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Biomedical subjects

E W Fordham

Publications and source records attributed to E W Fordham.

At least 37 records · Page 2Linked to original sources

Coronary artery disease: detection by phase analysis of rest/exercise radionuclide angiocardiograms.

Thirty-six patients with chest pain but no myocardial infarction or conduction defects and 4 volunteers (3 normals and 1 with asymptomatic aortic insufficiency) underwent radionuclide angiocardiography. Phase analysis was performed and the standard deviation (SD) ("spread") and skewness ("asymmetry") of the left ventricular (LV) phase histogram determined at rest and during maximum exercise. The SD of the LV phase histogram was of no value; however, when -0.1 was taken as the upper limit of normal skewness at maximum exercise, skewness was equally as sensitive as conventional criteria for coronary artery disease (CAD) and also more specific. The authors conclude that LV histogram skewness during maximum exercise may be superior to conventional criteria for detection of CAD with rest/exercise radionuclide angiocardiograms.

Adult↗

Noninvasive identification of initial site of abnormal ventricular activation by least-square phase analysis of radionuclide cineangiograms.

Least-square phase analysis (LSPA) of radionuclide cineangiograms demonstrates the sequence of onset of inward ventricular movement noninvasively. To validate the method and explore its ability to identify abnormal initial sites of ventricular activation, LSPA was applied to 14 patients with pacemakers (one with electrodes in two locations) (group 1) and three patients with recurrent ventricular tachycardia (VT) (group 2) who had undergone electrophysiologic endocardial mapping. The segment in which the site of initial ventricular activation was located was correctly identified in 13 of 15 paced studies and in two of three group 2 patients during VT. Pacing increased the duration of spread of onset of inward ventricular movement, and the duration of spread of onset correlated well with the duration of the QRS (r = 0.80). The sequence of onset of inward ventricular movement during VT was similar to the sequence of depolarization in all three group 2 patients. These preliminary results suggest that the sequence of onset of ventricular contraction as depicted by LSPA is a valid representation of the actual contraction sequence and that LSPA or radionuclide cineangiography correctly identifies abnormal sites of initial ventricular activation.

Arrhythmias, Cardiac↗

Sequence and timing of ventricular wall motion in patients with bundle branch block. Assessment by radionuclide cineangiography.

We determined the sequence and timing of inward ventricular wall motion by least-square phase analysis of radionuclide cineangiograms in 10 patients with left bundle branch block (LBBB), five patients with right bundle branch block (RBBB) and 11 patients with normal conduction. All LBBB and RBBB patients had normal coronary arteries and no segmental wall motion abnormalities. The left ventricle (LV) was divided into eight segments and the right ventricle (RV) into three; sequence and timing were scored by three observers. In normal subjects, wall motion begins in either or both ventricles and ends in the LV or both ventricles. In patients with LBBB it begins in the RV and ends in the LV; in patients with RBBB is begins in the LV and ends in the RV or both ventricles. The intraventricular wall motion is also altered in the ventricle ipsilateral to a bundle branch block. In LBBB, the mean time of onset of LV wall motion is delayed 1.9 frames (38 msec), whereas RV wall motion is normal. In RBBB, the onset of RV wall motion is delayed 1.3 frames (26 msec), whereas LV wall motion is not delayed.

Adult↗

Bone scintigram in cardiac amyloidosis: a case report.

Intense, diffuse localization of Tc-99m-pyrophosphate was demonstrated in the right and left ventricles of a patient with biopsy-proved amyloidosis and severe congestive heart failure. This finding is strong presumptive evidence of myocardial infiltration by amyloid in the presence of biopsy-proven amyloidosis elsewhere in the body.

Adult↗

Cleansing the colon in gallium-67 scintigraphy: a prospective comparison of regimens.

Colonic accumulation of gallium-67 frequently complicates the interpretation of gallium-67 scintigrams. Although various modes of cleansing the colon prior to scintigraphy have been suggested, there is controversy over their efficacy and none have been tested prospectively. Three hundred nine patients undergoing gallium-67 scintigraphy were randomly assigned to one of four cleansing regimens: (1) a high fiber diet (78 patients); (2) castor oil (76); (3) milk of magnesia and cascara (76); and (4) not preparation (79). Patient compliance rates for the four regimens were 17%, 32%, 36%, and 46%, respectively. After noncompliant patients were excluded, gallium-67 scintigrams were graded for colonic activity on a scale of 0-3 by three independent, experienced observers. Gallium-67 activity in the colon was significantly less after administration of castor oil than after no preparation (p = 0.047). A high fiber diet also resulted in a substantial reduction of colonic activity when compared with no preparation; the difference, however, was not statistically significant (p = 0.083). Regimen 3 did not produce significantly better results than regimen 4 (p = 0.42). A major impediment to the success of any cleansing regimen seems to be poor compliance of patients.

Castor Oil↗

Distribution of hypertrophic pulmonary osteoarthropathy.

Radionuclide bone scanning is a sensitive detector of new bone formation. It offers the possibility of more complete description of the distribution of hypertrophic pulmonary osteoarthropathy. The scintigraphic findings in 48 confirmed cases of hypertrophic pulmonary osteoarthropathy (HPO) are described. Several new observations about the involvement of bones and distribution pattern have been made: the skull (mandible and/or maxillae) was involved in 42% of cases, the scapulae in 67%, and the patellae in 50%. Clavicles were involved in 33% of cases. With the exception of the humerus, the proximal and distal portions of each long bone were involved with equal frequency. Involvement of the extremities was invariably present, and disease almost always appeared more active in the lower than in the upper extremities. Asymmetric involvement of the extremities was noted in 17% of cases, and there was irregular involvement in 15%. Differentiation of metastatic disease from HPO by bone scanning is generally not difficult, since the most frequent patterns of distribution of these two conditions are entirely different.

Adolescent↗

In vivo stability and distribution of [131I]iodomethyl trimethylammonium chloride: concise communication.

[131I]iodomethyl trimethylammonium chloride (I-131 TMA) was prepared by the isotope-exchange reaction of diiodomethane with Na131I, followed by reaction with trimethylamine. A specific activity of 20 microCi/mg was obtained. Tissue distributions following intravenous injection of I-131 TMA in mice showed that between 10 min and 2 hr, the highest accumulations of radioactivity were in the urine, kidney, and heart. The uptake of this compound in the heart was very rapid, and the levels of radioactivity remained fairly high up to 2 hr. At 10, 30, 60, and 120 min the heart-to-blood ratios were, respectively, 10.2, 7.7, 8.3, and 9.6. Thyroid uptake of this compound in the rats and analysis of urine samples of the mouse indicated no extensive deiodination of the compound in vivo. These results show that this compound does have potential for use in myocardial imaging. In addition, its stability in vivo makes it very useful for the radiolabeling of compounds containing quaternary ammonium moieties.

Animals↗

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↗

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↗

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↗

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↗

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↗