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Thứ Năm, 27 tháng 8, 2015

J U M 9-2015

Selected Abstracts
  1. Abstract 1 of 8Original Research
Comparison Between Various Color Spectra and Conventional Grayscale Imaging for Detection of Parenchymal Liver Lesions With B-Mode Sonography
Objectives—The electronic colorization of grayscale B-mode sonograms using various color schemes aims to enhance the adaptability and practicability of B-mode sonography in daylight conditions. The purpose of this study was to determine the diagnostic effectiveness and importance of colorized B-mode sonography.
Methods—Fifty-three video sequences of sonographic examinations of the liver were digitized and subsequently colorized in 2 different color combinations (yellow-brown and blue-white). The set of 53 images consisted of 33 with isoechoic masses, 8 with obvious lesions of the liver (hypoechoic or hyperechoic), and 12 with inconspicuous reference images of the liver. The video sequences were combined in a random order and edited into half-hour video clips.
Results—Isoechoic liver lesions were successfully detected in 58% of the yellow-brown video sequences and in 57% of the grayscale video sequences (P = .74, not significant). Fifty percent of the isoechoic liver lesions were successfully detected in the blue-white video sequences, as opposed to a 55% detection rate in the corresponding grayscale video sequences (P= .11, not significant). In 2 subgroups, significantly more liver lesions were detected with grayscale sonography compared to blue-white sonography.
Conclusions—Yellow-brown–colorized B-mode sonography appears to be similarly effective for detection of isoechoic parenchymal liver lesions as traditional grayscale sonography. Blue-white colorization in B-mode sonography is probably not as effective as grayscale sonography, although a statistically significant disadvantage was shown only in the subgroup of hyperechoic liver lesions.
o    © 2015 by the American Institute of Ultrasound in Medicine
2.      Abstract 2 of 8Original Research
Neonatal Lung Sonography
Interobserver Agreement Between Physician Interpreters With Varying Levels of Experience
Objectives—To assess the reliability of lung sonography in neonates between physician interpreters with different degrees of experience.
Methods—We retrospectively reviewed lung sonograms from neonates admitted to a neonatal intensive care unit with respiratory distress in the first 24 hours of life. The first scans were selected; only patients with available video clips documenting both hemithoraxes were included. The clips were independently examined by 4 different experienced observers blinded to clinical data. The interpreting physicians made a codified sonographic diagnosis, and the Cohen κ coefficient was used to measure the reliability between a proven experienced main interpreter and expert (κ1), intermediate (κ2), and beginner (κ3) control interpreters. We also calculated the specific agreement on respiratory distress syndrome and transient tachypnea of the neonate.
Results—Four hundred sixty-five clips were taken from 114 neonates examined over a 16-month period. The patients’ median gestational age (range) was 34 weeks (25–41 weeks), and the median birth weight (range) was 2085 g (608–4134 g). Eighty-eight percent of examinations were performed within 24 hours after birth. The overall κ coefficients (95% confidence intervals) were κ1 = 0.94 (0.88–1.00); κ2 = 0.72 (0.61–0.83); and κ3 = 0.81 (0.71–0.90). For respiratory distress syndrome, κ1 = 0.94 (0.87–1.00); κ2 = 0.90 (0.81–0.99); and κ3 = 0.87 (0.78–0.97). For transient tachypnea of the neonate, κ1 = 0.95 (0.89–1.00); κ2 = 0.76 (0.64–0.88); and κ3 = 0.81 (0.70–0.91).
Conclusions—In neonates with early respiratory distress, lung sonography has high interobserver agreement even between interpreters with varying levels of experience.

o    © 2015 by the American Institute of Ultrasound in Medicine
  1. Abstract 3 of 8Original Research
Extension of the Thoracic Spine Sign
A New Sonographic Marker of Pleural Effusion
Objectives—Dyspnea is a common emergency department (ED) condition, which may be caused by pleural effusion and other thoracic diseases. We present data on a new sonographic marker, the extension of the thoracic spine sign, for diagnosis of pleural effusion.
Methods—In this prospective study, we enrolled a convenience sample of undifferentiated patients who underwent computed tomography (CT) of the abdomen or chest, which was performed as part of their emergency department evaluations. Patients underwent chest sonography to assess the utility of the extension of the thoracic spine sign for diagnosing pleural effusion. The point-of-care sonographic examinations were performed and interpreted by emergency physicians who were blinded to information in the medical records. Sonographic results were compared to radiologists’ interpretations of the CT results, which were considered the criterion standard.
Results—Forty-one patients were enrolled, accounting for 82 hemithoraces. Seven hemithoraces were excluded from the analysis due to various limitations, leaving 75 hemithoraces for the final analysis. The median time for completion of the sonographic examination was 3 minutes. The sensitivity and specificity for extension of the thoracic spine were 73.7% (95% confidence interval [CI], 48.6%–89.9%) and 92.9% (95%CI, 81.9%–97.7%), respectively. Overall, there were 5 hemithoraces with false-negative results when using the extension sign. Of those 5 cases, 4 were found to have trace pleural effusions on CT. When trace pleural effusions were excluded in a subgroup analysis, the sensitivity and specificity of extension of the thoracic spine were 92.9% (95% CI, 64.2%–99.6%) and 92.9% (95% CI, 81.9%–97.7%).
Conclusions—We found the extension of the thoracic spine sign to be an excellent diagnostic tool for clinically relevant pleural effusion.
o     2015 by the American Institute of Ultrasound in Medicine
  1. Abstract 4 of 8Original Research
Diagnosis of Placenta Accreta by Uterine Artery Doppler Velocimetry in Patients With Placenta Previa
Objectives—To evaluate the potential value of uterine artery Doppler velocimetry in diagnosing placenta accreta.
Methods—Clinical records of all deliveries between April 1991 and March 2013 were retrospectively analyzed. Cases of intrauterine growth restriction, pregnancy-induced hypertension, multiple pregnancies, fetal anomalies, chromosomal abnormalities, and maternal medical illnesses such as cardiovascular disease, renal disease, and diabetes mellitus were excluded. A total of 11,210 cases were evaluated, including 403 cases of placenta previa without accreta (placenta previa) and 39 cases of placenta previa with accreta (placenta accreta). All patients underwent uterine artery Doppler velocimetry to measure the mean resistive index and pulsatility index (PI) in the third trimester. The analysis included participant characteristics such as age, parity, abortion history, previous cesarean delivery, gestational age at delivery, neonatal sex, and birth weight.
Results—The mean uterine artery PI was significantly lower in the placenta accreta group compared to previa alone (0.51 versus 0.57; P = .002). The odds ratios for placenta accreta were 2.4 for 2 or more previous abortions (P = .011) and 5.3 and 7.0 for 1 and 2 or more previous cesarean deliveries (P = .001 and .005). With an increase in the mean PI by 0.01, the odds ratio for placenta accreta decreased by 0.94 (P < .001). The area under the receive operating characteristic curve was 0.72 for previous cesarean delivery alone, increasing to 0.77 with the combination of the mean PI and previous cesarean delivery (P = .047).
Conclusions—This study suggests that the mean PI measured by uterine artery Doppler velocimetry is reduced in patients with placenta accreta compared to those without accreta. The diagnostic accuracy of placenta accreta can be potentially improved if uterine artery Doppler values and the history of cesarean delivery are combined.
o    © 2015 by the American Institute of Ultrasound in Medicine

  1. Abstract 5 of 8Original Research
Assessment of Substantial Liver Fibrosis by Real-time Shear Wave Elastography in Methotrexate-Treated Patients With Rheumatoid Arthritis
Objectives—A concern about methotrexate (MTX)-related liver fibrosis in patients with rheumatoid arthritis (RA) is still unresolved. This study investigated the correlation between liver stiffness and the cumulative MTX dose and the risk factors associated with substantial liver fibrosis assessed by real-time shear wave elastography (SWE), a recently introduced technique to evaluate liver stiffness in patients with RA.
Methods—Data from 185 patients with RA were prospectively collected. Patients were divided into 3 groups according to cumulative MTX dose (group 1, total dose <1500 1500="" 2="" 3="" and="" group="" mg="">4000 mg) and compared with healthy control participants. A Pearson correlation analysis was performed to evaluate correlations between liver stiffness and other clinical and laboratory variables. Substantial liver fibrosis was defined as liver stiffness of greater than 8.6 kPa by SWE. Associated factors were tested in a multivariate logistic analysis.
Results—The mean liver stiffness value in healthy controls was significantly lower than in patients with RA treated with MTX (P< .006), but there was no significant difference among the MTX groups. Liver stiffness and the cumulative MTX dose was not correlated. Substantial liver fibrosis was detected only in 9 patients (4.9%). Multivariate analysis adjusted by age and sex revealed that only a high body mass index (odds ratio, 1.79; 95% confidence interval, 1.34–2.39; P < .001) was associated with liver stiffness of greater than 8.6 kPa.
Conclusions—Substantial liver fibrosis on SWE was observed in about 5% of MTX-treated patients with RA and was associated with only a high body mass index but not with the cumulative MTX dose, suggesting that other comorbidities might have a more important role in liver fibrosis.
o    © 2015 by the American Institute of Ultrasound in Medicine

  1. Abstract 6 of 8Original Research
Examination of Subcutaneous Tissue Thickness in the Thigh Site for Intramuscular Injection in Obese Individuals
Objectives—The aim of the study was to investigate the thickness of subcutaneous (SC) tissue in the dorsogluteal and thigh sites in obese adults and its suitability for intramuscular injection using a standard-length needle.
Methods—The sample for this prospective study consisted of 54 obese adults who presented to the ultrasound unit of the radiology clinic of a university hospital in the province of İzmir, Turkey, between June 2012 and August 2013. The study received Institutional Review Board approval, and informed written consent was obtained from all participants. The thickness of the SC tissue in the dorsogluteal and thigh sites was measured by sonography. The sonographic measurements were performed by a radiology specialist.
Results—The mean thicknesses of the SC tissue were 61.70 ± 15.73 mm in the dorsogluteal site, 27.05 ± 8.52 mm in the rectus femoris site, and 23.23 ± 8.44 mm in vastus lateralis site. The SC tissue was thicker in the dorsogluteal than the thigh site (P < .001).
Conclusions—A standard needle used in intramuscular injections to the thigh site would be effective in reaching the muscle in the rectus femoris and vastus lateralis sites in all men and in 77.8% of women, although it is not usually adequate for gluteal injection.
o    © 2015 by the American Institute of Ultrasound in Medicine
  1. Abstract 7 of 8Original Research
B-Lines in Assessment of Pulmonary Hypertension in Patients With Interstitial Lung Diseases
Feasibility of Transthoracic Lung Sonographic Signs
Objectives—This study was conducted to evaluate the value of sonographic B-lines (previously called “comet tail artifacts”) in assessment of pulmonary hypertension in patients with interstitial lung diseases.
Methods—One hundred thirty-four patients with clinically diagnosed interstitial lung diseases complicated by pulmonary hypertension underwent transthoracic lung sonography and Doppler echocardiography for assessment of the presence of B-lines, the distance between them, and the pulmonary artery (PA) systolic pressure. A correlation analysis and a receiver operating characteristic curve analysis were performed.
Results—All patients had diffuse bilateral B-lines. The maximum number of B-lines seen in any positive zone (not a summation) was significantly correlated with the severity of PA systolic pressure (r= 0.812; P< .0001), and a linear regression equation could be demonstrated: that is, y = 6.06 x + 17.57, where x and y represent the number of B-lines and PA systolic pressure, respectively. A cutoff of more than 4 B-lines seen in any positive zone had 89.5% sensitivity, 85.0% specificity, and 87.2% accuracy in predicting elevated PA pressure (>30 mm Hg).
Conclusions—The number of B-lines is useful in assessment of pulmonary hypertension, especially when tricuspid regurgitation and pulmonary valve regurgitation do not exist or cannot be satisfactorily measured by Doppler echocardiography.
o    © 2015 by the American Institute of Ultrasound in Medicine
  1. Abstract 8 of 8Original Research
Optic Nerve Sheath Diameter Increase on Ascent to High Altitude
Correlation With Acute Mountain Sickness
Objectives—Elevated optic nerve sheath diameter on sonography is known to correlate with increased intracranial pressure and is observed in acute mountain sickness. This study aimed to determine whether optic nerve sheath diameter changes on ascent to high altitude are associated with acute mountain sickness incidence.
Methods—Eighty-six healthy adults enrolled at 1240 m (4100 ft), drove to 3545 m (11,700 ft) and then hiked to and slept at 3810 m (12,500 ft). Lake Louise Questionnaire scores and optic nerve sheath diameter measurements were taken before, the evening of, and the morning after ascent.
Results—The incidence of acute mountain sickness was 55.8%, with a mean Lake Louise Questionnaire score ± SD of 3.81 ± 2.5. The mean maximum optic nerve sheath diameter increased on ascent from 5.58 ± 0.79 to 6.13 ± 0.73 mm, a difference of 0.91 ± 0.55 mm (P = .09). Optic nerve sheath diameter increased at high altitude regardless of acute mountain sickness diagnosis; however, compared to baseline values, we observed a significant increase in diameter only in those with a diagnosis of acute mountain sickness (0.57 ± 0.77 versus 0.21 ± 0.76 mm; P = .04). This change from baseline, or Δ optic nerve sheath diameter, was associated with twice the odds of developing acute mountain sickness (95% confidence interval, 1.08–3.93).
Conclusions—The mean optic nerve sheath diameter increased on ascent to high altitude compared to baseline values, but not to a statistically significant degree. The magnitude of the observed Δ optic nerve sheath diameter was positively associated with acute mountain sickness diagnosis. No such significant association was found between acute mountain sickness and diameter elevation above standard cutoff values, limiting the utility of sonography as a diagnostic tool.
o    © 2015 by the American Institute of Ultrasound in Medicine

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