Schizophrenia syndromes associated with changes in ventricle-to-brain ratios: a serial high-resolution three-dimensional magnetic resonance imaging study in first-episode schizophrenia patients using subvoxel registration and semiautomated quantification.

A cohort of patients with first-episode schizophrenia was dichotomised into two age- and sex-matched groups of clinical syndromes, the active and withdrawn, and underwent high-resolution three-dimensional magnetic resonance imaging at baseline and 8 months later. A cohort of age- and sex-matched normal controls was also imaged at the same time intervals. The application of subvoxel registration and semiautomated quantification techniques demonstrated a significantly different outcome in ventricular changes between the two groups of patients.

Changes in brain size in hepatic encephalopathy: a coregistered MRI study.

Magnetic resonance imaging (MRI) coregistration techniques can be used to track changes in brain volume. We aimed to determine whether treatment in chronic liver disease altered brain size. The study group comprised nine patients with cirrhosis (7 Child's grade B and 2 Child's grade C).

Magnetic resonance imaging in preeclampsia and eclampsia complicated by visual disturbance and other neurological abnormalities.

This study describes magnetic resonance imaging findings in women presenting with neurological complications associated with preeclampsia and eclampsia. One eclamptic and two preeclamptic women were studied after presenting with postpartum neurological events. In two women the brain increased in size on the initial follow-up images, following the same pattern seen in normal pregnancy.

Fatigue and primary biliary cirrhosis: association of globus pallidus magnetisation transfer ratio measurements with fatigue severity and blood manganese levels.

Background And Aim: Fatigue is the commonest symptom in primary biliary cirrhosis (PBC), affecting individuals at all stages of disease. The pathogenesis of fatigue in PBC is unknown although rat models suggest a central nervous system (CNS) cause. We examined the hypothesis that a CNS abnormality related to cholestasis, rather than cirrhosis per se, underlies this symptom.

Magic angle imaging of the achilles tendon in patients with chronic tendonopathy.

Aims: To assess the Achilles tendon in patients with chronic tendonopathy using magnetic resonance (MR) magic angle imaging, and to compare the appearances and uptake of contrast medium in abnormal tendons with those in normal tendons.

Material And Methods: Eight patients with chronic Achilles tendonopathy and five normal controls were examined with the long axis of the tendon placed at 55 degrees and at 0 degrees to the main magnetic field. Conventional two-dimensional (2D) multi-slice images were obtained and T1 values were calculated before, and for up to 1h after the administration of intravenous gadodiamide.

Subvoxel image registration of multislice (2D) magnetic resonance images in patients with high-grade gliomas of the brain.

Aims: To implement a multislice two-dimensional (2D) T2-weighted sequence suitable for subvoxel image registration and to assess its usefulness in detecting change in high-grade intracranial gliomas.

Materials And Methods: Twenty patients with high-grade gliomas were studied on two or more occasions. T2-weighted multislice pulse sequences with a Gaussian slice profile, 50% overlapping slices and nearly isotropic voxels were acquired.

Changes in brain size with treatment in patients with hyper- or hypothyroidism.

Background And Purpose: Although neuropsychological symptoms and signs are common in thyroid disease, their organic substrate is unknown. We performed brain MR imaging in patients with hyperthyroidism or hypothyroidism before and after treatment and correlated the results with hormonal markers.

Methods: Eight patients with hyperthyroid disease and three with hypothyroid disease underwent imaging within 1-2 days of a thyroid hormone testing.

Contrast-enhanced magic-angle MR imaging of the Achilles tendon.

Objective: The objective of this study was to image the Achilles tendon with MR imaging at the magic angle (the long axis of the tendon at 55 degrees relative to the direction of the main static magnetic field [B(0)]) to detect signal from the tendon, to measure the T1 of the tendon, and to determine patterns of contrast enhancement in control subjects and patients.

Conclusion: Mean T1 values of 311 +/- 30 msec (at 1.0 T) were found in six volunteers.

Change in brain size during and after pregnancy: study in healthy women and women with preeclampsia.

Background And Purpose: Qualitative decreases in maternal brain size have been observed late in pregnancy. The aim of this study was to quantitatively evaluate changes to the maternal brain during and after healthy pregnancy and to compare these changes with those observed in cases of preeclampsia.

Methods: Three-dimensional T1-weighted MR volume images were obtained in nine healthy participants before and after delivery.

Magnetic resonance: magic angle imaging of the Achilles tendon.

Tendons do not normally produce detectable signals with conventional magnetic-resonance techniques and are recognised as dark signal voids. However, if tendons are examined at 55 degrees to the static magnetic field (the "magic angle"), signals become detectable and the tendons can become the brightest structure on the image. We have used this approach to establish tendon relaxation times and magnetisation transfer ratios and to show contrast enhancement.

FLAIR imaging using nonselective inversion pulses combined with slice excitation order cycling and k-space reordering to reduce flow artifacts.

High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered by Inversion-time for each Slice Position" (KRISP) to achieve constant contrast in a multislice acquisition. Theory shows that with this method the CSF point spread function (PSF) has a minimum at the center and attenuated side lobes, providing CSF suppression, but residual edge signals remain.

Contributions of an adiabatic initial inversion pulse and K-space re-ordered by inversion-time at each slice position (KRISP) to control of CSF artifacts and visualization of the brain in FLAIR magnetic resonance imaging.

Aim: The aim of this study was to compare the performance of three fluid attenuated inversion recovery (FLAIR) pulse sequences for control of cerebrospinal fluid (CSF) and blood flow artifacts in imaging of the brain. The first of these sequences had an initial sinc inversion pulse which was followed by conventional k-space mapping. The second had an initial sinc inversion pulse followed by k-space re-ordered by inversion time at each slice position (KRISP) and the third had an adiabatic initial inversion pulse followed by KRISP.

Reduction of CSF and blood flow artifacts on FLAIR images of the brain with k-space reordered by inversion time at each slice position (KRISP).

Background And Purpose: Our purpose was to test a new variant of the fluid-attenuated inversion-recovery (FLAIR) sequence that was designed to reduce CSF and blood flow artifacts by use of a non-slice-selective inversion pulse and k-space reordered by inversion time at each slice position (KRISP).

Methods: With the KRISP FLAIR sequence, the slice order was cycled so that each inversion time (TI) was associated with a region of k-space rather than a particular slice, and the effective inversion time (TI(eff)) was chosen to null the signal from CSF. Scans were obtained with both conventional and KRISP FLAIR sequences.

A serial longitudinal quantitative MRI study of cerebral changes in first-episode schizophrenia using image segmentation and subvoxel registration.

Lateral ventricular enlargement is the most consistently replicated brain abnormality found in schizophrenia. This article reports a first episode, longitudinal study of ventricular volume using high-resolution serial magnetic resonance imaging (MRI) and recently developed techniques for image registration and quantitation. Baseline and follow-up (on average 8 months later) MRI scans were carried out on 24 patients and 12 controls.

Evaluation of a FLAIR sequence designed to reduce CSF and blood flow artifacts by use of k-space reordered by inversion time at each slice position (KRISP) in high grade gliomas of the brain.

The objective of this study was to compare conventional and KRISP (k-space reordered by inversion time at each slice position) fluid-attenuated inversion recovery (FLAIR) sequences in high grade gliomas for artifact control, conspicuity of intracranial structures, and lesions as well as sensitivity to contrast enhancement. Artifacts were lower with the KRISP FLAIR sequence, and the conspicuity of all assessed structures and lesions was better. The degree of contrast enhancement was similar with T1-weighted and KRISP FLAIR sequences.

Reduction of CSF artifacts on FLAIR images by using adiabatic inversion pulses.

The purpose of this study was to investigate the possibility that some artifactual high signals produced in CSF with fluid-attenuated inversion-recovery MR sequences could be due to inhomogeneity in the amplitude of the initial inversion pulse, and that this problem could be reduced or eliminated by the use of adiabatic inversion pulses. Studies with four volunteers showed dependence of high CSF signals in the posterior fossa on radiofrequency pulse amplitudes and that these signals could be eliminated by the use of adiabatic inversion pulses. Two illustrative clinical cases are included.

Eicosapentaenoic acid treatment in schizophrenia associated with symptom remission, normalisation of blood fatty acids, reduced neuronal membrane phospholipid turnover and structural brain changes.

The administration of the omega-3 fatty acid eicosapentaenoic acid (EPA) to a drug-naive patient with schizophrenia, untreated with conventional antipsychotic medication, led to a dramatic and sustained clinical improvement in both positive and negative symptoms. This was accompanied by a correction in erythrocyte membranes of abnormalities in both n-3 and n-6 highly unsaturated fatty acids and with reduced neuronal membrane phospholipid turnover, as evidenced by serial 31-phosphorus cerebral magnetic resonance spectroscopy. Using recently developed techniques of image segmentation, subvoxel registration and quantitation, analysis of serial high-resolution 3D cerebral MRI scans showed that, in the year before EPA treatment, cerebral atrophy was taking place and that this atrophy was reversed by six months of EPA treatment.

Cerebral ventricular asymmetry in schizophrenia: a high resolution 3D magnetic resonance imaging study.

Lateral ventricular volume asymmetries in schizophrenia were studied using high resolution 3D magnetic resonance imaging in conjunction with segmentation and quantitation techniques. Comparisons were made between two clinical syndromes that have been associated with opposite patterns of functional hemispheric activation, namely an active and a withdrawn syndrome. Ratios of both left to right ventricular volume and left to right ventricle-to-brain ratios differed significantly between the two groups.

Cerebral bioenergetics in stable chronic obstructive pulmonary disease.

Cerebral intracellular energy production (cerebral bioenergetics) via oxidative phosphorylation and the production of adenosine triphosphate (ATP) is critical to cerebral function. To test the hypothesis that patients with chronic stable hypoxia also generate neuronal ATP via an anaerobic metabolism, we studied the changes in cerebral (31)P magnetic resonance spectra ((31)P MRS) in patients with stable chronic obstructive pulmonary disease (COPD), and compared the results with MR spectra from similar areas of the brain in control subjects. Ten patients with stable COPD (age: 65 +/- 9 yr [mean +/- SD]; Pa(O(2)): 8.

Two methods for semi-automated quantification of changes in ventricular volume and their use in schizophrenia.

Two semi-automated methods for quantification of ventricular volume change from baseline and follow-up magnetic resonance imaging scans have been developed. Technique 1 employs direct segmentation of the ventricles from both the scans using thresholding and contour extraction. Technique 2 operates on difference images produced by voxel based intensity subtraction of the baseline from the registered follow-up images.

Regions of interest tracking in temporal scans based on statistical analysis of gray scale and edge properties and registration of images.

Precise measurement of T1 is needed for its use in temperature monitoring in vivo. Movement of tissue relative to fixed regions of interest can result in large variations in apparent T1, with consequent substantial errors in the measured temperature. This paper evaluates methods of tracking regions of interest as tissue moves during a study in an effort to minimize errors from this cause.

Cerebral swelling after normothermic cardiopulmonary bypass.

Background: Marked cerebral swelling visible on magnetic resonance images has been found immediately after hypothermic (28 degrees C) cardiopulmonary bypass. The mechanism is unknown, but indices of cerebral ischemia are seen during rewarming from hypothermic bypass that are not present with normothermic bypass (37 degrees C).

Methods: T1-weighted and fluid-attenuated inversion recovery magnetic resonance images were taken of seven patients undergoing routine coronary artery bypass surgery before, 1 h, and 7 days after the operation using normothermic bypass.