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Magnetic Resonance Imaging Examination (magnetic + resonance_imaging_examination)
Selected AbstractsIncreased melatonin concentrations in children with growth hormone deficiencyJOURNAL OF PINEAL RESEARCH, Issue 2 2007Michal Karasek Abstract:, A relationship between melatonin and growth hormone (GH) is poorly understood. We compare circadian melatonin rhythms in short children with normal and decreased GH secretion. The analysis included 22 children (20 boys and 2 girls) aged 11.1,16.9 yr (mean ± S.E.M. = 14.1 ± 0.3 yr) with short stature (height SDS below ,2.0). Based on the GH peak in stimulation tests patients were divided into two groups: idiopathic short stature (ISS, n = 11; GH peak , 10 ng/mL) and GH deficiency (GHD, n = 11; GH peak < 10 ng/mL). In all patients the circadian melatonin rhythm was assessed on the basis of nine blood samples, collected in 4-hr intervals during the daytime and 2-hr intervals at night, with dark period lasting from 22:00 to 06:00 hr. Magnetic resonance imaging examination excluded organic abnormalities in central nervous system in all patients. Melatonin concentration at 24:00, 02:00 and 04:00 hr as well as the area under curve of melatonin concentrations (AUC) were significantly higher in the patients with GHD than in individuals with ISS. Significant correlations between GH secretion and melatonin concentrations at 24:00, 02:00 and 04:00 hr, and AUC were also observed. On the basis of these data it seems that the assessment of nocturnal melatonin secretion might be a valuable diagnostic tool used for the improvement of the difficult diagnosis of short stature in children. [source] Cutaneous sclerosing perineurioma of the digitINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 9 2006Toshitsugu Nakamura MD An 11-year-old Japanese girl noticed a small nodule, with mild tenderness, on the right index finger 5 years before visiting our outpatient clinic. She had no familial history of neurofibromatosis or past history of traumatic injury at the site of the tumor. Physical examination revealed a slightly elevated, subcutaneous, nodular tumor in the volar aspect between the proximal and distal interphalangeal joints of the digit (Fig. 1A). By magnetic resonance imaging examination, the tumor showed low density on both T1- and T2-weighted images, and was located just adjacent to the tendon with no invasive signs. The tumor was extirpated; at operation, it was well circumscribed and mobile without adhesion to adjacent tendon or nerve, and was easily removed. Figure 1. (a) Slightly elevated subcutaneous tumor (arrow) on the volar aspect of the right index finger. (b) gross appearance of the extirpated tumor, showing a well-circumscribed, whitish solid nodule Grossly, the tumor was a well-circumscribed, firm nodule (10 mm × 8 mm × 5 mm in size) (Fig. 1B). The cut surface was whitish, homogeneous, and solid without cystic lesions. Histologically, it was an unencapsulated, paucicellular dense, fibrous nodule with a concentric circular arrangement of collagen bundles (Fig. 2A). Amongst the fibrous bundles, a small number of ovoid/epithelioid or plump spindle cells were arranged in a corded, trabecular, or whorled (onion bulb-like) pattern (Fig. 2B); a storiform pattern was not noted. These cells were relatively uniform and had a somewhat elongated, slightly hyperchromatic nucleus with fine granular chromatin. Neither nuclear pleomorphism nor multinucleated cells were evident, and necrosis and mitotic figures were not observed. Periodic acid,Schiff (PAS) stain after diastase digestion highlighted the corded or whorled pattern of the tumor cells by encasing them. For immunohistochemical examination, formalin-fixed, paraffin-embedded serial tissue sections were stained by a labeled streptavidin,biotin method. The tumor cells were positive for vimentin and epithelial membrane antigen (EMA) (Fig. 3A), and negative for pan-cytokeratin, carcinoembryonic antigen (CEA), CD34, ,-smooth muscle actin, desmin, and CD68. Type IV collagen and laminin (Fig. 3B) were detected along the cords or whorls of the tumor cells, similar to the staining pattern of the diastase-PAS reaction. Schwann cells and axonal components, immunoreactive for S100 protein and neurofilament, respectively, were focally detected just adjacent to the cords or whorls, although the tumor cells per se did not express these proteins. Consequently, the tumor was found to be perineurial in origin and was diagnosed as cutaneous sclerosing perineurioma. Figure 2. (a) Low-power view of the tumor, showing an unencapsulated, paucicellular, dense, fibrous nodule with a concentric circular arrangement of collagen bundles (hematoxylin and eosin stain: original magnification, ×15). (b) Higher magnification of the tumor, showing ovoid or epithelioid cells arranged in cords or whorls in the abundant collagen bundles (hematoxylin and eosin stain: original magnification, ×150) Figure 3. Immunohistochemical profiles of the tumor. The tumor cells are positive for epithelial membrane antigen (a) and are surrounded by laminin (b) (original magnification, ×150) [source] Antiplatelet therapy and spontaneous perirenal hematomaINTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2005KEISUKE YAMAMOTO Abstract This case report clarifies an adverse reaction of antiplatelet therapy which has been a standard prophylactic method for patients harboring significant risks of thromboembolic events. A 71-year-old Japanese man who had been taking aspirin tablets (81 mg) for a year presented with sudden colic pain in the left flank region. An abdominal computed tomography scan revealed a significant perirenal hematoma of the left kidney. There were no pathological kidney conditions, such as renal tumors, calculi or vascular diseases, found by magnetic resonance imaging examination. After cessation of aspirin administration followed by conservative management, the hematoma completely disappeared 6 months later. This is the first documented case of spontaneous perirenal hematoma secondary to low-dose aspirin treatment. While such unpleasant events occur extraordinarily, this should be noted as a severe risk of antiplatelet therapy. [source] Microemboli may link spreading depression, migraine aura, and patent foramen ovaleANNALS OF NEUROLOGY, Issue 2 2010Ala Nozari MD Objective Patent foramen ovale and pulmonary arteriovenous shunts are associated with serious complications such as cerebral emboli, stroke, and migraine with aura. The pathophysiological mechanisms that link these conditions are unknown. We aimed to establish a mechanism linking microembolization to migraine aura in an experimental animal model. Methods We introduced particulate or air microemboli into the carotid circulation in mice to determine whether transient microvascular occlusion, insufficient to cause infarcts, triggered cortical spreading depression (CSD), a propagating slow depolarization that underlies migraine aura. Results Air microemboli reliably triggered CSD without causing infarction. Polystyrene microspheres (10,m) or cholesterol crystals (<70,m) triggered CSD in 16 of 28 mice, with 60% of the mice (40% of those with CSD) showing no infarcts or inflammation on detailed histological analysis of serial brain sections. No evidence of injury was detected on magnetic resonance imaging examination (9.4T; T2 weighted) in 14 of 15 selected animals. The occurrence of CSD appeared to be related to the magnitude and duration of flow reduction, with a triggering mechanism that depended on decreased brain perfusion but not sustained tissue damage. Interpretation In a mouse model, microemboli triggered CSD, often without causing microinfarction. Paradoxical embolization then may link cardiac and extracardiac right-to-left shunts to migraine aura. If translatable to humans, a subset of migraine auras may belong to a spectrum of hypoperfusion disorders along with transient ischemic attacks and silent infarcts. ANN NEUROL 2010;67:221,229 [source] Magnetic Resonance Analysis of Postsurgical Temporal LobectomyJOURNAL OF NEUROIMAGING, Issue 3 2001Taoufik M. Alsaadi MD ABSTRACT Background and Purpose. The effect of temporal lobe transection area, volume of postoperative gliosis, and surgical technique on patients' seizure-free outcome is unknown. The authors studied the effects of these variables on patients' seizure-free outcome. Methods. A retrospective review of magnetic resonance imaging examinations acquired 3 to 18 months after temporal lobe resection was carried out for 18 patients with intractable temporal lobe seizures and known postsurgical outcomes for more than 2 years. The total volume of radiologically probable gliosis evident on axial proton-density-weighted images was calculated for each patient using software on an independent console. The total area of temporal lobe surface transected by the scalpel was calculated as well, using sagittal T1-weighted images. The total volume of gliosis, the total area of transected temporal lobe, and the specific type of surgery (sparing vs no sparing of the superior temporal gyrus) were then correlated with the postsurgical outcome of the patients. An examiner with no prior knowledge of the patients' postsurgical outcomes carried out the above calculations and measurements. The patients' postoperative outcome was defined using Engel classifications, and patients were divided into two groups: group A with Engel class 1 (n= 9) and group B with Engel classes 2,4 (n= 9). Results. The mean volumes of postoperative gliosis were not significantly different between group A (3592.3 mm3) and group B (4270 mm3). The mean area of transected temporal lobe was also similar between group A (1865.2 mm2) and group B (1930 mm2). With regard to surgical technique, there were 5 subjects who had the superior temporal gyrus resected and 13 who did not. Eighty percent of patients with the superior temporal gyrus resected were Engel class 1 or 2, whereas only 20% were of Engel class 3 or 4. Conclusion. The authors found no clear association between postoperative outcome and residual temporal lobe gliosis, the surgical technique, or the total area of temporal lobe transected by the scalpel. [source] | ||||||||||