Magnetic resonance spectroscopy in differential diagnosis of ovarian tumors: diagnostic ability and limitations

Solopova A.E., Ternovoy S.K., Ustuzhanin D.V., Makatsaria A.D.

To prospectively evaluate the ability and limitations of single voxel proton MR-spectroscopy (MRS) in differential diagnosis of ovarian tumors.
1 - I.M. Sechenov First Moscow State Medical University.
2 - A.L. Myasnikov Russian cardiology Research Center. Moscow, Russia.



 

 

 

 

 

 

 

 

 

Materials and methods. From 2015 to 2016 34 patients aged 32 to 75 years (mean 56±7,6) with 36 tumors of the ovary with a clear visualized solid component (SC) were included in the study. Diagnostic algorithm consisted of clinical examination, ultrasound, tumor markers analysis (CA-125, CA-19.9), MRI with dynamic contrast enhancement and MR-spectroscopy (Philips Achieva 3T TX MR-system). Single voxel proton MR-spectroscopy was performed using PRESS sequence with the following parameters: TR 1500, TE 130, voxel size 1-2 cm, before and after intravenous contrast enhancement (DCE). The spectral characteristics of the tumors solid component was analyzed: resonance peaks of choline, N-acetyl aspartate (NAA), creatine, lipids, and t the choline-to creatine (Cho/Cr), NAA-to-creatine (NAA/Cr) and lipid-to-creatine (Lip/Cr) ratios were measured, the comparative evaluation of the above parameters in benign and malignant ovarian tumors were performed with respect to the significance of the obtained differences, the factors determining the reproducibility of the technique, limitations were analyzed. Results. The distribution of identified ovarian tumors by histological type and malig-nancy grade: 47.2% of benign tumors (N=17): fibroma – 22,2% (8), tecoma – 8,3% (3), cystadenofibroma – 16,7% (6); 52,7% - malignant tumors (N=19): cystadenocarcinoma – 33,3% (12), clear cell adenocarcinoma– 13,8% (5), stromal sex cord tumor – 5,6% (2). Staging of malignant ovarian tumors was performed according to the FIGO classification: 3 (15,8%) classified as I A, 6 (31.6%) were classified as II A, 4 (21%) – II C, 5 (26,3%) – III C, 1(5,3%) –IV. The maximal size of the tumors ranged from 14.5 mm to 128 mm (average of 62.5±19.6 mm). Increasing concentration of choline (clear peak) was obtained in all (100%) malignant and 12/14 (85.7 %) of benign tumors. The creatine peak observed in 13/15 (86.7%) of malignant and in 10/14 (71,4%) benign tumors, respectively. MRS comparative analysis showed better results while performed after DCE as the tumor size could be easily evaluated. The mean Cho/Cr ratio was 6.51 ± 0.78 in SCs of be-nign versus 9.16 ± 0.74 in SCs of malignant tumors, with significant difference (p = 0.001). There were no statistically significant differences between benign and malignant tumors in the NAA/Cr (p = 0.42) and Lip/Cr ratios (p = 0.16). Conclusion. The Cho/Cr ratio is the most informative spectral parameter in differen-tial diagnosis of benign and malignant ovarian tumors. MRS showed better results while performed after DCE because of better voxel positioning.

 

Keywords: ovarian cancer, MR-spectroscopy, MRI, ovarian tumors.

 

Corresponding author: Solopova A.E., Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript

 

For citation: : Travina M.L., Popov A.G., Popov S.A., Kulikova E.V. Inclusion cyst in breast tissue. REJR 2017; 7 (1):-. DOI:10.21569/2222-7415-2016-6-2-91-96.

Received: 12.12.2016 Accepted: 30.01.2017