Neuropathologic features in adults with 22q11.2 deletion syndrome.

The 22q11.2 deletion syndrome (22qDS) is the most common microdeletion syndrome in humans. Its multisystem manifestations include congenital anomalies and neuropsychiatric disorders such as schizophrenia.

Selective reduction of blood flow to white matter during hypercapnia corresponds with leukoaraiosis.

Background And Purpose: Age-related white matter disease (leukoaraiosis) clusters in bands in the centrum semiovale, about the occipital and frontal horns of the lateral ventricles, in the corpus callosum, and internal capsule. Cerebrovascular anatomy suggests that some of these locations represent border zones between arterial supply territories. We hypothesized that there are zones of reduced cerebrovascular reserve (susceptible to selective reductions in blood flow, ie, steal phenomenon) in the white matter of young, healthy subjects, the physiological correlate of these anatomically defined border zones.

Mapping cerebrovascular reactivity using blood oxygen level-dependent MRI in Patients with arterial steno-occlusive disease: comparison with arterial spin labeling MRI.

Background And Purpose: Blood oxygen level-dependent MRI (BOLD MRI) of hypercapnia-induced changes in cerebral blood flow is an emerging technique for mapping cerebrovascular reactivity (CVR). BOLD MRI signal reflects cerebral blood flow, but also depends on cerebral blood volume, cerebral metabolic rate, arterial oxygenation, and hematocrit. The purpose of this study was to determine whether, in patients with stenoocclusive disease, the BOLD MRI signal response to hypercapnia is directly related to changes in cerebral blood flow.

Comparison of the effects of independently-controlled end-tidal PCO(2) and PO(2) on blood oxygen level-dependent (BOLD) MRI.

Purpose: To assess the effect of changes in end-tidal partial pressure of O(2) (PETO(2)) on cerebrovascular reactivity (CVR) estimated from changes in blood oxygen level-dependent (BOLD) signal during cyclic changes in end-tidal partial pressure of CO(2) (PETCO(2)).

Materials And Methods: BOLD response to fixed cyclic step changes in PETCO(2) (range = 30.4-48.

Cerebral white matter deficiencies in pedophilic men.

The present investigation sought to identify which brain regions distinguish pedophilic from nonpedophilic men, using unbiased, automated analyses of the whole brain. T1-weighted magnetic resonance images (MRIs) were acquired from men who demonstrated illegal or clinically significant sexual behaviors or interests (n = 65) and from men who had histories of nonsexual offenses but no sexual offenses (n = 62). Sexual interest in children was assessed by participants' admissions of pedophilic interest, histories of committing sexual offenses against children, and psychophysiological responses in the laboratory to erotic stimuli depicting children or adults.

Evidence of brain mitochondrial activities after oxygen inhalation by 31P magnetic resonance spectroscopy at 3T.

The purpose of this study was to explore mitochondrial activities after oxygen inhalation by 31P magnetic resonance spectroscopy. Six healthy volunteers were studied using a GE 3T scanner. A spin-echo MRS sequence was utilized with a GE service coil.

Prediction of hemorrhagic transformation after acute ischemic stroke using hyperintense MCA sign.

Purpose: The hyperintense appearance of the middle cerebral artery (HMCA) sign consists of a thickened MCA stem with a blurred intense signal on contrast enhanced T1-weighted magnetic resonance imaging (T1W MRI). In this article, we define it and determine its incidence, diagnostic value, and reliability by comparison with magnetic resonance angiography and digital subtraction angiography. MATERIALS AND METHIODS: Non-contrast CT and immediately subsequent MRI were performed on 30 consecutive patients with acute ischemic stroke within 6 hours after symptom onset.

Combination 3D TOP with 2D PC MRA Techique for cerebral blood flow volume measurement.

To demonstrate the discrepancy of cerebral blood flow volume (BFV) estimation with 2D phase-contrast (2D PC) MRA guided with 3D time-of-flight (3D TOF) MR localization by using an "internal" standard. 20 groups of the common (CCA), internal (ICA), and external (ECA) carotid arteries in 10 healthy subjects were examined with 2D PC MRA guided by 3D TOF MR angiograms. The sum BFV of the internal and external carotid arteries was then compared with the ipsilateral common carotid artery flow.

Can we use 1H MRS shimming values to obtain 31P spectra?

The perfect shimming of 31P magnetic resonance spectroscopy (MRS) is not easy in vivo. The purpose of this study was to examine the feasibility of using 1H MRS shimming values to obtain 31P spectra in a same sequence. Both phantom and volunteer studies were carried out in this study.

Neuro MR: protocols.

Clinical MRI depends on a symbiosis between MR physics and clinical requirements. The imaging solutions are based on a balance between the "palette" of available image contrasts derived from nuclear spin physics and tissue biophysics, and clinical determinants such as the anticipated pathology and efficient use of imaging time. Imaging is therefore optimized to maximize diagnostic sensitivity and specificity through the development of protocols organized along the lines of major disease categories.

The venous distension sign: a diagnostic sign of intracranial hypotension at MR imaging of the brain.

Background And Purpose: Patients with intracranial hypotension (IH) demonstrate intracranial venous enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from the normal appearance of this segment, which usually has a slightly concave or straight lower margin.

A quantitative and reproducible method to assess cord compression and canal stenosis after cervical spine trauma: a study of interrater and intrarater reliability.

Study Design: Reliability study.

Objective: To assess the intrarater and interrater reliability of a recently described technique to measure of maximum canal compromise (MCC) and maximum spinal cord compression (MSCC) using digitized and magnified images in the setting of traumatic cervical spinal cord injury (SCI).

Summary Of Background Data: The extent of MCC and MSCC is of clinical and prognostic value in the setting of traumatic cervical SCI.

Neuro MR: principles.

The principles of contrast mechanisms and fast pulse sequences underlying neurological and neuroradiological application of MRI are introduced in this part of a two-part review. In particular, the relaxation time constants T(1), T(2), and T(2) (*) are introduced, along with pulse sequences harnessing their contrast, spin-echo, fast spin echo (FSE), inversion recovery (IR), gradient recalled echo (GRE), and echo planar imaging (EPI). The use of gadolinium (Gd)-based contrast is discussed in both T(1)- and T(2) (*)-weighted sequences.

Sensorimotor cortical plasticity during recovery following spinal cord injury: a longitudinal fMRI study.

Background: Although the consequences of spinal cord injury (SCI) within the spinal cord and peripheral nervous system have been studied extensively, the influence of SCI on supraspinal structures during recovery remains largely unexplored.

Objective: To assess temporal changes in cortical sensorimotor representations beginning in the subacute phase following SCI and determine if an association exists between the plastic changes within cortical sensorimotor areas and recovery of movement postinjury.

Methods: Functional magnetic resonance imaging (fMRI) was used to study 6 SCI patients for 1 year, beginning shortly postinjury, and 10 healthy control individuals.

Visual-spatial ability and fMRI cortical activation in surgery residents.

Background: We previously reported that a particular type of visual-spatial ability, mental rotation of visual forms, correlates with surgical performance in residents. In the current study, we used functional magnetic resonance imaging (fMRI) to identify patterns of cortical activation associated with mental rotation ability in those same residents.

Methods: Seventeen surgery residents underwent fMRI scan while performing a mental rotations test (MRT) and a perceptual matching task as a control (CON) for nonimagery components, such as visual attention.

Tumor effects on cerebral white matter as characterized by diffusion tensor tractography.

Background: Diffusion tensor MRI fiber tractography (DTT) is the first non-invasive in vivo technique for delineating specific white matter (WM) tracts. In cerebral neoplasm, DTT can be used to illustrate the relationship of the tumor with respect to adjacent WM trajectories.

Methods: Fiber tractography was used in this study to assess tumor-induced changes in WM trajectories in three cases of cerebral neoplasm: glioblastoma multiforme, meningioma, and anaplastic astrocytoma.

Construction of Optimal Velocity Encoding for Cerebral Blood Flow Volume Measurement with Phase-Contrast MRA.

Purpose: Accurate velocity encoding is crucial for quantification of arterial inflow and venous outflow in intracranial diseases. The purpose of this study was to optimize the velocity encoding of phase-contrast (PC) MRA and quantify cerebral blood flow in normal volunteers.

Methods: Ten healthy volunteers were examined on a GE 1.

Improving spatial signal homogeneity in MR 2D chemical shift imaging using outer volume saturation bands.

Many endeavors of improving chemical shift imaging (CSI) techniques have been made during last two decades. Good examples of two-dimensional CSI and three-dimensional CSI can be found in the literature. However, clinical CSI using available sequences is still not satisfactory.

In vivo MRI of cancer cell fate at the single-cell level in a mouse model of breast cancer metastasis to the brain.

Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single-cell level.

Off-pump coronary bypass surgery: risk of ischemic brain lesions in patients with atheromatous thoracic aorta.

Purpose: The purpose of this study was to determine if there is an association between the proximal thoracic aortic (ascending aorta and aortic arch) atheroma and ischemic brain lesions on diffusion-weighted magnetic resonance imaging (DW-MRI) after on-pump (ONCAB) and off-pump (OPCAB) coronary artery bypass surgery.

Methods: Patients who underwent ONCAB surgery (n = 13) and who had aortic atheroma > 2 mm were compared to a risk-adjusted prospective cohort of patients (n = 13) undergoing OPCAB surgery. Transesophageal echocardiography and epiaortic scanning were performed to assess the proximal thoracic aorta.

Focal Lesion in Splenium of Corpus Callosum on FLAIR MRI: Common Findings in Aged Patients.

Focal high signal intensity in the splenium of the corpus callosum on fluid-attenuated inversion-recovery (FLAIR) images is generally considered an abnormal MR finding. The aim of this study was to determine the frequency of this finding in elderly patients and review the differentiation from other diseases with the similar findings. FLAIR images of 132 patients with suspect CNS disease were retrospectively reviewed.

Separate brain regions code for salience vs. valence during reward prediction in humans.

Predicting rewards and avoiding aversive conditions is essential for survival. Recent studies using computational models of reward prediction implicate the ventral striatum in appetitive rewards. Whether the same system mediates an organism's response to aversive conditions is unclear.

Idiopathic intracranial hypertension: the validity of cross-sectional neuroimaging signs.

The aim of this study was to evaluate the accuracy of previously reported neuroimaging signs in establishing or excluding the diagnosis of idiopathic intracranial hypertension (IIH). In a retrospective study, 30 patients with confirmed IIH and 56 controls were evaluated with brain magnetic resonance imaging. All examinations were evaluated in a blinded fashion by three neuroradiologists for the presence or absence of the 'traditional' signs of IIH: empty sella turcica, deformation of the pituitary, slit-like ventricles, 'tight' subarachnoid spaces, flattening of the posterior globe, protrusion of the optic nerve, enhancement of the optic nerve head, distension of the optic nerve sheath and vertical tortuosity of the optic nerve.