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Biomedical subjects

M P Sandler

Publications and source records attributed to M P Sandler.

At least 19 recordsLinked to original sources
PubMed1992

Noninvasive detection of heart transplant rejection with positron emission scintigraphy.

Positron emission tomography has recently been used to evaluate ischemic heart disease through changes in myocardial blood flow and carbohydrate metabolism. Positron-emitting tracers were evaluated for their ability to detect acute allograft rejection after heterotopic cardiac transplantation in the rat. Sham-operated controls, nonrejecting isografts, and rejecting allografts were evaluated. Decay-corrected uptake of 13NH3 and 18F 2-fluoro 2-deoxyglucose (FDG) reflects blood flow and glucose flux, respectively. Histologic examination of rejecting allografts documented mild rejection at 4 days and severe acute rejection by 8 days. All isografts were free from rejection. Uptake of FDG is greater in rejecting allografts than in nonrejecting isografts during both severe rejection (2.4% +/- 0.8% versus 0.7% +/- 0.4%; p less than 0.02) and mild rejection (2.1% +/- 0.6% versus 0.4% +/- 0.1%; p less than 0.02). Uptake of NH3 in severely rejected grafts is reduced compared with nonrejecting grafts (0.6% +/- 0.3% versus 1.7% +/- 1.1%; p less than 0.02). There is no difference in NH3 uptake during mild rejection (1.8% +/- 0.7% versus 1.3% +/- 0.3%; p greater than 0.05). Uptake of FDG and NH3 in native hearts of animals from all experimental groups is not significantly different from that in sham-operated controls. Glucose may be a preferred metabolic substrate during rejection. Our data support a humoral mechanism for substrate preference during transplant rejection and a potential diagnostic role for positron emission tomography.

Ammonia↗
PubMed1992

Staging lung carcinoma with a Tc-99m labeled monoclonal antibody.

Thirty-three patients with biopsy-proven lung cancer and a total of 150 lesions diagnosed by conventional staging procedures were imaged using a Tc-99m labeled monoclonal Fab fragment of an IgG2B murine monoclonal antibody (MoAb) (NR-LU-10, NeoRx Corporation). Immunoscintigraphy demonstrated 100% of primary and 78% of metastatic lesions. MoAb imaging detected 88% of lesions in 12 small cell lung cancer (SCLC) patients and 77% of lesions in 21 non-small cell lung cancer (NSCLC) patients. Based on initial evaluation by other methods, 29 sites of MoAb activity were not associated with evidence of disease. Eleven of these were subsequently shown to represent sites of metastases; 18 remain unconfirmed. Four of ten patients studied with limited NSCLC had eight unsuspected lesions on MoAb imaging. Confirmation of unsuspected lesions in two patients altered initial clinical staging, and surgical therapy was abandoned. This study demonstrates that Tc-99m labeled NR-LU-10 can accurately stage patients with lung cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed1991

MR imaging and MIBG scintigraphy of pheochromocytomas and extraadrenal functioning paragangliomas.

To compare the potential of magnetic resonance (MR) imaging and scintigraphy performed with radiotracer-labeled metaiodobenzyl-guanidine (MIBG) in localization and characterization of functioning paragangliomas, the authors analyzed results of both modalities in 33 patients. Overall sensitivity for detection was 91% for MR imaging and 80% for MIBG scintigraphy. MR imaging demonstrated 100% of adrenal paragangliomas and 75% of extraadrenal paragangliomas, whereas MIBG scintigraphy revealed 75% and 88%, respectively. MIBG scintigraphy was more specific in the characterization of paragangliomas than MR imaging (100% vs 82%). However, MR imaging demonstrated nine other lesions not seen on scintigrams. On the basis of their results and other considerations, the authors believe MR imaging is the preferred initial technique when a functioning paraganglioma is suspected.

3-Iodobenzylguanidine↗
PubMed1990

Effects of beta-adrenergic blockade in acute myocardial infarction: evaluation by radionuclide ventriculography.

In acute myocardial infarction, beta-adrenergic blockade might depress left ventricular contractility or improve contractility by reducing ischemia. Gated equilibrium radionuclide ventriculography and cuff blood pressure were employed in 10 patients to assess the left ventricular systolic pressure/volume (P/V) ratio as an index of contractility before and after intravenous metoprolol 9.3 +/- 2.5 hr after onset of infarction. In 13 normal subjects, the baseline left ventricular PV ratio was 3.5 and the left ventricular ejection fraction (LVEF) was 70%, both greater than the patients with infarction. In the patients after blockade, the systolic blood pressure decreased (p = 0.02), and the left ventricular end-systolic volume increased (p = 0.003), thus decreasing the P/V ratio from 1.7 to 1.4 (p = 0.003), while the ejection fraction (EF) was unchanged (55% versus 52%). The right ventricular ejection fraction (RVEF) decreased from 50% to 43% (p = 0.004). Thus, radionuclide ventriculography demonstrated that left ventricular contractility was reduced in patients with acute myocardial infarction and that beta-adrenergic blockade further decreased left ventricular contractility and right ventricular performance.

Adrenergic beta-Antagonists↗
PubMed1990

Recent advances in thyroid imaging.

Thyroid imaging has evolved from early radionuclide rectilinear thyroid scanning to the recently developed technique of single photon emission computed tomography. At the same time, x-ray fluorescent scanning, ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography have improved identification of the thyroid gland. The appropriate use and relative roles of these imaging modalities in the investigation of patients with thyroid disease are discussed.

Diagnostic Imaging↗
PubMed1989

Dipyridamole radionuclide ventriculography: a test with high specificity for severe coronary artery disease.

Ventricular dysfunction induced by dipyridamole would be evidence of myocardial ischemia in patients with limited ability to undergo standard exercise testing. Radionuclide ventriculography before and after intravenous dipyridamole infusion was compared with the results of exercise radionuclide ventriculography in a prospective study of 31 patients undergoing coronary angiography. Among these patients, 21 (68%) had significant coronary artery disease (greater than or equal to 50% stenosis), 19 (61%) had severe coronary disease (greater than or equal to 70% stenosis) and 10 (32%) were "normal" (less than 50% stenosis). The left ventricular ejection fraction was calculated, and regional wall motion was scored on a 6 unit scale. In the normal patients, the ejection fraction (+/- SEM) increased 5.6 +/- 2% (units) during exercise and 7.9 +/- 1 units after dipyridamole (both p less than or equal to 0.004 compared with that during rest). However, in patients with coronary artery disease, the ejection fraction failed to increase during exercise or after dipyridamole. In the patients with coronary artery disease, regional wall motion decreased by 4.1 +/- 0.5 units during exercise (p less than 0.003) and by 1.8 units after dipyridamole (p less than 0.02). Receiver operating characteristic analysis demonstrated general comparability between the sensitivity and specificity of exercise and dipyridamole ventriculography, with "optimal" operating points that favored choosing high sensitivity for the former and high specificity for the latter. Specific subsets of patients with severe coronary atherosclerosis were analyzed with use of these criteria. In patients with severe stenosis (greater than or equal to 70%), the sensitivity of dipyridamole ventriculography was 67% compared with 89% for exercise ventriculography. However, at these levels of sensitivity, the specificity of dipyridamole ventriculography was 92% compared with 67% for exercise ventriculography. In this and other subsets of patients, the specificity of dipyridamole ventriculography exceeded that of exercise ventriculography. Thus, it is concluded that dipyridamole radionuclide ventriculography is moderately sensitive and highly specific for detecting severe coronary atherosclerosis. This technique provides a widely applicable, useful alternative to exercise ventriculography in the diagnosis of coronary atherosclerosis in patients who have limited exercise tolerance.

Adult↗
PubMed1989

Multimodality imaging of the thyroid gland.

The continued development of high technology in the rapidly expanding field of computer-based imaging has had a significant impact on many areas of diagnostic imaging. The problem of rising medical costs emphasizes the importance of reaching a diagnosis by the most straightforward and cost-effective method while providing minimal patient discomfort. This responsibility to the patient and the medical care system rests with the physician. It is therefore essential that both imaging and referring physicians have a broad background of information regarding the potential limitations and relative merits of both old and new technologies available to patients with thyroid disorders. The appropriate utilization and relative roles of these imaging modalities have been discussed with respect to the individual clinical problem in this chapter.

Diagnostic Imaging↗
PubMed1989

Diagnosis of allograft renal vein thrombosis.

Allograft renal vein thrombosis has been reported in 1 to 4% of the renal transplants. Salvage of the graft is possible only if there is prompt recognition and operative intervention. We present the case of a living-related renal transplant that was salvaged because of early diagnosis of allograft renal vein thrombosis by correlation of the radioisotopic angiogram, renogram and duplex doppler sonography.

Adolescent↗
PubMed1989

Neuroblastoma: imaging evaluation by sequential Tc-99m MDP, I-131 MIBG, and Ga-67 citrate studies.

Fourteen children with histopathologically confirmed neuroblastoma underwent sequential correlative imaging studies using I-131 MIBG, Tc-99m MDP, and Ga-67 citrate during various stages of the disease. Of the patients 86% showed I-131 MIBG accumulation in the primary tumoral site, whereas 71% showed Tc-99m MDP and 79% Ga-67 citrate uptake. In 86% at least one of the two latter radiopharmaceuticals concentrated in the primary tumor. The use of all three radiopharmaceuticals raised the detection rate to 93%. Of the osseous or extraosseous metastases 100% were detected by Tc-99m MDP studies. The I-131 MIBG studies were positive in 71% of the osseous metastases and in 70% of the extraosseous metastases. No Ga-67 citrate uptake was demonstrated in osseous metastases, although one extraosseous lung metastasis concentrated this radiopharmaceutical. Tc-99m MDP bone imaging was the best method for diagnosing metastatic spread of the disease and for monitoring the results of treatment. Primary tumor uptake was best indicated by I-131 MIBG. Both Ga-67 citrate and I-131 MIBG were superior to Tc-99m MDP with regard to accurately demonstrating the extent of primary tumors. Only Tc-99m MDP indicated the relationship of these tumors to the kidneys and neighboring osseous structures, providing early screening of kidney compression. Ga-67 citrate study was mainly indicated in tumors with catecholamine depletion, which failed to concentrate the other two radiopharmaceuticals. I-131 MIBG proved especially useful in detecting neuroblastoma with negative Tc-99m MDP and Ga-67 citrate studies and also proved to be helpful with those cases in which I-131 MIBG was planned for therapy. The following strategy is suggested for evaluating neuroblastoma.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Iodobenzylguanidine↗
PubMed1989

Correlative radionuclide and magnetic resonance imaging in evaluation of the spine.

The authors retrospectively compared magnetic resonance images and bone scintigraphy obtained from 144 patients. Fifty-six patients having a known primary malignancy were evaluated for metastases (Group 1), and 88 patients were evaluated for back pain (Group 2). Interpretation was normal in 36/144 patients (11 in Group 1 and 25 in Group 2), and similar abnormal foci were visualized in the osseous spine in 54/144 patients (32 in Group 1 and 22 in Group 2). Magnetic resonance imaging showed abnormalities in the osseous spine that were not visualized on bone scintigraphy in 43/144 patients (10 in Group 1 and 33 in Group 2); these included bone metastasis, benign neoplasm (hemangioma), Schmorl's node, intervertebral disk disease, and bone disease (osteophyte, spondylolisthesis, facet hypertrophy). In addition, magnetic resonance imaging showed epidural or paravertebral extension of the tumor or infection in 37/144 patients (30 in Group 1 and 7 in Group 2). Bone scintigraphy demonstrated abnormalities not visualized on magnetic resonance imaging in 11/144 patients (3 in Group 1 and 8 in Group 2). Bone scintigraphy showed abnormalities in locations not evaluated by magnetic resonance imaging but relevant to the symptomatology or disease in 42/144 patients (37 in Group 1 and 5 in Group 2). These data indicate that magnetic resonance imaging and bone scintigraphy are complementary. Bone scintigraphy remains the best screening procedure to show the location of abnormal areas in the spine and elsewhere in the skeleton. Magnetic resonance imaging is useful in differentiating neoplasm, infection, intervertebral disk disease, and, in some instances, degenerative bone disease.

Humans↗
PubMed1989

Correlative pediatric imaging.

Nuclear medicine, ultrasound, and magnetic resonance imaging (MRI) are considered ideal imaging modalities for pediatric patients. The future is even more promising for pediatric imaging with the development of newer and improved radiopharmaceuticals, instrumentation and diagnostic modalities such as positron emission tomography, labeled monoclonal antibodies, and faster dynamic and contrast enhanced MRI methods. However, correlation of more conventional imaging modalities with nuclear medicine, ultrasound and MRI remain essential for optimal patient care.

Bone Diseases↗
PubMed1988

Thyroid carcinoma masquerading as a solitary benign hyperfunctioning nodule.

Focal hot nodules on iodine thyroid images are associated with an exceedingly low incidence of malignancy. Most previously reported hot carcinomas represent the coexistence of small malignancies in or adjacent to a benign hot lesion. Described here is a 3-cm papillary carcinoma that fulfilled the criteria for benignancy on Tc-99m and I-123 imaging. Coincidental carcinoma within a benign lesion was excluded by detailed scintigraphic-pathologic correlation of the tumor. The implications of this case on the management of the solitary hot nodule are discussed and the literature reviewed.

Aged↗
PubMed1988

Cat-scratch disease: report of a case with liver lesions and no lymphadenopathy.

The usual presentation of cat-scratch disease (CSD) is a subacute regional lymphadenitis following cutaneous inoculation. We present the case of a 10-yr-old white female with a 4-wk history of abdominal pain and fever, without associated lymphadenopathy. A 67Ga scintigram showed inhomogenous uptake by the liver. An abdominal computed tomographic (CT) scan revealed multiple low density lesions in the liver and the spleen, that were confirmed at laparotomy. Stellate microabscesses were seen on a wedge biopsy of the liver and a CSD antigen skin test was positive. CSD should be considered in the differential diagnosis of liver lesions, even in the absence of lymphadenopathy. This case emphasizes the importance of inhomogeneous 67Ga uptake by the liver.

Abscess↗