[Early detection of synchronous thyroid carcinoma and malignant melanoma by fluorodeoxyglucose positron emission tomography]. / Detection précoce d'un carcinome thyroïdien et d'un mélanome malin synchrones par une tomographie par emission de positron a la fluorodeoxyglucose: cas clinique.

Functional tumor imaging using Fluorodeoxyglucose positron emission tomography (FDG-PET) is a new method in clinical oncology. The 18 FDG, is a glucose analog that accumulates in cells in proportion to the rate of glucose metabolism, and increased carbohydrate metabolism has been recognized as a feature of malignant cells versus normal cells. In addition, it permits the detection of metastases or synchronous tumours not discovered by anatomic imaging. Although detection of the primary site of disease is usually accomplished well with conventional techniques, the performance of FDG-PET may be useful to determine tumours that are not clinically evident. The authors describe a case of early detection of synchronous thyroid carcinoma by FDG-PET in a young patient opereted on for a malignant melanoma on his arm.

Ischemic heart disease in black South African stroke patients.

BACKGROUND AND PURPOSE: Stroke patients in western countries frequently have coronary artery disease (CAD). In black Africans, CAD has been reported as being rare in both stroke patients and the general population. In this study, an attempt has been made to determine the prevalence of CAD in a black South African stroke population. METHODS: The prevalence of CAD was determined by indicators identified through a series of 5 observational studies in black patients diagnosed with stroke. CAD indicators included (1) bedside diagnosis in 741 patients; (2) resting ECG in 555 consecutively admitted patients; (3) a combination of clinical examination, cardiac ultrasound, radionuclide scintigraphy, and multigated blood pool studies in 102 consecutively admitted patients; (4) thallium scintigraphy in 60 patients; and (5) necropsy in 23 patients. RESULTS: On bedside questioning, only 0.7% complained of previous angina. There was no history given of myocardial infarction (MI), but documentation of this was found in the clinical notes of 0.7% of the patients. In the resting ECG study, evidence of myocardial ischemia was present in 14.6% and MI in 2.1%. In the combined study, cardiac ischemia was documented on ECG in 12.7% of patients and evidence of previous MI in 5.8%. Cardiac scintigraphic studies revealed changes of myocardial ischemia in 31.7% and MI in 13.3% of the 60 patients studied. Four (17.4%) of 23 patients in the necropsy study had histological evidence of previous MI, and 50% of all patients had evidence of >50% atherosclerotic stenosis in 1, 2, or 3 coronary arteries. CONCLUSIONS: The prevalence of CAD in black African stroke patients is significantly higher than has been documented in the general nonstroke black population as well as in stroke patients. Black stroke patients may have a risk for CAD similar to that of their white counterparts.

Thyroidal radioisotope uptake in euthyroid cats: a comparison between 131I and 99mTcO4.

Two thyroidal evaluation systems in euthyroid cats (n = 12) were compared. A single, confirmed hyperthyroid cat was included for interest. Firstly, thyroidal uptake of an intravenous bolus of approximately 111 MBq (3 mCi) 99MTcO4 was estimated by using a scintillation camera and calculating the ratio of thyroid to salivary activities at 20 min and 4 h. Thyroid to salivary activity ratios were 1:1 at 20 min and 2:1 at 4 h. Two discrete areas of salivary uptake were identified, namely a parotid/mandibular complex and a more rostral buccal/sublingual complex. These results were compared to radioiodine uptake of an oral dose of approximately 0.925 MBq (25 microCi) 131I using a standard thyroid uptake system, measured at 1, 2, 4, 6, 8, 10, 12, 24 and 48 h after administration. Mean radioiodine thyroidal uptake started at 33% at 1 h, stabilised at 21% between 4 and 24 h, and dropped to 18% at 48 h. There was a significant correlation between the early thyroid:salivary ratio of the parotid/mandibular complex and the radioiodine uptake at 12 h.

[Late form with psychiatric presentation of Wilson's disease, with pseudo-compulsive stereotyped movements. Neuro-radiological correlations]. / Forme tardive à présentation psychiatrique de la maladie de Wilson, avec mouvements stéréotypés pseudo-compulsifs. Corrélations neuro-radiologiques.

Wilson's disease rarely starts after the third decade and may present with misleading psychiatric signs. We observed a 39-year-old white male who developed hysterical behaviour followed by frank delusional psychosis. Secondary neurological symptoms like astasia and dyarthria were misinterpreted as drug-induced. Despite a treatment with D-penicillamine and zinc sulfate there was further deterioration with anarthria and pseudo-compulsive stereotypies. These latter signs cleared after five months, whereas astasia and abasia remained the same and MRI imaging showed further deterioration characterized by marked bilateral putaminal cavitation. SPECT imaging could not predict the clinical evolution. Our case emphasizes that Wilson's disease can have variable initial presentations, and confirms the relationship between pseudo-compulsive stereotypies and bilateral lenticular lesions, as already described in other diseases of the basal ganglia.

The baboon model under anesthesia for in vivo cerebral blood flow studies using single photon emission computed tomographic (SPECT) techniques.

Single photon emission computed tomography of the brain can be useful in animal experimentation directed toward cerebral conditions. A well established and understood baboon model, necessarily under anesthesia, could be especially valuable in such investigations. Six normal baboons were studied under various anesthetic agents and their combinations: ketamine, thiopentone, pentobarbitone, and halothane. Cerebral blood flow (CBF) studies were performed with 99mTc-HMPAO. CBF effects from various anesthesia were detected, requiring careful choice of the anesthesia for cerebral investigations.

Use of indium-111-labelled platelets in black stroke patients. A pilot study.

Human blood platelets labelled with indium-111 oxine have been shown to accumulate on damaged vascular surfaces and abnormal platelet deposition has been demonstrated in the carotid arteries of white stroke patients. Gamma scintigraphy of the carotid and cerebral arteries of 5 black stroke patients and 5 age- and sex-matched controls using 111In-labelled platelets showed no abnormal accumulation indicative of carotid artery disease.

Time profile; space- and time-condensed images.

A method has been developed to generate "condensed images" and to produce instantaneously time-activity curves from rectangular regions of interest. It uses readily available tomographic software. Examples of esophageal transit and thyroid perfusion are shown. Further developments are discussed.

The cardiovascular status of the black stroke patient.

The cardiac status of 102 consecutive black stroke patients entered to the Medunsa Stroke Databank was determined. Cardiological examination, echocardiography and a gated blood pool scan revealed structural and/or functional cardiac abnormalities in 73.6% of patients. Rheumatic heart disease was diagnosed in 15.6%, mitral valve prolapse in 5.8% and mitral annulus calcification in 4.9% of cases. 'Possible' cardiac sources of cerebral embolism were detected in 22.5% and 'definite' sources in 23.5% of patients. Hypertensive heart disease was diagnosed in 35.2% and cardiomyopathy in 13.7% of the study population. Ischaemic heart disease was present in 6.86%. Ultrasonography revealed ventricular bands in 29.4% of patients. The high incidence of structural cardiac abnormalities detected by non-invasive means is in keeping with recent studies in white stroke patients.

Using the "integral spleen" method of radiorenogram analysis and a baboon model to compare the diagnostic usefulness of technetium-99m-diethylenetriamine pentaacetic acid to that of various technetium-99m-mercaptoacetyltriglycene formulations and iodine-123-hippuran.

In light of the high price of commercially available mercaptoacetyltriglycene (MAG3) it was decided to attempt a local MAG3-formation and to test this against diethylenetriamine pentaacetic acid (DTPA), 123I-Hippuran, and commercial MAG3 for diagnostic radiorenographic capabilities also in conjunction with furosemide and captopril. A baboon model (n = 6) was used, and the parameters evaluated were obtained by the "integral spleen" method of radiorenogram analysis. Although the images and parameters pointed to 123I-Hippuran and commercial MAG3 as the ideal renal scanning agents and to DTPA as the least so, with the local product an acceptable alternative, the differences were not significant enough to warrant either the purchase of the commercial product or the extensive development of the local product. Inexpensive 99mTc-DTPA in conjunction with modern computer techniques will probably supply most of the answers.

Importance of cholescintigraphy and inferior vena cava flow studies in the differential diagnosis of hepatocellular carcinoma.

In order to assess the usefulness of inferior vena cava flow studies and cholescintigraphy complementary to the routine static liver scintigraphy in the differential diagnosis of hepatocellular carcinoma (HCC), we studied 37 patients with a proven diagnosis of HCC and 11 patients with a liver abcess or cyst. The procedure followed was 1) a 99mTc-colloid flow study of the inferior vena cava (IVC) and iliac veins followed by static liver imaging and 2) cholescintigraphy using a dynamic acquisition mode to determine the perfusion as well as the concentration/excretion of the liver and pathological area. The hepatic perfusion index (HPI) was calculated by the "slope" method of Sarper et al.: Radiology 141:179-184 (1981) and the "area" method of Biersack et al.: Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklear medizin. Erganzungsband 126:47-52 (1977). The results were compared with data previously collected in patients without liver disease (control) and other liver pathologies.

Evaluation of the clinical validity of the "integral spleen" method of renography analysis from parameter changes induced by pharmacological and surgical intervention.

A set of controlled experimental animal procedures involving pharmacological and surgical interventions was carried out to assess the clinical validity of the parameters calculated by the "integral spleen" method of renography analysis. There appeared to be a good correlation between the observed changes of these parameters and current pathophysiological information. In particular, the described method includes an original calculation of the filtration fraction without blood and urine sampling or a second tracer injection. This calculation was experimentally validated here.

A progressive radiorenographic (99mTc-DTPA) presentation of surgically induced renal vein hypertension in baboons.

A 99mTc-DTPA radiorenographic study, supported by excretory urography, blood chemistry and eventually histology was performed on 8 chacma baboons (Papio ursinus) after surgical induction of unilateral renal vein hypertension. Frequent sequential repeat renograms during 6 post-operative months detected fluctuating renal behaviour but did not reveal typical course of the disease. Neither did any one of the radiorenographic parameters (TP, T1/2, FF, relative clearances and perfusion) prove to be more sensitive than the others in detecting abnormalities. Initial microscopic or macroscopic haematuria and proteinuria in general eventually cleared up. Light microscopy demonstrated only mild abnormalities. The effects of venous occlusion of the kidney and the prognosis seemed to be variable as was reflected by radiorenography.

Evaluation of different formulae for the study of platelet survival.

The International Committee of Standardization in Haematology has recommended in 1977 three methods for calculating the mean platelet survival time of isotope labelled platelets, although in recent years other mathematical equations were also suggested for the determination of platelet survival times. Seven different methods of calculating the mean survival time for normals were investigated and were compared with one another.

A comparison of 111In-labelled polymer beads and 99mTc-Sn-colloid as solid food and semi-solid food tracers for scintigraphic gastric emptying studies.

In order to establish the efficacy of labelling a solid meal and a semi-solid meal with either 111In-labelled polymer beads or 99mTc-tin colloid beagle dogs were fed variously labelled meals of different consistencies and then monitored by scintigraphy for gastric motility patterns. The labelling with each tracer was either performed by thoroughly mixing it into the food before cooking, or alternatively by surface labelling after the food had been cooked. For the 99mTc-Sn-colloid tracer no difference was found in the measured gastric emptying times resulting from either pre-cooking labelling or surface labelling of the meals. Cooking the tracer together with the ingredients does however seem to promote a firm entrapment of the 111In-polymer beads into a solid protein, and in this manner the 111In-labelled resin appears to be a reliable solid food tracer. Surface labelling with 111In-polymer beads of a solid meal with a smooth texture fails totally and the tracer empties with the liquid phase.

Radionuclide studies in upper gastro-intestinal ulceration--are they reliable? A pilot study of 6 patients.

Endoscopy is at present the diagnostic technique of choice in the evaluation and detection of upper gastro-intestinal tract ulceration. Because of the physical discomfort suffered by patients during endoscopic examination, the search for better and less invasive methods of examination (especially in the unco-operative and seriously ill patient) continues. According to reports from the Orient, sucralfate (Ulsanic; Continental Ethicals) has prominent ulceravid properties. These properties are being used in conjunction with a tagging agent, in this case technetium-99m, as a diagnostic method for the detection and localization of upper gastro-intestinal ulceration. In this pilot study on 6 patients the positive findings of others regarding the specificity and promise of this method could not be confirmed.

The detection and evaluation of drug-induced changes in the gastrointestinal motility of beagle dogs using a 111In-labelled resin mixed into a standard meal as tracer.

An investigation was performed to establish the usefulness of 111In-labelled polymer beads mixed into a standard meal as a tracer of gastrointestinal(GI)-motility changes due to the influence of various drugs. The labelled polymer beads were well mixed into the food, which was then fed to healthy beagle dogs undergoing drug therapy. GI motility was monitored using a gamma camera and data processor. The results were compared to those obtained from corresponding placebo studies on the same dogs. A significant acceleration of gastric emptying and colon transit was noted under the influence of a gastric and intestinal prokinetic coded R51619. No influence on GI motility could, however, be detected after the administration of a calcium-blocking agent to the dogs.

Gastrointestinal scintigraphy using 99mTc- or 111In-labelled polymer beads.

In order to establish normal and pathological stomach emptying characteristics by external measurement of a radioactive meal using a gamma camera and computer system, it is necessary for the radioactively labelled substance to have the same behaviour in the stomach as the ingested food. Resins containing chelating groups which enable binding to either reduced 99mTcO4- or 111In+3 were tested for their suitability as tracers mixed into solid food. The preparation of such styrene-divinyl-benzene resins containing either triethylenetetramine substituents or the fully carboxymethylated derivatives is discussed, as well as the procedures of labelling with either 99mTc-pertechnetate or 111In-chloride. An evaluation of the resins for gastrointestinal scintigraphy was performed on 3 chacma baboons and a male human volunteer with encouraging results.

Standardisation of tracer and type of meal in the evaluation of gastric emptying and colon transit rates in normal beagle dogs.

The transit 111In-labelled polymer beads of different particle sizes in the stomach and colon of five healthy Beagle dogs was monitored after intake of different kinds of meal by a gamma camera and data processor system. The various meals studied were a solid balanced type of dog food mixed with milk, pure milk, and finally a meal of raw meat. The polymer beads carried triethylenetetramine type functions which efficiently chelated 111In+3 from an aqueous solution of InCl3. These labelled beads were well mixed into the food before being offered to the dogs. Gastric emptying curves from which half-times of emptying (T 1/2) could be obtained are presented and statistically compared. Good quality images with quantification of the colon transit rate also became possible. It appeared that standardisation of the tracer and of the meal is compulsory for relevant and reproducible results.