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At least 397 records · Page 22Linked to original sources
PubMed1993

Magnetic resonance imaging of the elbow.

With the current popularity of racket and throwing sports, the number of individuals seeking medical care for elbow pain and dysfunction has increased rapidly. Before the development and implementation of magnetic resonance imaging (MRI), radiologic imaging examinations provided the treating physician limited information to determine the precise etiology of elbow disorders, because they usually involve soft-tissue structures. With MRI, it is now possible to accurately assess the integrity of the ligaments, tendons, and muscles surrounding the elbow, and to detect pathologic changes in these tissues secondary to acute macrotrauma or chronic microtrauma, e.g., overuse injuries. By defining the nature and extent of these abnormalities, the choice of the appropriate therapeutic regimen is facilitated. With MRI, it is also now possible to noninvasively evaluate the natural history of these soft-tissue disorders and to determine the effects of different therapeutic interventions.

Elbow Joint↗
PubMed2006

Clinical and imaging study of human immunodeficiency virus-1-infected youth receiving highly active antiretroviral therapy: pilot study using magnetic resonance spectroscopy.

In the initial assessment of children with new-onset seizures, the suggestion that electroencephalography (EEG) should be standard and that magnetic resonance imaging (MRI) should be optional has been questioned. The purposes of this children (four boys) with vertically transmitted stable HIV infection had a neurologic examination, neuropsychologic testing, and a neuroimaging study. The structural magnetic resonance imaging (MRI) and metabolic changes (magnetic resonance spectroscopy) were compared with the cognitive, clinical, and laboratory results. Our results for the eight children who completed the magnetic resonance spectroscopic study showed that a high N-acetylaspartate (NAA) to choline ratio correlated significantly with IQ subtests of arithmetic (r = .74; P < .034) and comprehension (r = .77; P = .025). Our results suggest that lower NAA and higher choline values represent neuronal dysfunction and inflammation that can be recognized before anatomic changes appear on MRI. In addition, a low NAA to Cho ratio correlated with poor performance. These data suggest that magnetic resonance spectroscopy can be used as a follow-up tool in addition to the structural MRI. Moreover, a change in a child's performance with a concomitant change in NAA and choline, as measured with magnetic resonance spectroscopy, could indicate the need for more aggressive intervention.

Adolescent↗
PubMed1998

Physiologic MRI of a tumefactive multiple sclerosis lesion.

Structural and physiologic MRI were performed after subacute onset of left hemiparesis in a patient with MS. MRI showed a large ring-enhancing lesion with surrounding edema and mass effect; differential diagnosis included a neoplasm or a large MS plaque. Physiologic MRI showed reduced blood flow and magnetization transfer, as well as increased diffusion, in the large lesion. Because these findings suggested a tumefactive MS plaque rather than a neoplasm, the patient received steroid treatment for acute MS exacerbation. Three months later the patient improved clinically and on MRI.

Adult↗
PubMed1999

Gender differences in temporal lobe structures of patients with schizophrenia: a volumetric MRI study.

OBJECTIVE: The temporal lobe and associated structures have been previously implicated in the neuroanatomy of schizophrenia. This study was designed to assess the potential influence of gender on the morphology of temporal lobe structures, including the superior temporal gyrus and the amygdala/hippocampal complex, in patients with schizophrenia and to examine whether schizophrenic patients differ morphologically in these structures from comparison subjects. METHOD: Magnetic resonance imaging was used to measure the volume of temporal lobe structures, including the superior temporal gyrus, the amygdala/hippocampal complex, and the temporal lobe (excluding the volumes of the superior temporal gyrus and amygdala/hippocampal complex), and two comparison areas--the prefrontal cortex and caudate--in 36 male and 23 female patients with schizophrenia and 19 male and 18 female comparison subjects. RESULTS: There was a significant main effect of diagnosis in the superior temporal gyrus and the amygdala/hippocampal complex, with smaller volumes in patients than in comparison subjects. There was a significant gender-by-diagnosis-by-hemisphere interaction for temporal lobe volume. Temporal lobe volume on the left was significantly smaller in male patients than in male comparison subjects. Female patients and female comparison subjects demonstrated no significant difference in temporal lobe volume. There were no statistically significant gender interactions for the superior temporal gyrus, the amygdala/hippocampal complex, or the comparison regions. CONCLUSIONS: These findings suggest that there may be a unique interaction between gender and the pathophysiologic processes that lead to altered temporal lobe volume in patients with schizophrenia.

Adult↗
PubMed1992

[Efficacy of magnetic resonance imaging in treatment of neuroblastoma].

Magnetic resonance imaging (MRI) was performed in 36 children with neuroblastoma at Chiba University from 1984 through 1989, and 29 patients of them were discussed about efficacy of MRI in treatment of neuroblastoma in this paper and the results were as follows. 1) MRI was difficult to differentiate tumor from normal kidney in the image intensity and was more efficient in determining the relationship of tumor to liver and to vascular structures. 2) MRI was better than CT in detecting the size and extent of tumor mass and in identifying lymph node spread using multiple planes. 3) MRI was more efficient than CT in defining displacement and encasement of renal vessels by tumor. It was useful to predict to reserve kidney before surgery. 4) MRI was useful to monitor tumor response to combined modalities of therapy. A favorable response was seen as a change in the image intensity in bone marrow metastases of neuroblastoma.

Adrenal Gland Neoplasms↗
PubMed1994

[The role of magnetic resonance in studying hypertrophic cardiomyopathy: the echocardiographic correlations and clinical implications].

Clinical studies evaluating the role of magnetic resonance imaging (MRI) in patients with hypertrophic cardiomyopathy are scanty. To assess the capability of MRI to define the presence, distribution and severity of left ventricular hypertrophy, the prevalence and clinical implications of right ventricular hypertrophy, the prevalence and clinical implications of myocardial structural abnormalities, MRI and echocardiography were performed in 37 unselected patients (age 10-72 years, mean 38 +/- 19) with hypertrophic cardiomyopathy. The concordance between the two methods was 100% in the diagnosis and classification of left ventricular hypertrophy as asymmetric, concentric or apical. A significant linear correlation was found between echocardiography and MRI measurements of interventricular septum (r = 0.69, p < 0.0001, SEE = 4) and left ventricular posterior wall (r = 0.67, p < 0.0001, SEE = 2.4). Right ventricular hypertrophy (right anterior wall diastolic thickness > 5 mm) was disclosed by MRI in 23/33 patients (70%). In this group, left posterior wall thickness and left atrial diameter were higher (15 +/- 4 versus 11 +/- 2 mm, p < 0.01 and 45 +/- 9 versus 38 +/- 5 mm, p < 0.05 respectively). On T2 weighted sequences, areas of reduction of signal intensity, probably caused by myocardial fibrosis, were detected in 16 cases (43%). This group was characterized by a higher value in maximal septal thickness (26 +/- 7 versus 21 +/- 6 mm, p < 0.05) and in maximal left posterior wall thickness (15 +/- 9 versus 7 +/- 8 mm, p < 0.01). All the 3 cases with dilated and hypokinetic left ventricle showed this type of tissue abnormality.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Periureteric effects of electromagnetic shock waves.

The effect of electromagnetic shock waves on the ureter and periureteric soft tissue was investigated in 10 patients who underwent extracorporeal shock wave lithotripsy (ESWL) for lower ureteric stones. Seven patients were males and 3 females, their ages ranged between 15 and 52. The number of shock waves applied varied between 3000 and 6000, at a mean of 19 kV. The patients were examined after their first ESWL. Magnetic resonance imaging (MRI) was performed within 6 hours of treatment by a Magnetom 1 Tesla Unit. No haematoma, fluid collection or abnormality was detected in the periureteric space, muscle or surrounding structures by MRI. Although subcapsular, intra- or perirenal haematomas can be observed in patients with kidney stones treated with ESWL, it appears to be safe for lower ureteric stones.

Adolescent↗
PubMed1993

Cortical atrophy and other brain magnetic resonance imaging (MRI) changes after extremely high-altitude climbs without oxygen.

The purpose of the present study is to detect by means of MRI any structural changes in the brain and their correlation with the clinical history of climbers who have ascended to extremely high altitudes without supplementary oxygen. Clinical history, neurological examinations and brain MRI were obtained from a group of 26 climbers who ascended to over 7000 m without supplementary oxygen, and the results were compared with a control group (n = 21) of healthy subjects. All the MRI studies were carried out between 26 days and 36 months after return to sea level. Significant neuropsychological disorders were experienced by all climbers during the ascent with residual neurobehavioural impairment after returning to sea level in 58% of them. The neurological examination was normal in all subjects. Almost half of the climbers showed MRI abnormalities (46%). Characteristic signal patterns of cortical atrophy were detected in five subjects. Periventricular hyperintensity lesions in the T2-weighted images were observed in other five climbers. Both types of lesions were found in two subjects. These pathological findings did not correlate with age, sex, clinical symptoms, maximal altitude reached, or length of exposure to extreme altitude. The exact long-term pathological significance of these MRI abnormalities is as yet unknown.

Adult↗
PubMed1993

Do thalamic lesions really cause vertical gaze palsies?

Two patients with thalamic infarctions presented with vertical gaze palsies. Magnetic resonance imaging (MRI) demonstrated extension of the lesions into the upper midbrain. A common vascular supply to both areas, and the inability of computed tomography (CT) scans to adequately assess posterior fossa structures, necessitate MRI of the mesencephalon in the assessment of all patients with vertical gaze dysfunction. These cases shed further doubt regarding a specific role of the thalamus in control of vertical eye movements.

Adult↗
PubMed2005

Contralateral hemimicrencephaly and clinical-pathological correlations in children with hemimegalencephaly.

In paediatric epilepsy surgery patients with hemimegalencephaly (HME; n = 23), this study compared clinical, neuroimaging and pathologic features to discern potential mechanisms for suboptimal post-hemispherectomy developmental outcomes and structural pathogenesis. MRI measured affected and non-affected cerebral hemisphere volumes for HME and non-HME cases, including monozygotic twins where one sibling had HME. Staining against neuronal nuclei (NeuN) determined grey and white matter cell densities and sizes in HME and autopsy cases, including the non-affected side of a HME surgical/autopsy case. By MRI, the affected hemisphere was larger and the non-affected side smaller in HME compared with non-HME children. The affected HME side showed enlarged abnormal deep grey and white matter structures and/or T2-weighted hypointensity in the subcortical white matter in 75% of cases, suggestive of excessive pre-natal neurogenesis and heterotopias. Histopathological examination of the affected HME side revealed immature-appearing neurons in 70%, polymicrogyria (PMG) in 61% and balloon cells in 45% of cases. Compared with autopsy cases, in HME children NeuN cell densities on the affected side were increased in the molecular layer and upper cortex (+244 to +18%), decreased in lower cortical layers (-35%) and increased in the white matter (+139 to +149%). Deep grey matter MRI abnormalities and/or T2-weighted white matter hypointensity correlated with the presence of immature-appearing neurons and PMG on histopathology, decreased NeuN cell densities in lower cortical layers and a positive history of infantile spasms. Post-surgery seizure control was associated with decreased NeuN densities in the molecular layer. In young children with HME and epilepsy, these findings indicate that there are bilateral cerebral hemispheric abnormalities and contralateral hemimicrencephaly is a likely explanation for poorer post-surgery seizure control and cognitive outcomes. In addition, our findings support the hypothesis that HME pathogenesis probably involves somatic mutations that affect each developing cerebral hemisphere differently with more neurons than expected on the HME side.

Antigens, Nuclear↗
PubMed1999

[Imaging of syringomyelia].

MRI is the best imaging method to evaluate syringomyelia. It is important to study from the posterior cranial fossa to the sacro-lumbar region and also the supra-tentorial structures. This complete analysis is essential to classify the syringomyelia and to investigate other associated malformations. Radiographs and CT scan are useful to analyze bone structures. For MRI, the new sequences with phased-array coils are also very important to study the entire spinal cord and the posterior fossa. It is essential to study the spinal cord with sagittal and axial spin echo T1 and fast spin echo T2 weighted images with sometimes coronal view, particularly when the patient presents a scoliosis, to have a correct morphological and functional evaluation. MRI gives an excellent study of the spinal cord with an excellent analysis of a primitive or foraminal syringomyelia, but also traumatic, infectious or post arachnoiditis syringomyelia. Spin echo T1 weighted images with injection of gadolinium can be used if an intra-medullary tumor is suspected. MRI is also useful for the post-operative follow up to evaluate the persistence of the medullary cyst and the enlargement of the foramen magnum.

Brain↗
PubMedDate not supplied

MRI study of posterior fossa structures and brain ventricles in bipolar patients.

Previous brain imaging studies have suggested anatomical abnormalities in posterior fossa structures and brain ventricles in bipolar patients. Such abnormalities could possibly be implicated in the pathophysiology of bipolar disorder. Twenty-two DSM-IV bipolar outpatients (mean age+/-S.D.=36+/-10 years) and 22 healthy controls (mean age+/-S.D.=38+/-10 years) underwent an 1.5T MRI (3D-gradient echo-imaging SPGR), performed in the coronal plane (TR=25 ms, TE=5 ms, slice thickness=1.5 mm). The brain structures of interest were traced blindly with a semi-automated software. No significant differences were found between bipolar patients and healthy controls for any posterior fossa measures, or for measures of third or lateral ventricles (MANOVA, age covariate, P>0.05). Age was directly correlated with 3rd ventricle volumes in bipolar patients (Pearson correlation coefficient=0.458, P=0.032), but not in healthy controls (Pearson correlation coefficient=0.313, P=0.155). There was a significant direct correlation between the number of prior illness episodes and right lateral ventricle volumes (Partial correlation coefficient=0.658, P=0.011). Familial patients had smaller left and right cerebellar hemispheres and total vermis volumes, and larger left lateral ventricle volumes compared with non-familial ones (MANOVA, age covariate, P<0.05). In this preliminary study, we were not able to replicate previous findings of abnormalities in cerebellum or brain ventricles in bipolar individuals. However, there were suggestions that abnormalities in cerebellum, vermis, and lateral ventricle sizes may be present in familial cases of the disorder, which should be further examined in future studies with larger patient samples.

Adult↗
PubMed1996

Cerebral perfusion abnormalities in therapy-resistant epilepsy in childhood: comparison between EEG, MRI and 99Tcm-ECD brain SPET.

We performed 99Tcm-ethyl cysteinate dimer (ECD) interictal single photon emission tomography (SPET) in 26 children with severe therapy-resistant epilepsy. All the children underwent a detailed clinical examination, an electroencephalogram (EEG) investigation and brain magnetic resonance imaging (MRI). In 21 of the 26 children, SPET demonstrated brain blood flow abnormalities, in 13 cases in the same territories that showed EEG alterations. MRI showed structural lesions in 6 of the 26 children, while SPET imaging confirmed these abnormalities in only 5 children. The lesion not detected on SPET was shown to be 3 mm thick on MRI. Five symptomatic patients had normal SPET. In one of these patients, the EEG findings were normal and MRI revealed a small calcific nodule (4 mm thick); in the others, the EEG showed non-focal but diffuse abnormalities. These data confirm that brain SPET is sensitive in detecting and localizing hypoperfused areas that could be associated with epileptic foci in this group of patients, even when the MRI image is normal.

Adolescent↗
PubMedDate not supplied

Computed tomography and magnetic resonance imaging of cavernous sinus enlargement in a dog with unilateral exophthalmos.

Computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) were performed on a dog with a two year history of unilateral exophthalmos occurring two years following head trauma. On CT images, an expansile enhancing mass was present along the right intracranial cavernous sinus and extended through the orbital fissure into the retrobulbar space. With MRI, the structure appeared as a signal void due to the presence of rapidly flowing blood. Gadolinium enhancement of the adjacent brain was not present. A vascular origin of the lesion was confirmed with MRA. Based on the CT and MRI findings, the enlarged cavernous sinus and associated ophthalmic plexus were believed to represent an arterialized aneurysm, most likely the result of traumatic arteriovenous fistulization. Treatment consisted of surgical enucleation. At the time of this report, 29 months later, the dog remains free of clinical signs.

Animals↗
PubMed1995

FDG-PET and volumetric MRI in the evaluation of patients with partial epilepsy.

We performed interictal FDG-PET- and MRI-based hippocampal volumetric measurements on 18 adult patients with complex partial epilepsy of temporal lobe origin in whom we had identified their ictal focus by video-telemetry EEG. Sixteen patients (89%) had regional hypometabolism, 11 (61%) had focal 1.5-tesla T2-weighted MRI (two structural abnormalities, nine hippocampal formation [HF] increased T2 signal), and nine (50%) had absolute HF atrophy ipsilateral to the temporal ictal focus. Ten (55%) had abnormal L/R HF ratios, nine ipsilateral to the EEG focus. All patients with abnormal MRI volumetric studies had focal PET abnormalities. Only seven had both abnormal HF volume ratios and T2 MRI (all increased HF T2 signal). There was a significant correlation between hippocampal volume and inferior mesial and lateral temporal lobe cerebral metabolic rate of glucose asymmetry index (p < 0.01), suggesting that hypometabolism may reflect hippocampal atrophy. PET is more sensitive than MRI volumetry in identifying the ictal focus but does not provide additional information when HF atrophy is present.

Adolescent↗
PubMedDate not supplied

Intraosseous cholesterol granuloma of radius showing a lamellar structure on MR images: a case report.

We report a case of an intraosseous cholesterol granuloma in the radius showing a lamellar structure on MRI. T1-weighted imaging revealed a central area of mildly increased signal intensity with a surrounding low-intensity layer. On T2-weighted images, the central lesion demonstrated low-intensity signals, and the surrounding area exhibited a lamellar structure with three layers of high, low, and high intensity from the inside. On histological examination, the central area was found to consist of cholesterine crystals embedded in erythrocytes, and in the surrounding lamellar structure collagenous tissue may have provided the low signals, with vessel- and giant cell-enriched structures present at both the inner and outer margins, presumably evoking the high-intensity signals. The present lesion may have been formed by chronic hemorrhage into a preexisting simple bone cyst.

Adult↗
PubMed2005

Spatially resolved measurement of rock core porosity.

Density weighted, centric scan, Conical SPRITE MRI techniques are applied in the current work for local porosity measurements in fluid saturated porous media. The methodology is tested on a series of sandstone core samples. These samples vary in both porosity and degree of local heterogeneity due to bedding plane structure. The MRI porosity measurement is in good agreement with traditional gravimetric measurements of porosity. Spatially resolved porosity measurements reveal significant porosity variation in some samples. This novel MRI technique should have applications to the characterization of local porosity in a wide variety of porous media.

Journal Article↗
PubMed1998

[The value of structural neuroimaging in the selection of patients for epileptic surgery].

UNLABELLED: The aim of this study was to investigate the value of structural neuroimaging with MRI in the selection of patients for epilepsy surgery. We sought to determine whether MRI influenced decision concerning resective surgery and whether MRI provided much more useful information than enhanced CT. MATERIALS AND METHODS: Neuroimaging studies, MRI and CT, of 300 patients; 265 with partial and 35 with primary generalized seizures, evaluated for surgical treatment of epilepsy were analysed. The MRIs and CTs were interpreted using visual diagnostic criteria and findings were correlated with the EEG changes and clinical semiology. RESULTS: MRIs identified structural lesions in 142, CTs in 96 of all patients. The clinical semiology (partial seizures), MRI, CT and EEG focal findings were concordant in 72 cases. The group of 34 patients had resective surgery. The 7 patients were also operated with MRI and CT focal abnormalities discordant with EEG changes. Also one patient with primary generalized epilepsy and temporal lobe lesion (glioma) had resective surgery. MRI studies revealed structural lesions in 48 patients with normal CT studies. The 43 patients with partial epilepsy had normal CTs and lesions in MRIs; the 34 cases revealed correlation with the EEG findings in 29 temporal and 5 extratemporal regions. Surgery were performed in 23 cases. Also one with partial seizures and MRI detected hippocampal atrophy was operated, despite of generalized EEG patterns. In contrast CT revealed two patients with normal MRI and focal changes. The patients with partial seizures and only CT abnormalities (focal calcifications) were not operated due to discordant EEG findings. In group of 132 patients with normal neuroimaging studies and EEG identified seizure focus only 27 had anterior temporal lobectomy. CONCLUSION: MRI studies gave additional information in case of 16% patients with intractable epilepsy in comparison with CT findings. Resective epilepsy surgery was almost twice as often performed when MRIs revealed structural abnormality. In operated patients, diagnostic sensitivity of structural MRI, CT and EEG to neurophatology were 70.6%, 46.7 and 92.4% respectively.

Adolescent↗