Myoepithelial carcinoma of tibia mimic giant cell tumor: a case report with emphasis on MR features.

Intraosseous myoepithelial carcinoma is an extremely rare type of bone tumor that most often presents in the long tubular bones, but also occurs in small tubular bones and the axial skeleton. We report the radiographic images and complete magnetic resonance (MR) features of a 44-year-old male with right knee pain of 7 months' duration. The radiographic findings and convention MR images indicated a giant cell tumor of the bone. The dynamic contrast-enhanced images showed a patent with the early wash-in and early wash-out usually noted in a giant cell tumor of the bone. Only water restriction on diffusion-weighted imaging (DWI) showed the malignant impression. Care should be taken when conventional images indicate giant cell tumor of the bone, as intraosseous myoepithelial carcinoma, although rare, can mimic this more common diagnosis. Further studies with DWI are warranted.

A quantitative image analysis using MRI for diagnosis of biliary atresia.

PURPOSE: Biliary atresia is a life-threatening disease that needs early diagnosis and management. Recently, MRI images have been used for the diagnosis of biliary atresia with improved accuracy of diagnosis when other imaging modalities such as ultrasonography are equivocal. This study aimed to evaluate the juxta-hilar extrahepatic biliary tree using MRI images to determine a quantitative value for diagnosing biliary atresia. MATERIALS AND METHODS: This retrospective study was approved by the Ethical Committee at Mackey Memorial Hospital (IRB Number: 15MMHIS149e). Between January 2010 and December 2015, twenty-five patients with surgically confirmed biliary atresia were enrolled (age 18-65 days). Another 25 patients with clinically or surgically diagnosed idiopathic neonatal hepatitis (age 6-64 days) and 20 patients with non-hepatobiliary disease (age 6-65 days) were considered control group and normal subjects, respectively. The diameter of the enlarged, T2-hyperintense structure was measured using MRI images by two radiologists both blinded. The cut-off value for a biliary atresia diagnosis was obtained by area under the curve analysis. RESULTS: The diameter of the T2-hyperintense structure at porta hepatis in biliary atresia (4.79 ±â€¯1.14 mm) is larger than in idiopathic neonatal hepatitis (1.72 ±â€¯0.42 mm) or in non-hepatobiliary disease (1.72 ±â€¯0.35 mm) (p < 0.05). The optimum cut-off value for diagnosing biliary atresia was 3.1 mm with 98% sensitivity and 98% specificity. CONCLUSION: The value of the enlarged, T2-hyperintense structure measured on MRI images was significantly increased in biliary atresia and may be useful in diagnosing biliary atresia.

[Characteristics and evolution of hydrochemical compositions of freshwater lake in Tibetan plateau].

Freshwater lake of the Tibetan plateau has great ecological value and extreme vulnerability. The water samples have been collected in Daggyaima Co at an altitude of 5 080 m +/- 10 m. This study has investigated the sources, the major controlling factors of the major ions, and hydrochemical evolution trend according to the hydrochemical composition of water samples. The results showed that the major cations and anion of lake water were Ca(2+), Na(+) and HCO3(-), respectively, and the hydrochemical type was HCO3 -Ca, The total dissolved solid (TDS) was in the range of 71.2-199.8 mg x L(-1). The concentrations of EC, Ca(2+) and HCO3(-) in water samples from Southeast areas were relatively low resulted from the rich aluminum and poor calcium of geological background and the dilution effect of surface runoff. The Na(+)/(Na(+) + Ca(2+)) of water samples was 0.08-0.75, Cl(-) /(Cl(-) + HCO3(-)) was 0.11-0.35, Ca/Na was 0.58, Mg/Ca was 0.12, and HCO3/Na was 1.46, which suggested that the hydrochemical composition of the lake water was mainly controlled by silicate rock weathering based on Gibbs model and analysis of elemental stoichiometry. The minerals participated in weathering processes included plagioclase (anorthite, albite), potassium feldspar, biotite, calcite, dolomite, gypsum, rock salt, etc. The average value of K/Na was 0.059, indicating the weathering level of potassium feldspar was relatively low. The saturation index (SI) of calcite, dolomite, gypsum, quartz and hematite contained in the lake was higher than zero, while the SI of rock salt was lower than 0, revealing the trend that the freshwater lake is turning into salt water lake in Tibetan Plateau.

[Weathering seasonal variations in karst valley in southwest China].

Jialing River is a 1st grade tributary of upstream Yangzi River. In two years, Samples were collected monthly in Wentang Gorge section of Jialing River and analyzed multi-parameters including hydrochemistry and isotopes. Thus, a general result was concluded that the hydrochemical characteristic of Jialing River in Wentang gorge is controlled by weathering of stratum and the hydrochemical type is HCO3(-) -Ca. Most irons were influenced by dilution, which had higher concentrations in dry season than that in rainy season, but nitrate. Nitrate, which was controlled by human activities, has higher concentrations in rainy season. However, some other analyst revealed weathering impacts. The contrast ratio of (Ca(2+) + Mg2+) and HCO3- were between 0.5-1, the same as (Ca(2+) + Mg2+) and (HCO3(-) + SO4(2-)), Which implied that the weathering impacts in this basin was mainly carbonated and sulfate weathering of carbonated, and sulphate rocks weathering was not so significant. The values of delta13C(HCO3- in Jialing River were -8.74 per thousand(-) - 7.36 per thousand, and delta34S(SO)(4)2 - was 14.43 per thousand in dry season and 12.21 per thousand in rainy season. The data of isotopes inferred that, in rainy season sulfate weathering of carbonated and sulphate rocks weathering both had more impacts and sulphate rocks weathering played a more important role than sulfate weathering of carbonated, but, in dry season, carbonated weathering of carbonated was more meaningful.

[Spatial and temporal variability of nitrate contaminant in groundwater in Jinfo Mt. area, Chongqing, China].

The geochemical background of nitrate in groundwater in Jinfo Mt. area was determined, and spatial and temporal variability of nitrate contaminant was analyzed using geochemical, statistical and GIS methods. Twenty-three samples were collected from groundwater discharge points in the study area during 1976-1977, 2004-2006 and 2009, and mass concentration of nitrate in groundwater was tested. The results showed that the geochemical background of nitrate in groundwater in study area was in the range of 0.72-2. 00 mg x L(-1), and the threshold of anomaly was 3.20 mg x L(-1). During 2004-2006 and 2009, the average values of nitrate concentration in groundwater in Jinfo Mt. natural reserve were 2.08, 2.67, 2.59 and 3.92 mg x L(-1); and were 39.08, 25.46, 17.99 and 13.73 mg x L(-1) in the groundwater out of the reserve; the average over-limit rates (standard limit NO3(-) -N < or = 10mg x L(-1)) were 451.64%, 478.61%, 331.85% and 145.67%; the maximum over-limit rates were 1 475.81%, 1 080.39%, 538.20% and 361.78%. Results of interpolation showed that the high value centers of nitrate concentration in groundwater in study area were changing over time, but districts with low nitrate concentration in groundwater in study area were distributed along Jinfo Mt. natural reserve. The application of environmental policy measures and industrial restructuring implemented were reasonable and successful, which had a positive effect to environmental protection.