scholarly journals Image quality and focal lesion detection on T2-weighted MR imaging of the liver: Comparison of two high-resolution free-breathing imaging techniques with two breath-hold imaging techniques

2007 ◽  
Vol 26 (2) ◽  
pp. 323-330 ◽  
Author(s):  
Seung Soo Lee ◽  
Jae Ho Byun ◽  
Hye-Suk Hong ◽  
Seong Ho Park ◽  
Hyung Jin Won ◽  
...  
Keyword(s):  
High Resolution ◽  
Image Quality ◽  
Mr Imaging ◽  
Imaging Techniques ◽  
Free Breathing ◽  
Lesion Detection ◽  
Focal Lesion ◽  
Breath Hold

Abstract 15240: Evaluation of the Performance and Safety of Wideband Cardiac MRI in Patients With a Cardiac Implantable Electronic Device (CIED)

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sarah M Schwartz ◽  
Ashitha Pathrose ◽  
Ali Serhal ◽  
Ryan Avery ◽  
Ann Ragin ◽  
...  
Keyword(s):  
Image Quality ◽  
Electronic Device ◽  
Pulse Sequences ◽  
Free Breathing ◽  
Whole Body ◽  
Breath Hold ◽  
Single Shot ◽  
Before And After ◽  
Order Of Magnitude ◽  
Chest X Ray

Introduction: Wideband late gadolinium enhancement (LGE) CMR is capable of suppressing image artifacts induced by cardiac implanted electronic devices (CIEDs). We implemented our own wideband segmented (seg) breath-hold and wideband single-shot (SS) free-breathing LGE pulse sequences and used them clinically since 2016. The purpose of this study was to evaluate image quality and CMR safety of wideband LGE compared to standard LGE. Methods: We retrospectively identified 54 consecutive patients (mean age: 61±15 years; 31% females) with CIED (33 t-ICD, 4 s-ICD, 15 pacemaker, 1 CRT-D, 1 CRT-P) who underwent CMR at 1.5T (Avanto, Siemens). Standard seg, wideband seg, and wideband SS LGE used standard imaging parameters. 16 myocardial segments were scored for scar/myocardial conspicuity and presence of any visual artifact on a 5-point Likert scale (1:worst; 3:acceptable; 5:best). Distance between center of the heart and CIED (CXR D) was measured on chest X-ray. Whole-body specific absorption rate (SAR) was read from DICOM metadata. Device changes were calculated from pre- and post- device interrogation measurements. Results: Both wideband seg and SS LGE consistently produced better image quality than standard LGE (Figure 1A). Median conspicuity and artifact scores were significantly better for wideband seg (F=20.6, p<0.001) and wideband SS (F=24.2, p<0.001) LGE compared to standard LGE. There was a trend in conspicuity and artifact scores with CIED distance for standard LGE (rho=0.476, p=0.02), but not wideband LGE scans (Figure 1B, 1C). Whole-body SAR averaged for both wideband scans (0.15±0.04 W/kg) was one order of magnitude below the 2.0 W/kg FDA limit. Device parameters (sensing, impedance, threshold, battery level) did not differ before and after CMR including wideband LGE. Conclusions: Both wideband seg and SS LGE scans produced improved image quality compared to standard LGE while maintaining CMR safety. *The first two authors (SS and AP) contributed equally

scholarly journals Radial-based acquisition strategies for pre-procedural non-contrast cardiovascular magnetic resonance angiography of the pulmonary veins

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Pascale Aouad ◽  
Ioannis Koktzoglou ◽  
Bastien Milani ◽  
Ali Serhal ◽  
Jose Nazari ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Image Quality ◽  
Healthy Subjects ◽  
Respiratory Gating ◽  
Free Breathing ◽  
Breath Hold ◽  
Thin Slab ◽  
Excellent Correlation ◽  
Acquisition Strategies ◽  
Stack Of Stars

Abstract Background Computed tomography angiography (CTA) or contrast-enhanced (CE) cardiovascular magnetic resonance angiography (CMRA) is often obtained in patients with atrial fibrillation undergoing evaluation prior to pulmonary vein (PV) isolation. Drawbacks of CTA include radiation exposure and potential risks from iodinated contrast agent administration. Free-breathing 3D balanced steady-state free precession (bSSFP) Non-contrast CMRA is a potential imaging option, but vascular detail can be suboptimal due to ghost artifacts and blurring that tend to occur with a Cartesian k-space trajectory or, in some cases, inconsistent respiratory gating. We therefore explored the potential utility of both breath-holding and free-breathing non-contrast CMRA, using radial k-space trajectories that are known to be less sensitive to flow and motion artifacts than Cartesian. Main body Free-breathing 3D Cartesian and radial stack-of-stars acquisitions were compared in 6 healthy subjects. In addition, 27 patients underwent CTA and non-contrast CMRA for PV mapping. Three radial CMR acquisition strategies were tested: (1) breath-hold (BH) 2D radial bSSFP (BH-2D); (2) breath-hold, multiple thin-slab 3D stack-of-stars bSSFP (BH-SOS); and (3) navigator-gated free-breathing (FB) 3D stack-of-star bSSFP using a spatially non-selective RF excitation (FB-NS-SOS). A non-rigid registration algorithm was used to compensate for variations in breath-hold depth. In healthy subjects, image quality and vessel sharpness using a free-breathing 3D SOS acquisition was significantly better than free-breathing (FB) Cartesian 3D. In patients, diagnostic image quality was obtained using all three radial CMRA techniques, with BH-SOS and FB-NS-SOS outperforming BH-2D. There was overall good correlation for PV maximal diameter between BH-2D and CTA (ICC = 0.87/0.83 for the two readers), excellent correlation between BH-SOS and CTA (ICC = 0.90/0.91), and good to excellent correlation between FB-NS-SOS and CTA (ICC = 0.87/0.94). For PV area, there was overall good correlation between BH-2D and CTA (ICC = 0.79/0.83), good to excellent correlation between BH-SOS and CTA (ICC = 0.88/0.91) and excellent correlation between FB-NS-SOS and CTA (ICC = 0.90/0.95). CNR was significantly higher with BH-SOS (mean = 11.04) by comparison to BH-2D (mean = 6.02; P = 0.007) and FB-NS-SOS (mean = 5.29; P = 0.002). Conclusion Our results suggest that a free-breathing stack-of-stars bSSFP technique is advantageous in providing accurate depiction of PV anatomy and ostial measurements without significant degradation from off-resonance artifacts, and with better image quality than Cartesian 3D. For patients in whom respiratory gating is unsuccessful, a breath-hold thin-slab stack-of-stars technique with retrospective motion correction may be a useful alternative.

Free-breathing BLADE acquisition method improves T2-weighted cardiac MR image quality compared with conventional breath-hold turbo spin-echo cartesian acquisition

2020 ◽  
pp. 028418512092456
Author(s):  
Jingjing Liu ◽  
Hang Jin ◽  
Yinyin Chen ◽  
Caixia Fu ◽  
Caizhong Chen ◽  
...  
Keyword(s):  
Image Quality ◽  
Spin Echo ◽  
Free Breathing ◽  
Fat Suppression ◽  
Breath Hold ◽  
Signal Loss ◽  
Turbo Spin Echo ◽  
Turbo Spin ◽  
Imaging Sequence ◽  
Ghosting Artifacts

Background Cardiac magnetic resonance (MR) has become an essential diagnostic imaging modality in cardiovascular disease. However, the insufficient image quality of traditional breath-hold (BH) T2-weighted (T2W) imaging may compromise its diagnostic accuracy. Purpose To assess the efficacy of the BLADE technique to reduce motion artifacts and improve the image quality. Material and Methods Free-breathing TSE-T2W imaging sequence with cartesian and BLADE k-space trajectory were acquired in 20 patients. Thirty patients underwent conventional BH turbo spin-echo (TSE) T2W imaging and free-breathing BLADE T2W (FB BLADE-T2W) imaging. Twenty-one patients who had a signal loss of myocardium in BH short-axis T2W turbo inversion recovery (TSE-T2W-TIR) were scanned using free-breathing BLADE T2W turbo inversion recovery (BLADE TSE-T2W-TIR). The overall image quality, blood nulling, and visualization of the heart were scored on a 5-point Likert scale. The signal loss of myocardium, incomplete fat suppression near the myocardium, and the streaking or ghosting artifacts were noted in T2W-TIR sequences additionally. Results The overall imaging quality, blood nulling, and the visualization of heart structure of FB BLADE-T2W imaging sequence were significantly better than those of FB T2W imaging with Cartesian k-space trajectory and BH TSE-T2W imaging sequence ( P<0.01). The FB BLADE TSE-T2W-TIR reduces the myocardium signal dropout ( P<0.05), incomplete fat suppression near myocardium ( P<0.05), and the streaking and ghosting artifacts ( P<0.05) in comparison with the BH TSE-T2W-TIR. Conclusions FB BLADE T2W imaging provides improved myocardial visibility, less motion sensitivity, and better image quality. It may be applied in patients who have poor breath-holding capability.

scholarly journals Surgical anatomy and functional connectivity of the limbic system

2009 ◽  
Vol 27 (2) ◽  
pp. E3 ◽  
Author(s):  
Karl-Olof Lövblad ◽  
Karl Schaller
Keyword(s):  
High Resolution ◽  
Mr Imaging ◽  
Limbic System ◽  
Surgical Planning ◽  
Diffusion Tensor ◽  
Imaging Techniques ◽  
Surgical Anatomy ◽  
Neurosurgical Planning ◽  
Functional Mr Imaging ◽  
Molecular Information

Object The goal in this study was to highlight the potential of currently available imaging techniques for surgical planning of procedures in and around the limbic system. Methods The authors review traditional and newer imaging techniques as applied to neurosurgical planning. Today MR imaging techniques play a preponderant role. The various applications of functional techniques such as diffusion weighted, diffusion tensor, perfusion, and functional MR imaging methods are discussed. Results In addition to the high-resolution studies of anatomy that can be acquired, especially at higher field strengths (≥ 3 T), MR imaging now also offers the possibility of acquiring functional, metabolic, hemodynamic, and molecular information on normal and pathological brain processes. Conclusions The knowledge obtained using the various imaging techniques contributes substantially to understanding the disease processes in a way that drastically improves surgical planning.

Chronic Thromboembolic Pulmonary Hypertension: Pre- and Postoperative Assessment with Breath-hold MR Imaging Techniques

Radiology ◽  
2004 ◽  
Vol 232 (2) ◽  
pp. 535-543 ◽  
Author(s):  
Karl-Friedrich Jakob Kreitner ◽  
Sebastian Ley ◽  
Hans-Ulrich Kauczor ◽  
Eckhard Mayer ◽  
Thorsten Kramm ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Mr Imaging ◽  
Imaging Techniques ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Breath Hold ◽  
Postoperative Assessment ◽  
Thromboembolic Pulmonary Hypertension

Optimising diffusion-weighted MR imaging for demonstrating pancreatic cancer: a comparison of respiratory-triggered, free-breathing and breath-hold techniques

2012 ◽  
Vol 22 (10) ◽  
pp. 2186-2192 ◽  
Author(s):  
Nikolaos Kartalis ◽  
Louiza Loizou ◽  
Nick Edsborg ◽  
Ralf Segersvärd ◽  
Nils Albiin
Keyword(s):  
Pancreatic Cancer ◽  
Mr Imaging ◽  
Free Breathing ◽  
Breath Hold ◽  
Diffusion Weighted
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