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Objective:To explore whether left ventricular interstitial fibrosis is associated with left atrial enlargement and left atrial dysfunction in patients of hypertrophic cardiomyopathy(HCM) with preserved ejection fraction.Methods:From October 2018 to September 2021, 59 HCM including 30 with enlarged maximal left artrial volume index (LAVI max), 29 with normal LAVI max and 28 age-and gender-matched controls were retrospectively enrolled. Imaging protocol included cine sequence, late gadolinium enhancement and T 1 mapping.The relationships between left ventricular mass index (LVMI), quantitative myocardial fibrosis and left atrial-related indexes were analyzed. One-way analysis of variance with Bonferroni post hoc correction or Kruskal-Wallis was performed for continuous variables. Categorical variables were assessed using the Chi-square test or Fisher′s exact test. Pearson or Spearman analysis was used for linear or monotonic nonlinear correlations. Results:The left ventricular end-diastolic volume index, left ventricular end-systolic volume index, left ventricular cardiac output and LVMI of HCM with enlarged LAVI max group were higher than HCM with normal LAVI max group and control group( P<0.05).Correlation analysis showed that LVMI correlated positively with LAVI max( r=0.780, P<0.001) and minimal left artrial volume index (LAVI min) ( r=0.816, P<0.001), extracellular volume correlated positively with LAVI max( r=0.462, P<0.001) and LAVI min( r=0.483, P<0.001),%LGE was correlated positively with LAVI max( r=0.311, P<0.05) and LAVI min( r=0.327, P<0.05),left ventricular index interstitial volume was correlated negatively with left atrial ejection fraction of reservoir ( r=-0.669, P<0.001),left atrial ejection fraction of conduit ( r=-0.472, P<0.001),left atrial ejection fraction of pump ( r=-0.518, P<0.001)and left atrial expansion index( r=-0.626, P<0.001). Conclusion:There is association between LVMI and fibrosis and left atrial enlargement and phases dysfunction in HCM with preserved ejection fraction.
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Objective To investigate the characteristics of histogram analysis and differences of apparent diffusion coefficient ( ADC) for normal pancreas with different diffusion gradients of diffusion weighted imaging (DWI) at 3. 0T. Methods Three unidirectional diffusion gradients (X, Y or Z direction) and three orthogonal diffusion gradient DWI data of 21 volunteers with normal pancreas were retrospectively analyzed. The histogram parameters of mean ADC, percentile, skewness, peak and the like were measured based on home-made DWI post-processing software, and the differences on histogram parameters obtained from 4 different diffusion gradients were compared by using Kruskal Wallis test. Results There was no significant difference on the mean ADC, skewness, percentile and the like for normal pancreas among 3 unidirectional diffusion gradients and tri-orthogonal diffusion gradient DWIs, but there was significant difference on the mean kurtosis value ( X:3. 16 ± 1. 44, Y:4. 72 ± 2. 26, Z:4. 47 ± 2. 1, tri-orthogonal:3. 69 ± 1. 82; χ2 = -9. 84, P=0. 02). Further analyses results showed that the ADC kurtosis of normal pancreas obtained from X-directional diffusion gradient DWI was significantly smaller than that of the direction of Y or Z, and the difference was statistically significant (P<0.05). Conclusions The ADC kurtosis of normal pancreas is related to the direction of diffusion gradient in DWI, and the ADC kurtosis of normal pancreas obtained by X-direction diffusion gradient is the smallest.
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Objective@#To investigate the characteristics of histogram analysis and differences of apparent diffusion coefficient (ADC) for normal pancreas with different diffusion gradients of diffusion weighted imaging (DWI) at 3.0T.@*Methods@#Three unidirectional diffusion gradients (X, Y or Z direction) and three orthogonal diffusion gradient DWI data of 21 volunteers with normal pancreas were retrospectively analyzed. The histogram parameters of mean ADC, percentile, skewness, peak and the like were measured based on home-made DWI post-processing software, and the differences on histogram parameters obtained from 4 different diffusion gradients were compared by using Kruskal Wallis test.@*Results@#There was no significant difference on the mean ADC, skewness, percentile and the like for normal pancreas among 3 unidirectional diffusion gradients and tri-orthogonal diffusion gradient DWIs, but there was significant difference on the mean kurtosis value (X: 3.16±1.44, Y: 4.72±2.26, Z: 4.47±2.1, tri-orthogonal: 3.69±1.82; χ2 =-9.84, P=0.02). Further analyses results showed that the ADC kurtosis of normal pancreas obtained from X-directional diffusion gradient DWI was significantly smaller than that of the direction of Y or Z, and the difference was statistically significant (P<0.05).@*Conclusions@#The ADC kurtosis of normal pancreas is related to the direction of diffusion gradient in DWI, and the ADC kurtosis of normal pancreas obtained by X-direction diffusion gradient is the smallest.
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Objective To investigate the feasibility of computer-aided pancreas segmentation based on three-dimensional (3D) Dixon MRI at 3.0-T.Methods Five volunteers with health pancreas underwent upper abdominal 3D Dixon MRI at 3.0T with the same scan parameters while holding breath.The automatic segmentation of pancreas is based on the Medical Imaging Interaction ToolKit (MITK) with homemade software.A experienced radiologist performed manual segmentation and computer aided segmentation of the pancreas on the opposed phase and water phase images twice.Similarity was analyzed and compared for the manual and automated segmentations for the two group images.Similarity was presented as Dice coefficients.Results Both of the oppose phase and water phase images of Dixon MRI showed that the signal intensity of pancreas was higher than that of the surrounding tissue,the similarity of water phase was obviously higher than that of oppose phase and the differences were statistically significant.Based on Dixon MRI water phase and oppose phase images,the mean dice coefficients for the manual segmentations were 0.81 ± 0.01 and 0.85 ±0.03,respectively,for both the oppose phase and water phase images (P=0.013).For the automated segmentations,the dice coefficients were 0.69 ± 0.08 and 0.75 ± 0.03 for water phase images and the oppose images,respectively,and the difference was not statistically significant (P =0.155).Conclusions 3.0T oppose phase and water phase of Dixon images could clearly show the pancreas,and automated pancreas segmentation based on water phase Dixon MRI obtained higher similarity,which was feasible.
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Objective To describe the imaging findings of pancreatic and extra-pancreatic lesions of autoimmune pancreatitis (AIP),to improve the imaging diagnostic accuracy of AIP.Methods From 2011 to June 2014,38 AIP patients according to 2010 international consensus diagnostic criteria for AIP were included.Thirty-six patients underwent contrast enhanced CT scan,17 patients underwent contrast enhanced MRI,15 underwent MRCP,and the imaging data were retrospectively reviewed.Results In the 38 patients,the pancreas showed diffuse enlargement in 23,focal enlargement in 9,mixed enlargement in 6.All the patients demonstrated as progressive enhancement and gradually delayed enhancement.Fourteen cases showed diffusely irregular narrowing of the main pancreatic duct.Pseudo-capsule like structure was presented around the lesions in 24 cases.Extra pancreatic lesions included biliary duct involvement in 24 cases,renal lesions in 4 cases,peri-pancreas vessels involvement in 20 cases,8 cases with enlargement of lymph nodes.Conclusions AIP presents with characteristic imaging features in pancreas and extra pancreatic organs.Imaging tests are helpful in the early diagnosis of AIP.