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Objective@#To investigate the difference in the microstructure of gray matter nucleus in different movement subtypes of Parkinson’s disease (PD) by diffusion kurtosis imaging (DKI) technique, and to analyze the correlation with clinical manifestations.@*Methods@#Ninety-seven patients with PD and 83 healthy controls performed conventional MRI sequence and DKI sequence scan. The PD patients were classified into gait disorder subtype (PIGD, n=57) and tremor dominant subtype (TD, n=40)subtypes according to motor symptoms. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da), radial diffusivity(Dr), mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Dr) maps and data were generated by software after processing. DKI was performed for all subjects and data was collected from different brain regions in both hemispheres, including red nucleus(RN), substantia nigra pars reticulate(SNr), substantia nigra pars compacta(SNc), putamen(PUT), globus pallidus(GP), head of caudate nucleus (CN)and thalamus(THA).@*Results@#TD showed a higher MMSE score(P=0.019), but lower modified Hoehn-Yahr score than that in PIGD (P<0.001), there was no significant difference of age of onset, sex, limbs of onset or disease duration between two PD subgroups. Compared with healthy controls, both TD and PIGD showed down-regulated MD, Da and Dr and up-regulated Ka values(P<0.001); MK(0.83±0.26, 0.80±0.18) was increased in SNr both in TD and PIGD, while SNc, PUT and GP (0.84±0.20, 0.75±0.07, 0.81±0.14)were decreased only in TD (P=0.017, P=0.010, P=0.020, P<0.001, P=0.002). The Kr values of PUT and CN(0.71±0.17, 0.72±0.14) were reduced in PIGD, while CN(0.70±0.14) were reduced in TD respectively (P=0.002, P=0.031, P=0.007). The MK was lower in TD than that in PIGD (t=-2.214, P=0.029), and no significant difference was found in other grey matter nuclei between TD and PIGD(P>0.05). Moreover, there was no significant correlation between DKI value and disease duration, MMSE score or Hoehn-Yahr scale (P>0.05) in TD and PIGD.@*Conclusion@#There is heterogeneity of clinical symptoms between these two subgroups of PD. DKI can quantify the microstructural changes of grey matter nucleus in different type PD patient.
ABSTRACT
Objective To investigate the difference in the microstructure of gray matter nucleus in different movement subtypes of Parkinson’s disease (PD) by diffusion kurtosis imaging ( DKI) technique, and to analyze the correlation with clinical manifestations. Methods Ninety-seven patients with PD and 83 healthy controls performed conventional MRI sequence and DKI sequence scan. The PD patients were classi-fied into gait disorder subtype (PIGD,n=57) and tremor dominant subtype (TD,n=40)subtypes according to motor symptoms. Fractional anisotropy (FA),mean diffusivity (MD),axial diffusivity (Da),radial diffu-sivity(Dr),mean kurtosis (MK),axial kurtosis (Ka) and radial kurtosis (Dr) maps and data were genera-ted by software after processing. DKI was performed for all subjects and data was collected from different brain regions in both hemispheres,including red nucleus(RN),substantia nigra pars reticulate( SNr),sub-stantia nigra pars compacta(SNc),putamen(PUT),globus pallidus(GP),head of caudate nucleus (CN)and thalamus(THA). Results TD showed a higher MMSE score(P=0. 019),but lower modified Hoehn-Yahr score than that in PIGD (P<0. 001),there was no significant difference of age of onset,sex,limbs of onset or disease duration between two PD subgroups. Compared with healthy controls, both TD and PIGD showed down-regulated MD,Da and Dr and up-regulated Ka values(P<0. 001); MK(0. 83±0. 26,0. 80±0. 18) was increased in SNr both in TD and PIGD,while SNc,PUT and GP (0. 84± 0. 20,0. 75± 0. 07,0. 81± 0. 14) were decreased only in TD (P=0. 017,P=0. 010,P=0. 020,P<0. 001,P=0. 002). The Kr values of PUT and CN(0. 71±0. 17,0. 72±0. 14) were reduced in PIGD,while CN(0. 70±0. 14) were reduced in TD re-spectively (P=0. 002,P=0. 031,P=0. 007). The MK was lower in TD than that in PIGD (t=-2. 214,P=0. 029),and no significant difference was found in other grey matter nuclei between TD and PIGD ( P>0. 05). Moreover,there was no significant correlation between DKI value and disease duration,MMSE score or Hoehn-Yahr scale (P>0. 05) in TD and PIGD. Conclusion There is heterogeneity of clinical symptoms between these two subgroups of PD. DKI can quantify the microstructural changes of grey matter nucleus in different type PD patient.
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Objective To explore the feasibility and accuracy of dual-source CT (DSCT)in evaluating aortic regurgitation (AR). Methods Among 78 patients who underwent both DSCT and TTE,38 patients were diagnosed as AR and 40 without AR served as controls.Maximum regurgitant orifice area (ROA)in diastole was planimetrically measured with DSCT,and measurements were compared with semiquantitative classification of TTE.Results DSCT correctly identified 37 patients with AR.Compared with TTE,two patients were false positive and three patients were false negative findings by DSCT (sensitivity 92%,specificity 95%, positive predictive value 94%,and negative predictive value 93%).ROA measured by DSCT (0.32 cm2 ±0.44 cm2 )was signifi-cantly correlated with TTE classification (r=0.85,P<0.01).With receiver operating characteristic curve analysis,discrimination between degrees of AR with DSCT was high accurate when using cutoff ROAs of 0.08 cm2 and 0.58 cm2 .Conclusion Planimetric measurement of ROA with DSCT is accurate for the quantitative evaluation of AR.
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Objective To evaluate the application of measurement of T2*value,width of substantia nigra pars compacta (SNc) and the ratio of the width to the midbrain diameter in diagnosing Parkinson disease (PD) in early stage with susceptibility weighted imaging ( SWI) by 3T MR. Methods 59 patients with early stage idiopathic PD patients and 59 healthy controls,ranging in same ages and gender,had been scanned with routine sequences and SWI sequences by 3T MR. T2*value,width and the ratio of the width to the midbrain diameter of SNc were measured. The results of measurement were analyzed and compared. Results (1) The T2*values, width and the ratio of the width to the midbrain diameter was decreased in homolateral side SNc of symptoms of subjects with PD compared with the healthy controls ( 0.05) . Conclusion Measurement of T2*value, width and the ratio of the width to the midbrain diameter of SNc with SWI is reliable to diagnose PD.
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Objective To explore the feasibility and accuracy of dual-source computed tomography(DSCT)coronary angiography for evaluation the morphology and motion of aortic valve.Methods A total of 125 cases with suspected coronary artery disease un-derwent computed tomography coronary angiography and transthoracic echocardiography examination.Twenty CT data sets were re-constructed in 5% steps from 0% to 95% of R-R interval.The morphologic features,changes of motion and image quality of the aortic valve in cardiac cycle were observed and recorded with CT dynamic cine-mode technique.The differences of aortic opening area in the various phases of the systole were analyzed by using ANOVA.Results 92.3% of aortic valve images among the total 2500 phases were good enough for evaluated in the 125 patients examined.DSCT visualized 123 patients with tricuspid aortic valve while 2 patients with bicuspid aortic valve.27 patients with degenerative aortic valve disease were identified.CT correctly identified 26 patients with aor-tic insufficiency during diastole.Compared with TTE,3 patients were false positives and two patients were false negatives on DSCT. Aortic valve opening was seen in phase 0% to 35% in 92% of patients,and it was closed during phase 40% to 95% of R-R interval in 75.2% of patients.There were significant difference between the AVA in the various phases of the systole(F =2.97,P <0.05). Conclusion DSCT allows accurate and dynamic visualization of morphology and motion of aortic valve throughout the cardiac cycle. The area of the aortic opening is widest and image quality is best during midsystole.
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Objective To discuss the feasibility and accuracy of dual-source CT ( DSCT) in the evaluation of aortic stenosis ( AS) with transthoracic echocardiography ( TTE) as reference.Methods A total of 53 patients who underwent both DSCT and TTE were prospectively evaluated.All of them were assessed by TTE for aortic stenosis.Maximum aortic valve area ( AVA) in systolic phase was measured with DSCT , and was compared to that index obtained from the continuity equation on TTE.The severity of AS was graded as mild , moderate , or severe according to the AVA.Linear regression analysis and Bland-Altman plots were used to compare the AVA measured by using CT and TTE.Agreement on semi-quantitative grades of AS severity between the two methods was tested by using Kappa statistics.Results The mean AVA using DSCT was (1.45 ±0.35 ) cm2 compared to the mean AVA of ( 1.33 ±0.36 ) cm2 using TTE, with a significant correlation between them (r=0.92,P<0.01).Bland-Altman analysis demonstrated good inter-modality consistency between DSCT and TTE.However , DSCT demonstrated a slight overestimation of the AVA compared to TTE.As identified by TTE, there were 53 patients with AS, 13 with mild AS, 21 with moderate AS , and 19 with severe AS.In 3 patients DSCT showed no AS , TTE detected mild AS.In 6 cases, TTE had graded the stenosis as moderate , but the stenosis degree was graded as mild using DSCT.Kappa analysis showed a good agreement between the two methods on semi -quantitative grades of aortic stenosis severity (Kappa=0.75,P<0.01).Conclusion AVA measurements using DSCT is feasible and reasonably accurate for those patients with moderate to severe aortic stenosis.