Objective To investigate the feasibility of diffusion-weighted(DWI) MRI on basis of the intravoxel incoherent motion (IVIM) in nasopharyngeal carcinoma (NPC),and the diagnostic value of pure molecular diffusion coefficient (D),perfusion-related diffusion coefficient (D *) and perfusion fraction (f) in first onset NPC.Methods From December 2011 to January 2013,40 consecutive patients (26 men,14 women; median age,52 years) with suspected NPC were examined on a 3.0 T MR scanner.DW imaging was performed by using a single-shot echo-planar sequence with 13 b-values (0,10,20,30,50,80,100,150,200,300,400,600,800 s/mm2).MR imaging was compared with endoscopy and biopsy for the detection of NPC.Mean interval time between MR imaging examination and subsequent nasopharyngeal biopsy was 3 days (range,0-11 days).The subjects were divided into 2 groups according to the pathological results,group A was subjects with NPC (17 men,9 women; median age,35) and group B was ones with nasopharyngeal chronic hyperplastic inflammation(NPH) (9 men,5 women; median age,35).The D,D * and f were measured and compared in patients with first onset NPC and nasopharyngeal hyperplasia (Mann-Whitney test).Results IVIM DWI was successful in 24/26 with NPC and 12/14 with NPH.D value was significantly lower in A group compared with B group [mean,(0.70 ± 0.13) ×10-3 mm2/s vs (0.78 ± 0.05) × 10-3 mm2/s ; U =2.05,P ＜ 0.05],as was f value [mean,(16.25 ±1.46) ％ vs (26.20 ± 3.90) ％ ; U =11.16,P ＜ 0.01].However,D* value was significantly higher in Agroupas compared with B group[mean,(161.8 ±23.56) × 10-3 mm2/s vs (55.28 ± 17.05) × 10-3 mm2/s; U =13.90,P ＜0.01].Conclusions IVIM DWI is a feasible technique for investigating first onset NPC and D value has a certain value in differentiating NPC and NPH.D* value has an important potential value in distinguishing benign and malignant NPC.

Objective To explore the value of DWI ADC in the diagnosis of hepatic ischemia reperfusion injury (IRI) at 3.0 T and investigate the mechanism by comparison with liver enzyme and pathological findings. MethodsForty-two New Zealand white rabbits were divided randomly into ( n ＝ 6,each) six IRI groups by rank sum test. The IRI animals underwent left lobar ischemia for 60 min and were reperfused 0. 5 h, 2. 0 h, 6. 0 h, 12. 0 h, 24. 0 h and 48. 0 h later. One Sham operative group underwent laparotomy without liver ischemia. T2 WI, T1 WI, DWI and contrast-enhanced T, WI were performed with 3.0 T magnetic resonance imaging scanner in each group respectively. For DWI, b-values of 20, 50, 100,200,300,400,500 and 600 s/mm2 were used respectively. Blood samples were taken to detect the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) at different time points. Liver samples were examined histologically after MRI scanning. One-way analysis of variance (ANOVA) was used to determine differences, followed by LSD-t test for multiple comparisons. ResultsOverall, ADC decreased markedly at the early IRI phase ( 0. 5 h), drastically increased in the 2.0 h group, and then ascended slightly from 6. 0 h to 48.0 h after reperfusion, except for a transient decrease at the time point of 24. 0 h. When b values were 20, 50, 100,200 and 300 s/mm2, the ADC values in the Sham group were (3.47 ±0.53) × 10-3, (3.11 ±0.39) ×10-3, (2.87 ±0.19) ×10-3, (2.56 ±0.37) × 10-3 and (1.95 ±0.33) ×10-3mm2/s, (2.63±0.31)±10-3, (2.47±0.32) ×10-3, (2.12±0.38) ×10-3, (2.01±0.51) ×10-3and (1.61 ±0.17) ×10-3mm2/s in the 0.5 h group, (2.72 ±0.09) ×10-3, (2.51±0. 11) ×10-3, (2.28 ±0.30) ± 10-3, (1.96 ±0. 14) × 10-3 and (1.58 ±0. 17) × 10-3mm2/s in the 24.0 h group, respectively. ADC of 0. 5 h and 24. 0 h groups were significantly lower than that of Sham group (P＜0.05) when b value was under 300 mm2/s.In the Sham, 0.5 h, 2.0 h, 6.0 h, 12.0 h,24.0 h and 48. 0 h IRI groups, they were (80±8), (181 ±34), (413 ±62), (474 ±83), (424 ±41 ),(332 ±41 )and(302 ±39) U/L for the levels of ALT,and (79 ± 10), (454 ±55), (547 ±72), (607±31 ), (649 ±79), (785 ±49) and ( 1526 ± 167) U/L for the AST respectively. The levels of AST and ALT in IRI groups were significantly higher than those in the Sham group ( P ＜ 0. 01 ).Histological findings showed diffuse hepatocytes swelling and erythrocytes depositing in the hepatic sinusoids, portal area, central venous and arterials at the initial phase.With the injury aggravated, inflammatory cell infiltration,hepatocyte nuclear condensation of apoptosis, sinusoidal dissociation and coagulation necrosis developed eventually. Conclusion 3.0 T DWI can monitor the pathological process of rabbit liver ischemia reperfusion injury dynamically, and provides a feasible imaging modality for clinical diagnosis and treatment.

Objective To evaluate the value of cardiac MRI in the diagnosis of Ebstein anomaly (EA). Methods Twenty patients from February 2014 to April 2017 with EA confirmed by surgery were enrolled into this study. The analysis in all patients was made according to preoperative cardiac MRI, 2D TTE and surgical data, including the changes of tricuspid valve leaflets, Carpentier classification, the size and function of atrioventricle, late Gadolinium enhancement, the total right/left-volume index and cardiopulmonary bypass time,etc.The numbers of apicaldisplaced leaflets and development condition of all the leaflets were compared using the R×C χ2among the three groups.With surgical results as the reference standard, the diagnostic accuracy of the two groups for the development condition of all the leaflets were evaluated. One-way ANOVA was performed to compare the differences of the apicaldisplaced distance of septal leaflet, using these three methods. Comparisons of the total right/left-volume index, surgery-related data between patients with or without late gadolinium enhancement were performed by independent t test.Results (1) The results in anatomicalstructures, such as distance of apicaldisplacedseptal leaflet,displacement of each leaflet and the Carpentier classification, showed nostatistical difference among MRI,2D TTE and operational findings. The leaflet dysplasia defined by MRI and 2D TTE areequivalent to surgically defined severe dysplasia, and surgically defined mild to moderate dysplasia can't be identified by the former two methods. The overall diagnostic accuracy of MRI and 2D TTE to identify leaflet dysplasia were 41.3%(19/46) and 34.7%(16/46), respectively.(2) Functional right ventricular volume index decreased in 1 case, normal in 8 cases, increased in 11 cases;functional right ventricula rejection fraction decreased in 15 cases. Six patients' left ventricular volume index decreased, 13 remained in normal range, 1 showed increased;left ventricula rejection fraction decreased in 14 cases. (3)LGE was identified in 8 patients and non-LGE in 12. Difference of the total right/left-volume index [(7.12 ± 4.06) vs. (3.84 ± 2.10), P=0.029] between two groups was statistically significant. However, there was no statistical difference in extracorporeal circulation time, aorticcross-clamping time, intubation time, ICU residence time and postoperative hospital staybetween the LGE and non-LGE groups.Conclusions Cardiac MRI can relatively accurately evaluate the apicaldisplacement of leaflets and the morphological changes of the atria and ventricles, as well as quantitatively evaluate the ventricular function, which can rovide references for clinical diagnosis and severity evaluation of EA.

Achalasia is a primary esophageal motility disorder manifested by dysphagia and chest pain that impair patients’ quality of life, and it also leads to chronic esophageal inflammation by food retention and increases the risk of esophageal cancer. Although achalasia has long been reported, the epidemiology, diagnosis and treatment of achalasia are not fully understood. The current clinical dilemma of achalasia is mainly due to its unclear pathogenesis. In this paper, epidemiology, diagnosis treatment, as well as possible pathogenesis of achalasia will be reviewed and summarized. The proposed hypothesis on the pathogenesis of achalasia is that genetically susceptible populations potentially have a higher risk of infection with viruses, triggering autoimmune and inflammation responses to inhibitory neurons in lower esophageal sphincter.