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A Constantinesco

Publications and source records attributed to A Constantinesco.

At least 19 recordsLinked to original sources
PubMed1992

High resolution MRI of the normal finger at 0.1 T: anatomic correlations.

MR images of the fingers are obtained in a 128 x 128 or 256 x 256 matrix format using a prototype of a mini imager dedicated to the hand. The vertical field of 0.1 T is provided by an electro-magnet with an air gap of 15 cm equipped with a single solenoidal coil. No Faraday cage is used. The maximum in plane pixel resolution of 100 mu is obtained for a field of view of 2.5 cm with a slice thickness of 2 mm. The identification of fine structures of the finger is demonstrated by the anatomical and histological correlations. This type of imager which is adapted to very limited field of views demonstrate that high resolution MRI of limb extremities can be achieved at 0.1 T.

Fingers↗
PubMed1992

MRI of hand and wrist with a dedicated low field mini imager: preliminary report.

In this paper we describe the development and the early results of an MRI system designed specifically for imaging of the hand and wrist. The imager takes up little space, uses a small 0.1 Tesla water-cooled electro-magnet with a vertical magnetic field and a 15 cm air gap. The system is based on a PC micro-computer and an integrated image processing board. There is no need for a Faraday cage. The image resolution is less than 1 mm using a 128 x 128 matrix format for a typical slice thickness of 3 mm. It is possible to achieve a 0.2 mm per pixel spatial resolution when imaging the fingers.

Hand↗
PubMed1992

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↗
PubMed1992

Proton magnetic resonance relaxation times and biomechanical properties of human vascular wall. In vitro study at 4 MHz.

OBJECTIVES AND RATIONALE: Previous studies have suggested a relationship between tissue magnetic resonance (MR) relaxation times and its biomechanical behavior. To further investigate this relationship, the authors studied 41 human vascular wall samples from different anatomic localizations, including systemic and pulmonary arterial, as well as venous tissues. METHODS: The authors measured water content, proton MR T1 and T2 relaxation times, and two viscoelastic parameters of the samples at 4 MHz. RESULTS: T2, water content, and both viscoelastic variables significantly differed among the five anatomic localizations (P less than .05). Both T1 and T2 were significantly (P less than .05) and linearly related to viscoelastic parameters. Multiple linear regression showed that both viscoelastic parameters of a sample can be predicted from the measured values of T1 and T2. CONCLUSIONS: These results provide a basis for characterizing the mechanical stress of a tissue by knowing its MR relaxation times.

Adult↗
PubMed1991

MR imaging of hand and wrist with a dedicated 0.1-T low-field imaging system.

We describe the first results of a new magnetic resonance imaging (MRI) system specially developed for hand and wrist imaging. The system uses a small resistive water-cooled magnet with a vertical magnetic field of 0.1 T in an air gap of 15 cm. The console is based on a microcomputer with a vector signal processor and an image-processing board. There is actually no Faraday cage. For the whole hand, the in-plane spatial resolution is less than 1 mm in the 128 x 128-pixels format for typical slice thicknesses of 3 to 5 mm. Solenoidal volume coils for fingers were developed, giving, in the same matrix format, an in-plane high spatial resolution of 0.22 mm for a typical slice thickness of 3 mm.

Hand↗
PubMed1991

[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↗
PubMed1990

[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↗
PubMed1990

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↗
PubMed1989

[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↗
PubMed1988

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↗
PubMed1988

Detection of myocarditis during the first year after discovery of a dilated cardiomyopathy by endomyocardial biopsy and gallium-67 myocardial scintigraphy: prospective multicentre French study of 91 patients.

The purpose of this study was to assess the frequency of inflammatory lesions in the myocardium of subjects with dilated cardiomyopathy and to determine if there was any correlation between the results of two methods of evaluation, one (endomyocardial biopsy) invasive and the other (gallium-67 scintigraphy) noninvasive. Of 115 subjects recruited in seven centres, 91 met the inclusion criteria (left ventricular dilatation greater than or equal to 100 ml m-2 and ejection fraction less than 55% with normal coronary arteriography) and had endomyocardial biopsy (mean five specimens) and Ga-67 myocardial scintigraphy after several days. Scanning was considered doubtful 19 times and positive 13 times. The histologic count of mononuclear cells in the myocardial interstitium in 20 fields was greater than 5 cells field-1 in only four cases. No correlation was found between the two methods. Subjectivity in the choice of the criterion of positivity of Ga-67 scintigraphy and difficulties in identifying lymphocytes upon pathological examination were the major problems encountered. Despite limitations, both techniques suggest that cellular infiltrates are minimal and quite infrequent in dilated cardiomyopathy.

Adolescent↗
PubMed1988

[Revascularization in the acute phase of myocardial infarction. Study of left ventricular function in the 3d week and 6th month].

27 patients with primary myocardial infarction are treated, in the first 6 hours, with intravenous thrombolysis with immediate coronary angiographic control showing a patent artery in 76 p. cent of the cases. The treatment is completed with intracoronary thrombolysis (5 times) and transluminal angioplasty (6 times), enabling to obtain a patency rate of 88 p. cent. The overall left ventricular function is evaluated at D21 and in the 6th month (M6). Among anterior infarctions, those treated during the first three hours have a better ejection fraction (EF) at D21 than those treated later (40.3 p. cent +/- 6 versus 33.2 p. cent +/- -NS); this functional benefit is confirmed at M6 (42.8 p. cent +/- 12 versus 30.6 p. cent +/- 8; p less than 0.06). On the contrary, among inferior infarctions, the EF is comparable at D21 and M6 regardless of the early nature of the treatment. One patient died prematurely from a cerebral vascular accident which occurred during the thrombolysis. These results are in favor of a significant myocardial salvation in anterior infarctions revascularised at an early stage and of an active approach in order to obtain the most complete possible revascularisation.

Angioplasty, Balloon↗
PubMed1988

[Modifications in the contraction and relaxation of the left ventricle in chronic ischemic cardiopathies. Study using equilibrium angio-scintigraphy].

Our purpose was to confirm that abnormalities of left ventricular filling, which are associated with abnormalities of contraction, play an important part in the genesis of cardiac failure in chronic ischaemic heart disease. We used equilibrium radionuclide angiography of the cardiac cavities to study the behaviour of the left ventricle during contraction and relaxation in three groups of patients: a control group of 15 patients without cardiac disease (G2), and a group of 28 patients with chronic ischaemic heart disease complicated by cardiac failure (G3). From the overall activity-time curves and their first derivatives were calculated the ejection fraction, the peak ejection rate and the peak filling rate, as well as the time in the cardiac cycle when these appeared, the reference point in time being the end-diastole. Separately, an analysis of spatial distribution, pixel by pixel, of the elementary values of these times was developed with the help of new functional images constructed, pixel by pixel, from the first derivatives of the activity-time curves. These functional images were exploited by calculating histograms of times, and the width of the bars at mid-height was taken as the dispersion parameter expressed as a percentage of the cardiac cycle. There was a significant reduction of ejection fraction in groups G2 (49.8 +/- 11.6 p. 100) and G3 (36.3 +/- 15.4 p. 100) as compared to control group G1 (60.3 +/- 8.4 p. 100) (G1-G2 p less than 0.05; G2-G3 p less than 0.001; G1-G3 p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

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↗
PubMed1987

[A multidisciplinary approach to algodystrophy of the hand].

A multidisciplinary approach for the management of reflex sympathetic dystrophy at SOS Main of Strasbourg has been progressively adopted due to the severe functional sequelae of this disease. The TC99 bone scan in three phases has allowed us after a one week duration of the symptoms to make an early diagnosis and to start dynamic splinting in flexion. Our study compares two groups of patients, one with an early treatment and the other with delayed treatment. It shows a correlation between the stiffness of the affected hand and the isotopic findings. The benefit from an early dynamic splinting in flexion as evidenced by a clinical improvement is corroborated by the bone scan.

Combined Modality Therapy↗
PubMed1987

[Scintigraphy and esophageal pH measurement in adults with gastroesophageal reflux].

Thirty-seven adults with gastroesophageal reflux were explored by gastroesophageal scintigraphy and pH monitoring (three hours postprandial). Scintigraphy was less frequently positive than pH test in gastroesophageal reflux (81% versus 57%) with a significant difference. It is suggested that postprandial pH monitoring is reliable in the initial assessment of symptomatic gastroesophageal reflux.

Adult↗
PubMed1987

[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↗