Objective To investigate iron deposition level in patients with ischemic cerebrovascular disease and its correlation with cerebral small vessel disease (CSVD) imaging markers.Methods A total of 74 patients with first-ever transient ischemic attack (TIA) (median age:69 years old;30 males,44 females) and 77 patients with positive ischemic stroke history (median age:72 years old;43 males,34 females) were studied retrospectively.On phase image of susceptibility weighted imaging (SWI),regions of interest (ROIs) were manually drawn at the bilateral head of the caudate nucleus (CN),lenticular nucleus (LN),thalamus (TH),frontal white matter (FWM),and occipital white matter (OWM).The correlation between iron deposition level and the clinical and imaging variables was also investigated.Results Iron deposition level at LN was significantly higher in patients with previous stroke history (P ＜ 0.05).It was linearly correlated with the presence and number of cerebral microbleed (CMB) but not with white matter hyperintensity (WMH) and lacunar infarct.Conclusions Ischemia may cause iron deposition elevation at basal ganglia,and LN may be more susceptible to ischemia-induced alteration.CMB may be an independent risk factor for higher iron deposition.

Objective:To investigate the correlation between MRI signal for infrapatellar fat pad (IPFP) and pathological changes in knee osteoarthritis (KOA),and to analyze the role of IPFP in the development of knee osteoarthritis.Methods:A total of 114 subjects (without special knee disease) were enrolled for this study.The intensity of MRI signal for IPFP was determined by fat-suppressed proton-density-weighted turbospin-echo magnetic resonance imaging.Based on the cartilage defects and osteophytes of knee joint,the subjects were divided into a KOA group and a control group.The difference of MRI signal for IPFP between two groups was analyzed.Results:After excluding the potential confounders of age,gender and BMI,the intensity of MRI signal for IPFP was positively correlated with defections in patellar,medial femur,lateral tibial or knee joint (OR 1.333 to 2.168,P 0.006 to 0.023);the intensity of MRI signal for IPFP was also positively correlated with osteophytes in patellar,medial femur,lateral tibial or knee joint (OR 1.309 tol.781,P 0.004 to 0.046);the intensity of MR/signal for IPFP in the KOA group was significantly higher than that in the control group (P=0.028).Conclusion:The increase in the density of MRI signal for IPFP is an imaging manifestation for knee degeneration.IPFP inflammation and endocrine abnormalities may play an important role in KOA.

Objective To evaluate the metabolite pattern and the severity in patients with spinocerebellar ataxia type 3/ Machado-Joseph disease (SCA3/MJD) by 1H magnetic resonance spectroscopy (1H-MRS) on different cerebellar regions, including cerebellar vermis, cerebellar peduncles, cerebellar cortex, and dentatum. Methods Thirty-six SCA3/MJD patients, and 27 sex, age-matched healthy controls were scanned with 1H-MRS for N-acetylaspartate (NAA), choline (Cho) and creatine (Cr). We made cerebellar vermis, cerebellar peduncles, cerebellar cortex, and dentatum as the region of interests (ROI), and finally got access to NAA/Cr, Cho/Cr, and NAA/Cho ratios. We also examined the CAG repeat numbers of MJD1 gene, scored the 36 patients by the scale for the assessment and rating of ataxia (SARA), analyzed the differences in ratios between SCA3/MJD patients and the control group, and explored whether relevance existed between these ratios and duration of the disease, age of onset, CAG repeat times, and SARA scores respectively. Results The ratio of NAA/Cr in SCA3/MJD patients showed a significant reduction in the cerebellar cortex, dentatum, cerebellar vermis and medipeduncle (P<0.01) compared with the controls. The ratio of NAA/Cho also showed significant reduction in the dentatum and cerebellar vermis (P<0.01). A number of correlations were found between the metabolite ratios of 1H-MRS and duration of the disease, age of onset, expanded CAG and SARA score in SCA3/MJD patients. Conclusion 1H-MRS, which shows the neural metabolic changes in the cerebella of SCA3/MJD patients, provides useful information about the severity of SCA3/MJD.

OBJECTIVE: To evaluate the capability and limitation of magnetic resonance image(MRI)for Lumbar zygapophyseal joint cartilage through comparing pig lumbar zygapophyseal joint cartilage acquired from multiple MRI sequences of a 1.5 Tesla MR and gross specimens. METHODS: Six fresh lumbar spines from adult pigs were sagittaly scanned by Siemens 1.5 Tesla MR. The scan sequences included fast spin echo T1-weighted imaging (FSE T1WI), fast spin echo T2-weighted imaging (FSE T2 weighted T2WI), fat saturation proton density-weighted imaging (FS PDWI), 3-dimensional fast low angle shot imaging (3D-FLASH), and water excitation 3-dimensional fast low angle shot imaging (WE 3D-FLASH). Each scan sequence acquired images from the same layer. The signal-noise ratio (SNR) for articular cartilage, contrast-noise ratio (CNR) for cartilage versus bone cortex, cartilage versus bone marrow, and cartilage versus saline were calculated. Right after the scanning, the lumbar spines were snap-frozen, incised sagittally along the midline lumbar zypapophyseal joints, and photographed to compare the gross specimens with corresponding MRIs. The thickness of sagittal midline center of 6 pairs of lumbar(L₃/L₄) zypapophyseal joint cartilage was measured by vernier caliper. The thickness of the back ventral articular cartilage was added and then compared with corresponding MR images. RESULTS: 3D-FLASH (FA 20°) and WE 3D-FLASH (FA 20°) sequences had significant advantages compared with other sequences in imaging lumbar zypapophyseal joint cartilage, and were mostly close to the real thickness.(1) Comparison of the 4 flip angle (FA 10°, FA 20°, FA 30°, and FA 40°) 3D-FLASH sequences:The highest cartilage SNR and best CNR of cartilage versus bone cortex were both found in the 3D-FLASH(FA 20°) sequence, which was significantly different from the other three 3D-FLASH sequences.The satisfactory CNR of cartilage versus bone marrow, cartilage versus saline were found more in the 3D-FLASH(FA 20°) sequence. (2) Comparison of the 4 flip angle(FA 10°, FA 20°, FA 30°, and FA 40°) WE 3D-FLASH sequences: the highest cartilage SNR,best CNR of cartilage versus bone cortex,and best CNR of cartilage versus bone marrow were found in the WE 3D-FLASH (FA 20°) sequence, which was significantly different from the other three 3D-FLASH sequences. The CNR of cartilage versus saline was found more satisfactory in the WE 3D-FLASH (FA 20°) sequence. (3) The highest cartilage SNR and best CNR of cartilage versus bone cortex were both found in the 3D-FLASH (FA 20°) sequence, which was significantly different from those in the PDWI, FSE T1WI,and FSE T2WI sequences (P<0.05), but with no significance (P>0.05) in the WE 3D-FLASH (FA 20°) sequence. The highest CNR of cartilage versus bone marrow was seen in WE 3D-FLASH (FA 20°) sequence. It was statistically significant compared with that in FS PDWI,FSE T1WI, and T2WI sequences respectively, but the difference was not significant compared with 3D-FLASH (FA 20°) sequence (P>0.05). Both the FS PDWI and T2WI sequences displayed ideal CNR of cartilage versus saline, with no significant difference (P>0.05). The lower SNR of cartilage versus saline was shown in 3D-FLASH (FA 20°) and WE 3D-FLASH (FA 20°) sequence, and the difference was not significant (P>0.05). However, they were significantly different compared with FS PDWI and T2WI sequences (P<0.05). (4) WE 3D-FLASH (FA 20°) and 3D-FLASH (FA 20°) sequences were relatively better than the FS PDWI when comparing the thickness of articular cartilage, which was significantly different from the FS PDWI sequence (P<0.05). CONCLUSION The 3D-FLASH sequence and derived WE 3D-FLASH sequence have better definition of cartilage images and are mostly close to the real thickness, which possibly are the optimal scanning sequences for lumbar zypapophyseal joint articular cartilage MR imaging.
Animals ; Cartilage, Articular ; anatomy & histology ; Imaging, Three-Dimensional ; Lumbar Vertebrae ; anatomy & histology ; Magnetic Resonance Imaging ; methods ; Swine ; Zygapophyseal Joint ; anatomy & histology

Purpose MRI is one of the most effective methods in examining anterior cruciate ligament (ACL),but probability of misdiagnose and missed diagnosis still might exist.This research aims to investigate the effect of oblique coronal MRI views in individualized bent-knee position on the imaging findings of ACL.Materials and Methods Seventy healthy volunteers recruited by the Third Xiangya Hospital,Central South University from September 2016 to March 2017 were involved in this prospective study.3-T MRI combined with independently designed knee joint dynamic imaging auxiliary instrument was employed to perform a dynamic scan in the sagittal plane;the optimal bentknee angle with ACL basically in straight layers (angle of the individualized bent-knee position) was measured.Afterwards,oblique coronal MRI views (PDWI+FS) in both regular extended-knee position and individualized bent-knee position were conducted.And their separate effects on ACL imaging findings in oblique coronal MRI views were compared.Results Oblique coronal MRI scan in extended-knee position and individualized bent-knee position were 92.9％ (65/70) and 45.7％ (32/70) respectively in displaying the imaging of the whole ACL.The former outperformed the latter,and the difference was statistically significant (P＜0.001).Conclusion In contrast to oblique coronal MRI scan in extended-knee position,the scan in individualized bent-knee position elevates the performance of whole ACL imaging.

OBJECTIVES: Quantitative magnetic resonance imaging has been successfully applied to assess the status of cartilage biochemical components. This study aimed to investigate the performance of 3.0T magnetic resonance imaging T mapping combined with texture analysis for evaluating the early degeneration of lumbar facet joints. METHODS: A total of 38 patients (20 in the asymptomatic group and 18 in the symptomatic group) were enrolled. All patients underwent 3.0T magnetic resonance imaging conventional sequences, water excitation three-dimensional spoiled gradient echo sequence (3D-WATSc), and T mapping scans. The bilateral L and L/S lumbar facet joints were morphological graded using the Weishaupt criteria, T values, and texture parameters derived from T mapping of cartilage. The Kruskal-Wallis test was used to compare the differences of parameters among different groups. Multivariate logistic regression analysis was used to obtain the independent predictive factors for evaluating the early degeneration of lumbar facet joints. Receiver operating characteristic (ROC) curve was performed and the area under curve (AUC) was calculated. Spearman correlation analysis was used to evaluate the correlation of the independent predictors of cartilage T value and texture parameters with the subjects' Japanese Orthopedic Association (JOA) score or Visual Analogue Scale (VAS) score. RESULTS: A total of 148 facet joints were selected, including 70 in Weishaupt 0 (normal) group, 58 in Weishaupt 1 group, and 20 in Weishaupt 2-3 group. T value, entropy, and contrast increased significantly as the exacerbation of facet joint degeneration (all <0.05), while the inverse difference moment, energy, and correlation decreased (all <0.05). Entropy among different groups was significantly different (all <0.05), and the differences of T value, contrast, inverse difference moment, and energy between Weishaupt 0 and Weishaupt 1 groups, or Weishaupt 0 and Weishaupt 2-3 groups were statistically significant (all <0.05). Multivariate logistic regression analysis suggested that T value and inverse difference moment were the independent predictors for evaluating early degeneration of facet joints. The combination of T value with inverse difference moment achieved the best performance in distinguishing Weishaupt 0 from Weishaupt 1 (AUC=0.85), with sensitivity and specificity at 92.7% and 76.5%, respectively. In the symptom group, the cartilage T value combined inverse difference moment was positively correlated with JOA score (=0.475, <0.05) and VAS score (=0.452, <0.05). CONCLUSIONS 3.0T magnetic resonance imaging T mapping combined with texture analysis is helpful to quantitatively evaluate the early degeneration of lumbar facet joints, in which the T value and inverse difference moment show an indicative significance．.
Algorithms ; Humans ; Lumbar Vertebrae ; Magnetic Resonance Imaging ; Sensitivity and Specificity ; Spondylosis ; Zygapophyseal Joint

To explore the value of prostate imaging reporting and data system version 2 (PI-RADS V2) combined with quantitative parameters derived from apparent diffusion coefficient (ADC) map in the diagnosis of peripheral zone prostate cancer.
 Methods: A total of 50 patients who underwent prostate multiparametric MRI (mpMRI) with suspicious peripheral nodules were retrospectively enrolled, and all patients were biopsy-proven histologically. Two radiologists analyzed the position and category of peripheral zone lesions based on PI-RADS V2. Then 12 ADC quantitative parameters were calculated regarding each lesion on the ADC map by post-processing software. The lesions were divided into malignant group and benign group according to histopathological findings. The ADC quantitative parameters between groups were compared, and stepwise logistic regression analysis was used to build a discriminative model. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were performed to evaluate the diagnostic power and clinical benefit.
 Results: Twenty-eight peripheral zone prostate malignant lesions and 25 benign lesions were obtained finally. The area under the ROC curve, sensitivity and specificity to differentiate peripheral zone prostate malignant from benign lesions were as follows: 0.803, 60.71%, 92.00% (PI-RADS V2 score), 0.857, 89.29%, 76.00% (ADC model), and 0.891, 71.43%, 92.00% (combined model), respectively. The discriminative power of the combined model was significantly improved compared with PI-RADS V2 score (P=0.012). The combined model had relatively optimal overall net benefit, which outperformed the PI-RADS V2 score when threshold probability varied in the range of 0.05-0.27 and 0.46-0.81.
 Conclusion: PI-RADS V2 combined with quantitative analysis of ADC map improve the power in discriminating peripheral zone prostate cancer from benign lesions, and the clinical benefit as well.
Data Systems ; Diffusion Magnetic Resonance Imaging ; Humans ; Magnetic Resonance Imaging ; Male ; Prostatic Neoplasms ; diagnostic imaging ; Retrospective Studies

OBJECTIVES: Prediabetes is associated with an increased risk of cognitive impairment and neurodegenerative diseases. However, the exact mechanism of prediabetes-related brain diseases has not been fully elucidated. The brain structure of patients with prediabetes has been damaged to varying degrees, and these changes may affect the topological characteristics of large-scale brain networks. The structural covariance of connected gray matter has been demonstrated valuable in inferring large-scale structural brain networks. The alterations of gray matter structural covariance networks in prediabetes remain unclear. This study aims to examine the topological features and robustness of gray matter structural covariance networks in prediabetes. METHODS: A total of 48 subjects were enrolled in this study, including 23 patients with prediabetes (the PD group) and 25 age-and sex-matched healthy controls (the Ctr group). All subjects' high-resolution 3D T₁ images of the brain were collected by a 3.0 Tesla MR machine. Mini-mental state examination was used to evaluate the cognitive status of each subject. We calculated the gray matter volume of 116 brain regions with automated anatomical labeling (AAL) template, and constructed gray matter structural covariance networks by thresholding interregional structural correlation matrices as well as graph theoretical analysis. The area under the curve (AUC) in conjunction with permutation testing was employed for testing the differences in network measures, which included small world parameter (Sigma), normalized clustering coefficient (Gamma), normalized path length (Lambda), global efficiency, characteristic path length, local efficiency, mean clustering coefficient, and network robustness parameters. RESULTS: The network in both groups followed small-world characteristics, showing that Sigma was greater than 1, the Lambda was much higher than 1, and Gamma was close to 1. Compared with the Ctr group, the network of the PD group showed increased Sigma, Lambda, and Gamma across a range of network sparsity. The Gamma of the PD group was significantly higher than that in the Ctr group in the network sparsity range of 0.12-0.16, but there was no difference between the 2 groups (all P>0.05). The grey matter network showed an increased characteristic path length and a decreased global efficiency in the PD group, but AUC analysis showed that there was no significant difference between groups (all P>0.05). For the network separation measures, the local efficiency and mean clustering coefficient of the gray matter network in the PD group were significantly increased and AUC analysis also confirmed it (P=0.001 and P=0.004, respectively). In addition, network robustness analysis showed that the grey matter network of the PD group was more vulnerable to random damage (P=0.001). CONCLUSIONS The prediabetic gray matter network shows an increased average clustering coefficient and local efficiency, and is more vulnerable to random damage than the healthy control, suggesting that the topological characteristics of the prediabetes grey matter covariant network have changed (network separation enhanced and network robustness reduced), which may provide new insights into the brain damage relevant to the disease.
Humans ; Gray Matter/diagnostic imaging* ; Prediabetic State ; Magnetic Resonance Imaging ; Cerebral Cortex ; Brain