Standardized volume-rendering of contrast-enhanced renal magnetic resonance angiography

Purpose: To propose a technique for standardizing volume-rendering technique (VRT) protocols and to compare this with maximum intensity projection (MIP) in regard to image quality and diagnostic confidence in stenosis diagnosis with magnetic resonance angiography (MRA). Material and Methods: Twenty patients were examined with MRA under suspicion of renal artery stenosis. Using the histogram function in the volume-rendering software, the 95th and 99th percentiles of the 3D data set were identified and used to define the VRT transfer function. Two radiologists assessed the stenosis pathology and image quality from rotational sequences of MIP and VRT images. Results: Good overall agreement (mean κ = 0.72) was found between MIP and VRT diagnoses. The agreement between MIP and VRT was considerably better than that between observers (mean κ = 0.43). One of the observers judged VRT images as having higher image quality than MIP images. Conclusion: Presenting renal MRA images with VRT gave results in good agreement with MIP. With VRT protocols defined from the histogram of the image, the lack of an absolute gray scale in MRI need not be a major problem.

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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

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/s12968-021-00774-9 ◽

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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Quiescent-Interval Single-Shot Magnetic Resonance Angiography

Diagnostics ◽

10.3390/diagnostics8040084 ◽

2018 ◽

Vol 8 (4) ◽

pp. 84

Author(s):

Aman Saini ◽

Alex Wallace ◽

Hassan Albadawi ◽

Sailendra Naidu ◽

Sadeer Alzubaidi ◽

...

Keyword(s):

Magnetic Resonance ◽

Image Quality ◽

Magnetic Resonance Angiography ◽

Diagnostic Imaging ◽

Imaging Techniques ◽

Feasibility Studies ◽

Subsequent Treatment ◽

Single Shot ◽

Contrast Enhanced ◽

Diagnostic Imaging Techniques

Lower extremity peripheral arterial disease (PAD) is a chronic, debilitating disease with a significant global burden. A number of diagnostic imaging techniques exist, including computed tomography angiography (CTA) and contrast-enhanced magnetic resonance angiography (CEMRA), to aid in PAD diagnosis and subsequent treatment planning. Due to concerns of renal toxicity or nephrogenic systemic fibrosis (NSF) for iodinated and gadolinium-based contrasts, respectively, a number of non-enhanced MRA (NEMRA) protocols are being increasingly used in PAD diagnosis. These techniques, including time of flight and phase contrast MRA, have previously demonstrated poor image quality, long acquisition times, and/or susceptibility to artifacts when compared to existing contrast-enhanced techniques. In recent years, Quiescent-Interval Single-Shot (QISS) MRA has been developed to overcome these limitations in NEMRA methods, with promising results. Here, we review the various screening and diagnostic tests currently used for PAD. The various NEMRA protocols are discussed, followed by a comprehensive review of the literature on QISS MRA to date. A particular emphasis is placed on QISS MRA feasibility studies and studies comparing the diagnostic accuracy and image quality of QISS MRA versus other diagnostic imaging techniques in PAD.

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Contrast-Enhanced Magnetic Resonance Angiography Using a Novel Elastin-Specific Molecular Probe in an Experimental Animal Model

Contrast Media & Molecular Imaging ◽

10.1155/2018/9217456 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Carolin Reimann ◽

Julia Brangsch ◽

Jan Ole Kaufmann ◽

Lisa C. Adams ◽

David C. Onthank ◽

...

Keyword(s):

Magnetic Resonance ◽

Image Quality ◽

Magnetic Resonance Angiography ◽

Contrast Agent ◽

Mr Angiography ◽

Molecular Probe ◽

Time Resolved ◽

Clinical Dose ◽

Contrast Enhanced ◽

First Pass

Objectives. The aim of this study was to test the potential of a new elastin-specific molecular agent for the performance of contrast-enhanced first-pass and 3D magnetic resonance angiography (MRA), compared to a clinically used extravascular contrast agent (gadobutrol) and based on clinical MR sequences. Materials and Methods. Eight C57BL/6J mice (BL6, male, aged 10 weeks) underwent a contrast-enhanced first-pass and 3D MR angiography (MRA) of the aorta and its main branches. All examinations were on a clinical 3 Tesla MR system (Siemens Healthcare, Erlangen, Germany). The clinical dose of 0.1 mmol/kg was administered in both probes. First, a time-resolved MRA (TWIST) was acquired during the first-pass to assess the arrival and washout of the contrast agent bolus. Subsequently, a high-resolution 3D MRA sequence (3D T1 FLASH) was acquired. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for all sequences. Results. The elastin-specific MR probe and the extravascular imaging agent (gadobutrol) enable high-quality MR angiograms in all animals. During the first-pass, the probes demonstrated a comparable peak enhancement (300.6 ± 32.9 vs. 288.5 ± 33.1, p>0.05). Following the bolus phase, both agents showed a comparable intravascular enhancement (SNR: 106.7 ± 11 vs. 102.3 ± 5.3; CNR 64.5 ± 7.4 vs. 61.1 ± 7.2, p>0.05). Both agents resulted in a high image quality with no statistical difference (p>0.05). Conclusion. The novel elastin-specific molecular probe enables the performance of first-pass and late 3D MR angiography with an intravascular contrast enhancement and image quality comparable to a clinically used extravascular contrast agent.

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Comparison of Power Versus Manual Injection in Bolus Shape and Image Quality on Contrast-Enhanced Magnetic Resonance Angiography

Investigative Radiology ◽

10.1097/rli.0000000000000383 ◽

2017 ◽

Vol 52 (9) ◽

pp. 547-553 ◽

Cited By ~ 2

Author(s):

Takahiro Tsuboyama ◽

Gregor Jost ◽

Hubertus Pietsch ◽

Noriyuki Tomiyama

Keyword(s):

Magnetic Resonance ◽

Image Quality ◽

Magnetic Resonance Angiography ◽

Contrast Enhanced

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Diagnosis of supra-aortic artery stenosis: comparison of magnetic resonance angiography imaging methods with conventional digital subtraction angiography

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20181747 ◽

2018 ◽

Vol 6 (5) ◽

pp. 1509

Author(s):

Hale Aydin ◽

Agildere A. Muhtesem

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Digital Subtraction Angiography ◽

Maximum Intensity Projection ◽

Reconstruction Method ◽

Digital Subtraction ◽

Total Occlusion ◽

Contrast Enhanced ◽

Aortic Artery ◽

The Individual

Background: The aim of this study was to compare conventional digital subtraction angiography (DSA) with the multi-planar reformation (MPR) and maximum intensity projection (MIP) reconstruction of servical magnetic resonance angiography (MRA) in terms of detecting supra-aortic artery stenoses.Methods: In the study, 21 patients who had underwent 3D MRA and conventional DSA were retrospectively assessed. Axial MPR, coronal MIP reconstruction and contrast enhanced 3D MRA subtraction images of a total of 333 artery segments were independently assessed by 2 separate radiologists. Conventional DSA results were accepted as gold standard results. The overall and individual Kappa values of all methods were calculated.Results: Results of the conventional DSA analysis indicated total occlusion in 9 (2.7%), severe stenosis in 16 (4.8%), moderate stenosis in 90 (27.1%), mild stenosis in 105 (31.5%) and no stenosis in 113 (33.9%) arteries. While the k values of all methods were high which demonstrated strong relationships with the DSA method; the coronal MIP reconstruction method was found to be superior to other methods. The 3D MRA subtraction method did not yield better results in any of the individual comparisons.Conclusions: Our results indicate that the coronal MIP reconstruction method has higher correlation with conventional DSA results compared to the other two methods and may be used as an accurate first-line diagnostic method for supra-aortic artery stenoses.

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