BACKGROUND Octreotide is widely used for the treatment of acromegaly,neuroendocrine tumors,and secretory diarrhea.However,long-term octreotide treatment can increase the incidence of gallstones.Vicarious contrast medi...BACKGROUND Octreotide is widely used for the treatment of acromegaly,neuroendocrine tumors,and secretory diarrhea.However,long-term octreotide treatment can increase the incidence of gallstones.Vicarious contrast medium excretion(VCME)through the hepatobiliary system is well known.However,few studies have reported octreotide-induced acute gallstones following VCME.CASE SUMMARY A 69-year-old man presented with left lower back pain and hematuria caused by a fall.The patient had a history of polycystic kidney disease.VCME occurred following renal artery embolization for a ruptured polycystic kidney.After 5 d of treatment with octreotide,the patient developed acute gallstones and intrahepatic cholestasis which further induced pancreatitis and cholangitis.He was discharged after hemodialysis,antibiotics,and supportive treatments.CONCLUSION For patients with a high-risk of VCME,octreotide should be cautiously administered and carefully monitored.展开更多
Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography ang...Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.展开更多
AIM:To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography(CT) perfusion of rabbit VX2 tumor.METHODS:Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning...AIM:To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography(CT) perfusion of rabbit VX2 tumor.METHODS:Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning with a 24-h interval between a conventional tube potential(120 k Vp) protocol with 350 mg I/m L contrast medium and filtered back projection,and a low tube potential(80 k Vp) protocol with 270 mg I/m L contrast medium with iterative reconstruction.Correlation and agreement among perfusion parameters acquired by the conventional and low dose protocols were assessed for the viable tumor component as well as whole tumor.Image noise and tumor-to-liver contrast to noise ratio during arterial and portal venous phases were evaluated.RESULTS:A 38% reduction in contrast medium dose(360.1 ± 13.3 mg I/kg vs 583.5 ± 21.5 mg I/kg,P < 0.001) and a 73% decrease in radiation dose(1898.5 m Gy·cm vs 6951.8 m Gy·cm) were observed.Interestingly,there was a strong positive correlation in hepatic arterial perfusion(r = 0.907,P < 0.001;r = 0.879,P < 0.001),hepatic portal perfusion(r = 0.819,P = 0.002;r = 0.831,P = 0.002),and hepatic blood flow(r = 0.945,P < 0.001;r = 0.930,P < 0.001) as well as a moderate correlation in hepatic perfusion index(r = 0.736,P = 0.01;r = 0.636,P = 0.035) between the low dose protocol with iterative reconstruction and the conventional protocol for the viable tumor component and the whole tumor.These two imaging protocols provided a moderate but acceptable agreement for perfusion parameters and similar tumorto-liver CNR during arterial and portal venous phases(5.63 ± 2.38 vs 6.16 ± 2.60,P = 0.814;4.60 ± 1.27 vs 5.11 ± 1.74,P = 0.587).CONCLUSION:Compared with the conventional protocol,low contrast medium and radiation dose with iterative reconstruction has no significant influence on hepatic perfusion parameters for rabbits VX2 tumor.展开更多
Manganese compound with evident toxicity is widely employed as the contrast medium for clinicalexaminations such as magnetic resonance imaging(MRI).In the present work,a feasible way with the applica-tion of vacuum im...Manganese compound with evident toxicity is widely employed as the contrast medium for clinicalexaminations such as magnetic resonance imaging(MRI).In the present work,a feasible way with the applica-tion of vacuum impregnation and rotary evaporation was proposed to introduce manganese chloride hydrate intothe inner cavities of template - synthesized carbon nanotubes(CNTs),and then a process of alkali treatmentwas used to liberate the loaded CNTs from the template.It is notable that the alkali attack in the presence ofresidual oxygen also resulted in a series of changes in chemical compositions of guest substances,and the ulti-mate compound of manganese was found to be manganese oxide(Mn3O4) by X-ray diffraction and transmissionelectron microscopy.Determinations of energy dispersive spectrum under scanning electron microscopy showeda high-content filling(more than 50 wt%) of Mn3O4 in the loaded CNTs.This work developed a feasible andconvenient way for the encapsulation of guest substances to reduce bio-toxic effects.展开更多
Contrast medium induced nephropathy is the third most common cause of renal failure for inpatients and represents the 10% of all acute kidney injury occurring during hospital-stay. It is associated with prolonged hosp...Contrast medium induced nephropathy is the third most common cause of renal failure for inpatients and represents the 10% of all acute kidney injury occurring during hospital-stay. It is associated with prolonged hospitalization, cost increase and, above all, an unfavourable short- and long-term prognosis. Here, the authors discuss about the contrast medium induced nephropathy prevention strategies, from the identification of patients at risk and drugs potentially nephrotoxic, to the hydration with possible administration of drugs that appeared to be, in some contexts, nephron-protective, and finally we analyze the radiological procedure aimed at the correct choice of type and administration modality of the contrast medium according to current literature.展开更多
BACKGROUND Many imaging methods such as ultrasonography,computed tomography(CT),magnetic resonance imaging,and endoscopy are used to identify the problems or complications that occur in the perioperative period and to...BACKGROUND Many imaging methods such as ultrasonography,computed tomography(CT),magnetic resonance imaging,and endoscopy are used to identify the problems or complications that occur in the perioperative period and to determine the appropriate therapeutic approach.Specialists at surgical clinics and intensive care units sometimes need diagnostic procedures that can give quick results or reveal unexpected results.In particular,rapid on-site evaluation of patients followed under intensive care conditions has several advantages.AIM To determine the problems developing in patients in the perioperative period by contrast-enhanced abdominal X-ray(CE-AXR),revealing their current status or defining the effectiveness of CE-AXR.METHODS The files of the patients who underwent hepatopancreatobiliary or upper gastrointestinal surgery,whose CE-AXR film was taken,were reviewed retrospectively.Abdominal X-ray radiographs taken after ingestion of a watersoluble contrast agent(iohexol,300 mg,50 cc vial)and its application in a drain,nasogastric tube,or stent were evaluated.The contribution of the data obtained in patients who underwent CE-AXR to the diagnosis,follow-up,and treatment processes and the effectiveness of the application were investigated.RESULTS CE-AXR was applied to 131 patients in our clinic,most of whom underwent hepatopancreatobiliary or upper gastrointestinal surgery.It was determined that the data obtained from CE-AXR films taken in 98(74.8%)of the patients contributed to the diagnosis,treatment,and follow-up expectations and positively affected the clinical processes.CONCLUSION CE-AXR is a simple procedure that can be applied anywhere,especially in intensive care patients and at bedside,with a portable X-ray device.The simplicity of the procedure,less radiation exposure for the patients,less time wastage,reduction in the CT and endoscopy procedure burden and costs,quick results,rapid assessment of the situation,and enabling the monitoring of processes with repetitive procedures are important advantages.X-rays taken will be useful in terms of being a reference value during the follow-up period of the patient and determining the situation in medicolegal processes.展开更多
BACKGROUND Neurological complications are common in the management of venoarterial extracorporeal membrane oxygenation(VA-ECMO),with most patients requiring sedation and intubation,limiting the assessment of neurologi...BACKGROUND Neurological complications are common in the management of venoarterial extracorporeal membrane oxygenation(VA-ECMO),with most patients requiring sedation and intubation,limiting the assessment of neurological function.Therefore,we must rely on advanced neuroimaging techniques,such as computed tomography angiography(CTA)and computed tomography perfusion(CTP).Because ECMO changes the normal blood flow pattern,it may interfere with the contrast medium in some special cases,leading to artifacts and ultimately misleading clinical decisions.CASE SUMMARY A 61-year-old man presented to a local hospital with chest tightness and pain 1 d prior to presentation.The patient was treated with VA-ECMO after sudden cardiac and respiratory arrest at a local hospital.For further treatment,the patient was transferred to our hospital.The initial consciousness assessment was not clear,and routine CTP was performed to understand the intracranial changes,which suggested a large area of cerebral infarction on the right side;however,the cerebral oxygen was not consistent with the CTP results,and the reexamination of CTA still suggested a right cerebral infarction.To identify this difference,bedside transcranial Doppler was performed,and the blood flow on both sides was different.By reducing the ECMO flow,CTP reexamination showed that the results were normal and consistent with the clinical results.On day 3,the patient was alert and showed good limb movements.CONCLUSION In patients with peripheral VA-ECMO,cerebral perfusion confirmed by CTP and CTA may lead to false cerebral infarction.展开更多
随着中波转播台技术的发展,音频信号的高质量传输和监测变得至关重要。光电转换技术为信号传输带来高保真和低干扰的优势,但在传输过程中也可能遇到挑战,如介质不均匀性导致的细小干扰。音频比对监测技术能有效监控和保证广播内容的准...随着中波转播台技术的发展,音频信号的高质量传输和监测变得至关重要。光电转换技术为信号传输带来高保真和低干扰的优势,但在传输过程中也可能遇到挑战,如介质不均匀性导致的细小干扰。音频比对监测技术能有效监控和保证广播内容的准确性和真实性,利用先进的算法如梅尔频率倒谱系数(Mel Frequency Cepstral Coefficents,MFCC)来分析信号的质量。文章主要分析了音频比对监测的功能、原理及其在中波转播台的应用,以期通过中波转播平台进行音频监测来减少人为错误,降低故障率。展开更多
AIM: To provide the useful information for the diagnosis of liver cirrhosis by observing the morphology of peripheral hepatic vessels and the hemodynamics of microbubble arrival time in these vessels.METHODS: Twenty-o...AIM: To provide the useful information for the diagnosis of liver cirrhosis by observing the morphology of peripheral hepatic vessels and the hemodynamics of microbubble arrival time in these vessels.METHODS: Twenty-one subjects including 5 normal volunteers and 16 patients (liver cirrhosis, n=10;chronic hepatitis, n=6) were studied by contrast-enhanced coded phase inversion harmonic sonography (GE LOGIQ9 series) using a 6-8 MHz convex-arrayed wide-band transducer. The images of peripheral hepatic artery,portal and hepatic vein were observed in real-time for about 2 min after intravenous injection of Levovist. The time when microbubbles appeared in the peripheral vessels (microbubble arrival time) was also recorded. The morphologic changes of peripheral hepatic vasculature were classified as marked, slight, and no changes based on the regularity in caliber, course, ramification, and the delineation of vessels compared to normal subjects.RESULTS: The microbubble arrival time at peripheral artery, portal, and hepatic vein was shorter in cirrhotic patients than in chronic hepatitis patients and normal subjects. The marked, slight and no morphologic changes of peripheral hepatic vasculature found in 5 (5/6,83.3%), 1 (1/6, 16.7% ), and 0 (0/6, 0%) liver cirrhosis patients, respectively, and in 1 (1/10, 10%), 6 (6/10,60%), and 3 (3/10, 30%) chronic hepatitis patients,respectively. There was a significant difference between the two groups (P＜0.001).CONCLUSION: Evaluation of the hemodynamics and morphology of peripheral hepatic vasculature by contrast-enhanced coded pulse inversion harmonic sonography can provide useful information for the diagnosis of liver cirrhosis.展开更多
AIM: To investigate the value of contrast-enhanced C3-MODE technology in differentiating malignant nodules of liver from the benign ones. METHODS: Forty-six nodules in 36 patients (29 men and 7 women) were studied by ...AIM: To investigate the value of contrast-enhanced C3-MODE technology in differentiating malignant nodules of liver from the benign ones. METHODS: Forty-six nodules in 36 patients (29 men and 7 women) were studied by contrast-enhanced C3-MODE technology and contrast-enhanced CT in 1 wk before the biopsy or operation. A low MI monitor and a high MI flash imaging were intermittently performed. After the injection of contrast agent, the period from 10 to 30 s and the time later than 100 s were respectively defined as early arterial phase and the late phase. The vascularities of the liver nodules in the two phases were combined for differential diagnosis. Corresponding to the pathological diagnosis, the accuracy, sensitivity and specificity of contrast-enhanced C3-MODE technology were compared to those of contrast-enhanced CT. RESULTS: By C3-MODE technology, 33 of the 46 liver nodules were demonstrated as defected area in the late phase and were diagnosed as malignant tumors. Of them, 28 with hypervascularity in the early arterial phase were assessed as hepatocellular carcinoma, the other five nodules with rim-like enhancement in the early arterial phase were diagnosed as metastatic tumors. Thirteen nodules were shown as iso or hypervascularity in the late phase as well as centripetal filling in the early arterial phase and we made a diagnosis of hemangioma. Corresponding to the pathological results, the sensitivity, specificity and accuracy of contrast-enhanced C3-MODE technology in differentiating malignant and benign nodules in the liver were 97.0%, 92.3% and 95.7%, respectively. With comparison to those of contrast CT (sensitivity, 94.1%; specificity, 91.7%; accuracy, 93.5%), the difference was not significant. CONCLUSION: Contrast-enhanced C3-MODE technology can effectively differentiate malignant liver tumors from the benign nodules. It highly agrees diagnostically with the pathology. We suggest that it provides a new approach for differential diagnosis of liver nodules in addition to contrast-enhanced CT.展开更多
Biliary cystadenocarcinoma is a very rare malignant cystic tumor of the liver,which is often misdiagnosed due to a poor recognition of it.We report a case of a 60-year-old man with biliary cystadenocarcinoma with his ...Biliary cystadenocarcinoma is a very rare malignant cystic tumor of the liver,which is often misdiagnosed due to a poor recognition of it.We report a case of a 60-year-old man with biliary cystadenocarcinoma with his real time contrast enhanced ultrasound(CEUS)characteristics compared to those of computed tomography(CT)and magnetic resonance imaging(MRI),which were correlated with the surgical and pathologic findings.Cystic wall enhancement,internal septations and intra-cystic solid portions in the arterial phase were observed on CEUS after contrast agent injection.The enhancement was washed out progressively and depicted as hypo-enhancement in the portal and late phases.CT revealed a large irregular cystic lesion in the left liver lobe with no clear septations and solid components.MRI showed an irregular cystic occupying lesion with septations.展开更多
文摘BACKGROUND Octreotide is widely used for the treatment of acromegaly,neuroendocrine tumors,and secretory diarrhea.However,long-term octreotide treatment can increase the incidence of gallstones.Vicarious contrast medium excretion(VCME)through the hepatobiliary system is well known.However,few studies have reported octreotide-induced acute gallstones following VCME.CASE SUMMARY A 69-year-old man presented with left lower back pain and hematuria caused by a fall.The patient had a history of polycystic kidney disease.VCME occurred following renal artery embolization for a ruptured polycystic kidney.After 5 d of treatment with octreotide,the patient developed acute gallstones and intrahepatic cholestasis which further induced pancreatitis and cholangitis.He was discharged after hemodialysis,antibiotics,and supportive treatments.CONCLUSION For patients with a high-risk of VCME,octreotide should be cautiously administered and carefully monitored.
文摘Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.
基金National Natural Science Foundation of China,No.NSFC 81171389Key Program of Basic Research from Shanghai Municipal Science and Technology Commission,No.12JC1406500the Program of Shanghai Municipal Health Outstanding Discipline Leader,No.XBR 2013110
文摘AIM:To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography(CT) perfusion of rabbit VX2 tumor.METHODS:Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning with a 24-h interval between a conventional tube potential(120 k Vp) protocol with 350 mg I/m L contrast medium and filtered back projection,and a low tube potential(80 k Vp) protocol with 270 mg I/m L contrast medium with iterative reconstruction.Correlation and agreement among perfusion parameters acquired by the conventional and low dose protocols were assessed for the viable tumor component as well as whole tumor.Image noise and tumor-to-liver contrast to noise ratio during arterial and portal venous phases were evaluated.RESULTS:A 38% reduction in contrast medium dose(360.1 ± 13.3 mg I/kg vs 583.5 ± 21.5 mg I/kg,P < 0.001) and a 73% decrease in radiation dose(1898.5 m Gy·cm vs 6951.8 m Gy·cm) were observed.Interestingly,there was a strong positive correlation in hepatic arterial perfusion(r = 0.907,P < 0.001;r = 0.879,P < 0.001),hepatic portal perfusion(r = 0.819,P = 0.002;r = 0.831,P = 0.002),and hepatic blood flow(r = 0.945,P < 0.001;r = 0.930,P < 0.001) as well as a moderate correlation in hepatic perfusion index(r = 0.736,P = 0.01;r = 0.636,P = 0.035) between the low dose protocol with iterative reconstruction and the conventional protocol for the viable tumor component and the whole tumor.These two imaging protocols provided a moderate but acceptable agreement for perfusion parameters and similar tumorto-liver CNR during arterial and portal venous phases(5.63 ± 2.38 vs 6.16 ± 2.60,P = 0.814;4.60 ± 1.27 vs 5.11 ± 1.74,P = 0.587).CONCLUSION:Compared with the conventional protocol,low contrast medium and radiation dose with iterative reconstruction has no significant influence on hepatic perfusion parameters for rabbits VX2 tumor.
文摘Manganese compound with evident toxicity is widely employed as the contrast medium for clinicalexaminations such as magnetic resonance imaging(MRI).In the present work,a feasible way with the applica-tion of vacuum impregnation and rotary evaporation was proposed to introduce manganese chloride hydrate intothe inner cavities of template - synthesized carbon nanotubes(CNTs),and then a process of alkali treatmentwas used to liberate the loaded CNTs from the template.It is notable that the alkali attack in the presence ofresidual oxygen also resulted in a series of changes in chemical compositions of guest substances,and the ulti-mate compound of manganese was found to be manganese oxide(Mn3O4) by X-ray diffraction and transmissionelectron microscopy.Determinations of energy dispersive spectrum under scanning electron microscopy showeda high-content filling(more than 50 wt%) of Mn3O4 in the loaded CNTs.This work developed a feasible andconvenient way for the encapsulation of guest substances to reduce bio-toxic effects.
文摘Contrast medium induced nephropathy is the third most common cause of renal failure for inpatients and represents the 10% of all acute kidney injury occurring during hospital-stay. It is associated with prolonged hospitalization, cost increase and, above all, an unfavourable short- and long-term prognosis. Here, the authors discuss about the contrast medium induced nephropathy prevention strategies, from the identification of patients at risk and drugs potentially nephrotoxic, to the hydration with possible administration of drugs that appeared to be, in some contexts, nephron-protective, and finally we analyze the radiological procedure aimed at the correct choice of type and administration modality of the contrast medium according to current literature.
文摘BACKGROUND Many imaging methods such as ultrasonography,computed tomography(CT),magnetic resonance imaging,and endoscopy are used to identify the problems or complications that occur in the perioperative period and to determine the appropriate therapeutic approach.Specialists at surgical clinics and intensive care units sometimes need diagnostic procedures that can give quick results or reveal unexpected results.In particular,rapid on-site evaluation of patients followed under intensive care conditions has several advantages.AIM To determine the problems developing in patients in the perioperative period by contrast-enhanced abdominal X-ray(CE-AXR),revealing their current status or defining the effectiveness of CE-AXR.METHODS The files of the patients who underwent hepatopancreatobiliary or upper gastrointestinal surgery,whose CE-AXR film was taken,were reviewed retrospectively.Abdominal X-ray radiographs taken after ingestion of a watersoluble contrast agent(iohexol,300 mg,50 cc vial)and its application in a drain,nasogastric tube,or stent were evaluated.The contribution of the data obtained in patients who underwent CE-AXR to the diagnosis,follow-up,and treatment processes and the effectiveness of the application were investigated.RESULTS CE-AXR was applied to 131 patients in our clinic,most of whom underwent hepatopancreatobiliary or upper gastrointestinal surgery.It was determined that the data obtained from CE-AXR films taken in 98(74.8%)of the patients contributed to the diagnosis,treatment,and follow-up expectations and positively affected the clinical processes.CONCLUSION CE-AXR is a simple procedure that can be applied anywhere,especially in intensive care patients and at bedside,with a portable X-ray device.The simplicity of the procedure,less radiation exposure for the patients,less time wastage,reduction in the CT and endoscopy procedure burden and costs,quick results,rapid assessment of the situation,and enabling the monitoring of processes with repetitive procedures are important advantages.X-rays taken will be useful in terms of being a reference value during the follow-up period of the patient and determining the situation in medicolegal processes.
文摘BACKGROUND Neurological complications are common in the management of venoarterial extracorporeal membrane oxygenation(VA-ECMO),with most patients requiring sedation and intubation,limiting the assessment of neurological function.Therefore,we must rely on advanced neuroimaging techniques,such as computed tomography angiography(CTA)and computed tomography perfusion(CTP).Because ECMO changes the normal blood flow pattern,it may interfere with the contrast medium in some special cases,leading to artifacts and ultimately misleading clinical decisions.CASE SUMMARY A 61-year-old man presented to a local hospital with chest tightness and pain 1 d prior to presentation.The patient was treated with VA-ECMO after sudden cardiac and respiratory arrest at a local hospital.For further treatment,the patient was transferred to our hospital.The initial consciousness assessment was not clear,and routine CTP was performed to understand the intracranial changes,which suggested a large area of cerebral infarction on the right side;however,the cerebral oxygen was not consistent with the CTP results,and the reexamination of CTA still suggested a right cerebral infarction.To identify this difference,bedside transcranial Doppler was performed,and the blood flow on both sides was different.By reducing the ECMO flow,CTP reexamination showed that the results were normal and consistent with the clinical results.On day 3,the patient was alert and showed good limb movements.CONCLUSION In patients with peripheral VA-ECMO,cerebral perfusion confirmed by CTP and CTA may lead to false cerebral infarction.
文摘随着中波转播台技术的发展,音频信号的高质量传输和监测变得至关重要。光电转换技术为信号传输带来高保真和低干扰的优势,但在传输过程中也可能遇到挑战,如介质不均匀性导致的细小干扰。音频比对监测技术能有效监控和保证广播内容的准确性和真实性,利用先进的算法如梅尔频率倒谱系数(Mel Frequency Cepstral Coefficents,MFCC)来分析信号的质量。文章主要分析了音频比对监测的功能、原理及其在中波转播台的应用,以期通过中波转播平台进行音频监测来减少人为错误,降低故障率。
文摘AIM: To provide the useful information for the diagnosis of liver cirrhosis by observing the morphology of peripheral hepatic vessels and the hemodynamics of microbubble arrival time in these vessels.METHODS: Twenty-one subjects including 5 normal volunteers and 16 patients (liver cirrhosis, n=10;chronic hepatitis, n=6) were studied by contrast-enhanced coded phase inversion harmonic sonography (GE LOGIQ9 series) using a 6-8 MHz convex-arrayed wide-band transducer. The images of peripheral hepatic artery,portal and hepatic vein were observed in real-time for about 2 min after intravenous injection of Levovist. The time when microbubbles appeared in the peripheral vessels (microbubble arrival time) was also recorded. The morphologic changes of peripheral hepatic vasculature were classified as marked, slight, and no changes based on the regularity in caliber, course, ramification, and the delineation of vessels compared to normal subjects.RESULTS: The microbubble arrival time at peripheral artery, portal, and hepatic vein was shorter in cirrhotic patients than in chronic hepatitis patients and normal subjects. The marked, slight and no morphologic changes of peripheral hepatic vasculature found in 5 (5/6,83.3%), 1 (1/6, 16.7% ), and 0 (0/6, 0%) liver cirrhosis patients, respectively, and in 1 (1/10, 10%), 6 (6/10,60%), and 3 (3/10, 30%) chronic hepatitis patients,respectively. There was a significant difference between the two groups (P＜0.001).CONCLUSION: Evaluation of the hemodynamics and morphology of peripheral hepatic vasculature by contrast-enhanced coded pulse inversion harmonic sonography can provide useful information for the diagnosis of liver cirrhosis.
基金Supported by the Science Foundation of the Department of Science and Technology of Guangdong Province, No. 2002C30315
文摘AIM: To investigate the value of contrast-enhanced C3-MODE technology in differentiating malignant nodules of liver from the benign ones. METHODS: Forty-six nodules in 36 patients (29 men and 7 women) were studied by contrast-enhanced C3-MODE technology and contrast-enhanced CT in 1 wk before the biopsy or operation. A low MI monitor and a high MI flash imaging were intermittently performed. After the injection of contrast agent, the period from 10 to 30 s and the time later than 100 s were respectively defined as early arterial phase and the late phase. The vascularities of the liver nodules in the two phases were combined for differential diagnosis. Corresponding to the pathological diagnosis, the accuracy, sensitivity and specificity of contrast-enhanced C3-MODE technology were compared to those of contrast-enhanced CT. RESULTS: By C3-MODE technology, 33 of the 46 liver nodules were demonstrated as defected area in the late phase and were diagnosed as malignant tumors. Of them, 28 with hypervascularity in the early arterial phase were assessed as hepatocellular carcinoma, the other five nodules with rim-like enhancement in the early arterial phase were diagnosed as metastatic tumors. Thirteen nodules were shown as iso or hypervascularity in the late phase as well as centripetal filling in the early arterial phase and we made a diagnosis of hemangioma. Corresponding to the pathological results, the sensitivity, specificity and accuracy of contrast-enhanced C3-MODE technology in differentiating malignant and benign nodules in the liver were 97.0%, 92.3% and 95.7%, respectively. With comparison to those of contrast CT (sensitivity, 94.1%; specificity, 91.7%; accuracy, 93.5%), the difference was not significant. CONCLUSION: Contrast-enhanced C3-MODE technology can effectively differentiate malignant liver tumors from the benign nodules. It highly agrees diagnostically with the pathology. We suggest that it provides a new approach for differential diagnosis of liver nodules in addition to contrast-enhanced CT.
文摘Biliary cystadenocarcinoma is a very rare malignant cystic tumor of the liver,which is often misdiagnosed due to a poor recognition of it.We report a case of a 60-year-old man with biliary cystadenocarcinoma with his real time contrast enhanced ultrasound(CEUS)characteristics compared to those of computed tomography(CT)and magnetic resonance imaging(MRI),which were correlated with the surgical and pathologic findings.Cystic wall enhancement,internal septations and intra-cystic solid portions in the arterial phase were observed on CEUS after contrast agent injection.The enhancement was washed out progressively and depicted as hypo-enhancement in the portal and late phases.CT revealed a large irregular cystic lesion in the left liver lobe with no clear septations and solid components.MRI showed an irregular cystic occupying lesion with septations.
