The liver has a complex vascular anatomy with a unique dual blood supply.Clinical conditions of the liver vary widely and include disorders originating in the vascular and biliary systems as well as the parenchyma.In ...The liver has a complex vascular anatomy with a unique dual blood supply.Clinical conditions of the liver vary widely and include disorders originating in the vascular and biliary systems as well as the parenchyma.In most vascular disorders,the effects on the liver are generally subclinical because of its abundant blood supply.However,early diagnosis of such vascular diseases can significantly reduce patient morbidity and mortality.Because imaging findings of vascular disease are not always readily apparent,diagnosis can be difficult.Computed tomography angiography is an excellent imaging modality for visualizing the vascular anatomy of patients for treatment planning.In this review article,we focus on the vascular anatomy of the liver and the imaging findings in some acute hepatic vascular diseases.展开更多
BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awar...BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase.AIM To explore the value of multiple dose reduction techniques for CCTA.METHODS Consecutive normal and overweight patients were prospectively divided into two groups:Group A1,patients who received multiple dose reduction scans(n=82);and group A2,patients who received conventional scans(n=39).The scan parameters for group A1 were as follows:Isocentric scan,tube voltage=80 kV,and tube current control using 80%smart milliampere.The scan parameters for group A2 were as follows:Normal position,tube voltage=100 kV,and smart milliampere.RESULTS The average effective doses(EDs)for groups A1 and A2 were 1.13±0.35 and 3.36±1.30 mSv,respectively.There was a statistically significant difference in ED between the two groups(P<0.01).Furthermore,noise was significantly lower,and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1(P<0.01).Moreover,the subjective image quality(IQ)scores were excellent in both groups,in which there was no significant difference in subjective IQ score between the two groups(P=0.12).CONCLUSION Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.展开更多
BACKGROUND Aneurysmal subarachnoid hemorrhage is an emergency that can lead to a high mortality rate and many severe complications.It is critical to make a rapid radiological evaluation of ruptured intracranial aneury...BACKGROUND Aneurysmal subarachnoid hemorrhage is an emergency that can lead to a high mortality rate and many severe complications.It is critical to make a rapid radiological evaluation of ruptured intracranial aneurysms(RIAs)to determine the appropriate surgical treatment.AIM To assess the reliability of computed tomography angiography(CTA)in assessing different features of ruptured intracranial aneurysm and its impact on patient management.METHODS The final cohort of this study consisted of 146 patients with RIAs(75 male and 71 female)who underwent cerebral CTA.Their age ranged from 25 to 80,and the mean age±SD was 57±8.95 years.Two readers were asked to assess different features related to the aneurysm and perianeurysmal environment.Inter-observer agreement was measured using kappa statistics.Imaging data extracted from non-contrast computed tomography and CTA were considered to categorize the study population into two groups according to the recommended therapeutic approach.RESULTS The inter-observer agreement of both reviewers was excellent for the detection of aneurysms(K=0.95,P=0.001),aneurysm location(K=0.98,P=0.001),and(K=0.98,P=0.001),morphology(K=0.92,P=0.001)and margins(K=0.95,P=0.001).There was an excellent interobserver agreement for the measurement of aneurysm size(K=0.89,P=0.001),neck(K=0.85,P=0.001),and dome-to-neck ratio(K=0.98,P=0.001).There was an excellent inter-observer agreement for the detection of other aneurysm-related features such as thrombosis(K=0.82,P=0.001),calcification(K=1.0,P=0.001),bony landmark(K=0.89,P=0.001)and branch incorporation(K=0.91,P=0.001)as well as perianeurysmal findings including vasospasm(K=0.91,P=0.001),perianeurysmal cyst(K=1.0,P=0.001)and associated vascular lesions(K=0.83,P=0.001).Based on imaging features,87 patients were recommended to have endovascular treatment,while surgery was recommended in 59 patients.71.2%of the study population underwent the recommended therapy.CONCLUSION CTA is a reproducible promising diagnostic imaging modality for detecting and characterizing cerebral aneurysms.展开更多
BACKGROUND: Digital subtraction angiography (DSA) is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascular c...BACKGROUND: Digital subtraction angiography (DSA) is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascular complication. Three-dimensional computed tomography angiography (3D-CTA) can make up deficiencies of DSA; therefore, it is used in clinical therapy wider and wider. OBJECTIVE: To evaluate the clinical effect of 3D-CTA on disruption and hemorrhage of intracranial aneurysm pre- and post-operation and compare with the effect of DSA.DESIGN: Auto-control contrast observation.SETTING: Department of Neurosurgery, Shengjing Hospital of China Medical University.PARTICIPANTS: A number of 106 patients with disruption and hemorrhage of intracranial aneurysm were selected from the Department of Neurosurgery, Shengjing Hospital of China Medical University from January 2003 to April 2006. All patients were diagnosed with cranial operation and consent. There were 47 males and 59 females aged from 3-76 years with the mean age of (47±13) years. Among them, 82 patients had extensive subarachnoid hemorrhage (SAH), 7 had hemorrhage at longitudinal fissure, and 17 had hemorrhage at ambiens cisterna and lateral fissure. Moreover, intraventricular hematocele was accompanied on 13 patients and hematom on 9 patients. METHODS: ① 3D-CTA examination: Siemens SOMATOM Sensation 64 CT was used in this study. The thickness was 1 mm and interval of reconstruction was 0.8 mm. Localizing section was plainly scanned as the standard of canthus line. Scan ranged from 30 mm below sella to 50 mm above sella. Non-ion contrast medium of Omnipaque 350 (concentration of iodine was 350 g/L) was inserted into anterior vein of elbow with 18G trochar retained with high-pressured injectoc pum. The speed was 4.5 mL/s and the total volume was 80-100 mL with the means of 90 mL. Scan started at 10-20 s after injection of contrast medium. Original image was dealt with Leonardo workstation and retreated with Syngo software. Volume rendering and maximum intensity projection were used to reconstructed images. ② All 106 patients suffered from occlusion of aneurysm clamp. Before operation, 3D-CTA was undertaken and DSA was followed. After operation, patients were rechecked with 3D-CTA. MAIN OUTCOME MEASURES: Comparisons between 3D-CTA and DSA.RESULTS: All 106 patients were involved in the final analysis. ① Examination of 3D-CTA and DSA: Among 118 patients with aneurysm, 110 were checked with 3D-CTA and the detected rate was 93.2% (110/118). Among other 8 cases, 3 were negative and checked again with DSA; 1 had pericallosal aneurysm, 1 ophthalmic aneurysm, and 1 anterior choroidal artery of aneurysm. 3D-CTA results of other 5 cases were suspicious, and then, they were regarded as having aneurysm with DSA. Before operation, correlation among site, body, neck of aneurysm and peripheral anatomic structure were shown sufficiently. After operation, 82 patients were rechecked with 3D-CTA, which was complete occlusion, precise, unobvious constriction, emphraxis or remains as compared with 3D-CTA those pre-operation. ② Characteristics of 3D-CTA: With multiple vessels and angles, 3D-CTA observed the relationship between aneurysm neck and carried artery and showed thrombosis in cavity of aneurysm, calcification of aneurysm wall and peripheral structure of vessel at the same time. However, DSA could not detect the reactions mentioned above. It could delete image of cranium, simulate image of operative route, eliminate artifact induced by metal, but not distinguish blood stream direction. Meanwhile, posterior communicating artery was always poor during circle of Willis artery showing. CONCLUSION: ① 3D-CTA is characterized by simple operation and non-invasive showing vascular stereo structure and correlation. Therefore, it is significant for diagnosis and designing plan of operative approach and focal location pre-operation and evaluating effect post-operation. ② 3D-CTA does not completely replace DSA on the diagnosis of intracranial aneurysm.展开更多
Carotid artery stenosis causes narrowing of carotid lumens and may lead to brain infarction. The purpose of this study was to develop a semi-automated method of segmenting vessel walls, surrounding tissues, and more i...Carotid artery stenosis causes narrowing of carotid lumens and may lead to brain infarction. The purpose of this study was to develop a semi-automated method of segmenting vessel walls, surrounding tissues, and more importantly, the carotid artery lumen by contrast computed tomography angiography(CTA) images and to define the severity of stenosis and present a three-dimensional model of the carotid for visual inspection. In vivo contrast CTA images of 14 patients(7 normal subjects and 7 patients undergoing endarterectomy) were analyzed using a multi-step segmentation algorithm. This method uses graph cut followed by watershed and Hessian based shortest path method in order to extract lumen boundary correctly without being corrupted in the presence of surrounding tissues.Quantitative measurements of the proposed method were compared with those of manual delineation by independent board-certified radiologists. The results were quantitatively evaluated using spatial overlap surface distance indices. A slightly strong match was shown in terms of dice similarity coefficient(DSC) = 0.87±0.08; mean surface distance(D_(msd))= 0.32±0.32; root mean squared surface distance(D_(rmssd)) = 0.49±0.54 and maximum surface distance(D_(max))=2.14±2.08 between manual and automated segmentation of common, internal and external carotid arteries, carotid bifurcation and stenotic artery, respectively. Quantitative measurements showed that the proposed method has high potential to segment the carotid lumen and is robust to the changes of the lumen diameter and the shape of the stenosis area at the bifurcation site. The proposed method for CTA images provides a fast and reliable tool to quantify the severity of carotid artery stenosis.展开更多
Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Upper gastrointestinal endoscopy is currently recommended as the gold s...Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Upper gastrointestinal endoscopy is currently recommended as the gold standard modality for both diagnosis and treatment,with computed tomography traditionally playing a limited role in the diagnosis of acute NVUGIB.Following the introduction of multidetector computed tomography(MDCT),this modality is emerging as a promising tool in the diagnosis of NVUGIB.However,to date,evidence concerning the role of MDCT in the NVUGIB diagnosis is still lacking.The aim of our study was to review the current evidence concerning the role of MDCT in the diagnosis of acute NVUGIB.展开更多
BACKGROUND The aim of this study was to define clinical evidence supporting that triple ruleout computed tomography angiography(TRO CTA)is a comprehensive and feasible diagnostic tool in patients with novel coronaviru...BACKGROUND The aim of this study was to define clinical evidence supporting that triple ruleout computed tomography angiography(TRO CTA)is a comprehensive and feasible diagnostic tool in patients with novel coronavirus disease 2019(COVID-19)who were admitted to the emergency department(ED)for acute chest pain.Optimizing diagnostic imaging strategies in COVID-19 related thromboembolic events,will help for rapid and noninvasive diagnoses and results will be effective for patients and healthcare systems in all aspects.AIM To define clinical evidence supporting that TRO CTA is a comprehensive and feasible diagnostic tool in COVID-19 patients who were admitted to the ED for acute chest pain,and to assess outcomes of optimizing diagnostic imaging strategies,particularly TRO CTA use,in COVID-19 related thromboembolic events.METHODS TRO CTA images were evaluated for the presence of coronary artery disease,pulmonary thromboembolism(PTE),or acute aortic syndromes.Statistical analyses were used for evaluation of significant association between the variables.A two tailed P-value<0.05 was considered statistically significant.RESULTS Fifty-three patients were included into the study.In 31 patients(65.9%),there was not any pathology,while PTE was diagnosed in 11 patients.There was no significant relationship between the rates of pathology on CTA and history of hypertension.On the other hand,the diabetes mellitus rate was much higher in the acute coronary syndrome group,particularly in the PTE group(8/31=25.8%vs 6/16=37.5%,P=0.001).The rate of dyslipidemia was significantly higher in the group with pathology on CTA while compared to those without pathology apart from imaging findings of the pneumonia group(62.5%vs 38.7%,P<0.001).Smoking history rates were similar in the groups.Platelets,D-dimer,fibrinogen,C-reactive protein,and erythrocyte sedimentation rate values were higher in COVID-19 cases with additional pathologies.CONCLUSION TRO CTA is an effective imaging method in evaluation of all thoracic vascular systems at once and gives accurate results in COVID-19 patients.展开更多
<strong>Objective: </strong>Perivascular fat attenuation index (FAI) measurement on non-contrast-enhanced cardiac computed tomography (NCCT) has not been rigorously validated in previous studies. Herein, w...<strong>Objective: </strong>Perivascular fat attenuation index (FAI) measurement on non-contrast-enhanced cardiac computed tomography (NCCT) has not been rigorously validated in previous studies. Herein, we compared perivascular FAI values between NCCT and coronary computed tomography angiography (CCTA). We also investigated the variability and reproducibility of perivascular FAI measurement. <strong>Methods: </strong>A total of 44 patients who underwent NCCT and CCTA were included in this study. For NCCT, perivascular FAI was measured using three threshold settings: from <span style="white-space:nowrap;">−</span>30 to <span style="white-space:nowrap;">−</span>190 Hounsfield Units (HU), <span style="white-space:nowrap;">−</span>20 to <span style="white-space:nowrap;">−</span>180 HU, and <span style="white-space:nowrap;">−</span>10 to <span style="white-space:nowrap;">−</span>170 HU. For CCTA, perivascular FAI was measured using one threshold setting: from <span style="white-space:nowrap;">−</span>30 to <span style="white-space:nowrap;">−</span>190 HU. Perivascular FAI measurements by NCCT were compared with those by CCTA using the paired t-test, and correlations were assessed using Pearson’s correlation coefficient. The intra- and inter-observer variabilities for the measurements with NCCT and CCTA were evaluated with the intraclass correlation coefficient. <strong>Results:</strong> Perivascular FAI measurements with the threshold setting of <span style="white-space:nowrap;">−</span>30 to <span style="white-space:nowrap;">−</span>190 HU were significantly lower on NCCT than on CCTA. There were no significant differences between the perivascular FAI measurements at the remaining thresholds on NCCT and those on CCTA. The perivascular FAI at all thresholds on NCCT correlated significantly with those on CCTA. The intra- and inter-observer agreements were excellent for the measurements on NCCT and CCTA. <strong>Conclusion: </strong>There were significant differences between the perivascular FAI measurements on NCCT and CCTA. However, the differences could be modified by threshold adjustment.展开更多
The purpose of this research is to investigate the feasibility of using low contrast agent concentration with X-ray computed tomography in visualizing and diagnosing the human vascular system while minimizing the risk...The purpose of this research is to investigate the feasibility of using low contrast agent concentration with X-ray computed tomography in visualizing and diagnosing the human vascular system while minimizing the risk of toxicity to the patient. This research investigated the effect of several iodine contrast agent concentrations on the ability to extract and visualize human vessels using simulated computed tomography scans. Monte Carlo simulation was used to perform these computed tomography acquisitions. The simulated patient was based on actual computed tomography angiography data, where a technique was developed to simulate brain vessels with contrast agents ranging from 0 mg to 20 mg of iodine. The simulation used segmented patient data along with basic image processing techniques to model the various levels of iodine concentrations. Cone beam computed tomography projections of a patient injected with and without iodine were acquired in the simulations. Subtraction of the corresponding projections was performed to generate images caused by the contrast agent. Then, histogram analysis of these differences was used to assess the validity of extracting and visualizing the human vessels. The smallest amount of iodine, 0.5 mg, helped better visualize the brain vessels and 2 mg of iodine was high enough to show almost 90% of the vessels. Additionally, the vessels were clearly visible in all the subtracted images. This research showed very promising outcomes in using low concentrations of iodine. Thus, this study proposes for the pharmaceutical companies and others interested to clinically investigate and evaluate the efficacy of using low concentrations of iodine and the associated side effects.展开更多
Aortic dissection (AD) is a life-threatening clinical emergency requiring rapid diagnosis and effective intervention to improve patient survival and prognosis. Computed tomography angiography (CTA) can be used to diag...Aortic dissection (AD) is a life-threatening clinical emergency requiring rapid diagnosis and effective intervention to improve patient survival and prognosis. Computed tomography angiography (CTA) can be used to diagnose AD accurately and quickly, making it the first choice for diagnosing AD in an emergency. This article reviews the application of CTA in the diagnosis and treatment of AD.展开更多
Coronary artery disease(CAD)has become a major illness endangering human health.It mainly manifests as atherosclerotic plaques,especially vulnerable plaques without obvious symptoms in the early stage.Once a rupture o...Coronary artery disease(CAD)has become a major illness endangering human health.It mainly manifests as atherosclerotic plaques,especially vulnerable plaques without obvious symptoms in the early stage.Once a rupture occurs,it will lead to severe coronary stenosis,which in turn may trigger a major adverse cardiovascular event.Computed tomography angiography(CTA)has become a standard diagnostic tool for early screening of coronary plaque and stenosis due to its advantages in high resolution,noninvasiveness,and three-dimensional imaging.However,manual examination of CTA images by radiologists has been proven to be tedious and time-consuming,which might also lead to intra-and interobserver errors.Nowadays,many machine learning algorithms have enabled the(semi-)automatic diagnosis of CAD by extracting quantitative features from CTA images.This paper provides a survey of these machine learning algorithms for the diagnosis of CAD in CTA images,including coronary artery extraction,coronary plaque detection,vulnerable plaque identification,and coronary stenosis assessment.Most included articles were published within this decade and are found in the Web of Science.We wish to give readers a glimpse of the current status,challenges,and perspectives of these machine learning-based analysis methods for automatic CAD diagnosis.展开更多
Coronary computed tomography angiography(CCTA)is recommended as a frontline diagnostic tool in the non-invasive assessment of patients with suspected coronary artery disease(CAD)and cardiovascular risk stratification....Coronary computed tomography angiography(CCTA)is recommended as a frontline diagnostic tool in the non-invasive assessment of patients with suspected coronary artery disease(CAD)and cardiovascular risk stratification.To date,artificial intelligence(AI)techniques have brought major changes in the way that we make individualized decisions for patients with CAD.Applications of AI in CCTA have produced improvements in many aspects,including assessment of stenosis degree,determination of plaque type,identification of high-risk plaque,quantification of coronary artery calcium score,diagnosis of myocardial infarction,estimation of computed tomography-derived fractional flow reserve,left ventricular myocardium analysis,perivascular adipose tissue analysis,prognosis of CAD,and so on.The purpose of this review is to provide a comprehensive overview of current status of AI in CCTA.展开更多
This letter to the editor relates to the study entitled“The role of computed tomography for the prediction of esophageal variceal bleeding:Current status and future perspectives”.Esophageal variceal bleeding(EVB)is ...This letter to the editor relates to the study entitled“The role of computed tomography for the prediction of esophageal variceal bleeding:Current status and future perspectives”.Esophageal variceal bleeding(EVB)is one of the most common and severe complications related to portal hypertension(PH).Despite marked advances in its management during the last three decades,EVB is still associated with significant morbidity and mortality.The risk of first EVB is related to the severity of both PH and liver disease,and to the size and endoscopic appearance of esophageal varices.Indeed,hepatic venous pressure gradient(HVPG)and esophagogastroduodenoscopy(EGD)are currently recognized as the“gold standard”and the diagnostic reference standard for the prediction of EVB,respectively.However,HVPG is an invasive,expensive,and technically complex procedure,not widely available in clinical practice,whereas EGD is mainly limited by its invasive nature.In this scenario,computed tomography(CT)has been recently proposed as a promising modality for the non-invasive prediction of EVB.While CT serves solely as a diagnostic tool and cannot replace EGD or HVPG for delivering therapeutic and physiological information,it has the potential to enhance the prediction of EVB more effectively when combined with liver disease scores,HVPG,and EGD.However,to date,evidence concerning the role of CT in this setting is still lacking,therefore we aim to summarize and discuss the current evidence concerning the role of CT in predicting the risk of EVB.展开更多
Coronary artery abnormalities are the most important complications in children with Kawasaki disease(KD).Two-dimensional transthoracic echocardiography currently is the standard of care for initial evaluation and foll...Coronary artery abnormalities are the most important complications in children with Kawasaki disease(KD).Two-dimensional transthoracic echocardiography currently is the standard of care for initial evaluation and follow-up of children with KD.However,it has inherent limitations with regard to evaluation of mid and distal coronary arteries and,left circumflex artery and the poor acoustic window in older children often makes evaluation difficult in this age group.Catheter angiography(CA)is invasive,has high radiation exposure and fails to demonstrate abnormalities beyond lumen.The limitations of echocardiography and CA necessitate the use of an imaging modality that overcomes these problems.In recent years advances in computed tomography technology have enabled explicit evaluation of coronary arteries along their entire course including major branches with optimal and acceptable radiation exposure in children.Computed tomography coronary angiography(CTCA)can be performed during acute as well as convalescent phases of KD.It is likely that CTCA may soon be considered the reference standard imaging modality for evaluation of coronary arteries in children with KD.展开更多
BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data o...BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data on radiation dose in this group of children undergoing CTCA.AIM To audit the radiation dose of CTCA in children with KD.METHODS Study(December 2013-February 2018)was performed on dual source CT scanner using adaptive prospective electrocardiography-triggering.The dose length product(DLP in milligray-centimeters-mGy.cm)was recorded.Effective radiation dose(millisieverts-mSv)was calculated by applying appropriate age adjusted conversion factors as per recommendations of International Commission on Radiological Protection.Radiation dose was compared across the groups(0-1,1-5,5-10,and>10 years).RESULTS Eighty-five children(71 boys,14 girls)with KD underwent CTCA.The median age was 5 years(range,2 mo-11 years).Median DLP and effective dose was 21 mGy.cm,interquartile ranges(IQR)=15(13,28)and 0.83 mSv,IQR=0.33(0.68,1.01)respectively.Mean DLP increased significantly across the age groups.Mean effective dose in infants(0.63 mSv)was significantly lower than the other age groups(1-5 years 0.85 mSv,5-10 years 1.04 mSv,and>10 years 1.38 mSv)(P<0.05).There was no significant difference in the effective dose between the other groups of children.All the CTCA studies were of diagnostic quality.No child required a repeat examination.CONCLUSION CTCA is feasible with submillisievert radiation dose in most children with KD.Thus,CTCA has the potential to be an important adjunctive imaging modality in children with KD.展开更多
Esophageal variceal bleeding(EVB)is one of the most common and severe complications related to portal hypertension(PH).Despite marked advances in its management during the last three decades,EVB is still associated wi...Esophageal variceal bleeding(EVB)is one of the most common and severe complications related to portal hypertension(PH).Despite marked advances in its management during the last three decades,EVB is still associated with significant morbidity and mortality.The risk of first EVB is related to the severity of both PH and liver disease,and to the size and endoscopic appearance of esophageal varices.Indeed,hepatic venous pressure gradient(HVPG)and esophagogastroduodenoscopy(EGD)are currently recognized as the“gold standard”and the diagnostic reference standard for the prediction of EVB,respectively.However,HVPG is an invasive,expensive,and technically complex procedure,not widely available in clinical practice,whereas EGD is mainly limited by its invasive nature.In this scenario,computed tomography(CT)has been recently proposed as a promising modality for the non-invasive prediction of EVB.Although CT is only a diagnostic modality,thus being not capable of supplanting EGD or HVPG in providing therapeutic and physiological data,it could potentially assist liver disease scores,HVPG,and EGD in a more effective prediction of EVB.However,to date,evidence concerning the role of CT in this setting is still lacking.Our review aimed to summarize and discuss the current evidence concerning the role of CT in predicting the risk of EVB.展开更多
BACKGROUND Primary aortoduodenal fistula is a rare cause of gastrointestinal(GI)bleeding consisting of abnormal channels between the aorta and GI tract without previous vascular intervention that results in massive in...BACKGROUND Primary aortoduodenal fistula is a rare cause of gastrointestinal(GI)bleeding consisting of abnormal channels between the aorta and GI tract without previous vascular intervention that results in massive intraluminal hemorrhage.CASE SUMMARY A 67-year-old man was hospitalized for coffee ground vomiting,tarry stools,and colic abdominal pain.He was repeatedly admitted for active GI bleeding and hypovolemic shock.Intermittent and spontaneously stopped bleeders were undetectable on multiple GI endoscopy,angiography,computed tomography angiography(CTA),capsule endoscopy,and ^(99)mTc-labeled red blood cell(RBC)scans.The patient received supportive treatment and was discharged without signs of rebleeding.Thereafter,he was re-admitted for bleeder identification.Repeated CTA after a bleed revealed a small aortic aneurysm at the renal level contacting the fourth portion of the duodenum.A ^(99)mTc-labeled RBC singlephoton emission CT(SPECT)/CT scan performed during bleeding symptoms revealed active bleeding at the duodenal level.According to his clinical symptoms(intermittent massive GI bleeding with hypovolemic shock,dizziness,dark red stool,and bloody vomitus)and the abdominal CTA and ^(99)mTc-labeled RBC SPECT/CT results,we suspected a small aneurysm and an aortoduodenal fistula.Subsequent duodenal excision and duodenojejunal anastomosis were performed.A 7-mm saccular aneurysm arising from the anterior wall of the abdominal aorta near the left renal artery was identified.Percutaneous intravascular stenting of the abdominal aorta was performed and his symptoms improved.CONCLUSION Our findings suggest that ^(99)mTc-labeled RBC SPECT/CT scanning can aid the diagnosis of a rare cause of active GI bleeding.展开更多
BACKGROUND The course and variations of thyroid arteries must be understood by surgeons to prevent bleeding during operative procedures of the thyroid gland.There is limited scientific literature regarding the radiolo...BACKGROUND The course and variations of thyroid arteries must be understood by surgeons to prevent bleeding during operative procedures of the thyroid gland.There is limited scientific literature regarding the radiological anatomy of thyroid arteries in this geographical area,the Garhwal region of Sub-Himalayan belt,which is considered to be the endemic belt of goiter.Computed tomography angiography provides a three-dimensional orientation of the vascular and surgical anatomy of the entire cervical region.AIM To estimate the proportion of variation in origin of thyroid arteries using Computed Tomography Angiography.METHODS Using Computed Tomography Angiography,the presence and origin of the superior thyroid artery,inferior thyroid artery,and thyroid ima artery were observed and assessed.RESULTS Out of total 210 subjects,superior thyroid artery was seen to be emerging from external carotid artery in 77.1%cases.The artery was found to be originating at the level of bifurcation of common carotid artery in 14.3%cases,whereas in 8.6%cases,it emerged as a direct branch of the common carotid artery.Similarly,the inferior thyroid artery was observed to be emerging from thyrocervical trunk,subclavian artery and vertebral artery in 95.7%cases,3.3%and 1%cases,respectively.Thyroid ima artery was also reported in a subject,arising from the brachiocephalic trunk.CONCLUSION To avoid vascular injuries,excessive and uncontrollable bleeding,intra-operative difficulties,and post-operative issues,it is imperative for surgeons to be aware of the course and variations of thyroid arteries。展开更多
A high contrast to noise ratio(CNR)is always desirable for contrast-enhanced computed tomography angiography(CTA).To ensure a high CNR of the vascular images in CTA and potentially reduce the radiation exposure and co...A high contrast to noise ratio(CNR)is always desirable for contrast-enhanced computed tomography angiography(CTA).To ensure a high CNR of the vascular images in CTA and potentially reduce the radiation exposure and contrast usage,an adaptive bolus chasing method is proposed and evaluated compared to the existing constant-speed method.The proposed method is based on a local time and space parameter varying model of the contrast bolus.Optimal scan time for the next segment of the vasculature is estimated and predicted in real time and guides the computed tomography(CT)scanner table movement that guarantees that each segment of the vasculature is scanned with the maximum possible enhancement.Simulations and experimental results show that the proposed bolus chasing method outperforms the conventional constant-speed method substantially.展开更多
Aim:Anterolateral thigh(ALT)flap is widely used in reconstruction of various defects.Preoperative imaging facilitates perforator mapping,overcoming intraoperative uncertainty.The purpose of this study was to investiga...Aim:Anterolateral thigh(ALT)flap is widely used in reconstruction of various defects.Preoperative imaging facilitates perforator mapping,overcoming intraoperative uncertainty.The purpose of this study was to investigate the utility of multi-detector row computed tomography angiography(MDCTA)and a handheld Doppler in locating ALT perforators.Methods:Twenty patients were randomized into two groups.Group 1 patients received MDCTA and Doppler studies whereas Group 2 received only a Doppler study.The number,location,course,and source of all cutaneous and sizable perforators were compared with intraoperative findings.Surgeons’stress levels during flap harvest and flap harvest time were compared.Results:MDCTA findings correlated well with intraoperative findings for perforator type and segmental distribution with 100%concordance.Doppler alone had a 52%rate of concordance.The sensitivity and specificity for MDCTA in demonstrating the presence of perforators were 85.71%and 97.22%,respectively;whereas for Doppler alone the sensitivity and specificity were 80%and 87.91%,respectively.In demonstrating perforator source,MDCTA showed a sensitivity of 100%and specificity of 91.66%,with 100%accuracy.Sensitivity and specificity for sizable perforators were 90%each,with 88.88%accuracy.Doppler studies were unable to provide this information.Comparison of surgeon stress levels showed no differences between the two groups,although the time for flap harvest was significantly shorter in Group 1.Conclusion:MDCTA compared to Doppler is more sensitive,specific,and accurate with respect to location,course,and source of perforators.展开更多
文摘The liver has a complex vascular anatomy with a unique dual blood supply.Clinical conditions of the liver vary widely and include disorders originating in the vascular and biliary systems as well as the parenchyma.In most vascular disorders,the effects on the liver are generally subclinical because of its abundant blood supply.However,early diagnosis of such vascular diseases can significantly reduce patient morbidity and mortality.Because imaging findings of vascular disease are not always readily apparent,diagnosis can be difficult.Computed tomography angiography is an excellent imaging modality for visualizing the vascular anatomy of patients for treatment planning.In this review article,we focus on the vascular anatomy of the liver and the imaging findings in some acute hepatic vascular diseases.
基金Supported by Zhuhai Medical Research Fund,No.ZH3310200001PJL.
文摘BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase.AIM To explore the value of multiple dose reduction techniques for CCTA.METHODS Consecutive normal and overweight patients were prospectively divided into two groups:Group A1,patients who received multiple dose reduction scans(n=82);and group A2,patients who received conventional scans(n=39).The scan parameters for group A1 were as follows:Isocentric scan,tube voltage=80 kV,and tube current control using 80%smart milliampere.The scan parameters for group A2 were as follows:Normal position,tube voltage=100 kV,and smart milliampere.RESULTS The average effective doses(EDs)for groups A1 and A2 were 1.13±0.35 and 3.36±1.30 mSv,respectively.There was a statistically significant difference in ED between the two groups(P<0.01).Furthermore,noise was significantly lower,and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1(P<0.01).Moreover,the subjective image quality(IQ)scores were excellent in both groups,in which there was no significant difference in subjective IQ score between the two groups(P=0.12).CONCLUSION Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.
文摘BACKGROUND Aneurysmal subarachnoid hemorrhage is an emergency that can lead to a high mortality rate and many severe complications.It is critical to make a rapid radiological evaluation of ruptured intracranial aneurysms(RIAs)to determine the appropriate surgical treatment.AIM To assess the reliability of computed tomography angiography(CTA)in assessing different features of ruptured intracranial aneurysm and its impact on patient management.METHODS The final cohort of this study consisted of 146 patients with RIAs(75 male and 71 female)who underwent cerebral CTA.Their age ranged from 25 to 80,and the mean age±SD was 57±8.95 years.Two readers were asked to assess different features related to the aneurysm and perianeurysmal environment.Inter-observer agreement was measured using kappa statistics.Imaging data extracted from non-contrast computed tomography and CTA were considered to categorize the study population into two groups according to the recommended therapeutic approach.RESULTS The inter-observer agreement of both reviewers was excellent for the detection of aneurysms(K=0.95,P=0.001),aneurysm location(K=0.98,P=0.001),and(K=0.98,P=0.001),morphology(K=0.92,P=0.001)and margins(K=0.95,P=0.001).There was an excellent interobserver agreement for the measurement of aneurysm size(K=0.89,P=0.001),neck(K=0.85,P=0.001),and dome-to-neck ratio(K=0.98,P=0.001).There was an excellent inter-observer agreement for the detection of other aneurysm-related features such as thrombosis(K=0.82,P=0.001),calcification(K=1.0,P=0.001),bony landmark(K=0.89,P=0.001)and branch incorporation(K=0.91,P=0.001)as well as perianeurysmal findings including vasospasm(K=0.91,P=0.001),perianeurysmal cyst(K=1.0,P=0.001)and associated vascular lesions(K=0.83,P=0.001).Based on imaging features,87 patients were recommended to have endovascular treatment,while surgery was recommended in 59 patients.71.2%of the study population underwent the recommended therapy.CONCLUSION CTA is a reproducible promising diagnostic imaging modality for detecting and characterizing cerebral aneurysms.
文摘BACKGROUND: Digital subtraction angiography (DSA) is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascular complication. Three-dimensional computed tomography angiography (3D-CTA) can make up deficiencies of DSA; therefore, it is used in clinical therapy wider and wider. OBJECTIVE: To evaluate the clinical effect of 3D-CTA on disruption and hemorrhage of intracranial aneurysm pre- and post-operation and compare with the effect of DSA.DESIGN: Auto-control contrast observation.SETTING: Department of Neurosurgery, Shengjing Hospital of China Medical University.PARTICIPANTS: A number of 106 patients with disruption and hemorrhage of intracranial aneurysm were selected from the Department of Neurosurgery, Shengjing Hospital of China Medical University from January 2003 to April 2006. All patients were diagnosed with cranial operation and consent. There were 47 males and 59 females aged from 3-76 years with the mean age of (47±13) years. Among them, 82 patients had extensive subarachnoid hemorrhage (SAH), 7 had hemorrhage at longitudinal fissure, and 17 had hemorrhage at ambiens cisterna and lateral fissure. Moreover, intraventricular hematocele was accompanied on 13 patients and hematom on 9 patients. METHODS: ① 3D-CTA examination: Siemens SOMATOM Sensation 64 CT was used in this study. The thickness was 1 mm and interval of reconstruction was 0.8 mm. Localizing section was plainly scanned as the standard of canthus line. Scan ranged from 30 mm below sella to 50 mm above sella. Non-ion contrast medium of Omnipaque 350 (concentration of iodine was 350 g/L) was inserted into anterior vein of elbow with 18G trochar retained with high-pressured injectoc pum. The speed was 4.5 mL/s and the total volume was 80-100 mL with the means of 90 mL. Scan started at 10-20 s after injection of contrast medium. Original image was dealt with Leonardo workstation and retreated with Syngo software. Volume rendering and maximum intensity projection were used to reconstructed images. ② All 106 patients suffered from occlusion of aneurysm clamp. Before operation, 3D-CTA was undertaken and DSA was followed. After operation, patients were rechecked with 3D-CTA. MAIN OUTCOME MEASURES: Comparisons between 3D-CTA and DSA.RESULTS: All 106 patients were involved in the final analysis. ① Examination of 3D-CTA and DSA: Among 118 patients with aneurysm, 110 were checked with 3D-CTA and the detected rate was 93.2% (110/118). Among other 8 cases, 3 were negative and checked again with DSA; 1 had pericallosal aneurysm, 1 ophthalmic aneurysm, and 1 anterior choroidal artery of aneurysm. 3D-CTA results of other 5 cases were suspicious, and then, they were regarded as having aneurysm with DSA. Before operation, correlation among site, body, neck of aneurysm and peripheral anatomic structure were shown sufficiently. After operation, 82 patients were rechecked with 3D-CTA, which was complete occlusion, precise, unobvious constriction, emphraxis or remains as compared with 3D-CTA those pre-operation. ② Characteristics of 3D-CTA: With multiple vessels and angles, 3D-CTA observed the relationship between aneurysm neck and carried artery and showed thrombosis in cavity of aneurysm, calcification of aneurysm wall and peripheral structure of vessel at the same time. However, DSA could not detect the reactions mentioned above. It could delete image of cranium, simulate image of operative route, eliminate artifact induced by metal, but not distinguish blood stream direction. Meanwhile, posterior communicating artery was always poor during circle of Willis artery showing. CONCLUSION: ① 3D-CTA is characterized by simple operation and non-invasive showing vascular stereo structure and correlation. Therefore, it is significant for diagnosis and designing plan of operative approach and focal location pre-operation and evaluating effect post-operation. ② 3D-CTA does not completely replace DSA on the diagnosis of intracranial aneurysm.
文摘Carotid artery stenosis causes narrowing of carotid lumens and may lead to brain infarction. The purpose of this study was to develop a semi-automated method of segmenting vessel walls, surrounding tissues, and more importantly, the carotid artery lumen by contrast computed tomography angiography(CTA) images and to define the severity of stenosis and present a three-dimensional model of the carotid for visual inspection. In vivo contrast CTA images of 14 patients(7 normal subjects and 7 patients undergoing endarterectomy) were analyzed using a multi-step segmentation algorithm. This method uses graph cut followed by watershed and Hessian based shortest path method in order to extract lumen boundary correctly without being corrupted in the presence of surrounding tissues.Quantitative measurements of the proposed method were compared with those of manual delineation by independent board-certified radiologists. The results were quantitatively evaluated using spatial overlap surface distance indices. A slightly strong match was shown in terms of dice similarity coefficient(DSC) = 0.87±0.08; mean surface distance(D_(msd))= 0.32±0.32; root mean squared surface distance(D_(rmssd)) = 0.49±0.54 and maximum surface distance(D_(max))=2.14±2.08 between manual and automated segmentation of common, internal and external carotid arteries, carotid bifurcation and stenotic artery, respectively. Quantitative measurements showed that the proposed method has high potential to segment the carotid lumen and is robust to the changes of the lumen diameter and the shape of the stenosis area at the bifurcation site. The proposed method for CTA images provides a fast and reliable tool to quantify the severity of carotid artery stenosis.
文摘Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Upper gastrointestinal endoscopy is currently recommended as the gold standard modality for both diagnosis and treatment,with computed tomography traditionally playing a limited role in the diagnosis of acute NVUGIB.Following the introduction of multidetector computed tomography(MDCT),this modality is emerging as a promising tool in the diagnosis of NVUGIB.However,to date,evidence concerning the role of MDCT in the NVUGIB diagnosis is still lacking.The aim of our study was to review the current evidence concerning the role of MDCT in the diagnosis of acute NVUGIB.
文摘BACKGROUND The aim of this study was to define clinical evidence supporting that triple ruleout computed tomography angiography(TRO CTA)is a comprehensive and feasible diagnostic tool in patients with novel coronavirus disease 2019(COVID-19)who were admitted to the emergency department(ED)for acute chest pain.Optimizing diagnostic imaging strategies in COVID-19 related thromboembolic events,will help for rapid and noninvasive diagnoses and results will be effective for patients and healthcare systems in all aspects.AIM To define clinical evidence supporting that TRO CTA is a comprehensive and feasible diagnostic tool in COVID-19 patients who were admitted to the ED for acute chest pain,and to assess outcomes of optimizing diagnostic imaging strategies,particularly TRO CTA use,in COVID-19 related thromboembolic events.METHODS TRO CTA images were evaluated for the presence of coronary artery disease,pulmonary thromboembolism(PTE),or acute aortic syndromes.Statistical analyses were used for evaluation of significant association between the variables.A two tailed P-value<0.05 was considered statistically significant.RESULTS Fifty-three patients were included into the study.In 31 patients(65.9%),there was not any pathology,while PTE was diagnosed in 11 patients.There was no significant relationship between the rates of pathology on CTA and history of hypertension.On the other hand,the diabetes mellitus rate was much higher in the acute coronary syndrome group,particularly in the PTE group(8/31=25.8%vs 6/16=37.5%,P=0.001).The rate of dyslipidemia was significantly higher in the group with pathology on CTA while compared to those without pathology apart from imaging findings of the pneumonia group(62.5%vs 38.7%,P<0.001).Smoking history rates were similar in the groups.Platelets,D-dimer,fibrinogen,C-reactive protein,and erythrocyte sedimentation rate values were higher in COVID-19 cases with additional pathologies.CONCLUSION TRO CTA is an effective imaging method in evaluation of all thoracic vascular systems at once and gives accurate results in COVID-19 patients.
文摘<strong>Objective: </strong>Perivascular fat attenuation index (FAI) measurement on non-contrast-enhanced cardiac computed tomography (NCCT) has not been rigorously validated in previous studies. Herein, we compared perivascular FAI values between NCCT and coronary computed tomography angiography (CCTA). We also investigated the variability and reproducibility of perivascular FAI measurement. <strong>Methods: </strong>A total of 44 patients who underwent NCCT and CCTA were included in this study. For NCCT, perivascular FAI was measured using three threshold settings: from <span style="white-space:nowrap;">−</span>30 to <span style="white-space:nowrap;">−</span>190 Hounsfield Units (HU), <span style="white-space:nowrap;">−</span>20 to <span style="white-space:nowrap;">−</span>180 HU, and <span style="white-space:nowrap;">−</span>10 to <span style="white-space:nowrap;">−</span>170 HU. For CCTA, perivascular FAI was measured using one threshold setting: from <span style="white-space:nowrap;">−</span>30 to <span style="white-space:nowrap;">−</span>190 HU. Perivascular FAI measurements by NCCT were compared with those by CCTA using the paired t-test, and correlations were assessed using Pearson’s correlation coefficient. The intra- and inter-observer variabilities for the measurements with NCCT and CCTA were evaluated with the intraclass correlation coefficient. <strong>Results:</strong> Perivascular FAI measurements with the threshold setting of <span style="white-space:nowrap;">−</span>30 to <span style="white-space:nowrap;">−</span>190 HU were significantly lower on NCCT than on CCTA. There were no significant differences between the perivascular FAI measurements at the remaining thresholds on NCCT and those on CCTA. The perivascular FAI at all thresholds on NCCT correlated significantly with those on CCTA. The intra- and inter-observer agreements were excellent for the measurements on NCCT and CCTA. <strong>Conclusion: </strong>There were significant differences between the perivascular FAI measurements on NCCT and CCTA. However, the differences could be modified by threshold adjustment.
文摘The purpose of this research is to investigate the feasibility of using low contrast agent concentration with X-ray computed tomography in visualizing and diagnosing the human vascular system while minimizing the risk of toxicity to the patient. This research investigated the effect of several iodine contrast agent concentrations on the ability to extract and visualize human vessels using simulated computed tomography scans. Monte Carlo simulation was used to perform these computed tomography acquisitions. The simulated patient was based on actual computed tomography angiography data, where a technique was developed to simulate brain vessels with contrast agents ranging from 0 mg to 20 mg of iodine. The simulation used segmented patient data along with basic image processing techniques to model the various levels of iodine concentrations. Cone beam computed tomography projections of a patient injected with and without iodine were acquired in the simulations. Subtraction of the corresponding projections was performed to generate images caused by the contrast agent. Then, histogram analysis of these differences was used to assess the validity of extracting and visualizing the human vessels. The smallest amount of iodine, 0.5 mg, helped better visualize the brain vessels and 2 mg of iodine was high enough to show almost 90% of the vessels. Additionally, the vessels were clearly visible in all the subtracted images. This research showed very promising outcomes in using low concentrations of iodine. Thus, this study proposes for the pharmaceutical companies and others interested to clinically investigate and evaluate the efficacy of using low concentrations of iodine and the associated side effects.
文摘Aortic dissection (AD) is a life-threatening clinical emergency requiring rapid diagnosis and effective intervention to improve patient survival and prognosis. Computed tomography angiography (CTA) can be used to diagnose AD accurately and quickly, making it the first choice for diagnosing AD in an emergency. This article reviews the application of CTA in the diagnosis and treatment of AD.
基金Supported by the National Natural Science Foundation of China,Nos.61971350,81627807 and 11727813the National Key R&D Program of China,No.2016YFC1300300+3 种基金the China Postdoctoral Science Foundation,No.2019M653717Shaanxi Science Funds for Distinguished Young Scholars,No.2020JC-27Fok Ying Tung Education Foundation,No.161104and Program for the Young Topnotch Talent of Shaanxi Province.
文摘Coronary artery disease(CAD)has become a major illness endangering human health.It mainly manifests as atherosclerotic plaques,especially vulnerable plaques without obvious symptoms in the early stage.Once a rupture occurs,it will lead to severe coronary stenosis,which in turn may trigger a major adverse cardiovascular event.Computed tomography angiography(CTA)has become a standard diagnostic tool for early screening of coronary plaque and stenosis due to its advantages in high resolution,noninvasiveness,and three-dimensional imaging.However,manual examination of CTA images by radiologists has been proven to be tedious and time-consuming,which might also lead to intra-and interobserver errors.Nowadays,many machine learning algorithms have enabled the(semi-)automatic diagnosis of CAD by extracting quantitative features from CTA images.This paper provides a survey of these machine learning algorithms for the diagnosis of CAD in CTA images,including coronary artery extraction,coronary plaque detection,vulnerable plaque identification,and coronary stenosis assessment.Most included articles were published within this decade and are found in the Web of Science.We wish to give readers a glimpse of the current status,challenges,and perspectives of these machine learning-based analysis methods for automatic CAD diagnosis.
基金National Natural Science Foundation of China,No.82071920 and No.81901741and the Key Research&Development Plan of Liaoning Province,No.2020JH2/10300037.
文摘Coronary computed tomography angiography(CCTA)is recommended as a frontline diagnostic tool in the non-invasive assessment of patients with suspected coronary artery disease(CAD)and cardiovascular risk stratification.To date,artificial intelligence(AI)techniques have brought major changes in the way that we make individualized decisions for patients with CAD.Applications of AI in CCTA have produced improvements in many aspects,including assessment of stenosis degree,determination of plaque type,identification of high-risk plaque,quantification of coronary artery calcium score,diagnosis of myocardial infarction,estimation of computed tomography-derived fractional flow reserve,left ventricular myocardium analysis,perivascular adipose tissue analysis,prognosis of CAD,and so on.The purpose of this review is to provide a comprehensive overview of current status of AI in CCTA.
文摘This letter to the editor relates to the study entitled“The role of computed tomography for the prediction of esophageal variceal bleeding:Current status and future perspectives”.Esophageal variceal bleeding(EVB)is one of the most common and severe complications related to portal hypertension(PH).Despite marked advances in its management during the last three decades,EVB is still associated with significant morbidity and mortality.The risk of first EVB is related to the severity of both PH and liver disease,and to the size and endoscopic appearance of esophageal varices.Indeed,hepatic venous pressure gradient(HVPG)and esophagogastroduodenoscopy(EGD)are currently recognized as the“gold standard”and the diagnostic reference standard for the prediction of EVB,respectively.However,HVPG is an invasive,expensive,and technically complex procedure,not widely available in clinical practice,whereas EGD is mainly limited by its invasive nature.In this scenario,computed tomography(CT)has been recently proposed as a promising modality for the non-invasive prediction of EVB.While CT serves solely as a diagnostic tool and cannot replace EGD or HVPG for delivering therapeutic and physiological information,it has the potential to enhance the prediction of EVB more effectively when combined with liver disease scores,HVPG,and EGD.However,to date,evidence concerning the role of CT in this setting is still lacking,therefore we aim to summarize and discuss the current evidence concerning the role of CT in predicting the risk of EVB.
文摘Coronary artery abnormalities are the most important complications in children with Kawasaki disease(KD).Two-dimensional transthoracic echocardiography currently is the standard of care for initial evaluation and follow-up of children with KD.However,it has inherent limitations with regard to evaluation of mid and distal coronary arteries and,left circumflex artery and the poor acoustic window in older children often makes evaluation difficult in this age group.Catheter angiography(CA)is invasive,has high radiation exposure and fails to demonstrate abnormalities beyond lumen.The limitations of echocardiography and CA necessitate the use of an imaging modality that overcomes these problems.In recent years advances in computed tomography technology have enabled explicit evaluation of coronary arteries along their entire course including major branches with optimal and acceptable radiation exposure in children.Computed tomography coronary angiography(CTCA)can be performed during acute as well as convalescent phases of KD.It is likely that CTCA may soon be considered the reference standard imaging modality for evaluation of coronary arteries in children with KD.
文摘BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data on radiation dose in this group of children undergoing CTCA.AIM To audit the radiation dose of CTCA in children with KD.METHODS Study(December 2013-February 2018)was performed on dual source CT scanner using adaptive prospective electrocardiography-triggering.The dose length product(DLP in milligray-centimeters-mGy.cm)was recorded.Effective radiation dose(millisieverts-mSv)was calculated by applying appropriate age adjusted conversion factors as per recommendations of International Commission on Radiological Protection.Radiation dose was compared across the groups(0-1,1-5,5-10,and>10 years).RESULTS Eighty-five children(71 boys,14 girls)with KD underwent CTCA.The median age was 5 years(range,2 mo-11 years).Median DLP and effective dose was 21 mGy.cm,interquartile ranges(IQR)=15(13,28)and 0.83 mSv,IQR=0.33(0.68,1.01)respectively.Mean DLP increased significantly across the age groups.Mean effective dose in infants(0.63 mSv)was significantly lower than the other age groups(1-5 years 0.85 mSv,5-10 years 1.04 mSv,and>10 years 1.38 mSv)(P<0.05).There was no significant difference in the effective dose between the other groups of children.All the CTCA studies were of diagnostic quality.No child required a repeat examination.CONCLUSION CTCA is feasible with submillisievert radiation dose in most children with KD.Thus,CTCA has the potential to be an important adjunctive imaging modality in children with KD.
文摘Esophageal variceal bleeding(EVB)is one of the most common and severe complications related to portal hypertension(PH).Despite marked advances in its management during the last three decades,EVB is still associated with significant morbidity and mortality.The risk of first EVB is related to the severity of both PH and liver disease,and to the size and endoscopic appearance of esophageal varices.Indeed,hepatic venous pressure gradient(HVPG)and esophagogastroduodenoscopy(EGD)are currently recognized as the“gold standard”and the diagnostic reference standard for the prediction of EVB,respectively.However,HVPG is an invasive,expensive,and technically complex procedure,not widely available in clinical practice,whereas EGD is mainly limited by its invasive nature.In this scenario,computed tomography(CT)has been recently proposed as a promising modality for the non-invasive prediction of EVB.Although CT is only a diagnostic modality,thus being not capable of supplanting EGD or HVPG in providing therapeutic and physiological data,it could potentially assist liver disease scores,HVPG,and EGD in a more effective prediction of EVB.However,to date,evidence concerning the role of CT in this setting is still lacking.Our review aimed to summarize and discuss the current evidence concerning the role of CT in predicting the risk of EVB.
文摘BACKGROUND Primary aortoduodenal fistula is a rare cause of gastrointestinal(GI)bleeding consisting of abnormal channels between the aorta and GI tract without previous vascular intervention that results in massive intraluminal hemorrhage.CASE SUMMARY A 67-year-old man was hospitalized for coffee ground vomiting,tarry stools,and colic abdominal pain.He was repeatedly admitted for active GI bleeding and hypovolemic shock.Intermittent and spontaneously stopped bleeders were undetectable on multiple GI endoscopy,angiography,computed tomography angiography(CTA),capsule endoscopy,and ^(99)mTc-labeled red blood cell(RBC)scans.The patient received supportive treatment and was discharged without signs of rebleeding.Thereafter,he was re-admitted for bleeder identification.Repeated CTA after a bleed revealed a small aortic aneurysm at the renal level contacting the fourth portion of the duodenum.A ^(99)mTc-labeled RBC singlephoton emission CT(SPECT)/CT scan performed during bleeding symptoms revealed active bleeding at the duodenal level.According to his clinical symptoms(intermittent massive GI bleeding with hypovolemic shock,dizziness,dark red stool,and bloody vomitus)and the abdominal CTA and ^(99)mTc-labeled RBC SPECT/CT results,we suspected a small aneurysm and an aortoduodenal fistula.Subsequent duodenal excision and duodenojejunal anastomosis were performed.A 7-mm saccular aneurysm arising from the anterior wall of the abdominal aorta near the left renal artery was identified.Percutaneous intravascular stenting of the abdominal aorta was performed and his symptoms improved.CONCLUSION Our findings suggest that ^(99)mTc-labeled RBC SPECT/CT scanning can aid the diagnosis of a rare cause of active GI bleeding.
文摘BACKGROUND The course and variations of thyroid arteries must be understood by surgeons to prevent bleeding during operative procedures of the thyroid gland.There is limited scientific literature regarding the radiological anatomy of thyroid arteries in this geographical area,the Garhwal region of Sub-Himalayan belt,which is considered to be the endemic belt of goiter.Computed tomography angiography provides a three-dimensional orientation of the vascular and surgical anatomy of the entire cervical region.AIM To estimate the proportion of variation in origin of thyroid arteries using Computed Tomography Angiography.METHODS Using Computed Tomography Angiography,the presence and origin of the superior thyroid artery,inferior thyroid artery,and thyroid ima artery were observed and assessed.RESULTS Out of total 210 subjects,superior thyroid artery was seen to be emerging from external carotid artery in 77.1%cases.The artery was found to be originating at the level of bifurcation of common carotid artery in 14.3%cases,whereas in 8.6%cases,it emerged as a direct branch of the common carotid artery.Similarly,the inferior thyroid artery was observed to be emerging from thyrocervical trunk,subclavian artery and vertebral artery in 95.7%cases,3.3%and 1%cases,respectively.Thyroid ima artery was also reported in a subject,arising from the brachiocephalic trunk.CONCLUSION To avoid vascular injuries,excessive and uncontrollable bleeding,intra-operative difficulties,and post-operative issues,it is imperative for surgeons to be aware of the course and variations of thyroid arteries。
基金The work was supported partially by NSF ECS-0555394 and NIH/NIBIB EB004287.
文摘A high contrast to noise ratio(CNR)is always desirable for contrast-enhanced computed tomography angiography(CTA).To ensure a high CNR of the vascular images in CTA and potentially reduce the radiation exposure and contrast usage,an adaptive bolus chasing method is proposed and evaluated compared to the existing constant-speed method.The proposed method is based on a local time and space parameter varying model of the contrast bolus.Optimal scan time for the next segment of the vasculature is estimated and predicted in real time and guides the computed tomography(CT)scanner table movement that guarantees that each segment of the vasculature is scanned with the maximum possible enhancement.Simulations and experimental results show that the proposed bolus chasing method outperforms the conventional constant-speed method substantially.
文摘Aim:Anterolateral thigh(ALT)flap is widely used in reconstruction of various defects.Preoperative imaging facilitates perforator mapping,overcoming intraoperative uncertainty.The purpose of this study was to investigate the utility of multi-detector row computed tomography angiography(MDCTA)and a handheld Doppler in locating ALT perforators.Methods:Twenty patients were randomized into two groups.Group 1 patients received MDCTA and Doppler studies whereas Group 2 received only a Doppler study.The number,location,course,and source of all cutaneous and sizable perforators were compared with intraoperative findings.Surgeons’stress levels during flap harvest and flap harvest time were compared.Results:MDCTA findings correlated well with intraoperative findings for perforator type and segmental distribution with 100%concordance.Doppler alone had a 52%rate of concordance.The sensitivity and specificity for MDCTA in demonstrating the presence of perforators were 85.71%and 97.22%,respectively;whereas for Doppler alone the sensitivity and specificity were 80%and 87.91%,respectively.In demonstrating perforator source,MDCTA showed a sensitivity of 100%and specificity of 91.66%,with 100%accuracy.Sensitivity and specificity for sizable perforators were 90%each,with 88.88%accuracy.Doppler studies were unable to provide this information.Comparison of surgeon stress levels showed no differences between the two groups,although the time for flap harvest was significantly shorter in Group 1.Conclusion:MDCTA compared to Doppler is more sensitive,specific,and accurate with respect to location,course,and source of perforators.
