scholarly journals Motion Artifact Reduction in Contrast-Enhanced Dual-Energy Mammography – A Multireader Study about the Effect of Nonrigid Registration as Motion Correction on Image Quality

2021 ◽  
Author(s):  
Markus Sistermanns ◽  
Bernd Kowall ◽  
Mathias Hörnig ◽  
Karsten Beiderwellen ◽  
Detlev Uhlenbrock
Keyword(s):  
Image Quality ◽  
Motion Correction ◽  
High Energy ◽  
Dual Energy ◽  
Motion Artifacts ◽  
Nonrigid Registration ◽  
Correction Algorithm ◽  
Contrast Enhanced ◽  
The Mean

Purpose The technically caused delay between low-energy (LE) and high-energy (HE) acquisitions allows motion artifacts in contrast-enhanced dual-energy mammography (CEDEM). In this study the effect of motion correction by nonrigid registration on image quality of the recombined images was investigated. Materials and Methods Retrospectively for 354 recombined CEDEM images an additional recombined image was processed from the raw data of LE and HE images using the motion correction algorithm. Five radiologists with many years of experience in breast cancer diagnostic imaging compared side-by-side one conventional processed CEDEM image with the corresponding image processed by the motion correction algorithm. Every pair of images was compared based on six criteria: General image quality (1), sharpness of skin contour (2), reduction of image artifacts (3), sharpness of lesion contour (4), contrast of lesion (5), visibility of lymph nodes (6). These criteria were rated on a Likert scale (improvement: + 1, + 2; deterioration: –1, –2). Results The mean ratings concerning criteria 1–5 showed a superiority of the recombined images processed by the motion correction algorithm. For example, the mean rating of general image quality was 0.86 (95 % CI: 0.78; 0.93). Only the mean rating concerning criterion 6 showed an inferiority of the recombined images processed by the motion correction algorithm (–0.29 (–0.46; –0.13)). Conclusion The usage of nonrigid registration for motion correction significantly improves the general image quality and the quality of subordinate criteria on the recombined CEDEM images at the expense of somewhat reduced lymph node visibility in some cases. Key Points:  Citation Format

scholarly journals Motion Reduction for C-Arm Computed Tomography of the Pulmonary Arteries: Image Quality of a Motion Correction Algorithm in Patients with Chronic Thromboembolic Hypertension During Balloon Pulmonary Angioplasty

2021 ◽  
Author(s):  
Sabine Maschke ◽  
Thomas Werncke ◽  
Lena Sophie Becker ◽  
Julius Renne ◽  
Cornelia Lieselotte Angelika Dewald ◽  
...  
Keyword(s):  
Image Quality ◽  
Motion Correction ◽  
Pulmonary Arteries ◽  
Quality Criteria ◽  
Observer Agreement ◽  
Correction Algorithm ◽  
Contrast Enhanced ◽  
Quality Grade ◽  
Grade 3

Purpose To evaluate the feasibility and image quality of a motion correction algorithm for supra-selective C-arm computed tomography (CACT) of the pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing balloon pulmonary angioplasty (BPA). Materials & Methods CACT raw data acquired during 30 consecutive BPAs were used for image reconstruction using either standard (CACTorg) or a motion correction algorithm (CACTmc), using 400 iterations. Two readers independently evaluated 188 segmental and 564 sub-segmental contrast-enhanced pulmonary arteries in each reconstruction. The following categories were assessed: Sharpness of the vessel, motion artifacts, delineation of bronchial structures, vessel geometry, and visibility of treatable lesions. The mentioned criteria were rated from grade 1 to grade 3: grade 1: excellent quality; grade 2: good quality; grade 3: poor/seriously impaired quality. Inter-observer agreement was calculated using Cohen’s Kappa. Due to an excellent agreement, the ratings of both readers were merged. Differences in the assessed image quality criteria were evaluated using pairwise Wilcoxon signed-rank test. Results Inter-observer agreement was excellent for all evaluated image quality criteria (κ > 0.81). For all assessed image quality criteria, the ratings on CACTorg were good but improved significantly for CACTmc to excellent for the whole vascular tree (p < 0.01). When considering segmental and sub-segmental levels individually, all image quality criteria improved significantly for CACTmc on both levels (p < 0.01). While ratings of CACTmc were constant for both levels (segmental and sub-segmental) for all criteria, the ratings of CACTorg were slightly impaired for the sub-segmental arteries. Conclusion Motion correction for supra-selective contrast-enhanced CACT of the pulmonary arteries is feasible and improves the overall image quality. Key Points:  Citation Format

Effect of dose on image quality in a detector‐based dual‐exposure, dual‐energy system for chest radiography

2005 ◽  
Vol 46 (1) ◽  
pp. 41-47 ◽  
Author(s):  
T. Freund ◽  
F. Fischbach ◽  
U. Teichgraeber ◽  
E. Lopez Haenninen ◽  
H. Eichstaedt ◽  
...  
Keyword(s):  
Image Quality ◽  
Chest Radiography ◽  
Rating Scale ◽  
Energy System ◽  
Dual Energy ◽  
Motion Artifacts ◽  
Prototype System ◽  
Bone Structures ◽  
Dose Levels

Purpose: To assess the image quality of subtracted soft tissue and bone images of a CsI‐detector‐based dual‐energy system for chest radiography at varying dose levels. Material and Methods: We evaluated a CsI‐detector‐based, dual‐exposure, dual‐energy prototype system; 126 patients were categorized into groups of small, medium, and large. Fixed values were applied for mAs and mA. The patients were randomized into two groups with intended higher and lower speed pairs of approximately 400/1000 (high and low energy shot) and 200/500, respectively. True speed equivalents were calculated retrospectively using the detector dose. Image quality was evaluated by two highly experienced radiologists in consensus applying a rating scale of 1 to 5 for quality indicators such as image noise, residual bone structures, motion artifacts, and others. Results: Significantly decreased noise and a significant improvement for display of bone details in the bone image were noted with the higher dose, whereas a significant increase in motion artifacts reduced image quality at the higher dose. Conclusion: Radiation dose did not significantly influence the perception of dual‐energy image quality. Dual‐energy subtraction, as described, has the potential to become a future routine application in chest radiography.

Hybrid ECG-gated versus non-gated 512-slice CT angiography of the aorta and coronary artery: image quality and effect of a motion correction algorithm

2017 ◽  
Vol 59 (2) ◽  
pp. 170-179
Author(s):  
Ji Won Lee ◽  
Chang Won Kim ◽  
Geewon Lee ◽  
Han Cheol Lee ◽  
Sang-Pil Kim ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Image Quality ◽  
Coronary Arteries ◽  
Motion Correction ◽  
Aortic Wall ◽  
Correction Algorithm ◽  
Group 2 ◽  
Coronary Artery Image ◽  
Group 1

Background Using the hybrid electrocardiogram (ECG)-gated computed tomography (CT) technique, assessment of entire aorta, coronary arteries, and aortic valve can be possible using single-bolus contrast administration within a single acquisition. Purpose To compare the image quality of hybrid ECG-gated and non-gated CT angiography of the aorta and evaluate the effect of a motion correction algorithm (MCA) on coronary artery image quality in a hybrid ECG-gated aorta CT group. Material and Methods In total, 104 patients (76 men; mean age = 65.8 years) prospectively randomized into two groups (Group 1 = hybrid ECG-gated CT; Group 2 = non-gated CT) underwent wide-detector array aorta CT. Image quality, assessed using a four-point scale, was compared between the groups. Coronary artery image quality was compared between the conventional reconstruction and motion correction reconstruction subgroups in Group 1. Results Group 1 showed significant advantages over Group 2 in aortic wall, cardiac chamber, aortic valve, coronary ostia, and main coronary arteries image quality (all P < 0.001). All Group 1 patients had diagnostic image quality of the aortic wall and left ostium. The MCA significantly improved the image quality of the three main coronary arteries ( P < 0.05). Moreover, per-vessel interpretability improved from 92.3% to 97.1% with the MCA ( P = 0.013). Conclusion Hybrid ECG-gated CT significantly improved the heart and aortic wall image quality and the MCA can further improve the image quality and interpretability of coronary arteries.

Impact of a New Motion-Correction Algorithm on Image Quality of Low-Dose Coronary CT Angiography in Patients with Insufficient Heart Rate Control

2014 ◽  
Vol 21 (3) ◽  
pp. 312-317 ◽  
Author(s):  
Tobias A. Fuchs ◽  
Julia Stehli ◽  
Svetlana Dougoud ◽  
Michael Fiechter ◽  
Bert-Ram Sah ◽  
...  
Keyword(s):  
Heart Rate ◽  
Image Quality ◽  
Rate Control ◽  
Motion Correction ◽  
Coronary Ct Angiography ◽  
Low Dose ◽  
Correction Algorithm ◽  
Heart Rate Control ◽  
Coronary Ct

scholarly journals Radial self-navigated native magnetic resonance angiography in comparison to navigator-gated contrast-enhanced MRA of the entire thoracic aorta in an aortic patient collective

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Martina Correa Londono ◽  
Nino Trussardi ◽  
Verena C. Obmann ◽  
Davide Piccini ◽  
Michael Ith ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Quality ◽  
Magnetic Resonance Angiography ◽  
Thoracic Aorta ◽  
Aortic Root ◽  
Aortic Disease ◽  
Ascending Aorta ◽  
Scan Time ◽  
Contrast Enhanced

Abstract Background The native balanced steady state with free precession (bSSFP) magnetic resonance angiography (MRA) technique has been shown to provide high diagnostic image quality for thoracic aortic disease. This study compares a 3D radial respiratory self-navigated native MRA (native-SN-MRA) based on a bSSFP sequence with conventional Cartesian, 3D, contrast-enhanced MRA (CE-MRA) with navigator-gated respiration control for image quality of the entire thoracic aorta. Methods Thirty-one aortic native-SN-MRA were compared retrospectively (63.9 ± 10.3 years) to 61 CE-MRA (63.1 ± 11.7 years) serving as a reference standard. Image quality was evaluated at the aortic root/ascending aorta, aortic arch and descending aorta. Scan time was recorded. In 10 patients with both MRA sequences, aortic pathologies were evaluated and normal and pathologic aortic diameters were measured. The influence of artifacts on image quality was analyzed. Results Compared to the overall image quality of CE-MRA, the overall image quality of native-SN-MRA was superior for all segments analyzed (aortic root/ascending, p < 0.001; arch, p < 0.001, and descending, p = 0.005). Regarding artifacts, the image quality of native-SN-MRA remained superior at the aortic root/ascending aorta and aortic arch before and after correction for confounders of surgical material (i.e., susceptibility-related artifacts) (p = 0.008 both) suggesting a benefit in terms of motion artifacts. Native-SN-MRA showed a trend towards superior intraindividual image quality, but without statistical significance. Intraindividually, the sensitivity and specificity for the detection of aortic disease were 100% for native-SN-MRA. Aortic diameters did not show a significant difference (p = 0.899). The scan time of the native-SN-MRA was significantly reduced, with a mean of 05:56 ± 01:32 min vs. 08:51 ± 02:57 min in the CE-MRA (p < 0.001). Conclusions Superior image quality of the entire thoracic aorta, also regarding artifacts, can be achieved with native-SN-MRA, especially in motion prone segments, in addition to a shorter acquisition time.

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