Spiral computerized tomography (dual helical mode) as a detector of aorticatheromas in patients with stroke and systemic emboli: Additional benefit of the contrast-enhanced technique

Background: Protruding aortic atheromas are a potential source of stroke an d systemic emboli. The single modality currently available for their detect ion has been transesophageal echocardiography. However, TEE does not allow full visualization of the upper part of the ascending aorta and proximal ao rtic arch. Objectives: To investigate whether double helical computerized tomography - both with and without contrast injection - may represent a useful techniqu e for noninvasive detection of PAA in stroke patients. Methods: Forty consecutive patients greater than or equal to 50 years of ag e who sustained a recent ischemic stroke and/or systemic emboli (within 15 days after the onset of the event) were enrolled in the study and underwent TEE and DHCT without contrast injection using thin slice acquisition (3.2 mm thickness and 1.5 mm reconstruction increment). Ln addition, the last ei ght consecutive patients, alter obtaining an unenhanced scan, underwent a c ontrast-enhanced DHCT following peripheral intravenous injection of a small amount of contrast material (15 mi of diatrizoate). Results: PAAs were demonstrated by TEE in 18 patients (45%); in 16 of them (89%) the atheromas were recognized by DHCT Of the 22 patients without PAA on TEE, DHCT confirmed their absence in 18 (82%). DHCT yielded a sensitivit y of 89%, a specificity of 82%, and an overall accuracy of 85%. The total n umber of protruding plaques detected by TEE was 43, of which 41 (95%) were correctly identified by DHCT. The mean thickness of the plaques was 5.6+/-2 .4 mm on TEE, and 5.4+/-2.3 on DHCT (P=NS), with a good correlation between the modalities (r=0.84). Contrast-enhanced DHCT scans demonstrated absolut e equivalence to TEE in aortic areas defined as "clearly visualized by TEE. " DHCT detected PAA between the distal ascending aorta and the proximal arc h in seven patients; these atheromas were not included in the comparative a nalysis. In these "occult" areas, DHCT may be superior to TEE. Conclusions: DHCT without contrast injection using thin slice acquisition m ay become a useful modality for rapid noninvasive detection of PAA. Contras t-enhanced DHCT scans significantly improve imaging quality and may be supe rior to TEE in the upper ascending aorta and the proximal arch (areas not w ell visualized by TEE).