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Biomedical subjects

E W Fordham

Publications and source records attributed to E W Fordham.

17 recordsLinked to original sources
PubMed1992

Image normalization and background subtraction in T1-201/Tc-99m parathyroid subtraction scintigraphy. Effect on lesion detection.

The authors have developed two computer algorithms for T1-201/Tc-99m parathyroid subtraction scintigraphy that was performed on patients who subsequently underwent surgical exploration of the neck. Both methods employed a region-of-interest drawn around the thyroid/parathyroid glands for image realignment. The first algorithm normalized the Tl-201 and Tc-99m images using the ratio of maximum counts over the thyroid in each image. The second computer algorithm incorporated Tl-201 image background correction and normalization by the average of the ratios of maximum counts computed over each quadrant in both images. In 10 patients with confirmed parathyroid adenomas or hyperplasia, the first method yielded a 44% sensitivity. Upon reanalysis with the second algorithm, the sensitivity improved to 100%. Subsequently, in a total of 22 patients with 30 abnormal glands analyzed with the second algorithm, a sensitivity of 80% (94% for adenoma and 62% for hyperplasia) was achieved, with a specificity of 91%, as confirmed by surgery.

Algorithms↗
PubMed1979

Myocardial imaging with 134mCesium. Comparison of scintigraphic and cineradiographic results.

Thirty-four patients had noninvasive myocardial perfusion imaging at rest using 134mCs. The results were compared with the results of coronary cineangiography and left ventriculography. All 21 patients who had abnormal left ventriculograms had corresponding myocardial imaging defects. This group included 14 patients with electrocardiographic evidence of either an old inferior, anteroseptal, anterior, or anterolateral myocardial infarction. Thirteen patients had normal left ventriculograms: this group included 6 patients with 75% or greater obstruction of one or more coronary arteries and 7 patients with normal or insignificantly diseased vessels. Only 2 of these patients had abnormal myocardial images: both had severe obstruction of the proximal left anterior descending artery without collateral filling of this vessel. In the resting patient who has 134mCs myocardial imaging, we concluded that we primarily are visualizing varying degrees of scarred myocardium rather than reversibly ischemic myocardium.

Adult↗
PubMed1979

The relationship of computed tomography, gray-scale ultrasonography and radionuclide imaging in the evaluation of hepatic masses.

Hepatic scintigraphy, gray-scale ultrasonography, and computed tomography have proven to be useful in the initial detection and evaluation of hepatic masses. These studies appear to be complimentary since each provides information not available from the others. Hepatic scintigraphy is currently the method of choice for the initial evaluation of the liver for mass lesions as it is easily performed, relatively inexpensive, and affords detectability of intrahepatic mass lesions at least as great as that of ultrasonography or computed tomography. When a definite or suspected abnormality is seen by hepatic scintigraphy, computed tomography or ultrasonography may be helpful in providing better anatomic definition or clarification of the nature of the abnormality. The choice between these latter two modalities depends on the type of scanning equipment available and the observer's experience with each method.

Aged↗
PubMed1978

Gallium-67 imaging in the management of Hodgkin's disease and other malignant lymphomas.

Gallium-67 imaging is useful in the management of patients with malignant lymphoma, despite its obvious limitations. Data currently in the literature regarding the detectability of sites of lymphoma by 67Ga imaging should be regarded as representing the minimum that can be expected from the method, since all reported series are based on outmoded imaging techniques. The detectability of disease sites appears to vary with tumor histology and anatomic location. Gallium-67 imaging is most useful in following patients after treatment. However, it may justifiably play an important role in the initial staging of lymphoma if the prior probability of disease in the abdomen is low. Lymphoma in abdominal lymph node sites is at least as detectable by 67Ga imaging as by lymphangiography.

Abdominal Neoplasms↗
PubMed1978

The predictive value of myocardial perfusion scintigraphy after stress in patients without previous myocardial infarction.

Seventy-five patients who had chest pain but no history or ECG evidence of myocardial infarction (MI) underwent myocardial-stress perfusion scintigraphy (MSPS) with thallium-201, treadmill-stress testing (TST), and coronary cineangiography (CA). The sensitivities of MSPS and TST for coronary stenosis greater than or equal to 75% were 68% and 71%, respectively; their specificities were 97% and 79%, respectively (0.1 greater than p greater than 0.05). When the character of a patient's chest pain is considered, Bayesian analysis leads to the following conclusions: (a) MSPS can be useful in pre-CA screening of patients with chest pain but no MI if their pain is thought to be of uncertain or nonischemic origin: (b) the sensitivity of Tl-201 MSPS is not sufficient for pre-CA screening of patients without MI who have typical or atypical angina pectoris; (c) the sensitivity of MSPS would have to be approximately 95% in order for the test to be useful in pre-CA screening of patients who have atypical angina pectoris; (d) MSPS may be superior to TST in these applications; and (e) it is not clear that there is any advantage in combining MSPS and TST into a single screening test rather than using MSPS alone.

Cineangiography↗
PubMed1977

The complementary role of computerized axial transmission tomography and radionuclide imaging of the brain.

Computerized axial transmission tomography and radionuclide imaging are complementary procedures, and the following recommendations are made as to their use. Where there is no real clinical suspicion of intracranial disease, either modality can be used for "rule out" screening; the choice can frequently be made on the basis of which modality is cheaper or more quickly available. It should be remembered that "quicker" is often "cheaper". Total cost is determined, not only by the cost of the procedure, but also the per diem costs incurred in waiting for that procedure. Thus the more expensive modality may, in effect, be cheaper if delays are shorter. Screening of the elderly patient, particularly when atrophy or communicating hydrocephalus is of clinical concern, should be by the CT method because of its ability to visualize cerebrospinal fluid spaces. When clinical signs and symptoms point to intracranial abnormality, both modalities should be utilized. If either study done first is normal, use of the other modality is mandatory. When the first study is positive with pathognomonic findings for a specific disease, which totally explains the patient's neurologic problems, the second study need not be employed. Such examples might include the fresh cerebral hemorrhage demonstrated by CT imaging, the AV malformation defined by dynamic-static radionuclide imaging, or multifocal metastatic lesions defined by either. However, when the clinical picture is not totally and satisfactorily explained by the demonstrated disease, the other modality should also be employed. Under many circumstances, neither study will be so reliable, specific, and free of false-negative or false-positive findings as to warrant ignoring the additional information potentially available from the other study.

Astrocytoma↗
PubMed1977

Rectal perchlorate for unconscious patients prior to brain scintigraphy with pertechnetate: concise communication.

Patients undergoing brain scintigraphy with pertechnetate are frequently premedicated with oral perchlorate. However, the oral route is difficult to employ in unconscious or uncooperative patients or when oral intake is restricted. In such situations, rectal administration of sodium perchlorate dissolved in water is an effective alternative to oral administration.

Brain Diseases↗
PubMed1977

Cardiac blood pool imaging over the complete cardiac cycle with a multiformat imager.

A new method of obtaining scintigraphic images of the cardiac blood pool for the study of ventricular wall motion is described. The method, which is based upon an inexpensive modification of a commercial multiformat imaging device, yields a set of serial gated images covering the entire cardiac cycle. These images may be converted into a film loop to yield a continuous motion picture of the mechanical cycle of the heart.

Heart Function Tests↗
PubMed1976

Bone marrow scanning with 52iron (52Fe). Regeneration and extension of marrow after ablative doses of radiotherapy.

Extensively irradiated patients were studied from 0 to 73 months after irradiation by 52Fe bone marrow scanning. Marrow regeneration was observed in most patients after intervals of 12 months or longer. The degree of recovery was not dose-related and the marrow ablative dose was not defined with doses of 4000-5000 rads. Degree of recovery depended more upon the antomic region and/or sequence of fields treated; the last field treated invariably showed poorer regeneration when recovery was uneven. Active erythropoisis expanded into distal inactive erthropoietic sites from 3-12 months after irradiation and then decreased thereafter. Blood count cytopenias were almost always restricted to the first year after irradiation.

Adolescent↗
PubMed1976

Brain scanning with the Anger multiplane tomographic scanner as a second examination evaluation by the ROC method.

One hundred and one patients (43 abnormal, 58 normal) were re-examined with a commercial prototype of the Anger multiplane tomographic scanner after brain scintigraphy. The studies were interpreted independently by four observers of varying experience. Observer performance, in terms of ROC curves, was substantially better when interpreting the tomographic brain scans and camera scintigrams together or the tomographic scans alone than when interpreting the camera images alone. Re-examination with the scanner increases the accuracy of brain scintigraphy (observer performance) in cases in which there is difficulty distinguishing intracranial lesions from superficial foci of activity by camera scintigraphy alone.

Brain Neoplasms↗
PubMed1976

Brain scanning with the Anger multiplane tomographic scanner as a primary examination. Evaluation by the ROC method.

A commercial prototype of the Anger multiplane tomographic scanner was compared with a scintillation camera, in terms of observer performance, as a primary instrument for brain scintigraphy. Observer performance (diagnostic accuracy), expressed as ROC curves, was slightly better when reading the tomographic scans than when reading the camera images. In brain scintigraphy of a general population, the scanner has a small advantage over the scintillation camera. This advantage is directly proportional to the fraction of cases in which there is difficulty differentiating intracranial lesions from superficial foci of activity on the camera image.

Brain Neoplasms↗
PubMed1975

Modification of a rectilinear scanner to improve 67Ga scans.

A simple and inexpensive electrical modification of the pulse-height analyzers of the Ohio-Nuclear Model 84FD rectilinear scanner, which allows the use of wide pulse-height intervals, is described. The modified instrument is applied to 67Ga scanning, in which the increase acceptance of gamma rays produces scans of increased count density and improved image quality.

Gallium Radioisotopes↗