Detection of splenosis by radionuclide scanning

Splenosis is the autotransplantation of splenic tissue following trauma. The presence of residual nodules following splenectomy has been investigated by a sensitive scanning method employing reinjection of 99Tcm-labelled, heat-damaged autologous erythrocytes. Splenosis was detected in 11 of 19 patients who had had splenectomy for traumatic rupture of spleen. Four of them had multiple nodules, the others a single nodule. In one case, the splenic nodule did not take up the sulphur colloid, although it could be visualised on selective splenic scan. We found no splenic nodules in 23 patients who had splenectomy for non-traumatic reasons. It is concluded that the key factor in splenosis is trauma.     

Functional assessment of the total artificial heart by blood-pool radionuclide angiography

Blood-pool radionuclide angiography was used to image a patient with a Jarvik 7-(70) total artificial heart. Excellent delineation of the chambers was achieved, allowing assessment of the total artificial heart pumping function. Estimation of the left ventricular volumes, cardiac output, and filling rates by radionuclide angiography corresponded closely with those simultaneously obtained from the total artificial heart driving lines. Radionuclide angiography affords the unique possibility to assess the function of the artificial heart noninvasively.     

HIV-associated myositis detected by radionuclide bone scanning

We report a case of myositis associated with human immunodeficiency virus (HIV) reactivity which was demonstrated on bone scan in the presence of normal muscle enzymes, contrast computed tomography, and electromyography. The diagnosis was confirmed by muscle biopsy. Radionuclide bone scanning may be a valuable diagnostic tool in HIV positive patients who present with muscle pain and an otherwise normal diagnostic evaluation.     

Unsuspected sacral fractures: detection by radionuclide bone scanning

Unsuspected sacral fractures may present with confusing clinical, radiographic, and scintigraphic findings. Sacral fractures were diagnosed by radionuclide bone scans in 23 patients, most of whom were osteopenic and had only minor or no trauma. Symptoms usually consisted of low back pain, sometimes with radiculopathy, but some of the patients were asymptomatic and the fractures discovered coincidentally. Abnormalities on bone scanning consisted of increased uptake in the body of the sacrum and one or both sacral alae or only in a single sacral ala. A retrospective review showed abnormalities on radiographs in 11 of the 23 patients and in all four of the CT scans obtained, but the abnormalities were often overlooked or misinterpreted on the original reading. Bone biopsies of the sacrum, done in two patients to rule out metastatic disease, showed reactive bone formation consistent with fracture. Recognition of the characteristic scintigraphic patterns in sacral fractures and the frequency of these fractures in osteopenic patients can avoid mistaken diagnoses and unnecessary tests or treatment.     

Evaluation of regurgitant fraction of the left ventricle by gated cardiac blood-pool scanning using SPECT

Regurgitant fraction (RF) of patients with and without mitral regurgitation (MR) and/or aortic regurgitation (AR) was evaluated by gated cardiac blood-pool scanning using single photon emission computed tomography (SPECT). Using the stroke count image of a short-axis tomogram to separate the right atrium and ventricle, the left ventricular stroke count (LVSC) and right ventricular stroke count (RVSC) were determined. The RF equaled (LVSC - RVSC)/LVSC. Calculated RF in 14 subjects without significant regurgitation by contrast angiography was 5.8 +/- 5.9% (mean +/- s.d.), RF of 17 cases with angiographic regurgitation was 42.5 +/- 16.8% (p less than 0.001). The sensitivity of the radionuclide method compared to angiography was 94% (16/17 cases), and specificity was 100% (14/14 cases). RF of mild Re (1+ or 2+) was 26.0 +/- 8.9% (n = 6) and RF of severe Re (3+ or 4+) was 51.5 +/- 12.7% (n = 11) (p less than 0.001). Correlation between the RF determined with the radionuclide method and with cardiac catheterization was good (y = 5.85 + 0.700 x, r = 0.821, n = 17). We conclude that RF of MR and/or AR can be accurately evaluated by gated cardiac blood-pool scanning using SPECT.     

Detection of radionuclide impurities

The knowledge of radionuclide impurities is of great importance both for activity measurements as well as in the preparation of Radioactive Standard Reference Materials. It is relevant also in the field of Life Sciences. Equipment, measurement and evaluation methods, uncertainties and detection limits are discussed. OMH experiences on impurity tests of radionuclides frequently used in the Hungarian medical practice are outlined.     

Transverse-section radionuclide scanning in cisternography.

By applying the technique of transverse-section radionuclide scanning to cisternography, the structure and relationships of the basal cisterns and other subarachnoid spaces of the brain can be visualized more clearly and with more detail than is possible with routine imaging techniques. The ability of this method to separate overlapping areas of radioactivity ensures improved definition of space-occupying processes within the basal cisterns. In the evaluation by cisternography of patients with hydrocephalus and dementia, the transverse-section images clearly separated various normal and abnormal patterns, whereas the routine cisternogram images were equivocal.     

Ultrasonic and radionuclide scanning in pancreatic disease

Ultrasonic examination of the pancreas is rendered difficult by the echogenic characteristics of the organ, by its depth, by the overlying gas, and by bony structures and anatomic variations. The reintroduction of gray-scale imaging promises to simplify the technique and expand its usefulness. The 75Se-/-selenomethionine scan is a reliable test when performed after effective pancreatic stimulation with a scintillation camera that permits the angulation required to separate pancreas from liver. Gallium-67-citrate may be important for both mapping inflammatory processes and imaging some tumors. Retrograde pancreatography has developed into a rather reliable and sensitive method of visualizing pancreatic duct abnormalities. Angiography remains the most reliable technique for finding small lesions, while computerized axial tomography appears a promising modality in the near future. In acute pancreatitis, gallium scanning may find a place alongside plain films, GI series, and echography. Chronic pancreatitis appears best studied by pancreatography, possibly with selenomethionine scanning as a function study and echography to find associated mass lesions. Pseudocysts are most easily located by ultrasound examination. Screening for pancreatic carcinoma is done most effectively with selenomethionine scanning when the index of suspicion is low and with pancreatography or arteriography when it is high. Echography is useful for localization for aspiration biopsy and for sequential evaluation of therapeutic response. Islet-cell tumors are best found by angiographic studies.     

Quantitative radionuclide scanning in metabolic bone disease

A simple method of quantifying skeletal uptake of 99Tcm-methylene diphosphonate, using a rectilinear scanner and a simultaneously image standard, is described. The pattern of quantified uptake in ten regions of the skeleton, the sacro-iliac joints and kidneys in 57 controls and 54 patients with various metabolic bone disease is presented. This method distinguishes patients with primary hyperparathyroidism and osteomalacia from controls with a sensitivity adequate for clinical purposes. In primary hyperparathyroidism the increased skull uptake of tracer correlated well with levels of serum alkaline phosphatase, plasma parathyroid hormone, urinary hydroxyproline excretion and the degree of intracortical resorption in the metacarpal bones. The skull uptake in oestoporosis was normal or moderately elevated and correlated well with bone mass density measurements of the radius. Patients with osteomalacia also showed the greatest increase in tracer uptake in the skull. Patients with thyrotoxicosis differed from most other patients by showing moderately increased uptake in shafts of long bones. We propose our method of quantitative bone uptake as a useful noninvasive test to detect metabolic bone disease and to monitor responses to therapy of bone disease.     

Detection of noncalcified splenic hemangioma by radionuclide bone scan

Incidental accumulation of bone-scanning agents in a noncalcified splenic hemangioma was observed on a bone scan performed for staging carcinoma of the prostate in a 68-yr-old man. This entity may be considered in the gamut of splenic activity on bone scans.     

Detection of porencephaly by cerbral dynamic scanning

Routine cerebral dynamic scanning in two patients revealed unilateral focal areas of decreased radionuclide activity between the anterior and middle cerebral arteries; the subsequent brain scans were normal. Both patients were shown to have porencephaly by isotope cisternography and computed tomography (CT) scans. When a focal avascular area is noted on cerebral dynamic scanning in the presence of normal static images, the possibility of a porencephalic cyst should be considered.