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X Marchandise

Publications and source records attributed to X Marchandise.

At least 55 records · Page 3Linked to original sources
PubMed1995

Comparison of technetium-99m methoxyisobutylisonitrile and gallium-67 citrate scanning in the assessment of lymphomas.

The aim of this study was to compare the value of scintigraphy using technetium-99m methoxyisobutylisonitrile (MIBI) with that of scintigraphy using gallium-67 citrate in the assessment of Hodgkin's disease and non-Hodgkin's lymphoma and to relate these results with those of CT scan and MRI. Fifty-eight patients were included either for a follow-up examination or for monitoring of their treatment. Twenty-three residual masses were studied. A whole-body scan was performed, followed by single-photon emission computed tomography (SPET) 20 min after injection of 740 MBq of 99mTc-MIBI and 72 h after injection of 185 MBq of 67Ga citrate. The overall sensitivity of 99mTc-MIBI and 67Ga citrate was 71% and 68%, respectively, and the overall specificity was 76% and 44%, respectively. For residual masses, the sensitivity was 44% with both tracers and the specificity was 80% with 99mTc-MIBI and 53% with 67Ga citrate. The positive predictive values were 85% and 68% and the negative predictive values were 59% and 44%, respectively. The signal-to-background ratio was 1.5 for 99mTc-MIBI and 2 for 67Ga citrate. At present, 99mTc-MIBI cannot replace 67Ga citrate in the assessment of lymphomas.

Adult↗
PubMed1995

RF-transmitted CsI radio-isotopic ambulatory recorder for left ventricular ejection fraction monitoring.

We have developed a CsI multidetector probe in order to produce a nuclear ambulatory recorder to study simultaneously cardiac electric activity and the left ventricular ejection fraction. To make the device lighter, the electronics were designed with surface-mounted technology, and a serial data RF transmission system was used. The data are processed on a real-time basis using a portable microcomputer. Unlike other commercially available devices, this monitor avoids the problems of volume, weight, recording time capacity and slow off-line data processing. Our device permits global and regional analysis of the ejection fraction for a moderate manufacturing cost. It is intended primarily for ambulatory use and can easily be adapted to perform a monitoring function. The first tests on patients conducted using the prototype demonstrate the technical reliability and satisfactory operation of the device.

Cesium↗
PubMed1995

[Intraoperative radioisotope detection: review of the acquired experience and perspectives].

Intraoperative radio-isotope detection is an old idea which has been recently revived following the development of new detectors. The authors describe two points of view concerning this technique: external detection or surface detection. Based on the experience of more than 250 cases, they review the current status of the indications for ttris technique in endocrine surgery. They discuss the prospects of this technique in the light of the development of nuclear medicine and the basic requirements of surgery: new tracers and intraoperative scintigraphy.

Adrenal Gland Neoplasms↗
PubMed1995

[Scintigraphy of iodine 123 labelled serum amyloid P component in beta 2-microglobulin amyloidosis of hemodialysis].

UNLABELLED: To assess the iodine-123-labelled serum amyloid P component (SAP) scintigraphy in patients with haemodialysis-associated amyloidosis. PATIENTS: Eight patients with histologically proven beta 2-microglobulin amyloidosis. METHODS: Purified SAP was iodinated by a modified iodogen method. Whole body data were acquired with a large rectangular field gamma-camera. RESULTS: In 7 cases, articular uptake was observed in the symptomatic joints (shoulders, wrists, knees) or in view of bone cysts (wrists). Among the 3 patients with erosive arthropathy of the hands, only one had positive scintigraphy. None positive scintigraphic image was obtained in the spine or the hip joint. In one patient with multifocal amyloid joint disease, no positive image was noted. No abnormal visceral uptake was observed and particularly of the spleen except in one patient with liver uptake. CONCLUSION: I-123 SAP scintigraphy might be not very sensitive in diagnosing beta 2 amyloid deposits. This method needs further investigations and particularly in patients undergoing haemodialysis for more than 20 years.

Aged↗
PubMed1995

Methods for quantitative analysis of trabecular bone structure.

Bone mineral density accounts for 70% to 80% of the mechanical resistance of bone but is unrelated to bone tissue structure. The vertebral fracture risk increases with advancing age irrespective of whether or not bone mineral density decreases, suggesting that changes in bone microarchitecture contribute significantly to the development of osteoporosis. In contrast to bone mass, bone architecture is difficult to evaluate. Among the various methods developed to investigate bone structure, biomechanical studies are of limited value since they are done on cadaver bones. Measurement of microarchitectural parameters (e.g., mean trabecular thickness, density and separation) in bone specimens obtained by needle biopsy is the gold-standard technique. Parameters reflecting trabecular interconnections (e.g., total number of nodes and free ends) can also be measured on needle biopsy specimens. New techniques of as yet unproven validity include star volume and trabecular bone pattern factor measurement. Noninvasive techniques capable of supplying qualitative information about bone tissue are also under study. Ultrasonography can theoretically provide data on bone microarchitecture but has not yet been proven useful in clinical practice. Statistical, structural, or fractal analysis techniques can be used to evaluate bone texture on digitized roentgenograms, computed tomography sections, or magnetic resonance imaging displays; although this approach holds great promise, it is still under evaluation and has not yet been compared with histomorphometry. Lastly, the apparent relaxation time of bone marrow determined using magnetic resonance imaging may also provide information on bone structure.

Biomechanical Phenomena↗
PubMed1994

Automated computerized radiogrammetry of the second metacarpal and its correlation with absorptiometry of the forearm and spine.

The value of a new computerized radiogrammetric method of assessment of the second metacarpal has been evaluated, and its results have been compared with those of single (SPA) and dual photon absorptiometry measurements (forearm and spine) in 74 and 79 postmenopausal women, respectively. Standard hand X-rays were digitized by a video-camera connected to a microcomputer. The combined cortical thickness (CCT) was automatically calculated in a zone of 10 mm around the midpart of the second metacarpal. The intra- and interobserver coefficients of variation were close to 1%. The correlation between CCT and SPA of the proximal and midforearm (with a significant amount of cortical bone) was satisfactory (r = 0.62 and 0.50, respectively; P < 0.001). The correlation between CCT and osteodensitometry of sites comprising more trabecular bone were not so good (0.50 for lumbar and 0.44 for distal forearm bone mineral density, respectively), but still significant (P < 0.001). Radiogrammetry proved unaffected by a change of X-ray apparatus, as measurements of 48 metacarpals radiographed by two different kinds of X-ray apparatus were not significantly different. Radiogrammetry is by no means the best method to evaluate bone mass. Its automation did not improve the correlation with osteodensitometric values. Radiogrammetry is still of interest in mass screening, particularly when other more expensive techniques such as osteodensitometric methods of bone mass measurement are not readily available. Its automation makes it simpler, faster, and more precise, rendering its use easier on a larger scale.

Absorptiometry, Photon↗
PubMed1994

[Localized or systemic amyloidosis? Value and limitations of Iodine-123 labelled amyloid P component scintigraphy, role of biopsy of minor salivary glands].

We evaluated the value of serum amyloid P component scintigraphy (123I-SAP) and labial salivary gland biopsy in four patients with apparently localized amyloidosis. One patient had pharyngeal amyloidosis, the second laryngeal amyloidosis, the third retro-ocular amyloidosis and the fourth had carpal tunnel syndrome. Three patients (no 2, no 3, no 4) have abnormal whole body retention of 123I-SAP and positive labial salivary gland biopsy for amyloidosis. Only the first patient had effectively localized amyloidosis and local treatment was sufficient. Melphalan was given to the patients no 2 and no 3, colchicine was given to the patient no 4. Labial salivary gland biopsy and 123I-SAP scintigraphy may give positive argument for the diagnosis of systemic amyloidosis in patients with apparently localized amyloidosis.

Adult↗
PubMed1994

A miniature cesium iodide-photodiode detector for ambulatory monitoring of left ventricular function.

The physical characteristics of a portable nonimaging scintillation probe system for continuous ambulatory monitoring of the left ventricular function are described. The detector of the equilibrium radionuclide labeled blood pool is a single cesium iodide (CsI) crystal coupled to a silicium photodiode and interfaced to a microcomputer. The spatial properties of this small CsI crystal (1 x 1 x 1 cm3) were evaluated with various single-hole collimators. Linearity was studied in nonattenuating medium. Saturation began at 3000 cps, count loss was 10% at 4000 cps, maximal count rate was 24,000 cps. In attenuating medium, isocount curve of 5% of the maximal count rate was 100 mm deep and 160 mm wide. The most appropriate tested lead collimator to record the global ejection fraction of the left ventricle was a disc-shaped (thickness 5 mm, diameter 41 mm) single-hole (proximal aperture 8 mm, distal aperture 18 mm) collimator. Sensitivity was similar to the sensitivity of a sodium iodide nuclear probe. The detection performance appeared comparable to other available detector systems. Our results indicate that such a CsI-photodiode probe is a promising candidate for left ventricular function monitoring. The application to an ambulatory multicrystal detector system is presented and discussed.

Biophysical Phenomena↗
PubMed1994

Somatostatin analogs for the localization and preoperative treatment of an adrenocorticotropin-secreting bronchial carcinoid tumor.

The diagnosis of the ectopic ACTH syndrome often remains difficult. Although bilateral inferior petrosal sinus sampling has recently offered a new approach, it does not help to localize an occult nonpituitary tumor. We report the case of a 45-yr-old woman whose hypercortisolism highly suggested the ectopic ACTH syndrome: elevated urinary free cortisol (3234 nmol/day, normal 28-143) was not suppressed by the high-dose dexamethasone test (2789 nmol/day); increased plasma ACTH (21.8 pmol/L, normal 2-11.4) did not respond to the ovine CRH test (23.8 pmol/L); and pituitary magnetic resonance imaging was negative. The thorax computed tomographic scan showed a questionable 7-mm nodular lesion in the upper part of the left lung. Because a 3-day trial of octreotide administration (200 micrograms sc every 8 h) induced a dramatic clinical and biological response with a drop in urinary free cortisol from 1738 to 441 nmol/day we performed a scintigraphy with [111In]pentetreotide; it revealed a single-well limited area of abnormal uptake at the exact location of the suspected thoracic lesion. This nodule was removed surgically after preparation of the patient by a 1-month treatment with octreotide: the tumor proved to be a typical bronchial carcinoid, containing extremely high concentrations of immunoreactive ACTH (198 pmol/mg wet wt tissue) and POMC messenger RNA by Northern blot. The presence of somatostatin receptors in the tumor was confirmed by in vitro radioautography. After surgery plasma cortisol and ACTH were undetectable. Somatostatin radioanalog scintigraphy should be considered as a new investigative tool in patients with suspected ectopic ACTH syndrome.

ACTH Syndrome, Ectopic↗
PubMed1994

Technical note: magnetic resonance imaging of agarose gel phantom for assessment of three-dimensional dose distribution in linac radiosurgery.

An agarose gel phantom is used to evaluate the spatial distribution of the dose delivered by a linac radiosurgery device. Dependence of the absorbed dose on the T1 relaxation time is checked. T1 magnetic resonance images show the close correspondence between the actual absorbed dose distribution and the dose distribution expected by the treatment planning.

Gels↗
PubMed1994

Scintiscans and carcinoid tumors.

BACKGROUND: The presence of somatostatin receptors on carcinoid tumors mediates imaging of tumor extent and inhibition of tumor growth and marker secretion. This prospective study aimed to evaluate radiolabeled somatostatin analog scans in the therapeutic workup of carcinoids. METHODS: Twenty-one patients with carcinoids underwent 26 scans with iodine octreotide or indium pentetreotide. The results for tumor and metastases imaging were analyzed and compared with those of a short inhibition test of marker secretion and with those of metaiodobenzylguanidine scan. RESULTS: The sensitivity for obtaining images of the overall 43 tumor sites was 72%. We had no false-positive results. Unknown tumor sites were discovered in three patients. The results were slightly better with indium pentetreotide and metastases imaging. A positive scan did not always preclude responsiveness to the functional effect of octreotide. Results of somatostatin analog scans were better than those with metaidobenzylguanidine. The two techniques were complementary in one patient. CONCLUSIONS: The choice of treatment for patients with carcinoid tumors should benefit from functional inhibition test with octreotide and from indium pentetreotide and metaidobenzylguanidine scans.

3-Iodobenzylguanidine↗
PubMed1994

Iodine-123-Tyr-3-octreotide uptake in pancreatic endocrine tumors and in carcinoids in relation to hormonal inhibition by octreotide.

UNLABELLED: Uptake of 123I-Tyr-3-octreotide (TOCT) by hormone-secreting abdominal tumors was studied to compare scintigraphic observations with the reduction in hormone levels brought about by a brief therapeutic test. METHODS: A prospective study was conducted on 17 patients, totalizing 46 proven lesions, with endocrine tumors of the pancreas (10 patients, 20 lesions) and/or carcinoid metastases (8 patients, 26 lesions). Tumor hormonal hypersecretion was inhibited by octreotide. RESULTS: There was good agreement between the results of these examinations. CONCLUSIONS: The detection of abdominal tumors using this radiotracer is strongly related to its functional characteristics. Variations in the scintigraphic and test results according to different tumor types were in agreement with published data on the density of somatostatin receptors measured by in vitro studies or scintigraphy and by the therapeutic effects of octreotide.

Adult↗
PubMed1993

Iodine-123-labelled serum amyloid P component scintigraphy in amyloidosis.

This study describes the results of scintigraphy with iodine-123-labelled serum amyloid P component (SAP) as a means of establishing the distribution of organ involvement in amyloidosis. The significance of 123I-SAP scans obtained in 15 patients with biopsy-proven AA or AL amyloidosis is discussed. Biopsy-proven amyloidosis was typically confirmed by scintigraphy, though such confirmation was not obtained in the kidneys in six patients with histological proof of extensive renal amyloid deposition. This lack of uptake may have been due to the accumulation of a major part of the 123I-SAP in the spleen and/or liver. Twenty-four hour whole-body retention of 123I-SAP was higher in patients with amyloidosis than in controls. Twenty-four hour tracer accumulation of the radioactivity in the extravascular compartment was notably greater in patients than in controls and appeared to be a good diagnostic criterion. We conclude that 123I-SAP scintigraphy may be helpful for the evaluation of organ involvement not only in patients with biopsy-proven amyloidosis but also when a biopsy cannot be performed or when a strong suspicion of amyloidosis exists in spite of repeated negative biopsies.

Amyloidosis↗
PubMed1993

Bone mineral and fat measurement with a novel dual photon absorptiometer.

The authors have produced an original dual-photon absorptiometer, with specific algorithms, permitting real-time automatic bone recognition, to reduce examination time (to 5 min). It permits the simultaneous measurement of the mineral density of an area of bone (BMD), the fat percentage of the soft tissues (PFST) that surround it, and the variation in this percentage. It visually represents, on one and the same picture, freely defined in terms of dimension and definition, bone mineral distribution and fat mass distribution. The performances are analysed, using phantoms and taking ten control subjects, in the region of the femoral neck. The variations in PFST in the control subjects are compared with the measurements carried out in MRI in the same region. In all these control subjects, there is a regular decrease in PFST in this region along an upper external/lower internal axis. This decrease has been likened to a regression line, the slope of which, representing between -0.16 per cent of fat per cm and -1.7 per cent per cm, has a mean value of -0.81 per cent per cm. The BMD is thus reduced by 0-2.5 per cent, depending on the subjects.

Absorptiometry, Photon↗