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To evaluate the usefulness of cine-MRI for the quantitative assessment of aortic valve regurgitation, 31 patients (54 +/- 15 years of age; 22 M, 9 F) and 10 normal volunteers underwent a multi-modality imaging protocol comparing cine-MRI with color Doppler echocardiography and contrast aortography. Twenty-one patients had aortic regurgitation with an associated transvalvular gradient, 10 patients had pure valve incompetence. Aortic insufficiency as assessed by the signal void from regurgitant flow on cine-MRI was best analyzed on transversal tomograms. Both the volume of the signal void caused by turbulence above a threshold velocity, and the ratio of the diameters of the regurgitant jet and the outflow tract (dAL-Jet/DLVOT) were found to correlate closely with the (Seller's) angiographic regurgitant score by r = 0.86 each (p < 0.001), and the color Doppler echocardiographic index by r = 0.74 and 0.89, respectively (p < 0.001). Cine-MRI failed to differentiate the angiographic grades I and II, however, clearly separated grades II, III, and IV in contrast to other non-invasive imaging modalities. Moreover, a semiquantitative index derived from cine-MRI allowed a rapid assessment of the severity of regurgitation, similar to color Doppler echocardiography and the semiquantitative angiographic Seller's score. Thus, cine-MRI volumetric evaluation of transvalvular flow turbulences provides a useful and reproducible means to quantify aortic regurgitation. It also allows serial atraumatic investigations as a diagnostic alternative to color Doppler examination in patients less suitable for echocardiographic evaluation and may prove helpful in monitoring the natural course of aortic valve disease.

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BACKGROUND AND METHODS: This study was designed to assess the safety and reliability of new noninvasive imaging methods as compared with aortography in the diagnosis of dissection of the thoracic aorta. One hundred ten patients with clinically suspected aortic dissection followed a diagnostic protocol that included transthoracic and transesophageal color-flow Doppler echocardiography (TTE and TEE), contrast-enhanced x-ray computed tomography (CT), and magnetic resonance imaging (MRI). Imaging results were compared in a blinded fashion and validated independently against intraoperative findings in 62 patients, autopsy findings in 7, and the results of contrast angiography in 64. RESULTS: The sensitivities of MRI, TEE and x-ray CT for detecting dissection were similar, at 98.3, 97.7, and 98.3 percent, respectively; TTE had a sensitivity of only 59.3 percent (P < 0.005). The specificities of both TTE (83.0 percent) and TEE (76.9 percent) were lower than those of x-ray CT (87.1 percent) and MRI (97.8 percent; P < 0.05), mainly as a result of false positive findings in the ascending aorta. MRI and x-ray CT were more sensitive than TTE in detecting the formation of thrombus in the entire thoracic aorta (P < 0.05), but were not superior to TEE in this regard. CT was not effective in detecting an entry site or aortic regurgitation, but MRI and TEE accurately identified both. Two patients died during or soon after CT and TEE, and three died between retrograde angiography and surgery. CONCLUSIONS: A noninvasive diagnostic strategy using MRI in all hemodynamically stable patients and TEE in patients who are too unstable to be moved should be considered the optimal approach to detecting dissection of the thoracic aorta. Comprehensive and detailed evaluation can thus be reduced to a single noninvasive diagnostic test in the investigation of suspected dissection of the thoracic aorta.

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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.

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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.

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From 1980 to 1989, 84 patients underwent surgery for dissection of thoracic aortic aneurysms. According to the DeBakey classification there were 23 dissections of type I, 35 of type II and 26 of type III. Magnetic resonance imaging and combined transesophageal and transthoracic echocardiography are highly sensitive and specific methods for diagnosis and followup of aortic dissection. 10% of the patients had to undergo surgery again during the first 5 years. The 5-year-survival rate was 56.1% and the 10-year rate was 40.1%.

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The effects of increasing afterload on early diastolic dysfunction in 10 patients with hypertrophic non-obstructive cardiomyopathy were studied by computer assisted analyses of digitised M mode echocardiograms. Infusion of angiotensin II increased the end systolic pressure by a mean (SD) of 36.2 (10.3) mm Hg. As the afterload increased early diastolic dysfunction tended to become more normal: the interval and the change in dimension between minimal cavity dimension and mitral valve opening decreased and the duration of rapid diastolic filling and the accompanying change in dimension increased. None the less, the end diastolic dimension and thus the overall diastolic filling remained unchanged. Impaired early diastolic function in hypertrophic cardiomyopathy is at least partly caused by altered loading conditions.

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Intravenous thrombolysis with urokinase (60,000 U/h) was undertaken in 15 patients with large thrombi in the left ventricle (demonstrated by echocardiography) after myocardial infarction. Complete lysis was achieved in ten, partial in four. None had post-thrombolysis signs of arterial emboli, two patients developed haematuria and one had partial separation of the thrombus which required operative removal. Four patients who had a mean ejection fraction of 37 +/- 12% had died a sudden cardiac death within six months of the thrombolysis. Nine patients survived for up to four years without recurrence of thrombi: seven of them had been treated with aspirin (acetylsalicylic acid), two with coumarin derivatives. Two patients could not be followed-up. These preliminary results suggest that large left-ventricular thrombi can be successfully lysed by intravenous thrombolysis without significant complications, probably without recurrent thrombi.

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Thrombi in the left atrium are a frequent complication of mitral valve disease accompanied by left atrial enlargement. It is often difficult to recognize abnormal structures in this area with sufficient reliability by conventional transthoracic cross-sectional (2-D) echocardiography. Diagnosis is almost impossible with thrombi in the left atrial appendage. Transesophageal echocardiography presents a useful alternative. By this means thrombi in the left atrial appendage were diagnosed in seven of 24 patients with mitral stenosis on adequate anticoagulation, transthoracic 2-D echocardiography having given negative results. At subsequent valve replacement the results of transthoracic echocardiography were confirmed in all cases.

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Thrombi located in the left atrial appendage are frequently not detected with conventional two-dimensional echocardiography. The transesophageal echocardiographic approach readily visualizes left atrial morphology and may be used as an alternative. In 6 of 21 patients with mitral valve stenosis, a left atrial appendage thrombus was diagnosed by transesophageal two-dimensional echocardiography when transthoracic echocardiography had failed. The transesophageal echocardiographic findings were confirmed at surgery for mitral valve replacement in all cases.

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