Comparison of aortic root dimension changes during cardiac cycle between the patients with and without aortic valve calcification using ECG-gated 64-slice and dual-source 256-slice computed tomography scanners: results of a multicenter study.

With advent of transcatheter aortic valve implantation, using multislice computed tomography (MSCT) to provide detailed data about aortic root has become more crucial. We compared aortic dimension changes during cardiac cycle in patients with and without aortic valve calcification and evaluated its correlation with aortic valve calcium score in former group. Fifty-two patients with and 52 subjects without aortic valve calcification underwent coronary MSCT using two 64-slice and a dual-source 256-slice CT scanners. Aortic root dimensions were measured in both systolic and diastolic phases. Changes in annular maximum diameter (D(max)), minimum diameter (D(min)), cross sectional area and perimeter, three diameters of sinuses of Valsalva (V(a), V(b) and V(c)), sinotubular junction maximum (STJ(max)) and minimum (STJ(min)) diameters between systolic and diastolic phases (systole minus diastole) were -0.59 mm, -0.05 mm, -2.53 mm(2), -1.48 mm, +0.91 mm, +1.08 mm, +0.42 mm, +0.63 mm, +0.40 mm and in those without aortic calcification -0.33 mm, 0.00 mm, -6.92 mm(2), -0.41 mm, +0.30 mm, +0.38 mm, +0.61 mm, +0.33 mm, +0.20 mm in patients with aortic calcification, respectively. Apart from two diameters in sinuses of Valsalva (V(a) and V(b)), changes in all other diameters of aortic root during cardiac cycle were not significantly different between the two groups. Furthermore, in patients with aortic calcification, no significant correlation was detected between changes in nearly all aortic root dimensions during cardiac cycle and aortic valve calcium score or location of calcification (annular, commissural or both).

Impact of calcification on diagnostic accuracy of 64-slice spiral computed tomography for detecting coronary artery disease: a single center experience.

BACKGROUND: The main aim of our study was to investigate the influence of calcification on the accuracy of 64-slice computed tomography for identification of significant coronary artery disease. METHODS: A contrast-enhanced 64-slice computed tomography was performed prior to invasive coronary angiography in 168 consecutive patients with suspected coronary artery disease. All coronary segments 1.5 mm or larger in diameter were evaluated for the presence or absence of significant coronary artery stenosis, defined as a diameter reduction of >50%. The patients were also ranked by total calcium score which was expressed in Agatston units and the impacts of calcification on diagnostic accuracy of 64-slice computed tomography were assessed. Results were compared with quantitative coronary angiography as the standard of reference. RESULTS: The overall sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice computed tomography for detection of significant stenosis were: by segments, 95%, 98%, 91%, and 99%, respectively; by patient, 98%, 97%, 96%, and 99%, respectively; and by artery, 94%, 93%, 91%, and 95%, respectively. In mild and moderate calcium scores (0-418 Agatston units), the sensitivity was 100%, specificity was 93%, positive predictive value was 97% and negative predictive value was 100%. Severe calcification (>419 Agatston units) reduced the sensitivity, specificity, positive, and negative predictive values of multi-slice computed tomography to 89%, 60%, 89%, and 60%, respectively. CONCLUSION: Our study revealed that the 64-slice computed tomography is a highly accurate diagnostic modality for detecting hemodynamically significant coronary stenosis; however, severe calcification is considered as a shortcoming which limits the routine application of multi-slice computed tomography in daily practice.

Extralobar sequestration in anterior mediastinum with pericardial agenesis.

We report a very rare case of extralobar sequestration and pericardial agenesis in a 22-year-old man. A computed tomographic (CT) scan demonstrated an anterior mediastinal mass. No aberrant artery was preoperatively identified. The patient underwent surgery with an impression of thymoma. An extralobar sequestration receiving its blood supply from the left pulmonary artery, accompanied with pericardial agenesis, was noted at the time of operation. The anterior mediastinum is an unusual site for extralobar sequestions. It is recommended to include extralobar sequestration in the differential diagnosis of anterior mediastinal masses, even if the aberrant artery is not recognized on the computed tomographic scan.

Assessment of patients after coronary artery bypass grafting using 64-slice computed tomography.

The aim was to investigate the diagnostic accuracy of 64-slice computed tomography (CT) for the identification of obstructive disease in both bypass grafts and native coronary vessels in symptomatic patients with a history of coronary artery bypass grafting. Eighty-nine symptomatic patients (81 men; mean age 64 +/- 8 years) were prospectively studied 8 +/- 4.5 years after bypass surgery. A total of 287 grafts (89 arterial grafts, 198 venous grafts) and 1,183 segments in 356 native coronary arteries >1.5 mm in diameter were evaluated using 64-slice computed tomographic angiography for the detection of significant stenosis, defined as >or=50% decrease in diameter of artery. Results were compared with quantitative coronary angiography as the standard of reference. Sensitivity, specificity, and positive and negative predictive values of 64-slice CT for the detection of significant lesions in bypass grafts were 98%, 97%, 96%, and 99%, respectively. Segment-by-segment analysis of native coronary arteries and distal runoff vessels for the detection of significant obstructive disease yielded sensitivity of 93% with specificity of 88%. If analysis was restricted to nongrafted and distal runoff segments, sensitivity and specificity were 89% and 94%, respectively. The diagnostic accuracy of 64-slice CT was significantly lower for the evaluation of severely calcified segments. In conclusion, 64-slice CT was a valuable and noninvasive tool for accurate comprehensive assessment of bypass grafts and native coronary circulation. However, its usefulness was limited in the presence of heavy calcium deposits.