The impact of baseline calcified plaque volume on coronary rapid plaque progression by serial coronary computed tomography angiography in patients with type 2 diabetes.

OBJECTIVES: Patients with type 2 diabetes mellitus (T2DM) are susceptible to coronary artery disease (CAD), and coronary outcomes in these patients are heterogeneous. However, the impact of coronary plaque compositions on rapid plaque progression (RPP) in patients with T2DM has rarely been reported. This study aimed to investigate the association of coronary plaque compositions with rapid lesion volume progression in patients with T2DM. MATERIALS AND METHODS: A total of 159 subjects (aged 62.51 ± 10.3 years, 68.6% were male) who underwent serial coronary computed tomography angiography (CCTA) with type 2 diabetic status were enrolled. Annual change of plaque volume (PV) (mm3/year) was defined as PV change divided by inter-scan period. RPP was defined as the progression of plaque burden (PV divided by vessel volume multiplied by 100) ≥0.59%/year. Plaque components were compared between RPP and no RPP groups. Then all patients were divided into 3 groups according to the baseline calcified plaque volume tertiles. The outcome was whether RPP occurred. RESULTS: The median inter-scan period was 2.09 (range 1.41-3.33) years. The overall incidence of RPP was 61.0%. The calcified plaque volume decreased significantly in the RPP group as compared to the no RPP group. The risk of RPP (odds ratio [OR] 0.39; 95% confidence interval [CI]: 0.17-0.88; p = 0.024) was reduced in tertiles III as compared to that in tertiles I even after adjustment for baseline variables (OR 0.21; 95% CI: 0.07-0.63; p = 0.005). Moreover, adding the calcified plaque volume significantly raised the predictive value for the RPP (0.370, p = 0.030, and 0.059, p = 0.025, NRI, and IDI respectively) as compared to traditional factors. CONCLUSION: The baseline calcified plaque volume is an independent protective factor for the rapid progression of coronary atherosclerosis in patients with T2DM.

The calcified plaque volume of the coronary was significantly lower in T2DM subjects with RPP than in those without RPP.Higher levels of atherosclerotic calcification may have a protective value on plaque stabilization in patients with T2DM.Calcified plaque volume of the coronary should be considered when proposing risk stratification in T2DM patients.

Differentiating T2 hyperintensity in neonatal white matter by two-compartment model of diffusional kurtosis imaging.

In conventional neonatal MRI, the T2 hyperintensity (T2h) in cerebral white matter (WM) at term-equivalent age due to immaturity or impairment is still difficult to identify. To clarify such issue, this study used the metrics derived from a two-compartment WM model of diffusional kurtosis imaging (WM-DKI), including intra-axonal, extra-axonal axial and radial diffusivities (Da, De,// and De,⊥), to compare WM differences between the simple T2h and normal control for both preterm and full-term neonates, and between simple T2h and complex T2h with hypoxic-ischemic encephalopathy (HIE). Results indicated that compared with control, the simple T2h showed significantly increased De,// and De,⊥, but no significant change in Da in multiple premyelination regions, indicative of expanding extra-axonal diffusion microenvironment; while myelinated regions showed no changes. However, compared with simple T2h, the complex T2h with HIE had decreased Da, increased De,⊥ in both premyelination and myelinated regions, indicative of both intra- and extra-axonal diffusion alterations. While diffusion tensor imaging (DTI) failed to distinguish simple T2h from complex T2h with HIE. In conclusion, superior to DTI-metrics, WM-DKI metrics showed more specificity for WM microstructural changes to distinguish simple T2h from complex T2h with HIE.

Differentiation between Solitary Cerebral Metastasis and Astrocytoma on the Basis of Subventricular Zone Involvement on Magnetic Resonance Imaging.

PURPOSE: To determine the relationship between the subventricular zone (SVZ) and astrocytoma based on magnetic resonance imaging (MRI) and whether SVZ involvement can be used to distinguish solitary cerebral metastases (SCMs) from astrocytomas. METHODS: This retrospective study involved 154 patients with solitary low-grade astrocytoma (LGA), high-grade astrocytoma (HGA), and SCM, who underwent T1-weighted imaging (T1WI), Gd-DTPA-enhanced T1WI, and T2-weighted imaging (T2WI) or fluid-attenuated inversion recovery (FLAIR) T2WI. The spatial relationship between the tumor and SVZ was classified as "involvement" or "segregation" on contrast-enhanced T1WI for enhanced tumors and T2WI/FLAIR T2WI for non-enhanced tumors. Patient-based SVZ-contact rates were compared between the LGA, HGA, and SCM groups. The frequencies of involvement of various lateral ventricle regions by astrocytoma were compared. The correlation between SVZ involvement and tumor necrosis was analyzed. RESULTS: Patient-based SVZ-contact rates in SCM, LGA, and HGA were 24.1%, 68.8%, and 85.4%, respectively. Univariate analysis showed that the SVZ-contact rate was significantly different between SCM and astrocytoma (24.1% vs. 75.2% P < 0.001), also between LGA and HGA (68.1% vs. 85.4% P=0.037). After the tumor volume was adjusted as a covariate, SVZ-contact rates still differed between SCMs and astrocytomas (Odds ratio [OR]: 4.58, 95% Confidence interval [CI]: 1.65 to 12.8, P=0.004). Tumor volume differed between LGA and HGA (P< 0.001), and influenced the association between SVZ involvement and astrocytoma grade (P = 0.05). Among the lateral ventricle regions, the frontal horn was the most frequently involved by astrocytomas. SVZ-contact rates were higher in necrosis group compared with non-necrosis groups (83.9% vs. 50.0%, P < 0.001) among astrocytoma patients. Necrosis positively correlated with SVZ involvement in astrocytomas (rs = 0.342, P < 0.001), but did not correlate with SVZ involvement in SCMs (P = 0.193). CONCLUSIONS: Compared to SCMs, solitary cerebral astrocytomas exhibited spatial proximity to the SVZ, which might distinguish the supratentorial astrocytomas from SCMs.

Semi-quantitative assessment of brain maturation by conventional magnetic resonance imaging in neonates with clinically mild hypoxic-ischemic encephalopathy.

BACKGROUND: Mild hypoxic-ischemic encephalopathy (HIE) injury is becoming the major type in neonatal brain diseases. The aim of this study was to assess brain maturation in mild HIE neonatal brains using total maturation score (TMS) based on conventional magnetic resonance imaging (MRI). METHODS: Totally, 45 neonates with clinically mild HIE and 45 matched control neonates were enrolled. Gestated age, birth weight, age after birth and postmenstrual age at magnetic resonance (MR) scan were homogenous in the two groups. According to MR findings, mild HIE neonates were divided into three subgroups: Pattern I, neonates with normal MR appearance; Pattern II, preterm neonates with abnormal MR appearance; Pattern III, full-term neonates with abnormal MR appearance. TMS and its parameters, progressive myelination (M), cortical infolding (C), involution of germinal matrix tissue (G), and glial cell migration bands (B), were employed to assess brain maturation and compare difference between HIE and control groups. RESULTS: The mean of TMS was significantly lower in mild HIE group than it in the control group (mean ± standard deviation [SD] 11.62 ± 1.53 vs. 12.36 ± 1.26, P < 0.001). In four parameters of TMS scores, the M and C scores were significantly lower in mild HIE group. Of the three patterns of mild HIE, Pattern I (10 cases) showed no significant difference of TMS compared with control neonates, while Pattern II (22 cases), III (13 cases) all had significantly decreased TMS than control neonates (mean ± SD 10.56 ± 0.93 vs. 11.48 ± 0.55, P < 0.05; 12.59 ± 1.28 vs. 13.25 ± 1.29, P < 0.05). It was M, C, and GM scores that significantly decreased in Pattern II, while for Pattern III, only C score significantly decreased. CONCLUSIONS: The TMS system, based on conventional MRI, is an effective method to detect delayed brain maturation in clinically mild HIE. The conventional MRI can reveal the different retardations in subtle structures and development processes among the different patterns of mild HIE.

EADC Values in Diagnosis of Renal Lesions by 3.0 T Diffusion-Weighted Magnetic Resonance Imaging: Compared with the ADC Values.

Exponential apparent diffusion coefficient (EADC) is an indicator of diffusion-weighted imaging (DWI) and reflects the pathological changes of tissues quantitatively. However, no study has been investigated in the space-occupying kidney disease using EADC values. This study aims to evaluate the diagnostic role of EADC values at a high magnetic field strength (3.0 T) in kidney neoplastic lesions, compared with that of the ADC values. Ninety patients with suspected renal tumors (including 101 suspected renal lesions) and 20 healthy volunteers were performed MRI scanning. Diffusion-weighted imaging was performed with a single-shot spin-echo echo-planar imaging (SE-EPI) sequence at a diffusion gradient of b = 500 s/mm2. We found renal cell carcinoma (RCC) can be distinguished from angiomyolipoma, and clear cell carcinoma can be distinguished from non-clear cell carcinoma by EADC value. There was significant difference in overall EADC values between renal cell carcinoma (0.150 ± 0.059) and angiomyolipoma (0.270 ± 0.108) when b value was 500 s/mm2. When receiver operating characteristic (ROC) was higher than 0.192, the sensitivity and specificity of EADC value of renal cell carcinoma were 84.6 and 81.1 %, respectively. In conclusion, EADC map shows the internal structure of the kidney tumor more intuitively than the ADC map dose, and is also in line with the observation habits of the clinicians. EADC can be used as an effective imaging method for tumor diagnosis.

[Functional MRI study on thalamus activation induced by electrical stimulation of different intensities].

OBJECTIVE: To detect the activation pattern of the thalamus in human by the functional magnetic resonance imaging (fMRI) with the electrical stimulation of different intensities, and to explore the mechanism of this area in pain modulation. METHODS: Ten healthy right-handed volunteers were given different electrical stimulations of 1-, 2-, and 3- times pain threshold respectively. The whole-brain was scanned simultaneously by GE 1.5T magnetic resonance imaging system. The data were postprocessed by analysis of functional neuroimages (AFNI) to establish the regional activity maps of the thalamus. RESULTS: Patterns of functional activity showed a positive linear relationship between the activation signals and stimulation intensity in bilateral thalamus, whereas the BOLD signal of bilateral medial thalamus demonstrated that the curve was similar to the exponential function. Meanwhile, the activation in the contralateral lateral thalamus (cThl), but not the contralateral medial thalamus (cThm), was prominent compared with the corresponding ipsilateral subregions, and only the lateral thalamus displayed a contralateral biased representation while the medial thalamus lacked this property. CONCLUSION: Thalamus is one of the vital components in the pain modulation network, which can present spatial segregation activations with unique characteristics of stimulation intensity-response in each subregion. All the results are helpful to understand the crucial role of thalamus in processing the pain information.

[Anterior cingulate cortex involving in pain modulation-an functional magnetic resonance imaging study].

OBJECTIVE: To investigate the functional activation patterns of the subregions of anterior cingulate cortex (ACC) in human to electrical stimulation of different intensity with functional Magnetic Resonance Imaging (fMRI) and probe the contribution of this area in pain modulation network. METHODS: 10 healthy right-handed volunteers were studied with different electrical intensity stimulation of 1-, 2-, or 3-time pain threshold. The fMRI data were collected by GE signa 1.5T MRI system and postprocessed with software of Analysis of Functional Neuroimages (AFNI) to generate the regional activation maps of ACC, furthermore, the distinctive characteristics of stimulation-BOLD signal in ACC subregions were analyzed according to the fMRI maps from the average of the 10 subjects. RESULTS: The anterior portion of ACC (aACC) showed moderate pain-attention-related activation but not statistically related to the strength of stimulation (average activated pixels of P1, P2, P3 amounted to 324, 429, 562 respectively). The BOLD signal showed a positive linear relation with the increasing stimulation at the dorsal-posterior portion of ACC (average activated pixels of P1, P2, P3 were 311, 964, 1414), which indicated stimulus intensity-dependent responses. The ventral-posterior area of ACC (vpACC) demonstrated pain intensity encoding because the BOLD signal had no significant difference during innocuous condition but displayed remarkable distinction during noxious stimulation in this area (average activated pixels of P1, P2, P3 were 324, 429, 562). CONCLUSION: Subregions in ACC may play a varied role in the network of pain modulation. Each area of ACC displays segregated activation patterns in response to electrical stimulation with different strength.