Evaluation of an aortic annular pseudoaneurysm by MRI: comparison with echocardiography, angiography and surgery

The usefulness of cardiac CT in the diagnosis of perivalvular complications in patients with infective endocarditis

Objectives

The aim of the study was to compare the usefulness of cardiac CT to transthoracic (TTE) and transesophageal (TEE) echocardiography in the diagnosis of infective endocarditis (IE) and perivalvular complications using surgical inspection as the gold standard.

Material and methods

Fifty-three consecutive patients (42 men, mean age 58.3 ± 12.5) with IE requiring surgical procedures were enrolled in the study. All patients underwent preoperative TTE, TEE, and CT. The presence of vegetations, perivalvular abscess/pseudoaneurysm, leaflet perforation, inflammatory infiltration, and prosthesis dehiscence was assessed.

Results

We analyzed 71 affected valves (58 native, 13 prosthetic). Intraoperative assessment revealed 11 abscesses/pseudoaneurysms. Sensitivity and specificity of echocardiography (TTE + TEE) and CT were 63%, 90% and 81%, 90%, respectively. The combination of CT and echocardiography allowed diagnosing all abscesses/pseudoaneurysms. Inflammatory infiltration was found intraoperatively in 15 patients. Sensitivity and specificity of TEE and CT were 53%, 94% and 46%, 100%, respectively. Intraoperative assessment revealed leaflet perforation in 16 patients. Sensitivity and specificity of TEE and CT were 75%, 79% and 43%, 89%. The sensitivity of the combination of TTE + TEE + CT was 81%. Perivalvular leakage was found in eight patients with a prosthetic valve. Sensitivity and specificity of echocardiography and CT were 100%, 100% and 88%, 100%, respectively. TEE showed higher sensitivity (97%) than CT (89%) in the diagnosis of vegetations.

Conclusions

The combination of TTE, TEE, and CT increased the sensitivity for the detection of valvular and perivalvular complications of IE.

Key Points

• CT is a useful modality in the diagnosis of IE and its local complications in addition to echocardiography.

• For the detection of abscesses and pseudoaneurysms, CT is superior to echocardiography. Combining these two modalities can increase the sensitivity of diagnosing abscess/pseudoaneurysm up to 100%.

• Adding CT to TEE increases the sensitivity for detection of inflammatory infiltrate. CT is not superior to echocardiography in diagnosing vegetations, valvular leaflet perforations, and perivalvular leaks, but it can be a useful tool when echocardiography is indeterminate.

Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (MAIVF): A comprehensive review

Pseudoaneurysm in the region of the fibrous body between the mitral and aortic valve, the mitral-aortic intervalvular fibrosa (MAIVF), is a rare complication. The authors provide a comprehensive review of all relevant English-language articles published from 1966 to December 2009. Pseudoaneurysm of the MAIVF was identified in 88 patients in the medical literature and one from the authors' institution (total reported cases, 89). Endocarditis and aortic valve surgery were the most frequently associated causative factors. Symptoms and signs of infection, chest pain, heart failure or shortness of breath, and cerebrovascular accidents accounted for 77% of clinical presentations. The formation of a fistulous tract, coronary artery compression, and death were important described complications. Patients with ring abscesses in the MAIVF region and those with prosthetic aortic valves and histories of endocarditis are at higher risk for developing pseudoaneurysm of the MAIVF. Transesophageal echocardiography was able to identify all cases in which it was used. Surgical correction is the treatment of choice.

MR visualization of aortic valve vegetations

PURPOSE

The purpose of this report is to describe the MR findings of aortic vegetations in two patients.

METHOD

MR imaging using SE and fast GE (Fastcard) sequences was performed in the axial and coronal planes.

RESULTS

The vegetations were not visible with SE MRI, but were clearly visible with fast GE imaging (Fastcard). The vegetations appeared as areas of low signal at valve leaflets in contrast to the bright flowing blood.

CONCLUSION

MR evaluation in patients with infective endocarditis is useful in clarifying echocardiographic findings and establishing the diagnosis in previously undiagnosed patients.

Complementary role of MRI in infectious endocarditis

The usefulness of magnetic resonance for imaging of cardiac structures is well established. In this study, we evaluated the role of this technique in the diagnosis of perivalvular extension of infectious endocarditis. Our initial experience and the few case reports in the literature show that magnetic resonance imaging can complement echocardiography in the assessment of periannular extension of infectious endocarditis.

Pseudoaneurysms of the mitral-aortic intervalvular fibrosa: dynamic characterization using transesophageal echocardiographic and Doppler techniques

OBJECTIVES

The aim of this study was to provide a detailed description of echocardiographic and Doppler features of pseudoaneurysms involving the mitral-aortic intervalvular fibrosa and to compare echocardiographic and aortographic findings.

BACKGROUND

Infection of the aortic valve may spread to the aortic annulus, resulting in ring abscesses or pseudoaneurysms, or both, of the intervalvular fibrosa, which can alter patient management and prognosis.

METHODS

The echocardiographic and Doppler findings of 20 patients with pseudoaneurysms or ring abscesses, or both, were reviewed and compared with surgical and aortographic results.

RESULTS

A total of 23 lesions were identified, of which 16 were intervalvular pseudoaneurysms, and 7 were ring abscesses. Transthoracic echocardiography detected 43% of the lesions, whereas transesophageal echocardiography identified 90% (p < 0.01). The most distinct feature of the pseudoaneurysms was marked pulsatility, with systolic expansion and diastolic collapse (mean systolic area [+/- SD] 4.1 +/- 3.4 cm2 vs. diastolic mean area 1.8 +/- 2.2 cm2, p < 0.05). Using color Doppler, two types were identified: unruptured pseudoaneurysms (n = 9), which communicated only with the left ventricular outflow tract and had a distinct flow pattern, and ruptured pseudoaneurysms (n = 7), which, in addition, communicated with the left atrium or aorta. Compared with pseudoaneurysms, ring abscesses were smaller and nonpulsatile and showed either no flow or continuous systolic and diastolic flow, the site of paravalvular aortic insufficiency. In 10 patients who underwent aortography, three lesions were identified, and findings were concordant with echocardiography. However, in seven patients aortographic findings were normal, whereas echocardiography identified intervalvular pseudoaneurysms, all of which were documented at operation.

CONCLUSIONS

Intervalvular pseudoaneurysms are more frequently detected by transesophageal echocardiography than by aortography or transthoracic examination and exhibit distinct dynamic features and Doppler patterns that can further help characterize cavitary lesions in the aortic root and guide appropriate surgical intervention.

Detection of mycotic pseudoaneurysm of the ascending aorta using MRI

Mycotic pseudoaneurysms of the ascending aorta are rare cardiovascular lesions that carry the risk of potentially disastrous complications such as aortic rupture or widespread sepsis. Regardless of its location in the arterial system, this lesion carries a high mortality rate. Early diagnosis of mycotic pseudoaneurysm is paramount for optimizing the chances of surgical therapy. While imaging strategies of this lesion have included aortography, echocardiography, and computed tomography, the information gained from each of these individual studies may be acquired in a single MR imaging session. MRI offers the fundamental advantages of noninvasiveness, nonionization, and multiplanar imaging capabilities. Additionally, MRI provides excellent soft tissue contrast, a wide field of view, qualitative and quantitative flow analysis, and an independence of operator expertise or patient body habitus.

Diagnosis of aortic pseudoaneurysm by echocardiography

The diagnosis of pseudoaneurysm of the ascending aorta is of paramount importance because of its propensity to rupture. As the frequency of surgical procedures involving the aortic root and valve increases, an increase in the incidence of aortic pseudoaneurysm may be anticipated. We recently studied a patient who developed pseudoaneurysm of the ascending aorta following repair of a Type I aortic dissection, utilizing a composite graft. Two-dimensional echocardiography with color flow and pulsed Doppler imaging showed a large perigraft cavity communicating with the aorta. Echocardiography provides a safe noninvasive diagnostic tool for the evaluation of the aorta postoperatively and for screening for pseudoaneurysm formation in the follow-up period.

Demonstration of aortic lesions via cine magnetic resonance imaging

Cine-MRI was used to evaluate eight patients with known thoracic aorta disease. Included in this study were three aortic coarctations, two aortic dissections, an aneurysm, a posttraumatic pseudoaneurysm, and a patent ductus arteriosus. Cine-MRI was found to be valuable in the assessment of the pathologic anatomy and associated flow disturbances in these disorders. In seven cases, the images demonstrated the aortic lesion and aberrant blood flow. Our technique was unable to image the structural lesion in the patient with patent ductus arteriosus, but the abnormal blood flow was shown. Angiographic data were available on three of the cases to confirm the MR findings. The MRI images were obtained in axial, coronal, sagittal, and oblique planes using fast field echo acquisition technique of cine-MRI. We found the additional data or benefits provided by cine-MRI, when compared to cardiac gated spin echo images, to be most advantageous in the cases of aortic coarctation and dissection only.