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PubMedDate not supplied

Quantitative MRI of the brain in children with sickle cell disease reveals abnormalities unseen by conventional MRI.

Conventional MRI (cMRI) has shown that brain abnormalities without clinical stroke can manifest in patients with sickle cell disease (SCD). We used quantitative MRI (qMRI) and psychometric testing to determine whether brain abnormalities can also be present in patients with SCD who appear normal on cMRI. Patients 4 years of age and older with no clinical evidence of stroke were stratified by cMRI as normal (n = 17) or abnormal (n = 13). Spin-lattice relaxation time (T1) of gray and white matter structures was measured by the precise and accurate inversion recovery (PAIR) qMRI method. Patient cognitive ability was assessed with a standard psychometric instrument (WISC-III or WISC-R). In all 30 patients with SCD, qMRI T1 was lower than in 24 age- and race-matched controls, in cortical gray matter (P < .0006) and caudate (P < .0009), as well as in the ratio of gray-to-white matter T1 (P < .008). In the 17 patients who were shown to be normal by cMRI, qMRI T1 was still lower than in controls, in both cortical gray matter (P < .02) and caudate (P < .004). Histograms of voxel T1 show that the proportion of voxels with T1 values intermediate between gray and white matter (ie, consistent with encephalomalacia) was 9% higher than controls in patients shown to be normal by cMRI (P < .05) and 15% higher than controls in patients shown to be abnormal by cMRI (P < .0005). The full scale intelligence quotient (FSIQ) of all patients with SCD was 75, compared to the FSIQ of 88 in a historical control group of patient siblings (P < .001). The FSIQ of patients shown to be normal by cMRI was 79, significantly lower than the FSIQ of patient siblings (P < .04). The FSIQ of 71 in patients shown to be abnormal by cMRI was significantly lower than both the patient siblings (P < .005) and the patients shown to be normal by cMRI (P < .04). Patients shown to be abnormal by cMRI scored lower than patients shown to be normal by cMRI, specifically on the subtests of vocabulary (P = .003) and information (P = .03). Cognitive impairment is thus significant, even in patients with SCD who were shown to be normal by cMRI, suggesting that cMRI may be insensitive to subtle neurologic damage that can be detected by qMRI. Because cognitive impairment can occur in children normal by cMRI, our findings imply that prophylactic therapy may be needed earlier in the course of SCD to mitigate neurologic damage.

Adolescent↗

PubMed1997

[Acceptance of high field whole body MRI equipment, open MRI systems dedicated extremity scanners by patients].

To our knowledge no comparative studies investigating patients' acceptance of different MR systems have been published. We therefore studied a number of subjective criteria to evaluate both patients' acceptance of and subjective conditions during magnetic resonance imaging (MRI) studies. MRI studies were performed using four separate systems. Two were conventional body MR systems operating at 1.0 or 1.5 Tesla, another was a 0.2 Tesla open whole-body MR system, and the last was a 0.2 Tesla MR system dedicated to the study of extremities. Forty patients for each MR system (total of 160 patients) participated in a standardized, written interview focusing on aspects of their subjective condition, including their perception and acceptance of different factors relevant to the study on respective MR systems. The patients' subjective condition and acceptance was predominantly positive for all MR systems. Differences between MR systems were noted with respect to noise, width of patient gantry, comfort of patient positioning and degree of well-being. Such differences, however, do not lend preference to the use of one particular type of MR system. Therefore, the choice of MR system should be based on the technical features required for the intended studies.

Adolescent↗

PubMed1997

[MRI of fingers in systemic scleroderma. Initial results with contrast-enhanced studies using a dedicated MRI system].

PURPOSE: To estimate disease activity in patients with systemic sclerosis using contrast-enhanced MRI of the skin. MATERIAL AND METHODS: In a pre-study, sequences of a low-field (0.2 T) scanner (Artoscan, Esaote, Genova, Italy) were optimized for detection of intravenous contrast (0.1 mmol/l Gd-DTPA) in six patients with the autoimmune disease systemic scleroderma. Based on the results of the pre-study, 17 patients with scleroderma (7 sclerotic/10 active inflammatory disease) were scanned using gradient-spoiled 3D GRE sequences (FA 90 degrees, TR 100 ms, TE 18 ms), which had been established as most sensitive for intravenous contrast. Contrast enhancement of the skin was determined quantitatively by contrast-to-noise ratios (CNR), comparing post- to pre-contrast and dynamic scans (for 6 min, 1 acquisition/min). Patients in the chronic state with sclerodactylia and active inflammation of the hands were considered separately and compared to a control group (n = 10) matched according to age. RESULTS: CNR increase after intravenous contrast was significantly higher in patients with active disease (86 +/- 16% increase) than sclerosing disease (29 +/- 3%, p < 0.05) and the control group (4 +/- 2%, p < 0.05). The dynamic examination showed a significantly slower decrease after the peak rise in the first minute in patients with active disease (CNR 15.4 +/- 0.7 to 14.2 +/- 1.4) than in those with chronic disease (14.1 +/- 0.5 to 11.3 +/- 0.9, p < 0.05). DISCUSSION: Capillary leakage is the most likely explanation for the increased enhancement in patients with active scleroderma. Using sequences optimized for contrast detection, disease activity in the course of scleroderma and response to therapy can be determined by MRI in the future.

Adult↗

PubMed2003

Diffuse spinal and intercostal nerve involvement in chronic inflammatory demyelinating polyradiculoneuropathy: MRI findings.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon demyelinating disorder with a relapsing and remitting or continuously progressive course. Hypertrophic nerve roots, sometimes associated with gadolinium enhancement, has been reported more commonly in lumbar spine and less commonly in the brachial plexus and cervical roots; however, diffuse involvement of intercostal nerves bilaterally has never been reported previously. We present MRI findings which include diffuse enlargement and mild enhancement of roots and extraforaminal segments of nerves in all segments except a short segment between T12-L2 as well as all the intercostal nerves in a case of CIPD with a 10-year history.

Biopsy, Needle↗

PubMed2001

International investigation of breast MRI: results of a multicentre study (11 sites) concerning diagnostic parameters for contrast-enhanced MRI based on 519 histopathologically correlated lesions.

A multicentre study was undertaken to provide fundamentals for improved standardization and optimized interpretation guidelines of dynamic contrast-enhanced MRI. Only patients scheduled for biopsy of a clinical or imaging abnormality were included. They underwent standardized dynamic MRI on Siemens 1.0 (163 valid lesions > or = 5 mm) or 1.5 T (395 valid lesions > or = 5 mm) using 3D fast low-angle shot (FLASH; 87 s) before and five times after standardized bolus of 0.2 mmol Gd-DTPA/kg. One-Tesla and 1.5 T data were analysed separately using a discriminant analysis. Only histologically correlated lesions entered the statistical evaluation. Histopathology and imaging were correlated in retrospect and in open. The best results were achieved by combining up to five wash-in or wash-out parameters. Different weighting of false-negative vs false-positive calls allowed formulation of a statistically based interpretation scheme yielding optimized rules for the highest possible sensitivity (specificity 30%), for moderate (50%) or high (64-71%) specificity. The sensitivities obtained at the above specificity levels were better at 1.0 T (98, 97, or 96%) than at 1.5 T (96, 93, 86%). Using a widely available standardized MR technique definition of statistically founded interpretation rules is possible. Choice of an optimum interpretation rule may vary with the clinical question. Prospective testing remains necessary. Differences of 1.0 and 1.5 T are not statistically significant but may be due to pulse sequences.

Adult↗

PubMed2002

In vivo imaging of region and cell type specific neocortical neurodegeneration in Alzheimer's disease. Perspectives of MRI derived corpus callosum measurement for mapping disease progression and effects of therapy. Evidence from studies with MRI, EEG and PET.

Neuropathological studies in Alzheimer's disease (AD) indicate specific loss of layer III and V large pyramidal neurons in association cortex. These neurons give rise to long cortico-cortical connections, projecting through the corpus callosum, in an anterior-posterior topology. Based on these findings we hypothesized that regional corpus callosum atrophy may be a potential in vivo marker for neocortical neuronal loss in AD. To evaluate this hypothesis, we developed a method to measure cross-sectional area of the corpus callosum and of five corpus callosum subregions on midsagittal magnetic resonance imaging scans (MRI). In a subsequent series of six experimental studies using MRI, (18)FDG-PET and EEG, we investigated the relation of white matter hyperintensities (WMH) to corpus callosum size and correlated regional pattern of corpus callosum atrophy with regional cortical metabolic decline as well as intracortical coherencies. Mean total corpus callosum area was reduced significantly in AD patients compared to healthy age-matched controls, with the greatest changes in the rostrum and the splenium and relative sparing of the truncus. The regional pattern of corpus callosum atrophy was independent of WMH load and correlated significantly with pattern of regional metabolic decline measured with (18)FDG-PET, the degree of cognitive impairment and regional decline of bilateral intracortical-coherency in EEG in AD patients. We further found that hippocampus atrophy, as a marker of early allocortical degeneration, was more pronounced than total corpus callosum atrophy in mild stages of AD. Regional corpus callosum atrophy in mild disease, however, suggested early neocortical degeneration in AD. In a longitudinal study, AD patients showed significantly greater rates of corpus callosum atrophy than controls. Rates of atrophy correlated with progression of clinical dementia severity in AD. Our results indicate that regional corpus callosum atrophy in AD patients represents the loss of callosal efferent neurons in corresponding regions of the neocortex. As these neurons are a subset of cortico-cortical projecting neurons, region-specific corpus callosum atrophy may serve as a marker of progressive neocortical disconnection in AD. In combination with measurement of hippocampal atrophy, assessment of corpus callosum atrophy over time in individual patients is useful to evaluate effects on brain structure of currently developed drugs, thought to slow or modify AD progression.

Alzheimer Disease↗

PubMed2006

Functional MRI in the evaluation of oesophageal motility: feasibility, MRI patterns of normality, and preliminary experience in subjects with motility disorders.

PURPOSE: The aim of this study was to introduce functional magnetic resonance imaging (fMRI) with T1-weighted turbo fast low-angle shot (FLASH) sequences in the evaluation of oesophageal motility and morphology, to formulate MRI patterns of normality in healthy subjects and to demonstrate the feasibility of the method by obtaining a preliminary experience in the study of subjects affected by oesophageal motility disorders. MATERIALS AND METHODS: Thirty healthy volunteers and seven patients with radiological and manometric diagnoses of oesophageal motility disorders underwent fMRI with dynamic T1- weighted turbo-FLASH (TFL) sequences during the administration of oral contrast material. RESULTS: Evaluation of oesophageal function and morphology proved possible in all subjects, as well as the formulation of normality patterns. In patients with motility disorders, fMRI correctly visualised the typical alterations in agreement with radiological and manometric findings. CONCLUSIONS: Functional MRI sequences acquired during the administration of oral contrast material can evaluate oesophageal transit, providing information on motility and morphology; furthermore, this modality can properly visualise the typical functional and morphological alterations of motility disorders.

Adult↗

PubMedDate not supplied

MRI evaluation of "solitary" brain metastases with triple-dose gadoteridol: comparison with contrast-enhanced CT and conventional-dose gadopentetate dimeglumine MRI studies in the same patients.

The purpose of this investigation was to compare the sensitivity and safety of high dose gadoteridol (Pro Hance) with routine dose gadopentetate dimeglumine (Magnevist) in the detection of intracranial metastases on magnetic resonance imaging (MRI) when a solitary intracranial lesion was detected on contrast-enhanced cranial computed tomography (CT). Four patients, each with a solitary intracranial metastasis demonstrated on contrast-enhanced CT were studied prospectively with both 0.3 mmol/kg gadoteridol and 0.1 mmol/kg gadopentetate dimeglumine. Images were acquired before and immediately following contrast administration. Both of the MR studies were performed between two and six days of each other and within 1 wk of the cranial CT. Scan parameters and injection rates were identical on both occasions. Patient monitoring for the gadoteridol study included physical examination, vital signs and laboratory tests at several pre-determined times. Eighteen total metastases were demonstrated on MRI compared to the four on CT. Seven were visualized on the unenhanced MR images, nine on the scans using gadopentetate dimeglumine, and all eighteen on the scans using gadoteridol. Additional lesions were seen on the gadoteridol images in all four patients. No adverse events attributable to contrast media occurred. No significant changes in vital signs or laboratory values occurred.

Adenocarcinoma↗

PubMed2006

Contrast/Noise ratio on conventional MRI and choline/creatine ratio on proton MRI spectroscopy accurately discriminate low-grade from high-grade cerebral gliomas.

RATIONALE AND OBJECTIVES: Histopathology is the gold standard to establish the grade of brain tumors but biopsy and/or surgery are not always possible. The aim of this study is to determine whether histological grade of tumors may be predicted by means of conventional gadolinium-enhanced MRI and proton magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: In this study, we included 35 consecutive patients with single brain tumors and final histopathological verification: 12 had low-grade glioma, 16 had high-grade glioma, and 7 had single metastasis. Initially, we carried out T1 and T2 MRI paying attention to the following features: border definition, mass effect, heterogeneity of signal, perilesional edeme, hemorrhage, necrosis, and corpus callosum invasion. Gadolinium-enhancement was evaluated with the contrast-to-noise ratio (CNR). Next, single-voxel proton MRS was carried out to measure the absolute values of metabolites (N-acetyl-aspartate, creatine, choline, and myo-inositol) and their ratios in the area of maximum contrast enhancement. RESULTS: We found that gadolinium-enhancement measured with the CNR (CNR > 35.86) predicted malignancy at 82.6% sensitivity and 91.7% specificity (area under the curve, 0.88; 95% confidence interval [CI], 0.73-0.97). With regard to MRS a choline/creatine ratio higher than 1.56 predicted malignancy at 88.9% sensitivity and 91.7% specificity (area under the curve, 0.94; 95% CI, 0.78-0.99). When we combined the CNR value, the choline/creatine ratio, and the presence of lactates in a model of discriminant analysis the predictive power improved significantly with an area under the curve of 0.99% (95% CI, 0.87-1). However, the used techniques were unable to distinguish metastases from high-grade gliomas accurately. CONCLUSIONS: The intensity of contrast enhancement measured with the CNR, the choline/creatine ratio, and the presence of lactate were the most powerful variables to predict malignancy in brain tumors. The CNR is a simple, objective, and useful tool in the initial assessment of gliomas and metastases.

Adolescent↗

PubMed2006

A stereotaxic MRI template set for the rat brain with tissue class distribution maps and co-registered anatomical atlas: application to pharmacological MRI.

We describe a stereotaxic rat brain MRI template set with a co-registered digital anatomical atlas and illustrate its application to the analysis of a pharmacological MRI (phMRI) study of apomorphine. The template set includes anatomical images and tissue class probability maps for brain parenchyma and cerebrospinal fluid (CSF). These facilitate the use of standard fMRI software for spatial normalisation and tissue segmentation of rat brain data. A volumetric reconstruction of the Paxinos and Watson rat brain atlas is also co-localised with the template, enabling the atlas structure and stereotaxic coordinates corresponding to a feature within a statistical map to be interactively reported, facilitating the localisation of functional effects. Moreover, voxels falling within selected brain structures can be combined to define anatomically based 3D volumes of interest (VOIs), free of operator bias. As many atlas structures are small relative to the typical resolution of phMRI studies, a mechanism for defining composite structures as agglomerations of individual atlas structures is also described. This provides a simple and robust means of interrogating structures that are otherwise difficult to delineate and an objective framework for comparing and classifying compounds based on an anatomical profile of their activity. These developments allow a closer alignment of pre-clinical and clinical analysis techniques.

Animals↗

PubMed1998

MRI for physiology and function: technical advances in MRI of congenital heart disease.

Cardiovascular MRI is an active area of research, and the techniques and application are continuing to evolve. We have presented the basic categories of MRI techniques used to image the heart and have shown some examples of advanced techniques applied to the evaluation of congenital heart disease. The reader is referred to other articles for examples of these techniques in clinical practice.

Equipment Design↗

PubMed2001

Tumor angiogenesis of low-grade astrocytomas measured by dynamic susceptibility contrast-enhanced MRI (DSC-MRI) is predictive of local tumor control after radiation therapy.

PURPOSE: To assess regional cerebral blood volume (rCBV) as a surrogate marker of angiogenesis in patients with low-grade fibrillary astrocytoma before radiation therapy and to correlate measured values with clinical outcome after fractionated stereotactic radiotherapy (FSRT). METHODS: Twenty-five patients with histologically proven fibrillary astrocytomas were examined using dynamic susceptibility contrast-enhanced MRI before radiotherapy. Radiotherapy was delivered to mean and median total doses of 60.9 and 60 Gy, respectively (range 55.8-66 Gy). During MRI for treatment planning, 55 T2*-weighted gradient echo images were acquired before, during, and after i.v. contrast-bolus injection. The acquired signal-time curves were converted into concentration-time curves. By normalization to an arterial input function, absolute and relative rCBV values were calculated. Measured pretherapeutic rCBV data were correlated to outcome in terms of local control after FSRT. RESULTS: Mean pretherapeutic rCBV for astrocytomas was 6.5 +/- 3.7 ml/100 g tissue. Mean and median follow-up times were 47.8 and 52 months, respectively. Fifteen tumors recurred during the period, with a mean and median latency of 39.1 and 42 months, respectively. Tumors recurring earlier than 42 months after FSRT showed a higher pretreatment rCBV than tumors recurring later and tumors in continued local control (8.12 +/- 4.48 ml/100 g vs. 6.0 +/- 2.3 ml/100 g and 4.73 +/- 2.47 ml/100 g; p = 0.02 and p = 0.03). The respective ratios of tumor rCBV in early recurrent tumors to gray matter and white matter rCBV were 0.98 +/- 0.38 and 2.17 +/- 1.36 as compared with 0.79 +/- 0.14 and 1.44 +/- 0.29 in locally controlled tumors (p = 0.074 and p = 0.056). CONCLUSIONS: In fibrillary low-grade astrocytomas, a noninvasive assessment of angiogenesis as indicated by rCBV measurement was feasible. The present data suggest that high pretherapeutic angiogenic activity in low-grade astrocytomas indicates a subgroup of tumors at higher risk for early local recurrence or malignant transformation after FSRT.

Adult↗

PubMedDate not supplied

Diffusion-weighted MRI features of brain abscess and cystic or necrotic brain tumors: comparison with conventional MRI.

BACKGROUND AND PURPOSE: The purpose of this study was to determine whether diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) can be used to distinguish brain abscesses from cystic or necrotic brain tumors, which are difficult to distinguish by conventional magnetic resonance imaging (MRI) techniques. METHODS: Eleven consecutive patients with brain abscesses [10 pyogenic and 1 toxoplasmosis (in an AIDS patient)] and 15 with cystic or necrotic brain gliomas or metastases were enrolled in this study. None of these lesions had apparent hemorrhage based on T1-weighted image (T1WI). The DWI was performed using a 1.5-T system, single-shot spin-echo echo-planar pulse sequence with b=1000 s/mm(2). The ADC was calculated using a two-point linear regression method at b=0 and b=1000 s/mm(2). The ratio (ADCR) of the lesion ADC to control region ADC was also measured. RESULTS: Increased signal was seen in all of the pyogenic abscess cavities to variable degrees on DWI. In vivo ADC maps showed restricted diffusion in the abscess cavity in all pyogenic abscesses [0.65+/-0.16 x 10(-3) (mean+/-S.D.) mm(2)/s, mean ADCR=0.63]. The case with multiple toxoplasmosis abscesses showed low signal intensity on DWI and high ADC values (mean 1.9 x 10(-3) mm(2)/s, ADCR=2.24). All cystic or necrotic tumors but one showed low signal intensity on DWI and their cystic or necrotic areas had high ADC values (2.70+/-0.31 x 10(-3) mm(2)/s, mean ADCR=3.42). One fibrillary low-grade astrocytoma had a high DWI signal intensity and a low ADC value in its central cystic area (0.44 x 10(-3) mm(2)/s, ADCR=0.49). Postcontrast T1WIs yielded a sensitivity of 60%, a specificity of 27.27%, a positive predictive value (PPV) of 52.94%, and a negative predictive value (NPV) of 33.33% in the diagnosis of necrotic tumors. DWI yielded a sensitivity of 93.33%, a specificity of 90.91%, a PPV of 93.33%, and a NPV of 90.91%. The area under receiver operating characteristic (ROC) curves for postcontrast T1WI was 0.44 and DWI was 0.92. Analysis of these areas under the ROC curves indicates significant difference between postcontrast T1WI and DWI (P<.001). CONCLUSION: With some exceptions, DWI is useful in providing a greater degree of confidence in distinguishing brain abscesses from cystic or necrotic brain tumors than conventional MRI and seems to be a valuable diagnostic tool.

Brain↗

PubMed2001

MRI of Creutzfeldt-Jakob disease: imaging features and recommended MRI protocol.

Creutzfeldt-Jakob Disease (CJD) is a rare, progressive and invariably fatal neurodegenerative disease characterized by specific histopathological features. Of the four subtypes of CJD described, the commonest is sporadic CJD (sCJD). More recently, a new clinically distinct form of the disease affecting younger patients, known as variant CJD (vCJD), has been identified, and this has been causally linked to the bovine spongiform encephalopathy (BSE) agent in cattle. Characteristic appearances on magnetic resonance imaging (MRI) have been identified in several forms of CJD; sCJD may be associated with high signal changes in the putamen and caudate head and vCJD is usually associated with hyperintensity of the pulvinar (posterior nuclei) of the thalamus. These appearances and other imaging features are described in this article. Using appropriate clinical and radiological criteria and tailored imaging protocols, MRI plays an important part in the in vivodiagnosis of this disease.

Clinical Protocols↗

PubMed2002

MRI evaluation of the diaphragmal opening: using MRI parallel to the transsphenoidal surgical approach.

Twenty-six adult diaphragma sellae and infundibulae were examined by MRI parallel to the transsphenonidal surgical plane with attention given to the diaphragmal opening. The diaphragmal opening was observed in 11 cases (42.3%). The anteroposterior diame ter of the opening ranged from 4.0 to 14.0 mm (mean 8.8 mm), and the lateral diameter ranged from 6.0 to 14.0 mm (mean 9.5 mm). In the cases of open diaphragma sellae, the infundibulum tended to be located in the posterior part of the diaphragma sellae but this was not statisticallysignificant. On MRI parallel to the transsphenoidal surgical approach, the anatomy of the dia phragma sellae was well evaluated.

Adolescent↗

PubMed1999

MRI, quantitative MRI, SPECT, and neuropsychological findings following carbon monoxide poisoning.

Carbon monoxide (CO) poisoning has been shown to result in neuropathologic changes and cognitive impairments due to anoxia and other related biochemical mechanisms. The present study investigated brain-behaviour relationships between neuropsychological outcome and SPECT, MRI, and Quantitative magnetic resonance imaging (QMRI) in 21 patients with CO poisoning. Ninety-three per cent of the patients exhibited a variety of cognitive impairments, including impaired attention, memory, executive function, and mental processing speed. Ninety-five per cent of the patients experienced affective changes including depression and anxiety. The results from the imaging studies revealed that 38% of the patients had abnormal clinical MRI scans, 67% had abnormal SPECT scans, and 67% had QMRI findings including hippocampal atrophy and/or diffuse cortical atrophy evidenced by an enlarged ventricle-to-brain ratio (VBR). Hippocampal atrophy was also found on QMRI. SPECT and QMRI appear to be sensitive tools which can be used to identify the neuropathological changes and cerebral perfusion defects which occur following CO poisoning. Cerebral perfusion defects include frontal and temporal lobe hypoperfusion. Significant relationships existed between the various imaging techniques and neuropsychological impairments. The data from this study indicate that a multi-faceted approach to clinical evaluation of the neuropathological and neurobehavioural changes following CO poisoning may provide comprehensive information regarding the neuroanatomical and neurobehavioural effects of CO poisoning.

Adult↗

PubMedDate not supplied

MRI and cine MRI of asymmetric septal hypertrophic cardiomyopathy.

OBJECTIVE: This study was designed to determine MR and cine MR characteristics of asymmetric septal hypertrophic cardiomyopathy and to correlate MR and cine MR features with the severity of left ventricular outflow tract obstruction. MATERIALS AND METHODS: Ten consecutive patients with asymmetric septal hypertrophic cardiomyopathy [resting obstructive (n = 3), latent obstructive (n = 4), nonobstructive hypertrophic (n = 3)] and five healthy volunteers underwent MRI and cine MRI. Oblique two chamber and four chamber views were obtained in all cases. RESULTS: In the 10 patients, the mean +/- SD end-diastolic myocardial thickness was 22.7 +/- 6.3 mm in the basal septum and 13 +/- 3.9 mm in the posterolateral wall with a ratio of 1.76 +/- 0.30; the corresponding values were 10.6 +/- 1.1, 10.4 +/- 1.1, and 1.02 +/- 0.08 mm, respectively, in five healthy volunteers. The mean systolic thickening of the basal septum was 22 +/- 12%. This value was 49 +/- 4% in the five healthy volunteers. In resting obstructive hypertrophic cardiomyopathy, septal wall thickness was > or = 25 mm with a systolic thickening of 10%. A systolic anterior motion of the mitral valve was demonstrated in four patients with resting subaortic pressure gradients ranging from 28 to 120 mm Hg. A signal void area was demonstrated within the left ventricular outflow tract during systole in the seven patients with obstructive cardiomyopathy. This signal void area reached its maximum during early systole in the most severe obstructions and during midsystole in the less severe obstructions. CONCLUSION: In patients with asymmetric septal hypertrophic cardiomyopathy, gross correlation was demonstrated between severity of obstruction and several MR and cine MR features including increased end-diastolic thickness of the septal wall, decreased systolic thickening of the septal wall, systolic anterior motion of the mitral valve, and signal void area within the left ventricular outflow tract during systole.

Adult↗

PubMed2006

Differentiation of sCJD and vCJD forms by automated analysis of basal ganglia intensity distribution in multisequence MRI of the brain--definition and evaluation of new MRI-based ratios.

We present a method for the analysis of basal ganglia (including the thalamus) for accurate detection of human spongiform encephalopathy in multisequence magnetic resonance imaging (MRI) of the brain. One common feature of most forms of prion protein diseases is the appearance of hyperintensities in the deep grey matter area of the brain in T2-weighted magnetic resonance (MR) images. We employ T1, T2, and Flair-T2 MR sequences for the detection of intensity deviations in the internal nuclei. First, the MR data are registered to a probabilistic atlas and normalized in intensity. Then smoothing is applied with edge enhancement. The segmentation of hyperintensities is performed using a model of the human visual system. For more accurate results, a priori anatomical data from a segmented atlas are employed to refine the registration and remove false positives. The results are robust over the patient data and in accordance with the clinical ground truth. Our method further allows the quantification of intensity distributions in basal ganglia. The caudate nuclei are highlighted as main areas of diagnosis of sporadic Creutzfeldt-Jakob Disease (sCJD), in agreement with the histological data. The algorithm permitted the classification of the intensities of abnormal signals in sCJD patient FLAIR images with a higher hypersignal in caudate nuclei (10/10) and putamen (6/10) than in thalami. Defining normalized MRI measures of the intensity relations between the internal grey nuclei of patients, we robustly differentiate sCJD and variant CJD (vCJD) patients, in an attempt to create an automatic classification tool of human spongiform encephalopathies.

Algorithms↗