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Biomedical subjects

D Le Guludec

Publications and source records attributed to D Le Guludec.

At least 55 records · Page 3Linked to original sources

Usefulness of somatostatin receptor scintigraphy in the management of patients with Zollinger-Ellison syndrome. Groupe de Recherche et d'Etude du Syndrome de Zollinger-Ellison (GRESZE).

BACKGROUND: Management of patients with Zollinger-Ellison syndrome (ZES) depends on the presence of multiple endocrine neoplasia type 1 (MEN 1) or liver metastases, or both. Somatostatin receptor scintigraphy (SRS) detects previously unknown endocrine tumours. AIM AND METHODS: To evaluate SRS findings susceptible to modifying the management of patients with ZES-that is, relevant findings, and the specificity of these findings. The latter were defined according to our current therapeutic strategy in three subgroups of patients (sporadic, MEN 1, and liver metastases). PATIENTS: 85 consecutive patients without known extra-abdominal metastases were studied between September 1991 and March 1996. RESULTS: Relevant findings were found in 41% of 49 patients with sporadic disease but without liver metastases, in 22% of 18 patients with MEN 1 but without liver metastases, and in 17% of 18 patients with liver metastases. Follow up was available for 20 (74%) of 27 patients who had 23 relevant findings. Nineteen relevant findings (83%) were confirmed at a median of three (range 0.25-45) months of follow up; four (17%) were not confirmed at 30 (range 12-52) months (p = 0.025). Findings located in the duodenopancreatic area (90%), chest (100%), bone (100%), and liver (60%) were confirmed. Most findings for patients with MEN 1 involved the chest. CONCLUSION: SRS detects many anomalies susceptible to modifying management of patients with ZES, especially in those with sporadic disease. The specificity of hot spots located outside the liver seems very high. By contrast, the specificity of hot spots located in the liver remains to be evaluated when conventional imaging is negative.

Adult↗

Utility of indium-111-antimyosin scintigraphy for diagnosis of myocardial damage in systemic sclerosis.

The diagnosis of myocardial disease related to systemic sclerosis is often difficult, but it is clinically relevant since the occurrence of a specific ventricular dysfunction is of poor prognosis. This article reports a case of systemic sclerosis with a subacute episode of myocardial disease assessed by 111In-antimyosin antibody, a specific marker of the necrotic myocardial fiber.

Adult↗

False-positive somatostatin receptor scintigraphy due to an accessory spleen.

A patient with previous left caudal pancreatectomy and splenectomy presented with Zollinger-Ellison syndrome. Abdominal CT and endoscopic ultrasonography revealed a mass in the splenic area. Somatostatin receptor scintigraphy showed a nodular increase of the uptake corresponding to the lesion detected with conventional imaging. A second laparotomy was performed and the mass was resected. Histological analysis showed that the nodular lesion was an accessory spleen. Since physiologic uptake of 111In-pentetreotide is seen in the spleen, an accessory spleen mimicking a tumor, specially after previous splenectomy, may result in false-positive somatostatin receptor scintigraphy.

False Positive Reactions↗

[Detection of endocrine tumors of the digestive tract. Value and limitations of scintigraphy of somatostatin receptors].

Most neuroendocrin tumors (excepting insulinomas) carry a high density of somatostatin receptors which readily bind somatostatin analogs, allowing tumor and metastasis imaging with indium-labeled somatostasin analogs. For primary tumors (gastrinomas, carcinoid tumors), detection sensitivity is about 80%. The scintiscan adds complementary information to other imaging techniques including echoendoscopy. By combining indium-scan with echoendoscopy we have been able to detect 90% of the tumors in the upper duodenopancreatic area. In addition, scintigraphy detects tumors in about half of the patients with characteristic laboratory tests but negative imaging with other techniques. Metastases can also be detected; sensibility for liver is > 90%. The indium-scan is also positive in up to 20-30% of the patients after other imaging methods failed to identify metastasis. Finally, tumors found to be receptor-positive would respond better to treatment with somatostatin analogs.

Digestive System Neoplasms↗

Preoperative detection of duodenal gastrinomas and peripancreatic lymph nodes by somatostatin receptor scintigraphy. Groupe D'etude Du Syndrome De Zollinger-Ellison.

BACKGROUND & AIMS: Duodenal gastrinomas and peripancreatic lymph nodes are difficult to localize. The aim of this study was to evaluate the ability of Octreoscan scintigraphy to detect such tumors. METHODS: Results of Octreoscan scintigraphy in 21 consecutive patients with Zollinger-Ellison syndrome were compared with those of conventional imaging techniques, including endoscopic ultrasonography, and with the surgical findings. RESULTS: Surgical exploration found 27 duodenal and/or lymph node gastrinomas in 19 patients. None had pancreatic gastrinoma. Octreoscan scintigraphy was the only positive preoperative technique in 32% of the patients. The sensitivities of conventional techniques, Octreoscan scintigraphy, and their association were 58%, 58%, and 90%, respectively, for all resected gastrinomas. The smallest duodenal gastrinoma detected by Octreoscan scintigraphy measured 3 mm. Endoscopic ultrasonography detected all the tumors visualized by any other conventional technique and was considered falsely positive, as was Octreoscan scintigraphy, in 1 patient. Follow-up and comparison between the number of resected gastrinomas and the number of preoperative hot spots suggested that surgeons should find at least as many tumors as the number of hot spots. CONCLUSIONS: Octreoscan scintigraphy improved the preoperative detection of extrapancreatic gastrinomas, mainly by endoscopic ultrasonography. Surgeons should find at least as many gastrinomas as the number of hot spots.

Adult↗

Left ventricular myocardial uptake of a labeled somatostatin analog in carcinoid syndrome.

We report a case of left ventricular (LV) myocardial uptake of a labeled somatostatin analog in a patient with a carcinoid tumor of the small bowel. The patient developed liver metastases and a carcinoid syndrome, including right carcinoid heart disease, without right-to-left shunt on contrast ultrasonography or left ventricular myocardial metastases. The basis for visualization of the LV myocardium is probable somatostatin receptor upregulation.

Aged↗

[Post-infarction myocardial viability. Role of scintigraphic evaluation].

Myocardial scintigraphy is clinically relevant in the management of patients with previous myocardial infarction. The purpose of such investigation is first to quantify the infarcted area, secondly to detect and quantify a residual myocardial ischaemia and thirdly to evidence the presence of chronically hypoperfused and akinetic but potentially viable myocardium (hibernating myocardium). Thallium SPECT is to be preferred in this indication even if new tracers could be promising: fatty acids, 18Fluorodesoxyglucose imaged by PET or SPECT cameras. In such indications, stress tests should sometimes be completed with delayed or rest acquisitions. In case of negative stress and rest thallium SPECT, PET scans may be useful in patients with large myocardial infarction, severe left ventricular dysfunction, segmental wall motion asynergy, and absence of previously demonstrated residual ischaemia in order to select patients eligible for coronary revascularization or heart transplantation.

Humans↗

Evaluation of radionuclide angiography in diagnosis of arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVES: The accuracy of Fourier analysis of radionuclide angiography for the diagnosis of arrhythmogenic right ventricular cardiomyopathy was assessed versus X-ray right ventricular angiography. BACKGROUND: In patients with recurrent right ventricular tachycardia, the diagnosis of arrhythmogenic right ventricular cardiomyopathy is based on the presence of right ventricular wall motion abnormalities on conventional X-ray angiography without evidence of other heart disease. METHODS: X-ray and radionuclide angiography were prospectively compared in 73 patients with ventricular tachycardia. We analyzed the presence of a right ventricular enlargement, global hypokinesia and segmental wall motion abnormalities, using visual analysis for both techniques and Fourier analysis for radionuclide angiography. Disease was noted as absent or present and as diffuse or localized. The interobserver reproducibility of both techniques for the diagnosis of right ventricular wall motion abnormalities was tested in 27 randomly selected patients. RESULTS: According to X-ray angiography, 53 patients were considered to have arrhythmogenic right ventricular cardiomyopathy (22 diffuse, 31 localized forms) and 20 patients a normal right ventricle. The sensitivity of radionuclide angiography was 94.3%, specificity 90% and positive and negative predictive values 96% and 85.7%, respectively. Agreement for the location of the wall motion abnormalities was 60% for the apex, 76% for the outflow tract, 82% for the inferior wall and 74% for the free wall. The diagnostic interobserver reproducibility of X-ray and radionuclide angiography was 74% and 96.2%, respectively. CONCLUSIONS: In a selected cohort, Fourier analysis of radionuclide angiography is an accurate and reproducible tool for the diagnosis of arrhythmogenic right ventricular cardiomyopathy.

Adult↗

Nonlimited exercise test combined with high-dose dipyridamole for thallium-201 myocardial single-photon emission computed tomography in coronary artery disease.

Clinical, electrocardiographic, and thallium-201 single-photon emission computed tomography data were evaluated in 397 consecutive patients divided into 3 groups according to coronary hyperemic stimulation: 186 patients (group I; Ex) had maximal symptom-limited exercise ergometric stress testing, 93 patients (group II; Dip) had intravenous dipyridamole (0.7 to 0.8 mg/kg) stress testing, and 118 patients (group III; Dip+Ex) had dipyridamole (0.7 to 0.8 mg/kg) plus nonlimited (i.e., symptom-limited) exercise stress testing, achieving a maximal workload (mean +/- SD) of 102 +/- 37 W. Clinical tolerance was higher in Ex than in Dip groups (p < 0.01), and tended to be higher in Dip+Ex than in Dip groups (p = NS). Image quality--as judged by signal-to-noise ratios--was superior in Ex and Dip+Ex groups when compared with the Dip group (p < 0.01). Chest pain and electrocardiographic positivity were more frequent in the Dip+Ex group than in the Dip group (p < 0.05), despite more extensive coronary artery disease (CAD) in the Dip group; and reversible scintigraphic defects were more frequent in Dip+Ex versus Dip (p < 0.01) and in Ex versus Dip groups (p < 0.05) in patients with established CAD, as well as for the whole group. We conclude that, in patients unable to achieve 85% of their maximal predicted heart rate, the combination of high-dose dipyridamole plus nonlimited exercise stress testing is superior to dipyridamole stress testing alone, and comparable to maximal exercise testing.

Aged↗

Comparison using dynamic vectorcardiography and MIBI SPECT of ST-segment changes and myocardial MIBI uptake during percutaneous transluminal coronary angioplasty of the left anterior descending coronary artery.

The quantitative relation between ST-segment changes and the severity and extent of myocardial ischemia during coronary occlusion remains unclear. This study assesses whether ST-segment changes during percutaneous transluminal coronary angioplasty (PTCA) correlate with the amount of myocardium at risk, measured with technetium-99m hexakis 2-methoxyisobutyl isonitrile (MIBI; also called sestamibi) single-photon emission computed tomography (SPECT). Quantitative continuous dynamic vectorcardiography was performed during PTCA of the left anterior descending coronary artery in 11 patients (mean age 64.3 years) without previous myocardial infarction. Change in the magnitude of the ST vector (STc-VM) was continuously recorded. A standardized protocol of balloon inflations was used and technetium-99m MIBI was injected intravenously at the onset of the third inflation. SPECT imaging was performed 60 minutes later and compared to a rest acquisition. SPECT was quantified by bull's-eye analysis using: (1) the change in the pathologic/normal area count ratio (delta P/N) as an index of the severity of ischemia; and (2) planimetered defect size during PTCA as an indicator of the size of the area at risk. The delta P/N from baseline to balloon occlusion (22 +/- 11%) was correlated, albeit loosely, to the maximum value of STc-VM (245 +/- 186 microV, r = 0.62, p < 0.05), but there was no correlation between the size of the scintigraphic defect and STc-VM. Likewise, the sum of ST-segment elevation was correlated to delta P/N (r = 0.72, p < 0.02), but not to the size of the scintigraphic defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Myocardial perfusion imaging with technetium-99m-Tc NOET: comparison with thallium-201 and coronary angiography.

UNLABELLED: We compared TcN-NOET [bis(N-ethoxy, N-ethyl dithiocarbamato)nitrido 99mTc] and 201Tl images to estimate the utility of this compound in the detection of coronary artery disease (CAD). METHODS: Twenty-five patients undergoing cardiac catheterization had stress-redistribution-reinjection 201Tl SPECT imaging, stress-delayed (2, 4 and 6 hr postinjection) and rest-delayed (4 hr postinjection) TcN-NOET SPECT imaging. RESULTS: Nineteen patients had coronary stenosis > or = 50% and six were normal. Stress TcN-NOET and 201Tl imaging were concordant for the presence of CAD in 22/25 patients (88%, kappa = 0.76 +/- 0.20). The overall sensitivity of TcN-NOET SPECT imaging was 74% (14/19 patients) and 68% (13/19 patients) for 201Tl SPECT imaging. The specificity was 100% (6/6 patients) for both techniques. The overall agreement of TcN-NOET and 201Tl for the presence of disease in individual coronary arteries was 96% (72/75 arteries, kappa = 0.92 +/- 0.16). Segmental analysis of stress images showed a concordance in 211/225 segments (94%, kappa = 0.82 +/- 0.09). Comparison of the 4-hr images showed a concordance between 201Tl and TcN-NOET in 21/23 patients. Following TcN-NOET injection at rest, seven patients had a defect on the initial images, which had normalized 4 hr postinjection in four patients (57%). CONCLUSION: Perfusion imaging with TcN-NOET and 201Tl gives comparable diagnostic information in patients undergoing exercise testing for assessment of CAD. Because of the normalization of myocardial activity 4 hr after injection in some patients, we conclude that TcN-NOET is a potential technetium compound equivalent to 201Tl.

Adult↗

Somatostatin receptor scintigraphy in forty-eight patients with the Zollinger-Ellison syndrome. GRESZE: Groupe d'Etude du Syndrome de Zollinger-Ellison.

In patients with the Zollinger-Ellison syndrome, which is either sporadic or integrated into multiple endocrine neoplasia type 1, accurate localization of all the tumours is difficult and may have therapeutic implications. In an attempt to improve this localization, somatostatin receptor scintigraphy using [111In-DTPA-D-Phe1]-octreotide was performed prospectively in 48 consecutive patients with the Zollinger-Ellison syndrome. Thirty of them had the sporadic type of this disease. Scintigraphic data were compared with data obtained by conventional imaging methods, and also, in 32 selected patients, with those obtained by endoscopic ultrasonography. Somatostatin receptor scintigraphy showed abnormal tracer uptake in 39 patients (81%), in whom it correctly identified 50 of the 60 tumoral sites (83%) previously localized by the other imaging methods. In 17 patients (35%) somatostatin receptor scintigraphy disclosed abnormal tracer uptake at 18 different tumoral sites: 14 were located in the abdomen, including four in the liver and eight in the duodenopancreatic area, and four outside the abdomen, including two in the mediastinum. Six of the ten tumoral sites which were not correctly identified by somatostatin receptor scintigraphy were located in the duodenopancreatic area. However, in the 20 patients for whom conventional techniques failed to visualize any tumour in the duodenopancreatic area, somatostatin receptor scintigraphy was positive in ten (50%) whereas endoscopic ultrasonography was only positive in five (25%). In our patients with the Zollinger-Ellison syndrome, somatostatin receptor scintigraphy appeared to be a useful new addition to the battery of tests used for tumour detection.

Bone Neoplasms↗

Dual-isotope myocardial imaging: feasibility, advantages and limitations. Preliminary report on 231 consecutive patients.

Two hundred and thirty-one patients underwent dual-isotope myocardial imaging (rest thallium-201 followed by stress technetium-99m sestamibi). The feasibility of the procedure was excellent: camera scheduling flexibility was improved and the duration of the procedure was less than that of a classical stress-redistribution procedure. Interpretation of defects due to image attenuation was facilitated by the different attenuation properties of 201Tl and 99mTc-sestamibi in 11 of 19 patients. 201Tl cross-over on 99mTc was found to be 15% +/- 3% with doses of 201Tl and 99mTc-sestamibi of 3 and 10 mCi, respectively, and 7% +/- 2% with doses of 3 and 20 mCi. This protocol should preferentially be reserved for patients with a history of myocardial infarction and/or a basal left ventricular dysfunction, in whom assessment of myocardial viability is of major interest. Extensive clinical validation of the dual-isotope procedure is required and optimal acquisition and reconstruction parameters should be established.

Adult↗

Coronary spasm induced by dipyridamole during a myocardial scintigraphy.

A 59-year-old male underwent a dipyridamole myocardial scintigraphy. During dipyridamole infusion, a marked ST-segment elevation was observed in the inferior leads. After aminophylline injection, a short burst of ventricular tachycardia occurred, then the ST-segment elevation disappeared. The myocardial scintigraphy was consistent with myocardial ischemia of the inferior wall. The coronary angiography revealed no significant coronary lesion. Coronary spasm induced by dipyridamole remained the most probable mechanism for this complication.

Coronary Vasospasm↗

Functional evaluation of normal and ischemic kidney by means of gadolinium-DOTA enhanced TurboFLASH MR imaging: a preliminary comparison with 99Tc-MAG3 dynamic scintigraphy.

The functional value of TurboFLASH MR imaging in the assessment of dynamic contrast enhancement and renal perfusion anomalies was evaluated in seven patients, who also underwent renal scintigraphy in baseline conditions. The basal renograms obtained from MAG-3 scintigraphy (mercapto acetyl triglycine, MAG3-S) and from Gd-DOTA-enhanced turboFLASH MRI were compared. After hydration, the protocol used consisted in breath-hold coronal turboFLASH acquisitions after IV bolus of Gd-DOTA (4 s every 20 s during 10 min) for MRI, and IV bolus of 370 MBq of 99mTc-MAG3 followed by 60 frames of 1 s and then 120 frames of 10 s for MAG3-S. Relative renal functions were computed for both methods by calculation of the integral of the uptake phase between the first and the second minute. Renograms exhibited 10 normal and 4 ischemic kidneys. There was a close correlation between the contrast enhancement of MRI and isotopic uptake in normal and ischemic kidneys. Global renograms of MRI correlated with MAG3-S (r = .82, p < .001) with similar curve shape and time to peak. Relative renal function of the right and left kidney were closely correlated in all patients (r = .98, p < .001), although there was a tendency for MR to overestimate MAG3-S evaluation in kidneys with severe basal dysfunction. Enhanced turboFLASH provides noninvasive assessment of renal perfusion in patients with renovascular disease. Accurate renograms are obtained with dynamic-enhanced MRI, but the relative renal function seems to be overestimated in low values of ischemic kidneys, and needs further comparative evaluation.

Adult↗

In vivo quantification of myocardial muscarinic receptors in heart transplant patients.

BACKGROUND: Decreased myocardial adenylate cyclase activity in response to guanine nucleotide stimulation has been recently demonstrated in denervated myocardium of transplant patients, suggesting that changes in left ventricular muscarinic receptors may occur. METHODS AND RESULTS: The concentration and affinity constants of myocardial muscarinic receptors were determined by positron emission tomography with 11C-labeled methylquinuclidinyl benzilate (MQNB), a specific hydrophilic antagonist, in six transplant patients 4.7 +/- 2.3 months after surgery and in six normal subjects. Patients had no sign of cardiac rejection at endomyocardial biopsy. After intravenous injections of MQNB, time-activity curves were obtained over different regions of interest and were fitted to a nonlinear mathematical model. No difference in the concentration of muscarinic receptors was found in transplant patients compared with control subjects: 24 +/- 4 versus 26 +/- 7 pmol/mL tissue, respectively (P = NS). The association rate constant k+1, the dissociation rate constant k-1, and thus the equilibrium-dissociation constant Kd were the same in transplant patients compared with control subjects. CONCLUSIONS: Despite known decreased GTP-stimulated adenylate cyclase activity in transplant patients, the density and affinity constants of myocardial muscarinic receptors are not altered. This suggests abnormalities of the signal-transduction function, such as a change in the guanine nucleotide binding proteins.

Adult↗

Myocardial sarcoidosis. Clinical value of technetium-99m sestamibi tomoscintigraphy.

STUDY OBJECTIVE: The presence of defects on rest thallium 201 myocardial scintigraphy, reversible after dipyridamole infusion, was already demonstrated in myocardial localization of sarcoidosis. The present study compared the respective efficiency of a new tracer of myocardial blood flow, 99mTc sestamibi (sestamibi), vs thallium 201 (TI) for the diagnosis and follow-up of myocardial sarcoidosis. METHODS: Quantitative single photon emission computed tomography (SPECT) was performed in 37 consecutive patients with confirmed sarcoidosis and clinical suspicion of myocardial localization. Three successive scans were performed in all patients within the same day: rest TI SPECT, rest sestamibi SPECT, and dipyridamole sestamibi SPECT. Thirteen patients were reinvestigated after 3 months of corticosteroid therapy. The size and intensity of the defects were compared using a computerized quantitative analysis of bull's eye. RESULTS: At rest, sestamibi SPECT is more sensitive than TI, demonstrating significantly larger defects (28.1 +/- 13.2% vs 17.2 +/- 12.8% of bull's eye area, p < 0.001) and detecting abnormalities in seven more patients (24 vs 17). All patients with abnormal TI scans also had sestamibi abnormalities. After dipyridamole infusion, sestamibi defects decreased significantly (28.1 +/- 13.2% vs 15.2 +/- 12.3%, p < 0.001). This improvement correlated with the evolution of sestamibi SPECT performed in the 13 patients reinvestigated after corticosteroid therapy (r = 0.85, p < 0.001). CONCLUSIONS: We conclude that sestamibi SPECT is suitable for the diagnosis of myocardial sarcoidosis and represents an objective tool for the follow-up. The improvement after vasodilatation supports the hypothesis of reversible abnormalities in most of these patients and accurately predicts corticosteroid efficiency.

Adult↗