ABSTRACT
Objective:To investigate the feasibility of chest ultra-low dose CT (ULDCT) using deep learning reconstruction (DLR) for lung cancer screening, and to compare its image quality and nodule detection rate with ULDCT iterative reconstruction (Hybrid IR) and conventional dose CT (RDCT) Hybrid IR.Methods:The patients who underwent chest CT examination for pulmonary nodules in Peking Union Medical College Hospital from October 2020 to March 2021 were prospectively included and underwent chest RDCT (120 kVp, automatic tube current), followed by ULDCT (100 kVp, 20 mA). The RDCT images were reconstructed with Hybrid IR (adaptive iterative dose reduction 3D,AIDR 3D), and ULDCT was reconstructed with AIDR3D and DLR. Radiation dose parameters and nodule numbers were recorded. Image quality was assessed using objective noise, signal-to-noise ratio (SNR) of the main trachea and left upper lobe, subjective image scores of the lung and nodules. Subjective scores were scored by 2 experienced radiologists on a Likert 5-point scale. The difference of radiation dose was compared with paired t-test between ULDCT and RDCT.The differences of quantitative indexes, objective image noise and subjective scores of the three reconstruction methods were compared with one-way analysis of variance or Friedman test. Results:Forty-five patients were enrolled, including 17 males and 28 females, aged from 32 to 74 (55±11) years. The radiation dose of ULDCT was (0.17±0.01) mSv, which was significantly lower than that of RDCT [(1.35±0.41) mSv, t=15.46, P<0.001]. There were significant differences in the image noise and SNR in the trachea and lung parenchyma and in the CT value of the trachea among ULDCT-AICE, ULDCT-AIDR 3D and RDCT-AIDR 3D images ( P<0.05). Image noise in the trachea and lung parenchyma and CT value in the trachea of ULDCT-AICE were significantly lower than those of ULDCT-AIDR 3D ( P<0.05) and comparable to RDCT-AIDR 3D ( P>0.05). There were significant differences in subjective image scores of the lung and nodules among ULDCT-AICE, ULDCT-AIDR 3D and RDCT-AIDR 3D images (χ2=50.57,117.20, P<0.001). Subjective image scores of the lung and nodules for ULDCT-AICE were significantly higher than those of ULDCT-AIDR 3D ( P<0.05), and non-inferior to RDCT-ADIR 3D ( P>0.05). All 72 clinically significant nodules detected on RDCT-ADIR 3D were also noted on ULDCT-AICE and ULDCT-AIDR 3D images. Conclusions:Chest ULDCT using DLR can significantly reduce the radiation dose, and compared with Hybrid IR, it can effectively reduce the image noise and improve SNR, and display the pulmonary nodules well. The image quality and nodule detection are not inferior to RDCT Hybrid IR routinely used in clinical practice.
ABSTRACT
Objective:To explore the effect of deep learning reconstruction (DLR) on radiation dosage reduction and image quality of CTPA compared with hybrid iterative reconstruction (HIR).Methods:A total of 100 patients with suspected pulmonary embolism (APE) or indications for CTPA due to other pulmonary artery diseases in Peking Union Medical College Hospital from December 2020 to April 2021 were prospectively enrolled and divided into HIR group and DLR group according to block randomization, with 50 cases in each group. The patient′s gender, age and body mass index (BMI) were recorded. HIR group and DLR group underwent standard deviation (SD)=8.8 and SD=15 CTPA protocols in combination with HIR and DLR algorithm respectively. Other scanning parameters and contrast medium injection plan were the same. The effective dose (ED) and size-specific dose estimate (SSDE) were calculated. Regions of interest (ROIs) were drawn in the lumen of Grade 1-3 pulmonary arteries and bilateral paravertebral muscles. The corresponding CT and SD values were recorded to acquire signal to noise ratio (SNR) and contrast noise ratio (CNR). Based on a double-blind method, two radiologists evaluated the subjective noise, visualization of pulmonary arteries, and diagnostic confidence of the two groups by 5-point Likert scales. The inconsistent results were judged comprehensively by the third radiologist. Independent samples t-test was used to compare the demographic data, radiation dosage and quantitative image quality of the two groups. Mann-Whitney U test was used to compare the subjective noise, visualization of pulmonary arteries and diagnostic confidence between the two groups. Linear weighted Kappa coefficient was calculated to analyze the consistency of the qualitative scores between the two radiologists. Results:There were no significant differences in gender, age and BMI between the two groups ( P>0.05). The CT values of Grade1-3 pulmonary arteries and paravertebral muscle had no significant differences ( P>0.05). Compared with HIR group, the ED and SSDE in DLR group decreased by about 35% to 1.3 mSv and 4.20 mGy respectively, while the SNR (30±5) and CNR (26±5) of CTPA images were higher in DLR group than those in HIR group (23±5 and 20±5, with t=-6.60 and -5.90, respectively, both P<0.001). The subjective noise score was higher in DLR group than that in HIR group ( Z=-7.34, P<0.001). In addition, two radiologists showed excellent interobserver agreement in DLR group (Kappa=0.847, 95%CI 0.553-1.000). No significant differences were found in visualization of pulmonary arteries and diagnostic confidence between the two groups ( P>0.05). Conclusion:DLR further reduced the radiation dosage and improved the image quality of CTPA, with no detriment to diagnostic confidence. Thus DLR is worthy of clinical promotion.
ABSTRACT
Objective:To evaluate the effectiveness of deep learning reconstruction (DLR) compared with hybrid iterative reconstruction (Hybrid IR) in improving the image quality in chest low-dose CT (LDCT).Methods:Seventy-seven patients who underwent LDCT scan for physical examination or regular follow-up in Peking Union Medical College Hospital from October 2020 to March 2021 were retrospectively included. The LDCT images were reconstructed with Hybrid IR at standard level (Hybrid IR Stand) and DLR at standard and strong level (DLR Stand and DLR Strong). Regions of interest were placed on pulmonary lobe, aorta, subscapularis muscle and axillary fat to measure the CT value and image noise. The signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated. Subjective image quality was evaluated using Likert 5-score method by two experienced radiologists. The number and features of ground-glass nodule (GGN) were also assessed. If the scores of the two radiologists were inconsistent, the score was determined by the third radiologist. The objective and subjective image evaluation were compared using the Kruskal-Wallis test, and the Bonferroni test was used for multiple comparisons within the group.Results:Among Hybrid IR Stand, DLR Stand and DLR Strong images, the CT value of pulmonary lobe, aorta, subscapularis muscle and axillary fat had no significant differences (all P>0.05), but the image noise and SNR of pulmonary lobe, aorta, subscapularis muscle and axillary fat had significant differences(all P<0.05), and the CNR of images had significant difference( P<0.05), too. The CNR of Hybrid IR Stand images, DLR stand images and DLR strong images were 0.71 (0.49, 0.88), 1.06 (0.78, 1.32) and 1.14 (0.84, 1.48), respectively. Compared with Hybrid IR images, DLR images had lower objective and subjective image noise,higher SNR and CNR (all P<0.05). The scores of DLR images were superior to Hybrid IR images in identifying lung fissures, pulmonary vessels, trachea and bronchi, lymph nodes, pleura, pericardium and GGN (all P<0.05). Conclusions:DLR significantly reduced the image noise, and DLR images were superior to Hybrid IR images in identifying GGN in chest LDCT while maintaining superior image quality at relatively low radiation dose levels. Thus DLR images can improve the safety of lung cancer screening and pulmonary nodule follow-up by CT.
ABSTRACT
To summarize the clinical characteristics and chest CT findings of coronavirus disease 2019(COVID-19)patients in Peking Union Medical College Hospital(PUMCH). A total of 13 patients with COVID-19 confirmed at PUMCH from January 20 to February 6,2020 were selected as the research subjects.Their epidemiological histories,clinical characteristics,laboratory tests,and chest CT findings were analyzed retrospectively.The location,distribution,density,and other accompanying signs of abnormal lung CT lesions were recorded,and the clinical types of these patients were assessed. The clinical type was "common type" in all these 13 patients aged(46.8±14.7)years(range:27-68 years).Ten patients had a travel history to Wuhan or direct contact with patients from Wuhan,2 cases had recent travel histories,and 1 case had a travel history to Beijing suburb.The white blood cell(WBC)count was normal or decreased in 92.3% of the patients and the lymphocyte count decreased in 15.4% of the patients.Twelve patients(92.3%)had a fever,among whom 11 patients were admitted due to fever and 2 patients(15.4%)had low fever.Eight patients(61.5%)had dry cough.The CT findings in these 13 patients were all abnormal.The lesions were mainly distributed along the bronchi and under the pleura.The lesions were relatively limited in 8 patients(affecting 1-3 lobes,predominantly in the right or left lower lobe),and diffuse multiple lesions of bilateral lungs were seen in 5 patients.The CT findings mainly included ground glass opacities(GGOs)(=10,76.9%),focal consolidation within GGOs(=7,53.8%),thickened vascular bundle passing through the lesions(=10,76.9%),bronchial wall thickening(=12,92.3%),air bronchogram(=10,76.9%),vacuole signs in the lesions(=7,53.8%),fine reticulation and interlobular septal thickening(=3,23.1%),reversed halo-sign(=2,15.4%),crazy-paving pattern(=2,15.4%),and pleural effusion(=2,15.4%). Most of our patients diagnosed with COVID-19 at PUMCH had a travel history to Wuhan or direct contact with patients from Wuhan.The first symptoms of COVID-19 mainly include fever and dry cough,along with normal or reduced counts of WBC and lymphocytes.CT may reveal that the lesions distribute along the bronchi and under the pleura;they are typically localized GGOs in the early stage but can become multiple GGOs and infiltrative consolidation in both lungs in the advanced stage.Scattered vacuole signs may be visible inside the lesions in some patients.
Subject(s)
Adult , Aged , Humans , Middle Aged , Betacoronavirus , Coronavirus Infections , Diagnostic Imaging , Lung , Pandemics , Pneumonia, Viral , Diagnostic Imaging , Retrospective Studies , Tomography, X-Ray ComputedABSTRACT
Objective To investigate the effect of the levels of serum high sensitive C reactive protein and its clinical effect by bifidobacteria combined zinc in the treatment children with diarrhea.Methods 100 children with diarrhea from June 2013 to June 2016 in our hospital were selected and randomly divided into the control group and the experiment group,50 cases in the control group were get general routine treatment,such as dehydration and zinc supplement,50 cases in the experiment group were treated on the base of the control group with bifidobacteria.The clinical curative effect,the disappearance time of clinical symptoms of diarrhea and the level of serum high sensitive C reactive protein(CRP),interleukin-10(IL-10)and interleukin-6(IL-6)were observed and compared between two groups.Results After treatment,the total effective rate of the treatment group was higher than that of the control group,the clinical symptoms disappeared earlier than the control group,the difference was statistically significant(P<0.05).The serum CRP,IL-10 and IL-6 levels were lower than before treatment and the experiment group was more lower,the difference was statistically significant(P<0.05).Conclusion The clinical efficacy and recovery time of the combined application ofbifidobacteria and zinc in children with diarrhea is related to the decrease of serum CRP,IL-10 and IL-6 levels.
ABSTRACT
Objective Diagnosis of contrast-enhanced ultrasound ( CEUS) for small focal liver lesions under the background of hepatocirrhosis has been a difficult problem in clinical practice .CEUS has significantly improved the accuracy of liver cancer diagno-sis, but little research has been done in minimal lesions .The article was to investigate the diagnostic value of CEUS in liver cirrhosis with small focal liver lesions (≤2 cm) . Methods 70 patients with cirrhosis and 76 small focal hepatic lesions who were admitted in our hospital from March 2015 to August 2015 were examined by conventional ultrasound and CEUS .Comparative analysis was made be-tween the results of tests and pathology to calculate the sensitivity , specificity and accuracy of CEUS and conventional ultrasound . Results The sensitivity , specificity and accuracy in diagnosing small hepatic cancer lesions complicated with cirrhosis by CEUS and conventional ultrasound were 47.6%、79.4%、61.8%and97.6%、97.1%、97.4%,respectively.CEUS was in high consistence with the results of pathology ( Kappa 0.947) and significantly higher than those of conventional ultrasound (Kappa 0.259). Conclusion CEUS has high application value in the differential diagnosis of small focal he-patic lesions complicated with cirrhosis .
ABSTRACT
Computing thinking is one of the hotspots in computer education field,computer network is the core course of computer,and social information process is increasing the need of computer network professionals.The characteristics of computer network course,teaching of computer network course and problems related with teaching of computer network course were analyzed in aspects of its teaching contents,teaching methods and examination methods in order to train more excellent applied professionals of computer network and improve the computing thinking of undergraduates.The ways or methods for training the computing thinking of undergraduates were put forward,which can thus provide new ideas for the teaching reform of computer network course in colleges and universities.
ABSTRACT
BACKGROUND:Deer antlers are the unique mammalian organs which can periodical y regenerate, and the process is known as a stem cel-based event. Exploring the underlying mechanism of deer antler regeneration and indentifying the functional role of stem cellin mammalian organ regeneration are of great importance to regenerative biology and regenerative medicine. OBJECTIVE:To review the relevant literatures of the research progress in antler regeneration, as wel as effects of stem cells and cytokines on antler regeneration. METHODS:A computer-based online search of PubMed (1994-01/2012-10) was performed for acquiring the articles in English by using the key words of“deer antler;antler regeneration;stem cell. In addition, manual search was also performed for those literatures that cannot be readily obtained from internet search. Articles concerning antler regeneration histology, morphology, antler stem cells and micro-environmental studies, and related cytokines. Repetitive studies or articles that are unrelated to the criteria set for the article were excluded. RESULTS AND CONCLUSION:A total of 87 articles were obtained and final y 31 articles were selected. The key tissue types for antler regeneration are antlerogenic periosteum and pedicle periosteum, the cells within which are known as antler stem cells. The covering skin of antlerogenic periosteum and pedicle periosteum constitutes the functional niche for antler stem cells. Numerous cytokines are involved in the process of antler fast growing and ful regeneration, including insulin-like growth factor, sex hormones, human epidermal growth factor, and vascular endothelial growth factor. It is vital y important to identify the interacting molecules between the antler stem cells and their niche celltypes, and to define the role of each molecule that plays in antler regeneration, which wil greatly advance our knowledge of the stem cel-based mammalian organ regeneration.
ABSTRACT
To observe the D-dimer levels and the numbers of micro-embolic signals (MES) in atrial fibrillation patients with different thromboembolic risk scores. A total of 216 persistent atrial patients were classified according to their different scores with a range of 0 -6.They were also divided into two groups by ≥2 or ＜ 2 according to the CardiacFailure,Hypertension,Age,Diabetes,Stroke 2 (CHADS2) point system.D-dimer levels and the numbers of MES were detected in all patients.A rising trend of D-dimer level and the number of MES was observed with the increases of CHADS2 score. D-dimer level and the number of MES in group 0 or 1 score were significantly lower than those in other high score groups (P ＜ 0.05).And the number of MES in group 5 or 6 score was significantly higher than those in other low score groups (P ＜ 0.05).D-dimer level and the number of MES in the group of ≥ 2 score were significantly higher than those in group ＜ 2 score ( P ＜ 0.01 ).It suggests that D-dimer level and the nunber of MES may reflect the thromboembolic risks in atrial fibrillation patients.
ABSTRACT
Objective To investigate the clinical value of contrast-enhanced ultrasonography(CEUS) in evaluating treatment response of hepatocellular carcinoma after interventional therapy. Methods One hundred and three patients with 136 lesions of hepatocellular carcinoma confirmed by pathology were examined by common color ultrasound (US), contrast-enhanced CT, CEUS and DSA pre- and post-interventional treatment respectively. Results The sensitivity,specificity and accuracy of CEUS for focus judgment after interventional therapy were 95.8%, 95.6% and 98. 5% respectively. The sensitivity, specificity and accuracy of US in detecting tumor deactivation and residue were 92.3% ,77.4% and 83.1% respectively. CEUS were highly consistent with the results of enhanced CT/DSA (Kappa = 0.93) and significantly higher than those of US (Kappa = 0.66). Conclusions CEUS is useful to monitor the efficacy and guide treatment after interventional therapy.
ABSTRACT
Objective To observe the expressive changes of RhoA and phosphorylated myosin light chain in rat liver tissue undergoing hepatic fibrogenesis.Methods The liver histopathological changes were evaluated by hematoxylin and eosin staining and Masson's trichrome method.Western blot was used to determine the expressions of RhoA and p-MLC(Thr18/Ser19),and reverse transcription-polymerase chain reaction(RT-PCR) to determine the expression of RhoA mRNA.Results With the development of hepatic fibrogenesis,the protein expressions of RhoA and p-MLC(Thr18/Ser19) and the mRNA expression of RhoA were significantly increased.RhoA and p-MLC(Thr18/Ser19)correlated with ?-SMA positively,respectively.Conclusion Rho/ROCK signaling pathways are changed in the process hepatic fibrogenesis.
ABSTRACT
Objective To investigate the distribution of human papillomavirus(HPV) subtypes in condyloma acuminatum(CA) patients in Shenzhen People's Hospital and assess the association between HPV subtypes and cervix neoplasm.Methods Type specific prevalence and extent of multiple infection were assessed in the genital tract CA samples collected from 352 patients visiting Departments of dermatology or gynecology of Shenzhen People's Hospital during 2003-2004.PCR using MY09/11 as primer and reverse dot blot hybridization for the genotyping of 9-20 HPV subtypes.Results HPV type diversity was broad in the investigated CA patients.The low risk HPV type(HPV subtype 11,6) was dominant and multiple HPV infections occurred in 37% of HPV-positive samples.High risk HPV type was dominant in CA from cervix,especially in the high grade cervical intraepithelial neoplasia(CIN Ⅱ+),and multiple high risk HPV(HR-HPV) infection was found in 87% of HPV positive samples.Conclusion HPV subtypes 6 and 11 were dominant in the patients visiting Shenzhen People's Hospital.HPV subtypes 16 and 18 may be the main causes of malignant changes of cervix.
ABSTRACT
Objective It has been known that hepatopulmonary syndrome(HPS) is related to the imbalance between vasoconstrictors and vasodilators. The aim of the study is to examine the levels of plasma calcitonin gene related peptide (CGRP) and endothelin(ET) in patients with HPS for exploring their roles in HPS formation. Methods The levels of CGRP and ET were measured by radioimmunoassay in 16 cases of HPS, 30 cases of liver cirrhosis without HPS and 15 normal controls. Results The levels of plasma CGRP ((65?15)pg/ml) and ET((78?21)pg/ml) in 16 cases of HPS were significantly higher than those in liver cirrhosis (CGRP (51?15) pg/ml, ET (60?14) pg/ml) and in healthy controls (CGRP (32?12) pg/ml, ET (36?11) pg/ml) ( P 0.05). Conclusions The increase of plasma CGRP and ET is closely associated with the intrapulmonar vascular dilation of HPS and hypoxemia. The levels of plasma CGRP and ET in liver cirrhosis were significantly higher than those in healthy controls ( P