Volumetric Isotropic Turbo Spin Echo Acquisition Research Articles

Contrast-Enhanced High-Resolution Intracranial Vessel Wall MRI with Compressed Sensing: Comparison with Conventional T1 Volumetric Isotropic Turbo Spin Echo Acquisition Sequence.

ObjectiveCompressed sensing (CS) has gained wide interest since it accelerates MRI acquisition. We aimed to compare the 3D post-contrast T1-weighted volumetric isotropic turbo spin echo acquisition (VISTA) with CS (VISTA-CS) and without CS (VISTA-nonCS) in intracranial vessel wall MRIs (VW-MRI).Materials and MethodsFrom April 2017 to July 2018, 72 patients who underwent VW-MRI, including both VISTA-CS and VISTA-nonCS, were retrospectively enrolled. Wall and lumen volumes, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured from normal and lesion sites. Two neuroradiologists independently evaluated overall image quality and degree of normal and lesion wall delineation with a four-point scale (scores ≥ 3 defined as acceptable).ResultsScan coverage was increased in VISTA-CS to cover both anterior and posterior circulations with a slightly shorter scan time compared to VISTA-nonCS (approximately 7 minutes vs. 8 minutes). Wall and lumen volumes were not significantly different with VISTA-CS or VISTA-nonCS (interclass correlation coefficient = 0.964–0.997). SNR was or trended towards significantly higher values in VISTA-CS than in VISTA-nonCS. At normal sites, CNR was not significantly different between two sequences (p = 0.907), whereas VISTA-CS provided lower CNR in lesion sites compared with VISTA-nonCS (p = 0.003). Subjective wall delineation was superior with VISTA-nonCS than with VISTA-CS (p = 0.019), although overall image quality did not differ (p = 0.297). The proportions of images with acceptable quality were not significantly different between VISTA-CS (83.3–97.8%) and VISTA-nonCS (75–100%).ConclusionCS may be useful for intracranial VW-MRI as it allows for larger scan coverage with slightly shorter scan time without compromising image quality.

Spinal cord infarction presenting as Brown-S\xe9quard syndrome from spontaneous vertebral artery dissection: a case report and literature review

BackgroundSpinal cord infarction (SCI) is rarely caused by vertebral artery dissection (VAD), which is an important cause of posterior circulation stroke in young and middle-aged patients. We report the case of a middle-aged patient without obvious risk factors for atherosclerosis who had SCI from right VAD.Case presentationAn otherwise healthy 40-year-old man presented with acute right-sided body weakness. Six days earlier, he had experienced posterior neck pain without obvious inducement. Neurologic examination revealed a right Brown-Séquard syndrome. Magnetic resonance imaging (MRI) of the head was normal. Further, cervical spine MRI showed spinal cord infarction (SCI) on the right at the C1-C3 level. Three-dimensional high-resolution MRI (3D HR-MRI) volumetric isotropic turbo spin echo acquisition (VISTA) scan showed evidence of vertebral artery dissection (VAD). The patient was significantly relieved of symptoms and demonstrated negative imaging findings after therapy with anticoagulation (AC) and antiplatelets (AP) for 3 months.ConclusionsThe possibility of vertebral artery dissection (VAD) should be considered in the case of young and middle-aged patients without obvious risk factors for atherosclerosis. Furthermore the VISTA black blood sequence plays an important role in the pathological diagnosis of vertebral artery stenosis. Early correct diagnosis and active therapy are crucial to the prognosis.

3D black-blood 3T-MRI for the diagnosis of abdominal large vessel vasculitis.

To assess the value of a T1-3D black-blood turbo spin echo (TSE) sequence for the diagnosis of abdominal large vessel vasculitis (LVV). The study included 20 patients with abdominal LVV and 17 controls, who underwent a 3T-MRI scan using a modified T1-3D volumetric isotropic TSE acquisition and a segmented T1-3D turbo field echo sequence (T1-mVISTA/T1-eTHRIVE). Two radiologists independently analyzed the aorta for concentric contrast enhancement, concentric wall thickening, image quality, and flow artifact intensity (CCE/CWT/IQ/FAI; 4-point scales). The mean aortic wall thickness (MAWT) in post-contrast T1-mVISTA was compared between patients and controls. IQ of T1-mVISTA was rated good to excellent in 91.5% of 282 evaluated vessel segments with no or minor FAI present in 85.5%. The inter-observer reproducibility for the identification of CCE/CWT on T1-mVISTA was 0.92 and 0.93 (p < 0.001). The distribution of segmental inflammation in T1-mVISTA significantly correlated with T1-eTHRIVE (CCE, κ= 0.768; CWT, κ = 0.715; p < 0.001), resulting in a sensitivity, specificity, and positive predictive value of 100%, 81.3%, and 83.3%. The MAWT significantly differed between patients and controls (3.29 ± 0.81 vs. 2.24 ± 0.45mm; p < 0.001). T1-mVISTA enables the evaluation of the MAWT and allows the detection of abdominal LVV. • 3D T1w-mVISTA accurately depicted the large abdominal vessels. • 3D T1w-mVISTA enables accurate measurements of the abdominal aortic wall thickness. • 3D T1w-mVISTA is useful for the detection of abdominal LVV.

Three-dimensional spin-echo-based black-blood MRA in the detection of vasospasm following subarachnoid hemorrhage.

Black-blood MR angiography (BBMRA), which utilizes a non-T1 contrast spin-echo type technique, has been expected to overcome several issues associated with time-of-flight (TOF) MRA. To investigate the efficacy of BBMRA to detect vasospasms following subarachnoid hemorrhage (SAH). Retrospective. Seventeen patients with SAH in their early posttreatment period. BBMRA, which uses a volumetric isotropic turbo spin-echo acquisition (VISTA), and TOF-MRA on 1.5T scanners. Visualization of supratentorial arteries and veins in BBMRA was rated on a 4-point scale by two neuroradiologists. Another neuroradiologist independently assessed TOF-MRA. The degree of the vasospasm was then evaluated using a 3-point scale by the same readers. The diagnostic performance of the MRAs was evaluated using computed tomography angiography (CTA) or digital subtraction angiography (DSA) as the standard of reference. Wilcoxon signed rank test, McNemar test, and Cohen's kappa coefficient. BBMRA provided superior visualization of the anterior and middle cerebral arteries than TOF-MRA (P < 0.05). The depiction of the veins was more pronounced on BBMRA (P < 0.01). Of the 166 arterial segments evaluated by CTA or DSA, 23 (13.9%) could not be assessed using TOF-MRA because of high signal hemorrhage, whereas BBMRA enabled visualization of all the segments. Vasospasm was confirmed in 30 segments by CTA or DSA. The sensitivity, specificity, and positive and negative predictive values were 73, 96, 76, and 95 for TOF-MRA and 91, 100, 100, and 98 for BBMRA, respectively (P = 0.13 for sensitivity, P = 0.06 for specificity). The agreement of the degree of vasospasm between MRA and the standard of reference, as indicated by kappa value, was 0.71 (95% confidence interval [CI], 0.55-0.87) for TOF-MRA and 0.91 (95% CI, 0.82-0.99) for BBMRA. BBMRA, owing to its contrast properties, may be superior to TOF-MRA for the evaluation of intracranial arteries after SAH. 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:800-807.

Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

PurposeWe investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). MethodsA total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. ResultsStrong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). ConclusionsAlthough the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

3D T1-weighted black blood sequence at 3.0 Tesla for the diagnosis of cervical artery dissection

ObjectiveWe aimed to investigate the value of three-dimensional (3D) T1 volumetric isotropic turbo spin echo acquisition (VISTA) in the diagnosis of cervical artery dissection (CAD).MethodsWe prospectively included patients who were...

Recent advances in MRI in the preoperative assessment of anorectal malformations

ObjectiveTo prospectively evaluate the diagnostic accuracy of triplanar 2D magnetic resonance (MR) images versus the post processing reconstructed MR images generated from a single 3D VISTA sequence in children with anorectal malformations compared with the operative findings as the Golden standard. Materials and methodsThis study had institutional review board approval, and informed consent was obtained from all participants. There were 20 patients with anorectal anomalies age range (2months–3.5years), referred from the pediatric surgery unit for preoperative MRI. The 2D sequences included Coronal TSE T2 WI parallel to the plane of the anal canal as seen on the sagittal images, and Axial TSE T2 WI oblique, perpendicular to the coronal plane. Sagittal T2 weighted 3D-sequence; volumetric isotropic turbo spin echo acquisition (VISTA) was taken parallel to the mid-sagittal plane. ResultsComparing the two MR imagining protocols the acquisition time of the sagittal 3D sequence (6min 42s) was shorter than the total acquisition time of the 2D sequences (10min 12s) without jeopardizing the image quality or accuracy of the diagnostic information. MRI depicted the fistula in 94% (16 out of 17) of patients who were clinically proven fistulous, which is a privilege to detect associated anomalies on the same examination. The frequency of associated anomalies was 100% in high anorectal malformations (ARMs), 64% in intermediate and only 20% in low ARMs. From these associated anomalies vertebral anomalies were seen in 50% of patients. Concomitant cord anomalies were encountered in 60% of those with vertebral anomalies the most common of which was tethered cord observed in 35% of the patients. ConclusionMRI is a valuable diagnostic tool to diagnose type and level of ARM in addition to the privilege of associated anomalies detection on the same examination. The 3D sequence acquisition with multiplanar reconstruction has the advantage of time saving without compromise on image quality or the diagnostic accuracy compared to 2D images.

Plaques of Nonstenotic Basilar Arteries with Isolated Pontine Infarction on Three-dimensional High Isotropic Resolution Magnetic Resonance Imaging.

Background:There are few studies for evaluating plaque characteristics of nonstenotic basilar arteries (BA). Our aim was to determine entire BA plaques with a three-dimensional volumetric isotropic turbo spin-echo acquisition (VISTA) and investigate the differences between the patients with and without isolated pontine infarction (IPI).Methods:Twenty-four consecutive symptomatic patients with nonstenotic BA on time of flight magnetic resonance angiography (TOF MRA) were enrolled from China-Japan Friendship Hospital between January 2014 and December 2014. BA was classified as “normal” or “irregular” based on TOF MRA, and “normal wall”, “slight wall-thickening”, and “plaque” based on three-dimensional VISTA images. Outcomes from MRA and VISTA were compared. Patients were categorized as IPI and non-IPI groups based on the diffusion-weighted imaging. Clinical and plaque characteristics were compared between the two groups.Results:A total of 1024 image slices including 311 (30.37%) plaque slices, 427 (41.70%) slight wall-thickening slices, and 286 (27.93%) normal wall slices for the entire BA from 23 patients were finally included for analysis. VISTA images detected plaques in all the 9 (100%) irregular MRA patients and 7 of 14 (50%) normal MRA patients. IPI was found in 11 (47.83%) patients. Compared to non-IPI group, the IPI group had a higher percentage of plaque slices (P = 0.001) and lower percentage of normal wall slices (P = 0.014) than non-IPI group.Conclusions:Three-dimensional VISTA images enable detection of BA plaques not visualized by MRA. BA plaques could be found in both the IPI and non-IPI group. However, IPI group showed plaques more extensively in BA than the non-IPI group.

Imaging intracranial vessel wall pathology with magnetic resonance imaging: current prospects and future directions.

To date, the probable cause of ischemic stroke is often inferred from the size and location of the infarct, in combination with an evaluation of the heart and the presence of extracranial arterial occlusion or high-grade stenosis.1 Currently used conventional lumenography-based methods such as digital subtraction angiography, computed tomography angiography, and magnetic resonance (MR) angiography are used to determine the presence of such an acute occlusion or high-grade arterial stenosis. From extracranial studies, it is known that luminal narrowing may be absent in patients with severe atherosclerosis owing to arterial remodeling.2–4 Therefore, these methods do not provide information about the underlying pathological processes, which most often involve the vessel wall.5 Vessel wall changes such as vessel wall thickening, enhancement, or the presence of vulnerable atherosclerotic plaques without luminal stenosis are therefore often missed but might be of importance for a better understanding of ischemic stroke.6 Furthermore, intracranial atherosclerosis is an important cause of ischemic stroke7 and often involves the vessel wall. Patients with intracranial atherosclerosis have high recurrent stroke rates,8 and increasingly more attention is being directed to the assessment of the intracranial vessel wall, necessitating an imaging technique directly assessing the intracranial vessel wall. MR imaging (MRI) seems the most promising technique to reliably image intracranial vessel wall pathologies because of its superior soft tissue contrast. Recent advances in MRI9 have made it possible to obtain information about these abnormalities within the intracranial vessel wall, which provides an imaging tool to investigate the role of intracranial vessel wall abnormalities in the diagnosis of stroke. In this review, we discuss the current status of intracranial vessel wall MRI and its potential to identify different intracranial vessel wall pathologies. First, we present the state-of-the-art MRI methods to visualize the intracranial vessel wall …

Imaging of carotid artery vessel wall edema using T2-weighted cardiovascular magnetic resonance.

BackgroundAtherothrombosis remains a major health problem in the western world, and carotid atherosclerosis is an important contributor to embolic ischemic strokes. It remains a clinical challenge to identify rupture-prone atherosclerotic plaques before clinical events occur. Inflammation, endothelial injury and angiogenesis are features of vulnerable plaques and may all be associated with plaque edema. Therefore, vessel wall edema, which can be detected by 2D T2-weighted cardiovascular magnetic resonance (CMR), may be used as a dynamic marker of disease activity in the atherosclerotic plaque. However, 2D imaging is limited by low spatial resolution in the slice-select direction compared to 3D imaging techniques. We sought to investigate the ability of novel 3D techniques to detect edema induced in porcine carotid arteries by acute balloon injury compared to conventional 2D T2-weighted black-blood CMR.MethodsEdema was induced unilaterally by balloon overstretch injury in the carotid artery of nine pigs. Between one to seven hours (average four hours) post injury, CMR was performed using 2D T2-weighted short-tau inversion recovery (T2-STIR), 3D volumetric isotropic turbo spin echo acquisition (VISTA) and 3D T2 prepared gradient-echo (T2prep-GE). The CMR images were compared in terms of signal-to-noise ratio (SNR) and contrast-to-noise (CNR) ratio. Furthermore, the presence of vessel wall injury was validated macroscopically by means of Evans Blue dye that only enters the injured vessel wall.ResultsAll three imaging sequences classified the carotid arteries correctly compared to Evans Blue and all sequences demonstrated a significant increase in SNR of the injured compared to the non-injured carotid vessel wall (T2-STIR, p = 0.002; VISTA, p = 0.004; and T2prep-GE, p = 0.003). There was no significant difference between sequences regarding SNR and CNR.ConclusionThe novel 3D imaging sequences VISTA and T2prep-GE perform comparably to conventional 2D T2-STIR in terms of detecting vessel wall edema. The improved spatial coverage of these 3D sequences may facilitate visualization of vessel wall edema to enable detection and monitoring of vulnerable carotid atherosclerotic plaques.

Usefulness of Dual Echo Volumetric Isotropic Turbo Spin Echo Acquisition (VISTA) in MR Imaging of the Temporomandibular Joint

We investigated the ability to detect the articular disk and joint effusion of the temporomandibular joint (TMJ) of a method of dual echo volumetric isotropic turbo spin echo acquisition (DE-VISTA) additional fusion images (AFI). DE-VISTA was performed in the 26 TMJ of 13 volunteers and 26 TMJ of 13 patients. Two-dimensional (2D) dual echo turbo spin echo was performed in the 26 TMJ of 13 volunteers. On a workstation, we added proton density-weighted images (PDWI) and T2 weighted images (T2WI) of the DE-VISTA per voxel to reconstruct DE-VISTA-AFI. Two radiologists reviewed these images visually and quantitatively. Visual evaluation of the articular disk was equivalent between DE-VISTA-AFI and 2D-PDWI. The sliding thin-slab multiplanar reformation (MPR) method of DE-VISTA-AFI could detect all articular disks. The ratio of contrast (CR) of adipose tissue by the articular disk to that of the articular disk itself was significantly higher in DE-VISTA-AFI than DE-VISTA-PDWI (P<0.05) in patients and volunteers with closed or open mouth. In volunteers, the CR between adipose tissue and the disk on DE-VISTA-AFI was marginally significant to that on 2D-PDWI at opened mouth (P=0.071) and not significantly different (P=0.18) from that at closed mouth. Joint effusion could be identified in DE-VISTA-AFI in all 8 joints that had joint effusion in DE-VISTA-T2WI but in only 3 of those joints in 2D-T2WI. The CR of joint effusion to adipose tissue on DE-VISTA-AFI did not differ significantly from that on DE-VISTA-PDWI. However, using DE-VISTA-T2WI in addition to DE-VISTA-PDWI, we could visually identify joint effusion on DE-VISTA-AFI that could not be identified on DE-VISTA-PDWI alone. DE-VISTA-AFI can depict the articular disk and a small amount of joint effusion by the required plane of MPR using the sliding thin-slab MPR method.