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1.
电子束CT诊断肺动脉栓塞   总被引:3,自引:1,他引:3  
目的 ::评价电子束 CT(EBCT)对肺动脉栓塞的诊断价值与优势。方法 :对 2 0 0 2 - 0 5~ 2 0 0 3- 0 4经 EBCT确诊的 9例肺栓塞的 CT征象进行分析 ,探讨其诊断价值。结果 :左、右两侧段以上肺动脉发生栓塞的几率相近 ,右侧5 2 .6 % (71/ 135 ) ,左侧 4 9.6 % (6 7/ 135 ) ,右侧略高。但左侧闭塞的段以上肺动脉有 19支 ,右侧仅 4支。各叶段以上肺栓塞的发生率以下叶最高 ,达 6 1.1% (6 6 / 10 8) ,其次为上叶的 4 5 .8% (33/ 72 )和中叶及舌叶的 4 0 .7% (2 2 / 5 4 )。左、右中间肺动脉的栓塞率为 5 0 % (9/ 18)。 36 0支亚段肺动脉中有 115支栓塞 (31.9% ) ,其中明确的栓塞 76支 (包括 2 6支闭塞 ) ,可疑 39支。肺栓塞的 EBCT直接征象 :管腔内中心性或偏心性充盈缺损及“轨道征”、“漂浮征”和完全闭塞 (闭塞血管管径大于正常管径 )。间接征象 :偶可见“马赛克征”和梗死灶 ,多数见局限性肺纹理稀疏。另外还有胸水、肺动脉及右心轻度扩张等。结论 :电子束 CT扫描速度快 ,运动伪影小 ,对段以上肺栓塞能清晰显像并准确诊断 ,可作为肺栓塞的首选无创性检查方法。局限性是空间分辨率低 ,对亚段以下肺动脉栓塞的评价并不十分可靠。  相似文献   

2.
Computed tomography pulmonary angiography (CTPA) is now an established test in the diagnosis of suspected pulmonary embolism (PE). Some may argue that it has become the "one-stop" center for diagnosis and prognosis of acute PE and deep vein thrombosis (DVT). Current literature shows CTPA to be reliable and accurate. Management studies have shown patient outcomes are excellent when CTPA is used in the diagnostic algorithm. The addition of computed tomography venography (CTV) increases the sensitivity, which may be worth the added radiation in certain patient populations. Although measures of right heart function, pulmonary artery pressures, and clot burden via CTPA need to be standardized and further validated prospectively, this test may also play a prominent role in determining short-term outcomes in patients with established acute PE.  相似文献   

3.
Pulmonary embolism (PE) remains difficult to diagnose. Ventilation perfusion lung scan, the standard diagnostic test for PE, has poor overall sensitivity. The gold standard examination, pulmonary angiography, is invasive and has some risk, making clinicians reluctant to refer patients. In recent years, new diagnostic modalities have been investigated, including D-Dimer assays, spiral computed tomography (CT), and magnetic resonance imaging (MRI). The authors reviewed the literature and noted that the D-Dimer assays by ELISA or rapid ELISA design are approximately 90% to 95% sensitive, but are not specific for the diagnosis of pulmonary embolism. Spiral CT has been studied with conflicting results; however, in the largest studies the reported sensitivities are greater than approximately 85%. Electron beam CT is an alternative technique, which has not been as extensively studied. MRI is also useful for imaging the pulmonary arterial vasculature, but remains experimental. Although a more accurate assessment of the sensitivity of these new modalities will need to wait until a large angiographically controlled study, such as the planned PIOPED II, can be done, D-Dimer assay and spiral CT are often useful in the detection of pulmonary embolism. The authors make recommendations for their use in a diagnostic algorithm, as alternatives to the standard ventilation perfusion lung scan.  相似文献   

4.
Spiral computed tomography is a new noninvasive diagnostic test for pulmonary embolism. The method provides tomographic images of the thorax in the axial plane, which depict the thoracic wall, the mediastinum, the lungs, and the pulmonary vessels. Thrombotic emboli in the vessels are seen as intraluminal filling defects in the contrast-enhanced pulmonary arteries. The physical principles of spiral computed tomography and several technical considerations concerning image quality will be briefly discussed. The accuracy of spiral computed tomography in the detection of pulmonary embolism is discussed by way of an overview of published validation and clinical outcome studies encompassing spiral computed tomography and the diagnosis of pulmonary embolism.  相似文献   

5.
Endobronchial ultrasound (EBUS) is a new technique that can be used for the diagnostic imaging of central pulmonary thromboembolism (PE). In eight cases at our clinic, EBUS was used because of mediastinal lymphadenopathies or paramediastinal nodular lesions and at the same time images were obtained of a PE by means of EBUS. The PE was diagnosed before the EBUS with computed tomography (CT) of the lungs in all cases (5 women and 3 men). The repletion defects of all the cases compatible with a PE were clarified with CT-angiography. EBUS may be an alternative method for the diagnosis of PE, as it can indicate the presence of a thrombus in the central pulmonary arteries in hemodynamically-stable cases.  相似文献   

6.
Forty-six consecutive patients with pulmonary embolism (PE) who underwent pulmonary angiography, helical computed tomography (CT), and echocardiography in the investigators' emergency department were studied. It was determined that the CT right ventricular (RV)/left ventricular (LV) end-diastolic area ratio was correlated with PE obstruction and echocardiography. A CT RV/LV area ratio >1 had a sensitivity of 88% and a specificity of 88% in diagnosing significant PE. The present study suggests that helical CT may be used as a triage tool in acute PE for selecting high-risk patients, using calculation of the RV/LV area ratio to detect RV dysfunction.  相似文献   

7.
PURPOSE: We investigated the quality and usefulness of spiral computed tomography and three-dimensional reconstruction in children with obstruction of the central airways as a complication of congenital heart disease. MATERIALS AND METHODS: Spiral computed tomography with three-dimensional reconstruction was performed in 49 children with obstruction of the central airways seen as a complication of congenital heart disease. Spiral scanning was performed during breathing in 40, and after sedation with chloral hydrate in 38. Contrast medium was administered through a pedal venous route in 42. We analyzed the motion artifact, additional information provided by, and clinical usefulness, of the three-dimensional images. We also investigated the factors influencing the quality of the images. RESULTS: Stenoses were seen in the trachea in 21 patients, and in bronchuses in 28. Their causes were an anomaly of the aortic arch in 6, posterior displacement of the aortic arch in 7, posterior displacement of the ascending aorta in 5, compression of the brachiocephalic artery in 5, absent pulmonary valve syndrome in 6, displaced or dilated cardiovascular structure in 17, and pulmonary arterial sling in 2. Motion artifact caused mild or negligible degradation of images in all patients except 6. Breath-holding in non-sedated children produced more severe motion artifact than did cardiovascular pulsation. Three-dimensional images provided additional information over two-dimensional images in 11, and provided clinically useful information in 10. Contrast injection via the pedal route was better for the quality of three-dimensional images than brachiocephalic injection (p = 0.013). CONCLUSIONS: Three-dimensional computed tomography is useful in evaluation of obstruction of the central airways in children with congenital heart disease. Despite the fact that motion artifact is unavoidable, the quality of three-dimensional images is acceptable for making a proper and accurate diagnosis. A pedal route is recommended for injection of contrast medium.  相似文献   

8.
The diagnosis of pulmonary embolism (PE) requires objective testing. However, all imaging techniques have their own limitations and costs and cannot be performed in every patient with suspected PE. After decades of unfruitful research, several laboratory tests have been evaluated for suspected PE, the most promising being the D-dimer test. As a general rule, the specificity of D-dimers is too low to confirm PE. Conversely, several (but not all) D-dimer assays have a high sensitivity for diagnosing PE. Outcome studies indicate that the Vidas D-dimer and SimpliRED D-dimer can be used safely to withdraw anticoagulation when the pretest probability of PE is low (SimpliRED) or when it is low or moderate (Vidas). These results may however not apply to other D-dimer assays and clinicians should know the characteristics of the test used in their hospital. Blood gas analysis does not have sufficient sensitivity and specificity to confirm or exclude PE, but it may be used to evaluate the clinical probability of PE before other testing is done. The diagnostic value of the alveolar dead space fraction in patients with suspected PE is currently investigated. Initial data suggest that it needs to be combined with a D-dimer test to safely exclude PE. Brain natriuretic peptide and cardiac troponin have limited usefulness for diagnosing PE, but both tests may identify patients with a poor prognosis, in whom more aggressive treatment may be warranted.  相似文献   

9.
目的探讨螺旋CT肺动脉造影在老年肺动脉栓塞(PE)诊断中的临床应用价值。方法采用螺旋CT对66例老年PE患者行肺动脉增强扫描,其中多层、单层螺旋CT(MSCT,SCT)肺动脉造影检查者各为21和45例。结果分析66例老年PE患者的2728支肺动脉,MSCT、SCT肺动脉造影共显示926支肺动脉受累。直接征象为中心型充盈缺损、部分型充盈缺损、完全性阻塞、附壁性充盈缺损,约占33.9%;1206支段以上肺动脉中,依据直接征象MSCT、SCT分别检出240支/384支(62.5%)和481支/822支(58.5%),共721支/1206支,两者检出率无明显差别(P=0.037);1522支亚段肺动脉中,MSCT、SCT分别检出121支/484支(25.0%)和84支/1038支(8.1%),共205支/1522支,前者检出率明显高于后者(P=0.632)。平扫示间接征象共125例次。结论MSCT、SCT对段以上PE的诊断二者均有较高的准确度,MSCT对亚段PE的诊断有其优势。  相似文献   

10.
The requirement for a safe diagnostic strategy should be based on an overall posttest incidence of venous thromboembolism (VTE) of less than 1%, with a negative predictive value of more than 99 to 100% during 3-month follow-up. Compression ultrasonography (CUS) and spiral computed tomography (CT) currently are the methods of choice to confirm or rule out deep venous thrombosis (DVT) and pulmonary embolism (PE), respectively. CUS has a negative predictive value (NPV) of 97 to 98%, indicating the need to improve the diagnostic work-up of patients with suspected DVT by clinical score assessment and D-dimer testing. Spiral CT as a stand-alone method detects all clinically relevant PEs and a large number of alternative diagnoses. It rules out PE with a NPV of 98 to 99%. Spiral CT is expensive, emphasizing the need to improve the diagnostic work-up of patients with suspected PE by the use of clinical score assessment and D-dimer testing. Clinical score assessment for DVT and PE has not safely ruled out VTE in multicenter studies and in routine daily practices. Modification of the Wells clinical score assessment for DVT by elimination of the "minus 2 points" for alternative diagnosis will improve the reproducibility of the clinical score assessment. The combination of a first negative CUS and a negative SimpliRed or an enzyme-linked immunosorbent assay (ELISA) VIDAS D-dimer of < 1,000 ng/mL safely exclude DVT (NPV > 99%) irrespective of clinical score assessment and without the need to repeat CUS in approximately 60 to 70% of patients. The rapid quantitative and qualitative agglutination D-dimer assays for the exclusion of VTE are not sensitive enough as stand-alone tests and should be used in combination with clinical score assessment. A normal rapid ELISA VIDAS D-dimer test as a stand-alone test safely excludes DVT and PE, with a NPV of 99 to 100%, irrespective of clinical score, without the need of CUS or spiral CT. The combined strategy of a rapid ELISA VIDAS D-dimer followed by objective testing with CUS for DVT and by spiral CT for PE will reduce the need for noninvasive imaging techniques by 40 to 50%.  相似文献   

11.
Treatment of acute massive/submassive pulmonary embolism.   总被引:3,自引:0,他引:3  
Thirty-five consecutive patients with massive and submassive pulmonary embolism (PE) were reviewed. In 75% of these cases, PE could be suspected on the basis of electrocardiogram alone. Echocardiography was quite useful for diagnosing PE and assessing right ventricle after-load at the bedside. Spiral computer tomography was effective for obtaining a definitive diagnosis even in a relatively hemodynamically unstable patient. Thrombolysis therapy was given to 30 cases and was apparently effective in 17 cases (17/30, 56.7%). Percutaneous cardiopulmonary support (PCPS) was needed for 7 severe cases. Seven patients, including 5 of the PCPS recipients, underwent surgical embolectomy. Overall mortality was 28.6% (10/35), and surgical mortality was 28.6% (2/7). The significant predictors for mortality were systolic blood pressure <100 mmHg, dopamine >5 microg x kg(-1) min(-1), pH <7.4, PaCO2 >40 torr, base excesss <-5 mmol/L, urine output <0.8ml x kg(-1) x h(-1), intubation, cardiopulmonary resuscitation, duration from attack to emergency room >5h, shock duration >4h, aspartate aminotransferase >100U/L, alanine aminotransferase >100U/L and lactate dehydrogenase >600U/L. Predictors of surgical intervention were dopamine >5 microg x kg(-1) min(-1), shock duration >4h and PCPS. Early initiation of thombolysis therapy is recommended, except in case where it is absolutely contraindicated. Because it is difficult in the early phase of PE to make a decision to perform surgery, aggressive application of PCPS is recommended for the cardiogenic shock associated with massive PE.  相似文献   

12.
This clinical policy from the American College of Emergency Physicians is the revision of a 2003 clinical policy on the evaluation and management of adult patients presenting with suspected pulmonary embolism (PE).(1) A writing subcommittee reviewed the literature to derive evidence-based recommendations to help clinicians answer the following critical questions: (1) Do objective criteria provide improved risk stratification over gestalt clinical assessment in the evaluation of patients with possible PE? (2) What is the utility of the Pulmonary Embolism Rule-out Criteria (PERC) in the evaluation of patients with suspected PE? (3)What is the role of quantitative D-dimer testing in the exclusion of PE? (4) What is the role of computed tomography pulmonary angiogram of the chest as the sole diagnostic test in the exclusion of PE? (5) What is the role of venous imaging in the evaluation of patients with suspected PE? (6) What are the indications for thrombolytic therapy in patients with PE? Evidence was graded and recommendations were given based on the strength of the available data in the medical literature.  相似文献   

13.
IntroductionContrast-enhanced multidetector computed tomography (MDCT) is useful for the diagnosis of pulmonary embolism (PE). However, current guidelines do not support its use for risk assessment in acute PE patients.ObjectivesWe compared the prognostic impact of MDCT-derived indices regarding medium-term mortality in a population of intermediate- to high-risk PE patients, mostly treated by thrombolysis.MethodsThirty-nine consecutive patients admitted to an intensive care unit with acute PE were studied. All patients had a pulmonary MDCT on admission to the emergency room as part of the diagnostic algorithm. We assessed the following MDCT variables: right ventricular/left ventricular diameter (RV/LV) ratio, arterial obstruction index, pulmonary artery-to-aorta diameter ratio and azygos vein diameter. A 33-month follow-up was performed.ResultsMean age was 59.1±19.6 years, with 80% of patients receiving thrombolysis. Follow-up all-cause mortality was 12.8%. Of the MDCT-derived variables, only the RV/LV ratio had significant predictive value, being higher in patients who suffered the endpoint (1.6±0.5 vs. 1.9±0.4, p=0.046). Patients with an RV/LV ratio ≥1.8 had 11-fold higher medium-term all-cause mortality (3.8% vs. 38.8%, p<0.001). Regarding this endpoint, the c-statistic was 0.78 (95% CI, 0.60–0.96) for RV/LV ratio and calibration was good (goodness-of-fit p=0.594). No other radiological index was predictive of mortality.ConclusionsMDCT gives the possibility, in a single imaging procedure, of diagnosing and assessing the prognosis of patients with intermediate- to high-risk PE. Although further studies are needed, the simple-to-calculate RV/LV ratio has good discrimination and calibration for predicting poorer outcomes in patients with acute PE.  相似文献   

14.
Patel MM  Rayburn DB  Browning JA  Kline JA 《Chest》1999,116(5):1325-1332
BACKGROUND: Pulmonary embolism (PE) produces ventilation/perfusion mismatch that may be manifested in various variables of the volume-based capnogram (VBC). We hypothesized that a neural network (NN) system could detect changes in VBC variables that reflect the presence of a PE. METHODS: A commercial VBC system was used to record multiple respiratory variables from consecutive expiratory breaths. Data from 12 subjects (n = 6 PE+ and n = 6 PE-) were used as input to a fully connected back-propagating NN for model development. The derived model was tested in a prospective, observational study at an urban teaching hospital. Volumetric capnograms were then collected on 53 test subjects: 30 subjects with PE confirmed by pulmonary angiography or diagnostic scintillation lung scan, and 23 subjects without PE based on pulmonary angiography. The derived NN model was applied to VBC data from the test population. RESULTS: Seventeen VBC variables were used by the derived NN model to generate a numeric probability of PE. When the derived NN model was applied to VBC data from the 53 test subjects, PE was detected with a sensitivity of 100% (95% CI = 89% to 100%) and a specificity of 48% (95% CI = 27% to 69%). The likelihood ratio positive [LR(+)] for the VBC-NN test was 1.82 and the LR (-) was 0.1. CONCLUSION: This study demonstrates the feasibility of developing a rapid, noninvasive breath test for diagnosing PE using volumetric capnography and NN analysis.  相似文献   

15.
Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for its subsegmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of > 99%: a normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test. The positive predictive value of a high probability ventilation-perfusion lung scan (VP-scan) is only 85% to 87%. The combination of a low clinical score and a non-diagnostic VP-scan safely exclude PE without the need of angiography. The prevalence of PE and that of an alternative diagnosis in symptomatic patients with a non-diagnostic VP-scan are 10% to 20% and 30% to 45%, respectively. Helical spiral computed tomography (CT) detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic or high probability VP-scan. The positive predictive value of the spiral CT is > 95%. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in retrospective outcome studies and in prospective multicenter management studies indicate that the negative predictive value of a negative spiral CT preceded or followed by a negative compression ultrasonography (CUS) is > 99%. Therefore, a helical spiral CT can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. A negative rapid ELISA VIDAS D-dimer test result will reduce the need for helical spiral CT by 25% to 35%.  相似文献   

16.
The Age of CT Pulmonary Angiography   总被引:1,自引:0,他引:1  
With the introduction of multi detector-row CT (MDCT), computed tomography (CT) has been firmly established as the de facto first line test for imaging patients with suspected pulmonary embolism (PE). However, remaining concerns regarding CT's accuracy for diagnosis of isolated peripheral emboli have prevented the unanimous acceptance of this test as the standard of reference for imaging PE. Consequently, many patients with a chest CT scan negative for PE undergo additional testing for a definitive rule-out of PE, increasing radiation burden, risk of complications, and health care cost. After a decade of uncertainty, there is now conclusive evidence that computed tomography (CT), if positive, provides reliable confirmation of the presence of PE and, more importantly, if negative effectively rules out clinically significant PE. Current endeavors to streamline and facilitate workflow for CT diagnosis of PE will further improve the acceptance, utility, and importance of this test. Thus, rather than seeking further confirmation for the accuracy of CT for PE diagnosis, future efforts ought to be directed at harnessing the unique strengths of this test. Examples include improvements in workflow, CT derivation of right ventricular function parameters for triage and prognostication of patients with acute PE, and the comprehensive assessment of patients with acute chest pain for PE, coronary disease, aortic disease, and pulmonary disease by means of a single, contrast enhanced, ECG-synchronized CT scan. At the same time, efforts must be directed at refining clinical pathways to ensure appropriate use and avoid overutilization of this test.  相似文献   

17.
BACKGROUND: Echocardiographic evaluation of the pulmonary veins is inadequate at times. Cardiac catheterization, especially in sick neonates, may be a high-risk procedure. Helical computed tomography with three-dimensional reconstruction is noninvasive but remains an underutilized modality. METHODS AND RESULTS: Between January 2002 and February 2003, 7 computed tomography scans of children 3 weeks to 5 years of age were performed to evaluate the drainage of the pulmonary veins in suspected total anomalous venous drainage. Helical computed tomography (GE High speed Advantage) was performed using 2 mm sections, and rapid bolus hand injections of 2 ml/kg body-weight of nonionic intravenous contrast. Sagittal and coronal reformats, and three-dimensional reconstructions were performed, and reviewed by the radiologist. The findings were discussed with the pediatric cardiologist and surgeon involved in the case. The diagnoses included complex congenital heart disease (n = 5), isolated infradiaphragmatic total anomalous pulmonary venous connections (n = 1), and transposition of the great arteries with total anomalous pulmonary venous connections (n = 1). Cardiac computed tomography accurately demonstrated infradiaphragmatic total anomalous pulmonary venous connections in 4, and supracardiac drainage in 3 patients, in addition to the other cardiac findings. The findings on computed tomography scan correlated with surgical (n = 5) and/or angiographic findings (n = 2) in 7 patients. CONCLUSIONS: In sick, high-risk patients, cardiac computed tomography can be considered as an alternative to cardiac catheterization for the evaluation of pulmonary venous drainage.  相似文献   

18.
Pulmonary embolism (PE) remains a common and important clinical condition that cannot be accurately diagnosed on the basis of signs, symptoms, and history alone. In the absence of high pretest probability and with a negative high-sensitivity D-dimer test, PE can be effectively excluded; in other situations, diagnostic imaging is necessary. The diagnosis of PE has been facilitated by technical advancements and multidetector computed tomography pulmonary angiography, which is the major diagnostic modality currently used. Ventilation and perfusion (V/Q) scans remain largely accurate and useful in certain settings. Lower-extremity ultrasound can substitute by demonstrating deep vein thrombosis; however, if negative, further studies to exclude PE are indicated. In all cases, correlation with the clinical status, particularly with risk factors, improves not only the accuracy of diagnostic imaging but also overall utilization. Other diagnostic tests have limited roles. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The development and review of the guidelines include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.  相似文献   

19.
Ventilation-perfusion (V/Q) imaging has been used as the screening test for pulmonary embolism (PE) for many years with diagnostic algorithms developed as a result of the Prospective Investigation of Pulmonary Embolism Diagnosis study. The primary conclusions were that high probability V/Q scans were reliable indicators for PE and normal or near-normal scans were reliable in the exclusion of PE. With the increasing availability of spiral (helical) computed tomography (CT) and many studies showing a high degree of accuracy for PE, there is much support for the replacement of V/Q by spiral CT. This article reviews the literature concerning V/Q scanning, spiral (helical) CT, and the future potential for magnetic resonance in the diagnosis of PE.  相似文献   

20.
Intravenous injection of complete Freund's adjuvant (CFA) in rats has been proposed as an experimental model for pulmonary sarcoidosis, but only some animals develop granulomas. Because the detection of the presence of granulomas and evaluation of the extent of the reaction has required histological evaluation, this model has been of limited use in following the evolution of the granulomatous process. The present study evaluated the ability of lung computed tomography (CT) scanning to identify in vivo pulmonary granulomas induced by CFA in rats. Wistar rats were injected with CFA to induce pulmonary sarcoid-like granulomas, and the presence and extent of pulmonary abnormalities, as detected by spiral CT and histopathological analysis, were compared. Spiral CT had a high sensitivity and specificity for the detection of sarcoid-like granulomas in rats injected with CFA. The extent of the pulmonary granulomatous reaction as assessed by the two techniques strongly correlated (r=0.93, p<0.01). In contrast, the mean density of lungs containing granulomas was not significantly different from that of lungs with no granulomatous reaction. Thus, lung computed tomography appears to be a valuable tool for the in vivo evaluation of the pulmonary granulomatous reaction induced by complete Freund's adjuvant in rats. With the help of computed tomography, this experimental model should be suitable for the sequential study of pulmonary sarcoid-like granulomas, particularly in response to various therapeutic strategies.  相似文献   

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