Detection and follow-up of important extra-arterial lesions with helical CT angiography

To determine the prevalence and significance of extra-arterial findings detected prospectively on helical computed tomographic angiography (CTA).

The official reports of 802 consecutive CTAs performed over a 4.5-year period on 624 patients and the reports of all radiographic follow-up studies were reviewed for identification of important extra-arterial findings. Medical records and imaging studies of all patients with previously unknown extra-arterial findings on CTA were reviewed to assess follow-up. In cases where follow-up was not indicated in the medical record, referring physicians were contacted directly.

Important, previously unknown, extra-arterial findings were detected on 35 CTAs (4.4% of all CTAs, 5.6% of all patients), with 33 of 35 detected prospectively. Six lesions were consistent with and/or proven to be malignant. Important non-tumoural lesions were discovered on nine CTAs. Of 13 lesions with imaging features that were suspicious for malignancy. Five of these lesions proved to be benign, but radiographic and/or clinical follow-up was not obtained or could not be documented in eight patients.

With the increasing use of CTA as a replacement for conventional angiography, careful attention should be paid to the visualized extra-arterial structures. Extra-vascular findings that are believed to be significant, may not be adequately followed-up by referring vascular specialists.