Short-term MRI texture features of medial femoral cartilage after anterior cruciate ligament reconstruction / 中华创伤杂志

Objective:To investigate MRI texture features reflecting short-term medial femoral cartilage variations after anterior cruciate ligament (ACL) reconstruction.Methods:A retrospective case series analysis was conducted referring to the data of 20 patients who received ACL reconstruction at First Affiliated Hospital of Fujian Medical University from January 2017 to January 2020 including 17 males and 3 females, aged 23-43 years [(32.1±5.4)years]. The patients were evaluated before operation and at 1, 4, 12, 24, 48 weeks after operation: (1) the region of interest (ROI) in medial femoral cartilage was divided into ROI1 (meniscus anterior horn cartilage), ROI2 (meniscus body cartilage) and ROI3 (meniscus posterior horn cartilage) according to MRI image acquisition of the affected knee. The texture feature parameters were extracted for screening and analyzing to obtain the parameters reflecting sensitivity to cartilage variations; (2) the level of urinary C-telopeptide of type II collagen (uCTX-II) was measured by ELISA. At different time points, differences in texture feature parameters were compared to screen the parameters most sensitive to cartilage variations, and uCTX-II level were compared as well. Then, Pearson correlation analysis was used to determine the correlation between texture feature parameters most sensitive to cartilage variations and uCTX-II level.Results:After screening and analyzing, the horizontal direction of gray level non-uniformity (Horzl_GlevNonU) and Skewness of histogram (Skewness) of ROI3 were selected as sensitive texture feature parameters reflecting sensitivity to cartilage variations. There were significant difference in the Horzl_GlevNonU and Skewness of ROI3 before operation and at 1, 4, 12, 24, 48 weeks after operation (all P<0.05). Meanwhile, the Horzl_GlevNonU and Skewness of ROI3 were gradually increased over time, with a more significant tendency in the Horzl_GlevNonU. The Horzl_GlevNonU of ROI3 was similar at 4 weeks and 12 weeks after operation ( P>0.05), with significant differences at other time points (all P<0.05). The Skewness of ROI3 was significantly different at 1 week and 48 weeks after operation ( P<0.05), with insignificant differences at other time points (all P>0.05). The Horzl_GlevNonU of ROI3 was selected as the most sensitive texture feature parameter reflecting cartilage variations. Significant difference was reported in uCTX-II level before operation and at 1, 4, 12, 24, 48 weeks after operation (all P<0.05). After Pearson correlation analysis, the Horzl_GlevNonU of ROI3 was positively correlated with uCTX-II level before operation and at 1, 4, 12, 24, 48 weeks after operation ( r=0.554, 0.596, 0.550, 0.632, 0.756, 0.514, P<0.05 or 0.01). Conclusion:The Horzl_GlevNonU of ROI3 is the most sensitive texture feature parameter that reflects the early variations of medial femoral cartilage after ACL reconstruction and is positively correlated with uCTX-II level.

Prediction of nuclear grade of renal clear cell carcinoma based on MRI texture analysis in combination with imaging features / 中华放射学杂志

Objective:To explore the application value of MRI texture analysis in combination with imaging features to predict the WHO/International Society of Urological Pathology (ISUP) nuclear grading in pre-operative patients with clear cell renal carcinoma (ccRCC).Methods:MRI images of 78 patients diagnosed as ccRCC by surgical pathology from July 2016 to July 2020 in First Affiliated Hospital of Fujian Medical University were retrospectively analyzed. According to the WHO/ISUP grading system, the patients were divided into low grade group (49 cases, grade Ⅰ in 2 cases and grade Ⅱ in 47 cases) and high grade group (29 cases, grade Ⅲ in 25 cases and grade Ⅳ in 4 cases), and then were assigned to training set ( n= 63) and validation set ( n=15) in a ratio of 7∶3 using random indicator method. MRI radiological features were evaluated and MRI imaging texture features were extracted. The largest-diameter slice of lesion on cross-sectional images was selected and ROIs were drawn on T 2WI and corticomedullary phase (CMP) images, respectively. Quantitative texture analysis software MaZda was used to extract texture features, including gray-scale histogram, co-occurrence matrix, run-length matrix, gradient, autoregressive model and wavelet transform. The extracted texture features were preliminarily selected by the combination of Fisher, probability of classification errorand average correlation coefficient, and interaction information, and then the reduced texture parameters or imaging features were tested by the independent sample t test, Mann-Whitney U test or χ 2 test. Parameters with statistically significant differences were used to construct a multi-factors binary logistic regression model and the ROC curve was used to analyze its effectiveness in predicting high grade ccRCC. Results:In training set, there were significant differences intumor length, shape and margin, enhancement degree of CMP, vein thrombosis and 47 texture features between the low and high grade ccRCC groups. In the training set, 7 multi-factors binary logistic regression model were constructed, including radiological features model (M1), T 2WI texture features model (M2), CMP image texture features model (M3) and combination radiological features of T 2WI texture features model (M4), combination radiological features of CMP images texture features model (M5), combination T 2WI texture features of CMP images texture features model (M6) and combination of all features model (M7). The area under ROC curve of M7 in predicting nuclear grading of ccRCC was the largest, which were 0.901 (95% CI 0.828-0.974) and 0.820 (95% CI 0.564-0.974) in the training set and validation set, respectively. Conclusion:MRI texture analysis combined with imaging features is hopeful to be an effective preoperative noninvasive method in predicting WHO/ISUP grading of ccRCC.

A clinical study of 135 patients with cerebral vascular fenestrations / 中华神经科杂志

Objective To characterize the imaging features of cerebral vascular fenestrations and the clinical features of patients with cerebral infarction.Methods We retrospectively analyzed the magnetic resonance or CT imaging data of 135 cases of cerebral vascular fenestrations from January 2015 to July 2017 in the First Affiliated Hospital of Fujian Medical University.The location,morphology and the other associated vascular diseases were described.The patients who had cerebral infarction were also analyzed.Results One hundred and thirty-five fenestrations were noted at our institution,129 in arteries,and six in veins,the detection rate being 1.1％ (135/12 232).Basilar arteries were most common,which accounted for 53.3％ (72/129) of the fenestrations.Twenty-eight (20.7％) of these patients had other vascular malformations,with a total of 15 aneurysms,two moyamoya diseases,five venous malformations,two arteriovenous fistulas,and four cavernous hemangiomas.Nine patients had cerebral infarctions,of which five patients had fenestration-relevant cerebral infarctions,and no risk factors for cerebral infarctions were found except fenestration in one patient who was diagnosed with cryptogenic stroke.No acute cerebral infarctions or transient ischemic attack occurred in patients with fenestration-relevant cerebral infarctions who had long-term antiplatelet and statin therapy during follow-up.Conclusions Cerebral vascular fenestrations occur most frequently in the basilar artery and may combine with other malformations.Long-term antiplatelet and statin therapy can be used for cerebral infarctions patients with cerebral vascular fenestrations.

Preliminary application of multi-slice CT direct venography in lower extremity vein / 中国医学影像技术

Objective To discuss the injective method, contrast agent concentration and delay time of MSCT direct venography in lower extremity vein, in order to make optimal venographic schedule. Methods Thirty-two patients with lower extremity vein diseases underwent MSCT direct venography in using different concentration and injective rate of contrast agent, and the images were analyzed. The displaying ability of MSCT direct venography in lower extremity vein segment was compared with that of X-ray venography in 22 patients. Results Blood flow correlation constructed defect was the main factor impacting image quality of CT venography in lower extremity. The image scores between the groups of injective rate 1.5 ml/s and the group of 2.5 ml/s were statistically different (χ~2=5.495, P=0.019), whereas no difference of image score was found between the group of concentration of 25% and 15% (χ~2=3.333, P=0.068). The displaying ability of CT and X-ray venography in anterior tibial vein, posterior tibial vein, popliteal vein and femoral vein was not statistically different (χ~2=2.095, P=0.148). For iliac vein, the displaying ability of CT outstripped that of X-ray venography (χ~2=8.324, P=0.004). Conclusion With the schedule of delay time 50 s, injective rate 2.5 ml/s and concentration 45 mgI/ml (nonionic 300 mgI/ml and diluted 15%), MSCT direct venography in lower extremity can acquire satisfactory image, and its displaying ability of iliac vein is better than that of X-ray venography.