Delayed MDCT imaging results in increased enhancement in patients with head and neck neoplasms.

Objective: Using multidetector computed tomography, we compared the utility of a spilt bolus technique and the impact of performing delayed imaging compared with immediate imaging on tumor enhancement.

Methods: Thirty-seven patients with masses of the extracranial head and neck were imaged. An initial contrast bolus (50 cm) was administered over 30 seconds (1.

Effect of left atrial circumferential ablation for atrial fibrillation on left atrial transport function.

Background: The effects of left atrial (LA) circumferential ablation on LA function in patients with atrial fibrillation (AF) have not been well described.

Objectives: The purpose of this study was to determine the effect of LA circumferential ablation on LA function.

Methods: Gated, multiphase, dynamic contrast-enhanced computed tomographic (CT) scans of the chest with three-dimensional reconstructions of the heart were used to calculate the LA ejection fraction (EF) in 36 patients with paroxysmal (n = 27) or chronic (n = 9) AF (mean age 55 +/- 11 years) and in 10 control subjects with no history of AF.

Topographic analysis of the coronary sinus and major cardiac veins by computed tomography.

Background: The coronary sinus (CS) and its branches may play a role in the genesis of various arrhythmias. Applications of radiofrequency energy within the CS may be necessary. Atrio-esophageal fistula has been recognized as a complication of ablation along the posterior left atrial wall.

Effects of left atrial ablation of atrial fibrillation on size of the left atrium and pulmonary veins.

Objectives: The purpose of this study was to determine the effect of left atrial circumferential ablation on the size of the left atrium and pulmonary veins (PVs).

Background: The long-term effects of left atrial circumferential ablation on left atrial and PV size and anatomy have not been analyzed in quantitative fashion.

Methods: PV and left atrial sizes were analyzed in 41 consecutive patients (mean age 54 +/- 12 years) with paroxysmal (n = 25) or chronic (n = 16) atrial fibrillation.

Computed tomographic analysis of the anatomy of the left atrium and the esophagus: implications for left atrial catheter ablation.

Background: During left atrial (LA) catheter ablation, an atrioesophageal fistula can develop as a result of thermal injury of the esophagus during ablation along the posterior LA. No in vivo studies have examined the relationship of the esophagus to the LA. The purpose of this study was to describe the topographic anatomy of the esophagus and the posterior LA by use of CT.

Cerebral perfusion CT: technique and clinical applications.

Perfusion computed tomography (CT) is a relatively new technique that allows rapid qualitative and quantitative evaluation of cerebral perfusion by generating maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). The technique is based on the central volume principle (CBF = CBV/MTT) and requires the use of commercially available software employing complex deconvolution algorithms to produce the perfusion maps. Some controversies exist regarding this technique, including which artery to use as input vessel, the accuracy of quantitative results, and the reproducibility of results.

Computed tomography perfusion of squamous cell carcinoma of the upper aerodigestive tract. Initial results.

Objective: To define the computed tomography (CT) perfusion characteristics of head and neck squamous cell carcinoma.

Methods: Fourteen consecutive patients with untreated squamous cell cancers of head and neck underwent CT of the head and neck along with CT perfusion imaging through the primary site. For the perfusion studies, CT density changes in blood and tissues were kinetically analyzed using the commercially available CT Perfusion 2 software (General Electric Medical Systems.

Anatomy of the pulmonary veins in patients with atrial fibrillation and effects of segmental ostial ablation analyzed by computed tomography.

Introduction: The anatomic arrangement of pulmonary veins (PVs) is variable. No prior studies have quantitatively analyzed the effects of segmental ostial ablation on the PVs. The aim of this study was to determine the effect of segmental ostial radiofrequency ablation on PV anatomy in patients with atrial fibrillation (AF).

Limb and gender differences in the development of coordination in early infancy.

Young infants produce a variety of spontaneous arm and leg movements in the first few months of life. Coordination of leg joints has been extensively investigated, whereas arm joint coordination has mainly been investigated in the sitting position in the context of early reaching and grasping. The current study investigated arm and leg joint coordination of movements produced in the supine position in 10 fullterm infants aged 6, 12 and 18 weeks.