Biomedical subjects
Publications and source records attributed to D Rosenfeld.
The phase of an image obtained with many magnetic resonance imaging techniques is related to some physical variable of interest. This phase needs to be unwrapped, which is complicated by the presence of noise and multiple objects of irregular shape. A new two-dimensional phase unwrapping algorithm is presented, along with simulation results.
In magnetic resonance imaging (MRI), the original data are sampled in the spatial frequency domain. The sampled data thus constitute a set of discrete Fourier transform (DFT) coefficients. The image is usually reconstructed by taking inverse DFT. The image data may then be compressed using the discrete cosine transform (DCT). We present here a method of treating the data that combines two procedures, image reconstruction and data compression. This method may be particularly useful in medical picture archiving and communication systems (PACS) where both image reconstruction and compression are important issues.
Over a 34-month period, 1105 newborns weighing between 501 and 2000 g at birth were enrolled in a prospective study of the aetiology and consequences of neonatal brain haemorrhage. The three participating hospitals care for approximately 85% of births in the study weight range in Middlesex, Monmouth and Ocean counties, New Jersey. Cranial ultrasonographic imaging through the anterior fontanelle was carried out a mean age of 4.9 +/- 2.2 hours, 25.5 +/- 4.8 hours and 7.2 +/- 0.8 days to detect haemorrhage and other brain lesions. In 93.2% of study infants, scans were read by two independent expert readers (blind to the clinical status of the child) with submission of the scan to a third reader in cases of disagreement. Confirmation of both presence or absence and, when present, scan of first diagnosis of germinal matrix and/or intraventricular haemorrhage (GM/IVH) by two independent readers was achieved in 76.3% of study infants. The first two readers agreed as to presence or absence of GM/IVH in 82.4% of infants (Kappa = 0.56). Interobserver agreement was affected by the reported scan quality and by the number of scans available, but not by the hospital of origin, race or birthweight of the infant.
OBJECTIVE: To evaluate the variability of follicle stimulating hormone (FSH) and estradiol (E2) results from different laboratories. DESIGN: Prospective analyses of sera separated and frozen, obtained from 15 female patients in the follicular phase. All kits used for radioimmunoassay (RIA) for FSH were from the Second International Reference Preparation (IRP). Four different kits were used for FSH and three for E2. SETTING: Sera obtained from each patient were separated into five test tubes and frozen. Analysis of all samples was done on the same day in each one of five participating hospital-based RIA laboratories (North Shore, Cornell, Yale, Mount Sinai, and Norfolk). PARTICIPANTS: Fifteen consecutive patients from the assisted reproductive technology program at North Shore University Hospital participated in the study. MAIN OUTCOME MEASURES: After FSH and E2 levels were tabulated for each laboratory, mean levels were calculated. RESULTS: Using the Bonferroni adjusted pairwise multiple comparisons analysis, significant differences were found between three groups of laboratories within the FSH results and three different groups within the E2 results. CONCLUSIONS: [1] Different results may be obtained on the same sera for FSH and E2 at different laboratories; [2] for FSH, even though the same IRP is used, different results are reached; [3] for E2, even when the same kits are used, results may be significantly different. These results suggest that specific FSH and E2 levels used to predict chances for achieving a viable pregnancy through in vitro fertilization should be interpreted with caution across institutions.
In magnetic resonance imaging (MRI), the original data are sampled in the spatial frequency domain. The sampled data thus constitute a set of discrete Fourier transform (DFT) coefficients. The image is usually reconstructed by taking inverse DFT. The image data may then be efficiently compressed using the discrete cosine transform (DCT). We present here a method of using DCT to treat the sampled data, which combines two procedures, image reconstruction and data compression. This method may be particularly useful in medical picture archiving and communication systems (PACS) where both image reconstruction and compression are important issues.
My main objective in this article is to show the changes which take place in the inner world of a young patient after his father's suicide, and the identifications he goes through. I hope the clinical material presented succeeds in doing so. We can also see the solid primary identifications which made it possible for this patient to get better and achieve a cure. It was not my aim to embark on a theoretical discussion of primary and secondary identification, an extremely complex subject in the writings of Freud.
Preterm newborns may experience extended periods of hospitalization which disrupt the normal early contact between the newborn and its family. Variations in the frequency of visits to 164 preterm neonates in a neonatal intensive care unit were examined in relation to infant and family status variables and compliance with follow-up appointments at 3 months postterm. The mean number of visitors decreased from day 2 to day 12 of hospitalization and then remained stable through day 21. There was a corresponding increase in the number of days with no visitors through day 12, and then stabilization. Neonates who had intraventricular hemorrhages, whose parents did not live together, and who were not firstborn had the most days with no visitors. While the mother was hospitalized herself, her condition was the only variable related to percentage of no-visitor days. The sicker the mother, the more likely the newborn had no visitors. The greater the number of days with no visitors, the poorer the likelihood that the infant was brought to a 3-month follow-up clinic appointment.
The uterine adenofibroma is a form of mixed mesodermal tumor in which both epithelial and stromal components are benign. A case is presented in which a patient with this lesion was treated with excision of the tumor rather than hysterectomy. Two years later, she developed a recurrence of the lesion, which was again treated with wide local excision. A hysterectomy was done 9 months later, and a polypoid lesion was noted in the fundus of the uterus which on histologic examination was thought to be potentially either an adenofibroma precursor or a maturation of the previous cellular adenofibroma. Since uterine adenofibroma usually occurs in older patients, the standard treatment has been hysterectomy. Because of this patient's age, she was initially treated with a more conservative approach. However, despite the fact that the uterine adenofibroma is a benign lesion, it has an obvious potential to recur when treated conservatively.
A complete system has been developed to utilize histological serial sections for two- and three-dimensional image reconstructions. Eighty to 120 sections are digitized using a personal computing system augmented with a imaging board and CCD camera. The image files are transmitted to a VAX computer for processing and image reconstruction, and the processed images are transmitted back to the personal computer for display and recording using a film recorder or PostScript printer. The software developed for the system allows serial sections to be placed into proper registration in a 256(3) array, 256 grey levels. Autoradiographs of the sections are obtained in the presence of appropriate standards which are used to recalibrate grey levels to represent linearly the radioactivity of each pixel in the sections and scale the values to allow maximum use of the grey scale. Starting from coronally sectioned material the system has been used to analyse and reconstruct rat nasal turbinates. In two dimensions horizontal and sagittal sections have been obtained while in three dimensions back-to-front and surface-rendered images have been constructed. Useful rendering of differential metabolic activity within an organ of complex geometry has been obtained, and there appears to be no reason why the system cannot be used for any material for which serial sectioning is appropriate.
A case of autoimmune thyroiditis presenting as menstrual related mood disorder (MRMD) is described. The symptoms of the patient's prospectively confirmed MRMD remitted following thyroid hormone supplementation. Although most patients with prospectively confirmed MRMD are not clinically hypothyroid or hyperthyroid, the importance of routine thyroid function tests in the initial evaluation of MRMD is underscored by the successful treatment of this patient with thyroid hormone replacement.
We present our experiences with 41 consecutive cases of intussusception. Most cases had a preliminary barium enema performed that successfully reduced the intussusception in 12 cases. Twenty-nine patients were explored surgically; bowel resection was carried out in 6 patients, and surgical reduction was carried out in 23 cases.
A flexible, personal computer (PC) based, screen-graphics oriented pulse sequence editor called PULSE has been developed for nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI). PULSE is used to set such NMR spectroscopic parameters as the delay and duration of rf transmit and receive gates, rf phase, sampling times, and such imaging parameters as rf pulse shape and gradient waveforms. The output of PULSE is a set of programs that can be loaded into a hardware pulse programmer. With PULSE, any desired NMR or MRI pulse sequence can be programmed quickly and easily.