ABSTRACT
Objective To explore the feasibility of amide proton transfer (APT) MR imaging for the detection of basal ganglia abnormalities in patients with Parkinson' s disease (PD).Methods Twentyseven patients with PD and twenty-three age-matched normal control subjects underwent cerebral APT and structural MR imaging.The magnetic resonance ratio asymmetry (MTRasym) values at 3.5 ppm of bilateral globus pallidus,putamen and caudate were measured on APT images.MTRasym (3.5 ppm) values of cerebral structures between PD patients and control subjects were compared with independent-samples t test.Paired-samples t test was used to compare the difference of MTRasym (3.5 ppm) between the side of onset and contralateral side in patients with PD.The difference of MTRasym (3.5 ppm) among normal controls,early-stage PD,and advanced-stage PD patients was assessed with one-way analysis of variance.Results Compared to normal controls,MTRasym(3.5 ppm) values of globus pallidus,putamen and caudate were significantly increased in PD patients ((0.89 ±0.12)％ vs (0.57 ±0.16)％,(1.05 ± 0.11)％ vs (0.82 ± 0.15)％,(1.15 ±0.13)％ vs (0.78 ±0.19)％; t =3.311,2.562,3.277 respectively,all P values ＜ 0.05).Significant differences in MTRasym (3.5 ppm) values of these cerebral structures were observed among normal controls,early-stage PD and advanced-stage PD patients.And MTRasym (3.5 ppm) values in globus pallidus,putamen and caudate were significantly higher in early-stage PD patients than normal controls.In PD patients,even not statistically significant,MTRasym (3.5 ppm)values of sides of onset were slightly lower than contralateral sides.Conclusions APT MR imaging can sensitively identify the difference of MTRasym (3.5 ppm) in the basal ganglia between PD patients and normal controls.APT might be a useful tool to evaluate abnormal metabolite in basal ganglia of PD patients.
ABSTRACT
Objective To explore the feasibility of amide proton transfer (APT) MR imaging to detect cerebral abnormality of the substantia nigra and red nucleus in patients with Parkinson disease (PD). Methods Twenty-seven patients with PD and twenty-three age-matched healthy control subjects were recruited in this study. According to Hoehn&Yahr stages, PD group was divided into two subgroups:early-stage(n=14) and advanced-stage(n=13). PD with right limb onset were seen in 14 patients, and PD with left limb onset in 13 patients. All the PD patients and healthy controls underwent brain APT MR imaging. The magnetic resonance ratio asymmetry (MTRasym) values at 3.5 ppm of bilateral substantia nigra and red nucleus were measured on APT images. MTRasym(3.5 ppm)values of substantia nigra and red nucleus between PD patients and control subjects were compared with independent-samples t test. The difference of MTRasym(3.5 ppm)among normal controls, early-stage PD, and advanced-stage PD patients was assessed with one-way analysis of variance. Paired-samples t test was used to compare the difference of MTRasym (3.5 ppm) in substantia nigra and red nucleus between the side of onset and contralateral side in PD patients. Results Compared to normal controls, MTRasym(3.5 ppm) values of substantia nigra significantly decreased in PD patients[(0.96±0.35)%vs. (1.20±0.39)%respectively, t=-2.093 P=0.039]. No significant differences in MTRasym (3.5 ppm) values of red nucleus were observed between normal controls and PD patients[(0.97 ± 0.36)% vs. (1.09 ± 0.38)% respectively, t=-1.148, P=0.254]. Significant differences in MTRasym(3.5ppm) values of these cerebral structures were observed among normal controls, early-stage PD and advanced-stage PD [substantia nigra(1.20±0.30)%,(1.09±0.32)%and(0.81±0.37)%respectively, F=3.954, P=0.022;red nucleus(1.09±0.28)%,(1.21±0.35)%and(0.71±0.33)%respectively, F=7.563, P=0.001]. MTRasym(3.5 ppm) in substantia nigra showed a consistently decreasing tendency from normal controls to early-stage PD, to advanced-stage PD. MTRasym(3.5 ppm) values of sides of onset and contralateral sides of substantia nigra and red nucleus in PD patients had no significant statistically difference (substantia nigra(0.93 ± 0.33)% vs.(0.99 ± 0.30)%, t=-0.660, P=0.515; red nucleus(1.01 ± 0.36)% vs.(0.93 ± 0.29)%, t=0.545, P=0.590). Conclusions APT MR imaging can show sensitively the difference of MTRasym (3.5 ppm) in substantia nigra and red nucleus between early PD patients and normal controls, Thus, APT is a useful tool to diagnose PD and monitor the disease progression.
ABSTRACT
Objective To investigate the probable pathologic basis of amido proton transfer(APT) imaging by analysing APT signal intensity and pathologic features of different grades of glioma.Methods Twenty-eight patients with glioma confirmed by postoperative pathology underwent APT scan.All the patients were divided into two groups,including 11 cases in low grade (WHO Ⅰ and Ⅱ) and 17 cases in high grade (WHO Ⅲ and Ⅳ) group.The APT rate of tumor core was measured.The specimens were processed with routine hematoxylin-eosin (HE) staining and immunohistochemistry of Ki-67 and CD34.Independent-samples t test was used to detect the difference of APT rate,cellularity,microvessel density and Ki-67 labeling indices of tumor core between low grade and high grade group.Pearson correlation analysis and multi-variable linear regression analysis were used to detect the relationship of APT rate with cellularity,microvessel density and Ki-67 labeling indices of the tumor core.Results The APT rate,cellularity and proliferation index were (2.3±0.6) ％,(9.4±2.4) ％ and (14.2±5.4) ％ in low grade group,while (3.6±0.7) ％,(18.4±4.7) ％ and (31.7±4.5) ％ in high grade group,respectively.Microvessel density was (19.0±7.4) per high-power field in low grade group and (38.9±11.3) in high grade group.There were statistical differences of the APT rate,cellularity,microvessel density and proliferation index between the low grade group and the high grade group (t=-4.94,-5.89,-5.13,and-9.28,respectively,P＜0.01).The APT rate was positive correlated with cellularity,microvessel density and proliferation index.The coefficient of correlation were 0.904,0.598,and 0.750,respectively,(P＜0.01).Multiple linear correlative analysis showed that increasing cellularity (X1),microvessel density (X2) and proliferation index (X3) were the main factors for increasing APT rate,and the correlation equation was Y=0.801 + 0.12X1-0.003X2 + 0.026X3 (F=46.437,P＜0.01,R2=0.853).Conclusions The APT signal intensity of the tumor core could reflect the pathologic features of glioma.The APT rate was positive correlated with cellularity,microvessel density and proliferation index,which indicate the higher APT rate the higher grade tumor.