Maria I. Argyropoulou

MRI evaluation of the basal ganglia size and iron content in patients with Parkinson's disease

AbstractObjectiveTo evaluate by MRI the area size and the degree of iron accumulation in basal ganglia nuclei that are implicated in the pathogenesis of Parkinsons disease (PD).Methods40 patients with idiopathic PD and 40 controls were examined on a 1. 5 Tesla MR imager, using a multiecho SE sequence 2000/20, 40, 60, 80, 100, 120, 140, 160 (TR/TE). The T2 relaxation time (T2) and the area of substantia nigra zona compacta (SNc), substantia nigra zona reticulata (SNr), putamen (Pu), globus pallidus external (GPe), globus pallidus internal (GPi), caudate nucleus (CN), locus coeruleus (LC) and subthalamic nucleus (STN) were assessed.ResultsThe T2 of SNc (76. 8 ± 6. 0) was lower and of Pu (79.5 ± 6.0) and GPe (69.5 ± 7.0) was higher in patients than in controls (78.6 ± 3.8, 77.4 ± 3.9 and 67.3 ± 5.7, respectively), p < 0.05. The area of CN (125.9 ± 20.2) and Pu (201.5 ± 48.7) was higher in patients than in controls (110.7 ± 21.5 and 180.1 ± 41.1, respectively), p < 0.05. A more pronounced decrease in the T2 of SNc (73.6 ± 8.9) was observed when the more affected side of patients was evaluated separately. In patients with disease duration > 5 years the T2 of STN (71.5 ± 6.3) was lower and the area of Pu was higher (215.3 ± 54.9) compared with those with disease duration ≤ 5 years (75.8 ± 10.9 and 190.9 ± 41.0 respectively), p < 0.05.ConclusionsThese findings suggest that dysfunction of the basal ganglia circuitry in PD may affect iron content not only in SNc but in STN, Pu and GPe as well. Compensatory sprouting of the remaining dopaminergic fibers could account for the increased area of the CN and Pu.

Early Treatment Reduces the Cardiovascular Risk Factors in Newly Diagnosed Rheumatoid Arthritis Patients

OBJECTIVE To investigate subclinical atherosclerosis and the effect of treatment in patients with early rheumatoid arthritis (RA). PATIENTS AND METHODS Forty patients with early RA who met the revised American College of Rheumatology (ACR) criteria and disease duration of <1 year were included in the study. Smokers and patients with classical risk factors for atherosclerosis were excluded. The serum levels of total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol were determined in all patients before and after 1 year of therapy. Carotid artery intima-media thickness (IMT) and carotid plaque were measured before and after treatment. RA disease activity was measured using the 28 joint indices score (DAS-28) and clinical improvement was determined by the ACR response criteria. Forty-five age- and sex-matched nonsmoking volunteers were used as controls. All patients were treated with methotrexate and prednisone. RESULTS RA patients had a baseline mild dyslipidemia characterized by a decrease in serum HDL-C levels and a high TC/HDL-C atherogenic ratio compared with controls. Both lipid parameters were significantly improved after treatment (P<0.01). Common carotid artery IMTs at baseline were higher in RA patients compared with controls (P<0.05). After 1 year of therapy there was a significant decrease in the IMTs (P<0.001). Thirty-five patients (88%) achieved the ACR 20%, while 30 (75%) reached the ACR 50% response criteria. A significant decrease of DAS-28 was observed after treatment (P<0.03). CONCLUSIONS The atherogenic lipid profile and subclinical atherosclerosis are features of early RA, which improved after therapy. Early intervention and control of the disease activity may reduce the risk of atherosclerosis and cardiovascular events in patients with RA.

Glioma recurrence versus radiation necrosis: accuracy of current imaging modalities

Treatment for brain gliomas is a combined approach of surgery, radiation therapy and chemotherapy. Nevertheless, high-grade gliomas usually recur despite treatment. Ionizing radiation therapy to the central nervous system may cause post-radiation damage. Differentiation between post-irradiation necrosis and recurrent glioma on the basis of clinical signs and symptomatology has not been possible. Computed tomography (CT) and magnetic resonance imaging (MRI) suffer from significant limitations when applied to differentiate recurrent brain tumor from radiation necrosis. We reviewed the contribution of recent MRI techniques, single-photon emission CT and positron emission tomography to discriminate necrosis for glioma recurrence. We concluded that despite the progress being made, further research is needed to establish reliable imaging modalities that distinguish between true tumour progression and treatment-related necrosis.

Pathogenesis, detection and treatment of Achilles tendon xanthomas

Tendon xanthomatosis often accompanies familial hypercholesterolaemia, but it can also occur in other pathologic states. Achilles tendons are the most common sites of tendon xanthomas. Low‐density lipoprotein (LDL) derived from the circulation accumulates into tendons. The next steps leading to the formation of Achilles tendon xanthomas (ATX) are the transformation of LDL into oxidized LDL (oxLDL) and the active uptake of oxLDL by macrophages within the tendons. Although physical examination may reveal Achilles tendon xanthomas (ATX), there are several imaging methods for their detection. It is worth mentioning that ultrasonography is the method of choice in everyday clinical practice. Although several treatments for Achilles tendon xanthomas (ATX) have been proposed (LDL apheresis, statins, etc.), they target mostly in the treatment of the basic metabolic disorder of lipid metabolism, which is the main cause of these lesions. In this review we describe the formation, detection, differential diagnosis and treatment of ATX as well as the relationship between tendon xanthomas and atheroma.

MRI in the Characterization and Local Staging of Testicular Neoplasms

OBJECTIVE The purpose of this study was to assess the role of MRI in the preoperative characterization and local staging of testicular neoplasms. SUBJECTS AND METHODS MRI was performed on 33 patients referred because a testicular mass had been detected clinically and sonographically. Both T1- and T2-weighted sequences were performed with a 1.5-T MRI unit. Gadolinium chelate was administered IV in all cases. We recorded the presence of a lesion and whether the histologic diagnosis of testicular malignancy could have been predicted on the basis of MRI features. For testicular neoplasms, local extension of disease was studied. The MRI findings were correlated with the surgical and histopathologic results. RESULTS Histologic examination revealed 36 intratesticular lesions, 28 (78%) of which were malignant and eight benign. Thirteen malignant testicular tumors (46%) were confined within the testis, 12 (43%) had invaded the testicular tunicae or epididymis, and three (11%) had invaded the spermatic cord. The sensitivity and specificity of MRI in differentiating benign from malignant intratesticular lesions were 100% (95% CI, 87.9-100%) and 87.5% (95% CI, 52.9-97.7%). The rate of correspondence between MRI and histologic diagnosis in the local staging of testicular tumors was 92.8% (26/28). CONCLUSION MRI is a good diagnostic tool for the evaluation of testicular disease. It is highly accurate in the preoperative characterization and local staging of testicular neoplasms.

MRI evaluation of tissue iron burden in patients with β-thalassaemia major

Abstractβ-Thalassaemia major is a hereditary haemolytic anaemia that is treated with multiple blood transfusions. A major complication of this treatment is iron overload, which leads to cell death and organ dysfunction. Chelation therapy, used for iron elimination, requires effective monitoring of the body burden of iron, for which serum ferritin levels and liver iron content measured in liver biopsies are used as markers, but are not reliable. MRI based on iron-induced T2 relaxation enhancement can be used for the evaluation of tissue siderosis. Various MR protocols using signal intensity ratio and mainstream relaxometry methods have been used, sometimes with discrepant results. Relaxometry methods using multiple echoes achieve better sampling of the time domain in which relaxation mechanisms take place and lead to more precise results. In several studies the MRI parameters of liver siderosis have failed to correlate with those of other affected organs, underlining the necessity for MRI iron evaluation in individual organs. Most studies have included children in the evaluated population, but MRI data on very young children are lacking. Wider application of relaxometry methods is indicated, with the establishment of universally accepted MRI protocols, and further studies, including young children, are needed.

T2 relaxometry and fMRI of the brain in late-onset restless legs syndrome

Objective: To assess in patients with late-onset idiopathic restless legs syndrome (RLS) the brain iron content with magnetic resonance relaxometry, and brain activation during dorsiflexion and plantar flexion of both feet, using fMRI. Methods: The study was approved by the institutional review board, and informed consent was obtained. Twenty-five RLS patients (14 women, 11 men; age range 55–82 years; mean 66.5 ± 8.9 years; disease duration 6.5 ± 4.5 years) and 12 sex- and age-matched controls were studied. A T1-weighted high-resolution three-dimensional spoiled gradient echo sequence was used for structural imaging, a multislice spin echo Τ2-weighted sequence was used for T2 relaxometry, and a single-shot multislice gradient echo planar sequence was used for fMRI. The motor paradigm consisted of alternating periods of rest and movement, each 40 seconds in duration. Region of interest analysis was used on the T2 relaxometry maps. Statistical parametric mapping software was used for analysis of the functional data. Results: T2 relaxation time was significantly higher in patients than in controls in the substantia nigra pars compacta. Within-group analysis showed that both patients and controls activated the primary motor cortex, the primary somatosensory cortex, the somatosensory association cortex, and the middle cerebellar peduncles. Patients also activated the thalamus, putamen, middle frontal gyrus, and cingulate gyrus. Between-group analysis showed that patients had higher activation of the dorsolateral prefrontal cortex. Conclusion: Late-onset restless legs syndrome is associated with low iron content of the basal ganglia and increased activity of the dorsolateral prefrontal cortex. GLOSSARY: C = constant offset parameter added to compensate for background noise bias; CN = caudate nucleus; DMT1 = divalent metal transporter 1; DN = dentate nucleus; EPI = echo planar imaging; GP = globus pallidus; IRLS = International RLS Study Group Rating Scale; JHRLSS = Johns Hopkins RLS Severity Scale; MIP = maximum intensity projection; MR = magnetic resonance; PLMS = periodic limb movements in sleep; Pu = putamen; RLS = restless leg syndrome; RN = red nucleus; ROI = region of interest; SN = substantia nigra; SNc = substantia nigra pars compacta; SNr = substantia nigra pars reticulata; So = signal amplitude at echo time = 0; SPM = statistical parametric mapping; S(TE) = signal intensity at echo time; TE = echo time; Th = thalamus; TR = repetition time.

A six stage approach for the diagnosis of the Alzheimer's disease based on fMRI data

The aim of this work is to present an automated method that assists in the diagnosis of Alzheimers disease and also supports the monitoring of the progression of the disease. The method is based on features extracted from the data acquired during an fMRI experiment. It consists of six stages: (a) preprocessing of fMRI data, (b) modeling of fMRI voxel time series using a Generalized Linear Model, (c) feature extraction from the fMRI data, (d) feature selection, (e) classification using classical and improved variations of the Random Forests algorithm and Support Vector Machines, and (f) conversion of the trees, of the Random Forest, to rules which have physical meaning. The method is evaluated using a dataset of 41 subjects. The results of the proposed method indicate the validity of the method in the diagnosis (accuracy 94%) and monitoring of the Alzheimers disease (accuracy 97% and 99%).

Age-related grey matter changes in preterm infants: An MRI study

Grey matter (GM) maturation has not been previously studied in healthy preterm children. The purpose of this study was to evaluate the age dependency of GM development in 116 GM areas in preterm subjects. Sixty one preterm infants (corrected age: 13.7+/-9.92 months, gestational age: 33.4+/-1.9 weeks) with normal structural appearance on MRI were included in the study. Using a T1-weighted high resolution 3D spoiled gradient echo sequence, volumes of 116 GM areas were calculated after their segmentation using the Voxel Based Morphometry Toolboxes and the Individual Brain Atlas Statistical Parametric Mapping (IBASPM) software packages. Non linear regression analysis assessed age dependency of volume data for every GM area using the monoexponential function y=A-Bexp(-x/C). All supratentorial GM areas followed the monoexponential function model reasonably well. Cerebellar structures had a poor goodness of fit. Volume increase of the individual GM areas followed an inferior to superior and a posterior to anterior pattern. The putamen, thalamus, and caudate nucleus reached 99% of the final volume earlier than most cortical GM areas. The visual cortex and the postcentral and precentral cortices matured earlier than the parietal, frontal and temporal cortices. The fronto-occipital asymmetry or torque seen in adults was observed in the preterm infants; the left occipital areas reached maturation earlier than the right, while the right prefrontal and frontal areas matured earlier than the left. To conclude, GM development progresses in a region-specific manner coinciding with functional, phylogenetical and regional white matter (WM) maturation.

Diffusion-weighted MR imaging of normal and abnormal scrotum: preliminary results

Magnetic resonance (MR) imaging of the scrotum represents an important supplemental diagnostic tool in the evaluation of scrotal diseases. Diffusion-weighted (DW) MR imaging is a developing technique, proved to improve tissue characterization. We evaluated the feasibility and diagnostic performance of DW MR imaging in the detection and characterization of scrotal lesions. We retrospectively evaluated 31 scrotal lesions (23 intratesticular and 8 extratesticular) in 26 men. All MR examinations were performed on a 1.5-T unit, using a pelvic-phased array coil. DW sequences were obtained using a single shot, multislice spin echo planar diffusion pulse sequence and a b factor of 0 and 900 s mm(-2). The DW MR characteristics and the apparent diffusion coefficient (ADC) values of normal scrotal contents and scrotal diseases were evaluated. Comparison between the ADC values of normal scrotum, benign lesions and scrotal malignancies was performed. The accuracy of conventional sequences, DW images alone and DW imaging combined with conventional images in differentiating benign from malignant scrotal lesions was calculated. The ADC values of testicular malignancies were different from those of normal testis and benign intratesticular lesions, and the ADC values of benign extratesticular lesions from those of normal epididymis (P<0.05). The overall accuracy of conventional imaging, DW imaging alone and DW MR combined with conventional sequences in the characterization of intratesticular lesions was 91%, 87% and 100%, respectively. Our findings suggest that DW MR imaging and ADC values may provide valuable information in the diagnosis and characterization of scrotal diseases.