Effects of hyperoxia on resting state functional magnetic resonance imaging.

We studied the effect of oxygen inhalation during resting state functional MRI scanning in healthy control individuals. We hypothesized that resting state networks would be modified under hyperoxic conditions. Thirty-four normal volunteers were recruited for this study. All participants were scanned twice: once while breathing atmospheric air and once under hyperoxic conditions in a randomized order. Hyperoxic conditions were produced by administering 100% O2. Blood oxygen level-dependent T2* scans were obtained for each of the scans. Resting state networks were extracted using independent component analysis. A paired t-test showed that the resting state networks scans (default mode network, attention network and executive network) acquired under hyperoxic conditions had significantly higher Z-scores than scans performed under atmospheric air. Spectral analysis of the time-course signal in these networks also showed a difference in the total power of low frequencies between the two conditions. These results were reversed in the visual network. Clinical or research applications of oxygen-enhanced MRI need to take into account the modularly effects that hyperoxia exerts on the networks resting state functional MRI.

Dual-energy computed tomography angiography for evaluating the renal vascular variants.

BACKGROUND: Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed tomography (DECT) angiography to provide valuable information for surgery. METHODS: A total of 378 patients underwent DECT. The number, size, course and relationships of the renal vessels were retrospectively observed from the scans. Anomalies of renal arteries and veins were recorded and classified. Multiplanar reformations (MPR), maximum intensity projections (MIP), and volume renderings (VR) were used for analysis. RESULTS: In 378 patients (756 kidneys), renal artery variations were discovered and recorded in 123 kidneys (16.3%, 123/756) of 106 patients (28.0%, 106/378). Type IB (early branches of the only one main renal artery) and IC (accessory renal artery with only one main renal artery) were found most frequently with an incidence of 11.4% (43/378) and 14.5% (55/378). The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney (12.4% vs. 11.1%). The incidence of renal vein variations was detected in 104 patients (27.5%, 104/378). The incidence of venous variants in the right kidney was higher than in the left kidney (20.1% vs. 7.4%), but left renal vein variations were more complex. Variants of the left renal vein were detected in 28 patients including type 1 (circumaortic left renal vein) in eight cases, type 2 (retroaortic left renal vein) in seven cases, type 3 (abnormal reflux) in six cases, type 4 (late venous confluence of left renal vein) in five cases, and type 5 (rare type) in two cases. The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery (P = 0.037). CONCLUSIONS: The renal vascular variants are rather common and complex. DECT angiography can demonstrate the precise anatomy of the renal vessels, which is a benefit for renal transplantation or other renal operations.

[Application of apparent diffusion coefficient ratio in the diagnosis of bladder cancer grading pre-operation].

OBJECTIVE: To explore the value of apparent diffusion coefficient (ADC) ratio in the diagnosis of bladder cancer pre-operation by analyzing its differences among different grades of bladder cancer. METHODS: A total of 52 cases of bladder cancer were all definitely diagnosed with histological results.Routine examinations of magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) were performed preoperatively on each patient. ADC map was constructed in work station and ADC values of tumor and internal obturator muscle were measured (b = 800 s/mm(2)).Ratio of ADC was calculated with internal obturator muscle as reference site. Then the relationship between ADC ratio and bladder cancer grade was analyzed. RESULTS: Mean ratio of ADC of all tumors was 0.98±0.35, G1 (1.12±0.21) and G2 (0.67±0.29), the sensitivity and specificity of ADC ratio was 90.2% and 85.3% respectively with an optimal threshold of 0.96. The ratios of ADC of low-grade group were significantly higher than those of high-grade group while the values of non-muscle-invasive group were significantly higher than those of muscle-invasive group. The ratios of ADC of tumor were inversely associated with the malignancy degree of bladder cancer (r = -0.845, P < 0.05). CONCLUSION: The ratio of ADC of bladder cancer reflects the lesion tissue properties. And its measurement plays an important role in the diagnosis of bladder cancer grading pre-operation.

Quantitative measures of comb sign in Crohn's disease: correlation with disease activity and laboratory indications.

To determine retrospectively if quantitative measures of the comb sign at CT enterography correlated with laboratory indications in Crohn's disease. We retrospectively included 72 known CD patients (47 male and 25 female patients) and 41 normal controls who had undergone CT enterography (CTE) from 2008 to 2010 and had high-sensitive C reaction protein (Hs-CRP) and erythrocyte sedimentation rate (ESR) results. We divided the 72 CD patients into two groups based on disease activity which was determined by Rutgeerts' score. 41 patients were characterized as active disease while 31 patients were as inactive disease. For each individual, one reformatted coronal CTE image in which the comb sign (vasa recta) was most obviously displayed was selected by two experienced radiologists in a double blind manner. For each image, 20 regions of interest (ROI) with area of 1 cm(2) were drawn and placed over the site where the comb sign exists; the comb sign amount was counted in each ROI and recorded. Total amount of the comb sign were assessed from 20 ROI data. Quantitative comb sign results were compared with Hs-CRP and ESR level. Quantitative comb sign score is significantly higher in the CD group than in the control group at both the arterial stage and venous stage (P < 0.001). Quantitative comb sign score is obviously higher in active CD patients than in inactive CD patients both at arterial stage and venous stage (3.63 vs. 2.86 at arterial stage; 3.53 vs. 2.90 at venous stage). ESR level was well correlated with quantitative comb sign score both at arterial and venous stage whereas Hs-CRP has no significant correlation at either stage. Quantitative comb sign results did well in predicting CD activity with the accuracy rate of 78.4% at arterial stage and 80% at venous stage when using 3.33 as the cutoff of quantitative comb sign score. Quantitative comb sign score is a promising CTE parameter in predicting CD activity and be well correlates with the ESR level.

Crohn's disease: CT enterography manifestations before and after treatment.

PURPOSE: The purpose of this study was to determine whether CT enterography (CTE) changes of Crohn's disease (CD) after treatment correlated with clinical remission. MATERIALS AND METHODS: We retrospectively studied 50 known CD patients (male: 35; female: 15) with clinical remission in a period of 3 years (2005-2008). CD was diagnosed by clinical, enteroscopic and pathologic manifestations. Clinical remission was identified by experienced gastroenterologists using the combing criteria of clinical, endoscopy and laboratory tests. First CTE and endoscopy exams were performed during their first hospitalization in our hospital meanwhile CD diagnosis was made during that time. Repeated CTE and endoscopy exams were done after treatment. CTE findings were determined by two experienced radiologists with double-blind approach. Each patient was analyzed for the CTE parameters including bowel wall attenuation, bowel wall thickening (>3mm), bowel wall thickening types (type A: multilayered mural stratification; type B: two layers with strong mucosal enhancement and prominent low-density submucosa; type C: two layers without strong mucosal enhancement; type D: homogeneous enhancement) comb sign, luminal stenosis (mild: luminal diameter 2-3 cm; moderate: luminal diameter 1-2 cm; severe: luminal diameter<1cm) and the presence of extraenteric complications (such as fistulas and abscess). All the quantitative parameters were measured three times by each review. RESULTS: After treatment, bowel wall thickening was attenuated in 88% of CD patients. Thickness of bowel wall was decreased from 8.8 ± 2.8mm to 6.4 ± 1.9 mm (P<0.001). CT value of bowel wall in portal stage was also declined from 90.0 ± 15.4 (HU) to 73.4 ± 14.2 (HU (P<0.001). The percentage of patients with type A or B bowel wall thickening was decreased from 78.7% to 35.4%, while those with type C or D thickening was increased from 21.2% to 64.6% (P<0.001). The percentage of patients with comb sign was decreased from 88% to 60% (P=0.001). The percentage of patients with moderate or severe luminal stenosis was reduced from 74% to 32% (P<0.001). The ROC (receiver operating characteristic) analysis showed bowel wall attenuation (A(z)=0.89) and bowel wall thickness (A(z)=0.81) were the two best parameters to predict disease activity, and combining of these two values was better than using them solely (κ=0.71, P<0.001). The bowel wall attenuation (OR=9.56, P<0.001) and bowel wall thickness (OR=3.32, P=0.001) were significantly correlated with the disease activity in the following logistic regression analysis. CONCLUSION: Therapeutic effect of CD and disease activity can be properly evaluated by CTE.

The effects of hypertension and body mass index on diffusion tensor imaging in schizophrenia.

Recently, the negative effects of hypertension and elevated body mass index on cognitive functioning in schizophrenia have been reported (Friedman et al., 2010). Data suggests that cognitive changes in hypertensive patients from the general population may be mediated, in part, by white matter damage. Therefore, we performed diffusion tensor imaging (DTI) in the same subjects studied by Friedman et al. (2010) to investigate the effects of hypertension and elevated body mass index on the fractional anisotropy (FA) of several major white matter tracts. Significant interactions between a diagnosis of schizophrenia and hypertension on FA in several white matter regions were detected. Hypertension was associated with lower FA in the schizophrenic group and higher FA in the same tracts in the non-schizophrenic subjects. These results suggest hypertension-induced compensatory mechanisms in the brains of non-schizophrenic patients with hypertension which may be impaired in persons with schizophrenia.

Imaging features of small intestinal amyloidosis: a case report.

Amyloidosis is a rare disease characterized by forming pathological protein deposits in organs or tissues. The localized form of amyloidosis affecting small intestine is rare. We report a case of small intestine amyloidosis which presented gastrointestinal bleeding and abdominal pain. We also display radiologic features of amyloidosis of the small bowel which will add evidence to accurate diagnosis and management.

Early-phase endotoxic shock-induced myocardial injury increases iNOS and selectin expression in macaque primate.

BACKGROUND: Our previous study has established a macaque model with early-phase endotoxic shock. The present study further investigated myocardial and blood vessel injury in Macaques by examining the subsequent expression of ACP, selectins, iNOS, and cTnI in response to LPS treatment. METHODS: In an experiment with anaesthetised, instrumental macaques, eleven animals were randomised into: an En group (n=6), receiving a dose of 2.8 mg kg(-1) lipopolysaccharides (LPS) by i.v.; and a Co group (n=5), injected with normal saline of 1 ml kg(-1). Cytochemistry of acid phosphatase (ACPase) in heart was performed by electron microscope at 120 min following endotoxin injection. Three immunochemical stains, namely, L-selectin, P-selectin and iNOS protein in heart, were studied. In addition, cardiac troponin I (cTnI), L-selectin and P-selectin in plasma were detected. RESULTS: In the early phase of endotoxic shock, LPS caused myocardial lysosome damage. The data of immunochemical staining showed the thrombus formation in vessels and the increase of iNOS, L-Selectin and P-Selectin expression in heart, but LPS challenge did not change L-selectin, P-selectin and cTnI in plasma. CONCLUSION: The increase of iNOS, L-selectin and P-selectin protein expression following endotoxin administration may have caused vessel injury and myocardial damage in macaques.