The purpose of this study was to test a large sample of different coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in 64-slice multidetector-row computed tomography (MDCT) in vitro and to provide a catalogue of currently used coronary artery stents when imaged with state-of the-art MDCT. We examined 68 different coronary artery stents (57 stainless steel, four cobalt-chromium, one cobalt-alloy, two nitinol, four tantalum) in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70). Stents were imaged in axial orientation with standard parameters: 32 x 0.6 collimation, pitch 0.24, 680 mAs, 120 kV, rotation time 0.37 s. Four different image reconstructions were obtained with varying convolution kernels and section thicknesses: (1) soft, 0.6 mm, (2) soft, 0.75, (3) medium soft, 0.6, and (4) stent-optimized sharp, 0.6. To evaluate visualization characteristics of of the stent, the lumen diameter, intraluminal density and noise were measured. The high-resolution kernel offered significantly better average lumen visualization (57% +/-10%) and more realistic lumen attenuation (222 HU +/-66 HU) at the expense of increased noise (15.3 HU +/-3.7 HU) compared with the soft and medium-soft CT angiography (CTA) protocol (p<0.001 for all). Stents with a lumen visibility of more than 66% were: Arthos pico, Driver, Flex, Nexus2, S7, Tenax complete, Vision (all 67%), Symbiot, Teneo (70%), and Radius (73%). Only ten stents showed a lumen visibility of less than 50%. Stent lumen visibility largely varies depending on the stent type. Even with the improved spatial resolution of 64-slice CT, a stent-optimized kernel remains beneficial for stent visualization when compared with the standard medium-soft CTA protocol. Using 64-slice CT and high-resolution kernel, the majority of stent products show a lumen visibility of more than 50% of the stent diameter.

In the diagnostic algorithm of cardiac tumors, the noninvasive determination of malignancy and metastatic spread is of major interest to stratify patients and to select and monitor therapies. In the diagnostic work-up, morphologic imaging modalities such as echocardiography or magnetic resonance tomography offer information on, for example, size, invasiveness, and vascularization. However, preoperative assessment of malignancy may be unsatisfactory. The aim of this study was to evaluate the diagnostic value of 18 F-FDG PET and the incremental diagnostic value of an optimized CT score in this clinical scenario. Methods: 18 F-FDG PET/CT scans (wholebody imaging with low-dose CT) of 24 consecutive patients with newly diagnosed cardiac tumors were analyzed (11 men, 13 women; mean age 6 SD, 59 6 13 y). The maximum standardized uptake values (SUV max ) of the tumors were measured. Patients were divided into 2 groups: benign cardiac tumors (n 5 7) and malignant cardiac tumors (n 5 17) (cardiac primaries [n 5 8] and metastases [n 5 9]). SUV max was compared between the 2 groups. Results were compared with contrast-enhanced CT, using standardized criteria of malignancy. Histology served as ground truth. Results: Mean SUV max was 2.8 6 0.6 in benign cardiac tumors and significantly higher both in malignant primary and in secondary cardiac tumors (8.0 6 2.1 and 10.8 6 4.9, P , 0.01). Malignancy was determined with a sensitivity of 100% and specificity of 86% (accuracy, 96%), after a cutoff with high sensitivity (SUV max of 3.5) was chosen to avoid false-negatives. Morphologic imaging reached a sensitivity of 82% and a specificity of 86% (accuracy, 83%). Both false-positive and false-negative decisions in morphology could be corrected in all but 1 case using a metabolic threshold with an SUV max of 3.5. In addition, extracardiac tumor manifestations were detected in 4 patients by whole-body 18 F-FDG PET/CT. Conclusion: 18 F-FDG PET/ CT can aid the noninvasive preoperative determination of malignancy and may be helpful in detecting metastases of malignant cardiac tumors.

Purpose: To investigate the extent to which clinical status is affected by covering the left subclavian artery (LSA) with stent-grafts in the thoracic aorta. Methods: Stent-graft reconstruction of the thoracic aorta was performed in 23 patients (20 men; mean age 50.8 years, range 17–77) for management of rupture (n = 11), type B dissection (n = 9), or aneurysm (n = 3). All patients had bilaterally equal systolic and diastolic blood pressures (141.3 ± 19.8 and 78.9 ± 11.0 mmHg, respectively). Twenty Gore TAG and 1 Talent thoracic endografts were used; 2 cases required a combination of prostheses. In all patients, the stent-graft was intentionally placed to cover the LSA. Follow-up included clinical examination with blood pressure measurements and computed tomography during the first postoperative week and at 3-month intervals thereafter. Results: After coverage of the LSA by the stent-graft, systolic pressure fell by a mean 48.3 ± 23.4 mmHg. In 4 cases of proximal endoleak, however, systolic pressure fell by only 25.0 ± 15.0 mmHg. Twenty (78.5%) patients reported no complaints during a mean follow-up of 12.1 ± 7.3 months. Postinterventional complaints reported by 3 patients included exercise-dependent paresthesias; nonexercise-dependent, intermittent, and completely reversible dizziness; and a temperature difference between the upper extremities with no decrease in strength. Conclusions: Covering the LSA is generally well tolerated by patients and increases the landing zone for the placement of thoracic stent-grafts. Long-term studies, however, must investigate the hemodynamic effects of this procedure on the vertebrobasilar circulation.

The assessment of the plaque pattern improves diagnostic accuracy of CCTA to identify advanced atherosclerotic lesions. The CCTA finding of NRS has a high specificity and high positive predictive value for the presence of advanced lesions.