Phosphate-32 colloid radiosynovectomy in hemophilia: outcome of 125 procedures

Radiosynovectomy offers a potentially effective, minimally invasive option for patients with chronic hemarthrosis and synovitis. The long-term outcome of patients with hemophilia who were treated with phosphate-32 chromic phosphate radiosynovectomy was evaluated. One hundred twenty-five procedures in 81 patients were done. Two- to 10-year followup by age and joint included joint bleeding and quality-of-life assessment. In addition, a relative cost comparison, scintigraphic imaging, and evaluation of biodistribution of the radionuclide were done. Of 125 procedures, 54% resulted in complete cessation of bleeding into the treated joint after the procedure, and 73% of patients reported improved mobility of the treated joint. Of patients 18 years old and younger, 79% had a greater than 75% reduction in bleeding incidence, and of patients older than 40 years, only 56% had a similar reduction. Seventy-nine percent of patients surveyed had a significant improvement in quality of life attributable to the treated joint. No evidence of significant leakage was observed. Billing records analysis indicated that radiosynovectomy costs less than 5% of surgical synovectomy. Phosphate-32 chromic phosphate radiosynovectomy is a clinically useful, safe, and cost-effective outpatient procedure in the treatment of patients with chronic hemarthrosis and synovitis.

Inconsistent effects of the proline12 --> alanine variant of the peroxisome proliferator-activated receptor-gamma2 gene on body mass index in children and adolescent girls

OBJECTIVE

To ascertain whether variation in peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a nuclear ligand-dependent transcription factor affecting both adipocyte differentiation and insulin sensitivity, influences body mass index (BMI).

DESIGN

Association study.

SETTING

Academic research environment.

PATIENT(S)

Children with premature pubic hair and adolescent girls with hyperandrogenism.

INTERVENTION(S)

Assay for P12A and P115Q variants and measure BMI.

MAIN OUTCOME MEASURE(S)

BMI and PPAR-gamma genotypes.

RESULT(S)

Fourteen subjects were heterozygous for P12A; two were homozygous. None carried the P115Q allele. No significant differences in BMI or basal androstenedione concentrations between P12 carriers and noncarriers were found. Thirty-nine subjects had BMI values at two time points; mean BMI was significantly greater in the P12A carriers at time point 2. Those P12A carriers obese at time point 1 became more obese; lean mutation carriers tended to remain lean. Annual rate of increase in BMI was significantly greater in the P12A carriers than the noncarriers.

CONCLUSION(S)

Our findings suggest that P12A may be a genetic marker indicating risk for obesity persisting into adolescence. Future studies are needed to determine whether the divergent effects of P12A persist into adulthood, to elucidate the mechanism of this effect, and to replicate our findings in other populations.

32P chromic phosphate radiosynovectomy for chronic haemophilic synovitis

The principal medical consequence of haemophilia is the development of arthropathy, initiated by a haemarthrosis giving rise to chronic synovitis. Traditional methods of synovectomy include open excision and arthroscopy each of which require substantial amounts of clotting factor concentrate for several weeks, and in the case of open synovectomy, is often associated with loss of range of motion and arthrofibrosis. Radiosynovectomy, the intra-articular injection of low penetration radiocolloids, has been utilized outside the United States for over 20 years. Since 1988, our centre has performed 170 radiosynovectomies utilizing 32P chromic phosphate (32P). This study reports results of 130 32P radiosyovectomies with an average follow-up of 36.5 months (6-140 months). For primary procedures, excellent and good results (haemarthrosis reduction from 75 to 100%) were obtained in 79.2% of cases at 6 months to 8 years. For repeat procedures a combination of excellent and good results were obtained in 62.4% of cases at 6 months to 3 years. Regression analysis showed no correlation between results and age or degree of arthropathy. Radiation was well contained within the joint. There were no observed or identified complications. The procedure is highly cost effective in comparison to open surgical or arthroscopic synovectomy.

Radioiodine dosimetry in patients with end-stage renal disease receiving continuous ambulatory peritoneal dialysis therapy

In patients with end-stage renal disease (ESRD), Na131I dosages for thyroid cancer may have to be reduced to avoid excess radiation doses to red marrow, because radioiodine is primarily excreted by kidneys. In ESRD patients receiving continuous ambulatory peritoneal dialysis (CAPD) therapy (three to five 2-L exchanges daily) creatinine clearance rates are very low (mean, 7 mL/min), and radioiodine clearance rates may be proportionately reduced. Thus, radioiodine kinetic studies were performed in two hypothyroid CAPD patients with thyroid cancer, in eight euthyroid CAPD patients, and in eight thyroid cancer patients with normal renal function. All received Na131I or Na123I orally, with serial blood, urine, and/or dialysate sampling for 24-70 h. Dosimetry calculations were performed using the MIRDOSE3 computer program. In CAPD patients, serum radioiodine half-times were 5 times longer, and radioiodine clearance rates by urine plus dialysate were 20% of those in patients with normal renal function. Na131I dosages for the two CAPD patients with thyroid cancer were reduced from 150 mCi [5.6 gigabecquerels (GBq)] to 26.6 mCi (0.98 GBq) and 29.9 mCi (1.11 GBq), respectively, resulting in radiation doses to red marrow and total body comparable to those in patients with normal renal function who received a mean of 148 mCi (5.5 GBq) Na131I. Thus, in patients receiving continuous ambulatory peritoneal dialysis therapy, 5-fold reductions in radioiodine clearance rates require 5-fold decreases in Na131I dosages to avoid excessive radiation doses to total body and red marrow.

Comparative biodistribution of meta-Tetra(Hydroxyphenyl) chlorin in multiple species: clinical implications for photodynamic therapy

BACKGROUND AND OBJECTIVE

To optimize photodynamic therapy, it is necessary to know the distribution of photosensitizer in normal tissue as well as tumors and to know how well animal models match human. This study measured the biodistribution of meta-Tetra(Hydroxyphenyl) Chlorin (mTHPC) in three species of animals and in humans.

STUDY DESIGN/MATERIALS AND METHODS

mTHPC was injected intravenously into dogs, rabbits, and humans, and drug levels in various tissues were determined 6 days later. One dog was perfused with 3 L of saline to remove blood trapped within organs.

RESULTS

Absolute and relative concentrations of drug in specific tissues varied between species and between individuals. There was a general pattern of distribution. Highly vascularized tissues had the highest levels of mTHPC, not simply due to trapping of blood. mTHPC did not localize in bone and did not cross the blood-brain barrier. Humans had much higher levels of drug in their plasma and tissues than did animals.

CONCLUSIONS

First, drug retention varies from one tissue to another. Second, there is significant variability from one individual to another, whether animal or human. Third, current models cannot accurately predict from animal studies the optimum dose for humans. Measurement of photosensitizer level in plasma at time of treatment would allow optimal photodynamic dosing.

Cross-linking of Fc gamma receptor IIa and Fc gamma receptor IIIb induces different proadhesive phenotypes on human neutrophils

Activation of polymorphonuclear leukocytes (PMN) plays an important role in vascular injury associated with systemic vasculitis and in models of autoantibody- and immune complex-mediated disease. The potential role of intravascular activation of PMN, however, is confounded by the observation that some stimuli injected i.v. (e.g., IL-8 and C5a) lead to L-selectin shedding by PMN, which inhibits attachment to endothelium and may be functionally anti-inflammatory. To explore the impact of Fc gamma receptor (Fc gamma R)-mediated activation on the PMN adhesive phenotype, Fc gamma RIIa (CD32) and Fc gamma RIIIb (Cd16) were targeted with receptor-specific reagents, and the expression of adhesion molecules-mediating rolling (L-selectin) and firm adhesion (CD11b/CD18) was measured. Engagement of either Fc gamma RIIa or Fc gamma RIIIb leads to activation, demonstrated by degranulation (upregulation of CD66b), and to increased expression of total CD11b/CD18 and functional CD11b/CD18 (I-domain). In contrast, L-selectin shedding induced by PMN Fc gamma R was divergent. Despite the 5- to 10-fold greater expression and engagement at saturation, activation via Fc gamma RIIIb led to little or no change in L-selectin expression. Stimulation of PMN with intact murine anti-receptor IgG1 showed a contribution of Fc gamma RIIa receptor polymorphisms, underscoring the direct influences of Fc gamma R allotypes on receptor function. These observations suggest that Fc gamma RIIIb-mediated activation of circulating PMN may lead to a proadhesive phenotype likely to promote systemic vascular damage. This Fc gamma R-mediated adhesive phenotype will vary with the receptors engaged and their allotypes, which, in turn, reflect properties of the immune complex and the genetics of the host.

Cross-linking of Fc gamma receptor IIa and Fc gamma receptor IIIb induces different proadhesive phenotypes on human neutrophils

Activation of polymorphonuclear leukocytes (PMN) plays an important role in vascular injury associated with systemic vasculitis and in models of autoantibody- and immune complex-mediated disease. The potential role of intravascular activation of PMN, however, is confounded by the observation that some stimuli injected i.v. (e.g., IL-8 and C5a) lead to L-selectin shedding by PMN, which inhibits attachment to endothelium and may be functionally anti-inflammatory. To explore the impact of Fc gamma receptor (Fc gamma R)-mediated activation on the PMN adhesive phenotype, Fc gamma RIIa (CD32) and Fc gamma RIIIb (Cd16) were targeted with receptor-specific reagents, and the expression of adhesion molecules-mediating rolling (L-selectin) and firm adhesion (CD11b/CD18) was measured. Engagement of either Fc gamma RIIa or Fc gamma RIIIb leads to activation, demonstrated by degranulation (upregulation of CD66b), and to increased expression of total CD11b/CD18 and functional CD11b/CD18 (I-domain). In contrast, L-selectin shedding induced by PMN Fc gamma R was divergent. Despite the 5- to 10-fold greater expression and engagement at saturation, activation via Fc gamma RIIIb led to little or no change in L-selectin expression. Stimulation of PMN with intact murine anti-receptor IgG1 showed a contribution of Fc gamma RIIa receptor polymorphisms, underscoring the direct influences of Fc gamma R allotypes on receptor function. These observations suggest that Fc gamma RIIIb-mediated activation of circulating PMN may lead to a proadhesive phenotype likely to promote systemic vascular damage. This Fc gamma R-mediated adhesive phenotype will vary with the receptors engaged and their allotypes, which, in turn, reflect properties of the immune complex and the genetics of the host.

Radiosynovectomy's clinical applications and cost effectiveness: a review

It is apparent that from the work of the authors and many others, including the work of Rivard, Sledge, Zuckerman, among others, that radiosynovectomy has an important role to play in providing effective treatment of affected joints associated with rheumatoid arthritis and other forms of arthritis as well as the hemophiliac joint. The treatment offers relief from the effects of recurrent joint effusion with an approximately 60% to 66% favorable response and from recurrent hemarthrosis in the hemophiliac joint with an approximately 75% to 80% favorable response. The impact of providing radiosynovectomy as an alternative to surgical synovectomy is seen, where postoperative side effects such as joint stiffness are avoided, improved quality of life is repeatedly documented, and the cost savings in health care dollars, particularly evident in the hemophiliac joint in this relatively small population, are potentially enormous. With almost two million people in the United States suffering from rheumatoid arthritis, the potential savings in health care dollars is also enormous. As with any use of in vivo radiopharmaceuticals, the potential for radiation-induced damage exists. However, with a 25 plus year record of use, more optimally configured radiopharmaceuticals, and the addition of maneuvers to minimize potential joint leakage, the risk of radiation induced damage appears to be minimal. It appears as though radiosynovectomy is an effective as well as cost-effective alternative to surgical synovectomy and is becoming the procedure of choice particularly in the hemophiliac patient with recurrent hemarthrosis and synovitis who has failed medical therapy. It is also the procedure of choice in patients for whom surgery is contraindicated because of the presence of clotting factor inhibitors.

Technetium-99m-labeled red blood cell scans in the investigation of gastrointestinal bleeding

PURPOSE

Technetium-99m-labeled red blood cell scans (Tc99m RBC scan) are recommended to confirm gastrointestinal (GI) bleeding. It is controversial whether these scans are sufficient to localize the site of bleeding. This study evaluated the efficacy of RBC scans in confirming and localizing GI bleeding. Our hypothesis was that these scans were effective in localizing GI bleeding if positive within the continuous phase of imaging.

METHOD

Tc99m RBC scans were performed on a total of 80 patients over a four-year period to localize GI bleeding (59 male, 21 female; age range 6-88 (mean, 48) years). Films of 75 of the 80 patients were reread by a nuclear medicine physician who was blinded to the original reading and identity and history of the patient. Results of scans were compared with confirmatory studies.

RESULTS

A total of 21 patients had positive scans (28 percent). Of these, the site of bleeding in 16 of 21 patients (76 percent) was confirmed by angiography (4/16), endoscopy (10/16), surgery (10/16), or a combination of these. In 14 of the 16 confirmed studies (88 percent), RBC scan correctly localized site of bleeding by our rigid definition. In six patients (4 not confirmed, 2 erroneously localized), scans were positive only at greater than 15 hours. Ten of the 14 correctly localized studies and none of the incorrectly localized studies were positive in the continuous phase of imaging.

CONCLUSION

Tc99m RBC scan is effective in localizing GI bleeding when positive within the continuous phase of imaging. In this population supplemental angiography or endoscopy for the purpose of localization would seem unnecessary.

Discrepancies in thyroid uptake values. Use of commercial thyroid probe systems versus scintillation cameras

This study attempts to find the cause of differences observed between measurements of the thyroid uptake using a thyroid uptake probe and a gamma camera. The thyroid uptakes of 65 patients were measured using the gamma camera with a pinhole collimator and two commercially available thyroid uptake systems. Moreover, simulated thyroid uptake measurements using 0.111 to 7.4 MBq (3 to 200 microCi) of I-123 were also taken using the same probe systems and gamma cameras. Results of the patient and phantom studies were evaluated by regression analyses. The gamma cameras recorded counts in direct proportion to the amount of I-123 in the phantom, but the probe systems exhibited a non-linear relationship. A 20% loss of counts was observed with 1.48 Mq (40 microCi), and up to 50% at the dose relating to a clinically administered dose of 7.4 MBq (200 microCi) in the neck phantom. Because of severe dead-time losses at high count rates associated with counting the capsule standard, the uptake ratios were artifactually higher. The 65 patient study showed a similar trend with the probe technique yielding uptake ratios higher than the gamma camera. Users of thyroid uptake systems should calibrate their instrument's counting efficiency in the dose range of the I-123 activity to be used clinically. To obtain an accurate uptake ratio, the counts must be corrected by calibration factors corresponding to the efficiency of the probe at multiple counting rates including that from counting the intended dose before therapy.

Direct comparison of Tc-99m DTPA and Tc-99m HMPAO for evaluating brain death

Portable cerebral perfusion studies provide a quick and accurate alternative to traditional confirmatory examinations (such as four-vessel angiography and electroencephalography) to determine brain death. The authors retrospectively analyzed 26 cerebral perfusion studies using both Tc-99m DTPA and Tc-99m HMPAO. The flow agents gave identical results. Additionally, the delayed-phase Tc-99m HMPAO images gave the same results for brain death (14 positive and 12 negative) as the flow images from either agent. Because the Tc-99m HMPAO delayed images can be used for diagnosis, many technical problems become less crucial. Unlike Tc-99m DTPA, Tc-99m HMPAO normally visualizes the gray matter of the cerebellum, midbrain, and medulla. These areas must be evaluated to ensure that they meet the strict criteria for brain death. These differences and the present study suggest that Tc-99m HMPAO is a superior agent for cerebral perfusion studies to determine brain death.

Ga-67 uptake in cutaneous B-cell lymphoma

Cutaneous B cell lymphoma is not commonly seen and occurs in only 8.2% of non-Hodgkins lymphoma. Although Ga-67 uptake by cutaneous T cell lymphoma has been reported, the literature on Ga imaging in cutaneous, B cell lymphoma is limited. The authors report the gallium scan and clinical findings on 2 cases of cutaneous B cell lymphoma.

Radionuclide imaging in forme fruste of melorheostosis

Scintigraphy was instrumental in two histologically proven cases of forme fruste melorheostosis. Radionuclide bone scans demonstrated a moderately increased uptake of radiopharmaceutical localized to the "flowing" cortical hyperostosis of melorheostosis observed radiographically. The medullary portion of the affected bones showed no increase in tracer activity. In one case, imaging with Tl-201 chloride demonstrated increased focal activity of the lesion. These scintigraphic findings can help distinguish the mildest manifestation (forme fruste) of melorheostosis from the well-ossified lesions of myositis ossificans and parosteal or periosteal osteosarcoma. The findings of MRI are also described in one patient.

Hemarthrosis and synovitis associated with hemophilia: clinical use of P-32 chromic phosphate synoviorthesis for treatment

PURPOSE

To evaluate the clinical usefulness of phosphorus-32 chromic phosphate synoviorthesis in patients with hemophilia, recurrent hemarthrosis, and synovitis.

MATERIALS AND METHODS

Forty-four P-32 colloid synoviorthesis procedures were performed in 38 patients with these abnormalities. P-32 colloid was injected intramuscularly in a dose of 1.0 mCi (37.0 MBq) in adult knees and 0.5 mCi (18.5 MBq) in adult elbows. A thin-window Geiger-Müller counter was used to survey treated joints, lymph nodes, and liver in order to detect leakage from the joint. Follow-up extended to a maximum of 4 years after treatment.

RESULTS

No evidence of clinically significant leakage was seen. Twenty-two of 28 treatments (78%) with longer than 6 months follow-up were associated with improvement in range of motion and frequency of hemorrhage. Of 15 treatments with longer than 2 years follow-up, 10 (67%) were associated with improvement in range of motion; 12 (80%), with improvement in frequency of hemorrhage; and 12 (80%) with improvement in quality-of-life activities.

CONCLUSION

P-32 colloid synoviorthesis is a clinically useful out-patient procedure in patients with hemophilia, recurrent hemarthrosis, and synovitis in whom hemostatic therapy has failed.

Osteosarcoma presenting as intestinal obstruction

Osteosarcoma commonly presents with osseous and pulmonary metastases. We present an unusual case of extraosseous metastatic abdominal chondroblastic osteosarcoma presenting as intestinal obstruction.

Dermatofibrosarcoma protuberans of the toe. Findings on multiple imaging modalities

Dermatofibrosarcoma protuberans occurs early in life, is an unusual soft tissue tumor, and is uncommonly seen distal to knees. The authors present a rare case of dermatofibrosarcoma protuberans of the toe with different imaging modalities.

The evaluation of 186Re-labeled antibodies using N2S4 chelate in vitro and in vivo using tumor-bearing nude mice

We have recently described a method for radiolabeling monoclonal antibodies, with metallic radionuclides using a new chelating agent N2S3. Using this chelate the monoclonal antibodies Lym-1 and B72.3 were labeled with 186Re and their biological integrity was evaluated in vitro and in vivo. 186Re-labeled antibodies using N2S4 methodology were found to be stable in human serum and retained their immunoreactivity. Intravenous administration of 0.5 mCi 186Re-labeled antibodies resulted in partial or complete regression of tumor tissue in mice.

Synthesis and preliminary evaluation of a new chelate N2S4 for use in labeling proteins with metallic radionuclides

The successful attachment of various metallic radionuclides such as 99mTc to monoclonal antibodies for targeting tumor tissue in vivo depends upon the development and use of suitable bifunctional chelating agents. We have successfully synthesized a new N2S4 (compound 4) chelate. This chelate forms a stable complex with 99mTc and is capable of coupling to different proteins. The N2S4 compound is quite stable if kept as a hydrochloride salt and is coupled to antibody under neutral conditions with better than 95% efficiency without the loss of immunoreactivity.

Circumferential quantitative analysis of planar 201T1 myocardial scintigraphy in the diagnosis of coronary artery disease

Methodology for the computer analysis of 201T1 myocardial perfusion images has been developed by several laboratories. Substantial evidence of the advantage of this approach over visual inspection alone has been reported. The currently available computer analyses use different algorithms to analyze 201T1 kinetics in the myocardium. The authors evaluated and compared two widely used software programs, Medical Data System (MDS): a mean-count profile, and the Cedars Sinai (CS): a maximal-count profile, of planar 201T1 scintigraphy for their ability to detect coronary artery disease (CAD).

Interpretation of bone scans using a video display. A necessary step toward a filmless nuclear medicine department

Digital processing, storing, and interpretation of scintigraphic images from a PACS system has been postulated as an efficient, cost-saving measure that may obviate the need for analog film. In order to replace analog film, documentation that images can be interpreted from a digital video display with accuracy at least equal to film must be obtained. Analog film was compared with video images in 28 patients with cancer suspected to be metastatic to bone. Images were acquired with a gamma camera and processed in 256 x 256 word mode by the use of the Medical Data Systems A3 computer. Adjustment of gray scales provided operator-controlled digital contrast enhancement. Video and film images were independently interpreted by two experienced nuclear medicine physicians, each blinded to the other modality. A linear four-color scale was then substituted for the gray scale, and images again interpreted. Lesions were interpreted as positive or equivocal and verified through follow-up scans over a minimum of six months. Of the 28 patients, 22 proved to have metastases, in whom 129 lesions were confirmed by follow-up scintigrams. 124 of these lesions (96.1%) were detectable on both analog film and video images. An additional three proven metastatic lesions on video images were absent or equivocal on analog studies, increasing sensitivity for video images to 98.4%. Five further lesions seen on the video screen represented rib fractures and regressed on follow-up examination. All lesions seen on black-and-white video were also seen when the color scale was applied.(ABSTRACT TRUNCATED AT 250 WORDS)

Radionuclide angiography in suspected acute cholecystitis: further observations

Radionuclide angiography (RNA) and cholescintigraphy were performed prospectively in 300 patients with suspected acute cholecystitis (AC). Of 79 patients with positive RNA, 63 had AC (80%). Positive RNA was seen in 23 of 26 cases with gangrenous AC (88%) while 12 of the 26 had a positive "rim" sign (46%). All 12 patients with a positive "rim" sign had positive RNA. The "rim" sign may be caused by increased perfusion. Five of 6 patients with positive RNA and "obstructive" pattern had AC (83%). Patients with negative RNA and positive cholescintigraphy had a positive predictive value of 54% (31/57), while those with positive RNA and positive cholescintigraphy had a positive predictive value of 85% (57/67). RNA showed increased perfusion to nonbiliary pathology such as liver abscesses and pyelonephritis. Positive RNA increases the predictive value of cholescintigraphy and may be useful to shorten cholescintigraphic examinations.

An unusual scintigraphic pattern in sickle cell patients

We reviewed the nuclear medicine files of all patients enrolled in the sickle cell disease clinic who had had scans performed within the previous 5 years. We specifically looked for patterns of tracer uptake in these scans that would correlate with the severe anemia and consequent bone marrow hyperactivity of sickle cell patients. Thirty-three patients were included (21 men and 12 women) with a mean age of 26.8 years (range 17-48 years). The appearance of each of these patients' most recent scans was examined in the areas of the distal femurs, the proximal tibias and the distal tibias; a distinct triangular shaped pattern of increased activity was identified in these areas in a majority of patients. Thirty-three patients without sickle cell disease served as age-matched controls. This pattern was seen in 65.1% (95 out of 146 images) of the sickle cell patients' delayed images and 80.4% (82 out of 102 images) of their blood pool images. In contrast, the control patients demonstrated the triangular pattern in none of their blood pool studies (0%) and only 10.9% of their delayed bone images (P less than 0.001). The mean age of sickle cell patients with this pattern is 25.6 years which was significantly lower than that of those without this pattern (mean = 37.5 years, P less than 0.05). Given the high prevalence of this unique scintigraphic pattern in a group of patients with known accelerated bone marrow function, these findings may be scintigraphic evidence of bone marrow expansion. The patient's age appears to be an important factor in visualization of this pattern.

Gated intracoronary thallium201 scintigraphy: feasibility and potential clinical advantages

Visualization of ventricular walls with true global motion and myocardial thickening is not possible with use of present scintigraphic techniques. When thallium 201 (201TI) is injected intravenously (IV), only about 5% reaches the myocardium. However, if 201TI is injected intracoronarily, 100% reaches, and approximately 88% localizes in, the myocardium, which results in higher count rates than when given IV, permitting acceptable acquisition times for gated true wall motion studies. The authors describe a new technique using intracoronary (IC) 201TI to acquire high count rate, high contrast, and short acquisition time in gated true wall motion studies. Thirteen patients were studied at rest with gated IC thallium. Six of these patients also had resting IV 201TI myocardial studies. After routine coronary angiography, 0.75 mCi of 201TI was injected into each coronary artery. Multiple sequential one-minute gated studies were obtained in LAO and RAO projections, followed by sequential five-minute images for two hours to determine 201TI redistribution kinetics. Regions of interest over segments of left and right ventricles and background permitted definition of temporal and spatial distributions. Three one-minute gated studies were summed with a total count of 2,100 K for a three-minute acquisition. Myocardium-to-background ratios were as high as 13:1 with a mean of 11.4:1 in the IC study compared with 2.3:1 in the IV studies. Washout half-time in normal myocardium was 95 +/- 5 min. The detectability and size of perfusion defects were different on gated diastolic and systolic, nongated, and IV studies. Questionable defects seen on nongated studies or after IV administration were easily noted on gated diastolic images.(ABSTRACT TRUNCATED AT 250 WORDS)

Unusual pattern of lung uptake of technetium-99m sulfur colloid seen on the liver scan of a patient with pulmonary tuberculosis

In evaluating alcoholic liver disease in a patient with pulmonary tuberculosis, a liver-spleen scan was performed that showed an unusual uptake of sulfur colloid in the lungs. There was diffuse uptake in the left lung and portions of the right lower lung with absent uptake in the right upper lobe and portions of the right lower lung corresponding to areas of pulmonary consolidation. A perfusion lung scan confirmed absent pulmonary arterial perfusion in these areas and a gallium scan demonstrated active infection there.

Hepatobiliary and gallium imaging findings in gallbladder perforation: a case report and review of the literature

Gallbladder perforation is an unusual condition with a high mortality rate. Early detection with prompt surgical intervention can increase the survival rate. Hepatobiliary imaging using Technetium-99m-labeled iminodiacetic acid has been used for the diagnosis of gallbladder perforation. However, the results vary and are somewhat confusing. The authors report a case of gallbladder perforation with hepatobiliary imaging and an unusual gallium image; review the literature; and propose a classification of three different imaging patterns: 1) visualization of the gallbladder with bile leakage, 2) nonvisualization of the gallbladder with a photopenic fluid collection, and 3) nonvisualization of the gallbladder with bile leakage. These patterns may provide pathophysiologic information for surgeon.

The scintigraphic Murphy sign

Focal gallbladder tenderness is the most important physical finding in suspected acute cholecystitis. We describe a technique using palpation of the abdomen with the placement of a radioactive marker on the point of maximum tenderness. Correlation of the marked area to the location of the gallbladder fossa is made. This integration of palpation and scintigraphy might enhance the cholescintigraphic diagnosis of acute cholecystitis.

Food cobalamin malabsorption occurs frequently in patients with unexplained low serum cobalamin levels

Malabsorption of food-bound or protein-bound cobalamin with normal absorption of free cobalamin has been described in studies of patients with gastric dysfunction. We used the egg-yolk cobalamin absorption test to study 47 patients selected not because of known gastric disorders but because they had low serum cobalamin levels with normal Schilling test results. Their egg test results were significantly lower than in normal controls, while Schilling test results were normal. Twenty of the subjects had egg test excretion below 1.5%. No features distinguished them from the 27 who excreted more than 1.5% other than the presence of lower pepsinogen I:II ratios. Eight of 19 tested patients with food cobalamin malabsorption had no evidence of abnormal gastric status by blood tests and/or gastric analysis. Also noteworthy was the finding of food cobalamin malabsorption in 60% of tested patients who had neurologic, cerebral, or psychiatric abnormalities. Food cobalamin malabsorption appears to be associated frequently with otherwise unexplained low cobalamin levels. Low cobalamin levels in patients with normal Schilling test results cannot be dismissed as insignificant without also testing for food cobalamin malabsorption, whether or not the patients have known gastric dysfunction.

Hepatic photopenia in gallium imaging

Although Ga-67 has been used extensively in imaging many different conditions, much is yet unknown about the mechanisms by which gallium concentrates preferentially in tissues such as the liver. This paper reports three patients with markedly diminished hepatic uptake of gallium. The cases are examined in light of published data demonstrating such factors as transferrin levels, radiation, and chemotherapeutic agents as altering the hepatic uptake of gallium. Of the many factors believed to influence the biodistribution of gallium, none can definitively account for the lack of hepatic uptake in these patients.

Non Hodgkins lymphoma of the breast, unusual presentation: detection by 67Ga scintigraphy

Lymphomatous involvement of the breast is an uncommon cause of breast masses. A case is presented of a patient with bilateral breast involvement revealed by intense 67Ga uptake. Other foci of involvement were also detected scintigraphically, and confirmed by other imaging modalities. Multiagent chemotherapy resulted in significant clinical and scintigraphic regression of tumor, demonstrating the potential utility of 67Ga imaging in the follow-up of these patients.

Chronic berylliosis. Demonstration by gallium-67 imaging and magnetic resonance imaging

Ga-67 is known to localize in the lungs in a wide spectrum of pulmonary pathology. The nonspecific affinity of Ga-67 uptake in both inflammatory and neoplastic entities limits its utility in terms of pulmonary disease differential diagnosis. However, Ga-67 lung imaging has proven to be helpful in evaluating the extent of inflammatory activity, as well as in assessing responses to therapy. A case of active chronic berylliosis, a disorder in which Ga-67 uptake has not been previously reported is presented. There is diffuse bilateral Ga-67 pulmonary activity before therapy. Subsequent to steroid therapy, a marked decrease in pulmonary gallium uptake activity was noted with only residual hilar and mediastinal adenopathy noted.

Volume calculation by means of SPECT: analysis of imaging acquisition and processing factors

To assess the effect of image acquisition and processing factors on the volume calculated from single photon emission computed tomography (SPECT) images, the authors evaluated technical factors including image matrix size, size of the region of interest (ROI), activity concentration in the region, amount of background subtraction, type of reconstruction filter, section thickness, and number of projections. They found that the percentage of background subtraction was the single most important factor affecting volume calculation. The smaller the volume, the greater the amount of background subtraction needed before the ROI is drawn. As an acceptable means to circumvent the varying percentage of background subtraction for different volumes, a calibration curve was constructed relating the true volume with the calculated volume for a fixed percentage of background subtraction. The use of a 128 X 128 acquisition matrix and zooming of the reconstructed images were necessary for accurate calculation of volumes smaller than 300 mL.

Radionuclide and radiographic demonstration of condensing osteitis of the clavicle

Radionuclide and radiographic images of a case of condensing osteitis of the clavicle are presented. The clinical and radiographic features are discussed along with a differential diagnosis of sclerotic lesions of the clavicle.

Gallium-67 uptake in cutaneous lesions of mycosis fungoides

The literature on gallium imaging in mycosis fungoides is limited and conflicting. A case of mycosis fungoides with increased uptake of Ga-67 in clinically noninfected skin lesions is reported. The literature regarding mycosis fungoides and gallium imaging is reviewed.

Hepatobiliary scintigraphy and scintiangiography in abdominal trauma

Scintiangiography and hepatobiliary scintigraphy were performed in 45 patients with abdominal trauma. There were 18 gunshot wounds, six stab wounds, and 21 blunt injuries. Thirty-one of 45 patients showed abnormalities (69%). There were nine bilomas (4 with leaks), three leaks without biloma, (7 total leaks), five liver hematomas, three liver infarcts, one liver abscess, four renal injuries, one post-traumatic hepatic artery aneurysm, one acute acalculus cholecystitis, and four bowel injuries including one fistula, two obstructions, and one stricture. Two of the renal injuries and the hepatic artery aneurysm were identified only during scintiangiography. Eighteen of 38 gallbladders were not visualized despite normal bowel transit and delayed views to 4 hours (47%). Fourteen of 16 gallbladders were grossly normal at surgery, one had gallstones, and one had post-traumatic acalculus cholecystitis (6%). Hepatobiliary scintiangiography showed unique characteristics of vascular and renal lesions that were not seen on routine images. Sulfur colloid had no advantage over disofenin in evaluating liver injuries in nine cases. A high percentage of nonvisualized gallbladders (47%) were noted in acutely traumatized patients, and caution is recommended in diagnosing acute cholecystitis in the face of trauma.

Unsuspected pernicious anemia in a patient with sickle cell disease receiving routine folate supplementation

Although the issue of folate supplementation in sickle cell anemia remains controversial, routine supplementation has become common. The major drawback to indiscriminate folate therapy is the potential of masking findings of vitamin B12 (cobalamin) deficiency. This has been dismissed as a problem in sickle cell anemia because of the generally young age of the patients. However, because young blacks, especially women, are at higher risk for developing pernicious anemia than whites, sickle cell anemia and pernicious anemia can be expected to coexist occasionally. In this article we describe such a patient and recommend that routine folate supplementation should not be given in sickle cell anemia before determining the vitamin B12 status.

Aortic ejection fraction: a new hemodynamic parameter and its relationship to aortic insufficiency

Pulsations of the ascending aorta during fluoroscopy in patients with aortic insufficiency (AI) have been described. The authors present their observations of a similar phenomenon in patients who have AI undergoing scintiangiography. In addition, this paper describes a technique to validate and quantitate this finding. They studied 17 patients with documented AI and 14 subjects of a control group. First-pass studies were acquired in the RAO 15 degrees projection. Regions of interest were placed over the proximal aorta during systole and diastole. An aortic ejection fraction (AF) was determined. The calculated AEF data were correlated with the presence or absence of AI. The mean AEF from the 17 AI patients was 27.1 +/- 7.2%, while the mean for the non-AI group was 12.0 +/- 6.5% with p less than .001. An AEF of 18% separates the two groups with a sensitivity, specificity, and accuracy of 88%, 86%, and 87% respectively. Preliminary data demonstrate a mean reduction in AEF of 12.2 percentage points in 7 AI patients who underwent aortic valve replacement. The AEF may be a useful new parameter to evaluate hemodynamic changes associated with aortic valve replacement in patients with aortic insufficiency.

Kock continent ileal urinary reservoir. Anatomy and potential pitfalls of radionuclide imaging

The Kock continent ileal urinary reservoir (Kock pouch) is a new form of urinary diversion that, due to its advantages over previous techniques of urinary bypass, will probably become widespread in urologic practice. When bone imaging is performed in the presence of the Kock pouch, the unusual configuration of the pouch may obscure or simulate osseous lesions. An understanding of the surgical anatomy as well as the planar and SPECT scintigraphic appearances of the Kock pouch is necessary to avoid errors during interpretation. This series of 51 bone images reports on the variable scintigraphic appearance of the Kock pouch. In addition, the incidence and type of potentially avoidable pitfalls in the interpretation of bone imaging when this form of urinary diversion is used are evaluated.

Enterogastric reflux in suspected acute cholecystitis

Ninety patients undergoing Tc-99m disofenin hepatobiliary scintigraphy for suspected acute cholecystitis were assessed for enterogastric reflux. Seventy-seven cases showed bowel activity by one hour and were included in the study. Twenty-six percent (20/77) showed definite enterogastric reflux. The gastric activity tended to clear rapidly, even though patients remained supine during examination. Six of 20 patients (30%) with enterogastric reflux had gallbladder visualization. Of these six, one had acute cholecystitis and one had resolving acute cholecystitis with gallstone pancreatitis. There was one case each of pancreatitis, amebic abscess, sepsis, and one normal. Thus, of 20 patients with enterogastric reflux, 16 had acute cholecystitis (80%). Twenty-three of seventy-seven patients (30%) had surgically proven acute cholecystitis: of these, 16 of 23 (70% sensitivity) had gastric reflux, and 50 of 54 without acute cholecystitis did not have reflux (93% specificity). The overall accuracy of enterogastric reflux for acute cholecystitis is 86%. Gastric reflux seen on cholescintigraphy is a secondary sign of acute cholecystitis. Reflux may be related to duodenal irritation from the adjacent inflamed gallbladder.

Acute cholecystitis: diagnosis with radionuclide angiography

Radionuclide angiography and cholescintigraphy were performed with a bolus injection of technetium-99m disofenin in 65 patients with suspected acute cholecystitis. Acute cholecystitis was surgically confirmed in 23 of 25 cases in which radionuclide angiographic findings were positive (i.e., showed focal increased flow to the gallbladder region) (positive predictive value, 92%). Sensitivity and specificity of radionuclide angiography for detecting acute cholecystitis were 72% and 94% for cholescintigraphy. Three patients with scintigraphically visible gallbladders (at 45 minutes, 2.4 hours, and 4.5 hours) and positive angiograms had severe acute cholecystitis and abscess. All 20 patients with positive radionuclide angiographic and scintigraphic results had transmural acute cholecystitis. None of the nine patients with acute cholecystitis and false-negative angiograms had abscess or gangrene of the gallbladder. Use of radionuclide angiography may enable the prediction of the severity of acute cholecystitis, as nine of 25 patients with positive findings had either gangrenous cholecystitis or pericholecystic abscess. Positive findings on radionuclide angiograms may preclude the need to obtain delayed (beyond 1 hour) cholescintiscans.

Imaging of medullary thyroid carcinoma and hyperfunctioning adrenal medulla using iodine-131 metaiodobenzylguanidine

Scintigraphy with radiolabeled metaiodobenzylguanidine was performed in a patient with MEN Type IIa having a pheochromocytoma of the right adrenal gland, adrenomedullary hyperplasia of the left adrenal gland and a primary medullary thyroid carcinoma. The scintigraphic findings demonstrate visualization of all the above mentioned pathologies.