Gallium 67 scanning in rheumatoid arthritis

Gallium 67 scans were performed on both knees of 38 patients with rheumatoid arthritis. There was a significantly higher level of 67Ga accumulation in those knees with clinically active synovitis (p less than 0.001). Synovial white cell concentration was also elevated in the group with active synovitis. The white cell concentration correlated with the 67Ga knee/femoral ratio at the p less than 0.001 level. 67Ga activity in the synovial fluid was predominantly in the supinate and activity was also present in the synovium. The findings indicate that 67Ga uptake occurs in rheumatoid joints and reflects the degree of synovial inflammation.     

Diuretic renography and angiotensin converting enzyme inhibitor renography

Renovascular hypertension and renal outlet obstruction are two clinical conditions well evaluated by nuclear medicine techniques. They both require a specific intervention to challenge a specific aspect of renal functional reserve. Diuretic renography is the oldest common example in nuclear medicine where functional change in the kidney is provoked for diagnostic purposes. The kidney's tubular functional reserve, in this instance, is challenged to induce diuresis and increase urine flow. This intervention permits diuretic renography to retain an essential role in the evaluation of hydroureteronephrosis. Captopril renography is a more recent example of a similar principle and depends on a reactive renin-angiotensin system to identify a kidney responsible for RVH. In both renal outlet obstruction and RVH, an anatomic abnormality is also identified (hydronephrosis and RAS, respectively) at some point in the diagnostic workup. The final diagnosis in each instance, however, depends on evidence for a functional disorder, provoked and measured during the radionuclide interventional examination. These serve as excellent examples of the power of functional imaging to identify specific medical disorders.     

The mechanism of the localization of 67Gallium citrate in experimental abscesses

⁶⁷Ga accumulation in turpentine-induced abscesses, from 5 h to 20 days old, in the rat has been investigated, and the results indicate that this is dependent on polymorphonuclear leukocyte (PMN) infiltration of the inflamed site. ⁶⁷Ga concentration 24 h after injection correlates well with the activities of the lysosomal enzymes, aryl sulphatase and -glucuronidase, P0.001, and with the DNA content of the tissue. There is no direct relationship with the rate of DNA synthesis.The mechanism of lysosomal incorporation into PMNs is consistent with the factors involved in ⁶⁷Ga uptake into tumours and normal tissues.     

The usefulness of gallium-67 citrate scanning in testicular seminoma

An analysis of 77 consecutive patients with a histologic diagnosis of seminoma testis, assessed and treated at the Cross Cancer Institute between 1977 and 1982, is presented. Ga-67 citrate was first used in the assessment of patients with malignant testicular tumors in 1973. Following three years of study that supported the observation of the gallium-avid nature of seminoma, gallium scans became routine in the initial staging assessment and were used also when recurrence was suspected. From 1977 through 1982, 72 patients with biopsy-proven seminoma testis were assessed initially for extent of disease by Ga-67 scanning. Comparison with intravenous pyelography and bipedal lymphography was possible for accuracy of tumor assessment. The scan sensitivity was 83%, and the specificity was 95%. During the same period, gallium was studied in nonseminomatous testicular tumors but the results were disappointing and its use was discontinued. The gallium-avid nature of seminoma testis may be useful in determining the extent of disease.     

Incidentally detected thrombosed vein during 67Ga citrate scanning.

A patient with stage IVA Hodgkin's disease developed thrombosis of the right cephalic vein at the site of an indwelling catheter. A few weeks later, 72 and 96 hr scans after injection of 67Ga citrate revealed an increased linear uptake where the thrombosed vein was palpated. As far as we know, this is the first case showing abnormal uptake of this agent in a thrombosed vein. It is postulated that residual chronic inflammatory cells are responsible for 67Ga citrate uptake in this case.     

Dual isotope scanning with gallium-67 citrate and technetium-99m radiopharmaceuticals

The interpretation of Ga-67 scans is limited by the complex anatomic and physiologic distribution of Ga-67 and by the low resolution possible with this isotope. The use of a second isotope Tc-99m, tagged to an appropriate pharmaceutical allows the identification of anatomic landmarks. Computer acquisition of both the Ga-67 and Tc-99m images allows for subtraction of the Tc-99m images from the Ga-67 images and leads to precise localization of abnormal Ga-67 accumulations. Only a small percentage of the counts in the Tc-99m window are due to Ga-67 scatter and do not degrade the Tc-99m images. Cases illustrating the value of the dual-isotope technique are presented.     

Computerized double-tracer subtraction scanning with gallium-67 citrate in inflammatory diseases.

A gallium-67/technetium-99m subtraction technique was used with a variable weighting factor. That is, each image was separately set to 100%. Varying amounts of the Tc-99m images were subtracted from those of Ga-67. A total of 95 patients who had radiogallium scanning for suspected inflammatory disease were studied by the subtraction technique. Thirty of these patients had abnormal Tc-99m pyrophosphate bone scans, while 20 had abnormal radiogallium abdominal foci; 45 had defects in liver, spleen, or kidney images. The subtraction technique with variable weighting was highly successful in enhancing hot-spot visibility, and in providing information as to the anatomic location of the defect.     

Circulating angiotensin converting enzyme activity is correlated with muscle strength

PURPOSE: The D-variant of the angiotensin-1 converting enzyme (ACE) gene is associated with higher circulating and tissue ACE activity. Some studies have suggested a similar association of genotype with muscle strength or the gain in strength in response to training. This study has assessed the relationship between circulating ACE activity, strength, and the response to training. METHODS: Eighty-one untrained men were tested for quadriceps muscle strength, and 44 of these performed an 8-wk program of dynamic strength training of the quadriceps muscle group. Venous blood was obtained for assessment of circulating ACE activity before and after the training program. ACE genotype was also determined. RESULTS: At baseline, circulating ACE activity was significantly correlated with isometric (r = 0.25-0.29, P < 0.02) and isokinetic (r = 0.38, P < 0.0005) quadriceps muscle strength. ACE genotype also seemed to be related to pretraining muscle strength. However, circulating ACE activity showed no significant association with the 9-14% mean increases of muscle strength in response to the training intervention. ACE genotype also showed no association with the training-induced change in muscle strength. Circulating ACE activity did not change significantly after the training program. CONCLUSIONS: The data support a role for ACE in the regulation of human skeletal muscle strength, but do not confirm a role in altering the response to short-term training.     

67Gallium scintigraphy in myocarditis

Myocarditis was diagnosed by gallium-67 scintigraphy in a patient with a high angiotensin converting enzyme (ACE) level.