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Biomedical subjects

R Hardoff

Publications and source records attributed to R Hardoff.

11 recordsLinked to original sources

Scintigraphy of abdominal masses with 99mTc-labeled red blood cells.

Scintigraphy with 99mTc-labeled red blood cells was performed in five patients for demonstration of normal anatomy and in 18 patients for evaluation of suspected or apparent space-occupying abdominal lesions. In 14 cases of abdominal lesions, the study demonstrated the extent, vascularity, and relation of the lesion to neighboring organs. We found the method was primarily useful for evaluating cases of retroperitoneal tumor and vascular malformation.

Abdomen

Ultrastructural basis for different pertechnetate uptake patterns by various human brain tumours.

Patterns of pertechnetate uptake were correlated with ultrastructural properties of the endothelial wall in 14 human brain tumours. In tumours with reduced uptake of the radionuclide, intercellular tight junctions were observed whereas absence of intercellular tight junctions was characteristic of all tumours with an increased uptake of pertechnetate. In some tumours with increased uptake, fenestrated endothelial wall was seen while in others non-fenestrated wall was evident. We concluded that intercellular junctions and not fenestrations affect the permeability of brain tumours to pertechnetate.

Astrocytoma

Scintigraphic assessment of technetium 99m-diphosphonate uptake, vascularity and vessel permeability in human bone tumours.

Differences in the rate of uptake of 99Tcm-diphosphonate were found in 20 human bone tumours investigated. As some tumours have a slow rate of uptake it is suggested that the time used for routine scintigraphy at 3 hours is not always optimal and a further study should be performed in some cases. Various degrees of tumour vascularity and vessel permeability were found. The rate of diphosphonate uptake correlates with the vascularity, while it does not correlate with permeability which is generally increased as compared to normal bone.

Bone Neoplasms

Bone scintigraphy in primary tumors of the head and neck.

Bones of the face and skull may be involved directly by adjacent primary tumors of the head and neck. Radiography, at present the standard method for detection of bone involvement in such tumors, is not sufficiently sensitive. Of 22 patients who showed bone involvement in scintigraphy, radiography in 15 was initially normal, in 6 the extent of the lesion was not completely shown and only in 3 was it as informative as scintigraphy. Bone scintigraphy should become a standard method for evaluation of the context of bone invasion by tumors of the head and neck.

Bone and Bones

The value of delayed (24-hour) bone scintigraphy.

Delayed 24-hour scintigraphy was performed in 23 patients. It was found to be useful in enhancing abnormal uptake, enabling better anatomic localization and verifying doubtful uptakes in the 4-hour study. The underlying causes of these observations are probably a better lesion-to-blood ratio and a slow uptake in certain lesions.

Bone Neoplasms

Doughnut phenomenon in bone scintigraphy.

A doughnut phenomenon was observed in bone scintigraphy in three cases of metastatic thyroid carcinoma to the skull. Additional dynamic and static studies were performed to evaluate the relative roles of vascularity, vessel permeability and new bone formation in producing this phenomenon. This was accomplished through the use of 99mTc-diphosphonate, 99mTc-labeled red blood cells and 99mTc-pertechnetate. The important factor was found to be a new bone formation. Late uptake of diphosphonate was shown only in the periphery of the lesion, where formation of new bone takes place. This occurred even in the presence of increased vascularity and vessel permeability in the lesion as a whole.

Adenocarcinoma

Perfusion vascularity mismatch in liver hemangiomas.

Perfusion defect in the dynamic study and slow filling of the lesion by a blood pool agent were observed in three cases with large cavernous hemangiomas of the liver. This finding is explained by the low perfusion and the large blood volume of cavernous hemangiomas. When such a lesion is suspected a late blood pool study should be performed in order to demonstrate the true vascularity of the lesion.

Angiography

Chronic familial hyperphosphatasemia.

Two siblings displaying macrocrania and multiple skeletal deformities, as well as cardiomegaly, had high levels of serum alkaline phosphatase and markedly increased urinary hydroxyproline excretion. The radiological findings of chronic familial hyperphosphatasemia, which are typical of a rare bone-remodeling disease, are presented. Scintigraphy disclosed intense uptake of the radionuclide by the skeletons of both patients. This finding, considered to be related to abnormal collagen metabolism, can be used in the diagnosis and assessment of skeletal involvement in such patients.

Bone and Bones

Bone scintigraphy in scurvy.

Scintigraphic bone changes in two cases of scurvy are described, the cause being subperiosteal hematoma. Generalized increased uptake was shown in the affected femur at an early state of the disease. At a late stage, marked uptake both in the femoral shaft and surrounding tissue was seen causing scintigraphic appearance of widened ("club-shaped") femur.

Child, Preschool