Publications (24)98.22 Total impact
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Article: Ex-vivo MR imaging of liver intracellular contrast agents.
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ABSTRACT: The objective is to evaluate whether an ex-vivo model can be used to test intracellular contrast agents for MR imaging of the liver. T1 weighted inversion recovery, proton density spin echo and T2* weighted gradient echo images of the liver were acquired at 0.5 T in 10 rats before and 30 min after intravenous injection of 0.075 mmol/kg Gadolinium benzyloxypropionictetraacetate (Gd-BOPTA, n = 5) or 0.015 mmol/kg dextran magnetite (DM, n = 5), Four additional animals served as controls. After exsanguination and perfusion with saline and formalin, specimens of the liver and brain were embedded in an agar gel and examined with MR imaging one to three weeks later using the same protocol. In-vivo, the mean liver signal enhancement caused by Gd-BOPTA in T1, proton density and T2* weighted images was +23%, +28% and -70%, respectively. The mean liver signal enhancement caused by DM was -71%, -76% and -94%. In-vitro, no signal change was seen in the brain of animals injected with Gd-BOPTA and DM as compared to controls. Liver signal was increased by Gd-BOPTA and decreased by DM. Mean liver enhancement rate induced by Gd-BOPTA was +22%, +5% and +27% for T1, proton density and T2* weighted images, respectively. Mean liver enhancement rate induced by DM was -27%, -19% and -31%. MR imaging signal changes induced by liver intracellular contrast agents are still appreciable in an ex-vivo model. The latter might be useful for for preliminary investigation of intracellular contrast agents for MR imaging of the liver.Magnetic Resonance Imaging 02/1997; 15(4):469-74. · 1.99 Impact Factor -
Article: [Gadolinium-DTPA combined with a fat suppression technique in studies with magnetic resonance at 0.5 T in soft-tissue neoplasms].
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ABSTRACT: Combination of fat suppression techniques with intravenous paramagnetic contrast administration is usually performed using high-field MR systems. We combined a modified three-point Dixon technique for fat suppression with gadolinium-DTPA administration in the investigation of soft tissue neoplasms at 0.5 T. Nineteen patients with 21 neoplasms (14 primary malignant, 2 metastatic, 5 benign tumors) were examined. Examination protocol included unenhanced SE T1, PD and T2-weighted images. After the intravenous administration of gadolinium-DTPA (0.1 mmol/kg), a modified three-point Dixon technique provided three image sets, i.e., conventional T1-weighted SE images, fat-suppressed T1-weighted images and water-suppressed T1-weighted images. Two observers evaluated the lesions for conspicuity and size in three image groups: unenhanced T1-, PD and T2-weighted images, enhanced conventional T1-weighted images, enhanced T1-weighted images with fat suppression. Ten lesions showed greater conspicuity on enhanced fat-suppressed images than on unenhanced T1-, PD and T2- and enhanced conventional T1-weighted images. In 16 cases lesions were more conspicuous on enhanced water images than on conventional enhanced T1 images. Ten tumors exhibited a larger size (difference exceeding 20%) on enhanced fat-suppressed images. The combination of gadolinium with the modified Dixon technique improves the demonstration of soft tissue neoplasms at 0.5 T and allows lesion size to be measured more accurately.La radiologia medica 11/1994; 88(4):353-8. · 1.44 Impact Factor -
Article: [The Achilles tendon: echography at different frequencies. Comparative study].
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ABSTRACT: The authors report their experience with a comparative US study employing different-frequency probes (7.5, 10, 13 and 15 MHz) in Achilles tendon conditions. The study population included 49 patients, 37 of them athletes. All patients complained of the same symptoms: achillodynia in the middle third (group A, 29/49 cases), achillodynia in the lower end (group B, 16/49 cases), suspected partial rupture in the middle third (group C, 2/49 cases) and suspected distal rupture in the upper third (group D, 2/49 cases). In group A, the different frequencies yielded different results. 7.5 MHz frequencies yielded negative results in 13/29 patients, versus 3/29 with higher frequencies, which demonstrated peritenon inflammation in 10/29 cases. In the remaining 16 cases, where 7.5 MHz frequencies had shown tendon inflammation and degeneration, the higher frequencies confirmed the findings, even though their accuracy was greater. On the contrary, in the cases of distal achillodynia where pain was mainly due to inflammation of the retrocalcaneal bursa, the different frequencies yielded similar results, even though the higher ones proved more accurate in revealing tendon abnormalities--i.e., thickening, focal hypolucencies, spotty microcalcifications, irregularity of the bone lining. In group B, the different frequencies once again exhibited similar results showing a focal hypoechoic discontinuity which was correctly diagnosed on the basis of clinical history. Finally, as for group C, the lower frequencies gave better results because of the deeper location of the region of interest. In both cases a small blood collection was visible, between gastrocnemius and soleus, in the absence of clear-cut tendon lesions. No matter what the condition, the higher frequencies were extremely valuable since they allowed excellent demonstration of tendon anatomy. The tendon is enveloped by the peritenon, made of two macroscopically distinct sheaths the distinction of which is allowed by higher frequencies when a minimal amount of fluid is present. From the peritenon, the intratendon septa originate circumscribing spaces containing tendon fiber bundles. The vessels, which run longitudinally, are located within the confluence of the septa. On US images, the septa appear as thin hypoechoic stripes or small hyperechoic spots depending on the type of scan (longitudinal/axial). As to tendon fibers--i.e., tenocytes, collagen and elastic fibers--their pattern is homogeneous and hypoechoic since devoid of interfaces.La radiologia medica 07/1993; 85(6):741-7. · 1.44 Impact Factor -
Article: [Ultrasound-guided biopsy of small abdominal lesions. Methodology implications].
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ABSTRACT: In the present study the diagnostic accuracy of US-guided fine-needle biopsy was evaluated in a series of 219 abdominal lesions < or = 3 cm in diameter (21 between 0.6 and 1 cm; 83 between 1.1 and 2 cm; 115 between 2.1 and 3 cm). One-hundred-eighty-three of them were located in the liver and 36 in other abdominal organs (pancreas, 10, adrenals 9, lymphnodes 9, kidney 5, spleen 3). Biopsies were performed with "free-hand" technique using up-to-date ultrasound equipment. The demonstration of the correct location of the needle tip at the time of sampling was looked for with great care. The sensitivity rate was 93%, with a progressive improvement with the increase of the lesion size (83.3% between 0.6 and 1 cm; 91.1% between 1.1 and 2 cm; 95.4% between 2.1 and 3 cm). The specificity rate was 100%. In 207 cases in which the location of the needle tip was clearly demonstrated, the sensitivity reached 97.3% and the negative predictive value 93%. No noteworthy complications were observed. Ultrasonography is a highly reliable guidance modality also in biopsies performed on small abdominal lesions; if the correct location of the needle tip is clearly shown, even a diagnosis of benignity can be confidently made.La radiologia medica 10/1992; 84(4):410-5. · 1.44 Impact Factor
Top Journals
Institutions
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2010
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San Giuseppe Hospital
Arezzo, Tuscany, Italy
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1999–2010
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Università degli Studi di Firenze
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche
Florence, Tuscany, Italy
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2008–2009
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Hospital of Versilia
Viareggio, Tuscany, Italy
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1992–1998
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Università di Pisa
Pisa, Tuscany, Italy
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1993
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Università degli Studi del Sannio
Benevento, Campania, Italy
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