Ultrasound in medicine & biology
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Ultrasound Med Biol · Sep 2013
Clinical TrialUltrasonographic reference sizes of the median and ulnar nerves and the cervical nerve roots in healthy Japanese adults.
The objective of this study was to identify, for practical use, ultrasonographic reference values for nerve sizes at multiple sites, including entrapment and non-entrapment sites along the median and ulnar nerves and among the cervical nerve roots. We verified reliable sites and site-based differences between the reference values. In addition, we found associations between the reference nerve sizes and several physical characteristics (gender, dominant hand, age, height, weight, body mass index [BMI] and wrist circumference). ⋯ Site-based differences in nerve size were determined using one-way analyses of variance (p < 0.001). Intra- and inter-observer reliability was highest for the median nerve, at both the distal wrist crease and mid-humerus; at the arterial split along the ulnar nerve; and at the fifth cervical nerve root level. No systematic error was indicated by Bland-Altman analysis; the coefficients of variation were 5.5%-9.2% for intra-observer reliability and 7.1%-8.7% for inter-observer reliability.
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Ultrasound Med Biol · Sep 2013
Doppler flow velocity and intra-cranial pressure: responses to short-term mild hypocapnia help to assess the pressure-volume relationship after head injury.
To anticipate an increase in intra-cranial pressure (ICP), information about pressure-volume (p/v) compliance is required. ICP monitoring often fails at this task after head injury. Could a test that transiently shifts intra-cranial blood volume produce consistent information about the p/v relationship? Doppler flow velocities in the middle cerebral arteries (left: 80.8 ± 34.7 cm/s; right: 65.9 ± 28.0 cm/s) and ICP (16.4 ± 6.7 mm Hg) were measured in 29 patients with head injury, before and during moderate hypocapnia (4.4 ± 3.0 kPa). ⋯ Additionally, the ratio identified 12 patients deviating from the classic non-linear p/v curve (left: 5.7 ± 1.3, right: 5.8 ± 1.0 cm/s/kPa/mm Hg). They exhibited an almost proportional relationship between vasomotor and ICP responses (R = 0.69, p < 0.01). Results suggest that a test that combines the responses of two intra-cranial compartments may provide consistent information about intra-cranial p/v compliance, even if the parameters derived from ICP monitoring are inconclusive.
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Ultrasound Med Biol · Jun 2013
Clinical TrialCombination of high-resolution ultrasound-guided perivascular regional anesthesia of the internal carotid artery and intermediate cervical plexus block for carotid surgery.
All previously documented regional anesthesia procedures for carotid artery surgery routinely require additional local infiltration or systemic supplementation with opioids to achieve satisfactory analgesia because of the complex innervation of the surgical site. Here, we report a reliable ultrasound-guided anesthesia method for carotid artery surgery. High-resolution ultrasound-guided regional anesthesia using a 12.5-MHz linear ultrasound transducer was performed in 34 patients undergoing carotid endarterectomy. ⋯ Five cases required additional local infiltration with 1% prilocaine (2-6 mL) by the surgeon. Visualization with high-resolution ultrasound yields safe and accurate performance of the block. Because of the low rate of intra-operative supplementation, we conclude that the described ultrasound-guided perivascular anesthesia technique is effective for carotid artery surgery.
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Ultrasound Med Biol · Jun 2013
Quantitative shear wave elastography in the evaluation of metastatic cervical lymph nodes.
Our aim was to compare the diagnostic performance of shear wave elastography (SWE) with that of gray-scale ultrasound (US) in differentiating metastatic from benign lymph nodes in patients with head and neck malignancies. Maximum shear elasticity modulus (maxSM) was measured on SWE. The reference standard was pathologic diagnosis after surgery. ⋯ Accuracy, sensitivity and specificity were 94, 91 and 97%, respectively, for SWE, and 91, 88 and 94%, respectively, for gray-scale US. Multiple regression analysis showed that the maxSM value (r = 0.882) and gray-scale US criteria (r = 0.837) were independent variables. SWE may be a valuable quantitative reproducible method for characterizing cervical lymph nodes.
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Ultrasound Med Biol · May 2013
Comparative StudyInter-rater, intra-rater, and inter-machine reliability of quantitative ultrasound measurements of the patellar tendon.
The use of ultrasound (US) to perform quantitative measurements of musculoskeletal tissues requires accurate and reliable measurements between investigators and ultrasound machines. The objective of this study was to evaluate inter-rater and intra-rater reliability of patellar tendon measurements between providers with different levels of US experience and inter-machine reliability of US machines. Sixteen subjects without a history of knee pain were evaluated with US examinations of the patellar tendon. ⋯ Bland-Altman plots were constructed to measure validity and demonstrated a mean difference between sonographers of 0.03 mm(2) for CSA measurements and 0.2 mm for tendon length. Using well-defined scanning protocols, a novice and an experienced musculoskeletal sonographer attained high levels of inter-rater agreement, with similarly excellent results for intra-rater and inter-machine reliability. To our knowledge, this study is the first to report inter-machine reliability in the setting of quantitative musculoskeletal ultrasound.