• Investigative Magnetic Resonance Imaging
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• v.12 no.1
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• pp.20-26
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• 2008

Purpose : To present the T1 and T2 relaxation times of the major cerebral metabolites at 1.5T and 3.0T and compare those between 1.5T and 3.0T. Materials and Methods : Using the phantom containing N-acetyl aspartate (NAA), Choline (Cho), and Creatine (Cr) at both 1.5T and 3.0T MRI, the T1 relaxation times were calculated from the spectral data obtained with 5000 ms repetition time (TR), 20 ms echo time (TE), and 11 different mixing time (TM)s using STEAM (STimulated Echo-Acquisition Mode) method. The T2 relaxation times were obtained from the spectral data obtained with 3000 ms TR and 5 different TEs using PRESS (Point-RESolved Spectroscopy) method. The T1 and T2 relaxation times obtained at 1.5T were compared with those of 3.0T. Results : The T1 relaxation times of NAA were $2293\;{\pm}\;48\;ms$ at 1.5T and $2559\;{\pm}\;124\;ms$ at 3.0T (11.6% increase at 3.0T). The T1 relaxation times of Cho were $2540\;{\pm}\;57\;ms$ at 1.5T and $2644\;{\pm}\;76\;ms$ at 3.0T (4.1% increase at 3.0T). The T1 relaxation times of Cr were $2543\;{\pm}\;75\;ms$ at 1.5T and $2665\;{\pm}\;94\;ms$ at 3.0T (4.8% increase). The T2 relaxation times of NAA were $526\;{\pm}\;81\;ms$ at 1.5T and $468\;{\pm}\;74\;ms$ at 3.0T (11.0% decrease at 3.0T). The T2 relaxation times of Cho were $220\;{\pm}\;44ms$ at 1.5T and $182\;{\pm}\;35\;ms$ at 3.0T (17.3% decrease at 3.0T). The T2 relaxation times of Cr were $289\;{\pm}\;47\;ms$ at 1.5T and $275\;{\pm}\;57\;ms$ at 3.0T (4.8% decrease at 3.0T). Conclusion : The T1 relaxation times of the major cerebral metabolites (NAA, Cr, Cho), which were measured at the phantom, were 4.1%-11.6% longer at 3.0T than at 1.5T. The T2 relaxation times of them were 4.8%-17.3% shorter at 3.0T than at 1.5T. To optimize MR spectroscopy at 3.0T, TR should be lengthened and TE should be shortened.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.129-134
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• 2008

Purpose: We examined the roles of Ultrasonography conductors by analyzing the results of tissue biopsy of complex cystic masse under the guidance of breast US. Objects and methods: This study was performed to a group of 178 who showed breast US indicating complex cystic masses among 342 patients who were definitely diagnosed by tissue biopsies and operations in our hospital from June 30th, 2003 to June 30th, 2007. The evaluation of tissues around, calcification, the distribution state of blood flow were excluded from the analysis subjects and logic 200 made by GE corporation and gun for core biopsy(Kimal corp., K7/MBD23) were used in this study. Results: The biopsy results of 178 subjects showed FCC (fibrocystic change)(n=56 : 31.4%), Fibrosis (n=41 : 23.0%), Fibroadenoma (n=20 : 11.2%), Epithelial hyperplasia (n=17 : 9.6%), Carcinoma (n=15 : 8.4%), Fibroadipose (n=8 : 4.5%), Sclerosing adenosis (n=7 : 3.9%), Duct ectasia (n=5 : 2.8%), Papiloma (n=5 : 2.8%), and Fat necrosis (n=1 : 0.6%), Hemangioma (n=1 : 0.6%), Abscess (n=1 : 0.6%), Dystrophic calcification(n=1 : 0.6%). Conclusion: The US showed that the results of the tissue biopsy of complex cystic masses were mostly carcinoma(8.4%). Most of them were benign and only 9.6% of epithelial hyperplasia which has high progression rate into malignant tumors epidemically showed malignancy. Most of them were included in the spectrum of fibrous cystic nodule. Even though these results are confirmed, further studies are required. As a result, a nodule which is not certified by US should be right to take the tissue biopsy, but if it's difficult due to patients or another reasons, re-check tests in three months are required. And systemic ultrasonography evaluation should be well recognized to conduct more careful and specific tests.