Fat embolism syndrome.

The fat embolism syndrome is clinically evident in approximately 0.5-2.0% of patients with long bone fractures. The clinical signs and symptoms are evident in 60% of patients within 24 hours and 85% of patients within 48 hours after trauma. A patient is reported who complained of dyspnea and hemoptysis approximately 72 hours after sustaining a fracture to the distal tibia and fibula. Radionuclide ventilation/perfusion imaging was obtained to rule out pulmonary thromboemboli. Perfusion imaging demonstrated the characteristic diffuse, subsegmental ("mottled") appearance of fatty emboli to the lung.

Population characteristics and absorbed dose to the population from nuclear medicine: United States--1982.

Those in the U.S. population who receive nuclear medicine examinations have been characterized by age and sex. Males received 42% of examinations while females received 58%. More than one-third of the examinations were done on persons older than 64 y of age and more than two-thirds on patients older than 45 y of age. The per caput effective dose equivalent from nuclear medicine procedures in 1982 was 140 muSv (14 mrem); whereas, the per caput age-specific effective dose equivalent to the U.S. population was 50 muSv (5.9 mrem). These can be compared with 2 mSv (200 mrem) from natural background.

Thyroid radiation absorbed dose from diagnostic procedures in U.S. population.

According to a 1981 survey of thyroid imaging methods in the United States, radionuclide thyroid scans and uptake studies increased 250%-300% between 1966 and 1981, while the U.S. population increased only 17%. Collective absorbed dose decreased from 18 X 10(6) rad (18 X 10(4) Gy) in 1966 to 13.9 X 10(6) rad (13.9 X 10(4) Gy) in 1981. The decrease was due to the use of iodine 123 and technetium 99m pertechnetate rather than iodine 131 (I-131 was used for 100% of scans and uptake studies in 1966 and 10% and 54%, respectively, in 1981) and also to fewer free-standing thyroid uptake studies (150,000 in 1966 and 33,000 in 1981). Even with reduced usage, I-131 still accounted for 93% of the collective absorbed dose in 1981. If I-131 were eliminated from diagnostic procedures, the annual absorbed dose would decrease to 1.4 X 10(6) rad (1.4 X 10(4) Gy). The number of radiation-induced cancer cases would also be reduced.

Trends and utilization of nuclear medicine in the United States: 1972-1982.

In the decade 1972-1982, in vivo nuclear medicine procedures in the United States increased from 3.3 million to about 7.5 million per annum. This growth has been the result of a markedly increased frequency in some types of examinations; particularly bone, liver, lung, and cardiovascular imaging. The only type of imaging in which a decrease in frequency has been observed has been in radionuclide brain imaging. Examination of these trends illustrates the difficulty in forecasting, even over time periods as short as 5 years. Competing tests have largely replaced radionuclide imaging in some areas; although in other areas, such as cardiac nuclear medicine, competing technologies appear to have been additive in terms of the frequency of examinations. Comparison with recent data from other countries indicates that the frequency of nuclear medicine procedures in the United States is probably the highest in the world.

Radionuclide thyroid studies: a survey of practice in the United States in 1981. Special report.

A survey was conducted to determine the radiopharmaceuticals and radionuclide imaging methods used for thyroid studies in the U.S. in 1981. The final sample, made up of 299 hospitals, was taken from a random sample consisting of 10% (337) of U.S. hospitals performing nuclear medicine studies. The survey showed that over one half of thyroid scans were obtained with Tc-99m pertechnetate and over one half of uptake studies were performed with I-131. Uptake determinations accompanied 78% of scans. Only 8% of the uptake studies were performed without scans. I-123 was more commonly used on the west coast and in the northeast, and there was interest in a more readily available and less expensive supply of I-123. Thyroid studies accounted for 6.7% of all nuclear imaging procedures. Approximately 7,760,000 nuclear medicine imaging procedures were performed in the U.S. in 1981.

Tc-99m PYP scanning following low voltage electrical injury.

An adolescent boy sustained low voltage electrical injury to his extremities when he inadvertently touched a low tension (440 volts) wire with a metal tube. Early in his hospital course, he was evaluated with Tc-99m pyrophosphate whole body scanning for the extent of his injuries. The scintigraphic findings correlated well with his subsequent clinical course.

Sulfur colloid distribution in normal hips.

The normal distribution of Tc-99m sulfur colloid is described in 100 patients with no clinical or radiographic evidence of hip disorders. Two-thirds of the patients had uptake in the femoral neck and some uptake in the femoral head. In the other one-third, no uptake was detected in either femoral head. A high degree of symmetry was noted. Judging both the symmetry and pattern of uptake in both hips is important in evaluating femoral head vasculature after a fracture.

Intrathoracic kidney on radionuclide renography. A case report.

A child with an asymptomatic mass in the lower right thorax was evaluated with sonography, intravenous urography, and radionuclide renography. High renal ectopia was only diagnosed with radionuclide renography.

Ascites causing a false-positive radionuclide liver image.

False-positive radionuclide liver images can occur due to impingement on the liver by adjacent normal anatomic structures or adjacent pathologic masses or fluid collections. A patient with ascites in the anterior subphrenic space had an apparent "cold" lesion in the left lobe of the liver. Ultrasonography demonstrated a normal left lobe and localized the fluid collection.

Radionuclide bone scan, radiographic bone survey, and alkaline phosphatase: studies of limited value in asymptomatic patients with ovarian carcinoma.

Bone scans or skeletal surveys were obtained in 104 patients with ovarian carcinoma. No metastases were identified at staging in the 43 patients with Stage I or II disease. Four patients in the entire series had osseous metastases. Three of the 40 patients with Stage III epithelial ovarian carcinoma had osseous metastases at the time of staging. All of these were Grade III lesions. One Stage I, Grade III patient demonstrated osseous metastases two years after initial diagnosis. None of the four patients with osseous metastases had an elevated alkaline phosphatase; three of the four had bone pain. Based on these results, it is suggested that radiographic bone survey and radionuclide bone scans are not indicated as screening procedures in asymptomatic patients with ovarian carcinoma.

Utility of radionuclide liver/spleen scanning and serum enzyme level in detecting hepatic metastases from ovarian carcinoma.

One hundred-five patients with ovarian carcinoma had radionuclide liver/spleen scanning done at the time of staging. Of the 105 initial scans, eight were interpreted as having hepatocellular dysfunction. Seven of these eight had abnormal liver function studies. One patient had a hepatic cyst but had elevated liver function studies. Six patients demonstrated hepatic metastases (at the time of staging). All but one of these occurred in Stage IV tumors of epithelial origin (adenocarcinoma). No hepatic metastases were demonstrated in Stage I or II tumors, and only one Stage III epithelial carcinoma had hepatic metastases. Three patients developed hepatic metastases during the course of treatment. All nine patients with hepatic metastases had abnormal concurrent liver function studies. It is suggested that screening for liver metastases in patients with ovarian carcinoma is of limited value in patients with normal liver function studies.

Radionuclide liver and bone scanning in the evaluation of patients with endometrial carcinoma.

Staging bone scans or skeletal surveys were obtained of 97 patients with endometrial carcinoma. Of the 77 patients with Stage I or II disease, no metastases were identified at staging. Three patients in the entire series demonstrated bony metastases; all of these metastases were detectable by radionuclide bone scan and radiographic bone survey. Eighty-nine patients were examined with radionuclide liver/spleen scanning at the time of staging. Four of the 89 initial scans were interpreted as demonstrating hepatocellular disease, and all four patients had abnormal liver function studies. Only one patient demonstrated a possible hepatic metastasis at initial diagnosis. This patient also had abnormal liver function studies. Based on these results, bone surveys and radionuclide bone scans are not indicated as screening procedures in endometrial carcinoma. It is suggested that screening for liver metastases in patients with endometrial carcinoma is not warranted in patients with normal liver function studies.

Diagnostic imaging of choledochal cysts.

A review of the literature concerning the diagnostic accuracy of various imaging modalities for choledochal cysts indicates that both ultrasound and scintigraphic methods have approximately 80% accuracy. Oral cholecystography and intravenous cholangiography methods have between 60 and 80% accuracy. Ultrasound is recommended as the initial preoperative test of choice, with hepatobiliary scintigraphy or CT scanning being most useful for postoperative evaluation.

The scintigraphic pattern of acute renal vein thrombosis.

The radiographic pattern of acute renal vein thrombosis is well known; however, the scintigraphic appearance has not been described. A scintigraphic pattern of delayed blood flow to a relatively large kidney and delayed blood flow to a relatively large kidney and delayed accumulation of l-131-Hippuran should be considered suggestive of acute renal vein thrombosis in the appropriate clinical setting.

Sensitivity of radionuclide brain imaging and computerized transaxial tomography in detecting subdural hematoma.

In a series of 23 patients with surgically proven subdural hematoma of durations ranging between two days to seven months, the detection rate of Tc-99m-pertechnetate brain imaging was higher than computerized transaxial tomography (CT). With dynamic perfusion scanning, the detection rate was 71.5%. However, when combined with sequential static images obtained at 10 minutes, 2 hours and 3--4 hours, the detection rate rose to 92% regardless of the duration of the disease. In contrast, CT demonstrated the hematoma in 52% of the cases. In another 28% the diagnosis was suggested through nonconclusive evidence or presence of contralateral shift of midline structures. Lastly, the result of CT scanning was dependent on the size of the subdural hematoma as evaluated at the time of operation.