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Biomedical subjects

F Terrier

Publications and source records attributed to F Terrier.

At least 19 recordsLinked to original sources
PubMed1995

[Prevalence of medullary sponge kidney in patients with and without nephrolithiasis].

Reports on the prevalence of medullary sponge kidneys have given conflicting results. The present work is aimed at defining the prevalence of this abnormality in renal stone formers compared with a non-stone-forming control population by strict radiological criteria. Three separate studies have been carried out: the retrospective analysis of 191 intravenous urographies, which had been performed in 1988; the respective prospective analysis of 104 consecutive intravenous urographies and of 149 consecutive urographies, which had been performed at the end of intravenous digitalized subtraction renal angiographies. The 444 patients were classified according to presence or absence of nephrolithiasis. After exclusion of 70 patients (16%) of which the X-ray didn't fulfill the quality criteria, urographies were classified as 'medullary sponge kidneys', 'papillary blush' or 'negative' according to the radiological aspect of the papillae. Diagnosis of medullary sponge kidneys was based on presence of at least three linear or round papillary opacities seen in at least on papilla even of one kidney on late films (at least ten minutes after injection of contrast medium), taken without ureteral obstruction or abdominal compression. Overall results reveal that prevalence of a medullary sponge kidney in renal stone formers (8.5%) is significantly (p < 0.01) higher than in the control population (1.5%) and higher than what has been generally reported. Results of the retrospective and of both prospective analysis did not significantly differ. The best diagnostic tool to unmask medullary sponge kidneys remains urography.

Angiography, Digital Subtraction↗
PubMed1994

Three-dimensional reconstruction of a levator claviculae muscle.

During routine radiological examination of a 72 year-old woman a soft-tissue shadow in the left posterior triangle of the neck was observed. Three-dimensional reconstruction of this structure suggested that it might be a muscular variant: a levator claviculae muscle. In our case it took origin from the upper part of the cervical column and was inserted into the lateral third of the clavicle. With this example as a background, the general significance of anatomical muscular variants for modern imaging techniques is discussed.

Aged↗
PubMed1994

Measurement of lactate in acutely ischemic rat kidneys using magnetic resonance spectroscopy.

RATIONALE AND OBJECTIVES: Quantification of lactate in the kidney by 1H magnetic resonance spectroscopy (MRS) is a difficult task because of the presence of large amounts of peri-renal fat. When an editing scheme is used to detect lactate that filters out all resonances except lactate, there is no suitable metabolite to serve as an internal standard. In this study, the authors evaluate the potential of MRS to measure the absolute lactate concentration in rat kidneys during acute ischemia using MRS. MATERIALS AND METHODS: The authors propose a method based on a double resonance lactate editing scheme used in combination with the fully relaxed water peak as an internal standard. Experiments were performed on the left kidney rendered ischemic in eight rats. RESULTS: Renal lactate concentrations measured by MRS were compared with values derived from chemical analysis. The mean (+/- standard deviation) renal lactate concentrations measured by MRS and determined chemically were 12 +/- 1.2 umol/g, and 12.94 +/- 1.07 umol/g wet weight, respectively. The coefficient of variation for paired observations was 2.96%, indicating excellent agreement between the two methods used for measuring lactate. DISCUSSION: The study results demonstrate that it is possible to assess the lactate concentration in a rat model of ischemic kidney with MRS and suggest that the total lactate pool is detectable by this method under these experimental conditions.

Animals↗
PubMed1993

Cine gradient-echo MR imaging in the evaluation of cardiovascular diseases.

The contributions of cine gradient-echo (GRE) magnetic resonance imaging were compared with those of spin-echo (SE) imaging for the evaluation of morphologic, functional, and flow alterations in 78 cases of congenital and acquired cardiac diseases. High temporal and spatial resolution cine GRE images (256 phase-encoding steps, 256 x 256 acquisition matrix interpolated to 512 x 512 for display, 16-64 frames per cycle) and SE images were acquired in each case. Cine GRE images provided a better diagnostic evaluation than SE images in several cases: (a) both masses and thrombi could be differentiated from flow artifacts; (b) abnormalities in cardiac function, such as infarction, abnormal wall motion, and ventricular dysfunction, could be evaluated; (c) small defects, shunts, and abnormal communications could be clearly seen; and (d) valvular regurgitations, poststenotic flow alterations, and aortic coarctation could be assessed. Cine GRE imaging was also valuable for postoperative evaluations. The authors believe that cine GRE imaging is a useful addition to SE sequences, especially for the assessment of blood flow and cardiac function.

Adolescent↗
PubMed1993

[Imaging of the pericardium using magnetic resonance].

Evaluation of the pericardium has been rediscovered with the advent of sectional imaging modalities such as magnetic resonance. Owing to the improved image quality, faster imaging and cine display, MRI has proved to have a useful role in assessment of the pericardium. This article illustrates the authors' wide experience with MRI of normal and abnormal pericardium in numerous patients. The anatomy of the normal pericardium is reviewed, as are the different MR imaging techniques used Advantages of MRI in specific situations are discussed. Congenital anomalies are covered but particular attention is paid to acquired diseases, such as pericardial effusions, with emphasis on the characterization of the different pericardiac fluid collections. Pericardial thickening and constrictive pericarditis, which are easily differentiated from restrictive cardiomyopathy, are also discussed. Finally, primary and metastatic tumors are described.

Heart Neoplasms↗
PubMed1992

Alterations in hepatic fructose metabolism in cirrhotic patients demonstrated by dynamic 31phosphorus spectroscopy.

Quantitative liver function tests are based on the clearance concept and measure the plasma disappearance of a test compound such as galactose. Metabolism is inferred to be predominantly hepatic, and usually no knowledge is obtained of the true time course of metabolite formation. Dynamic 31phosphorus magnetic resonance spectroscopy after intravenous administration of fructose directly measures hepatic sugar metabolism. To determine the feasibility and the utility of 31P magnetic resonance spectroscopy, we studied the responses of six healthy subjects and nine patients with nonalcoholic cirrhosis to a fructose load. Results were related to the impairment of hepatic function assessed by the galactose-elimination capacity test. Liver spectra were acquired in a 1.5 T whole-body nuclear magnetic resonance unit with a surface coil (9-cm diameter) placed ventrally on the liver; the one-dimensional chemical-shift imaging technique was used to obtain spectra from tissue slices parallel to the surface coil. After a basal spectrum had been obtained, fructose (250 mg/kg) was injected intravenously, and further spectra were collected sequentially every 6 min for 1 hr. Formation of monophosphate esters (9% +/- 5% vs. 20% +/- 8% of total area; p less than 0.01) and utilization of inorganic phosphate (5% +/- 4% vs. 11% +/- 3% of total area; p less than 0.005) were markedly decreased in cirrhotic patients. These measures correlated with the severity of the impairment of liver function measured by the galactose-elimination capacity (r = 0.53 to 0.69; p less than 0.05). We conclude that dynamic 31P magnetic resonance spectroscopy is a safe, clinically feasible test that allows detailed insights into biochemical events in liver disease.

Adenosine Triphosphate↗
PubMed1992

Lactate mapping in ischemic rat kidneys using 1H spectroscopic imaging.

RATIONALE AND OBJECTIVES: Biochemical studies have shown that during renal ischemia, lactate is built up predominantly in the medulla and less in the cortex. The authors intend to confirm such a difference in lactate concentration between these two zones of the kidney by means 1H magnetic resonance (MR) spectroscopy. METHODS: In 10 rats, the authors used four-dimensional (n = 4) and three-dimensional (n = 6) spectroscopic imaging to investigate the left kidney after occlusion of the renal artery. RESULTS: By this technique, a map of the intrarenal lactate distribution was obtained during ischemia. It was determined that lactate concentration is indeed higher in the medulla than in the cortex, as verified by chemical analysis (17 +/- 4 versus 9 +/- 4 mumol/g). CONCLUSIONS: By correlating biochemical and morphologic information, localized MR spectroscopy combined with imaging is a powerful tool for investigating pathophysiologic mechanisms.

Animals↗
PubMed1991

Continuous 5-day infusion of ifosfamide with mesna in inoperable pancreatic cancer patients: a phase II study.

Phase II studies on ifosfamide and mesna in pancreatic cancer have mostly been inconclusive. In all of these studies ifosfamide was administered as an i.v. bolus or by short infusions. Since dose fractionation of ifosfamide over several days increases its therapeutic index, we chose to maximize the dose fractioning by selecting a continuous-infusion schedule (1.75 g/m2 on days 1-5 every 21-28 days, with mesna 60%-100% of the ifosfamide dose up to 12 h after ifosfamide). Since 1987 29 patients (performance status less than or equal to 2) with advanced inoperable adenocarcinoma of the pancreas were studied (8 women and 21 men; median age 58 years: 36-73 years). A total of 25 patients are evaluable for response (1 ineligible; 3 inevaluable: 2 early deaths due to disseminated intravascular coagulation, 1 refusal). One female patient with a complete response on computed tomography scan (after five cycles) but residual liver metastases on surgical exploration survived for 473 days. Three male patients with partial response survived for 205, 335 and 355 days. Six more patients with minor response (3) or no change (3) but significant decrease of tumour marker CA 19-9 had a median survival of 213 days (106-243). Responders seemed to benefit in terms of pain relief and general well-being. The median overall survival of all patients was 148 days (21-473). Haematotoxicity was rarely dose-limiting [median nadirs: white blood cells = 2.1 x 10(9)/l (0.45-6.4), Hb = 10.7 g/dl (7.5-13), platelets = 137 x 10(9)/l (21-411)]. Nausea and vomiting were mild with prophylactic oral metoclopramide. No central nervous system toxicity or urotoxicity was observed. Alopecia was seen in all patients who had received at least two cycles. Continuous infusion of ifosfamide was generally well tolerated and useful for palliation in 10 of 25 patients. A higher dose intensity is recommended.

Adenocarcinoma↗
PubMed1991

Magnetic resonance angiography of abdominal vessels: early experience using the three-dimensional phase-contrast technique.

Based on three-dimensional acquisition of three sequences sensitive to one flow-direction, abdominal magnetic resonance phase-contrast angiography (MRA) was performed in 13 volunteers and 20 patients. The subjects received no antiperistaltic medication and were allowed to breath normally during the three acquisition periods of 11 minutes. The frequency of demonstration of the normal aorta, superior mesenteric and right and left renal arteries was 100%/100%/91%/100%, and of the inferior vena cava, splenic, superior mesenteric and portal veins was 92%/67%/92%/100%, respectively, whereas other abdominal vessels were seen less constantly. In renal artery stenosis or occlusion, MRA detected eight out of nine pathological arteries, missed only a minimal stenosis and was never false positive. In all 10 cases of portal hypertension, MRA demonstrated the venous collaterals detected by conventional angiography and in six cases showed more collaterals, particularly paravertebral vessels. A Budd-Chiari syndrome was investigated as well. If the accuracy of MRA can be proved in larger studies, it may become an important diagnostic tool in evaluating abdominal vascular pathology, such as renal artery stenosis or portal hypertension.

Abdomen↗
PubMed1991

Detection of flexor tenosynovitis by magnetic resonance imaging: its relationship to diurnal variation of symptoms.

Fifteen patients with noninfectious arthritis and morning stiffness were examined clinically, and with magnetic resonance imaging (MRI) at the metacarpophalangeal level of one hand in the evening and early the following morning. Our purpose was to determine the prevalence of hand flexor tenosynovitis, and to look for diurnal changes in the swelling state of the flexor tendon sheaths as a possible cause for morning stiffness. MRI showed a higher prevalence of flexor tenosynovitis than clinically suspected by using the pinch test. We could not observe an increase in soft tissue swelling in the morning compared to the evening.

Adult↗
PubMed1990

[Magnetic resonance angiography. Work in progress].

Rapid progress has been made in the development and clinical application of magnetic resonance (MR) techniques for creating angiogram-like images of blood vessels. Combinations of techniques such as gradient-echo pulse sequences and flow compensation (bright blood imaging) or presaturation (black blood imaging) permit the signal intensities of moving spins to be altered, so as to generate contrast between flowing blood and stationary tissues. Postprocessing of the images allows the creation of projection angiograms, which show the vasculature in a large slice of the body. Preliminary studies suggest a variety of potential clinical applications, including intracranial arteriovenous malformations and aneurysms, carotid artery disease, portal hypertension, renal artery stenosis, peripheral arterial disease and venous thrombosis. At present, MR angiography is not directly competitive with conventional contrast angiography because of lower spatial resolution and loss of signal from flow turbulence and from slow flow. Nonetheless, it is proving to be a useful clinical tool for the investigation of vascular pathology involving the head and body.

Angiography↗
PubMed1990

[Magnetic resonance in oncology].

The physical and biological background to magnetic resonance imaging (MRI) in patients with neoplasms is reviewed. The clinical indications for this method of diagnosis, staging, and follow-up of malignant neoplasms are discussed on the basis of the guidelines given by the MRI Consensus Conference on April 25-26, 1989, in Berne. MRI is the modality of choice in patients with neoplasms of the central nervous system and the musculoskeletal system. Further emerging indications for MRI are neoplasma of the ENT region, liver, and pelvic organs. Finally, the foreseeable developments in MRI and in magnetic resonance spectroscopy (MRS) are mentioned.

Abdominal Neoplasms↗
PubMed1990

[Nuclear spin tomography in synovitis: experimental and clinical results].

We report our experimental and clinical results in the evaluation of synovitis using magnetic resonance imaging (MRI), and discuss them in the light of the literature. Using rheumatoid arthritis in the rat as a model, we have shown that MRI is more sensitive than physical examination and X-ray for the diagnosis of early soft-tissue inflammation in arthritis. On the basis of MRI findings, in patients with morning stiffness we have found an incidence of tenosynovitis higher than that reported in the literature. Because other groups have demonstrated the usefulness of MRI for the evaluation of inflammatory cartilage and bony lesions in arthritis as well, we anticipate that this method will assume increasing importance in the diagnosis and monitoring of rheumatoid arthritis and related diseases.

Animals↗
PubMed1989

Study of acute renal ischemia in the rat using magnetic resonance imaging and spectroscopy.

Magnetic resonance (MR) imaging and spectroscopy, chemical lactate measurements, and microscopic examinations were performed to investigate acute renal ischemia in rats. MR images (1H) and spectra (31P and 1H) were acquired on a 2.0-T superconducting small-bore magnet by using implanted coils. Occlusion of the renal artery induced a significant decrease in signal intensity of the renal parenchyma on T2-weighted images, which was most obvious in the outer medulla (-50 +/- 15%, n = 8, P less than 0.001) and was the result of venous congestion, as verified histologically, 31P spectroscopy demonstrated a drop in pH from 7.3 +/- 0.2 to 6.6 +/- 0.2 (n = 18, P less than 0.001), characterized by a time constant (Tc) in the same range as that of the depletion of ATP (2.3 +/- 1.3 min versus 1.9 +/- 1.2 min, n = 10, P = ns). By means of 1H spectroscopy, a lactate peak was detected within 1.5 to 4 min of ischemia, still increasing in intensity after 1 h of ischemia. The Tc of the lactate buildup (15.9 +/- 7.5 min, n = 8) was significantly longer than that of the drop in pH (P less than 0.005). The chemically measured intrarenal concentration of lactate was 1.3 +/- 0.5 mumol/g in control kidneys and 8.7 +/- 3.2 mumol/g (P less than 0.005) in kidneys made ischemic for 1 h. The present study demonstrated important features of acute renal ischemia: (a) acute ischemia induces venous congestion in the medulla; (b) accumulation of lactate is not the main cause of the intracellular acidification observed during ischemia.

Animals↗