Efficacy of preoperative dual-phase sestamibi scanning in hyperparathyroidism.

PURPOSE: The objective of this article is to evaluate our experience with sestamibi scanning in patients with primary and secondary hyperparathyroidism. PATIENTS AND METHODS: A retrospective review of patients referred to the radiology department at the University of Kansas Medical Center for parathyroid studies between January 1, 1993, and August 1, 1998, was done. Patients included in the study were those who underwent both dual-phase technetium (Tc-99m) sestamibi scanning and subsequent parathyroidectomy at our institution (n = 34). Twenty-six patients had primary hyperparathyroidism and 8 patients had secondary hyperparathyroidism. Fifteen had previous history of neck exploration. RESULTS: Sensitivity of sestamibi scans in detection of all abnormal pathology in cases of primary hyperparathyroidism was 60% overall. Among the subset of adenoma cases, sensitivity was 82% (14/17). Among cases of primary parathyroid hyperplasia, no scan correctly localized all abnormal glands; however 60% (3/5) showed localization of at least one hyperplastic gland. Of the 2 patients with parathyroid carcinoma, in only one case was there evidence of sestamibi retention in the correct thyroid lobe. In patients with secondary hyperparathyroidism, sestamibi scanning was successful in identifying all hyperplastic tissue in only one case (sensitivity 13%). In 7 of the 8 cases of secondary hyperparathyroidism, the scan localized at least one hyperplastic gland. CONCLUSION: Sestamibi scanning is useful in the localization of abnormal pathology in cases of primary hyperparathyroidism, especially adenomas. In cases of hyperplasia, whether attributable to primary or secondary hyperparathyroidism, sestamibi imaging is less successful.

Unexpected stomach uptake of technetium-99m-MDP.

Two pediatric cases are described in which the results of each patient's bone scan demonstrated abnormal stomach uptake. There have been a number of reports in the literature describing stomach uptake of bone agents, however, it is an uncommon finding.

Doppler US of helical flow in the portal vein.

In helical portal venous blood flow, the usual laminar flow in the portal vein is replaced by a spiral. This changes the color Doppler ultrasound (US) appearance to one of alternating or parallel red and blue bands. Duplex US may appear to show hepatopetal, hepatofugal, or simultaneous bidirectional flow depending on placement of the cursor within the helix. Helical portal venous flow is unusual in normal individuals (2.2% of 135 patients). Its presence should prompt further scrutiny for signs of liver disease, particularly portosystemic shunts, as in 20% of 41 patients who subsequently underwent liver transplantation. It is a normal finding immediately after liver transplantation (43% of 35 patients) and transjugular intrahepatic portosystemic shunt (TIPS) creation (28% of 36 patients). In both liver transplant and TIPS recipients, helical flow is usually transient. Its persistence long after transplantation in association with a prolonged increase in portal venous velocity is a useful sign of portal vein stenosis. Helical flow may also occur in cases of neoplastic invasion or displacement of the portal vein.

Strontium 89 therapy for the palliation of pain due to osseous metastases.

OBJECTIVE: To present the current state of systemic radiopharmaceutical therapy for the palliation of pain in individuals with metastatic cancer and to evaluate the palliative effect and degree of hemotoxicity of strontium chloride 89 (89Sr) in patients with painful osteoblastic metastases primarily from prostate and breast cancer. DATA SOURCES AND STUDY SELECTION: A MEDLINE search through December 1994 was performed to identify English-language studies that met the following criteria. All eligible studies reported treatment of patients with painful osteoblastic bony metastases primarily from prostate or breast cancer treated with intravenous 89Sr. For study eligibility, evaluation of clinical response as assessed by the Karnofsky index, need for pain medication, or changes in mobility or sleep patterns was required. Hemotoxicity data were a requirement. A minimum of 10 prostate cancer cases was necessary for study inclusion. Only those studies assessing clinical response following one injection of 89Sr were included. Preliminary reports of cooperative studies were not included. Doses of 89Sr ranged from 0.6 MBq/kg (16 microCi/kg) to 400 MBq (10.8 mCi) per patient. Evaluation of patients for at least 3 months following 89Sr treatment was required. In addition, two studies examining issues of cost with regard to 89Sr treatment were identified. DATA EXTRACTION: Baseline pain assessment and periodic pain estimates as measured by the Karnofsky index, medication diaries, changes in mobility, sleep patterns, and/or ability to work were the basis for assessment of response. Baseline and periodic complete blood cell counts were the basis for hemotoxicity evaluation. DATA SYNTHESIS: Palliation and hemotoxicity data were analyzed separately for each study. Some improvement occurred in as many as approximately 80% of patients. Several studies demonstrated complete relief of pain in at least 10% of patients The nadir of platelet and white blood cell counts appears at approximately 4 to 8 weeks following injection, with a partial return to baseline by 12 weeks. As many as 10 injections spaced 3 months apart have been given to some patients with repeated palliative effect and without serious hemotoxicity. Reinjection may be limited by a platelet count below 60 x 10(9)/L, a white blood cell count below 2.4 x 10(9)/L, or the absence of osteoblastic skeletal metastasis as seen on bone scan. Studies examining treatment costs suggest that 89Sr may decrease costs associated with palliation of pain due to metastatic disease. CONCLUSIONS: As many as 80% of selected patients with painful osteoblastic bony metastases from prostate or breast cancer may experience some pain relief following 89Sr administration. In addition, as many as 10% or more may become pain free. Duration of clinical response may average 3 to 6 months in some cases. Hemotoxicity is mild. A decrease in treatment costs with administration of 89Sr to patients with painful osteoblastic bony metastases from prostate cancer may occur. These observations reflect the preliminary nature of knowledge in this field and point to the need for larger clinical trials of the use of 89Sr palliation.

From the archives of the AFIP. Musculoskeletal angiomatous lesions: radiologic-pathologic correlation.

Vascular lesions of bone and soft tissue are relatively common musculoskeletal neoplasms. Hemangioma is the most frequently encountered angiomatous lesion. Osseous hemangioma commonly involves the spine and calvaria and often has a characteristic radiographic appearance, with either coarsened trabeculae lying adjacent to the vascular channels or multifocal lytic areas creating a honeycomb pattern. Soft-tissue hemangioma is the most frequent soft-tissue neoplasm of infancy and childhood. Radiography and computed tomography (CT) may show phleboliths in cavernous soft-tissue hemangioma. The magnetic resonance (MR) imaging appearance, however, is often more distinctive, because fat overgrowth and serpentine vascular channels can be seen. Lymphangioma usually occurs in the neck and axillae of young children as a soft-tissue mass composed of large cavernous spaces and is well evaluated with CT, ultrasound, or MR imaging. Vascular lesions can also diffusely involve both bone and soft tissue in angiomatosis. A group of more aggressive vascular neoplasms, including hemangioendothelioma, hemangiopericytoma, and angiosarcoma, may have a nonspecific imaging appearance; however, the vascular pattern can be recognized in some cases, allowing radiologic diagnosis. Imaging is important throughout the evaluation of angiomatous lesions for detection, diagnosis, preoperative assessment, and treatment.

Screening cerebrovascular patients for silent myocardial ischemia with stress testing and ambulatory left ventricular function monitor.

Patients with symptomatic cerebrovascular disease suffer a high mortality from myocardial ischemia, which may occur during rest or following the conclusion of exercise. In a pilot study, we screened 11 patients with transient cerebral ischemic attack or stroke for silent myocardial ischemia using bicycle ergometer stress testing with electrocardiographic (EKG) monitoring and ambulatory left ventricular function monitoring (VEST). Three of 11 patients had nondiagnostic exercise EKGs due to failure to achieve their target heart rates during exercise but had positive VEST tests during and after exercise. One patient was falsely positive. VEST may be useful in combination with stress EKG for the detection of silent myocardial ischemia in cerebrovascular patients, but further assessment of the sensitivity and specificity in this patient population needs to be accomplished.

Clinical experience with strontium-89 in prostatic and breast cancer patients.

Bone metastases are a major problem in the clinical management of patients with breast or prostate cancer. Severe bone pain can be a particularly debilitating effect of metastatic disease, resulting in a growing dependency on opioid analgesics and a reduced quality of life in patients who have a short time to survive. The radiopharmaceutical strontium-89 has been demonstrated to be generally well tolerated as well as effective in reducing metastatic bone pain in breast or prostate cancer patients. Unlike other radioisotopes or external radiation treatments, it represents systemic, targeted therapy that is simple and fast to administer in an outpatient setting. Data accumulated over the last 15 years demonstrates that 89Sr provides pain relief in up to 80% of patients with bony metastases arising from breast or prostatic malignancies. Pain palliation is maintained for several months, along with improvements in functional status and quality of life. As many as one fifth of 89Sr-treated patients become pain free and require no further pain medication. The adverse effects of intravenous 89Sr are minimal. Bone marrow toxicity is observed in many patients, resulting in some reduction of platelet and white blood cell counts. Despite reductions of 20% to 30%, these hematologic effects are generally reversible and the majority of patients maintain platelet counts that are within normal limits. Strontium-89 is effective systemic radioisotopic therapy for the palliation of painful bony metastases from breast and prostate carcinoma.

Radionuclide therapy of intractable bone pain: emphasis on strontium-89.

Management of bone pain in patients with multiple osseous metastases is a significant clinical problem. Phosphorus-32 has been used as systemic radioisotope therapy for the management of bone pain for over 40 years. However, significant hematological depression usually results and its use is limited. More recently, the bone-seeking radiopharmaceuticals strontium-89, samarium-153-ethylenediaminetetramethylene phosphonic acid, and rhenium-186-hydroxyethylidene diphosphonate have all been used as palliative treatment for patients with clinically significant bone pain. Excellent clinical responses with acceptable hematological toxicity have been observed. The clinical results rival those of external beam radiation therapy, with fewer systemic and hematological side effects. Systemic radionuclide therapy is indicated in the management of patients with painful metastatic prostate cancer in bone as soon as they escape primary hormonal management. This therapy also should play a role in the management of many patients with advanced breast cancer metastatic to bone. The role of radionuclidic therapy in osseous metastases from other malignancies is still being investigated. These compounds also hold promise as primary therapy for tumors of osseous origin. Systemic radionuclide therapy of painful bony metastases will become common in nuclear medicine practice in the next decade.

Image data compression using a new floating-point digital signal processor.

A new dual-ported, floating-point, digital signal processor has been evaluated for compressing 512 and 1,024 digital radiographic images using a full-frame, two-dimensional, discrete cosine transform (2D-DCT). The floating point digital signal processor operates at 49.5 million floating point instructions per second (MFLOPS). The level of compression can be changed by varying four parameters in the lossy compression algorithm. Throughput times were measured for both 2D-DCT compression and decompression. For a 1,024 x 1,024 x 10-bit image with a compression ratio of 316:1, the throughput was 75.73 seconds (compression plus decompression throughput). For a digital fluorography 1,024 x 1,024 x 8-bit image and a compression ratio of 26:1, the total throughput time was 63.23 seconds. For a computed tomography image of 512 x 512 x 12 bits and a compression ratio of 10:1 the throughput time was 19.65 seconds.

Regioselectivity in the sulfation of dermatan sulfate and methyl 4,6-O-benzylidene-alpha-D-idopyranoside.

The sulfation of dermatan sulfate by SO3-trimethylamine in N,N-dimethylformamide led to substitution initially at HO-6 of residues of 2-acetamido-2-deoxy-beta-D-galactopyranosyl 4-sulfate (1), to produce the 4,6-disulfate (6). When this step reached a level of greater than 50%, sulfation occurred with equal facility at HO-2 and HO-3 of residues of alpha-L-idopyranosyluronic acid (2), giving rise to a mixture of 2-,3-, and 2,3-disulfates. An analogous substitution pattern was observed for HO-2 and -3 of a simpler idopyranose unit, in the sulfation of methyl 4,6-O-benzylidene-alpha-D-idopyranoside (12). This lack of regioselectivity in the reaction of 2 (and 12) contrasts markedly with the high affinity of the reagent for HO-3 of residues of alpha-L-idopyranosyluronic acid present in a modified form of heparin. It is attributed to a difference between the two polymers in the relative orientation of their neighboring amino sugar residues, whereby there is an unobstructed access of the reagent in one instance, and hindrance of HO-2 selectively in the other. Enzymolysis by chondroitinase ABC was found to yield unsaturated disaccharide containing residues of 4,6-disulfate, as well as larger fragments containing unsaturated glycosyl groups derived from L-idopyranosyluronic acid 2-sulfate, evidence of a relatively broad enzyme specificity. The presence of extra sulfate groups in dermatan sulfate did not enhance its weak antithrombotic activity, as measured by anti Xa assay, in disagreement with earlier reports.

A novel method for differentiating dextran sulfate from related sulfated polysaccharides.

A method is described for unequivocal identification of dextran sulfate, based on combined chemical desulfation and dextranase enzymolysis of dextran sulfate moieties to isomaltose, a specific indicator of dextran-type precursors. The method was developed using high-resolution (300 MHz) 1H NMR spectroscopy for assurance of the molecular transformations, identification, and estimation of the hydrolysis products. Overall conversion of approximately 80% of highly sulfated and moderately sulfated dextran sulfates was realized. Both 2-D 1H and 13C NMR spectra of a dextran sulfate (MW 500,000) clarified the extent of sulfation (75%) at C-4 and confirmed that sulfation at positions C-2 and C-3 was virtually complete. Estimation of the hydrolysis products (isomaltose, major; alpha-D-glucose, minor) is not restricted to 1H NMR now that the desulfation-enzymolysis methodology has been established; rather, it can be performed using HPLC or GLC (with derivatization).

Sulfation of some chemically-modified heparins. Formation of a 3-sulfate analog of heparin.

A modified form of heparin containing residues of nonsulfated alpha-L-idopyranosyluronic acid (7) in place of the normal 2-sulfate (1) was sulfated with sulfur trioxide-trimethylamine in dimethylformamide at 0 and 25 degrees. Examination of the reaction products by n.m.r. spectroscopy showed that sulfation occurred selectively at C-3 of residue 7, to give a new polymer that may be described as a 3-sulfate analog of heparin. A slower substitution reaction led subsequently to sulfation at C-3 of 2-deoxy-2-sulfamino-alpha-D-glucopyranosyl 6-sulfate residues (2), although this was accompanied by partial N-desulfation of 2. An analogous pattern of O-sulfation-N-desulfation was observed for the residues of 2 in two other modified heparins, one containing residues of 2,3-anhydro-alpha-L-gulopyranosyluronic acid and the other residues of alpha-L-galactopyranosyluronic acid, in place of residues of 1. The galacto diastereomer exhibited relatively low regioselectivity, as it was found to be sulfated at C-2 or C-2.3, or both. Selective resulfation of free amino groups gave the products that were examined for anticoagulant activity and susceptibility to enzymolysis by heparinase. Antithrombin-binding affinity measurements were also carried out. Although none of the materials had significant anti-Xa activity, nor were they affected by heparinase, their patterns of binding to antithrombinagarose were not dissimilar to that of heparin.

Wide area networks for teleradiology.

Teleradiology networks transmit digital radiographic images from one location to another. These networks are wide area networks. Teleradiology networks are used for diagnostic purposes and preview tasks. Wide area networks for teleradiology use public service switching. The use of fiber optics networks provide reduced costs and increased flexibility. An example is presented that compares the cost of teleradiology networks.