PubMed Health⌕ Search

Biomedical subjects

P Zanco

Publications and source records attributed to P Zanco.

36 records · Page 2Linked to original sources
PubMed1995

Usefulness of 99mTc-MIBI stress myocardial SPECT bull's-eye quantification in coronary artery disease.

99mTc-methoxy-isobutyl isonitrile (MIBI) myocardial SPECT quantification performed using a Bull's-eye polar map, was evaluated and compared with visual analysis in 120 patients with proven or suspected CAD. The study series comprised 106 men and 14 women, age 37-75 years (mean 51 +/- 6), 68 of whom had had a prior myocardial infarction. Coronary angiography was taken as the gold standard: one-vessel disease was present in 24 patients, two-vessel disease in 39, and three-vessel disease in 44, whereas no significant stenosis was documented in 13 cases. Forty age-matched subjects (26 men, 14 women), with less than a 5% chance of having CAD, were enrolled to establish the normal database for males and females. ROC analysis was used to calculate the optimal thresholds for the definition of the disease extension in each vascular territory of the Bull's-eye polar map: 10% for LAD, 8% for LCX, and 20% for RCA territory. The sensitivity/specificity ratio of the scintigraphy was: 75/82% with the visual and 78/74% with the quantitative analysis for LAD; 60/90% with visual and 72/64% with visual and 70/62% with quantitative analysis for RCA territory. The sensitivity/specificity ratios for the CAD diagnosis were similar with the visual and the Bull's-eye analysis in 92/61% and 93/61% respectively. Bull's-eye analysis agreed with visual analysis in 296/360 vessels. Two and three-vessel disease were most frequently observed using the Bull's-eye approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The role of 111In-octreotide scintigraphy in the detection of APUD tumours: our experience in eighteen patients.

111In-Octreotide scintigraphy has been recently proposed as a sensitive technique for the detection of neuroendocrine tumours, based on the high radiotracer affinity towards the somatostatin receptors expressed by the APUD-system cells. In the present study, a group of 18 patients with carcinoid tumours and gastrointestinal (GI) apudomas was investigated to assess the accuracy of Octreotide scintigraphy in localizing primitive, recurrent or metastatic lesions. Both planar and SPECT studies were obtained 4 hours after the i.v. injection of 111In-Octreotide (111 MBq); planar images were also carried out 24 hours later. In accordance with other authors, the sensitivity of the method was found to be very high (94%) in our group of patients; only in one case of nesidioblastosis was the scintigraphy negative. No differences in sensitivity were observed between the planar and SPECT studies, but the latter provided a better topographic localization of the neoplastic foci. It should be pointed out that in 7 cases (3 primitive, 1 recurrent and 3 metastatic lesions) scintigraphy correctly localized the tumour, when the other morphological techniques, such as echography, computed tomography or magnetic resonance, failed. On the basis of our data, we believe that Octreotide scintigraphy should be the first study performed in the evaluation of patients affected by APUD tumours.

Angiography↗
PubMed1993

Dopamine receptor SPET imaging in Parkinson's disease: a [123I]-IBZM and [99mTc]-HM-PAO study.

Single photon emission tomography (SPET) with the novel ligand [123I]-IBZM was used to image central dopamine D2 receptors in Parkinson's disease (PD) patients. The aim was to assess basal ganglia (BG) receptor densities in relation to the response to L-dopa therapy. To better characterize the clinical potential of [123I]-IBZM SPET, each patient underwent a second study with the regional perfusion tracer [99mTc]-HM-PAO. Tracer activity ratios were calculated for caudate and putamen with mean activity over the cerebellar hemispheres as internal standard. In PD patients we found a significant decline of mean caudate [123I]-IBZM activity, as compared with age-matched control subjects. However, when patients were grouped according to their therapeutic behavior, the [123I]-IBZM uptake in BG ganglia regions of the PD patient group with a poor and fluctuating response to L-dopa was significantly reduced from mean values of patients with a sustained response to L-dopa therapy. [99mTc]-HM-PAO caudate and putamen uptake indexes in PD were similar to control values, even in patients with deteriorated therapeutic response. Our results indicate that BG D2 receptor alterations in PD may contribute to the altered response to L-dopa.

Adult↗
PubMed1991

Proposal of a modified scintigraphic method to evaluate duodenogastroesophageal reflux.

Hepatobiliary scintigraphy with 99mTc-HIDA offers a noninvasive method to detect duodenogastric reflux. Biliary reflux was graded using the persistence rather than the intensity of the radioactive refluxate: Grade 0 was considered the absence of reflux, minimal reflux, or reflux in the first 10-15 min; Grade 1 was repetitive reflux lasting less than 10 min; Grade 2 was persistent reflux; and Grade 3 was reflux up to the esophagus. Twenty-five patients with foregut symptoms were studied and results were compared to 24-hr gastric pH monitoring. Scintigraphy and pH monitoring agreed in 15 out of 25 patients (60%), but no correlation was found with the endoscopic findings. The rationale for this approach is based on pathophysiologic evidence that damage to gastric and/or esophageal mucosa is mainly related to the prolonged contact time with duodenal contents. This technique seems to allow a complete functional evaluation of the esophagogastroduodenal tract without causing adjunctive irradiation or discomfort to the patient.

Adult↗
PubMed1989

Immunoscintigraphic detection of venous thrombosis of the lower extremities by means of human antifibrin monoclonal antibodies labeled with 111In.

A new monoclonal antibody specific for the beta-chain of human fibrin (C22A) and labeled with 111In has been obtained and successfully used in rabbits and dogs for the in vivo detection of venous thrombosis. Studies in humans are currently ongoing. In order to assess the diagnostic value of 111In-antifibrin for the detection of venous thrombosis of the lower extremities, the authors investigated 25 consecutive patients. Ten patients had clinical and instrumental (contrast phlebography and duplex scanning) evidence of acute deep venous thrombosis (DVT), 3 had a long-standing DVT with relapsing episodes of swelling and pain, 5 had superficial venous thrombosis, and the remaining 7 had no signs of thrombosis at all. Twenty patients were being treated with heparin. All patients received 111In-antifibrin at the dose of 74 MBq IV and were scanned with a large field of view gamma camera coupled with a high-energy, parallel-hole collimator at 30 minutes and three, six, and twenty-four hours postinjection. Only the persistence of an abnormal uptake at twenty-four hours confirmed by two observers at visual inspection was considered as positive. A positive result was obtained in 9 of 10 DVT patients (90% sensitivity) and in all SVT patients. The single DVT patient with a negative 111In-antifibrin test had the longest interval between scintigraphy and onset of symptoms (fifty-five days). Thus, the age of thrombi represented a substantial limitation for the test. A false-positive result was obtained in a single SVT patient, in whom also a deep involvement, unconfirmed by phlebography, was suspected (91.6% specificity).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Scintigraphy of the parathyroid glands with 201TI: experience with 250 operated patients.

Parathyroid scintigraphy confirmed its validity in the preoperative localization of enlarged parathyroids, showing a sensitivity of 82% in a series of 250 patients suffering from primary hyperparathyroidism and successfully operated on. The glands better visualized were in an ectopic site or they were completely or partially outside the thyroid so that they were easily visible without employing digital image subtraction. This is nevertheless necessary to visualize parathyroids in a retrothyroid site but some problems arise, related not only to movements of the patient but also to the instrumentation to perform a correct image subtraction.

Adenoma↗
PubMed1988

[99mTc]-HM-PAO SPECT in Parkinson's disease.

Thirty-six patients affected by Parkinson's disease were studied using single photon emission computed tomography (SPECT) and [99mTc]-HM-PAO as a tracer. The scanning procedure was performed 16-24 h after discontinuation of specific therapy. Tracer activity ratios were determined in 10 pairs of cerebellar, cortical, and subcortical regions. Data were compared with those of 10 age-matched controls. Most of the regions examined did not show any relevant change between parkinsonian and control subjects. Notably, mean activity in striatal regions were similar in the two groups. Increased activity in caudate-putamen was found in patients who were on chronic DOPA therapy. Side-to-side asymmetries in the basal ganglia increased with the severity of the disease. Significant reductions of tracer uptake, from control values, were observed bilaterally in the parietal cortex. These deficits were more pronounced in patients with mental deterioration and in subjects who had been chronically treated with anticholinergic drugs. Parietal perfusion deficits in parkinsonian patients resemble those described in Alzheimer's dementia. These findings suggest that the heterogeneous alterations of regional cerebral blood flow (rCBF) in parkinsonian patients reflect the multifactorial pathophysiology of the disease.

Adult↗
PubMed1985

Radionuclear determination of glomerular filtration rate and renal plasma flow to detect early decrease of renal function in insulin dependent diabetes.

To evaluate the role of renal haemodynamic factors in the pathophysiology of diabetic nephropathy, we determined by radionuclear techniques glomerular filtration rate (GFR) and renal plasma flow (RPF) in 18 patients affected by insulin dependent diabetes mellitus (IDDM) in good metabolic control, with normal blood pressure and plasma creatinine. GFR and RPF measured in the same patients after ten months correlated with proteinuria and duration of diabetes. Our finding of a significant correlation between the decline of RPF and duration of diabetes may support the haemodynamic hypothesis of progression of diabetic nephropathy.

Adolescent↗
PubMed1981

Lymphocyte subpopulations in insulin-dependent diabetics with and without serum islet-cell autoantibodies.

The lymphocyte subpopulations of 26 insulin-dependent diabetics were studied. Thirteen of them had persistent pancreatic islet-cell serum antibodies (ICA) (mean (+/- SD) duration of diabetes 11 +/- 8 years). The others were ICA-negative (mean duration of diabetes 10 +/- 8 years). The mean fasting blood glucose in the week before the lymphocyte count was 1..37 +/- 0.45 g/l (two specimens for every patient). As controls 19 healthy volunteers, sex and age matched, were investigated. The T-lymphocyte count was no different in diabetics compared to controls. B-cells were significantly raised (p less than 0.01) in the ICA-positive group, when tested with anti-human gammaglobulin sera (IgG + IgA + IgM), anti-human IgM, while no difference was observed between ICA-negative patients and normal subjects. IgA-bearing lymphocytes were equally raised in both diabetic groups (p less than 0.05). These data show an altered immunological balance in type IB (autoimmune) diabetes, characterized by an increased number of B-lymphocytes.

Adolescent↗
PubMedDate not supplied

Prognostic evaluation of patients after myocardial infarction: incremental value of sestamibi single-photon emission computed tomography and echocardiography.

BACKGROUND: This study compares the prognostic value of 99mTc-labeled methoxyisobutyl isonitrile (MIBI) single-photon emission computed tomographic (SPECT) imaging, echocardiography, and other clinical and laboratory prognostic factors in the long-term risk stratification of patients with stable uncomplicated infarcts. METHODS AND RESULTS: Ninety-one consecutive patients affected by a first myocardial infarction without serious complications were enrolled. After at least 3 months from the infarction, they were submitted to stress-rest MIBI SPECT and rest echocardiography. Eighty-six patients completed a follow-up of at least 4 years (range 48 to 72 months; mean 55 months). By univariate (log-rank test) and multivariate analysis (Cox proportional hazards model), the main clinical, electrocardiographic, scintigraphic, and echocardiographic findings were evaluated and correlated statistically with the incidence of ensuing cardiac events. Twenty-five patients had cardiac events during the follow-up (four cardiac deaths, four myocardial infarctions, and 17 cases of unstable angina). At the multivariate analysis, the presence of reversible defects on MIBI SPECT (p = 0.008 and relative risk [RR] = 7.09), the wall motion score index, and the ejection fraction at echocardiography (respectively, p = 0.010, RR = 3.67, p = 0.036, and RR = 3.12), and stress angina (p = 0.007 and RR = 3.40) were significant and independent prognostic factors. CONCLUSIONS: In our long-term follow-up, MIBI SPECT and echocardiography appeared to be significant and independent prognostic tools in the risk stratification of patients with stable, uncomplicated infarcts, furnishing complementary information. The reversibility of MIBI defects appeared the best indicator for a bad prognosis.

Echocardiography↗
PubMedDate not supplied

The role of fluorine-18-deoxyglucose (FDG) positron emission tomography (PET) whole body scan (WBS) in the staging and follow-up of cancer patients: our first experience.

We report the results of FDG PET whole body scan in 75 cancer patients in whom tumor extent was defined by surgical, histological or cytological findings and clinical follow-up. Twenty-five had malignant lymphomas, 24 lung carcinomas, and 26 other types of solid tumors. Twenty-three patients were evaluated at disease onset, before therapy, and 37 at the moment of tumor recurrence; the remaining 15 patients were in complete remission after treatment and were taken as controls. Visual and quantitative PET results were compared with conventional imaging (US, CT scan and/or MRI, and Tc99m MDP bone scan). In the 60 patients with active disease, PET as well as conventional imaging were able to locate the primary tumor in all 23 patients studied at disease onset. However, with regard to lymph node and distant metastases, PET provided the same information as conventional imaging in 31 cases (51.6%), but revealed further neoplastic foci in 29 cases (48.4%), 21 in lymph nodes and 8 at distant sites. The sensitivity of PET, in comparison with conventional imaging, was 100% versus 100% for the detection of the primary tumor, 97.6% versus 55.8% for the localization of node metastases, and 100% versus 55.5% for the visualization of distant metastases. The specificity, calculated in the group of 15 disease-free patients, was 100% for PET and 86.6% for conventional imaging. The therapeutic approach was modified in 12 patients (20%) on the basis of the PET results. Furthermore, in 14 cases (23.3%) with advanced disease, PET provided complete information on tumor spread, otherwise obtainable only by taking together the results of all other diagnostic procedures. Our data indicate a higher accuracy of FDG PET whole body scan compared to conventional imaging techniques in the evaluation of metastatic spread both at initial diagnosis and during follow-up, with an important impact on therapeutic decision-making. Moreover, by providing complete information on tumor spread in some cases, PET can become a profitable tool in terms of cost reduction.

Deoxyglucose↗
PubMedDate not supplied

Diagnosis of bone and liver metastases in breast cancer comparing tumor markers and imaging techniques.

One hundred and forty-seven patients were examined by bone scintigraphy, ultrasonography and scintigraphic scan of the liver, at different times after surgical removal of a breast cancer, to rule out skeletal and hepatic metastases. At the same time as imaging procedures, serum levels of tumor markers (CEA, TPA and CA 15-3) were determined using radioimmunometric methods. One or more markers were elevated in all 13 patients with hepatic metastases; 9 out of 46 patients with bone metastases had all serum markers normal, with a sensitivity of 80%. Combined assay of the markers proved useful, TPA and CA 15-3 showing the best sensitivity in bone metastases, and all three markers in liver metastases.

Adult↗
PubMedDate not supplied

[Determination of glomerular filtration during sequential scintigraphy in the evaluation of separate renal function].

The serial renal scan, a rapid series of images obtained with a scintillation camera, is explained; it visualizes the arrival to the kidneys and the passage through the parenchyma and the pelvocalyceal system of 99mTc-DTPA, a tracer cleared by glomerular filtration. Dynamic imaging of the kidneys provides more extensive information regarding anatomical structure and renal function that cannot be obtained by other noninvasive techniques. Computerized data analysis provides a lot of parameters, such as global and parenchymal transit times, useful in differentiating obstructive from non-obstructive uropathy, and total and separate glomerular filtration rate. 99mTc-DTPA computer-assisted scintigraphy is recommended as a routine method in nephro-urologic conditions where an accurate evaluation of separate renal function is required.

Child↗
PubMedDate not supplied

[Prevalence of clinically silent pulmonary embolism in deep venous thrombosis of the legs].

BACKGROUND: Thromboembolic venous disease is a possible lethal condition which is very often present in clinical practice. The aim of this study was to evaluate the prevalence of clinically occult pulmonary embolism (PE) in a group of patients with recent proximal deep venous thrombosis (DVT), and the relationship between prevalence of PE and DVT extension, echographic features of the thrombi, anticoagulant therapy administered. MATERIALS AND METHODS: The study enrolled 93 patients with DVT of the proximal lower extremities, without clinical symptoms and signs of PE. All patients were submitted to echo color-Doppler and ventilation-perfusion lung scan. The results were analysed by a score system for the echographic scan and by a series of probability criteria, as recommended by the PIOPED investigators, for the lung scan. RESULTS: All patients were recognised to suffer from proximal DVT. High probability lung scans for PE were found in 43 subjects (46.2%), intermediate probability in 14 (15%), low probability in 7 (7.7%), very low-normal in 29 (31.1%). The prevalence of PE failed to show any significant difference with respect to DVT extension, ultrasonographic features of the thrombi and anticoagulant therapy administered. CONCLUSIONS: The results obtained show a high prevalence of asymptomatic PE in patients with DVT, and suggest the need of an extensive use of lung scan in this kind of patients, and the utility of an early detection of DVT, in order to establish an intense antithrombotic therapy, irrespective of the extension of the thrombus with US.

Aged↗