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T R Miller

Publications and source records attributed to T R Miller.

At least 145 records · Page 8Linked to original sources
PubMed1991

Characterization by image cytometry of duct epithelial proliferative disease of the breast.

To develop a morphometric model of premalignant breast epithelium, we evaluated 120 lesions classified as nonproliferative disease (n = 20), hyperplasia (n = 20), moderate hyperplasia (n = 20), atypical hyperplasia (n = 20), carcinoma in situ (n = 20), and carcinoma (n = 20) in tissue from surgical biopsy or mastectomy. Atypical hyperplasia, a component of duct epithelial proliferative disease, has frequently been described in breasts with carcinoma. Atypical hyperplasia is generally viewed as premalignant or as a marker of increased risk for breast cancer. Measurements of nuclei in breast lesions were obtained with the Leitz TAS Plus on 4-microns sections stained for DNA with the Azure A Feulgen reaction. Nuclei of duct epithelial lesions had morphometric features that displayed changes from nonproliferative disease to carcinoma. The morphometric data from each lesion were compared among the six disease groups. Means of nuclear area, perimeter, maximum and minimum diameter, and large dark and large light intranuclear areas increased with higher degrees of proliferative abnormality. When the six groups of lesions were compared using the means of the first four nuclear features, atypical hyperplasia was significantly different (P less than 0.05) from carcinoma and non-proliferative lesions, but not from hyperplasia, moderate hyperplasia, or carcinoma in situ. These findings suggest that objective morphometric descriptors for characterizing significant proliferative lesions can be established using image cytometry. The progressive increases also suggest that proliferative breast disease is a continuum that includes premalignant lesions.

Azure Stains↗
PubMed1991

Cytomorphometry of uveal melanoma. Comparison of fine needle aspiration biopsy samples with histologic sections.

A number of approaches are being investigated to increase the prognostic accuracy for uveal melanoma patients; the standard deviation of nucleolar area measurements and the DNA content appear to correlate better with survival than do classic histologic parameters. The utility of performing cytomorphometric measurements on fine needle aspiration (FNA) biopsy samples was prospectively analyzed for 24 eyes containing uveal melanomas that were examined with both 25-gauge FNA biopsy and standard histologic techniques. "Masked" analysis of the cellular composition of the 24 cases showed the presence or absence of epithelioid cells to be accurately predicted on the FNA samples in all cases. Image analysis cytomorphometric measurements of nucleolar area showed marked variability (with r less than 0.4) when FNA and histologic samples from the same case were compared. The relationship between these measurements was affected by cell type, sampling, specimen processing and investigator experience.

Biopsy, Needle↗
PubMed1991

Three-dimensional display in nuclear medicine and radiology.

As three-dimensional displays become more common in nuclear medicine and radiology, it is important to know when they should be employed. Selection of the appropriate three-dimensional rendering method requires an understanding of the techniques and both their advantages and limitations. This review article is intended to provide an introduction to three-dimensional rendering techniques. Methods in surface mapping, surface rendering, and volume rendering are presented, with discussion of specific clinical applications in nuclear medicine, computed tomography, and magnetic resonance imaging.

Diagnostic Imaging↗
PubMed1990

Metastatic ciliary body carcinoid tumor.

A 50-year-old man with a history of systemic carcinoid had decreased right eye vision and a darkly pigmented cilio-choroidal mass. Results of ultrasonographic and fluorescein angiographic examinations were consistent with a malignant melanoma. Fine-needle aspiration biopsy of the lesion identified it as a carcinoid metastasis. The patient refused both radiation and enucleation; complete excision with a cyclochoroidectomy was performed. Histopathologic examination showed a carcinoid neoplasm covered by marked hyperplasia of the retinal pigment epithelium that produced the pigmented appearance of the lesion.

Biopsy, Needle↗
PubMed1990

Lack of correlation of clinical breast examination with high-risk histopathology.

PURPOSE: Routine breast examination frequently finds differences in palpable density and palpable nodularity, but it is not known if these differences correlate with the presence of high-risk histopathology. PATIENTS AND METHODS: To test for a relationship between clinical breast examination and histopathology, we devised separate, 4-point scales of clinical density and nodularity and validated these scales by repeat examinations 4 or more months apart in 199 separate breasts (the scale was the same or within 1 point on repeat examination 87% of the time for density and 90% for nodularity). We then used these two clinical scales to compare density and nodularity to histopathology of breast tissue at the margins of segmental resections in 60 women undergoing breast-conserving treatment of primary breast cancer. In cases such as these, a large sample of "normal" tissue is intentionally removed when the wide excision is done to obtain negative margins. Histopathology at the margins was graded according to the consensus panel of the American College of Pathology; as might be expected in women with previous cancer, some higher-risk histopathology was found in 37% of cases. A relationship was sought using Spearman's rank correlation coefficient. RESULTS: Neither clinical breast density (rho = 0.16) nor clinical breast nodularity (rho = 0.01) related to the presence of high-risk histopathology in the underlying tissue. Interestingly, breast nodularity increased with age (rho = 0.28), and clinical density and nodularity were inversely related (rho = -0.28). CONCLUSION: We conclude that neither clinical breast density nor nodularity correlates with histopathology and that it is unlikely that a larger study would find a clinically useful correlation. Therefore, a clinical examination should not be used to decide that high-risk histopathology is likely to be present in an individual woman's breast.

Adult↗
PubMed1990

Hospital-wide distribution of nuclear medicine studies through a broadband digital network.

Nuclear medicine provides a good environment for the evaluation of picture archiving and communication systems (PACS) because of the relatively small quantity of digital data that are generated, leading to reduced requirements for storage, display, and transmission compared with those found in radiology. The PACS in nuclear medicine is characterized by use of a single computer as a central storage, display, and analysis node. Images are acquired with use of small, low-cost computers attached to each camera. This network configuration offers advantages of convenience, but with great reliance on a single computer. A campus-wide picture network is under development at Washington University employing broadband cable television technology supplemented by baseband Ethernet (Digital Equipment Corp, Maynard, MA) components. All areas of diagnostic radiology and nuclear medicine are connected via a PACS testbed project. A radiology information system, supporting over 250 terminals, provides digital tracking of patients and report generation and retrieval. A new image workstation is under development in conjunction with Digital Equipment Corp. This system will permit display in multiple windows of report information and images from various modalities. A lung scan demonstration project is now beginning that is designed to test the value of a PACS in nuclear medicine. Digitally acquired chest radiographs will be displayed on an image workstation in nuclear medicine along with digital ventilation and perfusion lung scans. It is hoped that time-consuming logistic bottlenecks now encountered in lung scan interpretation will be reduced.

Computer Communication Networks↗
PubMed1990

The clinical role of radionuclide imaging in cardiac transplantation.

Cardiac transplantation is developing into a routine therapy with widespread availability. Nuclear medicine studies play an important role in evaluating potential transplant recipients and in providing documentation of the severity of ventricular dysfunction and the presence of ischemic but viable myocardium. Nuclear cardiology has increased our knowledge of the physiology of cardiac transplants and is now playing an increasing adjunctive role in management. Radionuclide ventriculography performed early after transplantation can identify patients both with abnormal biventricular function resulting from preservation injury and with isolated right ventricular dysfunction. It also provides important functional data that complements the cardiac biopsy in allograft rejection. New techniques such as 111In antimyosin antibodies and 111In lymphocytes have potential value for the accurate, noninvasive diagnosis of rejection. PET promises to improve the ability to diagnose coronary atherosclerosis of the allograft.

Coronary Disease↗
PubMed1990

A71378: a CCK agonist with high potency and selectivity for CCK-A receptors.

Receptors for the brain and gut peptide cholecystokinin (CCK) have been classified into two classes, CCK-A and CCK-B. To date, peptide analogues with selectivity for the CCK-B receptors have been identified, and selective antagonists for CCK-A and CCK-B receptors have been reported as well; until now, there have been no reports of highly selective CCK-A agonists. Herein we describe the properties of A71378 [desamino-Try(SO3H)-Nle-Gly-Trp-Nle-(N-methyl)Asp-Phe-NH2], a highly selective CCK-A receptor ligand. Characterization of A71378 was carried out in the guinea pig pancreas, cortex, gastric gland, and ileum, as well as in NCI-H345 cells. The IC50 values of A71378 for the pancreatic CCK-A, cortical CCK-B, and gastrin receptor were 0.4 nM, 300 nM, and 1,200 nM, respectively. A71378 proved to be a potent agonist in eliciting pancreatic amylase secretion (EC50 = 0.16 nM) and ileal muscle contraction (EC50 = 3.7 nM). In contrast, A71378 was relatively weak (EC50 = 600 nM) in mobilizing intracellular calcium from NCI-H345 cells, which express CCK-B/gastrin receptors. The high potency and selectivity of A71378 for the CCK-A over CCK-B and gastrin receptors is unprecedented among CCK peptides. Studies on CCK-7 analogues indicate that N-methylation of the Asp residue is responsible for the observed selectivity for CCK-A receptors. This discovery of a selective CCK-A agonist should prove valuable for studies aimed at understanding the physiological roles of CCK-A receptors in the brain and periphery.

Amino Acid Sequence↗
PubMed1990

Design and use of PET tomographs: the effect of slice spacing.

With modern positron tomographs producing 14, 21, or more transaxial slices, the effects of slice spacing on quantitative reconstruction and three-dimensional displays must be evaluated. This analysis can be approached in terms of the partial volume effect, quantified by the recovery coefficient, or in terms of sampling theory leading to the concept of aliasing. The axial recovery coefficient varies as a function of the position of an object in relation to the slices, with greater variability for larger slice spacings and finer axial resolutions. The aliased image power varies in the same way. The variability in the recovery coefficient and aliasing increase when smaller objects are imaged. Tomographs should be designed with slice spacing approximately half the full-width at half-maximum axial resolution of the tomograph; finer spacing does not appear to confer significant advantages. Thus, quantification and display in positron tomography depend on slice spacing, resolution, and object size.

Equipment Design↗
PubMed1990

The clinical utility of radionuclide ventriculography in cardiac transplantation.

To assess ventricular function in patients who have undergone cardiac transplantation, 247 radionuclide ventriculograms were performed on 94 patients. During the first three days after transplantation, 19% demonstrated left ventricular dysfunction and 41% showed isolated right ventricular dysfunction. In 95 cases, radionuclide ventriculography was performed within 24 hr of myocardial biopsy. A reduction in left ventricular ejection fraction to less than 50% was significantly more common with moderate-severe rejection than with mild rejection. In six instances in which there was discordance between ventriculography and biopsy, radionuclide ventriculography proved particularly useful: three cases showed severe left ventricular dysfunction despite only mild rejection by biopsy, and three cases with ventricular dysfunction from rejection were missed by the initial biopsy. Thus, radionuclide ventriculography can provide functional data in transplant patients that is complementary to myocardial biopsies since biopsy grade is a poor predictor of left ventricular function and biopsy can miss significant rejection.

Biopsy↗
PubMed1990

Three-dimensional functional images of myocardial oxygen consumption from positron tomography.

Images from positron emission tomography (PET) are usually presented as transaxial slices portraying tissue radioactivity. Studies can be difficult to interpret from transaxial images, and the temporal changes in tissue tracer concentrations which permit quantitative determinations of metabolism and perfusion are not displayed. We have developed a method to give quantitatively accurate three-dimensional images of myocardial oxygen consumption from serial images of the myocardial washout of carbon-11-acetate. Following i.v. bolus injection, data are collected for 20-30 min. The time-activity curves for each pixel in the transaxial slices are fit to a monoexponential function to determine the washout rate, which is directly related to the rate of myocardial oxygen utilization. Thus, functional images of myocardial oxygen consumption are produced for all seven slices of PET data. A previously developed method is then used to generate realistic and quantitatively accurate three-dimensional images.

Acetates↗
PubMed1990

A controlled clinicopathologic study of myocardial fibrosis in systemic sclerosis (scleroderma).

Clinicopathologic correlations of myocardial fibrosis were examined in 54 autopsied patients with scleroderma and 54 age and sex matched autopsy controls. Thirty eight (70%) of the patients with scleroderma had myocardial fibrosis compared to 20 (37%) of the controls (p less than 0.005). There was no significant difference in the prevalence of contraction band necrosis in the patients with scleroderma (22%) compared to controls (17%). Patients with scleroderma with left ventricular dysfunction in the absence of other causative factors clinically had a greater prevalence of both advanced myocardial fibrosis (60%) and contraction band necrosis (40%) than did the other patients with scleroderma or the controls. We conclude that patients with scleroderma with the greatest likelihood of advanced myocardial fibrosis can be identified clinically, and their findings are consistent with the presence of microvascular coronary vasospasm, a "myocardial Raynaud's phenomenon."

Adult↗
PubMed1990

Volume rendering in three-dimensional display of SPECT images.

Three-dimensional display utilizing volume rendering is valuable in the display of SPECT data. Volume rendering enhances continuity of structures compared to slice display, and cine display of volume rendered images facilitates understanding of spatial relationships. Image contrast and noise characteristics were analyzed for depth-weighted maximum activity projection, a form of volume rendering proposed by the authors for "hot spot" imaging in nuclear medicine. Contrast in the rendered images was nearly equal to that in slice display, and substantially improved compared to planar images. Image noise was reduced compared to both projection and slice display. Rendered images may be generated automatically in only a few minutes following filtered backprojection, permitting routine clinical use.

Bone and Bones↗
PubMed1989

Leukostasis: a phenomenon of prolymphocytic leukemia.

We are reporting a case of a patient with prolymphoctic leukemia complicated by fatal leukostasis. Multiple leukemic thrombi and leukoaggregates were demonstrated on postmortem examination in both the brain and lungs. This represents the first report pathologically documenting leukostasis in a chronic lymphoid malignancy.

Brain Diseases↗
PubMed1989

Interactive reconstruction in single-photon tomography.

A new method is described to allow interactive selection of the reconstruction filter at the time of interpretation of images from single-photon tomography. In the filtered back projection algorithm, the only part of the reconstruction process requiring user interaction is the selection of the window function. Since the ramp and window filters have different purposes, they can be separated, placing the window at the end of the reconstruction process as a three-dimensional filter. All stages of reconstruction except the window filtering are performed before the physician begins to interpret the study. The three-dimensional filtering is performed very rapidly with use of the Chebyshev convolution algorithm. A 64 x 64 x 64 pixel cube of data is filtered in 13-33 s using filters of 3-11 lengths. Smaller volumes of image data can be filtered in less than 1 s; thus, the user can interactively choose any desired filter for a given tomographic study at the time of interpretation of the images.

Algorithms↗