ABSTRACT
Objective To observe imaging characteristics and changes of vivo two-dimension multi-voxel proton magnetic resonance spectroscopy (~1H-MRS) in the rabbit models of VX2 hepatic carcinoma after high intensity focused ultrasound (HIFU) treatment. Methods VX2 hepatic carcinoma models were established in 20 New Zealand rabbits. Routine MR and 2-dimentional ~1H-MRS scanning were performed before and after HIFU treatment. The central regions of interest (ROI) of the VX2 tumor, tumor border and paratumor normal liver tissues were selected. The Cho/Cr and Lip/Cr of the same ROI before and after HIFU treatment were compared. Results Total 28 satisfied spectrogram diagram of ~1H-MRS were brought into statistical analysis. Of all the spectra, 6 metabolite peaks were detected as lipids (Lip), glutamine and glutamate complex (Glx), choline (Cho), lactate (Lac) and creatine (Cr). Cho and Lac peak in tumor center and tumor border regions after HIFU treatment were higher than those before HIFU treatment. Lip peak was lower than before, and major metabolites of paratumor normal liver tissues did not changed significantly. Statistical differences of Cho/Cr and Lipid/Cr of tumor center and border region were found between before and after HIFU treatment (P＜0.05). Conclusion Two-dimension multi-voxel ~1H-MRS can reflect major changes in the level of metabolites of different ROI for hepatic VX2 carcinoma after HIFU treatment.
ABSTRACT
Objective To assess the clinical significance of endoscopic ultrasonography (EUS) in the diagnosis and preoperative staging of gastric cancer. Methods EUS was carried out in 22 patients inclu-ding 17 gastric cancer patients and 5 patients in suspicion. Helical CT scanning was performed in all of the patients and fine needle aspiration biopsies ( FNAB) were administrated to 5 suspicious patients. Compared the results of operation and pathology with those of tumor staging by estimating the depth of tumor invasion ( T) , local lymph node metastasis ( N) and metastasis to neighboring or remote organs ( M) in order to esti-mate the accuracy of diagnosis and TNM staging. The sensitivity and specificity of tumor-node-metastasis staging of gastric cancer by EUS were compared with those of the spiral CT according to the final histopatho-logical results. Results In 5 suspicious patients specimens were successfully obtained by FNAB under the guide of EUS with the pathological diagnosis of adenocarcinoma in 4 cases and signet ring cell carcinoma, 1 case. All patients underwent radical gastrectomy except one in T1N0M0, staging was treated by endoscopic mucosal resection (EMR). The sensitivity and specificity of EUS in T, N, and M stage were 84.9% and 74. 2% , 92. 1% and 77. 1% , 63. 4% and 87. 5% respectively; whereas those of CT in T, N, and M stage were 27. 3% and 75% , 31.5% and 100% , 50% and 100% respectively. The sensitivity of EUS in T and N staging were higher than those of CT with significant statistical difference (P