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Biomedical subjects

F Chierichetti

Publications and source records attributed to F Chierichetti.

At least 37 records · Page 2Linked to original sources
PubMed1997

Morphological and functional study of a case of superficial siderosis of the central nervous system.

We here describe a case of superficial siderosis (SS) of the central nervous system (CNS), occurring in a patient with a previous lesion of the brachial plexus. Of the only 96 cases that have been described in the literature so far, there are now five with a positive history of a lesion due to the evulsion of the roots of the brachial plexus. This is the first time that, in addition to CT and MRI morphological investigations, an SS patient has also been studied metabolically by means of PET in an attempt to find new clues that may help to clarify the pathogenesis of the disease.

Central Nervous System Diseases↗
PubMed1996

Three-phase bone scan pattern in asymptomatic uncemented total knee arthroplasty.

In this study we investigated the bone scan pattern in a homogeneous group of asymptomatic patients implanted with the same type of total knee arthroplasty (TKA) and with a minimum follow-up of 2 years. Twenty-nine patients (21 females, 8 males, mean age 62 years), with a total of 30 uncemented Hofmann TKAs, were entered in the study. The time interval from surgery to scintigraphic evaluation ranged from 2 to 4 years. Bone scan was performed using the three-phase technique and images were interpreted by visual analysis using a three-point scale for the dynamic and blood pool phases and a five-point scale for the bone phase. Areas of increased periprosthetic technetium-99m methylene diphosphonate (MDP) uptake were observed until 4 years after surgery. However, comparing the TKAs implanted 2, 3 and 4 years previously, a decreasing pattern in tracer uptake intensity was noted this being more evident in the femoral and lateral tibial components. In some cases, a persistently elevated tracer uptake, not exceeding a moderate grade, was found in the medial tibial component. In conclusion, increased periprosthetic 99mTc-MDP uptake is a common finding in asymptomatic uncemented Hofmann TKAs for a prolonged period after surgery, but the uptake intensity is generally mild or moderate and shows a characteristic decreasing pattern over time. Furthermore, in contrast with other types of asymptomatic knee implants previously investigated, no case of high or very high bone uptake was recorded with this type of implant. We may speculate that scintigraphic parameters of normality, and pathology, should be determined for each type of TKA. It is likely that, with the uncemented Hofmann TKA, a high or very high tracer uptake or a progressive increase in the uptake intensity is suggestive of the presence of complications.

Female↗
PubMed1996

Reduced striatal dopamine receptors in Alzheimer's disease: single photon emission tomography study with the D2 tracer [123I]-IBZM.

Many patients with Alzheimer's disease (AD) develop parkinsonian symptoms, suggesting an overlapping between AD and Parkinson's disease (PD). However, pathologic and neurochemical studies indicate that the involvement of the dopamine system may be different in the two conditions. Using single photon emission tomography, we determined the relative specific striatal uptake (striatum to cerebellum ratio) of the D2 receptor ligand [123I]-IBZM in 15 AD patients without overt extrapyramidal symptoms (three subjects presented mild rigidity and bradykinesia) and nine age-matched controls. Mean specific activity in striatal regions of AD patients (1.35 +/- 0.09) was significantly reduced from control mean (1.59 +/- 0.03). Because such changes were evident even in the absence of overt parkinsonian symptomatology, our data indicate that alterations of striatal D2 receptors may be part of the pathologic abnormalities of AD. In addition, the mechanisms underlying extrapyramidal symptoms in AD (decline of postsynaptic striatal dopamine receptors) appear different from the prevalent presynaptic nigrostriatal alterations typical of PD.

Aged↗
PubMed1996

Changing approach to gastroenteropancreatic tumours. Case report of a gastrinoma metastasis localized by somatostatin-receptor scintigraphy.

A 60-year-old female with a history of chronic pancreatitis and previous pancreaticojejunostomy has been submitted to distal gastric resection for recurrent perforating ulcers. A carcinoid tumour was identified in the surgical specimen. Hypergastrinaemia was subsequently diagnosed and tumour localization was carried out by a new scintigraphic technique with 111In-Pentetreotide. The tumour was found to be a metastasis confined to a peripancreatic lymph node. Surgery was successful, and 6 months later the patient is still eugastrinaemic. The different imaging methods for the identification of gastrinomas are discussed together with the current therapeutic options.

Duodenal Neoplasms↗
PubMed1996

Functional meaning of scintigraphic and echographic patterns, and of circulating anti-peroxidase antibodies in asymptomatic chronic thyroiditis.

Asymptomatic chronic thyroiditis (ACT) is a variant of the autoimmune thyroiditis characterized by the presence of circulating anti-thyroid antibodies and the absence of palpable goiter. Thyroid function can be normal but a considerable percentage of ACT patients tend to develop subclinical hypothyroidism over time and thus periodical controls of thyroid hormones and TSH levels are needed. At present, useful parameters for predicting the functional outcome of ACT patients are lacking. To investigate this aspect, we evaluated 57 consecutive ACT patients (51 females, 6 males, aged 22-56 years) by means of thyroid 99mTc-pertechnetate scintigraphy and echography, and by measuring the serum level of anti-peroxidase antibodies (TPOAbs), FT4, T3 and TSH. At first observation, 30 patients were euthyroid whereas 27 had subclinical hypothyroidism. No patient had been previously treated with thyroid hormones. Thyroid scan showed a normal pattern or a diffuse and mild irregular uptake, without differences between euthyroid and subclinical hypothyroid patients. TPOAb levels tend to be higher in patients with subclinical hypothyroidism in comparison to the euthyroid patients (5893 +/- 1423 and 3943 +/- 912 UI/mL, respectively) but the difference was not statistically significant by using Student's "t"-test. Echography showed a normal pattern in 14 patients, while a diffuse hypoechoic pattern in the other cases, mild in 12, moderate in 19 and marked in 12, was found. A significantly higher prevalence of subclinical hypothyroidism was observed in the group of patients with a moderate or marked hypoechoic pattern in comparison to the group with a normo-echoic or mild hypoechoic pattern (70.4% versus 23.0%, Fisher's exact test p = 0.00003). Furthermore, the 3 patients who developed thyroid failure during a one-year follow-up also presented a moderate or marked hypoechoic pattern. Our data suggest that the echo-pattern can be a useful predictor of thyroid failure in ACT patients and thus the echographic evaluation should be included in the diagnostic protocol of these patients.

Adult↗
PubMed1996

[Surgical treatment of post-mastectomy lymphedema of the upper limb].

The authors analyze their experience of surgical treatment of post-mastectomy lympho-edemas of the upper arm. They have performed 14 operations, each upon patients with praecox or later oedema, following Cariati's classification, and with median age of 56.5 years. Seven patients were present at the follow-up in 6 has been performed microsurgical lympho-venous anastomosis, in 1 a fasciotomy of the forearm and in 1 patient some silastic tubes were positioned in her subcutaneous tissue. An improvement of the subjective symptoms has been recorded in 57.14% of the patients, while the objective ones have improved in 50% of the patients. The authors think that the microsurgical treatment of the lymphedema post-mastectomy of the upper arm is the first choice nowadays.

Adult↗
PubMed1995

Myocardial technetium-99m sestamibi single-photon emission tomography as a prognostic tool in coronary artery disease: multivariate analysis in a long-term prospective study.

To date several studies have evaluated the accuracy of thallium-201 myocardial scan in risk stratification of coronary artery disease (CAD), while reports using technetium-99m methoxyisobutylisonitrile (MIBI), a tracer particularly suited to single-photon emission tomographic (SPET) imaging, are lacking. To rectify this omission, a prospective study was started in 1988 and at present 176 consecutive, and thus unselected, patients have been enrolled. All of them have been submitted to stress-rest MIBI SPET for the diagnosis or evaluation of CAD; 147 patients (121 males and 26 females, aged 53 +/- 9 years) have completed a surveillance period of at least 36 months following the scintigraphic study (range 36-60 months, mean 43). Sixty-one patients had a documented previous myocardial infarction. The mean pre-test likelihood of CAD was 44% in the patients without prior infarction. The main anamnestic, clinical, EKG and scintigraphic findings were evaluated and statistically correlated with the incidence of ensuing cardiac events using both univariate (chi-square test) and multivariate analysis (logistic regression model). Twenty-nine patients suffered from a cardiac event during the follow-up period (i.e. three cardiac deaths, six myocardial infarctions and 20 cases of unstable angina). Statistical multivariate analysis identified MIBI scan as the only highly significant and independent prognostic predictor [P = 0.006, relative risk (RR) = 17.62]. In detail, the most important scintigraphic parameters were the presence of a reversible defect (P = 0.0089, RR = 5.11) and the extension of the stress perfusion defect (P = 0.0255, RR = 3.27). The presence of typical angina proved to be a slightly significant predictor (P = 0.051, RR = 2.45), while no other examined parameter showed a significant correlation with a bad prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina, Unstable↗
PubMed1995

Three-phase bone scintigraphy pattern of loosening in uncemented hip prostheses.

The three-phase bone scintigraphy pattern of loosening in uncemented hip prostheses (UHPs) has not previously been elucidated. We evaluated 28 patients with complicated UHPs who had undergone total hip arthroplasty a very long time previously (range 3-20 years, mean 8.4). All the patients were surgically reviewed: 26 UHPs were found to be loosened and two infected. Nine asymptomatic UHPs were taken as controls. The dynamic phase was invariably negative in both loosened and asymptomatic UHPs while markedly positive in the infected ones. The blood pool phase was positive to various degrees in 16 of the 26 loosened UHPs as well as in the infected UHPs, but was invariably negative in painless replacements. In the bone phase, areas of significantly (discrete to marked) increased uptake were observed in all the loosened prostheses as well as in two-thirds of the asymptomatic ones. However, the regions of the lesser trochanter and/or tip and/or shaft were involved exclusively in the case of the loosened UHPs, and diffuse periprosthetic uptake was found only with loosened or infected implants. Areas of slight methylene diphosphonate (MDP) uptake were found at every periprosthetic site and areas of discrete to marked MDP uptake were commonly found in the acetabulum and/or the greater trochanter with both loosened and painless prostheses and are thus considered to be nonspecific findings.

Bone Cements↗
PubMed1995

Corticobasal degeneration: neuropsychological assessment and dopamine D2 receptor SPECT analysis.

We report a case of clinically diagnosed corticobasal degeneration, in whom neuropsychological testing was performed along with functional imaging with IBZM SPECT. HM-PAO SPECT showed marked perfusion asymmetry in parietal cortical regions, lower to the right, contralateral to the most affected side. IBZM SPECT, which gives information about postsynaptic dopaminergic D2 receptors, showed severe reduction of tracer uptake in the right basal ganglia. Our findings suggest that a postsynaptic lesion in the basal ganglia might account for the lack of response of extrapyramidal motor symptoms to dopaminergic agonists in corticobasal degeneration.

Adult↗
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

Alterations of striatal dopamine D2 receptors contribute to deteriorated response to L-dopa in Parkinson's disease: a [123I]-IBZM SPET study.

Single photon emission tomography with the ligand [123I]-IBZM was used to image central dopamine D2 receptors in Parkinson's disease patients. The aim was to assess striatal receptor densities in relation to response to L-Dopa therapy. In the parkinsonian patients group who were untreated until SPET study and in the group of patients with a sustained response to chronic L-Dopa, striatal [123I]-IBZM uptake did not differ significantly from mean values of the control group. On the contrary, significantly diminished uptake of [123I]-IBZM was found in the basal ganglia regions of the group of patients who developed a complicated/fluctuating response to chronic L-Dopa treatment. Our results indicate that striatal D2 receptor alterations in Parkinson's disease may contribute to the altered response to L-Dopa.

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↗
PubMed1994

Single photon emission computed tomography with [99Tc]-HM-PAO and [123I]-IBZM in Alzheimer's disease and dementia of frontal type: preliminary results.

Dementia of frontal type (DFT) is a fairly common degenerative disease distinct from Alzheimer's disease (AD), whose reportedly distinctive instrumental feature is frontal lobe hypoperfusion on SPECT. We evaluated the cortical dopaminergic system in 6 AD, 5 DFT, and 6 control subjects with SPECT and both [99Tc]-HM-PAO, a perfusion tracer, and [123I]-IBZM, a D2 postsynaptic ligand. Both in AD and DFT patients, [99Tc]-HM-PAO SPECT showed a relative frontal hypoperfusion. On the contrary, [123I]-IBZM SPECT showed significantly reduced ligand uptake in superior frontal regions of DFT (0.89 +/- 0.08 relative to control subjects) as compared to AD patients (0.97 +/- 0.02; difference of means: 0.08, 95% Confidence Interval 0.004 to 0.156; p = 0.041). Results suggest more marked involvement of the frontal cortical dopaminergic system in DFT than in AD patients.

Aged↗
PubMed1994

Effects of exercise-induced alterations of cardiac physiology on nuclear perfusion imaging.

The effects produced on nuclear perfusion images by exercise-induced changes in the heart and respiration rate and possible transient myocardial stunning are not well understood. In this study we attempted to indirectly evaluate the potential artifacts created by exercise-induced changes in cardiac physiology. Twenty patients with prior myocardial infarction and suspected peri-infarct ischemia were studied by 99mTc-MIBI imaging. Two SPECT perfusion studies were performed after 99mTc-MIBI administration at rest. The first acquisition was carried out 90 minutes after injection of the tracer. Immediately afterwards, the patients underwent a stress test followed by a second acquisition (exercise stress superimposed on rest tracer distribution). A standard stress perfusion scan was also performed 48 hours later. Superimposed exercise stress produced artifactual defects in the resting distribution of the tracer in 15 out of 20 patients (68 of 360 segments). Standard stress images demonstrated concordant defects in 48 of these segments, indicating the concomitant presence of ischemia and stunning. This study indicates that exercise-induced changes in cardiac physiology may result in artifactual perfusion defects in scintigraphic images acquired shortly after the stress.

Adult↗
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↗
PubMed1993

Aplasia of the radial artery.

A 2-year-old girl with asymmetrical upper limbs and underdevelopment of the bones of the left forearm, wrist and hand with associated muscular and osteal hypoplasia is described. Doppler ultrasonography of the arterial trunks of the upper limb suggested a normal ulnar trunk in the left upper arm, an arterial vessel extending from the bend of the elbow to the distal third of the forearm, and the absence of any other arterial trunks in the radial region. Angiography confirmed that vascularization of the forearm was sustained by the ulnar artery, which supported the dorsal arch of the carpus and digital arteries arising from it. The interosseal artery was morphologically normal but there was aplasia of the radial artery. It is suggested that this malformation is the result of suppressed development of the vascular system of the left radial segment as other pathologies normally associated with the condition were absent.

Angiography↗