Assessment Of Coronary Arterial Stents By Multislice-Ct Angiography (original) (raw)
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Non-invasive assessment of coronary artery stent patency with multislice CT: preliminary experience
La Radiologia medica
PURPOSE: To evaluate the diagnostic accuracy of multislice computed tomography coronary angiography (MSCT-CA) in the detection of in-stent restenosis. MATERIALS AND METHODS: Forty-two patients (33 male, 9 female, mean age 58+/-8 years) previously subjected to percutaneous implantation of coronary stent with suspected in-stent restenosis, underwent a 16-row MSCT (Sensation 16, Siemens) examination. The average time between stent implantation and MSCT-CA was 7.4+/-5.3 months. The following scan parameters were used: collimation 16x0.75 mm, rotation time 0.42 s, feed 3.0 mm/rot., kV 120, mAs 500. After administration of iodinated contrast material (Iomeprol 400 mgI/ml, 100 ml at 4 ml/s) and bolus chaser (40 ml of saline at 4 ml/s) the scan was completed in <20 s. All segments with a stent were assessed by two observers in consensus and were graded according to the following scheme: patent stent, in-stent intimal hyperplasia (IIH) (lumen reduction <50%), in-stent restenosis (ISR) ...
European Radiology, 2009
The aim of this study was to test a large sample of the latest coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in dual-source multidetector row CT (DSCT) in vitro and to provide a CT catalogue of currently used coronary artery stents. Twenty-nine different coronary artery stents (19 steel, 6 cobalt-chromium, 2 tantalum, 1 iron, 1 magnesium) were examined in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density −70 HU). Stents were imaged in axial orientation with standard parameters: 32 × 0.6 collimation, pitch 0.24, 400 mAs, 120 kV, rotation time 0.33 s. Image reconstructions were obtained with four different convolution kernels (soft, medium-soft, standard high-resolution, stent-dedicated). To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density, and noise were measured. The stent-dedicated kernel offered best average lumen visualization (54 ± 8.3%) and most realistic lumen attenuation (222 ± 44 HU) at the expense of increased noise (23.9 ± 1.9 HU) compared with standard CTA protocols (p < 0.001 for all). The magnesium stent showed the least artifacts with a lumen visibility of 90%. The majority of stents (79%) exhibited a lumen visibility of 50–59%. Less than half of the stent lumen was visible in only six stents. Stent lumen visibility largely varies depending on the stent type. Magnesium is by far more favorable a stent material with regard to CT imaging when compared with the more common materials steel, cobalt-chromium, or tantalum. The magnesium stent exhibits a lumen visibility of 90%, whereas the majority of the other stents exhibit a lumen visibility of 50–59%.
International Journal of Cardiology, 2008
Metallic stent struts cause imaging artifacts on multidetector computed tomography (MDCT) which interfere with the assessment of in-stent coronary restenosis. We examined the degree of image distortion of implanted coronary stents on MDCT, comparing different stent types, sizes and orientation. We quantified stent dimensions and image distortion of 151 non-opacified coronary stents in 89 patients (81% men, age 65+/-10 years) who underwent MDCT with a 40 slice MDCT scanner. Stent dimension by MDCT was compared with measurements obtained from quantitative coronary angiographic (QCA) in the immediate post-implantation angiogram and with manufacturers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; data. Stent image quality was good for 107 stents (71%), moderate for 38 (25%) and poor in 6 (4%), 2 (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1%) of which were not assessable. Blooming artifact resulted in a mean MDCT luminal (inner) diameter 30+/-14% smaller than QCA diameter (2.0+/-0.5 vs 2.9+/-0.3 mm, p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and a mean outer diameter exceeding QCA by 31+/-14% (3.8+/-0.5 vs 2.9+/-0.3 mm, p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). MDCT luminal stent diameter was unrelated to strut thickness or the vessel stented but appeared to be smaller for vertically orientated stents (p=0.017), cobalt alloy (vs stainless steel) (p=0.011) and also for different stent types (p=0.006). The luminal dimension of implanted coronary stents, as visualized with 40 slice MDCT, was one third smaller than on invasive angiography. This decrease in visualized stent luminal diameter forms the basis for the difficulty in accurate assessment of in-stent restenosis by MDCT.
Journal of Experimental and Clinical Medicine, 2013
Coronary artery stenting is currently treatment of choice for management of coronary artery disease. Stent restenosis is the most important problem during follow up. Conventional coronary angiography is the gold standart for assessment of intracoronary stent patency. It is an invasive method and even though rare, has some significant risks. For this reason, noninvasive imaging methods are necessary to evaluate stent patency. Noninvasive methods such as the exercise test, myocardial perfusion scintigraphy and stress echocardiography could not reach enough diagnostic accuracy. Multislice computed tomography (MSCT) has been under investigation for stent restenosis detection. Aim of this study is to investigate usefulness of the 16-slice CT for evaluation of stent patency in patients with suspicion of stent restenosis. Thirty six patients were included in the study and 16-slice CT and conventional coronary angiographies were performed in all patients. The results of 16-slice CT and conventional coronary angiography were compared. Sufficient or good quality imaging with 16-slice CT angiography was obtained in 69% of all patients. Sixteen-slice CT angiography detected 42/49 (86%) stents and gave the correct localization for all of the detected stents. Stent lumen could be assessed in 30 (61%) stents and according to the results of luminal assessment, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 16-slice MSCT were calculated as 33%, 95%, 75%, 77% and 77%, respectively. According to these results, the diagnostic performance of 16-slice CT angiography for detection of stent restenosis was relatively low. However, the assessment of relatively small number of stents because of insufficient heart rate control did not allow reliable and precise evaluation. Our results showed that diagnostic capacity of 16-slice CT angiography for detection of coronary stent restenosis is limited.
Heart, 2013
Objective To evaluate the agreement between multislice CT (MSCT) and intravascular ultrasound (IVUS) to assess the in-stent lumen diameters and lumen areas of left main coronary artery (LMCA) stents. Design Prospective, observational single centre study. Setting A single tertiary referral centre. Patients Consecutive patients with LMCA stenting excluding patients with atrial fibrillation and chronic renal failure. Interventions MSCT and IVUS imaging at 9-12 months follow-up were performed for all patients. Main outcome measures Agreement between MSCT and IVUS minimum luminal area (MLA) and minimum luminal diameter (MLD). A receiver operating characteristic (ROC) curve was plotted to find the MSCT cutoff point to diagnose binary restenosis equivalent to 6 mm 2 by IVUS. Results 52 patients were analysed. Passing-Bablok regression analysis obtained a β coefficient of 0.786 (0.586 to 1.071) for MLA and 1.250 (0.936 to 1.667) for MLD, ruling out proportional bias. The α coefficient was −3.588 (−8.686 to −0.178) for MLA and −1.713 (−3.583 to −0.257) for MLD, indicating an underestimation trend of MSCT. The ROC curve identified an MLA ≤4.7 mm 2 as the best threshold to assess instent restenosis by MSCT. Conclusions Agreement between MSCT and IVUS to assess in-stent MLA and MLD for LMCA stenting is good. An MLA of 4.7 mm 2 by MSCT is the best threshold to assess binary restenosis. MSCT imaging can be considered in selected patients to assess LMCA in-stent restenosis.
Imaging of coronary artery stents using multislice computed tomography: in vitro evaluation
European radiology, 2003
The aim of this study was to evaluate imaging features of different coronary artery stents during multislice CT Angiography (MSCTA). Nineteen stents made of varying material (steel, nitinol, tantalum) and of varying stent design were implanted in plastic tubes with an inner diameter of 3 mm to simulate a coronary artery. The tubes were filled with iodinated contrast material diluted to 200 Hounsfield units (HU), closed at both ends and positioned in a plastic container filled with oil (-70 HU). The MSCT scans were obtained perpendicular to the stent axes (detector collimation 4x1 mm, table feed 2 mm/rotation, 300 mAs, 120 kV). Axial images and multiplanar reformations were evaluated regarding artifact size, lumen visibility, and intraluminal attenuation values. Artifacts characterized by artifactual thickening of the stent struts leading to apparent reduction in the lumen diameter and increased intraluminal attenuation values were observed in all cases. The stent lumen was totally o...
Assessment of coronary artery stents by 16 slice computed tomography
Heart, 2006
Objective: To analyse coronary stents with multislice spiral computed tomography (MSCT) in comparison with coronary angiography.Patients and methods: 310 patients referred for conventional coronary angiography underwent MSCT on the next day (16 × 0.75 mm cross section, 420 ms rotation, 110 ml contrast agent intravenously at 4 ml/s). Two independent blinded reviewers analysed the MSCT.Results: 143 patients had previous stenting
In-vitro assessment of coronary artery stents in 256-multislice computed tomography angiography
BMC Research Notes, 2014
The important detection of in-stent restenosis in cardiovascular computed tomography (CT) is still challenging. The first study assessing the in-vitro stent lumen visualization of the state of the art 256-multislice CT (256-MSCT), which was performed by our research group, yielded promising results. As the applied technical approach is not suitable for daily routine, we assessed the capability of the 256-MSCT and its different reconstruction kernels for the coronary stent lumen visualization employing a clinically applicable technique in a phantom study. Results: The XCD kernel showed significantly lower artificial lumen narrowing (ALN) values (overall ALN < 40%) than the other reconstruction kernels (CC, CD, XCB) irrespective of the stent caliber. The ALN of coronary stents with a diameter >3 mm was significantly lower than of stents with a smaller caliber. The ALN difference between stents with a diameter of 3 mm and smaller ones was not statistically significant. Yet, the lumen visualization of the smaller stents was impaired by a halo effect. The XCD kernel showed more constant attenuation values throughout the different stent diameters than the other reconstruction kernels. Conclusions: The 256-MSCT provides a good lumen visualization of coronary stents with a diameter >3 mm. The assessment of stents with a diameter of 3 mm seems feasible but has to be validated in further studies. The clinical evaluation of smaller stents cannot be recommended so far. The XCD kernel showed the best lumen visualization and should therefore be applied in addition to the standard cardiac reconstruction kernels when assessing coronary artery stents using 256-MSCT.
Journal of Medical Science And clinical Research, 2021
Background: Coronary artery disease (CAD) is the leading cause of morbidity and mortality in industrialized society. To treat patients with obstructive atherosclerosis, percutaneous coronary intervention with stent implantation is routinely performed, which considerably reduces the rate of restenosis as compared with balloon angioplasty. Aim of the Work: to evaluate multi-detector CT angiography as a less invasive technique in the assessment of the coronary stent patency and compared with the conventional angiography findings (as a gold standard technique). Patients and Methods: This study included 50 patients with prior coronary stent deployment, 32 of them (64%) underwent conventional angiography as a gold standard for evaluation of the patency of the coronary stents. The indications of conventional angiography were unstable angina in 10 cases out of the 32 cases (31.25 %), while the rest were performed to assess stent patency after suspected instent re-stenosis or atypical chest pain in 22 cases out of 32 (68.75 %). Results: In this study CT angiography compared to the conventional angiography as a gold standard technique gave us a sensitivity of 92.3%, a specificity of about 100 %, an accuracy of about 95.6 %, PPV of 100% and NPV of 90.5 % as regarding patent stent taking into consideration that 2 stents were non evaluable due to narrow stent caliber (2.5mm.) but proved patent by conventional angiography, but these results will much improved if the non evaluable stents removed from statistical analysis. Conclusion: Our study recommends usage of latest multi-detector row CT scanners as a first-line tool for the noninvasive evaluation of patients with suspected instent restenosis especially with stents diameter ≥ 3mm. and helps to identify factors that influence the assess ability of coronary artery stents by 320 MDCT scanners, namely, stent type and diameter.