Feasibility of Intravoxel Incoherent Motion for Differentiating Benign and Malignant Thyroid Nodules.

RATIONALE AND OBJECTIVES: This study aimed to preliminarily investigate the feasibility of intravoxel incoherent motion (IVIM) theory in the differential diagnosis of benign and malignant thyroid nodules. MATERIALS AND METHODS: Forty-five patients with 56 confirmed thyroid nodules underwent preoperative routine magnetic resonance imaging and IVIM diffusion-weighted imaging. The histopathologic diagnosis was confirmed by surgery. Apparent diffusion coefficient (ADC), perfusion fraction f, diffusivity D, and pseudo-diffusivity D* were quantified. Independent samples t test of IVIM-derived metrics were conducted between benign and malignant nodules. Receiver-operating characteristic analyses were performed to determine the optimal thresholds as well as the sensitivity and specificity for differentiating. RESULTS: Significant intergroup difference was observed in ADC, D, D*, and f (p < 0.001). Malignant tumors featured significantly lower ADC, D and D* values and a higher f value than that of benign nodules. The ADC, D, and D* could distinguish the benign from malignant thyroid nodules, and parameter f differentiate the malignant tumors from benign nodules. The values of the area under the curve for parameter ADC, D, and D* were 0.784 (p = 0.001), 0.795 (p = 0.001), and 0.850 (p < 0.001), separately, of which the area under the curve of f value was the maximum for identifying the malignant from benign nodules, which was 0.841 (p < 0.001). CONCLUSION: This study suggested that ADC and IVIM-derived metrics, including D, D*, and f, could potentially serve as noninvasive predictors for the preoperative differentiating of thyroid nodules, and f value performed best in identifying the malignant from benign nodules among these parameters.

[Effect of total anthraquinone in rheum on aquaporin 2 expression in rat distal colon].

OBJECTIVE: To investigate effect of total anthraquinone in rheum on aquaporin 2 expression in rat distal colon. METHOD: SD rats were randomly divided into control group, low dose group, middle dose group and high dose group. Gavaged to control group, and treated group were administered saline and total anthraquinone in rheum with dosage of 0.14, 2.5, 4.5 g x kg(-1) x d(-1), respectively. All rats were put sacrificed after 5 days and stool in full length colon was gently collected to detect water content stool. Distal colon was removed to detect AQP2 expression with immunohistochemistry, western blot and RT-PCR. RESULT: No diarrhea was found in low dose group and control group, there were not significant difference water content of stool and AQP2 expression between low dose group and control group. However, soft feces and loose stools occurred in diarrheic dose group, loose stools and watery stool appeared in high dose group. Stool water content increased in diarrheic dose group and High dose group, expression of AQP2 decreased evidently in these two groups (P < 0.01). CONCLUSION: Total anthraquinone in rheum can reduce the transcription and translation of AQP2 in rats' distal colon, increase fecal water content, which probably is one of the mechanisms of diarrhea caused by total anthraquinone in rheum.

[Application of histochemical staining in diagnosis of osteosarcomas].

OBJECTIVE: To study the histochemical staining in the diagnosis of osteosarcoma. METHODS: To compare the effectiveness of picrosirius red, improved Ponceau trichrome and Masson trichrome staining methods on bone formation tissues in conventional osteosarcoma, paraosteal osteosarcoma, periosteal osteosarcoma, extraskeletal osteosarcoma, inflammatory myofibroblastic tumour, malignant fibrohistiocytoma, chondrosarcoma, fibrosis with ossification and calcification. RESULTS: With modified Ponceau trichrome staining, bone formation tissues showed a homogenous, orange-red interblended with blue in color. From osteoid to mature bone the color changed from orange-red, light blue to dark blue. Fibrotic tissue was stained blue in color with striated appearance. Cartilage was not stained. Picrosirius red method gave bone formation tissues homogenous staining. Along with bone maturation, from osteoid tissue to mineralized bones, the color showed changes from light red, yellow, orange-red, red to dark purple. The cartilage demonstrated homogenous light red in color. Fibrous tissue stained red interblended with yellow in color, striated in shape. With Masson trichrome staining osteoid displayed pale blue and mineralized bone showed dark blue in color. Fibrotic tissue showed a striated blue staining. CONCLUSION: The modified Ponceau trichrome and Picrosirius red staining methods are better than Masson trichrome to demonstrate bone formation tissue in osteosarcoma. The former two methods could be also used in study on bone formation.