| LDR | | 04073nam u200541 4500 |
| 001 | | 000000420098 |
| 005 | | 20190215164213 |
| 008 | | 181129s2018 |||||||||||||||||c||eng d |
| 020 | |
▼a 9780438021662 |
| 035 | |
▼a (MiAaPQ)AAI10826905 |
| 035 | |
▼a (MiAaPQ)ucla:16880 |
| 040 | |
▼a MiAaPQ
▼c MiAaPQ
▼d 247004 |
| 082 | 0 |
▼a 616 |
| 100 | 1 |
▼a Martin, Thomas Boyd. |
| 245 | 10 |
▼a Advancing Quantitative Perfusion Abdominal Imaging. |
| 260 | |
▼a [S.l.]:
▼b University of California, Los Angeles.,
▼c 2018. |
| 260 | 1 |
▼a Ann Arbor:
▼b ProQuest Dissertations & Theses,
▼c 2018. |
| 300 | |
▼a 111 p. |
| 500 | |
▼a Source: Dissertation Abstracts International, Volume: 79-10(E), Section: B. |
| 500 | |
▼a Includes supplementary digital materials. |
| 500 | |
▼a Adviser: Kyunghyun Sung. |
| 502 | 1 |
▼a Thesis (Ph.D.)--University of California, Los Angeles, 2018. |
| 520 | |
▼a Purpose. |
| 520 | |
▼a To develop and investigate a self-gated MR imaging technique to improve motion compensation robustness for dynamic contrast enhanced MRI, to develop and evaluate a low-dose CT perfusion reconstruction technique, and to develop motion tracking fo |
| 520 | |
▼a Methods. |
| 520 | |
▼a A 3D dual-echo golden angle stack-of-radial gradient echo sequence was developed such that a fat-only self-gated signal (SGSF) could be extracted using a two-point Dixon method. The SGSF was validated by i) numerical simulations of SGSF in the p |
| 520 | |
▼a A previously developed MRI reconstruction technique called k-space weighted image contrast (KWIC) was used to reduce the number of x-ray projections per gantry rotation, therefore reducing the radiation dose for CT perfusion (CTP) imaging. KWIC |
| 520 | |
▼a The 3D golden angle stack-of-radial gradient echo sequence and KWIC reconstruction were then used to scan sixty-one pregnant women. Forty-eight subjects were scanned between 14-18 weeks and 19-24 weeks gestational age (GA). Thirteen additional p |
| 520 | |
▼a Results. |
| 520 | |
▼a Numerical simulation showed that the fat extraction for SGS has less than 15% error at Deltaf = +/-0-50 Hz. There is strong correlation between SGS and SGSF (mean correlation = 0.91), and video motion curve and SGSF (mean correlation coefficient |
| 520 | |
▼a For the CT perfusion the numerical simulations showed that KWIC were unaffected by the undersampling/dose reduction (down to 12.5% dose) with KWIC reconstruction compared to the fully sampled FBP reconstruction. The normalized root-mean-square-e |
| 520 | |
▼a In uterine motion we observed the mean duration of the contractions was significantly longer by 26.5 seconds during GA 14-18 weeks compared to GA 19-24 weeks (p=0.034) and significantly longer for male fetuses versus female fetuses (p=0.044 |
| 520 | |
▼a Conclusions. |
| 520 | |
▼a Respiratory motion correction in the liver can be achieved using fat-only SGS with minimal error in the fat-water separation. The proposed technique has potential implications for more robust motion correction for liver dynamic contrast enhanced |
| 520 | |
▼a The low dose CTP study demonstrates that KWIC preserves perfusion metrics for CTP with substantially reduced dose. Clinical implementation will require further investigation into methods of rapid switching of a CT X-ray source. |
| 520 | |
▼a There is a significant difference in the duration of uterine contractions between the two gestational ages examined and the fetal sex. No association in maternal motion during early gestation was seen between GA, fetus sex and placental position |
| 590 | |
▼a School code: 0031. |
| 650 | 4 |
▼a Medical imaging. |
| 690 | |
▼a 0574 |
| 710 | 20 |
▼a University of California, Los Angeles.
▼b Biomedical Physics 0119. |
| 773 | 0 |
▼t Dissertation Abstracts International
▼g 79-10B(E). |
| 773 | |
▼t Dissertation Abstract International |
| 790 | |
▼a 0031 |
| 791 | |
▼a Ph.D. |
| 792 | |
▼a 2018 |
| 793 | |
▼a English |
| 856 | 40 |
▼u http://www.riss.kr/pdu/ddodLink.do?id=T14998953
▼n KERIS
▼z 이 자료의 원문은 한국교육학술정보원에서 제공합니다. |
| 980 | |
▼a 201812
▼f 2019 |
| 990 | |
▼a ***1012033 |