Image contrast in CT is mostly dependent on elements with high atomic weight, such as calcium, iron, and iodine The concentrations of these elements can be calculated from dual-energy x-ray data based on their characteristic attenuation patterns Dual-energy CT may can be helpful in neuroimaging to: Differentiate between hemorrhage and iodinated contrast agents in brain parenchyma Improve CT ang...

Background: In the CT assessment of the carotid plaque, the analysis of the attenuation value is a fundamental parameter in order to classify the type of the tissue that composes the plaque. The purpose of this paper is to assess the intra-plaque attenuation variability in order to verify the potential reproducibility of HU measurements. Methods: In this retrospective study, 68 consecutive pati...

We present a 39-year old man with mesenteric ischaemia. The initial unenhanced images of the, non-oral contrast CT abdomen clearly demonstrated increased density in a significant length of the small bowel and in the veins of the adjacent mesentery. Mesenteric ischaemia is a difficult diagnosis both clinically and radiologically and we demonstrate the potential benefits of an unenhanced abdomina...

Contrast enhanced magnetic resonance angiography enables one to visualize the vascular system of the human body. Typically, using conventional measurement techniques, one three-dimensional volume of the vascular system can be measured during the passage of the contrast agent. More recently, medical doctors desire time-information of the blood-flow, or want to scan time-dependent phenomena. To e...

Negative product value for coronary artery disease is 98% to 99%. Therefore, the number of unnecessary cardiac catheterization procedures is reduced as the usefulness of CT systems for examination of the coronary arteries improves. In the bolus-tracking method, in which an ROI is placed in the ascending aorta to trigger scanning, scanning may not be performed at the optimal time of contrast enh...

Contrast-enhanced MR studies were compared with noncontrast MR and contrast-enhanced CT scans in the evaluation of intraparenchymal brain metastases. Fifty consecutive inpatients were studied with short and long repetition time (TR) sequences before and after the administration of gadopentetate dimeglumine. In addition, a delayed short TR sequence was performed. The contrast CT, noncontrast MR,...

OBJECTIVES To determine the effective dose and CT dose index (CTDI) for a range of imaging protocols using the Sirona GALILEOS(®) Comfort CBCT scanner (Sirona Dental Systems GmbH, Bensheim, Germany). METHODS Calibrated optically stimulated luminescence dosemeters were placed at 26 sites in the head and neck of a modified RANDO(®) phantom (The Phantom Laboratory, Greenwich, NY). Effective dose...