Ultrasound in medicine & biology
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Ultrasound Med Biol · May 2015
Comparative StudyTranscranial ultrasound to detect elevated intracranial pressure: comparison of septum pellucidum undulations and optic nerve sheath diameter.
Two ultrasound tests that can be used to assess increased intracranial pressure (ICP) at the bedside are described. In outpatients receiving lumbar puncture and in intensive care patients with invasive ICP monitoring, we measured the optic nerve sheath diameter (ONSD) with transbulbar B-mode sonography and septum pellucidum undulation (SPU) induced by repeated passive head rotation with transtemporal M-mode sonography. We assessed the sensitivity and specificity of ONSD and SPU in the prediction of ICP >20 cm H2O. ⋯ The sensitivity of the SPU test was 75% and the specificity 100% (n = 32, p < 0.001). Although the SPU test may not feasible in some patients, it has high sensitivity and specificity comparable to those of ONSD measurement. The SPU test and ONSD may be useful alternatives to fundoscopy in clinical routine, preferably in combination.
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Ultrasound Med Biol · May 2015
An ultrasonographic technique to assess the jugular venous pulse: a proof of concept.
The purpose of the work described here was to investigate the feasibility of assessing the jugular venous pulse (JVP) using ultrasound (US) equipment. Three young healthy subjects underwent a B-mode US scan of the internal jugular vein (IJV) to acquire a sonogram sequence in the transverse plane. On each acquired sonogram, the IJV contour was manually traced, and both the cross-sectional area (CSA) and the perimeter were measured. ⋯ We compared 390 manually traced contours of the IJV cross-sectional area with corresponding values semi-automatically calculated by an algorithm developed in-house. For all subjects, the sensitivity, specificity and accuracy were around 95%, 85% and 90% respectively. We found that a diagram reflecting the JVP can be obtained by analyzing a B-mode sonogram sequence of the IJV; such a diagram can result in a new methodology to assess the IJV functionality.
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Ultrasound Med Biol · May 2015
Comparative StudyComparison of three methods for the confirmation of laryngeal mask airway placement in female patients undergoing gynecologic surgery.
The laryngeal mask airway (LMA) is a supraglottic device that is commonly used to provide lung ventilation during general anesthesia. LMA placement needs to be confirmed to provide adequate lung ventilation. To investigate the feasibility of using ultrasound examination, compared with clinical tests and fiberoptic laryngoscopy, to confirm LMA placement, we performed a clinical study of 64 female patients classified as American Society of Anesthesiologists Physical Status I or II who were scheduled for gynecologic surgery with LMA insertion for airway management. ⋯ Of the 64 women, placement was confirmed as acceptable in 89.1% by clinical tests, in 59.4% by fiberoptic laryngoscope assessment and in 67.2% by ultrasound examination. With respect to patients with oropharyngeal leaks classified as high, there were no differences in confirmation of acceptable placement between clinical tests and ultrasound examinations (p = 0.092), but the number of patients determined to have acceptable placement by ultrasound examination was greater than that determined by fiberoptic laryngoscopy (p = 0.034). Thus, ultrasound examination is a superior technique for confirming the seal on the LMA.
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Ultrasound Med Biol · May 2015
Observational StudyUltrasonographic assessment of optic nerve sheath diameter during pediatric laparoscopy.
This study investigated the extent of the raised intracranial pressure resulting from carbon dioxide (CO2) pneumoperitoneum by ultrasonographically measuring optic nerve sheath diameter (ONSD) in children undergoing laparoscopic surgery. Twenty-five children aged less than 9 y (53.1 ± 23.3 mo, mean ± standard deviation) and scheduled for an elective laparoscopic surgery participated. ⋯ In all enrolled patients, any neurologic complications were not observed during the intra-operative or post-operative period. In children undergoing laparoscopic surgery, an increase in ONSD was ascertained during CO2 pneumoperitoneum, and thus the corresponding increase in intracranial pressure could be predicted.
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Ultrasound Med Biol · May 2015
Comparative StudyImproved correlation between carotid and coronary atherosclerosis SYNTAX score using automated ultrasound carotid bulb plaque IMT measurement.
Described here is a detailed novel pilot study on whether the SYNTAX (Synergy between percutaneous coronary intervention with TAXUS and cardiac surgery) score, a measure of coronary artery disease complexity, could be better predicted with carotid intima-media thickness (cIMT) measures using automated IMT all along the common carotid and bulb plaque compared with manual IMT determined by sonographers. Three hundred seventy consecutive patients who underwent carotid ultrasound and coronary angiography were analyzed. SYNTAX score was determined from coronary angiograms by two experienced interventional cardiologists. ⋯ This current automated algorithm revealed a significantly stronger correlation between cIMT and coronary SYNTAX score as compared with the sonographer's cIMT measurements with multiple cardiovascular risk factors. We benchmarked our correlation between the automated cIMT that includes bulb plaque and SYNTAX score against a previously published (Ikeda et al. 2013) AtheroEdgeLink (AtheroPoint) correlation between the automated cIMT that does not include bulb plaque and SYNTAX score and had an improvement of 44.58%. By sampling cIMT in the bulb region, the automated cIMT technique improves the degree of correlation between coronary artery disease lesion complexity and carotid atherosclerosis characteristics.