Initial experience of correlating parameters of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging at 3.0 T in nasopharyngeal carcinoma.

PURPOSE: To determine the correlation between intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters. METHODS: Thirty-eight newly diagnosed NPC patients were prospectively enrolled. Diffusion-weighted images (DWI) at 13 b-values were acquired using a 3.0-T MRI system. IVIM parameters including the pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f), DCE-MRI parameters including maximum slope of increase (MSI), enhancement amplitude (EA) and enhancement ratio (ER) were calculated by two investigators independently. Intra- and interobserver agreement were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Relationships between IVIM and DCE-MRI parameters were evaluated by calculation of Spearman's correlation coefficient. RESULTS: Intra- and interobserver reproducibility were excellent to relatively good (ICC = 0.887-0.997; narrow width of 95 % limits of agreement). The highest correlation was observed between f and EA (r = 0.633, P < 0.001), with a strong correlation between f and MSI (r = 0.598, P = 0.001). No correlation was observed between f and ER (r = -0.162; P = 0.421) or D* and DCE parameters (r = 0.125-0.307; P > 0.119). CONCLUSION: This study suggests IVIM perfusion imaging using 3.0-T MRI is feasible in NPC, and f correlates significantly with EA and MSI. KEY POINTS: Assessment of tumour perfusion is important in nasopharyngeal carcinoma. DCE-MRI provided perfusion information with the use of intravenous contrast media. Perfusion information could be provided by non-invasive IVIM MRI. IVIM parameter f correlated with DCE-MRI parameters.

[Mechanism of microRNA-100-5p on mammalian target of rapamycin in temporomandibular arthritis].

PURPOSE: To investigate the mechanism of microRNA-100-5p (miR-100-5p) on mammalian target (mTOR) of rapamycin in temporomandibular arthritis. METHODS: Sixty SD rats were randomly divided into group A, group B, group C, group D, and group E, with 12 rats in each group. Rat models of temporomandibular arthritis were prepared by injecting sodium iodoacetate solution into the bilateral spaces of temporomandibular joint. After establishment, group C was injected pcDNA3.1-miR-100-5p recombinant plasmid, group D was injected mTOR inhibitor rapamycin, group E was injected with pcDNA3.1-miR-100-5p recombinant plasmid and rapamycin, and group A was injected same amount of normal saline in the same way. Various indexes were observed in each group, including morphological changes of temporomandibular joint tissues, matrix metalloproteinase-3 (MMP-3), MMP-1, MMP-13, interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), miR-100-5p, mTOR expression. The data were processed using SPSS 22.0 software package. RESULTS: In group B, the structure of temporomandibular joint was fuzzy, with synovial hyperplasia, vascular dilatation, clustered cells and a large amount of inflammatory infiltration. Histopathological changes of temporomandibular joint in each interventional group were improved to different degrees compared with group B, among which group E showed the most obvious improvement. The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1ß and TNF-α in group B were significantly higher than those in group A(P＜0.05). The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1ß and TNF-α in group C, group D and group E were significantly lower than those in group B(P＜0.05). The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1ß and TNF-α in group D were not significantly different from those in group C (P＜0.05). The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1ß and TNF-α in group E were significantly lower than those in group D (P＜0.05). The expression level of miR-100-5p in group E was significantly higher than that in group B (P＜0.05). The expression level of mTOR protein in group E was significantly lower than that in group B (P＜0.05). CONCLUSIONS: MicroRNA-100-5p may alleviate temporomandibular arthritis by down-regulating the expression of mTOR.

Imaging Anatomy of Waldeyer's Ring and PET/CT and MRI Findings of Oropharyngeal Non-Hodgkin's Lymphoma.

BACKGROUND: This study was conducted to analyze positron emission tomography (PET) / computed tomography (CT) and magnetic resonance imaging (MRI) performance with oropharyngeal non-Hodgkin's lymphoma (ONHL). MATERIALS AND METHODS: The complete image data of 30 ONHL cases were analyzed, all patients were performed PET / CT and MRI examination before the treatment, with the time interval of these two inspections not exceeding 14 days. The distribution, morphology, MRI signal characteristics, enhancement feature, standardized uptake value (SUV) max value and lymph node metastasis way of the lesions were analyzed. RESULTS: Among the 30 cases, 23 cases were derived from the B-cell (76.7%), 5 cases were derived from the peripheral T cells (16.7%) and 2 cases were derived from the NK/T cells (6.7%). 19 cases exhibited the palatine tonsil involvement (63.3%). As for the lesion appearance, 10 cases appeared as mass, 8 cases were the diffused type and 12 cases were the mixed type. 25 cases exhibited the SUVmax value of PET / CT primary lesions as 11 or more (83.3%). MRI showed that all patients exhibited various degrees of parapharyngeal side-compressed narrowing, but MRI still exhibited the high-signal fat, and the oropharyngeal mucosa was intact. 25 cases were associated with the neck lymph node metastasis, among who 22 cases had no necrosis in the metastatic lymph nodes, while the rest 3 cases exhibited the central necrosis in the metastatic lymph nodes. CONCLUSIONS: PET / CT and MRI have important value in diagnosing and determining the lesion extent of ONHL.

[Study of preoperative MRI staging of tongue carcinoma in relation to pathological findings].

OBJECTIVE: To study the features of tongue carcinoma in magnetic resonance imaging (MRI) and the value of MRI in the preoperative clinical staging of malignancy. METHODS: Thirty-nine patients with tongue carcinoma underwent MRI examination, the findings of which were analyzed for staging of the tumors in comparison with the pathological findings. RESULTS: MRI showed good performance in displaying tumor invasion, invasion depth and extension but failed in distinguishing and qualitative identification of the lymph nodes less than 1 cm. The sensitivity of MRI for clinical staging of T1, T2, T3, and T4 primary tumors, in accordance with tumor node metastasis (TNM) staging system, was 100%, 83.3%, 90.9% and 82.6% with specificity of 73.5%, 83.5%, 63.6% and 82.6%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of the lymph nodes were 60.8%, 75.0%, 77.8% and 76.2%, respectively. The sensitivity of MRI for the American Joint Committee on Cancer (AJCC) staging was 100%, 85.7%, 92.3% and 88.9%, respectively for stage I, II, III and IV tumors, with specificity of 66.7%, 76.3%, 76.9% and 77.8%, respectively. Lymph nodes metastasis occurred in 0%, 37.5%, 81.6% and 88.2% of the cases with tumor invasion depth of less than 3, 3-6, 6-9 and more than 9 mm respectively, without any significant differences between the latter 2 groups of cases (P>0.05). CONCLUSION: MRI offers important evidence for TNM and AJCC staging of tongue carcinoma, and the MRI features in conjunction with clinical manifestations and tumor invasion depth are instrumental in improving the accuracy of preoperative staging of the tumors.