The Clinical Application Of Proton Magnetic Resonance Spectroscopy In Orbital Tumors

Objective 1. To investigate the clinical application of proton magnetic resonance spectroscopy ('MRS) in orbital tumors. 2. To determine content of acetic acid and lactic acid of orbital tumors in vitro. 3. To study whether content of acetic acid and lactic acid of sample of orbital tumors in vitro and content of acetic acid and lactic acid of orbital tumors in vivo have the same identical value or not. 4. To study character of 'HNMR spectroscopy (9. 395T) of orbital tumors in vitro.5. To study whether character of 'HNMR spectroscopy of orbital tumors in vitro and character of 'HMRS of orbital tumors in vivo are identical or not. Methods 1.A11 cases with pathologically-proved tumors had underwent 'HMRS. Single-voxel localized 'HMRS was performed at 1. 5T in all patients suspected of having tumors on MR images. A corresponding PRESS(NAA, Cho, Cr, Ace, Lac)were obtained from normal-forehead brain parenchyma in each patient for comparison with the spectra from known area of pathology at the same side. 2. Tumor samples of 6 cases (including 2 cases cavernous hemangioma> 1 case inflammatory pseudotumo^ 1 case inonu 1 case venous hemangion^ 1 case eosinophilic granuloma) were divided into two portion, content of Lactic acid of one portion was estimated by Lactic acid kit; content of Acetic acid of one portion was estimated by Acetic acid kit. 3. Lac/Ace value which was estimated by Acetic acid kit and Lactic acid kit with Lac/Ace value which was estimated by 'HMRS were compared. 4. 'HNMR spectrum of 18 cases of tumor samples (including 5 cases cavernous hemangion^ 2 case malignant lymphoma > 1 case meningioma and etc.) were measured by 400MHz NMR BRUKER HR/MAS (9. 395T)probe. Results 1. Curve-areas of each metabolites for all orbital tumors was significant different, especially, a significant difference existed in curve-areas of Ace and Lac between benign and malignant orbital tumors (P<0.05).2. Lac/Ace value which was estimated by Acetic acid kit and Lactic acid kit was3. 79 + 0. 48; Lac/Ace value which was estimated by 'HMRS was 3. 48?. 10. There is nosignificant difference in the two results (t=0. 4140. 05), 3. The results showed that high resolution 'H spectra can be obtained for orbital tumors by using the HR/MAS probe, proton MR spectroscopy detected a variety of metabolites in orbital tumors and the main detectable metabolites are N-acetyl-aspartate(NAA), choline-containing compounds(Cho), creatine(Cr), acetate(Ace)and lactate(Lac)and etc. There is no significant difference in the peak odds (Cr/Lac> Cho/Cr> Lac/Ace) (t-test, P>0.05). Conclusion l.'HMRS provides a helpful technique of quantitative analysis for diagnosis of orbital tumors on MR images. 2. Contents of acetic acid and lactic acid of sample of orbital tumors in vitro and content of acetic acid and lactic of orbital tumors in vivo have the same identical value. 3. Characters of 'HNMR spectroscopy of orbital tumors in vitro and character of 'HMRS of orbital tumors in vivo are identical. 4. It is suggested that the application of 'HMRS in diagnosis and differential diagnosis of benign and malignant orbital tumors is meaningful.