Prediction of microvascular invasion in hepatocellular carcinoma with magnetic resonance imaging using models combining deep attention mechanism with clinical features / 南方医科大学学报

OBJECTIVE@#To investigate the consistency and diagnostic performance of magnetic resonance imaging (MRI) for detecting microvascular invasion (MVI) of hepatocellular carcinoma (HCC) and the validity of deep learning attention mechanisms and clinical features for MVI grade prediction.@*METHODS@#This retrospective study was conducted among 158 patients with HCC treated in Shunde Hospital Affiliated to Southern Medical University between January, 2017 and February, 2020. The imaging data and clinical data of the patients were collected to establish single sequence deep learning models and fusion models based on the EfficientNetB0 and attention modules. The imaging data included conventional MRI sequences (T1WI, T2WI, and DWI), enhanced MRI sequences (AP, PP, EP, and HBP) and synthesized MRI sequences (T1mapping-pre and T1mapping-20 min), and the high-risk areas of MVI were visualized using deep learning visualization techniques.@*RESULTS@#The fusion model based on T1mapping-20min sequence and clinical features outperformed other fusion models with an accuracy of 0.8376, a sensitivity of 0.8378, a specificity of 0.8702, and an AUC of 0.8501 for detecting MVI. The deep fusion models were also capable of displaying the high-risk areas of MVI.@*CONCLUSION@#The fusion models based on multiple MRI sequences can effectively detect MVI in patients with HCC, demonstrating the validity of deep learning algorithm that combines attention mechanism and clinical features for MVI grade prediction.

Present status and future prospect of accreditation of proficiency testing provider in the area of laboratory medicine in China / 中华检验医学杂志

The accreditation of Proficiency Testing Provider ( PTP) has gone through more than a decade in China.Over the past ten years, from nonexistence to existence, the domestic PTPs in the area of laboratory medicine have gradually standardized and developed.By reviewing the international and domestic practice, this paper gives an outline of the present status of the accreditation of PTP in the area of laboratory medicine, explores the difference with other countries, the main problems and some suggestions for improvement, and makes a prospect of the development of the accreditation of PTP in the area of laboratory medicine in China.

Determination of urine oxalate level in rats with renal calcium oxalate calculus by high-performance liquid chromatography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a method of high-performance liquid chromatography (HPLC) for determining the urine oxalate levle in rats with renal calcium oxalate calculus.</p><p><b>METHODS</b>Totally 24 SPF Wistar healthy male rats were randomly divided into control group(n=12)and ethylene glycol (EG) group (n=12). Rats in EG group were administered intragastrically with 2% ammonium chloride (AC)2 ml/rat per day+1% ethylene glycol (EG), along with free access to drinking water.The control group was fed with deionized water, along with the intragastric administration of normal saline (1 ml per day). Twenty-eight days after modelling, the 24-hour urine samples were collected, and the urine oxalic acid levels were determined using HPLC and the results were compared with those of catalytic spectrophotometry using oxidation of methyl. During the HPLC, the samples were separated on Aglient 5TC-C18 (250×4.6 mm,5 Μm), eluted with mixture of methanol (0.1 mol/L) and ammonium acetate (15:85) at 1.2 ml/min, and detected at 314 nm, with the column temperature being 20 ℃.</p><p><b>RESULTS</b>The standard curves of high and low concentrations of oxalic acid were y=5909.1x+378730, R² =0.9984 and y=7810.5x-16635, R² =0.9967,respectively. The lowest detectable concentration in this method was 5 Μg/ml. The linear high concentration range of oxalate stood at 62.50-2000.00 Μg/ml, and the linear low concentration range of oxalate stood at 6.25-100.00 Μg/ml. Its average recovery was 95.1%, and its within-day and day-to-day precisions were 3.4%-10.8% and 3.8%-9.4%. Both HPLC and catalytic spectrophotometry showed significantly higher urinary oxalic acid concentration and 24 h urine oxalate level in EG group compared with the control group [urinary oxalic acid concentration: (736.35 ± 254.52) Μg/ml vs.(51.56 ± 36.34) Μg/ml,(687.35 ± 234.53) Μg/ml vs.(50.24 ± 42.34) Μg/ml;24 h urine oxalate level: (11.23 ± 4.12)mg vs.(0.87 ± 0.45)mg,(9.89 ± 3.55)mg vs. (0.77 ± 0.65)mg; all P<0.01]. No statistically significant difference was observed in the results of urinary oxalate concentration and 24 h urine oxalate level between HPLC and potassium chromate oxidation of methyl red spectrophotometry (all P>0.05).</p><p><b>CONCLUSION</b>HPLC is a simple, rapid, and precise method in detecting urine oxalate level in rats with renal calcium oxalate calculus, with high recovery rate.</p>