Detection of hypervascular brown tumors on three-phase bone scan.

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).

Fourier phase analysis of first-pass data: noninvasive detection of pulmonary sequestration.

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.

Radionuclide imaging in the assessment of lung injury.

Nuclear medicine imaging techniques are being more widely applied to study a variety of lung injuries. Ventilation and perfusion imaging is often superior to other roentgenographic techniques for establishing the diagnosis and demonstrating the extent of such injuries. At several large burn centers, the Xe-133 washout technique has become the cornerstone for diagnosing early inhalation injury. The overall accuracy of this procedure is 92%. Regional decreases in ventilation and perfusion can reliably localize aspirated radiolucent foreign bodies. Disproportionate perfusion changes are often the earliest indicator of radiation pneumonitis and other forms of vascular injury. Other types of injury, such as gastropulmonary aspiration, blunt trauma, and near-drowning, require further evaluation before the ultimate role of nuclear imaging is defined. An imaging technique to assess capillary permeability in the adult respiratory distress syndrome would be of great clinical benefits.

Preliminary assessment of computed tomography and satellite teleradiology from Operation Desert Storm.

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.

Noncardiac clinical applications of seven-pinhole tomography.

Clinical examples of various noncardiac seven-pinhole tomographic scans are shown. In many cases, this method of emission tomography can provide a very useful extension of standard planar nuclear medicine images. Major advantages of seven-pinhole tomography include reasonable cost and improved lesion detectability due to increased image contrast. Disadvantages include rather difficult patient positioning, nonuniform plane spacing with depth, and sometimes rather long data processing times because the presently available computer algorithms are maximized for cardiac scans.

Computer edge displays for cardiac wall motion evaluation.

Several computer display techniques in both black and white and color are described. Use of such techniques improves the qualitative evaluation of ECG-gated cardiac blood pool studies, especially by less experienced observers. Detection of wall motion at the interface between the myocardial wall and the labeled blood within the cardiac chambers is greatly enhanced. No additional equipment nor computer processing time is required to use these display schemes.

Another use for the seven-pinhole collimator. Routine nontomographic imaging of the thyroid.

Relatively few seven-pinhole collimator systems purchased within the last three years are still in routine use. This paper describes a nontomographic use of the collimator for thyroid scanning. One image is obtained which simultaneously shows seven different projections of the thyroid gland. The diagnosis of thyroid abnormalities can frequently be made from this single composite image without the requirement for additional images. Further information can be obtained when needed by computer processing the image into tomographic slices.

Gallium-67 scintigraphy in well-differentiated lymphocytic lymphoma of the skin.

Skin lymphomas are now divided into "T" or thymic cell lymphomas (mycosis fungoides being the principal type) and "B" cell lymphomas after the bursa of Fabricius. The "T" cell lymphomas all are identified by the thymic or cerebriform cell. Those lymphomas of the skin which do not contain these characteristic cells are derived from the bursa cells and are termed "B" cell lymphomas. A large percentage of these non "T" cell lymphomas have been histologically diagnosed as lymphocytic lymphoma of the skin (1). The authors had an opportunity to scan a patient with histologically proven lymphocytic lymphoma of the skin with Ga-67 and obtained on excellent correlation between gallium accumulation in the skin lesions and histologic confirmation of lymphocytic lymphoma.

Chest radionuclide angiography in the evaluation of pulmonary masses.

A retrospective analysis of 104 chest radionuclide angiography (CRNA) studies establishes the utility of this procedure in the evaluation of pulmonary malignancies and benign masses. Remarkable abnormalities in the perfusion of the lungs were identified in 36 (58%) of 62 cases that were not predictably normal or predictably abnormal form the clinical setting. While 60 of these 62 cases involved malignancy being evaluated for metastases, only 21 (34%) had metastases identified by radionuclide bone or liver-spleen scintigraphy. In addition to diagnosis of superior vena cava obstruction, the CRNA may have a more frequent application as an adjunct to routine scintigraphic studies directed to the identification of metastatic disease.

Fourier phase analysis in non-cyclic dynamic studies.

Single harmonic Fourier amplitude and phase (FA/P) analyses of 129 radionuclide angiographic (RNA) studies were found to reflect accurately the sequence and quantity of perfusion determined in the independently interpreted RNA studies. In addition, the anatomic detailing in peripheral studies (hands, feet, etc.) was considered superior to that obtained in RNA studies.

Xenon spill distribution and room clearance.

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.

192IrCl acid skin burn: case report and review of the literature.

A worker was contaminated following a chemical explosion that splashed an HNO3 radioactive solution containing approximately 180 MBq (5 mCi) 192Ir onto the left side of his face. Initial efforts reduced the contamination at least fivefold. Removal of a patch of contaminated hair was necessary. Most of the contamination was fixed to the skin; only a small amount of contamination was absorbed.

Tuboovarian abscess simulating giant colonic diverticulum.

The plain abdominal film finding of a large air-filled cavity has a differential diagnosis that includes giant colonic diverticulum, volvulus, giant Meckel's or other small-bowel diverticulum, emphysematous cystitis, vesicoenteric fistula, bowel duplication, and mesenteric cyst. The case presented here expands this differential diagnosis to include tuboovarian abscess with fistulous communication to the bowel.