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X-ray transform

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represents the attenuation data of a tomographic scan through an inhomogeneous medium whose density is represented by the function
51:, and coincides with it in two dimensions. In higher dimensions, the X-ray transform of a function is defined by integrating over 401: 371: 356: 250: 457: 351: 79:
of the X-ray transform is therefore of practical importance because it allows one to reconstruct an unknown density
452: 238:. The latter integral is not regarded in the oriented sense: it is the integral with respect to the 1-dimensional 261: 346: 94: 36: 254: 405: 375: 44: 321: 290: 239: 419: 389: 415: 385: 98: 91: 76: 52: 48: 400:, Mathematical Surveys and Monographs, vol. 39 (2nd ed.), Providence, R.I.: 446: 325: 365: 20: 427: 294: 436: 60: 56: 40: 370:, Translations of Mathematical Monographs, vol. 220, Providence, R.I.: 310:"The ultrahyperbolic differential equation with four independent variables" 59:
as in the Radon transform. The X-ray transform derives its name from X-ray
209:{\displaystyle Xf(L)=\int _{L}f=\int _{\mathbf {R} }f(x_{0}+t\theta )dt} 64: 435:, Progress in Mathematics (2nd ed.), Boston, M.A.: 364:
Gelfand, I. M.; Gindikin, S. G.; Graev, M. I. (2003) ,
125: 265: 208: 43:in 1938 that is one of the cornerstones of modern 8: 287:Mathematical Methods in Image Reconstruction 67:) because the X-ray transform of a function 285:Natterer, Frank; Wübbeling, Frank (2001). 182: 165: 164: 148: 124: 277: 398:Geometric analysis on symmetric spaces 264:can be written as an X-ray transform.( 7: 367:Selected topics in integral geometry 226:is an initial point on the line and 47:. It is very closely related to the 112:defined on the set of all lines in 266:Gelfand, Gindikin & Graev 2003 14: 249:The X-ray transform satisfies an 234:giving the direction of the line 83:from its known attenuation data. 166: 345:Berenstein, Carlos A. (2001) , 197: 175: 138: 132: 104:, then the X-ray transform of 1: 402:American Mathematical Society 372:American Mathematical Society 326:10.1215/S0012-7094-38-00423-5 251:ultrahyperbolic wave equation 426:Helgason, Sigurdur (1999), 396:Helgason, Sigurdur (2008), 352:Encyclopedia of Mathematics 479: 295:10.1137/1.9780898718324.fm 463:X-ray computed tomography 314:Duke Mathematical Journal 260:The Gaussian or ordinary 262:hypergeometric function 289:. Philadelphia: SIAM. 242:on the Euclidean line 210: 211: 308:Fritz, John (1938). 230:is a unit vector in 123: 458:Integral transforms 429:The Radon Transform 95:continuous function 92:compactly supported 206: 37:integral transform 16:Integral transform 453:Integral geometry 411:978-0-8218-4530-1 381:978-0-8218-2932-5 347:"X-ray transform" 55:rather than over 45:integral geometry 470: 439: 434: 422: 392: 359: 337: 336: 334: 332: 305: 299: 298: 282: 240:Lebesgue measure 215: 213: 212: 207: 187: 186: 171: 170: 169: 153: 152: 108:is the function 478: 477: 473: 472: 471: 469: 468: 467: 443: 442: 432: 425: 412: 395: 382: 363: 344: 341: 340: 330: 328: 307: 306: 302: 284: 283: 279: 274: 255:John's equation 225: 178: 160: 144: 121: 120: 99:Euclidean space 49:Radon transform 25:X-ray transform 17: 12: 11: 5: 476: 474: 466: 465: 460: 455: 445: 444: 441: 440: 423: 410: 393: 380: 361: 339: 338: 300: 276: 275: 273: 270: 223: 217: 216: 205: 202: 199: 196: 193: 190: 185: 181: 177: 174: 168: 163: 159: 156: 151: 147: 143: 140: 137: 134: 131: 128: 86:In detail, if 39:introduced by 33:John transform 15: 13: 10: 9: 6: 4: 3: 2: 475: 464: 461: 459: 456: 454: 451: 450: 448: 438: 431: 430: 424: 421: 417: 413: 407: 403: 399: 394: 391: 387: 383: 377: 373: 369: 368: 362: 358: 354: 353: 348: 343: 342: 327: 323: 319: 315: 311: 304: 301: 296: 292: 288: 281: 278: 271: 269: 267: 263: 258: 256: 252: 247: 245: 241: 237: 233: 229: 222: 203: 200: 194: 191: 188: 183: 179: 172: 161: 157: 154: 149: 145: 141: 135: 129: 126: 119: 118: 117: 115: 111: 107: 103: 100: 96: 93: 89: 84: 82: 78: 74: 70: 66: 62: 58: 54: 50: 46: 42: 38: 34: 30: 29:ray transform 27:(also called 26: 22: 428: 397: 366: 350: 329:. Retrieved 317: 313: 303: 286: 280: 259: 248: 243: 235: 231: 227: 220: 218: 113: 109: 105: 101: 87: 85: 80: 72: 68: 32: 28: 24: 18: 320:: 300–322. 57:hyperplanes 21:mathematics 447:Categories 437:Birkhauser 331:23 January 272:References 268:, 2.1.2). 61:tomography 41:Fritz John 357:EMS Press 195:θ 162:∫ 146:∫ 77:Inversion 63:(used in 65:CT scans 35:) is an 420:2463854 390:2000133 253:called 110:Xƒ 97:on the 418:  408:  388:  378:  219:where 106:ƒ 88:ƒ 81:ƒ 73:ƒ 69:ƒ 23:, the 433:(PDF) 90:is a 53:lines 406:ISBN 376:ISBN 333:2013 322:doi 291:doi 116:by 31:or 19:In 449:: 416:MR 414:, 404:, 386:MR 384:, 374:, 355:, 349:, 316:. 312:. 257:. 246:. 75:. 360:. 335:. 324:: 318:4 297:. 293:: 244:L 236:L 232:R 228:θ 224:0 221:x 204:t 201:d 198:) 192:t 189:+ 184:0 180:x 176:( 173:f 167:R 158:= 155:f 150:L 142:= 139:) 136:L 133:( 130:f 127:X 114:R 102:R

Index

mathematics
integral transform
Fritz John
integral geometry
Radon transform
lines
hyperplanes
tomography
CT scans
Inversion
compactly supported
continuous function
Euclidean space
Lebesgue measure
ultrahyperbolic wave equation
John's equation
hypergeometric function
Gelfand, Gindikin & Graev 2003
doi
10.1137/1.9780898718324.fm
"The ultrahyperbolic differential equation with four independent variables"
doi
10.1215/S0012-7094-38-00423-5
"X-ray transform"
Encyclopedia of Mathematics
EMS Press
Selected topics in integral geometry
American Mathematical Society
ISBN
978-0-8218-2932-5

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