Benign primary cardiac neoplasms are rare but may cause significant morbidity and mortality. However, they are usually treatable and can often be diagnosed with echocardiography, computed tomography (CT), or magnetic resonance (MR) imaging. Myxomas typically arise from the interatrial septum from a narrow base of attachment. Fibroelastomas are easily detected at echocardiography as small, mobile masses attached to valves by a short pedicle. Cardiac fibromas manifest as a large, noncontractile, solid mass in a ventricular wall at echocardiography and as a homogeneous mass with soft-tissue attenuation at CT. They are usually homogeneous and hypointense on T2-weighted MR images and isointense relative to muscle on T1-weighted images. Paragangliomas usually appear as large, echogenic left atrial masses at echocardiography and as circumscribed, heterogeneous masses with low attenuation at CT. These tumors are usually markedly hyperintense on T2-weighted MR images and iso- or hypointense relative to myocardium on T1-weighted images. Cardiac lipomas manifest at CT as homogeneous, low-attenuation masses in a cardiac chamber or in the pericardial space and demonstrate homogeneous increased signal intensity that decreases with fat-saturated sequences at T1-weighted MR imaging. Cardiac lymphangiomas manifest as cystic masses at echocardiography and typically demonstrate increased signal intensity at T1- and T2-weighted MR imaging. Familiarity with these imaging features and with the relative effectiveness of these modalities is essential for prompt diagnosis and effective treatment.

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Aneurysms of the Valsalva sinus (aortic sinus) can be congenital or acquired and are rare. They are more common among men than women and among Asians than other ethnic groups. Nonruptured aneurysms may be asymptomatic and incidentally discovered, or they may be symptomatic and manifest acutely with mass effect on adjacent cardiac structures. Ruptured Valsalva sinus aneurysms result in an aortocardiac shunt and may manifest as insidiously progressive congestive heart failure, severe acute chest pain with dyspnea, or, in extreme cases, cardiac arrest. Although both ruptured and nonruptured Valsalva sinus aneurysms may have potentially fatal complications, after treatment the prognosis is excellent. Thus, prompt and accurate diagnosis is critical. Most Valsalva sinus aneurysms are diagnosed on the basis of echocardiography, with or without angiography. However, both electrocardiographically gated computed tomography and magnetic resonance (MR) imaging can provide excellent anatomic depiction, and MR imaging can provide valuable functional information.

To determine late patient outcome and homograft durability, we reviewed 326 patients who received aortic (n = 230) or pulmonary (n = 118) cryopreserved homografts for right ventricular outflow reconstruction between January 1985 and October 1993. Patient survival, including operative mortality, 5 years after the operation was similar between the two groups (pulmonary homograft 86%, aortic homograft 80%; p = not significant by log-rank test). However, 5-year freedom from homograft failure was significantly better for pulmonary homografts (94% versus 70%, p < 0.01 by log-rank test). Late calcification was evaluated by chest roentgenography and echocardiography. Overall, 20% of aortic homografts became moderately or severely calcified compared with 4% of pulmonary homografts (p < 0.01). Twenty-six percent of aortic homografts in children 4 years old or younger had moderate or severe obstruction associated with calcification, whereas only 11% of aortic homografts in patients over 4 years of age had calcific obstruction (p < 0.01). No late deaths among patients receiving pulmonary homografts were related to graft failure; two late deaths in the aortic homograft group were homograft related. Risk factors for patient mortality and homograft failure (defined as either need for homograft replacement because of homograft failure or as homograft-related death) were identified by the Cox multivariate analysis. Aortic type of homograft was a significant risk factor for homograft failure (p < 0.0001), but type of homograft was not correlated with patient mortality. Age 4 years or younger was a significant risk factor for both mortality (p < 0.01) and homograft failure (p = 0.03) in aortic homograft recipients but not in pulmonary homograft recipients. These results indicate that both aortic and pulmonary homografts provided excellent intermediate-term patient survival after right ventricular outflow tract reconstruction, but pulmonary homografts are more durable than aortic homografts with less calcification and obstruction, especially among children 4 years old or younger.

A dynamic MR angiography technique, MR digital subtraction angiography (MR DSA), is proposed using fast acquisition, contrast enhancement, and complex subtraction. When a bolus of contrast is injected into a patient, data acquisition begins, dynamically acquiring a thick slab using a fast gradient echo sequence for 10-100 s. Similar to x-ray DSA, a mask is selected from the images without contrast enhancement, and later images are subtracted from the mask to generate angiograms. Complex subtraction is used to overcome the partial volume effects related to the phase difference between the flowing and stationary magnetization in a voxel. Vessel signal is the enhancement of flow magnetization resulting from the contrast bolus. MR DSA was performed in 28 patients, including vessels in the lungs, brains, legs, abdomen, and pelvis. All targeted vessels were well depicted with MR DSA. Corresponding dynamic information (contrast arrival time ta and duration of the arterial phase tav) was measured: ta/tav = 3.4/4.7 s for the lung, 10.3/4.9 s for the brain, 12.8/19.3 for the aorta, 15.2/12.6 s for the leg. MR DSA can provide dynamic angiographic images using a very short acquisition time.