Scintimaging of bronchopleural fistula. A simple method of diagnosis

A bronchopleural fistula in a patient with empyema was demonstrated by xenon-133 ventilation lung scanning. Because of its ease and simplicity, the ventilation study should be one of the first diagnostic tests performed when bronchopleural fistula is suspected.

Wedged Swan-Ganz catheter causing ventilation-perfusion mismatch. Case report and review of the literature

A ventilation-perfusion (V/Q) lung scan in a postoperative patient with a Swan-Ganz catheter showed an area of mismatch suggesting pulmonary embolism. Radiographs, as well as failure to get a venous return from the catheter suggested wedging. A pulmonary angiogram, performed after the Swan-Ganz catheter was pulled back, was essentially normal. An autopsy performed within 24 hours of the lung scan did not reveal pulmonary emboli. Wedged Swan-Ganz catheter was probably responsible for the V/Q mismatch.

Immediate effects of heavy exercise on the circulating thyroid hormones

Sera from 20 patients with suspected or known coronary artery disease were measured for thyroxine (T4), tri-iodothyronine (T3), tri-iodothyronine uptake ratio (T3UR), thyroid stimulating hormone (TSH), and reverse tri-iodothyronine (rT3), before and after maximal or near-maximal exercise. On the average the patients achieved 92% (rang 68-108) of the predicted maximum heart rate. There were no statistically significant differences between the pre- and the post-exercise serum levels of thyroid hormones. When five patients who achieved less than 90% of the predicted maximum heart rate were excluded, the results remained unchanged. It appears that the circulating thyroid hormones are not acutely affected after maximal or near-maximal exercise; however, the patient population was highly select.

Radiographic and scintigraphic skeletal imaging in patients with neuroblastoma: concise communication

Bone scans, bone-marrow scans, and radiographic skeletal surveys have been reviewed in 40 children with neuroblastoma. Bone scans are the most sensitive method for detecting metastases and should be used first. The additional yield from a skeletal survey is very small, so it should be done only if the bone scan is negative and major therapeutic decisions are to be made. Bone-marrow scans provide a sensitive method of identifying metastases, and may help in staging a patient as stage IV when the bone scan is negative.

"Cold spot" on bone scan at the site of primary osteosarcoma

A 5-year-old girl presented with a rapidly growing osteosarcoma of the proximal right tibia. The radiographically osteoblastic lesions appeared as a "cold" on the 99mTc-MDP bone scan. Possible explanations for this unusual finding on the bone scan are discussed.

Usefulness of bone marrow imaging in childhood malignancies

Two hundred six technetium-99m sulfur colloid bone marrow scans in 110 pediatrics patients were reviewed. The normal distribution of sulfur colloid in the lower extremities in various age groups was established. There was progressive loss of uptake with increasing age from less than two years to greater than ten years. Tumor replacement was seen as regions of decreased radioactivity, and the extent of the scan defect paralleled the response of the disease to therapy. Both chemotherapy and irradiation resulted in an extension of the Tc-99m SC to peripheral marrow sites. In irradiated areas, marrow scan defects were demonstrated and generally recovered normal activity by six months after the completion of therapy. Marrow scan abnormalities caused by tumor replacement were present in four patients despite normal bone scans and radiographs. Ultimate confirmation of tumor involvement was by needle aspiration or biopsy. Persistent marrow defects were seen in two patients with neuroblastoma who had remission of their disease: biopsy revealed myelofibrosis. Technetium-99m sulfur colloid bone marrow scanning is a sensitive monitor of altered marrow activity associated with pediatric hematologic or oncologic diseases.

Tc-99m diphosphonate imaging in the differential diagnosis of thyroid nodules

Early Tc-99m diphosphonate (DP) imaging was performed in 122 patients with cold thyroid nodules in an effort to differentiate benign nodules from malignant. Immediately upon completion of the routine 24-hour I-123 uptake and multiview pinhole imaging, Tc-99m DP was injected intravenously and three serial 3-minute anterior images of the thyroid gland were obtained. Follow-up information was available in 85 patients. All cystic lesions had less Tc-99m uptake as compared with the uptake in the normal parts of the thyroid. However, 48 of 50 solid nodules had Tc-99m DP uptake to the same or greater degree than did the normal gland. The other two had mixed pattern on ultrasound examination. Most of the carcinomas (8 of 10) and benign adenomas (15 of 22) had identical appearance on Tc-99m scans, i.e., uptake in the lesion being the same as in the normal thyroid. It appears that by using this technique it is possible to separate solid nodules from cystic, but not benign from malignant.

Scintigraphic evaluation of diabetic osteomyelitis: concise communication

We have reviewed the three-phase bone scans, radiographs, and histologic findings of 39 diabetic patients with serious foot problems. The sensitivity and specificity of bone scans were 83% and 75%, respectively, for osteomyelitis of the small bones of the foot. The positive and negative predictive values were 87% and 69%, respectively. The radiographs were less sensitive (62%) and less specific (69%), with predictive values of 80% (positive) and 47% (negative).

Abdominal masses in children: multiorgan imaging with 99mTc methylene diphosphonate

Technetium-99m methylene diphosphonate (99mTc MDP) imaging was performed in 29 consecutive children with abdominal masses. Dynamic images of the inferior vena cava were obtained by injecting the radiotracer in the feet. Serial renal images were obtained for the next 30 min. Routine bone imaging was performed at about 3 hr. The radionuclide studies of the inferior vena cava accurately diagnosed total obstruction and displacement to the left but not partial obstruction and displacement to the right. The abnormalities on early renal imaging included displacement (14), distortion (seven), obstruction (eight), and nonvisualization (one). All patients with Wilms tumor (eight) had either nonvisualized or distorted renal parenchyma. Patients with neuroblastoma (17) and other tumors (four) had displacement and obstruction. Soft-tissue accumulation of 99mTc MDP was noted in two Wilms tumors and 12 neuroblastomas.

Efficacy of noninvasive modalities of diagnosis of thrombophlebitis

In a blind prospective study of 158 limbs, Doppler ultrasound, pneumoplethysmography, and radionuclide venography (RNV) using 99mTc-MAA were compared to phlebography as methods of detecting thrombophlebitis. All three noninvasive modalities were very insensitive to isolated thrombus below the knee. In patients with extension of thrombus above the knee and isolated thrombus in the deep veins of the upper limb, Doppler ultrasound had a sensitivity of 81% and RNV had a sensitivity of 77%. All of the noninvasive modalities were found to be dependent on venous occlusion. Overall, pneumoplethysmography had a sensitivity of 28% and specificity of 96%, compared with 56% and 91%, respectively, for Doppler ultrasound and 51% and 84% for RNV. Based on these findings, phlebography would still seem to be the modality of choice in the diagnosis of thrombophlebitis.

Nuclear medicine studies in evaluation of skeletal lesions in children with histiocytosis X

Radiographs were compared with 99mTc scans of the bones and bone marrow as well as 67Ga-citrate scans to evaluate their sensitivity in identifying skeletal lesions in 21 children with histiocytosis X. Seven of 20 bone scans were completely normal in patients with extensive radiographic evidence of skeletal disease. In only one patient were bone scan changes demonstrated prior to radiographic abnormalities. None of the lesions was "cold" on the bone scans. 99mTc-sulfur colloid bone marrow scans and 67Ga-citrate whole-body scans were not valuable. Radiographic survey of the skeleton should be the primary diagnostic test employed in patients with histiocytosis X who have suspected skeletal lesions. Bone scans should be obtained only when the radiographs are normal or equivocal.

Leukocyte and 67Ga-citrate dynamics in experimental subcutaneous Streptococcus faecalis infections

The dynamics of white blood cell (WBC) and 67Ga-citrate accumulation were studied in rabbits with subcutaneous polyethylene chambers. Uninfected chamber fluid (CF) contained less than 1,000 WBCs/mm3, most of which were mononuclear. After 67Ga injection, radioactivity increased slowly in uninfected fluid, peaked between 24 and 48 hours, and then gradually decreased. 67Ga scans showed no uptake in excess of background levels around the uninfected chambers. After injection of Streptococcus faecalis directly into the chambers, bacterial concentrations initially decreased, increased by 4-24 hours, and then decreased slightly. WBCs began to increase 4 hours after infection due to influx of polymorphonuclear leukocytes. 67Ga localized in infected chambers before the increase in WBCs. Use of the subcutaneous chamber model could help elucidate the mechanism(s) of 67Ga accumulation at sites of inflammation.

Possible explanation of appearance of Warthin's tumor on I-123 and Tc-99m-pertechnetate scans

A 71-year old man presented with a parotid mass and a thyroid nodule. An I-123 scan revealed a "cold" nodule in the thyroid and uptake of the radioactive iodine in the parotid mass. On a Tc-99m-pertechnetate salivary gland scan, the parotid mass was "hot" and did not wash out with sodium perchlorate. At surgery, he was found to have a Warthin's tumor of the parotid gland and an adenomatous goiter. The reasons for the scan appearance of the Warthin's tumor are discussed. Since Warthin's tumors are benign and uptake of radioactive iodine in the extrathyroidal deposits of thyroid carcinoma is rare with the thyroid gland in place, the uptake of iodine by a salivary gland mass probably indicates a benign process.

Feasibility of low doses of I-131 for thyroid ablation in postsurgical patients with thyroid carcinoma

The feasibility of using low doses of I-131 (30 mCi) for ablation of thyroid remnants following surgery for papillary and follicular thyroid carcinoma was examined in 21 patients. Six weeks following near-total thyroidectomy and three days following intramuscular thyroid-stimulating hormone (10 IU), patients were given 30 mCi of I-131 and scans were performed 24 to 72 hours later. Remaining thyroid tissue was identifiable in the thyroid bed in 19 patients, and two patients also had evidence of cervical metastases. Patients with metastases received an additional 100 mCi of I-131. Follow-up I-131 scans were performed at nine to 15-month intervals in ten patients who initially received 30 mCi of I-131, and only one patient showed complete ablation of the residual thyroid tissue, whereas the remaining nine patients had persistent uptake of I-131 in the same regions in which the uptake was seen in the initial postoperative scans. One of the nine patients had evidence of a cervical metastasis as well. It is therefore apparent that total or near-total thyroidectomy rarely removes all thyroid tissue and that an "out-patient" dose of I-131 is not adequate for ablation of postoperative thyroid remnants.

Gastroesophageal reflux in infants and children comparative accuracy of diagnostic methods

To assess the diagnostic accuracy of methods employed for detection of gastroesophageal reflux, 30 infants and children with symptoms of GER were evaluated by upper gastrointestinal series, gastroesophageal scintiscan, measurement of mean resting lower esophageal sphincter pressure, esophageal intraluminal PH measurement (acid reflux test), and endoscopy. Fifteen control patients were also evaluated by the above studies. GER was demonstrated by UGI in 15 and by GE scintiscan in 17 study patients. LESP less than 15 mm Hg was noted in 12 and a positive acid reflux test was obtained in 29 study patients. Esophagitis was detected in two (of 30) study patients radiographically and in 15 (of 21) study patients by upper gastrointestinal endoscopy. Pulmonary aspiration of gastric contents was not detected by the radionuclide method. None of the 15 control patients had GER demonstrated with any of the above methods. These studies indicate that (1) the acid reflux test correlates most closely with symptoms of GER; (2) THE GE scintiscan is complementary to the UGI in the diagnosis of GER, i.e., the combination increases sensitivity; (3) normal LESP does not necessarily exclude GER; and (4) endoscopy is superior to the UGI in detecting the presence of esophagitis.