Cardiac and vascular MDCT: thoracic imaging

Congenital coronary artery anomalies: diagnosis with 64 slice multidetector row computed tomography coronary angiography: a single-centre study

Retrospective review of the congenital coronary artery (CA) anomalies detected by a 64-slice multidetector row computed tomographic (MDCT) angiography. The type of the anomaly, imaging characteristics, clinical relevance and the superiority of the MDCT over conventional coronary angiography are discussed. Multidetector row computed tomographic coronary angiography was carried out by the usual technique with 70 cc of non-ionic contrast agent and retrospective electrocardiogram gating. The volume data obtained were reconstructed in axial plane, along with volume-rendered three-dimensional reconstruction and virtual angioscopy in selected patients. The images were analysed by a radiologist, experienced in cardiac CT, and an experienced cardiologist. A retrospective review of the records was carried out, and subjects with congenital coronary anomalies were included in the study. Between 15 November 2005 and 27 February 2007, 1495 MDCT coronary angiograms were carried out. Eleven of them were found to have coronary anomalies. Five had absent left main CA. Two had interarterial course of the left main CA artery passing in between the right ventricular outflow tract and the root of aorta. In one patient, there was aberrant origin of right CA from the left aortic sinus with subsequent interarterial course and another one had aberrant origin of circumflex artery from the right aortic sinus. One patient each of congenitally absent circumflex artery and atresia of the right CA were found. Sixty-four slice MDCT coronary angiography provided accurate depiction of anomalous vessel origin and course along with the complex anatomical relation with the adjacent structures. CT can be considered as a first-line imaging method for delineating coronary arterial anomalies.

Quantification of aortic elasticity: development and experimental validation of a method using computed tomography

Aortic distensibility depending on aortic cross-sectional area changes is an important parameter for the grading of vascular diseases. This study measured aortic area changes by multidetector computed tomography. An image reconstruction algorithm was developed to assess aorta diameter and area as a function of the cardiac cycle with sufficient time resolution along the entire length of the aorta by four-detector row computed tomography. The algorithm was tested on porcine aortic specimens and compared with an optical reference method. The error of the relative vessel area change comparing the two methods was found to be about 3%. Initial tests on patient datasets indicate that clinical application is feasible. The proposed method has the advantage that it can easily be integrated into a modified routine CT angiography study and allows the measurement of aortic cross-sectional area changes.

Variation of the size of pulmonary venous ostia during the cardiac cycle: optimal reconstruction window at ECG-gated multi-detector row CT

The aim of this study was to investigate the variation of the size of pulmonary vein ostia during cardiac cycle using ECG-gated multi-detector row CT (MDCT). Nineteen patients were included in this study. Transaxial images at the level of right inferior pulmonary vein (RIPV) were reconstructed in increments of 5%. The ostial diameter of RIPV was measured, the reconstruction windows showing maximal and minimal diameters were selected. The ostial areas of four pulmonary veins were measured at axial image sets of two selected reconstruction windows. The measurement of RIPV revealed that the maximal diameter (1.50+/-0.32 cm) was generally 35% and the minimal diameter (1.28+/-0.28 cm) was usually at 85%. The measurement of ostial areas showed that the ostia enlarged at the end of ventricular systole when compared with those at the end of ventricular diastole, by the factors of 1.44+/-0.55 for the right superior, 1.25+/-0.23 for the right inferior, 1.45+/-0.81 for the left superior, and 1.31+/-0.26 for the left inferior pulmonary vein (P<0.05). The size of the pulmonary vein ostia is variable during the cardiac cycle and the measurement of the pulmonary veins should always be in the same phase of the cardiac cycle during the follow-up of patients.