A General Framework for Automated Accurate Calculation of <i>b</i>-Matrix (Auto-<i>b</i>) in Diffusion MRI Pulse Sequences

<div>Illustration of gradient pulses along the SPEN axis (a) and three rectangularization schemes for diffusion-sensitizing gradients: (b) <i>Rect 1</i>, (c) <i>Rect 2</i>, and (d) <i>Rect 3</i>. The gradient amplitude <svg height="15.3797pt" id="M94" style="vertical-align:-3.9436pt" version="1.1" viewbox="-0.0498162 -11.4361 14.6095 15.3797" width="14.6095pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M673 297H417L411 270C517 261 522 258 506 183L487 92C476 38 428 19 360 19C207 19 123 132 123 287C123 472 243 631 441 631C557 631 617 583 617 469L647 472C650 545 655 604 658 632C625 643 554 666 467 666C201 666 23 502 23 278C23 90 156 -16 339 -16C410 -16 501 6 569 24C566 43 567 70 573 101L589 183C604 259 607 262 667 271L673 297Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.892,-5.741)"><path d="M310 541L304 571C290 586 211 619 185 610L80 76L131 52L310 541Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.827,3.784)"><path d="M538 684C542 703 539 710 529 710C512 710 455 682 363 674L361 644H396C444 644 448 642 438 594L405 438C373 450 347 451 336 451C288 451 200 416 147 374C69 312 24 207 24 113C24 29 60 -12 94 -12C126 -12 156 4 196 30C231 53 296 100 346 166H348L328 81C311 10 325 -12 348 -12C380 -12 450 24 512 98L495 125C466 97 431 70 417 70C408 70 408 80 411 98L538 684ZM390 373L361 240C336 196 210 56 145 56C132 56 113 73 113 131C113 216 156 338 220 379C243 394 266 402 303 402C331 402 375 388 390 373Z"></path></g></svg> indicates that <i>Rect</i> 2 has a different amplitude from diffusion-sensitizing gradients (<span class="nowrap"><svg height="11.927pt" id="M95" style="vertical-align:-3.291101pt" version="1.1" viewbox="-0.0498162 -8.6359 14.6095 11.927" width="14.6095pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M673 297H417L411 270C517 261 522 258 506 183L487 92C476 38 428 19 360 19C207 19 123 132 123 287C123 472 243 631 441 631C557 631 617 583 617 469L647 472C650 545 655 604 658 632C625 643 554 666 467 666C201 666 23 502 23 278C23 90 156 -16 339 -16C410 -16 501 6 569 24C566 43 567 70 573 101L589 183C604 259 607 262 667 271L673 297Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.827,3.132)"><path d="M538 684C542 703 539 710 529 710C512 710 455 682 363 674L361 644H396C444 644 448 642 438 594L405 438C373 450 347 451 336 451C288 451 200 416 147 374C69 312 24 207 24 113C24 29 60 -12 94 -12C126 -12 156 4 196 30C231 53 296 100 346 166H348L328 81C311 10 325 -12 348 -12C380 -12 450 24 512 98L495 125C466 97 431 70 417 70C408 70 408 80 411 98L538 684ZM390 373L361 240C336 196 210 56 145 56C132 56 113 73 113 131C113 216 156 338 220 379C243 394 266 402 303 402C331 402 375 388 390 373Z"></path></g></svg>).</span></div>

Concepts in Magnetic Resonance Part B, Magnetic Resonance Engineering

fig9

Figure 9

Figure 9: A General Framework for Automated Accurate Calculation of <i>b</i>-Matrix (Auto-<i>b</i>) in Diffusion MRI Pulse Sequences 

Concepts in Magnetic Resonance Part B, Magnetic Resonance Engineering

A General Framework for Automated Accurate Calculation of b-Matrix (Auto-b) in Diffusion MRI Pulse Sequences

Figure 9