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PubMedDate not supplied

Detection of natural white spot caries lesions by an ultrasonic system.

Ultrasound has been used in industrial business as one of the nondestructive measurement methods. It was hypothesized that nondestructiveness of the ultrasonics could be useful in determination of demineralization of noncavitated carious lesions on human enamel. This investigation was designed to determine the presence of natural carious lesions on proximal surfaces of human molar teeth using an ultrasonic system compared to radiography and histology as the gold standards. Measurements were made directly from proximal surfaces of 20 mandible molar teeth with white spot carious lesion by 2 examiners independently with the ultrasonic system. Ultrasonic evaluation of each natural white spot lesion had a sensitivity of 88%, specificity of 86%, positive predictive value of 88% and a negative predictive value of 86%, and the chance-corrected agreement was also satisfactory (kappa=0.74) compared to histology. The radiograph demonstrated chance-corrected agreement of 0.41:0.38 for the first and second examiners, respectively. Duncan test analysis of the numerical values was significantly different for the intact and the noncavitated carious surfaces (p<0.05). The results indicated that the ultrasonic evaluation is a sensitive method for the detection of the natural white spot carious lesions and can differentiate the changes in elastic properties of enamel numerically.

Analysis of Variance↗

PubMed1985

Effects of coronary artery occlusion and reperfusion on cardiac cycle-dependent variation of myocardial ultrasonic backscatter.

We have recently reported a systematic variation in integrated ultrasonic backscatter throughout the cardiac cycle in canine hearts. This study was performed to determine whether the pattern of such variation is modified systematically by ischemia. Measurements of integrated ultrasonic backscatter in selected regions of normal, ischemic, and reperfused hearts were compared in view of known differences in systolic function of myocardium in each of these regions. Integrated ultrasonic backscatter (3-7 MHz) gated to the first derivative of left ventricular pressure was measured at the apex, midwall, and base in 10 dogs and at the apex before and during transient ischemia and reperfusion in four dogs. Quantitative integrated ultrasonic backscatter was referenced to a steel reflector. Cyclic variation of integrated ultrasonic backscatter was greatest at the apex [peak to trough variation 5.5 +/- 0.9 dB (mean +/- SE)] with the maximum near end diastole (-52.9 +/- 0.9 dB) and minimum near end systole (-58.4 +/- 1.0 dB). Variation at the apex (5.5 +/- 0.9 dB) and the midwall (4.3 +/- 0.8 dB) was greater than at the base (0.5 +/- 1.0 dB) (P less than 0.01 for either region compared with base). Left anterior descending coronary occlusion for 10 minutes in four of 10 dogs reduced variation at the apex to 0.4 +/- 1.5 dB (P less than 0.02 compared with preocclusion). Reperfusion for 2 hours restored apical cyclic variation to 3.9 +/- 1.7 dB, i.e., to values not significantly different from those before occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1997

A guinea-pig model of ultrasonically nebulized distilled water-induced bronchoconstriction.

Ultrasonically nebulized distilled water-induced bronchoconstriction (UNDW-IB) is specific to asthma. The mechanisms underlying UNDW-IB are not fully understood, and no reproducible animal model has been reported. The purpose of this study was to develop a guinea-pig model of UNDW-IB. Ultrasonically nebulized distilled water (UNDW) was inhaled 20 min after an aerosolized antigen challenge in passively sensitized and artificially ventilated guinea-pigs. UNDW was also inhaled 5 and 20 min after 0.1 mg x mL(-1) methacholine inhalation in nonsensitized animals. In addition, 0.1 mg x kg(-1) S-1452, a thromboxane A2 antagonist, or saline was given intravenously 5 min before UNDW inhalation in sensitized animals. The inhalation of UNDW caused bronchoconstriction, when inhaled 20 min after an antigen challenge in sensitized guinea-pigs. UNDW inhalation did not produce bronchoconstriction after saline inhalation in nonsensitized or sensitized guinea-pigs, or after antigen inhalation in nonsensitized animals. Methacholine-induced bronchoconstriction did not evoke UNDW-IB. Neither did S-1452 reduce the UNDW-IB. In conclusion, the guinea-pig model of ultrasonically nebulized distilled water-induced bronchoconstriction developed in this study suggests that allergic reaction, but not bronchoconstriction, can induce bronchial hyperresponsiveness to ultrasonically nebulized distilled water, and that thromboxane A2 is not involved in ultrasonically nebulized distilled water-induced bronchoconstriction.

Administration, Inhalation↗

PubMed2006

Production of ultrasonic vocalizations by Peromyscus mice in the wild.

BACKGROUND: There has been considerable research on rodent ultrasound in the laboratory and these sounds have been well quantified and characterized. Despite the value of research on ultrasound produced by mice in the lab, it is unclear if, and when, these sounds are produced in the wild, and how they function in natural habitats. RESULTS: We have made the first recordings of ultrasonic vocalizations produced by two free-living species of mice in the genus Peromyscus (P. californicus and P. boylii) on long term study grids in California. Over 6 nights, we recorded 65 unique ultrasonic vocalization phrases from Peromyscus. The ultrasonic vocalizations we recorded represent 7 different motifs. Within each motif, there was considerable variation in the acoustic characteristics suggesting individual and contextual variation in the production of ultrasound by these species. CONCLUSION: The discovery of the production of ultrasonic vocalizations by Peromyscus in the wild highlights an underappreciated component in the behavior of these model organisms. The ability to examine the production of ultrasonic vocalizations in the wild offers excellent opportunities to test hypotheses regarding the function of ultrasound produced by rodents in a natural context.

Journal Article↗

PubMed2005

Evaluation of ultrasonic atomization as a new approach to prepare ionically cross-linked chitosan microparticles.

Ultrasonic atomization was evaluated as a new approach for the preparation of ionically cross-linked controlled-release chitosan microparticles loaded with theophylline as the model drug, using tripolyphosphate (TPP) as counter-ion. It was possible to nebulize both 2% and 3% (w/v) chitosan solutions as a function of their viscosity, usually not processed by employing the conventional nebulizer. The results of the chitosan molecular characterization using the SEC-MALS analysis revealed that ultrasonic atomization caused a certain depolymerization, probably due to the main chain scission of the 1,4-glycosidic bond; however, Fourier transform-infrared spectroscopy revealed the absence of other chemical modifications. The ultrasonic atomization allowed preparation of TPP cross-linked chitosan microparticles mostly ranging between 50 and 200 mum. As regards manufacturing parameters, the linking time and washing medium were found to affect the properties of the microparticles, while the stirring rate of the TPP solution did not show any influence. The evaluation of the formulation variables revealed that chitosan concentration strongly affected both the feasibility of the ultrasonic atomization and the drug release. All the microparticles showed an encapsulation efficiency of > 50 % and, after an initial burst effect, a controlled release of drug for 48 h. In conclusion, the ultrasonic atomization could be proposed as a robust and innovative single-step procedure with scale-up potential to successfully prepare ionically cross-linked chitosan microparticles.

Biocompatible Materials↗

PubMed1998

Ultrasonic heel pad thickness measurements: a preliminary study.

The heel pad has an important role in pain-free locomotion due to its shock-attenuation function. Various diagnostic techniques are available to measure heel pad thickness. Ultrasonic measurement of the heel pad is inexpensive, involves no ionizing radiation and is portable, making it an ideal screening technique. Measurement errors may occur between different ultrasonic techniques used to measure heel pad thickness. A new standardized ultrasonic technique was performed on 15 healthy volunteers. The ultrasonic measurements were compared with the measurement obtained from a normal non-weightbearing heel pad thickness ultrasonic assessment. The results demonstrated a significant mean difference (p < 0.001) between the two techniques. The 95% confidence interval of the heel pad thickness difference indicated values between 7.68 and 9.13 mm. These results suggest that a standardized technique reduces the variability of measurement error when using weightbearing ultrasound, allowing a more reproducible diagnostic technique for assessing heel pad function, and improving patient management.

Adult↗

PubMed1976

The diagnosis of pleural effusion by ultrasonic and radiologic techniques.

The value of the A-mode ultrasonic technique and the radiologic method in the diagnosis of pleural effusion was assessed in 116 patients with diseases of the pleura. Ultrasonic and radiologic examinations, as well as needle punctures, were performed, and the results were compared statistically. The pleural fluid was detected by ultrasound in 93 percent (74) and by radiologic examination in 83 percent (66) of the 80 cases with such fluid. The absence of fluid was established by ultrasound in 89 percent (32/36) and by radiologic examination in 61 percent (22/36). For the first time the superiority of the ultrasonic method over the radiologic one was demonstrated, and the difference was most obvious in cases of small pleural effusion. Ultrasound permitted the detection of very small amounts (even 3 to 5 ml) of loculated pleural fluid. In contrast to the radiologic method, ultrasound permitted easy differentiation between loculated pleural fluid and pleural thickenings. The ultrasonic method appeared especially useful in the accurate localization and precise indicating of the site for needle aspiration of even the smallest fluid collections. It made possible thoracocentesis in 94 percent (154) of 163 instances. The practical value of the ultrasonic method, both in establishing diagnosis and in treatment, is emphasized.

Drainage↗

PubMed1985

The clinical value of measurements of the symphysis-fundus distance and ultrasonic measurements of the biparietal diameter in the diagnosis of intrauterine growth retardation.

The diagnostic efficiency in the prediction of intrauterine growth retardation (IUGR) of repeated measurements of the symphysis-fundus (SF) distance and repeated ultrasonic measurements of the biparietal diameter (BPD) was investigated in 377 pregnancies, all at risk for IUGR. Measurements of the SF distance were found to be more effective than ultrasonic BPD measurements for antenatal diagnosis of IUGR. For every correct diagnosis there were three false positive when using SF measurements and ten when using ultrasonic BPD measurements. When the SF method is used, repeated ultrasonic BPD measurements add very little information. The SF curve is a very simple and inexpensive method and should be used as a screening instrument for severe IUGR. When the SF curve is assessed as pathological, ultrasonic measurements also including other fetal dimensions than only BPD are recommended as a way of diagnosing IUGR.

Cephalometry↗

PubMed1998

Ultrasonic imaging of the temporomandibular joint: a clinical trial for diagnosis of internal derangement.

Kinematic imaging of the temporomandibular joint (TMJ) was applied for diagnosis of TMJ disorders using an ultrasonic diagnostic imaging system. Patients with a normal TMJ (male, 24 y 1 mon) and a symptomatic TMJ (female, 20 y 2 mon) were selected for imaging. The transducer must be placed in a specific location in order to propagate ultrasound through soft tissue because it is difficult for ultrasound to penetrate bone such as the condyle and the eminence. Therefore the ultrasonic images were not taken in sagittal cross-section, as is the case with magnetic resonance images. The ultrasonic diagnostic imaging system showed a transverse cross-section and no hard tissue images. It was difficult to become accustomed to these images, thus making it difficult to find differences between the normal TMJ and the symptomatic TMJ on the basis of static ultrasonic images alone. However a difference between the kinematic images of the normal and symptomatic TMJ was observed during jaw opening. Irregularity in the striated pattern of the soft tissue surrounding the condyle was observed in the image of the symptomatic TMJ. In order to make a precise diagnosis using ultrasonic imaging, it may be useful to understand the kinematics of the soft tissue surrounding the TMJ during jaw opening and closing.

Adult↗

PubMed2004

Use of high-power ultrasonic shears for laparoscopic ovariectomy in mares.

A method for performing laparoscopic ovariectomy with high-power ultrasonic shears in mares is described, along with results in 10 mares. Briefly, after epidural administration of detomidine and local anesthesia with mepivacaine, 3 cannulas were placed in each paralumbar fossa. A laparoscope was placed through the most dorsal cannula, and a grasping forceps was placed through the most ventral cannula and used to grasp and manipulate the ovary. The ultrasonic shears was then placed through the middle cannula. The jaws of the ultrasonic shears were closed across a portion of the ovarian pedicle, and the instrument was discharged until tissue within the jaws was transected; the process was repeated until the entire ovarian pedicle was transected. Following removal of the right ovary, it was passed to the left side of the abdomen and both ovaries were removed through an incision in the left paralumbar fossa. No major complications were identified in any of the 10 mares. However, excessive bleeding necessitating reapplication of the ultrasonic shears (2 ovaries) or application of ligating clips (8) was encountered with 10 of the 20 ovaries. Laparoscopic ovariectomy with a high-power ultrasonic shears appears to be safe in mares.

Animals↗

PubMed1989

Measuring bovine mammary gland blood flow using a transit time ultrasonic flow probe.

Lactating cattle were used to validate a transit time ultrasonic blood flow metering system for measuring mammary gland arterial blood flow. Blood flow probes were surgically placed around the right external pudic artery. An electromagnetic flow probe was implanted in tandem with the ultrasonic probe in two cows for comparative measurements. The absolute accuracy of the implanted flow probes was assessed in vivo by mechanical means on anesthetized cows after 2 to 3 wk of implantation. The zero offset of the ultrasonic probes ranged from -12 to 8 ml/min. When the ultrasonic probe was properly implanted, the slopes of the calibration curves were linear and ranged from .92 to .95, tracking absolute flow to within 8%. The transit time instrument's performance was examined under a variety of physiological conditions. These included milking and hormone injections. The transit time ultrasonic flow meter accurately measured physiological changes in mammary arterial blood flow in chronically prepared conscious cattle. Blood flow increased 29% during milking. Epinephrine decreased mammary blood flow by 90 to 95%. Oxytocin doses increased mammary blood flow by 15 to 24%.

Animals↗

PubMed1995

[Evaluation of cavernous artery by color Doppler ultrasonography--significance of ultrasonic beam angle].

Penile Doppler ultrasonography is widely accepted as an essential examination in the diagnosis of impotence. However, measurement blood flow velocity using Doppler ultrasonography may be subject to some errors. We performed color Doppler ultrasonography in 63 patients with normal penile vascular function as diagnosed using positive responses to intracavernous pharmacological stimulation. We compared the Doppler measurement results of the 126 cavernous arteries and the ultrasonic beam angles. We used a Hitachi EUB 515, a sonographic probe of 7.5 MHz, a sampling width of 0.8 mm, a sampling depth of 1 mm, and a wall motion filter was not used. Ultrasonic beam angles were 5 to 77 degrees. The mean peak systolic velocity and end diastolic velocity values were 40. 0 cm/s and 3.9 cm/sec, respectively. The peak systolic velocity and end diastolic velocity values remained stable regardless of the ultrasonic beam angles (Kruskal-Wallis test, p = 0.56, p = 0.70). However, the variance of values became greater when the ultrasonic beam angles was larger than 55 degrees in the case of peak systolic velocity (F test, p < 0.05) and 50 degrees in the case of end diastolic velocity (F test, p < 0.05), indicating a reduction in reliability. Resistance index variance was significantly higher when ultrasonic beam angle exceeds 50 degrees (F test, p < 0.05). We believe that we should accept only those cavernous artery peak systolic velocity measurements as reliable when the ultrasound beam angle is less than 55 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1983

Image processing to reduce ultrasonic speckle.

The most significant source of noise in contemporary ultrasonic images is ultrasonic speckle, a phenomenon relating to random interference of ultrasonic waveforms in transducer sample volumes. Averaging of a number of ultrasonic images, which are slightly spatially shifted with respect to one another, leads to image improvement via speckle reduction. Such processing may provide a useful improvement of clinical ultrasonic images.

Humans↗

PubMed1990

On the application of ultrasonic contrast agents for blood flowmetry and assessment of cardiac perfusion.

The stability, size, and ultrasonic properties of several ultrasonic microbubble contrast agents such as Albunex, SHU-454, 1% hydrogen peroxide, and sonicated solutions such as 70% and 50% dextrose, 70% sorbitol, 5% albumin, Renografin-76, and others were evaluated. Albunex was the only tested agent that was sufficiently stable over an extended period of time for in vitro ultrasonic characterization. The attenuation and backscatter coefficients of Albunex at 5 and 7.5 MHz were found to be linearly proportional to microsphere concentration at low concentrations (less than 0.01% for attenuation and less than 0.002% for backscatter). Also, Albunex was found to be more echogenic than soft tissues at 5 MHz even after being diluted to 0.0003% of the original concentration. Next, the feasibility of using this acoustic information for contrast blood flowmetry was investigated. In vitro flow estimates in a mock flow loop were made using only the ultrasonic properties of the contrast agent. Bolus injections of Albunex and indicator-dilution curves inferred from ultrasonic measurements were used to estimate calibrated flow rate ranging from 400 to 5000 mL/min. The flow estimates from attenuation measurements showed a good correlation with those from an independent method (r = 0.97), but the results from backscatter studies did not correlate well. These results demonstrate that attenuation measurement may be a feasible alternative for in vivo blood flow measurement in conjunction with the indicator dilution principle or estimation of tissue perfusion such as myocardial perfusion using a time-activity approach.

Albumins↗

PubMedDate not supplied

[Ultrasonic methods of functional diagnosis in urology].

The results of ultrasonic investigations (n = 15,822) and treatment of 7778 patients treated in the urological clinic of 1. M. Sechenov Moscow Medical Academy in 1985-1998. Functional ultrasonic diagnosis serves the basis for a new line in urology--application of ultrasonic methods with various pharmacological tests to improve the diagnosis and assess functional status of the kidneys and urinary tracts. Comparison of the findings of ultrasonic and other examinations in patients with urinary tract diseases with the operative and morphological findings characterizes diagnostic value of ultrasonic functional techniques in some diseases.

Diagnosis, Differential↗

PubMed2003

Ultrasonic prediction of term birth weight in Hispanic women. Accuracy in an outpatient clinic.

OBJECTIVE: To investigate the accuracy of ultrasonic fetal biometric algorithms for estimating term fetal weight. STUDY DESIGN: Ultrasonographic fetal biometric assessments were made in 74 Hispanic women who delivered at 37-42 weeks of gestation. Measurements were taken of the fetal biparietal diameter, head circumference, abdominal circumference and femur length. Twenty-seven standard fetal biometric algorithms were assessed for their accuracy in predicting fetal weight. Results were compared to those obtained by merely guessing the mean term birth weight in each case. RESULTS: The correlation between ultrasonically predicted and actual birth weights ranged from 0.52 to 0.79. The different ultrasonic algorithms estimated fetal weight to within +/- 8.6-15.0% (+/- 295-520 g) of actual birth weight as compared with +/- 13.6% (+/- 449 g) for guessing the mean birth weight in each case (mean +/- SD). The mean absolute prediction errors for 17 of the ultrasonic equations (63%) were superior to those obtained by guessing the mean birth weight by 3.2-5.0% (96-154 g) (P < .05). Fourteen algorithms (52%) were more accurate for predicting fetal weight to within +/- 15%, and 20 algorithms (74%) were more accurate for predicting fetal weight to within +/- 10% of actual birth weight than simply guessing the mean birth weight (P < .05). Ten ultrasonic equations (37%) showed significant utility for predicting fetal weight > 4,000 g (likelihood ratio > 5.0). CONCLUSION: Term fetal weight predictions using the majority of sonographic fetal biometric equations are more accurate, by up to 154 g and 5%, than simply guessing the population-specific mean birth weight.

Adult↗

PubMedDate not supplied

[Ultrasonic diagnosis of non-Hodgkin's lymphoma].

Analyzes the results of ultrasonic examinations of 111 patients with various forms of non-Hodgkin's lymphomas. Reviews ultrasonic semeiotics of non-Hodgkin's lymphadenopathy of the abdominal cavity and retroperitoneal space and of extranodal variants of lymphoma course (with involvement of the spleen and stomach). Suggests the most safe method for precision diagnostic aspiration biopsy of the spleen monitored by ultrasound. The author considers ultrasonic examination to be a valuable method for the diagnosis of non-Hodgkin's lymphomas; it is economic, rapid, safe, permits a simultaneous assessment of the status of many organs and systems. The results of ultrasonic examinations should be assessed in complex with the results of other diagnostic methods. Ultrasonic examination should be considered as a method of choice for monitoring patients with diagnosed non-Hodgkin's lymphoma.

Female↗

PubMed1992

Prediction of the small for gestational age infant: which ultrasonic measurement is best?

OBJECTIVE: To determine the most appropriate ultrasonic measurement for the prediction of a small for gestational age (SGA) infant. DATA SOURCES: A literature search of all English language journals over the last 15 years was undertaken. One hundred seventeen articles on the use of morphometric and Doppler ultrasonic measurements in the diagnosis of SGA were reviewed. METHODS OF STUDY SELECTION: Studies were included if antenatal and postnatal criteria for diagnosis were clearly defined and data for SGA and normal fetuses were reported, allowing the construction of a 2 x 2 table. DATA EXTRACTION AND SYNTHESIS: Studies with the same criteria were grouped according to whether the population was high or low risk. The sensitivity, odds ratio (OR), and false-positive rate were calculated for each study; summary statistics were then calculated for each ultrasonic measurement provided the individual sensitivities, ORs, and false-positive rates were not significantly different (P > .01). CONCLUSIONS: In high-risk subjects, abdominal circumference below the tenth percentile had the highest common sensitivity, and estimated fetal weight below the tenth percentile had the highest common OR. In studies in which morphometric and Doppler ultrasonic measurements were compared in the same subjects, the Doppler ORs tended to be lower than the ORs for morphometric measurements. In low-risk subjects, much lower ORs were found for all ultrasonic measurements. The heterogeneous nature of the studies reviewed may have contributed to the different results within each group.

False Positive Reactions↗