Digital subtraction angiography and ultrasound sonography for detection of occlusive carotid lesions in the neck

Digital subtraction angiography (DSA), high resolution real time B-mode scanner (HRS), and pulsed doppler sonography were used to examine the cervical carotid lesions. Seventeen patients were studied by DSA before or after conventional angiography. To obtain good images, exposures were performed in both oblique positions. Sometimes, repeat studies were required with different degrees of obliquity to obtain more information. Subtracted images were obtained in real time, and post processing, especially remasking, was used to improve the image quality. In 28 carotid arteries of 17 patients, good images were obtained through such procedures. The quality of detecting carotid lesions with DSA was fairly good (sensitivity of 85%, specificity of 100%, accuracy of 93%). HRS demonstrated minor irregularities or slight stenosis within the lumen of the carotid artery, while the doppler examination appeared to be more useful in demonstrating obstructions of the carotid artery. It was concluded that DSA is a safe and reliable non-invasive screening method for detection of occlusive carotid disease. (author)