| Autor: |
Foley WD; Department of Radiology, Medical College of Wisconsin, Milwaukee, 53226., Kneeland JB, Cates JD, Kellman GM, Lawson TL, Middleton WD, Hendrick RE |
| Jazyk: |
angličtina |
| Zdroj: |
AJR. American journal of roentgenology [AJR Am J Roentgenol] 1987 Dec; Vol. 149 (6), pp. 1155-60. |
| DOI: |
10.2214/ajr.149.6.1155 |
| Abstrakt: |
The relative efficacies of different spin-echo pulse sequences at 1.5 T were evaluated in the detection of focal hepatic disease. Pulse sequences compared were spin-echo with a repetition time (TR) of 200 msec and echo time (TE) of 20 msec, with six excitations; TR = 300 msec, TE = 20 msec, with 16 excitations (T1-weighted sequences); and a double spin-echo with TR = 2500 and TE = 25 and 70, with two excitations (proton-density-weighted and T2-weighted pulse sequences, respectively). Respiratory-motion compensation, which involved a recording of the phase-encoding gradients (Exorcist), was used for the last two sequences. Spin-echo with TR = 2500 msec and TE = 70 msec was superior in lesion detection and contrast-to-noise ratio. The proton-density-weighted and T2-weighted sequences with respiratory compensation produced better artifact suppression than did the short TR, short TE T1-weighted sequence with temporal averaging. In contradistinction to prior results at 0.6 T, T2-weighted pulse sequences appear superior to T1-weighted pulse sequences with multiple excitations for both lesion detection and artifact suppression at 1.5 T. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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