[en] To investigate whether there is an increased signal intensity (SI) of dentate nucleus (DN) and globus pallidus (GP) on unenhanced T1-weighted magnetic resonance imaging (MRI), in patients who had undergone multiple administrations of gadoxetate disodium. We retrospectively included stage III melanoma patients, who had been previously enrolled in a trial of adjuvant therapy and who had undergone whole-body contrast-enhanced MRIs with gadoxetate disodium every three months for their follow-up. The SI ratios of DN-to-pons and GP-to-thalamus on unenhanced T1-weighted images were calculated. The difference in SI ratios between the first and the last MRI examinations was assessed and a linear mixed model was performed to detect how SI ratios varied with the number of administrations. Eighteen patients were included in our study. The number of gadoxetate disodium administrations ranged from 2 to 18. Paired t-test did not show any significant difference in DN-to-pons (p=0.21) and GP-to-thalamus (p=0.09) SI ratios by the end of the study. DN-to-pons SI ratio and GP-to-thalamus SI ratio did not significantly increase with increasing the number of administrations (p=0.14 and p=0.06, respectively). Multiple administrations of gadoxetate disodium are not associated with increased SI in DN and GP in the brain. (orig.)

[en] To assess the independent prognostic value of standardized uptake value (SUV) and apparent diffusion coefficient (ADC), separately and combined, in order to evaluate if the combination of these two variables allows further prognostic stratification of patients with head and neck squamous cell carcinomas (HNSCC). Pretreatment SUV and ADC were calculated in 57 patients with HNSCC. Mean follow-up was 21.3 months. Semiquantitative analysis of primary tumours was performed using SUV_m_a_x_T_/_B, ADC_m_e_a_n, ADC_m_i_n and ADC_m_a_x. The prognostic value of SUV_m_a_x_T_/_B, ADC_m_e_a_n, ADC_m_i_n and ADC_m_a_x in predicting disease-free survival (DFS) was evaluated with log-rank test and Cox regression models. Patients with SUV_m_a_x_T_/_B ≥5.75 had an overall worse prognosis (p = 0.003). After adjusting for lymph node status and diameter, SUV_m_a_x_T_/_B and ADC_m_i_n were both significant predictors of DFS with hazard ratio (HR) = 10.37 (95 % CI 1.22-87.95) and 3.26 (95 % CI 1.20-8.85) for SUV_m_a_x_T_/_B ≥5.75 and ADC_m_i_n ≥0.58 x 10"-"3 mm"2/s, respectively. When the analysis was restricted to subjects with SUV_m_a_x_T_/_B ≥5.75, high ADC_m_i_n significantly predicted a worse prognosis, with adjusted HR = 3.11 (95 % CI 1.13-8.55). The combination of SUV_m_a_x_T_/_B and ADC_m_i_n improves the prognostic role of the two separate parameters; patients with high SUV_m_a_x_T_/_B and high ADC_m_i_n are associated with a poor prognosis. (orig.)

[en] To assess the diagnostic accuracy of MRI performed using surface coils, with and without contrast medium, in predicting thyroid and cricoid cartilage infiltration in laryngeal tumours, and to investigate whether the radiologist's experience influences diagnostic accuracy. We retrospectively enrolled patients with biopsy-proven laryngeal cancer who had undergone preoperative staging MRI and open surgery. Two radiologists with different experience (senior vs. junior) reviewed the MR images without (session A1) and with contrast medium (session A2) separately. We calculated the accuracy of MRI with and without contrast medium in detecting infiltration of the thyroid and cricoid cartilages. Interobserver agreement was calculated by Cohen's Kappa (k). Forty-two patients were enrolled, for a total of 62 cartilages. In session A1 the senior and junior radiologists showed an accuracy of 85% and 71%, respectively, with k = 0.53 (0.33-0.72). In session A2 the senior and junior radiologists showed an accuracy of 84% and 77%, respectively, with k = 0.68 (0.49-0.86). Staging of laryngeal tumours with surface coil MRI showed good diagnostic accuracy in assessing cartilaginous infiltration. We observed similar values of diagnostic accuracy for the analysis performed with and without contrast medium for the senior radiologist. (orig.)