The aim of the present study was to propose a model and a method to derive the oxyhemoglobin blood content in the retinal veins and arteries by full spectrum reflectometry measurements in the spectral zone from 430 to 680 nm. We proposed a mathematical equation expressed as a linear combination of two terms S(OHb)(λ) and S(Hb)(λ) representing the normalized spectral absorption functions of the hemoglobin and the oxyhemoglobin, one term λ(-n) representing the ocular media absorption with scattering, and a family of multi-Gaussian functions, which usefully compensate for the noncompatibility of the model and the experimental data in the red spectral zone. The present paper suggests that the spectral reflection function in the area from 520 to 580 nm is optimal in calculating the oxyhemoglobin concentration of the blood contained in the endothelial structures of retinal vessels. The model calculation needs a function (1/λ)(-n) that corrects for the ocular media absorption and light scattering on the vessels' structures. For the spectral area of lights with wavelength larger than 580 nm, the reflected light represents mainly the light scattering on the red blood cells.
\s=b\The 29th patient with a lingual osteoma is presented. This is the first case, to our knowledge, with preoperative radiographic and computed tomographic documentation. This rare, benign tumor almost always occurs as a pedunculated solitary mass that arises from the posterior tongue near the foramen cecum. The patients are usually young women who complain of dysphagia or fullness in the base of the tongue. The imaging findings and theories of the origin of this tumor are described. (Arch Otolaryngol Head Neck Surg 1989;115:989-990) The occurrence of an extraosseous osteoma in the tongue is rare, with only 28 patients having been reported in the literature.112 A review of these cases reveals that most patients are women in their third to fourth decades of life who present with a complaint of dysphagia or tongue swelling and in whom the oste¬ oma is located near the foramen cecum, just posterior to the circumvallate papillae. We present an addi¬ tional case that is the first one, to our knowledge, to have preoperative plain The patient, a 27-year-old woman, pre¬ sented to an otolaryngologist for evalua¬ tion of a tongue mass found on a routine physical examination. The patient was aware of a "lump" at the back of her throat for the past 12 years. Results of a physical examination revealed a 2-cm firm pedunculated mass that had its origin just to the left of the foramen cecum at the base of the tongue. The results of the remaining phys¬ ical examination were normal and her medical history was noncontributory. A CT scan was performed. The lateral scout view (Fig 1) revealed an ossified mass overlying the base of the tongue. Axial CT scans revealed a densely ossified mass just poste¬ rior to the base of the tongue (Fig 2) and no definite soft-tissue attachment to the tongue base was seen. The patient was taken to the operating room and the mass was excised with an elliptical 1-cm margin of normal tongue mucosa and musculature.Pathologic findings revealed an osteoma with overlying lingual mucosa. The patient has had an uneventful postoperative course.COMMENT A review of the literature allows a rather consistent clinical and patho¬ logic composite to be made for patients who have osteomas of the tongue. About three quarters (75% ) of the cases are women who have an average age of 28 years, and there is no apparent race predilection.5 Ap¬ proximately 40% of the patients have complained of either dysphagia or a sensation of fullness in the midline posterior third of the tongue.The lesions have varied from 0.5 to 2.0 cm in diameter and most have been pedunculated with their origin being near the foramen cecum. In all except one case the osteoma has been solitary with two osteomas being reported in a single patient.10 Surgical excision has been curative in all cases.Histologically these lesions are mature osteomas that are surrounded by a thin acellular layer of fibrous connective tissue, which is, in turn, covered by a stratified squamous epi¬ thelium like that of the normal lin¬ gual mucosa.With the exception of le...
A new method of assessing the severity of aortic regurgitation severity by magnetic resonance imaging has been developed. Two groups were studied: 20 controls (age = 58 +/- 19 years) without valvular aortic disease, and 24 patients (age = 62 +/- 13 years) with chronic aortic insufficiency evaluated by magnetic resonance and aortic root cineangiography within 1 week of each other. A magnetic resonance sequence (TR = 35 ms/TE = 12 ms/flip angle = 20 degrees/magnet = 1.5 T) was acquired in a plane containing the thoracic aorta. A transverse saturation band 30 mm wide was positioned 30-40 mm above the aortic valve. Aortic insufficiency was graded; the importance of end-diastolic retrograde movement in the saturation band in the descending aorta was noted. Magnetic resonance was also compared to Doppler echocardiography in 20 patients. In the controls, we found that retrograde blood flow was absent (18/20) or mild (2/20). In contrast, the presence of marked retrograde movement in a saturation band across the thoracic aorta was always associated with severe aortic regurgitation (angiographic grade III or IV). This rapid method (imaging time less than 20 min) can be applied in most patients with aortic regurgitation and is likely to be helpful when echocardiography is not possible or gives inconclusive results.
High activity labeled platelets could be useful for the detection and observation of small foci of thrombosis by gamma-camera imaging. Therefore platelets were labeled with 111In-oxine containing increasing activities of 111In to determine the elimiting amount of this tracer that did not cause cell damage. A labeling procedure was employed so that all the chemical parameters remained constant except the amount of 111In. Platelet damage was studied by ADP-induced aggregability according to the Born procedure and by scanning and ultrastructural electron microscopy. Platelets labeled with the lowest activity 2.2 MBq/ml of platelet suspension (10(9) cells/ml) showed no alterations. With the highest activity studied, (22 MBq/ml) aggregability decreased by two-thirds and great changes in the shape of the platelets were seen by electron microscopy. These modifications were attributed to the decay of 111In predominantly located in the platelet cytosol. Labeling of platelets with an activity higher than 7.4 MBq/ml is unsuitable for detection of thrombosis since normal platelet functions are not retained.
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