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1.
Rapid and accurate detection of great vessel disease is of enormous importance in clinical practice. The search continues for the best technique to evaluate critically ill patients with acute aortic dissection and/or acute pulmonary embolism. Because of its speed and excellent spatial resolution, ultrafast computed tomography (CT) is a very useful tool and may alter the management of patients with aortic disease. Other techniques, such as magnetic resonance imaging (MRI) and transesophageal echocardiography (TEE) are also used in the diagnosis of aortic dissection. Each technique has advantages and pitfalls. At this time it is likely that one technique will complement the other. With further technical improvements, both MRI and ultrafast CT are likely to emerge as the diagnostic tests of choice. In the future, further validation and comparative studies in the acute setting may help to identify the most accurate and useful technique.  相似文献   

2.
BACKGROUND: Patients with suspected thoracic aortic dissection require early and accurate diagnosis. Aortography has been replaced by less invasive imaging techniques including transesophageal echocardiography (TEE), helical computed tomography (CT), and magnetic resonance imaging (MRI); however, accuracies have varied from trial to trial, and which imaging technique should be applied to which risk population remains unclear. We systematically reviewed the diagnostic accuracy of these imaging techniques in patients with suspected thoracic aortic dissection. METHODS: Published English-language reports on the diagnosis of thoracic aortic dissection by TEE, helical CT, or MRI were identified from electronic databases. Sensitivity, specificity, and positive and negative likelihood ratios were pooled in a random-effects model. RESULTS: Sixteen studies involving a total of 1139 patients were selected. Pooled sensitivity (98%-100%) and specificity (95%-98%) were comparable between imaging techniques. The pooled positive likelihood ratio appeared to be higher for MRI (positive likelihood ratio, 25.3; 95% confidence interval, 11.1-57.1) than for TEE (14.1; 6.0-33.2) or helical CT (13.9; 4.2-46.0). If a patient had shown a 50% pretest probability of thoracic aortic dissection (high risk), he or she had a 93% to 96% posttest probability of thoracic aortic dissection following a positive result of each imaging test. If a patient had a 5% pretest probability of thoracic aortic dissection (low risk), he or she had a 0.1% to 0.3% posttest probability of thoracic aortic dissection following a negative result of each imaging test. CONCLUSION: All 3 imaging techniques, ie, TEE, helical CT, and MRI, yield clinically equally reliable diagnostic values for confirming or ruling out thoracic aortic dissection.  相似文献   

3.
BACKGROUND. Aortic dissection requires prompt and reliable diagnosis to reduce the high mortality. The purpose of this study was to assess the reliability of both ECG-triggered magnetic resonance imaging (MRI) and transesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) for the diagnosis of thoracic aortic dissection and associated epiphenomena. METHODS AND RESULTS. Fifty-three consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol in random order; imaging results were compared and validated against the independent morphological "gold standard" of intraoperative findings (n = 27), necropsy (n = 7), and/or contrast angiography (n = 53). No serious side effects were encountered with either imaging method. In contrast to a precursory screening transthoracic echogram, the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta irrespective of its location. The specificity of TEE, however, was lower than the specificity of MRI for a dissection (TEE, 68.2% versus MRI, 100%; p less than 0.005), which resulted mainly from false-positive TEE findings confined to the ascending segment of the aorta (TEE, 78.8% versus MRI, 100%; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation, or pericardial effusion. CONCLUSIONS. Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. TEE, however, is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE as a semi-invasive diagnostic procedure after a precursory screening transthoracic echogram in suspected aortic dissection, but they establish MRI as an excellent method to avoid false-positive findings. Anatomic mapping by MRI may emerge as the most comprehensive approach and morphological standard to guide surgical interventions.  相似文献   

4.
The purpose of this study was to assess the reliability of conventional transthoracic and transoesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) and ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of thoracic aortic dissection and associated epiphenomena. A total of 53 patients with clinically suspected aortic dissection were subjected to a transthoracic and transoesophageal ultrasound examination and magnetic resonance imaging; the results of each imaging modality were compared and validated against the morphological standards of contrast angiography (n = 53) and/or intraoperative findings (n = 27) or autopsy (n = 7). In this series no deleterious events were encountered with either non-invasive imaging method. In contrast to conventional echocardiography the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta, irrespective of its location. However, the specificity of TEE was lower than the specificity of MRI for a dissection (TEE 68.2% versus MRI 100%; p less than 0.005), which resulted from false positive TEE findings mainly confined to the ascending segment of the aorta (specificity of TEE 78.8% versus 100% by MRI; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation or pericardial effusion. Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. However, TEE is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE after a precursory screening transthoracic echogram in suspected aortic dissection, but will establish MRI as an excellent method to avoid false positive findings. Anatomical mapping by MRI may emerge as a promising comprehensive approach and, eventually, as a morphological standard to guide surgical interventions.  相似文献   

5.
Objectives. This study sought to describe the ability of transesophageal echocardiography (TEE) to document the presence of penetrating atherosclerotic aortic ulcers and their complications.Background. TEE has greatly enhanced our ability to assess patients with suspected aortic disease. However, the utility of this technique in the diagnosis of penetrating atherosclerotic aortic ulcers is still undefined.Methods. TEE was performed prospectively in 194 patients to evaluate aortic disease. Twelve patients with the diagnosis of aortic ulcers or their complications were specifically studied. The diagnosis was confirmed by pathologic studies in six patients and by an additional diagnostic technique (angiography, computed tomography or magnetic resonance imaging) in the other six. All 12 patients were hypertensive and presented with chest or back pain; the mean age was 65 years (range 56 to 79). The initial working diagnosis was acute aortic dissection in nine patients. Aortic ulcers were located in the descending thoracic aorta in eight patients, the aortic arch in two and the ascending aorta in two.Results. TEE could detect aortic ulcers or their complications in 10 patients but failed to detect these lesions in the remaining 2 (1 with aortic ulcers in the distal ascending aorta and 1 with aortic ulcers in the aortic arch). In four patients, aortic ulcers were detected as a calcified focal outpouching of the aortic wall and were associated with concomitant aneurysmal dilation of the aorta in two patients and with a small localized intramural hematoma in one. TEE visualized a partially thrombosed pseudoaneurysm complicating an aortic ulcer in the descending thoracic aorta of two patients. Four patients had an aortic ulcer complicated by a “limited aortic dissection” in the descending aorta that could be detected by TEE. Five patients underwent operation, two because of aneurysmal dilation of the aorta and three because of aortic dissection; two patients died of aortic rupture; the remaining five did well (11-month follow-up) without operation.Conclusions. Aortic ulcers should be included in the differential diagnosis of chest or back pain, especially in elderly hypertensive patients. These ulcers and their complications may be recognized by TEE.  相似文献   

6.
Aortic regurgitation (AR) with intimal intussusception, secondary to aortic dissection, is relatively rare and the images are interesting findings. We report a typical case of severe AR with intimal intussusception, secondary to DeBakey type I aortic dissection, detected by contrast-enhanced computed tomography (CECT) and transesophageal echocardiography (TEE). Since there are three types of aortic regurgitation with aortic dissection, it is imperative to consider the most appropriate intervention for AR. The combination of CECT, TEE, and surgical findings may play an important role in determining the optimum surgical procedure for AR with aortic dissection.  相似文献   

7.
Imaging of aortic aneurysms and dissection: CT and MRI   总被引:18,自引:0,他引:18  
There are numerous approaches to the diagnosis of aortic aneurysms and aortic dissection. Echocardiography, computed tomography (CT), and magnetic resonance imaging (MRI) have enthusiastic proponents promoting each technique, which to some extent obscures the real value of each technique. This review examines the role of these techniques in the diagnosis of aortic disease, with special reference to the most recent published literature and an emphasis on the use of CT and MRI. For most patients with chronic aortic disease, MRI is the most appropriate investigation. In acute situations, CT scanning is usually the most useful technique, with echocardiography added for those with ascending aortic disease or cardiac complications.  相似文献   

8.
Acute aortic dissection is a clinical emergency. Its prognosis is related mainly with prompt and accurate diagnosis, as well as rapid treatment. In this paper we review the importance of different imaging techniques in the diagnosis of patients with acute aortic syndrome. Aortic dissection, intramural haematoma, and penetrating aortic ulcer are discussed.  相似文献   

9.
Thirty-five consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol using comprehensive echocardiography and ECG-triggered MRI with multi-slice spin echo and cine sequences in random order. The purpose of this dual imaging study was to compare the diagnostic accuracy of two-dimensional and color-coded Doppler echocardiography using the conventional transthoracic (TTE) and the transesophageal approach (TEE) with magnetic resonance imaging (MRI) for the exact morphologic evaluation and anatomical mapping of the thoracic aorta. The results of each diagnostic method were validated independently against the gold standard of intraoperative findings (n=17), necropsy (n=4) or contrast angiography (n=22).Compared to conventional transthoracic echocardiography both TEE and MRI were more reliable in detecting aortic dissections (TTE vs TEE: p<0.02; TTE vs MRI: p<0.01) and associated epiphenomena. Moreover, the reliability of TTE decreased significantly from proximal to distal segments of the aorta, e.g. from the ascending segment to the arch (p<0.05) and to the descending aorta (p<0.005), whereas the sensitivities of both TEE and MRI were excellent irrespective of the site of dissection. With regard to epiphenomena such as thrombus formation and entry location, MRI emerged as the optimal method for detailed morphologic information in all segments of the aorta. No serious side effects were encountered with either method.Thus, in patients with suspected acute or subacute aortic dissections the echocardiographic assessment should include the transesophageal approach for significant improvement of the moderate sensitivity and specificity of TTE. Both TEE and MRI are non-traumatic, safe and diagnostically accurate to identify and classify acute and subacute dissections of the thoracic aorta irrespective of their location. MRI provides superb anatomical mapping of all type A and B dissections and more detailed information on the site of entry and thrombus formation than TEE. These features of TEE and MRI may render retrograde contrast angiography obsolete in the setting of thoracic aortic dissection and may encourage surgical interventions exclusively on the basis of noninvasive imaging.  相似文献   

10.
Purpose: To verify the diagnostic potentialities of conventional magnetic resonance imaging (MRI), breath-hold 3D contrast enhanced MR angiography (C3D MRA) and transesophageal echocardiography (TEE) in patients surgically treated for type A aortic dissection. Materials and methods: Twenty-nine patients (21 males and 8 females), surgically treated for type A aortic dissection, were evaluated with MRI using a 1.5 T (GE Horizon Echospeed 8.2) with standard gated SE sequences and breath-hold 3D fast SPGR after intravenous Gd injection (0.2 mmol/kg). 3D MIP reconstruction was obtained. TEE evaluation was performed with a HP 2000 system and a biplane 5 MHz probe. The sizes of aortic root, distal anastomosis, descending aorta and periprosthetic thickening were measured. Regional false lumen and aortic branch involvement were also evaluated. Results: Concordance among TEE, conventional MRI and C3D MRA was observed in the evaluation of aortic root (MRI vs. C3D MRA r = 0.93; MRI vs. TEE r = 0.84; C3D MRA vs. TEE r = 0.84) and descending aorta (r = 0.94, 0.91 and 0.92, respectively). The interobserver variability was also very low. Inadequate agreement was observed for distal anastomosis. C3D MRA was inadequate in the evaluation of periprosthetic thickening; r = 0.73 was obtained between MRI and TEE. For qualitative data: TEE was inadequate in the evaluation of the abdominal aorta and branches. C3D MRA depicted supra-aortic vessel involvement in more cases than the other techniques. Conclusion: C3D MRA is a fast and accurate technique in the evaluation of the endoluminal alterations and involvement of the aortic branches. Conventional MRI allows a direct evaluation of the aortic wall and periaortic tissue. TEE is less accurate in the evaluation of aortic branches and abdominal aorta.  相似文献   

11.
Aortic dissection requires prompt and reliable diagnosis. The purpose of this study was to assess the accuracy and limitations of transesophageal echocardiography (TEE) for the diagnosis of aortic dissection. Twenty seven patients with clinically suspected aortic dissection were investigated by means of TEE. TEE results were compared to intraoperative findings (n=18), necropsy (n=4), and magnetic resonance imaging (n=5). The DeBakey classification was used for differentiation of dissection type. Twenty-three patients (85%) were correctly identified as having aortic dissection. Four false-positive TEE findings (15%) were confined to the nondissecting aneurysm of the ascending aorta in elderly patients. Retrospectively we found that protruding atherosclerotic plaques were recognized as small intimal flaps. Type of dissection was correctly diagnosed in all 23 patients, the primary entry site was identified in 15 patients (65%), aortic regurgitation was found in 55.5% of patients, and pericardial effusion was detected in 33.3%. We conclude that TEE allows accurate diagnosis and classification of aortic dissection. However, some cases could be overdiagnosed in lesions of the ascending aorta, especially in nondissecting aneurysms. Another limitation of TEE is the inability to define the primary entry site in some cases. Still, overall results may favor TEE as the primary bedside diagnostic procedure to identify patients requiring urgent surgical intervention.Presented at the 35th World Congress, International College of Angiology, Copenhagen, Denmark, July 1993  相似文献   

12.
Modern diagnostic imaging modalities for ascending aortic dissection include transesophageal echocardiography (TEE), computed tomography angiography (CTA), and magnetic imaging resonance (MRI). All have extremely high sensitivity and specificity for detection of an intimal flap to diagnose ascending aortic dissection. We present a case of fatal cardiac tamponade caused by a limited aortic dissection not detected by multiple imaging modalities. This may represent a class of aortic dissection variant that cannot be detected by conventional testing. A high index of suspicion should be maintained in the appropriate clinical setting and should prompt serial imaging and even consideration for preemptive surgical exploration.  相似文献   

13.
Transesophageal echocardiography (TEE) provides a rapid and accurate diagnosis in patients with dissection of the thoracic aorta. The procedure is considered to be safe. We report a case where rupture of a dissecting thoracic aneurysm occurred during attempted TEE in a patient, who had been clinically stable for 1 week. TEE was performed because aortic valve endocarditis was suspected, and the procedure did not include close surveillance of the blood pressure. Careful manipulation of the probe, adequate sedation, monitoring, and treatment of acute rises in blood pressure was recommended in patients with even a slight suspicion of dissection undergoing TEE.  相似文献   

14.
The purpose of this study was to retrospectively assess the reliability of ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of acute and subacute thoracic aortic dissection and associated clinical epiphenomena. 67 patients were subjected to MRI; the diagnostic results were compared with morphological standards. 25 patients had type A, 12 patients type B dissection. In 30 cases a dissection was excluded. 17 patients with aortic dissection had acute onset of symptoms, 10 patients had subacute onset of symptoms. 17 patients revealed thrombosis of the false lumen, which was found in the descending aorta in 59% of the cases. Aortic regurgitation and pericardial effusion was most often associated with type A dissection (Table 1). Three patients were studied while on mechanical ventilation. Scan time for MRI ranged from 15 to 71 minutes with an average of 46 +/- 18 minutes. In this series no deleterious events were encountered related to MRI diagnostics. In contrast to previously published data using other noninvasive techniques the sensitivity of MRI was 100% for detecting a dissection in the ascending segment of the thoracic aorta. Moreover, the specificity of MRI for a dissection was 100% and thus higher than previously published data using transesophageal echocardiography. Sensitivity and specificity for detection and correct classification of type B dissection was 100% and 100% respectively (Table 2). In addition, MRI proved to be sensitive in detecting the formation of thrombus material in the false lumen of the ascending aorta (92%), the aortic arch (100%) and the descending segment (88%). Specificity for exclusion of suspected thrombus material even proved to be slightly higher with 100% in the ascending and descending aorta and 96.1% in the aortic arch (Table 3). The site of entry to a dissection was detected in 78%, with a sensitivity of 76% in the ascending and 92% in the descending aorta. The involvement of side branches in the dissecting process was identified in 60%. There were no false positive findings concerning side branch involvement. Aortic regurgitation and pericardial effusion were detected in 100% and 100%, respectively (Tables 1 and 2). MRI performed even in acute cases proved to be a atraumatic, safe and highly sensitive method to identify and classify acute and subacute dissections of the entire thoracic aorta. Limited patient access was not associated with an increased risk and mechanical ventilation did not interfere with MRI. These results may establish MRI as a valid and promising noninvasive technique to establish the diagnosis in patients with thoracic aortic dissection.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

15.
IntroductionIn the last decade, remarkable advances have been made in noninvasive imaging of aortic diseases. The aim of this article was to provide a comprehensive review of these imaging modalities. Echocardiography plays an important role in the diagnosis and follow-up of aortic diseases. Transthoracic echocardiography (TTE) permits adequate assessment of several aortic segments, particularly aortic root and proximal ascending aorta. Transoesophageal echocardiography (TEE) overcomes the limitations of TTE in thoracic aorta assessment. TTE and TEE should be used in a complementary manner. Although TEE is the technique of choice in the diagnosis of aortic dissection, TTE may be used as the initial modality in the emergency setting. Intimal flap in proximal ascending aorta, pericardial effusion/tamponade and left ventricular function can be easily visualised by TTE. TEE information (entry tear location, mechanisms and severity of aortic regurgitation and true lumen compression) is essential for selecting and monitoring surgical and endovascular treatment and detecting possible complications. Computed tomography has the advantage of providing optimum morphological information of the entire aorta and the accuracy of size measurements. Magnetic resonance imaging offers good morphological and dynamic information on the aorta without radiation, although in clinical practice its availability is lower.ConclusionsThe considerable advances in imaging techniques have greatly increased our understanding of aortic diseases. Not only clinical presentation and required information, but also local availability of imaging equipment and staff expertise in this field, should be considered to indicate echocardiography, computed tomography or magnetic resonance, in the assessment of different aortic diseases and their circumstances.  相似文献   

16.
Each year acute aortic dissection is diagnosed in 2,000 individuals in the United States. Acute aortic dissection is no longer a catastrophic event because this problem can be rapidly diagnosed with current medical technology, and therefore promptly treated with medication and surgery. Consequently, patients with aortic dissection can survive for 10 to 20 or more years after the initial event. However, there is considerable current debate regarding the most optimal technique(s) for the diagnosis of aortic dissection. Moreover, little information is available on the best methods for the long-term assessment and treatment of patients who have been successfully treated for acute aortic dissection. This report reviews the current techniques that are available for the diagnosis of aortic dissection and discusses the important issues regarding the acute and long-term treatment of patients with this problem.  相似文献   

17.
Transesophageal echocardiography (TEE) is superior to other imaging techniques for the diagnosis of aortic trauma. It can accurately, rapidly, and safely diagnose life-threatening conditions such as aortic rupture, pseudoaneurysm, traumatic aortic dissection, and intramural hematoma. TEE is useful for the diagnosis and prevention of iatrogenic aortic trauma induced by cardiovascular surgery, intraaortic procedures, and cardiopulmonary resuscitation.  相似文献   

18.
The diagnostic value of imaging techniques for aortic dissection.   总被引:4,自引:0,他引:4  
Previous studies conducted in high-risk populations have reported high predictive values and accuracies for diagnostic imaging techniques for aortic dissection. To see how these techniques perform in low-risk populations, we used Bayes' theorem to calculate predictive values and accuracies for angiography, CT, MRI, and TEE. In high-risk populations (disease prevalence = 50%), positive predictive values were all greater than 85%. In intermediate risk populations (disease prevalence = 10%), positive predictive values were greater than or equal to 90% for CT, MRI, and TEE, but were 65% for angiography. In low-risk populations (disease prevalence = 1%), positive predictive values were 100% for MRI and less than or equal to 50% for angiography, CT, and TEE. In all three populations, negative predictive values and accuracies were greater than or equal to 85%. From these results we conclude that diagnostic imaging techniques for aortic dissection do not perform as well in low-risk populations as they do in high-risk populations.  相似文献   

19.
目的:探讨胸主动脉疾病的术中应用经食管超声心动图(TEE)的价值及适应证。方法:本文报道8例(15~63岁,平均年龄44.5岁)不同类型胸主动脉疾病术中TEE监测结果。病例包括先天性主动脉瓣上狭窄、升主动脉瘤、主动脉夹层及主动脉夹层伴假性动脉瘤、胸降主动脉假性动脉瘤、主动脉瓣脱垂等。结果:8例患者的术中检查与术前诊断全部吻合。术中TEE发现1例主动脉夹层累及左锁骨下动脉,而术前磁共振成像未能提示。此外,术中TEE还显示2例胸降主动脉内的粥样硬化斑块。结论:初步显示术中TEE可即刻评价手术效果,对拟行主动脉瓣成形术的患者最有价值;为避免升主动脉粥样斑块的脱落导致术后体循环尤其是脑栓塞,对于高龄患者也积极提倡术中TEE监测。  相似文献   

20.
BACKGROUND: To identify patients (pts) at risk of late complications, follow-up after surgery for type A aortic dissection is essential. We assessed the value of echocardiography to monitor patients after surgery for type A aortic dissection. METHODS: 80 out of 108 pts operated between 1989 and 1999 for type A aortic dissection survived surgery. 62 pts with at least one TEE, CT or MRI examinations during follow-up were included in this study. All pts had transthoracic echocardiography (TTE), 53 transesophageal echocardiography (TEE), 51 had CT, and 39 had MRI. RESULTS: At the first follow-up, 12 of 48 pts with aortic valve sparing surgery presented with aortic insufficiency >I degrees detected using echocardiography. 16 pts evolved a distal aortic aneurysm of over 5 cm, all seen in TEE, CT and MRI. A distal intimal flap was present in 39 pts and could be seen in TEE, CT and MRI in all patients. A new proximal aortic root dissection took place in 5 pts. Progressive aortic pathology led to reoperation in 9 pts. TEE was especially useful in 2 pts to confirm redissection, in 1 pt to rule out redissection assumed by CT, and in 1 with paraprosthetic blood flow after ascending aortic replacement. MRI led to additional information in 1 patient with false aneurysm of the distal anastomosis and 1 with redissection not seen in TEE 6 month before. CT and MRI were superior to TEE in demonstrating aortic arch pathology, whereas TEE was more effective in showing the flow pattern and residual entry sites. CONCLUSIONS: Echocardiography is an effective and cost-saving diagnostic tool to monitor pts after surgery for type A aortic dissection, and should be the method of choice to ascertain aortic pathology initially after surgery. Follow-up intervals and need for additional CT or MRI should be determined afterwards according to specific pathologies.  相似文献   

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