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PubMed1995

Value of magnetic resonance imaging in patients with penile induration (Peyronie's disease).

Magnetic resonance imaging (MRI) is a noninvasive procedure that enables exact imaging of penile anatomy. A total of 34 patients with clinical Peyronie's disease underwent palpation, ultrasound and MRI after intracavernous injection of 10 micrograms. prostaglandin E1. MRI images were obtained before and after intravenous application of gadolinium-diethylenetriaminepentaacetic acid. In 34 patients 45 plaques were palpable. Ultrasound revealed evidence of lesions in 66.6% of the cases. On MRI 36 of 45 palpable plaques (80%) were detected. Not palpable or sonographically revealed indurations could be shown in 4 cases. After intravenous application of gadolinium-diethylenetriaminepentaacetic acid 4 plaques demonstrated contrast enhancement, thus indicating local inflammatory activity. The combination of clinical examination and sonography remains the method of choice for diagnosis and observation of patients with Peyronie's disease. MRI enables exact imaging of penile structures but it does not provide a significant advantage over standard investigative procedures.

Adult↗
PubMed1993

[Cystic dystrophy in an aberrant pancreas. Contribution of computerized tomography and MRI].

Case report of a cystic dystrophia appearing in an ectopic pancreas. The clinical diagnosis was preoperatively suspected by the findings of CT scan revealing a tumor located in the wall of the duodenum and by the data of MRI indicating its cystic and fibrotic structure. A focus of reacting pancreatitis was found in the vicinity of the cystic dystrophia while the remaining pancreas was normal. The surgical treatment was a duodenopancreatectomy, justified by the potential risks of complications.

Cysts↗
PubMed1993

PET studies on the early and differential diagnosis of Parkinson's disease.

A number of neurodegenerative diseases can manifest as parkinsonian disorders. Structural imaging, such as CT and MRI, is of limited value for differentiating these diseases. PET can demonstrate the selective patterns of disruption of regional cerebral metabolism and neurotransmitter systems associated with subcortical degenerations, such as Parkinson's disease, striatonigral degeneration, progressive supranuclear palsy, and corticobasal degeneration. It can also determine, where underlying Parkinson's disease may be suspected, whether nigral dysfunction is present in patients with isolated tremor or drug-associated rigidity. Finally, PET can detect the presence of subclinical disruption of the dopaminergic system in at-risk subjects, such as relatives of patients with Parkinson's disease, or subjects exposed to nigral toxins, such as MPTP. With the advent of putative neuroprotective agents for Parkinson's disease, PET can help identify patients with early disease who might benefit from therapy with these agents and monitor their disease progression.

Brain↗
PubMedDate not supplied

[Glomus tumors in head and neck: assessment with magnetic resonance].

Glomus tumors originate from paranglionic tissues. In head and neck, these lesions are mainly found near carotid bifurcation, X nerve, jugular bulb or middle ear. These tumors have a low growing rate and are hypervascularized. Their histology show "nonchromaffin" cells and vascular structures involved by a fibrous matrix. MRI, CT and angiography are imaging methods used in glomus tumor. The author describe four cases of jugulo-timpanic glomus tumors studied by MRI, showing their main findings and the value of this method to detection of these lesions.

Adolescent↗
PubMed1996

[A case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT].

We report a case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT. The patient was 5-year-old girl with vocal and motor tic. There was no evidence of structural abnormality on magnetic resonance imaging (MRI). Electroencephalogram (EEG) showed spikes and sharp waves on both frontal lobes and parietal lobes (left-side dominant). 99mTc-HMPAO SPECT demonstrated focal regions of hyperperfusion in the both frontal lobes, both parietal lobes and right temporal lobe corresponding to the abnormal findings detected by EEG. It also demonstrated an area of hyperperfusion in the right basal ganglia. It is suggested that 99mTc-HMPAO SPECT is useful for the diagnosis and the understanding of the clinical state of tic disorder.

Brain↗
PubMed1999

A single case report of healing through specific martial art therapy: comparison of MRI to clinical resolution in severe cervical stenosis: a case report.

OBJECTIVES: A 76-year-old patient with chronic and severe spinal cord compression secondary to cervical stenosis, a cervical osteophyte, and a herniated intervertebral cervical disk had lasting resolution of symptoms after completing a specific, martial art-based, physical therapy program. We wanted to determine if there were structural changes in the cervical spine that could account for the prompt resolution of symptoms. DESIGN: A 76-year-old female completed 8 weeks of a specific, martial art-based, physical therapy. The pretherapy and posttherapy cervical magnetic resonance images (MRIs) were compared. A follow-up evaluation was done at 1 year. RESULTS: The patient was symptom-free within 8 weeks of the start of therapy. She remained symptom-free at 1 year follow-up evaluation. There were no obvious structural differences in the pretherapy and posttherapy MRI studies. CONCLUSIONS: Resolution of symptoms was directly related to the specific martial art therapy. However, there were no changes in the pretherapy and posttherapy MRI studies, suggesting a significant adaptation to the spinal compression had occurred. These data suggest a viable option to surgery in elderly patients with chronic and severe cervical spinal stenosis.

Aged↗
PubMed1996

Gliomatosis cerebri presenting with optic nerve involvement: MRI.

Gliomatosis cerebri is a rare form of astrocytoma characterized by extreme infiltration of the brain structure in conjunction with a relative paucity of clinical findings. We describe the MRI findings in a patient with gliomatosis cerebri widely infiltrating the brain who presented with symptoms related to involvement of the optic nerves and chiasm. Contrast-enhanced MRI showed enlargement of the optic nerves and chiasm with pathological enhancement; T2-weighted images showed extensive infiltration of the brain by tumor. Histopathologic examination of the biopsy specimen showed anaplastic astrocytoma with gemistocytic predominance and a diagnosis of gliomatosis cerebri was reached.

Adult↗
PubMed2005

Entorhinal cortex involvement in human mesial temporal lobe epilepsy: an electrophysiologic and volumetric study.

PURPOSE: Several studies have demonstrated diminution in the volume of entorhinal cortex (EC) ipsilateral to the pathologic side in patients with temporal lobe epilepsy (TLE). The relation between the degree of EC atrophy and the epileptogenicity of this structure has never been directly studied. The purpose of the study was to determine whether atrophy of the EC evaluated by the quantitative magnetic resonance imaging (MRI) method is correlated with the epileptogenicity of this structure in TLE. METHODS: Intracerebral recordings (SEEG method) of seizures from 11 patients with mesial TLE were analyzed. Seizures were classified according to patterns of onset: pattern 1 was the emergence of a low-frequency, high-amplitude rhythmic spiking followed by a tonic discharge, and pattern 2 was the emergence of a tonic discharge in the mesial structures. A nonlinear measure of SEEG signal interdependencies was used to evaluate the functional couplings occurring between hippocampus (Hip) and EC at seizure onset. MRI volumetric analysis was performed by using a T(1)-weighted three-dimensional gradient-echo sequence in TLE patients and 12 healthy subjects. RESULTS: Significant interactions between Hip and Ec were quantified at seizure onset. The EC was found to be the leader structure in most of the pattern 2 seizures. Volumetric measurements of EC demonstrated an atrophy in 63% of patients ipsilateral to the epileptic side. A significant correlation between the strength of EC-Hip coupling and the degree of atrophy was found. In addition, in those patients that had a normal EC volume, the EC was never the leader structure in Ec-Hip coupling. CONCLUSIONS: These results validate the potential role of volumetry to predict the epileptogenesis of the EC in patients with hippocampal sclerosis and MTLE.

Adolescent↗
PubMed1996

Positron emission tomography metabolic data corrected for cortical atrophy using magnetic resonance imaging.

The correct interpretation of clinical positron emission tomography (PET) data depends largely on the physical limits of the PET scanner. The partial volume effect (PVE) is related to the size of the studied object compared to the spatial resolution. It represents one of the most important limiting factors in quantitative data analysis. This effect is increased in the case of atrophy, as in patients with Alzheimer disease (AD), and it influences measurement of the metabolic reduction generally seen in cerebral degeneration. In this case, interpretation can be biased, because cortical activity will be underestimated due to the atrophy. In general, anatomical images of AD patients have shown diffuse atrophy, while PET studies have found widespread hypometabolism affecting the parietal and temporal lobes. Although hypometabolic areas usually correspond to atrophic regions, they also occur without such changes. Thus, the aim is to differentiate authentic hypometabolism (decrease of glucose consumption per unit volume of gray matter) from that due to PVE from atrophy (cell loss). Consequently, we are using a method for three-dimensional (3D) correction of human PET data with 3D magnetic resonance imaging (MRI). We measured atrophy and metabolism by using both T1-weighted MR images and high and medium resolution PET scans. We injected 12 patients and controls with [18F]fluorodeoxyglucose for glucose consumption measurements. Atrophy was estimated in the following way. We isolated the cerebral structures, using a segmentation technique on the MRI scans, into gray matter (GM), white matter, and cerebrospinal fluid. We superimposed the PET images onto the MR images to obtain anatomo-functional correlations. We degraded the segmented MR images to the resolution of the PET images by a convolution process to create a PET image correction map. We corrected the metabolic PET data for the PVE. We studied the cerebral metabolic rate of glucose in the GM where metabolic variation is the most relevant to AD. By dealing with problems relating to the sensitivity to the segmentation and to the PET-MRI coregistration, computation of MRI convolution processes provided the degree of PVE on a pixel-by-pixel basis, allowing correction of hypometabolisms contained in GM PET values. Global cortical metabolism increased after correction for PVE by, on average, 29 and 24% for tomographs acquired with medium (TTV03 LETI) and high (ECAT 953B CTI/Siemens) resolution, respectively, whereas the cortical metabolism increased by 75 and 65% for the respective tomographs in AD patients. The difference of metabolism between scans after correction for PVE was less than before correction, decreasing from 31 to 17%. This difference was most marked in the frontal and temporal lobes. Fusion imaging allowed correction for PVE in metabolic data using 3D MRI and determination of whether a change in the apparent radiotracer concentration in PET data reflected an alteration in GM volume, a change in radiotracer concentration per unit volume of GM, or both.

Adult↗
PubMed1999

Remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome: a prospective follow up and magnetic resonance imaging study.

OBJECTIVE: To determine the clinical characteristics of patients with "pure" remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome, and to investigate its relation with polymyalgia rheumatica (PMR). Magnetic resonance imaging (MRI) was used to describe the anatomical structures affected by inflammation in pure RS3PE syndrome. METHODS: A prospective follow up study of 23 consecutive patients with pure RS3PE syndrome and 177 consecutive patients with PMR diagnosed over a five year period in two Italian secondary referral centres of rheumatology. Hands or feet MRI, or both, was performed at diagnosis in 7 of 23 patients. RESULTS: At inspection evidence of hand and/or foot tenosynovitis was present in all the 23 patients with pure RS3PE syndrome. Twenty one (12%) patients with PMR associated distal extremity swelling with pitting oedema. No significant differences in the sex, age at onset of disease, acute phase reactant values at diagnosis, frequency of peripheral synovitis and carpal tunnel syndrome and frequency of HLA-B7 antigen were present between patients with pure RS3PE and PMR. In both conditions no patient under 50 was observed, the disease frequency increased significantly with age and the highest frequency was present in the age group 70-79 years. Clinical symptoms for both conditions responded promptly to corticosteroids and no patient developed rheumatoid arthritis during the follow up. However, the patients with pure RS3PE syndrome were characterised by shorter duration of treatment, lower cumulative corticosteroid dose and lower frequency of systemic signs/symptoms and relapse/recurrence. Hands and feet MRI showed evidence of tenosynovitis in five patients and joint synovitis in three patients. CONCLUSION: The similarities of demographic, clinical, and MRI findings between RS3PE syndrome and PMR and the concurrence of the two syndromes suggest that these conditions may be part of the same disease and that the diagnostic labels of PMR and RS3PE syndrome may not indicate a real difference. The presence of distal oedema seems to indicate a better prognosis.

Age Distribution↗
PubMed2005

Brain surface parameterization using Riemann surface structure.

We develop a general approach that uses holomorphic 1-forms to parameterize anatomical surfaces with complex (possibly branching) topology. Rather than evolve the surface geometry to a plane or sphere, we instead use the fact that all orientable surfaces are Riemann surfaces and admit conformal structures, which induce special curvilinear coordinate systems on the surfaces. Based on Riemann surface structure, we can then canonically partition the surface into patches. Each of these patches can be conformally mapped to a parallelogram. The resulting surface subdivision and the parameterizations of the components are intrinsic and stable. To illustrate the technique, we computed conformal structures for several types of anatomical surfaces in MRI scans of the brain, including the cortex, hippocampus, and lateral ventricles. We found that the resulting parameterizations were consistent across subjects, even for branching structures such as the ventricles, which are otherwise difficult to parameterize. Compared with other variational approaches based on surface inflation, our technique works on surfaces with arbitrary complexity while guaranteeing minimal distortion in the parameterization. It also offers a way to explicitly match landmark curves in anatomical surfaces such as the cortex, providing a surface-based framework to compare anatomy statistically and to generate grids on surfaces for PDE-based signal processing.

Algorithms↗
PubMed2000

The contribution of MRI in the differential diagnosis of posterior fossa damage.

In multiple sclerosis patients, magnetic resonance imaging (MRI) frequently detects lesions in the brain stem and cerebellum. However various pathologies that have a predelection to occur in posterior fossa parenchyma may share similar features with inflammatory-demyelinating lesions. In this paper, we review the contribution of MRI to the differential diagnosis of posterior fossa pathology. Vascular lesions due to chronic hypoperfusion and arteriolosclerosis or occlusion of the main supplying arteries of the posterior circulation leading to acute infarction frequently produce characteristic pontine or cerebellar lesions. Neoplastic disease, in particular pontine gliomas in younger patients may have similar MRI features and may be difficult to distinguish from inflammatory-demyelinating lesions. Central pontine myelinolysis usually occurs in severely ill patients but the pontine MRI changes have an overlapping profile with inflammatory demyelination. Diffuse axonal injury of the midbrain and brainstem after head trauma and atrophy of posterior fossa structures in degenerative diseases may appear similar on MRI to tissue changes also seen frequently in MS. Analysis of the MRI appearance and clinical information is most often useful to narrow the fairly long list of differential diagnoses of posterior fossa pathology.

Brain Diseases↗
PubMed2004

Biomechanics of back pain.

This paper offers a mechanistic account of back pain which attempts to incorporate all of the most important recent advances in spinal research. Anatomical and pain-provocation studies show that severe and chronic back pain most often originates in the lumbar intervertebral discs, the apophyseal joints, and the sacroiliac joints. Psychosocial factors influence many aspects of back pain behaviour but they are not important determinants of who will experience back pain in the first place. Back pain is closely (but not invariably) associated with structural pathology such as intervertebral disc prolapse and endplate fractures, although age-related biochemical changes such as those revealed by a 'dark disc' on MRI have little clinical relevance. All features of structural pathology (including disc prolapse) can be re-created in cadaveric specimens by severe or repetitive mechanical loading, with a combination of bending and compression being particularly harmful to the spine. Structural disruption alters the mechanical environment of disc cells in a manner that leads to cell-mediated degenerative changes, and animal experiments confirm that surgical disruption of a disc is followed by widespread disc degeneration. Some people are more vulnerable to spinal degeneration than others, largely because of their genetic inheritance. Age-related biochemical changes and loading history can also affect tissue vulnerability. Finally the concept of 'functional pathology' is introduced, according to which, back pain can arise because postural habits generate painful stress concentrations within innervated tissues, even though the stresses are not high enough to cause physical disruption.

Biomechanical Phenomena↗
PubMed2005

Homozygote for mutation c.1204 + 1G > A of the ARSA gene presents with a late-infantile form of metachromatic leukodystrophy and a rare MRI white matter lesion type.

The metachromatic leukodystrophy (MLD)--causing mutation c.1204 + 1G > A damages an intron-exon splice site recognition sequence. This results in a complete loss of enzymatic activity of arylsulfatase A (ARSA) protein molecules. We have found a late-infantile type MLD-patient to be homozygous for this mutation, which was not reported earlier, but is consistent with previous suggestions. Interestingly, the cerebral magnetic resonance imaging (MRI) in this patient displayed linear or punctuate structures radiating in the demyelinated white matter, which resembled the patterns described in Pelizaeus-Merzbacher disease. It should be emphasised that whenever a cerebral MRI demonstrates the "tigroid" or "leopard-skin" demyelination pattern not only Pelizaeus-Merzbacher disease, but also metachromatic leukodystrophy diagnosis should be considered; this suggests the necessity of ARSA activity estimations in patients with such specific MRI patterns.

Cerebroside-Sulfatase↗
PubMed2004

Proteoglycan and collagen sensitive MRI evaluation of normal and degenerated articular cartilage.

Quantitative magnetic resonance imaging (MRI) techniques have earlier been developed to characterize the structure and composition of articular cartilage. Particularly, Gd-DTPA(2-)-enhanced T1 imaging is sensitive to cartilage proteoglycan content, while T2 relaxation time mapping is indicative of the integrity and arrangement of the collagen network. However, the ability of these techniques to detect early osteoarthrotic changes in cartilage has not been demonstrated. In this study, normal and spontaneously degenerated bovine patellar cartilage samples (n=32) were investigated in vitro using the aforementioned techniques. For reference, mechanical, histological and biochemical properties of the adjacent tissue were determined, and a grading system, the cartilage quality index (CQI), was used to score the structural and functional integrity of each sample. As cartilage degeneration progressed, a statistically significant increase in the superficial T2 (r=0.494, p<0.05) and a decrease in superficial and bulk T1 in the presence of Gd-DTPA(2-) (r=-0.681 and -0.688 (p<0.05), respectively) were observed. Gd-DTPA(2-)-enhanced T1 imaging served as the best predictor of tissue integrity and accounted for about 50% of the variation in CQI. The present results reveal that changes in the quantitative MRI parameters studied are indicative of structural and compositional alterations as well as the mechanical impairment of spontaneously degenerated articular cartilage.

Animals↗
PubMedDate not supplied

[Quantitative volumetric analysis of the hippocampus, amygdala and entorhinal cortex: normative database for the adult Portuguese population].

INTRODUCTION: Atrophy of the hippocampus, amygdala and entorhinal cortex can be found in neurodegenerative diseases, head trauma and epilepsy and are expressed by means of volume reductions. The ability to detect these changes quantitatively depends on accurate comparisons with normative databases. AIM: To present standard magnetic resonance imaging (MRI) volumes of the mesio-temporal lobe structures and an objective statistical methodology for contrasting pathological states. SUBJECTS AND METHODS: Volumes of the right and left hippocampi, amygdalae and entorhinal cortex were measured from MRI in 34 right-handed healthy volunteers, aged 19-52 years. Data were normalized for the individual variation in total intracranial volume. Reproducibility was confirmed by intra/inter-observer tests. The statistical analyses included asymmetry comparisons, correlations between volumes and tests to assess the influence of age, gender and general morphometry (body mass index and height). For each volume, we further defined a normative interval by means of 99% confidence ellipses, accordingly to Hotteling's method. RESULTS: Right-left asymmetry in the volumes of the hippocampus and entorhinal cortex was a normal finding. Structures located in the right hemisphere were larger than the left by a small but statistically significant amount. No asymmetry was found in the amygdala. There was no correlation in-between these volumes. Gender differences were exclusively noted in the absolute amygdala volumes (male > female) but were eliminated by the normalization procedure. No effect of age or morphometry was seen in the absolute or normalized volumes (except for a milder correlation between hippocampal volumes and height). Confidence ellipses were built for every structure and provided a precise reading of the data. Particularly, it allowed for a clear distinction of pathological asymmetries and bilateral cases. CONCLUSION: These normative volumes serve as a reference for the assessment of pathologic groups within similar age-range. The use of a single graphic representation simplifies the clinical interpretation and enhances the precision of the results.

Adult↗
PubMed1993

Three-dimensional brain metabolic imaging in patients with toxic encephalopathy.

Thirty-three workers, ages 24 to 63, developed clinical toxic encephalopathy after exposure to neurotoxins and were studied by SPECT brain scans. Five were exposed to pesticides, 13 were acutely exposed to mixtures of solvents, 8 were chronically exposed to mixtures of hazardous wastes that contained organic solvents, 2 were acutely exposed to phosgene and other toxins, and 5 had exposures to hydrogen sulfide. Twenty-nine had neuropsychological testing and all had a medical history and physical. Of the workers who had a clinical diagnosis of toxic encephalopathy, 31 (93.9%) had abnormal SPECT brain scans with the most frequent areas of abnormality being temporal lobes (67.7%), frontal lobes (61.3%), basal ganglia (45.2%), thalamus (29.0%), parietal lobes (12.9%), motorstrip (9.68%), cerebral hemisphere (6.45%), occipital lobes (3.23%), and caudate nucleus (3.23%). Twenty-three out of 29 (79.3%) neuropsychological evaluations were abnormal. Other modalities when performed included the following percentages of abnormals: NCV, 33.3%; CPT sensory nerve testing, 91.3%; vestibular function testing, 71.4%; olfactory testing, 89.2%; sleep EEG analysis, 85.7%; EEG, 8.33%; CT, 7.14%; and MRI brain scans, 28.6%. The complex of symptoms seen in toxic encephalopathy implies dysfunction involving several CNS regions. This series of patients adds to the previous experience of brain metabolic imaging and demonstrates that certain areas of the brain are typically affected despite differences in toxin structure, that these lesions can be globally defined by SPECT/PET brain scans, that these lesion correlate well with clinical and neuropsychological testing, and that such testing is a useful adjunct to previous methods. EEG and structural brain imaging such as CT and MRI are observed to have poor sensitivity in this type of patient. Additional metabolic imaging studies need to be done to explore dose, time, and specific toxin effects as well as mechanisms of toxicity and olfactory migration.

Adolescent↗
PubMed1993

Magnetic resonance imaging (MRI), neurobehavioral testing, and toxic encephalopathy: two cases.

The objective of this investigation was to examine cerebral magnetic resonance imaging (MRI) pathology and functional deficits demonstrated by neuropsychological testing in cases of toxic encephalopathy. Two subjects, occupationally exposed to toxic chemicals, were studied. As part of their neurological assessment, MRI was done and each underwent a neuropsychological battery for patients with toxic exposures (White et al. Clin. Neuropharmacol. 13(5), 392-412, 1990). In Case 1, who was exposed to inorganic mercury, MRI showed mild central and cortical atrophy. Punctiform foci (T2) were noted in both frontal regions underlying the precentral gyri and in the subcortical myelin. Neuropsychological testing showed problems in cognitive flexibility, cognitive tracking, inhibiting perseveration, fine manual motor coordination, visuospatial analysis and organization, memory, and affect and personality. In Case 2, who was exposed to 2.6-dimethyl-4-heptanone, MRI showed multiple small foci in the white matter and pons. Neuropsychological testing indicated affective changes, deficits in manual motor speed, verbal fluency, visuospatial organization, and short-term memory. Lack of aphasia in patients with toxic encephalopathy indicates that neurotoxins probably affect subcortical and mesial temporal structures more than cortical gray matter. These MRI studies show subcortical sites of pathology.

Behavior↗