Dual-energy CT angiography in peripheral arterial occlusive disease—accuracy of maximum intensity projections in clinical routine and subgroup analysis

Kau, Thomas; Eicher, Wolfgang; Reiterer, Christian; Niedermayer, Martin; Rabitsch, Egon; Senft, Birgit; Hausegger, K. A.

doi:10.1007/s00330-011-2099-1

Cited by 58 publications

(31 citation statements)

References 23 publications

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“…DE bone removal was feasible in carotid or peripheral arteries compared with conventional bone removal techniques (10,11). In addition, accuracy of bone and plaque removal using DECT was promising in carotid (12,13) and peripheral arteries (14). However, the performance of calcified plaque subtraction in peripheral arteries might be affected by variables such as vessel diameter or contrast material concentration.…”

Section: Introductionmentioning

confidence: 99%

Dual-energy computed tomography angiography: virtual calcified plaque subtraction in a vascular phantom

Jin

Chung

Park

et al. 2017

Acta Radiologica Open

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BackgroundMaterial decomposition of dual-energy computed tomography (DECT) enables subtraction of calcified plaque.PurposeTo evaluate the accuracy of lumen area measurement in calcified plaque by subtraction of DECT and to determine the effect of contrast material concentration, lumen diameter, density, and thickness of calcified plaque for the measurement.Material and MethodsVessel phantoms were made with six lumen diameters (5.7, 4.9, 3.9, 3.0, 1.9, and 1.3 mm) and six types of calcified plaques with three densities and two thicknesses were attached. CT scans were performed with three contrast material concentrations (62, 111, and 170 mg iodine/mL). Lumen area discrepancy (AD) was calculated by subtracting the measured lumen area from a reference value. The lumen area underestimation percentage (AU), defined as (AD/reference value) × 100, was calculated. General linear model analysis was used to test the effect of variables for log-transformed AU (ln_AU).ResultsThe AD and AU was calculated to be 6.1 ± 4.8 mm2 and 69.8 ± 29.4%, respectively. Ln_AU was significantly affected by contrast material concentration (P < 0.001), calcium density (P = 0.001), plaque thickness (P = 0.010), and lumen diameter (P < 0.001). Ln_AU was significantly higher in 62 mg iodine/mL than in 111 or 170 mg iodine/mL (P < 0.001 for both). Ln_AU was significantly lower at a lumen diameter of 5.7 mm than 3.9 mm (P = 0.001) or 3.0 (P < 0.001).ConclusionCalcified plaque subtraction in DECT substantially underestimates measurements of lumen area. Higher enhancement in larger vessels ensures more accurate subtraction of calcified plaque.

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Section: Introductionmentioning

confidence: 99%

Dual-energy computed tomography angiography: virtual calcified plaque subtraction in a vascular phantom

Jin

Chung

Park

et al. 2017

Acta Radiologica Open

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“…DECT is a recently developed technique that offers a diversity of applications for improving image visualization and material differentiation, based on CT attenuation obtained from two tube voltages (2,7,8). The bone removal algorithm of DECT plays a major role in confirming the diagnosis and evaluation of the disease progress (8)(9)(10). Image quality, in general, is improved with DECT due to the utilization of low energies.…”

Section: Introductionmentioning

confidence: 99%

“…Stent lumen visibility for small stents was reported in a phantom study at high keV when the third generation of dual-source CT and DECT was used (6). For large stent evaluation such as those in peripheral arteries, DECT may improve stent visualization and decrease blooming artifacts better than that for small stents.DECT is a recently developed technique that offers a diversity of applications for improving image visualization and material differentiation, based on CT attenuation obtained from two tube voltages (2,7,8). The bone removal algorithm of DECT plays a major role in confirming the diagnosis and evaluation of the disease progress (8-10).…”

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confidence: 99%

Dual energy CT angiography in peripheral arterial stents: optimal scanning protocols with regard to image quality and radiation dose

Almutairi

Safran

AlZaabi

et al. 2017

Quant. Imaging Med. Surg.

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Background: To determine the optimal scanning protocols of dual energy computed tomography angiography (DECTA) in terms of radiation dose and image quality assessment at different keV levels, and compare it with conventional computed tomography angiography (CTA) in patients treated with peripheral arterial stents.Methods: Twenty-nine patients with previous stent placement in peripheral arteries were evaluated with DECTA. Images were reconstructed with virtual monochromatic spectral imaging (VMS) at 65, 68, 70 and 72 keV and adaptive statistical iterative reconstruction (ASIR) at 50% compared with CTA. Image quality comprising image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed, and radiation dose was compared. Effects of different type of peripheral arterial stents on image quality were also evaluated. Fifty-six uniquely identified stents that were located in common iliac arteries (CIA), external iliac arteries (EIA) and superficial femoral arteries (SFA) were evaluated.Results: Within subjects, the results showed that DECTA images (VMS) had less noise than the CTA images for CIA, EIA and SFA stents, with the lowest noise at 72 keV. Also, the VMS images had greater SNR than the CTA images for the EIA stents (P<0.05); and the VMS images had greater CNR than the CTA images for CIA, EIA, and SFA stents (P<0.001). Also, on CT attenuation, VMS continued to outperform CTA, but to a lesser extent. Between subjects, average VMS noise varied significantly with the type of the stent used (P=0.025) for CIA stents. Radiation dose was highly significant between DECTA and conventional CTA scans (6.98 vs. 7.40 mSv, P=0.047). Conclusions:We conclude that an optimal scanning protocol consisting of 72 keV and 50% ASIR leads to better image quality for DECTA in peripheral arterial stenting when compared to conventional CTA. Quant Imaging Med Surg 2017;7(5):520-531 qims.amegroups.com few motion artifacts, and generation of 3D visualizations (3). Despite these benefits, it has its own limitation, such as the potential risk of contrast medium-induced nephrotoxicity, the presence of blooming artifacts caused by stent struts, and high radiation dose. Further, MDCT has difficulty in differentiating different materials related to peripheral arterial stents. As assessment of in-stent restenosis is closely related to stent materials, this may lead to an overestimation of the lesion severity. Blooming and beam hardening artifacts which are commonly seen in the conventional CT angiography (CTA) hamper the accurate assessment of instent restenosis (4), but these artifacts can be eliminated in dual-energy CT (DECT) applications. Huang et al. reported an improvement of correction with DECT (4). In a recent study by Mangold et al., reduction of blooming artifacts in imaging peripheral arterial stents with improved image quality was achieved when 70 or 80 keV was used (5). Stent lumen visibility for small stents was reported in a phantom study at high keV when the third generation of dual-source CT and DECT wa...

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“…Dual energy CT (DECT) has been increasingly used in different clinical applications, including direct angiography and bone removal,(Ruzsics et al , 2008; Tran et al , 2009; Watanabe et al , 2009; Kau et al , 2011) assessment of lung perfusion,(Thieme et al , 2012; Zhang et al , 2013a) characterization of renal calculi,(Primak et al , 2007; Graser et al , 2009) and generation of virtual unenhanced CT images. (De Cecco et al , 2010) Conventional DECT reconstruction theory requires two full-size projection datasets with two different energy spectra.…”

Section: Introductionmentioning

confidence: 99%

Dual energy CT with one full scan and a second sparse-view scan using structure preserving iterative reconstruction (SPIR)

Wang

Zhu

2016

Phys. Med. Biol.

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Conventional dual-energy CT (DECT) reconstruction requires two full-size projection datasets with two different energy spectra. In this study, we propose an iterative algorithm to enable a new data acquisition scheme which requires one full scan and a second sparse-view scan for potential reduction in imaging dose and engineering cost of DECT. A bilateral filter is calculated as a similarity matrix from the first full-scan CT image to quantify the similarity between any two pixels, which is assumed unchanged on a second CT image since DECT scans are performed on the same object. The second CT image from reduced projections is reconstructed by an iterative algorithm which updates the image by minimizing the total variation of the difference between the image and its filtered image by the similarity matrix under data fidelity constraint. As the redundant structural information of the two CT images is contained in the similarity matrix for CT reconstruction, we refer to the algorithm as structure preserving iterative reconstruction (SPIR). The proposed method is evaluated on both digital and physical phantoms, and is compared with the filtered-backprojection (FBP) method, the conventional total-variation-regularization-based algorithm (TVR) and Prior-Image-Constrained-Compressed-Sensing (PICCS). SPIR with a second 10-view scan reduces the image noise STD by a factor of one order of magnitude with same spatial resolution as full-view FBP image. SPIR substantially improves over TVR on the reconstruction accuracy of a 10-view scan by decreasing the reconstruction error from 6.18% to 1.33%, and outperforms TVR at 50 and 20-view scans on spatial resolution with a higher frequency at the modulation transfer function value of 10% by an average factor of 4. Compared with the 20-view scan PICCS result, the SPIR image has 7 times lower noise STD with similar spatial resolution. The electron density map obtained from the SPIR-based DECT images with a second 10-view scan has an average error of less than 1%.

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Dual-energy CT angiography in peripheral arterial occlusive disease—accuracy of maximum intensity projections in clinical routine and subgroup analysis

Abstract: While correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia.

Cited by 58 publications

References 23 publications

Dual-energy computed tomography angiography: virtual calcified plaque subtraction in a vascular phantom

Dual-energy computed tomography angiography: virtual calcified plaque subtraction in a vascular phantom

Dual energy CT angiography in peripheral arterial stents: optimal scanning protocols with regard to image quality and radiation dose

Dual energy CT with one full scan and a second sparse-view scan using structure preserving iterative reconstruction (SPIR)

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