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The present study aimed to investigate the value of intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) in the preoperative prediction of the histologic differentiation of hepatocellular carcinoma (HCC). Seventy HCC patients were scanned with a 3.0 T magnetic resonance scanner. The values of apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (D), fast apparent diffusion coefficient (D*), and the fraction of the fast apparent diffusion coefficient (f) were measured. Analysis of variance was used to compare the differences in parameters between groups with different degrees of histologic differentiation. p −3 mm2/s, 1.16 ± 0.17 × 10−3 mm2/s, 0.98 ± 0.21 × 10−3 mm2/s, and 1.06 ± 0.15 × 10−3 mm2/s, 0.88 ± 0.16 × 10−3 mm2/s, 0.76 ± 0.18 × 10−3 mm2/s, respectively, and all differences were significant. The D* and f values of the three groups were 32.87 ± 14.70 × 10−3 mm2/s, 41.68 ± 17.90 × 10−3 mm2/s, 34.54 ± 18.60 × 10−3 mm2/s and 0.22 ± 0.07, 0.23 ± 0.08, 0.18 ± 0.07, respectively, with no significant difference. When the cut-off values of ADC and D were 1.25 × 10−3 mm2/s and 0.97 × 10−3 mm2/s, respectively, their diagnostic sensitivities and specificities for distinguishing well differentiated HCC from moderately differentiated and poorly differentiated HCC were 73.3%, 85.5%, 86.7%, and 78.2%, and their areas under the ROC curve were 0.821 and 0.841, respectively. ADC and D values can be used preoperatively to predict the degree of histologic differentiation in HCC, and the D value has better diagnostic value.

In NF 1 patients, significant numbers of so-called unidentified bright objects (UBOs) can be found. The aim of the study was to investigate whether the detectability of UBOs increases at 3T by comparing Proton density-weighted images (PDw) with fluid-attenuated inversion recovery (FLAIR) sequences.A total of 14 NF1 patients (7 male, 7 female, between 8 and 26 years old, mean age 15.4 years) were examined by a 3T magnetic resonance scanner. The presence of UBOs was evaluated on PD-w and FLAIR images by 4 evaluators. Detectability was rated by a three-point scoring system: lesions which were "well defined/detectable", "suspicious" or "detected after a second look". The Wilcoxon signed-rank test was used for comparisons between the raters. The level of significance was P 0.05.Significantly more lesions were marked as "well defined/detectable" in the PD-w Sequence compared to FLAIR at 3T (P 0.001 for all four evaluators together, as well as for each evaluator separately). In particular, PD-w proved to be superior for detecting UBOs located in the medulla oblongata, dentate nucleus and hippocampal region, regardless of the level of the raters' experience.This is the first study which compares FLAIR and PD-w at 3T for the diagnosis of UBOs in NF1. At this field strength significantly more UBOs were detected in the PD-w compared to FLAIR sequences, especially for the infratentorial regions. As UBOs occur at very early stages of the disease in patients with suspected NF1, PD-w might aid in the early diagnosis when using 3T scanners.

Aggregation of tau into neurofibrillary tangles (NFTs) is characteristic of tauopathies, including Alzheimer's disease. Recent advances in tau imaging have attracted much attention because of its potential contributions to early diagnosis and monitoring of disease progress. Fluorine-19 magnetic resonance imaging (19F-MRI) may be extremely useful for tau imaging once a high-quality probe has been formulated. In this investigation, a novel fluorine-19–labeling compound has been developed as a probe for tau imaging using 19F-MRI. This compound is a buta-1,3-diene derivative with a polyethylene glycol side chain bearing a CF3 group and is known as Shiga-X35. Female rTg4510 mice (a mouse model of tauopathy) and wild-type mice were intravenously injected with Shiga-X35, and magnetic resonance imaging of each mouse's head was conducted in a 7.0-T horizontal-bore magnetic resonance scanner. The 19F-MRI in rTg4510 mice showed an intense signal in the forebrain region. Analysis of the signal intensity in the forebrain region revealed a significant accumulation of fluorine-19 magnetic resonance signal in the rTg4510 mice compared with the wild-type mice. Histological analysis showed fluorescent signals of Shiga-X35 binding to the NFTs in the brain sections of rTg4510 mice. Data collected as part of this investigation indicate that 19F-MRI using Shiga-X35 could be a promising tool to evaluate tau pathology in the brain. © 2017 Wiley Periodicals, Inc.

Magnetic resonance-guided focused ultrasound is one of the emerging non-invasive technologies offering both image guidance and thermal monitoring. In recent years transcranial application of this technology is starting to impact heavily the neuroscience field. We present here the imaging protocol and the technological methods successfully used with a transcranial magnetic resonance-guided focused ultrasound system certified for clinical treatments of functional neurological disorders, integrated for the first time with a 1.5T magnetic resonance scanner. Compared to the body radiofrequency coil (the one commonly used with transcranial magnetic resonance-guided focused ultrasound system integrated with 3T magnetic resonance scanners), the use of a dedicated two channel coil enabled a signal-to-noise ratio gain up to five times higher.

Background To evaluate whether readout-segment echo-planar imaging (RS-EPI) can provide better image quality in assessing bladder cancer than single-shot echo-planar imaging (SS-EPI) and to compare quantitative imaging parameters derived from both techniques. Methods Seventy patients with bladder lesions were enrolled and underwent diffusion-weighted imaging on a 3 Tesla magnetic resonance scanner using axial RS-EPI and SS-EPI techniques. Two observers independently assessed the susceptibility, detectability, motion artefacts and blurring of the images using qualitative scores. The signal-to-noise ratio (SNR), signal intensity ratio (SIR), contrast-to-noise ratio (CNR) and ADC values of the bladder lesions were measured and compared between the two techniques and between two observers. Qualitative and quantitative comparisons of image quality were performed using the Wilcoxon signed-rank test and paired t-test. In addition, the agreement of the ADC measurements was evaluated using ICC values and Bland-Altman plots. Results Sixty-eight patients were included in the final analysis. The scores of image susceptibility, detectability and blurring for RS-EPI were significantly higher than those for SS-EPI (all p 0.05). The ICC values and Bland-Altman plots also showed excellent agreement between the measured ADC values of the bladder lesions. Conclusions The RS-EPI technique provides significantly better image quality in patients with bladder cancer than the SS-EPI technique, without a significant difference in the ADC value.

Introduction Oscillating gradient spin-echo (OGSE) sequences can shorten diffusion times by replacing the long-lasting diffusion-sensitizing gradients used in pulsed gradient spin-echo (PGSE) methods with rapidly oscillating gradients. To obtain information regarding the internal structure of choroid plexus cysts that appear hyperintense on diffusion-weighted imaging (DWI), we investigated the apparent diffusion coefficient (ADC) values acquired with a shorter diffusion time using an OGSE sequence. Material and methods Twenty-seven patients with choroid plexus cysts were scanned using a 3 T magnetic resonance scanner. DWI was performed with both OGSE and PGSE, with effective diffusion times (Δeff) of 6.5 and 35.2 ms, respectively. ADC values for choroid plexus cysts, white matter (WM), and cerebrospinal fluid (CSF) were measured. The ADC values obtained with the shorter and longer diffusion times were compared using the Wilcoxon signed-rank test. P Results The ADC values of choroid plexus cysts and WM were significantly higher at the Δeff of 6.5 ms on OGSE than with the Δeff of 35.2 ms on PGSE. The ADC values of CSF were significantly lower at the Δeff of 6.5 ms on OGSE than with the Δeff of 35.2 ms on PGSE. The ADC values of choroid plexus cysts were lower than the ADC values of CSF with Δeff of 35.2 and 6.5 ms. Conclusions The dependence of ADC values on the diffusion time in choroid plexus cysts suggested spatially restricted diffusion. In measurements obtained with short diffusion times, the lower ADC values for choroid plexus cysts in comparison with the CSF indicated the presence of spatially restricted diffusion and increased cyst viscosity.

Objective This is a comprehensive study to establish a diagnosis-specific gray matter deficit model for major depressive disorder (MDD) and panic disorder (PD). Method: We enrolled 53 patients with first-episode medication-naive PD, 54 healthy controls and 53 patients with first-episode medication-naive MDD in this study. They were age, handedness and gender matched. All participating subjects all received baseline structural scanning by the 3-Tesla magnetic resonance scanner. The optimized voxel-based morphometry was performed on the 3 groups of subjects and the ANOVA analysis was used to estimate the inter-group gray matter differences between each group. Results: The PD group had higher gray matter volume than MDD group in the right medial frontal cortex and right temporal gyrus. The PD group had gray matter reductions in the right inferior frontal gyrus and right insula. The MDD group had gray matter reductions in bilateral medial frontal cortex, right superior frontal gyrus, right superior temporal gyrus and bilateral cerebellums. Conclusion: The gray matter alterations of fronto-insula and fronto-temporo-cerebellum regions probably would be specific for PD and MDD respectively. In addition, the differences of gray matter volume in the fronto-temporal regions would be helpful to differentiate MDD from PD.

Background: Differentiating benign from malignant sinonsal lesions is essential for treatment planning as well as determining the patient′s prognosis, but the differentiation is often difficult in clinical practice. The study aimed to determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can improve the performance in differentiating benign from malignant sinonasal tumors. Methods: This retrospective study included 197 consecutive patients with sinonasal tumors (116 malignant tumors and 81 benign tumors). All patients underwent both DW and DCE-MRI in a 3-T magnetic resonance scanner. Two different settings of b values (0,700 and 0,1000 s/mm 2 ) and two different strategies of region of interest (ROI) including whole slice (WS) and partial slice (PS) were used to calculate apparent diffusion coefficients (ADCs). A DW parameter with WS ADCs b0,1000 and two DCE-MRI parameters (time intensity curve [TIC] and time to peak enhancement [Tpeak]) were finally combined to use in differentiating the benign from the malignant tumors in this study. Results: The mean ADCs of malignant sinonasal tumors (WS ADCs b0,1000 = 1.084 × 10−3 mm 2 /s) were significantly lower than those of benign tumors (WS ADCs b0,1000 = 1.617 × 10−3 mm 2 /s, P < 0.001). The accuracy using WS ADCs b0,1000 alone was 83.7% in differentiating the benign from the malignant tumors (85.3% sensitivity, 81.2% specificity, 86.4% positive predictive value [PPV], and 79.5% negative predictive value [NPV]). The accuracy using DCE with Tpeak and TIC alone was 72.1% (69.1% sensitivity, 74.1% specificity, 77.5% PPV, and 65.1% NPV). Using DW-MRI parameter was superior than using DCE parameters in differentiation between benign and malignant sinonasal tumors (P < 0.001). The accuracy was 87.3% (90.5% sensitivity, 82.7% specificity, 88.2% PPV, and 85.9% NPV) using DW-MRI combined with DCE-MRI, which was superior than that using DCE-MRI alone or using DW-MRI alone (both P < 0.001) in differentiating the benign from the malignant tumors. Conclusions: Diffusion-weighted combined with DCE-MRI can improve imaging performance in differentiating benign from malignant sinonasal tumors, which has the potential to improve diagnostic accuracy and to provide added value in the management for these tumors.

ObjectiveTo use 4D-flow MRI to characterize hemodynamics of transverse and sigmoid sinus in venous pulsatile tinnitus (PT) patients and to investigate their differences vs healthy controls.MethodsA total of 21 patients with venous PT and 11 healthy controls were included in the retrospective study. All participants underwent 4D-flow and magnetic resonance venography scan in a 3.0T magnetic resonance scanner. All visualization, quantification, and analysis of 4D-flow data were performed using dedicated software. Two independent reviewers evaluated the existence of vortex or turbulence. Covariance analysis adjusted for age was used to compare average through-plane velocity (Vtp_avg), maximum through-plane velocity (Vtp_max), average velocity (Vavg), maximum velocity (Vmax), average blood flow (Flowavg), and pulsatility index (PI) between PT and control group.ResultsThere were hemodynamic differences between PT patients and healthy controls. Compared with the control group, the PT group showed significantly higher Vtp_avg, Vtp_max, Vavg, Vmax, and Flowavg, and slightly higher PI. For the assessment of flow pattern, inter-reader reproducibility was excellent (κ = 1.00). Vortex or turbulence was observed in PT patients with good sensitivity (86.4%) and specificity (90.9%). Drainage dominance was more frequently observed in patients (15/21, 71.4%) than healthy controls (4/11, 36.4%).ConclusionsSignificant hemodynamic differences were found between venous PT patients and healthy controls with 4D-flow MRI. Hemodynamic conditions could serve as noninvasive biomarkers for diagnosis and treatment evaluation of venous PT.Classification of evidenceThis study provides Class III evidence that 4D-flow MRI accurately identifies patients with venous PT.

Background: There are limited studies on wall imaging of human basilar artery (BA). Our aim was to investigate remodeling mode of advanced BA atherosclerosis using 3-T MRI. Methods: Thirty-two consecutive symptomatic patients with atherosclerotic BA stenosis ≥70% were imaged with a 3-T magnetic resonance scanner. Proton density-weighted (PDW) cross-sectional images with submillimeter voxel size were obtained. The vessel area (VA) and lumen area (LA) at the maximal lumen narrowing (MLN) site and reference site were measured. Intraobserver and interobserver variability was determined by intraclass correlation coefficient (ICC). Wall area (WA) was estimated by VA − LA. Plaque size (PS) was estimated by WA at MLN site − reference WA. Percent plaque burden was calculated as (PS/VA at MLN site) × 100%. Remodeling index (RI) was the ratio of VA at MLN site to reference VA. RI ≥1.05 was defined as positive remodeling (PR) and RI Results: Measurements of cross-sectional BA images were available in 30 of 32 patients. Intraobserver or interobserver variability was small, with ICC ranging from 0.955 to 0.996. The mean RI of the 30 patients was 1.2 ± 0.4. PR was found in 19 (63.3%) patients and non-PR in 11 (36.7%) patients. Compared with the non-PR group, the PR group had greater PS (15.0 ± 9.3 mm 2 vs 6.4 ± 3.9 mm 2 , p = 0.007) and greater percent plaque burden (50.5 ± 9.9% vs 28.5 ± 12.7%, p Conclusions: 3-T high-resolution PDW imaging is a reproducible tool for measuring BA dimensions. In patients with advanced BA atherosclerosis, PR lesions are more frequently observed and contain larger plaques than non-PR lesions.

The study of focal pathology by single-voxel magnetic resonance spectroscopy (MRS) is hampered by the impossibility to study tissue heterogeneity or compare the metabolite signals in breast lesion directly to those in unaffected tissue. Multivoxel MRS studies, while potentially allowing for truly quantitative tissue characterization, have up to now also been far from quantitative with, for example, the signal-to-noise ratio of the choline (Cho) signal serving as measure of tumor activity. Shown in this study is that in a standard clinical setting with a regular 1.5-T magnetic resonance scanner, it is possible to perform quantitative multivoxel MRS. With the use of literature values for the T1 and T2 relaxation times of Cho and water in fibroglandular breast tissue and tumors, one can determine the concentrations of Cho in different tumor compartments and surrounding tissues in two brief multivoxel MRS measurements. This opens excellent perspectives to quantitative diagnostic and follow-up studies of focal pathology such as lesions suspected of breast cancer. (C) 2010 Elsevier Inc. All rights reserved.

Purpose: To identify and measure the mean size of the utricular macula using 3-T imaging. Methods: One hundred one examinations using a 3-T magnetic resonance scanner and standard temporal bone protocol were performed over a 9-month period. Asymptomatic sides were then retrospectively evaluated using the axial T2-driven equilibrium sequence (0.3-mm slice thickness). We performed the following analyses: (1) reported frequency at which this structure could be identified and (2) calculated the mean size of the utricular macula. Results: The utricular macula was identified in all 101 cases as an ellipsoid area of T2 hypointensity in the utricle. The average anteroposterior x transverse x craniocaudal dimensions were 1.7 x 1.5 x 1.0 mm. Conclusions: The utricular macula is consistently identified with 3-T imaging in asymptomatic patients.

Glutathione (GSH) is implicated in the pathophysiology of schizophrenia. Previous brain spectroscopy studies, however, have been inconsistent, and there is little data available from first episode psychosis patients. This study compared brain GSH in a first episode cohort ( n = 30) to controls ( n = 18), using magnetic resonance spectroscopy (MRS), examining a temporal lobe voxel. Short-echo (TE 30 ms) acquisition proton MRS was performed on a 3T clinical magnetic resonance scanner. Comparison of the first-episode and control groups' GSH concentrations revealed a significant main effect of group ( F 1,46 = 4.7, p = 0.035), but no main effect of hemisphere ( F 1,46 = 2.3, p = 0.137) or group-by-side interactions ( F 1,46 = 0.4, p = 0.513). Medial temporal lobe GSH concentrations in the first episode group were 22% higher than those in the control group. This study provides further evidence of significant perturbations in brain GSH in first episode psychosis, and supports a broader involvement of GSH in the pathophysiology of schizophrenia.

Evaluation of the ossification of the medial clavicular epiphysis plays a key role in forensic age estimation, particularly in determining whether the age of 18 has been attained. A key research objective in the forensic age estimation field at present is to establish non-X-ray methods for investigating the clavicle. This paper looks at the use of magnetic resonance imaging for evaluating the developmental state of the medial clavicular epiphysis. Clavicle specimens obtained from autopsies of 125 female and 270 male subjects aged from 10 to 30 were examined using a 3-T magnetic resonance scanner. One FFE-3D-T1 gradient echo sequence and one 2D-T2 turbo spin echo sequence were acquired. In each case, two investigators undertook a consensual determination of the ossification stage of the medial clavicular epiphysis using recognised classification systems. To determine intra-observer and inter-observer agreement, 80 clavicle specimens were subjected to repeat evaluation. We present statistics relating to the ossification stages. The inclusion of established sub-stages of clavicular ossification offers an additional option for determining whether a subject has attained the age of 18 which is applicable in both sexes. For both sexes, the minimum ages for ossification stages 4 and 5 allow conclusions to be drawn about a subject's age at a point in time lying several years in the past. Magnetic resonance imaging is a valid investigatory procedure for determining the ossification stage of the medial clavicular epiphysis. This paper makes a contribution to expanding the range of methods available for forensic age estimation.

OBJECTIVE We explored how a novel T1-weighted 3-dimensional (3D) fast spin echo (FSE) sequence (Cube; GE, Waukesha, Wis) might outperform conventional 2-dimensional (2D) FSE techniques for contrast-enhanced imaging of the pituitary and parasellar region. METHODS Ninety-one patients were imaged with 3D Cube and conventional 2D FSE on a 3.0-T magnetic resonance scanner. Two neuroradiologists independently assessed images for anatomical delineation (infundibulum, optic apparatus, and cavernous sinus), degree of artifact, and confidence in lesion definition or exclusion using a 5-point scale. In addition, the readers were asked to rank overall preference. RESULTS Readers A and B found 3D Cube to be better or equal to 2D FSE in 84% and 86% of the cases. Three-dimensional Cube provided significantly better images than 2D FSE with respect to delineation of the infundibulum (P < 0.0001), cavernous sinus (P < 0.0001), optic apparatus (P = 0.002 for reader A and P = 0.265 for reader B), and fewer artifacts at the sellar floor (P < 0.0001). Three-dimensional Cube provided greater lesion conspicuity or confidence in lesion exclusion (P < 0.0001). CONCLUSIONS Three-dimensional Cube provides superior quality with thinner slices as well as diminished artifact and can replace conventional 2D FSE sequences for routine evaluations of the pituitary and parasellar region.

Our study group previously measured pituitary volumes and found a relationship between somatoform disoders and pituitary volumes. Therefore, in conversion disorder, another somatoform disorder, we hypothesized that pituitary gland volumes would be reduced. Twenty female patients and healthy controls were recruited to the present investigation. The volumes of the pituitary gland were determined by using a 1.5 Tesla magnetic resonance scanner. We found that the pituitary gland volumes of the patients with conversion disorder were significantly smaller than those of healthy control subjects. In the patients with conversion disorder but not in the healthy control group, a significant negative correlation between the duration of illness and pituitary gland volume was determined. In summary, in the present study, we suggest that the patients with conversion disorder have smaller pituitary volumes compared to those of healthy control subjects. Further studies should confirm our data and ascertain whether volumetric alterations determined in the patients with conversion disorder can be changed with treatment or if they change over time.

We sought to determine whether noninvasive planimetry of the mitral valve area (MVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with mitral stenosis (MS).Accurate assessment of MVA is particularly important for the management of patients with valvular stenosis. Current standard techniques for assessing the severity of MS include echocardiography (ECHO) and cardiac catheterization (CATH).In 22 patients with suspected or known MS, planimetry of MVA was performed with a 1.5-T magnetic resonance scanner using a breath-hold balanced gradient echo sequence (true FISP). Data were compared with echocardiographically determined MVA (ECHO-MVA, n = 22), as well as with invasively calculated MVA by the Gorlin-formula at (CATH-MVA, n = 17).The correlation between MRI- and CATH-MVA was 0.89 (p0.0001), and the correlation between MRI- and ECHO-MVA was 0.81 (p0.0001). The MRI-MVA slightly overestimated CATH-MVA by 5.0% (1.60 +/- 0.45 cm(2) vs. 1.52 +/- 0.49 cm(2), p = NS) and ECHO-MVA by 8.1% (1.61 +/- 0.42 cm(2) vs. 1.48 +/- 0.42 cm(2), p0.05). On receiver-operating characteristic curve analysis, a value of MRI-MVA below 1.65 cm(2) indicated mitral stenosis (CATH-MVAor =1.5 cm(2)), with a good sensitivity and specificity (89% and 75%, respectively).Magnetic resonance planimetry of the mitral valve orifice in mitral stenosis offers a reliable and safe method for noninvasive quantification of mitral stenosis. In the clinical management of patients with mitral stenosis, it has to be considered that planimetry by MRI slightly overestimates MVA, as compared with MVA calculated echocardiographically and at catheterization.

Study design Prospectively acquire magnetic resonance images of the neck in normal subjects and patients with radiculopathy to measure and compare measures of the facet joint space thickness and volume. Objective The goal was to determine whether there is any difference in facet joint architecture between the 2 populations with the head in each of neutral and pain-eliciting rotation. Summary of background data Degeneration and altered mechanics of the facet joint can result in pathological nerve root compression and pain. Although lumbar facet joint space thinning has been reported in the context of low back pain, few studies have quantified the cervical facet joint space, especially in the context of pain. Methods The cervical spine of 8 symptomatic and 10 asymptomatic subjects was imaged in the sagittal plane in a 3T magnetic resonance scanner, using a T2-pulse sequence optimized for bone imaging. The facet joint space was identified and segmented in the acquired images. The thickness and volume of the facet joint space, and their changes between positions, were computed from the 3-dimensional representation for all cervical levels on both sides. Results Generally, the facet joint space thickness and volume were smaller in the symptomatic subjects than in the asymptomatic subjects. The differences were more robust on the left, especially in neutral and left torsion. The changes in both volume and thickness from neutral to torsion were also different in sign and magnitude at isolated joint levels between the 2 populations. Conclusion Quantification of the facet joint space architecture in the cervical spine of patients with radiculopathy is feasible using standard magnetic resonance imaging sequences. Measurements of the facet space thickness and volume, and their changes, from both pain-free and painful positions, can provide context for localizing potential sources of painful tissue loading. Level of evidence 3.

Background: Several types of coated and uncoated self-expandable stents composed of various metals are available for palliation of malignant esophageal stenoses and fistulas. We encountered poor visualization of the mediastinum and skeletal axis with magnetic resonance imaging in a patient with a Gianturco self-expandable stent. Methods: To evaluate potential problems, such as stent migration in the magnetic field of the magnetic resonance scanner (MRI) and artifacts in the images, we studied four types of expandable stents: the Ultraflex (titanium alloy), the covered Wall stent (nitinol), the Gianturco stent (Cook), and the modified Gianturco stent (Song)—the last two being made of stainless steel. Results: An appreciable attraction force and torque, as measured ex vivo by suspending the stent in a Perspex device, was found for both Gianturco stents. In particular, the Gianturco (Cook) stent is pulled toward the head with a force of 7 g ; however, it is uncertain whether this is a potential risk for dislodgement. In addition, gross artifacts in the images, studied by putting the stents in a cylindric phantom filled with a diluted gadolinium solution, made the magnetic resonance useless for imaging in a wide area around the Gianturco stents of stainless steel. No problems with magnetic resonance image quality were encountered for the titanium-based Ultraflex and Wall stents. Conclusions: Specific information on the type of stent is necessary before a magnetic resonance imaging examination is planned. (Gastrointest Endosc 1997;46:424-9.)

For gliomas, the goal of surgery is maximal tumour removal with the preservation of neurological function. We evaluated the contribution of the combination of diffusion tensor imaging-based fibre tracking (DTI-FT) of the pyramidal tract (PT) integrated to the navigation and subcortical direct electrical stimulations (DESs) to surgical outcomes.Ten patients underwent surgery for gliomas located in close relationship with the subcortical course of the PT. Preoperative DTI was performed with a three-Tesla magnetic resonance scanner applying an echo-planar sequence with 20 diffusion directions. DTI-FT data were systematically loaded into the navigation for intraoperative guidance. When the resection closely approached the PT as illustrated on navigation images, subcortical DESs were used to confirm the proximity of the PT by observing motor responses. The location of all subcortically stimulated points with positive motor response was correlated with the illustrated PT. Motor deficits were evaluated pre- and postoperatively, and compared with the extent of tumour removal.DTI-FT of the PT was successfully performed in all patients. A total of fifteen positive subcortical DESs were obtained in 8 of 10 patients; in these cases, the mean distance from the stimulated point to the PT was 6.2 ± 3.6 mm. The mean tumoural volumetric resection was 90.8 ± 10.4%, with a gross total resection in four patients. At one month after surgery, only one patient had a slight impairment of motor function (decreased fine motor hand skills).DTI-FT is an accurate technique to map the PT in the vicinity of brain tumours. By combining anatomical (DTI-FT) and functional (subcortical DES) studies for intraoperative localization of the PT, the authors achieved a good volumetric resection of tumours located in eloquent motor areas, with low morbidity. Careful use of this protocol requires the knowledge of some pitfalls, mainly the occurrence of brain shift during removal of large tumours.

Fluorescence recording of neural activity in the magnetic resonance scanner is a new strategy for examining the cellular underpinnings of blood oxygenation level–dependent (BOLD) functional magnetic resonance imaging (fMRI).

Background: Delayed onset of vastus medialis (VM) activity compared with vastus lateralis activity is a reported cause for patellofemoral pain. The delayed onset of VM activity in patellofemoral pain patients likely causes an imbalance in muscle forces and lateral maltracking of the patella; however, evidence relating VM activation delay to patellar maltracking is sparse. The aim of this study was to investigate the relationship between VM activation delay and patellar maltracking measures in pain-free controls and patellofemoral pain patients. Hypothesis: Patellar tilt and bisect offset, measures of patellar tracking, correlate with VM activation delay in patellofemoral pain patients classified as maltrackers. Study Design: Case control study; Level of evidence, 3. Methods: Vasti muscle activations were recorded in pain-free (n = 15) and patellofemoral pain (n = 40) participants during walking and jogging. All participants were scanned in an open-configuration magnetic resonance scanner in an upright weightbearing position to acquire the position of the patella with respect to the femur. Patellar tilt and bisect offset were measured, and patellofemoral pain participants were classified into normal tracking and maltracking groups. Results: Correlations between VM activation delay and patellar maltracking measures were statistically significant in only the patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset ( R2 = .89, P < .001, with patellar tilt during walking; R2 = .75, P = .012, with bisect offset during jogging). There were no differences between the means of activation delays in pain-free and all patellofemoral pain participants during walking ( P = .516) or jogging ( P = .731). Conclusion: There was a relationship between VM activation delay and patellar maltracking in the subgroup of patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset. Clinical Relevance: A clinical intervention such as VM retraining may be effective in only a subset of patellofemoral pain participants—namely, those with excessive tilt and excessive bisect offset measures. The results highlight the importance of appropriate classification of patellofemoral pain patients before selection of a clinical intervention.

Purpose: This study tested the hypothesis that the muscle metabolic responses of 9- to 12-yr-old children and young adults during incremental quadriceps exercise are dependent on age and sex. Methods: Fifteen boys, 18 girls, 8 men, and 8 women completed a quadriceps step-incremental test to exhaustion inside a magnetic resonance scanner for determination of the muscle metabolic responses using 31P-magnetic resonance spectroscopy. Quadriceps muscle mass was determined using magnetic resonance imaging scans enabling comparison of metabolic data at a normalized power output. Results: The power output and the energetic state at the Pi/PCr and pH intracellular thresholds (IT) were independent of age and sex. The rate of change in Pi/PCr against power output after the ITPi/PCr (S2) was lower in boys (0.158 +/- 0.089) and girls (0.257 +/- 0.110) compared with men (0.401 +/- 0.114, P < 0.001) and women (0.391 +/- 0.133, P = 0.014), respectively, with sex differences present for children only (P = 0.003). Above the ITpH, S2 was more rapid in the men (-0.041 +/- 0.022, P = 0.003) and girls (-0.030 +/- 0.013, P = 0.011) compared with boys (-0.019 +/- 0.007), with no differences between the girls and the women (-0.035 +/- 0.015, P = 0.479). The increase in Pi/PCr at exhaustion was lower in boys (0.85 +/- 0.38) than that in men (1.86 +/- 0.65, P < 0.001) and in girls (1.78 +/- 1.25) than that in women (4.97 +/- 3.52, P = 0.003), with sex differences in both the child (P = 0.005) and the adult groups (P = 0.019). Conclusions: During moderate-intensity exercise, muscle metabolism appears adult-like in 9- to 12-yr-old children, although both age- and sex-related differences in the "anaerobic" energy turnover are present during high-intensity exercise

Magnetic resonance spectroscopy enables the in vivo analysis of certain aspects of brain biochemistry. Reduced N-acetylaspartate in key regions of schizophrenia has been reported repeatedly but not without controversy. Our objective is to investigate whether reduced N-acetylaspartate concentrations determined without correction for individual T2 relaxation time (referred to as ‘apparent tNAA concentration’) are due to a reduced absolute N-acetylaspartate concentration or to altered relaxation properties. For this purpose we measured absolute concentrations while evaluating individual T2 relaxation times. We evaluated the metabolite concentrations and metabolite/water relaxation times of a frontal white matter voxel from 23 patients who met DSM-IV criteria for schizophrenia and 29 healthy control subjects with similar age at a 3 T magnetic resonance scanner. A significantly reduced N-acetylaspartate concentration as well as shortened N-acetylaspartate's T2 relaxation time in the schizophrenic patient group was found. The apparent N-acetylaspartate concentration difference between healthy controls and patients with schizophrenia increased with the echo time due to a decreased N-acetylaspartate's T2 in the schizophrenic group. No group difference was found for any other metabolite concentration or metabolite/brain water relaxation time. These findings of reduced N-acetylaspartate as well as shortened N-acetylaspartate's T2 relaxation time give further evidence for microstructural white matter changes in schizophrenia. Furthermore, they elucidate why reports of a reduced N-acetylaspartate concentration in schizophrenia were not always corroborated.

Accurate pre-operative assessment of tumor grade is important for the selection of appropriate treatment strategies. The aim of this study was to retrospectively evaluate whether the fiber density index (FDi) and fractional anisotropy (FA) via diffusion tensor MRI (DTI) could assist with pre-operative diagnosis of glioma grade. A total of 31 patients who had histologically confirmed gliomas underwent DTI performed using a 1.5-Tesla magnetic resonance scanner. To reconstruct the white matter adjacent to the tumor, DTI fiber tracking (DTI-FT) using an FA threshold of 0.15 was implemented. Regions of interest (ROIs) were defined (i–iv) as: the tumor center (ROI i); white matter adjacent to the tumor (ROI ii); contralateral centrum semiovale (ROI iii); and the homologous fiber tracts to ROI ii in the contralateral hemisphere (ROI iv). We calculated six parameters from different ROIs and compared high-grade and low-grade gliomas: FA values and ratios; FDi values and ratios with an FA threshold of 0.15; and FDi values and ratios with an FA threshold of 0.25. The results showed that FA ratios and FDi ratios with FA thresholds of 0.25 were significantly different between patients with high-grade and low-grade gliomas. This may be useful for developing surgical strategies and appraising patient prognosis.

Friedreich ataxia (FRDA) is characterized by GAA expansions in the intron 1 of the frataxin gene correlating with disease onset and progression as well as cardiac affection. Accordingly, FRDA patients with early disease onset show a clear impairment of mitochondrial function in the myocardium. The purpose of this study was to investigate cardiac function and high-energy phosphate metabolism in FRDA patients with late disease onset. Using a 1.5 T magnetic resonance scanner, cardiac phosphorus-31 two-dimensional chemical shift imaging was performed in ten patients (seven male, three female) with a late onset of FRDA and in 35 healthy, male controls. Ejection faction (EF) and interventricular septum thickness (IST) were determined by echocardiography. The differences in left ventricular phosphocreatine (PCr) to β-adenosine triphosphate (β-ATP) ratios between both groups were not significant. FRDA patients had increased ISTs (10.8 ± 1.6 vs. 9.7 ± 0.9 mm; p = 0.048), which correlated significantly with the left ventricular PCr to β-ATP ratios (r = −0.644; p = 0.04), and decreased EFs (52.24 ± 7.72% vs. 64.09 ± 4.25%; p = 0.001) compared to normal controls. In contrast to FRDA patients with early disease onset, our patients collective exhibited a normal, probably compensated cardiac mitochondrial function, whereby IST and EF were mildly altered.

Study design Observational case study on a female contortionist. Objective To investigate how the human spine of a young athlete aligns during extreme body contortions. Summary of background data To our knowledge, there are no data available in the literature on the spinal kinematics under extreme body contortions. Methods Conventional and kinematic magnetic resonance imaging was used to study a 22-year-old female Chinese contortionist. The images were analyzed with regard to abnormal segmental motion and degenerative alterations. Results No abnormal segmental motion was observed. The patient had a normal spine beside a mild anterior displacement of L1 relative to L2, with mild disc degeneration and small anterior spondylosis. In addition, a mild disc degeneration was observed at T4/5. No other abnormal findings were diagnosed. Conclusions The kinematic magnetic resonance investigation of the presented case did not reveal any evidence for abnormal segmental motion or subluxation in extreme body contortions and indicates that this excessive motion results from extreme spinal flexibility.

A 78-year-old woman suffered a stroke inside a magnetic resonance scanner while being imaged because of a brief transient ischemic attack 2 hours earlier. Diffusion-weighted images obtained 11 minutes after stroke showed tissue injury not found on initial images. The data show early, abrupt diffusion changes in hypoperfused tissue, adding to our understanding of the progression of microstructural abnormalities in the hyperacute phase of stroke.

There have been divergent reports on the prevalence and severity of white matter hyperintensities (WMH) on brain magnetic resonance (MR) images in subjects with bipolar disorder. In the present study, evaluations were made on the prevalence and severity of WMH in subjects with bipolar disorder using contiguous 3-mm thick MR slices as well as fluid attenuated inversion recovery (FLAIR) images. A detailed WMH rating system was employed to assess these WMH. A total of 43 bipolar patients, as diagnosed by the Structured Clinical Interview from the Diagnostic and Statistical Manual-IV (SCID-IV), and 39 healthy comparison subjects were scanned using a 1.5-T whole body GE magnetic resonance scanner. WMH were assessed with a modified composite version of the Fazekas' and Coffey's rating scales to detect less severe WMH. Periventricular and subcortical WMH were coded separately. Subjects with bipolar disorder had greater prevalence of WMH abnormalities than comparison subjects (Bipolar, grade 1 = 11.6%, grade 2 = 9.3%, grade 3 = 7.0%; Comparison, grade 1 = 5.1%, grade 2 = 2.6%, grade 3 = 0%). This difference is mainly due to the differences in deep WMH (Bipolar, grade 1 = 14.0%, grade 2 = 14.0%; Comparison, grade 1 = 7.7%, grade 2 = 0%). The current study confirms the higher prevalence of WMH in subjects with bipolar disorder. Differences of small-sized WMH abnormalities between groups were successfully detected using a large number of bipolar subjects and thinner sliced MR images with FLAIR.

STUDY DESIGN In vivo flexion-extension and axial rotation magnetic resonance imaging (MRI) studies of the cervical spine were performed inside a positioning device. OBJECTIVE To determine the functional changes of neuroforaminal size that occur during flexion-extension and axial rotation of the cervical spine in healthy persons. SUMMARY OF BACKGROUND DATA Kinematic MRI studies of the cervical spine were performed to obtain detailed information about the functional changes that occur in neuroforaminal size during flexion-extention and axial rotation. The results were compared with published data of in vitro functional flexion-extension and axial rotation studies of the cervical spine. METHODS Inside a positioning device, the cervical spines of 30 healthy persons were examined in a whole-body magnetic resonance scanner from 40 degrees of flexion to 30 degrees of extension at nine different angle positions. In addition, axial rotation was performed at neutral position (0 degrees ) and at 20 degrees and 40 degrees of axial rotation to both sides. The images were analyzed with respect to the neuroforaminal size at each position using a reformatted 3D-FISP sequence. RESULTS At flexion, widening of the neuroforaminal size of up to 31% (compared with neutral position, 0 degrees ) was observed. Conversely, at extension a decrease in the size of the neuroforamen of up to 20% was recognized. At 20 degrees and 40 degrees of ipsilateral rotation of the head, a reduction in the neuroforaminal size of up to 15% and 23%, respectively, compared with the neutral position was noted. In contrast, a widening of the foraminal size was recognized on the contralateral side of 9% and 20% at 20 degrees and 40 degrees rotation. Statistically significant differences (p

The infraclavicular brachial plexus block first described by Raj et al. was supposed to anesthetize all the main peripheral nerves of the brachial plexus without the risk of pneumothorax. However, in performing the block, we have had difficulties finding the nerves at the cord level. Therefore, we questioned whether the recommended needle direction (the “Raj line”) guides the needle close enough to the cords. We therefore designed an anatomic study to answer this question and to assess the risks of entering the pleura and axillary vein. Ten volunteers were examined noninvasively in an open model magnetic resonance scanner. The Raj line deviated greatly from a defined location on the cords by a mean of 26 (range 14‐39) mm, always caudad, and posterior to the target in nine cases. Further, the needle trajectory’s shortest distance to the pleura was only 10 (0‐27) mm, and in one case, it hit the pleura. Finally, the Raj line’s distance to the axillary vein was also short, 11 (0‐18) mm. We conclude that a modification of the method is necessary to guide the needle closer to the cords and further away from the pleura and the axillary vein. A more lateral needle insertion seems beneficial. Implications: Using a magnetic resonance scanner, the anatomical basis of Raj’s infraclavicular method for brachial plexus blockade was examined in volunteers. The results show that the method should be modified to make it more precise and to provide less risk of complications. (Anesth Analg 1999;88:593‐8)

AIM: To determine the optimal b value of diffusion-weighted imaging for detecting active inflammation in Crohn’s disease. METHODS: Thirty-one patients clinically diagnosed with active Crohn’s disease were referred for magnetic resonance examination. All patients were scanned on a 3.0T magnetic resonance scanner using the same protocol involving four different b values (800, 1500, 2000 and 2500 s/mm2). The diagnostic effect of diffusion-weighted imaging was evaluated and compared with endoscopic findings. The diffusion-weighted image quality of four b value groups was evaluated and apparent diffusion coefficient was measured for both normal and inflammatory intestinal segments. RESULTS: The contrast-to-noise ratio and signal-to-noise ratio were not satisfied when b value 2000 or 2500 s/mm2 was adopted (36.52 ± 14.95 vs 34.78 ± 24.83, P > 0.05; 53.58 ± 23.45 vs 47.58 ± 29.67, P > 0.05). The qualitative image quality was not enough to meet diagnostic requirement. No matter which b value was chosen, the apparent diffusion coefficient of inflammatory intestinal segments was significantly lower than that of normal intestinal segments (1.38 ± 0.28 vs 2.00 ± 0.38, P < 0.01; 1.09 ± 0.20 vs 1.50 ± 0.28, P < 0.01; 0.95 ± 0.19 vs 1.34 ± 0.28, P < 0.01; 0.88 ± 0.14 vs 1.20 ± 0.21, P < 0.01). The lesion detection rate (90.32%), diagnostic sensitivity (81.18%) and specificity (95.10%) would be appropriate when b value 1500 s/mm2 was adopted. CONCLUSION: High b value is suitable for intestinal DW examination on a high field MR scanner.

Regional in vivo proton magnetic resonance spectroscopy provides quantitative data on selected chemical constituents of brain. We imaged 16 volunteers with clinically definite multiple sclerosis on a 1.5 tesla magnetic resonance scanner to define plaque-containing volumes of interest, and obtained localized water-suppressed proton spectra using a stimulated echo sequence. Twenty-five of 40 plaque-containing regions provided spectra of adequate quality. Of these, 8 spectra from 6 subjects were consistent with the presence of cholesterol or fatty acids; the remainder were similar to those obtained from white matter of normal volunteers. This early experience with regional proton spectroscopy suggests that individual plaques are distinct. These differences likely reflect dynamic stages of the evolution of the demyelinative process not previously accessible to in vivo investigation.

Sixty-four patients with possible, probable, or definite multiple sclerosis (McAlpine criteria) were clinically evaluated using the expanded disability status scale (EDSS) and Scripps neurologic rating scale (NRS). All were examined with a 0.15T magnetic resonance scanner using T2- and T1-weighted images. Correlations between EDSS and NRS scores and severity of disease detected on magnetic resonance imaging were determined. Significant correlations existed between EDSS and NRS with magnetic resonance ratings. Moderate correlations were observed in the motor, cerebellar, and brainstem subgroups of the clinical scales. Significant low correlations existed in the mood/mentation, vision (optic nerves), and bowel/bladder subgroups. Clinical and neuroimaging limitations may account for the lack of higher correlations. Significant correlations suggest the utility of magnetic resonance imaging in monitoring disease progression, and it may prove to be the technique of choice in following up patients with multiple sclerosis.