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ObjectiveTo assess the microstructural involvement of gray matter in recovered COVID-19 patients using Synthetic MRI. MethodsThis study was conducted in 29 recovered COVID-19 patients， including severe group （SG， n=11） and ordinary group （OG， n=18）. Healthy volunteers matched by age， sex， BMI and years of education were selected as a healthy control group （HC=23 cases）. Each subject underwent synthetic MRI to generate quantitative T1 and T2 maps， and the T1 and T2 maps were segmented into 90 regions of interest （ROIs） using automatic anatomical labeling （AAL） mapping. T1 and T2 values for each ROI were obtained by averaging all voxels within the ROIs. The T1 and T2 values of the 90 brain regions between the three groups were compared. ResultsRelative to HC， the SG had significantly higher T2 values in bilateral orbital superior frontal gyrus， bilateral parahippocampal gyrus， bilateral putamen， bilateral middle temporal gyrus， bilateral Inferior temporal gyrus， left orbital superior frontal gyrus， left orbital inferior frontal gyrus， left gyrus rectus， left anterior cingulate and paracingulate gyri， right median cingulate and paracingulate gyri， left posterior cingulate gyrus， and left supramarginal gyrus （P＜0.05）； Relative to OG， SG showed significantly increased T2 values in the left rectus gyrus， left parahippocampal gyrus， bilateral middle temporal gyrus， and bilateral inferior temporal gyrus （P＜0.05）. Relative to HC， the T1 values of SG were significantly increased in bilateral orbital superior frontal gyrus， left rectus gyrus， left anterior cingulate and paracingulate gyri， right posterior cingulate gyrus， left parahippocampal gyrus， left lingual gyrus， left putamen， left thalamus（P＜0.05）； Relative to OG， the T1 values of SG were significantly higher in the right posterior cingulate gyrus， right calcarine fissure and surrounding cortex， and left putamen （P＜0.05）. ConclusionsEven after recovering from COVID-19， patients may still have persistent or delayed damage to their brain gray matter structure， which is correlated with the severity of the condition. SyMRI can serve as a sensitive tool to assess the extent of microstructural damage to the central nervous system， aiding in early diagnosis of the disease.
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Objective:To explore the value of synthetic MRI and dynamic contrast-enhanced MRI (DCE-MRI) in differentiating benign and malignant breast lesions.Methods:Totally 116 patients (female, aged 22-80 years) with suspicious breast lesions found by clinical examination in General Hospital of Ningxia Medical University from September 2020 to March 2021 were retrospectively analyzed. All patients received synthetic MRI and DCE-MRI scans, and the quantitative parameters of synthetic MRI [T 1, T 2, proton density (PD) value before enhancement of breast lesions (T 1pre, T 2pre, PD pre) and T 1, T 2, PD value after enhancement of breast lesions (T 1Gd, T 2Gd, PD Gd)] were measured. The difference before and after enhancement (?T 1, ?T 2, ?PD) and the ratio before and after enhancement(T 1ratio, T 2ratio, PD ratio) were calculated. All lesions were confirmed by biopsy or surgery. Independent sample t test was used to compare the differences of parameters between benign and malignant lesions, and parameters with statistically significant differences were analyzed by multivariate logistic regression to screen out independent predictors for the diagnosis of breast malignant lesions. The efficacy of quantitative parameters alone and in combination with DCE-MRI, was evaluated by the receiver operating characteristic (ROC) curve. Results:Of 116 patients, 27 patients were benign and 89 patients were malignant. T 2pre, PD pre, T 2Gd, PD Gd, ?T 2, T 1ratio and T 2ratio values of malignant patients were lower than those of benign lesions ( P<0.05). Multivariate logistic regression analysis showed that T 2pre (OR=0.961,95%CI 0.926-0.993, P=0.022)and PD pre(OR=0.945, 95%CI 0.908-0.979, P=0.003) were independent predictors of breast malignant lesions. The area under ROC curve (AUC) of T 2pre+PD pre in differentiating benign and malignant breast lesions was 0.77, and the accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 0.84, 0.87, 0.68, 0.92 and 0.56, respectively. The AUC of T 2pre+PD pre combined with DCE-MRI in differentiating benign and malignant breast lesions was 0.95, indicating the best diagnostic efficiency, and higher than that of DCE-MRI alone (0.92)( Z=2.20, P<0.05). Conclusions:T 2pre and PD pre values of synthetic MRI can be used as reference parameters for differentiating benign and malignant breast lesions. Synthetic MRI combined with DCE-MRI can effectively improve the diagnostic efficiency of breast malignant lesions.
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Objective:To investigate the diagnostic value of quantitative parameters of synthetic MRI in patients with prostate cancer (PCa).Methods:From April 2018 to April 2019, 25 PCa patients confirmed by whole-mount pathology were prospectively enrolled in Beijing Hospital. All patients underwent prostate MRI examinations including DWI and synthetic MRI. Four kinds of tissue types were identified in pathology, including PCa, stromal hyperplasia (SH), glandular hyperplasia (GH) and prostatitis. According to the pathological results, quantitative parameters including ADC, T 1, T 2 and proton density (PD) values were measured on DWI and synthetic MRI. One-way analysis of variance or Kruskal-Wallis H test was performed to compare the difference of each parameter among PCa, SH or GH in the transitional zone (TZ). The difference of each parameter between PCa and prostatitis in the peripheral zone (PZ) was evaluated by using independent sample t test or Mann-Whitney U test. The diagnostic performance of each parameter in discriminating PCa from other benign conditions was evaluated by using ROC curve. Area under the curve (AUC) of each parameter was compared by using DeLong test. Results:The overall differences of T 1, T 2 PD and ADC values were statistically significant among PCa and other benign conditions. The T 1, T 2 and ADC values of PCa in the TZ were lower than those in the SH ( P=0.041, 0.030,<0.001) and GH (all P<0.001). The PD value of PCa in the TZ was lower than that in the GH ( P=0.040). The differences of T 1, T 2, PD and ADC values between PCa and prostatitis in the PZ were significant ( P<0.05). The AUC of ADC value (0.943) was higher than that of T 1 (0.691, P=0.001), PD (0.555, P=0.002) and T 2 (0.754, P=0.016) values in differentiating PCa from SH. For discriminating PCa and GH, T 1, T 2 and ADC showed similar AUC ( P>0.05), which were higher than AUC of PD value ( P=0.001). For discriminating PCa and prostatitis, T 1, T 2, PD and ADC values showed similar AUC ( P>0.05). Conclusions:Quantitative parameters of synthetic MRI were practical tools for discriminating PCa from other benign pathologies.
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OBJECTIVE: To evaluate the feasibility of synthetic magnetic resonance imaging (MRI) compared to conventional MRI for the diagnosis of internal derangements of the knee at 3T. MATERIALS AND METHODS: Following Institutional Review Board approval, image sets of conventional and synthetic MRI in 39 patients were included. Two musculoskeletal radiologists compared the image sets and qualitatively analyzed the images. Subjective image quality was assessed using a four-grade scale. Interobserver agreement and intersequence agreement between conventional and synthetic images for cartilage lesions, tears of the cruciate ligament, and tears of the meniscus were independently assessed using Kappa statistics. In patients who underwent arthroscopy (n = 8), the sensitivity, specificity, and accuracy for evaluated internal structures were calculated using arthroscopic findings as the gold standard. RESULTS: There was no statistically significant difference in image quality (p = 0.90). Interobserver agreement (κ = 0.649– 0.981) and intersequence agreement (κ = 0.794–0.938) were nearly perfect for all evaluated structures. The sensitivity, specificity, and accuracy for detecting cartilage lesions (sensitivity, 63.6% vs. 54.6–63.6%; specificity, 91.9% vs. 91.9%; accuracy, 83.3–85.4% vs. 83.3–85.4%) and tears of the cruciate ligament (sensitivity, specificity, accuracy, 100% vs. 100%) and meniscus (sensitivity, 50.0–62.5% vs. 62.5%; specificity, 100% vs. 87.5–100%; accuracy, 83.3–85.4% vs. 83.3–85.4%) were similar between the two MRI methods. CONCLUSION: Conventional and synthetic MRI showed substantial to almost perfect degree of agreement for the assessment of internal derangement of knee joints. Synthetic MRI may be feasible in the diagnosis of internal derangements of the knee.