Volume Isotropic Turbo Spin Echo Research Articles

Evaluating the Efficacy of Volume Isotropic Turbo Spin Echo Acquisition Versus T2-Weighted Turbo Spin Echo Imaging in the Diagnosis of Nerve Root and Perineuronal Pathologies in Spinal Disorders

Evaluating the Efficacy of Volume Isotropic Turbo Spin Echo Acquisition Versus T2-Weighted Turbo Spin Echo Imaging in the Diagnosis of Nerve Root and Perineuronal Pathologies in Spinal Disorders

Magnetic resonance imaging thicknesses and apparent diffusion coefficient values of the endometrium and junction zone in women of reproductive age.

The endometrium and uterine junction zone often change throughout the menstrual cycle. Some pathological conditions may appear normal in uterine imaging, which will lead to missed diagnosis and misdiagnosis. To evaluate the changes in the thickness and apparent diffusion coefficient (ADC) values of the endometrium and uterine junction zone throughout the menstrual cycle in magnetic resonance imaging (MRI) of women of reproductive age. Data were collected from 40 healthy women of reproductive age with regular menstrual cycles from January 2017 to April 2018. They underwent four total MRI sessions during the menstrual, proliferation, and early and late secretive phases. The main MRI sequences were T2-weighted (T2W) volume isotropic turbo spin echo acquisition (VISTA) spectral attenuated inversion recovery (SPAIR) and diffusion-weighted imaging (b = 0, 600, 800, 1000 s/mm2), which were used to measure the thicknesses and ADC values of endometrium and uterine junction zone. First, the endometrium was thinnest during the menstrual phase and thickest in the late secretive phase. Second, the uterine junction zone was thinnest in the late secretive phase and thickest in the menstrual phase. Third, the ADC values of the endometrium were lowest in the menstrual phase and peaked in the early secretive phase. Finally, the ADC values of the uterine junction zone were lowest in the menstrual phase and peaked in the late secretive phase. The endometrium and uterine junction zone showed cyclic changes. Radiologists should consider these changes in the thickness and ADC values when analyzing MRI images of the uterus.

Quantitative assessment of microstructural evolution of intracranial aneurysm wall by vessel wall imaging.

This study aimed to evaluate new quantitative parameters of aneurysm wall enhancement (AWE) on magnetic resonance vessel wall imaging (VWI) in differentiating between the stable and evolving unruptured intracranial aneurysms (UIAs). Thirty-eight consecutive patients with UIAs (27 stable and 11 evolving) underwent VWI with contrast-enhanced 3D T1 volume isotropic turbo spin echo acquisition. The voxel-based enhancement maps were created using pre- and post-contrast images. The aneurysmal lumen with signal suppression by black-blood method was segmented. Then, one voxel outer and inner layers of the lumen contour were automatically segmented. The shape features of the aneurysms and AWE of the two layers were compared between stable and evolving groups. The shape features, including aneurysm volume, surface, and compacity were significantly different between the stable and evolving groups (P = 0.024, 0.028, and 0.033, respectively). Stable and evolving groups also differed significantly in the AWE at the union of outer and inner layers of the aneurysm wall (P = 0.0082) but not in that of the outer or inner layer alone. Multivariate logistic regression analysis revealed significant differences in aneurysm volume, surface, and AWE at the union of outer and inner layers between the two groups (P = 0.0029, 0.0092, and 0.0033, respectively). Receiver operating characteristics curve analysis revealed that the area under the curve of the logistic regression model was 0.89. Quantitative combined analysis of aneurysm shape features and AWE of the union of outer and inner layers were effective for differentiating between stable and evolving UIAs.

Application of Contrast-Enhanced 3-Dimensional T2-Weighted Volume Isotropic Turbo Spin Echo Acquisition Sequence in the Diagnosis of Prolactin-Secreting Pituitary Microadenomas

This study aimed to investigate the value of contrast-enhanced 3-dimensional (3D) T2-weighted (T2W) Volume Isotropic Turbo Spin Echo Acquisition (VISTA) sequence in prolactin-secreting pituitary adenoma diagnosis. We enrolled 158 patients with hyperprolactinemia. Coronal dynamic contrast-enhanced (DCE) T1 spin echo and T2W VISTA sequences were performed. The detection of pituitary microadenomas in 3 imaging groups (DCE magnetic resonance imaging [MRI], VISTA, and DCE MRI + VISTA) were compared using McNemar test and χ2 test. The DCE MRI + VISTA group detected 28 more pituitary microlesions than DCE MRI alone. Among these, 20 lesions were clearly observed on VISTA images but were negative on DCE MRI. The combined sequences showed higher sensitivity (85.3%) and diagnostic accuracy (89.2%) for adenoma detection than any of the sequences alone (P < 0.01). We noted that in 65.7% of the patients with adenoma (46 of 70), a "hypointense rim" was present around the lesion on the VISTA images. Of them, 11 patients underwent surgery. Histopathology confirmed that the "hypointense rim" was a pseudocapsular structure at the edge of the adenoma. For patients with hyperprolactinemia, the 3D T2W VISTA sequence is an important supplement to DCE MRI, because it could improve the detection rate of pituitary microadenomas.

Better continuity of the facial nerve demonstrated in the temporal bone on three-dimensional T1-weighted imaging with volume isotropic turbo spin echo acquisition than that with fast field echo at 3.0 tesla MRI.

Three-dimensional (3D) T1-weighted imaging (T1WI) is used for evaluation of the facial nerve. The signal intensity of normal and pathological facial nerves has been well evaluated at both 1.5T and 3.0T MRI after gadolinium (Gd)-enhancement with various pulse sequences. However, the continuity of the facial nerve has not been evaluated on 3D-T1WI. This study aims to compare the continuity of the normal facial nerve in the temporal bone demonstrated on T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA), which is a spin-echo sequence, to that on T1-weighted fast field echo (T1-FFE), which is a gradient-echo sequence, at 3.0T MRI. Forty-four normal facial nerves in 22 healthy volunteers were imaged with both sequences using 3.0T MRI without Gd-enhancement. The facial nerves were evaluated visually by two neuroradiologists in four anatomical segments with a 3-point grading system of continuity. The continuity was assessed by summing the grades of the four segments as a total score. The grades at each segment and the total scores were compared statistically between the T1-VISTA and T1-FFE. The grades in all segments and the total score were significantly higher with T1-VISTA than those with T1-FFE. T1-VISTA was superior to demonstrate the facial nerve as a continuous anatomical structure in the temporal bone at 3.0T MRI.

Neurovascular Compression Confirmed by 3D T2-Weighted Volume Isotropic Turbo Spin-Echo Acquisition Sequence in Trigeminal Neuralgia

Key Words: Trigeminal neuralgia, Neurovascular compression, Three-dimensional magnetic resonance imaging

Volume Isotropic Turbo Spin Echo Acquisition Magnetic Resonance Imaging Pulse Sequence in Assessment of Temporomandibular Disorders

Background: Magnetic resonance imaging is the chief imaging modality used in assessment of temporomandibular disorders.Aim of the study: This study aimed to investigate the validity of Volume ISotropic Turbo spin echo Acquisition (VISTA) pulse sequence in the assessment of temporomandibular disorders.Subjects and Methods: Fifteen patients with temporomandibular joint related complaints performed MRI bilaterally using VISTA proton density and two-dimensional proton density turbo spin echo pulse sequences. Four-point scale was used to assess the clarity of articular disc position, disc morphology, cortical bone delineation, and overall image quality of both tested techniques. Besides, the final diagnosis of each case was obtained.Results: The main and standard deviation of traditionally used 2D proton density images in determination of disc position, disc morphology, delineation of cortical bone and overall image quality were (2.57± 0.49), (2.37± 0.60), (2.8± 0.4), (2.57± 0.49), respectively. While those for VISTA images were (1.8± 0.4), (1.53± 0.72), (2.1± 0.60), (1.7± 0.64) with the same order. The final diagnosis was similar in both techniques in 25 cases out of 30.Conclusion: Volume ISotropic Turbo Spin Echo Acquisition (VISTA) magnetic resonance pulse sequence could reveal the temporomandibular joint related structures, but with less image quality than that of traditionally used two-dimensional proton density images.

Thirty Minutes of Running Exercise Decreases T2 Signal Intensity but Not Thickness of the Knee Joint Cartilage: A 3.0-T Magnetic Resonance Imaging Study.

Recent studies showed a potential of magnetic resonance imaging (MRI), which can be used as an additional tool for diagnosing cartilage degeneration in the early stage. We designed a cross-sectional study in order to evaluate knee joint cartilage adaptation to running, using 3.0-T MRI equipped with the 3-dimensional turbo spin echo (VISTA = Volume ISotropic Turbo spin echo Acquisition) software. By this thickness (mm) and signal intensity (mean pixel value) can be quantified, which could be closely related to the fluid content of the knee joint cartilage, before and after running. A total of 22 males, aged 18 to 35 years, dominant (right) and nondominant (left) knees were assessed before and after 30 minutes of running. Cartilage thickness and signal intensity of surfaces of the patella, medial and lateral femoral and tibial condyles were measured. Cartilage thickness of the lateral condyle decreased at the dominant knee, while it increased at the medial tibial plateau. Signal intensity decreased at all locations, except the lateral patella in both knees. The most obvious decrease in signal intensity (10.6%) was at the medial tibial plateau from 949.8 to 849.0 of the dominant knee. There was an increase in thickness measurements and decrease in signal intensity in medial tibial plateau of the dominant knee after 30 minutes of running. This outcome could be related to fluid outflow from the tissue. Greater reductions in the medial tibial plateau cartilage indicate greater load sharing by these areas of the joint during a 30-minute running.

Is the Grafted Tendon Shifted Anteriorly in the Femoral Tunnel at the Postremodeling Phase After Anterior Cruciate Ligament Reconstruction? A Clinical MRI Study.

Background:Based on previous in vitro studies, it has been commonly believed that during anterior cruciate ligament (ACL) reconstruction with hamstring tendon, the grafted tendon is shifted anteriorly in the tunnel permanently after the graft is anchored to the tunnel wall. However, this has not been proven by in vivo studies.Hypothesis:At 1 year after anatomic double-bundle ACL reconstruction, the grafted tendons may not be shifted anteriorly in the femoral tunnel but anchored to the bony wall at the center of the tunnel.Study Design:Case series; Level of evidence, 4.Methods:Participants consisted of 40 patients who underwent anatomic double-bundle ACL reconstruction. The grafted tendons located in the femoral tunnel were examined 1 year after surgery using 2 different magnetic resonance imaging (MRI) protocols. In the first substudy, with 20 patients, the grafted tendon location was evaluated on an inclined sagittal multiplanar reconstruction (MPR) image taken using a standard T2-weighted protocol. In the second substudy with the remaining 20 patients, tendon location was evaluated on a pure axial MPR image taken using a VISTA (volume isotropic turbo spin echo acquisition) protocol.Results:On the inclined sagittal T2-weighted images of the anteromedial (AM) graft, the anterior width of the newly formed fibrous tissue, which surrounded the tendon graft, was significantly greater than the posterior width (P = .001). The center of the grafted tendon was slightly (mean, 2.5% of the tunnel diameter) but significantly (P = .0310) shifted posteriorly from the tunnel center. On the axial T2-VISTA images, the center of the AM graft was slightly but significantly shifted posteriorly (3.9%; P = .022) and medially (5.5%; P = .002) from the tunnel center. The center of the posterolateral (PL) graft was not significantly shifted to any direction from the center of the tunnel.Conclusion:The grafted tendons were not shifted anteriorly in the femoral tunnel 1 year after anatomic double-bundle ACL reconstruction. The PL graft was located approximately at the center of the tunnel outlet, while the AM graft was slightly but significantly shifted posteriorly and proximally.

Periportal lymphatic system on post-hepatobiliary phase Gd-EOB-DTPA-enhanced MR imaging in normal subjects and patients with chronic hepatitis C.

We sought to evaluate visualization of periportal lymphatics and lymph nodes (lymphatic system) on Gd-EOB-DTPA-enhanced magnetic resonance (MR) images using a fat-suppressed T2-weighted sequence with 3-dimensional (3D) volume isotropic turbo spin echo acquisition (VISTA) at 3.0 T in normal subjects and patients with chronic hepatitis C. MR imaging was performed in 254 subjects between June 2013 and May 2016. After applying inclusion and exclusion criteria, the final population was 31 normal subjects and 34 patients with chronic hepatitis C. Images were acquired after the hepatobiliary phase following intravenous administration of Gd-EOB-DTPA, which causes signal loss in the bile ducts, to facilitate the visualization of the periportal lymphatic system. Two radiologists assessed the visualization of the periportal lymphatic system in 31 normal subjects. The axial dimensions of the main periportal lymphatic system in normal subjects were measured and compared with those of 34 patients with chronic hepatitis C using the Mann-Whitney U-test, and their correlation with a hepatic fibrosis marker, the Fibrosis-4 (FIB-4), was assessed using Spearman's rank correlation test. The periportal lymphatic system was detected as high signal intensity areas surrounding the portal vein up to the third branches by each reader in all normal subjects. The axial dimensions of the main periportal lymphatic system in patients with chronic hepatitis C were significantly larger than those in normal subjects (p<0.0001), and showed a significantly positive correlation with the FIB-4 score (ρ=0.73, p<0.001). Fat-suppressed T2-weighted MR imaging with 3D-VISTA acquired after the hepatobiliary phase on Gd-EOB-DTPA-enhanced imaging may be a useful noninvasive method for evaluating the periportal lymphatic system and the degree of hepatic fibrosis.

Evaluation of basilar artery atherosclerotic plaque distribution by 3D MR vessel wall imaging.

Basilar artery (BA) atherosclerosis is an important cause of perforator stroke in the brainstem due to plaque involvement of the perforator ostia in BA dorsal or lateral walls. Therefore, to acquire information on plaque distribution is important to better understand and prevent the perforator stroke. This study aimed to comprehensively evaluate BA plaque distribution with 3D magnetic resonance imaging (MRI) vessel wall imaging. Consecutive patients with cerebrovascular symptoms and stenosis or irregular luminal surface of BA were recruited and underwent BA 3D proton density-weighted volume isotropic turbo spin echo acquisition (VISTA) imaging at 3T. The cross-sectional and longitudinal distribution of BA plaque were analyzed with a custom-developed tool. In all, 85 BA plaques were detected in 61 recruited patients. For cross-sectional distribution, the prevalence of plaque involvement in the ventral, left, dorsal, and right quadrant of BA wall was 74.1%, 70.6%, 67.1%, and 62.4%, respectively. Of the 85 plaques, 17.7% involved one quadrant and 82.3% involved two or more quadrants. The most severe plaque region was more commonly situated at lateral walls (66.1%) as compared to ventral (23.2%, P < 0.001) and dorsal walls (10.6%, P < 0.001). Longitudinally, plaques were more frequently found to occur at BA segment distal than proximal to anterior inferior cerebellar artery (AICA) (63.5% vs. 36.5%). Taking advantage of 3D MR vessel wall imaging, BA plaques were found to more likely affect lateral walls and form in BA distal to AICA, where most perforators originate, suggesting that it might be useful to characterize BA plaque distribution before aggressive treatment for prevention of perforator stroke. J. Magn. Reson. Imaging 2016;44:1592-1599.

Three-dimensional isotropic T2-weighted fast spin-echo (VISTA) ankle MRI versus two-dimensional fast spin-echo T2-weighted sequences for the evaluation of anterior talofibular ligament injury

To compare the performance of axial images of the ankle joint on three-dimensional (3D) volume isotropic turbo spin echo acquisition (VISTA) with that of two-dimensional (2D) fast spin echo (FSE) T2-weighted images for the diagnosis of anterior talofibular ligament (ATFL) injury. This retrospective study included 101 patients who underwent both 2D FSE T2-weighted and 3D VISTA magnetic resonance imaging (MRI) of the ankle. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of both sequences were measured. The anatomical identification score and diagnostic performances of both sequences were evaluated by two radiologists. The diagnostic performances of 3D VISTA and 2D FSE images were analysed in terms of sensitivity, specificity, and accuracy for diagnosing ATFL injury. Surgically or clinically confirmed diagnoses were used as reference standards. The margin sharpness scores on 3D VISTA were significantly inferior to those of 2D FSE (p<0.001). Other scores (entire length, entire width) were not significantly different between the two imaging methods. The SNRs and CNRs of 3D VISTA were significantly higher than those of 2D FSE (p<0.001). When diagnoses were classified as normal and abnormal, the specificity of the 3D VISTA images for the diagnosis of ATFL injury was 95.7%, significantly superior to 2D FSE (84.3-85.7%). There were no significant differences between 3D VISTA and 2D FSE images in sensitivity or accuracy for diagnosis (p=0.227-1.000), with the exception of accuracy by reader 1 (p=0.039). 3D VISTA imaging has a diagnostic performance comparable to that of 2D FSE for the diagnosis of ATFL injury, although 3D VISTA is inferior to 2D FSE for the evaluation of margin sharpness. Replacing axial and coronal images with 3D VISTA can save imaging time without negatively impacting the diagnostic ability for ATFL injury.

Lymphatic pathway around the pancreatic head and extrahepatic bile duct: evaluation using MR imaging at 3.0-T.

To evaluate the utility of spectral presaturation with inversion recovery (SPIR) T2-weighted images with 3-dimensional (3D) volume isotropic turbo spin echo acquisition (VISTA) at 3.0-T for the detection of the normal lymphatic systems located around the pancreatic head and extrahepatic bile duct. Fifty-six patients with suspected hepatic or pancreaticobiliary diseases and diagnosed as normal or benign pathologies were evaluated as having normal lymphatic systems. The protocol consisted of SPIR T2-weighted sequences with 3D-VISTA. The lymphatic systems were defined as fluid signal intensity structures and divided into eight portions and interobserver agreement was evaluated using weighted kappa statistics. Three readers graded the visualization of each portion using a five-point scale. The detectability of each portion was calculated by defining grades 1-2 as detectable and grades 3-5 as undetectable. Interobserver agreement regarding the visualization grades was moderate to almost perfect. All readers rated the detectability of the lymphatic systems of the superior and posterior portions of the pancreatic head, pericholedochal, right abdominoaortic, and interaorticovenous portions as 100%, and that of the anterior portion of the pancreatic head as 98.2%. For the inferior portion of the pancreatic head, the detectability was 100% for reader 2 and 96.4% for readers 1 and 3. The lymphatic systems located around the pancreatic head and extrahepatic bile duct could be sufficiently visualized on SPIR T2-weighted images with 3D-VISTA at 3.0-T.

Fat-suppressed volume isotropic turbo spin echo acquisition (VISTA) MR imaging in evaluating radial and root tears of the meniscus: Focusing on reader-defined axial reconstruction

ObjectiveTo assess the diagnostic value of fat-suppressed (FS) three-dimensional (3D) volume isotropic turbo spin echo acquisition (VISTA) imaging in detecting radial and root tears of the meniscus, including the reader-defined reformatted axial (RDA) plane. Materials and methodsTwenty-three patients with arthroscopically confirmed radial or root tears of the meniscus underwent magnetic resonance imaging (MRI) with 2D and FS 3D VISTA sequences. MRIs were reviewed independently by two musculoskeletal radiologists blinded to the arthroscopic findings. Sensitivity, specificity, accuracy, and interobserver agreement were calculated for radial and root tears. Both radiologists reported confidence scale for the presence of meniscal tears in 2D axial imaging, 3D axial imaging, and RDA imaging, based on a five-point scale. Wilcoxon's signed rank test was used to compare confidence scale. ResultsThe sensitivity, specificity, and accuracy of FS 3D VISTA MR imaging versus 2D MR imaging were as follows: 96%, 96%, and 96% versus 91%, 91%, and 91%, respectively in reader 1, and 96%, 96%, and 96% versus 83%, 91%, and 87%, respectively, in reader 2. Interobserver agreement for detecting meniscal tears was excellent (κ=1) with FS 3D VISTA. The confidence scale was significantly higher for 3D axial images than 2D imaging (p=0.03) and significantly higher in RDA images than 3D axial image in detecting radial and root tears. ConclusionsFS 3D VISTA had a better diagnostic performance in evaluating radial and root tears of the meniscus. The reader-defined reformatted axial plane obtained from FS 3D VISTA MR imaging is useful in detecting radial and root tears of the meniscus.

Quantitative Assessment and Ligament Traceability of Volume Isotropic Turbo Spin Echo Acquisition (VISTA) Ankle Magnetic Resonance Imaging: Fat Suppression versus without Fat Suppression

Ankle is one of the most complex human joints and is vulnerable to injury (1, 2). Imaging numerous ligaments and tendons that run in various planes is sometimes challenging. To overcome this problems, three-dimensional (3D) acquisition magnetic resonance (MR) imaging techniques, that allows multiplanar reconstruction and reduces partial-volume INTRODUCTION �Received; March 15, 2013�Revised; April 17, 2013 �Accepted; May 3, 2013 This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2012R1A1A2007991). Corresponding author : Sungjun Kim, M.D. Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 135720, Korea. Tel. 82-2-2019-3510, Fax. 82-2-3462-5472 E-mail : agn70@yuhs.ac Quantitative Assessment and Ligament Traceability of Volume Isotropic Turbo Spin Echo Acquisition (VISTA) Ankle Magnetic Resonance Imaging: Fat Suppression versus without Fat Suppression

Detection of Brain Metastases by 3-Dimensional Magnetic Resonance Imaging at 3 T

This study aimed to compare the diagnostic performance in the detection of brain metastases between contrast-enhanced T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA) and 3-dimensional T1-weighted fluid-attenuated inversion recovery (3D-T1-FLAIR) imaging at 3 T. Two neuroradiologists selected 129 true (metastases) and 70 false (vessels and artifacts) lesions on the contrast-enhanced T1-VISTA and 3D-T1-FLAIR images of 14 cancer patients with hyperintense brain lesions. Four blinded neuroradiologists distinguished between the true and false lesions, using a 5-point confidence rating scale. The receiver operating characteristic analysis was performed to compare the diagnostic performance. Contrast-to-noise ratio of the true lesions was also compared between the 2 sequences by using paired t tests. For lesions less than 3 mm, the area under curve and sensitivity achieved by T1-VISTA imaging were significantly greater than 3D-T1-FLAIR imaging. The contrast-to-noise ratio was also significantly greater with T1-VISTA imaging. The contrast-enhanced T1-VISTA imaging is better suited than 3D-T1-FLAIR imaging, for detection of small metastases.

Qualitative and Quantitative Assessment of Isotropic Ankle Magnetic Resonance Imaging: Three-Dimensional Isotropic Intermediate-Weighted Turbo Spin Echo versus Three-Dimensional Isotropic Fast Field Echo Sequences

ObjectiveTo compare the image quality of volume isotropic turbo spin echo acquisition (VISTA) imaging method with that of the three-dimensional (3D) isotropic fast field echo (FFE) imaging method applied for ankle joint imaging.Materials and MethodsMR imaging of the ankles of 10 healthy volunteers was performed with VISTA and 3D FFE sequences by using a 3.0 T machine. Two radiologists retrospectively assessed the tissue contrast between fluid and cartilage (F-C), and fluid and the Achilles tendon (F-T) with use of a 4-point scale. For a quantitative analysis, signal-to-noise ratio (SNR) was obtained by imaging phantom, and the contrast ratios (CRs) were calculated between F-T and F-C. Statistical analyses for differences in grades of tissue contrast and CRs were performed.ResultsVISTA had significantly superior grades in tissue contrast of F-T (p = 0.001). Results of 3D FFE had superior grades in tissue contrast of F-C, but these result were not statistically significant (p = 0.157). VISTA had significantly superior CRs in F-T (p = 0.002), and 3D FFE had superior CRs in F-C (p = 0.003). The SNR of VISTA was higher than that of 3D FFE (49.24 vs. 15.94).ConclusionVISTA demonstrates superior tissue contrast between fluid and the Achiles tendon in terms of quantitative and qualitative analysis, while 3D FFE shows superior tissue contrast between fluid and cartilage in terms of quantitative analysis.

3D isotropic turbo spin-echo intermediate-weighted sequence with refocusing control in knee imaging: comparison study with 3D isotropic fast-field echo sequence

Three-dimensional (3D) turbo spin-echo (TSE) images have been used in imaging of the extremities and comparable diagnostic performance to two-dimensional (2D) TSE images has been reported in several studies. However, comparison of the 3D isotropic TSE intermediate-weighted sequence and 3D FFE sequence in terms of image quality has not been investigated. To compare the image quality of a 3D isotropic TSE intermediate-weighted sequence with refocusing control (volume isotropic turbo spin echo acquisition [VISTA]) and a 3D isotropic fast-field echo (FFE) sequence of the knee joint. 3.0 T knee MRI with VISTA and 3D FFE sequences was performed in 10 healthy volunteers (3 men, 7 women; age range 26-30 years). Two radiologists with specialties in the musculoskeletal system assessed tissue contrast between the fluid-cruciate ligament (F-L), fluid-meniscus (F-M), and fluid-cartilage (F-C) based on a 4-point scale (1, poor; 2, fair; 3, good; and 4, excellent). Statistical analysis for inter-observer agreement and differences in grades in tissue contrast between VISTA and 3D FFE images (Wilcoxon signed-rank) were performed. For a quantitative analysis, the signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Image contrast ratios (CRs) were calculated between F-L, F-M, and F-C in volunteer images of VISTA and 3D FFE and compared statistically with a paired t-test. Based on qualitative analysis, VISTA had statistically superior grades of tissue contrast in F-L (P < 0.001) and F-M (P < 0.001). 3D FFE had superior but not statistically significant (P = 0.317) grades in F-C. Based on quantitative analysis, the SNR of the phantom imaging was higher in VISTA than that in 3D FFE (28.18 vs. 14.90). VISTA had superior CRs in F-L (P < 0.001) and F-M (P < 0.001). 3D FFE had superior CR in F-C (P = 0.038). The VISTA sequence was superior in tissue contrast between F-M and F-L, and 3D FFE was superior in tissue contrast between F-C, subjectively and quantitatively.

3.0T MR Imaging of the Cranial Arterial Wall for the Strategy of Stroke Prevention

3.0T refined MRI reveals the anatomical structures clearly. Operative findings correspond well with MRI findings. The authors have used this equipment for prevention of stroke. Especially evaluation of the arterial wall is important for this purpose. Showing illustrative cases including operative ones, the authors discuss the MRI findings and strategy of treatment. The examinations of the Carotid artery (CA) and vertebro-basilar artery (VBA) were performed with 3.0T MRI (Philips Achiva 3.0T, Holland). Specialized sequences for each arterial wall were planned after TOF-MRA screening. The sequences include T1, T2 VISTA (3D Fatsaturation Volume ISotropic Turbospinecho Acquisition), mPROSET (Multiple Principle Selective Excitation Technique), B-FFE(Balanced Fast Field Echo) and T1 and T2 Black Blood. Intentionally directed pictures were acquired with reconstruction. Components of the plaque were estimated with the combination of the intensity of each picture. Distributions of carotid plaques were well demarcated and its components were diagnosed. Prognosis of each plaque was estimated and the surgical and/or non-surgical treatment plan was secured. Preoperative MRI plaque findings and the specimens from carotid endarterectomy (CEA) correlated well. The stability of the plaque could be evaluated, which afforded the decision of timing and method of operation. Lacerated walls of VBA dissection were well illustrated and strategies were planned. Intra-aneurysmal thrombus was revealed and its development was imaged. The wall of the unruptured aneurysm could be evaluated but not always. 3.0T MRI provides more anatomical and pathological information than conventional MRI. Prognosis of each lesion could be estimated. Routine examination of the cranial arterial wall contributes to the prevention of stroke.