Nuclear magnetic resonance: let's consolidate the ground before getting excited!
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Homeopathy↗
Biomedical subjects
J L Demangeat
Publications and source records attributed to J L Demangeat.
Effects of potentization.
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Drug Synergism↗
Stimulated salivary pertechnetate clearance revisited: correlation with dynamic scintigraphic indices in Sicca syndrome.
PURPOSE: The stimulated salivary clearance of Tc-99m pertechnetate (SSCP) introduced in 1985 by Blue and Jackson is revisited here in patients with known or possible salivary disorders and correlated with most commonly cited and up-to-date quantitative indices obtained from standard dynamic salivary scintigraphy. METHODS: An SSCP test was performed after dynamic salivary scintigraphy in 19 patients with oral or ocular dryness, among whom 7 had Sjögren's syndrome. Many scintigraphic indices were calculated: salivary to background ratio (S/B[t]), background-corrected uptake U[t]), maximal uptake (Umax), cumulative gland uptake (CGU), initial slope of the uptake curve (IS), stimulated excretion velocity (SEV), stimulated excretion fraction (SEF), and excreted activity (EA). RESULTS: The SSCP test was well tolerated, except in two patients in whom it had to be interrupted. Clearance values ranged from 5 to 40 ml/minute, with a clear-cut bimodal distribution centered around 15 to 20 ml/ minute. Six of the seven patients with Sjögren's syndrome had values less than 15 ml/minute. SSCP was closely correlated with all uptake indices (S/B, U, Umax, CGU, and IS) and uptake-related indices (EA, ISxSEF) (P < 0.01). A poor correlation was found with the excretion index SEV (P = 0.06) and none with SEF. CONCLUSIONS: SSCP is a quick and objective means to investigate the sicca syndrome that may be useful in most clinical situations. It reflects the parenchymatous salivary gland function and will provide a means to assess and predict salivary gland involvement. Dynamic salivary scintigraphy remains necessary in very early stages because of its high sensitivity rate and ability to locate the impaired gland, or in severe stages in which lemon juice could be deleterious.
Adult↗
The pitfalls of planar three-phase bone scintigraphy in nontraumatic hip avascular osteonecrosis.
PURPOSE: This study documented the previously reported lower sensitivity of routine planar three-phase bone scintigraphy (BS) performed using a high-resolution parallel-hole collimator compared with MRI to diagnose nontraumatic avascular necrosis of the hip (AVN). METHODS: Six observers reviewed 143 bone scintigrams obtained in patients with nontraumatic hip pain (n = 120) or a control group (n = 23). All patients had a standard radiograph and MRI within 2 months of the BS. Of 280 hips, 148 (53%) were painful on the day of the examination. The osteonecrosis group (AVN) consisted of 93 instances of AVN in 58 patients. Although it departs from the clinical situation, this method evaluated the intrinsic performance of the imaging method. The data were analyzed using a receiver operating characteristic method. RESULTS: For the six observers, the A(z) values were 0.65, 0.67, 0.66, 0.67, 0.73, and 0.79, respectively, and 0.66, 0.71, 0.75, 0.81, 0.81, 0.82, and 0.84 after removing hip diseases other than AVN through data manipulation. Bone marrow edema, as seen on MRI, was the most frequently reported misleading sign in false-positive diagnoses, especially in the early or late phases of the disease. False-negative diagnoses misclassified the scans as "asymptomatic hips" in 28 of 30 cases. Twenty-two of 30 scans appeared normal, but these AVN lesions were small (<25%) and were discovered by chance on MRIs that displayed bilateral involvement associated with radiographic evidence (stage 0 or 1). Thirteen of 20 patients were followed for 3 or more years, and only one worsened. CONCLUSIONS: BS is not indicated to diagnose possible contralateral AVN if the hip is asymptomatic. This study emphasizes the results from the literature; if indicated, a radionuclide hip investigation requires the use of a pin-hole collimator, a SPECT study with scatter correction and iterative reconstruction algorithms, or both.
Adult↗
Increase in radionuclide left ventricular ejection fraction after cardioversion of chronic atrial fibrillation in idiopathic dilated cardiomyopathy.
To assess the potential improvement in left ventricular ejection fraction after cardioversion of chronic atrial fibrillation to sinus rhythm in idiopathic dilated cardiomyopathy, we studied prospectively 17 patients, aged 58 +/- 6 years, by radionuclide angiocardiography at rest. Left ventricular ejection fraction was determined before treatment and at a mean delay of 4.7 months after cardioversion. Return to sinus rhythm was obtained in 12 patients, pharmacologically or by electrical cardioversion. Five patients remained in atrial fibrillation. No clinical, echocardiographic or haemodynamic finding could predict the success of cardioversion. In chronic atrial fibrillation, the ejection fraction did not change significantly: 30.0 +/- 9.1% (19 to 44%) at the first evaluation and 29.5 +/- 8.3% (22 to 41%) after 4.7 months. After successful cardioversion, left ventricular ejection fraction improved from 32.1 +/- 5.3% (24 to 41%) to 52.9 +/- 9.7% (37 to 71%) (P less than 0.001). The difference was 20.8 +/- 11.3% and left ventricular ejection fraction was normalized in 50% (6/12) of the patients. There was a significant reduction in the cardiothoracic ratio on chest X-rays and of the left ventricular end-diastolic diameter on echocardiography; fractional shortening increased (27.7 +/- 4.3% vs 20.3 +/- 2.7%, P less than 0.01). A third evaluation was realized after a mean delay of 11.7 months in the patients with successful cardioversion. Sinus rhythm was present in 83% (10/12) of the patients: seven patients were reevaluated by radionuclide angiography. The improvement in left ventricular function observed at the 4.7 months evaluation was still present. In two patients with recurrence of atrial fibrillation, there was a severe deterioration of left ventricular systolic function.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
[Congestive heart failure with intact systolic function].
A retrospective study was undertaken of the cases of patients admitted for congestive cardiac failure over a 4 year period, and investigated by radionuclide angiography to determine the prevalence of cardiac failure with normal left ventricular systolic function, to document the underlying mechanisms of this condition and to assess whether the clinical data could predict the presence or absence of left ventricular systolic dysfunction. After excluding patients with significant valvular disease, severe renal failure, or myocardial infarction in the previous 2 months, the study population comprised 152 patients divided into 2 groups: Group I (N = 112) with abnormal systolic function (radionuclide ejection fraction less than 45%) and Group II (N = 40) with normal systolic function (radionuclide ejection fraction greater than or equal to 45%). The clinical, echocardiographic and radionuclide angiographic data was analysed (global ejection fraction in both groups and peak filling rate in Group II). The patients in Group II (26% of the total study population) were older (66.5 +/- 12.4 vs 61.3 +/- 12.3 years, p less than or equal to 0.02), were more often female (35% vs 17.9%, p less than or equal to 0.02), had acute cardiac failure (75% vs 37%, p less than 0.00001), and were frequently hypertensive (65% vs 39%, p less than or equal to 0.005). Univariate analysis of clinical and radiological signs did not show any significant difference between the two groups except for increased jugular venous pressure and cardiomegaly which were more common in Group I (56% vs 25%, p less than 0.00001 and 93% vs 68%, p less than or equal to 0.00001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Local intravenous treatment of algodystrophy of the hand: buflomedil versus guanethidine, long term follow-up].
This report compares the results obtained after treatment of reflex sympathetic dystrophies (algodystrophies) of the hand by pharmacological segmental blocks with buflomedil (51 cases) versus guanethidine (30 cases). The results were similar for all the different stages of algodystrophies treated: 65% satisfactory to excellent results with buflomedil, versus 63% with guanethidine. The sooner the algodystrophy is treated after its onset, the better the results. On TPBS, when the technique is effective, both hemovelocity and blood pool return to normal, along with the improvement in the patient's condition. Early and delayed bone fixations evolve independently of the treatment. These techniques should always be associated with active, mild physiotherapy, and in some cases with dynamic splints in order to prevent the development of functional sequelae in the form or capsulo-aponeurotic retraction.
Adult↗
Alterations in left ventricular diastolic function in chronic ischemic heart failure. Assessment by radionuclide angiography.
Using radionuclide angiography at rest, we studied several parameters of left ventricular systolic and diastolic function in 60 patients divided into three groups, a control group (G1) of 15 patients and two groups of patients with chronic ischemic heart disease and previous anterior wall myocardial infarction but without aneurysm or dyskinetic wall motion, a second group (G2) of 23 patients with no history of heart failure, and a third group (G3) of 22 patients in New York Heart Association (NYHA) class II or III of heart failure. Ejection fraction, peak emptying, and peak filling rates, in addition to times to reach peak rates, were evaluated after constructing a global time-activity curve and its first time derivative. In addition, we computed the first time-derivative curves for each image pixel and obtained functional images (MIN/MAX images) representing the distribution of times to peak emptying or filling rates Using a left ventricular region of interest, time histograms were generated, and indexes of dispersion of times to peak rates, defined as the full width at half maximum of the histograms, were obtained. Significant (p less than or equal to 0.01) differences were observed among all groups for ejection fraction, peak emptying rate, and peak filling rate. The decrease of the peak filling rate still remained significant from group G1 to group G3 even after adjustment for differences in ejection fraction and heart rate. Peak filling rate was linearly correlated with ejection fraction in the population with ischemic heart disease (G2 + G3) (r = 0.68, p less than or equal to 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary Disease↗
[Diminution of thyroid stimulating hormone level but normal levels of thyroid hormones. Demonstration of occult hyperthyroidism].
The finding of a low basal concentration of thyroid-stimulating hormone (TSH) in the absence of high thyroid hormone levels is difficult to understand. In order to elucidate the meaning of such a dissociation, 22 patients without history of thyroid disease and showing clinical signs compatible with thyrotoxicosis were explored by the thyrotrophin-releasing hormone (TRH) test, by thyroid radioisotope scanning and, in case of high nodular uptake, by the triiodothyronine suppression test. A specific surgical, isotopic or medical treatment was instituted in the 17 patients who had a high nodular uptake unsupressible by triiodothyronine. During a clinicobiological re-evaluation carried out 6 months later, a significant clinical improvement was observed in 8 patients, and 12 patients whose free thyroxine level had decreased showed normal TSH levels. These results underline the value of thyroid radioisotope scanning in patients with isolated diminution of TSH. They confirm the reality of occult hyperthyroidism with normal thyroid hormone levels by the benefits observed after specific treatment.
Aged↗
[Monoclonal anti-AFP immunoscintigraphy of human hepatocellular carcinoma. Influence of biological, anatomical and vascular factors].
The actual interest of immunoscintigraphy for the detection of alphafetoprotein-producing liver tumors was investigated by both visual examination and quantitative analysis in 61 patients with either hepatocellular carcinoma (39 patients, group I), secondary liver cancer (11 patients, group II), or non tumoral liver (9 cirrhosis, 2 healthy liver, group III): All patients received injections of 123I-anti-alphafoetoprotein monoclonal antibodies and planar scans were performed after 28 hours. Only 18 out of 39 hepatocellular carcinoma-bearing patients had a positive scan (46 p. 100). Such a moderate sensibility was due to a striking inhibitory influence of cirrhosis: the positivity rate was 6/24 and 12/15 respectively when hepatocellular carcinoma was and was not associated with cirrhosis (p less than 0.01). Specificity was also moderate (55 p. 100) for detection of hepatocellular carcinoma in tumor-bearing patients (group I and II). In the absence of cirrhosis, the intensity of the tumoral uptake was highly correlated with high serum alphafoetoprotein level (p less than 0.001) and tumor arterial hypervascularization (p less than 0.01). Anti-alphafoetoprotein monoclonal antibody uptake by the extratumoral liver was found to be very specific of hepatocellular carcinoma since it was high in 23 out of 39 patients of group I but in only 1 out of 22 in groups II and III (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Is anti-alphafetoprotein immunoscintigraphy a promising approach for the diagnosis of hepatoma? Implications of a quantitative study in 41 patients.
The actual interest of immunoscintigraphy for the detection of liver tumours was investigated by both visual examination and quantitative analysis in 41 patients with hepatoma (HCC, 21 cases, 13 AFP-secreting), other primary or secondary liver cancer (9 cases), testicular cancer (2 cases) and cancer free cirrhosis (9 cases). All patients were injected with 123I-anti-alphafetoprotein (AFP) monoclonal antibodies (MAbs) and scans were performed after 28 +/- 2 h. In the hepatoma-bearing patients, 11 positive anti AFP scans were found; 9 of them had an enhanced serum; besides, 3 non HCC tumours were also detected. With respect to hepatoma diagnosis, sensitivity was 52.5% and specificity 66.5%. For all hepatomas, it was striking that the positivity rate was 2/10 and 9/11, respectively, when HCC was and was not associated with cirrhosis. Among 6 patients with a positive anti AFP scan who were also injected with control anti hCG 123I-MAb, 5 positive anti hCG scans were surprisingly found, with specificity indices ranging between 1.00 and 1.75. The quantitative study also highlighted the importance for hepatoma detection of specific and non specific factors such as serum AFP, tumoural vascularization, non tumoural liver uptake and intrahepatic distribution of HCC. Anti AFP immunoscintigraphy appears as a poorly sensitive and moderately specific method for hepatoma diagnosis. In contrast, non tumoural liver uptake level could be more useful for discriminating HCC from liver metastases and perhaps to detect the early extension of HCC.
Adult↗
Three-phase bone scanning in reflex sympathetic dystrophy of the hand.
Three-phase bone scanning was performed in 181 patients suffering from reflex sympathetic dystrophy (RSD) of the hand. Four quantitative parameters were defined as follows: (a) hemovelocity and (b) blood pool (determined from the Fourier processing of angiographic data); (c) early (3-5 min) and (d) delayed (2-3 hr) bone fixation. Three significant stages of RSD were demonstrated scintigraphically. Stage I (0-20 wk from onset) demonstrated increases in velocity, blood pool, and early and delayed fixations. At stage II (20-60 wk) blood velocity and blood pool were normalized, but early and delayed hyperfixation persisted. During stage III (60-100 wk) blood velocity and blood pool were reduced on the affected hand, and early and delayed fixations were normalized. Such abnormality of decreased hemodynamic parameters may become associated with bone hypofixation in stage III. Early treatment of RSD (as compared with delayed treatment) has been demonstrated to induce normalization of hemovelocity (p less than 0.05), blood pool (p less than 0.02), and joint stiffness (p less than 0.001) without any change in the bone fixation; therefore, three-phase bone scanning may provide useful information regarding the pathophysiologic and clinical evolution of RSD.
Bone and Bones↗
[Coronarography-scintigraphy comparison of the effects of trinitrin-spray in 15 patients with coronary disease].
15 patients with coronary disease underwent a dual investigation, angiographic and scintigraphic, first without treatment and after administration of 0.8 mg of sub-lingual trinitrin-spray. The radiocinema angiography enables to explore variations of the coronary and stenosic diameter, the duration of the opacification (inverse of circulatory velocity) and the tonality of the network. Plane scintigraphy with T1201 enables to quantify the regional fixation in 9 myocardiac territories, as well as the global fixation with the myocardium/background noise ratio and the index of mean perfusion deficit. The diameter of healthy arteries and the pre- and post-stenotic segments of the diseased arteries are uniformly dilated after trinitrin (11.5-12.5%) while the stenoses are on an average unchanged (+ 1.2% NS). 4 cases of stenotic dilatations were observed, but without any decrease of the degree of stenosis (the pre-stenotic diameter increasing in the same proportions), nor any scintigraphic improvement. On scintigraphy, no difference of the myocardium/background noise ratio nor the mean deficit index was observed after trinitrin, which demonstrates the non-variation of the total coronary output. On the contrary, a redistribution of the regional activity (and therefore of the regional coronary flow) is observed in 10 patients. In comparing the stenotic areas which improve on scintigraphy (group I) and those which do not improve or deteriorate (group II) with the modifications of the arterial diameters under trinitrin, a correlation does not appear to be present. Also, the tonality is uniformly increased in both groups. The circulatory velocity is, however, significantly decreased in group II.(ABSTRACT TRUNCATED AT 250 WORDS)
Aerosols↗
[Developmental profile of scintigraphic parameters within 3 weeks following primary myocardial infarction without any attempt at revascularization].
30 patients with a transmural primary myocardial infarction conventionally treated, are explored by myocardial scintigraphy using thallium 201, and calculation of a lesional score (L.S) and angio-scintigraphy on the first day (D1) and at three weeks (D21). The results of these examinations are compared to those of coronography at D21. Anterior necroses present a myocardial fixation defect and a dysfunction of the left ventricle which are more severe than in inferior necroses. Patients with a marked fixation defect (L.S 2) at D1, present a low ejection fraction (EF) becoming significantly worse at D21. Coronary permeability is accompanied by an appreciable improvement of the myocardial fixation from D1 to D21 and a stability of EF. On the contrary, if the occlusion persists, the fixation defect is stable and the EF decreases significantly. In this study, the coronary permeability appears to be associated to a perservation of the ischemic myocardium which may only be demonstrated by knowing the evolution of the various parameters during the first three weeks of the infarction.
Coronary Angiography↗
Three phase bone scanning as an aid to early diagnosis in reflex sympathetic dystrophy of the hand. A study of eighty-nine cases.
In reflex sympathetic dystrophy, three phase radionuclide bone scanning with Tc-99m methylene diphosphonate is preferred. The first phase corresponds to the dynamic behavior of the tracer. After appropriate data processing (by Fourier's analysis), three functional images may be obtained. The second phase corresponds to the tissues fixation of the tracer 5 to 10 minutes after the injection. Based on the results of 89 cases of post-traumatic or postsurgical reflex sympathetic dystrophy observed in 128 patients investigated with this method, diagnostic sensitivity was 96%, while specificity was 86%. The scintigraphic patterns observed during the 100 week period after the initial trauma demonstrate the precocity and the significance of circulatory and tissues phenomena as well as their variations according to treatment. The scintigraphic criteria of regression or stabilization of disease are discussed.
Adolescent↗
[Clinical value of thallium-201 myocardial scintigraphy with dipyridamole performed before and after aortocoronary bypass].
In addition to preoperative coronary angiography, 63 patients undergoing coronary bypass surgery also had myocardial scintigraphy with dipyridamole 1 to 2 days before surgery, resting scintigraphy 10 after bypass and a repeat scintigraphy with dipyridamole 3 to 6 months later. The myocardium was divided into 5 segments. In each segment the perfusion was classified as: normal, presence of a reversible defect (redistribution), presence of a permanent defect (no redistribution). A comparison of pre-and postoperative scintigraphies led to the following conclusions. Three to six months after bypass, improved perfusion was observed in 65.6% os ischaemic segments, showing that surgery was very effective. On the other hand, the immediate postoperative control (10 days) only showed improved perfusion in 42.5% of the ischaemic segments: this interval was too short to appreciate the benefits of coronary bypass. There was a good correlation between the scintigraphic improvement after surgery and the reversibility of the zones of hypofixation of Thallium before surgery. When the defect was reversible, 80% of the revascularised segments were improved. Fifty-eight per cent of non-reversible defects before surgery were unchanged by the revascularisation procedure. However, the absence of redistribution during preoperative scintigraphy was not synonymous with definitive myocardial lesions and does not represent a contra-indication to coronary bypass surgery; in fact, improved perfusion was observed in 42% of these constant defects. The quality of recovery depends on the condition of the muscle: only segments with normal motion can be improved. Degradation of the clinical condition of patients was always related to aggravation(lack of improvement in 1 case) of scintigraphy.(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary Artery Bypass↗
[Redistribution of 201 Tl after myocardial scintigraphy with dipyridamole: value in the detection of coronary stenosis and ventricular kinetic anomalies].
One hundred and eight-four patients suspected of having coronary artery disease underwent coronary and left ventricular angiography and Tl 201 myocardial scintigraphy with dipyridamole including images of redistribution after 3-4 hours. The results of scintigraphy were assessed visually in all cases and by quantitative analysis in 91 patients. Comparison of early (DIP) and late (REDIS) images showed three types of response: 1) no hypofixation on either (10 patients), 2) a constant defect (59 patients), 3) a reversible defect (115 patients, including 21 cases of "paradoxical" redistribution). The value of the redistribution images was assessed in the diagnosis of coronary stenosis and in the evaluation of ventricular wall function in post-stenotic zones. The following results were obtained: Visual analysis of the DIP scintigraphy alone gave 17 false positive and 8 false negative results (sens: 95%, spec: 41%). The false negative results were all observed in patients at high risk. The DIP/REDIS scintigraphy (considered normal if both images were normal) gave 20 false positive but only 1 false negative result (sens: 99%, spec: 32%). In addition, the negative predictivity increased from 60 to 90%. The considerable reduction in the number of false negative results was due to the detection of "paradoxical" redistribution. The finding indicates that late films must be taken systematically even if the early scintigraphy is normal. Quantitative analysis of DIP scintigraphy was less sensitive and more specific than visual analysis (sens: 82.7%, spec: 68.7%; NVP: 46%). The same was observed when the redistribution films were processed (DIP/REDIS): significantly increased sensitivity and negative predictive value at the cost of a lower specificity (sens: 96%, spec: 41%; NPV: 70%). No significant differences were observed between the type of scintigraphic defect (constant or reversible) and the probability of coronary stenosis (positive predictive value 93 and 86% respectively). "Paradoxical" redistribution corresponded to a pathological situation (PPV: 85%). A correlation was found between the reversible or permanent nature of the hypofixation and left ventricular function. Out of 142 segments showing reversible defects, 112 (79%) had normal or subnormal motion (moderate hypokinesia). Reversibility therefore usually indicated conservation of the viability of post-stenotic zones. Significant wall abnormalities were found in 62% of 140 segments with constant defects, mostly corresponding to infarction; however, in 38% there was no abnormality of wall motion or electrical changes of necrosis.(ABSTRACT TRUNCATED AT 400 WORDS)
Angiocardiography↗
Consequences of the chronic cutaneous application of iodinated antiseptics on the thyroid function in the guinea-pig.
The effect of the chronic cutaneous application of iodine-containing substances on the thyroid function was studied in the guinea-pig. Six iodinated products were daily applied at the rate of 2 g/kg/day for 90 days. We find a quasi-abolition in the thyroid 131I-uptake (reflecting the transcutaneous absorption of free iodine) and an important transient thyroidal hyperproduction during the first month. Then, this primary hyperthyroidism induces a strong pituitary negative feed-back so that the levels of the circulating hormones T3 and T4 are normalized at the end of the experiment; a new hormonal balance is reached with a TSH level reduced by half compared to its normal value.
Animals↗