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F Smaltino

Publications and source records attributed to F Smaltino.

At least 19 recordsLinked to original sources
PubMed1999

Exploring brain function with magnetic resonance imaging.

Since its invention in the early 1990s, functional magnetic resonance imaging (fMRI) has rapidly assumed a leading role among the techniques used to localize brain activity. The spatial and temporal resolution provided by state-of-the-art MR technology and its non-invasive character, which allows multiple studies of the same subject, are some of the main advantages of fMRI over the other functional neuroimaging modalities that are based on changes in blood flow and cortical metabolism. This paper describes the basic principles and methodology of fMRI and some aspects of its application to functional activation studies. Attention is focused on the physiology of the blood oxygenation level-dependent (BOLD) contrast mechanism and on the acquisition of functional time-series with echo planar imaging (EPI). We also provide an introduction to the current strategies for the correction of signal artefacts and other image processing techniques. In order to convey an idea of the numerous applications of fMRI, we will review some of the recent results in the fields of cognitive and sensorimotor psychology and physiology.

Artifacts↗
PubMed1999

Ultrasonographic evidence of joint thickening reversibility in acromegalic patients treated with lanreotide for 12 months.

BACKGROUND: A major cause of morbidity and functional disability in acromegaly is represented by axial and peripheral arthropathy. OBJECTIVE: The effect of a 12-month treatment with lanreotide (LAN) on arthropathy in 12 untreated acromegalic patients has been evaluated. Twelve healthy subjects served as controls. STUDY DESIGN: Open prospective. STUDY PROTOCOL: Articular cartilage thickness of shoulder, wrist and knee, as well as the size of the heel tendons, was measured by ultrasonic (USG) examination before, monthly for the first 3 months and quarterly thereafter, during treatment with 60-90 mg/month of LAN. The achievement of safe GH and IGF-I levels was considered when fasting GH was below 5 mU/l and IGF-I levels were normalized for age. RESULTS: Before treatment, thickening of shoulder, wrist and knee cartilages, and of heel tendons, was found in all patients compared with controls (P < 0.01). During the first 3 months of LAN treatment, a significant decrease in circulating GH (from 86.8 +/- 19.8 to 25.6 +/- 9.8 mU/l) and IGF-I levels (from 624 +/- 47.8 to 412.2 +/- 44.5 microg/l) was observed. Overall, a slight decrease was noted in all the articular sites examined, but it reached statistical significance only at the right shoulder (P < 0. 001). However, a notable improvement of joint pain and active and passive articular mobility were recorded in all patients, as well as of weakness, soft tissue swelling, hyperhydrosis and headache. After 6 months of LAN treatment, a further significant decrease was observed at the level of the right shoulder (P < 0.01) and the right knee (P < 0.01). Eight patients achieved safe GH and IGF-I levels. After 12 months of LAN treatment, a significant decrease was observed at the level of all the articular sites examined (P < 0.01), as well as at the level of both heel tendons (P < 0.01). Safe GH and IGF-I levels were achieved in all but one of the patients who, similarly, had a significant decrease in shoulder, wrist and both heel tendon thicknesses. The thickness reduction of right shoulder cartilage, a non-weight-bearing joint, was significantly greater than that observed at the level of the right and left knee cartilages and heel tendons (37.4 +/- 4.4% vs. 18 +/- 6.1%, 19.3 +/- 4.4%, 16.5 +/- 4.2%, and 13.7 +/- 5.5%, respectively, P < 0.01). No difference was found in thickness decrease of all sites examined between the eight patients achieving safe GH levels after 3-6 months, and the remaining four patients, or between patients with estimated disease duration below (n = 6) or above 10 years (n = 6). CONCLUSIONS: Improvement in articular and periarticular soft tissue hypertrophy of the shoulder and wrist, two non-weight-bearing joints, but also of the knees, two weight-bearing joints, and heel tendons, was obtained by suppressing GH and IGF-I levels for 12 months with LAN treatment, although complete reversal of joint thickening was not achieved. Since no difference in the response to treatment, in terms of joint size decrease, was found between patients with short or long disease duration, treatment longer than 12 months may be needed to reverse the acromegalic arthropathy completely.

Acromegaly↗
PubMed1998

[Three-dimensional imaging with computerized tomography. Etiologic considerations and methods for studying temporo-mandibular joints].

INTRODUCTION: The temporomandibular joint (TMJ) had always been studied with conventional tomography and, more recently, with Magnetic Resonance Imaging. Computed Tomography (CT) can demonstrate periarticular soft tissues only. Recently, the introduction of three-dimensional (3D) CT reconstructions with dedicated softwares permitted to demonstrate functional changes in the TMJ with a simple and accurate measurement system. MATERIAL AND METHODS: We examined 347 patients with TMJ disorders using two different 3rd generation CT units and acquiring two series of scans, with the mouth closed and in maximum opening. 3D reconstructions on predefined planes were obtained with a dedicated software and integrated with the electronic measurements of the following morphologic and functional parameters: zygomatic tubercle height, axis of sagittal inclination of the mandibular condyle, TMJ movement range and changes in torsion/dislocation of condylar angle. RESULTS AND DISCUSSION: CT showed the TMJ easily. This examination lasts about 10 minutes, plus 10-15 more minutes for 3D reconstructions. Some artifacts were found on 3D images--thresholding artifacts, defined as pseudoforamina and pseudocalcifications. Neverthless, 3D imaging can easily demonstrate an articular district which is very complex in both morphology and function, supporting or replacing similar subconscious processes made by radiologists themselves. This technique was well accepted by all our patients and functional results were always in agreement with clinical findings. Moreover, CT is the only technique showing both TMJ sides at the same time. Our measurement system was easy to perform, repeatable and comparable also thanks to its potentials of standardization on different CT units. CONCLUSIONS: CT with 3D reconstructions appears the gold standard technique for functional TMJ studies. Even though it provides no information on the joint disk--which MRI does--3D CT permits easy and accurate measurements of both TMJ sides which can support clinical findings.

Humans↗
PubMed1998

[Magnetic resonance angiography of the epiaortic vessels of the thorax].

INTRODUCTION: Magnetic Resonance angiography (MRA) is an accurate and non-invasive diagnostic method to evaluate vascular disease. On the basis of its technological advancements, this technique has gained an important role in the diagnostic protocol of cerebral and cervical vascular diseases. Nonetheless, MRA efficacy changes in different anatomic districts as a consequence of the specific anatomy and flow features. Cardiac and respiratory artifact and different coil sensitivity also affect MRA results. For these reasons, intrathoracic epiaortic vessels are a difficult applications for MRA. MATERIAL AND METHODS: We examined 20 patients affected with epiaortic atherosclerosis with MRA, carried out with an 0.5 T MR unit (Vectra, GE). Examinations consisted of Phase Contrast (PC) 3D sequences (TR/TE/FA/Venc = 30/13/45/30-50), with 3 axes of flow encode, matrix 128 x 256, 2 mm partition thickness, and axial and/or coronal acquisition volume. The MRA was repeated after Gd-DTPA intravenous perfusion and a qualitative and quantitative evaluation of pre- and post-contrast results was performed. Specific parameters of evaluation were: angiographic contrast, contrast to noise ratio, saturation effect of longitudinal magnetization, contrast between arteries and veins. All patients were examined with Doppler US and angiography. MRA data were compared to angiography in order to establish MRA sensitivity and specificity. RESULTS AND CONCLUSIONS: PC sequences showed high accuracy in the examination of the proximal tract of epiaortic vessels; Gd-DTPA administration substantially improved MRA results. The perspectives of technological improvement will probably candidate PC MRA to be a valid alternative to US-Doppler and, perhaps, to angiographic study.

Adult↗
PubMed1997

Nitric oxide-haemoglobin interaction: a new biochemical hypothesis for signal changes in fMRI.

A new hypothesis on the origin of activation-induced signal changes in functional magnetic resonance imaging (fMRI) is presented, involving transient formation of paramagnetic species, i.e. methaemoglobin (Hb+) and nitrosylhaemoglobin (Hb-NO), by reaction of nitric oxide (NO) with oxy-(Hb-O2) and deoxyhaemoglobin (Hb). Hb+ and Hb-NO, generated in erythrocytes, were found to produce marked concentration-dependent signal intensity changes when examined by T1-, T2- and T2*-weighted MRI. Intravenous administration of ascorbic acid (3 g) to healthy volunteers, to specifically reduce any Hb+ formed during brain activation, markedly decreased fMRI signal changes during standard tasks, suggesting a blood flow-independent effect produced by the reductant. These results open a new perspective on the fMRI evaluation of physiological processes associated with task-specific activation of brain structures.

Brain↗
PubMed1997

[Doppler color ultrasonography with contrast media in the study of eye and orbit neoplasms].

We investigated the diagnostic efficacy of the i.v. administration of a sonography (US) contrast agent to study eye and orbit tumors at different stages. We administered Levovist (Schering), an air microbubble stabilized by fatty acid, which is specific for angiographic indications. Baseline color Doppler US was performed on 24 selected patients and tumor vascularization patterns were classified into three classes. Color Doppler signal enhancement was assessed after contrast agent administration and the signal-to-noise ratio (SNR) was improved in 70% of cases, which helped identify vascular patterns and improved flowmetric accuracy. The Doppler effect was also improved and vascular signal was always enhanced. The SNR was improved also by the postcontrast detection of small vessels missed on baseline scans. Doppler signal enhancement was proportional to precontrast vascularization and depended on tumor size, with poor results in lesions < 5 mm. In contrast, vascular signal spots with increased postcontrast echogenicity sometimes caused excessive noise affecting the results. No correlation was found between signal enhancement and lesion histotype or between signal and lesion site. Treated lesions exhibited poorer contrast agent enhancement. The examination technique must be accurate and the various parameters set optimally, especially the velocity scale, gain and filtration; the unit must feature adequate recording capabilities (mm/s). To conclude, we believe that the routine use of i.v. US contrast agents will play a major role in improving diagnostic imaging in oculistics also thanks to the lack of untoward reactions and to the ease of contrast agent preparation.

Adult↗
PubMed1997

[Pancreatic fractures: the role of CT and the indications for endoscopic retrograde pancreatography].

PURPOSE: To assess the role and the diagnostic yield of CT and of endoscopic retrograde cholangiopancreatography (ERCP) in the study of emergency pancreatic injuries from blunt abdominal trauma. MATERIAL AND METHODS: January, 1992, to December, 1996, eleven subjects with pancreatic trauma were operated on. The patients were 8 men and 3 women (mean age: 28.4 years, range: 15-47 years) with pancreatic traumas of different severity but all with gland fracture and severe ductal injuries. Direct radiography was performed in all cases in different projections: CT with 1 cm slice thickness and feed was also performed. A contrast agent was administered orally in 8/11 patients and i.v. in 11/11. ERCP was performed in supine recumbency within 12 hours of trauma; a hypotonic agent was administered i.v. in 5 cases. The examination was successful in 10 patients. Wirsung duct studies were extended to the biliary tract in 6 cases. RESULTS: Pancreatic traumas were never isolated and usually associated with other abdominal injuries in the liver, spleen, small intestine, kidneys (by frequency) and with injuries in other body regions--the chest in 8/9 cases, limbs in 7/9, the spine in 4/9 and the skull-brain in 3/9 cases. Pancreatic fractures were mostly cervical and 3 of them were bifocal. The radiologic findings of pneumoperitoneum (4 cases), sentinel loop (3), paralytic ileum (11), air-fluid levels (9) were always aspecific. CT had 66.7% sensitivity, with over-all accuracy of pancreatic involvement by trauma in 5/11 cases and specific findings of fracture in 1/11 cases. CT showed associated parenchymal injuries in both the abdomen and other sites. ERCP diagnostic accuracy and sensitivity topped 100% in the demonstration of ductal injuries. DISCUSSION: Pancreatic traumas are usually a rather uncommon event. They are classified as major and minor according to the extent and severity of ductal involvement. Injury site corresponds to the direction of impact force, but the neck is the preferential site for fractures because it is compressed within the spine and extended. Clinical findings are usually aspecific and questionable and diagnostic imaging, especially CT, plays therefore a major role in treatment planning. However, CT provides mainly indirect signs and fails to depict ductal rupture. Despite its difficult technical execution in emergency, ERCP shows ductal injuries with extreme accuracy and specificity, which finding is indispensable for treatment planning. CONCLUSIONS: Both CT and ERCP are necessary tools to diagnose pancreatic fractures: the former because it provides indispensable panoramic findings and the latter because it is the only method showing ductal involvement. Therefore, both techniques should be used for accurate surgical planning, which is a crucial step for the prognosis of these injuries. Cost-effectiveness and safe execution are well balanced.

Abdominal Injuries↗
PubMed1996

[Anal endosonography: the study technic and the correlations between the normal and echographic anatomy].

The authors report on 16 healthy volunteers examined with anal endosonography. The US examinations were performed with a dedicated Bruel and Kjaer 1846 unit equipped with a 7-MHz probe (type 1850) with 360 degrees circular mechanic movement. A rigid plastic cone filled of degassed water is mounted on the probe to ensure the symmetrical representation of the anal canal. A condom with gel on both the internal and the external surfaces is put on the cone. The peculiar anatomy of the single layers which form the anal canal determines their different US patterns. Endosonography was performed on three levels, i.e., deep, intermediate and superficial planes. In the deep plane (at the anorectal junction) anal endosonography demonstrates: epithelial-subepithelial complex (intermediate echogenicity); internal sphincter muscle (low echogenicity), made of smooth muscular fibers; longitudinal muscle (intermediate echogenicity), made of smooth and striated muscular fibers; puborectal muscle (high echogenicity), made of striated muscular fibers, and perineal body, which has a longitudinal shape in men and a transverse shape in women. In the intermediate plane anal endosonography demonstrates: epithelial-subepithelial complex, internal sphincter muscle, longitudinal muscle, and external sphincter muscle (high echogenicity), made of striated muscular fibers. In the superficial plane (distal anal canal extremity), anal endosonography demonstrates: epithelial-subepithelial complex and external sphincter muscle. Internal sphincter muscle thickness was measured and the results follow: while the average thickness was 2.1 mm, we had 1.8 mm in 12 patients under 44 and 2.6 mm in 4 patients over 44 years old. This finding is in agreement with literature data. External sphincter muscle thickness did not vary significantly in the two groups.

Adolescent↗
PubMed1996

[Role of anal endosonography in inflammation and trauma of the anal canal].

Anal endosonography (US) is a valuable tool to represent the normal anatomy of the anal canal and also to reliably examine patients with anal conditions. Our series consisted of 40 patients with suspected inflammatory and traumatic conditions of the anal canal submitted to anal US, which showed the presence of abscesses in 18 patients with suspected anal canal inflammation. A fistula was associated in 14 of the 18 patients and US after air injection easily showed a cutaneous orificium in 6 of the 14 patients. Anal US showed the presence and site of all abscessual foci and fistulae, also identifying the inner orificium and the involvement of muscular sphincteral structures, which is useful information to plan the most appropriate medical or surgical treatment. As for traumas, anal US is also a useful tool for identifying sphincteral injuries secondary to blunt trauma and for following-up sphincteral reconstruction with graciloplasty. Twenty-two patients with suspected sphincteric trauma were examined and anal US showed a sphincteral injury in 7 of 13 patients with acute postpartum-related symptoms; the clinical picture was ascribed to postpartum stretching of the pudendal nerve in 6 other patients. Finally, this method can be very useful in the follow-up of anal diseases, both to study surgical drainages and in the postoperative study of anal fistulae.

Anal Canal↗
PubMed1994

First experience with a new echographic contrast agent.

The intravenous injection of an ultrasound contrast agent can enhance signals from blood flow. Broad toxicological and pharmaceutical studies in animals confirmed the safety and efficacy of an ultrasound contrast agent made of microparticles of galactose with stabilised microbubbles in watery suspension (SH U 508 A). In this paper 10 patients with different malignant orbital and ocular tumours have been evaluated with an echo colour Doppler machine before and after the injection of SH U 508 A. An enhancement of the Doppler signals in the lesions in different degrees has been detected. This echographic contrast agent seems to be very important not only in the evaluation of vascular lesions, but also in evaluating the effectiveness of radiotherapy in malignant tumours and could spread the echographic indications in several other ophthalmic fields.

Adult↗
PubMed1994

[High resolution computerized tomography in the study of the lung parenchyma. Possibility of a low-dose protocol].

High-resolution CT (HRCT) is a useful technique to investigate minimal diffuse lung disease. Two major limitations of HRCT are the higher radiation dose to the patient than in conventional CT of the chest and therefore the impossibility to study the lungs completely. These limitations can be partially overcome by using a low-dose protocol with mAs reduction. In our preliminary experience on 19 patients affected with various lung diseases, the low-dose protocol exhibited poorer image quality but almost equivalent anatomical detailing; the diagnostic yield was higher than that of conventional HRCT. Thus, in our experience, low-dose HRCT makes an interesting compromise in the study of lung parenchyma.

Adult↗
PubMed1994

[Dynamic single-slice computed tomography in the pretreatment evaluation of hepatocarcinoma in cirrhosis].

Hepatocellular carcinomas (HCCs) are currently treated with surgery, transcatheter chemoembolization and percutaneous alcoholization; all methods require accurate in vivo anatomopathology of the lesion. The authors report their personal experience with 58 HCCs on cirrhosis which were studied with dynamic single-slice CT after the injection of water-soluble iodate contrast medium with automatic injector in a peripheral vein. Three semiologic patterns were identified according to lesion density on pre- and post-contrast images. The active portion of the lesion could be differentiated from the necrotic one in 100% of cases. Moreover, the necrotic lesion was differentiated from possible still viable tumor portions but with vacuolar degeneration phenomena. These findings allowed the authors to calculate the growth rate and the infiltrative capability of the single neoplastic masses. Finally, the dynamic evaluation of parenchymal enhancement allowed abnormal tissue vascularization due to arterioportal communication to be demonstrated in 7 cases. The authors conclude the dynamic single-slice CT allows the accurate assessment of HCC foci, of tumor tissue vascularization and of perilesional liver parenchyma. Therefore, dynamic single-slice CT is suggested as the technique of choice to study small HCCs before treatment.

Adult↗
PubMed1993

[Errors of magnetic resonance in the diagnosis of small renal tumors].

MR examinations were performed on 16 patients with small (< 35 mm diameter) solid renal tumors previously diagnosed with US and/or CT. The study was aimed at assessing MR accuracy in the identification and characterization of this type of lesion. The studies were performed with a 0.5 T GE MR Max Plus unit, with no paramagnetic contrast medium administration. MRI detected the lesion in 15 cases (93.7%). In 3/15 patients (18.7%) the tumors had signal patterns similar to those of simple renal cysts--i.e., homogeneously hypointense on T1 and markedly hyperintense on T2-weighted images. In one patient (6.2%) MRI failed to detect the lesion. In the extant 12 cases the tumors were correctly demonstrated but had different signal patterns. On T1-weighted images 6 lesions were hypointense, 2 hyperintense because of hemorrhagic content, and 4 exhibited poor contrast with the surrounding renal parenchyma. On T2-weighted images 4 lesions were inhomogeneously hyperintense, 3 were hypointense because of fibrosis or old blood content, and in 5 cases contrast between the tumor and the renal parenchyma was poor. The authors conclude that T1-weighted MR images, in a midfield MR unit, are more sensitive than T2-weighted images in identifying small renal tumors. MRI is less accurate in the evaluation of these lesions than CT and US. In particular, since small renal lesions may be misdiagnosed as simple cysts, the use of other imaging modalities--e.g., US and CT--is recommended if a renal cyst is first identified on MR images.

Diagnostic Errors↗