BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innova...BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.展开更多
Are all prime numbers linked by four simple functions? Can we predict when a prime will appear in a sequence of primes? If we classify primes into two groups, Group 1 for all primes that appear before ζ (such that , ...Are all prime numbers linked by four simple functions? Can we predict when a prime will appear in a sequence of primes? If we classify primes into two groups, Group 1 for all primes that appear before ζ (such that , for instance 5, ), an even number divisible by 3 and 2, and Group 2 for all primes that are after ζ (such that , for instance 7), then we find a simple function: for each prime in each group, , where n is any natural number. If we start a sequence of primes with 5 for Group 1 and 7 for Group 2, we can attribute a μ value for each prime. The μ value can be attributed to every prime greater than 7. Thus for Group 1, and . Using this formula, all the primes appear for , where μ is any natural number.展开更多
For about 50 years, angiography represented the only imaging method for studying carotid arteries in order to detect the presence of pathological stenosis due to atherosclerotic plaque. Recently, thanks to the use of ...For about 50 years, angiography represented the only imaging method for studying carotid arteries in order to detect the presence of pathological stenosis due to atherosclerotic plaque. Recently, thanks to the use of non-invasive methods, physicians are able to study and quantify the presence of carotid atherosclerosis in vivo These procedures have enabled the introduction of new concepts: (1) the degree of carotid stenosis is approxi- mate to the volume and extension of carotid plaque; and (2) a set of parameters, easily identifiable by com- puted tomography angiography, magnetic resonance angiogram and ultra-sound echo-color Doppler, are closely linked to the development of ischemic symptoms and can significantly increase the risk of stroke regard- less of the degree of stenosis. In light of these findings vulnerable plaques should be identified early, and the role of Digital Subtraction Angiography which is a purely technical luminal technique should be determined.展开更多
BACKGROUND: Over 355 patients have received ortho- topic liver transplantation ( OLT) at this hospital since 1993. Preoperative imaging studies of both hepatic vessels and parenchyma in these recipients bettered surgi...BACKGROUND: Over 355 patients have received ortho- topic liver transplantation ( OLT) at this hospital since 1993. Preoperative imaging studies of both hepatic vessels and parenchyma in these recipients bettered surgical plan- ning or even precluded the necessity of surgery. Here we report our preliminary results of modified magnetic reso- nance angiography ( MRA ) using sensitivity encoding ( SENSE) through comparative study with conventional digital subtraction angiography (DSA) and CT arterial por- tography (CTAP). METHODS: Sixteen patients with suspected liver diseases were included in the study. All of them received both dy- namic MRI of the liver using SENSE and digital DSA with CTAP within a two-week interval. The four-phase MRA was reconstructed from source images of the coronal dy- namic study. The arterial phase of the modified MRA was compared with DSA in the evaluation of hepatic arteries and the portal phase compared with CT portography recon- structed from source images of CTAP. In dynamic study of the liver, a fixed dose (20 ml) of contrast medium and scan timing were used. RESULTS: The main branches and variations of the hepatic arterial system were well shown on the modified MRA, al- though the marginal branches of hepatic arteries were of poor quality. The figures of portal veins on MRA were as clear as or superior to those of CTAP. In addition, the su- prarenal inferior vena cava (IVC) was well demonstrated on MRA and/or non contrast-enhanced coronal balanced fast-field echo (b-FFE) scan sequence in most cases. MRI detected most parenchymal lesions of the liver and hemo- dynamics of these lesions could be evaluated on source ima- ges of the modified MRA. MRI/MRA also serendipitously revealed several extrahepatic disease entities or variations that were not found on DSA/CTAP. CONCLUSIONS: The modified MRA using SENSE is a cost-effective modality of examination for the demonstra- tion of the whole hepatic vascular system. Combined with MRI, it has the potential as a one-stop imaging modality in the preoperative evaluation in fields such as OLT.展开更多
In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Pet...In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The longterm overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.展开更多
Spectral subtraction is used in this research as a method to remove noise from noisy speech signals in the frequency domain. This method consists of computing the spectrum of the noisy speech using the Fast Fourier Tr...Spectral subtraction is used in this research as a method to remove noise from noisy speech signals in the frequency domain. This method consists of computing the spectrum of the noisy speech using the Fast Fourier Transform (FFT) and subtracting the average magnitude of the noise spectrum from the noisy speech spectrum. We applied spectral subtraction to the speech signal “Real graph”. A digital audio recorder system embedded in a personal computer was used to sample the speech signal “Real graph” to which we digitally added vacuum cleaner noise. The noise removal algorithm was implemented using Matlab software by storing the noisy speech data into Hanning time-widowed half-overlapped data buffers, computing the corresponding spectrums using the FFT, removing the noise from the noisy speech, and reconstructing the speech back into the time domain using the inverse Fast Fourier Transform (IFFT). The performance of the algorithm was evaluated by calculating the Speech to Noise Ratio (SNR). Frame averaging was introduced as an optional technique that could improve the SNR. Seventeen different configurations with various lengths of the Hanning time windows, various degrees of data buffers overlapping, and various numbers of frames to be averaged were investigated in view of improving the SNR. Results showed that using one-fourth overlapped data buffers with 128 points Hanning windows and no frames averaging leads to the best performance in removing noise from the noisy speech.展开更多
With dual-radiopharmaceutical (DR) parathyroid scintigraphy, imaging with 99mTcO4-or 123I-NaI is combined with 99mTc-sestamibi scintigraphy for localization of parathyroid adenomas. The set images are then either visu...With dual-radiopharmaceutical (DR) parathyroid scintigraphy, imaging with 99mTcO4-or 123I-NaI is combined with 99mTc-sestamibi scintigraphy for localization of parathyroid adenomas. The set images are then either visually compared or digitally subtracted to aid in interpretation. While both EANM and SNMMI guidelines recommend use of digital subtraction over visual interpretation alone, to date, the few formal comparisons performed have not demonstrated superiority. The purpose of this investigation is to rigorously assess the added value of digital subtraction over visual interpretation alone using simultaneously-acquired 123I-NaI and 99mTc-sestamibi images. Materials: 90 consecutive patients with DR parathyroid scintigraphy for primary hyperparathyroidism who underwent successful parathyroidectomy were included. DR planar acquisition was performed 15 minutes post injection using 10% dual energy windows. Digital subtraction was subsequently performed using commercially available software. Images were independently reviewed by 3 nuclear medicine trainees and 2 experienced nuclear medicine physicians with and without digital subtraction. Results were compared with surgical and histopathologic findings, which served as ground truth. Results: 90 patients had a total of 91 confirmed parathyroid lesions. All 5 readers had significantly greater sensitivity with digital subtraction compared with visual interpretation alone while specificity was not significantly diminished. Area under the ROC curve was significantly greater with digital subtraction in 3 of 5 readers. Agreement was greater among trainees and experienced physicians when using digital subtraction. Conclusion: Using an optimized DR planar co-imaging technique, digital subtraction significantly improved inter-observer agreement and confidence of interpretation and increased sensitivity, without diminishing specificity.展开更多
Objective To investigate the feasibility of subtraction coronary computed tomographic(CT)angiography(SubCCTA)to decline calcium artifacts and improve diagnostic accuracy in the presence of coronary calcification and a...Objective To investigate the feasibility of subtraction coronary computed tomographic(CT)angiography(SubCCTA)to decline calcium artifacts and improve diagnostic accuracy in the presence of coronary calcification and analyze the factors that influence SubCCTA.Methods A total of 294 patients suspected of having coronary artery diseases underwent coronary computed tomographic angiography(CCTA)and SubCCTA.Coronary stenoses were blindly evaluated by two experienced radiologists,which were compared with invasive coronary angiography(ICA).Multiple statistical indexes were adopted to analyze the value of SubCCTA for the diagnosis of calcium stenoses.Results The diagnosable rate of SubCCTA was 67.2%(n=197),and the non-diagnosable rate was 32.8%(n=97).Using SubCCTA,the false positive rate decreased from 56.5%to 17.4%,and the corresponding diagnostic accuracy was increased from 83.6%to 92.9%.Univariate logistic regression analysis showed that height(OR=1.029,95%CI=1.001–1.058),weight(OR=1.025,95%CI=1.004–1.046),left ventricular size(OR=1.018,95%CI=1.007–1.030),cardiothoracic ratio(OR=39.917,95%CI=1.244–1281.098),the average heart rate(OR=0.866,95%CI=0.836–0.896)and heart rate range(OR=0.882,95%CI=0.853–0.912)might be the factors influencing SubCCTA.Conclusion This study suggested that SubCCTA could help improve diagnostic accuracy in the presence of calcium plaques.Moreover,several factors were discovered for the first time to possibly influence SubCCTA,which will be helpful in improving the subtracted image quality.展开更多
Objective To identify genes that may be related to embryo implantation Materials & Methods The PCR subtraction technique was applied at implantation and inter-plantation sites on day 4. 5 of pregnancy in mice. Two...Objective To identify genes that may be related to embryo implantation Materials & Methods The PCR subtraction technique was applied at implantation and inter-plantation sites on day 4. 5 of pregnancy in mice. Two novel Expressed Sequence Tags (ESTs ), EST8 and EST81 were identified; their expression in tissues was analyzed by Northern blotting, and their full-length cDNAs were synthesized by PCR.Results We found that these two novel ESTs (EST8and EST81) were noticeably expressed in implantation site in the mouse on day 4. 5 of pregnancy. EST8 was expressed at high level in livers and implantation sites of the mice, while at low level in ovaries and inter-plantation sites. EST81 was predominantly expressed in implantation site and ovary, and at low level in all other tissues. Their complete cDNAs, 1 665bp and 1 264 bp respectively, were synthesized by using PCR.Conclusion The two full-length cDNAs were responsible for embryo implantation,and their functions need to be further studied.展开更多
BACKGROUND Basal joint arthritis is a common disease which is especially present in postmenopausal women. A variety of procedures have been described once conservative treatment has failed. The purpose of our study is...BACKGROUND Basal joint arthritis is a common disease which is especially present in postmenopausal women. A variety of procedures have been described once conservative treatment has failed. The purpose of our study is to present a novel surgical technique based on a clinical case with three-year follow-up which is highly effective, even after failure of previous procedures. CASE SUMMARY We present a case of a 39 year-old-woman who suffered from recurring, persistent, sharp left thumb pain for several years After two operative procedures, she presented again with intolerable, sharp pain over the trapeziometacarpal joint, and wished to proceed with a pain relieving procedure or arthroplasty. Intraoperatively, the articular surfaces appeared well, without any bare areas of bone or eburnation, resulting in the decision to perform a “subtraction hemiarthroplasty”. A shortening osteotomy of the os trapezium was performed by removing a slice of 8-9 mm bone, without damaging the joint cartilages. The osteotomy was stabilized using two screws, the ligament and capsular tissue was suture imbricated, and a cut down on the translation and a dorsal radial ligament reconstruction were performed. Three years after the final procedure, a long-term follow-up demonstrates excellent results, pain free with full range-of-motion. CONCLUSION Subtraction hemiarthroplasty with ligament tightening imbrication and reconstruction of the radial ligament led to excellent results in motion and pain.展开更多
BACKGROUND Acute gastrointestinal bleeding(GIB)is a life-threatening medical emergency with high morbidity and mortality.Transcatheter embolization with endovascular coils under digital subtraction angiography guidanc...BACKGROUND Acute gastrointestinal bleeding(GIB)is a life-threatening medical emergency with high morbidity and mortality.Transcatheter embolization with endovascular coils under digital subtraction angiography guidance is a common and effective method for the treatment of GIB with high technical success rates.Duodenal ulcers caused by coils wiggled from the branch of the gastroduodenal artery,which is a rare complication,have not previously been reported in a patient with right intrathoracic stomach.CASE SUMMARY A 62-year-old man had undergone thoracoscopy-assisted radical resection of esophageal cancer and gastroesophageal anastomosis 3 years ago,resulting in right intrathoracic stomach.He was admitted to the hospital 15 mo ago for dizziness and suffered acute GIB during his stay.Interventional surgery was urgently performed to embolize the branch of the gastroduodenal artery with endovascular coils.After 15 mo,the patient was re-admitted with a chief complaint of melena for 2 d,esophagogastroduodenoscopy and abdominal computed tomography revealed that some endovascular coils had migrated into the duodenal bulb,leading to a deep ulcer.Bleeding was controlled after conservative treatment.Seven months later,duodenal balloon dilatation was performed to relieve the stenosis after the removal of a few coils,and the patient was safely discharged with only one coil retained in the duodenum due to difficulties in complete removal and risk of bleeding.Mild melena recurred once during the long-term follow-up.CONCLUSION Although rare,coil wiggle after interventional therapy requires careful attention,effective precautionary measures,and more secure alternative treatment methods.展开更多
Aiming at the problem of music noise introduced by classical spectral subtraction,a shorttime modulation domain(STM)spectral subtraction method has been successfully applied for singlechannel speech enhancement.Howeve...Aiming at the problem of music noise introduced by classical spectral subtraction,a shorttime modulation domain(STM)spectral subtraction method has been successfully applied for singlechannel speech enhancement.However,due to the inaccurate voice activity detection(VAD),the residual music noise and enhanced performance still need to be further improved,especially in the low signal to noise ratio(SNR)scenarios.To address this issue,an improved frame iterative spectral subtraction in the STM domain(IMModSSub)is proposed.More specifically,with the inter-frame correlation,the noise subtraction is directly applied to handle the noisy signal for each frame in the STM domain.Then,the noisy signal is classified into speech or silence frames based on a predefined threshold of segmented SNR.With these classification results,a corresponding mask function is developed for noisy speech after noise subtraction.Finally,exploiting the increased sparsity of speech signal in the modulation domain,the orthogonal matching pursuit(OMP)technique is employed to the speech frames for improving the speech quality and intelligibility.The effectiveness of the proposed method is evaluated with three types of noise,including white noise,pink noise,and hfchannel noise.The obtained results show that the proposed method outperforms some established baselines at lower SNRs(-5 to +5 dB).展开更多
Objective: To evaluate the value of digital subtraction angiography (DSA) in management of endovascular graft exclusion (EVGE) for abdominal aortic aneurysms. Methods: Monitored by DSA and fluoroscopy, stent-graft com...Objective: To evaluate the value of digital subtraction angiography (DSA) in management of endovascular graft exclusion (EVGE) for abdominal aortic aneurysms. Methods: Monitored by DSA and fluoroscopy, stent-graft complex were introduced into the aneurysm sac via femoral arteries and were deployed at the proximal and distal necks to exclude the sac from circulation. Results: The success rate of deployment was 94. 74% (36/38). Endoleaks occurred in 4 cases. One converted to open surgery because of sac rupture 4 days after deployment. Thrombosis and stenosis occurred in 2 cases. Three patients died shortly after the operation (< 3 months). Conclusion: DSA can monitor EVCE on real-time throughout the whole procedure. It can meet the needs of measurement, location, evaluating, detecting, and also can be much helpful in correcting complications. Moreover, it provides large visual field and operating space, and is a very important monitoring method for EVGE.展开更多
External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative c...External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative carious lesions. This study investigated the diagnostic value of digital subtraction radiography in detecting external root resorption. This was a descriptive study conducted using the lab trial method. Artificially-induced external root resorption was created in different sizes at the coronal and apical aspects of 20 premolar teeth. Digital radiographs were obtained of each tooth under standard conditions and these radiographs were subtracted by imaging devices. The subtracted images and the digital radiographs were observed by three radiologists. Chi-square, Kappa test, and Z-test were used to analyze the data. The mean of general sensitivity of digital subtraction radiography and direct digital radiography was low in diagnosing 0.05 mm lesions (Sen = 35%), yet, the accuracy index was good for all lesions (Acc ≥ 65%). Other diagnostic parameters were also acceptable. Both types of radiography worked better in diagnosing coronal than apical lesions (P > 0.05). The interpreters (observers) showed a better performance in diagnosing external root resorption using digital subtraction radiography compared to digital radiography. Both modalities were exact and accurate in detecting 0.05 mm lesions as well as other lesions. However, the results of digital subtraction radiography were not significantly different from those of direct digital radiography.展开更多
By digital subtraction angiography(DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The me...By digital subtraction angiography(DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The merits and demerits of DSA in observing the ophthalmic artery were discussed. Eye Science 1994; 10: 157- 162.展开更多
It is challenging to attempt to obtain CT perfusion (CTP) images of the hyperdense tissues, which could conceal the density of contrast material during perfusion study. We report a new technique of subtraction CTP (SC...It is challenging to attempt to obtain CT perfusion (CTP) images of the hyperdense tissues, which could conceal the density of contrast material during perfusion study. We report a new technique of subtraction CTP (SCTP) to compensate the shortcomings. SCTP post-processed by perfusion software for the data of post-perfusion images subtracting pre-perfusion corresponding images slice by slice in CTP source images is technically feasible without any adverse effects on patients. It provides a new functional imaging with quantitatively hemodynamic indexes of tissue microcirculation and reflects accurately the change of blood flow in tissues and organs.展开更多
The present study was performed to determine the potential of applying dual-energy subtraction (DES) digital tomo-synthesis to basic physical evaluations. Volumetric X-ray DES digital tomosysnthesis was used to obtain...The present study was performed to determine the potential of applying dual-energy subtraction (DES) digital tomo-synthesis to basic physical evaluations. Volumetric X-ray DES digital tomosysnthesis was used to obtain an image of a detectability phantom (an artificial lesion). The image quality of DES digital tomosynthesis was compared to that of DES radiography. The purpose of this study was to determine enhanced visibility quantified in terms of the contrast- to-noise ratio, figure-of-merit, and root-mean-square error. In the in-focus plane, the image quality is better by DES digital tomosynthesis than by DES radiography. The potential usefulness of DES digital tomosynthesis for evaluating a detectability phantom was demonstrated. Further studies are required to determine the ability of DES digital tomosyn-thesis to quantify the spatial relationships between the artificial lesion components of these devices, as well as to iden- tify lesions with diagnostic consequences.展开更多
Objective:To systematically evaluate the efficacy and safety of Loquat Qingfei Yin(LQFY)in the treatment of acne.Methods:Using computer retrieval,comprehensive collection of the full text database of Chinese journals ...Objective:To systematically evaluate the efficacy and safety of Loquat Qingfei Yin(LQFY)in the treatment of acne.Methods:Using computer retrieval,comprehensive collection of the full text database of Chinese journals till December 2020(CNKI),Wanfang Data Knowledge Service Platform(Wanfang),Viper Database(VIP),PubMed,Cochrane Library,Medline were included in the LQFY addition or subtraction treatment of acne randomized controlled trial(RCT).Screening of the literatures included in the Note Express 3.2.0.Assessment of the risk of bias in trials using Cochrane collaboration tools,and used Rev Man 5.3 to evaluate the curative effect.Results:25 RCT,all in Chinese,there were 2257 cases.Of the 1216 cases who were treated,control group was 1041 cases.A random effect model was used for Meta analysis.The results showed that the effective rate of the treatment group was significantly higher than that of the control group,Differences were statistically significant(P=0.94,I2==0%),RR=2.87,CI[2.25,95 per cent 3.67],P<0.00001.Conclusion:There are limited evidence that LQFY is safe and effective in treating acne.However,this conclusion needs to be confirmed by a more large-scale,multi-center,high-quality RCTs.展开更多
On July 6,2016,China Textile Innovation Conference Shishi Forum was held in Shishi,Fujian,with the theme of'exploring innovative gene for textile products',focusing on the discussion of how to enhance the qual...On July 6,2016,China Textile Innovation Conference Shishi Forum was held in Shishi,Fujian,with the theme of'exploring innovative gene for textile products',focusing on the discussion of how to enhance the quality and efficiency of supply,how to activate and release effective demand;how to explore innovative gene for textile products from the nature of the product on the foundation of'ingenuity spirit',so as to boost reconstruction and展开更多
文摘BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.
文摘Are all prime numbers linked by four simple functions? Can we predict when a prime will appear in a sequence of primes? If we classify primes into two groups, Group 1 for all primes that appear before ζ (such that , for instance 5, ), an even number divisible by 3 and 2, and Group 2 for all primes that are after ζ (such that , for instance 7), then we find a simple function: for each prime in each group, , where n is any natural number. If we start a sequence of primes with 5 for Group 1 and 7 for Group 2, we can attribute a μ value for each prime. The μ value can be attributed to every prime greater than 7. Thus for Group 1, and . Using this formula, all the primes appear for , where μ is any natural number.
文摘For about 50 years, angiography represented the only imaging method for studying carotid arteries in order to detect the presence of pathological stenosis due to atherosclerotic plaque. Recently, thanks to the use of non-invasive methods, physicians are able to study and quantify the presence of carotid atherosclerosis in vivo These procedures have enabled the introduction of new concepts: (1) the degree of carotid stenosis is approxi- mate to the volume and extension of carotid plaque; and (2) a set of parameters, easily identifiable by com- puted tomography angiography, magnetic resonance angiogram and ultra-sound echo-color Doppler, are closely linked to the development of ischemic symptoms and can significantly increase the risk of stroke regard- less of the degree of stenosis. In light of these findings vulnerable plaques should be identified early, and the role of Digital Subtraction Angiography which is a purely technical luminal technique should be determined.
文摘BACKGROUND: Over 355 patients have received ortho- topic liver transplantation ( OLT) at this hospital since 1993. Preoperative imaging studies of both hepatic vessels and parenchyma in these recipients bettered surgical plan- ning or even precluded the necessity of surgery. Here we report our preliminary results of modified magnetic reso- nance angiography ( MRA ) using sensitivity encoding ( SENSE) through comparative study with conventional digital subtraction angiography (DSA) and CT arterial por- tography (CTAP). METHODS: Sixteen patients with suspected liver diseases were included in the study. All of them received both dy- namic MRI of the liver using SENSE and digital DSA with CTAP within a two-week interval. The four-phase MRA was reconstructed from source images of the coronal dy- namic study. The arterial phase of the modified MRA was compared with DSA in the evaluation of hepatic arteries and the portal phase compared with CT portography recon- structed from source images of CTAP. In dynamic study of the liver, a fixed dose (20 ml) of contrast medium and scan timing were used. RESULTS: The main branches and variations of the hepatic arterial system were well shown on the modified MRA, al- though the marginal branches of hepatic arteries were of poor quality. The figures of portal veins on MRA were as clear as or superior to those of CTAP. In addition, the su- prarenal inferior vena cava (IVC) was well demonstrated on MRA and/or non contrast-enhanced coronal balanced fast-field echo (b-FFE) scan sequence in most cases. MRI detected most parenchymal lesions of the liver and hemo- dynamics of these lesions could be evaluated on source ima- ges of the modified MRA. MRI/MRA also serendipitously revealed several extrahepatic disease entities or variations that were not found on DSA/CTAP. CONCLUSIONS: The modified MRA using SENSE is a cost-effective modality of examination for the demonstra- tion of the whole hepatic vascular system. Combined with MRI, it has the potential as a one-stop imaging modality in the preoperative evaluation in fields such as OLT.
文摘In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The longterm overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.
文摘Spectral subtraction is used in this research as a method to remove noise from noisy speech signals in the frequency domain. This method consists of computing the spectrum of the noisy speech using the Fast Fourier Transform (FFT) and subtracting the average magnitude of the noise spectrum from the noisy speech spectrum. We applied spectral subtraction to the speech signal “Real graph”. A digital audio recorder system embedded in a personal computer was used to sample the speech signal “Real graph” to which we digitally added vacuum cleaner noise. The noise removal algorithm was implemented using Matlab software by storing the noisy speech data into Hanning time-widowed half-overlapped data buffers, computing the corresponding spectrums using the FFT, removing the noise from the noisy speech, and reconstructing the speech back into the time domain using the inverse Fast Fourier Transform (IFFT). The performance of the algorithm was evaluated by calculating the Speech to Noise Ratio (SNR). Frame averaging was introduced as an optional technique that could improve the SNR. Seventeen different configurations with various lengths of the Hanning time windows, various degrees of data buffers overlapping, and various numbers of frames to be averaged were investigated in view of improving the SNR. Results showed that using one-fourth overlapped data buffers with 128 points Hanning windows and no frames averaging leads to the best performance in removing noise from the noisy speech.
文摘With dual-radiopharmaceutical (DR) parathyroid scintigraphy, imaging with 99mTcO4-or 123I-NaI is combined with 99mTc-sestamibi scintigraphy for localization of parathyroid adenomas. The set images are then either visually compared or digitally subtracted to aid in interpretation. While both EANM and SNMMI guidelines recommend use of digital subtraction over visual interpretation alone, to date, the few formal comparisons performed have not demonstrated superiority. The purpose of this investigation is to rigorously assess the added value of digital subtraction over visual interpretation alone using simultaneously-acquired 123I-NaI and 99mTc-sestamibi images. Materials: 90 consecutive patients with DR parathyroid scintigraphy for primary hyperparathyroidism who underwent successful parathyroidectomy were included. DR planar acquisition was performed 15 minutes post injection using 10% dual energy windows. Digital subtraction was subsequently performed using commercially available software. Images were independently reviewed by 3 nuclear medicine trainees and 2 experienced nuclear medicine physicians with and without digital subtraction. Results were compared with surgical and histopathologic findings, which served as ground truth. Results: 90 patients had a total of 91 confirmed parathyroid lesions. All 5 readers had significantly greater sensitivity with digital subtraction compared with visual interpretation alone while specificity was not significantly diminished. Area under the ROC curve was significantly greater with digital subtraction in 3 of 5 readers. Agreement was greater among trainees and experienced physicians when using digital subtraction. Conclusion: Using an optimized DR planar co-imaging technique, digital subtraction significantly improved inter-observer agreement and confidence of interpretation and increased sensitivity, without diminishing specificity.
基金supported by Hubei Health Committee of China(No.WJ2019M119).
文摘Objective To investigate the feasibility of subtraction coronary computed tomographic(CT)angiography(SubCCTA)to decline calcium artifacts and improve diagnostic accuracy in the presence of coronary calcification and analyze the factors that influence SubCCTA.Methods A total of 294 patients suspected of having coronary artery diseases underwent coronary computed tomographic angiography(CCTA)and SubCCTA.Coronary stenoses were blindly evaluated by two experienced radiologists,which were compared with invasive coronary angiography(ICA).Multiple statistical indexes were adopted to analyze the value of SubCCTA for the diagnosis of calcium stenoses.Results The diagnosable rate of SubCCTA was 67.2%(n=197),and the non-diagnosable rate was 32.8%(n=97).Using SubCCTA,the false positive rate decreased from 56.5%to 17.4%,and the corresponding diagnostic accuracy was increased from 83.6%to 92.9%.Univariate logistic regression analysis showed that height(OR=1.029,95%CI=1.001–1.058),weight(OR=1.025,95%CI=1.004–1.046),left ventricular size(OR=1.018,95%CI=1.007–1.030),cardiothoracic ratio(OR=39.917,95%CI=1.244–1281.098),the average heart rate(OR=0.866,95%CI=0.836–0.896)and heart rate range(OR=0.882,95%CI=0.853–0.912)might be the factors influencing SubCCTA.Conclusion This study suggested that SubCCTA could help improve diagnostic accuracy in the presence of calcium plaques.Moreover,several factors were discovered for the first time to possibly influence SubCCTA,which will be helpful in improving the subtracted image quality.
文摘Objective To identify genes that may be related to embryo implantation Materials & Methods The PCR subtraction technique was applied at implantation and inter-plantation sites on day 4. 5 of pregnancy in mice. Two novel Expressed Sequence Tags (ESTs ), EST8 and EST81 were identified; their expression in tissues was analyzed by Northern blotting, and their full-length cDNAs were synthesized by PCR.Results We found that these two novel ESTs (EST8and EST81) were noticeably expressed in implantation site in the mouse on day 4. 5 of pregnancy. EST8 was expressed at high level in livers and implantation sites of the mice, while at low level in ovaries and inter-plantation sites. EST81 was predominantly expressed in implantation site and ovary, and at low level in all other tissues. Their complete cDNAs, 1 665bp and 1 264 bp respectively, were synthesized by using PCR.Conclusion The two full-length cDNAs were responsible for embryo implantation,and their functions need to be further studied.
文摘BACKGROUND Basal joint arthritis is a common disease which is especially present in postmenopausal women. A variety of procedures have been described once conservative treatment has failed. The purpose of our study is to present a novel surgical technique based on a clinical case with three-year follow-up which is highly effective, even after failure of previous procedures. CASE SUMMARY We present a case of a 39 year-old-woman who suffered from recurring, persistent, sharp left thumb pain for several years After two operative procedures, she presented again with intolerable, sharp pain over the trapeziometacarpal joint, and wished to proceed with a pain relieving procedure or arthroplasty. Intraoperatively, the articular surfaces appeared well, without any bare areas of bone or eburnation, resulting in the decision to perform a “subtraction hemiarthroplasty”. A shortening osteotomy of the os trapezium was performed by removing a slice of 8-9 mm bone, without damaging the joint cartilages. The osteotomy was stabilized using two screws, the ligament and capsular tissue was suture imbricated, and a cut down on the translation and a dorsal radial ligament reconstruction were performed. Three years after the final procedure, a long-term follow-up demonstrates excellent results, pain free with full range-of-motion. CONCLUSION Subtraction hemiarthroplasty with ligament tightening imbrication and reconstruction of the radial ligament led to excellent results in motion and pain.
文摘BACKGROUND Acute gastrointestinal bleeding(GIB)is a life-threatening medical emergency with high morbidity and mortality.Transcatheter embolization with endovascular coils under digital subtraction angiography guidance is a common and effective method for the treatment of GIB with high technical success rates.Duodenal ulcers caused by coils wiggled from the branch of the gastroduodenal artery,which is a rare complication,have not previously been reported in a patient with right intrathoracic stomach.CASE SUMMARY A 62-year-old man had undergone thoracoscopy-assisted radical resection of esophageal cancer and gastroesophageal anastomosis 3 years ago,resulting in right intrathoracic stomach.He was admitted to the hospital 15 mo ago for dizziness and suffered acute GIB during his stay.Interventional surgery was urgently performed to embolize the branch of the gastroduodenal artery with endovascular coils.After 15 mo,the patient was re-admitted with a chief complaint of melena for 2 d,esophagogastroduodenoscopy and abdominal computed tomography revealed that some endovascular coils had migrated into the duodenal bulb,leading to a deep ulcer.Bleeding was controlled after conservative treatment.Seven months later,duodenal balloon dilatation was performed to relieve the stenosis after the removal of a few coils,and the patient was safely discharged with only one coil retained in the duodenum due to difficulties in complete removal and risk of bleeding.Mild melena recurred once during the long-term follow-up.CONCLUSION Although rare,coil wiggle after interventional therapy requires careful attention,effective precautionary measures,and more secure alternative treatment methods.
基金National Natural Science Foundation of China(NSFC)(No.61671075)Major Program of National Natural Science Foundation of China(No.61631003)。
文摘Aiming at the problem of music noise introduced by classical spectral subtraction,a shorttime modulation domain(STM)spectral subtraction method has been successfully applied for singlechannel speech enhancement.However,due to the inaccurate voice activity detection(VAD),the residual music noise and enhanced performance still need to be further improved,especially in the low signal to noise ratio(SNR)scenarios.To address this issue,an improved frame iterative spectral subtraction in the STM domain(IMModSSub)is proposed.More specifically,with the inter-frame correlation,the noise subtraction is directly applied to handle the noisy signal for each frame in the STM domain.Then,the noisy signal is classified into speech or silence frames based on a predefined threshold of segmented SNR.With these classification results,a corresponding mask function is developed for noisy speech after noise subtraction.Finally,exploiting the increased sparsity of speech signal in the modulation domain,the orthogonal matching pursuit(OMP)technique is employed to the speech frames for improving the speech quality and intelligibility.The effectiveness of the proposed method is evaluated with three types of noise,including white noise,pink noise,and hfchannel noise.The obtained results show that the proposed method outperforms some established baselines at lower SNRs(-5 to +5 dB).
文摘Objective: To evaluate the value of digital subtraction angiography (DSA) in management of endovascular graft exclusion (EVGE) for abdominal aortic aneurysms. Methods: Monitored by DSA and fluoroscopy, stent-graft complex were introduced into the aneurysm sac via femoral arteries and were deployed at the proximal and distal necks to exclude the sac from circulation. Results: The success rate of deployment was 94. 74% (36/38). Endoleaks occurred in 4 cases. One converted to open surgery because of sac rupture 4 days after deployment. Thrombosis and stenosis occurred in 2 cases. Three patients died shortly after the operation (< 3 months). Conclusion: DSA can monitor EVCE on real-time throughout the whole procedure. It can meet the needs of measurement, location, evaluating, detecting, and also can be much helpful in correcting complications. Moreover, it provides large visual field and operating space, and is a very important monitoring method for EVGE.
文摘External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative carious lesions. This study investigated the diagnostic value of digital subtraction radiography in detecting external root resorption. This was a descriptive study conducted using the lab trial method. Artificially-induced external root resorption was created in different sizes at the coronal and apical aspects of 20 premolar teeth. Digital radiographs were obtained of each tooth under standard conditions and these radiographs were subtracted by imaging devices. The subtracted images and the digital radiographs were observed by three radiologists. Chi-square, Kappa test, and Z-test were used to analyze the data. The mean of general sensitivity of digital subtraction radiography and direct digital radiography was low in diagnosing 0.05 mm lesions (Sen = 35%), yet, the accuracy index was good for all lesions (Acc ≥ 65%). Other diagnostic parameters were also acceptable. Both types of radiography worked better in diagnosing coronal than apical lesions (P > 0.05). The interpreters (observers) showed a better performance in diagnosing external root resorption using digital subtraction radiography compared to digital radiography. Both modalities were exact and accurate in detecting 0.05 mm lesions as well as other lesions. However, the results of digital subtraction radiography were not significantly different from those of direct digital radiography.
文摘By digital subtraction angiography(DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The merits and demerits of DSA in observing the ophthalmic artery were discussed. Eye Science 1994; 10: 157- 162.
文摘It is challenging to attempt to obtain CT perfusion (CTP) images of the hyperdense tissues, which could conceal the density of contrast material during perfusion study. We report a new technique of subtraction CTP (SCTP) to compensate the shortcomings. SCTP post-processed by perfusion software for the data of post-perfusion images subtracting pre-perfusion corresponding images slice by slice in CTP source images is technically feasible without any adverse effects on patients. It provides a new functional imaging with quantitatively hemodynamic indexes of tissue microcirculation and reflects accurately the change of blood flow in tissues and organs.
文摘The present study was performed to determine the potential of applying dual-energy subtraction (DES) digital tomo-synthesis to basic physical evaluations. Volumetric X-ray DES digital tomosysnthesis was used to obtain an image of a detectability phantom (an artificial lesion). The image quality of DES digital tomosynthesis was compared to that of DES radiography. The purpose of this study was to determine enhanced visibility quantified in terms of the contrast- to-noise ratio, figure-of-merit, and root-mean-square error. In the in-focus plane, the image quality is better by DES digital tomosynthesis than by DES radiography. The potential usefulness of DES digital tomosynthesis for evaluating a detectability phantom was demonstrated. Further studies are required to determine the ability of DES digital tomosyn-thesis to quantify the spatial relationships between the artificial lesion components of these devices, as well as to iden- tify lesions with diagnostic consequences.
文摘Objective:To systematically evaluate the efficacy and safety of Loquat Qingfei Yin(LQFY)in the treatment of acne.Methods:Using computer retrieval,comprehensive collection of the full text database of Chinese journals till December 2020(CNKI),Wanfang Data Knowledge Service Platform(Wanfang),Viper Database(VIP),PubMed,Cochrane Library,Medline were included in the LQFY addition or subtraction treatment of acne randomized controlled trial(RCT).Screening of the literatures included in the Note Express 3.2.0.Assessment of the risk of bias in trials using Cochrane collaboration tools,and used Rev Man 5.3 to evaluate the curative effect.Results:25 RCT,all in Chinese,there were 2257 cases.Of the 1216 cases who were treated,control group was 1041 cases.A random effect model was used for Meta analysis.The results showed that the effective rate of the treatment group was significantly higher than that of the control group,Differences were statistically significant(P=0.94,I2==0%),RR=2.87,CI[2.25,95 per cent 3.67],P<0.00001.Conclusion:There are limited evidence that LQFY is safe and effective in treating acne.However,this conclusion needs to be confirmed by a more large-scale,multi-center,high-quality RCTs.
文摘On July 6,2016,China Textile Innovation Conference Shishi Forum was held in Shishi,Fujian,with the theme of'exploring innovative gene for textile products',focusing on the discussion of how to enhance the quality and efficiency of supply,how to activate and release effective demand;how to explore innovative gene for textile products from the nature of the product on the foundation of'ingenuity spirit',so as to boost reconstruction and
