Possibilities of multiparametric MRI in the differential diagnosis of histological types of cervical cancer in the preoperative period
Magnetic resonance imaging (MRI) is sensitive and specific method of study in patients with cervical cancer (CC). A number of studies have demonstrated the possibility to determine histological type (squamous cell cancer and adenocarcinoma) and the degree of differentiation of this type of tumor by using the apparent diffusion coefficient maps (ADC-map) compiled on the basis of diffusion-weighted images (DWI) (p <0.05). We have tested whether a more accurate assessment of the histological type and tumor grade in the preoperative stage is possible, by using a wide range of MRI techniques. According to multiparametric MRI, which included T2-weighted imaging (WI), DWI with reconstruction of ADC-maps and dynamic MRI with contrast enhancement, performed in 90 patients with histologically verified cervical cancer, it was shown that adenocarcinoma is characterized by a high intensity and less heterogeneity of MRI signal in fat-suppressed T2WI images as compared to squamous cell carcinoma. Furthermore, patients with adenocarcinomas who underwent dynamic MRI with contrast enhancement had curves with gradually higher change in MRI-signal intensity on T1WI images in 15 seconds after detection of the magnetic resonance contrast agent (MRCA) in tumor, continuous increase in MRI signal intensity (when observing for about 2.5 minutes) after detection of MRCA in tumor, while in case of squamous cell cancer – a lower variation in MRI signal intensity in T1WI mode to 10-20 second after detection of MRCA in the tumor followed by a biphasic course of the curve, dependence of MRI-signal on time and formation of the “plateau” or the same signal decrease down to 125 sec (about 2.5 min) as well as less signal heterogenecity in the period from 10-20 sec to 125 sec (about 2.5 min) after MRCA detection in tumor. The differences were statistically significant (p <0.05), and had sensitivity and specificity up to 0.76 and 0.75, respectively for particular signs. According to binary logistic regression that combines all the relevant parameters in a complex – up to 0.80 and 0.86 or 0.96 and 0.67, respectively. For poorly- and well differentiated adenocarcinomas it was shown significant difference in heterogeneity of MRI signal of the tumor compared to unaffected tissue with the following sensitivity and specificity: ≈1.00; 0.83 (poorly differentiated) and 0.75; 0.96 (well differentiated) respectively.