Detection of thyroid nodules by physical examination and high‐resolution ultrasonography was compared using small groups of blinded, experienced physician examiners working with a sample of 2441 ...persons from Estonia, most of whom were Chernobyl nuclear reactor clean‐up workers. A random subsample of 113 (5%) persons was subjected to triple control examinations with both physical examination and high‐resolution ultrasonography. Positive high‐resolution ultrasonographic findings were considerably more reproducible among different observers than were positive physical examination findings. Agreement between methods was poor. Nodules were found in 169 (6.9%) subjects by physical examination and in 249 (10.2%) subjects by high‐resolution ultrasonography. Physical examination found only 53 (21%) of the 249 nodules found by high‐resolution ultrasonography. High‐resolution ultrasonography did not confirm the existence of 115 (68%) of the 169 nodules found by physical examination. Only 6.4% of nodules less than 0.5 cm in diameter, as based on high‐resolution ultrasonographic results, were detected by physical examination. Physical examination detection improved with increasing nodule size but was still only 48.2% for nodules larger than 2 cm. Physical examination was relatively effective in detecting nodules in the isthmus of the thyroid gland but much less so for nodules in the upper pole of the gland. Clinical evaluation and epidemiologic studies of nodular thyroid disease stand to benefit from the greater sensitivity and specificity of ultrasonographic examinations.
To characterize chest radiographic features of Hantavirus pulmonary syndrome.
Initial and follow-up chest radiographs from 16 patients with confirmed Hantavirus pulmonary syndrome were reviewed for ...radiographic findings of either cardiogenic pulmonary edema or pulmonary edema due to increased permeability of the alveolar capillary membranes.
Findings indicative of interstitial edema were present more frequently (14 88% of 16 patients) than is typically seen in adult respiratory distress syndrome (5%). Alveolar flooding subsequently developed in 11 (69%) of 16 patients and was not the peripheral pattern usually seen in the acute phase of adult respiratory distress syndrome. Overall mortality was 43%. Lung specimens obtained at autopsy showed a pattern of endothelial leak with minimal epithelial injury.
The lung disease caused by Hantavirus in these patients may explain the findings of interstitial edema and central alveolar filling atypical of adult respiratory distress syndrome. Recognition of the radiographic pattern will be important in identifying this apparently widespread cause of increased permeability pulmonary edema.
The purpose of these studies was to investigate actual xenon gas clearance times under different exhaust conditions, to compare them with the calculated clearance times, to observe the distribution ...of the xenon gas while it was being exhausted from the room, and to determine the cause of a stationary xenon cloud that appeared on some clinical images. Clearance times with and without a flexible exhaust hose placed next to a simulated 133Xe gas spill were compared with clearance times measured in a room with all exhaust closed off. Two gamma cameras were used to observe the transport and exhaust of xenon following a simulated spill. Clearance times with the flexible exhaust hose were less than one minute because the xenon gas was removed before it had a chance to disperse into the room. Conventional room clearance calculations based on uniform mixing and measured exhaust rates yielded a clearance time of 22 min. The source of an artifactual stationary cloud image was discovered to be a small amount of xenon trapped between the collimator and camera face. A negative pressure and dedicated exhaust can be even more effective in exhausting spilled xenon from a room than air transfer calculations predict. The authors believe the flexible hose should always be used.
Nuclear medicine Fourier phase analysis of first-pass data was used to evaluate blood flow to cystic lung masses in two children suspected of having pulmonary sequestrations. In both cases, the ...Fourier images provided a rapid, noninvasive, inexpensive analysis of the blood supply to the masses and permitted identification of the masses as pulmonary sequestrations. The analysis does not depend on the location of the mass and demonstrates the location of systemic rather than pulmonic arterial blood supply to the mass. In one case, Fourier analysis identified a second source of systemic blood supply not visible with other imaging modalities. Preoperative assessment of a cystic lung mass using Fourier analysis enables noninvasive classification of the mass as a pulmonary sequestration with systemic blood supply and aids the surgeon in resection.
A patient with hyperparathyroidism secondary to chronic renal failure had multiple bony lesions with increased activity on both immediate static as well as delayed scintiphotos. One lesion in the ...distal femur was also exceptionally hot on the flow phase. Plain radiographs demonstrated lytic lesions with sclerotic margins and a narrow zone of transition. Open biopsy revealed histology consistent with brown tumor (osteoclastoma).
Computed tomography at military transportable hospitals was used for the first time during the recent Operation Desert Storm in the Saudi Arabian desert. Scan quality was excellent and the scans ...proved clinically important in patient management. A teleradiology link via satellite to the U.S. mainland was also successfully employed. The objectives of the teleradiology link were to validate the concept distant interpretation of images obtained on the battlefield and to provide specialty radiology consultation. This technology shows great promise for future applications, both for combat casualty care and for civilian disaster medical support operations.
Before implementing one of two new LVEF radionuclide gated ventriculogram (MUGA) systems, the results from 312 consecutive parallel patient studies were evaluated. Each gamma‐camera acquisition was ...simultaneously processed by semi‐automatic Medasys Pinnacle and by fully automatic and semiautomatic Philips nuclear medicine computer systems. The Philips systems yielded LVEF results within ±5LVEF percentage points of the Medasys system in fewer than half of the studies. The remaining values were higher or lower than those from the long‐used Medasys system. These differences might have changed cancer patient chemotherapy clinical decisions. As a result, our institution elected not to implement either new system.
PACS: 87.57.U‐ Nuclear medicine imaging
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