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At least 541 records · Page 30Linked to original sources

PubMed2003

[Dynamic observation on ultrasonographic image during chemotherapy of hepatic cystic echinococcosis and a proposal for ultrasonic classification].

OBJECTIVE: To submit a proposal for the classification of ultrasonographic image in patients with hepatic cystic echinococcosis, on the basis of characteristic and distribution of ultrasonic image of hydatid cysts in cases and systematic observation on dynamic changes of sonographic image under treatment with emulsion albendazole and in relation to clinical efficacy. METHODS: The ultrasonic image of 645 cysts in 497 cases with liver cystic echinococcosis was classified. The distribution of different types of image in patients was analyzed. A comparative analysis of correspondence between the sonographic type and clinical efficacy was made in association with the rule of changes in ultrasonic features during chemotherapy. RESULTS: The ultrasonographic image of hydatid cysts was divided into six types. The distribution of ultrasonic types in patients reflected the process of natural evolution of cysts in human bodies. The dynamic change of ultrasonic image during treatment was identical with the natural evolution process of hydatid cysts. CONCLUSION: The proposal for ultrasonographic classification submitted reflects a long evolutionary process from growth to death of hydatid cysts in human body. The dynamic change of hydatid cysts during chemotherapy indicated that the effect of drug has accelerated this process. Therefore this classification may be applied in diagnosis and to judge the chemotherapeutic efficacy of cystic echinococcosis.

Adolescent↗

PubMed2004

An evaluation of effective radiuses of bulk-wave ultrasonic transducers as circular piston sources for accurate velocity measurements.

The effective radius of a bulk-wave ultrasonic transducer as a circular piston source, fabricated on one end of a synthetic silica (SiO2) glass buffer rod, was evaluated for accurate velocity measurements of dispersive specimens over a wide frequency range. The effective radius was determined by comparing measured and calculated phase variations due to diffraction in an ultrasonic transmission line of the SiO2 buffer rod/water-couplant/SiO2 standard specimen, using radio-frequency (RF) tone burst ultrasonic waves. Fourteen devices with different device parameters were evaluated. The velocities of the nondispersive standard specimen (C-7940) were found to be 5934.10 +/- 0.35 m/s at 70 to 290 MHz, after diffraction correction using the nominal radius (0.75 mm) for an ultrasonic device with an operating center frequency of about 400 MHz. Corrected velocities were more accurately found to be 5934.15 +/- 0.03 m/s by using the effective radius (0.780 mm) for the diffraction correction. Bulk-wave ultrasonic devices calibrated by this experimental procedure enable conducting extremely accurate velocity dispersion measurements.

Journal Article↗

PubMed2003

[Relationship between ultrasonic findings and pathological features in patients with chronic viral hepatitis B and C].

OBJECTIVES: To explore the relation of ultrasonic findings to pathological features in cases of chronic viral hepatitis B and C. METHODS: The ultrasonic and pathological findings were analyzed in 130 patients with chronic viral hepatitis B and 106 with chronic viral hepatitis C. RESULTS: In patients with hepatitis B, the ultrasonic echo was thicker and more intensive and uneven cords were found. These findings were closely related to the pathological findings (P less than 0.001). In those with hepatitis C, the ultrasonic echo was slight and dense, which was also closely related to the pathological findings (P less than 0.001). In the patients complicated with fatty liver, the ultrasonic findings were also different (P less than 0.001). CONCLUSION: Ultrasonography is helpful for differential diagnosis of hepatitis B and hepatitis C.

Adult↗

PubMed1991

Ultrasonically guided interstitial Nd-YAG laser diffuser tip hyperthermia: an in vitro study.

Ultrasonically guided interstitial Nd-YAG laser diffuser tip hyperthermia is a new technique that involves placement of a laser fiber in solid tissue under ultrasound guidance followed by irradiation from within the area to be treated. We have previously described a diffuser tip modification of the bare laser fiber, that proved to produce spherical coagulations of predictable size. In the present paper we describe the development of an ultrasonically guided technique which permits simultaneous laser irradiation and interstitial temperature measurements under real time ultrasound monitoring. The laser lesion appeared on the ultrasound image as a hyperechoic area growing in size with time as energy was applied. Macroscopically the laser lesion emerged as a sphere with a central cavity delineated by a rim of charred tissue and beyond this a larger zone of whitish coagulation. The correlation coefficient (Pearson's r) between ultrasonically and macroscopically measured diameter of the laser lesion was calculated to r = 0.89. It is concluded that ultrasonically guided interstitial Nd-YAG laser diffuser tip hyperthermia may have a potential as a tool in the future treatment of ultrasonically visible neoplasias like liver metastases and prostate cancer.

Animals↗

PubMed1990

[Ultrasonic semeiotics and diagnosis of acute cholecystitis].

From analysis of the results of ultrasonic examination in 1,428 patients with acute cholecystitis the authors determined the semeiotics of various forms and complications of the disease. The most common ultrasonic sign of acute cholecystitis is a triad of symptoms: enlarged gallbladder, thickened walls, and fixed hyperchostructures with an acoustic shadow in the projection of the neck of the gallbladder. Ultrasonic examination allows the presence of destructive cholecystitis to be detected with high precision on basis of the sign of a double gallbladder contour. Complications like pericystic infiltration, pericystic abscess with or without perforation, empyema of the gallbladder, acute pancreatitis, and choledocholithiasis can also be recognized in patients with acute cholecystitis by ultrasonic examination. Comparison of the data of ultrasonic examination with those obtained in laparoscopy or operation showed that the diagnosis coincided in 98.9% of cases.

Acute Disease↗

PubMed1989

[Development of a system for ultrasonic three-dimensional reconstruction of fetus].

We have developed a system for ultrasonic three-dimensional (3-D) fetus reconstruction using computers. Either a real-time linear array probe or a convex array probe of an ultrasonic scanner was mounted on a position sensor arm of a manual compound scanner in order to detect the position of the probe. A microcomputer was used to convert the position information to what could be recorded on a video tape as an image. This image was superimposed on the ultrasonic tomographic image simultaneously with a superimposer and recorded on a video tape. Fetuses in utero were scanned in seven cases. More than forty ultrasonic section image on the video tape were fed into a minicomputer. The shape of the fetus was displayed three-dimensionally by means of computer graphics. The computer-generated display produced a 3-D image of the fetus and showed the usefulness and accuracy of this system. Since it took only a few seconds for data collection by ultrasonic inspection, fetal movement did not adversely affect the results. Data input took about ten minutes for 40 slices, and 3-D reconstruction and display took about two minutes. The system made it possible to observe and record the 3-D image of the fetus in utero non-invasively and therefore is expected to make it much easier to obtain a 3-D picture of the fetus in utero.

Computer Systems↗

PubMed1987

[An experimental and clinical study on the dissecting aortic aneurysm--usefulness of magnetic resonance imaging and the ultrasonic pulsed Doppler duplex system].

In the treatment of dissecting aortic aneurysm, it is important to understand the exact conditions of the disease. For this purpose Aortography (AOG) and X-ray computerized tomography (CT) have been used. Magnetic Resonance Imaging (MRI) and the ultrasonic pulsed Doppler duplex system are completely non-invasive and may be used instead of AOG and CT. Experimental aortic dissection was done surgically using modified Blanton's method in 8 mongrel dogs. MRI and the ultrasonic pulsed Doppler duplex system were used on these dogs before and after surgery which consisted of surgical closure of entry and insertion of Ivalon Sponge to false lumen. MRI patterns were classified into three: i.e., low, middle, and high intensity. The ultrasonic pulsed Doppler duplex system patterns were classified into four: i.e., normal flow, to and fro, turbulent flow and wall motion patterns respectively. These patterns of MRI and the ultrasonic pulsed Doppler duplex system were closely correlated to autopsy findings. These results indicated that MRI and the ultrasonic pulsed Doppler duplex system are useful to evaluate the changes of figures and hemodynamics of the false lumen. In the clinical study, MRI was performed on 26 patients of dissecting aortic aneurysm before and after surgery. These results were compared with those of AOG and CT. In the detection of the intimal flap, the main arterial branches, and the location of the entry and reentry, MRI was superior to CT and almost equal to AOG.

Aortic Dissection↗

PubMed1987

B-mode ultrasonic imaging in the preoperative evaluation of saphenous vein.

This prospective study was undertaken to determine if B-mode ultrasonic imaging of the greater saphenous vein can provide reliable information about anatomy, sites of valves, and location of major tributaries or duplicate systems. Preoperative ultrasonic imaging was performed on 15 consecutive patients prior to in situ saphenous bypass. The findings of the ultrasonic evaluations were compared with the intraoperative findings. Preoperative assessment of the greater saphenous vein was performed with a high resolution real-time B-mode ultrasonic imager. The procedure was performed with the patient seated with the leg extended. The saphenous vein was imaged starting at the ankle. A waterproof pen was used to mark the vein. The locations of valves and tributary vessels were marked and the diameter of the saphenous vein was recorded. These results were compared with operative findings. In all 15 patients, the saphenous vein was imaged. There was 100 per cent accuracy in the detection and location of valve sites. In one patient, the proximal portion of the vein was thrombosed and this was detected by the B-mode scan. There was exact correlation in 14 of 15 limbs (93%). The one error was due to the examiners' failure to identify a triple venous system; only a double venous system was identified by scan in this patient. The actual venous diameter was consistently within 0.5 mm of that measured by the ultrasound imager. In all patients, the ultrasound image demonstrated the correct anatomic location and size of the vein. In conclusion, B-mode ultrasonic imaging provides an accurate description of the anatomy of the saphenous vein, without the morbidity associated with contrast venography.

Aged↗

PubMed1984

[2-dimensional ultrasonic scanning of the abdominal aorta in arterial hypertension patients].

The diagnostic value of two-dimensional ultrasonic scanning of the abdominal portion of the aorta was studied in 72 patients with arterial hypertension. Twenty-eight of these patients who presented no abnormalities by radiopaque and ultrasonic aortography served as control. The test group was comprised of the remaining 44 patients with symptomatic arterial hypertension associated with nonspecific aortoarteritis, atherosclerosis of the aorta and renal arteries and aortal malformation. Four major types of changes of the ultrasonic scanogram in cases of pathology of the abdominal portion of the aorta were identified. Ultrasonic aortography is a sufficiently informative method as compared to radiopaque aortography. The technique is relatively simple and has no contraindications for use. Ultrasonic scanning of the abdominal portion of the aorta should be conducted at the first stage of examination of patients with arterial hypertension.

Adult↗

PubMedDate not supplied

[Ultrasonic and computerized tomographic examinations in the diagnosis of suppurative-inflammatory diseases of organs of the abdominal cavity and retroperitoneal space].

Comprehensive ultrasonic and x-ray computer-aided tomographic (RCAT) examinations were carried out in 97 patients with 120 pyo-inflammatory foci in the abdominal cavity and retroperitoneal space. On the whole the sensitivity of ultrasonic examinations was 68%, that of RCAT 88%. RCAT was superior to ultrasonic examinations in the diagnosis of extra-organic (inter-intestinal, subdiaphragm, etc.) involvement, pancreonecrosis, and splenic abscesses. The advantages of this method were not so evident in the detection of liver and kidney abscesses and of gauze postoperative foreign bodies. Potentialities of an ultrasonic method were somewhat superior in localization of a pathologic focus in the pancreas in differentiation from a common cyst. Ultrasonic examinations should be widely used as a primary method and should to a certain measure determine the necessity of RCAT use in the diagnosis of pyo-inflammatory diseases of the abdominal cavity and retroperitoneal space organs.

Abdominal Abscess↗

PubMed1994

Anthropometric or ultrasonic measurements in assessment of visceral fat? A comparative study.

The main aim of the study (study 1) was to compare the accuracy of anthropometric and ultrasonic measurements in assessing the amount of visceral adipose tissue. An additional aim (study 2) was to verify ultrasound technique precision. Study 1: using computed tomography (CT) L4-L5 adipose tissue area as a gold standard we compared the accuracy of waist/hip circumference ratio, sagittal diameter and ultrasonic measurements of intra-abdominal depth in assessing the amount of visceral adipose tissue. Study 2: ultrasonic measurements of the intra-abdominal muscle-vertebra distance were made in triplicate by three different operators. In study 1, 24 volunteers were used; body mass index (BMI): 19-43. In study 2, 22 volunteers were used; BMI 20-42. In study 1, ultrasonic measurements of the abdominal depth correlated best with CT visceral adipose tissue area (r = 0.89 - 0.91). In study 2, inter-operator and intra-operator mean variation coefficients were about 7% and 5% respectively. We concluded that using a well standardized technique and properly trained operators, ultrasonic measurement of intra-abdominal depth is a valid method in assessing the amount of visceral adipose tissue.

Adipose Tissue↗

PubMed1994

Preoperative histologic diagnosis of chest wall invasion by lung cancer using ultrasonically guided biopsy.

Before operation, we evaluated the usefulness of ultrasonically guided needle biopsy to detect histologically invasion of the chest wall by tumor in patients with lung cancer. Ultrasonically guided needle biopsy, computed tomography, and ultrasonography were done in 29 patients with lung cancer. In all of them, chest wall invasion was histologically confirmed by thoracotomy. As for the diagnosis of chest wall invasion, sensitivity, specificity, and accuracy of ultrasonically guided needle biopsy diagnosis were 61.5%, 100%, and 82.8%, respectively; for diagnosis by computed tomographic scan these figures were 69.2%, 75.0%, and 72.4%, respectively; and for diagnosis by ultrasonography they were 76.9%, 68.8%, and 72.4%, respectively. We had no false-positive cases in the ultrasonically guided needle biopsy assessment and no fatal complications or implantation metastases. Our results indicate that ultrasonically guided needle biopsy is safe and useful for preoperative histologic diagnosis of chest wall invasion in cases in which combined chest wall resection is being considered in patients with lung cancer.

Aged↗

PubMed1996

Study on ultrasonically guided fine-needle aspiration cytology for breast disorders with high-resolution transducer.

The author participated in the development annular array transducer. The author used this new device in 147 patients (aged 43.4 years ranging from 21 to 81 years) and ultrasonically detected 193 breast lesions including 126 nonpalpable ones (65.3%). After that, the author performed 234 punctures for aspiration cytology using the same device and 22 gauge needle. The needle tip was intralesionally identified in 174 of the 234 punctures (74.4%) and 146 of the 193 lesions (75.6%). The sensitivity, specificity and accuracy of cytological diagnosis were 72.7% (8/11), 91.2% (31/34) and 86.7% (39/45), respectively. No cell could be aspirated in 61 of the 146 lesions (41.8%). These results were comparable to those obtained from the conventional devices. Annular array transducer will increase the frequency of ultrasonic detection of small breast lesions. Fine needle aspiration cytology under ultrasonic guide with this new device will efficiently and speedily rule out malignant lesions and facilitate management of benign lesions at the outpatient department. This study suggests that ultrasonically malignant lesions should immediately be examined histologically without undergoing cytological examination. It should be noted that some cystic lesions are concentrated and accompanied by positive internal echoes. These cystic lesions show a change in size on the ultrasonic image after aspiration and contain paste- or gruel-like material.

Adult↗

PubMed1998

Ultrasonic modulation of scattered light in turbid media and a potential novel tomography in biomedicine.

Ultrasonic modulation of scattered laser light was used to image objects buried in tissue-simulating turbid media. The ultrasonic wave focused into the turbid media modulated the laser light passing through the ultrasonic field. The modulated laser light collected by a photomultiplier tube reflected primarily the local mechanical and optical properties in the zone of ultrasonic modulation. A raster scanning over a heterogeneous turbid medium yielded an image of the medium based on the ultrasound-modulated optical signal. The detectability of modulated signal was estimated using diffusion theory. The dependence of the modulated signal on the off-axis distance of the detector from the optic axis and on the amplitude of ultrasound was studied. The mechanisms of ultrasonic modulation of scattered light are discussed. A theory based on the field autocorrelation function is reviewed as well.

Lasers↗

PubMedDate not supplied

[The determination of cardiac output by the dilution of ultrasonic blood density].

The authors propose assessing cardiac output (CO) by diluting the blood ultrasonic properties. For measuring CO, the peripheral artery and vein were connected with a catheter, and ultrasonic flowmetric pickup was attached to the shunt. Indicator (0.9% sodium chloride) was injected into the central vein. Changes in the blood ultrasonic characteristics during the indicator flow were recorded by ultrasonic flowmeter. Dilution curves were computer processed. The method was tried in 7 experimental dogs and clinically in 11 patients and compared with the thermodilution method. The coefficient of correlation was 0.98 in experiment and 0.97 in clinical trials. Dilution of ultrasonic density of the blood helps accurately assess the CO and is highly informative, which is confirmed by a strong correlation with the results of thermodilution. The method is simple, little invasive, realized using available equipment, the indicators are cheap and available, and repeated studies can be performed within short periods of time.

Animals↗

PubMedDate not supplied

Development of ultrasonic investigations in medicine and biology in the U.S.S.R.

Ultrasonic research in biology and medicine, both fundamental and applied, has become so vast in scope, that a mere listing of specific subject-areas would take up too much space. This article is intended to give an overview of Soviet scientists' contribution to the field, with the emphasis on the most important and promising subject-areas which are now given priority in the U.S.S.R. Among specific subject-areas in ultrasonics are the studies of the biological action of ultrasound and ultrasonic safety in medicine, the effect of focused ultrasound, acoustic spectroscopy of solutions of biological media and acoustic specification of biological objects, acoustic visualization and microscopy and clinical ultrasonics.

Animals↗

PubMed1979

Clinical improvement of gingival conditions following ultrasonic versus hand instrumentation of periodontal pockets.

A study utilizing a split-mouth design in 18 subjects and with four operators was performed in order to compare the effect of hand and ultrasonic instrumentation of periodontal pockets. Contralateral pairs of teeth with pockets of comparable depth were treated by either hand or ultrasonic instruments. Instrumentation was repeated after 4 weeks. Pocket depth, bleeding on probing and gingival fluid measurements were used for evaluation. A gradual reduction of pocket depth and number of bleeding points took place throughout the 8-week experimental period. Clinically significant differences were not observed comparing the effect of hand instruments to ultrasonics for any of the operators. The amounts of gingival fluid were similar for both methods of instrumentation at the final examination. Thus, the present study failed to demonstrate any significant differences between the effect of ultrasonic root debridement and hand instrumentation in the treatment of 4-6 mm deep periodontal pockets.

Adult↗

PubMed1999

The physics of soft tissue fragmentation using ultrasonic frequency vibration of metal probes.

The physics of soft tissue fragmentation using ultrasonic frequency vibration of metal probes has been discussed, including a comparison and contrast of ultrasound radiation and ultrasonic surgery and a brief history of ultrasonic surgery. Three theories of interaction and an assessment of power flow have been presented. Many unanswered questions remain concerning the physics of soft tissue fragmentation using ultrasonic frequency vibratory energy. This effort has hopefully contributed to a better understanding of the general principles involved.

Adipose Tissue↗