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Objective To evaluate the imaging features of nigrosome-1 in Parkinson's disease (PD) with a 3 T scanner by susceptibility weighted imaging (SWI),and to explore its clinical relevance.Methods Thirty-two patients with primary PD diagnosed by neurologists were collected.Healthy controls matched to their age and gender were recruited during the same period (n=20).All subjects underwent routine brain magnetic resonance imaging (MRI) and sensitive weighted imaging (SWI).The SWI images of the subjects were evaluated to evaluate nigrosome-1 by blinded investigators.Then,the correlation between imaging features and clinical data was analyzed.Results In the PD group,21 cases of bilateral "absent swallow-tail sign",five cases of bilateral "indecisive swallow-tail sign",five cases of "absent swallow-tail sign" on one side and "indecisive swallow-tail sign" on the other side,and one case of bilateral "clear swallow-tail sign" were found.The course of the "absent swallow-tail sign" group (56 (54) months) was significantly longer than the "non-absent swallow-tail sign" group (18 (18) months;U=-2.47,P=0.01).The Hoehn-Yahr stage was significantly higher in the "absent swallow-tail sign" group (2.0 (0.5)) than in the "non-absent swallow-tail sign" group (1.5 (0.5),U=-2.21,P=0.03).There was also a statistically significant difference in the Unified Parkinson's Disease Rating Scale score (24 (8),13 (14)) between the two groups (U=-2.91,P=0.01).However,there were no statistically significant differences between the two groups in the Hamilton Depression Scale score (5 (2) vs 5 (7),U=-0.10,P=0.94) and the Hamilton Anxiety Scale score (3.0 (2.5) vs 3.0 (3.0),U=-0.02,P=1.00).Conclusion The images of nigrosome-1 by SWI are closely related to the severity of the condition and motor symptoms of patients with PD,which can reflect the severity of the disease.
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Objective Using MRI compatible OxyLiteTM fiber-optic microprobes to verify the reliability of detecting the oxygenation changes in rats C6 glioma by BOLD fMRI with non- hemodynamic response function (non-HRF) post-processing algorithm. Methods A total of 20 male SD rats were used to establish the subcutaneous C6 glioma model. GRE-EPI BOLD fMRI scans were performed in the tumor-bearing rats with Carbogen inhalation after anatomic scans using 1.5 T MR imaging system with Micro-47 microscopic coil. Fiber-optic microprobes were implanted in tumor to acquire the dynamic pO2 indications during BOLD fMRI scan.“Oxy-localization map”and“oxy-amplitude map”were generated from BOLD functional image data by non-HRF post-processing algorithm analysis. A ROI about 1.5 mm on a side centered to the tip of microprobe was defined on the MRI morphological image, and then was copied onto the“oxy-localization map”and“oxy-amplitude map”to extract the values of significant re-oxygenation (T), percent BOLD signal change (ΔPSC). The mean difference of pO2(ΔpO2) measured by fiber-optic microprobes before(pO2-Air)and after (pO2-Car)Carbogen inhalation in the ROI areas was calculated. Correlation analysis was madebetween cov (T value, Δ pO2) and cov (ΔPSC value, Δ pO2). The difference between pO2-Air and pO2-Car were tested by Mann Whitney U test. Results pO2 was successfully measured and recorded from 23 points in tumor using fiber-optic microprobe during the BOLD fMRI scan. The analysis results both of physiological and functional imaging parameters were as follows: pO2-Air=2.285(19.056) mmHg,pO2-Car=14.701(48.390)mmHg,ΔpO2=8.107(33.557)mmHg,ΔPSC=0.402(2.192)%,T=2.025 (8.293). (1) 10 points were identified clearly in parenchyma area of tumor. The mean value of pO2 during air inhalation [19.462(21.511)mmHg] significantly increased after Carbogen inhalation [59.904(56.710)mmHg] (U=14.000,P=0.007). (2) 5 points were identified in tumor necrosis area. The mean value of pO2 during air inhalation [0.149(0.479)mmHg] showed no significant change comparing with Carbogen inhalation[0.273 (8.050)mmHg](U=9.000,P=0.465). (3) 8 points were identified in the boundary of tumor parenchyma and necrosis areas. Among which, 5 showed the similar pO2 change to that located in tumor necrosis area, 2 showed the similar to the tumor parenchyma. However, the pO2 showed continuously decrease after Carbogen inhalation in the last 1 point. TheΔpO2 measured from the total of 23 points correlated positively toΔPSC and T value extracted from the corresponding ROI (r=0.660,0.576,P<0.01). TheΔpO2 measured from 10 points in tumor parenchyma correlated positively to ΔPSC(r=0.717,P=0.020). Conclusion“Oxy-localization map”and“oxy-amplitude map”generated from BOLD fMRI combined with non-HRF post-processing algorithm could show reliably not only the location but also the extent where the re-oxygenation occurred within tumor.
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Objective To explore the MRI features of patients with multiple system atrophy (MSA) and Parkinson's disease (PD) for providing early evidence in differential diagnosis. Methods The MRI features of 24 patients with MSA, 30 patients with PD and 30 healthy people as controls were retrospectively analyzed. Abnormal intensity in MRI included the hot-cross bun sign and the slitlike changes. The atrophies of brain included cerebellar, middle cerebellar peduncles, medulla oblongata and pon. Cerebral ventricle dilatation included fourth ventricle and cisterna pontis. The midbrain area, pons area and middle cerebellar peduncles width were measured. Results All patients with MSA had at least one of the features observed on MR images, and there were some differences in the subtypes of MSA. The high sensitive features were the atrophies of middle cerebellar peduncles (79.2%), the atrophies of pons (79.2%) and the hot-cross bun sign (75.0%). The parameters with high specificity and high positive predictive value were hot-cross bun sign (both 100%), the slit-like sign (both 100%), the atrophies of middle cerebellar peduncles (93.3% and 90.1%), and the atrophies of pons (96.7% and 95.0%). MSA group had the statistically significantly decreased values of pons area, midbrain area and middle cerebellar peduncles width [(288. 7±75. 4) mm2, (127.8±25.8) mm2 and (10. 7±2.8) mm, respectively], as compared with PD group [(477. 5 ± 54. 3) mm2, (145.9±21.6) mm2 and (16.2±1.3) mm, respectively] and healthy group [(454. 5±36. 8) mm2 , (146.4±17.4) mm2 and (16.7±1.2) mm, respectively] (all P ＜0. 05). Conclusions The routine MRI is helpful in differential diagnosis between MSA and PD and has some values in diagnosing the subtypes of MSA.
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Objective To evaluate the correlation between the irradiation dose and superparamagnetic iron oxide (SPIO) enhanced MR imaging of the irradiated liver. Methods 25 rabbits were separated randomly into 5 groups. 3 days after focal irradiation (0, 10, 20, 30 and 40Gy), MR imaging was performed before and after SPIO injection with TSE-T 2W sequence, and the number of Kupffer cell containing SPIO particles was counted. The characteristics of MR enhancement were evaluated according to the pathological findings.Results The liver injury induced by no less than 30Gy irradiation can be detected by SPIO-enhanced T 2 weighted imaging (P
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Objective To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (MRI) in the diagnose of prostatic cancer and benign prostatic hyperplasia (BPH), and to determine the correlation between dynamic MRI findings with angiogenesis.Methods Thirty-two cases of prostatic cancer and 40 cases of BPH underwent dynamic contrast-enhanced MRI.All the patients in this study were diagnosed by histopathology.The results of dynamic contrast-enhanced MRI were evaluated by early-phase enhancement parameters and time-signal intensity curves (SI-T curves), and the curves were classified according to their shapes as type Ⅰ, which had steady enhancement; type Ⅱ, plateau of signal intensity; and type Ⅲ, washout of signal intensity.The pathologic specimens of region of interest (ROI) were obtained, and HE staining, immunohistochemical vascular endothelial growth factor (VEGF), and microvessel density (MVD) measurements were performed.The relationships among dynamic contrast-enhanced MRI features, VEGF, and MVD expression were analyzed.Results In the early-phase enhancement parameters of dynamic contrast-enhanced MRI, onset time,maximum signal intensity, and early-phase enhancement rate differed between prostatic cancer and BPH(P