sequence ZTE on a 3.0T GE scanner. Assessment Baseline CT and ZTE images were processed to extract skull measures associated with treatment success: skull density ratio (SDR), skull thickness, and angle of incidence. Eight new metrics were proposed. CT and ZTE‐based measures were compared. Each subject's energy–temperature curve was processed to extract a global estimate of efficiency and a measure of nonlinearity. These parameters were then correlated with the skull measures. Statistical Tests Linear regression analysis to compare ZTE vs. CT‐based measures, measures vs. efficiency, and measures vs. nonlinearity. Paired t‐test to assess nonlinearity. Results CT and ZTE‐based measures were significantly correlated (P < 0.01). In particular, classical metrics were robustly replicated (P < 0.001). The energy–temperature curves showed a nonlinear (logarithmic) relationship (P < 0.01). This nonlinearity was greater for thicker skulls (P < 0.01). Efficiency was correlated with skull thickness (P < 0.001) and SDR (P < 0.05). Data Conclusion The feasibility of ZTE‐based screening has been proven, potentially making it possible to avoid ionizing radiation and the extra imaging session required for CT. The characterization of the influence that skull properties have on tcMRgFUS may serve to develop patient‐specific heating models, potentially improving control over the treatment outcome. The relationship of skull thickness with efficiency and nonlinearity empowers the role of this metric in the definition of such models. In addition, the lower association of SDR with the energy–temperature curves emphasizes the need of revisiting this metric. Level of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1583–1592.

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Section: Discussionmentioning

confidence: 99%

Zero TE MRI applications to transcranial MR‐guided focused ultrasound: Patient screening and treatment efficiency estimation

Caballero‐Insaurriaga

Rodríguez‐Rojas

Martínez‐Fernández

et al. 2019

Magnetic Resonance Imaging

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“…In the case of calcaneal assessment, the focus of interest are the temperature variations of the foot, which are the subject of a work in progress [51].…”

Section: Quantitative Ultrasoundmentioning

confidence: 99%

Bone imaging: Traditional techniques and their interpretation

Boehm¹,

Link²

2004

Curr Osteoporos Rep

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Patients with osteoporosis have to be diagnosed at an early stage to prevent fractures, the worst complication of this disease. Currently, measurements of bone mineral density (BMD) are used most frequently in the diagnosis of osteoporosis. According to the World Health Organization, osteoporosis is defined on the basis of BMD measurements that are compared with those of a healthy, young, female population. The best established techniques to measure BMD are dual x-ray absorptiometry of the lumbar spine and proximal femur and quantitative computed tomography of the lumbar spine. Conventional radiographs are not suited to assess bone mass, but they are important in the diagnosis and differential diagnosis of osteoporotic fractures. Quantitative ultrasound and structure analysis, based on high-resolution magnetic resonance imaging and computed tomography, are newer techniques in the diagnosis of osteoporosis that also focus on the assessment of bone structure.

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“…Other technical issues potentially affecting the utility of QUS include the dependence of measurements on temperature and acoustic coupling, the properties of soft tissues overlying bone and the absence of a universally accepted QUS phantom for cross-calibration between scanners. Manufacturer-specific phantoms exist but are not anthropomorphic, making quality control and cross-calibration among scanners challenging [6,12,13].…”

Section: Introductionmentioning

confidence: 99%