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C Catalano

Publications and source records attributed to C Catalano.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Magnetic resonance angiography of the intracranial circle using magnetization transfer contrast (MTC)].

Magnetic Resonance Angiography (MRA) is becoming an accurate technique to study vascular conditions, especially when the intracranial circulation is involved. Nevertheless, the contrast-to-noise (C/N) ratio in MRA images is often inadequate to obtain diagnostic images. C/N ratio can be increased by using magnetization transfer contrast (MTC), the technique which allows to reduce the signal from the stationary tissues surrounding vascular structures. To demonstrate the value of MTC, 10 healthy volunteers and 10 patients with different cerebral vascular conditions were examined. All exams were performed using 3D MOTSA (Multiple Overlapping Thin Slab Acquisition) Time of Flight sequences, with and without MTC. A quantitative analysis was carried out in the images with and without MTC, measuring the signal intensity value in the regions of interest at the vascular and stationary structures. A qualitative analysis was also carried out with a double blind study by two independent radiologists. Our results showed that MTC allows to reduce stationary tissues signal intensity, without affecting flowing blood signal intensity. Therefore, the C/N ratio is increased, thus allowing better depiction of smaller peripheral branches. In conclusion, MTC applied to intracranial MRA allows image quality to be markedly improved, with an overall increase in the diagnostic accuracy of this technique.

Cerebrovascular Circulation↗
PubMed1995

[Magnetic resonance cholangiopancreatography. A new method of noninvasive biliopancreatic diagnosis].

Magnetic Resonance cholangiopancreatography (MRCP) is a new noninvasive imaging technique for the visualization of the biliary ducts with cholangiographic images similar to those obtained with ERCP and PTC, but with no contrast agent injection. In this paper, we report on our preliminary experience with a mild-field strength magnet (0.5T) and TSE sequences, acquired with respiratory compensation. The images were compared with ERCP images to compare diagnostic quality. Eighteen patients were examined: the biliary tract was dilated because of chronic pancreatitis in 3 patients, because of choledochal stones in 9, of carcinoma of the pancreatic head in 4, of lymphadenopathy in one patient. A patient submitted to choledochoduodenostomy and waiting for cholecystectomy was also examined. MRCP was performed with a superconductive magnet at 0.5T. Volumetric images on coronal planes were acquired; a T2-weighted TSE sequence (TR = 5000, TE = 244, Nex = 4, ETL = 45; acquisition time = 14 min 10 s) with respiratory compensation was also performed. The images were reconstructed on coronal planes at different angles with the MIP algorithm. All patients were then submitted to ERCP and one to PTC. In all patients, the intrahepatic biliary tracts, hepatic ducts and choledochus were completely demonstrated, with very good image quality in 16 cases and good in 2. The Wirsung duct was always visualized in all the 9 patients with mild to severe dilation. In conclusion, MRCP can be considered a valuable alternative to diagnostic ERCP. Further studies are necessary for better assessment of the potential advantages and pitfalls of this technique.

Adult↗
PubMed1995

[Identification of pancreatic insulinomas. The role of magnetic resonance].

Insulinomas are the most common endocrine tumors of the pancreas. Although their clinical and biochemical diagnosis is extremely accurate, these lesions must be correctly located preoperatively to plan the best possible treatment. Many different noninvasive diagnostic techniques have been proposed, with only partially satisfying results. For many years such non-invasive modalities as arteriography have been considered the most reliable and accurate diagnostic tools. Recently, however, MRI has been proposed for best pancreas imaging, especially for tumor detection, and its results have been excellent especially thanks to its optimal contrast resolution. Fat-suppressed and turbo-spin-echo (TSE) sequences now yield even better results. In our study we examined 21 patients, whose symptoms were typical of insulinoma, using two different 0.5T magnets, one of which with 15 mT/m gradients. We used T1-weighted spin-echo (SE) sequences with and without respiratory compensation, SE ad TSE T2-weighted and fat-suppressed T1-weighted SE sequences. In 16 patients the lesions were correctly diagnosed and located, as confirmed at surgery. In the other 5 patients, MRI failed to locate the insulinomas. Three of these 5 patients were submitted to surgery, during which palpation and intraoperative US findings were also negative for a solid mass. The remaining 2 patients underwent clinical follow-up. Our study demonstrated that MRI, especially with fat-suppressed and T2-weighted TSE sequences, is a very accurate modality to detect pancreatic insulinomas and can therefore be proposed as the only preoperative technique.

Adolescent↗
PubMed1993

Erythrocyte sodium-lithium countertransport activity and total body insulin-mediated glucose disposal in normoalbuminuric normotensive type 1 (insulin-dependent) diabetic patients.

Insulin resistance in Type 1 (insulin-dependent) diabetes mellitus may be associated with raised erythrocyte sodium-lithium countertransport activity in patients with hypertension, or nephropathy, or both. However, in these circumstances it is difficult to separate the impact of hypertension, hyperlipidaemia and nephropathy on erythrocyte sodium-lithium countertransport from that of insulin resistance. We have therefore examined the relationship between insulin-mediated glucose disposal and erythrocyte sodium-lithium countertransport in 41 normotensive (mean blood pressure 120/74 mmHg), normoalbuminuric (mean albumin excretion 6.2 micrograms/min), normolipidaemic (mean serum cholesterol 4.3 mmol/l and mean serum triglycerides 1.0 mmol/l) Type 1 diabetic patients. Erythrocyte sodium-lithium countertransport was on average 0.31 mmol Li.h-1.l erythrocytes-1 (range 0.07-0.69). Nine patients had values above 0.40 mmol Li.h-1.l erythrocytes-1 (0.51 +/- 0.10 mmol Li.h-1.l erythrocytes-1). The patients with high erythrocyte sodium-lithium countertransport were matched for age, sex, BMI, HbA1 and duration of diabetes, with nine patients with normal erythrocyte sodium-lithium countertransport. Insulin-mediated glucose disposal was evaluated during the last hour of a euglycaemic clamp (insulin 0.015 U.kg-1.h-1; blood glucose clamped at 7.0 mmol/l). The free insulin levels were comparable between the patients with high and normal erythrocyte sodium-lithium countertransport (37.2 +/- 14.7 mU/l and 34.7 +/- 17.2 mU/l respectively). Insulin-mediated glucose disposal was on average 3.1 +/- 1.5 (range 0.8-6.8) mg.kg-1.min-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effect of posture and acute glycaemic control on the excretion of retinol-binding protein in normoalbuminuric insulin-dependent diabetic patients.

1. It has been suggested that tubular damage may precede glomerular damage at the onset of diabetic nephropathy. This may be reflected by increased urinary excretion of low-molecular-mass proteins, such as retinol-binding protein. 2. We have measured the urinary excretion rate of retinol-binding protein overnight, during orthostasis and during a hyperinsulinaemic euglycaemic clamp (blood glucose concentration 7.0 mmol/l) with stable diuresis in 34 normotensive, normoalbuminuric insulin-dependent diabetic patients and in 10 normal control subjects. Normal control subjects were not clamped. A further four normoalbuminuric insulin-dependent diabetic patients were rendered euglycaemic without a water load. 3. Overnight retinol-binding protein excretion rate was 58 (16-157) [median(range)] ng/min in patients with insulin-dependent diabetes and 32 (15-72) ng/min in control subjects (P < 0.01). The excretion rate did not change during orthostasis [patients with insulin-dependent diabetes, 67 (3-173) ng/min; control subjects, 23 (5-78) ng/min]. During the euglycaemic clamp retinol-binding protein excretion rate increased to 383 (78-4897) ng/min in patients with insulin-dependent diabetes (P < 0.01). An average increment in retinol-binding protein excretion rate of greater than 4000% was noted after acute euglycaemia in those patients with insulin-dependent diabetes who were not water-loaded. 4. In insulin-dependent diabetes, both overnight and orthostatic retinal-binding protein excretion was not correlated with fasting blood glucose concentration, HbA1, fructosamine or duration of diabetes. The absolute and incremental excretion rates of retinol-binding protein during the clamp were, however, correlated with both fasting blood glucose concentration and glucose excretion rate (rs = 0.41-0.48, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Increased red cell sodium lithium countertransport activity, total exchangeable sodium, and hormonal control of sodium balance in normoalbuminuric type 1 diabetes.

The relationship between erythrocyte sodium lithium countertransport activity (SLC), total exchangeable sodium (NaE), and hormonal control of renal function was examined in 40 normotensive, normoalbuminuric, non-neuropathic Type 1 diabetic subjects, of whom 8 had elevated SLC (> 0.40 mmol Li h-1l-1 rbc). Eleven health controls with normal SLC, who were of comparable age, body mass, and blood pressure were also studied. By contrast with healthy controls, SLC in Type 1 diabetes was not associated with plasma renin activity (PRA), aldosterone, systolic blood pressure or lean body mass. SLC was also unrelated to atrial natriuretic peptide (ANP) (Type 1 diabetes only) and NaE. NaE was not correlated with any other variables. The relationships between PRA and aldosterone in healthy controls were retained in Type 1 diabetes (R2 0.37 supine, p = 0.00001, and 0.27 ambulant, p = 0.0005), as were respective direct and inverse relations between vasopressin and ANP and both PRA (rs 0.54 to 0.57, rs -0.43 to -0.53), and aldosterone (rs 0.78 to 0.80, rs -0.71 to -0.80). Fasting free serum insulin and vasopressin were both inversely related to ANP (rs -0.91 and -0.71, respectively). In the absence of autonomic dysfunction, hypertension or early nephropathy in Type 1 diabetes, increased SLC or exchangeable sodium were unrelated to each other or with hormonal control of sodium balance, but the homeostatic factors controlling hormonal interaction appear to be maintained. The interaction between insulin and hormonal control of sodium and water balance may be modified by circulating free insulin concentrations.

Adolescent↗
PubMed1993

[Hypermedia software for teaching anatomy of the upper abdomen with computerized tomography and magnetic resonance].

The authors have developed a hypermedia program for creating a tutorial of CT and MR anatomy of the upper abdomen. The program was created on a Mcintosh computer, with the Supercard software: it is made up of a series of windows, each of them containing images, texts, schematic representations and sound. Moreover, each window contains buttons which are activated with the mouse and allow different kinds of function, all created by the authors to be displayed. In particular, navigation buttons allow the users to move in the program either sequentially or non-linearly, according to their needs. The possibility of obtaining information and schematic representations is given by specific buttons. There are also multiple buttons hidden in the images which, when activated, allow the name of the selected organ to be displayed. In conclusion, this program can be especially helpful since it allows different data sets to be integrated to provide the user with complete information. Moreover, the program allows learning to be controlled, that is the user to be informed on timing and methods for more effective studying.

Abdomen↗
PubMed1993

[Angiography with magnetic resonance of the ++carotid arteries. Evaluation of clinical results obtained with low magnetic field equipment].

Magnetic Resonance Angiography (MRA) is the latest diagnostic technique for the noninvasive evaluation of cardiovascular conditions. This technique has proved to be especially useful in the study of carotid arteries. All the clinical studies reported to date have been obtained at high or medium field strength; our purpose is to assess the clinical value of MRA in the evaluation of carotid arteries at low field strength. All the exams were performed with an 0.2 T permanent magnet, using the 2D time of flight (TOF) technique, the only one which is currently available on our equipment. Forty-two patients with clinical diagnosis of cerebrovascular insufficiency were examined. In all cases MRA findings were confirmed with digital subtraction angiography (DSA), which was considered the gold standard. The double-blind evaluation of the results showed high agreement of the two techniques in 70 of 84 carotid arteries. A mild tendency to overestimation was observed in 4 normal cases considered as mild stenoses on MRA, in 2 cases with mild stenosis considered as discrete stenoses on MRA and in 1 case of severe stenosis considered as an occlusion on MRA. Underestimation was seen in 1 case of mild stenosis considered as normal on MRA, in 2 cases of discrete stenosis which appeared as mild stenoses on MRA and in 2 cases of occlusion considered as severe stenoses. Our study showed high agreement between MRA and DSA results, which means that high quality exams can be obtained even at low field strength. Further progress can be expected when 3D TOF and phase-contrast techniques will be introduced.

Adult↗
PubMed1993

Magnetic resonance angiography: current clinical applications.

Magnetic Resonance Angiography (MRA) is the newest non-invasive procedure for the evaluation of the vascular system. The basis to obtain images of vessels from Magnetic Resonance (MR) data rely upon the specific signal alteration determined by flowing blood. By using special techniques only these signals are evidenced, with cancelling of the surrounding stationary tissues. Clinical applications are reviewed in this paper. They include: Evaluation of intracranial vessels with important adjunct information to those obtained by conventional MR images; Definition of cerebrovascular disease including the carotid artery with good correlation with Digital Subtraction Angiography (DSA); Evidence of abdominal vessels, with clear imaging of abdominal aortic aneurysms; Definition of renal arteries; although problems exist, the technique may become useful in the future for the screening of renovascular hypertension; Visualization of peripheral vessels; initial results indicate a potential application in the evaluation of peripheral run-off distal to occlusions.

Carotid Artery Diseases↗
PubMed1992

Acute metabolic and hormonal responses to the inhibition of lipolysis in non-obese patients with non-insulin-dependent (type 2) diabetes mellitus: effects of acipimox.

1. Increased rates of fatty acid oxidation are frequently observed in patients with non-insulin-dependent diabetes mellitus and may contribute to hyperglycaemia by both decreasing peripheral glucose disposal and, more importantly, by increasing the rate of gluconeogenesis and therefore hepatic glucose output. Despite this relationship between lipid and carbohydrate metabolism, fasting glucose concentrations do not fall acutely in patients with non-insulin-dependent diabetes mellitus when plasma non-esterified fatty acid concentrations and lipid oxidation rates are decreased, questioning the importance of this interaction to glycaemic control. We have therefore measured the acute changes that occur 120-150 min after administration of 500 mg of the antilipolytic agent acipimox in eight non-obese male patients with non-insulin-dependent diabetes mellitus. 2. After administration of acipimox, lipolysis was inhibited as reflected by lower plasma non-esterified fatty acid (0.05 +/- 0.02 versus 0.55 +/- 0.05 mmol/l, P less than 0.001) and blood glycerol (8 +/- 1 versus 56 +/- 8 mumol/l, P less than 0.001) concentrations. The lipid oxidation rate was decreased (0.63 +/- 0.05 versus 1.02 +/- 0.08 mg min-1 kg-1, P less than 0.001), whereas there was a significant increase in the carbohydrate oxidation rate (1.93 +/- 0.17 versus 1.22 +/- 0.18 mg min-1 kg-1, P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗
PubMed1992

A double blind study of the effect of acipimox on serum lipids, blood glucose control and insulin action in non-obese patients with type 2 diabetes mellitus.

Hyperlipidaemia, in particular raised concentrations of serum triglycerides, together with raised plasma non-esterified fatty acid concentrations, is common in patients with Type 2 (non-insulin-dependent) diabetes mellitus and may be associated with insulin insensitivity. Thirty non-obese Type 2 diabetic patients (15 controlled with diet alone and 15 with diet plus oral sulphonylurea therapy) were therefore recruited to take part in a double-blind, randomized, crossover comparison of acipimox (250 mg three times daily for 3 months) and placebo. Serum lipids, blood glucose control, insulin sensitivity, and glucose tolerance were measured before and after each treatment period. There was a significant decrease in serum triglycerides (2.05 +/- 1.08 vs 2.91 +/- 1.75: p < 0.005), cholesterol (5.66 +/- 1.02 vs 6.26 +/- 1.17: p = 0.0005), and apoprotein B (1.32 +/- 0.23 vs 1.44 +/- 0.25: p < 0.05) while HDL cholesterol and apoprotein A-1 concentrations were unchanged. There was no change in blood glucose control measured by fasting glucose, insulin, and HBA, concentrations, but there was a significant improvement in insulin action assessed by glucose-insulin infusion. Although plasma non-esterified fatty acid concentrations were lower during the oral glucose tolerance test after acipimox, there was no difference in either the peak or 2-h plasma glucose concentrations and the total area under the glucose curve did not change. Acipimox was well tolerated and no patients withdrew from the study for drug-related symptoms. Thus, acipimox effectively lowers serum cholesterol and triglycerides in patients with Type 2 diabetes without adversely altering blood glucose control, and appears to improve insulin sensitivity.

Analysis of Variance↗
PubMed1992

Carotid arteries: evaluation with low-field-strength MR angiography.

Magnetic resonance (MR) angiography of neck vessels was performed with a 0.2-T permanent magnet by using a two-dimensional, time-of-flight technique. Thirty-one patients were included in the study. The imaging parameters used included a repetition time of 60 msec, an echo time of 10 msec, a 90 degrees flip angle, and a 192 x 256 matrix; 40-50 sequential two-dimensional sections were acquired through the neck. Stenosis was graded on a scale of 1-5. Correlation of digital and MR angiography was made in the clinically nonrelevant cases (stenoses of grades 1 and 2), with overestimation to grade 3 in six cases. Two grade 3 stenoses were overestimated as grade 4. Severe stenoses were correctly characterized in all but one case, which was underestimated because of a segmental short extension of the stenotic lesion. Obstructions were found in two cases. Areas with a lack of signal were observed in four patients with severe stenosis and in two with tortuous arteries. Correct diagnosis, however, was achieved with analysis of the maximum intensity projection animation display. Low-field-strength MR angiography has the same clinical value as that performed with high field strengths.

Adult↗