|
|
|
BRL Abstracts Database |
|
Your search for ultrasound produced 3296 results. Page 264 out of 330
| Title |
The production of blood cell stasis and endothelial damage in the blood vessels of chick embryos treated with ultrasound in a stationary wave field. |
| Author |
Dyson M, Pond JB, Woodward B, Broadbent J. |
| Journal |
Ultrasound Med Biol |
| Volume |
|
| Year |
1974 |
| Abstract |
Blood cell flow can be arrested in living tissue by exposing it to ultrasound in a stationary wave field. The cells form bands at half wavelength intervals in the blood vessels. The process is generally reversible, and during dissociation the bands assume a parabolic profile in vessels where flow is laminar. Under optimum conditions, in the chick embryo, the minimum intensity required for stasis is less than 0.5 W/cm(^2) at 3 MHz with continuous irradiation. The threshold intensity varies with the type, size, and orientation of the vessel, and with the heart rate. Electron microscopy reveals damage to some of the endothelial cells lining the embryonic vessels in which stasis has occured. Methods of avoiding stasis are suggested and the mechanisms of stasis are discussed. |
| Title |
The propagation of high amplitude sound waves. |
| Author |
Hiedemann EA, Klein WR, Mayer WG. |
| Journal |
Rep Dept Navy Off Nav Res |
| Volume |
|
| Year |
1964 |
| Abstract |
This technical report consists of reprints of papers published between August 1964 and June 1964 by the staff and graduate students supported by the U.S. Naval Research Office, acoustics programs. I. An investigation of light diffracted by wide, high frequency ultrasound beams; Klein WR, Hiedemann EA. II. Effects of transducer alignment on light diffraction by ultrasonic waves; Mayer WG. III. Light diffraction by ultrasonic waves for oblique incidence; Mayer WG. IV. Mode conversion of ultrasonic waves at flat boundaries; Mayer WG. |
| Title |
The question of damage in ultrasonic therapy. |
| Author |
Hueter TF. |
| Journal |
J Acoust Soc Am |
| Volume |
|
| Year |
1954 |
| Abstract |
Criteria are suggested for ensuring the proper use of ultrasound in physical therapy and in particular for avoiding damage to patients. |
| Title |
The rationale and efficacy of applying multiple imaging techniques for breast examination: X-ray mammography and ultrasound visualization. |
| Author |
kelly-Fry E. |
| Journal |
SPIE |
| Volume |
|
| Year |
1983 |
| Abstract |
Since failure to biopsy a malignant mass during a relatively early stage of its development will result in a severely shortened life span for the patient, breast imaging techniques must be capable not only of detecting a mass, but of differentiating between the image characteristics of a benign and a malignant tumor. Ideally, the applied technique should be equally capable when used to examine the young breast and the older breast. The specific advantages and disadvantages of x-ray mammography and of ultrasound visualization, as well as the rationale of balancing the disadvantages of one technique with the advantages of the other, are discussed in this presentation. |
| Title |
The rationale for ultrasound imaging of breasts compressed and positioned in the modes applied in x-ray mammography. |
| Author |
Kelly-Fry E, Romilly-Harper AP. |
| Journal |
IBUS Workshop |
| Volume |
|
| Year |
1995 |
| Abstract |
No abstract available. |
| Title |
The reaction of a transplantable rat wilms' tumor to ultrasound. |
| Author |
Longo FW, Tomashefsky P, Tannenbaum M. |
| Journal |
Ultrason Med |
| Volume |
|
| Year |
1977 |
| Abstract |
No Abstract Available. |
| Title |
The relationship between interaction mechanisms of ultrasound in biological materials and IN-SITU measurements of ultrasound. |
| Author |
O'Brien WD Jr. |
| Journal |
U S Deptof Health, Edu and Welfare |
| Volume |
|
| Year |
1974 |
| Abstract |
No abstract available. |
| Title |
The relationship between ultrasonic attenuation and speed in tissues and constituents: Water, collagen, protein, and fat. |
| Author |
Pohlhammer JD, O'Brien WD Jr. |
| Journal |
Book Chapter |
| Volume |
|
| Year |
1980 |
| Abstract |
No abstract available. |
| Title |
The rician inverse gaussian distribution: A new model for non-rayleigh signal amplitude statistics. |
| Author |
Eltoft T. |
| Journal |
IEEE Trans Image Process |
| Volume |
|
| Year |
2005 |
| Abstract |
In this paper, we introduce a new statistical distribution
for modeling non-Rayleigh amplitude statistics, which we have
called the Rician inverse Gaussian (RiIG) distribution. It is a mixture
of the Rice distribution and the inverse Gaussian distribution.
The probability density function (pdf) is given in closed form as a
function of three parameters. This makes the pdf very flexible in
the sense that it may be fitted to a variety of shapes, ranging from
the Rayleigh-shaped pdf to a noncentral Χ2-shaped pdf. The theoretical basis of the new model is quite thoroughly discussed, and
we also give two iterative algorithms for estimating its parameters
from data. Finally, we include some modeling examples, where we
have tested the ability of the distribution to represent locale amplitude
histograms of linear medical ultrasound data and single-look
synthetic aperture radar data. We compare the goodness of fit of
the RiIG model with that of the K model, and, in most cases, the
new model turns out as a better statistical model for the data. We
also include a series of log-likelihood tests to evaluate the predictive
performance of the proposed model.
Index Terms—Non-Gaussian signal statistics, non-Rayleigh amplitude
statistics, speckle model, synthetic aperture radar (SAR)
speckle model, ultrasonic speckle model. |
| Title |
The risk of exposure to diagnostic ultrasound in postnatal subjects: nonthermal mechanisms. |
| Author |
Church CC, Carstensen EL, Nyborg WL, Carson PL, Frizzell LA, Bailey MR. |
| Journal |
J Ultrasound Med |
| Volume |
|
| Year |
2008 |
| Abstract |
This review examines the nonthermal physical mechanisms by which ultrasound can harm tissue in postnatal patients. First the physical nature of the more significant interactions between ultrasound and tissue is described, followed by an examination of the existing literature with particular emphasis on the pressure thresholds for potential adverse effects. The interaction of ultrasonic fields with tissue depends in a fundamental way on whether the tissue naturally contains undissolved gas under normal physiologic conditions. Examples of gas-containing tissues are lung and intestine. Considerable effort has been devoted to investigating the acoustic parameters relevant to the threshold and extent of lung hemorrhage. Thresholds as low as 0.4 MPa at 1 MHz have been reported. The situation for intestinal damage is similar, although the threshold appears to be somewhat higher. For other tissues, auditory stimulation or tactile perception may occur, if rarely, during exposure to diagnostic ultrasound; ultrasound at similar or lower intensities is used therapeutically to accelerate the healing of bone fractures. At the exposure levels used in diagnostic ultrasound, there is no consistent evidence for adverse effects in tissues that are not known to contain stabilized gas bodies. Although modest tissue damage may occur in certain identifiable applications, the risk for induction of an adverse biological effect by a nonthermal mechanism due to exposure to diagnostic ultrasound is extremely small. |
Page 1
| 2
| 3
| 4
| 5
| 6
| 7
| 8
| 9
| 10
| 11
| 12
| 13
| 14
| 15
| 16
| 17
| 18
| 19
| 20
| 21
| 22
| 23
| 24
| 25
| 26
| 27
| 28
| 29
| 30
| 31
| 32
| 33
| 34
| 35
| 36
| 37
| 38
| 39
| 40
| 41
| 42
| 43
| 44
| 45
| 46
| 47
| 48
| 49
| 50
| 51
| 52
| 53
| 54
| 55
| 56
| 57
| 58
| 59
| 60
| 61
| 62
| 63
| 64
| 65
| 66
| 67
| 68
| 69
| 70
| 71
| 72
| 73
| 74
| 75
| 76
| 77
| 78
| 79
| 80
| 81
| 82
| 83
| 84
| 85
| 86
| 87
| 88
| 89
| 90
| 91
| 92
| 93
| 94
| 95
| 96
| 97
| 98
| 99
| 100
| 101
| 102
| 103
| 104
| 105
| 106
| 107
| 108
| 109
| 110
| 111
| 112
| 113
| 114
| 115
| 116
| 117
| 118
| 119
| 120
| 121
| 122
| 123
| 124
| 125
| 126
| 127
| 128
| 129
| 130
| 131
| 132
| 133
| 134
| 135
| 136
| 137
| 138
| 139
| 140
| 141
| 142
| 143
| 144
| 145
| 146
| 147
| 148
| 149
| 150
| 151
| 152
| 153
| 154
| 155
| 156
| 157
| 158
| 159
| 160
| 161
| 162
| 163
| 164
| 165
| 166
| 167
| 168
| 169
| 170
| 171
| 172
| 173
| 174
| 175
| 176
| 177
| 178
| 179
| 180
| 181
| 182
| 183
| 184
| 185
| 186
| 187
| 188
| 189
| 190
| 191
| 192
| 193
| 194
| 195
| 196
| 197
| 198
| 199
| 200
| 201
| 202
| 203
| 204
| 205
| 206
| 207
| 208
| 209
| 210
| 211
| 212
| 213
| 214
| 215
| 216
| 217
| 218
| 219
| 220
| 221
| 222
| 223
| 224
| 225
| 226
| 227
| 228
| 229
| 230
| 231
| 232
| 233
| 234
| 235
| 236
| 237
| 238
| 239
| 240
| 241
| 242
| 243
| 244
| 245
| 246
| 247
| 248
| 249
| 250
| 251
| 252
| 253
| 254
| 255
| 256
| 257
| 258
| 259
| 260
| 261
| 262
| 263
| 264
| 265
| 266
| 267
| 268
| 269
| 270
| 271
| 272
| 273
| 274
| 275
| 276
| 277
| 278
| 279
| 280
| 281
| 282
| 283
| 284
| 285
| 286
| 287
| 288
| 289
| 290
| 291
| 292
| 293
| 294
| 295
| 296
| 297
| 298
| 299
| 300
| 301
| 302
| 303
| 304
| 305
| 306
| 307
| 308
| 309
| 310
| 311
| 312
| 313
| 314
| 315
| 316
| 317
| 318
| 319
| 320
| 321
| 322
| 323
| 324
| 325
| 326
| 327
| 328
| 329
| 330
|
|
|
|
