Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of silent metastases from malignant melanoma.

Correct staging is crucial for the management and prognosis of patients with malignant melanoma. The aim of this prospective study was to compare staging by whole-body positron emission tomography using fluorine-18 fluorodeoxyglucose (18F-FDG) with staging by conventional methods. Thirty-eight patients with malignant melanoma of clinical stage II (local recurrence, in-transit and regional lymph node metastases) or III (metastases to other sites than in stage II) were included in the study. The results of the PET scans were compared with those obtained by clinical examination, computed tomography, ultrasound, radiography, and liver function tests and histology or clinical follow-up. With 18F-FDG PET we found for all foci a sensitivity of 97% and a specificity of 56%, compared with 62% and 22%, respectively, when using routine methods. For intra-abdominal foci, the sensitivity and specificity were 100% for both 18F-FDG PET and routine methods. Corresponding figures for pulmonary/intrathoracic foci were 100% and 33%, respectively. Of the patients included in this study, 34% would not have been staged correctly by conventional methods alone. We conclude from this study that 18F-FDG PET is a sensitive method superior to conventional methods for detecting widespread metastases from malignant melanoma. Mutilating surgery of no benefit can thereby be avoided. 18F-FDG PET is useful as a supplement to clinical examination in melanoma staging.

The value of scintigraphy in hips with slipped capital femoral epiphysis and the value of radiography and MRI after 10 years.

Preoperative bone scintigraphy of the femoral head in 33 hips with slipped capital femoral epiphysis, showed no relation to duration of symptoms or degree of slip. The preoperative uptake was always normal or increased. Two hips had postoperative femoral head uptake below normal, both had complications affecting the vascular supply, resulting in necrosis of the femoral head and severe arthrosis. At follow-up after 10 (5-15) years of 28 hips, no relation could be demonstrated between Adolescent Hip Questionnaire which included clinical data, and radiography or magnetic resonance imaging. We only recommend scintigraphy after complications jeopardizing the vascular supply of the femoral head in slipped capital femoral epiphysis.

Bronchial artery perfusion scintigraphy to assess bronchial artery blood flow after lung transplantation.

UNLABELLED: The bronchial arterial system is inevitably interrupted in transplanted lungs when removing the organs from the donor, but it can be reestablished by direct bronchial artery revascularization (BAR) during implantation. The purpose of this study was to visualize and quantify the distribution of bronchial artery perfusion after en bloc double lung transplantation with BAR, by injecting radiolabeled macroaggregated albumin directly into the bronchial artery system. METHODS: BAR was performed using the internal mammary artery as conduit. Patients were imaged 1 mo (n = 13) or 2 y (n = 9) after en bloc double lung transplantation with BAR. Immediately after bronchial arteriography, 100 MBq macroaggregated albumin (45,000 particles) were injected through the arteriographic catheter. Gamma camera studies were then acquired in the anterior position. At the end of imaging, with the patient remaining in exactly the same position, 81mKr-ventilation scintigraphy or conventional intravenous pulmonary perfusion scintigraphy or both were performed. Images were evaluated by visual analysis, and a semiquantitative assessment of the bronchial arterial supply to the peripheral parts of the lungs was obtained with conventional pulmonary scintigraphy. RESULTS: The bronchial artery scintigraphic images showed that the major part of the bronchial arterial flow supplied central thoracic structures, but bronchial artery perfusion could also be demonstrated in the peripheral parts of the lungs when compared with conventional pulmonary scintigraphy. There were no differences between scintigrams obtained from patients studied 1 mo and 2 y post-transplantation. CONCLUSION: Total distribution of bronchial artery supply to the human lung has been visualized in lung transplant patients. This study demonstrates that this nutritive flow reaches even the most peripheral parts of the lungs and is present 1 mo as well as 2 y after lung transplantation. The results suggest that bronchial artery revascularization may be of significance for the long-term status of the lung transplant.

Bone scintigraphy of human temporomandibular joints during Herbst treatment: a case report.

Bone scintigraphy results were compared with changes shown on orthopantomographic radiographs in a patient with facial asymmetry, before, during, and after Herbst treatment, and followed up with control of growth activity in the temporomandibular joints (TMJs) after long-term retention. The present study showed that new bone formation (modelling) was initiated asymmetrically in TMJs during treatment. The results indicate that late development of right/left asymmetry in the occlusion can be corrected and normalized using the Herbst appliance therapy, stimulating a differentiated 'catch up' growth (modelling) in the TMJ with condyles. After treatment, original growth with asymmetric activity in the TMJ was re-established. This growth activity may re-establish the asymmetry in the sagittal occlusion and the face of the patient. It is therefore recommended that the occlusion should be maintained with an appliance which stabilizes the occlusion until cessation of the primary, endochondral growth.

Scintigraphic assessment of focal platelet accumulations following infrainguinal bypass surgery in humans.

Enothelial injury is assumed to be of pathogenetic significance in the development of graft stenoses, which remain a major cause of failure of peripheral bypasses. The aim of this study was to assess endothelial injury related to infrainguinal bypass surgery by indium-111 platelet scintigraphy. In 28 patients undergoing in situ vein (n = 24), composite vein-polytetrafluoroethylene (PTFE) (n = 1) or PTFE (n = 3) bypass surgery, assumed vascular injuries were recorded intraoperatively. Autologous indium-111-labelled platelets were injected into the inflow artery immediately after restoration of flow in the graft. Platelet deposition was assessed by gamma-camera images of thigh and crus obtained 4 and/or 24 h after surgery. Areas of focally increased activity were recorded and graded as moderate or intense. In the 24 vein bypasses, a median of two (range 0-5) areas of focally increased radioactivity were seen at the proximal anastomosis (n = 21), in the body of the graft (n = 20) or at the distal anastomosis (n = 9). The activity was moderate in 27 cases and intense in 23 cases. Scintigraphic evidence of focal platelet aggregation in vein grafts was not correlated with preoperative antiplatelet therapy or vein graft diameter. Only 2 of the 20 intragraft platelet depositions occurred in areas where intra-operative vascular injury was suspected. In the composite graft and the PTFE grafts, diffuse activity was observed throughout the entire bypass. In conclusion, focal activity accumulations, suggesting localized endothelial injury, were observed in the majority of in situ vein bypasses, in particular at the sites of the anastomoses. Prosthetic bypasses were characterized by diffuse platelet aggregation.

Restricted postexercise pulmonary diffusion capacity and central blood volume depletion.

Pulmonary diffusion capacity for carbon monoxide (DLCO), regional electrical impedance (Z0), and the distribution of technetium-99m-labeled erythrocytes together with concentration of plasma atrial natriuretic peptide (ANP) were determined before and after a 6-min "all-out" row in nine oarsmen and in six control subjects. Two and one-half hours after exercise in the upright seated position, DLCO was reduced by 6 (-2 to 21; median and range) %, the thoracic-to-thigh electrical impedance ratio (Z0 thorax/Z0 thigh) rose by 14 (-1 to 29) %, paralleled by a 7 (-3 to 11) % decrease and a 3 (-5 to 12) % increase in the thoracic and thigh blood volume, respectively. These responses were associated with a decrease in the plasma ANP concentration from 15 (13-31) to 12 (9-27) pmol/l (P < 0.05). Similarly, in the supine position, Z0 thorax/Z0 thigh increased by 10 (-5 to 28) % when DLCO was reduced 12 (6-26) % (P < 0.05), whereas DLCO remained stable in the control group. The increase in Z0 thorax/Z0 thigh and the corresponding redistribution of the blood volume in both body positions show that approximately one-half of the postexercise reduction of DLCO is explained by a decrease in the pulmonary blood volume. The role of a reduced postexercise central blood volume is underscored by the lower plasma ANP, which aids in upregulating the blood volume after exercise in athletes.

Myocardial sestamibi single-photon emission tomography: variations in reference values with gender, age and rest versus stress?

Reference data files support the evaluation of myocardial perfusion single-photon emission tomography (SPET). The aim of this study was to create a large reference data base for technetium-99m sestamibi SPET, age and gender matched to the general patient population. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a likelihood of coronary artery disease of less than 5% underwent rest and maximal exercise 99mTc-sestamibi SPET with a 2-day protocol and 180 degrees elliptical rotation. The normalized activity values of 99mTc-sestamibi in the inferior wall differed significantly between men and women. Age variations were found for men in the anterior wall. Normalized activity values in all four walls were strikingly similar during rest and stress. Our results suggest that the use of reference files in 99mTc-sestamibi SPET requires a gender- and, for males, possibly an age-matched reference population. Different reference files at rest and during stress might not be necessary.

The occurrence of false-positive technetium-99m sestamibi bull's eye defects in different reference databases. A study of an age- and gender-stratified healthy population.

Myocardial perfusion single-photon emission tomographic (SPET) imaging has been shown to be sensitive in the detection of coronary artery disease (CAD), whereas its specificity has been suboptimal. The aim of the present study was to study the frequency of abnormal bull's eye perfusion defects in a large age-stratified group of healthy subjects undergoing myocardial SPET assessed by comparison with two existing commercially available reference databases. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a less than 5% likelihood of CAD underwent rest and exercise technetium-99m sestamibi SPET. The false-positive response rate, defined as a significant reversible defect, was 12% when compared to the CEqual database and 29% when compared to the Cedars-Sinai database. With the CEqual program, rest defects occurred in 12% of the subjects. Defects occurred more often in women than in men, but the difference did not attain statistical significance. Significant defects were most frequent in the inferior wall and in women in the anterior wall as well. The distribution of defects was independent of age. Our results suggest that the specificity of 99mTc-sestamibi myocardial SPET using commercially available reference files is suboptimal. The risk of obtaining a false-positive test result in subjects undergoing 99mTc-sestamibi myocardial SPET with a very low likelihood of CAD was higher than anticipated. With both reference files false-positive test results were most frequently observed in the inferior wall. Our data suggest that commercial reference files for myocardial SPET need to be optimised, and should be used with caution. The use of attenuation correction may prove to be a major step forward.

Prenatal hydronephrosis caused by aberrant renal vessels: a follow-up challenge. Reports of two cases.

With routine use of obstetric ultrasonography, fetal low-grade hydronephrosis is commonly detected, but may resolve spontaneously after birth. Two cases are presented to illustrate that in some cases such findings can express intermittent hydronephrosis caused by aberrant renal vessels. Renal deterioration later in childhood may be a consequence.

[Preoperative scintigraphic localization of hyperfunctioning parathyroid glands]. / Praeoperativ scintigrafisk lokalisation af hyperfungerende parathyreoideakirtler.

Preoperative identification of hyperfunctioning parathyroid glands was performed by 99m-Tc-sestamibi scintigrams in 29 patients with hyperparathyroidism. Out of 30 histopathologically proven diseased parathyroid glands 21 were identified by scintigraphy. The diagnostic specificity (PVpos) was 88%. All diseased glands weighing more than 1200 mg were identified by scintigraphy including four glands in the mediastinum. 99m-Tc-sestamibi scintigraphy can identify the larger hyperfunctioning parathyroid glands with high reliability. The method was of great value in situations with ectopic abnormal parathyroid glands.

Relationship between small-intestinal transit rate and intestinal absorption of (14)C-labelled mannitol and (51)Cr-labelled ethylenediaminetetraacetic acid in healthy subjects.

BACKGROUND: Although the small-intestinal transit rate is generally considered to influence the urinary excretion of markers of intestinal permeability, no study has until now formally addressed the importance of this influence in humans. METHODS: Ten healthy subjects ingested a test solution containing (99m)Tc-labelled diethylenetriaminepentaacetic acid ((99)mTc-DTPA), (14)C-labelled mannitol ((14)C-mannitol), and (51)Cr-labelled ethylenediaminetetraacetic acid ((51)Cr-EDTA). After ingestion, the small-intestinal transit rate of (99)mTc-DTPA was measured with the gamma camera technique. Urine was collected for time periods of 0-2 h, 2-4 h, and 4-6 h to measure the excretion of absorbed (14)C-mannitol and (51)Cr-EDTA. Moreover, the distribution volume and plasma clearance of (14)C-mannitol and (51)Cr-EDTA were determined in each subject. RESULTS: A positive correlation was found between mean small-intestinal transit time and 0- to 6-h urinary excretion of (14)C-mannitol. The study did not show any correlation between small-intestinal transit rate and 0- to 6-h urinary excretion of (51)Cr-EDTA. Urinary excretion of neither (14)C-mannitol nor (51)Cr-EDTA was affected by distribution volume or urine volume. A positive correlation was observed between plasma clearance and 0- to 6-h urinary excretion of (14)C-mannitol, whereas plasma clearance did not influence the urinary excretion of (51)Cr-EDTA. CONCLUSIONS: Small-intestinal transit rate seems to have a significant effect on 0- to 6-h urinary excretion of (14)C-mannitol, whereas small intestinal transit rate does not influence the timed urinary excretion of (51)Cr-EDTA.

Follow-up of prenatally diagnosed unilateral hydronephrosis.

Based on previous experience with prenatally diagnosed unilateral hydronephrosis, we found that the primary indications for surgical intervention should be symptoms or functional impairment of the hydronephrotic kidney. Nonoperative management of neonates without symptoms and with normal function of the affected kidney was proposed. However, the strategy of treatment after prenatally diagnosed hydronephrosis is still controversial. We studied 28 consecutive children with suspected unilateral pelviureteral junction obstruction and a normal contralateral kidney. The overall follow-up period varied between 2.5 months and 6 years (median 2 years). Eleven children had normal function of the hydronephrotic kidney and were managed nonoperatively throughout the follow-up period. None of these demonstrated any symptoms and the renal function remained normal. A further 4 children with normal function of the affected kidney were managed nonoperatively, but later had a pyeloplasty performed because of either symptoms or deterioration of renal function. Eleven children had a pyeloplasty performed after the first renography showed that the hydronephrotic kidney provided less than 40% of total renal function. The age at pyeloplasty was 3 weeks- 7 months (median 6 weeks). In all cases but 1 the function of the affected kidney improved. Two patients with impaired hydronephrotic renal function were not operated upon. Our results indicate no need to change the strategy of treatment.

Planar 201Tl scintigraphy in ischaemic heart disease: a critical re-evaluation of qualitative and quantitative data analysis.

The aims of the present study were to examine the observer agreement of qualitative (visual) and quantitative (computer-assisted) analysis of planar 201Tl imaging and to compare the diagnostic values of these methods in the detection of infarcted and exercise-induced ischaemic myocardium. The study population comprised of 119 patients (aged 24-77 years) referred consecutively for stress thallium scintigraphy for either diagnostic reasons (n = 42, 35%) or for further evaluation of known coronary artery disease (CAD) (n = 77, 65%). The interobserver agreement was low with the qualitative method and significantly higher with the quantitative method: Kappa-values 0.29-0.39 vs. 0.80-0.92, P < 0.00001. Sensitivity and specificity for the detection of previous Q-wave infarct was significantly higher with the quantitative method (94% and 94%) compared to the qualitative method (77% and 74%), P < 0.01. The corresponding predictive values of a positive and a negative test were 96% and 92% vs. 80% and 70% (P < 0.01). In 86 patients in whom coronary angiography was performed the two methods did not differ significantly regarding sensitivity, specificity and predictive values for the diagnosis of reversible ischaemia or rather CAD. However, when 22 patients with a maximal exercise heart rate < 80% of the predicted target heart rate were excluded the sensitivity was increased with both techniques and was significantly higher with the quantitative method. We conclude that qualitative image analysis has an unacceptably low reproducibility and that quantitative image analysis increases the diagnostic value of 201Tl scintigraphy considerably in both the detection of previous infarcts and, provided a sufficient exercise level is achieved, in the disclosure of reversible myocardial ischaemia.

In vivo kinetics of 111indium-labelled autologous granulocytes following i.v. administration of granulocyte-macrophage colony-stimulating factor (GM-CSF).

Administration of both glycosylated and non-glycosylated recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) induces an immediate transient granulocytopenia of 1-3 hours' duration. In order to explore this phenomenon, granulocytes were labelled with 111Indium and the effect on the kinetics of granulocytes after administration of rhGM-CSF was studied in 10 previously untreated patients with malignant lymphoma. For both types and doses of rhGM-CSF, a significant and dramatic accumulation of the 111Indium-labelled granulocytes was observed in the lung within a few minutes after i.v. injection of rhGM-CSF. The accumulation of radioactivity coincided with the pronounced and transient granulocytopenia in peripheral blood. The 111Indium-labelled granulocytes later reappeared in the peripheral blood, indicating reversible pulmonary vascular margination of the granulocytes. Half-life of labelled granulocytes after reappearance was comparable to half-life values under normal conditions. The transient accumulation of granulocytes in the pulmonary vessels seems not to be of clinical importance in the management of patients, but it may to some degree explain previously described side-effects, such as transient hypoxemia ("first-dose" reaction) following administration of rhGM-CSF.

Measurement of glomerular filtration rate in adults: accuracy of five single-sample plasma clearance methods.

After an intravenous injection of a tracer that is removed from the body solely by filtration in the kidneys, the glomerular filtration rate (GFR) can be determined from its plasma clearance. The method requires a great number of blood samples but collection of urine is not needed. In the present investigation the total plasma clearance of 51Cr-EDTA (ethylenediaminetetra-acetate) was assessed from 13 blood samples taken 5-300 min post-injection in 44 adult patients with GFR greater than 15 ml min-1. In 34 of these patients the plasma clearance of 99Tcm-DTPA (diethylenetriaminepenta-acetate) was determined simultaneously. Using these clearance values as reference the accuracy of six simplified methods were studied: five single-sample methods and one five-sample method. The standard error of estimate (SEE) of the single-sample methods ranged from 4.2 to 7.5 ml min-1 using EDTA, and from 3.8 to 6.3 ml min-1 using DTPA. SEE of the five-samples method was 3.0 ml min-1 (EDTA) and 3.1 ml min-1 (DTPA). The single-sample methods given by Christensen & Groth (1986) and by Tauxe (1986) are recommended for daily use, as SEE was small even at low GFR values. In patients with GFR less than 80 ml min-1, in whom a highly accurate determination is needed, a multiple samples method is recommended, e.g., Brøchner-Mortensen (1972).

Left ventricular performance in alcoholic patients without chronic liver disease.

Left ventricular performance was studied non-invasively in 24 chronic alcoholics without liver disease. Twelve patients who had abstained from drinking for at least one month (group A) and 12 sex and age matched patients who had ceased drinking during the preceding 24 hours (group B) were studied at rest and during 50% submaximal exercise. Cardiac output and stroke volume were measured by first passage and left ventricular ejection fraction by multigated radionuclide cardiography. Twelve healthy sex and age matched controls were also studied. Haemodynamic variables were similar in group A and the controls, except that in group A left ventricular end systolic volume index did not decrease during exercise. In group B the heart rate was increased both at rest and during exercise and plasma noradrenaline concentrations were increased. The stroke volume index did not increase significantly during exercise in group B. In addition, the increase in left ventricular ejection fraction was smaller in group B than in controls. End systolic contraction was reduced in group B patients and diastolic blood pressure was increased. These results suggest that cardiac abnormalities in chronic alcoholics may be reversed after cessation of drinking if no chronic liver disease is present. Recent alcohol consumption increases sympathetic nervous activity, impairs cardiac contractility, and increases afterload during physical stress.

Haemodynamic response to exercise in patients with alcoholic liver cirrhosis.

Physical work capacity was evaluated by a multistage bicycle exercise test in 29 patients, 22 men and seven women aged 35-61 years (mean 49) with alcoholic liver cirrhosis and in a sex- and age-matched control group. The maximal work load was reduced in the patient group, mean 122 vs. 186 watts in men (P less than 0.001), and 60 vs. 119 watts in women (P less than 0.005). Resting heart rate was higher in patients (91 vs. 78 beats X min-1, P less than 0.005), and the maximal heart rate was lower (159 vs. 170 beats X min-1, P less than 0.001) compared with controls. Thirteen of 29 (45%) patients compared with 5 of 29 (17%) control subjects had an increase in left ventricular ejection fraction of less than or equal to 5% during exercise (P less than 0.05). The present results suggest that an impaired capacity of the cardiac function to respond adequately to physical stress may at times contribute to the reduced physical work capacity seen in patients with alcoholic liver cirrhosis.

Background correction factors in renography with single probe detectors.

The background correction factor was determined with [131I]albumin, FA, in eighty-six patients with various nephro-urological diseases, with [131I]hippuran in eighty unilaterally nephrectomized patients (FH), and in twenty-five patients in whom the renogram showed background configuration, FH, B. FH was approximately the same on the left and the right side, the mean values being 1.39 and 1.35, respectively. FA showed a significant side difference, the mean values being 1.30 and 1.19 on the right side, respectively. FH, B was higher than FH, which shows that some uptake of hippuran can take place in apparently non functioning kidneys.