Radionuclide scanning in the evaluation of Kaposi sarcoma.

A patient with Kaposi sarcoma showed increased uptake of sodium pertechnetate Tc 99m over both clinically evident and occult regions of involvement. The clinically negative but scan-positive regions showed pathologic lesions by biopsy. Gallium citrate Ga 67 and bleomycin sulfate labeled with indium 111 (111In) did not concentrate in the lesions, which suggest that Kaposi sarcoma, despite its resemblance to lymphoma, differs from lymphoma substantially with reference to raionuclide uptake. This report confirms that sodium pertechnetate Tc 99m is the most sensitive agent for diagnostic and therapeutic evaluation of patients with Kaposi sarcoma and suggests taht gallium citrate Ga 67 or bleomycin 111In may be useful in the differentiation of Kaposi sarcoma from lymphoma.

Neutralizing antibodies to bovine thyrotropin in immunized patients with thyroid cancer.

Bovine thyrotropin (bTSH) was administered to 17 patients who had thyroid carcinoma. Anti-bTSH antibodies in the patients' sera were detected by three methods: 1) cross-reaction of sera in a homologous bTSH RIA, 2) [125I]bTSH binding to the patients' sera using charcoal to separate bound from free fractions, and 3) gel filtraton to detect [125I]bTSH bound to anti-bTSH in patients' sera. Immunoreactive anti-bTSH antibodies were thus demonstrated in 14 patients. These patients showed specific binding of their sera to [125I]bTSH with the charcoal separation of free from bound hormone. A high titer of antiserum (1:10,000) was found in those patients whose sera reacted strongly in the bTSH RIA (greater than 50 mu U/ml). The binding capacity of the serum of 1 patient was estimated as 2,600 mu U/ml serum. Ten of the patients' sera which showed immunoreactivity to bTSH neutralized bTSH activity in the McKenzie mouse bioassay but did not neutralize the activity of human TSH in this bioassay. Repeated administration of bTSH to 14 patients resulted in development of immunoreactive and neutralizing anti-bTSH antibodies. Development of immunological resistance to bTSH appears inevitable in patients who receive repeated injections of this hormone. Because of the loss of effectiveness of bTSH by antibody formation, the repeated diagnostic and therapeutic use of bTSH is not recommended.

Hair analysis for detection of phencyclidine in newly admitted psychiatric patients.

The authors implemented a new procedure for analyzing phencyclidine (PCP) content in hair. They compare the results of analyses of hair with results of analyses of blood and urine in 47 patients newly hospitalized with acute psychiatric illness. Hair analysis identified 11 patients who had used PCP, and blood and urine analyses did not identify any among the sample population. In three patients, the results of hair analysis aided in establishing a diagnosis of PCP intoxication. The authors discuss interpretations of their findings and psychiatric applications of this new technique.

Diagnosis of delayed cerebral radiation necrosis following proton beam therapy.

A 27-year-old man developed delayed cerebral radiation necrosis following proton beam therapy to an arteriovenous malformation. Neuroimaging with technetium 99m diethylenetriamine penta-acetic acid and positron emission tomographic scanning with fludeoxyglucose F 18 aided in his evaluation. Significant improvement of his neurologic deficits resulted from corticosteroid therapy. Clinical resolution was corroborated by serial computed tomographic scans demonstrating regression of the abnormality (a mass lesion). Various facets of radiation injury are discussed, including pathogenesis, risk factors, diagnosis, and therapy.

Effects of H1 blocking agents on age-related osteopenia in the mouse.

Old female B6AF1 mice were given acidified tap water, distilled water, one of five H1 blockers or chlorpheniramine (an H1 blocker) and trifluoperazine (a phenothiazine with no H1 blocking activity) in their drinking water for 5 months, and the effects of these agents on bone mineral metabolism were assessed by determining ash weights of femur, ilium and sacrum at the end of the study. In one experiment 24 h whole-body retention (WBR) of Tc 99m methylene diphosphonate (Tc 99m MDP, an indicator of bone metabolism) was measured at the beginning of the study and 40 days later. It was found that: promethazine and dimenhydrinate were the most effective of the H1 blockers in preventing age-related loss of bone mass; distilled water, chlorpheniramine, and chlorpheniramine plus trifluoperazine had no effect on the loss of bone mass; mean bone mass in the groups given meclizine and pyrilamine were greater than but not significantly different from that in the control group given acidified tap water; and only promethazine induced a significant reduction in the WBR of Tc 99m (the other H1 blockers induced small but not significant reductions).

Age-related osteopenia in the mouse: effects of an H1 blocker, a phenothiazine, and promethazine.

Mature and old B6AF1 and B6D2F1 mice were given acidified tap water or promethazine HCl (a phenothiazine with H1 receptor blocking activity), chlorpheniramine (an H1 blocker) or trifluoperazine (a phenothiazine with no H1 blocking activity) in their drinking water, and the effects of these agents on bone mineral content were assessed by intermittently measuring the 24-h whole body retention of Tc 99m methylene diphosphonate (Tc 99m MDP, an indicator of bone metabolism) and at the end of the studies by determining ash weights of femur, ilium and sacrum. It was found that 24-h retention of Tc 99m MDP was elevated in old mice as it is in old osteopenic humans, that promethazine but not chlorpheniramine or trifluoperazine inhibited bone loss in aging mice, and that there was a correlation between decrease in retention of Tc 99m MDP and decreased bone loss. These preliminary results suggest that the ability of promethazine to inhibit age-related bone loss may not be mediated through its action as an H1 blocker or as a phenothiazine. However, more agents of each type need to be tested before this point can be established.

In vivo evaluation of age-associated changes in delayed-type hypersensitivity.

The effectiveness of a recently developed isotopic in vivo assay for the measurement of delayed-type hypersensitivity (DTH) was compared to that of the conventional skin sensitization assay based on the ear-swelling index. DTH was measured in young and old C57BL/6 mice under conditions of normal health, spontaneous reticular cell sarcoma, Sendai virus infections and under the above conditions, while being treated with a potential immunorestorative agent, mercaptoethanol. A good correlation was observed between the two types of assay. However the reliability and sensitivity of the isotopic assay was found to be superior to the conventional skin sensitization assay. Thus, under optimum conditions, the swelling assay showed a 35% decline in DTH in old mice, and the isotopic assay a 62% decline.

Primary or working memory in frontal lobe epilepsy: An 18FDG-PET study of dysfunctional zones.

INTRODUCTION: We previously demonstrated that patients with frontal lobe epilepsy show deficits on a visual working memory paradigm and that this paradigm produces increased 18FDG uptake in the dorsolateral prefrontal cortex (DPFC), premotor cortex, angular and supramarginal gyri, basal forebrain, and ventral frontal poles of normal subjects when compared with a control task. We hypothesized that subjects with frontal lobe epilepsy would have impaired frontal activation during this task. METHODS: One resting and two activated images were obtained with 18FDG-PET in 15 subjects and 14 controls. One was a delayed (DMS) and one an immediate (IMS) match to sample paradigm. Discriminant and factor analyses were used to analyze the data, supplemented by selected t tests. RESULTS: No differences in glucose uptake were found between the DMS and IMS in the epilepsy subjects, in distinct contrast to controls. A comparison between controls and epilepsy subjects showed differences both ipsilateral and contralateral to the epileptic focus in the frontal regions involved in the task, with small changes in nonfrontal, task-related regions as well. The task itself brought out or highly exaggerated differences seen at rest. There was weak evidence that other frontal and temporal regions were attempting to compensate for the DPFC deficit. CONCLUSION: A unilateral epileptic focus is capable of suppressing function along a large task-related circuit ipsilateral and contralateral to the focus. Peripheral cortical regions compensate poorly for the area of dysfunction.

Technetium-99m-Sn-pyrophosphate pharmaco-kinetics and bone image changes in parathyroid disease.

Skeletal abnormalities in 12 patients with primary hyperparathyroidism, five patients with pseudohypoparathyroidism, and three patients with hypoparathyroidism were studied to compare the diagnostic sensitivity of bone radiologic examination to that of radionuclide studies using 99mTc-Sn-pyrophosphate (99mTc-PPi) a skeletal-seeking radiopharmaceutical. The results were compared with bone mineral content as measrued by the Norland--Cameron densitometer. Kinetic data of the blood disappearance and plasma clearance of 99mTc-PPi were obtained and compared with data of control subjects without evidence of parathyroid disease. Bone imaging with 99mTc-PPi may be more sensitive than routine skeletal radiographs and bone mineral analysis for the evaluation of skeletal abnormalities in patients with parathyroid disfunction. The enhanced plasma clearance of the tracer observed in patients with primary hyperparathyroidism may reflect the direct effect of excessive parathyroid hormone on the renal handling of 99mTc-Sn-pyrophosphate.

Serum thyroglobulin, a monitor of differentiated thyroid carcinoma in patients receiving thyroid hormone suppression therapy: concise communication.

Serum thyroglobulin levels were obtained in 86 patients who had undergone thyroidectomy and I-131 ablation for differentiated thyroid cancer, and who were receiving or had recently discontinued thyroid hormone suppression therapy. Excellent correlation was observed between serum thyroglobulin levels in patients receiving thyroid hormone suppression therapy and I-131 imaging studies. Serum thyroglobulin levels equal to or below 20 ng/ml indicate the absence of thyroid carcinoma, and values exceeding 60 ng/ml were indicative of active thyroid cancer but may include some patients without clinical evidence of disease. Intermediate serum thyroglobulin levels were observed in a small number of patients with postsurgical thyroid remnants or active disease. Serum thyroglobulin levels are of considerable value in monitoring the activity of thyroid cancer in patients who are receiving thyroid hormone suppression therapy.

Biplanar cardiac blood-pool tomography.

Dynamic transverse axial wall tomograms of the left ventricle (LV) are reconstructed by a new technique from anterior and LAO views acquired with a conventional scintillation camera imaging the distribution of in-vivo Tc-99m-labeled red blood cells. By confining reconstruction to the singular contiguous uniform concentration of activity in the LV, the requisite angular samplings for a given level of accuracy are substantially reduced in this restricted form of emission computed tomography (ECT). Static phantom studies using a series of volumes having various cross-sectional dimensions demonstrate tomographic edge reconstruction with less than or equal to 12% rms radial error. The dynamic cardiac ECT is demonstrated in a series of representative patient studies by reconstruction of wall tomograms in the end-diastolic and end-systolic phases of the 28-frame cardiac cycle. In contrast to the conventional dual multiframe projection views, the motion tomograms derived from the reconstructions clearly show the complete three-dimensional perspective of wall displacement.

Left-ventricular ejection fraction and segmental wall motion by peripheral first-pass radionuclide angiography.

A computerized edge-detection method was developed to obtain radionuclide ventriculograms for analysis of left-ventricular ejection fraction and segmental wall motion from first-pass studies following i.v. injection of radionuclide. The accuracy of this technique was examined in 21 patients undergoing cardiac catheterization. Tc-99m DTPA was injected into an antecubital vein, with data acquisition in the 30 degrees RAO projection by a gamma scintillation camera interfaced to a computer. A computerized profile analysis was used to determine objectively the edge of the left-ventricular blood pool. Time-activity curves were generated, and the ejection fraction was calculated from sequential end-diastolic and end-systolic count rates. The values for ejection fraction correlated well with those obtained by single-plane contrast ventriculography (r = 0.95). End-diastolic and end-systolic images were reconstructed from the time-activity curve. To analyze segmental wall motion, the left-ventricular outline was divided into five segments and the motion of each segment was graded qualitatively from 1 to 5. Seventy-five of 105 segments had the same grade as the wall motion determined by contrast angiography, and 102 of 105 were within one grade. (P less than 0.001). These findings demonstrate the accuracy of this improved technique for objective, rapid, and noninvasive determination of left-ventricular function.

Diagnosis of hepatic hemangioma using multiple-radionuclide and ultrasound techniques.

Two cases of heptatic hemangioma are reported in which multiple-radionuclide and ultrasound techniques were combined in the diagnostic process. Blood pool imaging rather than perfusion imaging proved to be the most definitive diagnostic procedure. The application of radionuclide and ultrasound studies in the differential diagnosis of focal lesions of the liver is discussed.

Malignant transformation of a Hürthle cell tumor: case report and survey of the literature.

Hürthle cell carcinoma is a relatively uncommon type of well-differentiated thyroid carcinoma. Its diagnosis has been controversial due to the difficulty in separating Hürthle cell adenoma from Hürthle cell carcinoma, thus the term Hürthle cell tumor is often used to describe both lesions. The present case of anaplastic giant-cell carcinoma in an 81-yr-old woman arose in a Hürthle cell tumor. This case illustrates the propensity of Hürthle cell tumor to undergo "malignant transformation" and argues for a more aggressive approach to such tumors.

Kinetics of 99mTc-labeled pyrophosphate and polyphosphate in man.

Thekinetic of 99mTc-labeled pyrophosphate were compared with those of polyphosphate in ten patients in a combined study. Both agents cleared from the blood in a biexpoential fashion. The clearance half-time of Exponent I was the same for both and was shorter than the clearance half-time of Exponent ii. Urinary excretion of both agents was the same during the first hour but during the next 3 hr Tc-pyrophosphate cleared at a slightly more rapid rate, resulting in lower blood background radioactivity. Both agents were bound loosely to plasma proteins, mainly to globulin fractions. The sensitivity of lesion detection was similar for both. Excellent bone images were obtained with both agents. The images with Tc-pyrophosphatewere consistently superior owing to the low blood background and they took less time to accumulate an identical number of counts from identical regions. With the amount of 99mTc-complex used, no hyocalcemia or tetany was noted, nor was there any significant effect on 1-hr serum levels of inorganic phosphours and alkaline phosphatase. Four hours after injection, 9.5% of the dose of Tc-pyrophosphate was circulating in blood, 31.7% was excreted in urine, and the remaining 58.8% was taken up by bone and other tissues. The corresponding values with Tc-polyphosphate were 12.5% in blood, 29.0% in urine, and 58.5% in bone and other tissues. Among the soft tissues, the genitourinary system is most consistently visualized. It is concluded that both Tc-pyroposphate and Tc-polyphosphate are excellent skeletal-imaging agents and that Tc-pyrophosphate appears slightly superior to Tc-polyphosphate.

Ben Cassen and the development of the rectilinear scanner.

The development of the rectilinear scanner by Benedict Cassen was preceded by his successful fabrication of a directional scintillation detector probe. In 1950, Cassen assembled the first automated scanning system that was comprised of a motor driven scintillation detector coupled to a relay printer. The scanner was used to image thyroid glands after the administration of radioiodine. Initial studies that were performed at the West Los Angeles Veterans Administration Medical Center led to the extensive use of the scanning system for thyroid imaging during the early 1950s. Cassen's development of the rectilinear scanner was a defining event in the evolution of clinical nuclear medicine. In 1956, Kuhl and his colleagues developed a photographic attachment for the Cassen scanner that improved its sensitivity and resolution. With the development of organ-specific radiopharmaceuticals, a commercial model of this system was widely used during the late 1950s until the early 1970s to scan the major body organs. The decline of the rectilinear photoscanner began in 1973 with the advent of computed axial tomography.

Treatment of malignant thyroid disease.

Surgery is the primary form of therapy in the management of malignant thyroid disease. A near-total thyroidectomy is the preferred approach. Radioactive iodine is used for supplementary ablation therapy and for definitive therapy in differentiated tumors of papillary or follicular cell type. Thyroid-stimulating hormone (TSH) is administered in conjunction with radioactive iodine therapy, since tumor uptake appears to be directly related to endogenous TSH levels. Therapeutic doses of radioactive iodine range from 100 to 200 mCi of 131 I depending on tumor distribution. Adequate thyroid hormone replacement therapy resulting in the suppression of TSH is of considerable value in the prevention of tumor recurrence. Due to the possibility of late recurrence, patients should be followed for indefinite periods by means of diagnostic imaging studies at 1-2 yr intervals. Despite 30 yr of experience, the therapeutic efficacy of radioactive iodine remains controversial. However, in recent years, there has been mounting evidence indicating increased survival and decreased tumor recurrence in radioactive iodine-treated patients. External radiation therapy is reserved for anaplastic carcinoma and lymphoma, and adenocarcinomas that are refractory to radioactive iodine. Chemotherapy experience is limited; however, some reduction in the size of metastatic lesions has been observed after the administration of adriamycin.

Localized brain metabolic response correlated with potentials evoked by words.

Evoked potentials (EPs) measure synaptic current flows that propagate from brain to scalp, Alternatively, positron emission tomography (PET) using fluoro-deoxyglucose (FDG) can measure the increased glucose metabolism supporting this synaptic activation. It is difficult to localize the brain activity-generating EPs from their scalp distribution, because activity originating in different regions tends to produce overlapping scalp topographies. In contrast, FDG-PET provides better spatial resolution for activity throughout the brain, but shows only the total metabolism integrated over a 30-min uptake period. We combined the temporal and psychological resolution of EPs with the spatial resolution of PET to help define when and where in the brain words are encoded for meaning.

Nuclear medicine in diagnosis and treatment of diseases of the head and neck. I. Salivary and parathyroid gland disease and one identification and staging of head and neck tumors.

The advent of both improved imaging systems and new radioactive agents has increased the effectiveness of nuclear medicine in diagnosing and treating diseases of the head and neck. In this first in a series of two articles, the role of nuclear medicine is discussed in the evaluation of diseases of the salivary and parathyroid glands, and in the identification and staging of head and neck tumors. Radionuclide studies of the salivary glands are useful in the identification of tumors and the evaluation of gland function. Such studies are a valuable adjunct in the diagnosis of Sjögren's syndrome and of acute and chronic inflammatory disease. Radionuclide imaging also has been helpful in the detection of adenomata and hyperplasia of the parathyroid glands and often complements ultrasonography localization procedures. The advent of gallium-67 imaging has improved the staging of head and neck tumors.

Nuclear medicine in diagnosis and treatment of diseases of the head and neck: II.

The advent of both improved imaging systems and new radioactive agents has increased the effectiveness of nuclear medicine in diagnosing and treating diseases of the head and neck. In this second of two articles, we discuss radionuclide bone imaging and the role of nuclear medicine in the management of thyroid disease. Radionuclide bone imaging is useful in the differential diagnosis of sinusitis, the early detection of head and neck fracture, the assessment of temporomandibular joint disease, and the identification of local extension of primary head and neck carcinoma. In the management of thyroid disease, radionuclide technology is uniquely helpful in the diagnostic evaluation of the thyroid nodule and radioactive iodine continues to play a major role in thyroid cancer therapy.