In vivo 1H MR spectroscopy of thyroid carcinoma

To determine if proton magnetic resonance spectroscopy (H-1 MRS) of thyroid carcinoma is feasible and to determine if H-1 MRS spectra of malignant tumors differ from that of normal thyroid tissue. We performed H-1 MRS at 1.5 T at echo-times (TE) 136 and 272 ms to examine eight patients with thyroid cancer (primary tumour or nodal metastasis) larger than 1 cm(3) in size and five volunteers with normal thyroids. Spectra acquired from six primary tumors (three anaplastic carcinomas, two papillary carcinomas and one follicular carcinoma) and two nodes (two papillary carcinoma metastases) were analyzed in the time-domain using a non-linear least squares fitting algorithm with incorporation of prior knowledge. Choline (3.2 ppm) was identified in all solid carcinomas with a mean choline/creatine of 4.3 at TE 136 ms and 5.4 at TE 272 ms. Ratios for malignant tumors at TE 136 ms ranged from 1.6 in well differentiated follicular carcinoma to 9.4 in anaplastic carcinoma. No choline was detected in normal thyroid tissues. Our results showed that H-1 MRS is a feasible technique for the evaluation of malignant thyroid tumors larger than I cm 3 and that proton spectra of malignant tumors differ from that of normal thyroid tissue. (c) 2004 Elsevier Ireland Ltd. All rights reserved.