Detection and characterization of crystal suspensions using single-source dual-energy computed tomography: a phantom model of crystal arthropathies.

Objectives: The aim of this study was to perform phantom measurements to prove the feasibility of single-source dual-energy computed tomography (DECT) of the extremities using a volume scan mode. In addition, we, for the first time, wanted to determine which concentrations of monosodium urate (MSU) in gout and calcium pyrophosphate (CP) in pseudogout are needed to detect or distinguish these soft tissue depositions with DECT.

Materials And Methods: We created a hand-shaped plastic phantom assembled with a descending order of concentrations of MSU (6.

ECG-edit function in multidetector-row computed tomography coronary arteriography for patients with arrhythmias.

Background: ECG-gating is necessary for cardiac computed tomography, but is not suitable for arrhythmias, so the aim of this study was to evaluate the usefulness of the ECG-edit function for this purpose.

Methods And Results: Of 1,221 patients undergoing 64-row multidetector-row computed tomography coronary angiography (coronary MDCT), 123 patients (28 atrial fibrillation (Af), 39 premature atrial contractions (PAC), 42 premature ventricular contractions (PVC), 3 PAC + PVC, 10 sinus arrhythmias (SA), and a second-degree atrioventricular block (2 degrees AVB)) had arrhythmias necessitating the ECG-edit function. Short R-R interval was deleted and mid-diastolic phases were selected from the long R-R intervals using the "R+absolute time" method.

[Automatic selection of optimal cardiac-phase in coronary CT angiography--its clinical usefulness for patients with atrial fibrillation].

The optimal cardiac phases for coronary CT angiography (CTA) are end-systole and mid-diastole, in which cardiac movement is slow. In conventional methods, these cardiac phases are determined by visual selection. We have compared the images in the optimal cardiac phases that were selected by the conventional method and cardiac-phase search software (Phase Navi), and examined the clinical usefulness of Phase Navi in patients with atrial fibrillation.