scholarly journals Wave-controlled aliasing in parallel imaging magnetization-prepared gradient echo (wave-CAIPI MPRAGE) accelerates speed for pediatric brain MRI with comparable diagnostic performance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Younghee Yim ◽  
Mi Sun Chung ◽  
Su Yeong Kim ◽  
Na Mi Lee ◽  
Jun Soo Byun ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Image Quality ◽  
Parallel Imaging ◽  
Reliable Method ◽  
Pediatric Patients ◽  
Motion Artifacts ◽  
Gradient Echo ◽  
Post Contrast ◽  
Scan Time ◽  
Intracranial Lesions

AbstractWe aimed to compare accelerated post-contrast magnetization-prepared rapid gradient-echo (MPRAGE) using wave-controlled aliasing in parallel imaging (wave-CAIPI) with conventional MPRAGE as a reliable method to diagnose intracranial lesions in pediatric patients. A total of 23 consecutive pediatric patients who underwent post-contrast wave-CAIPI and conventional MPRAGE (scan time: 2 min 39 s vs. 5 min 46 s) were retrospectively evaluated. Two radiologists independently assessed each image for the presence of intracranial lesions. Quantitative [contrast-to-noise ratio (CNR), contrast rate (CR), and signal-to-noise ratio (SNR)] and qualitative parameters (overall image quality, gray-white matter differentiation, demarcation of basal ganglia and sulci, and motion artifacts) were also surveyed. Wave-CAIPI MPRAGE and conventional MPRAGE detected enhancing and non-enhancing intracranial lesions with 100% agreement. Although wave-CAIPI MPRAGE had a lower SNR (all p < 0.05) and overall image quality (overall analysis, p = 0.02) compared to conventional MPRAGE, other quantitative (CNR and CR) and qualitative parameters (gray-white differentiation, demarcation of basal ganglia and sulci, and motion artifacts) were comparable in the pooled analysis and between both observers (all p > 0.05). Wave-CAIPI MPRAGE was a reliable method for diagnosing intracranial lesions in pediatric patients as conventional MPRAGE at half the scan time.

scholarly journals New Imaging Strategies Using a Motion-Resistant Liver Sequence in Uncooperative Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Bong Soo Kim ◽  
Kyung Ryeol Lee ◽  
Myeng Ju Goh
Keyword(s):  
Image Quality ◽  
Parallel Imaging ◽  
Spin Echo ◽  
Improve Patient Care ◽  
Motion Artifact ◽  
Motion Artifacts ◽  
Single Shot ◽  
Minimization Method ◽  
Rapid Acquisition ◽  
Imaging Results

MR imaging has unique benefits for evaluating the liver because of its high-resolution capability and ability to permit detailed assessment of anatomic lesions. In uncooperative patients, motion artifacts can impair the image quality and lead to the loss of diagnostic information. In this setting, the recent advances in motion-resistant liver MR techniques, including faster imaging protocols (e.g., dual-echo magnetization-prepared rapid-acquisition gradient echo (MP-RAGE), view-sharing technique), the data under-sampling (e.g., gradient recalled echo (GRE) with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), single-shot echo-train spin-echo (SS-ETSE)), and motion-artifact minimization method (e.g., radial GRE with/without k-space-weighted image contrast (KWIC)), can provide consistent, artifact-free images with adequate image quality and can lead to promising diagnostic performance. Understanding of the different motion-resistant options allows radiologists to adopt the most appropriate technique for their clinical practice and thereby significantly improve patient care.

scholarly journals Penerapan Teknik Parallel Imaging Pada Pesawat MRI 0,35 Tesla Untuk Optimalisasi Kualitas Informasi Anatomi Pada MRI Lumbal Pembobotan T1WI dan T2WI Potongan Sagital

2015 ◽  
Vol 1 (1) ◽  
pp. 19-22
Author(s):  
Gatot Murti Wibowo ◽  
Dartini Dartini ◽  
Hari Prayitno
Keyword(s):  
Image Quality ◽  
Parallel Imaging ◽  
Imaging Techniques ◽  
Spin Echo ◽  
Clinical Image ◽  
Good Imaging ◽  
Scan Time ◽  
Significant Difference ◽  
Lumbar Mri

Background : Parallel imaging is one of the MRI Scanning techniques used to reduce the overall scan time when the patients with unvoluntary movement being examined with a low magnetic field of 0,35 T.  This research aims to determine the difference between the clinical image quality of the conventional turbo spin echo (TSE) with mSENSE and that of the TSE with GRAPPA parallel imaging techniques from which resulting the MRI T1 and T2 Weighted Images (T1WI and T2WI) sagittal view of lumbar spines, and to define the techniques that clinically provide the most approriate anatomical information.Methods :  This experimental study is made performed by the MRI 0.35 T in which 10 patients who had hernia nucleus pulposus (HNP) desease participated in the experiments ramdomly. The appointed Radiologists blended in the image evaluation using an image checklist to assess the visualisation of anatomical organs on the resulted sagittal lumbar MRI T1WI and T2WI. The two non-parametric statistical tools, Friedman test and the post hoc Wilcoxon matched pairs test, is used to analyze all the data descriptively. Testing the resesearch hypotheses with 95% of confident interval is to proved the differences between resulted sagittal lumbar MRI T1WI and T2WI..Results : The results shown there is a significant difference on the image quality of anatomical information when conventional TSE, parallel imaging-mSENSE and -GRAPPA, with T1WI are applied in the imaging techniques. When those imaging techniques are employed to obtain T2WI, the result is not significant in  contrast.Conclusion : Good imaging techniques with adequate clinical image quality are ranked sequently as the conventional TSE, the  mSENSE and GRAPPA.

scholarly journals Highly Accelerated Vessel-Selective Arterial Spin Labelling Angiography using Sparsity and Smoothness Constraints

2019 ◽  
Author(s):  
Sophie Schauman ◽  
Mark Chiew ◽  
Thomas W. Okell
Keyword(s):  
Image Quality ◽  
Compressed Sensing ◽  
Arterial Spin Labeling ◽  
Parallel Imaging ◽  
Spin Labeling ◽  
Dominant Factor ◽  
Image Domain ◽  
In Vivo Experiments ◽  
Scan Time

AbstractPurposeTo demonstrate that vessel-selectivity in arterial spin labeling angiography can be achieved without any scan time penalty or noticeable loss of image quality compared to conventional arterial spin labeling angiography.MethodsSimulations on a numerical phantom were used to assess whether the increased sparsity of vessel-encoded angiograms compared to non-vessel-encoded angiograms alone can improve reconstruction results in a compressed sensing framework. Further simulations were performed to study whether the difference in relative sparsity between non-selective and vessel-selective dynamic angiograms were sufficient to achieve similar image quality at matched scan times in the presence of noise. Finally, data were acquired from 5 healthy volunteers to validate the technique in vivo. All data, both simulated and in vivo, were sampled in 2D using a golden angle radial trajectory and reconstructed by enforcing both image domain sparsity and temporal smoothness on the angiograms in a parallel imaging and compressed sensing framework.ResultsRelative sparsity was established as a primary factor governing the reconstruction fidelity. Using the proposed reconstruction scheme, differences between vessel-selective and non-selective angiography were negligible compared to the dominant factor of total scan time in both simulations and in vivo experiments at acceleration factors up to R = 34. The reconstruction quality was not heavily dependent on hand-tuning the parameters of the reconstruction.ConclusionThe increase in relative sparsity of vessel-selective angiograms compared to non-selective angiograms can be leveraged to achieve higher acceleration without loss of image quality, resulting in the acquisition of vessel-selective information at no scan time cost.

Impact of a fast free-breathing 3-T abdominal MRI protocol on improving scan time and image quality for pediatric patients with tuberous sclerosis complex

2019 ◽  
Vol 49 (13) ◽  
pp. 1788-1797 ◽  
Author(s):  
Rene Balza ◽  
Camilo Jaimes ◽  
Seretha Risacher ◽  
Heather I. Gale ◽  
Jessica Mahoney ◽  
...  
Keyword(s):  
Image Quality ◽  
Tuberous Sclerosis ◽  
Tuberous Sclerosis Complex ◽  
Pediatric Patients ◽  
Free Breathing ◽  
Scan Time ◽  
Abdominal Mri ◽  
Mri Protocol

Abstract WP125: Accelerated 3d Isotropic High-resolution Multi-contrast Intracranial Vessel Wall MRI For Large Artery Stroke Evaluation

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Niranjan Balu ◽  
Zechen Zhou ◽  
Mahmud Mossa-basha ◽  
Chun Yuan
Keyword(s):  
Image Quality ◽  
Vessel Wall ◽  
Complex Geometry ◽  
Plaque Morphology ◽  
Black Blood ◽  
Large Artery ◽  
Step Method ◽  
Post Contrast ◽  
Isotropic Resolution ◽  
Scan Time

Introduction: Intracranial large-artery atherosclerotic disease (ICAD) is a leading cause of death and morbidity worldwide. Vessel Wall Imaging (VWI) has potential to stratify disease beyond current angiographic methods by identifying plaque morphology and components directly. Plaque component identification requires a multi-contrast black-blood protocol. High isotropic resolution is also required due to small vessels and their complex geometry and therefore typical ICAD VWI protocols require long scan times. Aim: To develop a 3D 0.5 mm isotropic multi-contrast ICAD VWI with scan time of less than 30 minutes. Methods: Experiments were carried out on a Philips Ingenia 3T scanner with 32 channel head coil. Acceleration by K-space undersampling using CUSTOM method and compressed sensing reconstruction using STEP method [1] was used to reduce scan times. The following protocol was optimized on phantoms and volunteers: Survey scan was followed by 3D TOF, T1 weighted VISTA, PD weighted DANTE [2] VISTA, SNAP [3]. After single dose gadolinium contrast injection a post-contrast T1 weighted VISTA is obtained. Protocol parameters were optimized such that total scan time is 25 mins with all scans (except survey) being 0.5mm isotropic. Results: CUSTOM acceleration factors of 4X to 5X provided good image quality. Representative image quality (pre-contrast) is shown in figure 1. Total scan time for the multi-contrast protocol was 30 minutes including patient setup time. Studies on ICAD patients are ongoing with the optimized protocol. Conclusions: Multi-contrast 3D 0.5mm isotropic resolution MRI protocol was developed to scan ICAD patients within 30 minute scan time. Acceleration tailored for VWI allowed reducing scan times from 2 hours to less than 30 minutes thereby providing a clinically usable ICAD VWI multi-contrast protocol. References: [1] Zhou Z et al, MRM 2016, [2] Li L et al, MRM 2012, [3] Wang et al, MRM 2013.

scholarly journals Pre-contrast T1-weighted imaging of the spinal cord may be unnecessary in patients with multiple sclerosis

2021 ◽  
Author(s):  
Isabelle Riederer ◽  
Mark Mühlau ◽  
Claus Zimmer ◽  
Magaly Gutbrod-Fernandez ◽  
Nico Sollmann ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Spinal Cord ◽  
Image Quality ◽  
Detection Rate ◽  
List Type ◽  
Diagnostic Confidence ◽  
Post Contrast ◽  
Scan Time ◽  
Spinal Mri

Abstract Objectives Multiple sclerosis (MS) is an inflammatory disease frequently involving the spinal cord, which can be assessed by magnetic resonance imaging (MRI). Here, we hypothesize that pre-contrast T1-w imaging does not add diagnostic value to routine spinal MRI for the follow-up of patients with MS. Methods 3-T MRI scans including pre- and post-contrast T1-w as well as T2-w images of 265 consecutive patients (mean age: 40 ± 13 years, 169 women) with (suspected) MS were analyzed retrospectively. Images were assessed in two separate reading sessions, first excluding and second including pre-contrast T1-w images. Two independent neuroradiologists rated the number of contrast-enhancing (ce) lesions as well as diagnostic confidence (1 = unlikely to 5 = very high), overall image quality, and artifacts. Results were compared using Wilcoxon matched-pairs signed-rank tests and weighted Cohen’s kappa (κ). Results Fifty-six ce lesions were found in 43 patients. There were no significant differences in diagnostic confidence between both readings for both readers (reader 1: p = 0.058; reader 2: p = 0.317). Inter-rater concordance was both moderate regarding artifacts (κ = 0.418) and overall image quality (κ = 0.504). Thirty-one black holes were found in 25 patients with high diagnostic confidence (reader 1: 4.04 ± 0.81; reader 2: 3.80 ± 0.92) and substantial inter-rater concordance (κ = 0.700). Conclusions Availability of pre-contrast T1-w images did not significantly increase diagnostic confidence or detection rate of ce lesions in the spinal cord in patients with MS. Thus, pre-contrast T1-w sequences might be omitted in routine spinal MRI for follow-up exams, however not in special unclear clinical situations in which certainty on contrast enhancement is required. Key Points Availability of pre-contrast T1-w images does not increase diagnostic confidence or detection rate of contrast-enhancing lesions in the spinal cord of MS patients. Excluding pre-contrast T1-w sequences reduces scan time, thus providing more time for other sequences or increasing the patients’ compliance.

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