Atypical unilateral acute pyelonephritis initially diagnosed by scinti-studies

A patient with vague and atypical symptoms is described in whom the radionuclide dynamic and static imaging studies proved to be more useful than a preceding excretory urogram for the diagnosis of unilateral pyelonephritis.

Iodinated bleomycin: an unsatisfactory radiopharmaceutical for tumor localization

Cobalt-57-bleomycin is a clinically useful tumor-localizing agent, but attempts to label bleomycin (BLEO) with other radionuclides have been made because of the long physical half-life of 57Co. As an alternative labeling approach, we iodinated BLEO both directly on the imidazole ring and indirectly by reaction with N-succinimidyl 3-(4-hydroxy, 3-iodophenyl) propionate. Directly iodinated BLEO retained antibacterial activity, but in tumor-bearing rats it showed a lower tumor-to-blood ratio (2.3) at 2 hr than did 57Co-BLEO (11.8). The antibacterial activity of the indirectly labeled BLEO was markedly reduced and this material showed a tumor-to-blood ratio of 0.55 at 2 hr. The radioiodinated bleomycins are not suitable substitutes for 57Co-BLEO as tumor-imaging radiopharmaceuticals.

False positive 125I fibrinogen test

125I fibrinogen test was performed in 20 selected patients who presented with symptoms suggestive of deep venous thrombosis. The incidence of a false positive study was found to be very high: 90%. An increased accumulation of fibrinogen was noted over recent, well-healed surgical incisions, diffuse or focal inflammatory sites, hematoma and also, following a venogram or arthrogram test. The large number of coincidental circumstances that result in an abnormal accumulation of 125I fibrinogen lead us to believe that venogram is the procedure of choice in patients with symptoms simulating thrombophlebitis.

Gallium-67 citrate in cerebral infarction

Cerebral scans were obtained on 30 "stroke" patients first with 99mTc pertechnetate and subsequently with 67Ga citrate. Of the 26 patients with abnormal 99mTc static scans, 17 (65%) showed the same abnormality in gallium citrate scans also. In 4 patients with positive technetium flow studies but negative static scans, no abnormality was seen in the scans obtained after gallium citrate injection. In none of the patients was the relative concentration of radioactivity in the lesion greater in the gallium image than in the technetium image. This study proves the nonspecificity of gallium citrate and thus its inability to differentiate cerebral tumor from cerebral infarction just on the basis of localization of gallium.

Technetium-99m-pyridoxylideneglutamate, a new agent for gallbladder imaging: comparison with 131I-rose bengal

Two agents used for hepatobiliary studies, 131I-rose bengal and 99mTc-pyridoxylideneglutamate, have been compared in rabbits. The 99mTc radiopharmaceutical is rapidly cleared from the blood by the liver and rapidly excreted through the common bile duct into the duodenum. Because of its rapid removal from the liver, visualization of the gallbladder and biliary passages was obtained within 15 min after injection in experimental animals.

Arthroscintigraphy with technetium albumin in diagnosis of pseudophlebitis (Baker's) cyst

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Cobalt-labeled bleomycin--a new radiopharmaceutical for tumor localization. A comparative clinical evaluation with gallium citrate

The efficacy of 57Co-labeled bleomycin as a tumor-scanning agent was evaluated in 50 patients with malignant tumor. In terms of sensitivity, labeled bleomycin was found to be a superior agent for malignant tumor detection when compared with 67Ga-citrate (p less than or equal to 0.005). Maximum sensitivity (96%) was found in epidermoid carcinomas. Because of rapid blood clearance and rapid excretion by the kidneys, interpretation of 57Co-bleomycin scans is facilitated.

Extra-osseous localization of 99Tcm-Sn pyrophosphate

99Tcm-Sn pyrophosphate bone scans of 250 patients referred for skeletal metastatic survey were analysed to determine the frequency of abnormal extra-osseous localization and the various pathological causes. Twenty-six patients demonstrated abnormal extra-osseous concentration. There were three false positives. Sixty-five per cent of the extra-osseous lesions concentrating pyrophosphate were malignant (carcinoma of lung and breast, metastatic hepatic carcinoma, chondrosarcoma) and the remainder were benign lesions, e.g. sarcoidosis, soft-tissue calcification, post-surgical and irradiation sites. An incidental finding was the unusual frequency of accumulation of pyrophosphate in various joints, especially the knees and shoulders in asymptomatic patients above 70 years of age.

New compounds: fatty acid and long chain hydrocarbon derivatives containing a strong chelating agent

Fatty acid and long chain hydrocarbon analogs that contain a strong chelating group were synthesized as part of an effort to determine if the biological function of the fatty acid can be used to transport metallic isotopes to the myocardium.

Patterns of excretion of radioactive chelates in obstructive uropathy

Radioactive chelates such as 99mTc-DTPA are advantageous in ranal imaging, particularly in defining functional and morphological abnormalities of the excretory tract. In a review of more than 200 studies, 19 cases of lower-tract disease were diagnosed by the gamma camera image alone. In 16 of them, the diagnosis was confirmed by excretory urography. Normal radionuclide patterns are described and compared with the characteristic findings in caliectasis, hydronephrosis, and hydroureter. By facilitating evaluation of renal perfusion, renal glomerular function, and gross renal structure as well as good difinition of excretory function, radioactive chelate imaging is ideally suited for use as general screening test.

The role of brain scanning in the differential diagnosis of seizures

Of 200 patients with seizures who had brain scans, the studies were abnormal in 86% of patients with tumours and in 67% of those with strokes. The scan detected 84% of the 19 potentially curable lesions. There were no false positive studies. Seventy-nine per cent of patients with seizures of less than one year's duration had an abnormal scan; however, the scan was also abnormal in 22% of patients with non-focal seizures of less than one year's duration.

Observations on the maturation of thyroid function in early fetal life

Serum samples were obtained from 21 normal human fetuses after therapeutic abortion for psychiatric indications. Fetal crown-rump length ranged from 5.2 to 22.5 cm, corresponding to the gestational age of 65-168 days.Serum thyroxine, assayed by a modification of the Murphy-Pattee method, was identified in the second smallest fetus examined at 78 days gestation. Thereafter it increased rapidly, maintaining a significant linear correlation with crown-rump length until term (r = 0.800, P < 0.001). Free thyroxine (FT4) also increased in a linear relation to gestational age (r = 0.908, P < 0.001), but reached term levels by 18-20 wk. Radioimmunoassayable thyroid-stimulating hormone (TSH) was detected at 78 days gestation. Levels increased rapidly with advancing gestation, so that by 16 wk almost all were within the range of term infants. After 16 wk gestation, levels were usually greater than 4.0 muU/cc, higher than that seen in normal children. No correlation was demonstrated between the serum TSH levels and total thyroxine. TSH and FT4, however, increased in a parallel manner with a significant positive correlation. This suggested that fetal TSH secretion was responsive to FT4 levels from very early in gestation, possibly as early as 11 wk.Thyroxine-binding globulin (TBG) was detected in a fetus of 78 days gestation (1.4 mug/100 ml). Levels increased rapidly, paralleling the rise in serum thyroxine and maintaining a linear correlation with crownrump length (r = 0.864, P < 0.001). Thyroxine-binding prealbumin binding capacity (TBPA) in fetuses 14-24 wk gestation was comparable with that seen at term. When examining the distribution of tracer amounts of thyroxine-(131)I (T4-(131)I) between the thyroxine-binding proteins, it was found that a major fraction was bound to TBPA and albumin during the early part of gestation. This decreased linearly with maturation of the fetus as the fraction bound to TBG increased. By 20 wk gestation fetal TBG was able to bind 78% of tracer despite a TBG capacity of only 7.7 mug/100 ml. This appeared to be the result of relatively low concentrations of TBPA and albumin during this period of gestation. The theoretical association constant calculated for fetal and newborn TBG was found to be similar to that estimated for normal adult males and females.

Diagnosis of pulmonary embolism. A correlative study of the clinical, scan, and angiographic findings

Seventy-one patients with suspected pulmonary embolism had both pulmonary scans and angiograms. Clinically it was impossible to predict the absence or presence of subsequent angiographic evidence of pulmonary embolism in the individual patient. In 24 patients the scans showed defects that were believed to indicate a high probability of pulmonary embolism-namely, perfusion defects that corresponded to specific anatomical segments of the lung together with normal chest radiographs or radiographs suggestive of pulmonary embolism. Specific angiographic evidence of pulmonary embolism was found in 18 (75%) of these patients. Diffuse, patchy, and non-segmental perfusion defects were seen in 28 patients. Only seven (25%) of this group had angiographic abnormalities specific for embolism. In 12 patients with normal lung scans none showed subsequent evidence of embolism by angiography. It is concluded firstly that lung scanning is a sensitive screening procedure for pulmonary embolism and, secondly, that segmental perfusion defects are highly suggestive of pulmonary embolism.