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The possibility of detecting unknown internal carotid artery stenoses in patients undergoing biphasic multidetector computed tomography (MDCT) for current or previous head and neck cancer was investigated in 52 patients who underwent four-row MDCT (4 mm x 1.25 mm collimation, pitch 3, kVp 120, mAs 140; 90-100 ml of non-ionic contrast agent at 2 ml/s, early and late phases). Vessel stenoses were classed as severe (70-99%), moderate (30-69%), or mild (<30%). Internal carotid arteries (ICAs) with vessel stenosis was found in 37 patients (age 67.0+/-9.8 years, median 69 years) and 67 ICAs. Four patients (age 65.5+/-9.7 years) had severe stenosis, all of them associated with contralateral moderate stenosis. Seventeen patients (age 70.35+/-9.78 years) had moderate stenosis, bilateral (n=7), associated with contralateral mild stenosis (n=8), unilateral (n=2). Sixteen patients (age 64.8+/-9.8 years) had mild stenosis, bilateral (n=10) or unilateral (n=6). Of the four patients with unknown MDCT-detected severe stenosis, three had a change of therapy: one endarterectomy before tumor surgery, one combined vascular and tumor surgery, and one patient with a previously treated hypopharyngeal cancer had carotid stenting. In conclusion, of 52 patients, four (7.7 %) had unknown severe ICA stenoses, three of them with relevant impact on therapy. ICAs should be carefully evaluated for atherosclerotic disease using biphasic MDCT for head and neck cancer.

Purpose: To evaluate image quality and cardiovascular enhancement after triphasic injection in 64-slice-CT coronary angiography (c-CTA). Methods: c-CTA of twenty-two asymptomatic patients following triphasic injection (65ml-contrast bolus + mixed 30ml-contrast and 20ml-saline bolus + 50ml-saline chaser) were retrospectively reviewed. Attenuation in the great vessels, cardiac chambers, and coronary arteries in 13 places were measured by region of interest. Also, differences in enhancement between the right coronary artery (RCA) and the right cardiac chambers (RCA versus right atrium or RA; RCA versus right ventricle or RV) were analyzed. Quality of images and contrast-related streak artifacts were subjectively assessed by 2 radiologists in consensus on a 4-point scale. Results: There was excellent enhancement in the coronary arteries (mean range 395.84-429.90 Hounsfield Units or HU), ascending aorta (mean 448.58 HU), descending aorta (mean 433.49 HU), and pulmonary artery (mean 385.45 HU). There was adequate difference in attenuation between RCA versus RA (mean range 126.12-148.43 HU) and RCA versus RV (mean range 50.34-72.66 HU). There was high and inhomogeneous attenuation in the superior vena cava (mean 509.23 HU). The quality of images was considered good (mean 1.6; 1 = excellent, 2 = good, 3 = moderate, 4 = low) and contrast-related streak artifacts were considered low (mean 2.9; 1 = severe, 2 = moderate, 3 = low, 4 = absent) by two radiologists. Conclusions: Our triphasic contrast injection provides excellent cardiovascular enhancement with minimal contrastrelated streak artifacts, particularly in the right cardiac chambers while adequately differentiating the right coronary artery.

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