Israel Medical Association Journal

Background: Protruding aortic atheromas are a potential source of stroke and systemic emboli. The single modality currently available for their detection has been transesophageal echocardiography. However, TEE does not allow full visualization of the upper part of the ascending aorta and proximal aortic arch.

Objectives: To investigate whether double helical computerized tomography- both with and without contrast injection - may represent a useful technique for noninvasive detection of PAA in stroke patients.

Methods: Forty consecutive patients ≥50 years of age 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). In addition, the last eight consecutive patients, after obtaining an unenhanced scan, underwent a contrast-enhanced DHCT following peripheral intravenous injection of a small amount of contrast material (15 ml 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 sensitivity of 89%, a specificity of 82%, and an overall accuracy of 85%. The total number 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 (γ=0.84). Contrast-enhanced DHCT scans demonstrated absolute equivalence to TEE in aortic areas defined as "clearly visualized by TEE." DHCT detected PAA between the distal ascending aorta and the proximal arch in seven patients; these atheromas were not included in the comparative analysis. In these "occult" areas, DHCT may be superior to TEE.

Conclusions: DHCT without contrast injection using thin slice acquisition may become a useful modality for rapid noninvasive detection of PAA. Contrast-enhanced DHCT scans significantly improve imaging quality and may be superior to TEE in the upper ascending aorta and the proximal arch (areas not well visualized by TEE).

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TEE= transesophgeal echocardiography

PAA= protruding aortic atheroma

DHCT= dual helical computerized tomography
 

Objectives: To report the experience at the first Israeli Linear Accelerator Radiosurgery Unit in the management of 44 patients with acoustic neurinomas.

Methods: We analyzed the clinical records and imaging studies of all patients undergoing radiosurgery for acoustic neurinomas between 1993 and 1997, and quanitified the changes in tumor volume, hearing status, and facial and trigeminal nerve function. The contribution of radiation dose and original tumor volume upon those variables was also studied.

Results: At a mean follow-up of 32 months (range 12–60), 98% of the tumors were controlled (75% had shrunk; 23% had stable volume). The actuarial hearing preservation rate was 71%. New transient facial neuropathy developed in 24% of the patients, persisting in mild degrees in 8%. Neuropathy correlated primarily with tumor volume. Tumors with volumes 4 ml were at high risk when marginal radiation doses were 1,400 cGy. Dose reduction to a maximum of 1,400 cGy produced no neuropathies in the last 20 patients, still preserving tumor control rates.

Conclusions: Radiosurgery is an effective and cost-efficient therapeutic modality for newly diagnosed acoustic neurinomas in the elderly or medically infirm population, and for all residual or recurrent tumors after conventional surgery.