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At least 865 records · Page 48Linked to original sources

PubMed2001

Ultrasonic vocalization responses in genetically high- and low-emotional rats.

Tsukuba High Emotional (THE) and Tsukuba Low Emotional (TLE) strains of rats have been congenitally bred for use in studies of emotionality. The current study investigated THE and TLE strain differences in the footshock-induced ultrasonic vocalization responses of adult male rats. Ultrasonic vocalization response inducibility (ratio of rats emitting ultrasounds) and vocalization activity in THE rats were statistically higher than in TLE rats. We next examined the causal relation between the ultrasonic vocalizations and the activation of the pituitary-adrenocortical axis in response to footshocks in these two strains of rats. Rats were sorted into two groups, vocalizing and non-vocalizing, after being exposed to the shock regimen daily for 5 successive days. Basal plasma concentrations of ACTH and corticosterone were not different between THE and TLE rats. After receiving footshocks, significant increases in plasma concentrations of ACTH and corticosterone were induced in both strains of rats. These increases in plasma concentrations of ACTH and corticosterone were significantly higher in THE than in TLE rats. However, in vocalizing and non-vocalizing rats of both strains, no statistical differences in plasma concentrations of ACTH and corticosterone were observed after footshocks. These findings suggest that the high emotionality of the adult male rats was reflected in the emission of ultrasounds, and that the emission of ultrasonic vocalizations might not be related to the activation of the pituitary-adrenocortical axis.

Adrenocorticotropic Hormone↗

PubMed1980

Ultrasonic pseudocalculus effect in psotcholecystectomy patients.

Nonvisualization of the gallbladder in ultrasonic cholecystography is noted in 15%--25% of patients with proven cholelithiasis. In this setting, the ultrasonic diagnosis of cholelithiasis and choledocholithiasis is made by detection of strong echoes with distal acoustic shadowing (calculus pattern). A similar pattern was detected in 17 of 26 postcholecystectomy patients, only one of whom had retained bile duct calculi. In the absence of surgical clips in the right upper abdomen (60% in our series), it is assumed that this ultrasonic pseudocalculus effect is caused by postoperative scar at the site of the gallbladder bed. Our data indicate that ultrasonic diagnosis of retained bile duct calculi in postcholecystectomy patients should be made with extreme caution.

Bile Duct Diseases↗

PubMed1999

Evaluation of human tooth structure with the ultrasonic imaging technique.

In recent years, ultrasonic waves have been an interesting subject for studies due to their wide range of applications in medical diagnoses. In this study, the acoustic properties of the structure of human teeth was determined with the ultrasonic imaging technique. This study may offer some fundamental findings related to the clinical application of the ultrasonic imaging technique in the further development of a virtual system for dental education and research. Twenty freshly-extracted permanent human teeth (10 molars and 10 premolars) were used to investigate their acoustic velocity and impedance by the ultrasonic image analyzing system with a high-resolution focusing probe. Additionally, the relationship between the acoustic properties and the hardness of the teeth was evaluated. It was found that the acoustic properties of the human teeth were influenced by factors related to their structure, such as degree of calcification, distribution of dentinal tubules, and volume of the dentin matrix. The acoustic velocity and impedance showed an apparent correspondence to the hardness of tooth. This analyzing system provides visual information related to tooth structure that can easily quantitatively evaluate their acoustic properties. It is expected that this system will have a wide range of applications and be further developed for clinical uses.

Acoustics↗

PubMed1992

Research applications of ultrasonic imaging in reproductive biology.

In the short time that transrectal ultrasonic imaging of the reproductive tract has been used as a research tool, many discoveries have resulted, some of which would otherwise have escaped detection for many years. Ultrasonography provides a wide array of morphologic information without invading or disturbing the tissues. Examinations can be done repeatedly over many days, or a dynamic event (e.g., ovulation) can be monitored in its entirety by continuous observation (e.g., 30 min). Inclusion of ultrasonic examinations in experimental protocols affords the opportunity to associate changing morphology with hormonal and other functional changes. If experimental testing is expected to involve changing morphology, ultrasonic imaging should be considered. End points can be measured or ranked and therefore data can be statistically analyzed for conventional hypothesis testing. The research potential of this technology and its adaptability for computer-assisted assessment go far beyond simplistic determination of ovulation, luteal formation, and pregnancy diagnosis. It is the authors' opinion that ultrasonic imaging is a revolutionary advance in reproductive research that is destined to rival the impact of other technologic breakthroughs, including radioimmunoassay.

Animals↗

PubMed1995

Real-time ultrasonic measurement of fat thickness and longissimus muscle area: I. Description of age and weight effects.

Serial ultrasonic measures of fat thickness (FTU) and longissimus muscle area (LMU) were taken on 180 feedlot steers representing 11 sire-breed groups at two 60-d intervals. Cattle then were slaughtered in four groups of 45 at 21-d intervals with ultrasonic measures taken at each interval. Analyses of variance indicated weight (WT) effects (P < .001) for all FTU measures and many of the LMU measures. Age was a source of variation (P < .05) for FTU and LMU over the first five measurement dates. Sire-breed (SBD) effects (P < .001) were prevalent for all FTU estimates and early LMU predictions. Some dam line and SBD x dam line interactions were detected (P < .1) for the FTU and LMU estimates. Age effects were described quadratically (P < .001) when FTU and LMU were regressed on age (R2 = 47 and 68%, respectively). When FTU and LMU were regressed on WT, effects were described quadratically (P < .001) with R2 values of 46 and 72%, respectively. Animals then were assigned to one of four biological types (BT) based on percentage of retail product (0-mm fat trim) using discriminant cluster analysis. Within BT, ultrasonic variables were regressed on age. Quadratic effects (P < .01) were detected for both FTU and LMU. Weight also contributed to variation observed in both ultrasonically measured variables for all BT (P < .001). These data indicate that changes in fat and muscle size as affected by age and weight are detectable using serially collected ultrasound measures. Furthermore, the age and weight relationships of predicted FTA and LMA varied across the four biological types. This suggests a need for derivation of biological type-specific age and(or) weight adjustment equations for cattle evaluation purposes.

Adipose Tissue↗

PubMedDate not supplied

Ultrasonic parameters of renal calculi and gall bladder stones as a function of density.

In this investigation, ultrasonic parameters of complex renal calculi and gall bladder stones, in vitro are measured using a double-probe contact by pulse-echo technique. Due to the variation in the chemical composition of the stones, a large variation in the value of ultrasonic parameters is found. A correlation between ultrasonic parameters and various renal calculi and gall bladder stone pathologies are also discussed. The ultrasonic parameters are found to vary as a function of density of the specimen used.

Cholelithiasis↗

PubMed1990

[Ultrasonographic study on kidneys in patients with chronic renal failure. Part I. Ultrasonic measurement of renal size and analysis of renal ultrasonotomograms].

Ultrasonograms of 546 kidneys were obtained in 280 patients undergoing chronic dialysis. Dialysed kidneys could be detected in 529 of the 546 kidneys (96.9%) by ultrasonic examination. The ultrasonic diagnoses on dialysed kidneys were contracted kidney in 313 kidneys (59.2%) and acquired cystic disease of the kidney in 107 kidneys (20.2%). Ultrasonic measurement of the size of kidney (length and thickness) revealed that the kidneys in patients with chronic renal failure were much smaller than normal ones. But the kidneys in patients undergoing dialysis for more than 8 years gradually increased in size with incidence of acquired renal cysts. The kidneys in patients with diabetic nephropathy were greater in length and thickness than those with chronic glomerulonephritis. Sonographic features of dialysed kidneys were unclear renal imaging, unidentified central echoes, cortico-medulla + border and increased parenchymal echogenicity. Irregularity of the renal contour had a tendency to increase in number with incidence of cysts in long-term dialysis patients. The ultrasonograms of the kidneys with diabetic nephropathy showed fewer changes than normal ones. No major complication of the kidney was detected in the present study. However, two retroperitoneal hematomas and one renal cell carcinoma developed within two years after this examination. We believe that regular screening of the kidneys by ultrasonic examination is mandatory in patients on chronic dialysis for early diagnosis and treatment of these complications.

Adolescent↗

PubMed1983

Experimental assessment of imaging variables associated with operative ultrasonic and radiographic cholangiography.

The comparative accuracies of operative ultrasonic and radiographic cholangiography to detect biliary calculi 1 mm in diameter inside tubes of different calibers were assessed. One hundred eighty tubes were prepared to provide ten tubes each for the following variables: three sizes of tubes (6, 13, 20 mm), three concentrations of contrast material (15, 30, 60 per cent), and presence or absence of calculi. Real-time B-mode ultrasound scans with a single gain and time gain compensation (TGC) setting were performed and contrast radiographs were also made at a single optimal exposure. Sixty ultrasonic and 180 radiographic examinations were studied. All ultrasonic interpretations were correct regardless of size of tube. Under optimal conditions, radiographic interpretations were also correct. However, whereas a single gain and TGC setting was applicable for all ultrasound examinations, variable contrast concentrations were required for the best radiographic imaging. Optimal radiographic contrast concentrations differed with tube diameters. The authors conclude that both ultrasonic and radiographic contrast imaging are highly accurate for the detection of small biliary calculi. However, contrast radiography requires stricter optimization of variables needed to provide the high accuracy. Thus, operative ultrasonography may be a more practical and reliable diagnostic procedure because of high sensitivity and greater ease of performance and interpretation.

Cholangiography↗

PubMed1984

Ultrasonically guided fine-needle aspiration biopsy of gastrointestinal mass lesions.

Ultrasonically guided fine-needle aspiration biopsy was performed in 78 patients with ultrasonically demonstrable typical gastrointestinal mass lesions. Of these patients, 61 later proved to have malignant lesions (18 in the stomach, three in the small intestine, and 40 in the colon or rectum), and 17 had benign lesions. In 50 of 61 cases of malignant lesions, the cytologic diagnosis was positive for cancer. There were no false positives. It is concluded that when a structure with the ultrasonic characteristics of a gastrointestinal mass lesion is disclosed, fine-needle aspiration biopsy can safely and conveniently differentiate between malignant and benign lesions in most cases. The ultrasonically guided biopsy is suggested as an alternative to endoscopically guided biopsy.

Biopsy, Needle↗

PubMed1975

Ultrasonically guided percutaneous fine needle biopsy of the pancreas.

By ultrasonic scanning, it is possible with reasonable accuracy to demonstrate space occupying lesions in the pancreas, and with a delicate ultrasonic technique, a puncture needle can be guided to a predetermined mass in the pancreas. In 25 patients with suspected pancreatic lesions, scanning demonstrated a solid mass lesion in the pancreas. Twenty-one patients had carcinoma; four had chronic pancreatitis. In 17 of the 21 patients with carcinoma, tumor cells were aspirated. The cells were numerous and easily recognizable, fulfilling the usual cytologic criteria of malignant disease. In three of the 16 patients with carcinoma, the aspirations were inadequate, and one showed normal pancreatic cells. In the four patients with chronic pancreatitis, normal pancreatic cells were aspirated. There were no immediate complications due to fine needle biopsy. The combination of ultrasonic scanning and ultrasonically guided percutaneous fine needle aspiration is an important adjunct to the management of pancreatic lesions.

Amylases↗

PubMedDate not supplied

[Evaluation of mechanical and ultrasonic characteristics of the lens nucleus].

Acoustic examinations of the lens were carried out in patients with cataracts of different degree of maturing and mechanical solidity of the nucleus was measured after surgery. An original method of ultrasonic examination with Humphrey's A/B scanning system was used. Ultrasonic density was 10-15% increased in more mature forms of cataract, which was confirmed by postoperative measurements of the nucleus solidity by means of 2034 TMR microhardness meter (the solidity was increased by 15-20 mN). Correlation between the findings of ultrasonic scanning and mechanical solidity was direct and strong (p < 0.05). Therefore, the proposed ultrasonic method can be used in cataract surgery for evaluating the solidity of the lens nucleus before surgery.

Adult↗

PubMed2000

[Effects of B-ultrasonic radiation during pregnancy on reproductive outcome].

OBJECTIVE: To study the effects of B-ultrasonic scanning during pregnancy on reproductive outcome, including pregnant outcome and neonatal status. METHODS: Data of reproductive outcome and B-ultrasonic examination were extracted from the questionnaires and obstetric records of 12,224 primigravidas in eight hospitals of Beijing during May 1992 to April 1993. Their reproductive outcomes were analyzed according to frequency and gestational weeks they had B-ultrasonic examination taken, adjusted for potential confounding factors, such as age at pregnancy, smoking and drinking during pregnant period and history of spontaneous abortion, by logistic regression. RESULTS: There was no statistically significant difference in reproductive outcomes between groups, who had B-ultrasonic examination taken for two, three and four times or more and who had only once, respectively, who had more than four times and who had less than three times, and who had their first examination before and after the eighth week of gestation, or before and after the 12th week of gestation. CONCLUSION: No adverse reproductive outcome due to exposure to diagnostic dose of B-ultrasound radiation during pregnancy has been found.

Abortion, Spontaneous↗

PubMed1975

Detection of thyroid cysts by ultrasonic examination.

Ultrasonic examination of 80 thyroid nodules was carried out in order to detect fluid-filled lesions of the gland. The results of preoperative ultrasonic examinations were compared with the findings at surgery. For the ultrasonic diagnosis "cyst", a predictive value of 88% was calculated. It is concluded that ultrasonic examination represents a reliable tool for the detection of thyroid cysts.

Cysts↗

PubMed2002

[Diagnostic value of ultrasonic examination in patients with different stages of liver fibrosis].

OBJECTIVE: To discuss the diagnostic value of ultrasonic examination in patients with early liver cirrhosis and the relation with different stages of liver fibrosis. METHODS: In the series, 263 patients with chronic hepatitis B were under taken liver biopsy and ultrasonic examination of type B for determination of liver cirrhosis images, width of the main portal vein and the splenic vein, tumefaction of the spleen. Data were analysed statistically. RESULTS: Sixties of 263 patients were diagnosed as early liver cirrhosis. The diagnostic sensitivity, specificity, misdiagnostic rate, missed diagnostic rate, and Jonden's index of ultrasonic examination for early liver cirrhosis were 52.5%, 88.3%, 11.7%, 47.5%, and 0.508, respectively. The width of the main portal vein with liver fibrosis of S1, S2, S3, and S4 were 10.93 mm +/- 1.25 mm, 11.35 mm +/- 1.06 mm,11.29 mm +/- 1.52 mm, and 11.4 8mm +/- 1.25 mm, respectively with statistic difference between S4 and S1 (P=0.03). The width of the spleen vein of S1, S2, S3, and S4 were 6.518 mm +/- 2.033 mm, 7.190 mm +/- 1.569 mm, 7.444 mm +/- 1.805 mm and 8.406 mm +/- 2.227 mm, respectively with statistic difference between S4 and S2 (P=0.035). The incidence of tumefaction of the spleen was increased with the degree of liver fibrosis. CONCLUSIONS: The diagnostic sensitivity of ultrasonic examination for early liver cirrhosis is low. The width of the main portal vein, the spleen vein and the incidence of tumefaction of the spleen are related with the degree of liver fibrosis. The regeneration node of liver cirrhosis may contribute to the development of portal hypertension.

Adolescent↗

PubMed1975

Ultrasonic examination of the pancreas.

Gray scale scanners allow the demonstration of much more anatomical detail than was possible with the older type scanners. The initial step in the ultrasonic examination of the pancreas is display of the anatomical detail of the portal vasculature which provides a guidepost to the pancreas. Pancreatitis is characterized by a diffusely enlarged echo-free pancreas. Pancreatic pseudocyst is almost always an echo-free unilocular fluid collection. The size of a pancreatic pseudocyst can be measured so that progress can be assessed. Pseudocysts located in the region of the tail of the pancreas may be best demonstrated by scanning from the back over the left kidney. Pancreatic pseudocysts may be partly solid. Pancreatic carcinoma appears as a localized relatively echo-free, poorly defined solid mass which attenuates the ultrasound beam. Pancreatic carcinoma smaller than 2 cm in diameter are particularly difficult to diagnose by ultrasonic examination. Pancreatic carcinoma may be difficult to distinguish from chronic pancreatitis. Dilated bile ducts can be demonstrated and point to extrahepatic biliary obstruction. Serial ultrasonic scans have been suggested as a means of monitoring the response of pancreatic tumors to therapy. The relative diagnostic value of endoscopic retrograde cannulation of the pancreatic ducts and ultrasound has not as yet been established. Ultrasonic examination is easier to perform and less expensive than any other pancreatic imaging procedure other than the upper gastrointestinal barium examination.

Acute Disease↗

PubMed2002

[Ultrasonic method of study and puncture biopsy in diagnosing thyroid nodules].

Results of diagnosis of thyroid nodes in 404 patients are analyzed. Ultrasonic examination and US-assisted puncture biopsy were carried out before operations. Their results were compared with ones of morphologic study performed after surgery. Solitary nodes were diagnosed in 171 (42.3%) patients, multiple--in 233 (57.7%). The most specific ultrasonic symptoms of different forms of thyroid nodes were revealed. Thyroid cancer is imaged as hypoechogenic node with clear and unclear contour, heterogeneous structure, multiple zones of hyperechogenicity and calcification. Adenomas are presented as isoechogenic homogenic nodes with clear border and cystic cavities. Colloid nodes picture is the same. Rathen often different morphologic forms of nodes are similar, thus ultrasonic examination permits to detect morphologic structure of nodes hypothetically only. Sensitivity of puncture biopsy for goiter, adenomas and cancer was 87.1, 92.9 and 69.7% respectively. Cancer was not diagnosed before surgery in 30.3% cases when colloid goiter or adenomas were suspected. In these cases small cancer was located amidst colloid nodes and didn't differ by ultrasonic symptoms. Diagnosis of malignant tumor in nodular goiter was highly precise. Morphologic form of cancer was verified cytologically in majority of cases.

Biopsy, Needle↗

PubMed2001

[Ultrasonic measurement of the elastic properties of goat condyles].

OBJECTIVE: The purpose of this experiment is to investigate the elastic properties of goat mandibular condyles and to provide basic constants for biomechanical study of temporomandibular joint. METHODS: A fresh goat mandible was adopted and the standard condyle specimen of 4 mm x 6 mm x 10 mm was obtained from it. The structure density of the condyle was determined according to Archimede's principle. The transmitting velocities of ultrasonic wave in different directions of goat condyles were measured by using the ultrasonic system, which was composed of a transmitting transducer of 1.25 MHz, a receiving transducer of 2.5 MHz, an ultrasonic analyzer (5052UA) and a digital storage oscilloscope (HP54601A). The elastic coefficients and technical constants could be calculated by elastic equations. RESULTS: The structural density of the sample and the wave velocities in different directions of the condyle were both obtained by direct measurement. And then, nine elastic coefficients and all of the technical constants of orthotropic condyles were calculated. CONCLUSION: 1. It is practicable to measure elastic properties of the condyle by using ultrasonic technique. 2. Goat condyles of the mandible are a type of anisotropic and linearly elastic material. 3. The direction perpendicular to the transverse ridge of the goat condyle has the highest Young's modulus. As to shear modulus, the direction along the transverse ridge shows the highest value.

Animals↗

PubMed2001

[Review of Recent Medical Ultrasonic Technology]

This paper was reviewed in recent progress of medical ultrasonic technology. Obviously in 21 century we face to the second generation of ultrasonic technology in medicine. First of all, B-mode imaging and Doppler color flow mapping have been improved by the digital beam forming technology. This technology leads to high research activity in the field of image processing such as automated tumor segmentation. Harmonic imaging is also newly developed technology. This technique uses harmonic component of echoes while the ultrasound waves are traveling through the nonlinear media such as biological tissues so that high quality images are obtained. Contrast echo method is expected to detect small echo signals from slow and small blood flow. Harmonic power Doppler imaging using micro bubbles is expected to detect early stage of cancer. Three dimensional real time imaging is next generation of ultrasonic image diagnosis system. Two dimensional array is a key technology to realize this imaging. Finally, ultrasonic therapy is described.

Journal Article↗