Role of Low Voltage Multidetector Row Computed Tomography Angiography Examination in Diagnosis of Causes of Acute Chest Pain

Abstract

TA allows the proper visualization of main vascular structures and has several advantages: minimal invasiveness, with a lower complication rate than that of angiography; generation of high spatial resolution images of both the arterial wall and the lumen; availability of multiplanar reconstructions (MPR) and three-dimensional (3D) reconstructions; and short examination times, allowing extended scan ranges. There is increasing concern regarding the risk benefit ratio for this examinations particularly in younger patients and in women who are at higher risk of carcinogenesis from diagnostic irradiation. Consequently, there has been considerable interest in the application of dose reduction techniques to CT angiographic examination including stratification of tube current, tube potential, or both to patient body weight and body mass index. Reductions in tube potential have been shown to result in a greater decrease in radiation dose than similar proportional decreases in tube current. Furthermore, reductions in tube potential have the added benefit of improving intravascular image signal on CT scans obtained with iodinated contrast material. The disadvantage of the low-energy technique is an increase in image noise, especially in areas with more attenuating tissue, such as in large patients. Low energy protocols may also deliver increased radiation to the skin.